iridoids and oleuropein

Alzheimer's Disease (AD) is the cause of around 60-70% of global cases of dementia and approximately 50 million people have been reported to suffer this disease worldwide. The leaves of olive trees (

Topics: Alzheimer Disease; Humans; Iridoid Glucosides; Iridoids; Olea; Plant Extracts; Plant Leaves; Polyphenols

Oleuropein is an ester of elenolic acid and hydroxytyrosol (3, 4-dihydroxyphenylethanol). It is a phenolic compound and the most luxuriant in olives. The detailed information related to the anticancer effects of oleuropein was collected from the internet database PubMed/Medline, ResearchGate, Web of Science, Wiley Online Library, and Cnki using appropriate keywords until the end of October 2021. Oleuropein has been shown to have antioxidant, anticancer, antiinflammatory, cardioprotective, neuroprotective, and hepatoprotective effects. Previous studies also revealed that oleuropein could effectively inhibit the malignant progression of esophageal cancer, gastric cancer, breast cancer, lung cancer, liver cancer, pancreatic cancer, ovarian cancer, prostate cancer, and cervical cancer. Recently, the role of oleuropein in inhibiting tumor cell proliferation, invasion, and migration and inducing tumor cell apoptosis has gained extensive attention. In this review, we have summarized the latest research progress related to the antioncogenic mechanisms and the potential role of oleuropein in targeting different human malignancies. Based on these findings, it can be concluded that oleuropein can function as a promising chemopreventive and chemotherapeutic agent against cancer, but its more detailed anticancer effects and underlying mechanisms need to be further validated in future preclinical as well as clinical studies.

Topics: Antineoplastic Agents; Humans; Iridoid Glucosides; Iridoids; Male; Pancreatic Neoplasms

Aging is associated with a low-grade, systemic inflammatory state defined as "inflammaging", ruled by the loss of proper regulation of the immune system leading to the accumulation of pro-inflammatory mediators. Such a condition is closely connected to an increased risk of developing chronic diseases. A number of studies demonstrate that olive oil phenolic compound oleuropein and its derivative hydroxytyrosol contribute to modulating tissue inflammation and oxidative stress, thus becoming attractive potential candidates to be used in the context of nutraceutical interventions, in order to ameliorate systemic inflammation in aging subjects. In this review, we aim to summarize the available data about the anti-inflammatory properties of oleuropein and hydroxytyrosol, discussing them in the light of molecular pathways involved in the synthesis and release of inflammatory mediators in inflammaging.

Topics: Antioxidants; Humans; Inflammation; Inflammation Mediators; Iridoid Glucosides; Iridoids; Olive Oil; Phenylethyl Alcohol

Unprecedented community containment measures were taken following the recent outbreak of COVID-19 in Italy. The aim of the study was to explore the self-reported future compliance of citizens with such measures and its relationship with potentially impactful psychological variables.. An online survey was completed by 931 people (18-76 years) distributed across the Italian territory. In addition to demographics, five dimensions were measured: self-reported compliance with containment measures over time (today, at 7, 14, 30, 60, 90, and 180 days from now) at three hypothetical risk levels (10, 50, 90% of likelihood of contracting the COVID-19), perceived risk, generalized anxiety, intolerance of uncertainty, and relevance of several psychological needs whose satisfaction is currently precluded.. The duration of containment measures plays a crucial role in tackling the spread of the disease as people will be less compliant over time. Psychological needs of citizens impacting on the compliance should be taken into account when planning an easing of the lockdown, along with interventions for protecting vulnerable groups from mental distress.. La apendicitis aguda (AA) es la urgencia quirúrgica abdominal más frecuente. No encontramos estudios específicos que evalúen el impacto de la pandemia causada por el coronavirus 2 (SARS-Cov-2) sobre la AA y su tratamiento quirúrgico. Analizamos la influencia de esta nueva patología sobre la AA.. Estudio observacional retrospectivo en pacientes intervenidos por AA desde enero hasta abril de 2020. Fueron clasificados según el momento de la apendicectomía, antes de la declaración del estado de alarma (Pre-COVID19) y después de la declaración del estado de alarma (Post-COVID19) en España. Se evaluaron variables demográficas, duración de la sintomatología, tipo de apendicitis, tiempo quirúrgico, estancia hospitalaria y complicaciones postoperatorias.. La pandemia por SARS-Cov-2 influye en el momento de diagnóstico de la apendicitis, así como en su grado de evolución y estancia hospitalaria. La peritonitis fue lo más frecuentemente observado. Una sospecha y orientación clínica más temprana, es necesaria para evitar un manejo inadecuado de este trastorno quirúrgico común.. The primary outcome is improvement in PaO. Findings will provide timely information on the safety, efficacy, and optimal dosing of t-PA to treat moderate/severe COVID-19-induced ARDS, which can be rapidly adapted to a phase III trial (NCT04357730; FDA IND 149634).. None.. The gut barrier is crucial in cirrhosis in preventing infection-causing bacteria that normally live in the gut from accessing the liver and other organs via the bloodstream. Herein, we characterised gut inflammation by measuring different markers in stool samples from patients at different stages of cirrhosis and comparing this to healthy people. These markers, when compared with equivalent markers usually measured in blood, were found to be very different in pattern and absolute levels, suggesting that there is significant gut inflammation in cirrhosis related to different immune system pathways to that seen outside of the gut. This provides new insights into gut-specific immune disturbances that predispose to complications of cirrhosis, and emphasises that a better understanding of the gut-liver axis is necessary to develop better targeted therapies.. La surveillance de l’intervalle QT a suscité beaucoup d’intérêt durant la pandémie de la COVID-19 en raison de l’utilisation de médicaments prolongeant l’intervalle QT et les préoccupations quant à la transmission virale par les électrocardiogrammes (ECG) en série. Nous avons posé l’hypothèse que la surveillance en continu de l’intervalle QT par télémétrie était associée à une meilleure détection des épisodes de prolongation de l’intervalle QT.. Nous avons introduit la télémétrie cardiaque en continu (TCC) à l’aide d’un algorithme de surveillance automatisée de l’intervalle QT dans nos unités de COVID-19. Les mesures automatisées quotidiennes de l’intervalle QT corrigé (auto-QTc) en fonction de la fréquence cardiaque maximale ont été enregistrées. Nous avons comparé la proportion des épisodes de prolongation marquée de l’intervalle QTc (QTc long), définie par un intervalle QTc ≥ 500 ms, chez les patients montrant une suspicion de COVID-19 ou ayant la COVID-19 qui avaient été admis avant et après la mise en place de la TCC (groupe témoin. La surveillance en continu de l’intervalle QT est supérieure à la norme de soins dans la détection des épisodes de QTc long et exige peu d’ECG. La réponse clinique aux épisodes de QTc long est sous-optimale.. Exposure to a model wildfire air pollution source modifies cardiovascular responses to HC challenge, suggesting air pollution sensitizes the body to systemic triggers.. Though the majority of HIV-infected adults who were on HAART had shown viral suppression, the rate of suppression was sub-optimal according to the UNAIDS 90-90-90 target to help end the AIDS pandemic by 2020. Nonetheless, the rate of immunological recovery in the study cohort was low. Hence, early initiation of HAART should be strengthened to achieve good virological suppression and immunological recovery.. Dust in Egyptian laying hen houses contains high concentrations of microorganisms and endotoxins, which might impair the health of birds and farmers when inhaled. Furthermore, laying hens in Egypt seem to be a reservoir for ESBL-producing Enterobacteriaceae. Thus, farmers are at risk of exposure to ESBL-producing bacteria, and colonized hens might transmit these bacteria into the food chain.. The lack of significant differences in the absolute changes and relative ratios of injury and repair biomarkers by contrast-associated AKI status suggests that the majority of mild contrast-associated AKI cases may be driven by hemodynamic changes at the kidney.. Most comparisons for different outcomes are based on very few studies, mostly low-powered, with an overall low CoE. Thus, the available evidence is considered insufficient to either support or refute CH effectiveness or to recommend one ICM over another. Therefore, further well-designed, larger RCTs are required.. PROSPERO database Identifier: CRD42016041953.. Untouched root canal at cross-section perimeter, the Hero 642 system showed 41.44% ± 5.62% and Reciproc R40 58.67% ± 12.39% without contact with instruments. Regarding the untouched area, Hero 642 system showed 22.78% ± 6.42% and Reciproc R40 34.35% ± 8.52%. Neither instrument achieved complete cross-sectional root canal debridement. Hero 642 system rotary taper 0.02 instruments achieved significant greater wall contact perimeter and area compared to reciprocate the Reciproc R40 taper 0.06 instrument.. Hero 642 achieved higher wall contact perimeter and area but, regardless of instrument size and taper, vital pulp during. The functional properties of the main mechanisms involved in the control of muscle Ca. This study showed that the anti-inflammatory effect of the iron-responsive product DHA in arthritis can be monitored by an iron-like radioactive tracer (. Attenuated vascular reactivity during pregnancy suggests that the systemic vasodilatory state partially depletes nitric oxide bioavailability. Preliminary data support the potential for MRI to identify vascular dysfunction in vivo that underlies PE. Level of Evidence 2 Technical Efficacy Stage 1 J. MAGN. RESON. IMAGING 2021;53:447-455.. La evaluación de riesgo es importante para predecir los resultados postoperatorios en pacientes con cáncer gastroesofágico. Este estudio de cohortes tuvo como objetivo evaluar los cambios en la composición corporal durante la quimioterapia neoadyuvante e investigar su asociación con complicaciones postoperatorias. MÉTODOS: Los pacientes consecutivos con cáncer gastroesofágico sometidos a quimioterapia neoadyuvante y cirugía con intención curativa entre 2016 y 2019, identificados a partir de una base de datos específica, se incluyeron en el estudio. Se utilizaron las imágenes de tomografía computarizada, antes y después de la quimioterapia neoadyuvante, para evaluar el índice de masa muscular esquelética, la sarcopenia y el índice de grasa visceral y subcutánea.. In this in vitro premature infant lung model, HF oscillation of BCPAP was associated with improved CO. Our results showed that HPC significantly promotes neurogenesis after MCAO and ameliorates neuronal injury.. Inflammatory markers are highly related to signs of systemic hypoperfusion in CS. Moreover, high PCT and IL-6 levels are associated with poor prognosis.. These findings indicate that Tetrapleura tetraptera fruit has a protective potential against stroke through modulation of redox and electrolyte imbalances, and attenuation of neurotransmitter dysregulation and other neurochemical dysfunctions. Tetrapleura tetraptera fruit could be a promising source for the discovery of bioactives for stroke therapy.

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Neurological disorders are increasing at a faster pace due to oxidative stress, protein aggregation, excitotoxicity, and neuroinflammation. It is reported that the Mediterranean diet including olives as a major dietary component prevents and ameliorates neurological anomalies. Oleuropein is the major bioactive component in different parts of the Olive (Olea europaea L.) tree. Several mechanisms have been reported for the neuroprotective role of oleuropein including induction of apoptosis and autophagy, enhancing the antioxidant pool of the cerebral region, decreasing the unnecessary release of proinflammatory cytokines and chemokines by deactivating the microglia cells and astrocytes thus preventing the occurrence of neuroinflammation. Regular intake of oleuropein seems to be correlated with decreased risks of neural disorders including Alzheimer's, Parkinson's, strokes, depression, anxiety, epilepsy, and others. This review majorly discusses the chemistry, biosynthesis, and metabolism of oleuropein along with an updated vision of its neuroprotective role in counteracting the acute and chronic neurodegenerative and neuropsychiatric disorders. Moreover, mechanisms by which oleuropein may prevent neurodegeneration are reviewed. PRACTICAL APPLICATION: Neurological disorders are negatively affecting the health and life quality of individuals around the globe. Although various medicinal solutions are available to tackle such ailments, none has proven to fully cure and being deprived of side effects. In this respect, the prevention of such disorders using natural remedies may be an effective strategy to overcome the incidence of the increasing cases. Furthermore, the natural compounds provide a safer alternative to pharmaceutical drugs. Hence, oleuropein from olive tree products is found to be efficacious against neurological disorders. This review provides an updated insight on the positive effects of oleuropein against neurodegenerative and neuropsychiatric disorders. The diet practitioners and nutraceutical companies may benefit from the provided information to design and develop strategies to improve the mental health of suffering individuals.

Topics: Humans; Iridoid Glucosides; Iridoids; Neuroinflammatory Diseases; Neuroprotective Agents

Oleuropein (Ole) is the main bioactive phenolic compound present in olive leaves, fruits and olive oil. This molecule has been shown to exert beneficial effects on several human pathological conditions. In particular, recent preclinical and observational studies have provided evidence that Ole exhibits chemo-preventive effects on different types of human tumors. Studies undertaken to elucidate the specific mechanisms underlying these effects have shown that this molecule may thwart several key steps of malignant progression, including tumor cell proliferation, survival, angiogenesis, invasion and metastasis, by modulating the expression and activity of several growth factors, cytokines, adhesion molecules and enzymes involved in these processes. Interestingly, experimental observations have highlighted the fact that most of these signalling molecules also appear to be actively involved in the homing and growth of disseminating cancer cells in bones and, ultimately, in the development of metastatic bone diseases. These findings, and the experimental and clinical data reporting the preventive activity of Ole on various pathological conditions associated with a bone loss, are indicative of a potential therapeutic role of this molecule in the prevention and treatment of cancer-related bone diseases. This paper provides a current overview regarding the molecular mechanisms and the experimental findings underpinning a possible clinical role of Ole in the prevention and development of cancer-related bone diseases.

Topics: Animals; Bone Diseases; Bone Remodeling; Cell Proliferation; Cellular Microenvironment; Disease Progression; Humans; Iridoid Glucosides; Iridoids

Covering: 2005 up to 2020Olive bioactive secoiridoids are recognized as natural antioxidants with multiple beneficial effects on human health. Nevertheless, the study of their biological activity has also disclosed some critical aspects associated with their application. Firstly, only a few of them can be extracted in large amounts from their natural matrix, namely olive leaves, drupes, oil and olive mill wastewater. Secondly, their application as preventive agents and drugs is limited by their low membrane permeability. Thirdly, the study of their biological fate after administration is complicated by the absence of pure analytical standards. Accordingly, efficient synthetic methods to obtain natural and non-natural bioactive phenol derivatives have been developed. Among them, semi-synthetic protocols represent efficient and economical alternatives to total synthesis, combining efficient extraction protocols with efficient catalytic conversions to achieve reasonable amounts of active molecules. The aim of this review is to summarize the semi-synthetic protocols published in the last fifteen years, covering 2005 up to 2020, which can produce natural olive bioactive phenols scarcely available by extractive procedures, and new biophenol derivatives with enhanced biological activity. Moreover, the semi-synthetic protocols to produce olive bioactive phenol derivatives as analytical standards are also discussed. A critical analysis of the advantages offered by semi-synthesis compared to classical extraction methods or total synthesis protocols is also performed.

Topics: Aldehydes; Cyclopentane Monoterpenes; Iridoid Glucosides; Iridoids; Olea; Olive Oil; Phenols; Phenylethyl Alcohol

The Mediterranean diet (MD) is a combination of foods mainly rich in antioxidants and anti-inflammatory nutrients that have been shown to have many health-enhancing effects. Extra-virgin olive oil (EVOO) is an important component of the MD. The importance of EVOO can be attributed to phenolic compounds, represented by phenolic alcohols, hydroxytyrosol, and tyrosol, and to secoiridoids, which include oleocanthal, oleacein, oleuropein, and ligstroside (along with the aglycone and glycosidic derivatives of the latter two). Each secoiridoid has been studied and characterized, and their effects on human health have been documented by several studies. Secoiridoids have antioxidant, anti-inflammatory, and anti-proliferative properties and, therefore, exhibit anti-cancer activity. This review summarizes the most recent findings regarding the pharmacological properties, molecular targets, and action mechanisms of secoiridoids, focusing attention on their preventive and anti-cancer activities. It provides a critical analysis of preclinical, in vitro and in vivo, studies of these natural bioactive compounds used as agents against various human cancers. The prospects for their possible use in human cancer prevention and treatment is also discussed.

Topics: Aldehydes; Animals; Anti-Inflammatory Agents; Antineoplastic Agents; Antioxidants; Cyclopentane Monoterpenes; Diet, Mediterranean; Glucosides; Humans; Iridoid Glucosides; Iridoids; Neoplasms; Olive Oil; Phenols; Phenylethyl Alcohol; Pyrans

The global pandemic of diabetes and diabetes complications confers heavy pressure on public health. Novel antidiabetes strategies with negligible unwanted effects are urgently needed. Currently, the anti-hyperglycemic potential of plant-based functional ingredients has been explored to provide alternative strategies. As a kind of dietary bioactive compound, oleuropein has aroused the growing interest of researchers in diabetes and diabetes complications management. This review reveals the research progress of oleuropein in treating diabetes and diabetes complications and summarizes the molecular mechanisms involved in these beneficial effects of oleuropein. Oleuropein achieves amelioration of diabetes, the mechanisms of which include the modulation of insulin secretion, the repairment islet morphology, the activation of hepatic AMP-activated protein kinase singling, and the improvement of glucose tolerance and insulin resistance. Oleuropein also can relieve diabetes complications including diabetic nephropathy, diabetes cardiovascular complications, diabetic retinopathy, poor wound healing, diabetic neuropathy, and diabetic testicular dysfunction. Oleuropein reverses cell apoptosis, regenerates tissues, restores the histological organization, and decreases oxidative stress in treating diabetes complications. Taken together, oleuropein is a promising compound for diabetes and diabetes complications management and can be used as a nutraceutical to fight against these diseases.

Topics: Diabetes Complications; Diabetes Mellitus; Diabetic Nephropathies; Humans; Iridoid Glucosides; Iridoids; Oxidative Stress

Olive (Olea europaea Linn., Fam. Oleaceae) is commonly known as Zaytoon in Mediterranean region. Its fruits and oil are essential components of Mediterranean diets. Olive tree is a prevalent plant species and one of the important cultivated crops of Mediterranean region. Oleuropein is a phenolic constituents of olive, which, along with its related compounds, has been indicated to be majorly responsible for its beneficial effects. Oleuropein is a secoiridoid type of phenolic compound and consists of three structural subunits: hydroxytyrosol, elenolic acid, and a glucose molecule. It is also reported to be the chemotaxonomic marker of olive. The oleuropein is reported to possess a number of biological activities including action against dyslipidemia, antiobesity, antidiabetic, antioxidant, antiatherogenic, antihypertensive, antiinflammatory, and hepatoprotective actions. The scientific evidence supports the role of oleuropein as a potential agent against metabolic syndrome. The present review discusses chemistry of oleuropein along with potential role of oleuropein with reference to pathophysiology of metabolic syndrome.

Topics: Adolescent; Adult; Antioxidants; Humans; Iridoid Glucosides; Iridoids; Metabolic Syndrome; Young Adult

Research into finding new uses for by-products of table olive and olive oil industry are of great value not only to the economy but also to the environment where olives are grown and to the human health. Since leaves represent around 10% of the total weight of olives arriving at the mill, it is worth obtaining high added-value compounds from those materials for the preparation of dietary supplements, nutraceuticals, functional food ingredients or cosmeceuticals. In this review article, olive tree (Olea europaea L.) leaf is reviewed as being a potential inexpensive, renewable and abundant source of biophenols. The importance of this agricultural and industrial waste is emphasised by means of describing its availability, nutritional and therapeutic effects and studies conducted on this field. © 2017 Society of Chemical Industry.

Topics: Anti-Infective Agents; Anti-Inflammatory Agents; Antihypertensive Agents; Antioxidants; Cosmeceuticals; Dietary Supplements; Fruit; Functional Food; Health Promotion; Humans; Hypoglycemic Agents; Iridoid Glucosides; Iridoids; Olea; Olive Oil; Phenols; Plant Extracts; Plant Leaves; Waste Products

Olive fruit is a significant and promising source of potential bioactive compounds such as oleuropein and hydroxytyrosol. Oleuropein is the ester of elenolic acid and 3,4-dihydroxyphenyl ethanol (HT). It is the main glycoside in olives, the degradation of which results in the formation of hydroxytyrosol in olive oil. Both plays a significant role in the reduction of coronary heart diseases and a certain type of cancers. Both olive oil phenols have an effective role counter to cell proliferation, cell growth, migration, invasion, and angiogenesis. They down regulate the expression of BCL-2 and COX-2 proteins, and reduced DNA damage. Hydroxytyrosol and oleuropein inhibited the multiple stages in colon carcinogenesis; initiation, promotion, and metastasis. They also provide protection against various human cancers including colorectal, skin, breast, thyroid, digestive, lung, brain, blood, and cervical. This review article discusses the anticancer perspectives and mechanisms of oleuropein and hydroxytyrosol in cell cultures and animal and human studies.

Topics: Animals; Antineoplastic Agents; Cell Movement; Cell Proliferation; Coronary Disease; DNA Damage; Humans; Iridoid Glucosides; Iridoids; Neoplasm Invasiveness; Neoplasms; Neovascularization, Pathologic; Olea; Olive Oil; Phenylethyl Alcohol; Pyrans

Lifestyle is the primary prevention of diabetes, especially type-2 diabetes (T2D). Nutritional intake of olive oil (OO), the key Mediterranean diet component has been associated with the prevention and management of many chronic diseases including T2D. Several OO bioactive compounds such as monounsaturated fatty acids, and key biophenols including hydroxytyrosol and oleuropein, have been associated with preventing inflammation and cytokine-induced oxidative damage, glucose lowering, reducing carbohydrate absorption, and increasing insulin sensitivity and related gene expression. However, research into the interaction of OO nutraceuticals with lifestyle components, especially physical activity, is lacking. Promising postprandial effects have been reported when OO or other similar monounsaturated fatty acids were the main dietary fat compared with other diets. Animal studies have shown a potential anabolic effect of oleuropein. Such effects could be further potentiated via exercise, especially strength training, which is an essential exercise prescription for individuals with T2D. There is also an evidence from in vitro, animal, and limited human studies for a dual preventative role of OO biophenols in diabetes and cancer, especially that they share similar risk factors. Putative antioxidative and anti-inflammatory mechanisms and associated gene expressions resulting from OO biophenols have produced paradoxical results, making suggested inferences from dual prevention T2D and cancer outcomes difficult. Well-designed human interventions and clinical trials are needed to decipher such a potential dual anticancer and antidiabetic effects of OO nutraceuticals. Exercise combined with OO consumption, individually or as part of a healthy diet is likely to induce reciprocal action for T2D prevention outcomes.

Topics: Diabetes Mellitus, Type 2; Dietary Fats; Dietary Supplements; Humans; Iridoid Glucosides; Iridoids; Life Style; Olive Oil; Phenylethyl Alcohol

The antimicrobial activity of phenolic compounds from Olea (O.) europaea Linné (L.) is part of the scientific discussion regarding the use of natural plant extracts as alternative food preservative agents. Although, the basic knowledge on the antimicrobial potential of certain molecules such as oleuropein, hydroxytyrosol or elenolic acid derivatives is given, there is still little information regarding their applicability for food preservation. This might be primarily due to the lack of information regarding the full antimicrobial spectrum of the compounds, their synergisms in natural or artificial combinations and their interaction with food ingredients. The present review accumulates available literature from the past 40 years, investigating the antimicrobial activity of O. europaea L. derived extracts and compounds in vitro and in food matrices, in order to evaluate their food applicability. In summary, defined extracts from olive fruit or leaves, containing the strongest antimicrobial compounds hydroxytyrosol, oleacein or oleacanthal in considerable concentrations, appear to be suitable for food preservation. Nonetheless there is still need for consequent research on the compounds activity in food matrices, their effect on the natural microbiota of certain foods and their influence on the sensorial properties of the targeted products.

Topics: Aldehydes; Anti-Infective Agents; Food Preservatives; Fruit; Iridoid Glucosides; Iridoids; Olea; Phenols; Phenylethyl Alcohol; Plant Extracts; Plant Leaves; Pyrans

Cancer comprises a collection of related diseases characterized by the existence of altered cellular pathways resulting in an abnormal tendency for uncontrolled growth. A broad spectrum, coordinated, and personalized approach focused on targeting diverse oncogenic pathways with low toxicity and economic natural compounds can provide a real benefit as a chemopreventive and/or treatment of this complex disease. Oleuropein, a bioactive phenolic compound mainly present in olive oil and other natural sources, has been reported to modulate several oncogenic signalling pathways. This review presents and critically discusses the available literature about the anticancer and onco-suppressive activity of oleuropein and the underlying molecular mechanisms implicated in the anticarcinogenic and therapeutic effects. The existence of limitations and the promising perspectives of research on this phenolic compound are also critically analyzed and discussed.

Topics: Animals; Anticarcinogenic Agents; Apoptosis; Chemoprevention; Humans; Iridoid Glucosides; Iridoids; MAP Kinase Signaling System; Neoplasms; Protein Kinase Inhibitors

Olive oil and table olives are rich sources of biophenols, which provides a unique taste, aroma and potential health benefits. Specifically, green olive drupes are enriched with oleuropein, a bioactive biophenol secoiridoid. Olive oil contains hydrolytic derivatives such as hydroxytyrosol, oleacein and elenolate from oleuropein as well as tyrosol and oleocanthal from ligstroside. Biophenol secoiridoids are categorized by the presence of elenoic acid or its derivatives in their molecular structure. Medical studies suggest that olive biophenol secoiridoids could prevent cancer, obesity, osteoporosis, and neurodegeneration. Therefore, understanding the biomolecular dynamics of oleuropein can potentially improve olive-based functional foods and nutraceuticals. This review provides a critical assessment of oleuropein biomolecular mechanism and computational mapping that could contribute to nutrigenomics.

Topics: Computer Simulation; Hydrolysis; Iridoid Glucosides; Iridoids; Mass Spectrometry; Oxidation-Reduction

Cancer cells exhibit enhanced proliferation rate and a resistance to apoptosis. Epidemiological studies suggest that olive oil intake is associated with a reduced risk of cancer. Olive oil, olives, and olive leaves contain many polyphenols, including oleuropein. Recently, several studies have demonstrated that oleuropein inhibits proliferation and induces apoptosis in different cancer cell lines. In addition, anticancer effects of oleuropein have been seen in animal studies. These effects are associated with oleuropein's ability to modulate gene expression and activity of a variety of different signaling proteins that play a role in proliferation and apoptosis. This article summarizes the existing in vitro and in vivo studies focusing on the anticancer effects of oleuropein and its effects on key signaling molecules. © 2017 BioFactors, 43(4):517-528, 2017.

Topics: Animals; Anthocyanins; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Humans; Iridoid Glucosides; Iridoids; Obesity

Olive oil and table olive biophenols have been shown to significantly enrich the hedonic-sensory and nutritional quality of the Mediterranean diet. Oleuropein is one of the predominant biophenols in green olives and leaves, which not only has noteworthy freeradical quenching activity but also putatively reduces the incidence of various cancers. Clinical trials suggest that the consumption of extra virgin olive oil reduces the risk of several degenerative diseases. The oleuropein-based bioactives in olive oil could reduce tumor necrosis factor α, interleukin-1β and nitric oxide. Therefore, the quality of olive biophenols should be preserved and even improved due to their disease-fighting properties.. Understanding the molecular dynamics of oleuropein is crucial to increase olive oil and table olive quality. The objective of this review is to provide the molecular dynamics and computational mapping of oleuropein.. The oleuropein molecular bond sequential breaking mechanisms were analyzed through unimolecular reactions under electron spray ionization, collision activated dissociations, and fast atom bombardment mass spectrometry.. Oleuropein is a biophenol-secoiridoid expressing different functionalities such as two π-bonds, two esters, two acetals, one catechol, and four hexose hydroxyls within 540 mw. The oleuropein solvent-free reactivity is leading to glucose loss and bioactive aglycone-dialdehydes via secoiridoid ring opening.. Oleuropein electron distribution revealed that the free-radical non-polar processes occur from its highest occupied molecular orbital, while the lowest unoccupied molecular orbital is clearly devoted to nucleophilic and base site reactivity. This molecular dynamics and computational mapping of oleuropein could contribute to the engineering of olive-based biomedicine and/or functional food.

Topics: Iridoid Glucosides; Iridoids; Molecular Dynamics Simulation; Molecular Structure; Quantum Theory

In TgCRND8 (Tg) mice we checked the dose-response effect of diet supplementation with oleuropein aglycone (OLE) at 12.5 or 0.5 mg kg. Four month-old Tg mice were equally divided into four groups and treated for 8 weeks with a modified low fat (5.0%) AIN-76 A diet (10 g day. OLE supplementation at 12.5 mg kg. Our results extend previous data showing that the effects of OLE on behavioural performance and neuropathology are dose-dependent and not closely related to OLE by itself. In fact, diet supplementation with the same dose of a mix of polyphenols found in olive mill waste water resulted in comparable neuroprotection.

Topics: Amyloid beta-Peptides; Amyloid beta-Protein Precursor; Animals; Behavior, Animal; Brain; Cognitive Dysfunction; Dietary Supplements; Disease Models, Animal; Dose-Response Relationship, Drug; Iridoid Glucosides; Iridoids; Mice, Transgenic; Olea; Peptide Fragments; Plaque, Amyloid; Polyphenols; Wastewater

Cancer is a multifaceted and genomically complex disease. Rapidly accumulating preclinical and clinical studies are emphasizing on wide ranging molecular mechanisms that underpin cancer development, progression and metastasis. Intratumor heterogeneity, loss of apoptosis, rapidly developing resistance against molecular therapeutics and off-target effects are some of the deeply studied resistance mechanisms. Data obtained through high-throughput technologies has considerably enhanced our understanding of the intracellular signaling cascades frequently dysregulated spatio-temporally. There is an ever-expanding list of synthetic and natural agents reported to activate tumor suppressor genes and inhibit oncogenes in cancer cells. Markedly reduced tumor growth has also been documented in xenografted mice administered with phytochemicals. Oleuropein is a bioactive ingredient isolated from various sources and there is evidence of complete regression of tumors in 9- 12 days in mice orally administered with Oleuropein. In this review we summarize recent developments in use of Oleuropein as an anticancer agent. Extraction and isolation of Oleuropein and how it modulates intracellular signaling network to induce apoptosis in cancer cells. Human epidermal growth factor receptor 2 (HER2) frequently overexpressed in breast cancer cells is inhibited by Oleuropein. Interestingly, trastuzumab efficacy was notably enhanced in Oleuropein treated breast cancer cells. There is still insufficient information related to Oleuropein mediated microRNA regulation in cancer cells. We still do not have information about regulation of different signaling cascades by Oleuropein which are deregulated in cancer. Future studies must converge on a deeper analysis of target molecular network of Oleuropein and its efficacy as a tumor growth inhibitor in xenografted mice.

Topics: Animals; Apoptosis; Humans; Iridoid Glucosides; Iridoids; Mice; Neoplasms; Proto-Oncogene Proteins c-akt; Reactive Oxygen Species; Signal Transduction

Virgin olive oil (VOO) is credited as being one of the many healthful components associated with the Mediterranean diet. Mediterranean populations experience reduced incidence of chronic inflammatory disease states and VOO is readily consumed as part of an everyday Mediterranean dietary pattern. VOO is rich in phenolic compounds and the health promoting benefits of these phenolics are now established. Recent studies have highlighted the biological properties of VOO phenolic compounds elucidating their anti-inflammatory activities. This paper will review current knowledge on the anti-inflammatory and nutrigenomic, chemoprotective and anti-atherosclerotic activities of VOO phenolics. In addition the concentration, metabolism and bioavailability of specific phenolic compounds will be discussed. The evidence presented in the review concludes that oleurepein, hydroxytyrosol and oleocanthal have potent pharmacological activities in vitro and in vivo; however, intervention studies with biologically relevant concentrations of these phenolic compounds are required.

Topics: Aldehydes; Animals; Anti-Inflammatory Agents; Biological Availability; Cyclopentane Monoterpenes; Dietary Supplements; Humans; Iridoid Glucosides; Iridoids; Olive Oil; Phenols; Phenylethyl Alcohol

The amyloid plaques and neurofibrillary tangles found in the Alzheimer's disease (AD) brain arise as a result of self-assembly into fibrillar material of amyloid-β protein (Aβ) and hyperphosphorylated tau, respectively, through a pathological process starting with the appearance of aggregation nuclei and neurotoxic oligomers. Accordingly, the search of inhibitors of oligomer nucleation and growth is considered a promising target to prevent amyloid toxicity. In recent years, a number of dietary factors including antioxidants, vitamins, and polyphenols have been characterized for their ability to protect cells stressed by several factors including the presence of amyloid deposits as well as to inhibit amyloid self-assembly and cytotoxicity and some of them are currently in clinical trial. The present review summarizes the findings on the beneficial effects against neurodegeneration and other peripheral inflammatory and degenerative diseases of oleuropein aglycone (OLE), a natural phenol abundant in the extra virgin olive oil. The data presently available suggest that OLE could provide a protective and therapeutic effect against a number of pathologies, including AD as well as obesity, type 2 diabetes, non-alcoholic hepatitis, and other natural or experimentally-induced pathological conditions. Such a protection could result, at least in part, in a remarkable improvement of the pathological signs arising from stress conditions including oxidative stress, an excessive inflammatory response, and the presence of cytotoxic aggregated material. In particular, the recent data on the cellular and molecular correlates of OLE neuroprotection suggest it could also play a therapeutic role against AD.

Topics: Alzheimer Disease; Anti-Inflammatory Agents; Cognition Disorders; Humans; Inflammation; Iridoid Glucosides; Iridoids; Nerve Degeneration; Plaque, Amyloid

The overall health beneficial action of olive oil phenolic components is well established. Recent studies have elucidated the biological effects of two isolated compounds, namely oleuropein and hydroxytyrosol, with particular attention on their antioxidant activity. Thus, a protective action has been demonstrated in preclinical studies against several diseases, especially cardiovascular and metabolic disorders. The present review will describe the biological effects of oleuropein and hydroxytyrosol, with particular attention on the molecular mechanism underlying the protective action on cardiovascular and metabolic alterations, as demonstrated by in vitro and in vivo experimental studies performed with the isolated compounds.

Topics: Animals; Cardiovascular Diseases; Diabetes Mellitus; Humans; Iridoid Glucosides; Iridoids; Metabolic Diseases; Olive Oil; Phenylethyl Alcohol; Plant Oils

The use of the products derived from the olive tree on human health dates back centuries. In several civilizations, the olive tree had and still has a very strong cultural and religious symbolism. Notably, the official seal and emblem of the World Health Organization features the rod of Asclepius over a world map surrounded by olive tree branches, chosen as a symbol of peace and health. Recently, accumulating experimental, clinical and epidemiological data have provided support to the traditional beliefs of the beneficial effect provided by olive derivates. In particular, the polyphenols present in olive leaves, olives, virgin (unrefined) olive oil and olive mill waste are potent antioxidant and radical scavengers with anti-tumor and anti-inflammatory properties. Here, we review the positive impact on human health of oleuropein, the most prevalent polyphenol present in olives. In addition, we provide data collected in our laboratory on the role of oleuropein in counteracting lipid accumulation in a mouse model of non-alcoholic fatty liver disease.

Topics: Animals; Anti-Infective Agents; Anti-Inflammatory Agents; Antineoplastic Agents; Antioxidants; Health; Humans; Iridoid Glucosides; Iridoids; Lipid Metabolism; Non-alcoholic Fatty Liver Disease; Olea; Polyphenols; Protective Agents

The phenolic compounds present in olive leaves (Olea europaea L.) confer benefits to the human health.. To review the scientific literature about the benefits of the polyphenols of olive leaves to human health.. Literature review in the LILACS-BIREME, SciELO and MEDLINE databases for publications in English, Portuguese and Spanish with the descriptors "Olea europaea", "olive leaves", "olive leaf", "olive leaves extracts", "olive leaf extracts", "phenolic compounds", "polyphenols", "oleuropein", "chemical composition", and "health". There were identified 92 articles, but only 38 related to the objectives of the study and 9 articles cited in the works were included due to their relevance.. The phenolic compounds present in olive leaves, especially the oleuropein, are associated to antioxidant, antihypertensive, hypoglycemic, hypocholesterolemic and cardioprotective activity. Furthermore, studies associate the oleuropein to an anti-inflammatory effect in trauma of the bone marrow and as a support in the treatment of obesity.. Introducción: Los compuestos fenólicos presentes en las hojas del olivo (olea europaea l.) conferir beneficios para la salud humana. Objetivos: Revisar la literatura científica sobre los beneficios de los polifenoles de hojas de olivo para la salud humana. Método: Revisión de la literatura en las bases de datos lilacs-bireme, scielo y medline para publicaciones en inglés, portugués y español con los descriptores “olea europaea”, “hojas de olivo”, “hoja de olivo”, “hojas de olivo extractos”, “los extractos de hoja de olivo”, “compuestos fenólicos”, “polifenoles”, “oleuropeína”, “composición química”, y “salud”. Se identificaron 92 artículos, pero sólo 38 en relación con los objetivos del estudio y 9 artículos citados en las obras se incluyeron debido a su relevancia. Resultados y discusión: Los compuestos fenólicos presentes en las hojas del olivo, especialmente la oleuropeína, se asocian a antioxidante, antihipertensivo, hipoglucemiante, actividad hipocolesterolémico y cardioprotector. además, los estudios asocian la oleuropeína a un efecto anti-inflamatorio en trauma de la médula ósea y como soporte en el tratamiento de la obesidad.

Topics: Animals; Anti-Inflammatory Agents; Anti-Obesity Agents; Antihypertensive Agents; Antioxidants; Cardiotonic Agents; Clinical Trials as Topic; Colitis; Drug Evaluation, Preclinical; Food, Organic; Humans; Hypoglycemic Agents; Hypolipidemic Agents; Iridoid Glucosides; Iridoids; Olea; Phytotherapy; Plant Leaves; Polyphenols

The Mediterranean diet appears to be associated with a reduced risk of several chronic diseases including cancer and cardiovascular and Alzheimer's diseases. Olive products (mainly olive oil and table olives) are important components of the Mediterranean diet. Olives contain a range of phenolic compounds; these natural antioxidants may contribute to the prevention of these chronic conditions. Consequently, the consumption of table olives and olive oil continues to increase worldwide by health-conscious consumers. There are numerous factors that can affect the phenolics in table olives including the cultivar, degree of ripening, and, importantly, the methods used for curing and processing table olives. The predominant phenolic compound found in fresh olive is the bitter secoiridoid oleuropein. Table olive processing decreases levels of oleuropein with concomitant increases in the hydrolysis products hydroxytyrosol and tyrosol. Many of the health benefits reported for olives are thought to be associated with the levels of hydroxytyrosol. Herein the pre- and post-harvest factors influencing the phenolics in olives, debittering methods, and health benefits of phenolics in table olives are reviewed.

Topics: Antioxidants; Diet, Mediterranean; Drug Stability; Flavonoids; Food Handling; Fruit; Health Promotion; Hot Temperature; Humans; Iridoid Glucosides; Iridoids; Olea; Phenol; Phenylethyl Alcohol; Pyrans; Seeds; Species Specificity

Olive tree (Olea europaea L.) leaves have been widely used in traditional remedies in European and Mediterranean countries such as Greece, Spain, Italy, France, Turkey, Israel, Morocco, and Tunisia. They have been used in the human diet as an extract, an herbal tea, and a powder, and they contain many potentially bioactive compounds that may have antioxidant, antihypertensive, antiatherogenic, anti-inflammatory, hypoglycemic, and hypocholesterolemic properties. One of these potentially bioactive compounds is the secoiridoid oleuropein, which can constitute up to 6-9% of dry matter in the leaves. Other bioactive components found in olive leaves include related secoiridoids, flavonoids, and triterpenes. The evidence supporting the potentially beneficial effects of olive leaves on human health are presented in this brief review.

Topics: Anti-Inflammatory Agents; Anticholesteremic Agents; Antihypertensive Agents; Antioxidants; Arteriosclerosis; Biological Availability; Flavonoids; Humans; Hypoglycemic Agents; Iridoid Glucosides; Iridoids; Olea; Phenols; Phytotherapy; Plant Extracts; Plant Leaves; Polyphenols; Pyrans

Unprecedented community containment measures were taken following the recent outbreak of COVID-19 in Italy. The aim of the study was to explore the self-reported future compliance of citizens with such measures and its relationship with potentially impactful psychological variables.. An online survey was completed by 931 people (18-76 years) distributed across the Italian territory. In addition to demographics, five dimensions were measured: self-reported compliance with containment measures over time (today, at 7, 14, 30, 60, 90, and 180 days from now) at three hypothetical risk levels (10, 50, 90% of likelihood of contracting the COVID-19), perceived risk, generalized anxiety, intolerance of uncertainty, and relevance of several psychological needs whose satisfaction is currently precluded.. The duration of containment measures plays a crucial role in tackling the spread of the disease as people will be less compliant over time. Psychological needs of citizens impacting on the compliance should be taken into account when planning an easing of the lockdown, along with interventions for protecting vulnerable groups from mental distress.. La apendicitis aguda (AA) es la urgencia quirúrgica abdominal más frecuente. No encontramos estudios específicos que evalúen el impacto de la pandemia causada por el coronavirus 2 (SARS-Cov-2) sobre la AA y su tratamiento quirúrgico. Analizamos la influencia de esta nueva patología sobre la AA.. Estudio observacional retrospectivo en pacientes intervenidos por AA desde enero hasta abril de 2020. Fueron clasificados según el momento de la apendicectomía, antes de la declaración del estado de alarma (Pre-COVID19) y después de la declaración del estado de alarma (Post-COVID19) en España. Se evaluaron variables demográficas, duración de la sintomatología, tipo de apendicitis, tiempo quirúrgico, estancia hospitalaria y complicaciones postoperatorias.. La pandemia por SARS-Cov-2 influye en el momento de diagnóstico de la apendicitis, así como en su grado de evolución y estancia hospitalaria. La peritonitis fue lo más frecuentemente observado. Una sospecha y orientación clínica más temprana, es necesaria para evitar un manejo inadecuado de este trastorno quirúrgico común.. The primary outcome is improvement in PaO. Findings will provide timely information on the safety, efficacy, and optimal dosing of t-PA to treat moderate/severe COVID-19-induced ARDS, which can be rapidly adapted to a phase III trial (NCT04357730; FDA IND 149634).. None.. The gut barrier is crucial in cirrhosis in preventing infection-causing bacteria that normally live in the gut from accessing the liver and other organs via the bloodstream. Herein, we characterised gut inflammation by measuring different markers in stool samples from patients at different stages of cirrhosis and comparing this to healthy people. These markers, when compared with equivalent markers usually measured in blood, were found to be very different in pattern and absolute levels, suggesting that there is significant gut inflammation in cirrhosis related to different immune system pathways to that seen outside of the gut. This provides new insights into gut-specific immune disturbances that predispose to complications of cirrhosis, and emphasises that a better understanding of the gut-liver axis is necessary to develop better targeted therapies.. La surveillance de l’intervalle QT a suscité beaucoup d’intérêt durant la pandémie de la COVID-19 en raison de l’utilisation de médicaments prolongeant l’intervalle QT et les préoccupations quant à la transmission virale par les électrocardiogrammes (ECG) en série. Nous avons posé l’hypothèse que la surveillance en continu de l’intervalle QT par télémétrie était associée à une meilleure détection des épisodes de prolongation de l’intervalle QT.. Nous avons introduit la télémétrie cardiaque en continu (TCC) à l’aide d’un algorithme de surveillance automatisée de l’intervalle QT dans nos unités de COVID-19. Les mesures automatisées quotidiennes de l’intervalle QT corrigé (auto-QTc) en fonction de la fréquence cardiaque maximale ont été enregistrées. Nous avons comparé la proportion des épisodes de prolongation marquée de l’intervalle QTc (QTc long), définie par un intervalle QTc ≥ 500 ms, chez les patients montrant une suspicion de COVID-19 ou ayant la COVID-19 qui avaient été admis avant et après la mise en place de la TCC (groupe témoin. La surveillance en continu de l’intervalle QT est supérieure à la norme de soins dans la détection des épisodes de QTc long et exige peu d’ECG. La réponse clinique aux épisodes de QTc long est sous-optimale.. Exposure to a model wildfire air pollution source modifies cardiovascular responses to HC challenge, suggesting air pollution sensitizes the body to systemic triggers.. Though the majority of HIV-infected adults who were on HAART had shown viral suppression, the rate of suppression was sub-optimal according to the UNAIDS 90-90-90 target to help end the AIDS pandemic by 2020. Nonetheless, the rate of immunological recovery in the study cohort was low. Hence, early initiation of HAART should be strengthened to achieve good virological suppression and immunological recovery.. Dust in Egyptian laying hen houses contains high concentrations of microorganisms and endotoxins, which might impair the health of birds and farmers when inhaled. Furthermore, laying hens in Egypt seem to be a reservoir for ESBL-producing Enterobacteriaceae. Thus, farmers are at risk of exposure to ESBL-producing bacteria, and colonized hens might transmit these bacteria into the food chain.. The lack of significant differences in the absolute changes and relative ratios of injury and repair biomarkers by contrast-associated AKI status suggests that the majority of mild contrast-associated AKI cases may be driven by hemodynamic changes at the kidney.. Most comparisons for different outcomes are based on very few studies, mostly low-powered, with an overall low CoE. Thus, the available evidence is considered insufficient to either support or refute CH effectiveness or to recommend one ICM over another. Therefore, further well-designed, larger RCTs are required.. PROSPERO database Identifier: CRD42016041953.. Untouched root canal at cross-section perimeter, the Hero 642 system showed 41.44% ± 5.62% and Reciproc R40 58.67% ± 12.39% without contact with instruments. Regarding the untouched area, Hero 642 system showed 22.78% ± 6.42% and Reciproc R40 34.35% ± 8.52%. Neither instrument achieved complete cross-sectional root canal debridement. Hero 642 system rotary taper 0.02 instruments achieved significant greater wall contact perimeter and area compared to reciprocate the Reciproc R40 taper 0.06 instrument.. Hero 642 achieved higher wall contact perimeter and area but, regardless of instrument size and taper, vital pulp during. The functional properties of the main mechanisms involved in the control of muscle Ca. This study showed that the anti-inflammatory effect of the iron-responsive product DHA in arthritis can be monitored by an iron-like radioactive tracer (. Attenuated vascular reactivity during pregnancy suggests that the systemic vasodilatory state partially depletes nitric oxide bioavailability. Preliminary data support the potential for MRI to identify vascular dysfunction in vivo that underlies PE. Level of Evidence 2 Technical Efficacy Stage 1 J. MAGN. RESON. IMAGING 2021;53:447-455.. La evaluación de riesgo es importante para predecir los resultados postoperatorios en pacientes con cáncer gastroesofágico. Este estudio de cohortes tuvo como objetivo evaluar los cambios en la composición corporal durante la quimioterapia neoadyuvante e investigar su asociación con complicaciones postoperatorias. MÉTODOS: Los pacientes consecutivos con cáncer gastroesofágico sometidos a quimioterapia neoadyuvante y cirugía con intención curativa entre 2016 y 2019, identificados a partir de una base de datos específica, se incluyeron en el estudio. Se utilizaron las imágenes de tomografía computarizada, antes y después de la quimioterapia neoadyuvante, para evaluar el índice de masa muscular esquelética, la sarcopenia y el índice de grasa visceral y subcutánea.. In this in vitro premature infant lung model, HF oscillation of BCPAP was associated with improved CO. Our results showed that HPC significantly promotes neurogenesis after MCAO and ameliorates neuronal injury.. Inflammatory markers are highly related to signs of systemic hypoperfusion in CS. Moreover, high PCT and IL-6 levels are associated with poor prognosis.. These findings indicate that Tetrapleura tetraptera fruit has a protective potential against stroke through modulation of redox and electrolyte imbalances, and attenuation of neurotransmitter dysregulation and other neurochemical dysfunctions. Tetrapleura tetraptera fruit could be a promising source for the discovery of bioactives for stroke therapy.

Topics: 3T3-L1 Cells; A Kinase Anchor Proteins; Acetates; Achilles Tendon; Acute Kidney Injury; Acute Pain; Acyclic Monoterpenes; Adenine Nucleotides; Adhesins, Escherichia coli; Adipocytes; Adipocytes, Brown; Adipogenesis; Administration, Inhalation; Administration, Oral; Adrenal Cortex Hormones; Adsorption; Adult; Aeromonas hydrophila; Africa; Aged; Aged, 80 and over; Agrobacterium tumefaciens; Air; Air Pollutants; Air Pollution; Air Pollution, Indoor; Algorithms; Alkaloids; Alkynes; Allosteric Regulation; Amines; Amino Acid Sequence; Amino Acids; Amino Acids, Branched-Chain; Aminoisobutyric Acids; Aminopyridines; Amyotrophic Lateral Sclerosis; Anaerobic Threshold; Angiography; Angiotensin II Type 1 Receptor Blockers; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animal Distribution; Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Ankle Joint; Anti-Bacterial Agents; Anti-HIV Agents; Anti-Inflammatory Agents; Antibodies, Bacterial; Antifungal Agents; Antimalarials; Antineoplastic Agents; Antineoplastic Agents, Phytogenic; Antioxidants; Antiretroviral Therapy, Highly Active; Antiviral Agents; Aotidae; Apelin; Apoptosis; Arabidopsis Proteins; Argentina; Arginine; Artemisinins; Arthritis, Experimental; Arthritis, Rheumatoid; Arthroscopy; Aspergillus; Aspergillus niger; Asteraceae; Asthma; ATP Binding Cassette Transporter, Subfamily B, Member 1; ATP Binding Cassette Transporter, Subfamily G, Member 2; Auditory Cortex; Autoantibodies; Autophagy; Bacteria; Bacterial Infections; Bacterial Proteins; Bacterial Typing Techniques; Base Composition; Base Sequence; Basketball; Beclin-1; Benzhydryl Compounds; Benzimidazoles; Benzo(a)pyrene; Benzofurans; Benzoxazines; Bereavement; beta Catenin; beta-Lactamase Inhibitors; beta-Lactamases; beta-Lactams; Betacoronavirus; Betaine; Binding Sites; Biofilms; Biological Assay; Biological Availability; Biological Evolution; Biomarkers; Biomechanical Phenomena; Biopolymers; Biopsy; Bismuth; Blood Glucose; Blood Platelets; Blood Pressure; Body Composition; Body Weight; Bone Marrow; Bone Marrow Cells; Bone Regeneration; Boron; Botrytis; Brain Ischemia; Brain Neoplasms; Brain-Derived Neurotrophic Factor; Brazil; Breast Neoplasms; Breath Tests; Bronchoalveolar Lavage Fluid; Burkholderia; C-Reactive Protein; Caenorhabditis elegans; Caenorhabditis elegans Proteins; Calcification, Physiologic; Calcium; Calcium Signaling; Calorimetry, Differential Scanning; Cameroon; Camptothecin; Candida; Candida albicans; Capillaries; Carbapenem-Resistant Enterobacteriaceae; Carbapenems; Carbohydrate Conformation; Carbon; Carbon Dioxide; Carbon Isotopes; Carcinoma, Ovarian Epithelial; Cardiac Output; Cardiomyopathy, Hypertrophic; Cardiotonic Agents; Cardiovascular Diseases; Caregivers; Carps; Case-Control Studies; Catalase; Catalysis; Cats; CD4 Lymphocyte Count; Cell Culture Techniques; Cell Differentiation; Cell Line, Tumor; Cell Membrane; Cell Movement; Cell Proliferation; Cell Survival; Cells, Cultured; Cellulose; Centrosome; Ceratopogonidae; Chickens; Child; China; Cholera Toxin; Choline; Cholinesterases; Chromatography, High Pressure Liquid; Chromatography, Liquid; Chromatography, Micellar Electrokinetic Capillary; Chromatography, Reverse-Phase; Chronic Disease; Cinnamates; Cities; Citrates; Climate Change; Clinical Trials, Phase III as Topic; Coal; Coal Mining; Cohort Studies; Coinfection; Colchicine; Colony Count, Microbial; Colorectal Neoplasms; Coloring Agents; Common Cold; Complement Factor H; Computational Biology; Computer Simulation; Continuous Positive Airway Pressure; Contrast Media; Coordination Complexes; Coronary Artery Bypass; Coronavirus 3C Proteases; Coronavirus Infections; Coronavirus Protease Inhibitors; Corynebacterium glutamicum; Cosmetics; COVID-19; Creatinine; Cross-Sectional Studies; Crotonates; Crystallography, X-Ray; Cues; Culicidae; Culture Media; Curcuma; Cyclopentanes; Cyclopropanes; Cymbopogon; Cystine; Cytochrome P-450 CYP2B6; Cytochrome P-450 CYP2C19; Cytochrome P-450 CYP2C19 Inhibitors; Cytokines; Databases, Genetic; Death; Dendritic Cells; Density Functional Theory; Depsides; Diabetes Mellitus, Type 2; Diamond; Diarylheptanoids; Dibenzofurans; Dibenzofurans, Polychlorinated; Diclofenac; Diet; Dietary Carbohydrates; Dietary Supplements; Diffusion Magnetic Resonance Imaging; Dioxins; Diphenylamine; Disease Outbreaks; Disease Susceptibility; Disulfides; Dithiothreitol; Dizocilpine Maleate; DNA Methylation; DNA-Binding Proteins; DNA, Bacterial; Dogs; Dose-Response Relationship, Drug; Double-Blind Method; Doublecortin Protein; Drosophila melanogaster; Droughts; Drug Carriers; Drug Combinations; Drug Delivery Systems; Drug Liberation; Drug Resistance; Drug Resistance, Bacterial; Drug Resistance, Neoplasm; Drug Screening Assays, Antitumor; Dust; Dynactin Complex; Dysferlin; Echo-Planar Imaging; Echocardiography; Edaravone; Egypt; Elasticity; Electrodes; Electrolytes; Emodin; Emtricitabine; Endometriosis; Endothelium, Vascular; Endotoxins; Energy Metabolism; Energy Transfer; 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Inflammation Mediators; Infrared Rays; Inhibitory Concentration 50; Injections, Intravenous; Interferon-gamma; Interleukin-23; Interleukin-4; Interleukin-6; Intermediate Filaments; Intermittent Claudication; Intestine, Small; Iridoid Glucosides; Iridoids; Iron; Isomerism; Isotope Labeling; Isoxazoles; Itraconazole; Kelch-Like ECH-Associated Protein 1; Ketoprofen; Kidney Failure, Chronic; Kinetics; Klebsiella pneumoniae; Lactams, Macrocyclic; Lactobacillus; Lactulose; Lakes; Lamivudine; Laparoscopy; Laparotomy; Laryngoscopy; Leucine; Limit of Detection; Linear Models; Lipid A; Lipopolysaccharides; Listeria monocytogenes; Liver; Liver Cirrhosis; Logistic Models; Longitudinal Studies; Losartan; Low Back Pain; Lung; Lupinus; Lupus Erythematosus, Systemic; Machine Learning; Macular Degeneration; Madin Darby Canine Kidney Cells; Magnetic Phenomena; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Magnetics; Malaria, Falciparum; Male; Mannans; MAP Kinase Signaling System; Mass Spectrometry; Melatonin; Membrane Glycoproteins; Membrane Proteins; Meniscectomy; Menisci, Tibial; Mephenytoin; Mesenchymal Stem Cells; Metal Nanoparticles; Metal-Organic Frameworks; Methionine; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Nude; Mice, Obese; Mice, Transgenic; Microbial Sensitivity Tests; Microcirculation; MicroRNAs; Microscopy, Video; Microtubules; Microvascular Density; Microwaves; Middle Aged; Minimally Invasive Surgical Procedures; Models, Animal; Models, Biological; Models, Molecular; Models, Theoretical; Molecular Docking Simulation; Molecular Structure; Molecular Weight; Morus; Mouth Floor; Multicenter Studies as Topic; Multiple Sclerosis; Multiple Sclerosis, Relapsing-Remitting; Muscle, Skeletal; Myocardial Ischemia; Myocardium; NAD; NADP; Nanocomposites; Nanoparticles; Naphthols; Nasal Lavage Fluid; Nasal Mucosa; Neisseria meningitidis; Neoadjuvant Therapy; Neoplasm Invasiveness; Neoplasm Recurrence, Local; Neoplasms, Experimental; Neural Stem Cells; Neuroblastoma; Neurofilament Proteins; Neurogenesis; Neurons; New York; NF-E2-Related Factor 2; NF-kappa B; Nicotine; Nitriles; Nitrogen; Nitrogen Fixation; North America; Observer Variation; Occupational Exposure; Ochrobactrum; Oils, Volatile; Olea; Oligosaccharides; Omeprazole; Open Field Test; Optimism; Oregon; Oryzias; Osmolar Concentration; Osteoarthritis; Osteoblasts; Osteogenesis; Ovarian Neoplasms; Ovariectomy; Oxadiazoles; Oxidation-Reduction; Oxidative Stress; Oxygen; Ozone; p38 Mitogen-Activated Protein Kinases; Pakistan; Pandemics; Particle Size; Particulate Matter; Patient-Centered Care; Pelargonium; Peptides; Perception; Peripheral Arterial Disease; Peroxides; Pets; Pharmaceutical Preparations; Pharmacogenetics; Phenobarbital; Phenols; Phenotype; Phosphates; Phosphatidylethanolamines; Phosphines; Phospholipids; Phosphorus; Phosphorylation; Photoacoustic Techniques; Photochemotherapy; Photosensitizing Agents; Phylogeny; Phytoestrogens; Pilot Projects; Plant Components, Aerial; Plant Extracts; Plant Immunity; Plant Leaves; Plant Oils; Plants, Medicinal; Plasmodium berghei; Plasmodium falciparum; Platelet Activation; Platelet Function Tests; Pneumonia, Viral; Poaceae; Pogostemon; Poloxamer; Poly I; Poly(ADP-ribose) Polymerase Inhibitors; Polychlorinated Biphenyls; Polychlorinated Dibenzodioxins; Polycyclic Compounds; Polyethylene Glycols; Polylysine; Polymorphism, Genetic; Polymorphism, Single Nucleotide; Population Dynamics; Portasystemic Shunt, Transjugular Intrahepatic; Positron Emission Tomography Computed Tomography; Postoperative Complications; Postprandial Period; Potassium Cyanide; Predictive Value of Tests; Prefrontal Cortex; Pregnancy; Prepulse Inhibition; Prevalence; Procalcitonin; Prodrugs; Prognosis; Progression-Free Survival; Proline; Proof of Concept Study; Prospective Studies; Protein Binding; Protein Conformation; Protein Domains; Protein Folding; Protein Multimerization; Protein Sorting Signals; Protein Structure, Secondary; Proton Pump Inhibitors; Protozoan Proteins; Psychometrics; Pulse Wave Analysis; Pyridines; Pyrrolidines; Quality of Life; Quantum Dots; Quinoxalines; Quorum Sensing; Radiopharmaceuticals; Rain; Random Allocation; Randomized Controlled Trials as Topic; Rats; Rats, Sprague-Dawley; Rats, Wistar; RAW 264.7 Cells; Reactive Oxygen Species; Receptor, Angiotensin, Type 1; Receptor, PAR-1; Receptors, CXCR4; Receptors, Estrogen; Receptors, Glucocorticoid; Receptors, Interleukin-1; Receptors, Interleukin-17; Receptors, Notch; Recombinant Fusion Proteins; Recombinant Proteins; Reducing Agents; Reflex, Startle; Regional Blood Flow; Regression Analysis; Reperfusion Injury; Reproducibility of Results; Republic of Korea; Respiratory Tract Diseases; Retrospective Studies; Reverse Transcriptase Inhibitors; Rhinitis, Allergic; Risk Assessment; Risk Factors; Rituximab; RNA, Messenger; RNA, Ribosomal, 16S; ROC Curve; Rosmarinic Acid; Running; Ruthenium; Rutin; Sarcolemma; Sarcoma; Sarcopenia; Sarcoplasmic Reticulum; SARS-CoV-2; Scavenger Receptors, Class A; Schools; Seasons; Seeds; Sequence Analysis, DNA; Severity of Illness Index; Sex Factors; Shock, Cardiogenic; Short Chain Dehydrogenase-Reductases; Signal Transduction; Silver; Singlet Oxygen; Sinusitis; Skin; Skin Absorption; Small Molecule Libraries; Smoke; Socioeconomic Factors; Soil; Soil Microbiology; Solid Phase Extraction; Solubility; Solvents; Spain; Spectrometry, Mass, Electrospray Ionization; Spectroscopy, Fourier Transform Infrared; Speech; Speech Perception; Spindle Poles; Spleen; Sporothrix; Staphylococcal Infections; Staphylococcus aureus; Stereoisomerism; Stomach Neoplasms; Stress, Physiological; Stroke Volume; Structure-Activity Relationship; Substrate Specificity; Sulfonamides; Surface Properties; Surface-Active Agents; Surveys and Questionnaires; Survival Rate; T-Lymphocytes, Cytotoxic; Tandem Mass Spectrometry; Temperature; Tenofovir; Terpenes; Tetracycline; Tetrapleura; Textiles; Thermodynamics; Thiobarbituric Acid Reactive Substances; Thrombin; Thyroid Hormones; Thyroid Neoplasms; Tibial Meniscus Injuries; Time Factors; Tissue Distribution; Titanium; Toluidines; Tomography, X-Ray Computed; Tooth; Tramadol; Transcription Factor AP-1; Transcription, Genetic; Transfection; Transgender Persons; Translations; Treatment Outcome; Triglycerides; Ubiquinone; Ubiquitin-Specific Proteases; United Kingdom; United States; Up-Regulation; Vascular Stiffness; Veins; Ventricular Remodeling; Viral Load; Virulence Factors; Virus Replication; Vitis; Voice; Voice Quality; Wastewater; Water; Water Pollutants, Chemical; Water-Electrolyte Balance; Weather; Wildfires; Wnt Signaling Pathway; Wound Healing; X-Ray Diffraction; Xenograft Model Antitumor Assays; Young Adult; Zoogloea

1. Oleuropein (Ole) is a major phenolic compound in

Topics: Animals; Chickens; Corticosterone; Dietary Supplements; Dose-Response Relationship, Drug; Down-Regulation; Gene Expression Regulation, Enzymologic; Glutathione Peroxidase; Hormones; Iridoid Glucosides; Iridoids; Male; Muscle Development; Muscle, Skeletal; Norepinephrine; Oxidation-Reduction; Protein Carbonylation; Real-Time Polymerase Chain Reaction; RNA, Messenger; Superoxide Dismutase; Superoxide Dismutase-1; Thyroid Hormones

The secoiridoid oleuropein, as found in olives and olive leaves, modulates some biomarkers of diabetes risk in vivo. A possible mechanism may be to attenuate sugar digestion and absorption.. We explored the potential of oleuropein, prepared from olive leaves in a water soluble form (OLE), to inhibit digestive enzymes (α-amylase, maltase, sucrase), and lower [. OLE inhibited intestinal maltase, human sucrase, glucose transport across Caco-2 monolayers, and uptake of glucose by GLUT2 in Xenopus oocytes, but was a weak inhibitor of human α-amylase. OLE, in capsules, in solution or as naturally present in olives, did not affect post-prandial glucose derived from bread, while OLE in solution attenuated post-prandial blood glucose after consumption of 25 g sucrose, but had no effect when consumed with 50 g of sucrose or glucose.. The combined inhibition of sucrase activity and of glucose transport observed in vitro was sufficient to modify digestion of low doses of sucrose in healthy volunteers. In comparison, the weak inhibition of α-amylase by OLE was not enough to modify blood sugar when consumed with a starch-rich food, suggesting that a threshold potency is required for inhibition of digestive enzymes in order to translate into in vivo effects.

Topics: Adolescent; Adult; Aged; Animals; Biological Transport; Blood Glucose; Cell Culture Techniques; Cross-Over Studies; Double-Blind Method; Female; Humans; Hydrolysis; In Vitro Techniques; Iridoid Glucosides; Iridoids; Male; Middle Aged; Models, Animal; Olea; Postprandial Period; Rats; Reference Values; Sucrose; Sugars; Young Adult

Consumption of dietary bioactives is an avenue to enhancing the effective healthiness of diets by attenuating the glycaemic response. The intestinal brush border enzyme sucrase-isomaltase (SI) is the sole enzyme hydrolysing consumed sucrose, and we previously showed the acute effects of olive leaf extract (OLE) on sucrase activity when given together with sugars both in vitro and in vivo. Here we tested whether OLE could affect sucrase expression when pre-incubated chronically, a "priming" effect not dependent on competitive interaction with SI, in both a cell model and a human intervention. Using differentiated Caco-2/TC7 cells, long-term pre-treatment with oleuropein-rich olive leaf extract (OLE) lowered SI mRNA, surface protein and activity, and attenuated subsequent sucrose hydrolysis. Based on these results, a randomised, double-blinded, placebo-controlled, crossover pilot study was conducted. OLE (50 mg oleuropein) was consumed in capsule form 3 times a day for 1 week by 11 healthy young women followed by an oral sucrose tolerance test in the absence of OLE. However this treatment, compared to placebo, did not induce a change in post-prandial blood glucose maximum concentration (Glc

Topics: Adolescent; Adult; Aged; Biomarkers; Blood Glucose; Caco-2 Cells; Cross-Over Studies; Dietary Sucrose; Double-Blind Method; Female; Gene Expression Regulation; Humans; Intestinal Mucosa; Iridoid Glucosides; Iridoids; Middle Aged; Olea; Plant Extracts; Plant Leaves; Postprandial Period; Sucrase-Isomaltase Complex; Time Factors; Treatment Outcome; Young Adult

Extra virgin olive oil lowers postprandial glycaemia. We investigated if oleuropein, a component of extra virgin olive oil, exerts a similar effect on postprandial glycaemia and the underlying mechanism.. Twenty healthy subjects were randomly allocated in a cross-over design to 20 mg oleuropein or placebo immediately before lunch. Postprandial glycaemia along with blood insulin, dipeptidyl-peptidase-4 (DPP-4) and glucagon-like peptide-1 and oxidative stress, which included soluble NADPH oxidase-derived peptide activity (sNox2-dp), 8-iso-prostaglandin-2α and platelet p47. After 2 h, subjects who assumed oleuropein had significantly lower blood glucose, DPP-4 activity and higher insulin and glucagon-like peptide-1 compared to placebo. Furthermore, sNox2-dp, 8-iso-PGF2α and platelet p47. These findings indicate that oleuropein improves postprandial glycaemic profile via hampering Nox2-derived oxidative stress.

Topics: Adult; Antioxidants; Blood Glucose; Cross-Over Studies; Double-Blind Method; Female; Healthy Volunteers; Humans; Hyperglycemia; Iridoid Glucosides; Iridoids; Male; NADPH Oxidase 2; Olive Oil; Oxidative Stress; Postprandial Period; Treatment Outcome

Dietary polyphenols have been demonstrated to favourably modify a number of cardiovascular risk markers such as blood pressure (BP), endothelial function and plasma lipids. We conducted a randomised, double-blind, controlled, crossover trial to investigate the effects of a phenolic-rich olive leaf extract (OLE) on BP and a number of associated vascular and metabolic measures.. A total of 60 pre-hypertensive [systolic blood pressure (SBP): 121-140 mmHg; diastolic blood pressure (DBP): 81-90 mmHg] males [mean age 45 (±SD 12.7 years, BMI 26.7 (±3.21) kg/m. Daytime [-3.95 (±SD 11.48) mmHg, p = 0.027] and 24-h SBP [-3.33 (±SD 10.81) mmHg, p = 0.045] and daytime and 24-h DBP [-3.00 (±SD 8.54) mmHg, p = 0.025; -2.42 (±SD 7.61) mmHg, p = 0.039] were all significantly lower following OLE intake, relative to the control. Reductions in plasma total cholesterol [-0.32 (±SD 0.70) mmol/L, p = 0.002], LDL cholesterol [-0.19 (±SD 0.56) mmol/L, p = 0.017] and triglycerides [-0.18 (±SD 0.48), p = 0.008] were also induced by OLE compared to control, whilst a reduction in interleukin-8 [-0.63 (±SD 1.13) pg/ml; p = 0.026] was also detected. Other markers of inflammation, vascular function and glucose metabolism were not affected.. Our data support previous research, suggesting that OLE intake engenders hypotensive and lipid-lowering effects in vivo.

Topics: Adult; Aged; Biomarkers; Blood Pressure; Body Mass Index; C-Reactive Protein; Cholesterol; Cross-Over Studies; Cytokines; Double-Blind Method; Humans; Inflammation; Iridoid Glucosides; Iridoids; Male; Middle Aged; Olea; Plant Extracts; Plant Leaves; Polyphenols; Risk Factors; Triglycerides; Young Adult

Osteoporosis is a skeletal disorder characterized by impaired bone turnover and compromised bone strength, thereby predisposing to increased risk of fracture. Preclinical research has shown that compounds produced by the olive tree (Olea europaea), may protect from bone loss, by increasing osteoblast activity at the expense of adipocyte formation. The aim of this exploratory study was to obtain a first insight on the effect of intake of an olive extract on bone turnover in postmenopausal women with decreased bone mass (osteopenia).. For that, a double blind, placebo-controlled study was performed in which participants were randomly allocated to either treatment or placebo groups.. 64 osteopenic patients, with a mean bone mineral density (BMD) T-score between -1.5 and -2.5 in the lumbar spine (L2-L4) were included in the study.. PARTICIPANTS received for 12 months daily either 250 mg/day of olive extract and 1000 mg Ca (treatment) or 1000 mg Ca alone (placebo). Primary endpoints consisted of evaluation of bone turnover markers. Secondary endpoints included BMD measurements and blood lipid profiles.. After 12 months, the levels of the pro-osteoblastic marker osteocalcin were found to significantly increase in the treatment group as compared to placebo. Simultaneously, BMD decreased in the placebo group, while remaining stable in the treatment group. In addition, improved lipid profiles were observed, with significant decrease in total- and LDL-cholesterol in the treatment group.. This exploratory study supports preclinical observations and warrants further research by showing that a specific olive polyphenol extract (Bonolive®) affects serum osteocalcin levels and may stabilize lumbar spine BMD. Moreover, the improved blood lipid profiles suggest additional health benefits associated to the intake of the olive polyphenol extract.

Topics: Aged; Biomarkers; Bone and Bones; Bone Density; Bone Diseases, Metabolic; Double-Blind Method; Female; Humans; Iridoid Glucosides; Iridoids; Lipids; Lumbar Vertebrae; Middle Aged; Olea; Osteocalcin; Osteoporosis, Postmenopausal; Phytotherapy; Placebos; Plant Extracts; Polyphenols; Postmenopause; Time Factors

The leaves of the olive plant (Olea europaea) are rich in polyphenols, of which oleuropein and hydroxytyrosol (HT) are most characteristic. Such polyphenols have been demonstrated to favourably modify a variety of cardiovascular risk factors. The aim of the present intervention was to investigate the influence of olive leaf extract (OLE) on vascular function and inflammation in a postprandial setting and to link physiological outcomes with absorbed phenolics. A randomised, double-blind, placebo-controlled, cross-over, acute intervention trial was conducted with eighteen healthy volunteers (nine male, nine female), who consumed either OLE (51 mg oleuropein; 10 mg HT), or a matched control (separated by a 4-week wash out) on a single occasion. Vascular function was measured by digital volume pulse (DVP), while blood collected at baseline, 1, 3 and 6 h was cultured for 24 h in the presence of lipopolysaccharide in order to investigate effects on cytokine production. Urine was analysed for phenolic metabolites by HPLC. DVP-stiffness index and ex vivo IL-8 production were significantly reduced (P< 0.05) after consumption of OLE compared to the control. These effects were accompanied by the excretion of several phenolic metabolites, namely HT and oleuropein derivatives, which peaked in urine after 8-24 h. The present study provides the first evidence that OLE positively modulates vascular function and IL-8 production in vivo, adding to growing evidence that olive phenolics could be beneficial for health.

Topics: Biological Availability; Blood Vessels; Cross-Over Studies; Cytokines; Double-Blind Method; Female; Humans; Inflammation; Iridoid Glucosides; Iridoids; Male; Olea; Phenols; Placebos; Plant Extracts; Plant Leaves; Pulse; Vascular Stiffness

An in vivo experiment was conducted to compare the effects of dietary supplementation with oleuropein and/or α-tocopheryl acetate on growth performance, serum lipid concentrations and lipid oxidation of Japanese quail meat during refrigerated storage. Performance and slaughtering parameters were not affected by dietary treatments. The diets supplemented with oleuropein at the levels of 150 or 200 mg/kg were more effective in delaying lipid oxidation in breast and thigh meats compared with the control diet. The dietary inclusion of neither vitamin E nor oleuropein at different levels did not significantly affect the fatty acid compositions of the breast meat compared with the control diet. The diets supplemented with oleuropein at the levels of 150 or 200 mg/kg had significantly the highest polyunsaturated fatty acid and omega-3 fatty acid contents in thigh meat compared with the vitamin E diet. The ratio of omega-6 fatty acids to omega-3 FAs in thigh meat of quails fed diet supplemented with vitamin E at the level of 200 mg/kg was equivalent to those of quails fed the diets supplemented with oleuropein at the levels of 100 and 150 mg/kg. The results showed that the dietary oleuropein supplementation at 150 mg/kg level may be used in quail diets enriched with the polyunsaturated fatty acids of vitamin E as a natural antioxidant.

Topics: alpha-Tocopherol; Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Coturnix; Diet; Dietary Supplements; Fatty Acids; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Lipids; Muscle, Skeletal

Phenolic compounds derived from the olive plant (Olea europaea L.), particularly hydroxytyrosol and oleuropein, have many beneficial effects in vitro. Olive leaves are the richest source of olive phenolic compounds, and olive leaf extract (OLE) is now a popular nutraceutical taken either as liquid or capsules. To quantify the bioavailability and metabolism of oleuropein and hydroxytyrosol when taken as OLE, nine volunteers (five males) aged 42.8 ± 7.4 years were randomized to receive either capsulated or liquid OLE as a single lower (51.1 mg oleuropein, 9.7 mg hydroxytyrosol) or higher (76.6 mg oleuropein, 14.5 mg hydroxytyrosol) dose, and then the opposite strength (but same formulation) a week later. Plasma and urine samples were collected at fixed intervals for 24 h post-ingestion. Phenolic content was analyzed by LC-ESI-MS/MS. Conjugated metabolites of hydroxytyrosol were the primary metabolites recovered in plasma and urine after OLE ingestion. Peak oleuropein concentrations in plasma were greater following ingestion of liquid than capsule preparations (0.47 versus 2.74 ng/mL; p = 0.004), but no such effect was observed for peak concentrations of conjugated (sulfated and glucuronidated) hydroxytyrosol (p = 0.94). However, the latter peak was reached earlier with liquid preparation (93 versus 64 min; p = 0.031). There was a gender effect on the bioavailability of phenolic compounds, with males displaying greater plasma area under the curve for conjugated hydroxytyrosol (11,600 versus 2550 ng/mL; p = 0.048). All conjugated hydroxytyrosol metabolites were recovered in the urine within 8 h. There was wide inter-individual variation. OLE effectively delivers oleuropein and hydroxytrosol metabolites to plasma in humans.

Topics: Absorption; Adult; Antioxidants; Chromatography, Liquid; Dose-Response Relationship, Drug; Female; Humans; Iridoid Glucosides; Iridoids; Male; Middle Aged; Olea; Phenylethyl Alcohol; Plant Extracts; Plant Leaves; Polyphenols; Pyrans; Tandem Mass Spectrometry

An excess of 70 million cutaneous surgical procedures are conducted annually in the United States that may result in scarring. Skin scars are a normal outcome of the tissue repair process. However, individuals with abnormal scarring may have aesthetic, psychological, and social consequences. As a result, there is a high patient demand for products that will reduce the scarring. The principles underlying scar formation are now better understood. Products are being developed to address those critical components of the wound-healing process, namely inflammation, hydration, and collagen maturation. A multicomponent scar product was previously shown effective in preventing exaggerated scarring in patients undergoing various surgical procedures. The present outpatient study was conducted in patients undergoing shave biopsies. Following reepithelialization, this investigator-blinded, randomized, 8-week trial compared twice-daily application of either the scar product or the standard of care, white petrolatum. Evaluation visits were conducted at baseline and at weeks, 1, 2, 4 and 8. Subjects were evaluated by the blinded investigator for clinical efficacy and tolerability using grading scales. Standardized digital photographs were taken at each visit, and subjects completed a self-assessment questionnaire regarding treatment effectiveness and satisfaction. Twenty-eight subjects completed the 8-week study. The scar product provided earlier improvements than the white petrolatum. At week 1, 70% of subjects receiving the scar product demonstrated at least 50% global improvement in scar appearance vs only 42% of the subjects receiving white petrolatum. The more rapid improvement was accompanied by greater reductions in stinging/burning and itching with the scar product at all visits. Importantly, there was also greater subject satisfaction with the scar product at all visits. This scar product may be useful in hastening the healing of cutaneous shave biopsies and reducing the stinging/burning and itching associated with the normal healing process.

Topics: Adult; Aged; Biopsy; Centella; Cicatrix; Diagnostic Self Evaluation; Double-Blind Method; Emollients; Female; Gels; Humans; Iridoid Glucosides; Iridoids; Male; Middle Aged; Petrolatum; Plant Extracts; Pruritus; Pyrans; Regional Blood Flow; Sensation; Skin; Skin Pigmentation; Vasodilator Agents; Young Adult

We aimed to assess the intralumenal stability of oleuropein in human gastric and small intestinal contents. We additionally aimed to assess the stability characteristics of oleuropein in media simulating the intralumenal conditions.. The intralumenal stability of oleuropein was assessed in aspirates from the stomach and the upper small intestine of healthy volunteers collected under both fasted and fed state conditions and in media simulating the intralumenal environment.. Oleuropein degraded in aspirates collected in the fasted state. When the initial concentration was about 50 microg/ml (close to expected intragastric concentration after single dose of commercially available products of oleuropein) the mean zero-order half-life of oleuropein in aspirates collected from the fasted small intestine was estimated to be 3.14 +/- 0.08 h at 37 degrees C (i.e. after oral administration in the fasted state, a substantial fraction of oleuropein degrades before reaching the intestinal mucosa). In contrast, oleuropein was stable in aspirates collected from the fed stomach; in small intestinal contents aspirated in the fed state the estimated zero-order degradation half-life was at least 12 h.. These data suggest that oleuropein should not have substantial intralumenal stability problems when administered in the fed state. Data collected in media simulating the intragastric and intraintestinal environment suggest that pH affects the stability of oleuropein only at low pH values (of about 2). At higher pHs degradation characteristics are at least partly affected by the presence of other scavengers of reactive oxygen species in the medium.

Topics: Chromatography, High Pressure Liquid; Dose-Response Relationship, Drug; Drug Stability; Fasting; Free Radical Scavengers; Gastric Juice; Gastric Mucosa; Gastrointestinal Contents; Humans; Hydrochloric Acid; Hydrogen-Ion Concentration; Intestine, Small; Iridoid Glucosides; Iridoids; Olea; Plant Leaves; Postprandial Period; Pyrans; Spectrophotometry, Ultraviolet; Stomach

Oleuropein, a phenolic compound derived from olive leaves and oil, is known to possess several biological properties, many of which may be attributed to its antioxidant and free radical-scavenging activities. Nevertheless, up to now, the cosmetic activity of this molecule has not been extensively investigated. The aim of this work was to evaluate the cosmetic properties of oleuropein against UVB-induced erythema. To this end, an emulsion and an emulgel containing oleuropein were prepared, applied and evaluated on healthy volunteers who had undergone UVB irradiation to investigate its protective and/or lenitive activity. Protective effect was assayed by application of topical preparations before irradiation and lenitive effect was evaluated after erythema induction. Vitamin E was used as the reference compound. Our study was carried out by using noninvasive techniques to assess specific skin parameters: barrier function, skin colour and microcirculation. Results clearly showed that oleuropein formulations highlighted lenitive efficacy by reducing erythema, transepidermal water loss and blood flow of about 22%, 35% and 30% respectively. The study allowed us to point out the lenitive property of oleuropein, opening the way to further trials to deepen our specific knowledge about this natural molecule, which could be used in association with other active ingredients in cosmetics to repair UV damages.

Topics: Administration, Topical; Adult; Antioxidants; Chromatography, High Pressure Liquid; Cosmetics; Emulsions; Erythema; Female; Humans; Iridoid Glucosides; Iridoids; Olea; Pilot Projects; Plant Leaves; Pyrans; Skin; Ultraviolet Rays

Topics: Antineoplastic Agents; Antioxidants; Iridoid Glucosides; Iridoids; Olea; Phytochemicals; Plant Extracts; Plant Leaves; Saudi Arabia

The present study focused on the effect of isothermal treatment (5-90 °C) and pH (2.0-6.0) of aqueous olive leaf phenolic extract solutions on the kinetics of degradation of single and total phenolic compounds and radical scavenging activity, with the objective of predicting and optimizing the thermal treatments in foods enriched with olive leaf extracts.. The major compound, oleuropein, showed higher degradation at low pH 2.0 and temperature-dependent reaction rates, which fitted well a first-order kinetic model, with an estimated activation energy of 98.03 ± 0.08 kJ mol. The present study can contribute to the knowledge related to oleuropein and phenolic fraction degradation as a result of matrix (pH) and processing. The kinetic parameters obtained could be applied for predicting and optimizing the thermal treatments in foods and drinks enriched with olive leaf extracts. © 2022 Society of Chemical Industry.

Topics: Antioxidants; Hot Temperature; Hydrogen-Ion Concentration; Iridoids; Olea; Phenols; Plant Extracts; Plant Leaves

Oleuropein plays a key role as a pro-oxidant as well as an antioxidant in cancer. In this study, the activity of oleuropein, in an in vitro model of ovarian (OCCs) and breast cancer cells (BCCs) was investigated. Cell viability and cell death were analyzed. Oxidative stress was measured by CM-H2DCFDA flow cytometry assay. Mitochondrial dysfunction was evaluated based on mitochondrial reactive oxygen species (ROS) and GPX4 protein levels. Further, the effects on iron metabolism were analyzed by measuring the intracellular labile iron pool (LIP). We confirmed that high doses of oleuropein show anti-proliferative and pro-apoptotic activity on HEY and MCF-7 cells. Moreover, our results indicate that low doses of oleuropein impair cell viability without affecting the mortality of cells, and also decrease the LIP and ROS levels, keeping them unchanged in MCF-7 cells. For the first time, our data show that low doses of oleuropein reduce erastin-mediated cell death. Interestingly, oleuropein decreases the levels of intracellular ROS and LIP in OCCs treated with erastin. Noteworthily, we observed an increased amount of ROS scavenging enzyme GPX4 together with a consistent reduction in mitochondrial ROS, confirming a reduction in oxidative stress in this model.

Topics: Antioxidants; Female; Humans; Iridoid Glucosides; Iridoids; Iron; Ovarian Neoplasms; Reactive Oxygen Species

Olea europaea is an economically significant crop native to Mediterranean countries. Its leaves exhibit several biological properties associated to their chemical composition. The aqueous ethanolic extracts of olive leaves from twelve different cultivars were analyzed by high performance liquid chromatography coupled to photodiode array and electrospray ionization mass spectrometry (HPLC/PDA/ESI-MS/MS). A total of 49 phytochemicals were identified in both positive and negative ionization modes. The identified compounds belonged to four classes of secondary metabolites including secoiridoids, flavonoids, pentacyclic triterpenoids and various phenolic compounds. Seasonal variation in chemical composition among the studied cultivars was apparent in autumn and spring. Secologanoside, oleuropein, hydroxy-oleuropein, demethyl oleuropein, gallocatechin, luteolin-O-hexoside, diosmetin, oleanolic acid and maslinic acid were detected in all cultivars in both seasons. Oleuropein-O-deoxyhexoside was tentatively identified for the first time in olive leaf extracts; detected only in the Spanish cultivar Picual (PIC) collected in spring. Also, dihydroxy-oxooleanenoic acid and hydroxy-oxooleanenoic acid, two bioactive pentacyclic triterpenes, were identified. Principle component analysis (PCA) showed good discrimination among the studied cultivars in terms of their botanical origin. This study is considered the first study for non-targeted metabolic profiling of different olive leaf cultivars cultivated in Egypt.

Topics: Chromatography, High Pressure Liquid; Flavonoids; Iridoid Glucosides; Iridoids; Olea; Plant Extracts; Plant Leaves; Seasons; Tandem Mass Spectrometry

The present study aims to assess the antioxidant and antiviral effectiveness of leaf extracts obtained from

Topics: Antioxidants; HeLa Cells; Humans; Iridoids; Neoplasms; Olea; Plant Extracts

Benign and malignant liver tumors are prevalent worldwide. However, there is no effective and comprehensive treatment option for many patients with malignant tumors. Thus, it is critical to prevent benign tumors from worsening, increasing the number of treatment options and effective medications against malignant liver tumors. Oleuropein is a natural and non-toxic product and inhibits tumor growth in various ways.. We employed bioinformatics analysis and molecular docking to identify potential targets of oleuropein. Surface plasmon resonance (SPR) was used to determine the direct binding strength of the target and compounds. Essential functionalities of the targets were analyzed using gene interference approaches. Transcriptomic studies were performed to observe the global genomic alterations occurring inside cells. Changes in glycolytic metabolites and gene and protein expressions were also detected. The anti-tumor benefits of oleuropein in vivo were determined using a tumor-bearing mouse model.. Glucose-6-phosphate isomerase (GPI) was found to be a direct target of oleuropein. GPI discontinuation in liver tumor cells altered the expression of many genes, causing glycogenolysis. GPI interference was associated with PYGM and PFKFB4 inhibitors to inhibit glycolysis in liver tumors. Oleuropein inhibited glycolysis and showed good anti-tumor activity in vivo without adverse side effects.. GPI is a crucial enzyme in glycolysis and the immediate target of oleuropein. GPI expression inside tumor cells affects different physiological functions and signal transduction. Oleuropein has depicted anti-tumor action in vivo without harmful side effects. Moreover, it can control tumor glycolysis through GPI.

