1-1-diphenyl-2-picrylhydrazyl and carvacrol

Chronic cerebral hypoperfusion (CCH) is a common phenomenon in many neurological diseases such as vascular dementia and Alzheimer's disease. Several drugs have been investigated to prevent and treat the CCH. The carvacrol (CAR) has been shown to have beneficial effects on various neurodegenerative and neuropsychiatric disorders. Accordingly, the present study was designed to evaluate the effect of CAR on neuronal damages in hippocampus in a well-defined model for CCH. Forty-eight male Wistar rats were equally divided into four groups of sham (A), CCH (B), CCH+ CAR 25, and 50 mg/kg/daily (C and D). The animals were subjected to permanent bilateral occlusion of the carotid arteries (2-vessel occlusion, 2VO) to induce CCH model. Cognitive function was evaluated by Morris water maze test. Morphological changes of hippocampus were assessed using Nissl staining. Free radical scavenging activity was measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Moreover, catalase (CAT) and superoxide dismutase (SOD) activities and lipid peroxidation levels were measured using biochemical analysis. CAR significantly improved the spatial learning and memory deficits assessed using the Morris water maze test. CAR also significantly attenuated neuronal necrosis as well as malondialdehyde (MDA) and elevated the levels of SOD and CAT activity in the hippocampus. The results indicate that CAR produces significant neuroprotective effects on neuronal damages induced by CCH. Protective effect of CAR may be mediated by antioxidative effect of this drug.

Topics: Animals; Biphenyl Compounds; Brain Ischemia; Catalase; Cymenes; Hippocampus; Male; Malondialdehyde; Memory; Neurons; Neuroprotective Agents; Picrates; Rats, Wistar; Spatial Learning; Superoxide Dismutase

An active film was prepared by corn starch (CS), polyvinyl alcohol (PVA) and carvacrol nanoemulsions (CNE). The microstructure and properties of CNE/corn starch/PVA (CNE/CSP) films were characterized and investigated. Scanning electron microscopy (SEM) revealed the uniform distribution of CNE and discontinuity of the film matrix. Fourier transform infrared (FT-IR) and rheological analysis indicated that CNE could weaken molecular interaction of the film matrix. X-ray diffraction (XRD) show that the films are amorphous and CNE has no effect on crystal structure of the films. Incorporation of CNE significantly increased the tensile strength, Young's modulus, elongation at break, barrier (water vapor and ultraviolet), antioxidant and antifungal activity. With the CNE incorporated, the optimal tensile strength, Young's modulus, elongation at break and antioxidant activity of the films can reach 12 MPa, 11 MPa, 133%, 81%, respectively. Minimum water vapor permeability was 3.1 × 10

Topics: Anti-Infective Agents; Antifungal Agents; Antioxidants; Biphenyl Compounds; Cymenes; Emulsions; Free Radical Scavengers; Nanoparticles; Permeability; Picrates; Polyvinyl Alcohol; Spectroscopy, Fourier Transform Infrared; Starch; Steam; Tensile Strength; Trichoderma; Water; X-Ray Diffraction; Zea mays

Carvacrol (CA) was firstly made into physically stable nanoemulsions using an innovative spontaneous emulsification method with carvacrol itself as oil phase without introducing other carrier oils. Self-crosslinking carboxymethyl chitosan (CMC) microgels via intermolecular hydrogen bonds were then fabricated using a simple solvent exchange method with ethanol as poor solvent. The CMC microgels obtained were rapidly deposited on the surface of tin foil using an electrospray technique to produce the CMC films. The stability of the films in water was further intensified by using Ca

Topics: Anti-Bacterial Agents; Antioxidants; Biphenyl Compounds; Chitosan; Colony Count, Microbial; Cymenes; Emulsions; Escherichia coli; Ethanol; Food Packaging; Gels; Humans; Hydrogen Bonding; Membranes, Artificial; Monoterpenes; Nanostructures; Picrates; Solvents; Staphylococcus aureus

Topics: Antioxidants; Biphenyl Compounds; Cyclohexenes; Cymenes; Glycine max; Iran; Limonene; Microbial Sensitivity Tests; Monoterpenes; Oils, Volatile; Picrates; Plant Extracts; Pseudomonas syringae; Seeds; Terpenes

The food industry needs to provide consumers with fresh and healthy products. In this context, food packaging plays an important role. Thus, certain essential oils are being incorporated into plastic polymers to confer better preservative properties. The oregano essential oil contains carvacrol and thymol, two important polyphenols. Considering their increasing use in active food packaging, the evaluation of their suitability and safety is of great interest. In the present work, a concentration-dependent increase in the antioxidant effects of carvacrol, thymol, and their mixture (10:1) was determined using DPPH and ABTS assays. In addition, the safety of these compounds was tested in vitro. Reactive oxygen species and glutathione levels were measured after exposing cells for 24 and 48 h to different concentrations of carvacrol, thymol and their mixture. The abilities of these compounds to protect against or revert the effects of H2O2 on cells were also studied. The results showed that oxidative stress plays a role in the damage induced by carvacrol and the mixture at high concentrations. However, at lower concentrations, both compounds and their mixture were shown, for the first time, to protect cells against the damage induced by the H2O2.

