phytosterols and Neoplasms

Cancer is the leading cause of mortality and morbidity worldwide, and its cases are rapidly increasing every year. Several factors contribute to the development of tumorigenesis. including radiation, dietary lifestyle, smoking, environmental, and genetic factors. The cell cycle is regulated by a variety of molecular signaling proteins. However, when the proteins involved in the cell cycle regulation are altered, cellular growth and proliferation are significantly affected. Natural products provide an important source of new drug development for a variety of ailments. including cancer. Phytosterols (PSs) are an important class of natural compounds reported for numerous pharmacological activities, including cancer. Various PSs, such as ergosterol, stigmasterol, sitosterol, withaferin A, etc., have been reported for their anti-cancer activities against a variety of cancer by modulating the tumor microenvironment via molecular signaling pathways discussed within the article. These signaling pathways are associated with the production of pro-inflammatory mediators, growth factors, chemokines, and pro-apoptotic and anti-apoptotic genes. These mediators and their upstream signaling are very active within the variety of tumors and by modulating these signalings, thus PS exhibits promising anti-cancer activities. However, further high-quality studies are needed to firmly establish the clinical efficacy as well the safety of the phytosterols.

Topics: Cell Division; Humans; Neoplasms; Phytosterols; Stigmasterol; Tumor Microenvironment

Phytosterols (PSs), classified into plant sterols and stanols, are bioactive compounds found in foods of plant origin. PSs have been proposed to exert a wide number of pharmacological properties, including the potential to reduce total and low-density lipoprotein (LDL) cholesterol levels and thereby decreasing the risk of cardiovascular diseases. Other health-promoting effects of PSs include anti-obesity, anti-diabetic, anti-microbial, anti-inflammatory, and immunomodulatory effects. Also, anticancer effects have been strongly suggested, as phytosterol-rich diets may reduce the risk of cancer by 20%. The aim of this review is to provide a general overview of the available evidence regarding the beneficial physiological and pharmacological activities of PSs, with special emphasis on their therapeutic potential for human health and safety. Also, we will explore the factors that influence the physiologic response to PSs.

Topics: Cardiovascular Diseases; Diet; Humans; Neoplasms; Phytosterols

Phytosterols and phytostanols are natural products present in vegetable oils, nuts, and seeds, or added to consumer food products whose intake is inversely associated with incidence and prognosis of several cancers. Randomized cancer prevention trials in humans are unfeasible due to time and cost yet the cellular processes and signaling cascades that underpin anti-cancer effects of these phytochemicals have been explored extensively in vitro and in preclinical in vivo models. Here we have performed an original systematic review, meta-analysis, and qualitative interpretation of literature published up to June 2020. MEDLINE, Scopus, and hand-searching identified 408 unique records that were screened leading to 32 original articles that had investigated the effects of phytosterols or phytostanols on cancer biology in preclinical models. Data was extracted from 22 publications for meta-analysis. Phytosterols were most commonly studied and found to reduce primary and metastatic tumor burden in all cancer sites evaluated. Expression of pAKT, and markers of metastasis (alkaline phosphatase, matrix metalloproteases, epithelial to mesenchymal transcription factors, lung and brain colonization), angiogenesis (vascular endothelial growth factor, CD31), and proliferation (Ki67, proliferating cell nuclear antigen) were consistently reduced by phytosterol treatment in breast and colorectal cancer. Very high dose treatment (equivalent to 0.2-1 g/kg body weight not easily achievable through diet or supplementation in humans) was associated with adverse events including poor gut health and intestinal adenoma development. Phytosterols and phytostanols are already clinically recommended for cardiovascular disease risk reduction, and represent promising anti-cancer agents that could be delivered in clinic and to the general population at low cost, with a well understood safety profile, and now with a robust understanding of mechanism-of-action.

Topics: Animals; Drug Evaluation, Preclinical; Neoplasms; Phytosterols

Microalgae are photosynthetic microorganisms that produce numerous bioactive molecules that can be used as food supplement to prevent chronic disease installation. Indeed, they produce phycobiliproteins, polysaccharides, lipids, carotenoids and sterolic compounds. The use of microalgae in human nutrition provide a mixture of these molecules with synergistic effect. The aim of this review is to present the specific roles played by the xanthophylls, and specifically astaxanthin and fucoxanthin, two high added value carotenoids, and by microalgal phytosterols such as β-sitosterol, campesterol and stigmasterol on several cell mechanisms involved in the prevention of cardiometabolic diseases and cancers. This review explains how these microalgal molecules modulate cell signaling pathways involved in carbohydrate and lipid metabolisms, inflammation, apoptosis, invasion and metastasis. Xanthophylls and phytosterols are involved in the reduction of inflammatory markers in relation with the regulation of the c-Jun N-terminal kinases and nuclear factor-kappa B signaling pathways, and suppression of production of pro-inflammatory mediators. Xanthophylls act on glucose and lipid metabolisms via both the upregulation of peroxisome proliferator-activated receptors (PPARs) and glucose transporters and its effects on the expression of enzymes involved in fatty acid synthesis and cholesterol metabolism. Their anti-cancer effects are related to the induction of intrinsic apoptosis due to down-regulation of key regulatory kinases. The anti-angiogenesis, anti-proliferative and anti-invasive effects are correlated with decreased production of endothelial growth factors and of matrix metalloproteinases. Phytosterols have a major role on cholesterol absorption via modification of the activities of Niemann-Pick C1 like 1 and ATP-binding cassette transporters and on cholesterol esterification. Their action are also related with the modulation of PPARs and sterol regulatory element-binding protein-1 activities.

