title: Free radical scavenging activity of grape seed extract and antioxidants by electron spin resonance spectrometry in an H(2)O(2)/NaOH/DMSO system.
abstract: The scavenging effects of grape seed extract (GSE) on free radicals formed in an H(2)O(2)/NaOH/DMSO system were examined using a spin-trapping electron spin resonance (ESR) method and compared with other natural antioxidants, ascorbic acid, dl-alpha-tocopherol, and beta-carotene. GSE reduced greatly the ESR signal intensity of superoxide radical-5,5-dimethyl-1-pyrroline-N-oxide (DMPO) adducts. GSE also exhibited weak scavenging activity on hydroxyl radical and a little scavenging activity on methyl radical. Ascorbic acid exhibited strong superoxide and hydroxyl radical scavenging activities, but it increased the amount of methyl radical at high concentration. dl-alpha-Tocopherol reduced the amount of superoxide anion, especially the amount of methyl radical. However, it slightly reduced the amount of hydroxyl radical. beta-Carotene reduced the amount of hydroxyl radical and methyl radical, but it also slightly reduced superoxide anion. In the case of combination use of beta-carotene and dl-alpha-tocopherol, all radical species were suppressed. Combination of GSE and dl-alpha-tocopherol also could reduce all radical species. beta-Carotene and dl-alpha-tocopherol could reduce the methyl radical formation induced by ascorbic acid.
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmaceutical Science, Hoshi University, Ebara 2-4-41, Shinagawa-ku, Tokyo 142, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Yamaguchi
authors.forename: Y
authors.initials: Y
authors.lastname: Yoshimura
authors.forename: H
authors.initials: H
authors.lastname: Nakazawa
authors.forename: T
authors.initials: T
authors.lastname: Ariga
mesh_terms: D004121:Dimethyl Sulfoxide / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006861:Hydrogen Peroxide / Q000737:chemistry; D010936:Plant Extracts / Q000494:pharmacology; D019685:Rosales / Q000196:embryology*; D012639:Seeds / Q000737:chemistry*; D012972:Sodium Hydroxide / Q000737:chemistry
chemical_list: D016166:Free Radical Scavengers; D010936:Plant Extracts; D012972:Sodium Hydroxide; D006861:Hydrogen Peroxide; D004121:Dimethyl Sulfoxide