Cancer chemoprevention by resveratrol: In vitro and in vivo studies and the underlying mechanisms (review)

Cancer, next only to heart diseases, is the second leading cause of deaths in the United States of America and many other nations in the world. The prognosis for a patient with metastatic carcinoma of the lung, colon, breast, or prostate (four of the most common and lethal forms of cancer, which together account for more than half of all deaths from cancer in the USA), remains dismal. Conventional therapeutic and surgical approaches have not been able to control the incidence of most of the cancer types. Therefore, there is an urgent need to develop mechanism-based approaches for the management of cancer. Chemoprevention via non-toxic agents could be one such approach. Many naturally occurring agents have shown cancer chemopreventive potential in a variety of bioassay systems and animal models, having relevance to human disease. It is appreciated that an effective and acceptable chemopreventive agent should have certain properties: (a), little or no toxic effects in normal and healthy cells; (b), high efficacy against multiple sites; (c), capability of oral consumption; (d), known mechanism of action; (e), low cost; and (f), acceptance by human population. Resveratrol is one such agent. A naturally occurring polyphenolic antioxidant compound present in grapes, berries, peanuts and red wine. In some bioassay systems resveratrol has been shown to afford protection against several cancer types. The mechanisms of resveratrol's broad cancer chemopreventive effects are not completely understood. In this review, we present the cancer chemopreventive effects of resveratrol in an organ-specific manner. The mechanisms of the antiproliferative/cancer chemopreventive effects of resveratrol are also presented. We believe that continued efforts are needed, especially well-designed pre-clinical studies in the animal models that closely mimic/represent human disease, to establish the usefulness of resveratrol as cancer chemopreventive agent. This should be followed by human clinical trials in appropriate cancer types in suitable populations.