Topics: Algorithms; Antioxidants; Benzothiazoles; Biphenyl Compounds; Caco-2 Cells; Cymenes; Drug Interactions; Food Packaging; Humans; Hydrogen Peroxide; Monoterpenes; Oxidants; Oxidative Stress; Picrates; Protective Agents; Reactive Oxygen Species; Sulfonic Acids; Thymol

This study discusses the similarities and differences between the antioxidant activities of some essential oils: thyme (Thymus vulgaris), basil (Ocimum basilicum), peppermint (Mentha piperita), clove (Caryophyllus aromaticus), summer savory (Satureja hortensis), sage (Salvia hispanica) and lemon (Citrus limon (L.) Burm.) and of their main components (thymol or estragole or menthol or eugenol or carvacrol or camphor or limonene) estimated by using 2,2'-Diphenyl-1-picrylhydrazyl, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt and β-carotene bleaching assays. The obtained data show that the antioxidant properties of essential oil do not always depend on the antioxidant activity of its main component, and that they can be modulated by their other components. The conclusions concerning the interaction of essential oil components depend on the type of method applied for assessing the antioxidant activity. When comparing the antioxidant properties of essential oils and their main components, the concepts of synergism, antagonism and additivity are very relevant.

Topics: Antioxidants; Benzothiazoles; beta Carotene; Biphenyl Compounds; Citrus; Cymenes; Monoterpenes; Ocimum basilicum; Oils, Volatile; Picrates; Satureja; Sulfonic Acids; Syzygium; Thymol; Thymus Plant

The composition of essential oil isolated from Satureja thymbra, growing wild in Libya, was analyzed by GC and GC-MS. The essential oil was characterized by γ-terpinene (39.23%), thymol (25.16%), p-cymene (7.17%) and carvacrol (4.18%) as the major constituents. Antioxidant activity was analyzed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method. It possessed strong antioxidant activity (IC50 = 0.0967 mg/mL). The essential oil was also screened for its antimicrobial activity against eight bacterial and eight fungal species, showing excellent antimicrobial activity against the microorganisms used, in particular against the fungi. The oil of S. thymbra showed bacteriostatic activity at 0.001-0.1 mg/mL and was bactericidal at 0.002-0.2 mg/mL; fungistatic effects at 0.001-0.025 mg/mL and fungicidal effects at 0.001-0.1 mg/mL. The main constituents thymol, carvacrol and γ-terpinene also showed strong antimicrobial activity. The commercial fungicide bifonazole showed much lower antifungal activity than the tested oil.

Topics: Anti-Bacterial Agents; Antifungal Agents; Antioxidants; Bacteria; Biphenyl Compounds; Cyclohexane Monoterpenes; Cymenes; Fungi; Gas Chromatography-Mass Spectrometry; Inhibitory Concentration 50; Libya; Microbial Sensitivity Tests; Monoterpenes; Oils, Volatile; Picrates; Plant Extracts; Satureja; Thymol

Antioxidant activity of a number of small (low molecular weight) natural compounds found in spices, condiments or drugs (gallic acid, sesamol, eugenol, thymol, carvacrol, vanillin, salicylaldehyde, limonene, geraniol, 4-hexylresorcinol, etc.) has been evaluated using electrochemical and DPPH• radical scavenging measurements. Structural analysis of the tested compound suggest a remarkable activity for phenol derivatives and the importance of the -R groups located on the phenolic ring in the molecule's ability to act as free radical scavenging as well as their influence in the electrochemical behavior. The voltammetric method can be used for the determination of the antioxidant capability in the same manner as the DPPH• radical scavenging because of the correlation found between oxidation potentials and anti-radical power (ARP = 1/EC₅₀). Such electrochemical determination is fast and cheap and allows making measurements under a variety of experimental conditions. The accuracy of the electrochemical measurements is the same for all the compounds, irrespective of their scavenging activity, the opposite of what occurs in the DPPH• test.