Topics: Apoptosis; Carbohydrate Metabolism; Cardiovascular Diseases; Cholesterol; Dietary Supplements; Humans; Lipid Metabolism; Metabolic Diseases; Microalgae; Neoplasms; Phytosterols; Signal Transduction; Sitosterols; Xanthophylls

Cancer is the second leading cause of death worldwide. Compelling evidence supports the hypothesis that the manipulation of dietary components, including plant compounds termed as phytochemicals, demonstrates certain important health benefits in humans, including those in cancer. In fact, beyond their well-known cardiovascular applications, phytosterols may also possess anticancer properties, as has been demonstrated by several studies. Although the mechanism of action by which phytosterols (and derivatives) may prevent cancer development is still under investigation, data from multiple experimental studies support the hypothesis that they may modulate proliferation and apoptosis of tumor cells. Phytosterols are generally considered safe for human consumption and may also be added to a broad spectrum of food matrices; further, they could be used in primary and secondary prevention. However, few interventional studies have evaluated the relationship between the efficacy of different types and forms of phytosterols in cancer prevention. In this context, the purpose of this review was to revisit and update the current knowledge on the molecular mechanisms involved in the anticancer action of phytosterols and their potential in cancer prevention or treatment.

Topics: Animals; Apoptosis; Cell Proliferation; Humans; Neoplasms; Phytosterols

Cancer is a global problem with no sign that incidences are reducing. The great costs associated with curing cancer, through developing novel treatments and applying patented therapies, is an increasing burden to developed and developing nations alike. These financial and societal problems will be alleviated by research efforts into prevention, or treatments that utilise off-patent or repurposed agents. Phytosterols are natural components of the diet found in an array of seeds, nuts and vegetables and have been added to several consumer food products for the management of cardio-vascular disease through their ability to lower LDL-cholesterol levels. In this review, we provide a connected view between the fields of structural biophysics and cellular and molecular biology to evaluate the growing evidence that phytosterols impair oncogenic pathways in a range of cancer types. The current state of understanding of how phytosterols alter the biophysical properties of plasma membrane is described, and the potential for phytosterols to be repurposed from cardio-vascular to oncology therapeutics. Through an overview of the types of biophysical and molecular biology experiments that have been performed to date, this review informs the reader of the molecular and biophysical mechanisms through which phytosterols could have anti-cancer properties via their interactions with the plasma cell membrane. We also outline emerging and under-explored areas such as computational modelling, improved biomimetic membranes and ex vivo tissue evaluation. Focus of future research in these areas should improve understanding, not just of phytosterols in cancer cell biology but also to give insights into the interaction between the plasma membrane and the genome. These fields are increasingly providing meaningful biological and clinical data but iterative experiments between molecular biology assays, biosynthetic membrane studies and computational membrane modelling improve and refine our understanding of the role of different sterol components of the plasma membrane.

Topics: Biophysical Phenomena; Cell Membrane; Diet; Humans; Neoplasms; Phytosterols

Phytosterols are naturally occurring compounds in plants, structurally similar to cholesterol. The human diet is quite abundant in sitosterol and campesterol. Phytosterols are known to have various bioactive properties including reducing intestinal cholesterol absorption which alleviates blood LDL-cholesterol and cardiovascular problems. It is indicated that phytosterol rich diets may reduce cancer risk by 20%. Phytosterols may also affect host systems, enabling antitumor responses by improving immune response recognition of cancer, affecting the hormone dependent endocrine tumor growth, and by sterol biosynthesis modulation. Moreover, phytosterols have also exhibited properties that directly inhibit tumor growth, including reduced cell cycle progression, apoptosis induction, and tumor metastasis inhibition. The objective of this review is to summarize the current knowledge on occurrences, chemistry, pharmacokinetics and potential anticancer properties of phytosterols in vitro and in vivo. In conclusion, anticancer effects of phytosterols have strongly been suggested and support their dietary inclusion to prevent and treat cancers.

