What is Resveratrol?
Resveratrol (trans-3,5,4'-trihydroxystilbene), belongs to a class of polyphenolic compounds called stilbenes , found largely in the skins of red grapes and root of Polygonum cuspidatum Sieb. et Zucc ( Japanese knotweed), is a component of Ko-jo-kon, an oriental medicine used to treat diseases of the blood vessels, heart and live.. Resveratrol is a fat-soluble compound that occurs in a trans and a cis configuration (see figure 1). Both cis- and trans-resveratrol also occur as glucosides (bound to a glucose molecule). Resveratrol-3-O-beta-glucoside is also called piceid.
While present in other plants, such as eucalyptus, spruce, and lily, and in other foods such as mulberries and peanuts, resveratrol's most abundant natural sources are Vitis vinifera, labrusca, and muscadine grapes, Polygonum cuspidatum Sieb.
Many studies suggest that consuming alcohol (especially red wine) may reduce the incidence of coronary heart disease (CHD). Several studies have demonstrated that resveratrol is an effective antioxidant. It inhibits lipid peroxidation of low-density lipoprotein (LDL), prevents the cytotoxicity of oxidized LDL, and protects cells against lipid peroxidation. It is thought that because it contains highly hydrophilic and lipophilic properties, it can provide more effective protection than other well-known antioxidants, such as vitamins C and E. On the other hand, it is less effective than the antioxidants quercetin and epicatechin found in red wine. Reduced platelet aggregation has also been demonstrated in studies on resveratrol, further contributing to its prevention of atherosclerosis. To date, most of the research on resveratrol's antioxidant and anti-platelet properties has been done in vitro (in an artificial environment using test-tube or tissue-culture preparations). Further studies in animals and humans are necessary to determine whether resveratrol supplementation makes sense.
Resveratrol is being studied to see how it affects the initiation, promotion, and progression of cancer. With regard to tumor initiation, it has been shown to act as an antioxidant by inhibiting free radical formation, and as an anti-mutagen in rat models. Resveratrol appears to decrease tumor promotion activity by inhibiting cyclooxygenase-1 (COX-1), an enzyme that converts arachidonic acid to pro-inflammatory substances that stimulate tumor-cell growth . Studies related to progression have found that resveratrol induced human promyelocytic leukemia cell differentiation and inhibited ribonucleotide reductase, an enzyme needed for DNA synthesis in proliferating cells . One appealing characteristic of resveratrol's anti-cancer potential is its minimal toxicity to blood-forming cells . More studies using both cellular and animal models are needed before any such data would be applicable to human use.
The similarity in structure between resveratrol and diethylstilbestrol (a synthetic estrogen) has prompted investigations into resveratrol's potential as a phytoestrogen (a plant compound that produces estrogen-like effects). However, these properties also stimulate the growth of human breast cancer cells . This finding seems contrary to its other anticancer activities, and is a cause for concern.
The Natural Products Association was cited in an article regarding a new dietary supplement that contains resveratrol, a substance researchers believe may help protect human cells from diseases such as cancer and arthritis.
Direct Antioxidant Activity
In the test tube, resveratrol effectively scavenges (neutralizes) free radicals and other oxidants and inhibits low density lipoprotein (LDL) oxidation . However, there is little evidence that resveratrol is an important antioxidant in vivo . After oral consumption of resveratrol, circulating and intracellular levels of resveratrol in humans are likely to be much lower than that of other important antioxidants, such as vitamin C, vitamin E and glutathione. Moreover, the antioxidant activity of resveratrol metabolites, which comprise most of the circulating resveratrol, may be lower than that of resveratrol.
Inhibition of Vascular Smooth Muscle Cell Proliferation
The proliferation of vascular smooth muscle cells plays an important role in the progression of atherosclerosis . Resveratrol has been found to inhibit the proliferation of vascular smooth muscle cells in culture .
Inhibition of Platelet Aggregation
Platelet aggregation is one of the first steps in the formation of a blood clot that can occlude a coronary or cerebral artery, resulting in myocardial infarction or stroke. Resveratrol has been found to inhibit platelet aggregation in vitro.
Safety & Adverse Effects
Resveratrol is not known to be toxic or cause adverse effects in humans, but there have been few controlled clinical trials. In rats, daily oral administration of trans-resveratrol at doses up to 300 mg/kg of body weight for 4 weeks resulted in no apparent adverse effects .
Pregnancy and Lactation
The safety of resveratrol-containing supplements during pregnancy and lactation has not been established. Since no safe level of alcohol consumption has been established at any stage of pregnancy, pregnant women should avoid consuming wine as a source of resveratrol.
Drug Interactions Anticoagulant and Antiplatelet Drugs
Resveratrol has been found to inhibit human platelet aggregation in vitro (42, 84). Theoretically, high intakes of resveratrol (e.g., from supplements) could increase the risk of bleeding when taken with anticoagulant drugs, such as warfarin (Coumadin), and antiplatelet drugs, such as clopidogrel (Plavix), dipyridamole (Persantine), non-steroidal anti-inflamatory drugs (NSAIDs), aspirin and others.