Topics: Acyclic Monoterpenes; Aldehydes; Antioxidants; Benzaldehydes; Benzodioxoles; Biphenyl Compounds; Condiments; Cyclohexenes; Cymenes; Electrochemical Techniques; Eugenol; Free Radicals; Gallic Acid; Hexanes; Hexylresorcinol; Limonene; Monoterpenes; Oxidation-Reduction; Phenols; Picrates; Prescription Drugs; Resorcinols; Spices; Terpenes; Thymol

Essential oils have been studied for their unique ability to act as antioxidants. Antioxidant activities of 423 essential oils of 48 different botanical families were evaluated for their antioxidant activities as free radical scavenging agents using the 1,1-diphenyl-2-picrylhydrazyl method. Seventy-three oils showed 50% or more inhibition at a concentration of 1.25 mg/mL. The 73 most active oil samples were further evaluated for their scavenging activities using series of dilutions to estimate their EC(50) . The EC(50) of the 73 most active oils ranged from 4 to 2000 μg/mL. Oils having an EC(50) of less than 300 μg/mL (20 selected samples) were subjected to β-carotene bleaching antioxidant activity test and more detailed analysis including thin layer chromatography, gas chromatography/mass spectrometry, high performance liquid chromatography and bioautography. Essential oils of the botanical families Lamiaceae and Myrtaceae were the most effective antioxidants. Thymol and carvacrol were the major constituents in most of the essential oils of the family Lamiaceae and eugenol was the major terpene in all of the essential oils of the family Myrtaceae.. Supplementation of food with spices containing essential oils may counteract and retard the process of oxidative damage, lipid oxidation and elevate antioxidant activity of the final product.

Topics: Antioxidants; Biphenyl Compounds; Chromatography, High Pressure Liquid; Cymenes; Dietary Supplements; Eugenol; Food Handling; Gas Chromatography-Mass Spectrometry; Lamiaceae; Lipid Metabolism; Monoterpenes; Myrtaceae; Oils, Volatile; Oxidative Stress; Picrates; Plant Extracts; Plant Oils; Spices; Terpenes; Thymol

This study was undertaken to determine the chemical composition and antioxidative capacity of Echinophora platyloba DC. essential oil, and its antimicrobial potency against Listeria monocytogenes, Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Salmonella typhimurium, Escherichia coli O157:H7, Pseudomonas aeruginosa, Candida albicans, Candida tropicalis, Rhodotorula rubra, and Rhodotorula mucilaginosa. The essential oil was analyzed by GC and GC-MS; and evaluated for its antioxidative and antimicrobial (singly or in combination with chitosan, nisin, monolaurin, or amphotericin B) activity. Thirty-three components were characterized representing 95.69% of the total oil composition in which thymol, trans-ocimene, carvacrol, and (E)-sesqui-lavandulol were the major constituents. The oil exhibited high scavenging (IC(50): 49.7 ± 2.3 μg/mL) and relative antioxidative activity (RAA%: 85.21 ± 0.4) in 1,1-diphenyl-2-picrylhydrazyl radicals and β-carotene/linoleic acid bleaching assays, respectively. The oil showed antimicrobial activity against L. monocytogenes, B. cereus, B. subtilis, S. aureus, S. typhimurium, E. coli O157:H7, P. aeruginosa, C. albicans, C. tropicalis, R. Rubra, and R. mucilaginosa. Moreover, R. mucilaginosa and P. aeruginosa were the most susceptible and most resistant organisms, respectively. Regarding the checkerboard data, 47 fractional inhibitory concentration index (FICIs) (≤ 0.5) indicated synergistic, whereas 7 FICIs (>0.5 to 1) indicated additive effect. Consequently, E. platyloba DC. essential oil could be used as a recommended natural antioxidant and antimicrobial substance for food preservation.

Topics: Acyclic Monoterpenes; Amphotericin B; Anti-Infective Agents; Antioxidants; Apiaceae; beta Carotene; Biphenyl Compounds; Chitosan; Cymenes; Drug Interactions; Drug Resistance, Multiple, Bacterial; Food Contamination; Food Microbiology; Gas Chromatography-Mass Spectrometry; Gram-Negative Bacteria; Gram-Positive Bacteria; Laurates; Linoleic Acid; Microbial Sensitivity Tests; Monoglycerides; Monoterpenes; Nisin; Oils, Volatile; Picrates; Plant Oils; Thymol