Topics: Animals; Antineoplastic Agents, Phytogenic; Diet; Humans; Neoplasms; Phytosterols

Hass avocados, the most common commercial avocado cultivars in the world, contain a variety of essential nutrients and important phytochemicals. Although the official avocado serving is one-fifth of a fruit (30 g), according to NHANES analysis the average consumption is one-half an avocado (68 g), which provides a nutrient and phytochemical dense food consisting of the following: dietary fiber (4.6 g), total sugar (0.2 g), potassium (345 mg), sodium (5.5 mg), magnesium (19.5 mg), vitamin A (43 μg), vitamin C (6.0 mg), vitamin E (1.3 mg), vitamin K1 (14 μg), folate (60 mg), vitamin B-6 (0.2 mg), niacin (1.3 mg), pantothenic acid (1.0 mg), riboflavin (0.1 mg), choline (10 mg), lutein/zeaxanthin (185 μg), phytosterols (57 mg), and high-monounsaturated fatty acids (6.7 g) and 114 kcals or 1.7 kcal/g. The avocado oil consists of 71% monounsaturated fatty acids (MUFA), 13% polyunsaturated fatty acids (PUFA), and 16% saturated fatty acids (SFA), which helps to promote healthy blood lipid profiles and enhance the bioavailability of fat soluble vitamins and phytochemicals from the avocado or other fruits and vegetables, naturally low in fat, which are consumed with avocados. There are eight preliminary clinical studies showing that avocado consumption helps support cardiovascular health. Exploratory studies suggest that avocados may support weight management and healthy aging.

Topics: Body Weight; Carbohydrates; Cardiovascular Diseases; Carotenoids; Dietary Fiber; DNA Damage; Eye Diseases; Fatty Acids; Food, Organic; Humans; Neoplasms; Nutrition Surveys; Osteoarthritis; Persea; Phenols; Phytosterols; Randomized Controlled Trials as Topic; Skin Diseases; Trace Elements; Vitamins

Phytosterols (PSs) are a group of plant derived steroid alcohols, with wide occurrence in vegetables and fruits. They are integral components of plant cell membranes, having stabilizing effects on phospholipids bilayer, just like cholesterol in animal cell membranes. Structural resemblance of PSs with cholesterol enables them to displace low-density lipoprotein (LDL) cholesterol in the human intestine. Protective effects of PSs against cardiovascular diseases (CVDs), colon and breast cancer developments have been widely documented. Several reports have been published on the potential dietary intake of common PSs, such as β-sitosterol, stigmasterol and campesterol, and their safety concerns. Ability of PSs to reduce cholesterol levels and risks associated with heart problems has made them a class of favorite food supplements. Nowadays functional foods supplemented with PSs have become an alternative and healthy tool to lower LDL-cholesterol levels in a natural way. However, excessive use of PSs has been observed to develop premature coronary artery disease in phytosterolemic patients, high risk of atherosclerotic CVDs, myocardial infarction and even impaired endothelial functions. This manuscript will highlight the recent developments in PSs with particular focus on their role as dietary supplements and in treatment of various heart- and cholesterol-related ailments. Recently explored side effects of PSs will also be discussed.

Topics: Animals; Anti-Inflammatory Agents; Anticholesteremic Agents; Antineoplastic Agents, Phytogenic; Diabetes Mellitus; Dietary Supplements; Humans; Immunologic Factors; Neoplasms; Phytosterols; Plants

The proportion of elderly is growing worldwide. This trend is in parallel to an increase in diseases, such as cardiovascular disease (CVD). Plant sterols and stanols (PS) consumption is known to decrease low-density lipoprotein-cholesterol (LDL-C) levels by 5-15%, and thus lower CVD risk. Yet, the effect of PS on LDL-C levels differs between individuals. Furthermore, PS have recently been investigated for the prevention of other age-related diseases. The objective of this review is to examine the benefits of PS on CVD as well as ageing-associated diseases. PS have the ability to significantly lower LDL-C; yet, the large inter-individual variability in the lowering of LDL-C may be due to subject characteristics, food matrix of PS, dose of PS, dietary background, frequency of intake of PS, the additive effect of other foods or drugs, as well as genetic factors. Further, PS may also have other potential beneficial effects including anti-atherogenic, anti-inflammatory, antioxidant and anti-cancer activities. Overall, dietary intervention strategies, such as incorporating PS into a healthy diet, should be recommended and implemented in older adult populations in order to prevent ageing-associated diseases and hence promote healthy ageing.

Topics: Aged; Aging; Cardiovascular Diseases; Cognition Disorders; Eye Diseases; Food, Fortified; Humans; Inflammation; Meta-Analysis as Topic; Neoplasms; Oxidative Stress; Phytosterols; Randomized Controlled Trials as Topic

To examine experimental evidence that has examined association of phytosterols and the reduction of the risk of cardiovascular disease and cancer.. Phytosterols exist as naturally occurring plant sterols that are present in the nonsaponifiable fraction of plant oils. Phytosterols are plant components that have a chemical structure similar to cholesterol except for the addition of an extra methyl or ethyl group; however, phytosterol absorption in humans is considerably less than that of cholesterol. In fact, phytosterols reduce cholesterol absorption, although the exact mechanism is not known, and thus reduce circulating levels of cholesterol. The efficacy of phytosterols as cholesterol-lowering agents have been shown when incorporated into fat spreads as well as other food matrices. In addition, phytosterols have been combined with other beneficial dietary components including fish and olive oils, psyllium and beta-glucan to enhance their effect on risk factors of cardiovascular disease. Phytosterols appear not only to play an important role in the regulation of cardiovascular disease but also to exhibit anticancer properties. A side effect associated with the consumption of phytosterols is that they reduce the blood levels of carotenoid. Nevertheless, it has been suggested that compensation for this impact on serum carotenoid levels can occur either by increasing the intake of carotenoid-rich foods or by taking supplements containing these carotenoids.. Dietary phytosterols appear to play an important role in the regulation of serum cholesterol and to exhibit anticancer properties.

