About Herbs

Bottom Line: In laboratory studies, resveratrol was shown to reduce inflammation, but human data is lacking.

A naturally occurring compound in the skins of red grapes and other botanicals, resveratrol has been shown to reduce inflammation. It also has antioxidant properties and may help to protect against atherosclerosis (thickening of arterial walls) and heart disease. Animal studies have shown that resveratrol has the ability to prevent certain cancer cells from dividing. Researchers now believe that it may also play a role in increasing life span in yeast cells. However, it is not clear if similar effects will be seen in humans.

Clinical trials have not been conducted so far to test the efficacy of resveratrol in humans.

Women who have estrogen receptor-positive cancers should not take resveratrol because it may cause certain cancer cells to multiply.

3,5,4'-trihydroxystilbene

Resveratrols, Trans-3,5,4'trihydroxystilbene, 3,5,4'-trihydroxy-trans-stilbene

Resveratrol is a polyphenolic compound found in the skins of red grapes. It is also found in peanuts, mulberries, spruce, eucalyptus, and some Chinese herbs. Resveratrol has antioxidant and anti-inflammatory properties as evidenced by its cardioprotective effects. It reduces the oxidation of low density lipoproteins (LDL) and inhibits aggregation of platelets and may offer protection against atherogenesis and coronary heart disease ^{(1) (2)}.Several cell culture and animal studies have shown that resveratrol inhibits proliferation of cancer cells by apoptosis and by exerting antiestrogenic effects ^{(3) (4) (5) (6)}. However, there is contradicting data from another study which showed that it acts as a phytoestrogen and could activate genes that are normally regulated by estrogen ⁽⁷⁾. According to other studies, resveratrol was found to inactivate some enzymes of the CYP450 family in tumor cells ^{(8) (9)}. Recently, resveratrol has been implicated in enhancing longevity based on preliminary data from experiments done in yeast cells ^{(10) (11)}. However, there is no data from clinical trials to verify these effects in humans. Women with hormone sensitive diseases, such as estrogen receptor-positive cancer should avoid resveratrol as it may stimulate the proliferation of certain tumor cells.

Resveratrol acts as an antioxidant and inhibits the oxidation of low density lipoproteins (LDL) ⁽¹⁾, aggregation of platelets, and eicosanoid synthesis, thereby may help to protect against atherosclerosis and coronary heart disease ⁽²⁾. It also acts as an anti-inflammatory agent by inhibiting cyclooxygenase (COX) activity ⁽¹²⁾ as well as the release of cytokines from macrophages in chronic obstructive pulmonary disease (COPD) ⁽¹³⁾. Laboratory studies have shown that resveratrol has estrogen-like properties and activates expression of genes that are regulated by estrogen ⁽⁷⁾. Other data from cell culture and animal experiments suggest that it plays a role in cancer chemoprevention during initiation, promotion, and progression of carcinogenesis ^{(12) (14)}. In vivo studies have also demonstrated the inhibitory effects of resveratrol on the growth of oral squamous carcinoma cells ⁽³⁾, human promyelocytic leukemia cells ⁽⁴⁾, human breast cancer cells ⁽⁵⁾, and neuroblastoma cells ⁽⁶⁾ resulting from induction of apoptosis and antiestrogenic property. Resveratrol was also found to inhibit the enzymes CYP1A1, CYP1A2, and CYP1B1 in tumor cells. This may be one of the mechanisms by which resveratrol exerts anti-tumor effects as some of these enzymes are known to be involved in the activation of procarcinogens and toxins ^{(8) (9)}. Preliminary data from recent experiments in yeast cells suggests that resveratrol may have a role in increasing life span which it does by activating a set of genes known as sirtuins ^{(10) (11)}.

Upon oral administration, resveratrol is rapidly absorbed in the gastrointestinal tract and undergoes glucoronidation and sulfation in the liver microsomes. More than 50% of the ingested resveratrol is eliminated in urine in 24 hrs ⁽¹⁵⁾.

As resveratrol exhibits estrogen-like properties and activates transcription by estrogen receptor that leads to stimulation of cancer cell proliferation, women with estrogen receptor-positive cancers should avoid resveratrol ⁽⁷⁾.

There is no data from clinical trials to support the beneficial effects of resveratrol in humans.