Onderzoek toont aan dat resveratrol in
druivenschillen kankercellen kan doden.*
Gematigd drinken van rode wijn blijkt ook goed te zijn tegen
kanker. Gematigd betekent 4 keer per week 1 glas. Bij meer drinken stopt het
effect en bij veel drinken is er net een grotere kans op kanker.
It's well known that drinking
red wine in moderation can have some health benefits, mainly attributed to a
compound called resveratrol. Now, scientists at the University of Virginia
Health System have discovered how.
They found how resveratrol
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 Marty Mayo, assistant professor of biochemistry
and molecular genetics at U.Va.
Mayo said that the resveratrol
in one glasses of wine three or four times a week is the right amount to block
the protein from feeding cancer cells. Drinking much more than that, however,
could stop this affect and, in fact, lead to a greater risk of cancer, he said.
The findings, discovered by
Fan Yeung, a postdoctoral fellow at U.Va., are published in the May 20 online
edition of the Journal of the European Molecular Biology Organization (EMBO)
found at: http://embojournal.npgjournals.com/.
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. Resveratrol is also sold
over-the-counter in the U.S. as a nutritional supplement.
For a number of years,
scientists have known that resveratrol acts as an anti-cancer agent, but its
role has not been well understood. Mayo and his team demonstrated that cancer
cells treated with resveratrol died because they became sensitive to a compound
called Tumor Necrosis Factor alpha (TNFa). The U.Va. Health System 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.
The use of NF-kB inhibitors
like resveratrol also has important implications for increasing the
effectiveness of cancer therapy. "Researchers are always looking for ways
to improve cancer therapy," Mayo said. "Current studies are using
compounds similar to TNFa in conjunction with resveratrol to kill cancer
cells." Clinical trials using this approach in patients are showing
encouraging results, Mayo said, and this research may explain why this combined
therapy is effective.
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's research on resveratrol was funded by grants from the National Cancer Institute and the Paul Mellon Prostate Cancer Institute. (mei 2004)