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.
Yoshikawa
T
T
First Department of Medicine, Kyoto Prefectural University of Medicine, Japan.
Naito
Y
Y
Tanigawa
T
T
Kondo
M
M
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