3D NMR structure of a complex between the amyloid beta peptide (1-40) and the polyphenol ε-viniferin glucoside: Implications in Alzheimer's disease

Background: Alzheimer's disease (AD) is a progressive neurodegenerative disorder. There is a consensus that A beta is a pathologic agent and that its toxic effects, which are at present incompletely understood, may occur through several potential mechanisms. Polyphenols are known to have wide-ranging properties with regard to health and for helping to prevent various diseases like neurodegenerative disorders. Thus inhibiting the formation of toxic AD assemblies is a reasonable hypothesis to prevent and perhaps treat AD Methods: Solution NMR and molecular modeling were used to obtain more information about the interaction between the A beta(1-40) and the polyphenol epsilon-viniferin glucoside (EVG) and particularly the A beta residues involved in the complex. Results: The study demonstrates the formation of a complex between two EVG molecules and A beta(1-40) in peptide characteristic regions that could be in agreement with the inhibition of aggregation. Indeed, in previous studies, we reported that EVG strongly inhibited in vitro the fibril formation of the full length peptides A beta(1-40) and A beta(1-42), and had a strong protective effect against PC12 cell death induced by these peptides. Conclusion: For the full length peptide A beta(1-40), the binding sites observed could explain the EVG inhibitory effect on fibrillization and thus prevent amyloidogenic neurotoxicity. General significance: Even though this interaction might be important at the biological level to explain the protective effect of polyphenols in neurodegenerative diseases, caution is required when extrapolating this in vitro model to human physiology. (C) 2013 Elsevier B.V. All rights reserved.