title: Comparison of antioxidant effectiveness of lipoic acid and dihydrolipoic acid.
abstract: The abilities of dihydrolipoic acid (DHLA) to scavenge peroxynitrite (ONOO(-) ), galvinoxyl radical, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cation radical (ABTS(+•) ), and 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH) were higher than those of lipoic acid (LA). The effectiveness of DHLA to protect methyl linoleate against 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH)-induced oxidation was about 2.2-fold higher than that of LA, and DHLA can retard the autoxidation of linoleic acid (LH) in the β-carotene-bleaching test. DHLA can also trap ∼0.6 radicals in AAPH-induced oxidation of LH. Moreover, DHLA can scavenge ∼2.0 radicals in AAPH-induced oxidation of DNA and AAPH-induced hemolysis of erythrocytes, whereas LA can scavenge ∼1.5 radicals at the same experimental conditions. DHLA can protect erythrocytes against hemin-induced hemolysis, but accelerate the degradation of DNA in the presence of Cu(2+) . Therefore, the antioxidant capacity of -SH in DHLA is higher than S-S in LA.
authors.affiliation: Department of Organic Chemistry, College of Chemistry, Jilin University, Changchun 130021, People's Republic of China.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhao
authors.forename: Zai-Qun
authors.initials: ZQ
authors.lastname: Liu
mesh_terms: D000578:Amidines / Q000737:chemistry / Q000494:pharmacology; D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology; D052160:Benzothiazoles / Q000737:chemistry; D001713:Biphenyl Compounds / Q000737:chemistry; D004247:DNA / Q000737:chemistry; D004655:Emulsions; D006427:Hemin / Q000737:chemistry / Q000494:pharmacology; D006461:Hemolysis / Q000187:drug effects; D053878:Hemolytic Agents / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D008042:Linolenic Acids / Q000737:chemistry; D016877:Oxidants / Q000737:chemistry; D010084:Oxidation-Reduction; D030421:Peroxynitrous Acid / Q000737:chemistry; D010851:Picrates / Q000737:chemistry; D013451:Sulfonic Acids / Q000737:chemistry; D008063:Thioctic Acid / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000494:pharmacology; D019207:beta Carotene / Q000737:chemistry
chemical_list: D000578:Amidines; D000975:Antioxidants; D052160:Benzothiazoles; D001713:Biphenyl Compounds; D004655:Emulsions; D053878:Hemolytic Agents; D008042:Linolenic Acids; D016877:Oxidants; D010851:Picrates; D013451:Sulfonic Acids; D019207:beta Carotene; D030421:Peroxynitrous Acid; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; C046728:2,2'-azobis(2-amidinopropane); D008063:Thioctic Acid; D006427:Hemin; C015144:dihydrolipoic acid; D004247:DNA; C004931:1,1-diphenyl-2-picrylhydrazyl