PROTECTIVE EFFECT OF PHILESIA MAGELLANICA (COICOPIHUE) FROM CHILEAN PATAGONIA AGAINST OXIDATIVE DAMAGE

Abstract

Philesia magellanica (P. magellanica) is a plant collected in the Chilean Patagonia. Its antioxidant properties were assessed in human erythrocytes exposed in vitro to oxidative stress induced by HClO. Scanning electron microscopy (SEM) observations showed that HClO induced a morphological alteration in the red blood cells from a normal discoid to a spherocytic form, and cells of unequal size. However, a concentration as low as 1 mM gallic acid equivalents (GAE) of P. magellanica aqueous extract neutralized the change effects of 50 µM HClO. On the other hand, 20 µM (GAE) of the extract considerably reduced the deleterious capacity of 0.25 mM HClO to induce hemolysis in red blood cells. In addition, X-ray diffraction experiments were performed in molecular models of the human erythrocyte membrane. These consisted in multilayers of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), classes of lipids preferentially located in the outer and inner monolayers, respectively of the human erythrocyte membrane. It was observed that P. magellanica only interacted with DMPC affecting its multilayer structure. It was also observed that 0.1 µM (GAE) of P. magellanica neutralized the structural perturbation induced by 0.05 and 0.5 mM HClO. These experiments confirmed the antioxidant properties of P. magellanica aqueous extracts.