Resveratrol, a compound found in grapes and red wine, lowers levels of the amyloid-beta peptides that cause the plaques in the brain leading to Alzheimer's disease, shows new research.
It could help to explain the large body of epidemiological evidence linking wine consumption to lower risk of dementia.
Writing in the 11 November issue of the Journal of Biological Chemistry, 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, describe adding resveratrol to cells which produce human amyloid-beta.
They found that levels of amyloid-beta in the treated cells were much lower than those in untreated cells.
The deposition of amyloid-beta peptides in the brain is one of the characteristic features of Alzheimer's disease.
But although resveratrol is naturally found in several plants, including grapes, berries and peanuts, and is particularly high in Pinot Noir grape varieties, Marambaud said that these concentrations are unlikely to be enough to reach the effect seen in his study.
"Resveratrol in grapes may never reach the concentrations required to obtain the effect observed in our studies," he said.
But he added: "Grapes and wine however contain more than 600 different components, including well-characterized antioxidant molecules. Therefore, we cannot exclude the possibility that several compounds work in synergy with small amounts of resveratrol to slow down the progression of the neurodegenerative process in humans."
Marambaud and his colleagues are now trying to explain how resveratrol exerts its effects in order to develop similar compounds to use in new drugs to treat Alzheimer's disease.
The researchers believe that resveratrol 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.
Resveratrol may also be effective in fighting other human amyloid-related diseases such as Huntington's, Parkinson's and prion diseases. Studies by a group at the Institut National de la Santé et de la Recherche Médicale in Paris, France headed by Christian Néri have recently shown that resveratrol may protect neurons against amyloid-like polyglutamines, a hallmark of Huntington's disease.