Topics: Animals; Carcinoma, Hepatocellular; Glycolysis; Iridoid Glucosides; Iridoids; Liver Neoplasms; Mice; Molecular Docking Simulation

Bisphenol A, or BPA, goes into the composition of a large number of products including sunglasses, infant's feeding bottles, receipts, or food packaging. Nowadays, there is a growing evidence that BPA may be at the origin of several physiological malignancies. Oleuropein and hydroxytyrosol extracted from olive leaves are highly investigated for numerous health benefits. The present work investigates the potential protective proprieties of olive leaf extracts against BPA-induced testicular damage in Wistar rats. Thirty-two animals were randomly divided into 4 groups: control, BPA-treated (10 mg/kg), BPA and oleuropein rich extract (16 mg/kg) treatment, and the last group treated with BPA and hydroxytyrosol rich extract (16 mg/kg). Biochemical parameters and histological and molecular analyses were evaluated. Our data demonstrated that BPA treatment caused significant alteration in biochemical parameters, disorganization of germinal epithelium, an up-regulation of p53 and Bax, and a reduction of Bcl-2 protein levels. The ingestion of oleuropein- and hydroxytyrosol-rich extracts attenuated BPA-induced biochemical and histological changes. In fact, olive leaf extracts enhanced the enzymatic antioxidant system and the level of Bcl-2, and reduced the expression of p53 and Bax. Fairly, our findings propose that olive leaf extracts may compete with BPA-induced reprotoxicity in vivo.

Topics: Animals; bcl-2-Associated X Protein; Iridoids; Male; Plant Extracts; Rats; Rats, Wistar; Tumor Suppressor Protein p53

In this study, to identify bioactive components of Olea europaea leaves extract (OLE), chemometrics analyses including bivariate correlation analysis and partial least squares regression were used to establish the relationships between the chromatograms and anti-photoaging effect of OLE samples. Firstly, the fingerprint of olive leaves extract was determined by high-performance liquid chromatography (HPLC). Photoaging models of HaCaT cells were established by UVB irradiation. The photoaging resistance of OLE was evaluated by cell viability using the MTT assay. Chemometrics analyses showed that compounds 14, 19, 20, 24, 26, and 28 might be the major anti-photoaging components of OLE. Furthermore, after separation by HSCCC and NMR identification, compound 19 is luteoloside and compound 24 is oleuropein. Oleuropein and luteoloside were docked with collagenase (MMP-1), stromelysin (MMP-3), and gelatinase (MMP-9), respectively. The results showed that oleuropein and luteoloside inhibited their activity by directly interacting with MMP-1, MMP-3, and MMP-9, thereby exhibiting anti-photoaging activity. The current bioassay and spectrum-effect relationships are proper for associating sample quality with the active ingredient, and our finding would provide foundation and further understanding of the quality evaluation and quality control of Olea europaea.

Topics: Iridoid Glucosides; Iridoids; Matrix Metalloproteinase 1; Matrix Metalloproteinase 3; Matrix Metalloproteinase 9; Olea; Plant Extracts; Plant Leaves

White rice is poor in health-promoting phytochemicals; therefore, the production of a phenol-enriched commodity is highly desirable. Recent findings on its enrichment via cooking in plant extracts are promising, yet studies employing aqueous extracts of olive leaves (OLs), containing well-recognized bioactive phenols (e.g. oleuropein) are absent. In addition, little is known about the levels of phenols that are maintained after rice drying and rehydration, an important aspect for the future design of 'ready-to-eat' functional rice.. The examination, for the first time, of white rice adsorption capacity of phenols from OLs upon cooking in infusions containing different levels of phenols, after freeze-drying and rehydration, showed the following: (i) the total phenol content, the antioxidant activity (assessed via 2,2-diphenyl-1-picrylhydrazyl radical and ferric reducing antioxidant power assays), the oleuropein and luteolin-7-O-glucoside levels increased dose dependently; (ii) upon rehydration, the average decrease of total phenol content and antioxidant activity values was significantly lower when an exact volume of water was used compared with an excess (~10% versus 63%). A similar trend was observed for oleuropein (36% versus 83%) and the luteolin-7-O-glucoside (24 versus 82%) levels; (iii) the dried enriched kernels were less bright with a hay-yellow hue (CIELab coordinates).. White rice enrichment with biophenols from OLs, a by-product of olive tree cultivation, was successful using a simple approach. Despite leaching upon freeze-drying/rehydration, sufficient amounts were maintained to obtain a functional rice that could serve as an alternative dietary source of OLs phenols to non-traditional olive tree product consumers or those refraining from sodium and fats. © 2023 Society of Chemical Industry.

Topics: Antioxidants; Cooking; Iridoids; Olea; Oryza; Phenol; Phenols; Plant Extracts; Plant Leaves

Olive leaf extract is a valuable source of phenolic compounds; primarily, oleuropein (major component) and rutin. This natural olive leaf extract has potential use as a therapeutic agent for cancer treatment. However, its clinical application is hindered by poor pharmacokinetics and low stability. To overcome these limitations, this study aimed to enhance the anticancer activity and stability of oleuropein and rutin by loading them into PEGylated Nano-phytosomes. The developed PEGylated Nano-phytosomes exhibited favorable characteristics in terms of size, charge, and stability. Notably, the anticolonic cancer activity of the Pegylated Nano-phytosomes loaded with oleuropein (IC50=0.14 μM) and rutin (IC50=0.44 μM) surpassed that of pure oleuropein and rutin alone. This outcome highlights the advantageous impact of Nano-phytosomes to augment the anticancer potential of oleuropein and rutin. These results present a promising pathway for the future development of oleuropein and rutin Nano-phytosomes as effective options for passive tumor-targeted therapy, given their improved stability and efficacy.

Topics: Antioxidants; Iridoid Glucosides; Iridoids; Neoplasms; Olea; Plant Extracts; Plant Leaves; Polyethylene Glycols; Rutin

Topics: Antioxidants; Fibroblasts; Humans; Hydrogen Peroxide; Iridoid Glucosides; Iridoids; Matrix Metalloproteinase Inhibitors; Pancreatic Elastase; Phenylethyl Alcohol; Polyphenols; Reactive Oxygen Species

A new phenolic glucoside (

Topics: Esters; Glucosides; Iridoid Glucosides; Iridoids; Molecular Structure; Olea

Recent and growing literature has reported that oleuropein (OLE), the main polyphenol in olive leaf extract, inhibits tumor cell proliferation and reduces the invasiveness properties of cancer cells; therefore, OLE may play a significant role in the development of new drugs for cancer treatment. These antineoplastic properties have been reported in many experimental cancer models, but the effect of OLE on seminoma cells is yet to be evaluated. In the present study, we demonstrate, for the first time, that OLE reduces cell viability in both intra- and extragonadal TCAM-2 and SEM-1 seminoma cells, respectively, in a dose-dependent manner. As shown by Western-blot analysis, OLE exposure reduced cyclin-D1 expression and upregulated p21

Topics: Apoptosis; Cell Proliferation; Humans; Iridoid Glucosides; Iridoids; Male; NF-kappa B; Olea; Plant Extracts; Seminoma; Testicular Neoplasms

The beneficial health effects of phytochemicals depend on their bioavailability and the form under which they reach systemic circulation, usually as phase II metabolites. The lack of authentic standards for these metabolites makes their quantification in biological samples challenging. A new analytical approach to get a more accurate quantification of oleuropein metabolites in biological samples after ingestion of olive leaf extract was proposed. This approach was based on the calculation of a response factor in QTOF MS for each metabolite, comparing their quantification in UV and MS using urine samples concentrated in the metabolites of interest. Glucuronide and sulfate conjugates of hydroxytyrosol and homovanillyl alcohol were more accurately quantified in plasma and urine and for the first time, oleuropein aglycone conjugates and their hydroxylated and hydrogenated derivatives were quantified after consumption of olive products. This approach could be extensible to the analysis of other phenolic metabolites when authentic standards are not available, opening a valuable method for bioavailability studies.

Topics: Glucuronides; Humans; Iridoid Glucosides; Iridoids; Olea; Plant Extracts; Sulfates

Wild varieties in nature are known to be better adapted to climate change and more resistant to arid conditions common in some regions of the world. Oil samples of two cultivated varieties, Chemlal and Lemli, and one sylvestris variety were collected at four different harvesting periods in the semi-arid region of Bouira, Algeria. The aim of this study was to determine the influence of the genetic and maturity factors on the quality indices (acidity, peroxides value, and the parameters K232, K270), fatty acids profile, phenolic composition, and antioxidant activity of monovarietal olive oils. The study showed that early harvest dates of the fruits produced oils richer in pigments and phenolic compounds, with high antioxidant activity registered in both wild and cultivated varieties. Moreover, all oil samples showed high values of secoiridoids exceeding 60-90% of total biophenols, with higher values found in oleaster oils, which are correlated with high resistance to oxidation attacks. UHPLC-DAD and UHPLC-HRMS analyses showed that the secoiridoids composition is dominated by a profile rich in several isomers of oleuropein and ligstroside aglycons, which in turn represent more than 60% of the total secoiridoids in olive and Oleaster oils. Furthermore, chemometric analysis on the data allowed a better appreciation of the sensitivity of the virgin olive oil composition to the changes in genetic and ripening factors. According to the principal component analysis, phenolic and fatty acid profiles were the most important components contributing to the discrimination between olive oil samples.

Topics: Algeria; Antioxidants; Chemometrics; Fatty Acids; Fruit; Glucosides; Iridoid Glucosides; Iridoids; Olea; Olive Oil; Phenols; Phoeniceae; Pyrans

This study investigates antioxidant capacity and protective effects of phenolic compounds oleuropein (OLP) and hydroxytyrosol (HT), present in olive oil and olive leaves, against H2O2-induced DNA damage in human peripheral lymphocytes. Antioxidant potency was determined using the measurement of radical-scavenging activity (ABTS∙+ assay), ferric reducing power (FRAP assay) and cupric reducing antioxidant capacity (CUPRAC assay). Both substances were found to be potent antioxidant agents due to their free radical-scavenging activities. Antigenotoxic effects of oleuropein and hydroxytyrosol against H2O2-induced damage in human lymphocytes were evaluated in vitro by alkaline comet assay. At tested concentrations (1, 5, 10 µmol L-1), oleuropein and hydroxytyrosol did not induce a significant increase of primary DNA damage in comparison with the negative control. Pretreatment of human lymphocytes with each of the substances for 120 min produced a dose-dependent reduction of primary DNA damage in the tested cell type. Hydroxytyrosol showed a better protective effect against H2O2-induced DNA breaks than oleuropein which could be associated with their free radical-scavenging efficacy.

Topics: Antioxidants; DNA Damage; Dose-Response Relationship, Drug; Free Radical Scavengers; Humans; Hydrogen Peroxide; Iridoid Glucosides; Iridoids; Lymphocytes; Olive Oil; Phenylethyl Alcohol

Olive-derived antioxidants have been shown to affect the oxidative status of meat and have also been associated with greater consumption of glucose, which might affect glycogen stores and muscle characteristics. This study evaluated the effect of oleuropein extract supplementation (OLE) versus vitamin E + Se (VE), and their combination (VEOLE), in pig diets, on pH, drip loss, the proportion of free fatty acids, and meat stability, and their prediction by blood oxidative status markers.. The drip loss of muscle was lower in antioxidant-supplemented groups when compared with controls. α-Tocopherol concentration and total fatty acids profile were not affected by dietary oleuropein supplementation. However, OLE and VEOLE had lower free n-3 polyunsaturated fatty acid (PUFA) levels when compared with VE and tended to have higher free monounsaturated fatty acid (MUFA) levels. Furthermore, the VEOLE group had lower free n-6 PUFA levels when compared with controls or VE, whereas the OLE group had intermediated values. Muscle samples from pigs subjected to the antioxidant-mixed supplementation (VEOLE) had lower malondialdehyde concentration when compared with the others. The VE and OLE groups showed intermediate malondialdehyde values. Chilled meat stability was highly correlated with antioxidant status in vivo.. The administration of 96 mg oleuropein kg

Topics: alpha-Tocopherol; Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Diet; Dietary Supplements; Fatty Acids, Nonesterified; Iridoid Glucosides; Iridoids; Meat; Muscle, Skeletal; Oxidation-Reduction; Selenium; Swine

The effect of micronization of granulometrically fractionated olive pomace (OP) on the bioaccessibility of polyphenols and the antioxidant capacity was investigated during sequential in vitro static digestion. Crude OP was fractionated in a 2-mm sieve (F1: > 2 mm; F2: < 2 mm) and then micronized (300 r min

Topics: Antioxidants; Caffeic Acids; Chromatography, High Pressure Liquid; Dietary Supplements; Digestion; Food Handling; Iridoid Glucosides; Iridoids; Olea; Olive Oil; Plant Extracts; Polyphenols; Principal Component Analysis; Tandem Mass Spectrometry

Topics: Anti-Infective Agents; Antibiotics, Antineoplastic; Cell Proliferation; Cell Survival; Cytotoxins; Dietary Supplements; Doxorubicin; Humans; Iridoid Glucosides; Iridoids; Osteosarcoma; Tumor Cells, Cultured

The present study explored the potential therapeutic role of oleuropein in sepsis-induced heart injury along with the role of GSK-3β/NF-kB signaling pathway.. Sepsis-induced myocardial injury was induced by cecal ligation and puncture (CLP) in rats. The cardiac injury was assessed by measuring the levels of cTnI and creatine kinase-MB (CK-MB). Sepsis-induced inflammation was assessed by measuring interleukin-6 (IL-6), IL-10 and HMGB1 levels. The different doses of oleuropein (5, 10, and 20 mg/kg) were given prior to CLP. Oleuropein (20 mg/kg) was administered after 6 hof CLP. The expressions of GSK-3β, p-GSK-3β (Ser9) and nuclear factor-κB (NF-κB) were measured in heart homogenates.. Cecal ligation and puncture was associated with myocardial injury, an increase in IL-6, a decrease in IL-10 and an increase in HMGB1. Moreover, it decreased the ratio of p-GSK-3β/GSK-3β and increased the expression of p-NF-kB. Pretreatment with oleuropein attenuated CLP-induced myocardial injury and systemic inflammation in a dose-dependent manner. Administration of oleuropein after the onset of CLP also attenuated cardiac injury and inflammation. It also restored CLP-induced changes in the HMGB1 levels, the ratio of p-GSK-3β/GSK-3β and expression of p- NF-kB.. Oleuropein attenuates sepsis-induced systemic inflammation and myocardial injury by inhibiting NF-kB and GSK-3β signaling.

Topics: Animals; Glycogen Synthase Kinase 3 beta; Heart Injuries; Iridoid Glucosides; Iridoids; NF-kappa B; Rats; Sepsis

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an endocrine disrupting compound and persistent organic pollutant that has been associated with diabetes in several epidemiological studies. Oleuropein, a major phenolic compound in olive fruit, is a superior antioxidant and radical scavenger. This study aimed to examine the effects of oleuropein against TCDD-induced stress response in a pancreatic beta cell line, INS-1 cells. Cells were pre-incubated with various concentrations of oleuropein and then stimulated with TCDD (10 nM) for 48 hrs. When treated with TCDD, INS-1 cells produced robust amounts of prostaglandin E

Topics: Environmental Pollutants; Insulin-Secreting Cells; Iridoid Glucosides; Iridoids; Polychlorinated Dibenzodioxins

Topics: Dermatologic Agents; Dietary Supplements; Humans; Iridoid Glucosides; Iridoids; Psoriasis

Olive leaves extract (OLE) was spray-dried with maltodextrin (MD) or inulin (IN) to study the evolution of oleuropein (OE) during in vitro gastrointestinal digestion, its bioaccessibility and potential bioavailability. In the case of OLE-MD, OE was partially degraded in gastric and intestinal conditions; whereas in OLE-IN, OE was released under gastric conditions and partially degraded under intestinal conditions. In both cases, the encapsulation of OLE led to higher OE contents at the end of digestion, compared with non-encapsulated OLE, suggesting a protective role of the polysaccharides by the formation of non-covalent polysaccharides-OE complexes. OE bioaccessibility was ten times higher (p ≤ 0.05) in OLE-MD and OLE-IN than in non-encapsulated OLE. However, OE potential bioavailability, evaluated by tangential filtration, was not detected. Encapsulation technology and the encapsulant agent used may determine the release of the encapsulated compounds at a specific-site and their effect on health.

Topics: Biological Availability; Biological Products; Digestion; Inulin; Iridoid Glucosides; Iridoids; Plant Leaves; Polysaccharides

The quality evolution of 14 extra-virgin olive oils (EVOOs), with different initial polyphenol and oleic acid (64.6-77.7%) levels, was determined during real-time storage in dark conditions at room temperature for 22 months. EVOOs with low (<20-200 mg/kg), medium (450-700 mg/kg), and high polyphenolic levels (750-1400 mg/kg) were used. We found high correlations among peroxide values, K

Topics: alpha-Tocopherol; Darkness; Food Storage; Iridoid Glucosides; Iridoids; Oleic Acid; Olive Oil; Oxidation-Reduction; Polyphenols; Taste; Time Factors

Unilateral ureteral obstruction (UUO) induces kidney injury. Oleuropein as a major compound of olive leaves modulates the inflammatory parameters and decreases oxidative stress. Accordingly, we evaluate the renoprotective effect of oleuropein against 3-day UUO rats. Forty rats were randomly divided into five groups (n = 8) including control, UUO and UUO + oleuropein groups (50, 100 and 200 mg/kg). UUO model was induced by left ureter ligation and continued for 3-day. Rats were treated synchronic daily for 3-day, then mean arterial pressure (MAP), renal perfusion pressure (RPP), renal blood flow (RBF), serum creatinine level, and also superoxide dismutase (SOD), glutathione peroxidase (GPx) activity levels and malondialdehyde (MDA) concentration (in the obstructed kidney) were measured. The western blotting method was applied to evaluate the Bax, Bcl-2, cleaved caspase-3 and TNF-α proteins expression level. The hematoxylin and eosin method was applied to evaluate the kidney tissue damage score (KTDS). UUO significantly increased RVR, KTDS, and MDA, cleaved caspase-3, Bax, serum creatinine and TNF-α protein levels (P < 0.05), and also significantly decreased RBF, SOD, and GPx and Bcl-2 protein expression levels (P < 0.001) in the obstructed kidney and oleuropein (200 mg/kg) significantly ameliorated the changes induced by UUO. Our findings showed that oleuropein has a renoprotective effect against 3-day UUO. The mechanisms underlying the observed effects may be related to its antioxidative stress, anti-apoptotic, and anti-inflammatory effects.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Caspase 3; Creatinine; Glutathione Peroxidase; Hemodynamics; Inflammation; Iridoid Glucosides; Iridoids; Kidney; Lipid Peroxidation; Male; Oxidative Stress; Rats, Wistar; Superoxide Dismutase; Tumor Necrosis Factor-alpha; Ureteral Obstruction

Topics: Animals; Beverages; Chromatography, Liquid; Diet, High-Fat; Gas Chromatography-Mass Spectrometry; Hyperlipidemias; Iridoid Glucosides; Iridoids; Male; Mice; Mice, Inbred ICR; Obesity; Olea; Phenylethyl Alcohol; Plant Leaves; Tandem Mass Spectrometry

Phenolic compounds largely contribute to the nutraceutical properties of virgin olive oil (VOO), the organoleptic attributes and the shelf life due to their antioxidant capabilities. Due to the relevance of malaxation in the oil extraction process, we tested the effects of malaxation time on the concentrations of relevant phenolic compounds in VOO, and we evaluated the influence of performing malaxation under vacuum. An increase in malaxation time significantly decreased the concentrations of aglycone isomers of oleuropein and ligstroside but, conversely, increased the oleocanthal and oleacein contents. Additionally, malaxation under vacuum led to an increase in phenolic contents compared to standard conditions carried out at atmospheric pressure. Finally, we explored the possibility of predicting the VOO oxidative stability on the basis of the phenolic profile, and a model (R

Topics: Aldehydes; Cyclopentane Monoterpenes; Fatty Acids; Food Handling; Glucosides; Iridoid Glucosides; Iridoids; Olive Oil; Oxidation-Reduction; Phenols; Pyrans; Temperature; Time Factors

Olive leaves farmed from trees are valuable for the production of functional extracts. Nonetheless, olive leaves (containing thin branches), which are separated during olives cleaning in the mill, have received little attention. In this context, a multiple response optimization was performed to maximize at once the yield, total phenolic content, oleouropein and antioxidant activity obtained by ultrasound-assisted extraction of this low-cost byproduct. The optimum was achieved using the following operational parameters: solid-to-liquid ratio, 5.9%; ethanol concentration, 47%; extraction time, 50 min. This enabled to obtain an extract with both high level of oleuropein and antioxidant activity. Besides oleuropein, other minor phenolic compounds were characterized in the extract, which could contribute to the antioxidant activity as Pearson correlation suggested. After this extraction step, how the phenolic extraction affects the recovery/profile of other constituents was evaluated, looking for the integral valorization of this resource towards the zero-waste.

Topics: Chemical Fractionation; Ethanol; Iridoid Glucosides; Iridoids; Olea; Phenols; Plant Leaves; Ultrasonic Waves

Topics: Animals; Dietary Fats; Iridoid Glucosides; Iridoids; Lipid Metabolism; Liver; Liver Diseases; Male; Olea; Phenylethyl Alcohol; Plant Extracts; Plant Leaves; Rats

The debittering of natural table olives is a very slow process. The effect of acetic, lactic and citric acids on the hydrolysis rate of oleuropein was studied in vitro and at pilot plant scale. The acid hydrolysis of oleuropein was faster with lactic and citric acids than acetic acid, running the experiments at the same pH of 3.8-4.0 units. The temperature exerted a high effect of the hydrolysis of oleuropein in a range of 10-30 °C and the concentration of the organic acid did not show a significant trend. Moreover, the in vitro results were confirmed with three lots of olives that presented a higher content of oleuropein after 3-7 months of preservation when they were processed with acetic acid rather than lactic acid and the opposite for hydroxytyrosol. These results open the possibility of accelerating the debittering of natural olives by preserving them with lactic acid instead of acetic acid.

Topics: Acetic Acid; Hydrolysis; Iridoid Glucosides; Iridoids; Lactic Acid; Olea

Depression is still one of challenging, and widely encountered disorders with complex etiology. The role of healthy diet and olive oil in ameliorating depression has been claimed. This study was designed to explore the effects of oleuropein; the main constituent of olive oil; on depression-like behaviors that are induced by repeated administration of corticosterone (40 mg/kg, i.p.), once a day for 21 days, in mice. Oleuropein (8, 16, and 32 mg/kg, i.p.) or fluoxetine (20 mg/kg, positive control, i.p.1) was administered 30 minutes prior to corticosterone injection. Sucrose consumption test, open-field test (OFT), tail suspension test (TST), and forced swimming test (FST) were performed. Reduced Glutathione (GSH), lipid peroxidation, and biogenic amines; serotonin, dopamine, and nor-epinephrine; levels were also analyzed in brain homogenates. Corticosterone treatment induced depression-like behaviors, it increased immobility time in the TST, OFT, and FST, decreased the number of movements in OFT, and decreased sucrose consumption. Corticosterone effect was associated with depletion of reduced glutathione and increase of lipid peroxidation, in addition to modification of biogenic amines; decreased serotonin and dopamine. Oleuropein or fluoxetine administration counteracted corticosterone-induced changes. In conclusion, oleuropein showed a promising antidepressant activity, that is evident by improving corticosterone-induced depression-like behaviors, and normalizing levels of biogenic amines.

Topics: Anhedonia; Animals; Behavior, Animal; Biogenic Amines; Brain; Corticosterone; Depression; Disease Models, Animal; Hindlimb Suspension; Immobilization; Iridoid Glucosides; Iridoids; Male; Mice; Movement; Neurotransmitter Agents; Oxidative Stress; Sucrose; Swimming

A simple method was developed for the extraction and purification of bacterial flagella with a yield of a concentration of 113.22 ± 5.64 mg mL

Topics: Escherichia coli; Fimbriae, Bacterial; Gold; Iridoid Glucosides; Iridoids; Listeria monocytogenes; Microbial Sensitivity Tests; Microscopy, Electron, Transmission; Mutagenicity Tests; Nanowires; Olea; Plant Leaves

Several studies published in the last decade suggest that the beneficial role of extra-virgin olive oil (EVOO) in human health is mostly attributable to the main secoiridoid derivatives (oleuropein, oleocanthal, and oleacein). Anti-cancer properties have also been demonstrated for certain compounds present in small quantities in EVOO, including oleuropein and hydroxytyrosol, which have been extensively studied, while minor attention has been given to the most abundant secoiridoid oleacein. The aim of our research was to study the molecular mechanisms underlying the anti-proliferative and anti-metastatic capacity of oleacein in the SH-SY5Y human neuroblastoma cell line. Our results demonstrate that oleacein is able to reduce the proliferation of the SH-SY5Y cells by blocking the cell cycle in the S phase and inducing apoptotic cell death through the increase in both Bax and p53 as well as a reduction in the Bcl-2 expression and STAT3 phosphorylation. Moreover, oleacein caused reduction in the SH-SY5Y cell adhesion and migration. Overall, these findings indicate that oleacein exerts anti-cancer effects against neuroblastoma cells, suggesting a promising role as a candidate against this type of cancer.

Topics: Aldehydes; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Cyclopentane Monoterpenes; Fibroblasts; Humans; Iridoid Glucosides; Iridoids; Neuroblastoma; Olive Oil; Phenols; STAT3 Transcription Factor

Olive leaves are considered a promising source of bioactives such as phenolic compounds and mannitol. The extraction of high added value products is an issue of great interest and importance from the point of view of their exploitation. However, the content of these compounds can differ between cultivars and extraction methods. In this work, six olive leaves cultivars, including three wild cultivars, and two extraction processes (an innovative and alternative technique, pressurized liquid extraction, and a conventional Soxhlet extraction) were evaluated and compared towards the selective recovery of bioactive compounds. The wild cultivars showed the highest content of phenolic and flavonoid compounds, being oleuropein the compound present in higher amount. Findings also revealed that the highest mannitol content in the extracts was observed with the commercial cultivars, specifically in Arbequina. It is thus possible to decide which cultivars to use in order to obtain the highest yield of each bioproduct.

Topics: Flavonoids; Iridoid Glucosides; Iridoids; Mannitol; Olea; Phenols; Plant Extracts; Plant Leaves; Pressure; Spain

The separation and purification of hydroxytysol and oleuropein from Olea europaea L. (olive) using a macroporous resin with a novel solvent system was systematically investigated. Static adsorption experiments with BMKX-4 resin revealed that the experimental data of both hydroxytysol and oleuropein fitted best to the pseudo-second-order kinetic and Freundlich isotherm models. The thermodynamic parameters indicated spontaneous and exothermic adsorption processes. The novel solvent system, composed of n-hexane:ethyl acetate:methanol:water in a (v/v/v/v) ratio of 1:9:1:9, had two phases (upper and lower). The separation and purification parameters of hydroxytysol and oleuropein were optimized using dynamic adsorption/desorption on a column packed with BMKX-4 resin. The effects of flow rates and volumes of the upper and lower phases on the separation efficiency were systematically studied. Under optimal conditions, the fraction of hydroxytysol in the final product increased by 6.34-fold from 0.46 to 2.96%, with a yield rate of 88.58% w/w, while that of oleuropein increased 4.17-fold from 11.40 to 47.59%, with a 93.31% w/w yield rate. These results may be help in selecting a suitable eluent for improved separation of macroporous adsorption resins.

Topics: Acetates; Adsorption; Hexanes; Iridoid Glucosides; Iridoids; Methanol; Olea; Particle Size; Porosity; Resins, Plant; Solvents; Surface Properties; Thermodynamics; Water

During chronic inflammation, macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL) have well established effects on gene networks that stimulate osteoclastogenesis, which is the culprit of several bone diseases. In this study, we investigated the anti-osteoclastogenic effects in vitro of oleuropein (OL) and its peracetylated derivative (Per-OL) by exploring the expression level of key hub genes involved in fate decision and lineage commitment, differentiation, and function of human blood monocyte-derived osteoclasts. Monocytes were purified from peripheral blood mononuclear cells of healthy individuals using commercial antibodies coated with magnetic beads and treated with M-CSF/RANKL in the presence or absence of OL or Per-OL (25 and 50 μM) for 6 days. We demonstrated that OL and especially Per-OL impair transcriptional gene circuits able to support osteoclastogenesis from human blood monocytes. Our results indicate that OL and notably Per-OL are promising candidates to control osteoclastogenesis.

Topics: Cell Differentiation; Cell Survival; Humans; Iridoid Glucosides; Iridoids; Molecular Structure; Monocytes; Osteoclasts; Osteogenesis

Cadmium (Cd) is a harmful pollutant which mainly affects the liver and kidney. In this work, we investigated the hepatoprotective effects of olive leaf extract based on oleuropein against hepatic cadmium toxicity in mice. Three groups of animals were used: the first one served as the control (C); the second one received intraperitoneal injection of cadmium 2 mg/kg b.w. (CD), administered five times during two weeks; and the third group received the same doses of Cd and simultaneously 16 mg/kg b.w. of oleuropein. Results showed that Cd induced a significant increase in liver injury biomarkers coupled with enhanced lipid peroxidation (MDA) and significant depletion of antioxidants (CAT and SOD). Histological and immunohistochemical analysis confirmed these findings. In fact, we observed a severe central lobular apoptosis and inflammation around central veins. Cotreatment with oleuropein significantly reduced the oxidative damage induced by cadmium. Our findings suggest that oleuropein could be used in the prevention of Cd hepatotoxicity.

Topics: Alanine Transaminase; Alkaline Phosphatase; Animals; Antioxidants; Aspartate Aminotransferases; Cadmium; Catalase; Immunohistochemistry; Iridoid Glucosides; Iridoids; L-Lactate Dehydrogenase; Lipid Peroxidation; Liver; Male; Mice; Olea; Plant Extracts; Plant Leaves; Superoxide Dismutase

This study aimed to evaluate the effect of oleuropein (OLE), the main phenolic compound present in olive leaves, on kidney ischemia-reperfusion injury (IRI) and to explore the underlying protective mechanism.. Rat kidneys were subjected to 60 min of bilateral warm ischemia followed by 120 min of reperfusion. OLE was administered orally 48 h, 24 h and 30 min prior to ischemia at doses of 10, 50 and 100 mg/kg body weight. The creatinine, urea, uric acid concentrations and lactate dehydrogenase (LDH) activity in plasma were evaluated. Oxidative stress and inflammation parameters were also assessed. Renal expression of AMP-activated protein kinase (p-AMPK), endothelial nitric oxide synthase (eNOS), mitogen-activated protein kinases (MAPK), inflammatory proteins and apoptotic proteins were evaluated using Western blot.. Our results showed that OLE at 50 mg/kg reduced kidney IRI as revealed by a significant decrease of plasmatic creatinine, urea, uric acid concentrations and LDH activity. In parallel, OLE up-regulated antioxidant capacities. Moreover, OLE diminished the level of CRP and the expression of cyclooxygenase 2 (COX-2). Finally, OLE enhanced AMPK phosphorylation as well as eNOS expression whereas MAPK, and cleaved caspase-3 implicated in cellular apoptosis were attenuated in the ischemic kidneys.. In conclusion, this study shows that OLE could be used as therapeutic agent to reduce IRI through its anti-oxidative, anti-inflammatory and anti-apoptotic properties.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Apoptosis; Dose-Response Relationship, Drug; Inflammation; Iridoid Glucosides; Iridoids; Kidney; Male; Oxidative Stress; Rats; Rats, Wistar; Reperfusion Injury; Time Factors

Inflammation and oxidative stress pathways have emerged as novel targets in the management of inflammatory bowel diseases (IBD). Targeting the drug to the inflamed colon remains a challenge. Nanostructured lipid carriers (NLCs) have been reported to accumulate in inflamed colonic mucosa. The antioxidant/antiinflamatory polyphenol oleuropein (OLE) was loaded in NLCs (NLC-OLE). NLC-OLE showed to be more effective in decreasing the TNF-α secretion and intracellular reactive oxygen species (ROS) by activated macrophages (J774) compared to the conventional form of OLE. OLE efficacy was preserved within NLC-OLE ameliorating inflammation in a murine model of acute colitis: reduced levels of TNF-α and IL-6, decreased neutrophil infiltration and improved histopathology of the colon were reported. In addition, NLC-OLE enhanced the ROS scavenging activity of OLE in the colon after oral administration. These data suggest that the proposed NLC-OLE could be a promising drug delivery system for OLE in IBD treatment.

Topics: Administration, Oral; Animals; Anti-Inflammatory Agents; Antioxidants; Cell Line; Colitis; Disease Models, Animal; Drug Carriers; Drug Delivery Systems; Inflammation; Iridoid Glucosides; Iridoids; Lipids; Macrophages; Male; Mice; Mice, Inbred C57BL; Nanostructures; Oxidative Stress; Reactive Oxygen Species

Loss of β-cell function and β-cell death is the key feature of type 2 diabetes mellitus (T2DM). One hypothesis for the mechanism of this feature is amyloid formation by the human islet amyloid polypeptide (hIAPP). Despite the global prevalence of T2DM, there are no therapeutic strategies for the treatment of or prevention of amylin amyloidosis. Clinical trials and population studies indicate the healthy virtues of the Mediterranean diet, especially the extra virgin olive oil (EVOO) found in this diet. This oil is enriched in phenolic compounds shown to be effective against several aging and lifestyle diseases. Oleuropein (Ole), one of the most abundant polyphenols in EVOO, has been reported to be anti-diabetic. Some of Ole's main derivative have attracted our interest due to their multi-targetted effects, including interference with amyloid aggregation path. However, the structure-function relationship of Ole and its metabolites in T2DM are not yet clear. We report here a broad biophysical approach and cell biology techniques that enabled us to characterize the different molecular mechanisms by which tyrosol (TYR), hydroxytyrosol (HT), oleuropein (Ole) and oleuropein aglycone (OleA) modulate the hIAPP fibrillation in vitro and their effects on cell cytotoxicity. The OleA formed by enolic acid and hydroxytyrosol moiety was found to be more active than the Ole and HT at low micromolar concentrations. We further demonstrated that OleA inhibit the cytotoxicity induced by hIAPP aggregates by protecting more the cell membrane from permeabilization and then from death. These findings highlight the benefits of consuming EVOO and the great potential of its polyphenols, mainly OleA. Moreover, they support the possibility to validate and optimize the possible pharmacological use of EVOO polyphenols for T2DM prevention and therapy and also for many other amyloid related diseases.

Topics: Acetates; Cell Survival; Cyclopentane Monoterpenes; Diabetes Mellitus, Type 2; Diet, Mediterranean; Fluorescence; Humans; Inhibitory Concentration 50; Iridoid Glucosides; Iridoids; Islet Amyloid Polypeptide; Islets of Langerhans; Microscopy, Atomic Force; Olive Oil; Phenylethyl Alcohol; Phospholipids; Pyrans; Structure-Activity Relationship

Olive leaves are well known for their high polyphenol content and beneficial effects to human health. The two main phenolic compounds of olive leaves are oleuropein and 3-hydroxytyrosol. Use of olive leaves as beer ingredient was evaluated, to investigate their contribution to bitterness and antioxidant activity of beer. Thirteen beer samples were produced, adding olive leaves during boiling at different boiling times, in different forms and concentrations. Three different forms were used: dry crumbled leaves, infusion, and atomized extract. The effects of olive leaves addition were evaluated through following analysis: total polyphenols content, oleuropein and 3-hydroxytyrosol content, antioxidant capacity, sensory analysis, shelf-life prediction. Results confirmed that addition of olive leaves highly increased polyphenol content of beers. Boiling time favored hydrolysis of oleuropein to 3-hydroxytyrosol. Antioxidant activity was not influenced by addition of olive leaves. Higher polyphenol content of beer samples increased colloidal instability of beer. Sensory analysis results demonstrated that about 10 g/L of olive leaves imparts a sour/astringent taste and herbal aroma. A lower quantity of olive leaves (about 5 g/L) allowed to obtain a beer with a pleasant sensory profile. PRACTICAL APPLICATION: Our research was inspired by both the high interest in alternative ingredients able to add nutraceutical value to traditional food, and by the growing craft beer market, with its constant research for innovative and characterizing ingredients. This project has several aims: evaluate if olive leaves could partially substitute hops in beer bittering (reducing costs); if their addition increase beer polyphenol content; which amount and using technique gives the best results in terms of polyphenol extraction and sensory profile; how this addition influence beer stability. This work could then encourage new research about the nutraceutical value of this new type of beer.

Topics: Antioxidants; Beer; Female; Food Handling; Humans; Humulus; Iridoid Glucosides; Iridoids; Male; Olea; Phenols; Phenylethyl Alcohol; Plant Extracts; Plant Leaves; Polyphenols; Taste

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease without an effective and safe treatment. Besides, macrophages are the major components of the innate immune system and play a critical role in the inflammation process in SLE. Secoiridoids from olive tree are phenolic compounds which have shown important pharmacological effects. Particularly, oleuropein (OL) has shown antioxidant, anti-inflammatory and immunomodulatory properties suggesting a potential application in a large number of inflammatory and reactive oxygen species (ROS)-mediated diseases. In addition, different studies have shown the importance of acyl derivatives of natural phenols due to their better hydrophilic/lipophilic balance.

Topics: Animals; Anti-Inflammatory Agents; Cytokines; Inflammasomes; Iridoid Glucosides; Iridoids; Lupus Erythematosus, Systemic; Macrophages; Macrophages, Peritoneal; Mice; Mice, Inbred BALB C; NLR Family, Pyrin Domain-Containing 3 Protein; Olea; Phenols; Terpenes

Articular cartilage and synovial tissue from patients with osteoarthritis (OA) show an overactivity of connexin43 (Cx43) and accumulation of senescent cells associated with disrupted tissue regeneration and disease progression. The aim of this study was to determine the effect of oleuropein on Cx43 and cellular senescence for tissue engineering and regenerative medicine strategies for OA treatment. Oleuropein regulates Cx43 promoter activity and enhances the propensity of hMSCs to differentiate into chondrocytes and bone cells, reducing adipogenesis. This small molecule reduce Cx43 levels and decrease Twist-1 activity in osteoarthritic chondrocytes (OACs), leading to redifferentiation, restoring the synthesis of cartilage ECM components (Col2A1 and proteoglycans), and reducing the inflammatory and catabolic factors mediated by NF-kB (IL-1ß, IL-6, COX-2 and MMP-3), in addition to lowering cellular senescence in OACs, synovial and bone cells. Our

Topics: Aged; Antirheumatic Agents; Cartilage, Articular; Cell Differentiation; Cell Line; Cellular Microenvironment; Cellular Senescence; Chondrocytes; Chondrogenesis; Collagen Type II; Connexin 43; Female; Fruit; Humans; Iridoid Glucosides; Iridoids; Male; NF-kappa B; Nuclear Proteins; Olea; Osteoarthritis; Osteogenesis; Polyphenols; Regeneration; Signal Transduction; Twist-Related Protein 1

Olive fruits and leaves are recognized to have great potential as natural sources of antioxidants. The major phenolic antioxidant component in these plant tissues is oleuropein. The antioxidant activity of olive fruits and leaves was evaluated in this study using multiple free-radical scavenging (MULTIS) methods, wherein we determined the scavenging abilities of different extracts against five reactive oxygen species (ROS; HO·, O

Topics: Antioxidants; Fruit; Iridoid Glucosides; Iridoids; Olea; Phenols; Plant Extracts; Plant Leaves; Reactive Oxygen Species

This study was designed to investigate the effects of emulsion formulations of oleuropein isolated from ethanol extract of olive leaf in streptozotocin-diabetic rats. The rats were treated with the administration of the emulsion containing oleuropein at a low (150 mg/kg b.wt.) and high (225 mg/kg b.wt.) dose for 30 days. At the end of the study, blood samples were drawn from the heart of the rats to determine blood glucose, alanine transaminase, and aspartate transaminase levels. In addition, their liver tissues were dissected to determine the levels of glutathione and thiobarbituric acid-reactive substances, and superoxide dismutase activity. According to the results for both dose treatments, a statistically significant increase in superoxide dismutase activities and glutathione levels of the treated diabetic rats was observed when compared with those of the diabetic control rats. On the other hand, a statistically significant decrease in the levels of thiobarbituric acid-reactive substances, aspartate transaminase and alanine transaminase of the treated diabetic rats was determined. It should be highlighted that the administrations at the high dose were more effective compared to that of the low dose. Furthermore, a substantial decrease in the blood glucose levels of the diabetic rats exposed to the high dose was observed.

Topics: Animals; Antioxidants; Blood Glucose; Catalase; Diabetes Mellitus, Experimental; Ethanol; Iridoid Glucosides; Iridoids; Liver; Olea; Plant Extracts; Plant Leaves; Rats; Rats, Wistar; Superoxide Dismutase

Olive leaf extract (OLE), prepared from the fresh or dried leaves of

Topics: Antioxidants; Iridoid Glucosides; Iridoids; Olea; Phenylethyl Alcohol; Phytochemicals; Plant Extracts; Plant Leaves; Plants, Medicinal; Polyphenols

Olive trees are often subjected to a prolonged dry season with low water availability, which induces oxidative stress. Arbuscular mycorrhizal (AM) symbioses can improve olive plant tolerance to water deficit. This study investigated several aspects related to drought tolerance in AM fungi olive plants. Non-AM and AM plants were grown under well-watered or drought-stressed conditions, and mycorrhizal growth response, neutral lipid fatty acid (NLFA)16:1ω5 and phospholipid fatty acid (PLFA) 16:1ω5 in roots (intraradical mycelium) and in soil (extraradical mycelium), carbohydrates (monosaccharides, disaccharides and polyols) and phenolic compounds (phenolic alcohols, flavonoids, lignans, secoiridoids and hydroxycinnamic acid derivatives) were determined. Results showed that the amounts of PLFA 16:1ω5 and NLFA 16:1ω5 were significantly influenced by drought stress conditions. The NLFA 16:1ω5/PLFA 16:1ω5 ratio showed a dramatic decrease (-62%) with the application of water deficit stress, indicating that AM fungi allocated low carbon to storage structures under stress conditions. Mannitol and verbascoside are the main compounds detected in the roots of well-watered plants, whereas oleuropein and mannitol are the main compounds differentially accumulated in the roots of water-stressed plants. The oleuropein/verbascoside ratio increased in the case of drought-stressed AM plants by 30%, while the mannitol/oleuropein ratio was decreased by 46%, when compared to the non-AM stressed plants. Mycorrhization therefore oriented the flux toward the biosynthetic pathway of oleuropein and the data suggest that sugar and phenolic compound metabolism may have been redirected to the formation of oleuropein in roots of AM stressed plants, that may underlie their enhanced tolerance to drought stress.

Topics: Droughts; Fungi; Iridoid Glucosides; Iridoids; Mannitol; Mycorrhizae; Olea; Plant Roots; Stress, Physiological; Symbiosis

Since olive leaf is a potential source of phenolic fraction that is assumed to have good antioxidative effects, we purposed to add its extract to the refined olive-pomace oil during heating to increase its oxidative stability. RP-UHPLC-DAD-QTOF-MS was employed to characterize the phenolic fraction.The oil samples were evaluated by measuring the polymers and the polar compounds and thus detecting specific oxidized compounds. Using this approach, the results showed that incorporating olive leaf extract in refined oil significantly reduced the formation of polymers from 14.39% to 10.45% and the oxidation state by the variation of extinction Δ

Topics: Chromatography, High Pressure Liquid; Food Additives; Food Handling; Glucosides; Hot Temperature; Iridoid Glucosides; Iridoids; Mass Spectrometry; Olea; Olive Oil; Oxidation-Reduction; Plant Extracts; Plant Leaves; Pyrans

The huge interest in the health-related properties of foods to improve health has brought about the development of sensitive analytical methods for the characterization of natural products with functional ingredients. Greek olive leaves and drupes constitute a valuable source of biophenols with functional properties. A novel ultra-high-performance liquid chromatography-quadrupole time of flight tandem mass spectrometry (UHPLC-QTOF-MS) analytical method was developed to identify biophenols through target and suspect screening in Greek olive leaves and drupes of the varieties: Koroneiki, Throumbolia, Konservolia, Koutsourelia, Kalamon, Petrolia, Amigdalolia, Megaritiki, Mastoeidis, Agouromanakolia, Agrilia, Adramitiani and Kolovi. The method's performance was evaluated using the target compounds: oleuropein, tyrosol and hydroxytyrosol. The analytes demonstrated satisfactory recovery efficiency for both leaves (85.9-90.5%) and drupes (89.7-92.5%). Limits of detection (LODs) were relatively low over the range 0.038 (oleuropein)-0.046 (hydroxytyrosol) and 0.037 (oleuropein)-0.048 (hydroxytyrosol) for leaves and drupes, respectively For leaves, the precision limit ranged between 4.7 and 5.8% for intra-day and between 5.8 and 6.5% for inter-day experiments, and for drupes, it ranged between 3.8 and 5.2% for intra-day and between 5.1 and 6.2% for inter-day experiments, establishing the good precision of the method. The regression coefficient (r

Topics: Chromatography, High Pressure Liquid; Geography; Greece; Hot Temperature; Iridoid Glucosides; Iridoids; Limit of Detection; Metabolomics; Olea; Phenylethyl Alcohol; Plant Extracts; Plant Leaves; Reproducibility of Results; Seasons; Seeds; Tandem Mass Spectrometry; Time Factors

Herbal bioactive compounds have captured pronounced attention considering their health-promoting effects as well as their functional properties. In this study, the binding mechanism between milk protein bovine β-lactoglobulin (β-LG), oleuropein (OLE) and safranal (SAF) found in olive leaf extract and saffron, respectively via spectroscopic and in silico studies. Fluorescence quenching information exhibited that interactions with both ligands were spontaneous and hydrophobic interactions were dominant. Also, the CD spectroscopy results demonstrated the increase in β-sheet structure and decrease in the α-helix content for both ligands. Size of β-LG-OLE complex was higher than β-LG-SAF due to the conformation and larger molecular size. Molecular docking and simulation studies revealed that SAF and OLE bind in the central calyx of β-LG and the surface of β-LG next to hydrophobic residues. Lastly, OLE formed a more stabilized complex compared to SAF based on the molecular dynamic simulation results.

Topics: Circular Dichroism; Cyclohexenes; Dynamic Light Scattering; Iridoid Glucosides; Iridoids; Kinetics; Lactoglobulins; Molecular Docking Simulation; Molecular Dynamics Simulation; Nanoparticles; Particle Size; Protein Structure, Secondary; Spectrometry, Fluorescence; Spectroscopy, Fourier Transform Infrared; Static Electricity; Terpenes

Persistent oxidative stress can lead to chronic inflammation and mediate most chronic diseases including neurological disorders. Oleuropein has been shown to be a potent antioxidant molecule in olive oil leaf having antioxidative properties.. The aim of this study was to investigate the protective effects of oleuropein against oxidative stress in human glioblastoma cells.. Human glioblastoma cells (U87) were pretreated with oleuropein (OP) essential oil 10 µM. After 30 minutes, 100 µM H2O2 was added to the cells for three hours. Cell survival was quantified by colorimetric MTT assay. Glutathione level, total oxidant capacity, total antioxidant capacity and nitric oxide levels were determined by using specific spectrophotometric methods. The relative gene expression level of iNOS was performed by qRT-PCR method.. According to viability results, the effective concentration of H2O2 (100µM) significantly decreased cell viability and oleuropein pretreatment significantly prevented the cell losses. Oleuropein regenerated total antioxidant capacity and glutathione levels decreased by H2O2 exposure. In addition, nitric oxide and total oxidant capacity levels were also decreased after administration of oleuropein in treated cells.. Oleuropein was found to have potent antioxidative properties in human glioblastoma cells. However, further studies and validations are needed in order to understand the exact neuroprotective mechanism of oleuropein.

Topics: Antioxidants; Cell Line, Tumor; Cell Survival; Glutathione; Humans; Hydrogen Peroxide; Iridoid Glucosides; Iridoids; Neurons; Neuroprotective Agents; Nitric Oxide Synthase Type II; Oxidative Stress

The quality of extra virgin olive oils is affected mainly by hydrolytic and oxidative reactions. The present paper investigated the changes of major and minor components and oxidation indices of three monovarietal extra virgin olive oils after 18 months of storage at room temperature and in dark glass bottles conditions. After storage, the basic quality parameters such as free acidity, peroxide values, extinction coefficients, fatty acids composition, chlorophyll and carotenoid content, did not exceed the upper limits set by European Community Regulations for extra-virgin olive oils. Given the importance of the phenolic fraction, UHPLC-HESI-MS metodology was used. A decrease in 3,4-DHPEA-EDA (oleacin) and p-HPEA-EDA (oleochantal) was detected whereas, an increase of tyrosol and hydroxytyrosol was measured as a consequence of degradation of ligstroside and oleuropein derivatives. Based on the results it is possible to observe the high nutritional value of the studied oils even after 18 months of conservation.

Topics: Fatty Acids; Food Quality; Food Storage; Glucosides; Iridoid Glucosides; Iridoids; Italy; Olive Oil; Oxidation-Reduction; Phenols; Pyrans

Feasibility and stability were evaluated of a continuous multi-batch process for converting oleuropein (OLE) from olive leaf extract to the bioactive product hydroxytyrosol (HT). Carrier beads made of three different materials (calcium alginate, chitosan with deacetylated α-chitin nanofibers (DEChN), or porous ceramic) were investigated for morphology, thermogravimetric, sorption, and viscoelastic properties. Enzymatic hydrolysis of OLE conducted in a packed bed bioreactor containing cellulase immobilized to carrier beads yielded OLE degradation rates of ~ 90% and an average HT yield of ~ 70% over 20 batches. Ultimately, inorganic porous ceramic beads were less costly and exhibited superior performance relative to organic carriers and thus were deemed most suitable for industrial-scale HT production. Systems utilizing enzyme immobilization within packed bed reactors hold promise for achieving efficient production of valuable bioproducts from discarded biomass materials.

Topics: Alginates; Biomass; Bioreactors; Cellulase; Ceramics; Chitosan; Enzymes, Immobilized; Hydrolysis; Iridoid Glucosides; Iridoids; Microscopy, Electron, Scanning; Olea; Phenylethyl Alcohol; Plant Leaves; Substrate Specificity; Thermogravimetry

Phosphatase PTP1B has become a therapeutic target for the treatment of type 2-diabetes, whereas recent studies have revealed that PTP1B plays a pivotal role in pathophysiology and development of breast cancer. Oleuropein is a natural, phenolic compound with anticancer activity. The aim of this study was to address the question whether PTP1B constitutes a target for oleuropein in breast cancer MCF-7 cells. The cellular MCF-7 breast cancer model was used in the study. The experiments were performed using cellular viability tests, Elisa assays, immunoprecipitation, flow cytometry analyses and computer modelling. Herein, we evidenced that the reduced activity of phosphatase PTP1B after treatment with oleuropein is strictly correlated with decreased MCF-7 cellular viability and cell cycle arrest. These results provide new insight into further research on oleuropein and possible role of the compound in adjuvant treatment of breast cancer.

Topics: Adenocarcinoma; Antineoplastic Agents; Breast Neoplasms; Cell Proliferation; Cell Survival; Humans; Iridoid Glucosides; Iridoids; MCF-7 Cells; Molecular Dynamics Simulation; Protein Tyrosine Phosphatase, Non-Receptor Type 1

Oleuropein (OP) is a bioactive compound derived from plants of the genus Oleaceae exhibiting antitumor properties in several human cancers, including non-small-cell lung cancer (NSCLC). Recent evidence suggests that OP has proapoptotic effects on NSCLC cells via the mitochondrial apoptotic pathway. However, the exact molecular mechanisms behind the apoptogenic action of OP in NSCLC are still largely unknown. Glyoxalase 2 (Glo2) is an ancient enzyme belonging to the glyoxalase system involved in the detoxification of glycolysis-derived methylglyoxal. However, emerging evidence suggests that Glo2 may have also nonenzymatic roles in some malignant cells. In the present study, we evaluated whether and how Glo2 participated in the proapoptotic effects of OP in NSCLC A549 cells. Our results indicate that OP is able to induce apoptosis in A549 cells through the upregulation of mitochondrial Glo2 (mGlo2), mediated by the superoxide anion and Akt signaling pathway. Moreover, our data shows that the proapoptotic role of mGlo2, observed following OP exposure, occurs via the interaction of mGlo2 with the proapoptotic Bax protein. Conversely, OP does not alter the behavior of nonmalignant human BEAS-2B cells or mGlo2 expression, thus suggesting a specific anticancer role for this bioactive compound in NSCLC. Our data identify a novel pathway through which OP exerts a proapoptotic effect in NSCLC and suggest, for the first time, a novel, nonenzymatic antiapoptotic role for this ancient enzyme in NSCLC.

Topics: A549 Cells; Apoptosis; bcl-2-Associated X Protein; Carcinoma, Non-Small-Cell Lung; Humans; Iridoid Glucosides; Iridoids; Lung Neoplasms; Mitochondria; Proto-Oncogene Proteins c-akt; RNA Interference; RNA, Small Interfering; Signal Transduction; Superoxide Dismutase; Superoxides; Thiolester Hydrolases; Up-Regulation

A comprehensive structural characterization of the complex family of isomeric forms related to Oleuropein aglycone (OA) detected in virgin olive oil (VOO) was performed by reverse phase liquid chromatography with electrospray ionization and Fourier-transform mass spectrometry (RPLC-ESI-FTMS), integrated by enzymatic/chemical reactions performed on Oleuropein, the natural precursor of OA. First, some of the OA-related isomers typically observed in VOO extracts were generated upon enzymatic hydrolysis of the glycosidic linkage of Oleuropein. This step mimicked the process occurring during olive drupes crushing in the first stage of oil production. The incubation of the enzymatic reaction mixture at a more acidic pH was subsequently performed, to simulate the conditions of olive paste malaxation during oil production. As a result, further isomeric forms were generated and the complex chromatographic profile typically observed for OA in olive oil extracts, including at least 13 different peaks/bands/groups of peaks, was carefully reproduced. Each of those chromatographic features could be subsequently assigned to specific types of OA-related isomers, belonging to one of four structurally different classes. Specifically, diastereoisomers/geometrical isomers corresponding to two different types of open-structure forms and to as many types of closed-structure, di-hydropyranic forms of OA, characterized by the presence of one or two carbonyl groups, according to the case, were evidenced. In addition, the presence of stable enolic/dienolic tautomers, providing an indirect structural confirmation for some OA isomers, was ascertained through RPLC-ESI-FTMS analyses performed under H/D exchange conditions, i.e. in the presence of deuterated water as one of the mobile phase solvents.

Topics: Acetates; beta-Glucosidase; Chromatography, Reverse-Phase; Cyclopentane Monoterpenes; Deuterium; Fourier Analysis; Hydrolysis; Iridoid Glucosides; Iridoids; Isomerism; Liquid-Liquid Extraction; Olea; Olive Oil; Pyrans; Tandem Mass Spectrometry

The objective of the present study was to investigate in vitro anticoccidial effect of olive pulp (Olea europaea L var. Chemlal) extract on the destruction of Eimeria spp. oocysts isolated from infected chickens naturally.. The olive pulp (OP) powder was stirred manually in aqueous ethanol in preparation for extraction using the microwave-assisted extraction system. The identification of the phenolic compounds was obtained by ultra-high-performance liquid chromatography-mass spectrometry with electrospray ionisation (HPLC-ESI-MS). The treatment of Eimeria oocyst with OP extract and standard compounds (quercetin and oleuropein) leads to their lysis as shown by the release of substances absorbing at 273 nm.. Our results showed that the maximum number of reduced oocysts was recorded after 8 h of incubation of optimum OP extract, quercetin and oleuropein for different periods of time. Also, the number of Eimeria oocysts decreased considerably with increase concentrations after adding the optimum of OP extract in concentration ranging from 0.023 to 0.371 mg/ml. Positive correlation between the optimum OP extract concentrations and the number of Eimeria oocysts reduced was R. To our knowledge, this is the first time that quercetin and oleuropein were tested to evaluate their anticoccidial activity. The findings of this study showed that phenolic compound of OP extract tested separately possesses anti-Eimeria spp. effect. Further studies should be carried out to test its in vivo efficacy of the OP bioactive compounds in broiler chickens.

Topics: Animals; Antiprotozoal Agents; Biological Products; Chickens; Coccidiosis; Eimeria; Iridoid Glucosides; Iridoids; Olea; Oocysts; Poultry Diseases; Quercetin

Two newly identified phytohormone cleaving esterases from Olea europaea are responsible for the glucosidase-initiated activation of the specialized metabolites ligstroside and oleuropein. Biosynthetic routes leading to the formation of plant natural products are tightly orchestrated enzymatic sequences usually involving numerous specialized catalysts. After their accumulation in plant cells and tissues, otherwise non-reactive compounds can be enzymatically activated, e.g., in response to environmental threats, like pathogen attack. In olive (Olea europaea), secoiridoid-derived phenolics, such as oleuropein or ligstroside, can be converted by glucosidases and as yet unidentified esterases to oleoside aldehydes. These are not only involved in pathogen defense, but also bear considerable promise as pharmaceuticals or neutraceuticals. Making use of the available olive genomic data, we have identified four novel methylesterases that showed significant homology to the polyneuridine aldehyde esterase (PNAE) from Rauvolfia serpentina, an enzyme acting on a distantly related metabolite group (monoterpenoid indole alkaloids, MIAs) also featuring a secoiridoid structural component. The four olive enzymes belong to the α/ß-hydrolase fold family and showed variable in vitro activity against methyl esters of selected plant hormones, namely jasmonic acid (MeJA), indole acetic acid (MeIAA), as well as salicylic acid (MeSA). None of the identified catalysts were directly active against the olive metabolites oleuropein, ligstroside, or oleoside 11-methyl ester. When employed in a sequential reaction with an appropriate glucosidase, however, two were capable of hydrolyzing these specialized compounds yielding reactive dialdehydes. This suggests that the esterases play a pivotal role in the activation of the olive secoiridoid polyphenols. Finally, we show that several of the investigated methylesterases exhibit a concomitant in vitro transesterification capacity-a novel feature, yielding ethyl esters of jasmonic acid (JA) or indole-3-acetic acid (IAA).

Topics: Esters; Glucosides; Iridoid Glucosides; Iridoids; Olea; Plant Proteins; Pyrans

Topics: Animals; Dietary Supplements; Disease Models, Animal; Heme Oxygenase-1; Inflammasomes; Iridoid Glucosides; Iridoids; Janus Kinases; Kidney; Lupus Nephritis; MAP Kinase Signaling System; Matrix Metalloproteinase 3; Membrane Proteins; Mice, Inbred BALB C; NF-kappa B; Nitric Oxide Synthase Type II; NLR Family, Pyrin Domain-Containing 3 Protein; STAT Transcription Factors; Terpenes

Meningitis is an inflammation of meninges encircled the brain and spinal cord. Currently it can be treated with second generation cephalosporins which were ended up with an unresolvable problem called Multi Drug Resistance (MDR). Hence, there is a need to develop a better herbal molecule to conflict the MDR.. Hot Blanching technique followed by ultra sound assisted extraction using bio-solvent aqueous glycerol was used to extract OLE from olive leaves. QbD tool was applied to predict the interactions between Critical Material Attributes (Ratio of solid Lipid X. Thermal studies reflect the formation of low ordered crystalline structure of lipid matrix which offers higher encapsulation of drug in NLC than physical mixture. CMA and CPP show significant effect on CQA and method operable design range was developed. Histo-pathological studies confirms that there is no signs of toxicity and in-vitro drug release studies reveals a rapid release of a drug initially followed by prolonged release of oleuropein upto 24 h. The absolute bioavailability of drug loaded NLC in brain was higher in IN route compared to NLC administered by IV route.. In a nutshell, challenges offered by the hydrophilic OLE for brain targeting can be minimized through lipidic nature of NLC. Graphical Abstract.

Topics: Administration, Intranasal; Administration, Intravenous; Animals; Biological Availability; Chemistry, Pharmaceutical; Computational Biology; Drug Liberation; Iridoid Glucosides; Iridoids; Lipids; Male; Nanostructures; Olea; Particle Size; Plant Leaves; Rats; Rats, Wistar; Surface-Active Agents

Major phenolic compounds from olive oil (ArOH-EVOO), oleuropein (Ole), tyrosol (Tyr), and

Topics: Cell Death; Cell Line, Tumor; Chromatography, Liquid; Coumaric Acids; Humans; Hydrogen Peroxide; Iridoid Glucosides; Iridoids; Neuroprotection; Neuroprotective Agents; Oxidation-Reduction; Phenylethyl Alcohol; Propionates; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry

Breast cancer is a leading cause of cancer fatalities among women worldwide. Of the more than 80% of patients who receive adjuvant chemotherapy, approximately 40% relapse. The majority of these patients die of disseminated metastatic disease, which emphasizes the need for new therapeutic strategies.. The study intended to investigate the anticancer effects of oleuropein (OL) and doxorubicin (DOX) individually and in combination on breast tumor xenografts and also to evaluate the molecular pathways involved.. The research team designed in vivo (animal) and in vitro (cell culture) studies.. The study was performed in the College of Science of King Saud University in the University Center for Women Students (Riyadh, Saudi Arabia).. The study involved 40 female, nude mice (BALB/c OlaHsd-foxn1).. The mice were injected subcutaneously with MDA-MB-231 human breast cancer cells. After the growth of tumors, the animals were randomly divided into 4 groups to receive intraperitoneal injections: (1) group 1 (control group)-dimethyl sulfoxide, (2) group 2 (intervention group)-50 mg/kg of OL, (3) group 3 (intervention group)-2.5 mg/kg of DOX, and (4) group 4 (intervention group)-1.5 mg/kg of DOX, immediately followed by 50 mg/kg of OL. The OL was extracted from Manzanillo olive trees (Olea europaea) grown in Tabouk, Saudi Arabia.. The measures included the isolation and primary culture of the tumor xenografts, apoptosis analysis by annexin V, cellular lysate preparation, and immunoblotting.. The volume of the tumor increased aggressively, reaching 173 mm3 in the control animals in a time-dependent manner. On the other hand, a sharp drop, to 48.7 mm3, in the volume of the tumor was observed with the 2 drugs combined, a more than 3-fold decrease. The effect was mediated through the induction of apoptosis via the mitochondrial pathway. The combined treatment downregulated the antiapoptosis and proproliferation protein, nuclear factor-kappa Β, and its main oncogenic target cyclin D1. Furthermore, it inhibited the expression of BCL-2 and survivin. This inhibition could explain the cooperative suppression of the proliferation of breast tumor xenografts and the induction of apoptosis by the combined effect of the compounds used.. The key findings clearly indicate the synergistic efficacy of DOX with natural and nontoxic OL against breast tumor xenografts.

Topics: Animals; Antibiotics, Antineoplastic; Apoptosis; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Doxorubicin; Female; Humans; Iridoid Glucosides; Iridoids; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Recurrence, Local

The mesothelial cells (MCs) play an important role in the morpho-functional alterations of the peritoneal membrane (PM) undergoing peritoneal dialysis (PD). MCs, through the epithelial-mesenchymal transition process (EMT), progressively acquire a myofibroblast-like phenotype, promoting peritoneal fibrosis (PF) and failure of peritoneal membrane function. Transforming growth factor β1 (TGFβ1), through canonical and non-canonical pathways, promotes the epithelial-mesenchymal transition (EMT) process leading to PF. To investigate the therapeutic potential of an olive leaf extract (OLE) on preserving peritoneal membrane function, we evaluated the effect of OLE on the TGFβ1-induced EMT in mesothelial cells, Met5A, and elucidated the underlying molecular mechanisms. As assessed by changes in the expression of epithelial, mesenchymal, and fibrotic cell markers (such as E-cadherin, N-cadherin, α-SMA, fibronectin, vimentin), levels of matrix metalloproteinases (MMP2 and MMP9), and cell migration, OLE inhibited the TGFβ1-induced EMT. Importantly, the beneficial effect of OLE was mediated by reduction of the TGFβ1-induced activation of Smad2/3 signaling and the mitigation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) phosphorylation. Smad/non-Smad signaling pathways, activated by TGFβ1, both reduce expression of epithelial marker E-cadherin which has a crucial role in EMT initiation. Interestingly, we observed that in presence of OLE activity of the E-cadherin, promoter was increased and concomitantly OLE reduced the nuclear content of its co-repressor SNAIL. Our results suggest the potential therapeutic of OLE to counteract fibrotic process in peritoneal dialysis patients.

Topics: Antigens, Differentiation; Cadherins; Cell Line; Cell Membrane; Epithelial-Mesenchymal Transition; Glucosides; Humans; Iridoid Glucosides; Iridoids; Olea; Peritoneal Dialysis; Phenols; Phenylethyl Alcohol; Plant Extracts; Signal Transduction; Smad Proteins, Receptor-Regulated; Transforming Growth Factor beta1

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antioxidants; Indomethacin; Iridoid Glucosides; Iridoids; Kidney; Kidney Diseases; Male; Oxidative Stress; Protective Agents; Rats; Rats, Sprague-Dawley; Treatment Outcome

Oleuropein is one of the most abundant phenolic compounds found in olives. Epidemiological studies have indicated that an increasing intake of olive oil can significantly reduce the risk of breast cancer. However, the potential effect(s) of oleuropein on estrogen receptor (ER)-negative breast cancer is not fully understood. This study aims to understand the anticancer effects and underlying mechanism(s) of oleuropein on ER-negative breast cancer cells in vitro. The effect of oleuropein on the viability of breast cancer cell lines was examined by mitochondrial dye-uptake assay, apoptosis by flow cytometric analysis, nuclear factor-κB (NF-κB) activation by DNA binding/reporter assays and protein expression by Western blot analysis. In the present report, thiazolyl blue tetrazolium bromide assay results indicated that oleuropein inhibited the viability of breast cancer cells, and its effects were more pronounced on MDA-MB-231 as compared with MCF-7 cells. It was further found that oleuropein increased the level of reactive oxygen species and also significantly inhibited cellular migration and invasion. In addition, the activation of NF-κB was abrogated as demonstrated by Western blot analysis, NF-κB-DNA binding, and luciferase assays. Overall, the data indicates that oleuropein can induce substantial apoptosis via modulating NF-κB activation cascade in breast cancer cells.

Topics: Apoptosis; Breast Neoplasms; Female; Humans; Iridoid Glucosides; Iridoids; MCF-7 Cells; NF-kappa B; Receptors, Estrogen

Distinct metastasis is one of the main causes of breast cancer (BC)-related mortality and epithelial-mesenchymal transition (EMT) is a primary step in metastasis dissemination. On the other hand, doxorubicin (DOX) is an effective chemotherapeutic agent against BC; unfortunately, its clinical use is limited by dose-dependent side effects. Therefore, extensive efforts have been dedicated to suppressing metastasis of BC and also to overcome DOX side effects together with keeping its antitumor efficacy. Studies supported the role of oleuropein (OLEU) in reducing DOX-induced side effects besides its antitumor actions. In this study, the antimigratory effect of OLEU was assessed and real-time PCR (RT-PCR) was used to detect OLEU effect on the expression level of EMT markers, in MCF-7 cells. The cytotoxic effect of OLEU and DOX was assessed by MTT assay, whereas the ratio of apoptosis was investigated by flow cytometry. The results showed that migration ability of MCF-7 cells remarkably decreased in OLEU treated group and RT-PCR results showed that OLEU may exert its antimigratory action by suppressing EMT through downregulation of sirtuin1 (SIRT1). Also, the results indicated that both OLEU and DOX were cytotoxic to MCF-7 cells, whereas DOX-OLEU cotreatment led to additive cytotoxicity and apoptosis rate. This study provides evidence regarding the suppressive role of OLEU on MCF-7 cells migration ability through suppression of EMT, and for the first time, it was proposed that SIRT1 downregulation can be involved in the OLEU antimigratory effect. Also, the findings demonstrated that OLEU can reduce DOX-induced side effects by reducing its effective dose.

Topics: Adenocarcinoma; Antineoplastic Agents, Phytogenic; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Biomarkers, Tumor; Breast Neoplasms; Cell Movement; Down-Regulation; Doxorubicin; Drug Synergism; Epithelial-Mesenchymal Transition; Female; Gene Expression Regulation, Enzymologic; Gene Expression Regulation, Neoplastic; Humans; Iridoid Glucosides; Iridoids; MCF-7 Cells; Neoplasm Invasiveness; Signal Transduction; Sirtuin 1

Topics: Apoptosis; Cell Line, Tumor; Enzyme Activation; Gene Expression Regulation, Neoplastic; Humans; Iridoid Glucosides; Iridoids; Lung Neoplasms; MAP Kinase Signaling System; Mitochondria; Neoplasm Proteins; p38 Mitogen-Activated Protein Kinases

Phenolic compounds present in extra virgin olive oil have recently attracted considerable attention due to their pharmacological activities. Among them oleacein (3,4-DHPEA-EDA), structurally related to oleochantal (4-HPEA-EDA), is one of the most studied. 3,4-DHPEA-EDA has been synthesized through decarboxylation of demethyloleuropein catalyzed by Er(OTf)

Topics: Animals; Biocatalysis; Cattle; Chymotrypsin; Hydrolases; Hydrolysis; Iridoid Glucosides; Iridoids; Olea; Pancreas

An olive leaf extract (OLE) was microencapsulated with sodium alginate (SA) by spray-drying to study the evolution of oleuropein (ORP) during in vitro gastrointestinal digestion, and its bioaccessibility and potential bioavailability from OLE and OLE-SA microparticles. Secoiridoids, flavonoids, simple phenols, oleosides and elenolic acid were identified in OLE. OLE/SA ratio 1:1.6 and inlet air temperature 135 °C were the optimal conditions for OLE-SA microparticles. ORP (70%) from OLE was degraded during gastric digestion, giving hydroxytyrosol and ORP-aglycone, whereas only the superficial ORP was released from microparticles. The remaining ORP from OLE was degraded under intestinal conditions, leading to oleosides; whereas alginate was swollen and disintegrated, releasing the ORP (90% of encapsulated ORP). ORP from both OLE and microparticles was degraded to hydroxytyrosol under colonic conditions. Encapsulation of OLE allowed the protection of ORP under gastric conditions and its controlled release at intestinal conditions, and higher bioaccessibility (58%) and potential bioavailability (20%).

Topics: Alginates; Chromatography, High Pressure Liquid; Desiccation; Iridoid Glucosides; Iridoids; Olea; Phenols; Plant Extracts; Plant Leaves; Spectrometry, Mass, Electrospray Ionization; Temperature

Breast cancer is the most common malignancy in the world with the highest rate of morbidity and mortality. Due to the several side effects of chemotherapy and radiotherapy, recent studies have focused on the use of herbal medicines. Epidemiological reports have shown the inverse relationship between breast cancer risk and intake of olive. Oleuropein (OLE) is a polyphenolic compound in virgin olive oil with antineoplastic properties and it is well tolerated by humans. Recent reports have shown that OLE has effects on the control of cancer by modulating epigenetics, such as histone deacetylase (HDAC) inhibition. However, the epigenetic mechanisms of OLE anticancer properties are yet to be properly investigated. Therefore, this study aimed to determine the therapeutic effects of OLE through the modulation of histone deacetylase 2 (HDAC2) and histone deacetylase 3 (HDAC3) expression in breast cancer cell line. MCF-7 cells were tested with and without OLE, and also the cell viability, apoptosis, and migration were examined. HDAC2 and HDAC3 expression genes were assessed by quantitative real-time polymerase chain reaction. It was found that OLE decreased the expression of both HDAC2 and HDAC3 (P < 0.05), induced apoptosis and retarded cell migration and cell invasion in a dose-dependent manner (P < 0.05). These results showed that OLE is a potential therapeutic and preventive agent for breast cancer.

Topics: Antineoplastic Agents; Breast Neoplasms; Cell Movement; Cell Survival; Female; Histone Deacetylase 2; Histone Deacetylases; Humans; Iridoid Glucosides; Iridoids; MCF-7 Cells

Aggregation of α-synuclein (αSN) is implicated in neuronal degeneration in Parkinson's disease and has prompted searches for natural compounds inhibiting αSN aggregation and reducing its tendency to form toxic oligomers. Oil from the olive tree (

Topics: alpha-Synuclein; Cell Line, Tumor; Cell Survival; Chromatography, Gel; Dose-Response Relationship, Drug; Fruit; Humans; Iridoid Glucosides; Iridoids; Light; Olea; Protein Aggregates; Structure-Activity Relationship

Tyrosol, hydroxytyrosol and oleuropein are among the major phenolic compounds in fruits, leaves and oils from Olea europaea L. These natural antioxidants molecules revealed several beneficial effects on human health, but a low bioavailability and accessibility to targeted site. Liposomes are drug/nutraceutical delivery carriers, used for driving bioactive molecules to desired target tissues, decreasing potential side effects and protecting the encapsulated molecule from enzymatic metabolic processes. In this study, zwitterionic liposomes containing tyrosol, hydroxytyrosol and oleuropein were synthesized and characterized for their size and surface charge. Particular attention was devoted to the determination of encapsulation efficiency (EE%), quantifying the loaded Tyr, HTyr and Ole amount, by using three different techniques: direct UV spectrophotometry, High Performance Liquid Chromatography and Trolox Equivalent Antioxidant Capacity assay. The results revealed higher EE% for oleuropein. Cyto-toxicity and cyto-compatibility of liposomes were also tested on human chondrocyte cells.

Topics: Acetates; Antioxidants; Catechols; Cells, Cultured; Chondrocytes; Dietary Supplements; Drug Delivery Systems; Humans; Iridoid Glucosides; Iridoids; Liposomes; Olea; Phenylethyl Alcohol

Esophageal cancer (EC) is among the severest cancers causing most fatalities around the world with an increasing incidence. Oleuropein exhibits anti-tumor properties in several human cancers. We aimed to investigate the effect of oleuropein in human EC, and to reveal the molecular target involved in EC tumorigenesis. Cell proliferation, migration and invasion assays were performed to assess the effect of oleuropein on EC cells. A xenograft tumor mouse model was utilized to assess the in vivo effect of oleuropein. Hypoxia-inducible factor-1α (HIF1α) and B-cell translocation gene 3 (BTG3) expressions were examined in oleuropein-treated EC cells. The regulatory effect of HIF1α on BTG3 mRNA was evaluated by chromatin immunoprecipitation and luciferase reporter assays. Oleuropein inhibited the growth of EC cells and xenograft EC tumor, as well as inhibiting HIF1α and upregulating BTG3 expressions. BTG3 mRNA expression was under hypoxia inhibition through the HRE in its promoter region. BTG3 knockdown abolished the inhibitory effect of oleuropein on EC cells in vitro, as well as on EC xenograft tumor in vivo. Oleuropein inhibits EC tumorigenesis through hypoxic suppression of BTG3 mRNA, supporting the clinical application of oleuropein, and HIF1α and BTG3 mRNA as potential molecular targets in treatment against EC.

Topics: Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Esophageal Neoplasms; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; Hypoxia-Inducible Factor 1; Iridoid Glucosides; Iridoids; Proteins; RNA Interference; RNA, Messenger

This study aims to develop and evaluate oleuropein loaded surface functionalized folate-targeted - PEG liposomes for the effective management of prostate cancer in an animal model.. Film hydration-cum-extrusion technique was used to produce liposomes. Particle size, entrapment efficiency, drug loading, electron microscopy, and drug release study were performed for the characterization. Cell viability and various in vitro studies (phosphatidylserine internalization, TUNEL assay, measurement of mitochondrial membrane potential and caspase-3 assay) were performed to compare the anticancer and apoptotic effects of developed liposomes against the plain oleuropein. Comparative pharmacokinetic profiling and anticancer efficacy studies including a change in tumor volume, body weight, and survival analysis were performed in mice model.. The developed liposomes (OL-FML) showed the particle size of 184.2 ± 9.16 nm, the zeta potential of 1.41 ± 0.24 mV, entrapment efficiency of 63.52 ± 4.15% and drug loading of 21.31 ± 2.37%. OL-FML showed higher in vitro anti-proliferative effect and apoptosis on 22Rv1 cells. In vivo pharmacokinetic study revealed a nearly 6 fold increase in the bioavailability of OL-FML (AUC. The study provides conclusive evidence for the utilization of combining passive and active targeting strategy to enhance the anticancer effect of OL.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Survival; Disease Models, Animal; Drug Liberation; Folic Acid; Humans; Iridoid Glucosides; Iridoids; Liposomes; Male; Mice; Mice, Inbred BALB C; Particle Size; Prostatic Neoplasms

'Brava' and 'Mansa de Figueiredo' extra-virgin olive oils (EVOOs) are two varieties identified from north-western Spain. A systematic phenolic characterization of the studied oils was undertaken by LC-ESI-IT-MS. In addition, the role of dietary polyphenols from these EVOOs has been evaluated against the inhibition of key enzymes (α-glucosidase and α-amylase) in the management of diabetes mellitus (DM). Oleuropein and ligstroside derivatives comprised 83% and 67% of the total phenolic compounds in 'Brava' and 'Mansa de Figueiredo' EVOOs, respectively. The main secoiridoids from oleuropein were DOA (3,4-DHPEA-EDA, 59 and 22 mg kg

Topics: Aldehydes; alpha-Amylases; alpha-Glucosidases; Cyclopentane Monoterpenes; Diabetes Mellitus, Type 2; Flavonoids; Glucosides; Glycoside Hydrolase Inhibitors; Hypoglycemic Agents; Iridoid Glucosides; Iridoids; Olive Oil; Phenols; Plant Extracts; Pyrans; Spain

More and more studies show that inflammation, pain and insomnia have become the main common diseases. Effective treatments of inflammation, pain and insomnia have become an issue of primary concern in clinical practice. Oleuropein (OLE), the main phenolic component of Mediterranean extra virgin olive oil, has shown many pharmacological properties. In the present study, the anti-inflammatory effect of OLE was firstly evaluated using RAW264.7 macrophages subjected to stimulation with lipopolysaccharide (LPSC). The results obtained revealed that OLE caused significant and dose-dependent downregulation of nitric (NO), COX-2, inducible NO synthase iNOS, and the inflammation-associated cytokines IL-6 and TNF-α. From the mechanism, the expression of COX-2, cytokines IL-6 and TNF-α OLE is closely related to analgesic and sedation effect. Further evaluations showed significant analgesic and sedative effects of OLE in tail-flick test and sedation test conducted in SD rats in vivo. All these results indicate that OLE has anti-inflammatory, analgesic and sedative effects both in vitro and in vivo.

Topics: Analgesics; Animals; Anti-Inflammatory Agents, Non-Steroidal; Cell Survival; Cyclooxygenase 2; Hypnotics and Sedatives; Interleukin-6; Iridoid Glucosides; Iridoids; Ketamine; Lipopolysaccharides; Mice; Nitric Oxide; Nitric Oxide Synthase Type II; Olea; Rats, Sprague-Dawley; RAW 264.7 Cells; Tail; Tumor Necrosis Factor-alpha; Up-Regulation

Topics: Iridoid Glucosides; Iridoids; Phenylethyl Alcohol

Acrylamide and phenolic compounds on both fresh and cooked olives were monitored by HPLC/MS-MS and reversed-phase-HPLC methods along different procedures: elaboration process, high hydrostatic pressure (HHP), cooking treatment and bioavailability evaluation. Acrylamide was not detected during the elaboration process and after HHP treatment. Hydroxytyrosol, tyrosol, oleuropein and verbascoside were the most important phenols after HHP treatment. The frying and baking processes on olives enhanced the formation of acrylamide and a significant reduction in the phenolic compounds. The frying process produced lower acrylamide concentration and less reduction of phenolic compounds than the baking process, while in the gastrointestinal digestion these compounds were slightly reduced if compared to the initial stage. As a conclusion, the best way to ingest high quantities of phenols and reduce acrylamide consumption is by ingesting the olives when they are fresh. In case the olives need to be cooked, specific time and temperature conditions shall be applied.

Topics: Acrylamide; Chromatography, High Pressure Liquid; Chromatography, Reverse-Phase; Cooking; Hydrostatic Pressure; Iridoid Glucosides; Iridoids; Olea; Olive Oil; Phenols; Phenylethyl Alcohol; Tandem Mass Spectrometry

Oleuropein belongs to the potent polyphenols of olive oil. Notably, it is considered as a potentially active anticancer agent. Herein, the anticancer efficiency of oleuropein, when used separately and in combination with the chemotherapeutic agent, 2-methoxyestradiol (2-ME), was investigated in highly metastatic osteosarcoma (OS) cells.. Human OS cells (143B OS cell line) were incubated with oleuropein and 2-ME, alone or in combination. Cell viability was determined by the MTT assay. Cell migration assays were used in order to determine the anti-migratory potential of the compounds, while their impact on autophagy was evaluated via the LC3-antibody-based detection assay. The interaction between oleuropein and 2-ME was determined via the CalcuSyn software.. Both anti-migratory and anti-proliferative effects of oleuropein were demonstrated on human OS cells. Anticancer effects of oleuropein were significantly enhanced after 2-ME addition. Treatment of 143B OS cell with oleuropein, alone or in combination with 2-ME resulted in induction of autophagy.. The obtained data suggest an anticancer effect of oleuropein, alone and in combination with 2-ME, on highly metastatic 143B OS cells. Notably, a synergism between oleuropein and 2-ME towards 143B OS cells was detected. The exact mechanism of this synergism needs to be further investigated; nonetheless, induction of nitro-oxidative stress and/or induction of autophagy are suggested.

Topics: 2-Methoxyestradiol; Antineoplastic Agents; Bone Neoplasms; Cell Line, Tumor; Cell Movement; Cell Survival; Drug Synergism; Humans; Iridoid Glucosides; Iridoids; Olive Oil; Osteosarcoma

While both maturity and light exposure are important factors determining olive fruit physiology, the relationship between maturity, canopy position and optimal harvesting time has not been well-studied. To understand the interaction of these factors, olive fruits from upper and lower layers of the canopy were harvested from September to January. Maturity, moisture and fat content of the fruit as well as the quality and minor components of the oil extracted were measured.. Lower light interception at the lower canopy positions resulted in differences in the fruits and oil extracted between canopy layers. Upper layer presented 60% of the overall production; fruit had one unit more of maturity index, 3% less moisture and 5% more fat content. Oil extracted from the upper layers presented higher concentration of oleuropein and ligstroside aglycone. Fruits from upper layers at maturity index of two had higher fat content and more total phenols in the oil extracted when compared with fruits from lower layer with the same maturity index.. Differences in oil composition between layers do not correlate with differences in the fruit maturity index; instead, fruit position is a determining factor for physiological processes related to fruit growth and oil composition. © 2019 Society of Chemical Industry.

Topics: Fruit; Iridoid Glucosides; Iridoids; Naphthols; Olea; Olive Oil; Phenols

Olive leaves contain higher amount of polyphenols than olive oil and represent a waste product from olive harvest and pruning of olive trees. The most abundant compound in olive leaves is oleuropein. Benefits of the topical application of olive leaves extract were previously reported, but little information is available on its photoprotective potential and the result of the association of this extract with organic UV filters in topical sunscreen formulations. The olive leaves extract photoprotective potential is less explored for both oral and topical photoprotection in comparison with other plants extracts and polyphenols, such as Polypodium leucotomos extract and resveratrol. There are increasing efforts towards developing more efficient sunscreens and a photoprotection assessement along with a better understanding of the photochemistry of naturally occurring sunscreens could aid the design of new and improved commercial sunscreen formulations. This study was designed to investigate the photoprotective potential of olive leaves extract standardized for oleuropein performing a set of in vitro and in silico tools as an innovative approach, highlighting yeast assays, in vitro Sun Protection Factor (SPF) and molecular modelling studies of UV absorption. This study supports the use of olive leaves extract for photoprotection, as an effective photoprotective, anti-mutagenic and antioxidant active, also showing a synergistic effect in association with UV filters with an improvement on in vitro SPF of sunscreen formulations.

Topics: Antioxidants; Iridoid Glucosides; Iridoids; Models, Molecular; Olea; Plant Extracts; Plant Leaves; Quantum Theory; Sun Protection Factor; Sunscreening Agents; Ultraviolet Rays

The present study aimed to evaluate the effects of oleuropein on ligature-induced alveolar bone loss. In this respect, osteoblastic activity, osteoclastic activity, inflammatory markers, and apoptosis were evaluated.. Oleuropein is a flavonoid, which has potent anti-inflammatory and bone-protective effects.. Thirty-two Wistar rats were divided into four experimental groups as following: control (C, n = 8) group; periodontitis (P, n = 8) group; periodontitis and low-dose oleuropein group (12 mg/kg/day oleuropein, LDO group, n = 8); and periodontitis and high-dose oleuropein group (24 mg/kg/day oleuropein, HDO group, n = 8). Periodontitis was induced via ligatures. Study period was 14 days, and animals were sacrificed at end of this period. Mandibles were examined via a stereomicroscope and underwent histological procedures. Osteoblast, tartrate-resistant acid phosphatase (TRAP)-positive osteoclast, and inflammatory cell counts were determined in hematoxylin-eosin stained sections. Inducible nitric oxide synthase (iNOS), bone morphogenetic protein-4, the cluster of differentiation (CD)-68, cysteine-aspartic proteases-3 (Caspase 3), and B-cell lymphoma-2 (Bcl-2) expressions were evaluated via immunohistochemistry.. Periodontitis group had highest alveolar bone loss, and these levels significantly decreased in LDO and HDO groups. Both 12 and 24 mg/kg oleuropein groups significantly increased osteoblast cell counts and decreased TRAP-positive osteoclast and inflammatory cell counts. BMP-4 and bcl-2 expressions were elevated in oleuropein groups while caspase-3 expressions decreased. iNOS and CD68 were higher in periodontitis group compared to control group, but there was no significant difference between other groups.. Oleuropein successfully decreased alveolar bone loss as a result of decreased osteoclastic activity, inflammation, and apoptosis and increased osteoblastic activity.

