Reprinted from:
www.mercola.com/2002/mar/16/grapes_cancer.htm
Grapes' Anti-fungal Agent May Fight Cancer
http://www.mercola.com/2002/mar/16/grapes_cancer.htm
Researchers reported that resveratrol is converted in the body to a known anti-cancer agent that can selectively target and destroy cancer cells.
Although previous studies have suggested that this phytoestrogen might prevent cancer, they said it was the first time that scientists had gained an insight into the underlying mechanism of the chemical's anticancer properties.
Resveratrol is a defensive molecule against fungus in grapes and other crops, and is found at higher levels in those which have not been treated with man-made fungicides.
Learning from nature in this way will help in our work to design drugs which are selectively activated in a tumor and can form the basis of anticancer treatments.
The researchers found that resveratrol is processed by the enzyme CYP1B1, which is found in a variety of different tumors. This converts resveratrol into piceatannol, a closely related phytoestrogen with known anticancer activity.
Previous research by the team has shown that this process is restricted to the tumor itself, limiting the toxicity to the cancer cells and serving to selectively destroy them.
The team is also looking into the beneficial effects of Brassica vegetables such as broccoli and cabbage that contain a molecule that activates the CYP1B1 enzyme.
Resveratrol (pronounced rez-VER-a-trawl), is one of a group of compounds (called phytoalexins) that are produced in plants during times of environmental stress such as adverse weather or insect, animal or pathogenic attack.
Resveratrol has been identified in more than 70 species of plants, including mulberries and peanuts. Grapes, however are particularly good sources. Resveratrol is found in the skin (not flesh) of grapes.
Fresh grape skin contains about 50 to 100 micrograms of resveratrol per gram, while red wine concentrations range from 1.5 to 3 milligrams per liter. This compound is also thought to be responsible, in part, for the cholesterol-lowering effects of red wine and may also explain why those consuming a Mediterranean-type diet (of which red wine consumption is characteristic) may have a reduced risk of heart disease.
Other studies have shown that resveratrol was effective during all three phases of the cancer process: initiation, promotion and progression.
Resveratrol was found to have antioxidant and antimutagenic activity and also increased levels of the phase II drug-metabolizing enzymes that are capable of metabolically detoxifying carcinogens, thereby ridding them from the body.
All three of these physiological effects are indicative of resveratrol preventing cancer initiation -- the initial, irreversible stage of the cancer process. Resveratrol also demonstrated antiinflammatory effects and inhibited the activity of the cyclooxygenase and hydroperoxidase enzymes (suggestive of antipromotion activity) in addition to causing the differentiation of human promyelocytic leukemia cells, indicating that this compound may also depress the progression phase of cancer.
British Journal of Cancer 2002;5
DR. MERCOLA'S COMMENT:
While resveratrol may have beneficial effects, it is wise to limit grape intake if you have evidence of high insulin levels, such as high blood pressure, high cholesterol, obesity or diabetes.
The extra fructose in the meat of the grape (which has no resveratrol) will only worsen insulin levels, which is likely to be a stronger influence on cancer than resveratrol.
Reprinted from:
www.mercola.com/2002/mar/16/grapes_cancer.htm