title: Sparing effect of procyanidins from Vitis vinifera on vitamin E: in vitro studies.
abstract: The sparing/recycling effect of a highly purified, high molecular weight fraction of catechin oligomers (procyanidins) from Vitis vinifera seeds on alpha-tocopherol was studied in both homogeneous solution and in heterogeneous phase (phosphatidylcholine liposomes and red blood cells). By HPLC and electron spin resonance (ESR) spectroscopy we evidenced that tocopheroxyl radical, induced by reaction of alpha-tocopherol with the stable radical DPPH (2,2-diphenyl-1-picrylhydrazyl) is recycled by procyanidins. In addition procyanidins significantly and dose-dependently spare vitamin E from consumption (HPLC monitoring) during the autooxidation phase of the HO-induced peroxidation of phosphatidylcholine, by 23% at the lowest concentration (0.5 microM) and by 65.5% at 3 microM. In this membrane model the combination of 0.5 microM procyanidins and 2 microM alpha-tocopherol results in a marked delay in the appearance of conjugated dienes in respect to the single antioxidants (synergistic interaction), while catechin showed to be active only at 5 microM. In red blood cells oxidatively stressed by UVB exposure, procyanidins at 0.1-1.0 microM prevent vitamin E loss, markedly decrease membrane lipid peroxidation, linearly related to the concentration of vitamin E in the membranes, and significantly delay the onset of hemolysis (catechin protects between 5 and 10 microM).
authors.affiliation: Istituto Chimico Farmaceutico Tossicologico, Milan, Italy. Roberto.MaffeiFacino@unimi.it
authors.forename: R
authors.initials: R
authors.lastname: Maffei Facino
authors.forename: M
authors.initials: M
authors.lastname: Carini
authors.forename: G
authors.initials: G
authors.lastname: Aldini
authors.forename: M T
authors.initials: MT
authors.lastname: Calloni
authors.forename: E
authors.initials: E
authors.lastname: Bombardelli
authors.forename: P
authors.initials: P
authors.lastname: Morazzoni
mesh_terms: D000818:Animals; D044946:Biflavonoids; D002392:Catechin / Q000302:isolation & purification / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D004578:Electron Spin Resonance Spectroscopy; D004912:Erythrocytes / Q000378:metabolism / Q000528:radiation effects; D015227:Lipid Peroxidation / Q000187:drug effects; D008081:Liposomes; D008297:Male; D044945:Proanthocyanidins; D051381:Rats; D017208:Rats, Wistar; D019685:Rosales / Q000737:chemistry*; D014466:Ultraviolet Rays; D014810:Vitamin E / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D044946:Biflavonoids; D008081:Liposomes; D044945:Proanthocyanidins; D014810:Vitamin E; C017674:procyanidin; D002392:Catechin