Topics: Alveolar Bone Loss; Animals; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Apoptosis; Bone Morphogenetic Protein 4; Caspase 3; Female; Inflammation; Iridoid Glucosides; Iridoids; Nitric Oxide Synthase Type II; Osteoblasts; Osteoclasts; Periodontitis; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Wistar; Tartrate-Resistant Acid Phosphatase

Breast cancer (BC) is one of the most common cancers among women worldwide. Genetic, epigenetic, and environmental factors play a crucial role in BC development. Because epigenetic imbalance occurs earlier than expression in carcinogenesis and is reversible, epigenetic reprogramming strategies could be more useful for cancer prevention and therapy. There is evidence indicating that the use of herbal compounds with low toxicity can offer a real benefit in the prevention or treatment of cancer. Oleuropein (OLE), as a natural polyphenol, has shown the anticancer property in cancers. In this study, we investigated for the first time the link between histone deacetylase (HDAC) and OLE to have an anticancer effect in BC. The potential apoptotic and anti-invasive effects of OLE were tested using MCF-7 cells. Transcript expression of HDAC1 and HDAC4 genes after treatment was determined using quantitative reverse transcription polymerase chain reaction. OLE obviously reduced invasiveness and cell viability and simultaneously induced cell apoptosis in MCF-7 cancer cells. Dose-dependent reduction of HDAC4 was observed, whereas apparent changes could not be observed in HDAC1 expression. The current research indicated that OLE can inhibit proliferation and invasion of cells by inducing apoptosis likely through modulation of an important epigenetic factor, HDAC4, in MCF-7 cells. OLE has the potential to be a therapeutic drug for BC prevention and treatment.

Topics: Anti-Infective Agents; Antineoplastic Agents, Phytogenic; Apoptosis; Cell Movement; Cell Proliferation; Dose-Response Relationship, Drug; Drug Repositioning; Female; Gene Expression Regulation, Neoplastic; Histone Deacetylase 1; Histone Deacetylases; Humans; Iridoid Glucosides; Iridoids; MCF-7 Cells; Repressor Proteins; Signal Transduction

Olive leaves have become a promising source of phenolic compounds and flavonoids with high added value. Phenolic compounds and flavonoids are important sources of antioxidants and bioactives, and one of the processes used to effectively produce them is extraction via solvents, using aqueous ethanol solutions. To obtain the highest extraction yield per kg of biomass, olive leaves were extracted using a conventional technique (dynamic maceration) and an emerging technology, such as pressurized liquid extraction. Studies of the factors that influence these processes were performed: temperature, leaf moisture content, solvent/solid, and aqueous ethanol concentration were optimized using the central composite and Box-Behnken experiment designs. Pressurized liquid extraction resulted in more efficient oleuropein and luteolin-7-O-glucoside extraction than dynamic maceration. The operational conditions for maximizing the recovery of phenolic compounds and flavonoids and antioxidant capacity were determined to be 190 °C, leaf moisture content of 5%, and aqueous ethanol concentration of 80%.

Topics: Antioxidants; Chromatography, High Pressure Liquid; Flavones; Flavonoids; Glucosides; Iridoid Glucosides; Iridoids; Olea; Phenols; Plant Extracts; Plant Leaves; Solvents; Temperature

Glioblastoma (GBM) is the most prevalent and deadliest subtype of glioma. Despite current innovations in existing therapeutic modalities, GBM remains incurable, and alternative therapies are required. Previously, we demonstrated that

Topics: Antineoplastic Agents, Alkylating; Antineoplastic Agents, Phytogenic; Brain Neoplasms; Cell Line, Tumor; Cell Proliferation; Cell Survival; Glioblastoma; Humans; Iridoid Glucosides; Iridoids; MicroRNAs; Olea; Plant Extracts; Plant Leaves; Temozolomide

Polyphenols are constituents of all higher plants. However, their biosynthesis is often induced when plants are exposed to abiotic stresses, such as drought. The aim of the present work was to determine the phenolic status in the roots of olive trees grown under water deficit conditions. The results revealed that roots of water-stressed plants had a higher content of total phenols. The main compound detected in well-watered olive tree roots was verbascoside. Oleuropein was established as the predominant phenolic compound of water-stressed plants. The oleuropein/verbascoside ratio varied between 0.31 and 6.02 in well-watered and water-stressed plants respectively, which could be a useful indicator of drought tolerance in olive trees. Furthermore, this study is the first to provide experimental evidence showing that luteolin-7-rutinoside, luteolin-7-glucoside and apigenin-7-glucoside were the dominant flavonoid glucosides in olive tree roots and showed the most significant variations under water stress.

Topics: Antioxidants; Apigenin; Droughts; Flavonoids; Glucosides; Iridoid Glucosides; Iridoids; Olea; Phenol; Phenols; Phenylethyl Alcohol; Plant Extracts; Plant Leaves; Plant Roots; Polyphenols; Spectrophotometry, Ultraviolet; Stress, Physiological; Water

Oleuropein, as an olive leaf extract antioxidant polyphenol, has been reported to be a free radical scavenger. This study was done to investigate the effects of oleuropein, against morphine-induced hippocampus neurotoxicity and memory impairment in rats. The Morris water maze (MWM) test was used to assess the effect of oleuropein (5, 15, and 30 mg/kg, i.p., co-administrated with morphine) on spatial learning and memory of male Wistar rats which were treated with morphine sulfate (45 mg/kg, s.c., 4 weeks). In order to evaluate the cleaved caspase-3, Bax, and Bcl2 protein expression (as biochemical markers of apoptosis) in CA1 area of hippocampus tissue, the western blot test was used. Also, to evaluate the oxidative stress status of hippocampus CA1 area tissue, the malondialdehyde (MDA) level, superoxide dismutase (SOD) activity, and glutathione peroxidase (GPx) activity were assessed. The data showed that oleuropein treatment (15 and 30 mg/kg) improves the spatial learning and memory impairments in morphine-treated animals. Also, oleuropein treatment decreased the apoptosis and oxidative stress levels in the hippocampus CA1 area of morphine-treated rats. Oleuropein can prevent the spatial learning and memory impairments in morphine-treated rats. Molecular mechanisms underlying the observed effects could be at least partially related to the inhibition of neuronal apoptosis and oxidative stress in the hippocampus CA1 area of morphine-treated rats.

Topics: Animals; Antioxidants; CA1 Region, Hippocampal; Glutathione Peroxidase; Iridoid Glucosides; Iridoids; Male; Maze Learning; Memory Disorders; Morphine; Neurotoxicity Syndromes; Oxidative Stress; Rats, Wistar; Spatial Learning; Superoxide Dismutase

Here, we evaluated the possible protective effects of oleuropein, the major phenolic constituent in virgin olive oil against glycerol-induced acute kidney injury (AKI) in rats.. Twenty-eight Sprague Dawley rats were allocated equally into four groups as follows: control group, oleuropein group (50 mg/kg body weight), AKI group and the oleuropein + AKI group. AKI was induced by injecting 50% glycerol (10 ml/kg body weight) intramuscularly.. Glycerol injection increased the kidney relative weight as well as rhabdomyolysis (RM)- and AKI-related index levels, including the levels of creatine kinase, lactate dehydrogenase, creatinine, urea, and Kim-1 expression. Additionally, alteration in oxidative conditions in renal tissue was recorded, as confirmed by the elevated malondialdehyde and nitric oxide levels and the decreased glutathione content. Concomitantly, the protein and mRNA expression levels of antioxidant enzymes were suppressed. Moreover, Nfe2l2 and Hmox1 mRNA expression was also downregulated. Glycerol triggered inflammatory reactions in renal tissue, as evidenced by the increased pro-inflammatory cytokines and Ccl2 protein and mRNA expression, whereas myeloperoxidase activity was increased. Furthermore, glycerol injection enhanced apoptotic events in renal tissue by increasing the expression of the pro-apoptotic proteins and decreasing that of anti-apoptotic. However, oleuropein administration reversed the molecular, biochemical, and histological alterations resulting from glycerol injection.. Our data suggest that oleuropein has potential as an alternative therapy to prevent or minimize RM incidence and subsequent development of AKI, possibly due to its potent anti-stress, anti-inflammatory, and anti-apoptotic effects.

Topics: Acute Kidney Injury; Animals; Antioxidants; Apoptosis; Cell Adhesion Molecules; Creatine Kinase; Creatinine; Glutathione; Glycerol; Inflammation; Iridoid Glucosides; Iridoids; Kidney; Male; Malondialdehyde; Nitric Oxide; Oxidation-Reduction; Oxidative Stress; Peroxidase; Rats; Rats, Sprague-Dawley; Rhabdomyolysis

A large spectrum of beneficial health properties has been attributed to olive leaves. This study was undertaken to characterize the bioactive compounds of commercial olive leaf extracts and olive leaves and their infusions. High variability of bioactive compounds was found among commercial samples. Polyphenol was detected in a range of 44-108 g kg

Topics: Diffusion; Iridoid Glucosides; Iridoids; Olea; Plant Extracts; Plant Leaves; Polyphenols

Breast Cancer (BC) is the leading cause of cancer-related deaths among women. As such, novel chemotherapeutic agents are urgently needed, especially for Triple-Negative Breast Cancer (TNBC). Hydroxytyrosol (HT) and Oleuropein (OL) are rich in olive oil, which is associated with a low occurrence of BC. However, the effects and mechanisms of action of HT and OL in BC cells are still unclear. This study aimed to explore the molecular mechanisms underlying the antitumor effect of HT and OL in TNBC.. TNBC MDA-MB-231 cells were treated with HT and OL in combination with Hepatocyte Growth Factor (HGF), rapamycin (Rapa, an inducer of autophagy) or 3-methyladenine (3-MA, an inhibitor of autophagy). Cell viability, migration, invasion, and autophagy signaling were analyzed by scratch assays, transwell migration assays, and Western blot analysis.. Treatment with HT or OL reduced MDA-MB-231 cell viability in a dose-dependent manner. MDAMB- 231 cells were more sensitive to HT treatment than OL treatment. Rapa treatment could significantly block HGF-induced MDA-MB-231 cell migration and invasion, suggesting that inhibition of autophagy could promote migration and invasion. Moreover, HT or OL treatment significantly suppressed HGF or 3-MA induced cell migration and invasion by reversing LC3-II/LC3-I and Beclin-1 downregulation and reversing p62 upregulation.. These data indicated that HT and OL may inhibit migration and invasion of TNBC cells by activating autophagy. These findings provide potential therapeutic strategies that target autophagy to limit the pathogenesis and progression of BC.

Topics: Antineoplastic Agents; Autophagy; Autophagy-Related Proteins; Cell Line, Tumor; Cell Movement; Cell Survival; Gene Expression; Humans; Iridoid Glucosides; Iridoids; Neoplasm Invasiveness; Phenylethyl Alcohol; Triple Negative Breast Neoplasms

Fatty acids, phenolic compounds, and tocopherols of Coratina, Bosana, Semidana, and Tonda di Cagliari virgin olive oils, were measured over a 45-day harvest period. Phenolic composition was the primary factor distinguishing Bosana, Tonda di Cagliari, and Semidana, whereas fatty acids differentiated Coratina and the other cultivars. Harvest period principally influenced oleacein, oleocanthal, oleuropein and ligstroside aglycones, and flavonoids. High phenolic content was observed for Coratina (1039-688 mg/kg) and Bosana (788-592 mg/kg). A drastic decrease in phenolic content was observed in Semidana (529-134 mg/kg) and Tonda di Cagliari (507-142 mg/kg) during the harvest period. These two cultivars also had low MUFA/PUFA (6.0-4.0 and 4.9-3.2 respectively), suggesting that these varieties should be harvested earlier in the season. These results provide information to producers for improved management of the harvesting process, which is strongly affected by varietal factors.

Topics: Agriculture; Aldehydes; Cyclopentane Monoterpenes; Fatty Acids; Flavonoids; Food Analysis; Glucosides; Iridoid Glucosides; Iridoids; Italy; Olea; Olive Oil; Phenols; Pyrans; Species Specificity; Tocopherols

Olive (Olea europaea) is a rich source of valuable bioactive polyphenols, which has attracted widespread interest. In this study, we combined targeted metabolome, Pacbio ISOseq transcriptome, and Illumina RNA-seq transcriptome to investigate the association between polyphenols and gene expression in the developing olive fruits and leaves. A total of 12 main polyphenols were measured, and 122 transcripts of 17 gene families, 101 transcripts of 9 gene families, and 106 transcripts of 6 gene families that encode for enzymes involved in flavonoid, oleuropein, and hydroxytyrosol biosynthesis were separately identified. Additionally, 232 alternative splicing events of 18 genes related to polyphenol synthesis were analyzed. This is the first time that the third generations of full-length transcriptome technology were used to study the gene expression pattern of olive fruits and leaves. The results of transcriptome combined with targeted metabolome can help us better understand the polyphenol biosynthesis pathways in the olive.

Topics: Alternative Splicing; Biosynthetic Pathways; Flavonoids; Fruit; Gene Expression Regulation, Plant; Iridoid Glucosides; Iridoids; Olea; Phenylethyl Alcohol; Plant Leaves; Polyphenols; Sequence Analysis, DNA; Transcriptome

Glutamate-induced neurotoxicity is related to excessive oxidative stress accumulation and results in the increase of neuronal cell death. In addition, glutamate has been reported to lead to neurodegenerative diseases, including Parkinson's and Alzheimer's diseases.It is well known that Fraxinus rhynchophylla contains a significant level of oleuropein (Ole), which exerts various pharmacological effects. However, the mechanism of neuroprotective effects of Ole is still poorly defined. In this study, we aimed to investigate whether Ole prevents glutamate-induced toxicity in HT-22 hippocampal neuronal cells. The exposure of the glutamate treatment caused neuronal cell death through an alteration of Bax/Bcl-2 expression and translocation of mitochondrial apoptosis-inducing factor (AIF) to the cytoplasm of HT-22 cells. In addition, glutamate induced an increase in dephosphorylation of dynamin-related protein 1 (Drp1), mitochondrial fragmentation, and mitochondrial dysfunction. The pretreatment of Ole decreased Bax expression, increased Bcl-2 expression, and inhibited the translocation of mitochondrial AIF to the cytoplasm. Furthermore, Ole amended a glutamate-induced mitochondrial dynamic imbalance and reduced the number of cells with fragmented mitochondria, regulating the phosphorylation of Drp1 at amino acid residue serine 637. In conclusion, our results show that Ole has a preventive effect against glutamate-induced toxicity in HT-22 hippocampal neuronal cells. Therefore, these data imply that Ole may be an efficient approach for the treatment of neurodegenerative diseases.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Cell Death; Cell Line; Dynamins; Fraxinus; Gene Expression Regulation; Glutamic Acid; Hippocampus; Iridoid Glucosides; Iridoids; Mice; Mitochondria; Mitochondrial Diseases; Neurodegenerative Diseases; Neurons; Neuroprotective Agents; Oxidative Stress; Phosphorylation; Proto-Oncogene Proteins c-bcl-2

The number and variety of bitter compounds originating from plants are vast. Whereas some bitter chemicals are toxic and should not be ingested, other compounds exhibit health beneficial effects, which is manifest in the cross-cultural believe that the bitterness of medicine is correlated with the desired medicinal activity. The bitter taste receptors in the oral cavity serve as sensors for bitter compounds and, as they are expressed in numerous extraoral tissues throughout the body, may also be responsible for some physiological effects exerted by bitter compounds. Chinese herbal medicine uses bitter herbs since ancient times for the treatment of various diseases; however, the routes by which these herbs modify physiology are frequently not well understood. We therefore screened 26 bitter substances extracted from medical herbs for the activation of the 25 human bitter taste receptors. We identified six receptors activated by in total 17 different bitter compounds. Interestingly, we observed a bias in bitter taste receptor activation with 10 newly identified agonists for the broadly tuned receptor TAS2R46, seven agonists activating the TAS2R14 and two compounds activating narrowly tuned receptors, suggesting that these receptors play dominant roles in the evaluation and perhaps physiological activities of Chinese herbal medicines.

Topics: Calcium; Dose-Response Relationship, Drug; Fibroblasts; HEK293 Cells; Humans; Iridoid Glucosides; Iridoids; Medicine, Chinese Traditional; Plant Extracts; Plants, Medicinal; Receptors, G-Protein-Coupled; Triterpenes

Post-traumatic stress disorder (PTSD) is a condition that develops after an individual has experienced a major trauma. This psychopathological response to traumatic stressors induces learning and memory deficits in rats. Oleuropein (OLE), a major compound in olive leaves, has been reported to possess several pharmacological properties, including anti-cancer, anti-diabetic, anti-atherosclerotic and neuroprotective activities. However, the cognitive effects of OLE and its mechanism of action have remained unclear in PTSD. In this study, we examined whether OLE improved spatial cognitive impairment induced in rats following single prolonged stress (SPS), an animal model of PTSD. Male rats were treated intraperitoneally (i.p.) with vehicle or various doses of OLE for 14 consecutive days after the SPS procedure. The SPS procedure resulted in cognitive impairment in the object recognition task and the Morris water maze test, which was reversed by OLE (100 mg/kg, i.p). Additionally, as assessed by immunohistochemistry and reverse transcription-polymerase chain reaction analysis, the administration of OLE significantly alleviated memory-associated decreases in the levels of brain-derived neurotrophic factor and cAMP response element-binding protein and mRNA in the hippocampus. Together, these findings suggest that OLE attenuated SPS-induced cognitive impairment significantly by inhibiting the expression of pro-inflammatory mediators in the rat brain. Thus, OLE reversed several behavioral impairments triggered by the traumatic stress of SPS and might be a potential useful therapeutic intervention for PTSD.

Topics: Animals; Brain-Derived Neurotrophic Factor; Cognition; Cytokines; Disease Models, Animal; Hippocampus; Iridoid Glucosides; Iridoids; Male; Rats; Rats, Sprague-Dawley; Stress Disorders, Post-Traumatic; Vasodilator Agents

Olive leaves are rich in polyphenolic compounds that are known to have antioxidant, antimicrobial, and anti-inflammatory activities. Therefore, olive leaf extract (OLE) is considered as a natural supplement. In this study we evaluated the antibacterial and the anti-inflammatory effect of OLE and its individual phenolic components in vitro. Polymorphonuclear cells (PMNCs) were isolated from the whole blood using Histopaque solution and cultured in RPMI-enriched medium. Tumor necrosis factor α (TNFα) level was determined by ELISA after 24 h of lipopolysaccharide stimulation. The antibacterial activity of OLE was determined by well diffusion assay. We found a significant decrease in TNFα secretion level in PMNCs culture treated with OLE. Oleuropein is the only OLE component that has shown anti-inflammatory effects at a concentration of 20 μg/mL. Furthermore, OLE exhibited antibacterial activity against some gram positive bacterial strains; however, gram negative bacterial strains were resistant to OLE. Downregulation of TNFα secretion in PMNCs culture in response to OLE treatment indicates that this polyphenol-rich extract has an anti-inflammatory effect, and oleuropein is the major OLE component responsible for this effect. The antibacterial activity of OLE is limited to gram positive bacteria.

Topics: Anti-Bacterial Agents; Anti-Inflammatory Agents, Non-Steroidal; Cell Survival; Cells, Cultured; Dietary Supplements; Disk Diffusion Antimicrobial Tests; Drug Resistance, Bacterial; Escherichia coli; Food Preservatives; Humans; Iridoid Glucosides; Iridoids; Lipopolysaccharides; Neutrophils; Olea; Osmolar Concentration; Plant Extracts; Plant Leaves; Pseudomonas aeruginosa; Staphylococcus; Tumor Necrosis Factor-alpha

The effect of the composition of twelve varieties of extra virgin olive oils (EVOOs) on their differentiation based in agronomic criteria and on the antioxidant capacity was studied. Principal component analysis permitted an overview of the samples and their compositions, showing evidence of grouping and correlation between antioxidant capacity, oleuropein and ligstroside derivatives (OLD) and specific extinction at 270. Oleic and linoleic acids, 3,4-DHPEA-EA and p-HPEA-EDA (OLD), unsaturated/saturated ratio and induction time (IT) allowed the correct classification of samples according to year of harvest, ripening stage and variety. The antioxidant capacity of EVOOs was satisfactory predicted through a partial least square model based on ΔK, hydroxytyrosol, pinoresinol, oleuropein derivate and IT. Validation of the model gave a correlation R>0.83 and an error of 7% for independent samples. This model could be a useful tool for the olive industry to highlight the nutritional quality of EVOOs and improve their marketing.

Topics: Agriculture; Antioxidants; Chile; Food Analysis; Furans; Glucosides; Iridoid Glucosides; Iridoids; Least-Squares Analysis; Lignans; Olive Oil; Phenylethyl Alcohol; Principal Component Analysis; Pyrans

A simple and very environmental friendly microwave assisted method to produce oleacein in good yield starting from the easily available oleuropein is here presented. The methodology is proposed to produce the appropriate amount of hydroxytyrosol derivatives to enrich a commercial oil for an oil which provides beneficial effects on the human health.

Topics: Aldehydes; Food Additives; Humans; Iridoid Glucosides; Iridoids; Phenols; Phenylethyl Alcohol; Plant Oils

Oleuropein, the main constituents of leaves and fruits of the olive tree, has been demonstrated to exert various therapeutic and pharmacological properties including antidiabetic effect. However, the effectiveness of oleuropein on glucose homeostasis in intact rat skeletal muscle ex vivo has never been explored. Therefore, our current study was carried out to investigate and confirm the beneficial effect of oleuropein (1.5 mM) on glucose uptake and on parameters relevant to the normal homeostatic mechanisms of glucose regulation in rat skeletal muscle. For this purpose, soleus muscles were incubated for 12 hr without (control) or with oleuropein, in the presence or absence of AMP-activated protein kinase (AMPK) inhibitor, compound C, or wortmannin, an inhibitor of phosphatidylinositol kinase. Oleuropein-stimulated glucose transport, plasmalemmal glucose transporter 4 (GLUT4), and phosphorylation of phosphatidylinositol kinase and AMPK were examined. We observed that oleuropein treatment enhanced glucose transport, GLUT4 translocation, and AMPK phosphorylation. The oleuropein-stimulated glucose uptake and GLUT4 translocation were inhibited by compound C and were not affected by wortmannin. These results suggest that increased glucose uptake induced by oleuropein might be mediated through activation of AMPK and the subsequent increase in GLUT4 translocation in skeletal muscles.

Topics: Animals; Glucose; Glucose Transporter Type 4; Homeostasis; Hypoglycemic Agents; Insulin; Iridoid Glucosides; Iridoids; Male; Rats; Rats, Wistar

Many studies reported that air pollution particulate matter (PM) exposure was associated with myocardial infarction (MI). Acrolein representing the unsaturated aldehydes, the main component of PM, derives from the incomplete combustion of wood, plastic, fossil fuels and the main constitute of cigarette smoking. However, the effect of acrolein on MI remains not that clear. In the current study, the effect of acrolein-exacerbated MI was investigated. In vivo, male Sprague-Dawley rats received olive leaf extract (OLE) followed by acrolein, then isoprenaline (ISO) was received by subcutaneous injection to induce MI. Results showed that the expression levels of GRP78 and CHOP, two major components of endoplasmic reticulum (ER) stress were higher in the combination of acrolein and ISO than those in ISO treatment. The apoptosis marker, Bax, was also higher while the anti-apoptosis indicator, Bcl2 expression was lower both at protein and mRNA levels in the combination group. Also, the acrolein-protein adducts and myocardial pathological damage increased in the combination of acrolein and ISO relative to the ISO treatment. Besides, cardiac parameters, ejection fraction (EF) and fractional shortening (FS) were reduced more significantly when acrolein was added than in ISO treatment. Interestingly, all the changes were able to be ameliorated by OLE. Since hydroxytyrosol (HT) and oleuropein (OP) were the main components in OLE, we next investigated the effect of HT and OP on cardiomyocyte H9c2 cell apoptosis induced by acrolein through ER stress and Bax pathway. Results showed that GRP78, CHOP and Bax expression were upregulated, while Bcl2 expression was downregulated both at the protein and mRNA levels, when the H9c2 cells were treated with acrolein. In addition, pretreatment with HT can reverse the expression of GRP78, CHOP, Bax and Bcl2 on the protein and mRNA levels, while there was no effect of OP on the expression of GRP78 and CHOP on the mRNA levels. Overall, all these results demonstrated that OLE and the main components (HT and OP) could prevent the negative effects of acrolein on myocardium and cardiomyocytes.

Topics: Acrolein; Animals; Apoptosis; Biological Products; Biomarkers; Cell Line; Cytoprotection; Disease Progression; Endoplasmic Reticulum Stress; Iridoid Glucosides; Iridoids; Isoproterenol; Male; Myocardial Infarction; Myocytes, Cardiac; Particulate Matter; Phenylethyl Alcohol; Rats; Rats, Sprague-Dawley

Oleuropein, ligstroside, and related hydrolysis products are key contributors to olive bitterness, and several of these phenolics are implicated in the prevention of lifestyle age-related diseases. While table olive processing methods are designed to reduce oleuropein, the impact of processing on ligstroside and related hydrolysis products (e.g., oleacein, oleocanthal, hydroxytyrosol glucoside, ligstroside aglycone, and oleuropein aglycone) is relatively unknown. Herein, levels of these compounds were measured in Spanish-style green (SP), Californian-style black ripe (CA), and Greek-style natural fermentation (GK) olives using rapid ultrahigh-performance liquid chromatography (UHPLC) tandem mass spectrometry (MS/MS). GK olives had the highest concentration of all compounds measured, with the exception of oleocanthal, which was highest in SP olives (0.081 mg kg

Topics: California; Chromatography, High Pressure Liquid; Fermentation; Food Handling; Fruit; Greece; Humans; Iridoid Glucosides; Iridoids; Molecular Structure; Olea; Phenols; Spain; Tandem Mass Spectrometry; Taste

Hydroxytyrosol (HT), a powerful antioxidant, clears free radicals and exhibits many biological activities. Because contents of HT are low in natural sources, bioconversion of oleuropein (OLE) to HT is of increasing interest. A biotechnological process was investigated to produce HT from OLE presented in olive leaf extract. Enzymatic hydrolysis using two cellulases with high β-glucosidase activity, Novozymes CTec2 and commercial cellulase KDN (Qingdao, People's Republic of China) was carried out at 50 °C for 12 H followed by raising the temperature to 90 °C for chemical hydrolysis. After 48 H of hydrolysis, an OLE degradation rate of 100% and a HT yield of 86-88% were achieved. These cellulases degrade OLE and release a glucose molecule. Chemical hydrolysis at a high temperature promotes the cleavage of ester bond and the formation of HT. This process has a promising alternative for production of HT comparing with acid hydrolysis which not only causes significant pollution to the environment but also makes difficult to the subsequent separation.

Topics: Antioxidants; Enzymes; Esters; Hot Temperature; Hydrolysis; Iridoid Glucosides; Iridoids; Olea; Phenylethyl Alcohol; Plant Extracts; Plant Leaves

This study aimed to identify the effects of olive leaf extract (OLE) on IFNγ, TNFα, TGFβ and nitric oxide (NO) resulted from macrophages infected with Leishmania major (L. major) amastigotes in the culture medium. High-performance liquid chromatography (HPLC) was used to analyse the level of Oleuropein in plant extract. To evaluate the immunomodulatory effects of OLE, the isolated BALB/c mice peritoneal macrophages were infected with L. major promastigotes and treated with 6.25, 12.5 and 25 μg/mL concentrations of OLE. To assess the cytokines, supernatants of cell cultures were harvested after 12, 24 and 48 hours. Cytokine production was evaluated by ELISA. Nitrite accumulation in the culture medium was assessed using the Griess reaction. The level of Oleuropein in the extract was 18.45% by HPLC. According to results, the production of IFNγ and TNFα was significantly increased when the infected and/or not infected macrophages with L. major promastigotes were affected by different concentrations of OLE. Conversely, the production of TGFβ was significantly decreased under the same conditions. Furthermore, the colorimetric determination of NO accumulation in the culture medium indicated that OLE has no effect on NO production. The study corroborates the immunomodulatory effects of OLE on L. major-infected macrophages.

Topics: Animals; Chromatography, High Pressure Liquid; Interferon-gamma; Iridoid Glucosides; Iridoids; Leishmania major; Leishmaniasis, Cutaneous; Macrophages; Male; Mice; Mice, Inbred BALB C; Nitric Oxide; Olea; Plant Extracts; Transforming Growth Factor beta1; Tumor Necrosis Factor-alpha

Oleuropein is considered as a new chemotherapeutic agent in human hepatocellular carcinoma (HCC) while, its exact underlying molecular mechanism still not yet explored. In addition, cisplatin is a standard anticancer drug against solid tumors with toxic side effects. Therefore, we conducted this study to assess antitumor activity of oleuropein either alone or in combination with cisplatin against HepG2, human HCC cell lines, via targeting pro-NGF/NGF signaling pathway.. HepG2 cells were treated with cisplatin (20, 50, 100 μM) and oleuropein (100, 200, 300 and 400 μM) as well as some of the cells were treated with 50 μM cisplatin and different concentrations of oleuropein. Gene expressions of nerve growth factor (NGF), matrix metalloproteinase-7 (MMP-7) and caspase-3 were evaluated by real time-PCR. In addition, protein levels of NGF and pro-form of NGF (pro-NGF) were measured by ELISA while, nitric oxide (NO) content was determined colorimetrically.. Cisplatin treatment showed a significant elevation of NO content and pro-NGF protein level with a marked reduction of NGF protein level in addition to the upregulation of caspase-3 along with downregulation of MMP-7 gene expressions in a dose-dependent manner. However, the combination of 50 μM cisplatin and 200 μM oleuropein showed the most potent effect on the molecular level when compared with oleuropein or cisplatin alone.. Our results showed for the first time that the anti-tumor activity of oleuropein against HCC could be attributed to influencing the pro-NGF/NGF balance via affecting MMP-7 activity without affecting the gene expression of NGF. Concurrent treatment with both oleuropein and cisplatin could lead to more effective chemotherapeutic combination against HCC.

Topics: Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Carcinoma, Hepatocellular; Caspase 3; Cell Line, Tumor; Cell Proliferation; Cisplatin; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Hep G2 Cells; Humans; Iridoid Glucosides; Iridoids; L-Lactate Dehydrogenase; Liver Neoplasms; Matrix Metalloproteinase 7; Nerve Growth Factor; Oxidative Stress; Signal Transduction

This study reports novel food-grade granules for co-delivery of L. plantarum 299v and a standardized extract of Olea europaea leaves (Phenolea®) as oral carrier of probiotics and hydroxytyrosol. Different granule formulations containing either L. plantarum 299v (Lac), or the olive leave extract (Phe) or their combination (Lac-Phe) have been successfully produced through wet granulation employing excipients generally regarded as safe as granulating/binding agents. L. plantarum cells withstood the manufacturing process and were stable upon storage at 4 °C for more than 6 months. In vitro dissolution studies in simulated gastro-intestinal fluids showed the capability of the granules to rapidly dissolve and deliver both olive leave phenols and living L. plantarum cells. In simulated digestion conditions, Lac and Lac-Phe granules protected L. plantarum against the harsh environment of the gastro-intestinal tract. Co-administration of Lac and Phe oral granules to healthy mice provided for higher amounts of hydroxytyrosol in urines as compared to Phe granules alone, suggesting that L. plantarum 299v boosted in vivo conversion of oleuropein to hydroxytyrosol. On the other hand, PCR-assisted profiling of the Lactobacillus population in faeces obtained from mice treated with Lac or Lac plus Phe confirmed that the probiotic arrived alive to colon and was there able to exert a sort of perturbing effect on the climax colonic microflora. Overall, these results pave the way towards the development of a nutraceutical useful for combined delivery of bioactive hydroxytyrosol and probiotics to colon site.

Topics: Administration, Oral; Animals; Bile; Drug Carriers; Drug Liberation; Feces; Gastric Juice; Iridoid Glucosides; Iridoids; Lactobacillus plantarum; Male; Mice; Olea; Phenylethyl Alcohol; Plant Extracts; Plant Leaves; Probiotics

Ligustrum lucidum secoiridoid glucosides have been demonstrated to treat various types of diseases such as inflammation, pain, hepatotoxicity and hyperlipidermic as well as tonic for liver and kidney. Matrix metalloproteinases (MMPs) play a key role upon the pathology of photoaging. The present computational study showed that among the six secoiridoid glucosides (ligustroside, lucidumoside A, lucidumoside C, neonuezhenide, oleoside dimethylester, and oleuropein), ligustroside and lucidumoside A competitively inhibit all MMP-1, MMP-3, and MMP-9 activities in the docking models. The molecular docking analysis revealed a network of interactions between MMP-1, MMP-3, and MMP-9 and the ligands; ligustroside and lucidumoside A, and oxygen-containing and hydrophobic functional groups appear to be responsible for these enhanced interactions. The effect of ligustroside and lucidumoside A on the transcription factor AP-1 action was also investigated using molecular docking and dynamics simulations. The experiments suggested that inhibition of an AP-1-DNA complex formation could be on account of the direct interference of AP-1 binding onto the DNA binding sequence by ligustroside and lucidumoside A. The results suggest that both compounds have the highest potential for application as an anti-aging agent with the MMP inhibitory and anti-transcriptional activities.

Topics: DNA; Humans; Iridoid Glucosides; Iridoids; Ligustrum; Matrix Metalloproteinase 1; Matrix Metalloproteinase 3; Matrix Metalloproteinase 9; Matrix Metalloproteinases; Models, Molecular; Molecular Docking Simulation; Protein Binding; Transcription Factor AP-1

Bisphenol A (BPA) can disturb the endocrine system and the organs that respond to endocrine signals in organisms, indirectly exposed during prenatal and/or early postnatal life. The present study was designed to assess the protective effect of phenolic compounds from olive leaves against BPA induced thyroid dysfunction and growth perturbation in young rats during lactation. The BPA disrupting effect on thyroid function was investigated by measuring changes in plasma levels of thyroid hormones. Free triiodothyronine (FT3) and thyroxine (FT4) were decreased in young rats breast-fed from mothers treated with bisphenol A. This effect was associated with an increase in the plasma level of thyroid-stimulating hormone (TSH). The histological and immunohistochemical study of the thyroid gland revealed a disturbance in morphological structure and thyroid cells function. Thyroid dysfunction led to a disruption in the skeletal bone growth of young rats. In fact, the infrared microspectroscopic analysis and histological examination of femoral bone showed significant changes in their histoarchitecture associated with a perturbation in the mechanism of bone tissue mineralization. The administration of oleuropein or hydroxytyrosol in BPA treated lactating mothers improved the thyroid cells function by enhancing thyroid hormone levels. Moreover, these phenolics increased the body growth characterized by an amelioration in the structure and the microstructure of femoral bone tissue. HPLC analysis of rats-breast milk indicated the presence of oleuropein and hydroxytyrosol, which could contribute to the protective effect against bisphenol A induced hypothyroidism in pups rats.

Topics: Animals; Animals, Suckling; Benzhydryl Compounds; Endocrine Disruptors; Female; Hypothyroidism; Iridoid Glucosides; Iridoids; Lactation; Olea; Phenols; Phenylethyl Alcohol; Plant Leaves; Protective Agents; Rats; Thyroid Hormones

Olive tree is one of the most valuable crops cultivated for its oil that is rich in antioxidants. The beneficial effects of oleuropein and hydroxytyrosol (HT), the most abundant and the most powerful antioxidant respectively, as well as tyrosol, HT's precursor molecule, are well studied however their biosynthetic pathways are not yet clarified. The transcriptome analysis of the young olive fruit, cultivar "Koroneiki", revealed transcripts of all the enzymes used to reconstitute the biosynthetic pathway of tyrosol and HT in other organisms. We also identified transcripts of the genes that encode for enzymes involved in the secologanin biosynthesis, oleuropein's precursor molecule. Following the transcriptome analysis, the relative expression of the transcripts was monitored during fruit development and compared to the concentration of the 3 metabolites they synthesize at the same developmental stages. The highest expression levels, accompanied by the maximum concentration of the three metabolites, was found in the young olive fruit. The correlation between the expression profile and the metabolites' concentration indicates that the transcripts were correctly identified and the synthesis of the compounds is regulated at a transcriptional level. Interestingly, HT showed a sudden increment in the final developmental stage of the black mature fruit that is attributed to oleuropein catabolism.

Topics: Fruit; Gene Expression Regulation, Plant; Genes, Plant; Iridoid Glucosides; Iridoids; Olea; Phenylethyl Alcohol

Age-associated diseases such as neurodegenerative and cardiovascular disorders are characterized by increased oxidative stress associated with autophagy dysfunction. Oleuropein aglycone (OA), the main polyphenol found in olive oil, was recently characterized as an autophagy inducer and a promising agent against neurodegeneration. It is presently unknown whether OA can have beneficial effects in a model of cardiac stress characterized by autophagy dysfunction. Here, we explored the effects of OA in cardiomyocytes with overexpression of monoamine oxidase-A (MAO-A). This enzyme, by degrading catecholamine and serotonin, produces hydrogen peroxide (H

Topics: Animals; Autophagy; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; Cell Nucleus; Iridoid Glucosides; Iridoids; Microscopy, Fluorescence; Monoamine Oxidase; Myocytes, Cardiac; Protective Agents; Rats; Reactive Oxygen Species; RNA Interference; RNA, Small Interfering; Tyramine

Studies have shown that oleuropein has antifungal, anti‑inflammatory, antiviral, antioxidant, anticancer and hypoglycemic functions. TTC solution staining was used to measure myocardial infarction size. A commercial kit was used to measure lactate dehydrogenase (LDH), creatinine kinase‑MB (CK‑MB), tumor necrosis factor‑α (TNF‑α), interleukin‑1β (IL‑1β), IL 6, superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA) and catalase levels. Western blot analysis was used to measure p53, p-MEK p-ERK and p‑IκBα protein expression. The present study reports that the protective effect of oleuropein also prevents against myocardial ischemia/reperfusion (myocardial I/R). The aim of this retrospective study was to evaluate this protective effect of oleuropein and the mechanisms by which myocardial I/R is prevented. Oleuropein inhibited myocardial infarction size, CK‑MB and LDH serum levels in a myocardial I/R rat model. Moreover, oleuropein also attenuated caspase‑3 activity, and p53, phosphorylated (p)‑mitogen‑activated protein kinase kinase (MEK), p‑extracellular signal‑regulated protein kinase (ERK) and p‑IκBα protein expression. TNF‑α, IL‑1β, IL‑6 and MDA were decreased; SOD, GSH and catalase levels inhibited TNF‑α, IL‑1β, IL-6 and MDA levels, and increased SOD, GSH and catalase levels in myocardial I/R rats treated with oleuropein. Rats orally administered the MEK inhibitor PD0325901, in addition to oleuropein, exhibited inhibited myocardial infarction size, CK‑MB and LDH serum levels compared with rats treated with oleuropein only. Rats treated with MEK inhibitor also exhibited suppressed caspase‑3 activity, p53, p‑MEK p‑ERK and p‑IκBα protein expression, TNF‑α, IL‑1β, IL‑6, SOD, GSH, MDA and catalase levels, and induced p‑signal transducer and activator of transcription 3 (STAT3) protein expression compared with rats treated with oleuropein only. Taken together, these results suggest that MEK/ERK/STAT3 signaling regulates the inhibition of myocardial I/R in rats treated with oleuropein.

Topics: Animals; Cardiotonic Agents; Iridoid Glucosides; Iridoids; Male; MAP Kinase Signaling System; Myocardial Reperfusion Injury; Myocardium; Rats, Sprague-Dawley; Signal Transduction; STAT3 Transcription Factor

In the present study, we investigated the protective effects of oleuropein- and hydroxytyrosol-rich extracts obtained from olive leaves against bisphenol A (BPA)-induced hyperlipidemia and liver injury in male rats. For this purpose, four groups of male rats (8 per group) were used: control group (Control), rats treated with BPA, rats treated with both BPA and oleuropein (OLE-BPA), and rats treated with both BPA and hydroxytyrosol (HYT-BPA). After 60 days of treatment, the results obtained using the DXA technique showed that treatment with BPA (10 mg per kg b.w.) increased the body weight and adipose tissue mass in male rats. Moreover, plasma levels of triglycerides, total cholesterol, LDL-cholesterol, AST, ALT, LDH, and TNF-α increased. The immunohistochemical analysis revealed a significant increase in the expression of COX-2 and p53 and a decrease in the expression of Bcl-2 related to liver inflammation. Oral administration of oleuropein and hydroxytyrosol-rich extracts obtained from olive leaves at 16 mg kg-1 reduced both the body weight and adipose tissue mass. These extracts were able to ameliorate liver damage and improve the elevated levels of TG and liver enzymes of BPA-treated rats possibly through enhancing CAT and SOD activities. Western blot results revealed that administration of the abovementioned extracts decreased the protein expression of NF-κB and TNF-α through the p38 signaling pathway. Overall, the findings suggest that the olive leaf extracts possess hypolipidemic and hepatoprotective effects against BPA-induced metabolic disorders through enhancing the antioxidative defense system and regulating the important signaling pathway activities.

Topics: Animals; Antioxidants; Benzhydryl Compounds; Humans; Iridoid Glucosides; Iridoids; Lipid Metabolism; Liver Diseases; Male; Olea; Phenols; Phenylethyl Alcohol; Plant Extracts; Plant Leaves; Rats

Hepatotoxicity induced by cyclophosphamide (Cyclo) is a major concern in clinical practice. This study was designed to investigate the possible cytoprotective effect of natural antioxidants as oleuropein and quercetin against Cyclo induced hepatotoxicity via the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway. Male Wistar rats were randomly divided into six groups and treated for 10 days as follow: Group I (Normal control) received saline, group II (Oleu control): received orally oleuropein 30 mg/kg/day, group III (Quer control): administered orally quercetin 50 mg/kg/day, group IV (Cyclo): received saline and injected with single intraperitoneal (i.p) dose of Cyclo 200 mg/kg at day 5, group V (Oleu ttt): treated with oleuropein plus Cyclo i.p. injection at day 5, and group VI (Quer ttt): treated with quercetin plus Cyclo i.p. injection at day 5. Injection of Cyclo showed marked increase in serum transaminases and alkaline phosphatase, hepatic malondialdehyde (MDA) and tumor necrosis factor-alpha (TNF-⍺) levels along with significant reduction in hepatic reduced glutathione (GSH), superoxide dismutase (SOD), and catalase levels in addition to downregulation of hepatic Nrf2 and HO-1 expressions and reduction in hepatic nuclear Nrf2 binding activity when compared with normal group. Histopathological examination of Cyclo treated rats revealed hepatic damage. Both oleuropein and quercetin exhibited an improvement in the biochemical and histopathological findings. In conclusion, the natural antioxidants oleuropein and quercetin counteract the Cyclo induced hepatotoxicity through activation of Nrf2/HO-1 signaling pathway with subsequent suppression of oxidative stress and inflammation.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Biological Products; Chemical and Drug Induced Liver Injury; Cyclophosphamide; Disease Models, Animal; Heme Oxygenase-1; Humans; Iridoid Glucosides; Iridoids; Liver; Male; NF-E2-Related Factor 2; Oxidative Stress; Quercetin; Rats; Rats, Wistar; Signal Transduction

Breast cancer (BC) is the leading cause of cancer mortality in women worldwide. It recently was proven that miRNAs play a critical role in BC development. The use of natural agents for control of cancer by modulating miRNAs is promising. Oleuropein is a natural polyphenolic agent with anti-neoplastic properties and is well tolerated by humans. This study was undertaken to determine the therapeutic effects of oleuropein through modulation of master oncomiRs (miR-21 and miR-155) in BC cells. The present study provides the first link between miRNA and oleuropein as a mechanism in BC. MCF-7 cells were tested with and without oleuropein and the cell viability, apoptosis, and migration were examined. The effect of oleuropein on miR-21 and miR-155 expression was assessed through qRT-PCR. It was found that oleuropein induced apoptosis and retarded cell migration and invasion in a dose-dependent manner in the human MCF7 BC cell line. It was observed that oleuropein significantly decreased expression of both miR-21 and miR-155 over time in a dose-dependent manner. These results demonstrate that oleuropein is a potential therapeutic and preventive agent for BC. Oleuropein exhibits an anti-cancer effect by modulation of tumor suppressor gene expression, which is targeted by oncomiRs.

Topics: Analysis of Variance; Apoptosis; Breast Neoplasms; Cell Movement; Cell Survival; Down-Regulation; Female; Gene Expression Regulation, Neoplastic; Humans; Iridoid Glucosides; Iridoids; MCF-7 Cells; MicroRNAs; Neoplasm Invasiveness

Airway inflammation has been implicated in evoking progressive pulmonary disorders including chronic obstructive pulmonary disease (COPD) and asthma as a result of exposure to inhaled irritants, characterized by airway fibrosis, mucus hypersecretion, and loss of alveolar integrity. The current study examined whether oleuropein, a phenylethanoid found in olive leaves, inhibited pulmonary inflammation in experimental models of interleukin (IL)-4-exposed bronchial BEAS-2B epithelial cells and ovalbumin (OVA)- or cigarette smoke (CS)-exposed BALB/c mice. Nontoxic oleuropein at 1-20 μM diminished eotaxin-1-mediated induction of α-smooth muscle actin and mucin 5AC in epithelial cells stimulated by IL-4 at the transcriptional levels. Oral supplementation of 10-20 mg/kg oleuropein reduced the airway influx of eosinophils and lymphocytes as well as IL-4 secretion in lung promoted by OVA inhalation or CS. In addition, oleuropein suppressed infiltration of macrophages and neutrophils through blocking OVA inhalation- and CS-promoted induction of ICAM-1, F4/80, CD68, and CD11b in airways. OVA-exposed pulmonary fibrosis was detected, while alveolar emphysema was evident in CS-exposed mouse lungs. In alveolar epithelial A549 cells exposed to CS extracts, oleuropein attenuated apoptotic cell loss. Collectively, oleuropein inhibited pulmonary inflammation leading to asthmatic fibrosis and alveolar emphysema driven by influx of inflammatory cells in airways exposed OVA or CS. Therefore, oleuropein may be a promising anti-inflammatory agent for treating asthma and COPD.

Topics: Animals; Apoptosis; Asthma; Cigarette Smoking; Emphysema; Humans; Immunoglobulin E; Interleukin-4; Iridoid Glucosides; Iridoids; Male; Mice; Mice, Inbred BALB C; Pneumonia

Oleuropein (OLE), a main constituent of olive, exhibits antioxidant and hypolipidemic effects, while it reduces the infarct size in chow- and cholesterol-fed rabbits. Peroxisome proliferator-activated receptor α (PPARα) has essential roles in the control of lipid metabolism and energy homeostasis. This study focused on the mechanisms underlying the hypolipidemic activity of OLE and, specifically, on the role of PPARα activation in the OLE-induced effect. Theoretical approach using Molecular Docking Simulations and luciferase reporter gene assay indicated that OLE is a ligand of PPARα. The effect of OLE (100 mg/kg, p.o., per day, ×6 weeks) on serum triglyceride (TG) and cholesterol levels was also assessed in adult male wild-type and Ppara-null mice. Molecular Docking Simulations, Luciferase reporter gene assay and gene expression analysis indicated that OLE is a PPARα agonist that up-regulates several PPARα target genes in the liver. This effect was associated with a significant reduction of serum TG and cholesterol levels. In contrast, OLE had no effect in Ppara-null mice, indicating a direct involvement of PPARα in the OLE-induced serum TG and cholesterol reduction. Activation of hormone-sensitive lipase in the white adipose tissue (WAT) and the liver of wild-type mice and up-regulation of several hepatic factors involved in TG uptake, transport, metabolism and clearance may also contribute in the OLE-induced TG reduction. In summary, OLE has a beneficial effect on TG homeostasis via PPARα activation. OLE also activates the hormone sensitive lipase in the WAT and liver and up-regulates several hepatic genes with essential roles in TG homeostasis.

Topics: Adipose Tissue, White; Animals; Cells, Cultured; Hepatocytes; Homeostasis; Iridoid Glucosides; Iridoids; Lipids; Luciferases; Male; Mice, Inbred Strains; Mice, Mutant Strains; Molecular Docking Simulation; Olea; PPAR alpha; Proprotein Convertase 9; Receptors, LDL; Triglycerides

Current chemotherapy drugs for pancreatic cancer only offer an increase in survival of up to six months. Additionally, they are highly toxic to normal tissues, drastically affecting the quality of life of patients. Therefore, the search for novel agents, which induce apoptosis in cancer cells while displaying limited toxicity towards normal cells, is paramount. The olive biophenols, oleuropein, hydroxytyrosol and tyrosol, have displayed cytotoxicity towards cancer cells without affecting non-tumorigenic cells in cancers of the breast and prostate. However, their activity in pancreatic cancer has not been investigated. Therefore, the aim of this study was to determine the anti-pancreatic cancer potential of oleuropein, hydroxytyrosol and tyrosol. Pancreatic cancer cells (MIA PaCa-2, BxPC-3, and CFPAC-1) and non-tumorigenic pancreas cells (HPDE) were treated with oleuropein, hydroxytyrosol and tyrosol to determine their effect on cell viability. Oleuropein displayed selective toxicity towards MIA PaCa-2 cells and hydroxytyrosol towards MIA PaCa-2 and HPDE cells. Subsequent analysis of Bcl-2 family proteins and caspase 3/7 activation determined that oleuropein and hydroxytyrosol induced apoptosis in MIA PaCa-2 cells, while oleuropein displayed a protective effect on HPDE cells. Gene expression analysis revealed putative mechanisms of action, which suggested that c-Jun and c-Fos are involved in oleuropein and hydroxytyrosol induced apoptosis of MIA PaCa-2 cells.

Topics: Apoptosis; Apoptosis Regulatory Proteins; Cell Cycle; Cell Line, Tumor; Humans; Iridoid Glucosides; Iridoids; Neoplasm Proteins; Olea; Pancreatic Neoplasms; Phenylethyl Alcohol

Olive leaf extract is a rich source of phenolic compounds and oleuropein which is well-known regarding its antioxidant and antimicrobial attributes. However, the mentioned phenolic compounds will lose their beneficial properties during storage and induce undesirable aftertaste in food products. In this study, olive leaf extract-bearing nanoliposomes were produced via the ethanol injection method and using phosphatidyl choline plus cholesterol as the reagents for the wall material. Later, the prepared nanocarriers were examined in regard to their zeta potential, stability, encapsulation efficiency, and particle size. Moreover, the prepared nanoliposome-loaded yogurt samples were examined considering syneresis, antioxidant activity, pH, acidity, color, and sensorial properties. The mean particle size of the fabricated nanoliposomes was in the range of 25-158 nm. Also, the entire formulation had a negative charge. The encapsulation efficiency was between 70.7 to 88.2%. Besides, the application of nanoliposomes in yogurt improved the antioxidant activity, and unlike the yogurt with nonencapsulated olive extract, no significant changes in color and sensorial attributes were observed and even the syneresis rate was minimized. To conclude, olive leaf phenolics can be entrapped within nanoliposomes with a considerable encapsulation efficiency for application in food products like yogurt to increase their nutritional value and public acceptance.

Topics: Antioxidants; Food Additives; Humans; Hydrogen-Ion Concentration; Iridoid Glucosides; Iridoids; Liposomes; Olea; Particle Size; Phenols; Plant Extracts; Plant Leaves; Taste; Yogurt

Olives and olive oil, a key food type of the Mediterranean diets, are packed with various important polyphenols including oleuropein (OLE), hydroxytyrosol (HTY) and tyrosol (TYR). OLE and HTY are highly powerful antioxidants and play a prime role in the therapeutics of free radical-related diseases. Their molecular stabilities and antioxidant properties can be improved by cyclodextrin (CD) encapsulation. Here, we present a systematic investigation on the inclusion complexes of β-CD-TYR (1), β-CD-HTY (2) and β-CD-OLE (3) by combined single-crystal structure determination, DFT complete-geometry optimization and DPPH antioxidant assay. X-ray analysis and DFT calculation reveal the preference of inclusion geometry with deep protrusion of the aromatic ring moieties of TYR, HTY and OLE from the β-CD O6-H-side, and the common host-guest stabilization scheme via intermolecular O-H⋯O hydrogen bonding interactions. No polyphenol OH group is shielded in the β-CD cavity, in contrast to the structures of β-CD-tea catechins complexes. The established host-guest O-H⋯O hydrogen bonds help to elevate antioxidant capacities of the olive polyphenols upon β-CD encapsulation. The order of antioxidant activity 2 >3 ≫ 1 based on the DPPH measurement is in fair agreement with their relative thermodynamic stabilities derived from DFT calculation.

Topics: beta-Cyclodextrins; Crystallography, X-Ray; Free Radical Scavengers; Hydrogen Bonding; Iridoid Glucosides; Iridoids; Models, Chemical; Molecular Structure; Phenylethyl Alcohol; Quantum Theory; Structure-Activity Relationship; Thermodynamics

In the present study, the aerial parts of the Laperrine olive (Olea europaea subsp. Laperrinei) are subjected to acid extraction and the chemical composition of the extracts is determined by HPLC-DAD. The main compounds found in all of extracts are: hydroxytyrosol (30.45%), tyrosol (0.69%), oleuropein (32.76%), ferrulic acid (17.77%), quercetin (31.57%) and hesperetin (6.90%).The extracts obtained from the leafy stems of Laperrine olive tree are tested on the moth Ephestia kuehniella flour. Their administration by inhalation of newly exuviated chrysalises extends the duration of nymphalid development and disturbs the exuviated adults reproduction, by reducing the period in which the eggs are being laid. Thus, compared to the control insects, the number of eggs laid by treated females is significantly reduced after the treatment by extracts. Besides, the administration of different extracts of adult butterflies has a premature mortality effect.

Topics: Animals; Chromatography, High Pressure Liquid; Female; Hesperidin; Insecticides; Iridoid Glucosides; Iridoids; Larva; Moths; Olea; Phenylethyl Alcohol; Plant Extracts; Plant Leaves; Quercetin

Chronic hyperalgesia and allodynia associated with progressive damage of peripheral neurons are the most prevalent complications of diabetes mellitus. Plants belonging to the family of Oleaceae were traditionally used in folk medicine for the management of diabetes.. The aim of this study was to investigate whether an aqueous extract from the leaves of Ligustrum vulgare (common privet) could be useful to target neuropathic pain in a rat streptozotocin (STZ) model of diabetes.. The chemical composition of the aqueous extract from privet leaf was characterized with the UHPLC-DAD-MS method and the analytical quantification of its constituents was performed with HPLC-DAD. Mechanical hyperalgesia and allodynia were evaluated with the Randall-Selitto and von Frey tests.. Our investigation revealed the presence of secoiridoids: oleacein (23.48 ± 0.87 mg/g), oleocanthal (8.44 ± 0.08 mg/g), oleuropein (1.50 ± 0.01 mg/g), as well as phenylpropanoids: echinacoside (6.46 ± 0.07 mg/g), verbascoside (4.03 ± 0.04 mg/g) and p-coumaroyl glucarates in the dried aqueous extract of privet leaves. Behavioral data indicated that chronic intraperitoneal administration of the extract (50-200 mg/kg) for 21 days resulted in a decrease in diabetes-induced hyperalgesia and allodynia. Blood glucose levels remained unaltered, while body weight and water intake decreased significantly.. The aqueous privet leaf extract could serve useful in facilitating treatment of painful diabetic neuropathy. Additionally, the study showed that the antihyperalgesic activity of Ligustrum vulgare leaf extract is not likely related to its antihyperglycemic properties.

Topics: Aldehydes; Animals; Chromatography, High Pressure Liquid; Cyclopentane Monoterpenes; Diabetes Mellitus, Experimental; Diabetic Neuropathies; Glucosides; Glycosides; Hyperalgesia; Iridoid Glucosides; Iridoids; Ligustrum; Male; Neuralgia; Phenols; Plant Extracts; Plant Leaves; Rats; Streptozocin

BACKGROUND In this study, we investigated the potential neuroprotective effect of oleuropein (OLE) on apoptotic changes via modulating Akt/glycogen synthase kinase 3 beta (Akt/GSK-3b) signaling in a rat model of cerebral ischemia/reperfusion injury (IRI). MATERIAL AND METHODS Sprague-Dawley male rats (12 weeks, n=200) were randomly assigned to 5 groups: sham group, vehicle (IRI+ vehicle) group, OLE (IRI+OLE) group, OLE+LY294002 (IRI+OLE+LY294002) group, and LY294002(IRI+LY294002) group. The rats were subjected to cerebral ischemia/reperfusion injury (IRI) model and treated once daily for 5 days with vehicle and OLE (100 mg/kg via intraperitoneal injection) after IRI injury. LY294002 (0.3 mg/kg) was intraperitoneally injected once at 30 min after IRI injury. Brain edema, neurological deficit, rotarod latencies, and Morris water maze (MWM) performance were evaluated after IRI. The number of dead cells were assayed by TUNEL staining. Western blot was used to detect the expression of Bcl-2, Bax, cleaved caspase-3 (CC3), neurotrophic factors, and the phosphorylation levels of Akt and GSK-3β. RESULTS Compared with the vehicle group, brain water content, neurological deficits, rotarod latencies, and escape latency following IRI were reduced in the OLE group. Cell apoptosis and reduced neurotrophic factor caused by IRI was also attenuated by OLE. Furthermore, increased p-Akt and decreased p-GSK-3β were caused by OLE, which were associated with decrease of Bax/Bcl-2 ratio and the suppression of Caspase-3 activity after IRI. Importantly, all the beneficial effects of OLE in the vehicle group were abrogated by PI3K inhibitor LY294002. CONCLUSIONS Cerebral ischemia was protected by OLE via suppressing apoptosis through the Akt/GSK-3β pathway and upregulating neurotrophic factor after IRI.

Topics: Animals; Apoptosis; Brain; Brain Ischemia; Disease Models, Animal; Glycogen Synthase Kinase 3 beta; Infarction, Middle Cerebral Artery; Iridoid Glucosides; Iridoids; Male; Neurons; Neuroprotective Agents; Oncogene Protein v-akt; Phosphatidylinositol 3-Kinases; Phosphorylation; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction

The biological activities of oleuropein (Ole) and its metabolites have been extensively documented and show a spectrum of highly interesting bioactivities, which demonstrates the potential of oleuropein for inclusion in food and beverages. In the present work, acetylated oleuropein (OleAc), a safe, biologically active semi-synthetic stable derivative of oleuropein, has been proposed as a facile alternative to make oleuropein more bioavailable and suitable for addition to fatty foods. Extra virgin olive oil (EVOO) has been proposed as a model of perishable food to evaluate the potential application of OleAc for the preparation of functional food and the impact of its formulation factors on the fragile nutritive components of EVOO. Both classical and ultrasound (US)-assisted enrichment procedures have been tested, and the evaluation of their effects on oil stability across time has been presented. Moreover, LC-MS analyses of hydrophilic extracts of target oils have been used to verify the stability of the acetylation of oleuropein over time after enrichment. Finally, a preliminary sensorial analysis has been performed in order to understand if this enrichment can result in oil taste modification. The present results are intended to provide preliminary support to meet the requirements of Novel Food status for OleAc.

Topics: Acetylation; Antioxidants; Chromatography, Liquid; Food Additives; Iridoid Glucosides; Iridoids; Magnetic Resonance Spectroscopy; Olive Oil; Plant Extracts; Plant Leaves; Polyphenols; Reactive Oxygen Species

Background Neurological deficits in hypoxic-ischemic encephalopathy, even with therapeutic hypothermia, are partially attributed to white matter injury. We theorized that proteasome insufficiency contributes to white matter injury. Methods and Results Neonatal piglets received hypoxia-ischemia ( HI ) or sham procedure with normothermia, hypothermia, or hypothermia+rewarming. Some received a proteasome activator drug (oleuropein) or white matter-targeted, virus-mediated proteasome knockdown. We measured myelin oligodendrocyte glycoprotein, proteasome subunit 20S (P20S), proteasome activity, and carbonylated and ubiquitinated protein levels in white matter and cerebral cortex. HI reduced myelin oligodendrocyte glycoprotein levels regardless of temperature, and myelin oligodendrocyte glycoprotein loss was associated with increased ubiquitinated and carbonylated protein levels. Ubiquitinated and carbonyl-damaged proteins increased in white matter 29 hours after HI during hypothermia to exceed levels at 6 to 20 hours. In cortex, ubiquitinated proteins decreased. Ubiquitinated and carbonylated protein accumulation coincided with lower P20S levels in white matter; P20S levels also decreased in cerebral cortex. However, proteasome activity in white matter lagged behind that in cortex 29 hours after HI during hypothermia. Systemic oleuropein enhanced white matter P20S and protected the myelin, whereas proteasome knockdown exacerbated myelin oligodendrocyte glycoprotein loss and ubiquitinated protein accumulation after HI . At the cellular level, temperature and HI interactively affected macroglial P20S enrichment in subcortical white matter. Rewarming alone increased macroglial P20S immunoreactivity, but this increase was blocked by HI . Conclusions Oxidized and ubiquitinated proteins accumulate with HI -induced white matter injury. Proteasome insufficiency may drive this injury. Hypothermia did not prevent myelin damage, protect the proteasome, or preserve oxidized and ubiquitinated protein clearance after HI .

Topics: Animals; Animals, Newborn; Asphyxia; Brain Ischemia; Cerebral Cortex; Gene Knockdown Techniques; Heart Arrest; Hypothermia; Hypoxia; Iridoid Glucosides; Iridoids; Leukoencephalopathies; Male; Myelin-Oligodendrocyte Glycoprotein; Proteasome Endopeptidase Complex; Random Allocation; Rewarming; Swine; White Matter

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by progressive enlargement of kidney cysts, leading to chronic kidney disease. Since the available treatment for ADPKD is limited, there is emerging interest for natural compounds as potential therapeutic candidates. The aim of our study was to investigate whether an olive leaf extract may be able to counteract the cyst growth in an in vitro model of ADPKD. We treated WT9-12 cells with an olive leaf extract (OLE). In monolayer culture we evaluated cell viability by the MTT assay, protein expression by western-blot analysis and apoptosis by DNA laddering and TUNEL assays. For functional studies we used transient transfection and ChIP assays. Intracellular calcium measurement was performed with a spectrofluorimeter using a fluorescent probe. 3D-cell-culture was used for cyst growth studies. OLE reduced the WT9-12 cell growth rate and affected intracellular signaling due to high c-AMP levels, as OLE reduced PKA levels, enhanced p-AKT, restored B-Raf-inactivation and down-regulated p-ERK. We elucidated the molecular mechanism by which OLE, via Sp1, transactivates the p21WAF1/Cip1 promoter, whose levels are down-regulated by mutated PKD1. We demonstrated that p-AKT up-regulation also played a crucial role in the OLE-induced anti-apoptotic effect and that OLE ameliorated intracellular calcium levels, the primary cause of ADPKD. Finally, using a 3D-cell-culture model we observed that OLE reduced the cyst size. Therefore, multifaceted OLE may be considered a new therapeutic approach for ADPKD treatment.

Topics: Apoptosis; Cell Line, Tumor; Cell Proliferation; Chromatin Immunoprecipitation; Cysts; Humans; In Situ Nick-End Labeling; Inhibitory Concentration 50; Iridoid Glucosides; Iridoids; Mitogen-Activated Protein Kinases; Olea; Plant Extracts; Plant Leaves; Polycystic Kidney, Autosomal Dominant; Promoter Regions, Genetic

Despite the evident influence of the cultivar on olive oil composition, few studies have been devoted to exploring the variability of phenols in a representative number of monovarietal olive oils. In this study, oil samples from 80 cultivars selected for their impact on worldwide oil production were analyzed to compare their phenolic composition by using a method based on LC-MS/MS. Secoiridoid derivatives were the most concentrated phenols in virgin olive oil, showing high variability that was significantly due to the cultivar. Multivariate analysis allowed discrimination between four groups of cultivars through their phenolic profiles: (i) richer in aglycon isomers of oleuropein and ligstroside; (ii) richer in oleocanthal and oleacein; (iii) richer in flavonoids; and (iv) oils with balanced but reduced phenolic concentrations. Additionally, correlation analysis showed no linkage among aglycon isomers and oleocanthal/oleacein, which can be explained by the enzymatic pathways involved in the metabolism of both oleuropein and ligstroside.

Topics: Aldehydes; Biological Variation, Population; Chromatography, Liquid; Cyclopentane Monoterpenes; Flavonoids; Glucosides; Iridoid Glucosides; Iridoids; Multivariate Analysis; Olea; Olive Oil; Phenols; Phytochemicals; Pyrans; Tandem Mass Spectrometry

The effect of a prophylactic oleuropein-rich diet before anesthesia accompanied by the widely-used steroid-based neuromuscular drug rocuronium on mast cell activation was investigated in the study.. 14 rabbits used in the study. The rabbits in the oleuropein group were given oleuropein-rich extract added to the animals' water at doses of 20 mg/kg oleuropein for 15 days orally. After 15 days, all rabbits in the two groups were given general anesthesia with rocuronium of 1 mg/kg. After 1 day, animals were sacrificed and the liver tissue sections stained with H&E, toluidine blue and tryptase for immunohistochemical study.. There was no statistically significant difference between ALT, AST and albumin averages of the oleuropein and control groups (p> 0.05). The tryptase average of the control group was higher than the tryptase average of the oleuropein group and this difference was statistically significant (p=0.003). The T. blue average in the oleuropein group was higher than the control group. However, there was no statistically significant difference between groups (p=0.482).. Rocuronium adverse effects, like hypersensitivity and anaphylaxis, may limit routine use of this substance. The use of oleuropein reduced the number of inflammatory cells and prevented degranulation.

Topics: Alanine Transaminase; Anesthesia, General; Animals; Anti-Inflammatory Agents; Aspartate Aminotransferases; Cell Aggregation; Cell Degranulation; Chromatography, High Pressure Liquid; Diet Therapy; Drug-Related Side Effects and Adverse Reactions; Immunohistochemistry; Iridoid Glucosides; Iridoids; Liver; Male; Mast Cells; Neuromuscular Nondepolarizing Agents; Pre-Exposure Prophylaxis; Rabbits; Random Allocation; Reproducibility of Results; Rocuronium; Serum Albumin

Topics: Antineoplastic Agents; Apoptosis; Cell Cycle; Cell Line, Tumor; Drug Resistance, Neoplasm; Humans; Iridoid Glucosides; Iridoids; Melanoma; Olea; Plant Extracts; Plant Leaves; Proto-Oncogene Proteins B-raf

Oleuropein (Ole) is one of the most plentiful phenolic compounds with antioxidant, anti-inflammatory, anti-atherogenic, hypoglycemic and hypolipidemic effects. The aim of our study was to establish whether the positive Ole-related effects on liver steatosis could be associated with autophagy. Female and male C57BL/6J mice were fed normal diet (ND) or high-fat diet (HFD) for eight weeks, and Ole was added or not for the following eight weeks. The autophagy-related proteins Akt, mTOR, AMPK, ULK1, Beclin-1, LC3B and p62/Sqstm1 were analyzed. Interestingly, Ole induced a different regulation of the Akt/mTOR pathway in female compared to male mice, but was able to activate the autophagic process in ND and HFD mice through AMPK-dependent phosphorylation of ULK1 at Ser555, regardless of the gender. Our work reveals the ability of Ole to induce, in liver of ND and HFD mice, autophagy independently by gender-specific mTOR activation. We highlight Ole as a novel therapeutic approach to counteract unhealthy diet-related liver steatosis by targeting autophagy.

Topics: AMP-Activated Protein Kinases; Animals; Apoptosis; Autophagy; Autophagy-Related Protein-1 Homolog; Caspase 3; Diet, High-Fat; Enzyme Activation; Female; Iridoid Glucosides; Iridoids; Liver; Male; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Proto-Oncogene Proteins c-bcl-2; Signal Transduction; TOR Serine-Threonine Kinases; Transcription, Genetic

Oleuropein mediates most of the beneficial effects of olive products. This study examined the role of oxidative stress in the effects of oleuropein on lipid profile and blood glucose in rats with simultaneous renovascular hypertension and type 2 diabetes. Eight groups (n = 7-9 each) of male Sprague-Dawley rats including a control, a type 2 diabetic, a renovascular hypertensive, a sham, a simultaneously hypertensive diabetic receiving vehicle, and 3 simultaneously hypertensive-diabetic receiving 20, 40, or 60 mg/kg/day oleuropein were used. Four weeks after treatment, blood glucose, lipid profile, and biomarkers of oxidative stress were measured, and glucose tolerance test (GTT) was performed. Simultaneously hypertensive diabetic rats had significantly higher blood pressure, blood glucose, and serum total cholesterol, low-density lipoprotein cholesterol (LDL-C), triglyceride and malondialdehyde. They also had lower serum high-density lipoprotein cholesterol, erythrocyte superoxide dismutase, and impaired glucose tolerance. Oleuropein significantly reduced blood pressure, blood glucose, and serum total cholesterol, LDL-C, triglyceride and malondoaldehyde. It also increased serum high-density lipoprotein cholesterol, erythrocyte superoxide dismutase, and improved glucose tolerance. The findings show that the model is associated with impaired glucose tolerance, and adverse lipid profile. They also show that oleuropein, partly by an antioxidant mechanism, improves glucose tolerance and changed lipid profile favorably.

Topics: Animals; Antioxidants; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Glucose Tolerance Test; Hypertension, Renal; Hypertension, Renovascular; Iridoid Glucosides; Iridoids; Lipids; Male; Malondialdehyde; Molecular Structure; Oxidative Stress; Rats; Rats, Sprague-Dawley; Streptozocin; Superoxide Dismutase

The solubilisation of polar and polyphenol antioxidant in vegetable oils was studied. It was shown that the use of a polyglyceryl-3-diisostearate (PG3DS), a bio-sourced emulsifier well known in cosmetics, increases the yield of solubilisation thanks to some aggregation properties analysed using x-ray scattering technique. We show indeed that PG3DS forms reverse aggregates with a critical concentration that depends on the oil polarity. PG3DS reverse aggregates are elongated with a polar core and cannot be really swollen by addition of water. This supramolecular organisation allows however an efficient solubilisation of polar antioxidants in vegetable oils.

Topics: Antioxidants; Benzhydryl Compounds; Cosmetics; Emulsifying Agents; Flavones; Glucosides; Glycerol; Humans; Iridoid Glucosides; Iridoids; Micelles; Phenylethyl Alcohol; Plant Oils; Solubility; Stearic Acids; Waxes

The influence of light exposure on the quality of commercially available extra-virgin olive oils (EVOOs) of different chemical composition was studied as a function of storage (11weeks) under conditions simulating market storage. By mildly stripping the polyphenols from oil 'A', with high levels of polyphenols and oleic acid, and oil 'B', exhibiting a medium level of polyphenols and a low level of oleic acid, 'C' and 'D' EVOOs were obtained. Ten EVOOs were produced as mixtures of these four oils. The initial concentrations of oleic acid and polyphenols in the 14 oils ranged from 64.5 to 77.7% and 18.1 to 1476.7mg/kg, respectively. The extinction coefficient K

Topics: alpha-Tocopherol; Food Storage; Iridoid Glucosides; Iridoids; Lighting; Oleic Acid; Olive Oil; Oxidation-Reduction; Polyphenols; Time Factors

Oleuropein is a primary phenolic compound found in olive leaf and Fraxinus rhynchophylla. Here, we investigated the impact of oleuropein on LPS-induced BV-2 microglial cells. Oleuropein suppressed the LPS-induced increase in pro-inflammatory mediators, such as nitric oxide, and pro-inflammatory cytokines, via inhibition of ERK/p38/NF-κB activation and reactive oxygen species (ROS) generation. Furthermore, it suppressed LPS-induced excessive mitochondrial fission, which regulates mitochondrial ROS generation and pro-inflammatory response by diminishing Drp1 dephosphorylation. Collectively, we demonstrated that oleuropein suppresses pro-inflammatory response of microglia by inhibiting Drp1-dependent mitochondrial fission. Our findings suggest a potential role of oleuropein in microglial inflammation-mediated neurodegenerative disorders.

Topics: Animals; Anti-Inflammatory Agents; Cell Line, Transformed; Cytokines; Dose-Response Relationship, Drug; Gene Expression Regulation; Intercellular Signaling Peptides and Proteins; Iridoid Glucosides; Iridoids; Lipopolysaccharides; Luminescent Proteins; MAP Kinase Signaling System; Mice; Microglia; Mitochondria; Mitochondrial Dynamics; Nerve Tissue Proteins; Nitric Oxide; Reactive Oxygen Species; RNA, Messenger; Transduction, Genetic

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Blood Pressure; Diet, Mediterranean; Humans; Hypertension; Iridoid Glucosides; Iridoids; Mice; Olea; Oxidative Stress; Parkinson Disease; Phenylethyl Alcohol; Rats

Previously, we reported that high-fat-diet (HFD)-induced obesity stimulates melanoma progression in the B16F10 allograft model. In this study, we examined whether oleuropein (OL), the most abundant phenolic compound in olives, inhibits HFD-induced melanoma progression. Four-week-old male C57BL/6N mice were fed a HFD-diet with or without OL. After 16 weeks of feeding, B16F10-luc cells were subcutaneously injected and the primary tumor was resected 3 weeks later. OL suppressed HFD-induced solid tumor growth. In the tumor tissues, OL reduced HFD-induced expression of angiogenesis (CD31, VE-cadherin, VEGF-A, and VEGFR2), lymphangiogenesis (LYVE-1, VEGF-C, VEGF-D, and VEGFR3), and hypoxia (HIF-1α and GLUT-1) markers as well as HFD-induced increases in lipid vacuoles and M2 macrophages (MΦs). All animals were euthanized 2.5 weeks after tumor resection. OL suppressed HFD-induced increases in lymph node (LN) metastasis; expression of VEGF-A, VEGF-C, and VEGF-D in the LN; and M2-MΦs and the size of adipocytes in adipose tissues surrounding LNs. Co-culture results revealed that the crosstalk between B16F10s, M2-MΦs, and differentiated 3T3-L1 cells under hypoxic conditions increased the secretion of VEGF-A and -D, which stimulated tube formation and migration of endothelial cells (HUVECs) and lymphatic endothelial cells (LEC), respectively. Additionally, OL directly inhibited the differentiation of 3T3-L1 preadipocytes and tube formation by HUVECs and LECs. The overall results indicated that dietary OL inhibits lipid and M2-MΦ accumulation in HFD-fed mice, which contributes to decreases in VEGF secretion, thereby leading to inhibition of angiogenesis and lymphangiogenesis.

Topics: Adipose Tissue; Allografts; Angiogenesis Inhibitors; Animals; Apoptosis; Cell Proliferation; Diet, High-Fat; Dietary Supplements; Hypoxia; Iridoid Glucosides; Iridoids; Lipid Metabolism; Lymphangiogenesis; Lymphatic Metastasis; Macrophages; Melanoma, Experimental; Mice; Neovascularization, Pathologic; Tumor Burden; Vascular Endothelial Growth Factors

Rheumatoid arthritis (RA) is a chronic and systemic inflammatory autoimmune disease mainly characterized by aggressive hyperproliferation of synovial fibroblasts (SFs). It is accompained by a massive infiltration of inflammatory immune cells inducing progressive matrix degradation, destruction of cartilage and bone erosion through the production of inflammatory mediators. Oleuropein is the most prevalent phenolic component in olive leaves, seed, pulp and peel of unripe olives and is responsible for the characteristic bitter taste of unprocessed olives. This secoiridoid possesses well-documented pharmacological properties, including antioxidant and anti-inflammatory properties, and is available as a food supplement in Mediterranean countries. However, to date, anti-arthritic effects of oleuropein on SFs have not been yet elucidated. Thus, the aim of the present study was to investigate the potential effects of oleuropein, on IL-1β-induced production of inflammatory mediators and oxidative stress in the human synovial sarcoma cell line (SW982). In order to gain a better insight into mechanisms of action, signaling pathways were also explored. Cell viability was determined using the sulforhodamine B (SRB) assay. The expression of inflammatory cytokines IL-6, TNF-α, MMP-1 and MMP-3 was evaluated by ELISA. Moreover, changes in the protein expression of cyclooxygenase (COX)-2, microsomal prostaglandin E synthase-1 (mPGES-1) as well as mitogen-activated protein kinase (MAPKs), nuclear factor kappa B (NF-κB), and nuclear factor-erythroid 2-related and heme oxygenase-1 (HO-1) signalling pathways were analysed by western blot. Oleuropein exerted anti-inflammatory and anti-oxidant effects via down-regulation of MAPK and NF-κB signaling pathways and induction of Nrf2-linked HO-1 controlling the production of inflammatory mediators decreasing IL-6 and TNF-α cytokines, MMP-1 and MMP-3 levels and mPGES-1 and COX-2 overexpression. Thus, oleuropein might provide a basis for developing a new dietary strategy for the prevention and management of RA.

Topics: Anti-Inflammatory Agents; Cell Line; Down-Regulation; Fibroblasts; Humans; Inflammation; Interleukin-1beta; Iridoid Glucosides; Iridoids; Oxidative Stress; Signal Transduction; Synovial Fluid; Tumor Necrosis Factor-alpha

The current systemic treatments of the various solid tumors involve Cisplatin (CIS)-based chemotherapy. Due to its cytotoxicity, this approach is limited. Moreover, the safety of CIS is only discussed especially in breast and stomach cancers. Therefore, we, for the first time, explored the restorative efficacy of oleuropein (OLE), in stomach and lung injuries induced by CIS. Sprague-Dawley rats were divided into eight groups: control CIS, OLE and CIS + OLE. Single dose of (7 mg/kg) CIS was administered intraperitoneally to CIS and CIS + OLE groups. After 24 h, 50, 100 and 200 mg/kg OLE was given for three consecutive days to OLE and CIS + OLE groups. The 8-OH-dG, total oxidative/antioxidant status (TOS/TAS) and malondialdehyde (MDA) levels were evaluated and histopathological analyses were performed on the studied tissues. The results indicated that CIS significantly increased 8-OH-dG, MDA and TOS levels and caused severe tissue damages. However, high dose of OLE induced a significant decrease in the 8-OH-dG, MDA levels, an increase in TAS levels and it restores CIS-induced tissue damages. We hope that the results of this study will provide an impetus for future studies on novel therapeutic strategies including the protective use of oleuropein in gastric and lung cancers due to chemotherapy.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antioxidants; Cisplatin; Deoxyguanosine; DNA Damage; Iridoid Glucosides; Iridoids; Lung Neoplasms; Male; Malondialdehyde; Molecular Structure; Oxidative Stress; Rats; Rats, Sprague-Dawley; Stomach Neoplasms

Oleuropein, a terpene-derived glycosylated secoiridoid biosynthesized exclusively by members of the Oleaceae family, is involved in a two-component defense system comprising a β-glucosidase that activates oleuropein into a toxic glutaraldehyde-like structure. Oleuropein and its deglycosylated derivatives have high pharmaceutical interest. In this study we determined that the in planta heterologous expressed OeGLU, an oleuropein-specific β-glucosidase from olive (

Topics: beta-Glucosidase; Cell Nucleus; Computer Simulation; Glycosylation; Iridoid Glucosides; Iridoids; Kinetics; Nuclear Localization Signals; Olea; Protein Binding; Protein Domains; Protein Folding; Protein Multimerization; Protein Structure, Quaternary; Structure-Activity Relationship

Olive leaves represent a quantitatively significant by-product of agroindustry. They are rich in phenols, mainly oleuropein, which can be hydrolyzed into several bioactive compounds, including hydroxytyrosol. In this study, water extract from olive leaves 'Biancolilla' was analyzed for polyphenol profile, DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and protective effect on differentiated Caco-2 cells. The efficacy of two enzymatic treatments in promoting the release of bioactive phenols was investigated: a) enzymatic extract from Wickerhamomyces anomalus, characterized by β-glucosidase and esterase activities; b) commercial β-glucosidase. Composition and bioactivity of the resulting extracts were compared. The results showed that the yeast-treated extract presented hydroxytyrosol content and DPPH radical scavenging activity comparable to those obtained using commercial β-glucosidase; however, it was showed the additional presence of hydroxycinnamic acids. In experiments on Caco-2 cells, the leaf extracts promoted the recovery of cell membrane barrier at different minimum effective concentrations. The high specificity of W. anomalus enzymatic extract may represent an effective tool for the release of bioactive phenols from olive by-products.

Topics: beta-Glucosidase; Biotransformation; Caco-2 Cells; Coumaric Acids; Esterases; Humans; Hydrolysis; Iridoid Glucosides; Iridoids; Olea; Phenols; Phenylethyl Alcohol; Plant Leaves; Polyphenols; Saccharomycetales

Oleuropein (OLE) is a natural secoiridoid that is derived from Olea europaea. OLE possesses cardioprotective effects in experimental models of hypertension, myocardial infarction, atherosclerosis and hyperlipidaemia. In the present study, the effects of OLE on experimental autoimmune myocarditis (EAM) were evaluated. EAM in rats were induced by subcutaneous injections of porcine cardiac myosin. Cardiac function parameters, myocardial pathology, myocardial inflammatory cell infiltration and nuclear factor kappa-B (NF-κB) expression were measured. Our data showed that the postmyocarditis rats exhibited increased left ventricular end systolic diameters, left ventricular end diastolic diameters, left ventricular end-diastolic pressures (LVEDP), and decreased ejection fractions. However, OLE significantly suppressed these changes in EAM rats. Histological analysis revealed that myosin induced miliary foci of discolouration on endocardial surfaces and extensive myocardial injuries with inflammatory cell infiltration were significantly improved by OLE therapy. A definitive positive correlation between the histological scores and LVEDP was observed. Moreover, OLE inhibited CD4

Topics: Animals; Autoimmune Diseases; Cardiac Myosins; Cardiotonic Agents; Cytokines; Disease Models, Animal; Iridoid Glucosides; Iridoids; Male; Mitogen-Activated Protein Kinases; Myocarditis; Myocardium; NF-kappa B; Rats, Inbred Lew; Signal Transduction; T-Lymphocytes; Ventricular Function, Left

Oleuropein is a glucosylated seco-iridoid present in olive fruits and leaves. Due to its broad spectrum of biological activities, including anticancer properties, oleuropein has attracted scientific attention for the past 20 years. The promising antiproliferative activity of an olive leaf extract enriched in oleuropein against a series of human cancer cell lines, prompted us to proceed with the semi-synthesis of 51 analogs of oleuropein. Following their initial screening against the estrogen receptor negative breast cancer cell line SKBR3, 7 analogs were shown to display significant cytotoxicity and were further tested against 6 additional solid tumor-derived and leukemic cell lines. The analog with the most promising antitumor activity (24) was selected for more detailed studies. 24 was non-toxic to peripheral blood mononuclear cells derived from healthy blood donors when tested at concentrations close to its half maximal inhibitory concentration. In vivo administration of 24 in melanoma-bearing mice resulted in reducing tumor size in a dose-dependent manner and in inducing anti-melanoma-reactive immune responses. Our results suggest that analog 24, emerging from the initial structure of oleuropein, represents a promising lead structure for further optimization.

Topics: Animals; Antineoplastic Agents; Cell Proliferation; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Humans; Iridoid Glucosides; Iridoids; Male; Melanoma, Experimental; Mice; Mice, Inbred C57BL; Molecular Structure; Structure-Activity Relationship; Tumor Cells, Cultured

Oleuropein, a bioactive compound found in all parts of olive tree, especially in leaves and branches, presents numerous health promoting properties that increase research and market interest the last few years. In addition, oleuropein degradation products, such as hydroxytyrosol, elenolic acid, and the aglycones also exhibit biological activities with different properties compared to the starting compound. Under this view, a commercial lipase preparation Lipolase 100L and a thermophilic β-glucosidase from Myceliophthora thermophila were used for the regioselective hydrolysis of oleuropein towards the production of the corresponding biologically active compounds. The enzymatic degradation products of oleuropein, such as hydroxytyrosol, elenolic acid and its glucoside, and oleuropein aglycones were identified by LC-HRMS/MS and NMR spectroscopy. The latter, was found as a mix of diastereomers of the monoaldehydic form of oleuropein aglycone, identified as (5S, 8R, 9S)-, (5S, 8S, 9S)- and (5S, 8R, 9R). The high substrate specificity exhibited by both lipase and β-glucosidase allows the successful tailoring of oleuropein towards the production of different biologically active compounds with significant potential in the cosmeceutical and food industry.

Topics: beta-Glucosidase; Fungal Proteins; Hydrolysis; Iridoid Glucosides; Iridoids; Lipase; Olea; Plant Leaves; Tandem Mass Spectrometry

Oleuropein and hydroxytyrosol are polyphenols that are extracted from olives and are major biological active components of olives and olive oil. Oleuropein and hydroxytyrosol exhibit interesting pharmacological effects on cells, and have been shown to have many health benefits such as anti-inflammatory effects. These effects were mainly attributed to their ability to scavenge the reactive oxygen species (ROS) produced by phagocytes such as neutrophils. The aim of this study was to investigate the effect of oleuropein and hydroxytyrosol on other neutrophil functions.. Human neutrophils were isolated from healthy donors. ROS production was measured by luminol-amplified chemiluminescence. Degranulation was assessed by measuring myeloperoxidase activity and Western blots. Chemotaxis was assessed by the under-agarose chemotaxis assay. Phosphorylated proteins were assessed by gel electrophoresis and Western blots.. We show that in addition to their ROS scavenging effect, oleuropein and hydroxytyrosol significantly inhibited the bacterial peptide N-formyl-methionyl-leucyl-phenylalanine (fMLF)-induced degranulation of azurophilic and specific granules as measured by myeloperoxidase and lactoferrin release, respectively. We also show that oleuropein and hydroxytyrosol reduced fMLF-induced neutrophil chemotaxis. Interestingly, both agents impaired the fMLF-induced AKT, p38MAPKinase, and ERK1/2 phosphorylation, signaling molecules that are involved in pathways regulating neutrophil functions.. Our data suggest that the anti-inflammatory properties of oleuropein and hydroxytyrosol are not only restricted to their ROS scavenging effect, but also involve the inhibition of two other major pro-inflammatory neutrophil functions.