The commercial essential oils of Citrus aurantium L., Cupressus sempervirens L., Eucalyptus globulus Labill., Foeniculum vulgare Mill. and Thymus vulgaris L., isolated by steam distillation by a company of Morocco were evaluated in terms of in vitro antioxidant activity through several methods. In vitro acetylcholinesterase inhibitory activity was also determined. Citrus limon (L.) Burm. f. oil was also studied, but it was obtained by peel expression. The best antioxidant was T. vulgaris oil, independent of the method used, mainly due to the presence of the phenolic monoterpenes thymol and carvacrol, which when studied as single compounds also presented the best activities. Concerning the acetylcholinesterase inhibition activity, E. globulus was the most effective. Nevertheless its main components 1,8-cineole and limonene were not the most active, a feature that corresponded to d-3-carene.

Topics: Acetylcholinesterase; Antioxidants; Bicyclic Monoterpenes; Biphenyl Compounds; Cholinesterase Inhibitors; Cyclohexanols; Cyclohexenes; Cymenes; Distillation; Enzyme Assays; Eucalyptol; Limonene; Lipid Peroxidation; Monoterpenes; Oils, Volatile; Oxidation-Reduction; Picrates; Plant Oils; Terpenes; Thiobarbituric Acid Reactive Substances; Thymol

Essential oils are known to possess antimicrobial and antioxidant activity while chitosan is a biocompatible polymer with antibacterial activity against a broad spectrum of bacteria. In this work, nanoparticles with both antioxidant and antibacterial properties were prepared by grafting eugenol and carvacrol (two components of essential oils) on chitosan nanoparticles. Aldehyde groups were first introduced in eugenol and carvacrol, and the grafting of these oils to chitosan nanoparticles was carried out via the Schiff base reaction. The surface concentration of the grafted essential oil components was determined by X-ray photoelectron spectroscopy (XPS). The antioxidant activities of the carvacrol-grafted chitosan nanoparticles (CHCA NPs) and the eugenol-grafted chitosan nanoparticles (CHEU NPs) were assayed with diphenylpicrylhydrazyl (DPPH). Antibacterial assays were carried out with a representative gram-negative bacterium, Escherichia coli (E. coli) and a gram-positive bacterium, Staphylococcus aureus (S. aureus). The grafted eugenol and carvacrol conferred antioxidant activity to the chitosan nanoparticles, and the essential oil component-grafted chitosan nanoparticles achieved an antibacterial activity equivalent to or better than that of the unmodified chitosan nanoparticles. Cytotoxicity assays using 3T3 mouse fibroblast showed that the cytotoxicity of CHEU NPs and CHCA NPs were significant lower than those of the pure essential oils.

Topics: Animals; Anti-Bacterial Agents; Antioxidants; Biphenyl Compounds; Cells, Cultured; Chitosan; Cymenes; Escherichia coli; Eugenol; Fibroblasts; Mice; Microbial Sensitivity Tests; Monoterpenes; Nanoparticles; Oxidation-Reduction; Picrates; Staphylococcus aureus

This study was designed to examine the in vitro antimicrobial and antioxidant activities of the essential oil and various extracts obtained from aerial parts of Thymus eigii. The essential oil was particularly found to possess stronger antimicrobial activity, whereas other nonpolar extracts and subfractions showed moderate activity and polar extracts remained almost inactive. GC-MS analysis of the oil resulted in the identification of 39 compounds, representing 93.7% of the oil; thymol (30.6%), carvacrol (26.1%), and p-cymene (13.0%) were the main components. The samples were also subjected to a screening for their possible antioxidant activity by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and beta-carotene-linoleic acid assays. In the former case, the polar subfraction of the methanol extract was found to be superior to all extracts tested, only 16.8 microg/mL of which provided 50% inhibition, whereas all extracts, particularly the polar ones, seem to inhibit the oxidation of linoleic acid in the latter case. These data were further supported by total phenolics analysis, indicating that the antioxidative potential of the extracts was closely related to their phenolic constituents.

