Free radical scavenging activity of the novel anti-ulcer agent rebamipide studied by electron spin resonance.
The anti-free radical action of rebamipide (2-(4-chlorobenzoylamino)-3-[2(1H)-quinolinon-4-yl] propionic acid, CAS 11911-87-6), a novel anti-ulcer agent, was investigated by electron spin resonance spectroscopy. A spin trapping method using 5,5-dimethyl-1-pyrroline-N-oxide showed that rebamipide dose-dependently decreased both the intensity of the hydroxyl radical spin adduct signal generated by the Fenton reaction and the intensity of the superoxide spin adduct generated from opsonized zymosan-stimulated neutrophils. A kinetic study showed that the second order rate constant for the reaction between rebamipide and hydroxyl radicals at pH 7.8 was 2.24 x 10(10) mol l-1 s-1. These results indicate in vitro antioxidant properties of rebamipide which is active as hydroxyl radical scavenger and inhibitor of superoxide production in neutrophils.
First Department of Medicine, Kyoto Prefectural University of Medicine, Japan.
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Yoshikawa
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Naito
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Tanigawa
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Kondo
D000409:Alanine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000897:Anti-Ulcer Agents / Q000494:pharmacology*; D015764:Bepridil / Q000031:analogs & derivatives; D001713:Biphenyl Compounds; D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers; D006801:Humans; D066298:In Vitro Techniques; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism; D010851:Picrates; D015363:Quinolones / Q000494:pharmacology*; D013481:Superoxides / Q000378:metabolism; D015054:Zymosan / Q000494:pharmacology
D000897:Anti-Ulcer Agents; D001713:Biphenyl Compounds; D003497:Cyclic N-Oxides; D016166:Free Radical Scavengers; D010851:Picrates; D015363:Quinolones; D013481:Superoxides; C017245:5,5-dimethyl-1-pyrroline-1-oxide; D015764:Bepridil; D015054:Zymosan; C004931:1,1-diphenyl-2-picrylhydrazyl; C052785:rebamipide; D000409:Alanine