Topics: Anti-Inflammatory Agents; Chemotaxis; Humans; Iridoid Glucosides; Iridoids; MAP Kinase Signaling System; Mitogen-Activated Protein Kinases; N-Formylmethionine Leucyl-Phenylalanine; Neutrophils; Phenylethyl Alcohol; Phosphorylation; Proto-Oncogene Proteins c-akt; Reactive Oxygen Species; Signal Transduction

Radiotherapy in ovarian cancer frequently invokes resistance; this severely compromises its therapeutic effect and results in poor clinical prognosis. How to overcome the acquired resistance and re-sensitize tumors to radiation is the central question in this clinical setting. Cancer cell survival was evaluated using a clonogenic assay. The microRNA expression profile was analyzed using a microarray. Transcript expression was determined using real time PCR. The expression of protein was determined by immunoblotting. Transcription activation was measured using a luciferase reporter assay. Transcription factor binding was determined using ChIP-PCR. Xenograft model was established and exposed to radiation with the simultaneous administration of oleuropein. Tumor growth was monitored. We demonstrated that treatment of oleuropein-sensitized ovarian cells with radiation altered the microRNA expression profile. The endogenous expression of miR-299 was suppressed by a hypoxia inducible factor and relieved in response to oleuropein, which in turn suppressed HPSE1 expression and consequently led to increased sensitivity to radiation. Our data elucidates an unappreciated mechanism mediating radiotherapy resistance in ovarian cancer and exploits the potential synergistic effect of oleuropein with radiation, which warrants further clinical investigation.

Topics: Animals; Cell Line, Tumor; Female; Gene Expression Regulation, Neoplastic; Glucuronidase; Humans; Hypoxia; Iridoid Glucosides; Iridoids; Mice; Mice, Inbred BALB C; MicroRNAs; Ovarian Neoplasms; Radiation-Sensitizing Agents

The stability of oleuropein, a natural antioxidant from Olea europaea, has been often studied in connection with thermal or enzymatic treatments, but very little is known about the effects of UV light. This work aimed at studying the UV-C effects on oleuropein standard solutions once dissolved in ethanol or water. During irradiation, aliquots were taken and analyzed by a flow injection system equipped with a multi-channel coulometric detector and a high-resolution mass spectrometer. The effects of irradiation were also studied by UV spectroscopy. The results show that oleuropein is relatively stable in water or ethanol, but that under UV-C light undergoes a series of fast decomposition reactions leading to hydroxytyrosol and elenolic acid. Overall, this study provides evidences that the degradation of oleuropein by UV-C light follows a mechanism dependent on the solvent used. Moreover, the solvent affects the resulting redox properties of the solution.

Topics: Antioxidants; Iridoid Glucosides; Iridoids; Olea; Plant Extracts

Oleuropein, a natural product derived from olive leaves, has reported anti-diabetic functions. However, detailed molecular mechanisms for how it affects β-cell functions remain poorly understood. Here, we present evidence that oleuropein promotes glucose-stimulated insulin secretion (GSIS) in β-cells. The effect is dose-dependent and stimulates the ERK/MAPK signaling pathway. We further demonstrated that oleuropein inhibits the cytotoxicity induced by amylin amyloids, a hallmark feature of type 2 diabetes. We demonstrated that these dual functions are structure-specific: we identified the 3-hydroxytyrosol moiety of oleuropein as the main functional entity responsible for amyloid inhibition, but the novel GSIS function requires the entire structure scaffold of the molecule.

Topics: Amyloid; Animals; Cell Line; Dose-Response Relationship, Drug; Flavonoids; Insulin; Insulin Secretion; Insulin-Secreting Cells; Iridoid Glucosides; Iridoids; Islet Amyloid Polypeptide; Microscopy, Electron, Transmission; Olea; Protein Kinases; Rats; Structure-Activity Relationship

The purpose of this study was the evaluation of the antioxidant activity of natural and semisynthetic polyphenol derivatives from Olea europea L., by assessing malondialdehyde (MDA), an important marker of oxidative stress.. Polyphenol as hydroxytyrosol, oleuropein, oleuropein aglycone as mix of four tautomeric forms and their respective acetyl-derivatives were obtained from olive leaves using semisynthetic protocols. These compounds were administered intraperitoneally to Wistar rats treated with paraquat, an herbicide which is able to cause oxidative stress after central administration. Malondialdehyde was derivatized with 2,4-dinitrophenylhydrazine to produce hydrazone that was purified by solid-phase extraction. Using high-performance liquid chromatography coupled with a diode array, free and total MDA was measured on homogenate rat brain as marker of lipid peroxidation. The analytical method was fully validated and showed linearity in the tested concentration range, with detection limit of 5 ng/ml. Recovery ranged from 94.1 to 105.8%.. Both natural and semisynthetic polyphenol derivatives from a natural source as olive leaves were able to reduce MDA detection. The more lipophilic acetyl-derivatives showed an antioxidant activity greater than parent compounds. This potency seems to put in evidence a strict correlation between lipophilicity and bioavailability.

Topics: Animals; Antioxidants; Brain; Chromatography, High Pressure Liquid; Disease Models, Animal; Iridoid Glucosides; Iridoids; Limit of Detection; Lipid Peroxidation; Male; Malondialdehyde; Olea; Oxidative Stress; Plant Extracts; Plant Leaves; Polyphenols; Rats; Rats, Wistar

A novel methodology is presented for the enhanced electrochemical detection of oleuropein in complex plant matrices by Graphene Oxide Pencil Grahite Electrode (GOPGE) in combination with a buffer modified with a Natural Deep Eutectic Solvent, containing 10% (v/v) of Lactic acid, Glucose and H

Topics: Biosensing Techniques; Electrochemical Techniques; Electrodes; Electrophoresis, Capillary; Graphite; Iridoid Glucosides; Iridoids; Limit of Detection; Olea; Oxides; Plant Extracts; Plant Leaves; Solvents

Cisplatin-based chemotherapy is responsible for a large number of renal failures, and it is still associated with high rates of mortality today. Oleuropein (OLE) presents a plethora of pharmacological beneficial properties. In this study we investigated whether OLE could provide sufficient protection against cisplatin-induced nephrotoxicity. With this aim, Sprague-Dawley rats were divided into eight groups: control; 7 mg/kg/d cisplatin, 50 mg/kg, 100 mg/kg, and 200 mg/kg OLE; and treatment with OLE for 3 days starting at 24 hours following cisplatin injection. After exposure to the chemotherapy agent and OLE, oxidative DNA damage was quantitated in the renal tissue of experimental animals by measuring the amount of 8-hydroxy-2'-deoxyguanosine (8-OHdG) adducts. Malondialdehyde (MDA) level, total oxidative stress (TOS), and total antioxidant status (TAS) were assessed to determine the oxidative injury in kidney cells. The histology of the kidney was examined using four different staining methods: hematoxylin-eosin (H&E), periodic acid Schiff (PAS), Masson trichrome, and amyloid. In addition, the blood urea nitrogen (BUN), uric acid (UA), and creatinine (CRE) levels were established. Our experimental data showed that tissue 8-OHdG levels were significantly higher in the cisplatin group when compared to the control group. The glomerular cells were sensitive to cisplatin as tubular cells. In addition, treatment with cisplatin elevated the levels of BUN, UA, CRE, and TOS, but lowered the level of TAS compared to the control group. The OLE therapy modulated oxidative stress in order to restore normal kidney function and reduced the formation of 8-OHdG induced by cisplatin. Furthermore, the OLE treatment significantly reduced pathological findings in renal tissue. We demonstrate for the first time that OLE presents significant cytoprotective properties against cisplatin-induced genotoxicity by restoring the antioxidant system of the renal tissue. According to our findings, OLE is a promising novel natural source for the prevention of serious kidney damage in current chemotherapies.

Topics: Animals; DNA Damage; Iridoid Glucosides; Iridoids; Kidney; Oxidative Stress; Rats; Rats, Sprague-Dawley

Osteoarthritis (OA) is the most common form of joint disease and is widespread in the elderly population and is characterized by erosion of articular cartilage, subchondral bone sclerosis and synovitis. Oleuropein (OL), a secoiridoid, is considered as the most prevalent phenolic component in olive leaves and seeds, pulp and peel of unripe olives and has been shown to have potent anti-inflammatory effects. However, its effects on OA have not been clearly elucidated. This study aimed to assess the effect of OL on human OA chondrocytes. Human OA chondrocytes were pretreated with OL (10, 50 and 100 μM) for 2 h and subsequently stimulated with IL-1β for 24 h. The production of NO, PGE2, MMP-1, MMP-13, and ADAMTS-5 was evaluated by the Griess reaction and ELISA assays. The messenger RNA (mRNA) expression of COX-2, iNOS, MMP-1, MMP13, ADAMTS-5, aggrecan, and collagen-II was measured by using real-time PCR. The protein expressions of COX-2, iNOS, p65, IκB-α, JNK, p-JNK, ERK, p-ERK, p38, and p-p38 were tested by using western blot. We found that OL significantly inhibited the IL-1β-induced production of NO and PGE2; expression of COX-2, iNOS, MMP-1, MMP-13, and ADAMTS-5; and degradation of aggrecan and collagen-II. Furthermore, OL dramatically suppressed IL-1β-stimulated NF-κB and MAPK activation. Immunofluorescence staining demonstrated that OL could suppress IL-1β-induced phosphorylation of p65 nuclear translocation. These results indicate that the therapeutic effect of OL on OA is accomplished through the inhibition of both NF-κB and MAPK signaling pathways. Altogether, our findings provide the evidence to develop OL as a potential therapeutic agent for patients with OA.

Topics: Anti-Inflammatory Agents; Chondrocytes; Cyclooxygenase 2; Female; Humans; Inflammation Mediators; Interleukin-1beta; Iridoid Glucosides; Iridoids; Male; Matrix Metalloproteinase 13; Middle Aged; Mitogen-Activated Protein Kinase Kinases; NF-kappa B; Osteoarthritis; Signal Transduction

The secoiridoid oleuropein is a non-flavonoid polyphenol, found in the fruit, leaves and food derivatives from Olea europea. Like other polyphenols it shows a very low toxicity towards healthy tissues and a protective action against cancer or neurodegeneration, but its mechanism of action is not yet understood. In the present report we have used optical and ESR spectroscopy as well as molecular modelling to demonstrate that oleuropein forms a complex with the transition metal copper; the dysmetabolism of this metal is suspected to be involved in both cancer and neurodegeneration. Experiments carried out with the aglycon derivative of oleuropein, produced by β-glycosidase treatment of oleuropein glycoside, showed that also the aglycon forms copper-complexes, but with different spectroscopic features than the glycosidic form. Molecular modelling analysis confirmed that two oleuropein molecules (glycosidic or aglycon forms) can easily coordinate one copper ion. The relationship between oleuropein and copper was investigated in SH-SY5Y human neuroblastoma cells. When cells were depleted of copper by treatment with the copper chelator triethylenetetramine (Trien), that binds copper with higher affinity than oleuropein, oleuropein was less toxic than to copper-adequate cells. Conversely, incubation of SH-SY5Y cells with exogenous copper sulphate increased cell susceptibility to oleuropein. Furthermore SH-SY5Y cells differentiated by retinoic acid pre-treatment showed a lower level of copper, and were more resistant to oleuropein treatment. The oleuropein aglycon was not toxic towards SH-SY5Y cells. In conclusion, the copper-oleuropein complex may be involved in the toxicity of oleuropein towards tumour cells, depending on their copper level.

Topics: Cell Differentiation; Cell Line, Tumor; Chelating Agents; Copper; Electron Spin Resonance Spectroscopy; Humans; Iridoid Glucosides; Iridoids; Models, Molecular; Neuroblastoma; Oxidative Stress; Temperature

Senescent cells display an increase in the secretion of growth factors, inflammatory cytokines and proteolytic enzymes, termed the "senescence-associated-secretory-phenotype" (SASP), playing a major role in many age-related diseases. The phenolic compounds present in extra-virgin olive oil are inhibitors of oxidative damage and have been reported to play a protective role in inflammation-related diseases. Particularly, hydroxytyrosol and oleuropein are the most abundant and more extensively studied. Pre-senescent human lung (MRC5) and neonatal human dermal (NHDF) fibroblasts were used as cellular model to evaluate the effect of chronic (4-6 weeks) treatment with 1 μM hydroxytyrosol (HT) or 10 μM oleuropein aglycone (OLE) on senescence/inflammation markers. Both phenols were effective in reducing β-galactosidase-positive cell number and p16 protein expression. In addition, senescence/inflammation markers such as IL-6 and metalloprotease secretion, and Ciclooxigenase type 2 (COX-2) and α-smooth-actin levels were reduced by phenol treatments. In NHDF, COX-2 expression, Nuclear Factor κ-light-chain-enhancer of activated B cells (NFκB) protein level and nuclear localization were augmented with culture senescence and decreased by OLE and HT treatment. Furthermore, the inflammatory effect of Tumor Necrosis Factor α (TNFα) exposure was almost completely abolished in OLE- and HT-pre-treated NHDF. Thus, the modulation of the senescence-associated inflammatory phenotype might be an important mechanism underlying the beneficial effects of olive oil phenols.

Topics: Anti-Inflammatory Agents; Biomarkers; Cell Line; Cells, Cultured; Cellular Senescence; Fibroblasts; Humans; Iridoid Glucosides; Iridoids; Olea; Phenols; Phenotype; Plant Extracts

Intracerebral haemorrhage (ICH) as a devastating form of stroke has remained a public health threat due to lack of FDA-approved therapy. Oxidative stress originated from blood cell degradation products plays a crucial role in the ICH pathogenesis. In this study we evaluated oleuropein, a potent natural antioxidant from olive, in a well-established rat ICH model from overall symptoms to detailed molecular mechanism.. ICH model was established by collagenase injection to the brain of rats, which were randomly divided into groups with vehicle mock treatment, followed by treatment with different doses of oleuropein via daily intraperitoneal injection post-ICH for 3days. The overall neurological deficit, brain edema level and blood-brain barrier (BBB) integrity were then measured in different treatment groups. To understand the protection mechanism of oleuropein in ICH, BBB structural components ZO-1 and occludin, oxidative stress and MAPK signalling pathways were also examined.. Oleuropein treatment showed overall alleviation of ICH-associated neurological deficit and brain edema in a dose dependent manner. Consistently, it could preserve the BBB structure and attenuate oxidative stress as well as ICH-induced MAPK activation in brain tissue.. Our study suggests oleuropein could be used as a promising therapeutic agent for ICH.

Topics: Animals; Antioxidants; Blood-Brain Barrier; Brain Edema; Cerebral Hemorrhage; Disease Models, Animal; Dose-Response Relationship, Drug; Injections, Intraperitoneal; Iridoid Glucosides; Iridoids; Male; MAP Kinase Signaling System; Oxidative Stress; Rats; Rats, Sprague-Dawley; Stroke

Oleuropein is the most important phenolic compound present in olive cultivars, but it is scarcely present in extra virgin olive oil (EVOO) due to its high hydrophilicity and degradability. Thus, a set of oleuropein aglycone derivatives were synthesized by transacetylation under mild conditions with the aim of circumventing these drawbacks and making the active moiety in oleuropein suitable to be added to food fats. The oleuropein aglycone (closed ring form) is obtained by hydrolyzing oleuropein using Lewis acid catalysis. Then, the permeation profiles as well as the antioxidant capacity of the oleuropein aglycone derivatives were evaluated by ORAC, DPPH assays and by ROS formation using the SH-SY5Y cell line. The biological activities of the obtained compounds exhibited a dependence on their level of lipophilicity.

Topics: Antioxidants; Cell Line; Cell Survival; Cells; Humans; Iridoid Glucosides; Iridoids; Molecular Structure; Olive Oil; Reactive Oxygen Species

The present study was designed to evaluate the antioxidant effects of oleuropein against oxidative stress in the hippocampal area of rats. We used seven experimental groups as follows: Control, Propofol, Propofol-Ketamine (Pro.-Ket.), Xylazine-Ketamine (Xyl.-Ket.), and three oleuropein-pretreated groups (Ole.-Pro., Ole.-Pro.-Ket. and Ole.-Xyl.-Ket.). The oleuropein-pretreated groups received oleuropein (15 mg/kg body weight as orally) for 10 consecutive days. Propofol 100 mg/kg, xylazine 3 mg/kg, and ketamine 75 mg/kg once as ip was used on the 11th day of treatment. Spatial memory impairment and antioxidant status of hippocampus were measured via Morris water maze, lipid peroxidation marker, and antioxidant enzyme activities. Spatial memory impairment and lipid peroxidation significantly increased in Xyl.-Ket.-treated rats in comparison to the control, propofol, Ole.-Pro. and Ole.-Pro.-Ket. groups. Oleuropein pretreatment significantly reversed spatial memory impairment and lipid peroxidation in the Ole.-Xyl.-Ket. group as compared to the Xyl.-Ket.-treated rats. There was no significant difference between the control and the propofol group in lipid peroxidation and spatial memory status. Superoxide dismutase and catalase activities both significantly decreased in Xyl.-Ket.-treated rats when compared to the control, propofol, Ole.-Pro., Ole.-Pro.-Ket., and Ole.-Xyl.-Ket. groups. In contrast, glutathione peroxidase activity in Xyl.-Ket.-treated rats significantly increased as compared to the control, propofol, Pro.-Ket., Ole.-Pro., and Ole.-Pro.-Ket. groups. We concluded that xylazine in combination with ketamine is an oxidative anesthetic drug and oleuropein pretreatment attenuates cognitive dysfunction and oxidative stress induced by anesthesia in the hippocampal area of rats. We also confirmed the antioxidant properties of propofol as a promising antioxidant anesthetic agent.

Topics: Anesthetics; Animals; Antioxidants; Catalase; Cognitive Dysfunction; Glutathione Peroxidase; Hippocampus; Iridoid Glucosides; Iridoids; Ketamine; Lipid Peroxidation; Male; Oxidative Stress; Propofol; Rats; Rats, Sprague-Dawley; Spatial Memory; Superoxide Dismutase; Xylazine

Fungal β-glucosidases were extensively studied regarding their various potential biotechnology applications. Here, we report the selection of Fusarium solani strain producing high yield of β-glucosidase activity. The effect of some factors on β-glucosidase production was studied including: Initial pH, medium composition, concentration of carbon and nitrogen sources, and particle size of raw substrates. The optimal enzyme production was obtained with 4 units of pH. The highest β-glucosidase activity was produced on 4% wheat bran (WB) as raw carbon sources, reaching 5 U/mL. A positive correlation between WB particle size and the β-glucosidase production level was settled. The last one was enhanced to 13.60 U/mL in the presence of 0.5% (w/v) of ammonium sulfate. Interestingly, the activated charcoal was used as an inexpensive reagent enabling a rapid and efficient purification prior step that improved the enzyme-specific activity. Eventually, F. solani β-glucosidase acts efficiently during the bioconversion process of oleuropein. Indeed, 82.5% of oleuropein was deglycosylated after 1 hr at 40°C. Altogether, our data showed that the β-glucosidase of F. solani has a potential application to convert oleuropein to ameliorate food quality.

Topics: beta-Glucosidase; Charcoal; Culture Media; Fusarium; Hydrogen-Ion Concentration; Iridoid Glucosides; Iridoids

In this study, the effect of temperature and ultrasonic application on extraction kinetics of polyphenols from dried olive leaf was investigated. Conventional (CVE) and ultrasonic-assisted extraction (UAE) were performed at 10, 20, 30, 50 and 70°C using water as solvent. Extracts were characterized by measuring the total phenolic content, the antioxidant capacity and the oleuropein content (HPLC-DAD/MS-MS). Moreover, Naik's model was used to mathematically describe the extraction kinetics. The experimental results showed that phenolic extraction was faster in UAE (ultrasonic-assisted extraction) than in CVE (conventional extraction), being extraction kinetics satisfactorily described using Naik model (include VAR>98%). Besides, the total phenolic content, the antioxidant capacity and the oleuropein content were significantly (p<0.05) improved by increasing the temperature in both CVE and UAE. Oleuropein content reached 6.57±0.18 being extracted approximately 88% in the first minute for UAE experiments.

Topics: Chemical Fractionation; Iridoid Glucosides; Iridoids; Kinetics; Olea; Phenols; Plant Leaves; Temperature; Ultrasonic Waves; Water

Hypertension is associated with increased reactive oxygen species (ROS) production in the paraventricular nucleus (PVN) of the hypothalamus. Oleuropein (OL) has a variety of biochemical roles, including antihypertensive and antioxidative functions. However, there have been few reports on the effects of OL on oxidative stress in the PVN on hypertension. In spontaneously hypertensive rats (SHR), eight-week administration of 60 mg/kg/day of OL significantly reduced blood pressure, pro-inflammatory cytokines and the expression of components of the renin-angiotensin system (RAS) compared with SHR rats treated with saline. Concomitantly, OL inhibited superoxide, and increased the antioxidant defense system in the PVN of SHR. We also found that OL increased mitochondrial biogenesis through mtDNA, PGC-1α, Complex II and Complex IV expression and regulated mitochondrial dynamics through the fusion-related protein Mfn2 and fision-related protein DRP1 to attenuate mitochondrial impairment. Furthermore, the phase II enzyme levels of Nrf2 and its downstream proteins NQO-1 and HO-1 were all markedly increased in the PVN of the OL-treated SHR group compared with the saline-treated SHR rats. Our findings demonstrate that OL administration can protect the PVN of the hypothalamus from oxidative stress by improving mitochondrial function through the activation of the Nrf2-mediated signaling pathway.

Topics: Animals; Antihypertensive Agents; Hypertension; Iridoid Glucosides; Iridoids; Male; Mitochondria; NF-E2-Related Factor 2; Oxidative Stress; Paraventricular Hypothalamic Nucleus; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Reactive Oxygen Species; Signal Transduction

Hydrolysis of oleuropein, the main phenol in olive (Olea europaea L.) leaf extracts, to oleuropein aglycon and other subsequent products in the hydrolytic pathway can be catalyzed by different enzymes. Three of the most used hydrolases were assayed to catalyze the process, and β-glucosidase from Aspergillus niger was selected. Acceleration of the enzymatic hydrolysis by ultrasound (US) was studied using a Box-Behnken design (duty cycle, amplitude, cycle time) and an oleuropein standard, and the optimum US conditions for achieving maximum yield of oleuropein aglycon were 0.5s/s duty cycle, 50% amplitude and 45s cycle. The method was applied to obtain oleuropein aglycon from commercial and laboratory extracts from olive leaves, which may have a pharmacological use as deduced by its healthy properties. The kinetics of the US-assisted enzymatic hydrolysis was monitored by analysis of the target compounds using liquid chromatography-tandem mass spectrometry.

Topics: Aspergillus niger; beta-Glucosidase; Chromatography, Liquid; Hydrolysis; Iridoid Glucosides; Iridoids; Olea; Plant Extracts; Plant Leaves; Tandem Mass Spectrometry; Ultrasonics

Topics: Catalase; Extracellular Signal-Regulated MAP Kinases; Gene Expression Regulation, Enzymologic; Glutathione Peroxidase; Glutathione Peroxidase GPX1; Humans; Hydrogen Peroxide; Iridoid Glucosides; Iridoids; Liver; MAP Kinase Kinase 4; Oxidative Stress; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Superoxide Dismutase-1

Much of the beneficial effects of olive products have been attributed to oleuropein. This study examined the effects of oleuropein in rats with heart failure induced by permanent ligation of left coronary arteries. Twenty-four hours after the operation, the rats were assigned to five groups including a sham assigned to receive vehicle (1 ml/day) and four coronary ligated groups assigned to receive vehicle or oleuropein at 5, 10, or 20 mg/kg/day. Five weeks later, echocardiographic and hemodynamic parameters, serum concentrations of oxidative stress, and inflammatory markers were determined. Myocardial infarction group receiving vehicle showed impaired hemodynamic and echocardiographic parameters as evidenced by decreased left ventricular systolic pressure, rate of rise and decrease of left ventricular pressure, stroke volume, ejection fraction, and cardiac output. In addition, significant reduction in superoxide dismutase and glutathione reductase was observed. Oleuropein treatment prevented the reduction of these variables. Moreover, the group had a significantly higher infarct size and serum malondialdehyde, interleukin-1β, and tumor necrosis factor-α than those of the sham group. Treatment with oleuropein prevented the increase of these variables. The results show that oleuropein attenuates the progression of heart failure, possibly by antioxidative and antiinflammatory effects.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Biomarkers; Disease Models, Animal; Disease Progression; Glutathione Reductase; Heart Failure; Hemodynamics; Inflammation Mediators; Interleukin-1beta; Iridoid Glucosides; Iridoids; Male; Malondialdehyde; Myocardial Infarction; Oxidative Stress; Rats, Sprague-Dawley; Superoxide Dismutase; Tumor Necrosis Factor-alpha; Ventricular Function, Left

Topics: Animals; Buffers; Cell Line; Electricity; Electrophoresis, Capillary; Flavanones; Glucosides; Iridoid Glucosides; Iridoids; Macrophages; Mice; Monoterpenes

Oleuropein is the pungent principle of raw olives. Oleuropein aglycone (OA) is a major phenolic compound in extra virgin olive oil and the absorbed form of oleuropein. We aimed to determine the mechanism underlying the nutritional effects of oleuropein and OA on interscapular brown adipose tissue (IBAT) in rats with high-fat (HF) diet-induced obesity by examining the agonistic activity of oleuropein and OA toward the transient receptor potential ankyrin 1 (TRPA1) and vanilloid 1 (TRPV1). Four-week-old male Sprague-Dawley rats were fed an HF (palm oil 30% wt:wt) diet alone or with oleuropein (HF-O, 1 g/kg diet) for 28 days. In rats fed HF-O compared to HF, urinary noradrenaline, adrenaline and UCP1 levels in IBAT were significantly higher, whereas plasma leptin levels and the total weight of the abdominal cavity adipose tissue were significantly lower. In anaesthetized 7-week-old male Sprague-Dawley rats, the OA (3.8 mg of intravenous injection)-induced increase in plasma noradrenaline secretion was suppressed by TRPA1 or TRPV1 antagonist and by a β2- or β3-adrenoceptor antagonist. Furthermore, OA-activated rat and human TRPV1s expressed on HEK293 cells at the same level as zingerone (pungent component in ginger). OA also activated humanTRPA1, and its potency was approximately 10-fold stronger than that for TRPV1. These findings suggest that OA is the agonist of both TRPA1 and TRPV1 and that OA enhances UCP1 expression in IBAT with a concomitant decrease in the visceral fat mass of HF-diet-induced obese rats through enhanced noradrenaline secretion via β-adrenergic action following TRPA1 and TRPV1 activation.

Topics: Acetates; Adipose Tissue, Brown; Animals; Catecholamines; Cyclopentane Monoterpenes; Diet, High-Fat; Epinephrine; HEK293 Cells; Humans; Iridoid Glucosides; Iridoids; Male; Norepinephrine; Obesity; Pyrans; Rats, Sprague-Dawley; Signal Transduction; TRPA1 Cation Channel; TRPV Cation Channels; Uncoupling Protein 1

This study has been aimed at providing a qualitative and quantitative evaluation of selected phytochemicals such as phenolic acids, flavonoids, oleuropein, fatty acids profile, and volatile oil compounds, present in wild olive leaves harvested in Portugal, as well as at determining their antioxidant and cytotoxic potential against human melanoma HTB-140 and WM793, prostate cancer DU-145 and PC-3, hepatocellular carcinoma Hep G2 cell lines, as well as normal human skin fibroblasts BJ and prostate epithelial cells PNT2. Gallic, protocatechuic, p-hydroxybenzoic, vanillic acids, apigenin 7-O-glucoside, luteolin 7-O-glucoside, and rutin were identified in olive leaves. The amount of oleuropein was equal to 22.64 g/kg dry weight. (E)-Anethole (32.35%), fenchone (11.89%), and (Z)-3-nonen-1-ol (8%) were found to be the main constituents of the oil volatile fraction, whereas palmitic, oleic, and alpha-linolenic acid were determined to be dominating fatty acids. Olive leaves methanol extract was observed to exerted a significant, selective cytotoxic effect on DU-145 and PC-3 cell lines. Except the essential oil composition, evaluated wild olive leaves, with regard to their quantitative and qualitative composition, do not substantially differ from the leaves of other cultivars grown for industrial purposes and they reveal considerable antioxidant and cytotoxic properties. Thus, the wild species may prove to be suitable for use in traditional medicine as cancer chemoprevention.

Topics: Antioxidants; Cell Line; Cell Survival; Chromatography, High Pressure Liquid; Flavonoids; Humans; Hydroxybenzoates; Iridoid Glucosides; Iridoids; Olea; Phytochemicals; Plant Extracts; Plant Leaves; Portugal

Oleuropein (OL) is a well-known anti-oxidative agent and is shown to reduce the hypoxia-inducible factor 1 α (HIF1α) protein expression after radiation. The current study investigated the effects of OL on radiation response in nasopharyngeal carcinoma (NPC).. Colony formation assay was performed to compare the radiation response in vitro. Xenograft mouse model was used to study the OL effects on radiation in vivo. Chromatin immunoprecipitation and luciferase reporter assays were performed to identify the relations among HIF1α, miR-519d and PDRG1. Stable HIF1α or PDRG1 overexpression, and miR-519d downregulation were performed to test the radiation response both in vitro and in vivo.. OL strongly enhanced radiosensitivity of NPC cells both in vitro and in vivo. Chromatin immunoprecipitation and luciferase reporter assays suggested miR-519d was a direct target of HIF1α, and PDRG1 was a direct target of miR-519d. Overexpression of HIF1α or PDRG1, and downregulation of miR-519d abolished the radiation sensitizing effects of OL.. Our study hereby demonstrates OL is a radiation sensitizing agent in NPC both in vivo and in vitro. OL treatment reduces the activity of HIF1α-miR-519d-PDRG1 pathway, which is essential to the radiosensitizing effects of OL.

Topics: Animals; Carcinoma; Cell Line, Tumor; Cell Proliferation; Cell Survival; DNA-Binding Proteins; Down-Regulation; Gene Expression Regulation, Neoplastic; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Iridoid Glucosides; Iridoids; Mice; MicroRNAs; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; Radiation-Sensitizing Agents; Xenograft Model Antitumor Assays

The proteasome catalyzes the degradation of many mis-folded proteins, which are otherwise cytotoxic. There is interest in the discovery of proteasome agonists, but previous efforts to do so have been disappointing.. The cleavage of small fluorogenic peptides is used routinely as an assay to screen for proteasome modulators. We have developed follow-on assays that employ more physiologically relevant substrates.. To demonstrate the efficacy of this workflow, the NIH Clinical Collection (NCC) was screened. While many compounds stimulated proteasome-mediated proteolysis of the pro-fluorogenic peptide substrates, most failed to evince activity in assays with larger peptide or protein substrates. We also show that two molecules claimed previously to be proteasome agonists, oleuropein and betulinic acid, indeed accelerate hydrolysis of the fluorogenic substrate, but have no effect on the turnover of a mis-folded protein in vitro or in cellulo. However, two small molecules from the NCC, MK-866 and AM-404, stimulate the proteasome-mediated turnover of a mis-folded protein in living cells by 3- to 4-fold.. Assays that monitor the proteasome-mediated degradation of larger peptides and proteins can distinguish bona fide agonists from compounds only able to stimulate the cleavage of short, non-physiologically relevant peptides.. A suite of assays has been established that allows the discovery of bona fide proteasome agonists. AM-404 and MK-866 can be useful tools for cell culture experiments, and can serve as scaffolds to generate more potent 20S stimulators.

Topics: Arachidonic Acids; Betulinic Acid; Biological Assay; Humans; Hydrolysis; Iridoid Glucosides; Iridoids; Pentacyclic Triterpenes; Peptides; Proteasome Endopeptidase Complex; Proteasome Inhibitors; Proteins; Proteolysis; Small Molecule Libraries; Triterpenes

Oleuropein, a well-known olive polyphenol, has been shown to mediate neuroprotection in Alzheimer's disease and cerebral ischemia. We investigated the effects of oleuropein on pentylenetetrazole (PTZ)-induced seizures in male NMRI mice, with diazepam as the standard drug. We also examined the possible involvement of opioidergic/nitrergic pathways in the probable effects of oleuropein. Intraperitoneal (i.p.) administration of different doses of oleuropein (10, 20 and 30 mg/kg) significantly increased the seizure threshold 60 min prior to induction of seizure, in a dose-dependent manner. Administration of naltrexone (10 mg/kg, i.p.), an opioid receptor antagonist, completely reversed the anticonvulsant effects of oleuropein (10 mg/kg). On the other hand, the anticonvulsant effect of oleuropein (10 mg/kg) was blocked by a non-effective dose of nonspecific inhibitor of nitric oxide synthase (NOS), L-NAME (1 and 10 mg/kg, i.p) and a selective inhibitor of neuronal NOS, 7-nitroindazole (30 mg/kg, i.p.). However, the nitric oxide precursor, L-arginine (30 and 60 mg/kg, i.p.) potentiated the anticonvulsant activity of oleuropein (10 mg/kg). A selective inducible NOS inhibitor, aminoguanidine (100 mg/kg, i.p.) did not change the anticonvulsant activity of oleuropein. It seems that the opioidergic system and constitutive neuronal NOS may be involved in the anticonvulsant properties of oleuropein.

Topics: Animals; Biological Products; Disease Models, Animal; Dose-Response Relationship, Drug; Iridoid Glucosides; Iridoids; Male; Mice; Olea; Pentylenetetrazole; Seizures

Glycation takes place both at the cellular level and at the extracellular matrix level and generates, consequently, advanced glycation end-products (AGEs) associated with chronic diseases and the aging process. Two olive leaf extracts concentrated in (i) oleuropein (OLE-A; 93.9 mg oleuropein g

Topics: Antioxidants; Glycation End Products, Advanced; Hep G2 Cells; Hepatocytes; Humans; Iridoid Glucosides; Iridoids; Olea; Phenylethyl Alcohol; Plant Extracts; Plant Leaves; Protein Carbonylation

Extra virgin olive oil has positive effects on health. Oleuropein is a polyphenolic compound present in olive-tree leaves, fruits (olives) and olive oil. It is responsible for the relevant organoleptic and biological properties of olive oil, including antiadipogenic properties. Thus, the effects of oleuropein on the adipogenesis of human bone-marrow mesenchymal stem cells were studied by transcriptomics and differential gene-expression analyses. Oleuropein could upregulate expression of 60% of adipogenesis-repressed genes. Besides, it could activate signaling pathways such as Rho and β-catenin, maintaining cells at an undifferentiated stage. Our data suggest that mitochondrial activity is reduced by oleuropein, mostly during adipogenic differentiation. These results shed light on oleuropein activity on cells, with potential application as a "nutraceutical" for the prevention and treatment of diseases such as obesity and osteoporosis.

Topics: Adipogenesis; beta Catenin; Fruit; Gene Expression Profiling; Humans; Iridoid Glucosides; Iridoids; Mesenchymal Stem Cells; Olea; Plant Extracts; Plant Oils

Collagen fibrils accumulate in excessive amounts and impair the normal functioning of the organ; therefore it stimulates the interest for identifying the compounds that could prevent the formation of fibrils. Herein, inhibition of self-assembly of collagen using oleuropein has been studied. The changes in the physico-chemical characteristics of collagen on interaction with increasing concentration of oleuropein has been studied using techniques like viscosity, UV-vis, CD and FT-IR. The inhibitory effect of oleuropein on fibril formation of collagen was proved using SEM. Circular dichroism and FT-IR spectra elucidates the alterations in the secondary structure of collagen suggesting non-covalent interactions between oleuropein and collagen. The decreased rate of collagen fibril formation also confirms the inhibition in the self-assembly of collagen. Hence, our study suggests that inhibition of the self-assembly process using oleuropein may unfold new avenues to treat fibrotic diseases.

Topics: Animals; Collagen; Iridoid Glucosides; Iridoids; Protein Aggregates; Protein Structure, Secondary; Rats

Oleuropein (OP), the predominant natural constituent of leaves of the olive tree, exerts anti-inflammatory and antioxidant effects. The purpose of this study was to assess the protective effects of OP under the conditions of paraquat (PQ)-induced oxidative stress in vitro, using the human hepatocarcinoma cell line, HepG2.. Cell viability and death were determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and 4',6-diamidino-2-phenylindole-propidium iodide staining, respectively. Superoxide anion and lipid peroxidation levels were evaluated using nitroblue tetrazolium and thiobarbituric acid-reactive substances assays, respectively. Apoptosis was assessed by measuring poly(ADP-ribose) polymerase (PARP) and caspase-3 (Casp-3) cleavage via immunoblotting and immunofluorescence analyses.. PQ induced a decrease in cellular viability by promoting necrosis through a mechanism involving superoxide generation and nuclear translocation of cleaved Casp-3. Co-treatment with OP afforded significant protection against the suppressive effects of PQ, as evident from increased cell viability, reduction of Casp-3 immunofluorescence, and normalization of β-tubulin expression levels. Unexpectedly, these OP-mediated protective effects were associated with increased superoxide and malondialdehyde generation and PARP cleavage.. OP protects HepG2 cells against PQ-induced necrosis by suppressing Casp-3 cleavage while concomitantly acting as a pro-oxidant agent. This paradoxical mechanism of action of OP requires further investigation.

Topics: Apoptosis; Caspase 3; Cell Death; Cell Line, Tumor; Cell Survival; Humans; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Olea; Plant Extracts; Plant Leaves; Reactive Oxygen Species; Superoxides

We propose the cell culture approach to investigate oleuropein (1) biogenesis in Olea europaea L. We suggest employing olive callus cultures to identify the iridoidic precursor of oleuropein. In fact, we confirmed that callus cells from olive shoot explants are able to produce key secoiridoid as 1. To enable this approach, we synthesised and characterised deuterium-labelled iridoidic precursors belonging both to the loganin and the 8-epiloganin series. These iridoids are [7,8-(2)H2]-7-deoxy-8-epi-loganin (2(D)), [8,10-(2)H2]-8-epi-loganin (4(D)) and [7,8-(2)H2]-7-deoxy-loganin (3(D)).

Topics: Deuterium; Iridoid Glucosides; Iridoids; Molecular Structure; Olea; Tissue Culture Techniques

This study was conducted to reveal that whether i.v. injection of oleuropein, the most potent polyphenolic antioxidant in olive leaf, has any effect on the magnitude of reperfusion arrhythmia in anesthetized rats or not.. Eighty male Wistar rats were divided into 8 groups of 10 each: groups 1 and 5 were assigned as the prophylactic and treatment control groups, groups 2 and 6 as the prophylactic and treatment groups with lidocaine (10 mg/kg), groups 3 and 4 as the prophylactic groups with 10 and 50 mg/kg oleuropein (i.v.), and groups 7 and 8 as the treatment groups with 10 and 50 mg/kg oleuropein (i.v.), respectively. Reperfusion injury was induced by 5-min regional ischemia and 15-min reperfusion of left anterior descending coronary artery. Heart rate, blood pressure, and electrocardiogram were monitored throughout the procedure.. blood pressure was significantly decreased by infusion of 50 mg/kg oleuropein in groups 4 and 8, but unlike the lidocaine as a standard anti-arrhythmic drug in groups 2 and 5 had not significant effect on heart rate. The onset of arrhythmia in groups received oleuropein (groups 3, 4, 7, and 8) was significantly delayed. The mortality rate due to irreversible ventricular fibrillation was also significantly reduced in groups 3, 4, 7, and 8. The effect of lidocaine in groups 2 and 5 was more potent than that in oleuropein group.. These findings indicate that i.v. injection of oleuropein possibly through its antioxidant activity reduces the magnitude of reperfusion-induced arrhythmia.

Topics: Anesthesia, Intravenous; Animals; Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Blood Pressure; Heart Rate; Iridoid Glucosides; Iridoids; Male; Myocardial Reperfusion Injury; Oleaceae; Pre-Exposure Prophylaxis; Rats; Rats, Wistar; Treatment Outcome

The main phenolic secoiridoid oleuropein and active constituent from olive tree (Olea europaea, Oleaceae), has demonstrated anti-inflammatory properties in intestinal inflammation and anti-tumoral effects in different cancer cells. In this study, we evaluated the chemoprevention of oleuropein in a model of azoxymethane (AOM)/Dextran sulfate sodium (DSS)-induced colorectal cancer (CRC) in C57BL/6 mice and the modulatory effect on the Th17 response in DSS acute colitis.. Oleuropein protected from AOM/DSS-induced CRC by improving clinical symptoms, disease activity index score as well as suppressed the growth and multiplicity of colonic tumors. Treatment with oleuropein reduced intestinal IL-6, IFN-γ, TNF-α, and IL-17A concentration, and decreased cyclooxygenase-2, Bax and proliferating cell nuclear antigen protein expression. Western blot analysis also showed a markedly downregulation of CRC-related pathways as nuclear factor-κB (NF-κB), Wnt/β-catenin, phosphatidylinositol-3-kinase (P3IK)/Akt, and signal transducer and activators of transcription (STAT)3. In DSS acute model, oleuropein inhibited Th17 response, by decreasing CD4(+) Rorγt(+) IL-17(+) IFN-γ(+) T-cell subsets in the lamina propria, as well as IL-17A and IFN-γ expression.. Oleuropein as a dietary supplementation could be a promising protective agent against colitis-associated CRC.

Topics: Animals; Anticarcinogenic Agents; Azoxymethane; Cell Proliferation; Colitis; Colon; Colorectal Neoplasms; Cytokines; Dextran Sulfate; Female; Iridoid Glucosides; Iridoids; Mice, Inbred C57BL; Neoplasms, Experimental; Th17 Cells

A novel and rapid ultrasound- and salt-assisted liquid-liquid extraction coupled with high-performance liquid chromatography has been optimized by response surface methodology for the determination of oleuropein from olive leaves. Box-Behnken design was used for optimizing the main parameters including ultrasound time (A), pH (B), salt concentration (C), and volume of miscible organic solvent (D). In this technique, a mixture of plant sample and extraction solvent was subjected to ultrasound waves. After ultrasound-assisted extraction, phase separation was performed by the addition of salt to the liquid phase. The optimal conditions for the highest extraction yield of oleuropein were ultrasound time, 30 min; volume of organic solvent, 2.5 mL; salt concentration, 25% w/v; and sample pH, 4. Experimental data were fitted with a quadratic model. Analysis of variance results show that BC interaction, A(2) , B(2) , C(2) , and D(2) are significant model terms. Unlike the conventional extraction methods for plant extracts, no evaporation and reconstitution operations were needed in the proposed technique.

Topics: Chromatography, High Pressure Liquid; Fruit; Iridoid Glucosides; Iridoids; Liquid-Liquid Extraction; Olea; Plant Extracts; Plant Leaves; Ultrasonics

A multistage optimization of all the parameters affecting detection/response in an LTQ-orbitrap analyzer was performed, using a design of experiments methodology. The signal intensity, a critical issue for mass analysis, was investigated and the optimization process was completed in three successive steps, taking into account the three main regions of an orbitrap, the ion generation, the ion transmission and the ion detection regions. Oleuropein and hydroxytyrosol were selected as the model compounds. Overall, applying this methodology the sensitivity was increased more than 24%, the resolution more than 6.5%, whereas the elapsed scan time was reduced nearly to its half. A high-resolution LTQ Orbitrap Discovery mass spectrometer was used for the determination of the analytes of interest. Thus, oleuropein and hydroxytyrosol were infused via the instruments syringe pump and they were analyzed employing electrospray ionization (ESI) in the negative high-resolution full-scan ion mode. The parameters of the three main regions of the LTQ-orbitrap were independently optimized in terms of maximum sensitivity. In this context, factorial design, response surface model and Plackett-Burman experiments were performed and analysis of variance was carried out to evaluate the validity of the statistical model and to determine the most significant parameters for signal intensity. The optimum MS conditions for each analyte were summarized and the method optimum condition was achieved by maximizing the desirability function. Our observation showed good agreement between the predicted optimum response and the responses collected at the predicted optimum conditions.

Topics: Iridoid Glucosides; Iridoids; Phenylethyl Alcohol; Spectrometry, Mass, Electrospray Ionization; Syringes

The effects of chronic consumption of oleuropein-enriched (15% w/w) olive leaf extract (OLE) on blood pressure, endothelial function, and vascular oxidative and inflammatory status in spontaneously hypertensive rats (SHR) were evaluated. Ten Wistar Kyoto rats (WKY) and twenty SHR were randomly assigned to three groups: a control WKY group, a control SHR group and a SHR group treated with OLE (30 mg kg(-1)) for 5 weeks. Long-term administration of OLE reduced systolic blood pressure, heart rate, and cardiac and renal hypertrophy. OLE treatment reversed the impaired aortic endothelium-dependent relaxation to acetylcholine observed in SHR. OLE restored aortic eNOS phosphorylation at Ser-1177 and Thr-495 and increased eNOS activity. OLE eliminated the increased aortic superoxide levels, and reduced the elevated NADPH oxidase activity, as a result of reduced NOX-1 and NOX-2 mRNA levels in SHR. OLE reduced the enhanced vascular TLR4 expression by inhibition of mitogen-activated protein kinase (MAPK) signaling with the subsequent reduction of proinflammatory cytokines. In conclusion, OLE exerts antihypertensive effects on genetic hypertension related to the improvement of vascular function as a result of reduced pro-oxidative and pro-inflammatory status.

Topics: Animals; Antihypertensive Agents; Blood Pressure; Endothelium, Vascular; Gene Expression Regulation, Enzymologic; Hypertension; Iridoid Glucosides; Iridoids; NADPH Oxidases; Nitric Oxide Synthase Type II; Olea; Plant Extracts; Plant Leaves; Rats; Rats, Inbred SHR; Reactive Oxygen Species

Oleuropein possesses numerous health beneficial effects. We investigated the renoprotective effects of oleuropein against cisplatin (CP) induced kidney injury.. Male BALB/cN mice were orally gavaged with 5, 10 and 20 mg oleuropein/kg body weight for 2 days, 48 h after intraperitoneal injection of CP (13 mg/kg). Four days after CP administration, serum creatinine and blood urea nitrogen (BUN) levels were significantly elevated, with histopathological changes in renal tissue. In addition, renal oxidative stress was evidenced by increased expression of 3-nitrotyrosine (3-NT), 4-hydroxynonenal (4-HNE), cytochrome P450 E1 (CYP2E1) and heme oxygenase-1 (HO-1). The expression of nuclear factor-kappaB (NF-κB) p65, phospho-p65, tumor necrosis factor-alpha (TNF-α) and cyclooxygenase-2 (COX-2) in the kidneys increased upon CP treatment, suggesting renal inflammation. CP intoxication increased the expression of p53, Bax and caspase-3 and induced apoptosis in the kidneys. CP administration also resulted in enhanced phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK1/2). All these effects were dose dependently diminished by oleuropein. Oral administration of PD0325901, an MEK inhibitor, coincided with the oleuropein-mediated suppression of apoptotic, inflammatory and antioxidant markers.. The results of the current study suggest that oleuropein attenuated CP-induced acute renal injury, which was mediated through the inhibition of ERK signaling.

Topics: Acute Kidney Injury; Administration, Oral; Animals; Antineoplastic Agents; Apoptosis; Cisplatin; Enzyme Inhibitors; Iridoid Glucosides; Iridoids; Kidney; Male; MAP Kinase Signaling System; Mice, Inbred BALB C; Nephritis; Oxidative Stress; Protective Agents

The secoiridoids are the main class of specialized metabolites present in olive (Olea europaea L.) fruit. In particular, the secoiridoid oleuropein strongly influences olive oil quality because of its bitterness, which is a desirable trait. In addition, oleuropein possesses a wide range of pharmacological properties, including antioxidant, anti-inflammatory, and anti-cancer activities. In accordance, obtaining high oleuropein varieties is a main goal of molecular breeding programs. Here we use a transcriptomic approach to identify candidate genes belonging to the secoiridoid pathway in olive. From these candidates, we have functionally characterized the olive homologue of iridoid synthase (OeISY), an unusual terpene cyclase that couples an NAD (P)H-dependent 1,4-reduction step with a subsequent cyclization, and we provide evidence that OeISY likely generates the monoterpene scaffold of oleuropein in olive fruits. OeISY, the first pathway gene characterized for this type of secoiridoid, is a potential target for breeding programs in a high value secoiridoid-accumulating species.

Topics: Amino Acid Sequence; Biosynthetic Pathways; Crystallography, X-Ray; Fruit; Gene Expression Regulation, Plant; Iridoid Glucosides; Iridoids; Ligases; Molecular Sequence Data; Olea; Oxidoreductases; Phylogeny; Plant Proteins; Sequence Alignment; Transcriptome

Oleuropein has been recognized as an important medicinal compound because of its various biological properties, including anti-cancer, antidiabetic and anti-atherosclerotic activities. Here, we evaluate the antioxidant activity as well as the mechanism of the hypoglycemic effects of oleuropein in C2C12 cells and we establish the mechanism underlying these effects.. To perform this study, C2C12 cells viability was analyzed via MTT assay and the antioxidant activity was investigated by ROS and TBARS assays. Also, the effect of oleuropein on AMPK and PI3 kinase signaling pathways was evaluated.. Treatment with oleuropein was able to protect cells against H2O2 induced stress in cells. On the other hand, the molecular bases of its actions have been scarcely understood. Oleuropein significantly enhanced glucose consumption and the phosphorylation of AMPK (AMP-activated protein kinase/ACC (acetyl-CoA carboxylase)) and MAPKs (mitogen-activated protein kinases), but not PI3 kinase (Phosphatidylinositol 3-kinase)/Akt. However, the co-treatment of oleuropein and insulin improved the insulin sensitivity via insulin-dependent (PI3 kinase/Akt) and insulin independent (AMPK/ACC) pathways. These results could be confirmed from the findings of GLUT4 translocation which was strongly enhanced in the case of oleuropein.. Our results provide important insights for the possible mechanism of action of oleuropein as a therapeutic agent in diabetic patients.

Topics: AMP-Activated Protein Kinases; Animals; Cell Line; Cell Survival; DNA-Binding Proteins; Drug Synergism; Enzyme Activation; Hydrogen Peroxide; Hypoglycemic Agents; Insulin; Insulin Resistance; Iridoid Glucosides; Iridoids; Mice; Mitogen-Activated Protein Kinases; Muscle, Skeletal; Oxidative Stress; Phosphatidylinositol 3-Kinase; Phosphorylation; Protective Agents; Reactive Oxygen Species; Signal Transduction; Thiobarbituric Acid Reactive Substances; Transcription Factors

Oleuropein (OLE) was found to have anti-inflammatory and anti-oxidant effects. The latest study has shown that it can resist myocardial injury that follows an acute myocardial infarction and can rescue impaired spinal nerve cells. In this study, we investigated the neuroprotective effects of OLE on cerebral ischemia and reperfusion injury in a middle cerebral artery occlusion model in mice.OLE (100 mg/kg) was injected intraperitoneally 1h before ischemia. We found that the volume of cerebral infarction was significantly reduced after 75 min of ischemia and 24 h of reperfusion compared with the I/R (ischemia/reperfusion) group. This protective function occurred in a dose-dependent manner. We also found that treatment with OLE could reduce the cerebral infarct volume. The neuroprotective effect was prolonged from 2 h to 4 h when we injected OLE intracerebroventricularly after reperfusion. We then found that OLE can decrease the level of cleavedcaspase-3, an important marker of apoptosis, in the ischemic mouse brain. Finally, we explored the role of OLE in providing anti-apoptotic effects through the increased expression of Bcl-2 and the decreased expression of Bax, which are important markers in apoptosis. As shown above, the function and safety of OLE in cardiovascular disease may indicate that it is a potential therapeutic for stroke.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Brain; Caspase 3; Infarction, Middle Cerebral Artery; Iridoid Glucosides; Iridoids; Male; Mice, Inbred ICR; Neurons; Neuroprotection; Neuroprotective Agents; Olea; Plant Extracts; Plant Leaves; Proto-Oncogene Proteins c-bcl-2; Reperfusion Injury

Alzheimer's disease is a progressive neurodegenerative disorder with decline in memory. The role of oxidative stress is well known in the pathogenesis of the disease. The purpose of this study was to evaluate pretreatment effects of oleuropein on oxidative status and cognitive dysfunction induced by colchicine in the hippocampal CA1 area. Male Wistar rats were pretreated orally once daily for 10 days with oleuropein at doses of 10, 15 and 20 mg/kg. Thereafter, colchicine (15 μg/rat) was administered into the CA1 area of the hippocampus to induce cognitive dysfunction. The Morris water maze was used to assess learning and memory. Biochemical parameters such as glutathione peroxidase and catalase activities, nitric oxide and malondialdehyde concentrations were measured to evaluate the antioxidant status in the rat hippocampus. Our results indicated that colchicine significantly impaired spatial memory and induced oxidative stress; in contrast, oleuropein pretreatment significantly improved learning and memory retention, and attenuated the oxidative damage. The results clearly indicate that oleuropein has neuroprotective effects against colchicine-induced cognitive dysfunction and oxidative damage in rats.

Topics: Animals; Behavior, Animal; CA1 Region, Hippocampal; Caspase 3; Catalase; Cognitive Dysfunction; Colchicine; Glutathione Peroxidase; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Male; Malondialdehyde; Neuroprotective Agents; Nitric Oxide; Oxidative Stress; Rats; Rats, Wistar; Spatial Learning; Spatial Memory

Hemorrhagic cystitis is one of the devastating complications seen after receiving cyclophosphamide chemotherapy. Oleuropein is the most important phenolic compound of olive leaves that mediates most of its beneficial pharmacological properties. Herein, we investigated the possible uroprotective effect of oleuropein against cyclophosphamide induced hemorrhagic cystitis in a rat model. For this purpose, we measured bladder nitric oxide, reduced glutathione, catalase, tumor necrosis factor-alpha and vascular endothelial growth factor levels in addition to the bladder gene expression of intercellular adhesion molecule-1 after induction of hemorrhagic cystitis in the presence or absence of oleuropein. Histopathological examination of bladder tissues was also performed. After cyclophosphamide injection, we demonstrated a significant decrease in bladder reduced glutathione (39%) and catalase (55.4%) levels and a significant increase of nitric oxide (5.6 folds), tumor necrosis factor-alpha (3.3 folds), vascular endothelial growth factor (2 folds) and intercellular adhesion molecule-1 (8 folds) bladder contents when compared to those in normal control rats. Administration of oleuropein induced a marked elevation in bladder reduced glutathione (37.8%), catalase (100.4%) with a prominent reduction of bladder nitric oxide (40%), tumor necrosis factor-alpha (35.9%) and vascular endothelial growth factor (56.2%) levels along with downregulation of intercellular adhesion molecule-1 bladder expression (73.1%) in comparison to cyclophosphamide treated rats levels. Our data demonstrated that oleuropein counteracts the harmful effects of cyclophosphamide on the bladder through its antioxidant and anti-inflammatory activities. Oleuropein exerts a definite uroprotective effect against cyclophosphamide induced hemorrhagic cystitis in rats.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Cyclophosphamide; Cystitis; Disease Models, Animal; Gene Expression Regulation; Hemorrhage; Humans; Intercellular Adhesion Molecule-1; Iridoid Glucosides; Iridoids; Male; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Urinary Bladder

It has been shown that oleuropein, a phenolic compound in the fruit and leaves of the olive tree (Olea europaea) induces mammalian uncoupling protein 1 (UCP1) expression via an increased secretion of noradrenaline and adrenaline. This study investigated the effects of oleuropein on avian UCP (avUCP) expression as well as genes related to mitochondrial oxidative phosphorylation and biogenesis in cultured avian muscle cells, together with reactive oxygen species generation. Oleuropein induced avUCP as well as peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), nuclear respiratory factor-1 (NRF1), mitochondrial transcription factor A (TFAM) and ATP5a1 (a component of mitochondrial adenosine triphosphate synthase) gene expression and cytochrome c oxidase activity, indicating the induction of mitochondrial biogenesis. Sirtuin-1 (SIRT1) gene expression was also up-regulated by this compound, which could contribute to an increase in PGC-1α activity. Oleuropein suppressed the level of superoxide generation per mitochondrion, possibly via the up-regulation of avUCP and manganese superoxide dismutase (MnSOD) expression. Based on these findings, this study is the first to show that oleuropein may induce avUCP expression in avian muscle cells independent of the catecholamines, in which PGC-1α may be involved.

Topics: Animals; Cells, Cultured; Chickens; Gene Expression; Iridoid Glucosides; Iridoids; Male; Mitochondria; Muscle, Skeletal; Olea; Organelle Biogenesis; Oxidative Phosphorylation; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Reactive Oxygen Species; Superoxide Dismutase; Uncoupling Protein 1; Up-Regulation

The antimicrobial properties of olive leaf extract (OLE) have been well recognized in the Mediterranean traditional medicine. Few studies have investigated the antimicrobial properties of OLE. In this preliminary study, commercial OLE and its major phenolic secondary metabolites were evaluated in vitro for their antimicrobial activities against Escherichia coli and Staphylococcus aureus, both individually and in combination with ampicillin. Besides luteolin 7-O-glucoside, OLE and its major phenolic secondary metabolites were effective against both bacteria, with more activity on S. aureus. In combination with ampicillin, OLE, caffeic acid, verbascoside and oleuropein showed additive effects. Synergistic interaction was observed between ampicillin and hydroxytyrosol. The phenolic composition of OLE and the stability of olive phenols in assay medium were also investigated. While OLE and its phenolic secondary metabolites may not be potent enough as stand-alone antimicrobials, their abilities to boost the activity of co-administered antibiotics constitute an imperative future research area.

Topics: Ampicillin; Anti-Bacterial Agents; Bacteria; Caffeic Acids; Drug Synergism; Escherichia coli; Flavones; Glucosides; Herb-Drug Interactions; Iridoid Glucosides; Iridoids; Medicine, Traditional; Olea; Phenols; Phenylethyl Alcohol; Plant Extracts; Plant Leaves; Staphylococcus aureus

Transthyretin (TTR) is involved in a subset of familial or sporadic amyloid diseases including senile systemic amyloidosis (SSA), familial amyloid polyneuropathy and cardiomyopathy (FAP/FAC) for which no effective therapy has been found yet. These conditions are characterized by extracellular deposits primarily found in the heart parenchyma and in peripheral nerves whose main component are amyloid fibrils, presently considered the main culprits of cell sufferance. The latter are polymeric assemblies grown from misfolded TTR, either wt or carrying one out of many identified mutations. The recent introduction in the clinical practice of synthetic TTR-stabilizing molecules that reduce protein aggregation provides the rationale to search natural effective molecules able to interfere with TTR amyloid aggregation by hindering the appearance of toxic species or by favoring the growth of harmless aggregates. Here we carried out an in depth biophysical and morphological study on the molecular features of the aggregation of wt- and L55P-TTR involved in SSA or FAP/FAC, respectively, and on the interference with fibril aggregation, stability and toxicity to cardiac HL-1 cells to demonstrate the ability of Oleuropein aglycone (OleA), the main phenolic component of the extra virgin olive oil. We describe the molecular basis of such interference and the resulting reduction of TTR amyloid aggregate cytotoxicity. Our data offer the possibility to validate and optimize the use of OleA or its molecular scaffold to rationally design promising drugs against TTR-related pathologies that could enter a clinical experimental phase.

Topics: Animals; Cell Line; Iridoid Glucosides; Iridoids; Mice; Prealbumin; Spectroscopy, Fourier Transform Infrared

Oleuropein, a phenolic compound found in the olive leaf (Olea europaea), has been shown to have biological activities in different models. However, the effects of oleuropein on Ca(2+) homeostasis, cytotoxicity, cell cycle distribution and ROS signaling in liver cells have not been analyzed. Oleuropein induced [Ca(2+)]i rises only in HepG2 cells but not in AML12, HA22T or HA59T cells due to the different status of 3-hydroxy-3-methylglutaryl-CoA reductase expression. In HepG2 cells, this Ca(2+) signaling response was reduced by removing extracellular Ca(2+), and was inhibited by the store-operated Ca(2+) channel blockers 2-APB and SKF96365. In Ca(2+)-free medium, pretreatment with the ER Ca(2+) pump inhibitor thapsigargin abolished oleuropein-induced [Ca(2+)]i rises. Oleuropein induced cell cycle arrest which was associated with the regulation of p53, p21, CDK1 and cyclin B1 levels. Furthermore, oleuropein elevated intracellular ROS levels but reduced GSH levels. Treatment with the intracellular Ca(2+) chelator BAPTA-AM or the antioxidant NAC partially reversed oleuropein-induced cytotoxicity. Together, in HepG2 cells, oleuropein induced [Ca(2+)]i rises by releasing Ca(2+) from the ER and causing Ca(2+) influx through store-operated Ca(2+) channels. Moreover, oleuropein induced Ca(2+)-associated cytotoxicity that involved ROS signaling and cell cycle arrest. This compound may offer a potential therapy for treatment of human hepatoma.

Topics: Calcium; Cell Cycle; Hep G2 Cells; Homeostasis; Humans; Iridoid Glucosides; Iridoids; Olea; Plant Leaves; Reactive Oxygen Species; Signal Transduction

Oleuropein, which is the major compound of olive leaves, has been reported to exert several pharmacological properties, including anti-cancer, antidiabetic and anti-atherosclerotic activities. The objective of this study was to evaluate the effect of oleuropein on adiponectin level in high cholesterol diet (HCD) induced obesity in rat and the molecular mechanism underlying its activation. Our results showed that orally administered oleuropein (50 mg/kg) by gavage for 8 weeks decreased the body weight, adipose tissue mass and triglyceride and attenuated steatosis in liver. Moreover, the effect of oleuropein on adiponectin, an important hormone with fatty-acid oxidation properties, was evaluated and our data illustrated that oleuropein supplementation increased serum adiponectin concentration. The effects of oleuropein on protein expression related to lipogenic genes were investigated and our results showed that its administration significantly inhibited peroxisome proliferator-activated receptor γ (PPARγ), sterol regulatory element-binding protein-1c (SREBP-1c) and fatty-acid synthase (FAS). In addition, oleuropein stimulated the HCD-induced inhibition of AMP-activated protein kinase (AMPK) in epididymal adipose tissues. These results suggest that oleuropein exerts anti-obesity effects in HCD rats by activating AMPK and suppressing PPAR γ (Peroxisome proliferator-activated receptor γ) expression in adipose tissues. These data provide that oleuropein has important implications for preventing obesity.

Topics: Adiponectin; AMP-Activated Protein Kinases; Animals; Anti-Obesity Agents; Anticholesteremic Agents; Cholesterol; Enzyme Activation; Iridoid Glucosides; Iridoids; Lipid Metabolism; Lipids; Male; Obesity; PPAR gamma; Rats; Rats, Wistar; Sterol Regulatory Element Binding Protein 1

Neuroblastoma is one of the most common types of pediatric tumors that can spread quickly in neuronal tissues. Oleuropein which is active compound of olive leaves, belongs to polyphenols group and has antioxidant, anti-microbial, anti-inflammatory, anti-hypertensive and anti-carcinogenic effects. The aim of the study is to determine the therapeutic effects of oleuropein on cell proliferation, invasion, colony formation, cell cycle and apoptotic mechanisms in SH-SY5Y neuroblastoma cell line under in vitro conditions. The effect of oleuropein on cell viability was determined by XTT method. 84 cell cycle control and 84 apoptosis related genes were evaluated by RT-PCR. Effects of oleuropein on apoptosis were researched by TUNEL assay. Protein expressions were determined by western blot analysis. Effects of oleuropein on cell invasion, colony formation and migration were detected by matrigel-chamber, colony formation assay and wound-healing assay, respectively. IC50 value of oleuropein in SH-SY5Y cells was detected as 350 μM at 48th hours. It is determined that oleuropein causes cell cycle arrest by down-regulating of CylinD1,CylinD2,CyclinD3,CDK4,CDK6 and up-regulating of p53 and CDKN2A, CDKN2B, CDKN1A gene expressions. Oleuropein also induces apoptosis by inhibiting of Bcl-2 and activating of Bax,caspase-9 and caspase-3 gene expressions. Apoptotic cell ratio was found 36.4 ± 3.27% in oleuropein dose group. Oleuropein decreased invasion in SH-SY5Y cells and suppressed colony numbers in ratio of 53.6 ± 4.71%.Our results demonstrated that oleuropein can be a therapeutic agent in the treatment of neuroblastoma.

Topics: Antineoplastic Agents; Antioxidants; Apoptosis; Cell Division; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; G1 Phase Cell Cycle Checkpoints; Gene Expression Regulation, Neoplastic; Humans; In Situ Nick-End Labeling; Iridoid Glucosides; Iridoids; Neoplasm Invasiveness; Neuroblastoma; Wound Healing

The bitter taste of olives is mainly caused by the phenolic compound named oleuropein and the mechanism of its hydrolysis during the processing of natural green olives was studied. First, a rapid chemical hydrolysis of oleuropein takes place at a high temperature of 40°C and at a low pH value of 2.8, but the chemical hydrolysis of the bitter compound is slow at the common range of pH for these olives (3.8-4.2). However, decarboxymethyl elenolic acid linked to hydroxytyrosol and hydroxytyrosol have been found in a high concentration during the elaboration of natural green olives. When olives were heated at 90°C for 10min before brining, these compounds are not formed. Hence, the debittering process in natural green olives is due to the activity of β-glucosidase and esterase during the first months of storage and then a slow chemical hydrolysis of oleuropein happens throughout storage time.

Topics: beta-Glucosidase; Esterases; Food Handling; Food Storage; Hot Temperature; Hydrogen-Ion Concentration; Hydrolysis; Iridoid Glucosides; Iridoids; Olea; Phenols; Phenylethyl Alcohol; Pyrans; Salts; Taste

Enriching oils, such as olive oil, could be one solution to tackle the worldwide epidemic of vitamin D deficiency and to better fit with omega 3 (DHA) recommendations. However, data regarding the interactions occurring at the intestinal level between vitamin D and phenols from olive oil are scarce. We first determined the effect of polyphenols from a virgin olive oil, and a virgin olive oil enriched with DHA, on vitamin D absorption in rats. We then investigated the effects of 3 main olive oil phenols (oleuropein, hydroxytyrosol and pinoresinol) on vitamin D uptake by Caco-2 cells. The presence of polyphenols in the olive oil supplemented with DHA inhibited vitamin D postprandial response in rats (-25%, p<0.05). Similar results were obtained with a mix of the 3 polyphenols delivered to Caco-2 cells. However, this inhibitory effect was due to the presence of pinoresinol only. As the pinoresinol content can highly vary between olive oils, the present results should be taken into account to formulate an appropriate oil product enriched in vitamin D.

Topics: Animals; Caco-2 Cells; Docosahexaenoic Acids; Female; Furans; Humans; Intestinal Absorption; Iridoid Glucosides; Iridoids; Lignans; Olive Oil; Phenylethyl Alcohol; Polyphenols; Rats; Rats, Wistar; Vitamin D

The objective of this study is to investigate the potential preventive effect of oleuropein in an experimental arsenic toxicity in mice. For this purpose, mice were exposed to 5mg/kg/day sodium arsenite (NaAsO2) in drinking water and treated with 30mg/kg/day oleuropein for 15 days. At the end of the experiment, animals were sacrificed and selected organs were processed for biochemical and histopahtological investigations. Blood, liver, kidney and brain malondialdehyde (MDA) and nitric oxide (NO) levels were determined by colorimetric methods. Protein carbonyl content is measured by a commercial kit. Liver morphology and immunoreactivity for inducible NOS (iNOS) and endothelial NOS (eNOS) was evaluated microscopically. Level of NO was determined to decrease in blood and tissues whereas MDA increased in arsenic given mice. Tissue protein carbonyl content also increased in this group. Immunoreactivity for iNOS and eNOS was noted to increase with arsenic treatment. Oleuropein treatment had significant effects in normalizing the MDA and NO levels as well as protein carbonyl content. Immunohistochemical staining also showed reduction of the expression of iNOS and eNOS in liver. The results indicate that oleuropein ameliorates oxidative tissue damage by scavenging free radicals.

Topics: Animals; Arsenites; Free Radical Scavengers; Iridoid Glucosides; Iridoids; Liver; Male; Malondialdehyde; Mice; Nitric Oxide; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Oxidative Stress; Sodium Compounds

A highly sensitive, rapid and specific ultrahigh-performance liquid chromatography, coupled to negative electrospray ionization high-resolution tandem mass spectrometry, method was developed and validated in order to investigate the absorption of dietary oleuropein (OE) in human subjects. Serum samples were collected at predefined time points, after oral administration of an olive leaf extract enriched in OE (204.4 mg OE per capsule) to two subjects. Subsequently, samples were analyzed by the developed method after a simple solid-phase extraction step. Chromatographic separation was operated with aqueous formic acid, 0.1% (v/v), and acetonitrile following a gradient program at a flow rate of 0.45 mL/min in an RP-C

Topics: Adult; Chromatography, High Pressure Liquid; Humans; Iridoid Glucosides; Iridoids; Limit of Detection; Male; Reproducibility of Results; Tandem Mass Spectrometry; Young Adult

The antioxidant activity of olive leaf (OL) and cake (OC) extracts with different solvents was evaluated. 70% of aqueous ethanol extract of OL was chosen as the most antioxidant extract based on antiradical activity (DPPH) (95.4±0.3%) and oxygen radical absorbance capacity (ORAC) (0.82±0.07g equivalent Trolox per g of solution) assays. This OL extract was incorporated in two multilayer materials consisting of (i) polyethylene/polyethylene (PE/PE) film and (ii) polyethylene/paper (PE/P). These multilayers were exposed to a gas stream enriched in free radicals to evaluate the scavenging capacity of both materials. PE/PE film exhibited the highest scavenging activity of free radicals (78.8%). Migration of the phenolic compounds from olive by-products into two simulants was performed and demonstrated a non-migrating behavior. The limits of detection and quantification for oleuropein were 0.5μgkg(-1) and 1.7μgkg(-1) and for Luteolin-7-O-glucoside 1.3μgkg(-1) and 4.3μg kg(-1) respectively.

Topics: Antioxidants; Free Radicals; Iridoid Glucosides; Iridoids; Olea; Oxidation-Reduction; Phenols; Plant Extracts; Plant Leaves

Olive leaf extract is characterized by a high content of polyphenols (oleuropein, hydroxytyrosol and their derivatives), which is associated with its therapeutic properties. The objective of the present research was to evaluate the antifungal activity of olive leaf extract against Candida albicans ATCC 10231 and C. dubliniensis CBS 7987 strains. Minimum inhibitory concentrations (MIC) of the extract were determined by several in vitro assays. The extract showed a concentration depended effect on the viability of C. albicans with MIC value of 46.875 mg mL-1 and C. dubliniensis with MIC value 62.5 mg mL-1. Most sensitive methods for testing the antifungal effect of the extracts were the trypan blue exclusion method and fluorescent dye exclusion method while MIC could not be determined by the method according to the EUCAST recommendation suggesting that herbal preparations contain compounds that may interfere with this susceptibility testing. The fluorescent dye exclusion method was also used for the assessment of morphological changes in the nuclei of treated cells. According to the obtained results, olive leaf extract is less effective against the tested strains than hydroxytyrosol, an olive plant constituent tested in our previous study.

Topics: Anti-Bacterial Agents; Antifungal Agents; Antioxidants; Candida; Candida albicans; Cell Nucleus; Cell Nucleus Shape; Chromatography, High Pressure Liquid; Coloring Agents; Fluorescent Dyes; Iridoid Glucosides; Iridoids; Microbial Sensitivity Tests; Olea; Phenylethyl Alcohol; Plant Extracts; Plant Leaves; Trypan Blue

In this study, we evaluated the antiproliferative activity on two human osteosarcoma cell lines (MG-63 and Saos2) of oleuropein, an olive oil compound traditionally found in the Mediterranean diet. Oleuropein exhibited obvious cytotoxic effects on human osteosarcoma cells in a concentration- and time-dependent manner. Statistical analysis of IC50 by the Probit regression method suggested that oleuropein had similar toxic effects on both cell lines tested (IC50 range from 247.4-475.0 µM for MG63 cells and from 798.7-359.9 µM for Saos2 cells).

Topics: Cell Line, Tumor; Cell Proliferation; Humans; Iridoid Glucosides; Iridoids; Osteosarcoma; Phytotherapy; Plant Extracts

A simple and fast chromatographic method using ultraviolet diode-array detector (UV-DAD) was developed for the automatic high performance liquid chromatography (HPLC) determination of the title of oleuropein in a new dietary supplements in form of effervescent granules. The chromatographic separations were performed on a C18 core-shell column with detection at λ=232nm. The mobile phase consisted of deionized water with 0.1% TFA and acetonitrile under gradient conditions at a flow-rate of 0.8mL/min. Oleuropein and oleuroside present in the raw material were characterized by high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). The validation of the analytical procedure has been performed determining the following parameters: specificity, linearity, repeatability, reproducibility, accuracy, limit of quantification (LOQ), stability of the standard and sample solutions. Linear response was observed in fortified placebo solutions (determination coefficient: 0.9998). Intra-day precision (relative standard deviation, RSD) was ≤5.0% for peak area and for retention times (tR) without significant differences between intra- and inter-day data. The limits of quantitation (LOQ) was about 5μg/mL and 9pmol/inject. Oleuropein recovery studies gave good results (99.9%) with a R.S.D. of 0.5%. The speed of analysis and the stability of the solutions with a fluctuation Δ (%) ≤2.0 at room temperature means an undoubted advantage of the method allowing the simultaneous preparation of many samples and consecutive chromatographic analyses by using an autosampler. The developed method is suitable for the quality control of oleuropein in raw material and industrial products. The method can be applied in any analytical laboratory not requiring a sophisticated instrumentation.

Topics: Chromatography, High Pressure Liquid; Dietary Supplements; Iridoid Glucosides; Iridoids; Limit of Detection; Quality Control; Reproducibility of Results; Sensitivity and Specificity; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry

The effect of olive oil phenolic content and pattern on the physical properties and stability of olive oil mayonnaise-like emulsions has been investigated. Mayonnaises were formulated with either naturally phenolic-rich extra virgin olive oils or purified olive oil artificially enriched with a phenolic-rich olive extract and pure oleuropein. Mayonnaises were characterized by droplet size distribution, microstructure, textural properties and flow behaviour. The addition of phenolic extracts significantly affected the dispersion degree of the corresponding mayonnaise-like emulsions, their microstructure and physical stability especially in the systems prepared with purified olive oil treated with pure oleuropein and the highest olive phenolic extract concentration. The viscosity and back-extrusion analyses evidenced that the systems characterized by a relatively high content of phenolics, either natural or by addition, presented lower yield stress and viscosity indices and were easier to deform and to break. This study confirms the main role of olive phenolic compounds, and in particular that of oleuropein, in the dispersion state, and physical properties of emulsions with main effects on their quality and stability.

Topics: Emulsions; Iridoid Glucosides; Iridoids; Olive Oil; Phenols; Plant Oils

Oleuropein, the main phenolic compound of secoiridoids, has been proven to have inhibitory effects on various types of cancers. However, the antitumor effects and related mechanisms in glioma remain unclear. In the present study, U251 and A172 cells were used to assess the effects of oleuropein. Using cell viability assay, we found that oleuropein greatly inhibited the viability of the U251 and A172 cells. Additionally, flow cytometric apoptosis assay indicated that oleuropein induced the apoptosis of the two cell lines. Consistently, the inhibitory effects of oleuropein on migration and invasion were also observed in vitro. In regards to the mechanism, we found that oleuropein significantly decreased phosphorylation of AKT (p-AKT), accompanied by upregulation of Bax and downregulation of Bcl-2. We also found that there was a decrease in the expression levels of matrix metalloproteinase-2 (MMP-2) and MMP-9 after treatment with oleuropein. Furthermore, a specific phosphatidylinositol 3 kinase (PI3K) inhibitor, LY294002, enhanced the pro-apoptotic and anti-invasive effects induced by oleuropein, which suggested that oleuropein suppressed the growth and invasion of glioma cells via inhibition of AKT activity. Taken together, our results indicated that treatment with oleuropein may be an effective therapy for malignant glioma through suppression of tumor proliferation and invasion by inhibition of the AKT signaling pathway.

Topics: Antineoplastic Agents; Apoptosis; Blotting, Western; Brain Neoplasms; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Survival; Flow Cytometry; Glioma; Humans; Iridoid Glucosides; Iridoids; Neoplasm Invasiveness; Proto-Oncogene Proteins c-akt; Signal Transduction

Much research effort has been focused on investigating new compounds derived from low-cost sources, such as natural products, for treating leishmaniasis. Oleuropein derived from numerous plants, particularly from the olive tree, Olea europaea L. (Oleaceae), is a biophenol with many biological activities. Our previous findings showed that oleuropein exhibits leishmanicidal effects against three Leishmania spp. in vitro, and minimizes the parasite burden in L. donovani-infected BALB/c mice. The aim of the present study is to investigate the possible mechanism(s) that mediate this leishmanicidal activity.. We determined the efficacy of oleuropein in elevating ROS and NO production in L. donovani-infected J774A.1 macrophages and in explanted splenocytes and hepatocytes obtained from L. donovani-infected BALB/c mice. We also assessed the expression of genes that are related to inflammation, T-cell polarization and antioxidant defense, in splenocytes. Finally, we determined the ratios of specific IgG2a/IgG1 antibodies and DTH reactions in L. donovani-infected BALB/c mice treated with oleuropein.. Oleuropein was able to elevate ROS production in both in vitro and in vivo models of visceral leishmaniasis and raised NO production in ex vivo cultures of splenocytes and hepatocytes. The extensive oxidative stress found in oleuropein-treated mice was obviated by the upregulation of the host's antioxidant enzyme (mGCLC) and the simultaneous downregulation of the corresponding enzyme of the parasite (LdGCLC). Moreover, oleuropein was able to mount a significant Th1 polarization characterized by the expression of immune genes (IL-12β, IL-10, TGF-β1, IFN-γ) and transcription factors (Tbx21 and GATA3). Moreover, this immunomodulatory effect was also correlated with an inhibitory effect on IL-1β gene expression, rather than with the expression of IL-1α, IL-1rn and TNF-α. Furthermore, oleuropein-treated BALB/c mice mounted a delayed-type hypersensitivity (DTH) response and an elevated Leishmania-specific IgG2a/IgG1 ratio that clearly demonstrated an in vivo protective mechanism.. The ability of Oleuropein to promote a Th1 type immune response in L. donovani-infected BALB/c mice points towards the candidacy of this bioactive compound as an immunomodulatory agent that may complement therapeutic approaches to leishmaniasis.

Topics: Animals; Antiprotozoal Agents; Female; Humans; Interferon-gamma; Interleukin-10; Iridoid Glucosides; Iridoids; Leishmania donovani; Leishmaniasis, Visceral; Macrophages; Mice; Mice, Inbred BALB C; Olea; Oxidative Stress; Plant Extracts; Th1 Cells; Transforming Growth Factor beta1

Parkinson's disease (PD) is a progressive neurodegenerative disorder, primarily affecting dopaminergic neurons in the substantia nigra. There is currently no cure for PD and present medications aim to alleviate clinical symptoms, thus prevention remains the ideal strategy to reduce the prevalence of this disease. The goal of this study was to investigate whether oleuropein (OLE), the major phenolic compound in olive derivatives, may prevent neuronal degeneration in a cellular dopaminergic model of PD, differentiated PC12 cells exposed to the potent parkinsonian toxin 6-hydroxydopamine (6-OHDA). We also investigated OLE's ability to mitigate mitochondrial oxidative stress and modulate the autophagic flux. Our results obtained by measuring cytotoxicity and apoptotic events demonstrate that OLE significantly decreases neuronal death. OLE could also reduce mitochondrial production of reactive oxygen species resulting from blocking superoxide dismutase activity. Moreover, quantification of autophagic and acidic vesicles in the cytoplasm alongside expression of specific autophagic markers uncovered a regulatory role for OLE against autophagic flux impairment induced by bafilomycin A1. Altogether, our results define OLE as a neuroprotective, anti-oxidative and autophagy-regulating molecule, in a neuronal dopaminergic cellular model.

Topics: Animals; Autophagy; Cell Death; Iridoid Glucosides; Iridoids; Mitochondria; Nerve Degeneration; Oxidative Stress; Oxidopamine; Parkinson Disease; PC12 Cells; Rats; Reactive Oxygen Species; Superoxides

Poly(ADP-ribose) polymerase-1 (PARP1) activation contributes to the cascade of events initiated by amyloid-β (Aβ) peptide eventually leading to cell death in Alzheimer's disease brain. A significant accumulation of PAR polymers and increase of PARP1 expression were detected in the cortex at the early (3.5 months) and intermediate (6 months) stage of Aβ deposition in the TgCRND8 mouse model. Our previous data highlighted the beneficial effects of oleuropein aglycone (OLE), the main polyphenol found in the olive oil, against neurodegeneration both in cultured cells and in model organisms. Here we found that 8-week OLE treatment (50 mg/kg of diet) to 6-month-old TgCRND8 mice rescued to control values PARP1 activation and the levels of its product, PAR. In N2a neuroblastoma cells, PARP1 activation and PAR formation upon exposure to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) were abolished by pretreatment for 24 h with either OLE (100μM) or PARP inhibitors. A significant reduction of the NAD+ content, compared to controls, was found in N2a cells exposed to MNNG (100μM) for 90 min; the latter was slightly attenuated by cell treatment for 24 h with PJ-34 or with OLE. In vitro and in vivo, the OLE-induced reduction of PARP1 activation was paralleled by the overexpression of Sirtuin1 (SIRT1), and, in vivo, by a decrease of NF-κB and the pro-apoptotic marker p53. In N2a cells, we also found that OLE potentiates the MNNG-induced increase of Beclin1 levels. In conclusion, our data show that OLE treatment counteracts neuronal damage through modulation of the PARP1-SIRT1 interplay.

Topics: Animals; Brain; Cell Line, Tumor; Iridoid Glucosides; Iridoids; Mice; Mice, Transgenic; Poly (ADP-Ribose) Polymerase-1; Polyphenols; Sirtuin 1; Vasodilator Agents

Oleuropein and its hydrolysis products are olive phenolic compounds that have antimicrobial effects on a variety of pathogens, with the potential to be utilized in food and pharmaceutical products. While the existing research is mainly focused on individual genes or enzymes that are regulated by oleuropein for antimicrobial activities, little work has been done to integrate intracellular genes, enzymes and metabolic reactions for a systematic investigation of antimicrobial mechanism of oleuropein. In this study, the first genome-scale modeling method was developed to predict the system-level changes of intracellular metabolism triggered by oleuropein in Staphylococcus aureus, a common food-borne pathogen. To simulate the antimicrobial effect, an existing S. aureus genome-scale metabolic model was extended by adding the missing nitric oxide reactions, and exchange rates of potassium, phosphate and glutamate were adjusted in the model as suggested by previous research to mimic the stress imposed by oleuropein on S. aureus. The developed modeling approach was able to match S. aureus growth rates with experimental data for five oleuropein concentrations. The reactions with large flux change were identified and the enzymes of fifteen of these reactions were validated by existing research for their important roles in oleuropein metabolism. When compared with experimental data, the up/down gene regulations of 80% of these enzymes were correctly predicted by our modeling approach. This study indicates that the genome-scale modeling approach provides a promising avenue for revealing the intracellular metabolism of oleuropein antimicrobial properties.

Topics: Anti-Bacterial Agents; Bacterial Proteins; Glutamic Acid; Iridoid Glucosides; Iridoids; Metabolic Networks and Pathways; Microbial Sensitivity Tests; Nitric Oxide; Phosphates; Potassium; Staphylococcus aureus; Systems Biology

In the present study we investigated activity of oleuropein, a complex phenol present in large quantities in olive tree products, against opportunistic fungal pathogen

Topics: Antifungal Agents; Apoptosis; Candida albicans; Cell Adhesion; Hydrophobic and Hydrophilic Interactions; Iridoid Glucosides; Iridoids; Microbial Sensitivity Tests; Olea; Plant Preparations; Virulence Factors

Oleuropein is a phenolic compound of olive leaves. Enteric bacterial flora is very important for human health and diet is a directly affecting factor of enteric bacterial flora composition. In this study, it was hypothesized that oleuropein could reduce total aerobic bacterial count in rat caecal flora.. Twenty adult, male, Wistar albino rats were randomly divided into two groups. Group C (n=10) was fed with standard rat chow and water for 30 days. Group O (n=10) received olive leaf extract 20 mg/kg/day by intragastric gavage in addition to standard rat chow and water for 30 days. One gram of caecal content was collected from each rat and then consecutive 10-fold serial dilutions were prepared with a final concentration of 10-8. Then 0.1 ml of each dilution were spread onto the surfaces of Plate Count Agar and Violet Red Bile Glucose Agar to enumerate the aerobic enteric bacteria.. Total aerobic bacterial counts of Group O were significantly lower than of Group C in all agar plates inoculated with ceacal samples for every dilution (p<0.05).. Adding oleuropein to enteral feeding solutions of critically ill patients may be adventageous in the presence of clinical conditions predisposing to bacterial translocation by reducing enteric bacterial counts (Tab. 1, Ref. 32).

Topics: Animals; Anti-Infective Agents; Bacteria, Aerobic; Bacterial Translocation; Enterobacteriaceae; Humans; Intestinal Mucosa; Iridoid Glucosides; Iridoids; Male; Plant Extracts; Rats; Rats, Wistar

Oleuropein (Ole), naturally occurring phenolic compound found in olive products, is well known for its benefits for human health. In the present work, a simple, sensitive and rapid determination of Ole was achieved using a label-free electrochemical DNA biosensor. The application was related to the molecular interaction between Ole and double-stranded DNA (dsDNA). So, the voltammetric behavior of Ole at the surface of a DNA-immobilized chitosan-modified carbon paste electrode was studied using differential pulse voltammetry (DPV) where the oxidation peak current of Ole was measured as an analytical signal. A considerable increase was observed in the oxidation signal of Ole at the DNA-coated electrode compared with the DNA-free electrode, indicating the pre-concentration of Ole due to the interaction with the surface-confined DNA layer. In order to use the proposed sensor for real samples, different parameters affecting Ole signal such as, immobilization time and potential, accumulation time and pH, and stripping pH were optimized. Under optimized experimental conditions, a linear concentration range of 0.30-12μmolL(-1) with a detection limit of 0.090μmolL(-1) was obtained for Ole determination. The proposed biosensor was successfully applied to the determination of Ole in olive leaf extract and human serum samples.

