title: Membrane lipids protected from oxidation by red wine tannins: a proton NMR study.
abstract: Dietary polyphenols widespread in vegetables and beverages like red wine and tea have been reported to possess antioxidant properties that could have positive effects on human health. In this study, we propose a new in situ and non-invasive method based on proton liquid-state nuclear magnetic resonance (NMR) to determine the antioxidant efficiency of red wine tannins on a twice-unsaturated phospholipid, 1,2-dilinoleoyl-sn-glycero-3-phosphocholine (DLiPC), embedded in a membrane model. Four tannins were studied: (+)-catechin (C), (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin gallate (EGCG). The lipid degradation kinetics was determined by measuring the loss of the bis-allylic protons during oxidation induced by a radical initiator, 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (AAPH). The antioxidant efficiency, i.e. the ability of tannins to slow down the lipid oxidation rate, was shown to be higher for galloylated tannins, ECG and EGCG. Furthermore, the mixture of four tannins was more efficient than the most effective tannin, EGCG, demonstrating a synergistic effect. To better understand the antioxidant action mechanism of polyphenols on lipid membranes, the tannin location was investigated by NMR and molecular dynamics. A correlation between antioxidant action of tannins and their location at the membrane interface (inserted at the glycerol backbone level) could thus be established.
authors: Institute of Chemistry and Biology of Membranes and Nano-objects, UMR 5248, CNRS, University of Bordeaux, IPB, F-33600 Pessac, France.
authors: Aurélien L
authors: AL
authors: Furlan
authors: Institute of Chemistry and Biology of Membranes and Nano-objects, UMR 5248, CNRS, University of Bordeaux, IPB, F-33600 Pessac, France.
authors: Marie-Lise
authors: ML
authors: Jobin
authors: Unité de Génie Enzymatique et Cellulaire, FRE 3580, CNRS, Université de Picardie Jules Verne, F-80039 Amiens Cedex, France.
authors: Sébastien
authors: S
authors: Buchoux
authors: Institute of Chemistry and Biology of Membranes and Nano-objects, UMR 5248, CNRS, University of Bordeaux, IPB, F-33600 Pessac, France.
authors: Axelle
authors: A
authors: Grélard
authors: Institute of Chemistry and Biology of Membranes and Nano-objects, UMR 5248, CNRS, University of Bordeaux, IPB, F-33600 Pessac, France.
authors: Erick J
authors: EJ
authors: Dufourc
authors: Institute of Chemistry and Biology of Membranes and Nano-objects, UMR 5248, CNRS, University of Bordeaux, IPB, F-33600 Pessac, France. Electronic address: j.gean@cbmn.u-bordeaux.fr.
authors: Julie
authors: J
authors: Géan
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000494:pharmacology; D002722:Chlorobenzenes / Q000737:chemistry / Q000378:metabolism; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D007700:Kinetics; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008563:Membrane Lipids / Q000737:chemistry* / Q000378:metabolism; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D010084:Oxidation-Reduction / Q000187:drug effects; D010713:Phosphatidylcholines / Q000737:chemistry / Q000378:metabolism; D013997:Time Factors; D014920:Wine
chemical_list: D000975:Antioxidants; D002722:Chlorobenzenes; D008051:Lipid Bilayers; D008563:Membrane Lipids; D010713:Phosphatidylcholines; D002392:Catechin; C062669:epicatechin gallate; C045651:epigallocatechin gallate; C004944:chlorfenethol; C028694:1-palmitoyl-2-oleoylphosphatidylcholine; D004134:Dimyristoylphosphatidylcholine
keywords: Antioxidant efficiency; Lipid oxidation; Membrane location; Molecular dynamics; NMR; Tannins