Topics: Anticholesteremic Agents; Cardiovascular Diseases; Carotenoids; Cholesterol; Humans; Hypercholesterolemia; Neoplasms; Phytosterols

Phytosterol and stanol (or phytosterols) consumption reduces intestinal cholesterol absorption, leading to decreased blood LDL-cholesterol levels and lowered cardiovascular disease risk. However, other biological roles for plant sterols and stanols have also been proposed. The objective of this review is to critically examine results from recent research regarding the potential effects and mechanisms of action of phytosterols on forms of cancer. Considerable emerging evidence supports the inhibitory actions of phytosterols on lung, stomach, as well as ovarian and breast cancer. Phytosterols seem to act through multiple mechanisms of action, including inhibition of carcinogen production, cancer-cell growth, angiogenesis, invasion and metastasis, and through the promotion of apoptosis of cancerous cells. Phytosterol consumption may also increase the activity of antioxidant enzymes and thereby reduce oxidative stress. In addition to altering cell-membrane structure and function, phytosterols probably promote apoptosis by lowering blood cholesterol levels. Moreover, consumption of phytosterols by healthy humans at the recommended level of 2 g per day does not cause any major health risks. In summary, mounting evidence supports a role for phytosterols in protecting against cancer development. Hence, phytosterols could be incorporated in diet not only to lower the cardiovascular disease risk, but also to potentially prevent cancer development.

Topics: Animals; Anticarcinogenic Agents; Apoptosis; Diet; Humans; Neoplasms; Phytosterols

Olive oil, one of the oldest vegetable oils consumed without any refining, is associated with a reduced risk of a number of common cancers. Minor constituents of virgin olive oil have been suggested to be among the major chemopreventive components. A brief overview is presented of recent findings concerning the bioavailability of certain important olive oil minor components including efficient antioxidant polyphenols, the triterpene hydrocarbon squalene and beta-sitosterol, considered as putative nutritional biomarkers, in relation to the incidence of cancer.

Topics: Anticarcinogenic Agents; Antioxidants; Biological Availability; Biomarkers; Humans; Neoplasms; Olive Oil; Phenols; Phytosterols; Plant Oils; Squalene

Phytochemicals have been proposed to offer protection against a variety of chronic ailments including cardiovascular diseases, obesity, diabetes, and cancer. As for cancer protection, it has been estimated that diets rich in phytochemicals can significantly reduce cancer risk by as much as 20%. Phytosterols are specific phytochemicals that resemble cholesterol in structure but are found exclusively in plants. Phytosterols are absorbed from the diet in small but significant amounts. Epidemiological data suggest that the phytosterol content of the diet is associated with a reduction in common cancers including cancers of the colon, breast, and prostate. The means by which dietary phytosterols may be achieving these effects is becoming clearer from molecular studies with tumorigenic research models. Phytosterols affect host systems potentially enabling more robust antitumor responses, including the boosting of immune recognition of cancer, influencing hormonal dependent growth of endocrine tumors, and altering sterol biosynthesis. In addition, phytosterols have effects that directly inhibit tumor growth, including the slowing of cell cycle progression, the induction of apoptosis, and the inhibition of tumor metastasis. This review summarizes the current state of knowledge regarding the anticancer effects of phytosterols.

Topics: Absorption; Animals; Anticarcinogenic Agents; Apoptosis; Cell Cycle; Female; Humans; Immune System; Male; Neoplasms; Phytosterols; Signal Transduction

Sorghum is a rich source of various phytochemicals including tannins, phenolic acids, anthocyanins, phytosterols and policosanols. These phytochemicals have potential to significantly impact human health. Sorghum fractions possess high antioxidant activity in vitro relative to other cereals or fruits. These fractions may offer similar health benefits commonly associated with fruits. Available epidemiological evidence suggests that sorghum consumption reduces the risk of certain types of cancer in humans compared to other cereals. The high concentration of phytochemicals in sorghum may be partly responsible. Sorghums containing tannins are widely reported to reduce caloric availability and hence weight gain in animals. This property is potentially useful in helping reduce obesity in humans. Sorghum phytochemicals also promote cardiovascular health in animals. Such properties have not been reported in humans and require investigation, since cardiovascular disease is currently the leading killer in the developed world. This paper reviews available information on sorghum phytochemicals, how the information relates to current phytonutrient research and how it has potential to combat common nutrition-related diseases including cancer, cardiovascular disease and obesity.