More Information on Grape Skin
Botanical: Vitis vinifera
Family: Vitaceae (grape)
Other common names: Red Wine Grape, European Grape
Grape Skin supplement is an easy way to enjoy the many health benefits provided by nutritious grapes. Packed with vitamins and minerals, Grape Skin's proanthocynidins are the phytonutrients that are thought to provide a high degree of antioxidant capacity that fights free radical damage in the body. The resveratrol in Grape Skin is said to help fight carcinogens, lower cholesterol, combat cardiovascular disease and diminish damage caused by stroke.
Grapes appear to have originated in the Mediterannean regions of southern Europe and Middle East, thriving in deep, moist, humus-rich, neutral-to-alkaline soil in sun and warm climates; and the grape's hardiness varies according to the cultivar.
Going back thousands of years, the Grape was a wild vine. If untended, it grows like a tree and wraps around anything in its way, like ivy on walls, and different sub-species were created through natural selection, resulting in mutations of the vine.
Cultivation of the Grape occurred in pre-historic or early historic times in southwest Asia or southern Transcaucasia (Armenia and Georgia), and cultivation of the domesticated grape, Vitis vinifera, spread to other parts of the Old World over the years. Wine is the fermented juice of Grapes, and it has been used in various cultures for at least 4,500 years, originating most likely in the Middle East. Egyptian records, dating from 2500 B.C., refer to wines, and there are frequent references to wine in the Old Testament. Wine was also used by early Minoan, Greek and Etruscan civilizations, and we can thank the Roman army for introducing the rootstocks and winemaking throughout Europe as they created an expanding Roman Empire. Centuries later, the role of wine for sacramental use in Christian churches helped to maintain the industry after the fall of the Roman Empire.
Modern science has now confirmed the health benefits included in the juice, skin and seeds of the Red Grape, and Grape Skin and Red Wine extracts possess high concentrations of proanthocyanidins that confer high antioxidant and free radical benefits, as well as phenolic and polyphenolic compounds (including catechin, quercetin, resveratrol, et al) that combat platelet aggregation (clotting) in the blood. It is interesting to remember the "French Paradox." French diets include more than thirty percent more fat than the diets of Americans, but the French people suffer forty percent fewer heart attacks, and this is said to be due to their consumption of Red Wine. Researchers in France have compiled a guide, or textbook, that outlines the various treatments derived from Grape Seeds, Grape Skins, Red Wine and their respective benefits. The new trend has been dubbed "Vinotherapy," and spas throughout the world are beginning to explore the benefits of Red Wine Grapes as detoxifiers, strong antioxidants and cell regenerators. Grape Skin supplements provide a convenient way to enjoy this simple fruit's many healthy benefits.
Grape Skin contains high concentrations of the substance, trans-resveratrol, and health industry researchers have found that this substance may be the key to its source as an antioxidant that may help in the prevention of serious infection. According to Northwestern University, the significant amounts of resveratrol naturally present in Grape Skin has demonstrated potentially beneficial properties, including antioxidant, anticoagulant, anti-inflammatory and anticarcinogen effects.
Recent research shows that trans-resveratrol may interfere with the development of disease by blocking the actions of carcinogens, inhibiting the initiation and proliferation of diseased cells and causing pre-cancerous cells to revert to normal. Grape Skin contains proanthocyanidins, the phytonutrients that provide a high degree of antioxidant capacity that fights free radical damage in the body.
These compounds allow the body's cells to absorb vitamin C, which are thought to be helpful in protecting cells from the free radicals that can bind to and destroy cellular compounds.
These qualities may be helpful in building the immune system and fighting serious malignant disease and other infections.
With regard to good coronary health, Grape Skin may be very helpful in reducing platelet aggregation (clotting) in the blood, thereby reducing the risk of arteriosclerosis, stroke and heart attacks. Researchers at Northwestern University Medical School have found that a chemical in red wine is a form of estrogen called resveratrol (highly concentrated in the skin of grapes), and it may reduce the risk for cardiovascular disease. ( Resveratrol has a molecular structure similar to that of diethylstilbestrol, a synthetic estrogen.) The resveratrol in Grape Skin is said to raise the levels of high-density lipoproteins (HDLs or "good" cholesterol) in the blood, while decreasing the low-density lipoproteins (LDLs, or "bad" cholesterol) and thereby possibly helping to prevent heart attacks and strokes.
It is also said to prevent fat in the bloodstream from sticking together and clogging the arteries, which is thought to promote better circulation of blood throughout the body, especially to the heart.
Grape Skin may help to minimize brain damage from strokes.
Research has discovered that resveratrol can absorb free radicals, stopping them from doing any more damage to the brain.
The phytonutrients that contribute to the grape vine's resistance to viruses are thought to protect against some viral infections in humans as well.