Researchers discover why wine antioxidant kills cancer
activity of resveratrol, the compound found in red wine and thought
to be responsible for the drink's widely reported health benefits,
writes Wai Lang Chu.
The discovery has important implications for increasing the effectiveness of cancer therapy, with some clinical trials using resveratrol already showing encouraging results.
But it could also explain how resveratrol helps to control atherosclerosis, heart disease, arthritis, and autoimmune disorders, say the researchers.
Marty Mayo, assistant professor of biochemistry and molecular genetics at the University of Virginia, and his team report that the compound helps to starve cancer cells by inhibiting the action of a key protein that feeds them. The protein, called nuclear factor- kappa B (NF-kB), is found in the nucleus of all cells and activates genes responsible for cell survival.
"We used physiologically-relevant doses of resveratrol and found dramatic effects on human cancer cells," said Mayo.
The findings, which are published on the online edition of the Journal of the European Molecular Biology Organization (EMBO) demonstrated that cancer cells treated with resveratrol died because they became sensitive to a compound called Tumor Necrosis Factor alpha (TNFa). The researchers found that resveratrol initiated a reaction in the NF-kB molecule that caused the cancer cells essentially to self-destruct in a process called apoptosis.
"Current studies are using compounds similar to TNFa in conjunction with resveratrol to kill cancer cells," Mayo said.
"Clinical trials using this approach in patients are showing encouraging results. This research may explain why this combined therapy is effective and why researchers are always looking for ways to improve cancer therapy," he added.
Previous studies have also shown that resveratrol can help control atherosclerosis, heart disease, arthritis, and autoimmune disorders. Mayo believes the inhibition of NF-kB may be responsible in those disorders, as well, since NF-kB can control inflammatory responses.
Mayo addded that the total amount of reveratrol in one glass of wine three of four times a week is the right amount to block the protein from feeding cancer cells. However Mayo warned that drinking more than that would stop this effect and may actually lead to a greater risk of cancer.
Resveratrol is an antioxidant found in a number of plants, including grape skins, raspberries, mulberries and peanuts. Its job in nature is to fight fungus during the rainy season, and it is especially prevalent in grapes used in making red wine.
The compound is also sold over-the-counter in the US as a nutritional supplement although concerns have been raised regarding its bioavailability in some of the products on the market.