Topics: Animals; Anthocyanins; Antioxidants; Cardiovascular Diseases; Edible Grain; Fatty Alcohols; Flavonoids; Fruit; Humans; Molecular Structure; Neoplasms; Obesity; Phenols; Phytosterols; Proanthocyanidins; Sorghum; Tannins

Topics: Arachis; Coronary Disease; Fatty Acids, Monounsaturated; Health Promotion; Humans; Menu Planning; Neoplasms; Phytosterols; Resveratrol; Stilbenes; Stroke

The oil palm (Elaeis guineensis) is native to many West African countries, where local populations have used its oil for culinary and other purposes. Large-scale plantations, established principally in tropical regions (Asia, Africa and Latin America), are mostly aimed at the production of oil, which is extracted from the fleshy mesocarp of the palm fruit, and endosperm or kernel oil. Palm oil is different from other plant and animal oils in that it contains 50% saturated fatty acids, 40% unsaturated fatty acids, and 10% polyunsaturated fatty acids. The fruit also contains components that can endow the oil with nutritional and health beneficial properties. These phytonutrients include carotenoids (alpha-,beta-,and gamma-carotenes), vitamin E (tocopherols and tocotrienols), sterols (sitosterol, stigmasterol and campesterol), phospholipids, glycolipids and squalene. In addition, it is recently reported that certain water-soluble powerful antioxidants, phenolic acids and flavonoids, can be recovered from palm oil mill effluent. Owing to its high content of phytonutrients with antioxidant properties, the possibility exists that palm fruit offers some health advantages by reducing lipid oxidation, oxidative stress and free radical damage. Accordingly, use of palm fruit or its phytonutrient-rich fractions, particularly water-soluble antioxidants, may confer some protection against a number of disorders or diseases including cardiovascular disease, cancers, cataracts and macular degeneration, cognitive impairment and Alzheimer's disease. However, whilst prevention of disease through use of these phytonutrients as in either food ingredients or nutraceuticals may be a worthwhile objective, dose response data are required to evaluate their pharmacologic and toxicologic effects. In addition, one area of concern about use of antioxidant phytonutrients is how much suppression of oxidation may be compatible with good health, as toxic free radicals are required for defence mechanisms. These food-health concepts would probably spur the large-scale oil palm (and monoculture) plantations, which are already seen to be a major cause of deforestation and replacement of diverse ecosystems in many countries. However, the environmental advantages of palm phytonutrients are that they are prepared from the readily available raw material from palm oil milling processes. Palm fruit, one of only a few fatty fruits, is likely to have an increasingly substantiated place in human health

Topics: Africa, Western; Alzheimer Disease; Arecaceae; Cardiovascular Diseases; Cataract; Chronic Disease; Cognition Disorders; Dietary Fats, Unsaturated; Flavonoids; Food, Organic; Fruit; Humans; Lipid Metabolism; Macular Degeneration; Neoplasms; Nutritive Value; Oxidation-Reduction; Palm Oil; Phenols; Phytosterols; Plant Oils; Polyphenols

Phytosterols (plant sterols) are triterpenes that are important structural components of plant membranes, and free phytosterols serve to stabilize phospholipid bilayers in plant cell membranes just as cholesterol does in animal cell membranes. Most phytosterols contain 28 or 29 carbons and one or two carbon-carbon double bonds, typically one in the sterol nucleus and sometimes a second in the alkyl side chain. Phytostanols are a fully-saturated subgroup of phytosterols (contain no double bonds). Phytostanols occur in trace levels in many plant species and they occur in high levels in tissues of only in a few cereal species. Phytosterols can be converted to phytostanols by chemical hydrogenation. More than 200 different types of phytosterols have been reported in plant species. In addition to the free form, phytosterols occur as four types of "conjugates," in which the 3beta-OH group is esterified to a fatty acid or a hydroxycinnamic acid, or glycosylated with a hexose (usually glucose) or a 6-fatty-acyl hexose. The most popular methods for phytosterol analysis involve hydrolysis of the esters (and sometimes the glycosides) and capillary GLC of the total phytosterols, either in the free form or as TMS or acetylated derivatives. Several alternative methods have been reported for analysis of free phytosterols and intact phytosteryl conjugates. Phytosterols and phytostanols have received much attention in the last five years because of their cholesterol-lowering properties. Early phytosterol-enriched products contained free phytosterols and relatively large dosages were required to significantly lower serum cholesterol. In the last several years two spreads, one containing phytostanyl fatty-acid esters and the other phytosteryl fatty-acid esters, have been commercialized and were shown to significantly lower serum cholesterol at dosages of 1-3 g per day. The popularity of these products has caused the medical and biochemical community to focus much attention on phytosterols and consequently research activity on phytosterols has increased dramatically.