Topics: Biosensing Techniques; Chitosan; Electrochemical Techniques; Electrodes; Equipment Design; Humans; Hydrogen-Ion Concentration; Immobilized Nucleic Acids; Iridoid Glucosides; Iridoids; Limit of Detection; Olive Oil

Myocardial infarction causes a cascade of events, which leads to heart failure, debilitation and death. This study examined possible cardioprotective effect of oleuropein in rats with acute myocardial infarction. Male Sprague-Dawly rats were allocated to five groups: sham, myocardial infarction receiving vehicle, and three myocardial infarction receiving oleuropein at 10, 20, and 30 mg/kg/day for 7 days, and underwent sham operation or coronary ligation. Twenty-four hours later, animals underwent echocardiographic and hemodynamic studies, and infarct areas, serum concentrations of oxidative stress and inflammatory markers were determined. Myocardial infarction group receiving vehicle had significantly lower left ventricular developed and systolic pressures, rate of rise/decrease of left ventricular pressure, stroke volume, ejection fraction and cardiac output, and serum superoxide dismutase and glutathione reductase than those of sham group. Pretreatment with oleuropein prevented the reduction of these variables. Moreover, the group had a significantly higher serum malondialdehyde, interleukin-1β, TNF-α, creatin kinase-MB, and troponin I, lactate dehydrogenase, and infarct area than those of sham group. Pretreatment with oleuropein prevented the increase of these variables. The findings indicate that coronary ligation results in acute myocardial infarction characterized by impaired cardiac function, and oleuropein pretreatment prevented cardiac impairment partly by reducing oxidative stress and release of proinflammatory cytokines.

Topics: Animals; Biomarkers; Cardiotonic Agents; Creatine Kinase, MB Form; Disease Models, Animal; Electrocardiography; Hemodynamics; Interleukin-1beta; Iridoid Glucosides; Iridoids; L-Lactate Dehydrogenase; Male; Malondialdehyde; Myocardial Infarction; Oxidative Stress; Rats; Rats, Sprague-Dawley; Troponin I; Tumor Necrosis Factor-alpha; Ultrasonography; Vasodilator Agents

To assess the potential protective effects of three polyphenols oleuropein, rutin and curcumin, on joint ageing and osteoarthritis (OA) development.. Sixty 4-week-old Dunkin-Hartley guinea pigs were randomized into four groups and received daily during 31 weeks either standard guinea pig diet (control group) or a standard guinea pig diet enriched with oleuropein (0.025%), rutin (0.5%) or rutin/curcumin (0.5%/0.25%) association. Biomarkers of OA (Coll2-1, Coll2-1NO2, Fib3-1, Fib3-2, ARGS), as well as inflammation prostaglandin E2 (PGE2) were quantified in the serum. Histological assessments of knee cartilage and synovial membrane were performed at week 4 (five young reference guinea pigs) and week 35.. At week 35, guinea pigs in the control group spontaneously developed significant cartilage lesions with mild synovial inflammation. The histological scores of cartilage lesions and synovitis were well correlated with the increased level of serum biomarkers. Histologically, all treatments significantly reduced the cartilage degradation score (P < 0.01), but only oleuropein significantly decreased the synovial histological score (P < 0.05) and serum PGE2 levels (P < 0.01) compared to the control group. Coll2-1 was decreased by rutin and the combination of rutin/curcumin, Fib3-1 and Fib3-2 were only decreased by the rutin/curcumin mixture, while Coll2-1NO2 was significantly decreased by all treatments (P < 0.05).. Oleuropein and rutin ± curcumin significantly slowed down the progression of spontaneous OA lesions in guinea pigs. While no additive effect was seen in the curcumin + rutin group, the differential effects of oleuropein and rutin on inflammatory and cartilage catabolic markers suggest an interesting combination for future studies in OA protection.

Topics: Animals; Biomarkers; Curcumin; Guinea Pigs; Iridoid Glucosides; Iridoids; Male; Osteoarthritis; Rutin

The present study was aimed to assess the in vivo acute effects of oleuropein or/and pinoresinol, polyphenols widely diffused in natural sources, on rat pial microvascular responses during transient BCCAO and reperfusion.. Rat pial microcirculation was visualized by fluorescence microscopy through a closed cranial window. Pial arterioles were classified into five orders of branching. Capillaries were assigned order 0, the smallest arterioles order 1 and the largest ones order 5.. Rats subjected to BCCAO and reperfusion showed: arteriolar diameter decrease, microvascular leakage, leukocyte adhesion in venules, and reduction in capillary perfusion. Pretreatment with oleuropein or pinoresinol, a higher dose before BCCAO determined dilation in all arteriolar orders RE. Microvascular leakage was reduced as well as leukocyte adhesion and ROS formation, while capillary perfusion was protected. Inhibition of endothelium nitric oxide synthase prior to oleuropein or pinoresinol reduced the effect of these polyphenols on pial arteriolar diameter and leakage. These substances, administered together, prevented microvascular damage to a larger extent.. Oleuropein and pinoresinol were both able to protect pial microcirculation from I-reperfusion injury, to increase nitric oxide release and to reduce oxidative stress preserving pial blood flow distribution.

Topics: Animals; Arterioles; Brain Injuries; Cerebrovascular Circulation; Furans; Iridoid Glucosides; Iridoids; Lignans; Male; Microcirculation; Rats; Rats, Wistar; Reperfusion Injury; Vasodilator Agents

Amyloid-ß (Aß) fragments, oligomeric Aß aggregates, and pyroglutamylated-Aß peptides, as well as epigenetic mechanisms and autophagy dysfunction all appear to contribute in various ways to Alzheimer's disease progression. We previously showed that dietary supplementation of oleuropein aglycone, a natural phenol abundant in the extra virgin olive oil, can be protective by reducing Aß42 deposits in the brain of young and middle-aged TgCRND8 mice. Here, we extended our study to aged TgCRND8 mice showing increased pE3-Aß in the brain deposits. We report that oleuropein aglycone is active against glutaminylcyclase-catalyzed pE3-Aß generation reducing enzyme expression and interferes both with Aß42 and pE3-Aß aggregation. Moreover, the phenol astonishingly activates neuronal autophagy even in mice at advanced stage of pathology, where it increases histone 3 and 4 acetylation, which matches both a decrease of histone deacetylase 2 expression and a significant improvement of synaptic function. The occurrence of these functional, epigenetic, and histopathologic beneficial effects even at a late stage of the pathology suggests that the phenol could be beneficial at the therapeutic, in addition to the prevention, level.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Autophagy; Brain; Depression, Chemical; Dietary Supplements; Disease Progression; Epigenesis, Genetic; Female; Histone Deacetylase 2; Histones; Iridoid Glucosides; Iridoids; Male; Mice, Transgenic; Olive Oil; Peptide Fragments; Plant Oils; Protein Aggregates

Ischemic preconditioning, which is mediated by cell signaling molecules, protects the heart from ischemia-reperfusion injury by limiting the infarct size. Oleuropein, the main polyphenolic constituent of olives, reduced the infarct size in normal and cholesterol-fed rabbits when it was administered at a nutritional dose. The aim of the present study was to compare the effects of oleuropein and preconditioning in terms of the cell signaling and metabolism pathways underlying myocardial protection. Rabbits were randomly divided into six groups: the control group received 5 % dextrose for six weeks, the preconditioning group was subjected to two cycles of preconditioning with 5 min ischemia/10 min reperfusion, the O6 group was treated with oleuropein for six weeks, the Chol group was fed a cholesterol-enriched diet and 5 % dextrose for six weeks, and the CholO6 and CholO3 groups were treated with cholesterol and oleuropein for six and three weeks, respectively; oleuropein was dissolved in 5 % dextrose solution and was administered orally at a dose of 20 mg × kg(-1) × day(-1). All animals were subsequently subjected to 30 min myocardial ischemia followed by 10 min of reperfusion. At that time, myocardial biopsies were taken from the ischemic areas for the assessment of oxidative and nitrosative stress biomarkers (malondialdehyde and nitrotyrosine), and determination of phosphorylation of signaling molecules involved in the mechanism of preconditioning (PI3K, Akt, eNOS, AMPK, STAT3). The tissue extracts NMR metabolic profile was recorded and further analyzed by multivariate statistics. Oxidative biomarkers were significantly reduced in the O6, CholO6, and CholO3 groups compared to the control, preconditioning, and Chol groups. Considering the underlying signaling cascade, the phosphorylation of PI3K, Akt, eNOS, AMPK, and STAT-3 was significantly higher in the preconditioning and all oleuropein-treated groups compared to the control and Chol groups. The NMR-based metabonomic study, performed through the analysis of spectroscopic data, depicted differences in the metabolome of the various groups with significant alterations in purine metabolism. In conclusion, the addition of oleuropein to a normal or hypercholesterolemic diet results in a preconditioning-like intracellular effect, eliminating the deleterious consequences of ischemia and hypercholesterolemia, followed by a decrease of oxidative stress biomarkers. This effect is exerted through inducing precondit

Topics: Animals; Cholesterol; Disease Models, Animal; Hypercholesterolemia; Iridoid Glucosides; Iridoids; Male; Malondialdehyde; Myocardial Ischemia; Myocardial Reperfusion Injury; Myocardium; Olea; Oxidative Stress; Phosphatidylinositol 3-Kinases; Protective Agents; Rabbits; Signal Transduction; Tyrosine

Topics: Angiotensin II; Cell Culture Techniques; Humans; Iridoid Glucosides; Iridoids; Oxidative Stress; Stem Cells; Vascular Diseases; Vasodilator Agents

The enzymatic activity of raw protein olive leaf extract has been investigated in vivo, on olive leaf homogenate and, in vitro with pure oleuropein and other phenolic substrates. At least two types of enzymes were found to be involved in the degradation of endogenous oleuropein in olive leaves. As for the in vitro experiments, the presence of active polyphenoloxidase and β-glucosidase was determined by HPLC and UV-Visible spectroscopy. Interestingly, both the enzymatic activities were found to change during the storage of olive leaves. Specifically, the protein extracts obtained from fresh leaves showed the presence of both the enzymatic activities, because oleuropein depletion occurred simultaneously with the formation of the oleuropein aglycon, 3,4-DHPEA-EA. In comparison leaves subjected to the drying process showed a polyphenoloxidase activity leading exclusively to the formation of oxidation products responsible for the typical brown coloration of the reaction solution.

Topics: beta-Glucosidase; Catechol Oxidase; Chromatography, High Pressure Liquid; Iridoid Glucosides; Iridoids; Olea; Oxidation-Reduction; Plant Extracts; Plant Leaves; Plant Proteins

Oleuropein is one of the primary phenolic compounds present in olive leaf. In this study, the anti-inflammatory effect of oleuropein was investigated using lipopolysaccharide (LPS)-stimulated RAW 264.7 and a zebrafish model. The inhibitory effect of oleuropein on LPS-induced NO production in macrophages was supported by the suppression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). In addition, our enzyme immunoassay showed that oleuropein suppressed the release of pro-inflammatory cytokines such as interleukin-1β (IL-1β) and interleukin-6 (IL-6). Oleuropein inhibited the translocation of p65 by suppressing phosphorylation of inhibitory kappa B-α (IκB-α). Oleuropein also decreased activation of ERK1/2 and JNK, which are associated with LPS-induced inflammation, and its downstream gene of AP-1. Furthermore, oleuropein inhibited LPS-stimulated NO generation in a zebrafish model. Taken together, our results demonstrated that oleuropein could reduce inflammatory responses by inhibiting TLR and MAPK signaling, and may be used as an anti-inflammatory agent.

Topics: Animals; Anti-Inflammatory Agents; Cyclooxygenase 2; Inflammation; Interleukin-6; Iridoid Glucosides; Iridoids; Lipopolysaccharides; Macrophages; Mice; NF-kappa B; Olea; Plant Extracts; Plant Leaves; Zebrafish

Oleuropein is a polyphenol, that is found in extra‑virgin olive oil. Previous studies have shown that oleuropein inhibits cell proliferation and induces apoptosis in breast cancer, colorectal cancer and thyroid cancer. The aim of the present study was to investigate the effects of oleuropein in hepatocellular carcinoma (HCC) cells. The results of Cell Counting Kit 8 and flow cytometric analysis indicated that oleuropein effectively inhibited cell viability and induced apoptosis in HepG2 human hepatoma cells in a dose‑dependent manner, through activation of the caspase pathway. Proapoptotic Bcl‑2 family members, BAX and Bcl‑2, were involved in oleuropein‑induced apoptosis. The phosphatidylinositol 3‑kinase/protein kinase B (PI3K/AKT) signaling pathway was also shown to be involved in this process. Oleuropein was demonstrated to suppress the expression of activated AKT. In addition, AKT overexpression promoted cell survival following treatment with oleuropein, while inhibition of AKT promoted cell death. Furthermore, the data demonstrated that oleuropein induces the production of reactive oxygen species (ROS) and that the function of oleuropein is, at least partially, ROS‑dependent. These results suggest that oleuropein may be a promising novel chemotherapeutic agent in hepatocellular carcinoma.

Topics: Antineoplastic Agents; Apoptosis; bcl-2-Associated X Protein; Carcinoma, Hepatocellular; Caspases; Cell Line, Tumor; Glutathione; Hep G2 Cells; Humans; Iridoid Glucosides; Iridoids; Liver Neoplasms; Phosphatidylinositol 3-Kinase; Proto-Oncogene Proteins c-akt; Reactive Oxygen Species; Signal Transduction

Oleuropein (OE), the main polyphenol in olive leaf extract, is likely to decompose into hydroxytyrosol (HT) and elenolic acid under the action of light, acid, base, high temperature. In the enzymatic process, the content of OE in olive leaf extract and enzyme are key factors that affect the yield of HT. A selective enzyme was screened from among 10 enzymes with a high OE degradation rate. A single factor (pH, temperature, time, enzyme quantity) optimization process and a Box-Behnken design were studied for the enzymatic hydrolysis of 81.04% OE olive leaf extract. Additionally, enzymatic hydrolysis results with different substrates (38.6% and 81.04% OE) were compared and the DPPH antioxidant properties were also evaluated. The result showed that the performance of hydrolysis treatments was best using hemicellulase as a bio-catalyst, and the high purity of OE in olive extract was beneficial to biotransform OE into HT. The optimal enzymatic conditions for achieving a maximal yield of HT content obtained by the regression were as follows: pH 5, temperature 55 °C and enzyme quantity 55 mg. The experimental result was 11.31% ± 0.15%, and the degradation rate of OE was 98.54%. From the present investigation of the antioxidant activity determined by the DPPH method, the phenol content and radical scavenging effect were both decreased after enzymatic hydrolysis by hemicellulase. However, a high antioxidant activity of the ethyl acetate extract enzymatic hydrolysate (IC50 = 41.82 μg/mL) was demonstated. The results presented in this work suggested that hemicellulase has promising and attractive properties for industrial production of HT, and indicated that HT might be a valuable biological component for use in pharmaceutical products and functional foods.

Topics: Antioxidants; Biotransformation; Hydrolysis; Iridoid Glucosides; Iridoids; Olea; Phenylethyl Alcohol; Plant Extracts; Plant Leaves; Pyrans

In our continued investigation of plants from the family Oleaceae we have now investigated Picconia azorica endemic to the Azores. Like most species within the family it contains the oleoside-based secoiridoid glucosides ligstroside and oleuropein as the main compounds and in addition verbascoside and echinacoside. As with the previously investigated Picconia excelsa, it also contained the carbocyclic iridoid glucosides involved in the biosynthetic pathway to the oleoside derivatives. However, while P. excelsa contained loganin esterified with some monoterpenoid acids, P. azorica contains similar esters of 7-epi-loganic acid named Picconioside A and B. In addition were found the two 7-O-E/Z-cinnamoyl esters of 7-epi-loganic acid named Picconioside C and D.

Topics: Azores; Glucosides; Glycosides; Iridoid Glucosides; Iridoids; Molecular Structure; Oleaceae; Phenols; Pyrans

Oleuropein, the major secoiridoid compound in olive, is involved in a sophisticated two-component defence system comprising a β-glucosidase enzyme that activates oleuropein into a toxic glutaraldehyde-like structure. Although oleuropein deglycosylation studies have been monitored extensively, an oleuropein β-glucosidase gene has not been characterized as yet. Here, we report the isolation of OeGLU cDNA from olive encoding a β-glucosidase belonging to the defence-related group of terpenoid-specific glucosidases. In planta recombinant protein expression assays showed that OeGLU deglycosylated and activated oleuropein into a strong protein cross-linker. Homology and docking modelling predicted that OeGLU has a characteristic (β/α)8 TIM barrel conformation and a typical construction of a pocket-shaped substrate recognition domain composed of conserved amino acids supporting the β-glucosidase activity and non-conserved residues associated with aglycon specificity. Transcriptional analysis in various olive organs revealed that the gene was developmentally regulated, with its transcript levels coinciding well with the spatiotemporal patterns of oleuropein degradation and aglycon accumulation in drupes. OeGLU upregulation in young organs reflects its prominent role in oleuropein-mediated defence system. High gene expression during drupe maturation implies an additional role in olive secondary metabolism, through the degradation of oleuropein and reutilization of hydrolysis products.

Topics: Base Sequence; beta-Glucosidase; Fruit; Gene Expression; Hydrolysis; Iridoid Glucosides; Iridoids; Molecular Sequence Data; Olea; Plant Proteins; Sequence Analysis, DNA; Terpenes; Transgenes

As olive oil production increases, so does the amount of olive oil by-products, which can cause environmental problems. Thus, new ways to utilize the by-products are needed. In the present study, five bioactive characteristics of olive oil by-products were assessed, namely their antioxidant, anti-bacterial, anti-melanogenesis, anti-allergic, and collagen-production-promoting activities. First, the extracts of leaves (May and October), stems (May and October), flowers, olive milled waste, fruit pulp and seeds were prepared using two safe solvents, ethanol and water. According to HPLC and LC/MS analysis and Folin-Ciocalteu assay, the ethanol extracts of the leaves (May and October), stems (May and October) and flowers contained oleuropein, and the ethanol extract of the stems showed the highest total phenol content. Oleuropein may contribute to the antioxidant and anti-melanogenesis activities of the leaves, stems, and flowers. However, other active compounds or synergistic effects present in the ethanol extracts are also likely to contribute to the anti-bacterial activity of the leaves and flowers, the anti-melanogenesis activity of some parts, the anti-allergic activity of olive milled waste, and the collagen-production-promoting activity of the leaves, stems, olive milled waste and fruit pulp. This study provides evidence that the by-products of olive oil have the potential to be further developed and used in the skin care industry.

Topics: Animals; Anti-Allergic Agents; Antioxidants; Cell Line, Tumor; Fibroblasts; Flowers; Fruit; Humans; Iridoid Glucosides; Iridoids; Melanoma, Experimental; Microbial Sensitivity Tests; Olea; Olive Oil; Phenols; Plant Extracts; Plant Leaves; Plant Oils; Rats; Seeds; Skin; Solvents

The technological characteristics of five oleuropeinolytic strains of the Lactobacillus plantarum group selected within 135 isolates from table olives were investigated. The metabolism of phenolic compounds during elaboration of green (cv. Chalkidikis) and black (cv. Kalamata) olives under reduced salt conditions was evaluated. Olives of both cultivars were fermented in two different kinds of brine (Brine A containing 2.3% NaCl, 32.3 mM Ca-acetate and 33.9 mM Ca-lactate and Brine B containing 4% NaCl, pH 5.0 in both brines) by five selected strains of L. plantarum group. After 60 days of fermentation, the analysis of phenolic compounds was performed by HPLC and nine compounds were identified and quantified: oleuropein, hydroxytyrosol, tyrosol and vanillin and the phenolic acids protocatechuic, caffeic, p-hydroxybenzoic, vanillic and p-coumaric acid. The study can lead to the development of starter culture potentially active in biological debittering of olives during fermentation in order to unify the debittering and fermentation process during elaboration of table olives.

Topics: Food Handling; Food Microbiology; Fruit; Iridoid Glucosides; Iridoids; Lactobacillus plantarum; Olea; Phenols; Sodium Chloride

Interaction of oleuropein, the major bio-phenol in olive leaf and fruit, with salmon sperm double-stranded DNA was investigated by employing electronic absorption titrations, fluorescence quenching spectroscopy, competitive fluorescence spectroscopy, thermal denaturation and voltammetric studies. Titration of oleuropein with the DNA caused a hypochromism accompanied with a red shift indicating an intercalative mode of interaction. Binding constant of 1.4×10(4) M(-1) was obtained for this interaction. From the curves of fluorescence titration of oleuropein with the DNA, binding constant and binding sites were calculated to be 8.61×10(3) M(-1) and 1.05, respectively. Competitive studies with ethidium bromide (a well-known DNA intercalator) showed that the bio-phenol could take the place of ethidium bromide in the DNA intercalation sites. The interaction of oleuropein with DNA was also studied electrochemically. In the presence of the DNA, the anodic and cathodic peak currents of oleuropein decreased accompanied with increases in peak-to-peak potential separation and formal potential, indicating the intercalation of oleuropein into the DNA double helix. Moreover, melting temperature of the DNA was found to increase in the presence of oleuropein, indicating the stabilization of the DNA double helix due to an intercalative interaction.

Topics: Animals; DNA; Intercalating Agents; Iridoid Glucosides; Iridoids; Male; Models, Molecular; Nucleic Acid Conformation; Nucleic Acid Denaturation; Olea; Salmon; Spermatozoa

Potato, tomato, eggplant and pumpkin were deep fried, sautéed and boiled in Mediterranean extra virgin olive oil (EVOO), water, and a water/oil mixture (W/O). We determined the contents of fat, moisture, total phenols (TPC) and eighteen phenolic compounds, as well as antioxidant capacity in the raw vegetables and compared these with contents measured after cooking. Deep frying and sautéing led to increased fat contents and TPC, whereas both types of boiling (in water and W/O) reduced the same. The presence of EVOO in cooking increased the phenolics identified in the raw foods as oleuropein, pinoresinol, hydroxytyrosol and tyrosol, and the contents of vegetable phenolics such as chlorogenic acid and rutin. All the cooking methods conserved or increased the antioxidant capacity measured by DPPH, FRAP and ABTS. Multivariate analyses showed that each cooked vegetable developed specific phenolic and antioxidant activity profiles resulting from the characteristics of the raw vegetables and the cooking techniques.

Topics: Antioxidants; Benzothiazoles; Chlorogenic Acid; Chromatography, High Pressure Liquid; Cluster Analysis; Cooking; Cucurbita; Dietary Fats; Furans; Iridoid Glucosides; Iridoids; Lignans; Multivariate Analysis; Olive Oil; Phenols; Phenylethyl Alcohol; Rutin; Solanum lycopersicum; Solanum melongena; Solanum tuberosum; Sulfonic Acids; Vegetables

Myocardial infarction remains the major cause of global death due to cardiovascular diseases. This study aimed to assess the protective role of oleuropein in attenuating the cardiac remodeling in isoproterenol-induced myocardial infarction in rats.. Male Wistar rats were randomly divided into four groups, control, isoproterenol (Isop) and pretreated animals with oleuropein at two different doses (20 and 40 mg/kg) orally for 7 days and intoxicated with isoproterenol (Isop+Oleu20) and (Isop+Oleu40) groups. The subcutaneous injection of isoproterenol (100 mg/kg body weight) to untreated rats for two consecutive days showed significant increases in ST-segment elevation, heart weight index and alteration in the ECG pattern and hemodynamic function. Else, serum levels of cardiac troponin-T, creatine kinase isoenzyme (CK-MB), lactate dehydrogenase (LDH) and alanine aminotransferase (ALT) underwent a notable rise in serum of Isop group by (345, 82, 73 and 106%, respectively) as compared to normal rats. Isoproterenol-induced myocardial injury was evidenced by alteration in serum lipids profile and increased activities of pancreatic lipase by 94% and angiotensin-converting enzyme (ACE) by 78% which reflects the occurrence of cardiac remodeling process. The histopathological findings of the infarcted group showed myocardium necrosis and cells inflammatory infiltration. However, the treatment with oleuropein gave a good protection of the myocardium by decreasing cardiac injury markers specially troponin-T, restoring hemodynamic parameters and attenuating cardiac remodeling process through inhibition of ACE activity.. Oleuropein offers high preventive effects from cardiac remodeling process in rats with acute myocardial infarction.

Topics: Adrenergic beta-Agonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Dose-Response Relationship, Drug; Electrocardiography; Heart Function Tests; Hemodynamics; Iridoid Glucosides; Iridoids; Isoproterenol; Male; Myocardial Infarction; Olea; Plant Roots; Rats; Rats, Wistar; Vasodilator Agents; Ventricular Remodeling

Oleuropein promoted cultured human follicle dermal papilla cell proliferation and induced LEF1 and Cyc-D1 mRNA expression and β-catenin protein expression in dermal papilla cells. Nuclear accumulation of β-catenin in dermal papilla cells was observed after oleuropein treatment. Topical application of oleuropein (0.4 mg/mouse/day) to C57BL/6N mice accelerated the hair-growth induction and increased the size of hair follicles in telogenic mouse skin. The oleuropein-treated mouse skin showed substantial upregulation of Wnt10b, FZDR1, LRP5, LEF1, Cyc-D1, IGF-1, KGF, HGF, and VEGF mRNA expression and β-catenin protein expression.. These results demonstrate that topical oleuroepin administration induced anagenic hair growth in telogenic C57BL/6N mouse skin. The hair-growth promoting effect of oleuropein in mice appeared to be associated with the stimulation of the Wnt10b/β-catenin signaling pathway and the upregulation of IGF-1, KGF, HGF, and VEGF gene expression in mouse skin tissue.

Topics: Animals; Cell Line; Cell Proliferation; Hair Follicle; Humans; Intercellular Signaling Peptides and Proteins; Iridoid Glucosides; Iridoids; Male; Mice; Mice, Inbred C57BL; Up-Regulation; Wnt Signaling Pathway

Podocyte injuries are associated with progression of diabetic nephropathy (DN). Apelin, an adipocyte-derived peptide, has been reported to be a promoting factor for DN. In this study, we aim to determine whether apelin promotes progression of DN by inducing podocyte dysfunction. kk-Ay mice were used as models for DN. Apelin and its antagonist, F13A were intraperitoneally administered for 4 weeks, respectively. Renal function and foot process proteins were analysed to evaluate the effects of apelin on kk-Ay mice and podocytes. Apelin increased albuminuria and decreased podocyte foot process proteins expression in kk-Ay mice, which is consistent with the results that apelin receptor (APLNR) levels increased in glomeruli of patients or mice with DN. In cultured podocytes, high glucose increased APLNR expression and apelin administration was associated with increased permeability and decreased foot process proteins levels. All these dysfunctions were associated with decreased 26S proteasome activities and increased polyubiquitinated proteins in both kk-Ay mice and cultured podocytes, as demonstrated by 26S proteasome activation with cyclic adenosine monophosphate (cAMP) or oleuropein. These effects seemed to be related to endoplasmic reticulum (ER) stress, as apelin increased C/EBP homologous protein (CHOP) and peiFα levels while cAMP or oleuropein reduced it in high glucose and apelin treated podocytes. These results suggest that apelin induces podocyte dysfunction in DN through ER stress which was induced by decreased proteasome activities in podocytes.

Topics: Albumins; Animals; Apelin Receptors; Basement Membrane; Cell Membrane Permeability; Creatinine; Cyclic AMP; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Endoplasmic Reticulum Stress; Female; Glucose; Humans; Intercellular Signaling Peptides and Proteins; Iridoid Glucosides; Iridoids; Kidney; Kidney Function Tests; Male; Mice, Inbred C57BL; Middle Aged; Podocytes; Proteasome Endopeptidase Complex; Proteasome Inhibitors; Receptors, G-Protein-Coupled

Several naturally occurring dietary polyphenols with chemopreventive or anticancer properties are topoisomerase II poisons. To identify additional phytochemicals that enhance topoisomerase II-mediated DNA cleavage, a library of 341 Mediterranean plant extracts was screened for activity against human topoisomerase IIα. An extract from Phillyrea latifolia L., a member of the olive tree family, displayed high activity against the human enzyme. On the basis of previous metabolomics studies, we identified several polyphenols (hydroxytyrosol, oleuropein, verbascoside, tyrosol, and caffeic acid) as potential candidates for topoisomerase II poisons. Of these, hydroxytyrosol, oleuropein, and verbascoside enhanced topoisomerase II-mediated DNA cleavage. The potency of these olive metabolites increased 10-100-fold in the presence of an oxidant. Hydroxytyrosol, oleuropein, and verbascoside displayed hallmark characteristics of covalent topoisomerase II poisons. (1) The activity of the metabolites was abrogated by a reducing agent. (2) Compounds inhibited topoisomerase II activity when they were incubated with the enzyme prior to the addition of DNA. (3) Compounds were unable to poison a topoisomerase IIα construct that lacked the N-terminal domain. Because hydroxytyrosol, oleuropein, and verbascoside are broadly distributed across the olive family, extracts from the leaves, bark, and fruit of 11 olive tree species were tested for activity against human topoisomerase IIα. Several of the extracts enhanced enzyme-mediated DNA cleavage. Finally, a commercial olive leaf supplement and extra virgin olive oils pressed from a variety of Olea europea subspecies enhanced DNA cleavage mediated by topoisomerase IIα. Thus, olive metabolites appear to act as topoisomerase II poisons in complex formulations intended for human dietary consumption.

Topics: DNA Cleavage; DNA Topoisomerases, Type II; Drug Screening Assays, Antitumor; Fruit; Glucosides; Humans; Iridoid Glucosides; Iridoids; Olea; Phenols; Phenylethyl Alcohol; Plant Bark; Plant Extracts; Plant Leaves; Plasmids; Topoisomerase II Inhibitors

Olive leaf has great potential as a natural antioxidant, and one of its major phenolic components is oleuropein. In this study, the antioxidant activity of oleuropein against oxygen-centered radicals was measured by examining its sparing effects on the peroxyl radical-induced decay of fluorescein and pyrogallol red, in comparison with related compounds. The antioxidant capacity of oleuropein against lipid peroxidation was also assessed through its effect on the free radical-induced oxidation of methyl linoleate in a micelle system. On a molar basis, oleuropein and hydroxytyrosol inhibited the decay of fluorescein for longer than both homovanillic alcohol and the vitamin-E mimic 2-carboxy-2,5,7,8-tetramethyl-6-chromanol (Trolox), but did not suppress pyrogallol red decay in a concentration-dependent manner. Measurement of the fluorescein decay period revealed that the stoichiometric number of oleuropein and hydroxytyrosol against peroxyl radicals was twice that of Trolox, which is substantially higher than expectations based on chemical structure. Oleuropein and hydroxytyrosol were also more effective than Trolox and homovanillic alcohol at suppressing the oxidation of methyl linoleate in the micelle system. Thus, both oleuropein and hydroxytyrosol exhibit high antioxidative activity against lipid peroxidation induced by oxygen-centered radicals, but the high reactivity of phenolic/catecholic radicals makes their mechanism of action complex.

Topics: Antioxidants; Chromans; Free Radical Scavengers; Homovanillic Acid; Iridoid Glucosides; Iridoids; Linoleic Acids; Lipid Peroxidation; Micelles; Olea; Oxidation-Reduction; Phenylethyl Alcohol; Plant Leaves

Oleuropein, a phenolic compound found in abundance in olive leaves, has beneficial effects on various diseases. However, it is unknown whether an oleuropein-rich diet is efficacious against type 2 diabetic phenotypes. In this study, we investigated the effects of the oleuropein-containing supplement OPIACE, whose oleuropein content exceeds 35% (w/w), on the diabetic phenotypes in type 2 diabetes model Tsumura Suzuki Obese Diabetes (TSOD) mouse. TSOD mice were fed OPIACE at 4 weeks of age, i.e., before the TSOD mice exhibited diabetic phenotypes. We revealed that OPIACE attenuated hyperglycemia and impaired glucose tolerance in TSOD mice over the long-term (from 10 to 24 weeks of age) but had no effect on obesity. Furthermore, we demonstrated that OPIACE mildly reduced oxidative stress in TSOD mice by 26.2% and attenuated anxiety-like behavioral abnormality in aged TSOD mice. The results suggest that oleuropein suppresses the progression of type 2 diabetes and diabetes-related behavioral abnormality over the long-term.

Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 2; Diet; Disease Models, Animal; Glucose Tolerance Test; Humans; Hyperglycemia; Iridoid Glucosides; Iridoids; Male; Mice; Mice, Obese

Olea europaea L. leaves are an agricultural waste product with a high concentration of phenolic compounds; especially oleuropein. Oleuropein has been shown to exhibit anti-proliferative activity against a number of cancer types. However, they have not been tested against pancreatic cancer, the fifth leading cause of cancer related death in Western countries. Therefore, water, 50% ethanol and 50% methanol extracts of Corregiola and Frantoio variety Olea europaea L. leaves were investigated for their total phenolic compounds, total flavonoids and oleuropein content, antioxidant capacity and anti-proliferative activity against MiaPaCa-2 pancreatic cancer cells. The extracts only had slight differences in their phytochemical properties, and at 100 and 200 μg/mL, all decreased the viability of the pancreatic cancer cells relative to controls. At 50 μg/mL, the water extract from the Corregiola leaves exhibited the highest anti-proliferative activity with the effect possibly due to early eluting HPLC peaks. For this reason, olive leaf extracts warrant further investigation into their potential anti-pancreatic cancer benefits.

Topics: Antineoplastic Agents; Antioxidants; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Flavonoids; Humans; Iridoid Glucosides; Iridoids; Olea; Pancreatic Neoplasms; Phenols; Plant Extracts; Plant Leaves

Deltamethrin (DM) is a synthetic pyrethroid insecticide that can elicit neurotoxicity, leading to apoptosis. There is accumulating evidence that oleuropein (OE) has anti-apoptotic effect. The purpose of this study was to determine the anti-apoptotic effect of OE pretreatment in the neuronal cells of cerebral cortex.. Rats were randomly divided into four groups each containing five rats: DM-treated group (12.5 mg/kg, a single dose), OE-treated group (20 mg/kg per day), DM + OE-treated group, and vehicle group. Sections of the brain were obtained 24 hours after DM injection and studied for histopathological and immunohistochemistry assessment.. The histopathological assessments showed lesser characteristics of neural degeneration in DM + OE group compared with DM group. Greater Bcl-2 and attenuated Bax expression could be detected in the DM + OE treated-mice compared with DM group.. The results suggested that DM-induced neurotoxicity can be subsided by OE.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Cerebral Cortex; Female; Insecticides; Iridoid Glucosides; Iridoids; Neurons; Neuroprotective Agents; Neurotoxicity Syndromes; Neurotoxins; Nitriles; Proto-Oncogene Proteins c-bcl-2; Pyrethrins; Rats; Rats, Sprague-Dawley

To date, numerous studies have reported on the antidiabetic properties of various plant extracts through inhibition of carbohydrate-hydrolysing enzymes. The objective of this research was to evaluate the inhibitory effect of the hydroxytyrosol and the oleuropein against α-amylase and α-glucosidase. The hydroxytyrosol was purified from olive leaves. The result shows that the hydroxytyrosol had the strongest α-glucosidase inhibitory effect with IC50 values of 150 μM with mild inhibition against α-amylase. The enzyme kinetic studies, using Lineweaver-Burk indicated that, in the presence of the hydroxytyrosol, the Michaelis-Menton constant (Km) remained constant but the maximal velocity (Vmax) decreased, revealing a non-competitive type of inhibition with inhibition constants; Ki for the formation of the inhibitor-enzyme complex and Kis for the formation of the inhibitor-enzyme-substrate complex of 104.3 and 150.1 μM, respectively. On the other hand, oleuropein showedan uncompetitive inhibition. The concentrations used in this work were below cytotoxic levels observed at 400 μM. However, at 600 μM, the hydroxytyrosol significantly decreased viability of the Caco-2 cells (p < 0.05) and in the case of the oleuropein, there's an increase in cell number compared to control (p < 0.05). These results suggest that the hydroxytyrosol and oleuropein are two potential effective α-glucosidase inhibitors for management of postprandial hyperglycemia.

Topics: alpha-Amylases; alpha-Glucosidases; Caco-2 Cells; Cell Survival; Dose-Response Relationship, Drug; Glycoside Hydrolase Inhibitors; Humans; Hyperglycemia; Iridoid Glucosides; Iridoids; Olea; Phenylethyl Alcohol; Phytotherapy; Plant Leaves

Olive oil has been recognized to possess many therapeutic applications. Its beneficial effects arise from many causes, but one of them lies on the presence of oleuropein aglycone (OA). OA presents a plethora of pharmacological beneficial properties. Although there is a great research going on the effect of polyphenols and their derivatives on different aspects of health, much less knowledge is available of the molecular basis of their beneficial effects. Due to the prominent hydrophobic character of OA and its high phospholipid/water partition coefficient, some of its possible effects on biological systems might be related to its capacity to interact with and locate into the membrane. In this work we have aimed to locate the molecule of OA in two membrane model systems, i.e., POPC/Chol and POPC/POPG/Chol. OA locates in between the hydrocarbon acyl chains of the phospholipids but its specific location and molecular interactions differ depending on the lipid system. OA is nearer to the membrane surface in the POPC/Chol system but it is located at a deeper position in the POPC/POPG/Chol system. Furthermore, OA seems to interact stronger with POPG than with POPC, implying the existence of specific interactions with negatively-charged phospholipids. Some of the biological effects of OA could be due to its preferential location in the membrane depending on the membrane lipid composition as well as the existence of specific interactions with specific phospholipids.

Topics: Cholesterol; Iridoid Glucosides; Iridoids; Kinetics; Lipid Bilayers; Membrane Lipids; Molecular Dynamics Simulation; Molecular Structure; Phosphatidylcholines; Phosphatidylglycerols; Water

The healthy effects of plant polyphenols, some of which characterize the so-called Mediterranean diet, have been shown to arise from epigenetic and biological modifications resulting, among others, in autophagy stimulation. Our previous work highlighted the beneficial effects of oleuropein aglycone (OLE), the main polyphenol found in the extra virgin olive oil, against neurodegeneration both in cultured cells and in model organisms, focusing, in particular, autophagy activation. In this study we investigated more in depth the molecular and cellular mechanisms of autophagy induction by OLE using cultured neuroblastoma cells and an OLE-fed mouse model of amylod beta (Aβ) deposition. We found that OLE triggers autophagy in cultured cells through the Ca2+-CAMKKβ-AMPK axis. In particular, in these cells OLE induces a rapid release of Ca2+ from the SR stores which, in turn, activates CAMKKβ, with subsequent phosphorylation and activation of AMPK. The link between AMPK activation and mTOR inhibition was shown in the OLE-fed animal model in which we found that decreased phospho-mTOR immunoreactivity and phosphorylated mTOR substrate p70 S6K levels match enhanced phospho-AMPK levels, supporting the idea that autophagy activation by OLE proceeds through mTOR inhibition. Our results agree with those reported for other plant polyphenols, suggesting a shared molecular mechanism underlying the healthy effects of these substances against ageing, neurodegeneration, cancer, diabetes and other diseases implying autophagy dysfunction.

Topics: AMP-Activated Protein Kinases; Animals; Autophagy; Disease Models, Animal; Humans; Iridoid Glucosides; Iridoids; Mice; Signal Transduction; TOR Serine-Threonine Kinases

A high-performance thin-layer chromatographic methodology was developed and validated for the isolation and quantitative determination of oleuropein in two extracts of Olea europaea leaves. OLE_A was a crude acetone extract, while OLE_AA was its defatted residue. Initially, high-performance thin-layer chromatography was employed for the purification process of oleuropein with fast centrifugal partition chromatography, replacing high-performance liquid-chromatography, in the stage of the determination of the distribution coefficient and the retention volume. A densitometric method was developed for the determination of the distribution coefficients, KC = CS/CM. The total concentrations of the target compound in the stationary phase (CS) and in the mobile phase (CM) were calculated by the area measured in the high-performance thin-layer chromatogram. The estimated Kc was also used for the calculation of the retention volume, VR, with a chromatographic retention equation. The obtained data were successfully applied for the purification of oleuropein and the experimental results confirmed the theoretical predictions, indicating that high-performance thin-layer chromatography could be an important counterpart in the phytochemical study of natural products. The isolated oleuropein (purity > 95%) was subsequently used for the estimation of its content in each extract with a simple, sensitive and accurate high-performance thin-layer chromatography method. The best fit calibration curve from 1.0 µg/track to 6.0 µg/track of oleuropein was polynomial and the quantification was achieved by UV detection at λ 240 nm. The method was validated giving rise to an efficient and high-throughput procedure, with the relative standard deviation % of repeatability and intermediate precision not exceeding 4.9% and accuracy between 92% and 98% (recovery rates). Moreover, the method was validated for robustness, limit of quantitation, and limit of detection. The amount of oleuropein for OLE_A, OLE_AA, and an aqueous extract of olive leaves was estimated to be 35.5% ± 2.7, 51.5% ± 1.4, and 12.5% ± 0.12, respectively. Statistical analysis proved that the method is repeatable and selective, and can be effectively applied for the estimation of oleuropein in olive leaves' extracts, and could potentially replace high-performance liquid chromatography methodologies developed so far. Thus, the phytochemical investigation of oleuropein could be based on high-performance thin-layer chromatog

Topics: Centrifugation; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Iridoid Glucosides; Iridoids; Olea; Plant Leaves; Solvents

We have previously demonstrated that oleuropein (OL) and hydroxytyrosol (HT) reduce 17β-estradiol-mediated proliferation in MCF-7 breast cancer (BC) cells without affecting the classical genomic action of estrogen receptor (ER), but activating instead the ERK1/2 pathway. Here, we hypothesized that this inhibition could be mediated by a G-protein-coupled receptor named GPER/GPR30. Using the ER-negative and GPER-positive SKBR3 BC cells as experimental model, we investigated the effects of OL and HT on GPER-mediated activation of downstream pathways.. Docking simulations and ligand-binding studies evidenced that OL and HT are able to bind GPER. MTT cell proliferation assays revealed that both phenols reduced SKBR3 cell growth; this effect was abolished silencing GPER. Focusing on OL and HT GPER-mediated pathways, using Western blot analysis we showed a sustained ERK1/2 activation triggering an intrinsic apoptotic pathway.. Showing that OL and HT work as GPER inverse agonists in ER-negative and GPER-positive SKBR3 BC cells, we provide novel insights into the potential of these two molecules as tools in the therapy of this subtype of BC.

Topics: Apoptosis; Breast Neoplasms; Cell Proliferation; Extracellular Signal-Regulated MAP Kinases; Female; Humans; Iridoid Glucosides; Iridoids; Phenylethyl Alcohol; Receptors, Estrogen; Receptors, G-Protein-Coupled; Signal Transduction; Tumor Cells, Cultured

Preclinical studies suggest a potential protective effect of oleuropein in osteoporosis, and one of the proposed mechanisms is the modulation of the oxidative stress. Oleuropein bioavailability and its effect on antioxidant status in pre- and postmenopausal women are unknown. The aim of the present study was to investigate the oral bioavailability of an olive leaf extract rich in oleuropein (40 %) and its effect on antioxidant status in postmenopausal women compared to premenopausal women.. Premenopausal (n = 8) and postmenopausal women (n = 8) received 250 mg of olive leaf extract, blood samples (t = 0, 1, 2, 3, 4, 6, 8, 12, 16 and 24 h) were taken, and 24-h urine divided into five fractions was collected. Olive-leaf-extract-derived metabolites were analyzed in plasma and urine by HPLC-ESI-QTOF and UPLC-ESI-QqQ, and pharmacokinetics parameters were determined. Ferric reducing antioxidant ability and malondialdehyde levels were measured in plasma.. Plasma levels of hydroxytyrosol glucuronide, hydroxytyrosol sulfate, oleuropein aglycon glucuronide and oleuropein aglycon derivative 1 were higher in postmenopausal women. MDA levels were significantly decreased (32%) in postmenopausal women and inversely correlated with hydroxytyrosol sulfate levels. Postmenopausal women excreted less sulfated metabolites in urine than premenopausal women.. Our results suggest that postmenopausal women could be a target population for the intake of olive phenolics in order to prevent age-related and oxidative stress-related processes such as osteoporosis.

Topics: Adolescent; Adult; Aged; Antioxidants; Biological Availability; Chromatography, High Pressure Liquid; Female; Humans; Iridoid Glucosides; Iridoids; Malondialdehyde; Middle Aged; Olea; Oxidative Stress; Phenols; Plant Extracts; Plant Leaves; Postmenopause; Premenopause; Young Adult

Translational research needs valid animal models of disease to discover new pathogenetic aspects and treatments. In Alzheimer's disease (AD), transgenic models are of great value for AD research and drug testing.. It was the aim of this study to analyze the power of dietary polyphenols against neurodegeneration by investigating the effects of oleuropein aglycone (OLE), the main phenol in the extra virgin olive oil (EVOO), a key component of the Mediterranean diet (MD), in a mouse model of amyloid-β deposition.. TgCRND8 mice (3.5 months old), expressing the mutant KM670/671NL+V717F h-βAPP695 transgene, and wild-type (wt) mice were used to study in vivo the effects of an 8-week dietary supplementation with OLE (50 mg/kg of diet) [Grossi et al: PLoS One 2013;8:e71702], following the European Communities Council Directive 86/609 (DL 116/92) and National Guidelines (permit number: 283/2012-B).. OLE administration ameliorates memory dysfunction, raises a significant autophagic response in the cortex and promotes the proliferation of newborn cells in the subgranular zone of the dentate gyrus of the hippocampus.. Our findings support the beneficial effects of EVOO and highlight the possibility that continuous intake of high doses of OLE, both as a nutraceutical or as a food integrator, may prevent/delay the appearance of AD and reduce the severity of its symptoms.

Topics: Alzheimer Disease; Animal Feed; Animals; Brain; Diet, Mediterranean; Disease Models, Animal; Humans; Iridoid Glucosides; Iridoids; Mice, Transgenic; Neuroprotective Agents; Olive Oil; Plant Oils; Translational Research, Biomedical

Previous data have shown that oleuropein aglycone (OLE), the main secoiridoid phenol present in extra virgin olive oil, counteracts in vitro aggregation of the Aβ42 peptide and protects cultured cells and model organisms against aggregates toxicity. In this study we investigated the relative tissue toxicity of Aβ42 aggregated in vitro in the presence or in the absence of OLE by injecting the nucleus basalis magnocellularis (NBM) of adult male Wistar rats with a 1.5 μl solution containing OLE (450 μM) or Aβ42 (50 μM) aggregated in the absence (oligomers) or in the presence of 450 μM OLE. Control rats were injected with vehicle (1.5 μl). Thirty days after injection, the number of choline acetyltransferase (ChAT)-positive neurons, glia reaction and the Aβ peptide levels were detected by immunohistochemistry. An apparent reduction in the amount of soluble A11-positive oligomers was detected in the NBM injected with Aβ42 aggregated with OLE, as compared with the NBM injected with Aβ42 alone. In the latter case, the number of ChAT-positive neurons was significantly reduced (≈-33%) respect to that recorded in the NBM injected with phosphate buffer, OLE or Aβ42 aggregated with OLE. A markedly attenuated Aβ-induced astrocytes and microglia reaction was also found in the NBM injected with Aβ42 aggregated with OLE. Altogether, these data provide additional support to the anti-aggregation, neuroprotective and anti-inflammatory activities of this natural phenol, confirming its beneficial properties against neurodegeneration.

Topics: Amyloid beta-Peptides; Animals; Basal Nucleus of Meynert; Brain; Iridoid Glucosides; Iridoids; Male; Neuroglia; Neurons; Neuroprotective Agents; Peptide Fragments; Pyrans; Rats, Wistar

Oleuropein is a phenolic compound which is present in the olive leaf extract. The purpose of the present study was to investigate the neuroprotective effect of oleuropein as an antioxidant agent on the substantia nigra in aged rats.. Twenty 18-month-old Wistar rats (450-550 g) were randomly divided into control and experimental groups. The experimental group received a daily single dose of 50 mg/kg of oleuropein by oral gavage for 6 months. The control group received only distilled water. All rats were sacrificed two hours after the last gavage and the brains were removed and midbrains were cut. One part of the midbrains were homogenized and centrifuged. The tissue supernatant was assayed for lipid peroxidation (LPO) and antioxidant enzyme activities. The other part of midbrains fixed and embedded in paraffin, then processed for Nissl and immunohistochemistry (IHC) staining. Data was analyzed using SPSS by t-test. Differences were considered significant for P<0.05.. The level of LPO in midbrain of the rats was decreased significantly in the experimental group, but superoxide dismutase, catalase and glutathione peroxidase activities were increased in experimental group compared to control group (P<0.05). Morphometric analyses showed significantly that the experimental group had more neurons in substantia nigra pars compacta (SNc) either in Nissl or IHC staining when compared to control (P<0.05).. The results of the present study indicate that treatment of the old rats with oleuropein reduces the oxidative damage in SNc by increasing the antioxidant enzyme activities.

Topics: Aging; Animals; Antihypertensive Agents; Antioxidants; Catalase; Dopaminergic Neurons; Glutathione Peroxidase; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Male; Malondialdehyde; Mesencephalon; Neuroprotective Agents; Nissl Bodies; Oxidative Stress; Random Allocation; Rats; Rats, Wistar; Reactive Oxygen Species; Substantia Nigra; Superoxide Dismutase

Breast cancer is a major health problem worldwide. Olive oil induces apoptosis in some cancer cells due to phenolic compounds like oleuropein. Although oleuropein has anticancer activity, the underlying mechanisms of action remain unknown. The study aimed to assess the mechanism of oleuropin-induced breast cancer cell apoptosis.. p53, Bcl-2 and Bax gene expression was evaluated by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) in luminal MCF-7 cells.. Oleuropein-induced apoptosis was accompanied by up-regulation of both p53 and Bax gene expression levels and down-regulation in Bcl2.. Oleuropein induces apoptosis in breast tumour cells via a p53-dependent pathway mediated by Bax and Bcl2 genes. Therefore, oleuropein may have therapeutic potential in breast cancer patients by inducing apoptosis via activation of the p53 pathway.

Topics: Antihypertensive Agents; bcl-2-Associated X Protein; Blotting, Western; Breast Neoplasms; Cell Proliferation; Female; Gene Expression Regulation, Neoplastic; Humans; Iridoid Glucosides; Iridoids; Proto-Oncogene Proteins c-bcl-2; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tumor Cells, Cultured; Tumor Suppressor Protein p53

A previously developed method for measurement of oleocanthal and oleacein in olive oil by quantitative (1)H NMR was expanded to include the measurement of the monoaldehydic forms of oleuropein and ligstroside aglycons. The method was validated and applied to the study of 340 monovarietal Greek and Californian olive oils from 23 varieties and for a 3-year period. A wide variation concerning the concentrations of all four secoiridoids was recorded. The concentration of each one ranged from nondetectable to 711 mg/kg and the sum of the four major secoiridoids (named as D3) ranged from nondetectable to 1534 mg/kg. Examination of the NMR profile of the olive oil extract before and after contact with normal or reversed stationary chromatography phase proved the artificial formation of the 5S,8S,9S aldehydic forms of oleuropein and ligstroside aglycon isomers during chromatography. Finally, methyl elenolate was identified for the first time as a minor constituent of olive oil.

Topics: Glucosides; Iridoid Glucosides; Iridoids; Isomerism; Magnetic Resonance Spectroscopy; Olive Oil; Plant Oils; Pyrans

Oleuropein, a natural phenolic compound, prevents acute doxorubicin (DXR)-induced cardiotoxicity but there is no evidence regarding its role in chronic DXR-induced cardiomyopathy (DXR-CM). In the present study, we investigated the role of oleuropein in DXR-CM by addressing cardiac geometry and function (transthoracic echocardiography), cardiac histopathology, nitro-oxidative stress (MDA, PCs, NT), inflammatory cytokines (IL-6, Big ET-1), NO homeostasis (iNOS and eNOS expressions), kinases involved in apoptosis and metabolism (Akt, AMPK) and myocardial metabonomics. Rats were randomly divided into 6 groups: Control, OLEU-1 and OLEU-2 [oleuropein at 1000 and 2000 mg/kg in total, respectively, intraperitoneally (i.p.) for 14 days], DXR (18 mg/kg, i.p. divided into 6 equal doses for 2 weeks), DXR-OLEU-1 and DXR-OLEU-2 (both oleuropein and DXR as previously described). Impaired left ventricular contractility and inflammatory and degenerative pathology lesions were encountered only in the DXR group. The DXR group also had higher MDA, PCs, NT, IL-6 and Big ET-1 levels, higher iNOS and lower eNOS, Akt and AMPK activation compared to controls and the oleuropein-treated groups. Metabonomics depicted significant metabolite alterations in the DXR group suggesting perturbed energy metabolism and protein biosynthesis. The effectiveness of DXR in inhibiting cell proliferation is not compromised when oleuropein is present. We documented an imbalance between iNOS and eNOS expressions and a disturbed protein biosynthesis and metabolism in DXR-CM; these newly recognized pathways in DXR cardiotoxicity may help identifying novel therapeutic targets. Activation of AMPK and suppression of iNOS by oleuropein seem to prevent the structural, functional and histopathological cardiac effects of chronic DXR toxicity.

Topics: Animals; Antibiotics, Antineoplastic; Blotting, Western; Cardiomyopathies; Cell Proliferation; Doxorubicin; Echocardiography; Energy Metabolism; Immunoenzyme Techniques; Interleukin-6; Iridoid Glucosides; Iridoids; Male; Metabolomics; Myocytes, Cardiac; Oxidative Stress; Rats; Rats, Wistar; Vasodilator Agents

The dialdehydes oleacein (2) and oleocanthal (4) are closely related to oleuropein (1) and ligstroside (3), the two latter compounds being abundant iridoids of Olea europaea. By exploiting oleuropein isolated from the plant leaf extract, an efficient procedure has been developed for a one-step semisynthesis of oleacein under Krapcho decarbomethoxylation conditions. Highlighted is the fact that 5-lipoxygenase is a direct target for oleacein with an inhibitory potential (IC50: 2 μM) more potent than oleocanthal (4) and oleuropein (1). This enzyme catalyzes the initial steps in the biosynthesis of pro-inflammatory leukotrienes. Taken together, the methodology presented here offers an alternative solution to isolation or total synthesis for the procurement of oleacein, thus facilitating the further development as a potential anti-inflammatory agent.

Topics: Aldehydes; Anti-Inflammatory Agents; Arachidonate 5-Lipoxygenase; Cyclopentane Monoterpenes; Glucosides; Humans; Iridoid Glucosides; Iridoids; Lipoxygenase Inhibitors; Molecular Structure; Olea; Phenols; Plant Extracts; Plant Leaves; Pyrans

Oleuropein is a bioactive natural product from olives known to display a broad variety of health beneficial properties. However its presence in most edible olives is lowered due to debittering. In this respect, we envisaged the incorporation of oleuropein into dairy products (cow's milk and yogurt) aiming to produce novel functional foods. Additionally, an analytical method for the monitoring of oleuropein in milk and yogurt was also developed and validated. Oleuropein was not affected during heat treatment of milk, while during the milk fermentation process it was not hydrolysed by the produced acids. Oleuropein was not metabolised by lactic acid bacteria, did not inhibit their growth and its stability in the final products was proven. The novel products displayed same taste, colour and texture as the conventional ones. Results herein indicate that oleuropein can be added as an active ingredient in milk and yogurt preparations to provide two novel functional dairy products.

Topics: Animals; Cattle; Fermentation; Food Additives; Hot Temperature; Humans; Iridoid Glucosides; Iridoids; Milk; Taste; Yogurt

Hydroxytyrosol, tyrosol, and oleuropein, the main phenols present in extra virgin olive oil, have been reported to exert several biochemical and pharmacological effects. Here, we investigated the short-term effects of these compounds on lipid synthesis in primary-cultured rat-liver cells. Hydroxytyrosol, tyrosol and oleuropein inhibited both de novo fatty acid and cholesterol syntheses without an effect on cell viability. The inhibitory effect of individual compounds was already evident within 2 h of 25 μM phenol addition to the hepatocytes. The degree of cholesterogenesis reduction was similar for all phenol treatments (-25/30%), while fatty acid synthesis showed the following order of inhibition: hydroxytyrosol (-49%) = oleuropein (-48%) > tyrosol (-30%). A phenol-induced reduction of triglyceride synthesis was also detected. To clarify the lipid-lowering mechanism of these compounds, their influence on the activity of key enzymes of fatty acid biosynthesis (acetyl-CoA carboxylase and fatty acid synthase), triglyceride synthesis (diacylglycerol acyltransferase) and cholesterogenesis (3-hydroxy-3-methyl-glutaryl-CoA reductase) was investigated in situ by using digitonin-permeabilized hepatocytes. Acetyl-CoA carboxylase, diacylglycerol acyltransferase and 3-hydroxy-3-methyl-glutaryl-CoA reductase activities were reduced after 2 h of 25 μM phenol treatment. No change in fatty acid synthase activity was observed. Acetyl-CoA carboxylase inhibition (hydroxytyrosol, -41%, = oleuropein, -38%, > tyrosol, -17%) appears to be mediated by phosphorylation of AMP-activated protein kinase. These findings suggest that a decrease in hepatic lipid synthesis may represent a potential mechanism underlying the reported hypolipidemic effect of phenols of extra virgin olive oil.

Topics: Acetyl-CoA Carboxylase; AMP-Activated Protein Kinases; Animals; Cells, Cultured; Cholesterol; Diacylglycerol O-Acyltransferase; Down-Regulation; Fatty Acids; Hepatocytes; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Iridoid Glucosides; Iridoids; Lipids; Lipogenesis; Male; Olive Oil; Phenylethyl Alcohol; Phosphorylation; Plant Oils; Rats, Wistar

Nonalcoholic steatohepatitis (NASH) is characterized by hepatocyte injury and inflammatory cell infiltration, which has been linked to peripheral insulin resistance and increased levels of triglycerides in the liver. The purposes of this study were to establish a mouse model of NASH by feeding mice a 60% high-fat diet (HFD) and to demonstrate the anti-fibrotic effects of oleuropein, which has been shown to have anti-oxidant and anti-inflammatory properties, in this HFD-induced mouse model of NASH. C57BL/6 mice were divided into three groups: a regular diet group (Chow), a HFD group and an oleuropein-supplemented HFD group (OSD), which was fed a 0.05% OSD for 6 months. The effects of oleuropein in this model were evaluated using biochemical, histological and molecular markers. The expression levels of alpha-smooth muscle actin (α-SMA)and collagen type I in the HFD and OSD groups were evaluated using real-time PCR and western blotting. The body weight, biochemical marker levels, nonalcoholic fatty liver disease activity score, homeostasis model of assessment-insulin resistance (HOMA-IR) and leptin levels observed in the HFD group at 9 and 12 months were higher than those observed in the Chow group. The HOMA-IR and leptin levels in the OSD group were decreased compared with the HFD group. In addition, α-SMA and collagen type I expression were decreased by oleuropein treatment. We established a NASH model induced by HFD and demonstrated that this model exhibits the histopathological features of NASH progressing to fibrosis. Our results suggest that oleuropein may be pharmacologically useful in preventing the progression of steatohepatitis and fibrosis and may be a promising agent for the treatment of NASH in humans.

Topics: Actins; Animals; Antihypertensive Agents; Collagen Type I; Diet, High-Fat; Fatty Liver; Fibrosis; Iridoid Glucosides; Iridoids; Leptin; Liver; Mice; Mice, Inbred C57BL

In this study, we evaluated, in the mouse, the effects of 20 mg/kg i.p. daily administration for 15 consecutive days of a blend of polyphenols, containing mostly oleuropein, extracted from the olive leaves (Olea europaea) on brain nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) and on the expression of their receptors, TrkA, TrkB and p75. Polyphenols decreased the levels of reduced glutathione (GSH) and increased the levels of NGF and BDNF in the serum. In the brain, we found decreased levels of NGF and BDNF in the hippocampus and striatum but elevated levels of NGF in the olfactory lobes and hypothalamus and again BDNF potentiation in the olfactory lobes. No changes in TrkA, TrkB and p75 expression were observed. In conclusion, olive polyphenols may not only elicit an activation of the rodent olfactory system by increasing the levels of NGF and BDNF but also be stressing for the animal by reducing both the levels of hippocampal NGF/BDNF and serum GSH and increasing serum levels of NGF and BDNF.

Topics: Animals; Blotting, Western; Brain; Brain-Derived Neurotrophic Factor; Glutathione; Iridoid Glucosides; Iridoids; Male; Mice; Models, Animal; Nerve Growth Factor; Nerve Growth Factors; Neurons; Olea; Plant Leaves; Polyphenols; Receptor, trkA; Receptor, trkB; Receptors, Nerve Growth Factor

Olive leaves are rich in bioactive compounds, which are beneficial for humans. The objective of this work was to assess the influence of processing conditions (drying and extraction) of olive leaves on the extract's bioaccessibility. Thus, extracts obtained from dried olive leaves (hot air drying at 70 and 120 °C or freeze-drying) by means of conventional or ultrasound-assisted extraction were subjected to in vitro digestion. Antioxidant capacity, total phenolic content, and HPLC-DAD/MS/MS analysis were carried out during digestion. The dehydration treatment used for the olive leaves did not have a meaningful influence on bioaccessibility. The digestion process significantly (p<0.05) affected the composition of the extracts. Oleuropein and verbascoside were quite resistant to gastric digestion but were largely degraded in the intestinal phase. Nevertheless, luteolin-7-O-glucoside was the most stable polyphenol during the in vitro simulation (43% bioaccessibility). Therefore, this compound may be taken into consideration in further studies that focus on the bioactivity of olive leaf extracts.

Topics: Agriculture; Antioxidants; Dietary Supplements; Digestion; Food Handling; Glucosides; Humans; Hydrolysis; Industrial Waste; Iridoid Glucosides; Iridoids; Luteolin; Models, Biological; Olea; Phenols; Phytochemicals; Plant Extracts; Plant Leaves; Spain

The mechanism of oleuropein's antihypertensive effects was examined in rat model of simultaneous type 2 diabetes and renal hypertension (diabetic hypertensive). Five groups of male Sprague-Dawley rats including a control, a diabetic-hypertensive group receiving vehicle, and three diabetic-hypertensive groups receiving oleuropein at 20, 40, or 60 mg/kg/day were used. The duration of diabetes was 10 weeks; during the last 4 weeks of which, animals were hypertensive and received vehicle or oleuropein. Systolic blood pressure, glucose and malondialdehyde, heart rate, and maximal response to phenylephrine (PE) in the absence of nitro-L-arginine methyl ester (L-NAME) of oleuropein-treated groups were significantly lower than those of vehicle-treated group. Erythrocyte superoxide dismutase, maximal response to PE in the presence of L-NAME, and maximal response to acetylcholine (Ach) of oleuropein-treated groups were significantly higher than those of vehicle-treated group. The findings indicate that antihypertensive effects of oleuropein might be partly mediated by improving the release of nitric oxide, and antioxidant and sympathoplegic activities.

Topics: Acetylcholine; Animals; Antihypertensive Agents; Arginine; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Disease Models, Animal; Endothelium, Vascular; Hypertension, Renal; Iridoid Glucosides; Iridoids; Male; Molecular Structure; Nitric Oxide; Rats; Rats, Sprague-Dawley; Superoxide Dismutase

We investigated the feasibility of oleuropein as a cross-linking agent for fabricating three-dimensional (3D) porous composite scaffolds for bone tissue engineering. Human-like collagen (HLC) and nanohydroxyapatite (n-HAp) were used to fabricate the composite scaffold by way of cross-linking. The mechanical tests revealed superior properties for the cross-linked scaffolds compared to the uncross-linked scaffolds. The as-obtained composite scaffold had a 3D porous structure with pores ranging from 120 to 300 μ m and a porosity of 73.6 ± 2.3%. The cross-linked scaffolds were seeded with MC3T3-E1 Subclone 14 mouse osteoblasts. Fluorescence staining, the Cell Counting Kit-8 (CCK-8) assay, and scanning electron microscopy (SEM) indicated that the scaffolds enhanced cell adhesion and proliferation. Our results indicate the potential of these scaffolds for bone tissue engineering.

Topics: Animals; Bone and Bones; Cell Adhesion; Chitosan; Collagen; Durapatite; Humans; Iridoid Glucosides; Iridoids; Mice; Microscopy, Electron, Scanning; Nanostructures; Tissue Engineering; Tissue Scaffolds

In the present study, the individual colonic metabolism of the main components of the virgin olive oil phenolic fraction was evaluated by an in vitro model using human faecal microbiota. To assess differences in metabolism related to the molecular structure, four phenolic standards were selected, tyrosol, hydroxytyrosol, hydroxytyrosol acetate and oleuropein. After studying the in vitro colonic metabolism pathways of the individual phenols, the presence of their colonic metabolites was investigated in human faecal samples obtained before and after the sustained intake (3 weeks) of a daily dose of 25 mL of a phenol-enriched olive oil.. The in vitro colon fermentation of the four individual phenolic compounds revealed (i) an increase in phenolic acids, (ii) the stability of hydroxytyrosol and tyrosol and (iii) the high degradation of hydroxytyrosol acetate and oleuropein. Additionally, a moderate intake of a phenol-rich olive oil raised the concentration in human faeces of free hydroxytyrosol and phenylacetic and phenylpropionic acids.. The products of colonic catabolism of olive oil phenolic compounds could be good candidates for novel preventive strategies and open a promising line of research into the preventive action of olive oil phenols in colon and other bowel diseases.

Topics: Acetates; Catechols; Colon; Feces; Fermentation; Humans; In Vitro Techniques; Iridoid Glucosides; Iridoids; Kinetics; Microbiota; Nontherapeutic Human Experimentation; Olive Oil; Phenols; Phenylethyl Alcohol; Plant Oils

Oleuropein and its derivatives are the main phenolic compounds of Olea europaea L. leaf and fruit. The structure-antioxidant activity relationship was considered for studying the radical scavenging activity of this non-flavonoid family of the olive components using density functional theory (DFT). The structure of these compounds were optimized employing the B3LYP/6-31G (d,p) and the role of some structural CH positions was compared with phenolic OH sites on radical scavenging. As a result, a radical unique position (C3) in the oleuropein, characterized by low BDE (Bond Dissociation Enthalpy), reasonable spin density and electron distribution, was identified. The experimental results of the previous publications of oleuropein for NO and OH scavenging confirmed the presence of this unique active site in its molecular structure. According to the results, 2,2-diphenylpicrylhydrazyl (DPPH) cannot find this non-marginal active site. Therefore, DPPH may not be a determinant assay for all antioxidant comparisons. Solvent effects were considered in all calculations using a Polarized Continuum Model (PCM) at the B3LYP/6-31G (d,p) level. Solvation calculations were carried out for benzene (ε=2.3) to simulate the oil environment compared to gas phase.

Topics: Antioxidants; Flavonoids; Fruit; Iridoid Glucosides; Iridoids; Molecular Structure; Olea; Oxidation-Reduction; Phenols; Plant Extracts; Plant Leaves; Thermodynamics

The aim of this study was to determine whether hydroxytyrosol and oleuropein, the major phenols found in olives and olive oil, inhibit mast cell activation induced by immune and non-immune pathways. Purified peritoneal mast cells were preincubated in the presence of test compounds (hydroxytyrosol or oleuropein), before incubation with concanavalin A, compound 48/80 or calcium ionophore A23187. Dose-response and time-dependence studies were carried out. Comparative studies with sodium cromoglycate, a classical mast cell stabilizer, were also made. After incubation the supernatants and pellets were used to determine the β-hexosaminidase content by colorimetric reaction. The percentage of β-hexosaminidase release in each tube was calculated and taken as a measure of mast cell activation. Other samples of cell pellets were used for cell viability studies by the trypan blue dye exclusion test, or fixed for light and electron microscopy. Biochemical and morphological findings of the present study showed for the first time that hydroxytyrosol and oleuropein inhibit mast cell degranulation induced by both immune and non-immune pathways. These results suggest that olive phenols, particularly hydroxytyrosol and oleuropein, may provide insights into the development of useful tools for the prevention and treatment of mast cell-mediated disorders.

Topics: Animals; beta-N-Acetylhexosaminidases; Cell Degranulation; Dose-Response Relationship, Drug; Iridoid Glucosides; Iridoids; Male; Mast Cells; Olive Oil; Phenylethyl Alcohol; Plant Oils; Rats, Wistar

Oleuropein could inhibit growth and/or induce apoptosis in several cancer cell lines. In this study, we investigate how oleuropein strongly induces apoptotic cell death in HeLa human cervical carcinoma cells. Oleuropein induced HeLa cells apoptosis as demonstrated by induction of a sub-G(1) peak in flow cytometry and apoptosis-related morphological changes observed by fluorescence microscopy after being stained by Hoechst 33324. The results also showed that 150 - 200 μM oleuropein–treated HeLa cells were arrested at the G(2)/M phase. Western blot analysis revealed that the phosphorylated ATF-2, c-Jun NH(2)-terminal kinase (JNK) protein, p53, p21, Bax, and cytochrome c protein in the cytoplasm significantly increased in a dose-dependent manner after treatment of oleuropein for 24 h. Additionally, increasing levels of Bax in response to JNK/SPAK signaling, which formed mitochondrial membrane channels, accounted for releasing of cytochrome c and activation of caspase-9 and -3. SP600125 (20 μM), a JNK(1/2) inhibitor, markedly suppressed the formation of apoptotic bodies and JNK activation induced by oleuropein at 200 μM. Thus, oleuropein-induced apoptosis was activated by the JNK/SPAK signal pathway. The result shows that oleuropein holds promise as a potential chemotherapeutic agent for the treatment of HeLa cells.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Apoptosis Inducing Factor; Dose-Response Relationship, Drug; HeLa Cells; Humans; Iridoid Glucosides; Iridoids; JNK Mitogen-Activated Protein Kinases; Mitochondria

Olive (Olea europaea) leaf, an important traditional herbal medicine, displays cardioprotection that may be related to the cellular redox modulating effects of its polyphenolic constituents. This study was undertaken to investigate the protective effect of the ethanolic and methanolic extracts of olive leaves compared to the effects of oleuropein, hydroxytyrosol, and quercetin as a positive standard in a carbonyl compound (4-hydroxynonenal)-induced model of oxidative damage to rat cardiomyocytes (H9c2). Cell viability was detected by the MTT assay; reactive oxygen species production was assessed by the 2',7'-dichlorodihydrofluorescein diacetate method, and the mitochondrial membrane potential was determined using a JC-1 dye kit. Phospho-Hsp27 (Ser82), phospho-MAPKAPK-2 (Thr334), phospho-c-Jun (Ser73), cleaved-caspase-3 (cl-CASP3) (Asp175), and phospho-SAPK/JNK (Thr183/Tyr185) were measured by Western blotting. The ethanolic and methanolic extracts of olive leaves inhibited 4-hydroxynonenal-induced apoptosis, characterized by increased reactive oxygen species production, impaired viability (LD50: 25 µM), mitochondrial dysfunction, and activation of pro-apoptotic cl-CASP3. The ethanolic and methanolic extracts of olive leaves also inhibited 4-hydroxynonenal-induced phosphorylation of stress-activated transcription factors, and the effects of extracts on p-SAPK/JNK, p-Hsp27, and p-MAPKAPK-2 were found to be concentration-dependent and comparable with oleuropein, hydroxytyrosol, and quercetin. While the methanolic extract downregulated 4-hydroxynonenal-induced p-MAPKAPK-2 and p-c-Jun more than the ethanolic extract, it exerted a less inhibitory effect than the ethanolic extract on 4-hydroxynonenal-induced p-SAPK/JNK and p-Hsp27. cl-CASP3 and p-Hsp27 were attenuated, especially by quercetin. Experiments showed a predominant reactive oxygen species inhibitory and mitochondrial protecting ability at a concentration of 1-10 µg/mL of each extract, oleuropein, hydroxytyrosol, and quercetin. The ethanolic extract of olive leaves, which contains larger amounts of oleuropein, hydroxytyrosol, verbascoside, luteolin, and quercetin (by HPLC) than the methanolic one, has more protecting ability on cardiomyocyte viability than the methanolic extract or each phenolic compound against 4-hydroxynonenal-induced carbonyl stress and toxicity.

Topics: Aldehydes; Animals; Antioxidants; Caspase 3; Cell Survival; In Vitro Techniques; Iridoid Glucosides; Iridoids; Mitochondria; Myocytes, Cardiac; Olea; Oxidative Stress; Phenylethyl Alcohol; Plant Extracts; Plant Leaves; Polyphenols; Protective Agents; Protein Serine-Threonine Kinases; Quercetin; Rats; Transcription Factors

The aim of the present study was to investigate the antiobesity effect of oleuropein on high-fat diet (HFD) induced body weight gain and visceral adiposity in mice, and to explore the underlying mechanisms involved.. C57BL/6N mice were fed with a normal diet, HFD (40% fat of total energy), and HFD-supplemented with 0.03% oleuropein for 10 wk. Oleuropein significantly reduced HFD-induced body weight gain and visceral adiposity. Oleuropein also significantly reversed the HFD-induced elevations of adipogenic related gene expression involved in WNT10b- and galanin-mediated signalings in adipose tissue of mice. Consistent with in vivo findings, oleuropein dose-dependently suppressed lipid accumulation in 3T3-L1 cells during preadipocyte differentiation. Additionally, exposure of the 3T3-L1 preadipocytes to oleuropein resulted in a marked attenuation of the secreted frizzled-related protein 2 (WNT inhibitor) or galnon (galanin receptor agonist) induced cellular lipid accumulation.. This study demonstrated the oleuropein-reduced body weight gain and visceral adiposity in HFD-fed mice. The protective effect of oleuropein against HFD-induced adiposity in mice appeared to be mediated through the upregulation of genes involved in WNT10b-mediated signaling and downregulation of genes involved in galanin-mediated signaling cascades.

Topics: 3T3-L1 Cells; Adiposity; Animals; Cell Differentiation; Diet, High-Fat; Dose-Response Relationship, Drug; Galanin; Gene Expression Regulation; Hyperlipidemias; Iridoid Glucosides; Iridoids; Membrane Proteins; Mice; Mice, Inbred C57BL; Mice, Obese; Signal Transduction; Weight Gain; Wnt Proteins

Leishmania is a unicellular protozoan parasite causing a wide range of human diseases ranging from localized self-healing cutaneous lesions to fatal visceral infections.. The aim of the present study is to assess the cytotoxic, anti-proliferative, and apoptotic effects of oleuropein on Leishmania major promastigotes (MHOM/SA/84/JISH) and to compare its effects with the reference drug sodium stibogluconate (pentostam).. Cytotoxicity and promastigote proliferation were measured using MTT colorimetric assay. Furthermore, the Annexin V/propidium iodide staining technique followed by flow cytometry was used for studying the cell death properties of oleuropein.. In the present report we have shown that oleuropein, a pharmacologically safe, natural product of olive leaf, has a potent leishmanicidal effect. Indeed, oleuropein exhibits cytotoxic and anti-proliferative effects against Leishmania major promastigotes. Moreover, oleuropein triggers death through apoptosis, whereas pentostam induces death mainly via necrosis on Leishmania major promastigotes.. Here we demonstrate for the first time that the non-toxic, natural product oleuropein has apoptotic properties against Leishmania major promastigotes. Further studies are needed to investigate its molecular pathway.

Topics: Antimony Sodium Gluconate; Antiprotozoal Agents; Apoptosis; Dose-Response Relationship, Drug; Iridoid Glucosides; Iridoids; Leishmania major

The main Spanish table olive varieties supplied by different olive cooperatives were investigated for their polyphenol compositions and the endogenous enzymes involved in their transformations during two growing seasons. Olives of the Manzanilla variety had the highest concentration in total polyphenols, followed by the Hojiblanca and Gordal varieties. The Gordal and Manzanilla cultivars showed the highest polyphenol oxidase activities. The Gordal cultivar presented a greater β-glucosidase and esterase activity than the others. An important influence of pH and temperature on the optimal activity of these enzymes was also observed. The polyphenol oxidase activity increased with temperature, and peroxidase activity was optimal at 35 °C. The β-glucosidase and esterase activities were at their maximum at 30 and 55 °C, respectively. The oxidase and β-glucosidase activities were at their maximum at the pH of the raw fruit. These results will contribute to the knowledge of the enzyme transformation of oleuropein in natural table olives.

Topics: beta-Glucosidase; Catechol Oxidase; Enzyme Stability; Fruit; Hydrogen-Ion Concentration; Iridoid Glucosides; Iridoids; Olea; Plant Proteins; Spain; Temperature

Aging is associated with common conditions, including cancer, diabetes, cardiovascular disease, and Alzheimer's disease. The type of multi-targeted pharmacological approach necessary to address a complex multifaceted disease such as aging might take advantage of pleiotropic natural polyphenols affecting a wide variety of biological processes. We have recently postulated that the secoiridoids oleuropein aglycone (OA) and decarboxymethyl oleuropein aglycone (DOA), two complex polyphenols present in health-promoting extra virgin olive oil (EVOO), might constitute a new family of plant-produced gerosuppressant agents. This paper describes an analysis of the biological activity spectra (BAS) of OA and DOA using PASS (Prediction of Activity Spectra for Substances) software. PASS can predict thousands of biological activities, as the BAS of a compound is an intrinsic property that is largely dependent on the compound's structure and reflects pharmacological effects, physiological and biochemical mechanisms of action, and specific toxicities. Using Pharmaexpert, a tool that analyzes the PASS-predicted BAS of substances based on thousands of "mechanism-effect" and "effect-mechanism" relationships, we illuminate hypothesis-generating pharmacological effects, mechanisms of action, and targets that might underlie the anti-aging/anti-cancer activities of the gerosuppressant EVOO oleuropeins.

Topics: Aging; Antineoplastic Agents, Phytogenic; Drug Discovery; Iridoid Glucosides; Iridoids; Olive Oil; Plant Extracts; Plant Oils; Polyphenols

The influence of two operative parameters on the fermentation process of table olives from Taggiasca cultivar were investigated. Laboratory scale fermentations were performed using Lactobacillus plantarum as the only starter and in combination with Saccharomyces cerevisiae at three different temperatures (23, 30 and 37°C). Control tests used for each trial were fermented only by indigenous microflora. pH and phenolic compounds were monitored in the brine and olive flesh during the fermentation. Higher temperatures (37°C) enhanced notably the release of phenolic compounds in the brine. High performance liquid chromatography (HPLC) analysis of brines evidenced the complete hydrolysis of oleuropein after 100 days of fermentation at 37°C for all treatments. The antioxidant power of the extracts was linearly correlated to their polyphenol contents. The results confirmed the efficiency of treatments compared with the control tests for debittering process of table black olives. Phenolic compounds in the brines can be then extracted and used in food, cosmetic and pharmaceutical industries.

Topics: Antioxidants; Fermentation; Food Handling; Iridoid Glucosides; Iridoids; Lactobacillus plantarum; Olea; Phenols; Pyrans; Saccharomyces cerevisiae; Temperature

The presence of amyloid aggregates of the 42 amino acid peptide of amyloid beta (Aβ42) in the brain is the characteristic feature of Alzheimer's disease (AD). Amyloid beta (Aβ deposition is also found in muscle fibers of individuals affected by inclusion body myositis (sIBM), a rare muscular degenerative disease affecting people over 50. Both conditions are presently lacking an effective therapeutic treatment. There is increasing evidence to suggest that natural polyphenols may prevent the formation of toxic amyloid aggregates; this applies also to oleuropein aglycone (OLE), the most abundant polyphenol in extra virgin olive oil, previously shown to hinder amylin and Aβ aggregation. Here we evaluated the ability of OLE to interfere with Aβ proteotoxicity in vivo by using the transgenic CL2006 and CL4176 strains of Caenorhabditis elegans, simplified models of AD and of sIBM, which express human Aβ in the cytoplasm of body wall muscle cells. OLE-fed CL2006 worms displayed reduced Aβ plaque deposition, less abundant toxic Aβ oligomers, remarkably decreased paralysis and increased lifespan with respect to untreated animals. A protective effect was also observed in CL4176 worms but only when OLE was administered before the induction of the Aβ transgene expression. These effects were specific, dose-related, and not mediated by the known polyphenolic anti-oxidant activity, suggesting that, in this model organism, OLE interferes with the Aβ aggregation skipping the appearance of toxic species, as already shown in vitro for Aβ42.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Animals, Genetically Modified; Caenorhabditis; Disease Models, Animal; Humans; Iridoid Glucosides; Iridoids; Peptide Fragments; Pyrans; Vasodilator Agents

A highly sensitive and specific LC-MS/MS method was developed to investigate the in vivo bio-transformation of oleuropein in rat. Rat feces and urine samples collected after oral administration were determined by liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in the negative-ion mode. The assay procedure involves a simple liquid-liquid extraction of parent oleuropein and the metabolite from rat feces and urine with ethyl acetate. Chromatographic separation was operated with 0.1% formic acid aqueous and methanol in gradient program at a flow rate of 0.50 mL/min on an RP-C18 column with a total run time of 31 min. This method was successfully applied to simultaneous determination of oleuropein and its metabolites in rat feces and urine. De-glucosylation, hydrolysis, oxygenation and methylation were found to comprise the major metabolic pathway of oleuropein in rat gastrointestinal tract and three metabolites were absorbed into the blood circulatory system within 24 h after oral administration.

Topics: Animals; Biotransformation; Chromatography, High Pressure Liquid; Feces; Iridoid Glucosides; Iridoids; Liquid-Liquid Extraction; Male; Metabolic Networks and Pathways; Pyrans; Rats; Rats, Sprague-Dawley; Tandem Mass Spectrometry

The olive tree phenolic component oleuropein (OLE) and its derivatives have shown many biological properties, thus representing promising novel therapeutics for the treatment of several diseases, including neoplasia. In this study, we evaluated the activities of OLE and its peracetylated derivative (peracetylated oleuropein, Ac-OLE) against two thyroid tumor cell lines that host genotypic alterations detected in human papillary thyroid cancer. TPC-1 and BCPAP cells were treated with OLE and Ac-OLE, and the effects on viability were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, cell counting, and trypan blue exclusion assays. Antioxidant effects were analyzed by measuring the reactive oxygen species (ROS) in basal conditions and after treatment with hydrogen peroxide (H2O2). Activity of MAP kinase and PI3K-Akt signaling pathways was evaluated by examining the levels of phosphorylated ERK and Akt by western blot. We found that OLE significantly inhibited the proliferation of both cell lines. This effect was paralleled by a reduction of basal phospho-Akt and phospho-ERK levels and H2O2-induced ROS levels. A stronger effect was elicited by Ac-OLE either in inhibiting cell growth or as an antioxidant, in particular on BCPAP cells. Our results demonstrate that OLE and especially Ac-OLE inhibit in vitro thyroid cancer cell proliferation acting on growth-promoting signal pathways, as well as exerting antioxidant effects. Further studies will reveal the potential application as novel targeted therapeutics in thyroid cancer.

Topics: Antioxidants; Apoptosis; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Cell Survival; Extracellular Signal-Regulated MAP Kinases; Humans; Iridoid Glucosides; Iridoids; Proto-Oncogene Proteins c-akt; Pyrans; Reactive Oxygen Species; Thyroid Neoplasms

The anti-inflammatory effect of oleuropein (1), the major phenolic secoiridoid in Olea europaea, was evaluated in an experimental model of chronic colitis in mice. Animals were exposed to four repeated cycles of dextran sodium sulfate in drinking water followed by a 7-day rest period. Animals receiving a standard diet supplemented with 0.25% of 1 (equivalent to 500 mg/kg/day) for 56 days exhibited a decrease of inflammatory symptoms, as reflected by improvement of disease activity index and histopathological changes. It was found that 1 decreased inflammatory cell recruitment and the release of inflammatory cytokines interleukin (IL)-1β and IL-6 with increased IL-10 levels in colon tissue. Colon expression of cyclooxygenase-2 and inducible nitric oxide synthase was reduced significantly by 1. The anti-inflammatory molecular mechanism of 1 was associated with the suppression of the phosphorylation of p38 mitogen-activated protein kinase and might be mediated by up-regulation of annexin A1. In addition, 1 ameliorated intestinal wound healing in IEC-18 monolayers. Therefore, oleuropein seems to be a promising active molecule in experimental ulcerative colitis.

Topics: Animals; Anti-Inflammatory Agents; Colitis; Cyclooxygenase 2; Dextran Sulfate; Interleukin-10; Interleukin-1beta; Interleukin-6; Intestinal Mucosa; Iridoid Glucosides; Iridoids; Mice; Mice, Inbred C57BL; Molecular Structure; Nitric Oxide Synthase Type II; Olea; p38 Mitogen-Activated Protein Kinases; Pyrans; T-Lymphocytes

With the aim to enhance characterization of virgin olive oil (VOO), high resolution mass spectrometry (HRMS) and high resolution tandem mass spectrometry (HRMS/MS), in positive and negative electrospray ionization (ESI) modes, coupled to fused-core reverse phase chromatography, were applied to distinct VOO phenolic extracts after the optimization of chromatographic conditions, ESI and fragmentation parameters. HRMS, but also HRMS/MS resulted fundamental to progress in secoiridoids structural elucidation. The former revealed that the secoiridoid composition of VOO was far more complicated than previously reported, while the latter helped clarify product ion elemental composition allowing new fragmentations, in addition to those reported in the literature, to be put forward. In particular, for the first time, different product ions with the same nominal mass were unequivocally identified in the spectra of secoiridoid compounds, confirming the greater capacity of HRMS/MS to clarify structure than low-resolution MS. Furthermore, and differing from previous studies, the multiple isomers of the main VOO secoiridoids could be differentiated on the basis of their HR product ion spectra in positive mode.

