Inhibitory activity of stilbenes on Alzheimer's β-amyloid fibrils in vitro

Polymerization of the amyloid beta-peptide (A beta) has been identified as one of the major characteristics of Alzheimer's disease (AD). Thus, finding molecules to prevent the aggregation of A beta could be of therapeutic value in AD. We describe an original routine in vitro assay to search for inhibitors of A beta(25-35) fibril formation which uses UV-visible measurements and electron microscopy (EM). In particular, this routine assay was used to examine the effects of stilbenes, a well-known polyphenol class, as inhibitors of A beta fibril formation. The inhibitory properties of resveratrol (RES), piceid (PIC), resveratrol diglucoside (DIG), piceatannol (PIA), astringine (AST), and viniferin (VIN) were characterized and compared. RES and PIC effectively and dosedependently inhibited A beta polymerization while other polyphenols exerted less inhibition. Although the mechanism of anti-amyloidogenic activity is still unknown, these results support the hypothesis that stilbenes could be of therapeutic value in AD. (c) 2006 Elsevier Ltd. All rights reserved.