Topics: Animals; Anticholesteremic Agents; Antioxidants; Coronary Disease; Food Analysis; Humans; Intestinal Absorption; Neoplasms; Phytosterols; Plants; Triterpenes

"Bioactive compounds" are extranutritional constituents that typically occur in small quantities in foods. They are being intensively studied to evaluate their effects on health. The impetus sparking this scientific inquiry was the result of many epidemiologic studies that have shown protective effects of plant-based diets on cardiovascular disease (CVD) and cancer. Many bioactive compounds have been discovered. These compounds vary widely in chemical structure and function and are grouped accordingly. Phenolic compounds, including their subcategory, flavonoids, are present in all plants and have been studied extensively in cereals, legumes, nuts, olive oil, vegetables, fruits, tea, and red wine. Many phenolic compounds have antioxidant properties, and some studies have demonstrated favorable effects on thrombosis and tumorogenesis and promotion. Although some epidemiologic studies have reported protective associations between flavonoids or other phenolics and CVD and cancer, other studies have not found these associations. Various phytoestrogens are present in soy, but also in flaxseed oil, whole grains, fruits, and vegetables. They have antioxidant properties, and some studies demonstrated favorable effects on other CVD risk factors, and in animal and cell culture models of cancer. However, because phytoestrogens act both as partial estrogen agonists and antagonists, their effects on cancer are likely complex. Hydroxytyrosol, one of many phenolics in olives and olive oil, is a potent antioxidant. Resveratrol, found in nuts and red wine, has antioxidant, antithrombotic, and anti-inflammatory properties, and inhibits carcinogenesis. Lycopene, a potent antioxidant carotenoid in tomatoes and other fruits, is thought to protect against prostate and other cancers, and inhibits tumor cell growth in animals. Organosulfur compounds in garlic and onions, isothiocyanates in cruciferous vegetables, and monoterpenes in citrus fruits, cherries, and herbs have anticarcinogenic actions in experimental models, as well as cardioprotective effects. In summary, numerous bioactive compounds appear to have beneficial health effects. Much scientific research needs to be conducted before we can begin to make science-based dietary recommendations. Despite this, there is sufficient evidence to recommend consuming food sources rich in bioactive compounds. From a practical perspective, this translates to recommending a diet rich in a variety of fruits, vegetables, whole grains, le

Topics: Antioxidants; Cardiovascular Diseases; Carotenoids; Chronic Disease; Dietary Fiber; Estrogens, Non-Steroidal; Food; Humans; Isoflavones; Isothiocyanates; Lycopene; Monoterpenes; Neoplasms; Olive Oil; Phenols; Phytoestrogens; Phytosterols; Plant Oils; Plant Preparations; Resveratrol; Stilbenes; Tea

This paper reviews phytonutrients from rice bran that have shown promising disease-preventing and health-related benefits in experimental research studies. Candidate products studied and under investigation include: inositol and related compounds, inositol hexaphosphate (IP6 or phytate), rice oil, ferulic acid, gamma-oryzanol, plant sterols, tocotrienols and RICEO, a new rice-bran-derived product. Diseases in which preventive and/or nutraceutical effects have been detected include: cancer, hyperlipidemia, fatty liver, hypercalciuria, kidney stones, and heart disease. In addition, rice-bran products may have potential applications as nutritional ingredients in the context of their utility in functional foods.

Topics: Animals; Anticholesteremic Agents; Coumaric Acids; Dietary Fiber; Fatty Liver; Free Radical Scavengers; Heart Diseases; Hyperlipidemias; Inositol; Kidney Calculi; Neoplasms; Oryza; Phytosterols; Plant Extracts; Plant Oils; Rice Bran Oil; Triterpenes; Vitamin E

Whereas the cholesterol-lowering action of plant sterols and their derivatives has been well established, more recent results have produced new information concerning the similar effects of various mixtures and dose-response relationships. Moreover, although these materials have generally been viewed as safe for long-term use in almost all sectors of the population, some concerns remain regarding the impact of phytosterol consumption on other lipid-soluble nutrients, which need to be further addressed. Further work is also required to define the relationship between plant sterol consumption, circulating sterol levels, and risk of certain cancers.

Topics: Dose-Response Relationship, Drug; Humans; Neoplasms; Phytosterols; Safety; Sterols; Treatment Outcome

Although plant sterols (phytosterols) were chemically described in 1922, their biological role in human and animal health has been underestimated. Their ability to control cholesterol plasma levels in hypercholesterolimic patients was first described in 1983 when the structure of phytosterols implied that they could, by steric hindrance, inhibit the absorption of cholesterol from our diets. This has led to the development of functional foods containing high contents of these plant molecules or their esters as cholesterol controlling foods. Over the last 15 years, however, several reports have appeared in the literature indicating that phytosterols have some immunological activity as highlighted in animal models of inflammation or even in in-vitro and in-vivo models of cancer (colorectal and breast cancer). These findings were paralleled by epidemiological studies correlating the reduced risk of numerous diseases and the dietary intake of phytosterols. It is only in the last 10 years, however, that their direct immune modulatory activity on human lymphocytes has been proven and the mechanism of action in cancer cells has been elucidated. The use of phytosterols as supportive therapies in certain chronic conditions has been tested under clinical trial conditions. This review presents a summary of the in-vitro and in-vivo studies published to date.