Topics: Chromatography, Reverse-Phase; Glucosides; Iridoid Glucosides; Iridoids; Isomerism; Olive Oil; Oxygen; Plant Oils; Pyrans; Tandem Mass Spectrometry

Endothelial progenitor cells (EPCs) are responsible for neovascularization of ischaemic tissue and may participate in re-endothelization of an injured arterial wall. There is evidence that angiotensin II, by an increase of gp91phox expression and induction of ROS generation, accelerates cell senescence and impairs functions of EPCs. Oleacein is a main phenolic compound from olive oil, whereas oleuropein is present in olive leaves. Both compounds possess antioxidative, hypotensive and anti-inflammatory properties and show beneficial activity on the cardiovascular system. In this study, we examined whether oleoeuropein and oleacein could protect EPCs against impairment of their functions due to angiotensin-induced cell senescence. CD31(+)/VEGFR-2(+) cells were isolated from young healthy volunteers blood samples and cultured on fibronectin-coated plates with angiotensin (1.0μM) in presence or absence of increasing concentrations (from 1.0 to 10.0 μM) of oleoeuropein or oleacein. As compared to angiotensin II-treated cells, EPCs exposed to oleacein or oleuropein prior to angiotensin II showed a significant increase of proliferation and telomerase activity, and a decrease in the percentage of senescent cells and intracellular ROS formation. Oleacein and oleuropein restored migration, adhesion and tube formation of EPCs diminished by angiotensin II in a concentration-dependent manner. This effect was related to NF-E2-related factor 2 (Nrf2) transcription factor activation and the increase of heme oxygenase-1 (HO-1) expression.

Topics: Adult; Aldehydes; Angiotensin II; Cell Adhesion; Cell Movement; Cell Proliferation; Cells, Cultured; Cellular Senescence; Dose-Response Relationship, Drug; Endothelial Cells; Endothelium, Vascular; Healthy Volunteers; Heme Oxygenase-1; Humans; Iridoid Glucosides; Iridoids; NF-E2-Related Factor 2; Oxidative Stress; Phenols; Pyrans; Reactive Oxygen Species; Stem Cells

The claimed beneficial effects of the Mediterranean diet include prevention of several age-related dysfunctions including neurodegenerative diseases and Alzheimer-like pathology. These effects have been related to the protection against cognitive decline associated with aging and disease by a number of polyphenols found in red wine and extra virgin olive oil. The double transgenic TgCRND8 mice (overexpressing the Swedish and Indiana mutations in the human amyloid precursor protein), aged 1.5 and 4, and age-matched wild type control mice were used to examine in vivo the effects of 8 weeks dietary supplementation of oleuropein aglycone (50 mg/kg of diet), the main polyphenol found in extra virgin olive oil. We report here that dietary supplementation of oleuropein aglycone strongly improves the cognitive performance of young/middle-aged TgCRND8 mice, a model of amyloid-ß deposition, respect to age-matched littermates with un-supplemented diet. Immunofluorescence analysis of cerebral tissue in oleuropein aglycone-fed transgenic mice showed remarkably reduced ß-amyloid levels and plaque deposits, which appeared less compact and "fluffy"; moreover, microglia migration to the plaques for phagocytosis and a remarkable reduction of the astrocyte reaction were evident. Finally, oleuropein aglycone-fed mice brain displayed an astonishingly intense autophagic reaction, as shown by the increase of autophagic markers expression and of lysosomal activity. Data obtained with cultured cells confirmed the latter evidence, suggesting mTOR regulation by oleuropein aglycone. Our results support, and provide mechanistic insights into, the beneficial effects against Alzheimer-associated neurodegeneration of a polyphenol enriched in the extra virgin olive oil, a major component of the Mediterranean diet.

Topics: Amyloid beta-Protein Precursor; Animals; Autophagy; Brain; Cell Line; Cognition; Dietary Supplements; Female; Humans; Iridoid Glucosides; Iridoids; Male; Memory Disorders; Mice; Mice, Transgenic; Mutation; Olive Oil; Plant Oils; Polyphenols; Pyrans; TOR Serine-Threonine Kinases

Oleuropein (OE) is a secoiridoid glycoside, which occurs mostly in the Oleaceae family presenting several pharmacological properties, including antioxidant, cardio-protective, anti-atherogenic effects etc. Based on these findings OE is commercially available, as Herbal Medicinal Product (HMP), claimed for its antioxidant effects. As there are general provisions of the medicine regulating bodies e.g. European Medicines Agency, the quality of the HMP's must always be demonstrated. Therefore, a novel LC-MS methodology was developed and validated for the simultaneous quantification of OE and its main degradation product, hydroxytyrosol (HT), for the relevant OE claimed HMP's. The internal standard (IS) methodology was employed and separation of OE, HT and IS was achieved on a C18 Fused Core column with 3.1 min overall run time employing the SIM method for the analytical signal acquisition. The method was validated according to the International Conference on Harmonisation requirements and the results show adequate linearity (r(2) > 0.99) over a wide concentration range [0.1-15 μg/mL (n=12)] and a LLOQ value of 0.1 μg/mL, for both OE and HT. Furthermore, as it would be beneficial to control the quality taking into account all the substances of the OE claimed HMP's; a metabolomics-like approach has been developed and applied for the total quality control of the different preparations employing UHPLC-HRMS-multivariate analysis (MVA). Four OE-claimed commercial HMP's have been randomly selected and MVA similarity-based measurements were performed. The results showed that the examined samples could also be differentiated as evidenced according to their scores plot. Batch to batch reproducibility between the samples of the same brand has also been determined and found to be acceptable. Overall, the developed combined methodology has been found to be an efficient tool for the monitoring of the HMP's total quality. Only one OE HMP has been found to be consistent to its label claim.

Topics: Chromatography, Liquid; Herbal Medicine; Iridoid Glucosides; Iridoids; Oleaceae; Phytotherapy; Plant Preparations; Plants, Medicinal; Quality Control; Reference Standards; Reproducibility of Results; Tandem Mass Spectrometry

Pancreatic lipase digests dietary fats by hydrolysis, which is a key enzyme for lipid absorption. Therefore, reduction of fat absorption by the inhibition of pancreatic lipase is suggested to be a therapeutic strategy for obesity. From the EtOAc-soluble fraction of the stem barks of Fraxinus rhynchophylla (Oleaceae), four secoiridoids such as ligstroside (1), oleuropein (2), 2"-hydroxyoleuropein (3) and hydroxyframoside B (4) were isolated. The inhibitory activity of these compounds on pancreatic lipase was assessed using porcine pancreatic lipase as an in vitro assay system. Compound 4 showed the strongest inhibition on pancreatic lipase, which followed by compounds 1-3. In addition, compound 4 exerted inhibitory effect on pancreatic lipase in a mixed mechanism of competitive and noncompetitive manner. Taken together, F. rhynchophylla and its constituents might be beneficial to obesity.

Topics: Animals; Drug Evaluation, Preclinical; Enzyme Inhibitors; Fraxinus; Glucosides; Iridoid Glucosides; Iridoids; Lipase; Pancreas; Plant Bark; Pyrans; Swine

The aim of this work was to study the chemical characteristics of two Tunisian cultivars, namely Dhokar and Gemri-Dhokar, to analyse the fatty acids, sterols, triacylglycerols, triterpenic alcohols, and to determine the phenolic composition and oxidative stability.. Among the rare varieties, Gemri-Dhokar olive oil had the highest value of oleic acid (69.39%) whereas Dhokar oil was noteworthy for its lower content of phenolic compounds (94.56 mg kg(-1) gallic acid equivalents of oil) and presented the highest level of palmitic acid (19.37%). The main sterols found in all olive oil samples were β-sitosterol and Δ5-avenasterol, whereas cholesterol and 24-methylenecholesterol were also found in all samples but in lower amounts. Two triterpenic dialcohols (erythrodiol and uvaol) were also detected and their content ranged from 1.45 to 2.30%, in Gemri-Dhokar and Dhokar olive oil, respectively. Ten phenolic compounds were identified. In all samples, the main phenols found were oleuropein aglycon and pinoresinol. These phenolic compounds showed significant correlations with oxidative stability.. The analytical parameters of two oils that were determined in this study were greatly influenced by genetic factors (cultivar).

Topics: Alcohols; Drug Stability; Fatty Acids; Furans; Iridoid Glucosides; Iridoids; Lignans; Oleanolic Acid; Olive Oil; Oxidation-Reduction; Palmitic Acid; Phenols; Phytosterols; Plant Oils; Pyrans; Sitosterols; Species Specificity; Triglycerides; Triterpenes; Tunisia

The effects of oleuropein, a phenolic compound in extra virgin olive oil, on protein metabolism were investigated by measuring testicular testosterone and plasma corticosterone levels in rats fed diets with different protein levels. In Experiment 1, rats were fed experimental diets with different protein levels (40, 25 and 10 g/100 g casein) with or without 0.1 g/100 g oleuropein. After 28 days of feeding, the testosterone level in the testis was significantly higher and the plasma corticosterone level was significantly lower in rats fed the 40% casein diet with oleuropein than in those fed the same diet without oleuropein. The urinary noradrenaline level, nitrogen balance and hepatic arginase activity were significantly higher in rats fed the 40% casein diet with oleuropein supplementation than in those fed the 40% casein diet without oleuropein supplementation. In Experiment 2, the effects of oleuropein aglycone (a major phenolic compound in extra virgin olive oil and the absorbed form of oleuropein ingested in the gastrointestinal tracts) on the secretion of luteinizing hormone (LH) from the pituitary gland, which regulates testosterone production in the testis, were investigated in anesthetized rats. Plasma LH level increased dose dependently after the administration of oleuropein aglycone (P<.001, r=0.691). These findings suggest that dietary supplementation with 0.1 g/100 g oleuropein alters the levels of hormones associated with protein anabolism by increasing urinary noradrenaline and testicular testosterone levels and decreasing plasma corticosterone level in rats fed a high-protein diet.

Topics: Animals; Caseins; Corticosterone; Diet; Dietary Fats; Dietary Proteins; Dietary Supplements; Iridoid Glucosides; Iridoids; Luteinizing Hormone; Male; Norepinephrine; Olive Oil; Pituitary Gland; Plant Oils; Pyrans; Rats; Rats, Sprague-Dawley; Testis; Testosterone

The characterisation of virgin olive oils from two Tunisian cultivars, growing in the Tataouin zone, namely Jemri-Bouchouka, a rare olive cultivar, and Chemlali-Tataouin, was carried out. Several analytical parameters were evaluated; these include quality index, fatty acids, phenolic, chlorophyll, carotenoid, squalene, α-tocopherol compositions and oxidative stability.. Jemri-Bouchouka olive oil had the highest value of oleic acid (74.50%) while Chemlali-Tataouin olive oil had the highest value of oleic acid (69.39 %) and also was characterized by a high percentage of palmitic acid (14.75 %) which makes this oil freeze at a low temperature [corrected]. On the other hand, Jemri-Bouchouka oil was characterised by a low phenolic and α-tocopherol content (267.72 mg GAE kg⁻¹ and 278.34 mg kg⁻¹, respectively). Ten phenolic compounds were identified. The main phenols found in the two olive oils were oleuropein aglycon and pinoresinol. All phenolic compounds showed significant correlations with oxidative stability.. The analytical parameters of virgin olive oil that were determined in this study were greatly influenced by cultivar.

Topics: alpha-Tocopherol; Antioxidants; Fatty Acids; Food Quality; Food Storage; Fruit; Furans; Hydrogen-Ion Concentration; Iridoid Glucosides; Iridoids; Lignans; Lipid Peroxides; Olea; Oleic Acid; Olive Oil; Oxidation-Reduction; Palmitic Acid; Phenols; Pigments, Biological; Plant Oils; Pyrans; Species Specificity; Transition Temperature; Tunisia

Over the past decade, intense focus has been dedicated on investigating processes involved in the proteolysis of amyloid precursor protein (AβPP) and β-amyloid (Aβ) peptide metabolism, as possible targets for Alzheimer's disease (AD) therapy. To this goal, considerable research has been targeted on potential therapeutic use of compounds promoting non-amyloidogenic processing of AβPP. One of these compounds, oleuropein, a polyphenol constituent of extra virgin olive oil exhibiting a wide range of pharmacological properties, was shown to interact non-covalently with Aβ, an interaction that might be related to a potential protective role of oleuropein against Aβ aggregation. In the present study, it was demonstrated that oleuropein treatment of HEK293 cells stably transfected with the isoform 695 of human AβPP (APP695) leads to markedly elevated levels of sAPPα and to significant reduction of Aβ oligomers. These effects were associated with increased activity of matrix metalloproteinase 9 (MMP-9), whereas no significant alterations in the expression of secretases TACE, ADAM-10 or BACE-1 were observed. Similar results were obtained using the human neuroblastoma cell line SK-N-SH. The experimental data reveal an anti-amyloidogenic effect of oleuropein and suggest a possible protective role for oleuropein against AD, extending the spectrum of beneficial properties of this naturally occurring polyphenol.

Topics: Amyloid beta-Protein Precursor; Amyloid Precursor Protein Secretases; Antioxidants; Cell Line, Tumor; Humans; Iridoid Glucosides; Iridoids; Olea; Polyphenols; Pyrans

Olive leaves, an easily available natural low-cost material, constitute a source of extracts with significant antitumor activity that inhibits cell proliferation in several breast-cancer-cell models. In this work, a metabolite-profiling approach has been used to assess the uptake and metabolism of phenolic compounds from an olive-leaf extract in the breast-cancer-cell line SKBR3 to evaluate the compound or compounds responsible for the cytotoxic activity. For this, the extract was firstly characterized quantitatively by high-performance liquid chromatography coupled to electrospray ionization-quadrupole time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS). Then, SKBR3 cells were incubated with 200 μg/mL of the olive-leaf extract at different times (15 min, 1, 2, 24, and 48 h). A metabolite-profiling approach based on HPLC-ESI-QTOF-MS was used to determine the intracellular phenolic compounds, enabling the identification of 16 intact phenolic compounds from the extract and four metabolites derived from these compounds in the cell cytoplasm. The major compounds found within the cells were oleuropein, luteolin-7-O-glucoside and its metabolites luteolin aglycone and methyl-luteolin glucoside, as well as apigenin, and verbascoside. Neither hydroxytyrosol nor any of its metabolites were found within the cells at any incubation time. It is proposed that the major compounds responsible for the cytotoxic activity of the olive-leaf extract in SKBR3 cells are oleuropein and the flavones luteolin and apigenin, since these compounds showed high uptake and their antitumor activity has been previously reported.

Topics: Apigenin; Breast Neoplasms; Carcinoma; Cell Line, Tumor; Chromatography, High Pressure Liquid; Cytoplasm; Female; Flavones; Glucosides; Humans; Iridoid Glucosides; Iridoids; Luteolin; Olea; Phenols; Plant Extracts; Plant Leaves; Pyrans; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry

The olive polyphenols oleuropein and hydroxytyrosol were reported recently to produce extracellular hydrogen peroxide (H2O2) under standard culture conditions. The precise factors responsible for this production and the conditions promoting or retarding it are critical for the interpretation of the in vitro results. In this study, a systematic evaluation of the components of the most commonly used culture media revealed that sodium bicarbonate is the defining cause for the production of H2O2 by these polyphenols. The produced H2O2 caused extensive oxidative DNA damage and significant decrease in cell viability of cancer (MDA-MB-231) and normal (MCF-10A, STO) cells alike. Sodium pyruvate and the antioxidant N-acetyl cysteine (NAC) totally reversed these effects. Therefore, we conclusively identified the culture conditions that promote H2O2 production by these polyphenols, producing artifacts that may be misinterpreted as a specific anticancer activity. Our findings raise considerable questions regarding the use of culture media with sodium bicarbonate or sodium pyruvate as components, for the in vitro study of these and possibly other plant polyphenols.

Topics: Animals; Breast Neoplasms; Cell Line, Tumor; Culture Media; Female; Humans; Hydrogen Peroxide; Iridoid Glucosides; Iridoids; Mice; Olea; Oxidants; Oxidative Stress; Phenylethyl Alcohol; Plant Extracts; Plant Oils; Pyrans; Reactive Oxygen Species

Dietary olive oil supplementation and more recently, olive oil phenols have been recommended as important therapeutic interventions in preventive medicine. Ole has several pharmacological properties, including antioxidant, anti-inflammatory, antiatherogenic, anticancer, antimicrobial, and antiviral and for these reasons, is becoming an important subject of study in recent years. The aim of this study was to investigate the effects of Ole aglycone on the modulation of the secondary events in mice subjected to intestinal IRI. This was induced in mice by clamping the superior mesenteric artery and the celiac trunk for 30 min, followed by release of the clamp, allowing reperfusion for 1 h. After 60 min of reperfusion, animals were killed for histological examination of the ileum tissue and immunohistochemical localization of proinflammatory cytokines (TNF-α and IL-1β) and adhesion molecules (ICAM-1 and P-sel); moreover, by Western blot analysis, we investigated the activation of NF-κB and IκBα. In addition, we evaluated the apoptosis process, as shown by TUNEL staining and Bax/Bcl-2 expressions. The results obtained by the histological and molecular examinations showed in Ole aglycone-treated mice, a decrease of inflammation and apoptosis pathway versus SAO-shocked mice. In conclusion, we propose that the olive oil compounds, in particular, the Ole aglycone, could represent a possible treatment against secondary events of intestinal IRI.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Apoptosis; Blotting, Western; Cell Adhesion Molecules; Cytokines; Disease Models, Animal; Immunohistochemistry; In Situ Nick-End Labeling; Intestinal Diseases; Iridoid Glucosides; Iridoids; Male; Mice; Olive Oil; Plant Oils; Polyphenols; Pyrans; Reperfusion Injury

Breast cancer constitutes a major health problem for women worldwide. However, its incidence varies between populations and geographical locations. These variations could be diet-related, since there are several carcinogenic compounds in the modern diet, while natural products contain various anti-cancer elements. Several lines of evidence indicate that, in addition to their clear preventive effect, these compounds could also be used as therapeutic agents. In the present report we have shown that oleuropein, a pharmacologically safe natural product of olive leaf, has potent anti-breast cancer properties. Indeed, oleuropein exhibits specific cytotoxicity against breast cancer cells, with higher effect on the basal-like MDA-MB-231 cells than on the luminal MCF-7 cells. This effect is mediated through the induction of apoptosis via the mitochondrial pathway. Moreover, oleuropein inhibits cell proliferation by delaying the cell cycle at S phase and up-regulated the cyclin-dependent inhibitor p21. Furthermore, oleuropein inhibited the anti-apoptosis and pro-proliferation protein NF-κB and its main oncogenic target cyclin D1. This inhibition could explain the great effect of oleuropein on cell proliferation and cell death of breast cancer cells. Therefore, oleuropein warrants further investigations to prove its utility in preventing/treating breast cancer, especially the less-responsive basal-like type.

Topics: Antineoplastic Agents; Apoptosis; Breast Neoplasms; Cell Cycle; Cell Proliferation; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Electrophoresis, Polyacrylamide Gel; Female; Flow Cytometry; Humans; Iridoid Glucosides; Iridoids; MCF-7 Cells; Mitochondria; NF-kappa B; Olive Oil; Plant Oils; Pyrans; Receptors, Estrogen; Up-Regulation

Oleuropein (OL) is the most prominent phenolic compound in the fruit of olive tree. Although OL has shown powerful anticancer activity the underlying action mechanism remains largely unknown. The present study evaluated the effects of OL on hydroxityrosol (HT)-29 human colon adenocarcinoma cells in comparison to hydroxytyrosol, its hydrolysis product, and to elucidate the underlying anticancer molecular mechanisms involved. Cell proliferation was determined using SRB assay. Cell cycle and apoptosis were assessed by flow cytometry and changes in MAPK cascade protein expression, HIF-1α, p53, PPARγ, and NFKβ signaling pathways by Western blot. Although OL showed less potency than HT, in terms of cell growth inhibition, induced significant changes in cell cycle analysis and caused a significant increase in the apoptotic population. Both compounds produced a remarkable decrease in HIF-1α protein and an upregulation of p53 protein expression. However, no significant changes in IkB-α and MAPK cascade protein expressions were observed. HT produced a significant upregulation in peroxisome proliferator-activated receptor gamma (PPARγ) expression whereas OL failed. PPARγ upregulation may be one of the principal mechanisms of the tumor shrinkage by HT. Our novel findings demonstrate that OL limits the growth and induces apoptosis in HT-29 cells via p53 pathway activation adapting the HIF-1α response to hypoxia.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Cell Cycle; Cell Proliferation; Colorectal Neoplasms; Down-Regulation; HT29 Cells; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; I-kappa B Proteins; Iridoid Glucosides; Iridoids; NF-kappa B; NF-KappaB Inhibitor alpha; Olea; p38 Mitogen-Activated Protein Kinases; Phenylethyl Alcohol; PPAR gamma; Pyrans; Tumor Suppressor Protein p53

Parkinson disease (PD) is the most common progressive neurodegenerative disorder characterized by progressive death of midbrain dopaminergic neurons. Most neurodegenerative disease treatments are, at present, palliative. However, some natural herbal products have been shown to rescue neurons from death and apoptosis in some of neurodegenerative diseases. Not only Olea europaea L. olive oil, but also the leaves of this plant have been used for medical purposes. Olive leaf extract (OLE) is being used by people as a drink across the world and as an integral ingredient in their desire to maintain and improve their health. Here, we investigated the effects of OLE and its main phenolic component oleuropein on 6-hydroxydopamine (6-OHDA)-induced toxicity in rat adrenal pheochromocytoma (PC12) cells as an in vitro model of PD. Cell damage was induced by 150 μM 6-OHDA. The cell survival rate was examined by MTT assay. Generation of intra-cellular reactive oxygen species (ROS) was studied using fluorescence spectrophotometry. Immunoblotting and DNA analysis were also employed to determine the levels of biochemical markers of apoptosis in the cells. The data showed that 6-OHDA could decrease the viability of the cells. In addition, intra-cellular ROS, activated caspase 3, Bax/Bcl-2 ratio, as well as DNA fragmentation were significantly increased in 6-OHDA-treated cells. Incubation of cells with OLE (400 and 600 μg/mL) and oleuropein (20 and 25 μg/mL) could decrease cell damage and reduce biochemical markers of cell death. The results suggest that OLE and oleuropein have anti-oxidant protective effects against 6-OHDA-induced PC12 cell damage. The protective effects of OLE and oleuropein are correlative with their anti-oxidative and anti-apoptotic properties and suggest their therapeutic potential in the treatment of PD.

Topics: Animals; Antioxidants; Apoptosis; bcl-2-Associated X Protein; Biphenyl Compounds; Caspase 3; Cell Survival; DNA Fragmentation; Enzyme Activation; Free Radical Scavengers; Intracellular Space; Iridoid Glucosides; Iridoids; Olea; Oxidopamine; PC12 Cells; Picrates; Plant Extracts; Plant Leaves; Protective Agents; Pyrans; Rats; Reactive Oxygen Species

Impact of steam, hot water blanching and UV-C irradiation as pre-treatments on extraction of oleuropein and related biophenols from olive leaves (OLs), was investigated. Moreover, particle size effect of olive leaves and steam blanching duration were selected as independent variables to optimise steam blanching process in terms of oleuropein content (OC) and antioxidant activity (AC) of ethanolic extracts, by using response surface methodology. Optimum conditions for OC and AC were 10 min steam blanching of 20-11 and 3-1mm olive leaf fraction, respectively. Depending on the extraction procedure, at optimum conditions of steaming the results indicate that steam blanching of OL prior to extraction can significantly increase oleuropein yield from 25 to 35 times compared to non-steam blanched sample, whereas the antioxidant activity increased from 4 to 13 times. No significant UV-C effect was observed in OC and AC, while hot water blanched samples showed significantly higher oleuropein yields and antioxidant activity compared to untreated samples.

Topics: Food Handling; Iridoid Glucosides; Iridoids; Olea; Plant Leaves; Steam

The total phenolic content and antioxidant activities of olive leaf extracts were determined. Plant material was extracted with methanol and fractionated with solvents of increasing polarity, giving certain extracts. The qualitative changes in the composition of the extracts were determined after the storage of leaves for 22 h at 37°C, before the extraction. Total polyphenol contents in extracts were determined by the Folin-Ciocalteu procedure. They were also analysed by liquid chromatography-mass spectrometry. Their antioxidant activities were evaluated using the diphenyl picrylhydrazyl method and the β-carotene linoleate model assay. Moreover, the effects of different crude olive leaf extracts on the oxidative stability of sunflower oil at 40°C and sunflower oil-in-water emulsions (10% o/w) at 37°C, at a final concentration of crude extract 200 mg kg(-1) oil, were tested and compared with butylated hydroxyl toluene.

Topics: Antioxidants; Butylated Hydroxytoluene; Chromatography, Liquid; Emulsions; Iridoid Glucosides; Iridoids; Mass Spectrometry; Methanol; Olea; Oxidation-Reduction; Plant Extracts; Plant Leaves; Plant Oils; Polyphenols; Pyrans; Sunflower Oil

Oleuropein (OE) is a well-known antioxidant polyphenol from olive oil. The purpose of this study was to determine the potential neuroprotective effects of oleuropein in an experimental spinal cord injury model.. Rats were randomly divided into four groups of 21 rats each as follows: sham-operated group, trauma group, and OE treatment groups (20 mg/kg, i.p., immediately and 1 hour after spinal cord injury). Spinal cord samples were taken 24 hours after injury and studied for determination of malondialdehyde and glutathione levels, histopathological assessment, immunohistochemistry of Bax and Bcl-2, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling reaction. Behavioral testing was performed weekly up to 6 weeks post-injury.. The results showed that malondialdehyde levels were significantly decreased, and glutathione levels were significantly increased in OE treatment groups. Greater Bcl-2 and attenuated Bax expression could be detected in the OE-treated rats. OE significantly reduced terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive reaction and improved behavioral function than the trauma group.. These findings indicate that OE may be effective in protecting rat spinal cord from secondary injury.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Disease Models, Animal; Female; Glutathione; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Malondialdehyde; Neuroprotective Agents; Pyrans; Rats; Rats, Sprague-Dawley; Recovery of Function; Spinal Cord Injuries

Olives and olive products, an inevitable part of the Mediterranean diet, possess various beneficial effects, such as a decreased risk of cardiovascular disease and cancer. Oleuropein is a non-toxic secoiridoid found in the leaves and fruits of olive (Olea europaea L.). In this study, we have investigated the hepatoprotective activity of oleuropein in carbon tetrachloride (CCl(4))-induced liver injury in male BALB/cN mice. Oleuropein in doses of 100 and 200mg/kg was administered intraperitoneally (ip) once daily for 3 consecutive days, prior to CCl(4) administration (the preventive treatment), or once daily for 2 consecutive days 6h after CCl(4) intoxication (the curative treatment). CCl(4) intoxication resulted in a massive hepatic necrosis and increased plasma transaminases. Liver injury was associated with oxidative/nitrosative stress evidenced by increased nitrotyrosine formation as well as a significant decrease in superoxide dismutase activity and glutathione levels. CCl(4) administration triggered inflammatory response in mice livers by inducing expression of nuclear factor-kappaB, which coincided with the induction of tumor necrosis factor-alpha, cyclooxygenase-2 and inducible nitric oxide synthase. In both treatment protocols, oleuropein significantly attenuated oxidative/nitrosative stress and inflammatory response and improved histological and plasma markers of liver damage. Additionally, in the curative regimen, oleuropein prevented tumor necrosis factor-beta1-mediated activation of hepatic stellate cells, as well as the activation of caspase-3. The hepatoprotective activity of oleuropein was, at least in part, achieved through the NF-E2-related factor 2-mediated induction of heme oxygenase-1. The present study demonstrates antioxidant, anti-inflammatory, antiapoptotic, and antifibrotic activity of oleuropein, with more pronounced therapeutic than prophylactic effects.

Topics: Animals; Antioxidants; Carbon Tetrachloride; Chemical and Drug Induced Liver Injury; Disease Models, Animal; Glutathione; Heme Oxygenase-1; Iridoid Glucosides; Iridoids; Male; Mice; Mice, Inbred BALB C; Oleaceae; Oxidative Stress; Pyrans; Superoxide Dismutase

The possibility to improve the nutritional value of olive oil by enriching it in phenolic compounds from olive leaves (e.g., oleuropein) by ultrasonic maceration was studied. The experimental design used led to the following optimal extraction conditions: ultrasonic power of 60 W, temperature of 16°C and sonication duration of 45 min. The high total phenolic content (414.3 ± 3.2mg of oleuropein equivalent/kg of oil), oleuropein (111.0 ± 2.2mg/kg of oil) and α-tocopherol (55.0 ± 2.1g/kg of oil) concentrations obtained by optimized ultrasound-assisted extraction (UAE) proved the efficiency of this process when compared with the conventional solid-liquid extraction. Histochemical analyses showed that this efficiency is due to specific alteration of the phenol-containing leaf structures. Furthermore, the radical-scavenging activity of the processed oil (DPPH test) and its stability toward lipid autoxidation (heating test) confirmed its enrichment in antioxidants. Sensory evaluation of the enriched olive oil showed a slight increase in bitterness but an overall acceptability. Finally, the enriched olive oil was characterized by clear green color (L*, a*, b* parameters).

Topics: Iridoid Glucosides; Iridoids; Laboratories; Molecular Structure; Olive Oil; Phenols; Pilot Projects; Plant Oils; Pyrans; Sonication

Several olive oil phenolic compounds, such us oleuropein have attracted considerable attention because of their antioxidant activity, anti-atherosclerotic and anti-inflammatory properties. The aim of this experimental study was to determine the effect of oleuropein aglycone, a hydrolysis product of oleuropein, in the inflammatory response, in particular in the secondary injury associated with the mouse model of spinal cord trauma. The injury was induced by application of vascular clips to the dura via a four-level T5-T8 laminectomy in mice. Oleuropein aglycone was administered in mice (100 μg/kg, 40 μg/kg, 20 μg/kg, 10% ethanol, i.p.) 1h and 6h after the trauma. The treatment with oleuropein aglycone significantly decreased: (1) histological damage, (2) motor recovery, (3) nuclear factor (NF)-κB expression and IKB-α degradation, (4) protein kinase A (PKA) activity and expression, (5) pro-inflammatory cytokines production such as tumor necrosis factor (TNF-α) and interleukin-1β (IL-1β), 6) inducible nitric oxide synthase (iNOS) expression, (7) neutrophil infiltration, (8) lipid peroxidation, (9) nitrotyrosine and poly-ADP-ribose (PAR) formation, (10) glial cell-derived neurotrophic factor (GDNF) levels, (11) apoptosis (TUNEL staining, FAS ligand expression, Caspase 3, Bax and Bcl-2 expression). Thus, we propose that olive oil phenolic constituents such as oleuropein aglycone may be useful in the treatment of various inflammatory diseases.

Topics: Animals; Blotting, Western; In Situ Nick-End Labeling; Iridoid Glucosides; Iridoids; Male; Mice; Olive Oil; Plant Oils; Pyrans; Spinal Cord Injuries

Crude phenolic extracts (PE) have been obtained from naturally bearing Spanish extra-virgin olive oil (EVOO) showing different polyphenol families such as secoiridoids, phenolic alcohols, lignans, and flavones. EVOO-derived complex phenols (especially from the Arbequina variety olive) have been shown to suppress cell growth of SW480 and HT29 human colon adenocarcinoma cell lines. Inhibition of proliferation by EVOO-PE Arbequina variety extract was accompanied by apoptosis in both colon-cancer-cell lines and a limited G₂M cell-cycle arrest in the case of SW480 cells. The metabolized compounds from EVOO-PE in culture medium and cytoplasm of both cell lines were analyzed using nano-liquid chromatography (nanoLC) coupled with electrospray ionization-time-of-flight-mass spectrometry (ESI-TOF-MS). The results showed many phenolic compounds and their metabolites both in the culture medium as well as in the cytoplasm. The main compounds identified from EVOO-PE were hydroxylated luteolin and decarboxymethyl oleuropein aglycone.

Topics: Adenocarcinoma; Antineoplastic Agents, Phytogenic; Apoptosis; Biotransformation; Cell Proliferation; Chromatography, Liquid; Colonic Neoplasms; Culture Media, Conditioned; Cytoplasm; Decarboxylation; G2 Phase Cell Cycle Checkpoints; HT29 Cells; Humans; Hydroxylation; Iridoid Glucosides; Iridoids; Luteolin; Metabolomics; Nanotechnology; Olive Oil; Phenols; Plant Oils; Pyrans; Spectrometry, Mass, Electrospray Ionization

It has been shown that blockade of L-type calcium channels could abolish the development of opioid-induced antinociceptive tolerance. Here, the antitolerant effects of olive leaf extract (OLE) and its main component, oleuropein, which have a calcium channel blocker property were determined. Adult male Wistar rats were injected with morphine (20 mg/kg, i.p.) for 8 days to induce antinociceptive tolerance. Then OLE (50-200 mg/kg i.g.) and oleuropein (1-10 mg/kg i.p.) were injected concomitantly with morphine. The tail-flick test was used to assess the nociceptive threshold. The dorsal half of the lumbar spinal cord was assayed for the expression of L-type calcium channel using semiquantitative RT-PCR. The results showed that OLE (200 mg/kg) completely prevented morphine tolerance development. In addition, oleuropein in dose of 10 mg/kg, but not in 5 mg/kg, prevented the development of morphine antinociceptive tolerance. In addition, a significant increase in the mRNA levels of calcium channel (43.9%) was observed in the lumbar spinal cord of tolerant animals, which was reversed by effective of dose OLE. In conclusion, the results indicate that olive leaf extract has a potential antitolerant property against the chronic usage of morphine and that its main component, oleuropein, is responsible for such effect.

Topics: Analgesics, Opioid; Animals; Calcium Channel Blockers; Calcium Channels, L-Type; Drug Tolerance; Iridoid Glucosides; Iridoids; Male; Morphine; Olea; Pain Measurement; Plant Extracts; Pyrans; Rats; Rats, Wistar

The present study investigates oleuropein metabolism, as well as the involvement of β-glucosidase during the growth, development, and ripening of olive fruit. The results show that in olive fruit the in vivo formation and transformation of oleuropein takes place in three different stages. The first one is characterized by a net accumulation of oleuropein and occurs in the immature fruit. In the second stage, associated with the green and light-green fruits, oleuropein content is maintained practically constant, and finally, a third stage that begins in the green-yellow fruit is characterized by a progressive decline of the oleuropein concentration. Our findings confirm that in the absence of β-glucosidase the Damtoft-proposed pathway is active and that net synthesis of oleuropein is unquestionable. β-Glucosidase activity plays a key role in the oleuropein metabolism catalyzing its in vivo hydrolysis.

Topics: Agriculture; beta-Glucosidase; Fruit; Iridoid Glucosides; Iridoids; Olea; Organic Agriculture; Pyrans; Seasons

Currently, there is increasing interest in the in vivo protective effects of natural antioxidants found in dietary plants against oxidative damage caused by free radical species. Oxidative stress has been invoked as a causative agent in cancer and epidemiological data suggest that the consumption of fruits and vegetables may be associated with a lower incidence of cancer. The fruit of the Olea europaea L. and olive oil contain hundreds of phytochemicals and its extracts have recently been shown to exhibit antioxidant properties, due to the action of oleuropein. In view of these considerations, in this study, we investigated the effects of oleuropein on LNCaP and DU145 prostate cancer cell lines and on BPH-1 non-malignant cells. Oleuropein reduces cell viability and induces thiol group modifications, γ-glutamylcysteine synthetase, reactive oxygen species, pAkt and heme oxygenase-1. Exposing cell cultures to oleuropein induces an antioxidant effect on BPH-1 cells and a pro-oxidant effect on cancer cells. Our results confirm the beneficial properties of olive oil and oleuropein, suggesting its possible use as an adjuvant agent in the treatment of prostatitis, in order to prevent the transformation of hypertrophic to cancerous cells.

Topics: Antineoplastic Agents; Antioxidants; Cell Line, Tumor; Cell Proliferation; Cell Survival; Glutamate-Cysteine Ligase; Heme Oxygenase-1; Humans; Iridoid Glucosides; Iridoids; L-Lactate Dehydrogenase; Male; Necrosis; Prostatic Neoplasms; Proto-Oncogene Proteins c-akt; Pyrans; Reactive Oxygen Species; Sulfhydryl Compounds

Purified oleuropein from olive leaf extract has been shown to have antioxidant effects in our recent studies. Thus, the aim of this study was to assess the antioxidant abilities of oleuropein in comparison with ranitidine in ethanol-induced gastric damages via evaluation of ulcer index inhibition, antioxidant enzyme activities, and lipid peroxidation level. Fifty-six adult male Sprague-Dawley rats were divided into seven equal groups as follows: control group, ethanol group (absolute ethanol 1 ml/rat), oleuropein group (12 mg/kg), and oleuropein (6, 12, and 18 mg/kg) plus ethanol groups, as well as ranitidine (50 mg/kg) plus ethanol group. Pretreatment with oleuropein (12 and 18 mg/kg) significantly increased the ulcer index inhibition (percent), in comparison with oleuropein (6 mg/kg). Glutathione peroxidase (GPx) activity was significantly lower in the ethanol group when compared with the other groups whereas, treatment of rats with oleuropein (12 mg/kg) significantly increased glutathione content in gastric tissue when compared with the other groups, and lipid peroxidation was significantly reduced in the oleuropein- (12 and 18 mg/kg) and ranitidine-treated animals. Superoxide dismutase (SOD) and catalase (CAT) activities were both much higher in oleuropein-treated rats than the ethanol group, and although there was a moderate increase in SOD and CAT activities in ranitidine-treated rats, the differences were not significant. These findings suggest that oleuropein has beneficial antioxidant properties against ethanol-induced gastric damages in the rat. Therefore, it seems that a combination regimen including both antioxidant and antisecretory drugs may be beneficial in prevention of ethanol-mediated gastric mucosal damages.

Topics: Animals; Anti-Ulcer Agents; Antioxidants; Catalase; Ethanol; Gastric Mucosa; Glutathione; Glutathione Peroxidase; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Male; Oxidative Stress; Pyrans; Ranitidine; Rats; Rats, Sprague-Dawley; Stomach Ulcer; Superoxide Dismutase; Thiobarbituric Acid Reactive Substances

The aim of this work is to study the conversion of oleuropein-a polyphenol present in olives and olive oil by-products-into hydroxytyrosol, a polyphenol with antioxidant and antibacterial properties. The hydrolysis reaction is performed by lactic acid bacteria. Six bacterial strains (Lactobacillus plantarum 6907, Lactobacillus paracasei 9192, Lactobacillus casei, Bifidobacterium lactis BO, Enterococcus faecium 32, Lactobacillus LAFTI 10) were tested under aerobic and anaerobic conditions. The oleuropein degradation and hydroxytyrosol formation were monitored by HPLC. Results showed that oleuropein could be successfully converted into hydroxytyrosol. The most effective strain was Lactobacillus plantarum 6907, with a reaction yield of hydroxytyrosol of about 30 %. Different reaction mechanisms were observed for different microorganisms; a different yield was observed for Lactobacillus paracasei 9192 under aerobic or anaerobic conditions and an intermediate metabolite (oleuropein aglycone) was detected for Lactobacillus paracasei 9192 and Lactobacillus plantarum 6907 only. This study could have significant applications, as this reaction can be used to increase the value of olive oil by-products and/or to improve the taste of unripe olives.

Topics: Iridoid Glucosides; Iridoids; Lactobacillus; Olea; Phenylethyl Alcohol; Pyrans

The olive tree (Olea europaea L.) is often exposed to severe water stress during the summer season. In this study, we determined the changes in total phenol content, oleuropein and hydroxytyrosol in the leaves of four olive cultivars ('Gaidourelia', 'Kalamon', 'Koroneiki' and 'Megaritiki') grown under water deficit conditions for two months. Furthermore, we investigated the photosynthetic performance in terms of gas exchange and chlorophyll a fluorescence, as well as malondialdehyde content and antioxidant activity. One-year-old self-rooted plants were subjected to three irrigation treatments that received a water amount equivalent to 100% (Control, C), 66% (Field Capacity 66%, FC(66)) and 33% (Field Capacity 33%, FC(33)) of field capacity. Measurements were conducted 30 and 60 days after the initiation of the experiment. Net CO(2) assimilation rate, stomatal conductance and F(v)/F(m) ratio decreased only in FC(33) plants. Photosynthetic rate was reduced mainly due to stomatal closure, but damage to PSII also contributed to this decrease. Water stress induced the accumulation of phenolic compounds, especially oleuropein, suggesting their role as antioxidants. Total phenol content increased in FC(33) treatment and oleuropein presented a slight increase in FC(66) and a sharper one in FC(33) treatment. Hydroxytyrosol showed a gradual decrease as water stress progressed. Malondialdehyde (MDA) content increased due to water stress, mostly after 60 days, while antioxidant activity increased for all cultivars in the FC(33) treatment. 'Gaidourelia' could be considered as the most tolerant among the tested cultivars, showing higher phenolic concentration and antioxidant activity and lower lipid peroxidation and photochemical damage after two months of water stress. The results indicated that water stress affected olive tree physiological and biochemical parameters and magnitude of this effect depended on genotype, the degree of water limitation and duration of treatment. However, the severity as well as the duration of water stress might exceed antioxidant capacity, since MDA levels and subsequent oxidative damage increased after two months of water deficit.

Topics: Agricultural Irrigation; Antioxidants; Chlorophyll; Chlorophyll A; Dehydration; Genotype; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Malondialdehyde; Olea; Oxidative Stress; Phenols; Phenylethyl Alcohol; Photosynthesis; Plant Leaves; Plant Roots; Plant Transpiration; Pyrans; Stress, Physiological

Olive (Olea europaea L.) fruits contain numerous secondary metabolites, primarily phenolics, terpenes and sterols, some of which are particularly interesting for their nutraceutical properties. This study will attempt to provide further insight into the profile of olive phenolic compounds during fruit development and to identify the major genetic determinants of phenolic metabolism.. The concentration of the major phenolic compounds, such as oleuropein, demethyloleuropein, 3-4 DHPEA-EDA, ligstroside, tyrosol, hydroxytyrosol, verbascoside and lignans, were measured in the developing fruits of 12 olive cultivars. The content of these compounds varied significantly among the cultivars and decreased during fruit development and maturation, with some compounds showing specificity for certain cultivars. Thirty-five olive transcripts homologous to genes involved in the pathways of the main secondary metabolites were identified from the massive sequencing data of the olive fruit transcriptome or from cDNA-AFLP analysis. Their mRNA levels were determined using RT-qPCR analysis on fruits of high- and low-phenolic varieties (Coratina and Dolce d'Andria, respectively) during three different fruit developmental stages. A strong correlation was observed between phenolic compound concentrations and transcripts putatively involved in their biosynthesis, suggesting a transcriptional regulation of the corresponding pathways. OeDXS, OeGES, OeGE10H and OeADH, encoding putative 1-deoxy-D-xylulose-5-P synthase, geraniol synthase, geraniol 10-hydroxylase and arogenate dehydrogenase, respectively, were almost exclusively present at 45 days after flowering (DAF), suggesting that these compounds might play a key role in regulating secoiridoid accumulation during fruit development.. Metabolic and transcriptional profiling led to the identification of some major players putatively involved in biosynthesis of secondary compounds in the olive tree. Our data represent the first step towards the functional characterisation of important genes for the determination of olive fruit quality.

Topics: Amplified Fragment Length Polymorphism Analysis; Biosynthetic Pathways; Cytochrome P-450 Enzyme System; Fruit; Gene Expression Profiling; Genes, Plant; Glucosides; Iridoid Glucosides; Iridoids; Metabolomics; Olea; Phenols; Phenylethyl Alcohol; Plant Oils; Plant Proteins; Prephenate Dehydrogenase; Pyrans; Real-Time Polymerase Chain Reaction; RNA, Messenger; Species Specificity; Transcriptome

To look for optimum extraction techniques for oleuropein by boiling olive leaves at low temperature and reduced pressure.. According to single factor experiment (SFE) design, the effects of seven factors, the impact of seven factors, type of solvent, temperature, time, ratio of material to liquid, ethanol concentration, vacuum degree and extraction times, on extraction yield of oleuropein were investigated. Based on the results of SFE, four more important factors, temperature, time, ratio of material to liquid and ethanol concentration, were selected in L9 (3(4)) orthogonal experiment (OE) to compare with those extracted with traditional methods.. The optimum conditions for boiling extraction of oleuropein at low temperature and reduced pressure were as follows: temperature 60 degrees C, time 20 min, ratio of material to liquid 1:30 and ethanol concentration 85%. The conditions presented an extraction yield of 5.90%.. Compared with traditional extraction methods and the ultrasound assisted extraction method, boiling extraction techniques at low temperature and reduced pressure were so quick and efficient that it has a good application prospect.

Topics: Iridoid Glucosides; Iridoids; Liquid-Liquid Extraction; Olea; Plant Leaves; Pressure; Pyrans; Technology, Pharmaceutical; Temperature

Oleuropein, a bitter glucoside found in green olive leaves, and its metabolite hydroxytyrosol display powerful antioxidant activity both in vivo and in vitro. In this study, we hypothesized that the antioxidant activity of oleuropein could attenuate hepatic steatosis. To test this hypothesis, we established steatotic hepatocytes using HepG2 and FL83B cells treated with free fatty acids (FFAs) (oleate:palmitate, 2:1). To confirm hepatic steatosis, the intracellular lipid levels were quantitatively measured by Nile Red staining, and the sizes and distributions of lipid droplets were visualized by transmission electron microscopy. The expression of PAT family proteins as well as of adipose differentiation-related protein and tail interacting protein (TIP47) was evaluated by reverse transcriptase polymerase chain reaction and immunoblotting. To examine the cellular and molecular events associated with oleuropein, annexin V/propidium iodide staining and immunoblotting were performed. Oleuropein decreased the number and size of lipid droplets in FFA-treated cells and reduced intracellular triglyceride accumulation. However, it did not affect the expression of lipid droplets-associated PAT family proteins, including adipose differentiation-related protein and TIP47. In addition, oleuropein reduced FFA-induced extracellular signal-regulated kinase activation but had no effect on c-Jun N-terminal kinase or AKT activation. Given its protective effects against FFA-induced hepatocellular steatosis, oleuropein may be a lipid-lowering agent.

Topics: Acyltransferases; Adipogenesis; Extracellular Signal-Regulated MAP Kinases; Fatty Acids, Nonesterified; Fatty Liver; Hep G2 Cells; Hepatocytes; Humans; Hypolipidemic Agents; Iridoid Glucosides; Iridoids; JNK Mitogen-Activated Protein Kinases; Membrane Proteins; Olea; Perilipin-2; Perilipin-3; Phytotherapy; Plant Extracts; Plant Leaves; Proto-Oncogene Proteins c-akt; Pyrans; Reverse Transcriptase Polymerase Chain Reaction; Staining and Labeling; Triglycerides; Vesicular Transport Proteins

Breast cancer causes death due to distant metastases in which tumor cells produce matrix metalloproteinase (MMP) enzymes which facilitate invasion. Oleuropein, the main olive oil polyphenol, has anti-proliferative effects. This study aimed to investigate the effect of oleuropein on the metastatic and anti-metastatic gene expression in the MDA human breast cancer cell line. We evaluated the MMPs and TIMPs gene expression by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) in treated and untreated cells. This study demonstrated that OL may induce anti-metastatic effects on human breast cancer cells. We found that TIMP1,-3, and -4 were over-expressed after all periods of incubation in treated cancer cells compared to untreated cells, while MMP2 and MMP9 genes were down-regulated, at least initially. Treatment of breast cancer cells with oleuropein could help in prevention of cancer metastasis by increasing the TIMPs and suppressing the MMPs gene expressions.

Topics: Analysis of Variance; Antineoplastic Agents; Breast Neoplasms; Cell Line, Tumor; Down-Regulation; Gene Expression Regulation, Neoplastic; Humans; Iridoid Glucosides; Iridoids; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Neoplasm Metastasis; Pyrans; RNA, Messenger; Tissue Inhibitor of Metalloproteinase-1; Tissue Inhibitor of Metalloproteinase-3; Tissue Inhibitor of Metalloproteinase-4; Tissue Inhibitor of Metalloproteinases; Up-Regulation

The effects of oleuropein on the processes of osteoblastogenesis and adipogenesis in mesenchymal stem cells (MSCs) from human bone marrow have been studied. We report that oleuropein, a polyphenol abundant in olive tree products, reduces the expression of peroxisome proliferator-activated receptor gamma (PPARγ), inhibits adipocyte differentiation, and enhances differentiation into osteoblast.. Age-related bone loss is associated with osteoblast insufficiency during continuous bone remodeling. It has been suggested that the formation of osteoblasts in bone marrow is closely associated with adipogenesis, and age-related changes in this relationship could be responsible for the progressive adiposity of bone marrow which occurs with osteoporosis. In addition, the consumption of oleuropein, a major polyphenol in olive leaves and olive oil, has been associated with a reduction in bone loss.. We have analyzed the effects of oleuropein-at concentrations between 10(-6) and 10(-4) M-on the processes of osteoblastogenesis and adipogenesis in MSCs from human bone marrow.. The results show an increase in osteoblast differentiation and a decrease in adipocyte differentiation when there is oleuropein in the culture media. The gene expression of osteoblastogenesis markers, RUNXII, osterix, collagen type I, osteocalcin, or alkaline phosphatase (ALP), was higher in osteoblast-induced oleuropein-treated cells. Also, the ALP activity and extracellular matrix mineralization were higher when oleuropein was present in the media. Oleuropein in MSCs induced adipocytes to produce a decrease in the expression of the genes involved in adipogenesis, the PPARγ, lipoprotein lipase, or fatty acid-binding protein 4, and minor fat accumulation.. Our data suggest that oleuropein, highly abundant in olive tree products included in the traditional Mediterranean diet, could prevent age-related bone loss and osteoporosis.

Topics: Adipocytes; Adipogenesis; Antihypertensive Agents; Biomarkers; Bone Marrow; Humans; Iridoid Glucosides; Iridoids; Mesenchymal Stem Cells; Osteoblasts; Osteoclasts; Osteogenesis; PPAR gamma; Pyrans

Olive leaf extract provides nutritional support for detoxification at the cellular level, when the body is under stress. The present study aimed to evaluate the chemopreventive effect of oleuropein-rich extract (ORE) on 4-NQO-induced rat tongue carcinogenesis. Eighty male F344 rats, 6 weeks age were divided into 5 groups (10 animals each for groups 1 and 2 and 20 each for groups 3, 4, and 5). Group 1 served as an untreated control. Group 2 was given ORE-containing diet alone. Rats of groups 3, 4, and 5 were given daily 20 ppm 4-NQO in drinking water for 8 weeks. Group 4 was fed diets containing ORE, concomitantly with the time of carcinogen exposure and continued 1 week after its stoppage. Group 5 was fed diets mixed with ORE starting 1 week after cessation of 4-NQO treatment. The experiment was terminated when the rats aged 37 weeks, and all animals were euthanized. The tongues were carefully inspected for pathological lesions, excised, and were processed for c-Met and Ki-67 immunohistochemical examination. The gross inspection, histopathological and immunohistochemical results of the present study showed a beneficial regression effect of ORE on tumor progression, especially when it was administered concomitantly with 4-NQO rather than when given after the stoppage of the carcinogenic material. In conclusion, ORE has a chemopreventive role in tongue squamous cell carcinoma, and further studies are needed to explore the molecular mechanisms of its tumor suppressive effect at this level.

Topics: 4-Nitroquinoline-1-oxide; Animals; Anticarcinogenic Agents; Antioxidants; Carcinogens; Immunohistochemistry; Iridoid Glucosides; Iridoids; Ki-67 Antigen; Male; Olea; Phytotherapy; Plant Extracts; Plant Leaves; Proto-Oncogene Proteins c-met; Pyrans; Quinolones; Rats; Rats, Inbred F344; Tongue Neoplasms

Olive oil contains numerous phenolic components with well-recognized health-beneficial activity. The major phenolic compounds present in olives and virgin olive oil-hydroxytyrosol, oleuropein and the oleuropein aglycones 3,4-DHPEA-EA and 3,4-DHPEA-EDA-as well as some of their metabolites were studied in the present work, regarding their main structural preferences. Vibrational spectroscopy (Raman) coupled to theoretical methods were used, aiming at fully characterizing the systems and therefore enabling their quick and reliable identification in food samples.. The raman data, assisted by the theoretical simulations, allowed us to obtain the main geometrical and spectroscopic features of the olive oil constituents under study, which determine their known antioxidant and chemoprotective properties. In fact, it was verified that the spectra comprise distinctive bands for each compound, allowing their ready detection and differentiation.. This is the first reported study on the structural behaviour of olive oil phenolic compounds, and it established Raman spectroscopy as a rapid, non-destructive and reliable analytical technique for identifying these bioactive components in dietary extracts. It can surpass other analytical methods currently used, once it allows the concomitant identification of several olive oil components in a particular sample.

Topics: Antioxidants; Iridoid Glucosides; Iridoids; Olea; Olive Oil; Phenols; Phenylethyl Alcohol; Plant Oils; Pyrans; Spectrum Analysis, Raman

Hydrolysis of oleoside-type secoiridoid glucosides, oleuropein (1) and ligustroside (2), in the presence of β-glucosidase provided their aglycones, named (5S,8R,9S)-7-3,4-dihydroxyphenethyl elenolate (3) and (5S,8R,9S)-7-4-hydroxyphenethyl elenolate (4), respectively. The structures of 3 and 4 were identified by spectroscopic means and optical rotation measurements. Evaluation of the cytotoxic and epidermal growth factor receptor (EGFR) tyrosine kinase inhibitory activities of compounds 1-4 showed that compounds 3 and 4 exhibited moderate cytotoxicity against a disease-oriented panel of 39 human cancer cell lines in vitro, whereas compound 3 inhibited the enzyme.

Topics: beta-Glucosidase; Cell Line, Tumor; Cell Survival; Enzyme Inhibitors; ErbB Receptors; Humans; Iridoid Glucosides; Iridoids; Pyrans

Amyloid beta peptide (Abeta) aggregation leads to the senile plaque formation, a process that is strongly influenced by oxidative stress and is considered as the molecular basis of various neurodegenerative diseases, such as Alzheimer's disease (AD). Endogenous antioxidants or dietary derived compounds may down-regulate this process. In this study, the interaction of two antioxidants, oleuropein (OE) and melatonin (M), with Abeta is monitored through nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry. The concerted application of these two analytical techniques provides new experimental evidence and residue-specific insights into the interacting Abeta peptide amino acids that are implicated in this process. Both antioxidant compounds interact in a similar way with the peptide and cause chemical shift variations. The most pronounced resonance changes have been observed for the 1H-15N signals of N-terminal region and Leu17-Phe20 residues, as monitored by NMR titration studies.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Antioxidants; Humans; Iridoid Glucosides; Iridoids; Melatonin; Nuclear Magnetic Resonance, Biomolecular; Peptide Fragments; Pyrans

In Mediterranean folk medicine Olea europaea L. leaf (Ph.Eur.) preparations are used as a common remedy for gout. In this in vitro study kinetic measurements were performed on both an 80% ethanolic (v/v) Olea europaea leaf dry extract (OLE) as well as on nine of its typical phenolic constituents in order to investigate its possible inhibitory effects on xanthine oxidase (XO), an enzyme well known to contribute significantly to this pathological process. Dixon and Lineweaver-Burk plot analysis were used to determine K(i) values and the inhibition mode for the isolated phenolics, which were analysed by RP-HPLC for standardisation of OLE. The standardised OLE as well as some of the tested phenolics significantly inhibited the activity of XO. Among these, the flavone aglycone apigenin exhibited by far the strongest effect on XO with a K(i) value of 0.52 μM. In comparison, the known synthetic XO inhibitor allopurinol, used as a reference standard, showed a K(i) of 7.3 μM. Although the phenolic secoiridoid oleuropein, the main ingredient of the extract (24.8%), had a considerable higher K(i) value of 53.0 μM, it still displayed a significant inhibition of XO. Furthermore, caffeic acid (K(i) of 11.5 μM; 1.89% of the extract), luteolin-7-O-β-D-glucoside (K(i) of 15.0 μM; 0.86%) and luteolin (K(i) of 2.9 μM; 0.086%) also contributed significantly to the XO inhibiting effect of OLE. For oleuropein, a competitive mode of inhibition was found, while all other active substances displayed a mixed mode of inhibition. Tyrosol, hydroxytyrosol, verbascoside, and apigenin-7-O-β-D-glucoside, which makes up for 0.3% of the extract, were inactive in all tested concentrations. Regarding the pharmacological in vitro effect of apigenin-7-O-β-D-glucoside, it has to be considered that it is transformed into the active apigenin aglycone in the mammalian body, thus also contributing substantially to the anti-gout activity of olive leaves. For the first time, this study provides a rational basis for the traditional use of olive leaves against gout in Mediterranean folk medicine.

Topics: Allopurinol; Animals; Apigenin; Chromatography, High Pressure Liquid; Dose-Response Relationship, Drug; Enzyme Inhibitors; Gout; Iridoid Glucosides; Iridoids; Medicine, Traditional; Olea; Phenols; Plant Extracts; Plant Leaves; Plants, Medicinal; Pyrans; Uric Acid; Xanthine Oxidase

Oleuropein, a secoiridoid derived from olives and olive oil, has been known to possess antimicrobial, antioxidative, and anticancer activities. The purpose of the present study was to determine whether oleuropein has a protective effect against hepatic steatosis induced by a high fat diet (HFD) and to elucidate its underlying molecular mechanisms in mice.. Male C57BL/6N mice were fed a normal diet (ND), HFD, or an oleuropein-supplemented diet (OSD) for 10 weeks. The plasma and hepatic lipid levels were determined, and the hepatic gene and protein expression levels were analysed via RT-PCR and Western blotting, respectively.. The supplementation of HFD with oleuropein reversed the HFD-induced increases in liver weight along with plasma and hepatic lipid levels in mice. The expression of Wnt10b inhibitor genes, such as secreted firizzed-related sequence protein 5 and dickkopf homolog 2, was downregulated, whereas the β-catenin protein expression was upregulated in the liver of OSD-fed mice compared to HFD-fed mice. Fibroblast growth factor receptor 1 (FGFR1), phosphoextracellular-signal-regulated kinase 1/2, cyclin D, and E2F transcription factor 1, along with several key transcription factors and their target genes involved in adipogenesis, were downregulated by oleuropein. OSD-fed mice exhibited decreased expression of the toll-like-receptor-(TLR)-mediated signaling molecules (TLR2, TLR4, and myeloid differentiation primary-response gene 88) and proinflammatory cytokines, in their livers, as compared to HFD mice.. These results suggest that the protective effects of oleuropein against HFD-induced hepatic steatosis in mice appear to be associated with the Wnt10b- and FGFR1-mediated signaling cascades involved in hepatic lipogenesis, along with the TLR2- and TLR4-mediated signaling implicated in hepatic steatosis.

Topics: Animals; Antioxidants; beta Catenin; Body Weight; Dietary Fats; Disease Models, Animal; Extracellular Signal-Regulated MAP Kinases; Fatty Liver; Gene Expression; Iridoid Glucosides; Iridoids; Lipogenesis; Liver; Liver Cirrhosis; Male; Mice; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Organ Size; Pyrans; Signal Transduction; Toll-Like Receptors

Aculus olearius Castagnoli is a recently recorded species that damages olive fruits in the Mediterranean basin of Turkey. Thus, the effects of Eriophyid mites (Aculus olearius Castagnoli and Aceria oleae (Nalepa) (Acarina: Eriophyidae) on the olive fruits from Ayvalık variety in southern Turkey were studied for the first time in terms of some physical parameters and chemical constituents including some individual phenolics.. The Eriophyid damaged fruits had higher L* values (lighter colour) and tyrosol level (37.53 mg kg(-1) ) than the undamaged fruits (28.51 mg kg(-1) ) in August. In contrast, Eriophyid damaged fruits were darker in colour and had lower levels (25.77 mg kg(-1) ) of tyrosol than those of undamaged fruits (79.14 mg kg(-1) ) in October. Eriophyid damaged samples had higher values of vanillic acid than the undamaged samples. An increase in the average concentrations of hydroxytyrosol and p-coumaric acid was observed in the fruits harvested in August, whilst the oleuropein content decreased.. The harvest in October can be recommended regarding the higher dimensional values, total oil, dry matter and oleuropein contents. But the interaction between harvest time and Eriophyid damage was found effective in terms of tyrosol content and skin colour; as tyrosol values were lower in the fruits harvested in October and the fruits were darker. The resistance of undamaged fruits against Eriophyid damage can be linked to high tyrosol content of these fruits.

Topics: Animals; Color; Coumaric Acids; Fruit; Iridoid Glucosides; Iridoids; Mites; Olea; Phenylethyl Alcohol; Plant Diseases; Pyrans; Seasons; Species Specificity; Vanillic Acid

A highly sensitive, specific and simple LC-MS/MS method was developed to investigate in vivo bio-transformation of oleuropein in rat. Rat urine samples collected after the intravenous administrations were determined using liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in the negative-ion mode. The assay procedure involves a simple liquid-liquid extraction of parent oleuropein and the metabolite from rat urine with ethyl acetate. Chromatographic separation was operated with 0.1% formic acid aqueous and methanol in gradient program at a flow rate of 0.80 mL/min on an RP-C(18) column with a total run time of 30 min. This method has been successfully applied to simultaneous determination of oleuropein and its metabolite in rat urine. Oxygenation was found to be the major metabolic pathway of the oleuropein in rat after intravenous administration.

Topics: Acetates; Animals; Chromatography, Liquid; Formates; Injections, Intravenous; Iridoid Glucosides; Iridoids; Liquid-Liquid Extraction; Male; Methanol; Pyrans; Rats; Rats, Sprague-Dawley; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry

In this article, an efficient method was developed to screen, isolate and identify the major radical scavengers in the leaves of Olea europaea L. by DPPH-HPLC-DAD, HSCCC and NMR. The method of DPPH-HPLC-DAD was used to screen the major radical scavengers. It was found that three major constituents (A, B, C) in the extract of the leaves of O. europaea L. possessed potential antioxidant activities. In order to identify the chemical structures of those compounds, the HSCCC method with a two-phase solvent system composed of petroleum ether-ethyl acetate-water at an optimized volume ratio of 6:600:700 (v/v/v) together with column chromatography was developed to isolate and purify the active compounds. Pure compounds A (225 mg), B (10 mg) and C (12 mg) with purities 92.6, 95.1 and 96.4%, respectively, were obtained from the crude sample (500 mg). Their structures were identified as oleuropein (A), luteolin-7-O-glucoside (B) and verbascoside (C) by (1) H-NMR and (13) C-NMR.

Topics: Acetates; Chromatography, High Pressure Liquid; Flavones; Free Radical Scavengers; Glucosides; Iridoid Glucosides; Iridoids; Olea; Phenols; Plant Extracts; Plant Leaves; Pyrans

The Mediterranean diet, with a high content of olive oil, is associated with a reduced risk of coronary artery disease. The aim of this study was to determine the effect of oleuropein, one of the polyphenols in olive oil, on vascular smooth muscle cell (SMC) proliferation in vitro.. This was an experimental study.. Bovine vascular SMCs were cultured in the presence of 100 μM of oleuropein. On days 1, 3 and 5, cell number was counted. Cell cycle analysis was performed by flow cytometry. Cell cycle regulators were assessed by immunoblotting.. Cell proliferation in the presence of oleuropein was significantly inhibited by 92%. Cell cycle analysis revealed that oleuropein treatment blocked cells in the G1-S phase compared with the non-treated group. Among G1 phase regulators, retinoblastoma protein, cyclinD, p21 and p27 were not affected by oleuropein, but extracellular signal-regulated kinase 1/2 (ERK1/2) activation was inhibited. Growth of SMC treated with 100 μM of the mitogen-activated protein (MAP) kinase/ERK kinase 1 (MEK1) inhibitor PD98059 was also significantly inhibited by 70%.. Oleuropein inhibited SMC proliferation through a cell cycle block between the G1 and the S phases, which may be regulated by ERK1/2. These results suggest a mechanism by which olive oil consumption may have beneficial effects on cardiovascular mortality by inhibiting SMC proliferation.

Topics: Animals; Cattle; Cell Culture Techniques; Cell Cycle; Cell Proliferation; Iridoid Glucosides; Iridoids; Myocytes, Smooth Muscle; Olive Oil; Plant Oils; Pyrans; Time Factors; Vasodilator Agents

Tau isoforms constitute a family of microtubule-associated proteins that are mainly expressed in neurons of the central nervous system. They promote the assembly of tubulin monomers into microtubules and modulate their stability, thus playing a key structural role in the distal portion of axons. In Alzheimer's disease and related tauopathies, Tau aggregation into fibrillary tangles contributes to intraneuronal and glial lesions. We report herein the ability of three natural phenolic derivatives obtained from olives and derived food products to prevent such Tau fibrillization in vitro, namely hydroxytyrosol, oleuropein, and oleuropein aglycone. The latter was found to be more active than the reference Tau aggregation inhibitor methylene blue on both wild-type and P301L Tau proteins, inhibiting fibrillization at low micromolar concentrations. These findings might provide further experimental support for the beneficial nutritional properties of olives and olive oil as well as a chemical scaffold for the development of new drugs aiming at neurodegenerative tauopathies.

Topics: Humans; Iridoid Glucosides; Iridoids; Magnetic Resonance Spectroscopy; Microscopy, Electron, Transmission; Olea; Pyrans; tau Proteins

Several olive oil phenolic compounds, such us oleuropein have attracted considerable attention because of their antioxidant activity, anti-atherosclerotic and anti-inflammatory properties. The aim of this study was to investigate the effects of oleuropein aglycone, a hydrolysis product of oleuropein, in a mouse model of carrageenan-induced pleurisy.. Mice were anaesthetized and subjected to a skin incision at the level of the left sixth intercostals space. The underlying muscle was dissected and saline or saline containing 2% λ-carrageenan was injected into the pleural cavity.. Injection of carrageenan elicited an acute inflammatory response characterized by: infiltration of neutrophils in lung tissues (P < 0.01 versus sham. P < 0.01 versus carrageenan) and subsequent lipid peroxidation (P < 0.01 versus sham. P < 0.01 versus carrageenan), increased production of tumor necrosis factor-α and interleukin-1β (P < 0.01 versus sham. P < 0.01 versus carrageenan), increased expression of adhesion molecules, increased synthesis of nitric oxide (P < 0.01 versus sham. P < 0.01 versus carrageenan), nitrotyrosine and poly-ADP-ribose (P < 0.01 versus sham. P < 0.01 versus carrageenan). Administration of oleuropein aglycone 30 min after the challenge with carrageenan, caused a significant reduction of all the parameters of inflammation measured.. Thus, we propose that olive oil phenolic constituents may be useful in the treatment of various inflammatory diseases.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Carrageenan; Disease Models, Animal; Hydrolysis; Intercellular Adhesion Molecule-1; Interleukin-1beta; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Lung; Male; Mice; Nitric Oxide; Olive Oil; P-Selectin; Phenols; Plant Oils; Pleurisy; Poly Adenosine Diphosphate Ribose; Pyrans; Tumor Necrosis Factor-alpha; Tyrosine

Polyphenols reportedly exert physiological effects against diseases such as cancer, arteriosclerosis, hyperlipidemia and osteoporosis. The present study was designed to evaluate the effects of oleuropein, hydroxytyrosol and tyrosol, the major polyphenols in olives, on bone formation using cultured osteoblasts and osteoclasts, and on bone loss in ovariectomized mice. No polyphenols markedly affected the proliferation of osteoblastic MC3T3-E1 cells at concentrations up to 10μM. Oleuropein and hydroxytyrosol at 10 to 100μM had no effect on the production of type I collagen and the activity of alkaline phosphatase in MC3T3-E1 cells, but stimulated the deposition of calcium in a dose-dependent manner. In contrast, oleuropein at 10 to 100μM and hydroxytyrosol at 50 to 100μM inhibited the formation of multinucleated osteoclasts in a dose-dependent manner. Furthermore, both compounds suppressed the bone loss of trabecular bone in femurs of ovariectomized mice (6-week-old BALB/c female mice), while hydroxytyrosol attenuated H(2)O(2) levels in MC3T3-E1 cells. Our findings indicate that the olive polyphenols oleuropein and hydroxytyrosol may have critical effects on the formation and maintenance of bone, and can be used as effective remedies in the treatment of osteoporosis symptoms.

Topics: 3T3 Cells; Animals; Female; Flavonoids; Humans; Iridoid Glucosides; Iridoids; Male; Mice; Olea; Osteoblasts; Osteoclasts; Osteogenesis; Osteoporosis; Ovariectomy; Phenols; Phenylethyl Alcohol; Polyphenols; Pyrans

Amyloid aggregation starts with the initial misfolding of peptide/protein precursors, with subsequent structural rearrangement into oligomers and protofibrils; the latter eventually organize into fibrils with shared basic structural features, found deposited in amyloid diseases. Mounting evidence indicates early oligomers as the most toxic amyloid species; accordingly, the search of inhibitors of their growth is considered a promising target to prevent amyloid toxicity. We recently showed that oleuropein aglycon, a polyphenol abundant in the extra virgin olive oil, interferes with the aggregation of amylin (involved in type-2 diabetes), eliminating its cytotoxicity. Here we report that oleuropein aglycon also hinders amyloid aggregation of Aβ(1-42) and its cytotoxicity, suggesting a general effect of such polyphenol. In particular, by using a wide panel of different spectroscopic, immunologic, cell viability and imaging techniques we provide a more detailed description of Aβ(1-42) structural modifications arising in the presence of the inhibitor and the resulting cytotoxicity. We here report that the polyphenol eliminates the appearance of early toxic oligomers favouring the formation of stable harmless protofibrils, structurally different from the typical Aβ(1-42) fibrils. We also show that oleuropein aglycon is maximally effective when is present at the beginning of the aggregation process; furthermore, when added to preformed fibrils, it does not induce the release of toxic oligomers but, rather, neutralizes any residual toxicity possibly arising from the residual presence of traces of soluble oligomers and other toxic aggregates. The possible use of this polyphenol as anti-aggregation molecule is discussed in the light of these data.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Cell Line, Tumor; Humans; Iridoid Glucosides; Iridoids; Neuroprotective Agents; Peptide Fragments; Plant Extracts; Plaque, Amyloid; Polymers; Polyphenols; Pyrans

Leaves of olive trees are an abundant raw material in the Mediterranean basin. They contain large amounts of potentially useful phytochemicals and could play beneficial roles in health care. In the present study, the principal bioactive phenols in olive-leaf extracts (OLEs) have been identified and quantified, and their genotoxic/antigenotoxic, cytotoxic and apoptotic effects have been assessed. The Somatic Mutation and Recombination Test (SMART) in wing imaginal discs of Drosophila melanogaster has been performed to test the possible genotoxicity of overall OLE and the individual components oleuropein and luteolin at different concentrations. The same assay was able to detect antigenotoxic activity against hydrogen peroxide as oxidative genotoxicant. None of the extracts/phenols tested showed significant mutagenic activity. This fact, together with the antigenotoxic activity against H(2)O(2) detected for all these extracts/phenols, confirmed the safety of OLE, oleuropein and luteolin in terms of DNA protection. HL60 human promyelocytic leukemia cells were used to assess the cytotoxic effects of the extracts/phenols. OLE, oleuropein and luteolin showed a dose-dependent cytotoxic effect with different IC50 (10μl/ml, 170μM, and 40μM, respectively). DNA fragmentation patterns and cell staining with acridine orange and ethidium bromide indicated that the mechanism for the cytotoxic effect of OLE, oleuropein and luteolin was the apoptotic pathway, with DNA laddering and cytoplasmic and nuclear changes. These results could help explain the mechanism of action that underlies the beneficial effect of OLE, proposed as a nutraceutical in the prevention of human cancer.

Topics: Anticarcinogenic Agents; Antimutagenic Agents; Apoptosis; DNA Damage; HL-60 Cells; Humans; Iridoid Glucosides; Iridoids; Luteolin; Olea; Phenols; Plant Extracts; Plant Leaves; Plant Oils; Pyrans

The skin undergoes intrinsic aging as a normal course, but exposure to ultraviolet (UV) light results in major cumulative damage that manifests as the typical aged photodamaged skin. UV irradiation produces a sequence of changes within the skin layers starting with signaling processes following DNA damage and culminating in nonabsorbed fragmentation of collagen and other proteins within the extracellular matrix. These fragments promote the synthesis of matrix metalloproteinases (MMPs) that further aggravate the damage to the ground substance and add to fragment accumulation. This study describes a unique sequential approach to controlling this photodamage - inhibition of signaling, inhibition of MMPs, proteasome stimulation and mopping up of fragments, stimulation of procollagen and collagen production, and uniform packaging of new collagen fibers. Thus, a multifaceted approach is introduced with presentation of a unique product formulation based on these research principles.

Topics: Collagen; Fibroblasts; Humans; Iridoid Glucosides; Iridoids; Keratinocytes; Liliaceae; Matrix Metalloproteinases; Pentacyclic Triterpenes; Phosphatidylserines; Plant Extracts; Pyrans; Reactive Oxygen Species; Rejuvenation; Signal Transduction; Skin; Skin Aging; Ultraviolet Rays

This study developed a feasible process to simultaneously separate and purify polyphenols, including flavonoids and oleuropein, from the leaves of Olea europaea L. Macroporous resins were used as the separation and purification materials. The performance and separation capabilities of eight resins (D101, DM130, HPD450, LSA-21, LSA-40, 07C, LSD001 and HPD600) were systematically evaluated. The contents of target polyphenols in different extracts were determined using ultraviolet (for flavonoids) and high-performance liquid chromatographic (for oleuropein) methods. The static adsorption and desorption results showed that resin LSA-21 had better adsorption properties among the eight resins. Influential factors such as extraction method, pH value of feeding solution, desorption solution, adsorption kinetics and adsorption isotherm, etc. to the extraction and purification of these polyphenols were successively investigated on resin LSA-21.. The target flavonoids and oleuropein were selectively purified using resin LSA-21. Compared with the contents in raw leaves, the contents of total flavonoids and oleuropein in the final purified products were increased 13.2-fold (from 16 to 211 g kg(-1) ) and 7.5-fold (from 120 to 902 g kg(-1) ) with recovery yields of 87.9% and 85.6%, respectively.. This extraction and purification method could be used in the large-scale enrichment or purification of flavonoids, oleuropein and other polyphenols from O. europaea L. leaves or other herbal materials in industrial, food processing and medical manufacture.

Topics: Adsorption; Chromatography, High Pressure Liquid; Flavonoids; Iridoid Glucosides; Iridoids; Olea; Plant Leaves; Pyrans; Resins, Synthetic

Various pancreatic β-cell stressors, including cytokines, are known to induce oxidative stress, resulting in apoptotic/necrotic cell death and inhibition of insulin secretion. Traditionally, olive leaves or fruits are used for treating diabetes, but the cellular mechanism(s) of their effects are not known. We examined the effects of Olea europea L. (olive) leaf and fruit extracts and their component oleuropein on cytokine-induced β-cell toxicity. INS-1, an insulin-producing β-cell line, was preincubated with or without increasing concentrations of olive leaf or fruit extract or oleuropein for 24 hr followed by exposure to a cytokine cocktail containing 0.15 ng/mL interleukin-1β (IL-1β), 1 ng/mL interferon-γ (IFN-γ), and 1 ng/mL tumor necrosis factor-α (TNF-α) for 6 hr. The cytotoxicity was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) testing. Apoptosis was quantified by detecting acridine orange/ethidium bromide-stained condensed nuclei under a fluorescent microscope. The cells exposed to cytokines had a higher apoptotic rate, a decreased viability (MTT), and an increased caspase 3/7 activity. Both extracts and oleuropein partially increased the proportion of living cells and improved the viability of cells after cytokines. The protective effects of extracts on live cell viability were mediated through the suppression of caspase 3/7 activity. Oleuropein did not decrease the amount of both apoptotic and necrotic cells, whereas extracts significantly protected cells against cytokine-induced death. Cytokines led to an increase in reactive oxygen species (ROS) generation and inhibited glutathione level, superoxide dismutase activity, and insulin secretion in INS-1. Insulin secretion was almost completely protected by leaf extract, but was partially affected by fruit extract or oleuropein. Neither cytokines nor olive derivatives had a significant effect on cellular cytochrome c release and catalase activity. Moreover, the cells incubated with each extract or oleuropein showed a significant reduction in cytokine-induced ROS production and ameliorated abnormal antioxidant defense. The molecular mechanism by which olive polyphenols inhibit cytokine-mediated β-cell toxicity appears to be involving the maintenance of redox homeostasis.

Topics: Animals; Caspase 3; Caspase 7; Cell Death; Cell Line; Cytochromes c; Cytokines; Cytoprotection; Glutathione; Homeostasis; Insulin; Insulin Secretion; Insulin-Secreting Cells; Iridoid Glucosides; Iridoids; Mitochondria; Olea; Oxidation-Reduction; Plant Extracts; Polyphenols; Pyrans; Rats; Reactive Oxygen Species; Superoxide Dismutase

The aim of this study was to investigate the effect of oleuropein aglycone, an olive oil compound, on the modulation of the inflammatory response in mice subjected to collagen-induced arthritis (CIA). CIA was induced in mice by an intradermal injection of 100 μl of an emulsion containing 100 μg of bovine type II collagen (CII) and complete Freund's adjuvant (CFA) at the base of the tail. On day 21, a second injection of CII in CFA was administered. Mice developed erosive hind paw arthritis when immunized with CII in CFA. Macroscopic clinical evidence of CIA first appeared as periarticular erythema and edema in the hind paws. The incidence of CIA was 100% by day 28 in the CII-challenged mice and the severity of CIA progressed over a 35-day period with resorption of bone. The histopathology of CIA included erosion of the cartilage at the joint. Treatment with oleuropein aglycone starting at the onset of arthritis (day 25) ameliorated the clinical signs at days 26 to 35 and improved histological status in the joint and paw. The degree of oxidative and nitrosative damage was also significantly reduced in oleuropein aglycone-treated mice. Plasma levels of the proinflammatory cytokines were also significantly reduced by oleuropein aglycone. In addition, we have confirmed the beneficial effects of oleuropein aglycone on an experimental model of CIA in a therapeutic regimen of post-treatment, with treatment started at day 28, demonstrating that oleuropein aglycone exerts an anti-inflammatory effect during chronic inflammation and ameliorates the tissue damage associated with CIA.

Topics: Alcohol Oxidoreductases; Animals; Anti-Inflammatory Agents, Non-Steroidal; Arthritis, Experimental; Cattle; Collagen Type II; Cytokines; Dinoprostone; Disease Models, Animal; Disease Progression; Drug Administration Schedule; Drug Evaluation, Preclinical; Iridoid Glucosides; Iridoids; Joints; Male; Mice; Mice, Inbred DBA; Nitric Oxide Synthase Type II; Olive Oil; Peroxidase; Plant Oils; Pyrans

Oleuropein and hydroxytyrosol, which are antioxidant molecules found in olive leaves and oil, have been reported to exert several biochemical and pharmacological effects. These polyphenols are able to prevent low-density lipoprotein oxidation and protect cells against several diseases. Here, we studied the effect of these compounds on adipocyte differentiation in 3 T3-L1.. To perform this study, 3 T3-L1 preadipocytes viability was analysed via Trypan blue and MTT assays, and triglycerides were stained with Oil Red O. Adipogenesis related genes expression were checked by RT-PCR and qRT-PCR. Also, cells counting and flow cytometry were used to analyse the mitotic cell cycle during the adipogenesis clonal expansion phase.. Oleuropein and hydroxytyrosol dose-dependently suppressed intracellular triglyceride accumulation during adipocyte differentiation without effect on cell viability. PPARγ, C/EBPα and SREBP-1c transcription factors and their downstream targets genes (GLUT4, CD36 and FASN) were down-regulated after treatment by oleuropein and hydroxytyrosol. At 200 and 300 μmol/L oleuropein or 100 and 150 μmol/L hydroxytyrosol, the greatest effect on the adipogenesis process was observed during the early stages of differentiation. Flow cytometry revealed both polyphenols to inhibit the division of 3T3-L1 preadipocytes during mitotic clonal expansion and cause cell cycle delay. Furthermore, oleuropein and its derivate hydroxytyrosol decreased the transcriptional activity of SREBP-1c in a stable transfected 3T3-L1 cell line.. These findings indicate that both compounds are able to prevent 3T3-L1 differentiation by inhibition of the mitotic clonal expansion and downregulation of the adipogenesis related genes.

Topics: 3T3-L1 Cells; Adipocytes; Adipogenesis; Animals; Antioxidants; Cell Differentiation; Cell Survival; Dose-Response Relationship, Drug; Down-Regulation; Flow Cytometry; Iridoid Glucosides; Iridoids; Mice; Mitosis; Phenylethyl Alcohol; Pyrans; Reverse Transcriptase Polymerase Chain Reaction; Triglycerides

The aim of the study was a HPLC evaluation of the lipoxygenase activity inhibiting activity of a water infusion of Ligustrum vulgare L. leaves and selected isolates from it. The antiradical activity of the water infusion was determined using DPPH, ABTS and FRAP tests. Oleuropein and echinacoside concentrations in the water infusion were determined by HPLC. Water infusion, echinacoside and oleuropein were used for an antilipoxygenase activity assay using lipoxygenase isolated from rat lung cytosol fraction. Activity of 8-LOX, 12-LOX and 15-LOX were monitored through formation of 8-HETE, 12-HETE and 15-HETE, respectively. The water infusion exhibited the highest activity against all lipoxygenases, followed by oleuropein. Echinacoside was ineffective against LOXs in lower concentrations, while higher concentration showed similar inhibition on 8-LOX and 12-LOX. 15-LOX was affected more and the presence of echinacoside remarkably decreased its activity.

Topics: Animals; Anti-Inflammatory Agents; Chromatography, High Pressure Liquid; Cytosol; Glycosides; Hydroxyeicosatetraenoic Acids; Iridoid Glucosides; Iridoids; Ligustrum; Lipoxygenase; Lipoxygenase Inhibitors; Lung; Medicine, Traditional; Plant Extracts; Plant Leaves; Pyrans; Rats

Oleuropein, the major secoiridoid in olive tree leaves, possesses a wide range of health promoting properties. It has recently been shown to exhibit anti-inflammatory activity. We have evaluated the effect of oleuropein on dextran sulfate sodium (DSS)-induced experimental colitis in mice in order to provide insight into its mechanisms of action. Oral administration of oleuropein notably attenuated the extent and severity of acute colitis while reducing neutrophil infiltration; production of NO, IL-1β, IL-6, and TNF-α; expression of iNOS, COX-2, and MMP-9; and the translocation of the NF-κB p65 subunit to the nucleus in colon tissue. In LPS-stimulated peritoneal macrophages, the oleuropein metabolite, hydroxytyrosol, was shown to inhibit NO production, iNOS expression, NF-κB p65 subunit translocation, mRNA expression, and the release of IL-1β, IL-6, and TNF-α. These results suggest that the effect of oleuropein on DSS-induced colitis is associated with a decrease in the production of interleukins and expression of proteins, principally through reduction of NF-κB activation.

Topics: Acute Disease; Animals; Anti-Inflammatory Agents; Colitis; Cytokines; Dextran Sulfate; Female; Iridoid Glucosides; Iridoids; Macrophages, Peritoneal; Mice; Mice, Inbred BALB C; Nitric Oxide; Phenylethyl Alcohol; Pyrans

Neutrophil infiltration plays an important role in inflammatory reactions following spinal cord injury (SCI) and these cells cause substantial secondary tissue damage. The purpose of this study was to determine the effect of oleuropein (OE) on myeloperoxidase (MPO) activity as an index of neutrophil infiltration.. Rats were randomly divided into four groups of 7 rats each as follows: sham-operated group, trauma group, and OE treatment groups (20 mg/kg, i.p., immediately and 1 hour after SCI). Spinal cord samples were taken 24 hours after injury and studied for determination of MPO activity.. The results showed that MPO activity was significantly decreased in OE-treated rats.. On the basis of our findings, we propose that OE may be effective in protecting rat spinal cord from secondary damage by modulating of neutrophil infiltration.

Topics: Animals; Iridoid Glucosides; Iridoids; Male; Peroxidase; Pyrans; Rats; Rats, Sprague-Dawley; Spinal Cord; Spinal Cord Injuries

The phenolic fraction of a monovarietal extra virgin olive oil (EVOO) from Olea europaea L. var. Cornezuelo was studied by the hyphenated HPLC-DAD-SPE-NMR/MS techniques. This survey led to the identification of 25 main compounds. One was identified as a new diastereoisomer of the aldehydic form of oleuropein aglycone (AOA) and characterized by 1D and 2D NMR techniques. The relative configuration of this new AOA was determined as 5R*,8S*,9S* on the basis of the results obtained from the combination of NOE experiments and Monte Carlo conformational search calculations. Assuming, as for the described diastereoisomers, that the new AOA comes from the natural oleuropein aglycone (OA), the absolute configuration was proposed as 5S,8R,9R.

Topics: Aldehydes; Chromatography, High Pressure Liquid; Iridoid Glucosides; Iridoids; Magnetic Resonance Spectroscopy; Mass Spectrometry; Olea; Olive Oil; Phenols; Plant Oils; Pyrans; Solid Phase Extraction

Pancreatic amyloid deposits of amylin are a hallmark of Type II diabetes and considerable evidence indicates that amylin oligomers are cytotoxic to beta-cells. Many efforts are presently spent to find out naturally occurring molecules, or to design synthetic ones, able to hinder amylin aggregation or to protect cells against aggregate cytotoxicity. In this context, a protective effect of some polyphenols against amyloid cytotoxicity was reported. Actually dietary polyphenols are endowed with multiple health benefits, and extra virgin olive oil is attracting increasing interest as a source of these substances. Here, we investigated the effects on amylin aggregation and cytotoxicity of the secoiridoid oleuropein aglycon, the main phenolic component of extra virgin olive oil. We found that oleuropein, when present during the aggregation of amylin, consistently prevented its cytotoxicity to RIN-5F pancreatic beta-cells, as determined by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide test and caspase-3 activity assay. A lack of interaction with the cell membrane of amylin aggregates grown in the presence of oleuropein was shown by fluorescence microscopy and synthetic lipid vesicle permeabilization. Moreover, our ThT assay, circular dichroism analysis and electron microscopy images suggested that oleuropein interferes with amylin aggregation, resulting in a different path skipping the formation of toxic pre-fibrillar aggregates. These results provide a molecular basis for some of the benefits potentially coming from extra virgin olive oil consumption and pave the way to further studies on the possible pharmacological use of oleuropein to prevent or to slow down the progression of type II diabetes.

