Natural extracts as possible protective agents of brain aging.

A growing number of studies suggest that natural extracts and phytochemicals have a positive impact on brain aging. We examined the potential of the Ginkgo biloba extract EGb 761 and red wine-derived constituents on cell death produced by beta-amyloid (Abeta) peptides and oxidative stress, with respect to their possible deleterious role in age-related neurological disorders. We found that EGb 761, possibly through the antioxidant properties of its flavonoids, was able to protect hippocampal cells against toxic effects induced by Abeta peptides. Moreover, we showed that an exposure of rat hippocampal cells to the nitric oxide (NO) donor sodium nitroprusside (SNP) resulted in a decrease in cell survival and increase in reactive oxygen species (ROS) accumulation. However, EGb 761 and red wine-derived polyphenols protected against these events, due to their antioxidant activities, and their ability to block SNP-stimulated activity of protein kinase C (PKC). Taken together, these results support the hypothesis that dietary intake of natural substances may be beneficial in normal aging of the brain. Copyright 2002 Elsevier Science Inc.