Green Tea Antioxidant May Help Prevent Alzheimer's

May 31 -- FRIDAY, May 30 (HealthDay News) -- An antioxidant found in green tea appears to prevent the development of amyloid fibrils, a toxic protein associated with Alzheimer's and Parkinson's disease, a new study finds.

Amyloid plaque is commonly seen in the brains of Alzheimer's patients and appears to disrupt the function of cells. Strategies to prevent the development of amyloid plaque are one avenue being explored in the prevention and treatment of Alzheimer's.

Now, a German team says the tea antioxidant, called epigallocatechin gallate (EGCG), has potent anti-plaque ability.

"We can use small molecules like EGCG to convert certain misfolded structures of a protein into a new type of molecule, which is less toxic or not toxic for cells," said lead researcher Erich Wanker, from the Max Delbrueck Center for Molecular Medicine in Berlin.

The findings are published in the May 30 online edition of Nature Structural & Molecular Biology.

The accumulation of amyloid plaque in Alzheimer's and other neurodegenerative diseases, such as Parkinson's, are thought to be caused by the misfolding of certain proteins, which then become toxic to cells. The way proteins fold is key to their function, the researchers explained.

In experiments in the laboratory, the German team found that EGCG seems to change potentially harmful proteins into proteins that are not detrimental to brain cells. "We are able to convert a toxic structure into a less toxic structure," Wanker explained.

Because EGCG binds to unfolded proteins -- which are not associated with Alzheimer's -- the discovery could lead to medications that recognize the more troublesome proteins and convert them to harmless substances.

"This method could be more generally used to get rid of or remove the concentration of misfolded proteins in cells," Wanker said. "This strategy should be tested with patients. If treated early on, it could prevent the formation of amyloid plaque," he speculated.

Whether this type of treatment could reverse plaques that have already formed in the brain isn't known, Wanker said.