From foodconsumer.org
Red wine compound reduces Alzheimer's disease-causing peptides
By David Liu, Ph.D.
Nov 4, 2005, 10:18
Resveratrol, which is found in red grapes and red wine, may help fight Alzheimer's disease, and possibly other amyloid-related diseases such as Huntington's, Parkinson's and prion diseases, according to a study published in the Nov. 11 issue of the Journal of Biological Chemistry.
One characteristic of Alzheimer's disease is the deposition of amyloid-beta peptides in the brain. The study showed that resveratrol lowers the levels of amyloid-beta peptides in cells, which along with other evidence, led the researchers to believe that resveratrol may help Alzheimer's disease.
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 monitored amyloid-beta levels inside and outside the cells to assess the effectiveness of resveratrol on amyloid-beta peptides. They found that the treated cells had significantly lower amounts of amyloid-bata than the untreated cells.
The researchers believe resveratrol stimulates the degradation of amyloid-beta peptides by the proteasome, which can specifically digest proteins into short polypeptides and amino acids.
Other researchers, in past studies have suggested that resveratrol may act as an antioxidant to help rid free radials provoked by amyloid-beta peptides in the brain, in order to help Alzheimer's patients. Free radials generated from fatty acids are believed to cause Alzheimer's.
Regardless of how resveratrol affects Alzheimer's, eating grapes may not be enough to have an effect on the disease. "Resveratrol in grapes may never reach the concentrations required to obtain the effect observed in our studies," cautioned Marambaud. "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."
The goal of the current study was to understand the mechanism of how resveratrol acts against amyloid-beta, so that the researchers could have a better idea for the design of more effective compounds for the treatment of Alzheimer's.
"The observation that resveratrol has a strong anti-amyloidogenic activity is a powerful starting point for screening analogues of resveratrol for more active and more stable compounds, a task in which our laboratory is actively involved," said Marambaud. "We have already obtained analogues of resveratrol that are 20 times more potent than the original natural compound. We are now aiming to find more stable analogues and to test them in vivo in mice."
Previous studies show resveratrol may help fight other human amyloid-related diseases such as Huntington's, Parkinson's and prion diseases. For example, a French study found that resveratrol may protect neurons against amyloid-like polyglutamines, a hallmark of Huntington's disease.
In addition, other researchers have found that resveratrol has a protective effect against a range of health conditions, including chronic obstructive pulmonary disease (COPD), asthma, arthritis, and many types of cancers. It can also possibly extend the human lifespan.
Resveratrol is a natural polyphenol found in grapes, berries and peanuts, according to Marambaud. High concentrations of the polyphenol are found in red wine. Wines prepared from Pinot Noir grapes contain the highest amount of resveratrol. White wines have less than 5 percent of the amount found in most red wines.
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