Interactions of lipid bilayers and natural antioxidants

Abstract

Therapeutic effects of antioxidants have been investigated for their role on prevention and treatment of several diseases, but few studies report on the interaction of these natural substances with membranes. Recently it has been identified that the antioxidant curcumin modulates lipid bilayer properties. Moreover this action was reported to be similar to the effects of other amphiphilic molecules such as antimicrobial peptides. Studies based on model membranes evidenced that electrostatic and elastic characteristics of bilayers, which are due to their lipid composition, are important influences on the mechanisms of interactions, but few studies report how antioxidant substances change them. In the present step of the study the partition coefficients of curcumin and quercetin in zwitterionic (containing cholesterol or in its absence) and anionic phospholipid bilayers will be determined. These partition coefficients will be related to changes in the bilayers fluidity as determined by the fluorescence anisotropy of the probe chlorofil A.