Topics: Anti-Bacterial Agents; Antioxidants; beta Carotene; Biphenyl Compounds; Cymenes; Gas Chromatography-Mass Spectrometry; Lamiaceae; Linoleic Acid; Monoterpenes; Oils, Volatile; Oxidation-Reduction; Picrates; Plant Extracts; Plant Oils; Thymol

The essential oil, obtained by using a Clevenger distillation apparatus, and water-soluble (polar) and water-insoluble (nonpolar) subfractions of the methanol extract of Thymus pectinatus Fisch. et Mey. var. pectinatus were assayed for their antimicrobial and antioxidant properties. No (or slight) antimicrobial activity was observed when the subfractions were tested, whereas the essential oil showed strong antimicrobial activity against all microorganisms tested. Antioxidant activities of the polar subfraction and the essential oil were evaluated using 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radical, superoxide radical scavenging, and lipid peroxidation assays. The essential oil, in particular, and the polar subfraction of the methanol extract showed antioxidant activity. The essential oil was analyzed by GC/MS, and 24 compounds, representing 99.6% of the essential oil, were identified: thymol, gamma-terpinene, p-cymene, carvacrol, and borneol were the main components. An antimicrobial activity test carried out with fractions of the essential oil showed that the activity was mainly observed in those fractions containing thymol, in particular, and carvacrol. The activity was, therefore, attributed to the presence of these compounds. Other constituents of the essential oil, such as borneol, gamma-terpinene, and p-cymene, could be also taken into account for their possible synergistic or antagonistic effects. On the other hand, thymol and carvacrol were individually found to possess weaker antioxidant activity than the crude oil itself, indicating that other constituents of the essential oil may contribute to the antioxidant activity observed. In conclusion, the results presented here show that T. pectinatus essential oil could be considered as a natural antimicrobial and antioxidant source.

Topics: Anti-Bacterial Agents; Antioxidants; Bacteria; Biphenyl Compounds; Camphanes; Chemical Fractionation; Cyclohexane Monoterpenes; Cymenes; Free Radical Scavengers; Gas Chromatography-Mass Spectrometry; Lamiaceae; Lipid Peroxidation; Methanol; Monoterpenes; Oils, Volatile; Picrates; Plant Extracts; Plant Oils; Terpenes; Thymol

In the present study, essential oil from the leaves of Syrian oreganum [Origanum syriacum L. (Lauraceae)] grown in Turkish state forests of the Dortyol district, Turkey, was obtained by steam distillation. The chemical composition of oil was analysed by GC and GC-MS, and was found to contain 49.02% monoterpenes, 36.60% oxygenated monoterpenes and 12.59% sesquiterpenes. The major components are as follows: gamma-terpinene, carvacrol, p-cymene and beta-caryophyllene. Subsequently, the reducing power, antioxidant and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activities of the essential oil were studied. The reducing power was compared with ascorbic acid, and the other activities were compared with 2,6-di-tert-butyl-4-methyl phenol (BHT, butylated hydroxytoluene). The results showed that the activities were concentration dependent. The antioxidant activities of the oil were slightly lower than those of ascorbic acid or BHT, so the oil can be considered an effective natural antioxidant. Antimicrobial activities of the essential oil from the leaves of Origanum syriacum was also determined on 16 microorganisms tested using the agar-disc diffusion method, and showed antimicrobial activity against 13 of these.

Topics: Ampicillin; Anti-Infective Agents; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Cyclohexane Monoterpenes; Cymenes; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Escherichia coli; Free Radical Scavengers; Klebsiella pneumoniae; Micrococcus luteus; Monoterpenes; Nystatin; Oils, Volatile; Origanum; Picrates; Plant Leaves; Plant Oils; Plants, Medicinal; Polycyclic Sesquiterpenes; Sesquiterpenes; Staphylococcus aureus; Streptomycin; Turkey

2,2-Diphenyl-1-picrylhydrazyl radical (DPPH*) scavenging activity-guided fractionation of a leaf extract of Thymus vulgaris led to the isolation of the radical scavengers rosmarinic acid 1, eriodictyol, taxifolin, luteolin 7-glucuronide, p-cymene 2,3-diol, p-cymene 2,3-diol 6-6'-dimer, carvacrol, thymol, and a new compound, 2. The fractionation was considerably facilitated by using an on-line HPLC detector for radical scavenging activity. In this detector activity is monitored as the disappearance of the color of a postcolumn added stable radical after reacting with radical scavengers in a reaction coil. Compound 2, which consists of rosmarinic and caffeic acid moieties linked via a C-3'-C-8' ' ether bridge, was mainly elucidated by various NMR techniques and CD. Phenylpropanoid trimer 2 was a weaker and stronger radical scavenger than rosmarinic acid 1 in off-line TEAC and DPPH* assays, respectively.

Topics: Biphenyl Compounds; Chromatography, High Pressure Liquid; Cinnamates; Cymenes; Depsides; Flavonols; Free Radical Scavengers; Lithuania; Molecular Conformation; Molecular Structure; Monoterpenes; Picrates; Plant Leaves; Plants, Medicinal; Quercetin; Rosmarinic Acid; Structure-Activity Relationship; Terpenes; Thymus Plant