Topics: Adjuvants, Immunologic; Animals; Cholesterol; Disease Models, Animal; HIV Infections; Humans; Hypercholesterolemia; Immune Tolerance; Intestinal Absorption; Neoplasms; Phytosterols; Phytotherapy; Sitosterols; Tuberculosis, Pulmonary; Tumor Cells, Cultured

Topics: Animals; Ascorbic Acid; Benzopyrene Hydroxylase; beta Carotene; Carcinogens; Carotenoids; Chemical Phenomena; Chemistry; Diet; Dietary Fiber; DNA; Food; Glutathione; Glutathione Peroxidase; Glutathione Transferase; Hot Temperature; Humans; Inactivation, Metabolic; Neoplasms; Nitrosamines; Nitroso Compounds; Phenols; Phytosterols; Protease Inhibitors; Selenium; Vegetables; Vitamin A; Vitamin E

CHD is the leading cause of worldwide mortality. The prevalence of heart disease has been linked to the adoption of a sedentary lifestyle and the increased dietary dependence on saturated fats from animal sources and the intake of refined foods. Elevated blood cholesterol level is one of the major risk factors for CHD. While cholesterol-lowering drug therapy (statins) has been effective in reducing the risk of heart disease, there are those individuals who are unwilling or because of muscle pains or raised levels of liver or muscle enzymes are unable to take cholesterol-lowering medication. Fortunately, there is evidence linking a number of dietary components to CHD risk reduction. The strength of this evidence has prompted various regulatory bodies to advocate diet as the first line of defence for primary prevention of heart disease. It was therefore decided to combine four dietary components that have been shown to lower blood cholesterol concentrations (nuts, plant sterols, viscous fibre and vegetable protein) in a dietary portfolio in order to determine whether the combined effect is additive. In a metabolically-controlled setting this dietary portfolio has proved to be as effective as a starting dose of a first-generation statin cholesterol-lowering medication in reducing the risk of CHD. The dietary portfolio has also been shown to be effective in sustaining a clinically-significant effect in the long term under a 'real-world' scenario. However, success of the diet depends on compliance and despite the accessibility of the foods adherence has been found to vary greatly. Overall, the evidence supports the beneficial role of the dietary portfolio in reducing blood cholesterol levels and CHD risk.

Topics: Cholesterol; Coronary Disease; Diabetes Mellitus; Diet; Dietary Fiber; Dietary Proteins; Female; Humans; Male; Neoplasms; Nuts; Phytosterols; Phytotherapy; Plant Proteins; Risk Factors; Vegetables

Topics: HeLa Cells; Humans; Neoplasms; Phosphatidylinositol 3-Kinases; Phytosterols; Plant Extracts; Vernonia

Topics: Acacia; Animals; Cell Survival; Fatty Acids; Humans; Mice; Neoplasms; Phytosterols; Plant Extracts; Plant Leaves; Tumor Cells, Cultured

Topics: Cardiovascular Diseases; Humans; Neoplasms; Neurodegenerative Diseases; Osteoporosis; Oxysterols; Phytosterols

Natural products are considered important sources of potential chemotherapeutic agents. Here, we evaluated the antiproliferative activity and the toxicological effects of the methanolic extract and a pure compound obtained from Solanum capsicoides seeds. The phytochemical profile was analyzed by chromatographic and spectroscopy methods. The acute toxicity was assessed in mice orally treated with the extract (2000 mg/kg), in vitro hemolytic activity and micronucleus test. The mutagenicity, developmental toxicity, and lethal dose (LD50) of carpesterol were estimated by the Toxicity Estimation Software Tool (TEST) software. A sulforhodamine B assay was employed to evaluate the antiproliferative activity. The toxicological assays did not observe signs of toxicity, either during the behavioral observations or in the autopsies, as well as no mutagenicity and hemolytic activity. The carpesterol did not present mutagenic effect and hemolytic activity but presents developmental toxicology and LD50 of 410 mg/kg in toxicity estimations by the TEST software. The S. capsicoides extract exhibited antiproliferative activity mainly in leukemia (K562) cell lineage. However, carpesterol presented antiproliferative activity in glioma (U251), breast (MCF-7), kidney (786-0), ovary (OVCAR-03), and K562 cell lineages. The data obtained show that S. capsicoides extract presents antiproliferative and does not present toxicological effects. In addition, it was shown for the first time the antiproliferative and toxicological parameters of carpesterol.

Topics: Animals; Antineoplastic Agents, Phytogenic; Cell Proliferation; Female; Hemolysis; Humans; K562 Cells; Lethal Dose 50; MCF-7 Cells; Methanol; Mice; Micronucleus Tests; Neoplasms; Phytosterols; Phytotherapy; Plant Extracts; Plants, Medicinal; Seeds; Solanum; Solvents

Topics: Anticarcinogenic Agents; Antioxidants; Brassicaceae; Diet; Dietary Fiber; Dietary Proteins; Edible Grain; Fabaceae; Fatty Acids, Omega-3; Flavonoids; Food Handling; Fruit; Functional Food; Health Promotion; Humans; Isothiocyanates; Neoplasms; Nutrition Policy; Phytosterols; Prebiotics; Probiotics; Seeds; Vegetables; Water

Self-assembled nanoparticles were synthesized from water-soluble fructose-chitosan, substituted by succinyl linkages with phytosterols as hydrophobic moieties for self-assembly. The physicochemical properties of the prepared self-assembled nanoparticles were characterized by Fourier transform infrared spectroscopy, fluorescence spectroscopy, and transmission electron microscopy. Doxorubicin (DOX), as a model anticancer drug, was physically entrapped inside prepared self-assembled nanoparticles by the dialysis method. With increasing initial levels of the drug, the drug loading content increased, but the encapsulation efficiency decreased. The release profiles in vitro demonstrated that the DOX showed slow sustained released over 48 h, and the release rate in phosphate buffered saline (PBS) solution (pH 7.4) was much slower than in PBS solution (pH 5.5 and pH 6.5), indicating the prepared self-assembled nanoparticles had the potential to be used as a carrier for targeted delivery of hydrophobic anticancer drugs with declined cytotoxicity to normal tissues.

