title: Antioxidant Capacity of Gallic Acid in vitro Assayed on Human Erythrocytes.
abstract: Gallic acid (GA) is a polyphenol present in many plants. This study was aimed to investigate the molecular interaction of GA with the human erythrocyte membrane and to determine its antioxidant capacity. The molecular interaction with the membrane of human red cells and the antioxidant property was assayed on both human red cells and molecular models of its membrane. Observations by optical, scanning electron, and defocusing microscopy demonstrated that GA is capable to convert red cells from their normal biconcave shape to crenated echinocytes. This result indicates that GA molecules are positioned in the outer monolayer of the red cell membrane. Dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE) were selected as classes of phospholipids found in the outer and inner monolayers of the red cell membrane, respectively. X-ray diffraction and differential scanning calorimetry showed that GA was preferentially bound to DMPC bilayers. Experiments related to the antioxidant capacity of GA indicated that this compound offsets HClO oxidative capacity on DMPE bilayers. In addition, optical, scanning, defocusing microscopy, and hemolysis assays confirmed the protective capacity of GA against HClO deleterious effects on human red cells. As a conclusion, GA would be capable to block the access of oxidants into the lipid bilayer, and thus avoid their access into red cells.
authors: Faculty of Chemical Sciences, University of Concepción, Concepción, Chile. msuwalsk@udec.cl.
authors: Mario
authors: M
authors: Suwalsky
authors: Faculty of Chemical Sciences, University of Concepción, Concepción, Chile.
authors: José
authors: J
authors: Colina
authors: Center for Optics and Photonics, University of Concepción, Concepción, Chile.
authors: María José
authors: MJ
authors: Gallardo
authors: Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland.
authors: Malgorzata
authors: M
authors: Jemiola-Rzeminska
authors: Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland.
authors: Kazimierz
authors: K
authors: Strzalka
authors: Faculty of Exact and Natural Sciences, University of Antioquia, A.A. 1226, Medellín, Colombia.
authors: Marcela
authors: M
authors: Manrique-Moreno
authors: Center for Optics and Photonics, University of Concepción, Concepción, Chile.
authors: Benjamín
authors: B
authors: Sepúlveda
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D002152:Calorimetry, Differential Scanning; D002478:Cells, Cultured; D004910:Erythrocyte Membrane / Q000187:drug effects / Q000378:metabolism; D004912:Erythrocytes / Q000187:drug effects* / Q000378:metabolism* / Q000648:ultrastructure; D005707:Gallic Acid / Q000737:chemistry / Q000494:pharmacology*; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D008051:Lipid Bilayers; D015394:Molecular Structure; D010743:Phospholipids; D013816:Thermodynamics; D014961:X-Ray Diffraction
chemical_list: D000975:Antioxidants; D008051:Lipid Bilayers; D010743:Phospholipids; D005707:Gallic Acid
keywords: Antioxidant; Erythrocyte membrane; Gallic acid; Phospholipid bilayer