Resveratrol is classified as a polyphenol. Polyphenols make up a huge class of plant compounds that are further broken down into other classifications such as flavonoids and proanthocyanidins. Orally, resveratrol is used for atherosclerosis, lowering cholesterol levels, increasing HDL cholesterol levels, and preventing cancer.
Although the wide-ranging benefits of Resveratrol per se, have only fully emerged recently, the proanthocyanidin class of compounds has actually been extensively studied beginning in the 1970's, for their powerful vascular wall strengthening properties and free radical scavenging activity. Proanthocyanidins are a highly specialized group of bioflavonoids and are one of the most potent free radical scavengers known, possessing an antioxidant effect up to 50 times more potent then vitamin E and up to 20 times more powerful then vitamin C. Proanthocyanidins have been well understood for their cell membrane building capability, providing nutritional support to reduce capillary permeability and fragility. In the vascular system the anthocyanidins supports the integrity of vascular walls by increasing vitamin C levels within cells, decreasing the permeabilizing effect of proteolytic/lysosomal enzymes, stimulating the synthesis of collagen and connective tissue, and stabilizing cell membranes.
Resveratrol is also a member of a group of compounds called phytoalexins that are produced by plants during times of environmental stress such as adverse weather, pathogenic attack, insect attack or lack of nutrients. Resveratrol has been identified in more than 70 species of plants, including grapes, cranberries, mulberries, peanuts, and. Polygonnum.
Resveratrol is also classified as a Phyto-oestrogen. Phyto-oestrogens are substances in plants that mimic the beneficial effects of o oestrogen in the human body but without the potential harmful effects associated with o oestrogen replacement therapy. In fact phyto-oestrogens are known for their ability to protect against o oestrogen related cancers such as breast cancer in women and prostate cancer in men. As men age, testosterone increasingly breaks down into oestrogen, a well-known carcinogen. By occupying oestrogen receptor sites, phyto-oestrogens prevent oestrogen-associated cancer in both sexes.
Mechanism of Action
Resveratrol is a polyphenolic compound that exists in nature as cis- and trans- stereoisomers. Resveratrol is primarily found in red wine, red grape skins, purple grape juice, mulberries, and in smaller amounts in peanuts (513,2030,2956). Other sources include eucalyptus (Eucalyptus wandoo, Eucalyptus sideroxylon), spruce (Picea excelsa), and Bauhinia racemosa (2030). Polygonum cuspidatum, the roots of which are used in Chinese and Japanese traditional medicine, is considered to be one of the richest sources of trans-resveratrol (2030).
The trans-resveratrol content of wine is highly dependent on grape type, climate, and practices used to make the wine (9). White wines have very low trans-resveratrol concentrations. Pinot Noir consistently has the highest concentrations of trans-resveratrol, regardless of climate. Other red wines, including Cabernet Sauvignon, produced in cold, humid climates, such as Bordeaux and Canada, have higher trans-resveratrol content than those produced in hot, dry climates (2030). Unfermented grape juice does not contain resveratrol. Resveratrol is not found in significant quantities in fermented grape beverages that are stored in oak barrels, such as cognac (7864).
Resveratrol is rapidly absorbed with peak concentrations occurring within 30 minutes. Resveratrol is conjugated in the intestine and absorbed as the conjugated form. In plasma, resveratrol is found primarily as glucuronide or sulfate form. In vitro research has been done with unconjugated resveratrol. It is questionable whether free resveratrol absorption is sufficient to exert a pharmacologic effect. Research in humans suggests that quercetin taken orally doesn't reach serum concentrations at which in vitro activity has been seen (9174).
Resveratrol is a weak phyto oestrogen (2960). It binds to both alpha and beta oestrogen receptors, but its affinity for these receptors is about 7,000 times less than oestrogen (7865).
Resveratrol decreases the activity of inflammatory cytokines, which suggests a mechanism for reducing mortality in cardiovascular diseases and cancer (6126). Early research suggests resveratrol might reduce the risk of cancer (2948,2959). Biological activity in humans has not yet been described (2030). Preliminary evidence suggests that trans-resveratrol has antioxidant and antimutagenic activity (2948). It may also inhibit tumor growth and promote apoptosis (2958,2959,12482). Preliminary evidence suggests that trans-resveratrol interferes with blood coagulation by inhibiting cyclooxygenases 1 and 2 (COX-1 and COX-2), hydroperoxidases, 5-lipoxygenase (2030,2948), and platelet aggregation (2949,2950,2951,2952,2961). It also causes blood vessel dilation (2954).
The anti-inflammatory effects of resveratrol also suggest potential usefulness for inflammatory diseases such as arthritis. Preliminary evidence suggests resveratrol is a more potent anti-inflammatory agent than either aspirin or ibuprofen (12483); resveratrol seems to inhibit COX-1 and COX-2 (12482,12484).
Resveratrol inhibits formation of cholesterol in certain strains of bacteria (7863), but it is not known if this contributes significantly to cholesterol lowering in humans. In human colon cancer cells, resveratrol inhibits cell division and function of RNA and DNA. These effects are reversible and cell growth resumes 40 hours after exposure (7861). Preliminary data suggest that resveratrol may prevent liver cancer cells from invading local tissues (7862). Resveratrol inhibits the replication of herpes simplex virus. Although the mechanism of this action is not fully known, exposure to resveratrol within one hour of cellular infection appears to be most effective in arresting viral growth. This suggests that resveratrol reduces production of proteins needed to regulate viral proliferation (7866).
Resveratrol (trans-3,5,4'-trihydroxystilbene), a compound found largely in the skins of red grapes, is a component of Ko-jo-kon, an oriental medicine used to treat diseases of the blood vessels, heart [1,2], and liver . It came to scientific attention only four years ago, however, as a possible explanation for the "French Paradox" -- the low incidence of heart disease among the French people, who eat a relatively high-fat diet .