Topics: Amyloid; Cell Line; Circular Dichroism; Humans; Iridoid Glucosides; Iridoids; Islet Amyloid Polypeptide; Microscopy, Electron, Transmission; Microscopy, Fluorescence; Pyrans

Oleuropein (OE) is the cardinal bioactive compound derived from Olea europaea and possesses numerous beneficial properties for human health. However, despite the plethora of analytical methods that have studied the biological fate of olive oil-derived bioactive compounds, no validated methodology has been published to date for the simultaneous determination of OE, along with all its major metabolites. In this study, a liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI MS/MS) method has been developed and validated for the quantification of OE, simultaneously with its main metabolites hydroxytyrosol, 2-(3,4-dihydroxyphenyl)acetic acid, 4-(2-hydroxyethyl)-2-methoxy-phenol or homovanillyl alcohol, 2-(4-hydroxy-3-methoxyphenyl)acetic acid or homovanillic acid, and elenolic acid in rat plasma matrix. Samples were analyzed by LC-ESI MS/MS prior to and after enzymatic treatment. A solid-phase extraction step with high mean recovery for all compounds was performed as sample pretreatment. Calibration curves were linear for all bioactive compounds over the range studied, while the method exhibited good accuracy, intra- and inter-day precision. The limit of detection was in the picogram range (per milliliterof plasma) for HT and OE and in the nanogram range (per milliliter of plasma) for the other analytes, and the method was simple and rapid. The developed methodology was successfully applied for the simultaneous quantification of OE and its aforementioned metabolites in rat plasma samples, thus demonstrating its suitability for pharmacokinetics, as well as bioavailability and metabolism studies.

Topics: Animals; Chromatography, Liquid; Female; Iridoid Glucosides; Iridoids; Limit of Detection; Olea; Pyrans; Rats; Rats, Wistar; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry

Olive (Olea europaea L.) leaves have long been used in folk medicine and herbal tea in Europe and the Mediterranean area. The Mediterranean climate is characterized by high temperatures, and by strong ultraviolet B (UVB) radiation causing the skin to age, increasing wrinkling, pigmentation and skin thickness. The aim of this study was to examine the effects of an olive leaf extract and its component oleuropein on skin damage caused by acute UVB irradiation in C57BL/6J mice. The extract (300 or 1000 mg/kg) and oleuropein (25 or 85 mg/kg) were administered orally twice daily for 14 days. UVB was administered daily at a dose of 120 mJ/cm(2) for the first 5 days and then every other day for 9 days. Both treatments inhibited the increases in skin thickness induced by radiation. They also inhibited increases in the Ki-67- and 8-hydroxy-2'-deoxyguanosine-positive cell numbers, melanin granule area and matrix metalloproteinase-13 (MMP-13) expression. These preventive effects on UVB-induced skin damage might be caused in part by inhibiting the degradation of extracellular matrixes in the corium, and by the proliferation of epidermal cells through the inhibition of increases in MMP-13 levels and reactive oxygen species induced by irradiation.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Deoxyguanosine; Iridoid Glucosides; Iridoids; Ki-67 Antigen; Male; Matrix Metalloproteinase 13; Melanins; Mice; Mice, Inbred C57BL; Olea; Plant Extracts; Plant Leaves; Pyrans; Skin; Transforming Growth Factor beta1; Ultraviolet Rays

The content of polyphenols in table olives is highly influenced by the olive variety and the debittering process applied on the fruits. Nine commercial types of Greek table olives were examined for their content in oleuropein and hydroxytyrosol. A very simple extraction procedure and a chromatographic methodology were applied for the simultaneous quantitation of oleuropein (OE) and hydroxytyrosol (HT) in drupes, using boiling water extraction followed by direct HPLC analysis. Hydroxytyrosol was found in all the types of olives that were studied. Kalamata olives and Green "tsakistes" of the variety Megaritiki contained the highest quantity of hydroxytyrosol (1.8-2.0 mg/fruit) followed by Greek-style "chondrolies" with quantity 1.0 mg/fruit. Oleuropein was found in small quantities in two cases, but in the case of Throuba Thassos which is processed by dry salt in a traditional Greek way, oleuropein was found in important quantities (1.2 mg/fruit) recorded over a 4-year period. This is the most important finding of this study showing that this particular table olive type is a nutritional rich source of oleuropein. Additionally, assuming a usual consumption of 20 olive fruits per day, an approximate quantity of 25 mg of oleuropein per day can be considered as safe for human use, since it can be found in the usual diet.

Topics: Food Handling; Greece; Humans; Iridoid Glucosides; Iridoids; Nutritive Value; Olea; Phenylethyl Alcohol; Pyrans

The growth of many breast tumors is stimulated by estradiol (E2), which activates a classic mechanism of regulation of gene expression and signal transduction pathways inducing cell proliferation. Polyphenols of natural origin with chemical similarity to estrogen have been shown to interfere with tumor cell proliferation. The aim of this study was to investigate whether hydroxytyrosol (HT) and oleuropein (OL), two polyphenols contained in extra-virgin olive oil, can affect breast cancer cell proliferation interfering with E2-induced molecular mechanisms. Both HT and OL inhibited proliferation of MCF-7 breast cancer cells. Luciferase gene reporter experiments, using a construct containing estrogen responsive elements able to bind estrogen receptor alpha (ERalpha) and the study of the effects of HT or OL on ERalpha expression, demonstrated that HT and OL are not involved in ERalpha-mediated regulation of gene expression. However, further experiments pointed out that both OL and HT determined a clear inhibition of E2-dependent activation of extracellular regulated kinase1/2 belonging to the mitogen activating protein kinase family. Our study demonstrated that HT and OL can have a chemo-preventive role in breast cancer cell proliferation through the inhibition of estrogen-dependent rapid signals involved in uncontrolled tumor cell growth.

Topics: Anticarcinogenic Agents; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Enzyme Activation; Estradiol; Estrogen Receptor alpha; Female; Humans; Iridoid Glucosides; Iridoids; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Phenylethyl Alcohol; Protein Kinase Inhibitors; Pyrans; Transcriptional Activation

Oxidative stress may play an important role in the pathogenesis of non-alcoholic steatohepatitis (NASH). Oleuropein, the active constituent of olive leaf, possesses anti-oxidant, hypoglycaemic, and hypolipidaemic activities. We aimed to investigate the preventive effects of olive leaf extract on hepatic fat accumulation in a rat model of NASH.. Spontaneously hypertensive/NIH-corpulent rats were fed a diet of AIN-93G with or without olive leaf extract (500, 1000, 2000 mg/kg diet, and control; 5 rats each) for 23 weeks. Serological and histopathological findings, anti-oxidative activity, and the alteration of fatty acid synthesis in the liver were evaluated.. Histopathologically, a diet of AIN-93G containing more than 1000 mg/kg olive leaf extract had a preventive effect for the occurrence of NASH. Thioredoxin-1 expression in the liver was more evident in rats fed this diet, and 4-hydroxynonenal expression in the liver was less evident in these rats. There were no significant differences in the activities of hepatic carnitine palmitoyltransferase, fatty acid synthase, malic enzyme, and phosphatidic acid phosphohydrolase among the groups.. Our data suggest that olive leaf extract may help prevent NASH, presumably through its anti-oxidative activity.

Topics: Aldehydes; Animal Feed; Animals; Antioxidants; Blood Chemical Analysis; Disease Models, Animal; Fatty Liver; Iridoid Glucosides; Iridoids; Liver; Male; Olea; Organ Size; Oxidative Stress; Plant Leaves; Pyrans; Rats; Rats, Inbred SHR; Thioredoxins

Methanolic extracts prepared from dried leaves of Jasminum officinale f. var. grandiflorum (L.) Kob. (Spanish jasmine) inhibited seed germination and stunted both root and shoot length of the weeds Echinochloa crus-galli (L.) Beauv. and Phaseolus lathyroides L. The main active compound was isolated and determined by spectral data as a secoiridoid glucoside named oleuropein. In addition, a decrease in allelopathic efficacy appeared as the decomposition periods increased. The mitotic index in treated onion root tips decreased with increasing concentrations of the extracts and longer periods of treatment. Likewise, the mitotic phase index was altered in onion incubated with crude extract. Furthermore, crude extract produced mitotic abnormalities resulting from its action on chromatin organization and mitotic spindle.

Topics: Biological Assay; Cell Division; Chromatin; Cytogenetics; Germination; Iridoid Glucosides; Iridoids; Magnetic Resonance Spectroscopy; Methanol; Mitosis; Onions; Phaseolus; Plant Extracts; Plants; Pyrans; Seeds; Spindle Apparatus

In this work, high-performance liquid chromatography (HPLC) coupled to electrospray time-of-flight mass spectrometry (ESI-TOF-MS) and electrospray ion trap multiple-stage tandem mass spectrometry (ESI-IT-MS(2)) has been applied to screen phenolic compounds in olive leaf extracts. The use of a small particle size C18 column (1.8 micro) provided great resolution and made separation of a lot of isomers possible. The structural characterization was based on accurate mass data obtained by ESI-TOF-MS, and the nature of fragmentation ions were further confirmed by ESI-IT-MS(2) when possible. In addition, we employed tetrazolium salt (MTT)-based assays to assess the effects of olive leaf extracts on the growth of human tumor-derived cells. Upon this approach, we achieved an accurate profile of olive leaf phenolics along with the identification of several important isomers of secoiridoids and flavonoids. This will allow a better understanding of the complete composition of olive-leaf-bioactive compounds as well as their involvement in Olea europaea L. biochemical pathways. Importantly, olive leaf extracts exhibited dose-dependent inhibitory effects on the metabolic status (cell viability) of three breast cancer models in vitro. Since the tumoricidal activity of the extracts should be mainly attributed to the identified olive leaf phenolics, these findings warrant further investigation at the structure-function molecular level to definitely establish the anticancer value of these phytochemicals.

Topics: Antineoplastic Agents, Phytogenic; Breast Neoplasms; Carcinoma; Cell Survival; Chromatography, High Pressure Liquid; Cinnamates; Female; Flavonoids; Humans; Iridoid Glucosides; Iridoids; Olea; Phenols; Plant Leaves; Pyrans; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry

A gas chromatographic-mass spectrometric (GC-MS) method for qualitative and subsequent quantitative analysis of phenolic antioxidants compounds, presents in olive oil, in rat cerebrospinal fluid (CSF) after oral administration of compounds is proposed. The procedure involves the extraction of compounds from the samples by a traditional microliquid-liquid extraction method, followed by a silylation step before the GC-MS analysis. The chromatographic separation was performed by using a low bleed DB5-MS fused-silica capillary column. The presence of 21 phenolic compounds was tested in CSF extracts and only free tyrosol, hydroxytyrosol and ferulic acid were detected. Those compounds were then quantitatively determined using the proposed methology. The molecular ion for silylated compounds appears at 370 m/z for hydroxytyrosol, 282 m/z for tyrosol and 338 m/z for ferulic acid respectively, while the base peak appears at 267 m/z, 179 m/z and 338 m/z. alpha-Naphthol was used as a surrogate (216 and 201 m/z). The detection capabilities obtained were 74, 92 and 79 ng/mL respectively. The method was applied to the determination of trace amounts of compounds in rat cerebrospinal fluid after oral administration. The animals were fed with a standard chow diet (free of phenolic antioxidants) in order to avoid the influence of any other component of the diet on the CSF of the animals.

Topics: Administration, Oral; Animals; Antioxidants; Gas Chromatography-Mass Spectrometry; Iridoid Glucosides; Iridoids; Male; Phenols; Pyrans; Rats; Rats, Wistar

To purify the oleuropein crude extracts by sephadex LH-20 column chromatograph.. This experiment used fast protein chromatography system (AKTA FPLC) produced by Amersham, Sweden. The chromatography column (20 mm x 300 mm) was matched with protein purification instrument. Sephadex LH-20 was used in the Fast Protein Liquid Chromatography columns. The mobile phase was 50% ethanol with a flow velocity of 1.0 mL per minute and the detection wavelength was 254 nm. The content of oleuropein was determined by HPLC.. The purity of oleuropein was 82.9% after passing the column twice when the sample volume was 2 mL.. Sephadex LH-20 can be re-used and the regeneration is convenient, it also provides a reference for the production of oleuropein.

Topics: Chromatography, Gel; Chromatography, High Pressure Liquid; Dextrans; Ethanol; Iridoid Glucosides; Iridoids; Olea; Pyrans; Reproducibility of Results; Technology, Pharmaceutical

The purpose of the present study was to evaluate the in vitro antibacterial effects of different classes of important and common dietary phytochemicals (5 simple phenolics - tyrosol, gallic acid, caffeic acid, ferulic acid, and chlorogenic acid; chalcone - phloridzin; flavan-3-ol - (-) epicatechin; seco-iridoid - oleuropein glucoside; 3 glucosinolate hydrolysis products - allylisothiocyanate, benzylisothiocyanate and 2-phenylethylisothiocyanate) against Escherichia coli, Pseudomonas aeruginosa, Listeria monocytogenes and Staphylococcus aureus. Another objective of this study was to evaluate the effects of dual combinations of streptomycin with the different phytochemicals on antibacterial activity. A disc diffusion assay was used to evaluate the antibacterial activity of the phytochemicals and 3 standard antibiotics (ciprofloxacin, gentamicin and streptomycin) against the four bacteria. The antimicrobial activity of single compounds and dual combinations (streptomycin-phytochemicals) were quantitatively assessed by measuring the inhibitory halos. The results showed that all of the isothiocyanates had significant antimicrobial activities, while the phenolics were much less efficient. No antimicrobial activity was observed with phloridzin. In general P. aeruginosa was the most sensitive microorganism and L. monocytogenes the most resistant. The application of dual combinations demonstrated synergy between streptomycin and gallic acid, ferulic acid, chlorogenic acid, allylisothiocyanate and 2-phenylethylisothiocyanate against the Gram-negative bacteria. In conclusion, phytochemical products and more specifically the isothiocyanates were effective inhibitors of the in vitro growth of the Gram-negative and Gram-positive pathogenic bacteria. Moreover, they can act synergistically with less efficient antibiotics to control bacterial growth.

Topics: Anti-Bacterial Agents; Catechin; Cinnamates; Drug Combinations; Drug Evaluation, Preclinical; Drug Synergism; Escherichia coli; Gallic Acid; Hydrolysis; Iridoid Glucosides; Iridoids; Isothiocyanates; Listeria monocytogenes; Phenylethyl Alcohol; Phlorhizin; Pseudomonas aeruginosa; Pyrans; Staphylococcus aureus; Streptomycin

Oleuropein (Ole), hydroxytyrosol (Htyr), and tyrosol (Tyr) are three of the main phenolic compounds present in the olive tree (Olea europaea L.) that have important antioxidant properties. To investigate the role of these phenolic compounds in the metabolism of stems and roots of Olea europaea L. cv. Picual during olive ripening, we identify and quantify the concentration of Htyr, Tyr, and Ole by reversed-phase high-performance liquid chromatography (RP-HPLC). Rain-fed olive trees, 30 years old, under traditional cultivation were studied in Jaén (Spain). From August to November, seven representative samples of the ripening process were taken.. The concentration of these phenolic compounds proved higher in the stems than in the roots. From the middle of September to October the Htyr and Tyr concentration significantly increased in stems. The Ole concentration increased from the middle of September to the end of November. In the roots, the concentration of Htyr and Ole significantly declined during ripening.. Ole, Htyr, and Tyr are present in the stems and roots of the olive tree and significantly change in concentration during ripening, demonstrating the involvement of these compounds in the metabolism of both organs during this phase.

Topics: Antioxidants; Chromatography, High Pressure Liquid; Fruit; Iridoid Glucosides; Iridoids; Olea; Phenylethyl Alcohol; Plant Leaves; Plant Roots; Plant Stems; Pyrans; Seasons; Spain; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry

Oleuropein, an active constituent of olive leaf, has a variety of pharmacological activities associated with its capacity to scavenge reactive oxygen species. Oleuropein is also reported to have protective effects against non-alcoholic fatty liver disease (NAFLD) in vivo. In this study, gene expression profiling of hepatic tissues was examined, and transcription factors (TFs) with target genes that were modulated by oleuropein were identified to gain insights into the molecular mechanisms for the hepatoprotective action of this compound. C57BL/6N mice were fed either a high-fat diet (HFD) or 0.03% oleuropein-supplemented HFD for 10 weeks, after which their livers were subjected to oligo DNA microarray analysis. The oleuropein with which the HFD was supplemented reduced the hepatic mRNA level of the genes that encoded the key regulators of the hepatic fatty acid uptake and transport. In addition, the oleuropein reduced the expression of a number of hepatic genes involved in the oxidative stress responses and detoxification of lipid peroxidation products and proinflammatory cytokine genes. The (putative) candidate TFs that bound to the promoters of the genes regulated at least threefold (both up and down) by oleuropein were implicated in the lipogenesis, inflammation, insulin resistance, fibrosis, and cell proliferation and differentiation, which implies that the mechanisms that underlie the beneficial effects of oleuropein on NAFLD may be multifactorial.

Topics: Animals; Dietary Fats; Disease Models, Animal; Fatty Liver; Gene Expression Profiling; Gene Expression Regulation; Iridoid Glucosides; Iridoids; Lipid Metabolism; Liver; Male; Mice; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Nutrigenomics; Oligonucleotide Array Sequence Analysis; Pyrans; Transcription Factors

Olive oil and its minor constituents have been recommended as important dietary therapeutic interventions in preventive medicine. However, a question remains to be addressed: what are the effects of olive oil and its phenolic compounds on obesity-induced cardiac metabolic changes?. Male Wistar rats were divided into two groups (n = 24/group): (C) receiving standard-chow; (Ob) receiving hypercaloric-chow. After 21 days C and Ob groups were divided into four subgroups (n = 6/group):(C) standard-chow and saline; (C-Olive)standard-chow and olive-oil (3.0 g/kg.day); (C-Oleuropein)standard-chow and oleuropein (0.023 mg/kg/day); (C-Cafeic) standard-chow and cafeic-acid (2.66 mg/kg/day); (Ob)receiving hypercaloric-chow and saline;(Ob-Olive) hypercaloric-chow and olive-oil;(Ob-Oleuropein) hypercaloric-chow and oleuropein;(Ob-Cafeic) hypercaloric-chow and cafeic-acid. Treatments were given twice a week during 21 days.. After 42 days, obesity was evidenced in Ob rats from enhanced body-weight, surface-area, and body-mass-index. Energy-expenditure, oxygen consumption(VO2) and fat-oxidation were lower in Ob-group than in C. Despite no morphometric changes, Ob-Olive, Ob-Oleuropein and Ob-Cafeic groups had higher VO2, fat-oxidation, myocardial beta-hydroxyacyl coenzyme-A dehydrogenase and lower respiratory-quotient than Ob. Citrate-synthase was highest in Ob-Olive group. Myocardial lipid-hydroperoxide(LH) and antioxidant enzymes were unaffected by olive-oil and its compounds in obesity condition, whereas LH was lower and total-antioxidant-substances were higher in C-Olive and C-Oleuropein than in C.. The present study demonstrated for the first time that olive-oil, oleuropein and cafeic-acid enhanced fat-oxidation and optimized cardiac energy metabolism in obesity conditions. Olive oil and its phenolic compounds improved myocardial oxidative stress in standard-fed conditions.

Topics: 3-Hydroxyacyl CoA Dehydrogenases; Animals; Caffeic Acids; Calorimetry; Citrate (si)-Synthase; Iridoid Glucosides; Iridoids; Male; Myocardium; Obesity; Olive Oil; Phenols; Plant Oils; Pyrans; Rats; Rats, Wistar

The biosynthetic pathway of oleuropein (from 7-ketologanin, oleoside-11-methyl ester, 7-β-1-d-glucopyranosyl-11-methyl oleoside, and ligstroside to oleuropein) was investigated in two fruit species of Oleaceae, namely, Arbequina and Hojiblanca. Main oleuropein precursors and their metabolites, produced by the enzymatic hydrolysis mediated by β-glucosidase, were identified and quantified to establish the oleuropein transformation pathway. Changes in the concentration of these compounds were measured by direct control of in vivo fruit tissue during their ripening. High contents of aglycones at the initial stage of the process were caused by the high activity of β-glucosidase, which supports that oleuropein biosynthesis is coupled with enzymatic hydrolysis, producing its aglycone form. The low oleuropein content at this initial stage was caused by the imbalance between catabolic and anabolic pathways, favoring the former ones. Once the main polyphenol synthesis phase was completed, the biosynthetic capacity diminished and the content of all compounds decreased. Mass balance revealed that precursors of oleuropein, which are rapidly transformed by β-glucosidase and esterases, scarcely contributed to the accumulation of oleuropein. The biosynthetic pathway proposed by Damtoft applies for both varieties, but our study reveals that the β-glucosidase enzyme is involved in oleuropein synthesis. This enzyme shows high substrate specificity to oleuropein, which consequently is degraded to its aglycone form, with diminished efficacy of oleuropein biosynthesis. Different enzymatic activities of varieties will result in oleuropein accumulation and metabolic transformation of phenols.

Topics: beta-Glucosidase; Fruit; Glucosides; Iridoid Glucosides; Iridoids; Olea; Phenols; Plant Proteins; Pyrans

In this work, rapid-resolution liquid chromatography (RRLC) coupled to electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) and ion trap multiple mass spectrometry (IT-MS(n)) has been applied to separate and characterize eleven isomers of oleuropein aglycon in fourteen Spanish extra-virgin olive oils. After the extra-virgin olive oil sample had been dissolved in hexane and cleaned up by a diol-bonded phase solid-phase extraction (SPE) cartridge, the eluting extract was resolved in methanol and analyzed on an Angilent 1200 system with a 4.6 x 150 mm, 1.8 microm Zorbax Eclipse plus C18 column. Mass spectrometry was carried out on a Bruker Daltonics microTOF mass spectrometer and a Bruker Daltonics ion trap mass spectrometer. The characterization of isomers of oleuropein aglycon was based on accurate mass data and the isotope function of characteristic fragment ions in the studied compounds by TOF-MS, and the fragment ions were further confirmed by IT-MS(n). The fragmentation pathway of oleuropein aglycon was successfully elucidated and all possible transformations among isomers of oleuropein aglycon were suggested.

Topics: Chromatography, Liquid; Iridoid Glucosides; Iridoids; Isomerism; Olive Oil; Plant Oils; Pyrans; Sensitivity and Specificity; Solid Phase Extraction; Spain; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry

Doxorubicin (DXR) is a commonly used antineoplastic agent; however, its use is limited due to cardiotoxicity. Oxidative stress and consequent alterations of cardiac energetics are involved in the development of DXR toxicity. Oleuropein (Oleu) is a phenolic antioxidant, present in olive tree, reported to confer protection against DXR cardiotoxicity. In this study, NMR based-metabonomics was applied to characterize the metabolic profile of the acute DXR cardiotoxicity in rats and to evaluate the metabolic alterations conferred by co-treatment with Oleu. Wistar rats were divided into six groups and treated as follows: control group with a single injection of 2 mL normal saline intraperitoneally (i.p.), DXR group with a single dose of 20 mg/kg, i.p and DXR plus Oleu groups with 20mg/kg DXR i.p., and 100 or 200 mg/kg/BW of Oleu i.p. for 5 or 3 consecutive days starting either 2 days before or on the day of DXR administration. Hearts were excised 72 h after DXR treatment and (1)H-NMR spectra of aqueous myocardium extracts were recorded. Principal Component Analysis (PCA) and Partial Least Square Discriminant Analysis (PLS-DA) revealed differences in the metabolic profile between control and DXR attributed to several metabolites. A number of them were quantified by integration of the NMR spectra. Myocardial levels of acetate and succinate were increased in DXR compared to controls, while branched amino acids were decreased. These results correlate with nonenzymatic conversion of pyruvate to acetate and of alpha-ketoglutarate to succinate by DXR free radicals. Oleu completely restored the changes of metabolites to the normal levels. Acetate and succinate constitute novel biomarkers related to DXR, and Oleu treatment aids the compensation of distressed energy metabolic pathways.

Topics: Acetates; Animals; Antibiotics, Antineoplastic; Antihypertensive Agents; Antioxidants; Biomarkers; Cardiotonic Agents; Doxorubicin; Heart; Iridoid Glucosides; Iridoids; Male; Metabolomics; Myocardium; Nuclear Magnetic Resonance, Biomolecular; Pyrans; Rats; Rats, Wistar; Succinic Acid; Tissue Extracts

The impact of sampling parameters, that is, cultivar, leaf age, and sampling date, on the radical scavenging potential of olive leaf extracts was examined via the DPPH(*) and other assays. Total phenol content was estimated colorimetrically and by fluorometry, whereas phenol composition was assessed by RP-HPLC coupled with diode array, fluorometric, and MS detection systems. Oleuropein was not always the major leaf constituent. Considerable differences noted in individual phenol levels (hydroxytyrosol, oleuropein and other secoiridoids, verbascoside, and flavonoids) among samples were not reflected either in the total phenol content or in the radical scavenging potential of the extracts. It can be suggested that olive leaf is a robust source of radical scavengers throughout the year and that differentiation in the levels of individual components depends rather on sampling period than on cultivar or age. The latter does not present predictable regularity. Exploitation of all types of leaves expected in an olive tree shoot for the extraction of bioactive compounds is feasible.

Topics: Flavonoids; Free Radical Scavengers; Iridoid Glucosides; Iridoids; Olea; Phenols; Phenylethyl Alcohol; Plant Extracts; Plant Leaves; Pyrans; Species Specificity; Time Factors

Malaxation of olive paste must be considered to be much more than a simple physical separation, because a complex bioprocess takes place that is very relevant to the quality and composition of the final product. A combined study of the effect of kneading temperature and time on the minor composition of olive paste and its corresponding virgin olive oil, processed in an experimental oil mill (Pieralisi, Fattoria) with a working capacity of 200 kg/h, is reported. A large drop in the oleuropein content in the olive paste with respect to its initial content in the olive fruit (between 92 and 96%) was observed, which suggested its almost total degradation during the crushing operation. The major phenolic compound found in the olive paste during kneading was the dialdehydic form of elenolic acid linked to hydroxytyrosol (3,4-DHPEA-EDA, always higher than 60% of the total phenols). This greatly decreased during malaxation (from 5505 to 2317 mg/kg, on average). The content of phenolic compounds in virgin olive oil was much more affected by the malaxation temperature than the kneading time. For instance, the 3,4-DHPEA-EDA content increased by 220-630% in the two batches when the temperature was increased from 20 to 40 degrees C. A reduction in the C6 aldehydes was found in virgin olive oil as the malaxation temperature increased, especially in E-2-hexenal (30% reduction). In contrast, C6 aldehydes in the oils from the oil mill plant significantly increased as the malaxation time increased from 30 to 90 min, chiefly E-2-hexenal (about a 70% increase).

Topics: Aldehydes; Consumer Behavior; Food Handling; Fruit; Iridoid Glucosides; Iridoids; Olea; Olive Oil; Phenols; Phenylethyl Alcohol; Plant Oils; Pyrans; Temperature; Volatilization

Many studies have investigated the protective effects of oleuropein and hydroxytyrosol against cell injury, but few have investigated the protective effects of oleuropein aglycones 3,4-dihydroxyphenylethanol-elenolic acid (3,4-DHPEA-EA) and 3,4-dihydroxyphenylethanol-elenolic acid dialdehyde (3,4-DHPEA-EDA). The present work studied and compared the capacity of these four compounds, found at high concentrations in olive oil, to protect red blood cells (RBCs) from oxidative injury. The in vitro oxidative stress of RBCs was induced by the water-soluble radical initiator 2,2'-azo-bis(2-amidinopropane) dihydrochloride. RBC changes were evaluated either by optical microscopy or by the amount of hemolysis. All compounds were shown to significantly protect RBCs from oxidative damage in a dose-dependent manner. The order of activity at 20 microM was: 3,4-DHPEA-EDA > hydroxytyrosol > oleuropein > 3,4-DHPEA-EA. Even at 3 microM, 3,4-DHPEA-EDA and hydroxytyrosol still had an important protective activity. However, deleterious morphological RBC changes were much more evident in the presence of hydroxytyrosol than with 3,4-DHPEA-EDA. For the first time it was demonstrated that 3,4-DHPEA-EDA, one of most important olive oil polyphenols, may play a noteworthy protective role against ROS-induced oxidative injury in human cells since lower doses of this compound were needed to protect RBCs in vitro from oxidative mediated hemolysis.

Topics: Adult; Amino Acid Sequence; Erythrocytes; Female; Flavonoids; Humans; Iridoid Glucosides; Iridoids; Male; Membrane Proteins; Middle Aged; Molecular Sequence Data; Olive Oil; Phenols; Phenylethyl Alcohol; Plant Oils; Polyphenols; Pyrans

The interaction of pineal hormone melatonin, the histological dye thioflavin T, and the olive tree polyphenol oleuropein, with the 28 amino acid residue N-terminal fragment of the beta-amyloid peptide (beta-AP) of Alzheimer's disease, [beta-AP(1-28)], was detected in solution through the observation of transferred NOEs (trNOEs) in 1D and 2D NOE spectroscopy (NOESY) experiments. The trNOE method is applied for the first time in the detection of interactions of soluble beta-AP(1-28) with small molecules and may provide a means of screening for the identification of possible inhibitors of the formation of neurotoxic beta-AP assemblies.

Topics: Amyloid beta-Peptides; Benzothiazoles; Iridoid Glucosides; Iridoids; Magnetic Resonance Spectroscopy; Melatonin; Molecular Structure; Pyrans; Thiazoles

To develop an HPLC method for the determination of oleuropein in Syringa oblata.. An Aigilent ZORBAX SB- C18 column (4.6 mm x 250 mm, 5 microm) was used. The mobile phase was acetonitrile-water (21 : 79). The flow rate was 1.0 mL x min(-1). The detection wavelenghth was set at 232 nm and the column temperature was 30 degrees C.. The linear range of oleuropein were from 0.011 62 g x L(-1) to 1.162 g x L(-1). The average recovery was 98.7% with RSD 2.5% (n=9).. The method is reliable, accurate and specific. It can be used for quality control of the stem of Syringa oblata.

Topics: Acetonitriles; Benzoates; Chromatography, High Pressure Liquid; Drugs, Chinese Herbal; Iridoid Glucosides; Iridoids; Pyrans; Syringa; Vasodilator Agents

Jasminum officinale L. var. grandiflorum (JOG) is a folk medicine used for the treatment of hepatitis in south of China. Phytochemical studies showed that secoiridoid glycosides are the typical constituents of this plant.. The present study was undertaken to evaluate the effect of oleuropein (Ole) derived from the flowers of JOG on hepatitis B virus (HBV) replication in HepG2 2.2.15 cell line in vitro and duck hepatitis B virus (DHBV) replication in ducklings in vivo.. The extracellular hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) concentrations in cell culture medium were determined by ELISA. DHBV in duck serum was analyzed by dot blot.. Ole blocks effectively HBsAg secretion in HepG2 2.2.15 cells in a dose-dependent manner (IC(50)=23.2 microg/ml). Ole (80 mg/kg, intraperitoneally, twice daily) also reduced viremia in DHBV-infected ducks.. Ole therefore warrants further investigation as a potential therapeutic agent for HBV infection.

Topics: Animals; Antiviral Agents; Cell Line; Disease Models, Animal; Dose-Response Relationship, Drug; Ducks; Flowers; Hepatitis B; Hepatitis B Surface Antigens; Hepatitis B virus; Hepatitis B Virus, Duck; Hepatitis, Viral, Animal; Humans; Iridoid Glucosides; Iridoids; Jasminum; Phytotherapy; Plant Extracts; Pyrans; Viremia; Virus Replication

Recent studies suggest that olive leaf is a significant source of bioactive phenolic compounds comparable to olive oil and fruits. Identifying appropriate extraction methods is thus an important step to increase the yield of such bioactive components from olive leaf, which is otherwise agricultural waste. The present study evaluates phenolic contents and compositions of olive leaf extracted by several solvent methods and to further establish their antioxidant activities using various radical scavenging systems. Total flavonoid and phenolic contents were significantly higher in the 80% ethanol extract, butanol, and ethylacetate fractions than hexane, chloroform and water fractions (p<0.05). Oleuropein was identified as a major phenolic compound with considerable contents in these major three fractions and the extract that correlated with their higher antioxidant and radical scavenging. These results indicate that olive leaf contains significant amounts of oleuropein and phenolics, important factors for antioxidant capacity, which can be substantially modified by different extraction methods.

Topics: Agriculture; Antioxidants; Chloroform; Free Radical Scavengers; Hexanes; Industrial Waste; Iridoid Glucosides; Iridoids; Linoleic Acid; Olea; Oxygen; Peroxides; Phenol; Phenols; Plant Extracts; Pyrans; Water

An olive beta-glucosidase was purified to apparent homogeneity from mature fruits ( Olea europaea cv. Picual) by selective extraction and successive anion exchange and hydrophobic interaction chromatographic procedures. The enzyme was shown to be a homodimer made up of two identical subunits of 65.4 kDa. Optimum activity was recorded at pH 5.5 and 45 degrees C. The enzyme was active on the main olive phenolic glycosides, with maximum activity toward oleuropein (100%), followed by ligstroside (65%) and demethyloleuropein (21%). The enzyme showed very low activity with apigenin and luteolin glucosides and was not active on verbascoside and rutin. Kinetic values show that olive beta-glucosidase is 200-fold more active against oleuropein than against the synthetic substrate p-nitrophenyl-beta-d-glucopyranoside (pNPG). According to its catalytic properties, the implication of the purified olive beta-glucosidase on the synthesis of virgin olive oil phenolics is discussed.

Topics: beta-Glucosidase; Fruit; Glucosides; Glycosides; Hydrogen-Ion Concentration; Iridoid Glucosides; Iridoids; Olea; Olive Oil; Phenols; Plant Oils; Pyrans; Substrate Specificity

This study was designed to test the antidiabetic and antioxidative activities of olive leaf oleuropein and hydroxytyrosol. Diabetes in Wistar rats was induced by intraperitoneal injections of alloxan. The serum glucose and cholesterol, hepatic glycogen, the thiobarbituric acid-reactive substances (TBARS), and the components of hepatic and serum antioxidant system were examined. Diabetic rats showed hyperglycemia, hypercholesterolemia, increased lipid peroxidation, and depletion in the antioxidant enzymes activities. The administration, for 4 weeks, of oleuropein and hydroxytyrosol rich extracts, leading to 8 and 16 mg/kg body weight of each compound, significantly decreased the serum glucose and cholesterols levels and restored the antioxidant perturbations. These results suggested that the antidiabetic effect of oleuropein and hydroxytyrosol might be due to their antioxidant activities restraining the oxidative stress which is widely associated with diabetes pathologies and complications.

Topics: Animals; Antioxidants; Blood Glucose; Diabetes Mellitus, Experimental; Hypoglycemic Agents; Iridoid Glucosides; Iridoids; Liver; Male; Olea; Oxidative Stress; Phenylethyl Alcohol; Phytotherapy; Plant Extracts; Plant Leaves; Pyrans; Rats; Rats, Wistar

Chronic exposure to solar UV radiation damages skin, increasing its thickness and reducing its elasticity, and causes skin cancer. Our aim in this study was to examine the effects of an olive leaf extract and its component oleuropein on skin damage and the incidence of skin tumors caused by long-term UVB irradiation in hairless mice. Male hairless mice (5 wk old) were divided into 6 groups, including a non-UVB group, a vehicle-treated UVB group (control), 2 olive leaf extract-treated UVB groups, and 2 oleuropein-treated UVB groups. Five groups were UVB irradiated (36-180 mJ/cm(2)) 3 times each week for 30 wk and skin thickness and elasticity after UVB irradiation were measured every week. Olive leaf extract (300 and 1000 mg/kg) and oleuropein (10 and 25 mg/kg) were administered orally twice daily every day for 30 wk. The extract and oleuropein significantly inhibited increases in skin thickness and reductions in skin elasticity, and skin carcinogenesis and tumor growth. Furthermore, they prevented increases in the expression of matrix metalloproteinase (MMP)-2, MMP-9, and MMP-13 as well as in levels of vascular endothelial growth factor (VEGF) and cyclooxygenase-2 (COX-2) in the skin. Based on histological evaluation, they prevented increases in the expression of Ki-67 and CD31-positive cells induced by the irradiation. These results suggest that the preventative effects of the olive leaf extract and oleuropein on chronic UVB-induced skin damage and carcinogenesis and tumor growth may be due to inhibition of the expression of VEGF, MMP-2, MMP-9, and MMP-13 through a reduction in COX-2 levels.

Topics: Animals; Anticarcinogenic Agents; Blood Vessels; Cyclooxygenase 2; Dermis; Epidermis; Gene Expression Regulation, Enzymologic; Iridoid Glucosides; Iridoids; Male; Matrix Metalloproteinases; Mice; Mice, Hairless; Oleaceae; Plant Extracts; Plant Leaves; Pyrans; Skin; Ultraviolet Rays; Vascular Endothelial Growth Factor A; Vasodilator Agents

Nitrite, considered a biological waste and toxic product, is being regarded as an important physiological molecule in nitric oxide (NO) biochemistry. Because the interaction of dietary phenolic compounds and nitrite would be kinetically (due to the high concentrations achieved) and thermodynamically (on basis of the redox potentials) feasible in the stomach, we have studied the potential reduction of nitrite by polyphenols present in several dietary sources. By measuring the time courses of *NO production in simulated gastric juice (pH 2), the efficiency of the compounds studied is as follows: Epicatechin-3-O-gallate>quercetin>procyanidin B8 dimer>oleuropein>procyanidin B2 dimer>chlorogenic acid>epicatechin>catechin>procyanidin B5 dimer. The initial rates of *NO production fall in a narrow range (ca. 1-5 microMs(-1)) but the distinct kinetics of the decay of *NO signals suggest that competition reactions for *NO are operative. The proof of concept that, in the presence of nitrite, phenol-containing dietary products induce a strong increase of *NO in the stomach was established in an in vivo experiment with healthy volunteers consuming lettuce, onions, apples, wine, tea, berries and cherries. Moreover, selected mixtures of oleuropein and catechin with low nitrite (1 microM) were shown to induce muscle relaxation of stomach strips in a structure-dependent way. Data presented here brings strong support to the concept that polyphenols consumed in a variety of dietary products, under gastric conditions, reduce nitrite to *NO that, in turn, may exert a biological impact as a local relaxant.

Topics: Animals; Antioxidants; Catechin; Diet; Electrochemistry; Flavonoids; Food Analysis; Gastric Juice; Gastric Mucosa; In Vitro Techniques; Indicators and Reagents; Iridoid Glucosides; Iridoids; Male; Muscle Relaxation; Muscle, Smooth; Nitric Oxide; Nitrites; Phenols; Polyphenols; Pyrans; Rats; Rats, Wistar; Stomach; Vasodilator Agents

Oleuropein, the main phenolic compound in virgin olive oil, and several of its derivatives such as oleuropein aglycone, hydroxytyrosol, and their respective acetylated lipophilic forms were obtained by simple and environmentally friendly semisynthetic protocols. The same molecules were then tested in vitro and in vivo, comparing their intriguing anti-COX-1 and anti-COX-2 properties to those of well-known anti-inflammatory drugs such as ibuprofen and celecoxib. Finally, molecular modeling experiments displaying the most probable binding modes within the classical binding clefts of the enzymes suggest the heme moiety as a potential alternative target.

Topics: Binding Sites; Cyclooxygenase Inhibitors; Iridoid Glucosides; Iridoids; Molecular Conformation; Olea; Plant Extracts; Prostaglandin-Endoperoxide Synthases; Protein Binding; Pyrans

A continuous approach assisted by ultrasound for direct enrichment of edible oils (olive, sunflower, and soya) with the main phenols in olive leaves (i.e., oleuropein, verbascoside, apigenin-7-glucoside, and luteolin-7-glucoside) has been developed. Multivariate methodology was used to carry out a detailed optimization of the enrichment, and quantitation of the transferred compounds was based on LC-MS-MS in multiple reaction monitoring optimizing the most sensitive transition for each biophenol. Under the optimal working conditions, only 20 min is necessary to enrich the edible oils with 14.45-9.92 microg/mL oleuropein, 2.29-2.12 microg/mL verbascoside, 1.91-1.51 microg/mL apigenin-7-glucoside, and 1.60-1.42 microg/mL luteolin-7-glucoside. The enrichment method is carried out at room temperature and is organic-solvent-free; thus, the healthy properties of the edible oils improve as does their quality. Also, the low acquisition and maintenance costs of an ultrasound source and its application in a dynamic system make advisable the industrial implementation of the proposed method.

Topics: Apigenin; Dietary Fats, Unsaturated; Food, Fortified; Glucosides; Iridoid Glucosides; Iridoids; Luteolin; Olea; Phenols; Plant Leaves; Pyrans; Ultrasonics

An experimental setup based on a 2(3) full-factorial, central-composite design was implemented with the aim of optimising the recovery of polyphenols from olive leaves by employing reusable and nontoxic solutions composed of water/ethanol/citric acid as extracting media. The factors considered were (i) the pH of the medium, (ii) the extraction time and (iii) the ethanol concentration. The model obtained produced a satisfactory fit to the data with regard to total polyphenol extraction (R(2) = 0.91, p = 0.0139), but not for the antiradical activity of the extracts (R(2) = 0.67, p = 0.3734). The second-order polynomial equation obtained after analysing the experimental data indicated that ethanol concentration and time mostly affected the extraction yield, but that increased pH values were unfavourable in this regard. The maximum theoretical yield was calculated to be 250.2 +/- 76.8 mg gallic acid equivalent per g of dry, chlorophyll-free tissue under optimal conditions (60% EtOH, pH 2 and 5 h). Liquid chromatography-electrospray ionisation mass spectrometry of the optimally obtained extract revealed that the principal phytochemicals recovered were luteolin 7-O-glucoside, apigenin 7-O-rutinoside and oleuropein, accompanied by smaller amounts of luteolin 3',7-O-diglucoside, quercetin 3-O-rutinoside (rutin), luteolin 7-O-rutinoside and luteolin 3'-O-glucoside. Simple linear regression analysis between the total polyphenol and antiradical activity values gave a low and statistically insignificant correlation (R(2) = 0.273, p > 0.05), suggesting that it is not the sheer amount of polyphenols that provides high antioxidant potency; instead, this potency is probably achieved through interactions among the various phenolic constituents.

Topics: Antioxidants; Apigenin; Chromatography, Liquid; Ethanol; Flavonoids; Glucosides; Hydrogen-Ion Concentration; Iridoid Glucosides; Iridoids; Luteolin; Olea; Phenols; Plant Extracts; Plant Leaves; Polyphenols; Pyrans; Quercetin; Regression Analysis; Solvents; Spectrometry, Mass, Electrospray Ionization; Time Factors; Water

In order to confirm the traditional use of Ligustrum vulgare L. (common privet, Oleaceae) we investigated the inhibitory activity of different extracts from leaves (LlE), flowers (LflE) and fruits (LfrE) on metallopeptidases ACE and NEP.. Powdered plant materials were first extracted with water and then with ethyl acetate and n-butanol saturated with water. The metallopeptidases activity was determined using in vitro fluorimetric assays.. At a concentration of 100microg/ml the ethyl acetate extracts showed the highest activity. The bio-guided fractionation of the leaves extract led to the isolation of two iridoids which were identified by (1)H, (13)C and HETCOR NMR spectroscopy as oleuropein and ligstroside aglycones. Both compounds are dual ACE/NEP inhibitors with IC(50) of 20 and 25microM for ACE and IC(50) of 35 and 75microM for NEP, respectively. Secoirydoids glycosides, tyrozol and hydroxytyrozol, as well as, flavonoids present in the ethyl acetate extracts showed little or no inhibitory activity.. Our results partially support the diuretic and hypotensive activities of common privet.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Flowers; Fluorometry; Fruit; Glucosides; Inhibitory Concentration 50; Iridoid Glucosides; Iridoids; Ligustrum; Male; Medicine, Traditional; Neprilysin; Plant Extracts; Plant Leaves; Pyrans; Swine

Oleuropein-rich extracts from olive leaves and their enzymatic and acid hydrolysates, respectively rich in oleuropein aglycone and hydroxytyrosol, were prepared under optimal conditions. The antioxidant activities of these extracts were examined by a series of models in vitro. In this study the lipid-lowering and the antioxidative activities of oleuropein, oleuropein aglycone and hydroxytyrosol-rich extracts in rats fed a cholesterol-rich diet were tested. Wistar rats fed a standard laboratory diet or cholesterol-rich diets for 16 weeks were used. The serum lipid levels, the thiobarbituric acid reactive substances (TBARS) level, as indicator of lipid peroxidation, and the activities of liver antioxidant enzymes (superoxide dismutase (SOD) and catalase (CAT)) were examined. The cholesterol-rich diet induced hyperlipidemia resulting in the elevation of total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C). Administration of polyphenol-rich olive leaf extracts significantly lowered the serum levels of TC, TG and LDL-C and increased the serum level of high-density lipoprotein cholesterol (HDL-C). Furthermore, the content of TBARS in liver, heart, kidneys and aorta decreased significantly after oral administration of polyphenol-rich olive leaf extracts compared with those of rats fed a cholesterol-rich diet. In addition, these extracts increased the serum antioxidant potential and the hepatic CAT and SOD activities. These results suggested that the hypocholesterolemic effect of oleuropein, oleuropein aglycone and hydroxytyrosol-rich extracts might be due to their abilities to lower serum TC, TG and LDL-C levels as well as slowing the lipid peroxidation process and enhancing antioxidant enzyme activity.

Topics: Animals; Antioxidants; beta-Glucosidase; Catalase; Cholesterol, Dietary; Enzyme Activation; Heart; Hydrochloric Acid; Hydrolysis; Hypercholesterolemia; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Lipids; Liver; Male; Molecular Structure; Olea; Organ Size; Phenylethyl Alcohol; Plant Extracts; Plant Leaves; Pyrans; Rats; Rats, Wistar; Superoxide Dismutase; Thiobarbituric Acid Reactive Substances

The effects of oleuropein, a phenolic compound in extra virgin olive oil (EV-olive oil), on triglyceride metabolism were investigated by measuring the degree of thermogenesis in interscapular brown adipose tissue (IBAT), and noradrenaline and adrenaline secretions in rats. In Experiment 1, rats were given a high-fat diet (control diet) with the oleuropein supplementation of 1, 2 or 4 mg/kg of diet (0.1, 0.2 or 0.4% oleuropein diet, respectively). After 28 d of feeding, body weight, perirenal adipose tissue, epididymal fat pad, and plasma triglyceride, free fatty acid and total cholesterol concentrations were reduced by the 0.1, 0.2 or 0.4% oleuropein diet and were significantly lowest in rats fed the 0.4% oleuropein diet, as compared with those of rats fed with the control diet. The content of uncoupling protein 1 (UCP1) in IBAT and urinary noradrenaline and adrenaline excretions were significantly higher in rats fed the 0.1 or 0.2% oleuropein diet, as compared with those of rats fed with the control diet, although there were no significant differences in rats fed the 0.4% oleuropein diet. In Experiment 2, the effects of oleuropein on noradrenaline and adrenaline secretion were evaluated. The intravenous administration of oleuropein and oleuropein aglycone significantly increased plasma noradrenaline and adrenaline concentrations. Furthermore, oleuropein aglycone induced the secretions of noradrenaline and adrenaline about ten fold more potently than oleuropein. These results suggest that the phenolic compound oleuropein in EV-olive oil enhances thermogenesis by increasing the UCP1 content in IBAT and noradrenaline and adrenaline secretions in rats.

Topics: Adipose Tissue; Adipose Tissue, Brown; Adrenergic Agonists; Animals; Body Weight; Cholesterol; Dietary Supplements; Epinephrine; Fatty Acids, Nonesterified; Ion Channels; Iridoid Glucosides; Iridoids; Male; Mitochondrial Proteins; Norepinephrine; Olea; Olive Oil; Phenols; Plant Extracts; Plant Oils; Pyrans; Rats; Rats, Sprague-Dawley; Thermogenesis; Triglycerides; Uncoupling Protein 1

Toxoplasmosis is a parasitic disease caused by Toxoplasma gondii, with very few therapeutic treatment options. Typically, the choices for treatment are pyrimethamine and sulfadiazine, however their utility is limited because of drug toxicity and serious side effects. For these reasons, new drugs with lower toxicity are urgently needed. In this study, the compound oleuropein isolated from Fraxinus rhynchophylla showed anti-T. gondii effects in vitro and in vivo. In Madin-Darby bovine kidney cells, the selectivity of oleuropein was 8.9, which was higher than sulfadiazine and pyrimethamine (3.8 and 2.5, respectively). In infected mice, the inhibition ratio of T. gondii in the peritoneal cavity was 55.4% compared to the negative control group after treatment with 300 mg/kg oleuropein. In addition, inhibitory effects on granuloma, apoptosis, necrosis and cyst-formation were shown in sections of spleen and liver. Oleuropein is therefore a potentially useful anti-T. gondii candidate for clinical application.

Topics: Animals; Anti-Infective Agents; Cell Line; Cell Proliferation; Coloring Agents; Dogs; Female; Fraxinus; Iridoid Glucosides; Iridoids; Liver; Mice; Microbial Sensitivity Tests; Peritoneal Cavity; Pyrans; Spleen; Toxoplasma; Toxoplasmosis

The phenolic compounds of olive leaves and olive oils in the Mediterranean diet have been associated with a reduced incidence of heart disease. Accordingly, antioxidant-rich diets may prevent the deleterious effects of oxidative metabolism by scavenging free radicals, thus inhibiting oxidation and delaying atherosclerosis. The process involves phospholipase C activation and arachidonic acid metabolism, and is thought to reduce hydrogen peroxide (H(2)O(2)). In our study, an extract of Olea europaea L. leaves was used. The active phenolic compounds in this extract are part of the secoiridoid family, known for their capacity to scavenge H(2)O(2). The results from this study will help to improve our understanding of effects of polyphenol antioxidants in olive leaf extract on platelet function.. Full blood examination (FBE), platelet aggregation, and ATP release were performed on samples from fasting, normal, healthy male subjects. Platelet function at increasing concentrations of oleuropein was investigated through measures of platelet aggregation and ATP release from activated platelets.. Blood analysis (n=11) revealed a significant dose-dependant reduction in platelet activity with olive extract concentrations of 1.0% v/v (P<0.001). ATP Release showed a similar pattern (P=0.02).. Olive leaf polyphenols derived from O. europaea L. leaves inhibited in vitro platelet activation in healthy, non-smoking males. Further bioavailability studies need to be undertaken to determine the in vivo effect of extract on platelet function and to validate the present results.

Topics: Adenosine Triphosphate; Adult; Antioxidants; Blood Platelets; Dose-Response Relationship, Drug; Flavonoids; Humans; In Vitro Techniques; Iridoid Glucosides; Iridoids; Male; Middle Aged; Olea; Phenols; Plant Extracts; Plant Leaves; Platelet Aggregation; Polyphenols; Pyrans

Oleuropein, the main phenolic compound of olive fruit, has important antioxidant properties that are responsible for some of the nutritional properties of fruits and the defence mechanism of leaves. Polyphenol oxidase (PPO) activity changes during fruit ripening in many plants. We studied the kinetics and molecular properties of PPO in fruits and leaves of olive (Olea europaea L.) cv. 'Picual' trees and the relationship between PPO and oleuropein concentration during fruit ripening. Polyphenol oxidase showed hyperbolic kinetics in fruits and leaves. Significant increases in PPO specific activity, V(max), K(m )and catalytic efficiency occurred during fruit ripening. Based on SDS-PAGE under partially denaturing conditions and in-gel staining with DL-3,4-dihydroxyphenylalanine, PPO activity was found in one major protein of 55 and 50 kDA in fruits and leaves, respectively. During the last stages of fruit maturation, a second 36 kDa protein was observed in fruits but not in leaves, indicating that this protein could serve as a marker of the final phase of fruit maturation. Under fully denaturing conditions, only one 27.7 kDa immunoreactive band was detected in fruits. Both the amount of PPO activity and the amount of PPO protein increased significantly during fruit maturation. Immunohistochemical studies indicated that PPO is located in the epidermis, parenchyma and companion vascular cells of leaves as well as in the epidermis of fruit. During fruit maturation, oleuropein concentration measured by HPLC significantly decreased in fruits and increased in leaves.

Topics: Catechol Oxidase; Catechols; Chromatography, High Pressure Liquid; Fruit; Iridoid Glucosides; Iridoids; Kinetics; Nutritive Value; Olea; Phenols; Plant Leaves; Pyrans

Maturity is one of the most important factors associated with the quality evaluation of fruit and vegetables. This work aims to investigate the effect of the maturation process of the olive fruit on the phenolic fraction and fatty acid of irrigated Chétoui cultivar. The phenolic composition was studied by using reverse-phase high-performance liquid chromatography followed by LC-MS and GC-MS analyses and fatty acids by GC. Oleuropein was the major phenolic compound at all stages of ripeness. Unexpectedly, both phenolic compounds hydroxytyrosol and oleuropein exhibited the same trends during maturation. Indeed, the oleuropein levels decreased during the ripening process and were not inversely correlated with the concentrations of hydroxytyrosol. The antioxidant capacity of olive extracts was evaluated by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl and the beta-carotene linoleate model system. The IC 50 and AAC values of the olive extracts decreased from 3.68 to 1.61 microg/mL and from 645 to 431, respectively. There was a correlation between the antioxidant activity and the oleuropein concentration. The fatty acid composition was quantified in olive fruit during maturation and showed that fatty acids were characterized by the highest level of oleic acid, which reached 65.2%.

Topics: Antioxidants; Chromatography, High Pressure Liquid; Chromatography, Liquid; Fatty Acids; Free Radical Scavengers; Fruit; Gas Chromatography-Mass Spectrometry; Iridoid Glucosides; Iridoids; Olea; Oxidation-Reduction; Phenols; Pyrans

Abnormal accumulation and aggregation of amyloid-beta-peptide (Abeta) eventually lead to the formation and cerebral deposition of amyloid plaques, the major pathological hallmark in Alzheimer's disease (AD). Oleuropein (OE), an Olea europaea L. derived polyphenol, exhibits a broad range of pharmacological properties, such as antioxidant, anti-inflammatory, and antiatherogenic, which could serve as combative mechanisms against several reported pathways involved in the pathophysiology of AD. The reported noncovalent interaction between Abeta and OE could imply a potential antiamyloidogenic role of the latter on the former via stabilization of its structure and prevention of the adaptation of a toxic beta-sheet conformation. The established beta-sheet conformation of the Abeta hydrophobic carboxy-terminal region and the dependence of its toxicity and aggregational propensity on its secondary structure make the determination of the binding site between Abeta and OE highly important for assessing the role of the interaction. In this study, two different proteolytic digestion protocols, in conjunction with high-sensitivity electrospray ionization mass spectrometric analysis of the resulting peptide fragments, were used to determine the noncovalent binding site of OE on Abeta and revealed the critical regions for the interaction.

Topics: Amyloid beta-Peptides; Binding Sites; Cyclotrons; Fourier Analysis; Humans; Hydrolysis; Iridoid Glucosides; Iridoids; Peptide Fragments; Protein Binding; Protein Structure, Secondary; Pyrans; Spectrometry, Mass, Electrospray Ionization; Trypsin

Demethyloleuropein plays a major role in the defense mechanism of olive fruits. To understand how this molecule is metabolized during different stages of maturation of olive fruits, a biomolecular approach to identify the demethyloleuropein chemistry was employed. The beta-glucosidase activity in crude extracts was assayed spectrophotometrically using the chromogenic substrate p-nitrophenyl-beta-D-glucopyranoside. Demethyloleuropein was extracted and identified by HPLC-MS from both infected and uninfected olive fruits at different physiological stages. The release of more functionally relevant dialdehydes in uninfected fruits was investigated using ESIMS/ MS. In fruits harvested in October, the activity of beta-glucosidase was significantly enhanced in uninfected fruits when compared to the infected fruits. Quantitative differences in the demethyloleuropein content from uninfected fruits showed the highest values (5.09 mg/g) in October, whereas lower levels (4.44 mg/g) were found in infected fruits. The results demonstrated that demethyloleuropein derivatives could be influenced by beta-glucosidase activity to improve the quality of the olive products with the best dialdehyde nutraceutical content.

Topics: Animals; beta-Glucosidase; Chromatography, High Pressure Liquid; Chromogenic Compounds; Fruit; Glucosides; Iridoid Glucosides; Iridoids; Molecular Structure; Olea; Plant Extracts; Pyrans; Seasons; Spectrometry, Mass, Electrospray Ionization; Tephritidae

Oleuropein (oleu) is a natural phenolic antioxidant, which is present in elevated concentration in olives, olive oil and olive tree leaves. Doxorubicin (DXR) induced cardiotoxicity is mainly induced by oxidative stress but the precise mechanism remains obscure. However, there is evidence that high concentration of nitric oxide (NO) occurring as a result of iNOS induction and peroxynitrite formation may be involved in DXR cardiotoxicity. The aim of the present study was to evaluate a possible protective role of oleu in DXR induced cardiotoxicity in vivo. Fifty rats were divided into 6 groups and treated as follows: control group with a single injection of 2 ml normal saline intraperitoneally (i.p.), DXR group with a single dose of 20 mg/kg i.p, and DXR plus oleu groups with 20 mg/kg DXR i.p. and 100 or 200 mg/kg/BW of oleu i.p. for 5 or 3 consecutive days starting either 2 days before or on the day of DXR administration. Seventy-two hours after DXR treatment blood samples were collected for creatine phosphokinase (CPK), creatine phosphokinase-MB (CPK-MB), lactate dehydrogenase (LDH), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) assessments and the rats were then sacrificed. Hearts were used for general histology, iNOS immunohistochemical and Western blot analysis, and for determination of tissue concentrations of lipid peroxidation products, protein carbonyls (PCs), and nitrotyrosine (NT). DXR treated animals demonstrated very extensive cytoplasmic vacuolisation whereas much less vacuolisation was found in oleu treated groups. They also revealed a significant elevation of cardiac enzymes release into systemic circulation (P<0.05 vs saline). Both doses of Oleu tested and both treatment protocols reduced DXR elevated serum levels of CPK, CPK-MB, LDH, AST and ALT (P<0.05). Furthermore, it reduced DXR induced lipid peroxidation, PCs content, NT concentration and iNOS induction in myocardial tissue (P<0.05). Oleu exerts a protective effect by eliminating DXR induced cardiotoxicity expressed by the alteration of intracellular and peripheral markers. Combined oleu and DXR treatment improves the therapeutic outcome by preventing undesirable toxicity.

Topics: Acute Disease; Animals; Doxorubicin; Heart Diseases; Iridoid Glucosides; Iridoids; Male; Malondialdehyde; Nitrates; Nitric Oxide Synthase Type II; Nitrosation; Oleaceae; Oxidative Stress; Pyrans; Rats; Rats, Wistar; Tyrosine

The adsorption isotherms of oleuropein and rutin were evaluated at different temperatures, pH values, and solid/liquid ratios. The experimental data of adsorption isotherms were well fitted to a Langmuir model. The maximum adsorption capacities were determined as 108 mg of oleuropein/g of silk fibroin and 21 mg of rutin/g of silk fibroin. After adsorption of oleuropein and rutin, the antioxidant capacity of silk fibroin increased from 1.93 to 3.61 mmol of TEAC/g. Silk fibroin also gained antimicrobial activity against Staphylococcus aureus and Klebsiella pneumoniae after adsorption of olive leaf antioxidants. In a desorption process, 81% of rutin and 85% of oleuropein were removed from the adsorbent surface in 70% aqueous ethanol solution. Consequently, silk fibroin was found to be a promising biomaterial for the production of functional food or dietary supplements and for the purification of oleuropein and rutin from olive leaf extracts.

Topics: Adsorption; Anti-Infective Agents; Antioxidants; Fibroins; Flavonoids; Iridoid Glucosides; Iridoids; Olea; Phenols; Plant Leaves; Polyphenols; Pyrans; Rutin; Spectroscopy, Fourier Transform Infrared

We report molecular modeling and functional confirmation of Ole and HT binding to HIV-1 integrase. Docking simulations identified two binding regions for Ole within the integrase active site. Region I encompasses the conserved D64-D116-E152 motif, while region II involves the flexible loop region formed by amino acid residues 140-149. HT, on the other hand, binds to region II. Both Ole and HT exhibit favorable interactions with important amino acid residues through strong H-bonding and van der Waals contacts, predicting integrase inhibition. To test and confirm modeling predictions, we examined the effect of Ole and HT on HIV-1 integrase activities including 3'-processing, strand transfer, and disintegration. Ole and HT exhibit dose-dependent inhibition on all three activities, with EC(50)s in the nanomolar range. These studies demonstrate that molecular modeling of target-ligand interaction coupled with structural-activity analysis should facilitate the design and identification of innovative integrase inhibitors and other therapeutics.

Topics: Catalytic Domain; HIV Integrase; HIV Integrase Inhibitors; Iridoid Glucosides; Iridoids; Models, Molecular; Phenylethyl Alcohol; Pyrans; Structure-Activity Relationship

We have identified oleuropein (Ole) and hydroxytyrosol (HT) as a unique class of HIV-1 inhibitors from olive leaf extracts effective against viral fusion and integration. We used molecular docking simulation to study the interactions of Ole and HT with viral targets. We find that Ole and HT bind to the conserved hydrophobic pocket on the surface of the HIV-gp41 fusion domain by hydrogen bonds with Q577 and hydrophobic interactions with I573, G572, and L568 on the gp41 N-terminal heptad repeat peptide N36, interfering with formation of the gp41 fusion-active core. To test and confirm modeling predications, we examined the effect of Ole and HT on HIV-1 fusion complex formation using native polyacrylamide gel electrophoresis and circular dichroism spectroscopy. Ole and HT exhibit dose-dependent inhibition on HIV-1 fusion core formation with EC(50)s of 66-58nM, with no detectable toxicity. Our findings on effects of HIV-1 integrase are reported in the subsequent article.

Topics: Chromatography, Liquid; Circular Dichroism; Electrophoresis, Polyacrylamide Gel; HIV Envelope Protein gp41; HIV Integrase Inhibitors; HIV-1; Iridoid Glucosides; Iridoids; Mass Spectrometry; Models, Molecular; Phenylethyl Alcohol; Pyrans

The unprecedented acetonide of the antioxidant hydroxytyrosol has been synthesized by a two-step high-yielding procedure and found to be both purifiable by chromatography and stable over a wide pH range. The protection stabilizes hydroxytyrosol against oxidation, thereby allowing long-term storage. The protection can quantitatively be removed, under nonaqueous conditions, to afford pure hydroxytyrosol suitable for use as an additive in food and cosmetic preparations. Extension of the same methodology to the natural and easily accessible glycoside oleuropein, followed by saponification of the resulting complex mixture of acetonides, allowed hydroxytyrosol acetonide to be recovered in high yield. This constitutes a new interesting methodology to obtain the antioxidant hydroxytyrosol.

Topics: Antioxidants; Drug Stability; Food Additives; Iridoid Glucosides; Iridoids; Phenylethyl Alcohol; Pyrans

A low incidence of breast cancer in the Mediterranean basin suggests that a high consumption of Extra Virgin Olive Oil (EVOO) might confer this benefit. While the anti-HER2 oncogene effects of the main omega-9 fatty acid present in EVOO triacylglycerols (i.e., oleic acid) have been recently described, the anti-breast cancer activities of EVOO non-glyceridic constituents--which consist of at least 30 phenolic compounds--remained to be evaluated.. Semi-preparative HPLC was used to isolate EVOO polyphenols (i.e., tyrosol, hydroxytyrosol, oleuropein). Both the anti-proliferative and the pro-apoptotic effects of EVOO phenolics were evaluated by using MTT-based quantification of metabolically viable cells and ELISA-based detection of histone-associated DNA fragments, respectively. The nature of the interaction between oleuropein aglycone and the anti-HER2 monoclonal antibody trastuzumab (Herceptin) was mathematically evaluated by the dose-oriented isobologram technique. HER2-specific ELISAs were employed to quantitatively assess both the basal cleavage of the HER2 extracellular domain (ECD) and the expression level of total HER2. The activation status of HER2 was evaluated by immunoblotting procedures using a monoclonal antibody specifically recognizing the tyrosine phosphorylated (Phosphor-Tyr1248) form of HER2.. Among EVOO polyphenols tested, oleuropein aglycone was the most potent EVOO phenolic in decreasing breast cancer cell viability. HER2 gene-amplified SKBR3 cells were ~5-times more sensitive to oleuropein aglycone than HER2-negative MCF-7 cells. Retroviral infection of the HER2 oncogene in MCF-7 cells resulted in a "SKBR3-assimilated" phenotype of hypersensitivity to oleuropein aglycone. An up to 50-fold increase in the efficacy of trastuzumab occurred in the presence of oleuropein aglycone. A preclinical model of acquired autoresistance to trastuzumab (SKBR3/Tzb100 cells) completely recovered trastuzumab sensitivity (> 1,000-fold sensitization) when co-cultured in the presence of oleuropein aglycone. Indeed, the nature of the interaction between oleuropein aglycone and trastuzumab was found to be strongly synergistic in Tzb-resistant SKBR3/Tzb100 cells. Mechanistically, oleuropein aglycone treatment significantly reduced HER2 ECD cleavage and subsequent HER2 auto-phosphorylation, while it dramatically enhanced Tzb-induced down-regulation of HER2 expression.. Olive oil's bitter principle (i.e., oleuropein aglycone) is among the first examples of how selected nutrients from an EVOO-rich "Mediterranean diet" directly regulate HER2-driven breast cancer disease.

Topics: Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Breast Neoplasms; Cell Line, Tumor; Drug Resistance, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Genes, erbB-2; Humans; Iridoid Glucosides; Iridoids; Olive Oil; Plant Extracts; Plant Oils; Pyrans; Trastuzumab

A comparison between the results obtained by using HPLC-UV, HPLC-MS, and CE-UV for characterizing the deterioration of extra-virgin olive oil during heating (180 degrees C) was investigated, taking into account phenolic compounds. The concentration of several compounds belonging to four families of phenols (simple phenols, lignans, complex phenols, and phenolic acids) was determined in the samples after the thermal treatment by all three techniques. Hydroxytyrosol, elenolic acid, decarboxymethyl oleuropein aglycon, and oleuropein aglycon reduced their concentration with the thermal treatment more quickly than other phenolic compounds present in olive oil. HYTY-Ac and Lig Agl were demonstrated to be quite resistant to this kind of treatment, and the behavior of lignans could be outstanding, as they belong to the family most resistant to thermal treatment. Several "unknown" compounds were determined in the phenolic profiles of the oils after the thermal treatment, and their presence was confirmed in refined olive oils. The oxidative stability index (OSI time) was reduced from 25 to 5 h after 3 h of heating, whereas the peroxide value showed a minimum after 1 h of heating.

Topics: 3,4-Dihydroxyphenylacetic Acid; Antioxidants; Chromatography, High Pressure Liquid; Drug Stability; Electrophoresis, Capillary; Glucosides; Iridoid Glucosides; Iridoids; Mass Spectrometry; Olive Oil; Oxidation-Reduction; Peroxides; Phenols; Phenylethyl Alcohol; Plant Oils; Pyrans; Spectrophotometry, Ultraviolet; Thermodynamics

Normal human fibroblasts undergo replicative senescence due to both genetic and environmental factors. Senescence and aging can be further accelerated by exposure of cells to a variety of oxidative agents that contribute among other effects to the accumulation of damaged proteins. The proteasome, a multicatalytic nonlysosomal protease, has impaired function during aging, while its increased expression delays senescence in human fibroblasts. The aim of this study was to identify natural compounds that enhance proteasome activity and exhibit antiaging properties. We demonstrate that oleuropein, the major constituent of Olea europea leaf extract, olive oil and olives, enhances the proteasome activities in vitro stronger than other known chemical activators, possibly through conformational changes of the proteasome. Moreover, continuous treatment of early passage human embryonic fibroblasts with oleuropein decreases the intracellular levels of reactive oxygen species (ROS), reduces the amount of oxidized proteins through increased proteasome-mediated degradation rates and retains proteasome function during replicative senescence. Importantly, oleuropein-treated cultures exhibit a delay in the appearance of senescence morphology and their life span is extended by approximately 15%. In summary, these data demonstrate the beneficial effect of oleuropein on human fibroblasts undergoing replicative senescence and provide new insights towards enhancement of cellular antioxidant mechanisms by natural compounds that can be easily up-taken through normal diet.

Topics: Antioxidants; Cell Line; Cellular Senescence; Enzyme Activation; Enzyme Activators; Fibroblasts; Humans; In Vitro Techniques; Iridoid Glucosides; Iridoids; Oxidants; Oxidative Stress; Plant Extracts; Plant Leaves; Proteasome Endopeptidase Complex; Protein Conformation; Pyrans; Reactive Oxygen Species; Up-Regulation

Recent experimental study found that OLE (olive leaf extract) has anti-HIV activity by blocking the HIV virus entry to host cells [Lee-Huang, S., Zhang, L., Huang, P.L., Chang, Y. and Huang, P.L. (2003) Anti-HIV activity of olive leaf extract (OLE) and modulation of host cell gene expression by HIV-1 infection and OLE treatment. Biochem. Biophys. Res. Commun. 307, 1029; Lee-Huang, S., Huang, P.L., Zhang, D., Lee, J.W., Bao, J., Sun, Y., Chang, Y.-Tae, Zhang, J.Z.H. and Huang, P.L. (2007) Discovery of small-molecule HIV-1 fusion and integrase inhibitors oleuropein and hydroxytyrosol. Biochem. Biophys. Res. Commun. 354, 872-878, 879-884]. As part of a joint experimental and theoretical effort, we report here computational study to help identify and characterize the binding complexes of several main compounds of OLE (olive leaf extract) to HIV-1 envelop protein gp41. A number of possible binding modes are found by docking oleuropein and its metabolites, aglycone, elenolic acid and hydroxytyrosol, onto the hydrophobic pocket on gp41. Detailed OLE-gp41 binding interactions and free energies of binding are obtained through molecular dynamics simulation and MM-PBSA calculation. Specific molecular interactions in our predicted OLE/gp41 complexes are identified and hydroxytyrosol is identified to be the main moiety for binding to gp41. This computational study complements the corresponding experimental investigation and helps establish a good starting point for further refinement of OLE-based gp41 inhibitors.

Topics: Antiviral Agents; Computer Simulation; HIV Envelope Protein gp41; HIV-1; Humans; Hydrogen Bonding; Iridoid Glucosides; Iridoids; Models, Molecular; Molecular Structure; Olea; Phenylethyl Alcohol; Plant Extracts; Plant Leaves; Protein Binding; Pyrans; Thermodynamics

To study the conditions and parameters of the enrichment of oleuropein with macroporous resin.. Aqueous extract of Olea europaea leaves prepared through microwave extraction was adsorbed directly with macroporous resin D-101 and the impurities such sugar were washed out by water then oleuropein was eluted by 70% ethanol. HPLC was used to determine the content of oleuropein.. The contents of oleuropein increased from 5% to 21.6% in the solid, with 88.6% of recovery rate.. Macroporous resin D-101 fits in purification of water-soluble oleuropein. The process is simple and convenient and can be used for industrial production.

Topics: Adsorption; Chromatography, High Pressure Liquid; Drugs, Chinese Herbal; Ethanol; Iridoid Glucosides; Iridoids; Olea; Plant Leaves; Plants, Medicinal; Pyrans; Reproducibility of Results; Resins, Synthetic; Solubility; Technology, Pharmaceutical; Water

Phenolic compounds extracted from extra virgin olive oil have attracted considerable recent attention. One of the components, (-)-oleocanthal (1), an inhibitor of the COX-1 and COX-2 enzymes, possesses similar potency as the NSAID ibuprofen. In this, a full account, we disclose the first- and now second-generation syntheses of both enantiomers of the oleocanthals, as well as the first synthesis of the closely related (-)-deacetoxy-oleuropein aglycone and a series of related analogues for structure activity studies. To demonstrate the utility of the second-generation synthesis, multigram quantities of (-)-oleocanthal were prepared in 10 steps (14% overall yield) from commercially available D-lyxose.

Topics: Aldehydes; Anti-Inflammatory Agents, Non-Steroidal; Biological Products; Cerium; Chlorides; Cyclization; Cyclopentane Monoterpenes; Ethylenes; Iridoid Glucosides; Iridoids; Ketones; Molecular Structure; Olive Oil; Phenols; Plant Oils; Pyrans

Olive leaf extract, rich in oleuropein, formed an inclusion complex with beta-cyclodextrin (beta-CD) upon mixing of the components in aqueous media and subsequent freeze-drying. Inclusion complex formation was confirmed by differential scanning calorimetry (DSC). DSC thermograms indicated that the endothermic peaks of both the olive leaf extract and the physical mixture of olive leaf extract with beta-CD, attributed to the melting of crystals of the extract, were absent in DSC thermogram of inclusion complex. Moreover, DSC studies under oxidative conditions indicated that the complex of olive leaf extract with beta-CD was protected against oxidation, since it remained intact at temperatures where the free olive leaf extract was oxidized. Phase solubility studies afforded A L type diagrams, 1:1 complex stoichiometry, a moderate binding constant ( approximately 300 M (-1)), and an increase of the aqueous solubility by approximately 50%. The formation of the inclusion complex was also confirmed by nuclear magnetic resonance (NMR) studies of beta-CD solutions in the presence of both pure oleuropein and olive leaf extract. The NMR data have established the formation of a 1:1 complex with beta-CD that involves deep insertion of the dihydroxyphenethyl moiety inside the cavity from its secondary side.

Topics: beta-Cyclodextrins; Capsules; Chromatography, High Pressure Liquid; Iridoid Glucosides; Iridoids; Magnetic Resonance Spectroscopy; Olea; Plant Extracts; Plant Leaves; Pyrans; Solubility; Thermodynamics

The present study concerns the genotoxicity of olive mill waste water (OMWW) generated in mills producing olive oil in Morocco. The Vicia faba micronucleus test was used to evaluate the genotoxicity of OMWW and the six major phenolic compounds identified by HPLC in this effluent. Five dilutions of OMWW were tested: 0.1, 1, 5, 10 and 20%. Maleic hydrazide was used as a positive control. The results showed that OMWW was genotoxic at 10% dilution. In order to investigate the components involved in this genotoxicity, the six major phenols present in this effluent, oleuropein, gallic acid, 4-hydroxyphenyl acetic acid, caffeic acid, paracoumaric acid and veratric acid, were studied at concentrations corresponding to the genotoxic concentration of the OMWW itself. Two phenols, gallic acid and oleuropein induced a significant increase in micronucleus frequency in Vicia faba; the four other phenols had no significant genotoxic effect. These results suggest that under the experimental conditions of our assay, OMWW genotoxicity was associated with gallic acid and oleuropein.

Topics: Coumaric Acids; Gallic Acid; Industrial Waste; Iridoid Glucosides; Iridoids; Micronucleus Tests; Morocco; Olea; Phenols; Pyrans; Vicia faba; Water Pollution, Chemical

The inhibitors involved in the lactic acid fermentation of table olives were investigated in aseptic olive brines of the Manzanilla and Gordal varieties. Phenolic and oleosidic compounds in these brines were identified by high-performance liquid chromatography with ultraviolet and electrospray ionization mass spectrometry detection, and several substances were also characterized by nuclear magnetic resonance. Among these compounds, the dialdehydic form of decarboxymethyl elenolic acid linked to hydroxytyrosol showed the strongest antilactic acid bacteria activity, and its presence in brines could explain the growth inhibition of these microorganisms during olive fermentation. However, it was found that the dialdehydic form of decarboxymethyl elenolic acid, identified for the first time in table olives, and an isomer of oleoside 11-methyl ester were also effective against Lactobacillus pentosus and can, therefore, contribute to the antimicrobial activity of olive brines. It must also be stressed that the three new inhibitors discovered in table olive brines exerted a more potent antibacterial activity than the well-studied oleuropein and hydroxytyrosol.

Topics: Anti-Bacterial Agents; Chromatography, High Pressure Liquid; Fermentation; Iridoid Glucosides; Iridoids; Lactobacillus; Magnetic Resonance Spectroscopy; Microbial Sensitivity Tests; Olea; Phenylethyl Alcohol; Pyrans; Spectrometry, Mass, Electrospray Ionization; Spectrophotometry, Ultraviolet

Palm oil, olive oil, and sunflower oil were supplemented with an extract rich in polyphenols obtained from olive tree (Olea europaea) leaves at levels of 120 and 240 mg total polyphenols per kilogram of oil. Pan-frying of potatoes was performed in both the enriched and the nonsupplemented oils under domestic frying conditions. Total polyphenol content was estimated by the Folin-Ciocalteau assay, oleuropein was determined by HPLC analysis, while other individual polyphenols by GC/MS analysis. Fourteen polyphenol species were identified in the olive leaf extract, among which oleuropein predominated (1.25 g/kg olive leaves). All the enriched oils contained oleuropein before and after frying. Oleuropein as well as other polyphenol species were detected in all French fries cooked in enriched oils. Polyphenol intake by consuming French fries pan-fried in the enriched oils was calculated to be 6 to 31 times higher than that in the case of French fries fried in commercial oils, being dependent on the frying oil type.

Topics: Chromatography, High Pressure Liquid; Cooking; Dose-Response Relationship, Drug; Flavonoids; Food Handling; Food, Fortified; Gas Chromatography-Mass Spectrometry; Humans; Iridoid Glucosides; Iridoids; Olea; Olive Oil; Palm Oil; Phenols; Plant Extracts; Plant Leaves; Plant Oils; Polyphenols; Pyrans; Solanum tuberosum; Sunflower Oil

To study the chemical constituents of the flower of Jasminum officinale L. var. grandiflorum. The compounds were isolated and purified by re-crystallization and chromatography on silica gel and Sephadex LH-20 column. Their structures were elucidated on the physicochemical properties and spectral analysis. Seven glycosides were identified as kaempferol-3-O-alpha-L-rhamnopyranosyl (1-->3)-[alpha-L-rhamnopyranosyl (1-->6)]-beta-D-galactopyranoside (I), kaempferol-3-O-rutinoside (II), 7-ketologanin (III), oleoside-11-methyl ester (IV), 7-glucosyl-l1-methyl oleoside (V), ligstroside (VI), oleuropein (VII). Compound I is a new compound. Compounds III and V were isolated from the family of Jasminum for the first time and compounds II, IV and VI were isolated from Jasminum officinale L. var. grandiflorum for the first time.

Topics: Flowers; Glucosides; Iridoid Glucosides; Iridoids; Jasminum; Kaempferols; Oligosaccharides; Plants, Medicinal; Pyrans

Patients with diabetes mellitus are likely to develop certain complication such as retinopathy, nephropathy and neuropathy as a result of oxidative stress and overwhelming free radicals. Treatment of diabetic patients with antioxidant may be of advantage in attenuating these complications. Oleuropein, the active constituent of olive leaf (Olea europaea), has been endowed with many beneficial and health promoting properties mostly linked to its antioxidant activity. This study aimed to evaluate the significance of supplementation of oleuropein in reducing oxidative stress and hyperglycemia in alloxan-induced diabetic rabbits. After induction of diabetes, a significant rise in plasma and erythrocyte malondialdehyde (MDA) and blood glucose as well as alteration in enzymatic and non-enzymatic antioxidants was observed in all diabetic animals. During 16 weeks of treatment of diabetic rabbits with 20 mg/kg body weight of oleuropein the levels of MDA along with blood glucose and most of the enzymatic and non-enzymatic antioxidants were significantly restored to establish values that were not different from normal control rabbits. Untreated diabetic rabbits on the other hand demonstrated persistent alterations in the oxidative stress marker MDA, blood glucose and the antioxidant parameters. These results demonstrate that oleuropein may be of advantage in inhibiting hyperglycemia and oxidative stress induced by diabetes and suggest that administration of oleuropein may be helpful in the prevention of diabetic complications associated with oxidative stress.

Topics: Animals; Antioxidants; Blood Glucose; Body Weight; Diabetes Mellitus, Experimental; Disease Models, Animal; Hypoglycemic Agents; Iridoid Glucosides; Iridoids; Oleaceae; Phytotherapy; Plant Leaves; Pyrans; Rabbits

In this study, for the first time, the impact of the genetic factor on the contents of oleuropein in olive leaves was not only evaluated but the influence exerted by the color/age of leaves (green, green-yellowish, and yellow) and the collecting period (spring or autumn) was also evaluated. A repetitive high-resolution gas chromatographic quantitation method and an accurate high-performance liquid chromatographic method were developed. These analytical methods gave results showing a highly linear relationship. Samples of olive leaves were taken from seven major Italian olive cultivars, such as Dritta, Leccino, Caroleo, Coratina, Castiglionese, Nebbio, and Grossa di Cassano. Such a vegetal raw material could actually be exploited for recovering oleuropein, considered to be a high-added value molecule. This could be converted into hydrxytyrosol, a compound known to possess strong bioactive properties. Olive leaves showed considerable contents of oleuropein, which with some cultivars were even higher with respect to those present in the corresponding olive fruits (reported in the literature). The amounts of oleuropein in the collected leaves were markedly modified by the color/age and genetic factors, whereas meaningless variations were ascribable to the quantitation method and the collecting period factors. Various chemometrics, applied to the obtained analytical data, appeared to be effective in discriminating the samples on the basis of the above-examined experimental factors, thus confirming how these should be taken into account in future industrial recovery of oleuropein from olive leaves.

Topics: Analysis of Variance; Antioxidants; Chromatography, Gas; Color; Iridoid Glucosides; Iridoids; Olea; Plant Leaves; Pyrans; Seasons

A continuous approach for the ultrasound-assisted extraction of olive biophenols (OBPs) from olive leaves is proposed. Multivariate methodology was used to carry out a detailed optimisation of extraction. Under the optimal working conditions, complete extraction of the target analytes (namely, oleuropein, verbacoside, apigenin-7-glucoside and luteolin-7-glucoside with LODs 11.04, 2.68, 1.49 and 3.91 mg/kg, respectively) was achieved in 25 min. The extract was injected into a chromatograph-photodiode array detector assembly (HPLC-DAD) for individual separation-quantification. No clean-up or preconcentration steps were required. Gas chromatography-mass spectrometry (without derivatization of the analytes) was used to identify OBPs at concentrations below the LODs obtained by HPLC-DAD. The efficacy of ethanol-water mixtures to extract OBPs from olive leaves has been demonstrated and compared with that of a conventional method which requires 24h for complete extraction; so these mixtures can substitute toxic extractants used to date.

Topics: Chromatography, High Pressure Liquid; Gas Chromatography-Mass Spectrometry; Iridoid Glucosides; Iridoids; Olea; Phenols; Plant Leaves; Pyrans; Reproducibility of Results; Ultrasonics

Beta amyloid peptide (Abeta) is the major proteinaceous component of senile plaques formed in Alzheimer's disease (AD) brain. The aggregation of Abeta is associated with neurodegeneration, loss of cognitive ability, and premature death. It has been suggested that oxidative stress and generation of free radical species have implications in the fibrillation of Abeta and its subsequent neurotoxicity. For this reason, it is proposed that antioxidants may offer a protective or therapeutic alternative against amyloidosis. This study is the first report of the formation of the noncovalent complex between Abeta or its oxidized form and the natural derived antioxidant oleuropein (OE) by electrospray ionization mass spectrometry (ESI MS). ESI MS allowed the real time monitoring of the complex formation between Abeta, OE, and variants thereof. Several experimental conditions, such as elevated orifice potential, low pH values, presence of organic modifier, and ligand concentration were examined, to assess the specificity and the stability of the formed noncovalent complexes.

Topics: Amyloid beta-Peptides; Antioxidants; Humans; Hydrogen-Ion Concentration; In Vitro Techniques; Iridoid Glucosides; Iridoids; Kinetics; Macromolecular Substances; Molecular Structure; Oxidation-Reduction; Peptide Fragments; Protein Binding; Pyrans; Solutions; Spectrometry, Mass, Electrospray Ionization

The Mediterranean diet reduces the risk of coronary artery disease as a consequence of its high content of antioxidants, namely, hydroxytyrosol (HT) and oleuropein aglycone (OleA), typical of virgin olive oil. Because intercellular and vascular cell adhesion molecules (ICAM-1 and VCAM-1) and E-selectin are crucial for endothelial activation, the role of the phenolic extract from extra virgin olive oil (OPE), OleA, HT, and homovanillyl alcohol (HVA) on cell surface and mRNA expression in human umbilical vascular endothelial cells (HUVEC) was evaluated. OPE strongly reduced cell surface expression of ICAM-1 and VCAM-1 at concentrations physiologically relevant (IC50 < 1 microM), linked to a reduction in mRNA levels. OleA and HT were the main components responsible for these effects. HVA inhibited cell surface expression of all the adhesion molecules, whereas the effect on mRNA expression was weaker. These results supply new insights on the protective role of olive oil against vascular risk through the down-regulation of adhesion molecules involved in early atherogenesis.

Topics: Cell Adhesion Molecules; E-Selectin; Endothelium, Vascular; Gene Expression; Humans; Intercellular Adhesion Molecule-1; Iridoid Glucosides; Iridoids; Olive Oil; Phenylethyl Alcohol; Plant Oils; Pyrans; RNA, Messenger; Umbilical Veins; Vascular Cell Adhesion Molecule-1

Fifty lactobacilli isolated from black table olive brines were evaluated for their salt tolerance, resistance to oleuropein and verbascoside, and ability to grow in modified filter-sterilized brines. A strain of Lactobacillus pentosus was selected and used as a starter to ferment, in pilot plant, black olives (Itrana and Leccino cv.) in brines modified for pH, carbohydrate, and growth factor concentrations, at 28 degrees C. The temperature-controlled fermentation of Leccino cv. olives resulted in obtaining ready-to-eat, high-quality table olives in a reduced-time process. HPLC analysis of phenolic compounds from fermented olives showed a decrease of oleuropein, a glucoside secoiridoid responsible for the bitter taste of olive drupes, and an increase of the hydroxytyrosol concentration. The selected strain of L. pentosus (1MO) allowed the reduction of the debittering phase period to 8 days.

