Grape Epicatechin Conjugates Prevent Erythrocyte Membrane Protein Oxidation

• Published in: Journal of agricultural and food chemistry Vol. 60; no. 16; pp. 4090 - 4095
• Main Authors: Martínez, V, Ugartondo, V, Vinardell, M. P, Torres, J. L, Mitjans, M
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 25.04.2012; American Chemical Society, Books and Journals Division
• Subjects: antioxidant activity; Antioxidants; Biological and medical sciences; Catechin - pharmacology; cell membranes; epicatechin; Erythrocyte Membrane - drug effects; Erythrocyte Membrane - metabolism; Erythrocytes; Erythrocytes - drug effects; Erythrocytes - metabolism; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; gel electrophoresis; Grapes; Hematies; Humans; membrane fluidity; Membrane proteins; Membrane Proteins - metabolism; oxidation; Oxidation-Reduction - drug effects; Plant Extracts - pharmacology; Polifenols; Polyphenols; protein degradation; Proteïnes de membrana; Raïms; scanning electron microscopy; Vitis - chemistry; erythrocytes; AAPH; epicatechin; membrane protein; cell morphology; band 3; membrane fluidity; Flavanol; Membrane protein; Fruit; Flavonoid; Polyphenol; Morphology; Grape; Membrane; Oxidation; Cell
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf2051784

Epicatechin conjugates obtained from grape have shown antioxidant activity in various systems. However, how these conjugates exert their antioxidant benefits has not been widely studied. We assessed the activity of epicatechin and epicatechin conjugates on the erythrocyte membrane in the presence and absence of a peroxyl radical initiator, to increase our understanding of their mechanisms. Thus, we studied cell membrane fluidity by fluorescence anisotropy measurements, morphology of erythrocytes by scanning electron microscopy, and finally, red cell membrane proteins by sodium dodecyl sulfate–polyacrylamide gel electrophoresis. Our data showed that incubation of red cells in the presence of epicatechin derivatives altered membrane fluidity and erythrocyte morphology but not the membrane protein pattern. The presence in the medium of the peroxyl radical initiator 2,2′-azobis(amidinopropane) dihydrochloride (AAPH) resulted in membrane disruptions at all levels analyzed, causing changes in membrane fluidity, cell morphology, and protein degradation. The presence of antioxidants avoided protein oxidation, indicating that the interaction of epicatechin conjugates with the lipid bilayer might reduce the accessibility of AAPH to membranes, which could explain in part the inhibitory ability of these compounds against hemolysis induced by peroxidative insult.