Antioxidant action of thiopalmitic acid on microsomal lipid peroxidation.
The antioxidant action of thiopalmitic acid (SH-Pal) was studied in a lipid peroxidation system using microsomes from rat liver. The Fe(II)/ascorbic acid (AsA)-induced lipid peroxidation, as measured by the amount of thiobarbituric acid-reactive substances (TBA-RS), was progressively inhibited by the addition of increasing amounts of SH-Pal. The inhibitory effect of SH-Pal in this experimental system was greater than that of alpha-tocopherol, glutathione (GSH) and palmitic acid. The antioxidative effect was abolished gradually by the addition of increasing amounts of N-ethylmaleimide to the system. Similarly, microsomal lipid peroxidation induced by Fe(III)-ADP/NADPH or CCl4/NADPH was inhibited in a dose-dependent fashion by the addition of SH-Pal. Moreover, SH-Pal was able to reduce 1,1-diphenyl-2-picrylhydrazyl (DPPH). The alpha-tocopherol content of the microsomal lipid peroxidation system decreased rapidly when no SH-Pal was present. However, upon adding SH-Pal (90 microM), the decrease in the alpha-tocopherol content of the assay system was markedly reduced. These findings indicate that SH-Pal acts as an antioxidant and free radical scavenger in lipid peroxidation carried out by rat liver microsomes.
Tanaka
M
M
Showa College of Pharmaceutical Sciences, Tokyo, Japan.
Anzai
S
S
Takeno
K
K
Nakagawa
M
M
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology; D015764:Bepridil / Q000031:analogs & derivatives / Q000378:metabolism; D001713:Biphenyl Compounds; D002251:Carbon Tetrachloride / Q000494:pharmacology; D016166:Free Radical Scavengers; D066298:In Vitro Techniques; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism*; D010084:Oxidation-Reduction; D010169:Palmitic Acids / Q000494:pharmacology*; D010851:Picrates; D051381:Rats; D017208:Rats, Wistar; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014810:Vitamin E / Q000378:metabolism
D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010169:Palmitic Acids; D010851:Picrates; D017392:Thiobarbituric Acid Reactive Substances; C091863:thiopalmitic acid; D014810:Vitamin E; D000244:Adenosine Diphosphate; D015764:Bepridil; D002251:Carbon Tetrachloride; C004931:1,1-diphenyl-2-picrylhydrazyl; D001205:Ascorbic Acid