Topics: Fermentation; Food Handling; Fruit; Hydrogen-Ion Concentration; Iridoid Glucosides; Iridoids; Lactobacillus; Olea; Phenols; Phenylethyl Alcohol; Pyrans; Taste

This study was carried out to assess the dose-dependent bone-sparing effect of oleuropein, an olive oil phenolic compound with anti-inflammatory and anti-oxidative properties, on bone loss induced by talc granulomatosis in oestrogen-deficient rat.. Among 98 rats, 20 were sham-operated (SH) while the others (78) were ovariectomised (OVX). The SH and 26 OVX rats (controls) were given a standard diet for 100 days. The 52 remaining OVX rats were allocated to 4 groups that received oleuropein at 2.5, 5, 10 or 15 mg/kg body weight per day for 100 days. Three weeks before necropsy, an inflammation was induced by subcutaneous injections of talc in half of the SH and OVX rats and in all oleuropein-treated animals.. Castration was associated with a decreased bone mineral density (BMD). In OVX rats, inflammation, characterised by an increase of the spleen weight and plasma fibrinogen levels, exacerbated this bone loss, as shown by values of BMD of the total femur metaphyseal and diaphyseal subregions. The 4 doses of oleuropein reduced bone loss and improved inflammatory biomarkers excepted for 5mg/kg BW.. Every dose of oleuropein elicited protective effects on bone mass in this model of ovariectomy associated with inflammation, probably by modulating inflammatory parameters.

Topics: Animals; Anti-Infective Agents; Biomarkers; Bone Density; Bone Density Conservation Agents; Dose-Response Relationship, Drug; Female; Fibrinogen; Inflammation; Iridoid Glucosides; Iridoids; Olive Oil; Organ Size; Osteoporosis; Ovariectomy; Plant Oils; Pyrans; Random Allocation; Rats; Rats, Wistar; Spleen

Microwave assistance is proposed for the first time in order to accelerate the extraction of biophenols from olive leaves. Under optimal working conditions, obtained using a multivariate methodology, complete extraction of the target analytes was achieved in 8 min. The extracts required no clean-up nor concentration prior to injection into a chromatograph-photodiode array detector assembly for individual separation-quantification. The optimal extractant (an 80:20 ethanol-water mixture) was also used in the development of a stirring-based extraction method which required around 24 h for complete extraction of the target compounds. These mixtures can be used as replacements for toxic extractants, with a view to exploiting olive leaves in order to obtain biophenols for human use.

Topics: Gas Chromatography-Mass Spectrometry; Hydrogen-Ion Concentration; Iridoid Glucosides; Iridoids; Kinetics; Microwaves; Molecular Structure; Olea; Phenols; Plant Extracts; Plant Leaves; Pyrans

Thgoal of this study was to evaluate the efficacy of the antioxidant olive constituent, oleuropein, on infarct size, oxidative damage, and the metabolic profile in rabbits subjected to ischemia. Oleuropein, 10 or 20 mg/(kg x d), was administered to 8 groups that consumed a normal or hypercholesterolemic diet for 6 wk or only the higher dose for 3 wk. Circulating levels of malondialdehyde, protein carbonyl, nitrite+nitrate, cholesterol, triglycerides, SOD activity, and the metabolic profile were measured using 1H NMR spectra. In rabbits that consumed the normal diet, the infarct size (percentage of infarct to risk areas) was reduced by the administration of 10 mg oleuropein/(kg x d) (16.1 +/- 2.9%) or 20 mg oleuropein/(kg x d) for 3 wk (21.7 +/- 2.2%) or for 6 wk (24.3 +/- 1.3%) compared with the control group (48.05 +/- 2.0%, P < 0.05). Only the higher dose of 20 mg/(kg x d) reduced the infarct size in hypercholesterolemic rabbits (34.7 +/- 4.4% for 6 wk and 34.8 +/- 6.1% for 3 wk) compared with the cholesterol-fed control group (52.8 +/- 2.4%, P < 0.05). Oleuropein decreased the plasma lipid peroxidation product and protein carbonyl concentrations compared with the control groups, in which these factors increased relative to baseline due to ischemia and reperfusion. Furthermore, in rabbits administered oleuropein, RBC superoxide dismutase activity did not change during ischemia and reperfusion. This activity was significantly higher than in both control groups in which it was reduced by ischemia and reperfusion compared with baseline. Treatment for 6 wk with both doses of oleuropein reduced total cholesterol and triglyceride concentrations. 1H NMR spectra revealed a different profile of glycolysis metabolites in the oleuropein-treated groups compared with the controls. Oleuropein, for 3 or 6 wk, reduced the infarct size, conferred strong antioxidant protection and reduced the circulating lipids. This is the first experimental study in vivo that suggests the possibility of using an olive constituent in the treatment of ischemia.

Topics: Animals; Antihypertensive Agents; Antioxidants; Hypolipidemic Agents; Iridoid Glucosides; Iridoids; Lipids; Male; Malondialdehyde; Myocardial Ischemia; Olea; Phytotherapy; Pyrans; Rabbits

Oleuropein, a novel immunomodulator derived from olive tree, was assessed in vitro and in experimental sepsis by Pseudomonas aeruginosa. After addition in monocyte and neutrophil cultures, malondialdehyde, TNF-alpha, IL-6, and bacterial counts were estimated in supernatants. Acute pyelonephritis was induced in 70 rabbits after inoculation of pathogen in the renal pelvis. Intravenous therapy was administered in four groups postchallenge by one multidrug-resistant isolate (A, controls; B, oleuropein; C, amikacin; D, both agents) and in three groups postchallenge by one susceptible isolate (E, controls; F, oleuropein; G, amikacin). Survival was recorded; bacterial growth in blood and organs was counted; endotoxins (LPS), malondialdehyde, total antioxidant status, and TNF-alpha in serum were estimated. TNF-alpha and IL-6 of cell supernatants were not increased compared with controls when triggered by LPS and P. aeruginosa. Counts of multidrug-resistant P. aeruginosa were decreased in monocyte supernatants. Median survival of groups A, B, C, D, E, F, and G were 3.00, 6.00, 2.00, 10.00, 1.00, 5.00, and 1.00 days, respectively. Bacteria in blood were lower at 48 h in groups B and D compared with A and in groups F and G compared with E. Total antioxidant status decreased steadily over time in groups A, C, D, and G, but not in groups B and F. TNF-alpha of groups B, C, and D was lower than A at 48 h. Tissue bacteria decreased in group F compared with E. Oleuropein prolonged survival in experimental sepsis probably by promoting phagocytosis or inhibiting biosynthesis of proinflammatory cytokines.

Topics: Amikacin; Animals; Anti-Bacterial Agents; Antioxidants; Cells, Cultured; Humans; Immunologic Factors; Iridoid Glucosides; Iridoids; Male; Pseudomonas aeruginosa; Pseudomonas Infections; Pyrans; Rabbits; Sepsis; Survival

In this work, the pro-oxidant behavior of oleuropein (OLP, 1) is characterized in a Fenton-like experiment by means of ESR spectroscopy using the spin trap system DMSO and 4-(pyridyl-1-oxide)-N-tert-butyl nitrone (POBN) in phosphate buffer (PB) solution. Ferrous ions in the absence of hydrogen peroxide cause the formation of the stable nitroxide species 4 and 5 through the intermediate perferryl species. OLP displays its antioxidant activity in vitro blocking the oxidation path that leads to methoxyl radicals hence to the formation of the stable radical species 5. The role of the catechol moiety was proved when the perferryl experiments were repeated in the presence of the dimethylated oleuropein homologue (OLP-Met2, 2). The dual behavior of oleuropein, similar to that ascertained for other catechol and non-catechol natural active species, should provide warnings for its use as nutraceutical or as drug with manifold healing effects.

Topics: Antioxidants; Cyclic N-Oxides; Dimethyl Sulfoxide; Electron Spin Resonance Spectroscopy; Iridoid Glucosides; Iridoids; Olea; Oxidants; Plant Leaves; Pyrans; Pyridines

Oleuropein and other healthy olive biophenols (OBPs) such as verbacoside, apigenin-7-glucoside and luteolin-7-glucoside have been extracted from olive leaves by using superheated liquids and a static-dynamic approach. Multivariate methodology has been used to carry out a detailed optimisation of the extraction. Under the optimal working conditions, complete removal without degradation of the target analytes was achieved in 13 min. The extract was injected into a chromatograph-photodiode array detector assembly for individual separation-quantification. The proposed approach - which provides more concentrated extracts than previous alternatives - is very useful to study matrix-extractant analytes partition. In addition, the efficacy of superheated liquids to extract OBPs, the simplicity of the experimental setup, its easy automation and low acquisition and maintenance costs make the industrial implementation of the proposed method advisable.

Topics: Analytic Sample Preparation Methods; Apigenin; Glucosides; Hot Temperature; Hydrogen-Ion Concentration; Iridoid Glucosides; Iridoids; Luteolin; Olea; Phenols; Plant Leaves; Pyrans; Reproducibility of Results

Increasing interest in phenolic compounds in olives is due to their antioxidant and health-enhancing properties. In this study the phenolics in fruits of the Tunisian olive cultivar Chemlali were extracted by methanol-water and fractionated using Sephadex LH-20 column chromatography. The identification of phenolic monomers and flavonoids was based on separation by high-performance liquid chromatography equipped with a diode array detector followed by liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry analysis. Oleuropein, a secoiridoid glycoside esterified with a phenolic acid, was the major compound. Eight phenolic monomers and 12 flavonoids were also identified in Chemlali olives. Five flavonoids were isolated and purified using Sephadex LH-20 column chromatography and preparative paper chromatography. The antioxidant activity of the extract and the purified compounds was evaluated by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl and by using the beta-carotene-linoleate model assay. Acid hydrolysis of the extract enhanced its antioxidant activity. Hydroxytyrosol and quercetin showed antioxidant activities similar to that of 2,6-di-tert-butyl-4-methylphenol. A hydroxyl group at the ortho position at 3' on the B ring of the flavonoid nucleus could contribute to the antioxidant activity of the flavonoids.

Topics: Antioxidants; beta Carotene; Biphenyl Compounds; Chromatography, High Pressure Liquid; Flavonoids; Fruit; Gas Chromatography-Mass Spectrometry; Iridoid Glucosides; Iridoids; Molecular Weight; Olea; Phenols; Picrates; Pyrans; Tunisia

Oleuropein hydrolysis products, obtained both by endogenous beta-glucosidase and almond commercial one, were investigated by classic methodologies and by 1HNMR experiments. We found that both presence and relative amount of the different compounds in the reaction mixture are stricly related to the used enzyme.

Topics: Hydrolysis; Iridoid Glucosides; Iridoids; Magnetic Resonance Spectroscopy; Pyrans

The ferric complexing capacity of four phenolic compounds, occurring in olives and virgin olive oil, namely, oleuropein, hydroxytyrosol, 3,4-dihydroxyphenylethanol-elenolic acid (3,4-DHPEA-EA), and 3,4-dihydroxyphenylethanol-elenolic acid dialdehyde (3,4-DHPEA-EDA), and their stability in the presence of ferric ions were studied. At pH 3.5, all compounds formed a reversible 1:1 complex with ferric ions, but hydroxytyrosol could also form complexes containing >1 ferric ion per phenol molecule. At pH 5.5, the complexes between ferric ions and 3,4-DHPEA-EA or 3,4-DHPEA-EDA were relatively stable, indicating that the antioxidant activity of 3,4-DHPEA-EA or 3,4-DHPEA-EDA at pH 5.5 is partly due to their metal-chelating activity. At pH 7.4, a complex containing >1 ferric ion per phenol molecule was formed with hydroxytyrosol. Oleuropein, 3,4-DHPEA-EA, and 3,4-DHPEA-EDA also formed insoluble complexes at this pH. There was no evidence for chelation of Fe(II) by hydroxytyrosol or its derivatives. At all pH values tested, hydroxytyrosol was the most stable compound in the absence of Fe(III) but the most sensitive to the presence of Fe(III).

Topics: Drug Stability; Ferric Compounds; Hydrogen-Ion Concentration; Iridoid Glucosides; Iridoids; Olive Oil; Phenols; Phenylethyl Alcohol; Plant Oils; Pyrans

The aim of the current study was to investigate the antioxidant and cellular activity of the olive oil phenolics oleuropein, tyrosol, hydroxytyrosol, and homovanillic alcohol (which is also a major metabolite of hydroxytyrosol). Well-characterized chemical and biochemical assays were used to assess the antioxidant potential of the compounds. Further experiments investigated their influence in cell culture on cytotoxic effects of hydrogen peroxide and oxidized low-density lipoprotein (LDL), nitric oxide production by activated macrophages, and secretion of chemoattractant and cell adhesion molecules by the endothelium. Inhibitory influences on in vitro platelet aggregation were also measured. The antioxidant assays indicated that homovanillic alcohol was a significantly more potent antioxidant than the other phenolics, both in chemical assays and in prolonging the lag phase of LDL oxidation. Cell culture experiments suggested that the olive oil phenolics induce a significant reduction in the secretion of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 (and a trend towards a reduced secretion of monocyte chemoattractant protein-1), and protect against cytotoxic effects of hydrogen peroxide and oxidized LDL. However, no influence on nitric oxide production or platelet aggregation was evident. The data show that olive oil phenolics have biochemical and cellular actions, which, if also apparent in vivo, could exert cardioprotective effects.

Topics: Antioxidants; Arteriosclerosis; Cell Adhesion Molecules; Cells, Cultured; Chemokine CCL2; Endothelium; Homovanillic Acid; Hydrogen Peroxide; In Vitro Techniques; Intercellular Adhesion Molecule-1; Iridoid Glucosides; Iridoids; Lipoproteins, LDL; Macrophages; Nitric Oxide; Olive Oil; Phenols; Phenylethyl Alcohol; Plant Oils; Platelet Aggregation; Pyrans; Vascular Cell Adhesion Molecule-1

A simple and reproducible method for qualitative and quantitative analysis of phenolic compounds in virgin olive oils by solid-phase extraction (SPE), high performance liquid chromatography with diode array detector (HPLC-DAD), and HPLC-mass spectrometry (MS) in tandem mode was developed. The polar fraction was obtained from samples of three different virgin olive oils. Detection and quantification were performed at 280, 240, and 320 nm. For identification purposes, HPLC-MS/MS was equipped with turbo ion spray source in the negative-ion mode. Twenty compounds of twenty-three detected and quantified were characterized. The method showed satisfactory linearity (r > 0.99), good recovery, satisfactory precision, and appropriate limits of detection (LOD) and quantification (LOQ).

Topics: Benzaldehydes; Chromatography, High Pressure Liquid; Flavonoids; Glucosides; Hydroxybenzoates; Iridoid Glucosides; Iridoids; Mass Spectrometry; Olive Oil; Phenols; Plant Oils; Pyrans; Sensitivity and Specificity

Oleuropein (Ole) is the major phenolic constituent of the olive leaf (Olea europaea) and it is also present in olive oil and fruit. In the last years several compounds from olive tree, oleuropein among them, have shown a variety of biological activities such as antimicrobial or antioxidant. A phospholipid model membrane system was used to study whether the Ole biological effects could be membrane related. Ole showed a significant partition level in phospholipid membranes, i.e. 80%, at lipid-saturating conditions. Moreover, fluorescence quenching experiments indicated a shallow location for Ole in membranes. Ole promoted weak effects on zwiterionic phospholipids such as phosphatidylcholine or phosphatidylethanolamine. In contrast, differential scanning microcalorimetry, light scattering and fluorescence anisotropy pH titration studies revealed strong effects on anionic phospholipids such as phosphatidylglycerol at physiological pH and salt conditions. These effects consisted on perturbations at the phospholipid membrane surface, which might involve specific molecular interactions between Ole and the negatively charged phosphate group and therefore modify the phospholipid/water interface properties. It is proposed that Ole induces lipid structures similar to the gel-fluid intermediate phase (IP) described for PG membranes, in a similar way than low ionic strength does. These effects on phosphatidylglycerol may account for the antimicrobial activity of Ole.

Topics: Calorimetry, Differential Scanning; Fluorescence; Hydrogen-Ion Concentration; Iridoid Glucosides; Iridoids; Light; Membranes, Artificial; Olea; Phenols; Phosphatidylglycerols; Phospholipids; Pyrans; Scattering, Radiation

The inhibition of Staphylococcus aureus by oleuropein is shown to be largely due to hydrogen peroxide production by oleuropein. The reaction is initiated by noninhibitory levels of hydrogen peroxide present as a result of tryptone oxidation in the underlying medium. Inhibition is abolished by catalase and anaerobic incubation conditions, and the effect of tryptone can be replicated by exogenous H2O2. S. aureus strains with reduced catalase activity show greater sensitivity to oleuropein. A mechanism for hydrogen peroxide production is proposed. Inhibition is not entirely due to H2O2, since some organisms with similar sensitivity to H2O2 as S. aureus were resistant to oleuropein, suggesting that there may be a cooperative effect between H2O2 and oleuropein itself.

Topics: Anti-Infective Agents; Catalase; Colony Count, Microbial; Drug Interactions; Food Microbiology; Food Preservation; Hydrogen Peroxide; Iridoid Glucosides; Iridoids; Pyrans; Staphylococcus aureus

Oleuropein, a non-toxic secoiridoid derived from the olive tree, is a powerful antioxidant and anti-angiogenic agent. Here, we show it to be a potent anti-cancer compound, directly disrupting actin filaments in cells and in a cell-free assay. Oleuropein inhibited the proliferation and migration of advanced-grade tumor cell lines in a dose-responsive manner. In a novel tube-disruption assay, Oleuropein irreversibly rounded cancer cells, preventing their replication, motility, and invasiveness; these effects were reversible in normal cells. When administered orally to mice that developed spontaneous tumors, Oleuropein completely regressed tumors in 9-12 days. When tumors were resected prior to complete regression, they lacked cohesiveness and had a crumbly consistency. No viable cells could be recovered from these tumors. These observations elevate Oleuropein from a non-toxic antioxidant into a potent anti-tumor agent with direct effects against tumor cells. Our data may also explain the cancer-protective effects of the olive-rich Mediterranean diet.

Topics: Actins; Angiogenesis Inhibitors; Animals; Antineoplastic Agents, Phytogenic; Antioxidants; beta-Glucosidase; Cell Migration Inhibition; Cell Proliferation; Cytoskeleton; Humans; Iridoid Glucosides; Iridoids; Mice; Neoplasm Invasiveness; Olea; Pyrans; Tumor Cells, Cultured

In search for compounds, able to protect nuclear DNA in cells exposed to oxidative stress, extracts from olive leaves, olive fruits, olive oil and olive mill waste water were tested by using the "single cell gel electrophoresis" methodology (comet assay). Jurkat cells in culture were exposed to continuously generated hydrogen peroxide (11.8+/-1.5 microM per min) by direct addition into the growth medium of the appropriate amount of the enzyme "glucose oxidase" in the presence or absence of the tested total extracts. The protective effects of the tested extracts or isolated compounds were evaluated from their ability to decrease hydrogen peroxide-induced formation of single strand breaks in the nuclear DNA, while the toxic effects were estimated from the increase of DNA damage when the extracts or isolated compounds were incubated directly with the cells. Significant protection was observed in extracts from olive oil and olive mill waste water. However, above a concentration of 100 microg/ml olive oil extracts exerted DNA damaging effects by themselves in the absence of any H2O2. Extracts from olive leaves and olive fruits although protective, were also able to induce DNA damage by themselves. Main compounds isolated from the above described total extracts, like oleuropein glucoside, tyrosol, hydroxytyrosol and caffeic acid, were tested in the same experimental system and found to exert cytotoxic (oleuropein glucoside), no effect (tyrosol) or protective effects (hydroxytyrosol and caffeic acid). In conclusion, cytoprotective as well as cytotoxic compounds with potential pharmaceutical properties were detected in extracts from olive oil related sources by using the comet assay methodology.

Topics: Caffeic Acids; Chromatography, High Pressure Liquid; Comet Assay; DNA; DNA Damage; Humans; Hydrogen Peroxide; Iridoid Glucosides; Iridoids; Jurkat Cells; Nuclear Magnetic Resonance, Biomolecular; Olea; Olive Oil; Phenylethyl Alcohol; Plant Extracts; Plant Oils; Pyrans

Oleuropein (OLP, 1), the active ingredient present (i) in food integrators extracted from olive leaves, (ii) in table olives, and (iii) in extra virgin olive oils is a nutraceutical whose health benefits have been widely documented. A new analytical method for its assay, which is based on the utilization of atmospheric pressure chemical ionization tandem mass spectrometry and on the use of a synthetic labeled analogue, the 4-trideuteriocarboxyoleuropein (2), as an internal standard, is presented. The results obtained with extra virgin olive oils from different cultivars and different Italian regions are discussed.

Topics: Atmospheric Pressure; Iridoid Glucosides; Iridoids; Olive Oil; Plant Oils; Pyrans; Spectrometry, Mass, Electrospray Ionization; Spectrophotometry, Infrared; Tandem Mass Spectrometry; X-Ray Diffraction

A capillary zone electrophoresis method has been carried out to determine and quantitate some compounds of the polyphenolic fraction of virgin olive oil which have never previously been determined before using capillary electrophoresis, such as elenolic acid, ligstroside aglycon, oleuropein aglycon, and (+)-pinoresinol. The compounds were identified using standards obtained by semipreparative high-performance liquid chromatography (HPLC). A detailed method optimization was performed to separate the phenolic compounds present in olive oil using a methanol-water extract of Picual extra-virgin olive oil, and different extraction systems were compared (C18-solid phase extraction (SPE), Diol-SPE, Sax-SPE and liquid-liquid extraction). The optimized parameters were 30 mM sodium tetraborate buffer (pH 9.3) at 25 kV with 8 s hydrodynamic injection, and the quantitation was carried out by the use of two reference compounds at two different wavelengths.

Topics: Chromatography, High Pressure Liquid; Electrophoresis, Capillary; Flavonoids; Furans; Glucosides; Iridoid Glucosides; Iridoids; Lignans; Olive Oil; Phenols; Phenylethyl Alcohol; Plant Oils; Polyphenols; Pyrans

Phenolic compounds in Spanish virgin olive oil were analyzed by GC-MS after an SPE diol cartridge extraction and clean-up procedure. Posterior derivatization to trimethylsilyl (TMS) ethers using a mixture of hexamethyldisilazane:dimethylclorosilane (HMDS:DMCS) in pyridine (3:1:9) was performed. Several compounds were detected and 21 of them were identified. Free phenols such as hydroxytyrosol, tyrosol, tyrosyl and hydroxytyrosyl acetate, and aldehydic and dialdehydic forms of elenolic acid linked to tyrosol and hidroxytyrosol were the most abundant compounds. Likewise, oxidation products coming from the aldehydic and dialdehydic forms of elenolic acid, and of ligstroside and oleuropein aglycons, were detected, and their structure confirmed by other mass spectrometry technique, i.e., HPLC-APCI-MS. Individual oxidation products were isolated from an oxidized sample by preparative HPLC, converted to TMS ethers and re-analyzed by GC-MS. When necessary and for identification purposes, selective ion monitoring, namely, GC-MS-SIM, was employed. This is the first time that structures of oxidized forms are determined by GC-MS.

Topics: Gas Chromatography-Mass Spectrometry; Glucosides; Iridoid Glucosides; Iridoids; Molecular Structure; Olive Oil; Oxidation-Reduction; Phenols; Plant Oils; Pyrans

The present study was designed to evaluate the effect of olive oil and its main polyphenol (oleuropein) in ovariectomised rats with or without inflammation. Rats (6 months old) were ovariectomised or sham-operated as control. Ovariectomised rats were separated into three groups receiving different diets for 3 months: a control diet with 25 g peanut oil and 25 g rapeseed oil/kg (OVX), the control diet with 50 g olive oil/kg or the control diet with 0.15 g oleuropein/kg. The sham-operated group was given the same control diet as OVX. Inflammation was induced 3 weeks before the end of the experiment by subcutaneous injections of talc (magnesium silicate) in one-half of each group. The success of ovariectomy was verified at necropsy by the atrophy of uterine horns. Inflammation, oleuropein or olive oil intakes did not have any uterotrophic activity, as they had had no effect on uterus weight. The plasma concentration of alpha-1-acid glycoprotein (an indicator of inflammation) was increased in OVX rats with inflammation. With regard to bone variables, osteopenia in OVX was exacerbated by inflammation, as shown by a decrease in metaphyseal and total femoral mineral density. Both oleuropein and olive oil prevented this bone loss in OVX rats with inflammation. At necropsy, oleuropein and olive oil consumption had had no effect on plasma osteocalcin concentrations (marker of bone formation) or on urinary deoxypyridinoline excretion (marker of bone resorption). In conclusion, oleuropein and olive-oil feeding can prevent inflammation-induced osteopenia in OVX rats.

Topics: Animals; Anti-Infective Agents; Biomarkers; Bone Density; Bone Diseases, Metabolic; Bone Resorption; Dietary Fats, Unsaturated; Female; Inflammation; Iridoid Glucosides; Iridoids; Olive Oil; Organ Size; Orosomucoid; Osteogenesis; Ovariectomy; Plant Oils; Pyrans; Rats; Rats, Wistar; Uterus

The potential protective effects of oleuropein, a dietary antioxidant of olive oil, has been investigated in the isolated rat heart. The organs were subjected to 30 minutes of no-flow global ischemia and then reperfused. At different time intervals, the coronary effluent was collected and assayed for creatine kinase activity as well as for reduced and oxidized glutathione. In addition, the extent of lipid peroxidation was evaluated by measuring thiobarbituric acid reactive substance concentration in cardiac muscle. Pretreatment with 20 microg/g oleuropein before ischemia resulted in a significant decrease in creatine kinase and reduced glutathione release in the perfusate. The protective effect of oleuropein against the post-ischemic oxidative burst was investigated by measuring the release, in the coronary effluent, of oxidized glutathione, a sensitive marker of heart's exposure to oxidative stress. Reflow in ischemic hearts was accompanied by a prompt release of oxidized glutathione; in ischemic hearts pretreated with oleuropein, this release was significantly reduced. Membrane lipid peroxidation was also prevented by oleuropein. The reported data provide the first experimental evidence of a direct cardioprotective effect of oleuropein in the acute events that follow coronary occlusion, likely because of its antioxidant properties. This finding strengthens the hypothesis that the nutritional benefit of olive oil in the prevention of coronary heart disease can be also related to the high content of oleuropein and its derivatives. Moreover, our data, together with the well documented antithrombotic and antiatherogenic activity of olive oil polyphenols, indicate these antioxidants as possible therapeutic tools for the pharmacological treatment of coronary heart disease as well as in the case of cardiac surgery, including transplantation.

Topics: Animals; Creatine Kinase; Glutathione; In Vitro Techniques; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Male; Myocardial Ischemia; Myocardial Reperfusion Injury; Myocardium; Oxidative Stress; Pyrans; Rats; Rats, Sprague-Dawley; Thiobarbituric Acid Reactive Substances

For the first time the identification and quantification of phenolic compounds of the Olea europaea L. cv. Chemlali olive were carried out to examine their profile during maturation. The phenolic composition was studied by using reverse-phase high-performance liquid chromatography during all steps of fruit development. Oleuropein is the abundant phenolic compound in Chemlali olive, and its concentration increases during maturation. An indirect relationship between oleuropein content in olive fruit and hydroxytyrosol was observed. Weak changes in the amounts of the other phenolic monomers and flavonoids were also observed. The total phenolic content varied from 6 to 16 g/kg expressed as pyrogallol equivalents. Its highest level was found at the last maturation period. The antioxidant capacity of olive extracts was evaluated by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl. The IC(50) values of the olive extract ranged from 3.2 to 1.5 microg/mL. There was a correlation between antioxidant activity and total phenolic content of samples. The antioxidant activity increased with maturation. This could be attributed to the increase of the tolal phenol level with fruit development.

Topics: Antioxidants; Chromatography, High Pressure Liquid; Flavonoids; Iridoid Glucosides; Iridoids; Olea; Phenols; Pyrans; Tunisia

The structural modifications of the unsaturated fatty acid components of triglycerides in extra virgin olive oil (EVOO) following exposure to nitrite ions in acidic media were determined by two-dimensional (2D) NMR spectroscopy, aided by (15)N labeling and GC analysis, allowing investigation of the matrix without fractionation steps. In the presence of excess nitrite ions in a 1% sulfuric acid/oil biphasic system, extensive double bond isomerization of the oleic/linoleic acid components of triglycerides was observed associated with nitration/oxidation processes. Structurally modified species were identified as E/Z-nitroalkene, 1,2-nitrohydroxy, and 3-nitro-1-alkene(1,5-diene) derivatives based on (1)H, (13)C, and (15)N 2D NMR analysis in comparison with model compounds. Minor constituents of EVOO, including phenolic compounds and tocopherols, were also substantially modified by nitrite-derived nitrating species, even under milder reaction conditions relevant to those occurring in the gastric compartments. Novel nitrated derivatives of tyrosol, hydroxytyrosol, and oleuropein (6-8) were identified by LC/MS analysis of the polar fraction of EVOO and by comparison with synthetic samples. Overall, these results provide the first systematic description at the chemical level of the consequences of exposing EVOO to nitrite ions at acidic pH and offer an improved basis for further investigations in the field of toxic nitrosation/nitration reactions and dietary antinitrosating agents.

Topics: Acids; Alkenes; Antineoplastic Agents; Fatty Acids, Unsaturated; Gas Chromatography-Mass Spectrometry; Hydrogen-Ion Concentration; Ions; Iridoid Glucosides; Iridoids; Isomerism; Magnetic Resonance Spectroscopy; Nitrites; Nitrosation; Olive Oil; Phenols; Phenylethyl Alcohol; Plant Oils; Pyrans

We describe a liquid chromatography-electrospray ionisation tandem mass spectrometry method for the qualitative and quantitative determination of the secoiridoid oleuropein and its bioactive metabolite hydroxytyrosol in rat plasma and urine. Samples were prepared by liquid-liquid extraction using ethyl acetate with a recovery for both compounds of about 100% in plasma and about 60% in urine. The chromatographic separation was performed with a RP-ODS column using a water-acetonitrile linear gradient. The calibration curve was linear for both biophenols over the range 2.5-1000 ng/ml (LOD 1.25 ng/ml) for plasma and 5-1000 ng/ml (LOD 2.5 ng/ml) for urine. Plasma concentrations of oleuropein and hydroxytyrosol were measured after oral administration of a single dose (100 mg/kg) of oleuropein. Analysis of treated rat plasma showed the presence of unmodified oleuropein, reaching a peak value of 200 ng/ml within 2 h, with a small amount of hydroxytyrosol, whereas in urine, both compounds were mainly found as glucuronides.

Topics: Administration, Oral; Animals; Calibration; Iridoid Glucosides; Iridoids; Phenylethyl Alcohol; Pyrans; Rats; Sensitivity and Specificity

A method based on high-performance liquid chromatography (HPLC) with a diode array detection system was developed and validated aiming at the simultaneous determination of oleuropein (OE) and its metabolites, hydroxytyrosol (HT) and tyrosol (T), in human plasma. These phenolic components are believed to play a vital role in the prevention of coronary artery disease and atherosclerosis. The proposed method includes a clean-up solid-phase extraction procedure (using a C(18) column) with high recovery efficiency (85-100%). The statistical evaluation of the method reveals good linearity, accuracy and reproducibility for all the compounds analyzed with RSD values less than 6.5%, while the detection limit is 50 ng/ml for both OE and T and 75 ng/ml for HT. This assay can be employed in bioavailability studies of olive oil phenolic compounds, thus assisting the evaluation of their pharmacological role.

Topics: Biological Availability; Chromatography, High Pressure Liquid; Iridoid Glucosides; Iridoids; Pyrans; Reference Standards; Reproducibility of Results; Sensitivity and Specificity; Spectrophotometry, Ultraviolet

Oleuropein, the main glycoside present in olives, and hydroxytyrosol, the principal degradation product of oleuropein present in olive oil, have been linked to reduction of coronary heart disease and certain cancers. In the present study a direct and sensitive reversed-phase high-performance liquid chromatographic assay was developed for simultaneous quantification of both oleuropein and hydroxytyrosol. The plasma protein was precipitated with acetonitrile, samples were then centrifuged and supernatants were dried, and reconstituted with water prior to injection. The chromatographic analysis was carried out using a phenyl column and an isocratic elution of acidified water and acetonitrile with fluorescence detection at 281 and 316 nm for excitation and emission, respectively. The calibration curve was linear and limits of quantification were 30 ng/ml and 3 microg/ml for hydroxytyrosol and oleuropein, respectively. The method has been successfully applied to monitor oleuropein and hydroxytyrosol plasma levels in the rat.

Topics: Animals; Calibration; Chromatography, High Pressure Liquid; Iridoid Glucosides; Iridoids; Phenylethyl Alcohol; Pyrans; Rats; Sensitivity and Specificity; Spectrometry, Fluorescence

Several epidemiological and experimental studies have associated the intake of antioxidants, which are abundant in the Mediterranean diet, with a low incidence of cardiovascular disease. One possible mechanism of this action is the oxidative protection in low density lipoproteins (LDL). The aim of our study was to compare the antioxidative activity of diverse phenolic compounds present in virgin olive oil on these lipoproteins.. LDL was isolated from blood plasma of healthy volunteers by sequential ultracentrifugation. This was followed by oxidation with CuC12 in the presence of different concentrations of phenolic compounds and virgin olive oil extract. Production of conjugated dienes was determined by the continuous monitoring of increased absorbency at 234 nm as an indicator of LDL oxidation.. Virgin olive oil extract prolonged the latency phase and significantly lowered the progression rate (p < 0.05) at low concentrations (2 g/ml). This antioxidative effect was also observed with low concentrations (2 M) of caffeic acid and oleuropein (p < 0.05). However, it was necessary to increase the concentration of flavone up to 50 times to observe a similar effect (p < 0.05).. Both virgin olive oil extract enriched in phenolic compounds and phenolic compounds present in olive oil (caffeic acid and oleuropein) are potent antioxidants at very low concentrations. Thus, the beneficial effects of a Mediterranean diet may be partly due to the protective action of these compounds.

Topics: Antioxidants; Caffeic Acids; Diet, Mediterranean; Dietary Fats, Unsaturated; Flavones; Flavonoids; Humans; In Vitro Techniques; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Lipoproteins, LDL; Olive Oil; Oxidation-Reduction; Phenols; Plant Oils; Pyrans; Vasodilator Agents

Epidemiology suggests that Mediterranean diets are associated with reduced risk of cardiovascular disease. Because monocyte adhesion to the endothelium is crucial in early atherogenesis, we evaluated whether typical olive oil and red wine polyphenols affect endothelial-leukocyte adhesion molecule expression and monocyte adhesion.. Phytochemicals in olive oil and red wine, including oleuropein, hydroxytyrosol, tyrosol, elenolic acid, and resveratrol, with or without antioxidant activity, were incubated with human umbilical vein endothelial cells for 30 minutes, followed by co-incubation with bacterial lipopolysaccharide or cytokines to trigger adhesion molecule expression. At nutritionally relevant concentrations, only oleuropein, hydroxytyrosol, and resveratrol, possessing a marked antioxidant activity, reduced monocytoid cell adhesion to stimulated endothelium, as well as vascular cell adhesion molecule-1 (VCAM-1) mRNA and protein by Northern analysis and cell surface enzyme immunoassay. Reporter gene assays with deletional VCAM-1 promoter constructs indicated the relevance of nuclear factor-kappaB, activator protein-1, and possibly GATA binding sites in mediating VCAM-1 transcriptional inhibition. The involvement of nuclear factor-kappaB and activator protein-1 was finally demonstrated at electrophoretic mobility shift assays.. Olive oil and red wine antioxidant polyphenols at nutritionally relevant concentrations transcriptionally inhibit endothelial adhesion molecule expression, thus partially explaining atheroprotection from Mediterranean diets.

Topics: Animals; Antioxidants; Arteriosclerosis; Cattle; Cell Adhesion; Cells, Cultured; Diet; Endothelium, Vascular; Flavonoids; Gene Expression Regulation; Humans; Iridoid Glucosides; Iridoids; NF-kappa B; Olive Oil; Phenols; Phenylethyl Alcohol; Plant Oils; Polyphenols; Pyrans; Resveratrol; RNA, Messenger; Stilbenes; Transcription Factor AP-1; Transcription, Genetic; U937 Cells; Vascular Cell Adhesion Molecule-1; Wine

Animal and in vitro studies suggest that phenolic compounds in virgin olive oil are effective antioxidants. In animal and in vitro studies, hydroxytyrosol and its metabolites have been shown to be strong antioxidants. One of the prerequisites to assess their in vivo physiologic significance is to determine their presence in human plasma.. We developed an analytical method for both hydroxytyrosol and 3-O-methyl-hydroxytyrosol in plasma. The administered dose of phenolic compounds was estimated from methanolic extracts of virgin olive oil after subjecting them to different hydrolytic treatments. Plasma and urine samples were collected from 0 to 12 h before and after 25 mL of virgin olive oil intake, a dose close to that used as daily intake in Mediterranean countries. Samples were analyzed by capillary gas chromatography-mass spectrometry before and after being subjected to acidic and enzymatic hydrolytic treatments.. Calibration curves were linear (r >0.99). Analytical recoveries were 42-60%. Limits of quantification were <1.5 mg/L. Plasma hydroxytyrosol and 3-O-methyl-hydroxytyrosol increased as a response to virgin olive oil administration, reaching maximum concentrations at 32 and 53 min, respectively (P <0.001 for quadratic trend). The estimated hydroxytyrosol elimination half-life was 2.43 h. Free forms of these phenolic compounds were not detected in plasma samples.. The proposed analytical method permits quantification of hydroxytyrosol and 3-O-methyl-hydroxytyrosol in plasma after real-life doses of virgin olive oil. From our results, approximately 98% of hydroxytyrosol appears to be present in plasma and urine in conjugated forms, mainly glucuronoconjugates, suggesting extensive first-pass intestinal/hepatic metabolism of the ingested hydroxytyrosol.

Topics: Adult; Antioxidants; Female; Gas Chromatography-Mass Spectrometry; Humans; Iridoid Glucosides; Iridoids; Male; Middle Aged; Olive Oil; Phenylethyl Alcohol; Plant Oils; Pyrans

Interest in the in vivo biological activities of olive oil phenolics is rapidly growing, and different models and vehicles of administration are used worldwide. Matters of practicality determine the use of rats rather than humans as the model of choice. Also, growing interest in nutraceuticals is leading to the formulation of compounds containing olive oil phenols. In this study, we compared metabolism and urinary excretion of hydroxytyrosol [(HT), the most representative phenol of olive oil] between rats and humans by evaluating excretion of HT and its major metabolite, homovanillyl alcohol. Also, we compared human excretion of HT when consumed as a natural component of extra virgin olive oil, when added to refined olive oil, or when added to yogurt (as an approximation of functional food). Urinary excretion of HT was greater in humans than in rats, a species with a high basal excretion of HT and its metabolites. The high (234% of HT administered) excretion of free HT suggests that hydrolysis of oleuropein administered in humans (still an unresolved issue) occurs in vivo. Moreover, human HT excretion was much higher after its administration as a natural component of olive oil (44.2% of HT administered) than after its addition to refined olive oil (23% of HT administered) or yogurt (5.8% of dose or approximately 13% of that recorded after virgin olive oil intake). These data suggest that the rat is not the appropriate model for the study of HT metabolism and that HT-containing functional foods should be carefully formulated.

Topics: Animals; Antioxidants; Drug Combinations; Humans; Hydrolysis; Iridoid Glucosides; Iridoids; Olive Oil; Pharmaceutical Vehicles; Phenylethyl Alcohol; Plant Oils; Pyrans; Rats; Species Specificity; Yogurt

The activity of oleuropein, a phenolic glycoside contained in olive oil, was investigated in vitro against Mycoplasma hominis, Mycoplasma fermentans, Mycoplasma pneumoniae and Mycoplasma pirum. Oleuropein inhibited mycoplasmas at concentrations from 20 to 320 mg/l. The MICs of oleuropein to M. pneumoniae, M. pirum, M. hominis and M. fermentans were 160, 320, 20 and 20 mg/l, respectively.

Topics: Anti-Bacterial Agents; Iridoid Glucosides; Iridoids; Microbial Sensitivity Tests; Mycoplasma; Pyrans

This study presents the phenolic compounds profile of commercial Cornicabra virgin olive oils from five successive crop seasons (1995/1996 to 1999/2000; n = 97), determined by solid phase extraction reversed phase high-performance liquid chromatography (SPE RP-HPLC), and its relationship with oxidative stability, processing conditions, and a preliminary study on variety classification. The median of total phenols content was 38 ppm (as syringic acid), although a wide range was observed, from 11 to 76 ppm. The main phenols found were the dialdehydic form of elenolic acid linked to tyrosol (p-HPEA-EDA; 9 +/- 7 ppm, as median and interquartile range), oleuropein aglycon (8 +/- 6 ppm), and the dialdehydic form of elenolic acid linked to hydroxytyrosol (3,4-DHPEA-EDA; 5 +/- 8 ppm). In many cases the correlation with oxidative stability was higher when the sum of the dialdehydic form of elenolic acid linked to hydroxytyrosol (3,4-DHPEA-EDA) and oleuropein aglycon (r (2) = 0.91-0.96) or the sum of these two and hydroxytyrosol (r (2) = 0.90-0.97) was considered than was observed with HPLC total phenols (r (2)= 0.91-0.95) and especially with colorimetric determination of total polyphenols and o-diphenols (r (2) = 0.77-0.95 and 0.78-0.92, respectively). 3,4-DHPEA-EDA, p-HPEA-EDA, the aglycons of oleuropein and ligstroside, and HPLC total phenols content presented highly significant differences (p = 0.001-0.010) with respect to the dual- and triple-phase extraction systems used, whereas colorimetric total polyphenols content did not (p = 0.348) and o-diphenols showed a much lower significant difference (p = 0.031). The five variables that most satisfactorily classified the principal commercial Spanish virgin olive oil varieties were 1-acetoxypinoresinol, 4-(acetoxyethyl)-1,2-dihydroxybenzene (3,4-DHPEA-AC), ligstroside aglycon, p-HPEA-EDA, and RT 43.3 contents.

Topics: Chromatography, High Pressure Liquid; Colorimetry; Drug Stability; Flavonoids; Iridoid Glucosides; Iridoids; Olive Oil; Oxidation-Reduction; Phenols; Phenylethyl Alcohol; Plant Oils; Polymers; Polyphenols; Pyrans; Seasons

A new method based on the inhibitory effects of antioxidants on the oscillations of the hydrogen peroxide, acidic iodate, malonic acid, and Mn(II)-catalyzed system (known as the Briggs-Rauscher reaction), was used for the evaluation of antioxidative capacity. With this method, which works near the pH of the fluids in the stomach (pH approximately 2), a group of natural compounds present in fruits and vegetables or in medicinal plants assumed to have antioxidant capacity, was tested successfully. The aim of the present study is to evaluate the antioxidative properties of some active principles contained in vegetables and aromatic plants, namely, cynarin (from Cynara scolymus), rosmarinic acid (from Rosmarinus officinalis), echinacoside (from Echinacea species), puerarin (from Pueraria lobata), and oleuropein (from Olea europea). Also studied with the Briggs-Rauscher reaction method was the antioxidant activity of cyanidin 3-O-beta-glucopyranoside (from Citrus aurantium) in order to compare the results with those obtained by other methods. The conclusions on the dependency of the antioxidative activity on the pH of the testing system are given.

Topics: Antioxidants; Cinnamates; Cynara; Depsides; Echinacea; Flavonoids; Fruit; Glycosides; Hydrogen Peroxide; Hydrogen-Ion Concentration; Iodates; Iridoid Glucosides; Iridoids; Isoflavones; Malonates; Manganese; Olea; Phenols; Plants, Medicinal; Polymers; Pueraria; Pyrans; Rosmarinic Acid; Rosmarinus; Vegetables

A very simple method is proposed to produce, using non-homogeneous hyperthermophilic beta-glycosidase immobilised on chitosan, 3,4-dihydroxy-phenylethanol (hydroxytyrosol), a commercially unavailable compound with well known biological properties which justify a potential commercial application. Leaf extracts from Olea europaea with high oleuropein content are selected as substrate for biotransformation. Under the biotransformation conditions, high amounts of hydroxytyrosol are collected within a short space of time after being preliminarily purified by a non-treated chitosan column. This is possible due to the capacity of amino groups on the chitosan to bind aldehydic groups of molecules present at the end of the reaction. We have produced a natural and non-toxic product from vegetal source, as opposed to the molecule obtainable through chemical synthesis, as a candidate to test in vivo its biological properties. The proposed process may prove useful for a further application for recycling Olea europaea leaves. The radical-scavenging properties of the bioreactor eluates and their capacity to inhibit fatty acid peroxidation rates are characterized in order to make them candidates as substitutes for synthetic antioxidants commonly used to increase the shelf-life of food products as well as for their possible protective effect in human cells.

Topics: Antioxidants; Bioreactors; Biotransformation; Chromatography, Gas; Chromatography, High Pressure Liquid; Colorimetry; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Oleaceae; Phenylethyl Alcohol; Plant Extracts; Plant Leaves; Pyrans

Animal and in vitro studies suggest that olive oil phenols are effective antioxidants. The most abundant phenols in olive oil are the nonpolar oleuropein- and ligstroside-aglycones and the polar hydroxytyrosol and tyrosol. The aim of this study was to gain more insight into the metabolism of those phenols in humans. We measured their absorption in eight healthy ileostomy subjects. We also measured urinary excretion in the ileostomy subjects and in 12 volunteers with a colon. Subjects consumed three different supplements containing 100 mg of olive oil phenols on separate days in random order. Ileostomy subjects consumed a supplement with mainly nonpolar phenols, one with mainly polar phenols and one with the parent compound oleuropein-glycoside. Subjects with a colon consumed a supplement without phenols (placebo) instead of the supplement with oleuropein-glycoside. Ileostomy effluent and urine were collected for 24 h after supplement intake. Tyrosol and hydroxytyrosol concentrations were low (< 4 mol/100 mol of intake) in the ileostomy effluent, and no aglycones were detected. We estimated that the apparent absorption of phenols was at least 55-66% of the ingested dose. Absorption was confirmed by the excretion of tyrosol and hydroxytyrosol in urine. In ileostomy subjects, 12 mol/100 mol and in subjects with a colon, 6 mol/100 mol of the phenols from the nonpolar supplement were recovered in urine as tyrosol or hydroxytyrosol. In both subject groups, 5--6 mol/100 mol of the phenols was recovered from the polar supplement. When ileostomy subjects were given oleuropein-glycoside, 16 mol/100 mol was recovered in 24-h urine, mainly in the form of hydroxytyrosol. Thus, humans absorb a large part of ingested olive oil phenols and absorbed olive oil phenols are extensively modified in the body.

Topics: Absorption; Adult; Colon; Dietary Supplements; Drug Stability; Female; Humans; Ileostomy; Iridoid Glucosides; Iridoids; Male; Olive Oil; Phenols; Phenylethyl Alcohol; Placebos; Plant Oils; Pyrans

Typical components of the Mediterranean diet, such as olive oil and red wine, contain high concentrations of complex phenols, which have been suggested to have an important antioxidant role. The aim of the present work was to determine the inhibitory potency of compounds such as oleuropein, hydroxytyrosol, and other structurally related compounds, such as gallic acid, toward reactive oxygen species generation and free radical scavenging ability. The potency of these compounds was also examined with respect to protecting in vitro low-density lipoprotein oxidation. These studies indicate that complex phenols, such as hydroxytyrosol, and gallic acid both inhibit free radical generation and act as free radical scavengers. The use of three different approaches to determine antioxidant potency demonstrates that activity in one test does not necessarily correlate with activity in another. It was also demonstrated that the presence of two phenolic groups is not always associated with antioxidant activity.

Topics: Animals; Antioxidants; Aryl Hydrocarbon Hydroxylases; Bepridil; Biphenyl Compounds; Cytochrome P-450 CYP3A; Cytochrome P-450 Enzyme Inhibitors; Enzyme Inhibitors; Free Radical Scavengers; Gallic Acid; Humans; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Lipoproteins, LDL; Male; Microsomes, Liver; Olive Oil; Oxidoreductases, N-Demethylating; Phenylethyl Alcohol; Picrates; Plant Oils; Pyrans; Rats; Rats, Wistar; Reactive Oxygen Species; Steroid 16-alpha-Hydroxylase; Steroid Hydroxylases

The disappearance of the bitter taste of newly produced olive oil during storage is due to the enzymatic hydrolysis of the bitter-tasting secoiridoid compound known as oleuropein. Current knowledge attributes the enzymatic hydrolysis of the oleuropein to the beta-glucosidase present in the olives. The present study, however, has demonstrated for the first time that oleuropein present in olive oil can be hydrolysed by beta-glucosidase from the yeasts Saccharomyces cerevisiae and Candida wickerhamii. The enzymatic analyses carried out directly on the untreated olive oil and on sterilized olive oil inoculated with the above-mentioned yeasts proved the beta-glucosidase activity through the hydrolysis of both the synthetic substrate p-nitrophenyl-beta-D-glucopyranoside (PNPG) and the oleuropein. The absence of lipases in the isolated S. cerevisiae and C. wickerhamii examined lead us to believe that the yeasts contribute in a positive way towards the improvement of the organological quality of the oil without altering the composition of the triglycerides.

Topics: beta-Glucosidase; Candida; Food Handling; Food Microbiology; Hydrolysis; Iridoid Glucosides; Iridoids; Olive Oil; Plant Oils; Pyrans; Saccharomyces cerevisiae; Taste; Time Factors

Olea europaea (Oleaceae) leaves of 14 different cultivars have been studied by a new isocratic HPLC method. Qualitative and quantitative determinations of principal compounds were established for each cultivar. Oleuropein concentration was determined for each sampled tree, using coumarin as internal standard. Bid el Haman, Chemlali, Meski, Cailletier, Tanche, a Verdale-Picholine hybrid, and Lucques, in particular, had high oleuropein concentrations and could be useful sources for industrial extractions.

Topics: Antihypertensive Agents; Chromatography, High Pressure Liquid; Iridoid Glucosides; Iridoids; Magnoliopsida; Phenols; Plant Leaves; Plants, Medicinal; Pyrans; Species Specificity; Trees

The effects of the polyphenolic compounds from virgin olive oil: tyrosol, hydroxytyrosol and oleuropein on the non-enzymatic lipid peroxidation induced by ascorbate-Fe2+ of rat liver microsomes were examined. The inhibition of light emission (maximal induced chemiluminescence) by oleuropein was concentration dependent. Hydroxytyrosol showed a substantial degree of inhibition against ascorbate-Fe2+ induced lipid peroxidation in rat liver microsomes that was at least 6 times higher than that observed in the presence of oleuropein. Inhibition of lipid peroxidation by tyrosol was not observed. In rat liver microsomes incubated alone or in the presence of tyrosol, the fatty acid composition was profoundly modified when subjected to in vitro peroxidation mediated by ascorbate-Fe2+, with a considerable decrease of 18:2n6 and 20:4n6; however, changes in fatty acid composition were not observed when microsomes were incubated with hydroxytyrosol. When oleuropein was used at low concentration (5, 15 microM) a considerable decrease of 20:4n6 was observed, but 18:2n6 was not modified; at higher concentration (30, 60 microM) changes in fatty acid composition were not observed. There was a very good correlation between the presence of oxidized phospholipids and the changes in polyunsaturated fatty acids previously observed. Thus, hydroxytyrosol showed the highest protection again oxidized phospholipid formation. The presence of oleuropein at low concentration (5, 15 microM) does not prevent the formation of oxidized phospholipids (8.02 +/- 1.22 and 1.22 +/- 1.22) but concentration higher than 30 microM avoids completely the formation of this molecules whereas tyrosol at any concentration assayed was found to be ineffective and allows the formation not only of oxidized phospholipids but also of oxidized cholesterol.

Topics: Animals; Cholesterol; Fatty Acids; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Microsomes, Liver; Oxidation-Reduction; Phenylethyl Alcohol; Phospholipids; Pyrans; Rats; Rats, Wistar

The phenolic composition of olive fruits (Olea europaea L.) (cv. Picual, Villalonga, Alfafarenca, and Cornicabra) grown in different areas of Spain was studied by high performance liquid chromatography-mass spectrometry. Different levels of tyrosol, catechin, p-coumaric acid, rutin, luteolin, and oleuropein were observed in the different varieties analyzed. Treating the fruit with 0.3% Brotomax 50 days after anthesis had a beneficial effect on fruit size, oil content, levels of polyphenolic compounds, and Trolox-equivalent antioxidant activity (TEAC) in all the varieties analyzed.

Topics: Antioxidants; Catechin; Chromatography, High Pressure Liquid; Coumaric Acids; Flavonoids; Fruit; Iridoid Glucosides; Iridoids; Luteolin; Olive Oil; Phenols; Phenylethyl Alcohol; Plant Oils; Propionates; Pyrans; Rutin

The main reaction products obtainable by the hydrolysis of commercially available oleuropein by hyperthermophilic beta-glycosidase were purified and structurally characterized by UV and 1H and 13C NMR analyses. Their antioxidant activity, in particular their capacity to inhibit the fatty acid peroxidation rate, was studied. The molecular structures assigned revealed the presence of two elenolic acid forms presenting different antioxidant abilities closely correlated to their molecular structures, as well as an unstable elenolate which is a rearrangement product of the oleuropein aglycon. This molecule, under the reaction conditions (pH 7.0, 60 degrees C) required for beta-glycosidase activity, rapidly gives rise to 3,4-dihydroxy-phenylethanol (hydroxytyrosol).

Topics: Antioxidants; Glycoside Hydrolases; Hydrolysis; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Magnetic Resonance Spectroscopy; Pyrans

The major phenolics from the polar fraction of virgin olive oil (caffeic acid, oleuropein, tyrosol and hydroxytyrosol) have well-established antioxidant activities but their effects on reactive nitrogen species and nitrergic neurotransmission have not been fully investigated. The three catechol compounds were active as scavengers of nitric oxide generated spontaneously from the decomposition of sodium nitroprusside (approximately 50% inhibition achieved at 75 microM), and had similar ability to scavenge chemically generated peroxynitrite, as determined by an alpha1-antiproteinase inactivation assay (67.2%-92.4% reduction when added at 1 mM). Tyrosol was less active in these tests, but does not possess the catechol functionality. Despite their ability to interact with chemically prepared nitric oxide, neither oleuropein nor hydroxytyrosol at 5 microM altered NO*-mediated relaxations of the nerve-stimulated rat anococcygeus preparation, but this may be because the nitrergic transmitter is protected from the effects of externally applied scavengers. In conclusion, the phenolics found in virgin olive oil possess ability to scavenge reactive oxygen and nitrogen species that are implicated in human pathologies, but their impact may be restricted to those species present in the extracellular environment.

Topics: Animals; Antioxidants; Caffeic Acids; Dose-Response Relationship, Drug; Free Radical Scavengers; Iridoid Glucosides; Iridoids; Male; Muscle Relaxation; Muscle, Smooth; Neural Conduction; Nitrates; Nitric Oxide; Nitroprusside; Olive Oil; Phenols; Phenylethyl Alcohol; Plant Oils; Pyrans; Rats; Rats, Wistar

Complex phenols, such as the glycoside oleuropein and hydroxytyrosol, are found in high concentrations in the typical components of the Mediterranean diet. We have previously reported that oleuropein inhibits androstenedione 6 beta-hydroxylase activity, a CYP3A marker in human liver microsomes (Stupans, I., Stretch, G., Hayball, P., 2000. Olive oil phenols inhibit human hepatic microsomal activity. Journal of Nutrition. 130 2367-2370). Oleuropein, but not the structurally similar compounds hydroxytyrosol and secologanin, was found to be a mechanism-based inhibitor of androstenedione 6 beta-hydroxylase activity. Preincubation with 100 microM oleuropein and NADPH resulted in a significantly lower androstenedione 6 beta-hydroxylase activity when compared to preincubation carried out with oleuropein without NADPH, 0.11+/-0.01 nmol/mg microsomal protein/min compared with 0.29+/-0.03 nmol/mg microsomal protein/min (P<0.05). The inactivation exhibited pseudo-first-order kinetics. The maximal rate constant for inactivation (k(inactivation)) was calculated to be 0.09 min(-1) and the concentration of inactivator required for half maximal inactivation (Ki) was calculated to be 22.2 microM. Oleuropein was found to be a relatively weak inhibitor of CYP1A2-mediated 7-methoxyresorufin-O-deethylation (24% inhibition at 100 microM oleuropein), but not CYP2E1-mediated chlorzoxazone 6-hydroxylation. CYP1A2 did not undergo mechanism-based inactivation by oleuropein.

Topics: Aryl Hydrocarbon Hydroxylases; Cytochrome P-450 CYP1A1; Cytochrome P-450 CYP2E1; Cytochrome P-450 CYP3A; Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Diet; Enzyme Inhibitors; Humans; In Vitro Techniques; Iridoid Glucosides; Iridoids; Kinetics; Male; Mediterranean Region; Microsomes, Liver; NADP; Oxidoreductases, N-Demethylating; Pyrans; Steroid Hydroxylases

Storage of olive (Olea europaea) leaves for 22 h at 37 degrees C in closed plastic bags caused the content of a nonglycosidic secoiridoid, 3,4-dihydroxyphenylethyl 4-formyl-3-formylmethyl-4-hexenoate (3,4-DHPEA-EDA) to rise from 15% to 50% of the phenolic extract with corresponding falls in the content of oleuropein and two oleuropeindials, which were identified as precursors of 3,4-DHPEA-EDA. Pure product was isolated from one set of stored olive leaves in a 0.16% yield. Storage of olive leaves under various conditions showed that the moisture present in closed plastic bags was important for the formation of 3,4-DHPEA-EDA. The time taken to reach the maximum concentration of the product varied widely for different samples of olive leaves, with a shorter time for the sample with lower initial oleuropein content. The oleuropeindial precursors of the product were readily hydrolyzed to carboxylic acid derivatives, which have been identified by NMR. The antiradical activity of 3,4-DHPEA-EDA, evaluated by scavenging of 2,2-diphenyl-1-picrylhydrazyl radicals, was comparable to that of alpha-tocopherol.

Topics: Antioxidants; Food Handling; Iridoid Glucosides; Iridoids; Magnetic Resonance Spectroscopy; Olive Oil; Phenols; Plant Leaves; Plant Oils; Plants, Edible; Pyrans; Water

Treatment of the secoiridoids oleuropein (4), ligstroside (5) and methyloleoside (6) by beta-D-glucosidase in the presence of ammonium chloride led exclusively to monomeric pyridine alkaloids 7, 1, and 8. Dimeric 3,4,5-trisubstituted pyridines were obtained from methyloleoside (6) when ammonium chloride was generated in the reaction mixture by successive additions of ammonia and hydrochloric acid. The use of ammonium acetate permitted conversion of secoiridoids 4 and 5 into the naphthyridine alkaloid jasminine (3).

Topics: Alkaloids; Amination; Ammonia; beta-Glucosidase; Catalysis; Chromatography; Glucosides; Hydrochloric Acid; Iridoid Glucosides; Iridoids; Molecular Structure; Naphthyridines; Niacin; Nuclear Magnetic Resonance, Biomolecular; Oleaceae; Pyrans; Pyridines

The recombinant beta-glycosidase (EcS beta gly) from Sulfolobus solfataricus was immobilised on chitosan to perform the enzymatic hydrolysis of commercial oleuropein (heterosidic ester of elenolic acid and 3,4-dihydroxy-phenylethanol (hydroxytyrosol)) at two temperatures (60 and 70 degrees C). Interestingly, on the basis of the reasonable assumption that the enzyme hydrolyses only the sugar linkage, the biotransformation produces unstable aglycone species formed by oleuropein hydrolysis that, differently from some commercially available beta-glucosidases tested, give rise to the formation of hydroxytyrosol, at the operative temperatures of the bioreactor. The results of the biotransformation at 70 degrees C showed that the main products are hydroxytyrosol, and glucose, being the oleuropein aglycone present in low amount at the end of reaction. Both in single step approach or in recycle approach the amounts of glucose and oleuropein aglycone were lightly dependent from flow rate. The amount of hydroxytyrosol, increased on decreasing the flow rate of bioreactor in recycle approach, following a non-linear trend and obtaining the highest value at a flow rate of 15 ml h-1 while in the single step approach the 3,4-dihydroxy-phenylethanol was at its maximum at higher flow rate (16 ml h-1). For the hydrolysis of the oleuropein by bioreactor at 60 degrees C we used lower molar ratio oleuropein/enzyme only by the single step approach. In these conditions it is possible to obtain high amounts of only two products (glucose and hydroxytyrosol) in short time (2 h). The stability of the bioreactor at the operative temperatures showed a t1/2 of 30 days at 70 degrees C and a t1/2 of 56 days at 60 degrees C.

Topics: Bioreactors; Chitin; Chitosan; Enzymes, Immobilized; Glycoside Hydrolases; Hydrolysis; Iridoid Glucosides; Iridoids; Kinetics; Pyrans; Recombinant Proteins; Sulfolobus

On the basis of the results obtained with pilot studies conducted in vitro on human low density lipoprotein (LDL) and on cell cultures (Caco-2), which had indicated the ability of certain molecules present in olive oil to inhibit prooxidative processes, an in vivo study was made of laboratory rabbits fed special diets. Three different diets were prepared: a standard diet for rabbits (diet A), a standard diet for rabbits modified by the addition of 10% (w/w) extra virgin olive oil (diet B), a modified standard diet for rabbits (diet C) differing from diet B only in the addition of 7 mg kg(-1) of oleuropein. A series of biochemical parameters was therefore identified, both in the rabbit plasma and the related isolated LDL, before and after Cu-induced oxidation. The following, in particular, were selected: (i) biophenols, vitamins E and C, uric acid, and total, free, and ester cholesterol in the plasma; (ii) proteins, triglycerides, phospholipids, and total, free, and ester cholesterol in the native LDL (for the latter, the dimensions were also measured); (iii) lipid hydroperoxides, aldehydes, conjugated dienes, and relative electrophoretic mobility (REM) in the oxidized LDL (ox-LDL). In an attempt to summarize the results obtained, it can be said that this investigation has not only verified the antioxidant efficacy of extra virgin olive oil biophenols and, in particular, of oleuropein, but has also revealed a series of thus far unknown effects of the latter on the plasmatic lipid situation. In fact, the addition of oleuropein in diet C increased the ability of LDL to resist oxidation (less conjugated diene formation) and, at the same time, reduced the plasmatic levels of total, free, and ester cholesterol (-15, -12, and -17%, respectively), giving rise to a redistribution of the lipidic components of LDL (greater phospholipid and cholesterol amounts) with an indirect effect on their dimensions (bigger by about 12%).

Topics: Animals; Ascorbic Acid; Cholesterol; Chromatography, High Pressure Liquid; Copper; Dietary Fats; Female; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Lipoproteins, LDL; Olive Oil; Plant Oils; Pyrans; Rabbits; Triglycerides; Uric Acid; Vitamin E

Epidemiological studies have linked the Mediterranean diet with a low incidence of cardiovascular diseases. Olive oil, the major fat component of this diet, is characterized by antioxidant properties related to their content in catecholic components, particularly oleuropein aglycon. Therefore quantification of these components in edible oils may be important in determining the quality, and consequently its commercial value. The present method allows us to obtain the profile of the phenolic components of the oil from the methanolic extracts of the crude olive oil. In particular tyrosol, hydroxytyrosol, elenolic acid, deacetoxyligstroside and deacetoxyoleuropein aglycons, ligstroside and oleuropein aglycons, and 10-hydroxy-oleuropein are clearly identified by atmospheric pressure chemical ionization-mass spectrometry (APCI-MS). Moreover, oleuropein and its isomers present in the oil are quantified by APCI-MS/MS analysis of the extracts without preliminary separation from other phenolic compounds.

Topics: Dietary Fats, Unsaturated; Iridoid Glucosides; Iridoids; Mass Spectrometry; Molecular Structure; Olive Oil; Phenols; Plant Oils; Pressure; Pyrans; Sunflower Oil; Vasodilator Agents

Technomimetic NMR experiments were performed in accordance with the lye treatment adopted during table olive industrial procedures for the debittering process causing oleuropein degradation. The site selective hydrolysis of the two ester groups, characterizing the biophenolic secoiridoid molecule, was shown to be dependent on the different reactivities of these functionalities. The process is controlled by the experimental conditions exerted on the olive pulp and determined by the buffering capacity of the olive mesocarp and by the epicarp molecular components influencing the reactant penetration into the fruit pulp. The overall hydrolytic process of oleuropein, the bitter principle of olives, using the technomimetic experimental mode, gave rise to its catabolic derivatives, hydroxytyrosol, 11-methyloleoside, and the monoterpene glucoside, technomimetically produced, isolated, and structurally characterized by (1)H, (13)C, and COSY spectroscopy as the oleoside.

Topics: Hydrolysis; Iridoid Glucosides; Iridoids; Magnetic Resonance Spectroscopy; Pyrans

This study was undertaken to evaluate, in humans, the antioxidant activity of olive oil phenolics, namely hydroxytyrosol and oleuropein aglycone that share an orthodiphenolic (catecholic) structure. Human volunteers were administered olive oil samples containing increasing amounts of an olive oil phenolic extract that was characterized by gas-chromatography/mass spectrometry. The administration of phenol-rich oils was dose-dependently associated with a decreased urinary excretion of 8-iso-PGF(2alpha), a biomarker of oxidative stress. Also, a statistically significant negative correlation between homovanillyl alcohol (HValc, hydroxytyrosol's major metabolite, formed through the COMT system) and F(2)-isoprostanes excretion was found. Thus, the administration of oil samples with increasing, albeit low, concentrations of orthodiphenolic compounds, namely hydroxytyrosol and oleuropein aglycone, results in a dose-dependent reduction in the urinary excretion of 8-iso-PGF(2alpha). The statistically significant negative correlation between 8-iso-PGF(2alpha) and HValc urinary concentrations suggests that this metabolite better reflects the in vivo activities of hydroxytyrosol.

Topics: Adult; Antioxidants; Biomarkers; Catechols; Dietary Fats, Unsaturated; Dinoprost; F2-Isoprostanes; Gas Chromatography-Mass Spectrometry; Humans; Iridoid Glucosides; Iridoids; Olive Oil; Oxidative Stress; Plant Oils; Pyrans

Epidemiological studies have shown that the incidence of heart disease and certain cancers is lower in the Mediterranean region. This has been attributed to the high consumption of olive oil in the Mediterranean diet, which contains polyphenolic compounds with antioxidant activity. Although many in vitro studies have been performed to elucidate mechanisms by which these compounds may act, there are virtually no data relating to their fate after ingestion. Therefore, we decided to investigate the intestinal absorption of one of the major olive oil polyphenolics, oleuropein. To do this, a novel in situ intestinal perfusion technique was developed, and the absorption of oleuropein was studied under both iso-osmotic and hypotonic luminal conditions. Oleuropein was absorbed, with an apparent permeability coefficient (P:(app)) of 1.47 +/- 0.13 x 10(-6) cm/s (+/-SE) observed under iso-osmotic conditions. The mechanism of absorption is unclear but may involve transcellular transport (SGLT1) or paracellular movement. Under hypotonic conditions, the permeability of oleuropein was significantly greater (5.92 +/- 0.49 x 10(-6) cm/s, P: < 0.001). This increase is thought to be due to an increase in paracellular movement facilitated by the opening of paracellular junctions in response to hypotonicity. Overall, we determined that the olive oil polyphenolic oleuropein can be absorbed, albeit poorly, from isolated perfused rat intestine. Therefore, it is possible that it or its metabolites may confer a positive health benefit after the consumption of olive oil, most likely via an antioxidant mechanism.

Topics: Animals; Antioxidants; Biological Availability; Flavonoids; Hypotonic Solutions; Intestinal Absorption; Iridoid Glucosides; Iridoids; Membrane Glycoproteins; Models, Animal; Monosaccharide Transport Proteins; Olive Oil; Permeability; Phenols; Plant Oils; Polymers; Polyphenols; Pyrans; Rats; Sodium-Glucose Transporter 1; Time Factors

Interest in the health-promoting effects of virgin olive oil, an important part of the 'Mediterranean diet', prompted us to determine the anti-eicosanoid and antioxidant effects in leukocytes of the principal phenolic compounds from the 'polar fraction': oleuropein, tyrosol, hydroxytyrosol, and caffeic acid. In intact rat peritoneal leukocytes stimulated with calcium ionophore, all four phenolics inhibited leukotriene B4 generation at the 5-lipoxygenase level with effectiveness hydroxytyrosol > oleuropein > caffeic acid > tyrosol (approximate EC50 values: 15, 80, 200, and 500 microM, respectively). In contrast, none of these compounds caused substantial inhibition of thromboxane generation via the cyclo-oxygenase pathway. Hydroxytyrosol, caffeic acid, oleuropein, and tyrosol (decreasing order of effectiveness) also quenched the chemiluminescence signal due to reactive oxygen species generated by phorbol myristate acetate-stimulated rat leukocytes. None of these compounds were toxic to leukocytes at the concentrations tested. We conclude that the phenolics found in virgin olive oil possess an array of potentially beneficial lipoxygenase-inhibitory, prostaglandin-sparing, and antioxidant properties.

Topics: Animals; Antioxidants; Caffeic Acids; Dietary Fats, Unsaturated; Eicosanoids; Iridoid Glucosides; Iridoids; Leukocytes; Lipoxygenase Inhibitors; Male; Olive Oil; Phenylethyl Alcohol; Plant Oils; Pyrans; Rats; Rats, Wistar; Reactive Oxygen Species

Substantial evidence suggests that oxidative modifications of low density lipoproteins (LDL) critically contribute to the pathogenesis and progression of human atherosclerosis. Oxidized LDL (oxLDL) are present in atherosclerotic plaques and contain oxysterols that exhibit a variety of adverse biological activities. Antioxidants have also been shown to prevent LDL modification. We have therefore assessed the efficacy of virgin olive oil phenolic compounds in preventing oxidative modifications of human LDL oxidized by UV light.. Cholesterol oxides formed during LDL photo-oxidation were determined by UV-HPLC in the presence of different concentrations of phenolic compounds and their pure components (tyrosol and oleuropein), and probucol, a widely used synthetic antioxidant. Electrophoretic mobility was also assayed. The results demonstrate that phenolic compounds are much more potent in preventing cholesterol oxide formation and apoproteic moiety modification than their pure components and probucol.. The beneficial effects of a Mediterranean diet may be ascribable not only to the high unsaturated/saturated fatty acid ratio characteristic of olive oil, but also to the unique antioxidant properties of its phenolic compounds.

Topics: Anticholesteremic Agents; Antioxidants; Cholesterol; Chromatography, High Pressure Liquid; Electrophoresis, Agar Gel; Humans; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Lipoproteins, LDL; Olive Oil; Phenols; Phenylethyl Alcohol; Plant Oils; Probucol; Pyrans; Ultraviolet Rays

Secoiridoides (oleuropein and derivatives), one of the major classes of polyphenol contained in olives and olive oil, have recently been shown to inhibit or delay the rate of growth of a range of bacteria and microfungi but there are no data in the literature concerning the possible employment of these secoiridoides as antimicrobial agents against pathogenic bacteria in man. In this study five ATCC standard bacterial strains (Haemophilus influenzae ATCC 9006, Moraxella catarrhalis ATCC 8176, Salmonella typhi ATCC 6539, Vibrio parahaemolyticus ATCC 17802 and Staphylococcus aureus ATCC 25923) and 44 fresh clinical isolates (Haemophilus influenzae, eight strains, Moraxella catarrhalis, six strains, Salmonella species, 15 strains, Vibrio cholerae, one strain, Vibrio alginolyticus, two strains, Vibrio parahaemolyticus, one strain, Staphylococcus aureus, five penicillin-susceptible strains and six penicillin-resistant strains), causal agents of intestinal or respiratory tract infections in man, were tested for in-vitro susceptibility to two olive (Olea europaea) secoiridoides, oleuropein (the bitter principle of olives) and hydroxytyrosol (derived from oleuropein by enzymatic hydrolysis and responsible for the high stability of olive oil). The minimum inhibitory concentrations (MICs) calculated in our study are evidence of the broad antimicrobial activity of hydroxytyrosol against these bacterial strains (MIC values between 0.24 and 7.85 microg mL(-1) for ATCC strains and between 0.97 and 31.25 microg mL(-1) for clinically isolated strains). Furthermore oleuropein also inhibited (although to a much lesser extent) the growth of several bacterial strains (MIC values between 62.5 and 500 microg mL(-1) for ATCC strains and between 31.25 and 250 microg mL(-1) for clinical isolates); oleuropein was ineffective against Haemophilus influenzae and Moraxella catarrhalis. These data indicate that in addition to the potential employment of its active principles as food additives or in integrated pest-management programs, Olea europaea can be considered a potential source of promising antimicrobial agents for treatment of intestinal or respiratory tract infections in man.

Topics: Anti-Bacterial Agents; Bacteria; Dose-Response Relationship, Drug; In Vitro Techniques; Iridoid Glucosides; Iridoids; Microbial Sensitivity Tests; Phenylethyl Alcohol; Pyrans

New bioactive epimeric derivatives of oleuropein have been detected in olive fruits and structurally characterized by (1)H and (13)C NMR. These hydrolytic metabolites, obtained by enzymatic catalysis, can be molecular microcomponents, present in Mediterranean food, table olives, and olive oil, responsible for complex sensorial attributes and for pathogen natural defense.

Topics: Anti-Infective Agents; Iridoid Glucosides; Iridoids; Magnetic Resonance Spectroscopy; Models, Molecular; Molecular Conformation; Molecular Structure; Olive Oil; Plant Oils; Pyrans; Vegetables

The oleuropein hydrolytic conversion, under biomimetic conditions, induced by the endogenous enzymatic system of the olive fruit, has been monitored by the intermediate derivative formation through (1)H and (13)C NMR spectra; the assigned molecular structures reveal the identity of new bioactive biophenolic metabolites, the hemiacetal aglycon, and the two epimeric dialdehydes, which influence the pathogen antagonism of olive fruits and the hedonistic-sensorial characteristics of olive oil.

Topics: Carbon Isotopes; Hydrogen; Hydrolysis; Iridoid Glucosides; Iridoids; Magnetic Resonance Spectroscopy; Molecular Structure; Phenols; Pyrans; Vegetables

This work describes the unambiguous evaluation of the presence of oleuropein in virgin olive oils by ionspray tandem mass spectrometry (ISI-MS/MS). The oil samples obtained from different cultivars, such as Carolea, Cassanese, Coratina, Dolce di Rossano, Roggianella, and Tonda di Strongoli, grown in different geographical areas of Calabria, Italy, have shown an average content of oleuropein ranging from 1 ppb to 11 ppm. Commercial virgin oil samples, blended in some cases, contain significant amounts of this pharmacologically important antioxidant. The MS/MS methodology was applied in a triple-quadrupole instrument, through continuous scanning of the third analyzer to detect oleuropein in methanol extracts and in selected ion monitoring (SRM) for its quantitative assay.

Topics: Free Radical Scavengers; Humans; Iridoid Glucosides; Iridoids; Mass Spectrometry; Nutritive Value; Olive Oil; Plant Oils; Pyrans

The Mediterranean diet, rich in fresh fruits and vegetables, has been associated with a lower incidence of cardiovascular disease and cancer, partly because of its high proportion of bioactive compounds such as vitamins, flavonoids and polyphenols. The major lipid component of such diet is the drupe-derived olive oil, that can be distinguished from other seed oils for the peculiar composition of its non-triglyceride fraction. In fact, several minor components, including polyphenols, grant the oil its particular taste and aroma. Oleuropein, the most abundant among these components, has been shown to be a potent antioxidant endowed with antiinflammatory properties. We investigated the effects of oleuropein on NO release in cell culture and its activity toward nitric oxide synthase (iNOS) expression. The results show that oleuropein dose-dependently enhance nitrite production in LPS-challenged mouse macrophages. This effect was blocked by the iNOS inhibitor L-NAME, indicating increased iNOS activity. Also, Western blot analysis of cell homogenates show that oleuropein increases iNOS expression in such cells. Taken together, our data suggest that, during endotoxin challenge, oleuropein potentiates the macrophage-mediated response, resulting in higher NO production, currently believed to be beneficial for cellular and organismal protection.

Topics: Animals; Cells, Cultured; Iridoid Glucosides; Iridoids; Lipopolysaccharides; Macrophages; Mice; Nitric Oxide; Pyrans

The antimicrobial potential of eight phenolic compounds isolated from olive cake was tested against the growth of Escherichia coli, Klebsiella pneumoniae, Bacillus cereus, Aspergillus flavus and Aspergillus parasiticus. The phenolic compounds included p-hydroxy benzoic, vanillic, caffeic, protocatechuic, syringic, and p-coumaric acids, oleuropein and quercetin. Caffeic and protocatechuic acids (0.3 mg/ml) inhibited the growth of E. coli and K. pneumoniae. The same compounds apart from syringic acid (0.5 mg/ml) completely inhibited the growth of B. cereus. Oleuropein, and p-hydroxy benzoic, vanillic and p-coumaric acids (0.4 mg/ml) completely inhibited the growth of E. coli, K. pneumoniae and B. cereus. Vanillic and caffeic acids (0.2 mg/ml) completely inhibited the growth and aflatoxin production by both A. flavus and A. parasiticus, whereas the complete inhibition of the moulds was attained with 0.3 mg/ml p-hydroxy benzoic, protocatechuic, syringic, and p-coumaric acids and quercetin.

Topics: Aflatoxin B1; Anti-Bacterial Agents; Anti-Infective Agents; Antifungal Agents; Antioxidants; Aspergillus; Aspergillus flavus; Bacillus cereus; Bacteria; Caffeic Acids; Chromatography, High Pressure Liquid; Coumaric Acids; Escherichia coli; Fruit; Gallic Acid; Hydroxybenzoates; Iridoid Glucosides; Iridoids; Klebsiella pneumoniae; Parabens; Phenols; Propionates; Pyrans; Quercetin; Vanillic Acid

The growth of Salmonella enteritidis in a brain heart infusion medium was monitored using the traditional viable count method and by conductance measurements using a Rabit impedance instrument. Growth curves (log10 cfu ml-1 vs time) at three different concentrations of oleuropein (0, 0.2 and 0.8%), pH values in the range of 5-8 and incubation temperatures from 22 to 42 degrees C were modelled using the Gompertz equation. A good correlation between the maximum growth rate from the viable count method and the maximum slope of the conductance curve from the impedance instrument was established. Based on this correlation, the maximum specific growth rate of Salm. enteritidis was modelled as a function of the oleuropein concentration, initial pH values and the incubation temperature with a quadratic equation, using a new, large dataset of growth measurements by conductance. The developed model was validated by statistical comparison of predicted growth rates with growth rates determined by the viable count method, within the limits of the antimicrobial, pH and temperature domain.

Topics: Colony Count, Microbial; Culture Media; Dose-Response Relationship, Drug; Electric Impedance; Food-Processing Industry; Hydrogen-Ion Concentration; Iridoid Glucosides; Iridoids; Models, Biological; Pyrans; Salmonella enteritidis; Temperature

Oleuropein, tyrosol, squalene and the fraction of sterols and triterpenoid dialcohols from the unsaponifiable fraction obtained from virgin olive oil have been tested for possible cytostatic activity against McCoy cells, using 6-mercaptopurine as a positive control. The samples of sterols and triterpenic dialcohols showed a strong activity.

Topics: Antineoplastic Agents, Phytogenic; Cell Division; Cell Line; Humans; Iridoid Glucosides; Iridoids; Olive Oil; Phenylethyl Alcohol; Plant Oils; Pyrans; Squalene; Sterols; Triterpenes

This study was designed to investigate the in vitro effects of phenolic compounds extracted from olive oil and from olive derived fractions. More specifically, we investigated the effects on platelets of 2-(3,4-di-hydroxyphenyl)-ethanol (DHPE), a phenol component of extra-virgin olive oil with potent antioxidant properties. The following variables were studied: aggregation of platelet rich plasma (PRP) induced by ADP or collagen, and thromboxane B2 production by collagen or thrombin-stimulated PRP. In addition, thromboxane B2 and 12-hydroxyeicosatetraenoic acid (12-HETE) produced during blood clotting were measured in serum. Preincubation of PRP with DHPE for at least 10 min resulted in maximal inhibition of the various measured variables. The IC50s (concentration resulting in 50% inhibition) of DHPE for ADP or collagen-induced PRP aggregations were 23 and 67 microM, respectively. At 400 microM DHPE, a concentration which completely inhibited collagen-induced PRP aggregation, TxB2 production by collagen- or thrombin-stimulated PRP was inhibited by over 80 percent. At the same DHPE concentration, the accumulation of TxB2 and 12-HETE in serum was reduced by over 90 and 50 percent, respectively. We also tested the effects of PRP aggregation of oleuropein, another typical olive oil phenol, and of selected flavnoids (luteolin, apigenin, quercetin) and found them to be much less active. On the other hand a partially characterized phenol-enriched extract obtained from aqueous waste from olive oil showed rather potent activities. Our results are the first evidence that components of the phenolic fraction of olive oil can inhibit platelet function and eicosanoid formation in vitro, and that other, partially characterized, olive derivatives share these biological activities.

Topics: 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; Adenosine Diphosphate; Antioxidants; Collagen; Eicosanoids; Flavonoids; Humans; Hydroxyeicosatetraenoic Acids; Iridoid Glucosides; Iridoids; Olive Oil; Phenylethyl Alcohol; Plant Extracts; Plant Oils; Platelet Aggregation; Platelet Aggregation Inhibitors; Pyrans; Thromboxane B2

The inhibitory effect of commercial 'pure' oleuropein was tested against Salmonella enteritidis in a coliform broth and in reconstituted milk (model food system). It was found that the inhibition of this organism in the broth was influenced by the initial inoculum size, the pH of the medium and the concentration of additive. The inhibition was more pronounced in samples with low pH and low inoculum size. No such inhibition was evident in the model food system.

Topics: Animals; Culture Media; Hydrogen-Ion Concentration; Iridoid Glucosides; Iridoids; Milk; Pyrans; Salmonella enteritidis; Sodium Chloride; Time Factors

The Mediterranean diet, rich in fruit, vegetables, grain, and vegetable oil (mainly olive oil) is correlated with a lower incidence of coronary heart disease (CHD). Natural antioxidants contained in the Mediterranean diet might also play a role in the prevention of cardiovascular diseases, through inhibition of LDL oxidation. We tested this hypothesis "in vitro" by inducing LDL oxidation with copper sulphate and preincubating the samples with oleuropein, the bitter principle of olives, that is one of the major components of the polyphenolic fraction of olive oil. Oleuropein 10(-5) M effectively inhibited CuSO4-induced LDL oxidation, as assessed by various parameters. We demonstrate in this investigation that polyphenolic components of the Mediterranean diet interfere with biochemical events that are implicated in atherogenetic disease, thus proposing a new link between the Mediterranean diet and prevention of CHD.

Topics: Antioxidants; Copper; Copper Sulfate; Iridoid Glucosides; Iridoids; Lipoproteins, LDL; Oxidation-Reduction; Pyrans

The presence of low concentrations (0.1% w/v) of oleuropein, a phenolic compound extracted from olives, delayed the growth of Staphylococcus aureus in NZ amine A and brain heart infusion media modified by the addition of growth factors and glucose (NZA+ and BHI+), as indicated by changes in conductance, whilst higher concentrations (0.4-0.6% w/v) inhibited growth completely. Intermediate concentrations of oleuropein (0.2%) prevented growth in BHI+ but allowed growth to occur in NZA+ despite an extended lag phase (30 h). Concentrations of oleuropein > 0.2% inhibited growth and production of enterotoxin B in both types of media. Lower levels (0.1%) did not affect the final viable count and production of toxin in BHI+ but decreased the number of viable organisms and reduced the toxin production in NZA+ by eightfold. An increase in the concentration of oleuropein resulted in a decrease in the amount of glucose assimilated and consequently the amount of lactate produced. In addition, oleuropein prevented the secretion of a number of exoproteins. Addition of oleuropein during the exponential phase appeared to have no effect on the growth of Staph. aureus in NZA+.

Topics: Colony Count, Microbial; Conductometry; Culture Media; Dose-Response Relationship, Drug; Electrophoresis, Polyacrylamide Gel; Enterotoxins; Glucose; Iridoid Glucosides; Iridoids; Lactates; Lactic Acid; Pyrans; Staphylococcus aureus

Reversed phase high-performance liquid chromatography was applied for qualitative and quantitative analysis of secoiridoid oleuropein and some flavonoids in leaf and bud extracts of Olea europaea L. The RP-HPLC procedure is rapid and reproducible. The results of quantitative analysis, correlated with pharmacological activity, are reported here.

Topics: Chromatography, High Pressure Liquid; Flavonoids; Indicators and Reagents; Iridoid Glucosides; Iridoids; Plants; Pyrans; Solutions; Spectrophotometry, Ultraviolet

The phenolic compounds extracted from olives with ethyl acetate inhibited germination and outgrowth of Bacillus cereus T spores. Purified oleuropein, a well-characterized component of olive extract, inhibited these processes also. The addition of oleuropein and olive extracts 3 or 5 min after germination began, immediately decreased the rate of change of phase bright to phase dark spores and delayed significantly outgrowth.

Topics: Bacillus cereus; Fruit; Iridoid Glucosides; Iridoids; Phenols; Pyrans; Spores, Fungal