Topics: Antineoplastic Agents; Chemistry, Pharmaceutical; Chitosan; Doxorubicin; Drug Carriers; Fructose; Humans; Hydrogen-Ion Concentration; Microscopy, Electron, Transmission; Nanoparticles; Nanotechnology; Neoplasms; Phytosterols; Spectrometry, Fluorescence; Spectroscopy, Fourier Transform Infrared

A bioassay-guided fractionation of the CH(2)Cl(2) extract of Selaginella tamariscina yielded six sterols 1-6 such as (4α, 5α)-4, 14-dimethylcholest-8-en-3-one (1), ergosta-4, 6, 8(14), 22-tetraene-3-one (2), ergosterol endoperoxide (3), 7β-hydroxycholesterol (4), 7β-hydroxysitosterol (5), and 7α-hydroxysitosterol (6). The structures of isolated compounds were determined using spectroscopic methods. Among these isolates, compounds 2-5 showed potent cytotoxicity against five human tumor cells, while compounds 1 and 6 did not. In the case of compounds 1 and 2, 3-oxo sterol derivatives, compound 1 was inactive, but compound 2 showed potent cytotoxicity. In addition, compound 5 exhibited potent cytotxicity, but, compound 6 which is the 7-epimer of compound 5 was weakly active against tumor cell lines. Therefore, in the case of oxysterol derivatives, the cytotoxicity appeared to be affected by the structural differences, i.e. the configuration of hydroxyl group and the number of conjugated double bond. Taken all together, the present study isolated six sterols from S. tamariscina for the first time based on a bioassay-guided fractionation and indicated that isolated oxysterols could exhibit the cytotoxic effects against tumor cells, suggesting that S. tamariscina might be a promising candidate for the development of anticancer agents.

Topics: Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Drug Discovery; Drug Screening Assays, Antitumor; Humans; Inhibitory Concentration 50; Isomerism; Magnetic Resonance Spectroscopy; Molecular Structure; Neoplasms; Optical Rotation; Phytosterols; Plant Extracts; Selaginellaceae; Spectrometry, Mass, Fast Atom Bombardment; Spectrophotometry, Infrared; Transition Temperature

Phytosterols are plant sterols that are structurally similar to cholesterol and are characterized by anti-carcinogenic and anti-atherogenic properties. Beta-sitosterol and campesterol are the predominant phytosterols in blood. The present study aimed to analyse the reproducibility and overtime reliability of plasma beta-sitosterol and campesterol measurements. In order to study the reproducibility of the measurement (technical variability), three healthy premenopausal women donated a sample of their blood. Each blood sample was subdivided into six aliquots and analysed within the same run by the same laboratory technician. The intraclass correlation coefficients (ICCs) of the assay for plasma beta-sitosterol and campesterol were 0.88 and 0.94 (95% confidence intervals low bounds (95% CI(low)) were 0.66 and 0.82), respectively. To study the reliability of beta-sitosterol and campesterol measurement over time, seven premenopausal women were recruited. Over a 6-month period, each woman provided a fasting blood sample once a month at the same time of day, and the same numerical day of the luteal phase of her menstrual cycle (between the 20th and 24th day of her menstrual cycle). All plasma samples from the same individual were processed together at the same time by the same technician at the end of the 6-month period. The overtime ICCs of plasma beta-sitosterol and campesterol were 0.91 (95% CI(low) 0.49) and 0.58 (95% CI(low) 0.31), respectively. The high reproducibility and good overtime reliability of plasma beta-sitosterol and campesterol measurements indicate that they may be suitable for potential clinical and population-based studies on cancer prevention.

Topics: Adult; Anticarcinogenic Agents; Biomarkers, Tumor; Cholesterol; Female; Humans; Luteal Phase; Middle Aged; Neoplasms; Phytosterols; Reproducibility of Results; Sitosterols

Topics: Anticarcinogenic Agents; Food; Humans; Neoplasms; Phytosterols

Topics: Animals; Glycine max; Humans; Isoflavones; Neoplasms; Phytic Acid; Phytosterols; Protease Inhibitors; Saponins

Topics: Drug Combinations; Drug Evaluation; Fruit; Glycine max; Humans; Neoplasms; Otorhinolaryngologic Diseases; Phytosterols; Plant Extracts; Radiation Injuries; Radiodermatitis; Radiotherapy; Vitamin E