"Resveratrol is a natural polyphenol occurring in abundance in several plants, including grapes, berries and peanuts," explains study author Philippe Marambaud. "The polyphenol is found in high concentrations in red wines. The highest concentration of resveratrol has been reported in wines prepared from Pinot Noir grapes. Generally, white wines contain 1% to 5% of the resveratrol content present in most red wines."

One of the characteristic features of Alzheimer's disease is the deposition of amyloid-beta peptides in the brain. Philippe Marambaud and his colleagues at the Litwin-Zucker Research Center for the Study of Alzheimer's Disease and Memory Disorders in Manhasset, New York, administered resveratrol to cells which produce human amyloid-beta and tested the compound's effectiveness by monitoring amyloid-beta levels inside and outside the cells. They found that levels of amyloid-beta in the treated cells were much lower than those in untreated cells.

The researchers believe the compound acts by stimulating the degradation of amyloid-beta peptides by the proteasome, a barrel-shaped multi-protein complex that can specifically digest proteins into short polypeptides and amino acids.

However, eating grapes may not be a cure for Alzheimer's disease. "It is difficult to know whether the anti-amyloidogenic effect of resveratrol observed in cell culture systems can support the beneficial effect of specific diets such as eating grapes," cautions Marambaud. "Resveratrol in grapes may never reach the concentrations required to obtain the effect observed in our studies. Grapes and wine however contain more than 600 different components, including well-characterized antioxi
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Contact: Nicole Kresge
nkresge@asbmb.org
301-634-7415
American Society for Biochemistry and Molecular Biology
3-Nov-2005