CONICET | Buscador de Institutos y Recursos Humanos

Can membrane interactions be the basis for considering plant polyphenols as micronutrients? Cesar G. Fraga1,2, and Patricia I. Oteiza1 1Department of Nutrition, University of California, Davis, California, USA; and 2Physical Chemistry-PRALIB, School of Pharmacy and Biochemistry, University of Buenos Aires, Argentina Epidemiological evidence demonstrates that diets rich in fruits and vegetables promote health by attenuating or delaying the onset of various diseases, e.g. cardiovascular and neurodegenerative diseases, diabetes, and cancer. The chemical components involved, and the physiological and molecular mechanisms by which fruit and vegetables reduce the risk of disease, are still poorly understood. Flavonoids are polyphenols that are gaining acceptance as responsible for the health benefits offered by fruit and vegetables. Because of their chemical structure, flavanols and related procyanidins (PC) can scavenge free radicals, inactivate other pro-oxidants, and can also interact with a number of biological molecules. We have investigated in Jurkat and Caco-2 cells the effects of epicatechin (EC) and related procyanidins (PC) on cell oxidation. The obtained results indicate that primary targets of EC and PC antioxidant actions are localized at the cell membrane, involving the regulation of NADPH-oxidase activity, and an associated decrease of superoxide production. The proposed interactions of EC and PC with cell membrane (proteins) could better explain the health benefits of flavanols and other flavonoids by making compatible actual tissue levels with the observed antioxidant effects. This would provide a rationale to consider flavanols as micronutrients Supported by NIH AT2966, and UC Davis CHNR which was established with funding from the State of California Vitamin Price Fixing Consumer Settlement fund.