Interaction of the chlorogenic acid (CGA) with model lipid membranes and its influence in antiradicalary activity.

J.P. CEJAS; DISALVO, E.A.; M.A. FRÍAS

Congreso; XLVIII Reunión Anual de la Sociedad Argentina de Biofísica; 2019

The production of free radicals in living organisms has been associated with the oxidation of DNA, proteins and in particular membrane lipids. In the latter case, the alterations produced in its structure distort its functions, with the consequent pathological changes in the organism under study. This is one of the reasons why there is great interest in the study of natural antioxidants that, by eliminating free radicals in an effective way, can prevent many diseases directly associated with lipid peroxidation. CGA is an important natural antioxidant composed by an ester of caffeic acid and quinic acid that belongs to the group of polyphenols. Its strong antioxidant and antibacterial properties reduce the risk of diabetes, fungal infections and cancer, and also protect the liver and other organs. A high antioxidant activity with respect to the red blood cell membrane has also been reported [4] but its mechanism of action is not yet well defined. In this work, the interaction of CGA with model lipid membranes (monolayers with different lipid composition) was studied through changes in surface pressure (). The results show that CGA interacts with DMPC membranes and in a lesser extent with those of DPPC generating structural changes at the interface. The analysis of the kinetics of interaction of the antioxidant with DMPC membranes, shows that it occurs with significant structural changes in the membrane. Also, preliminary results show that positively charged radical species such as ABTS?+ form an association with CGA in the immediate proximity of the membrane, preventing its propagation. These results allow us to discuss the possible mechanism of action of the CGA depending on the hydration state of the lipid interface preventing lipid oxidation in the biological membranes.