Efficacy of taurine based compounds as hydroxyl radical scavengers in silica induced peroxidation.
While it is widely believed that taurine may play an important role in protecting cells against toxic injury by functioning as an antioxidant, there is a lack of evidence to support this hypothesis. In this study, electron spin resonance (ESR) was used to investigate the reaction of taurine and hypotaurine with hydroxyl radicals (.OH). The Fenton reaction (Fe(II) + H2O2-->Fe(III) + .OH + OH-) and the Cr(V)-mediated Fenton-like reaction (Cr(V) + H2O2-->Cr(VI) + .OH + OH-) were used as sources of .OH radicals. The results show that hypotaurine but not taurine effectively scavenges .OH radicals with a reaction rate constant of k = 1.6 x 10(10) M-1s-1. That is comparable with other efficient .OH radical scavengers. The effect of taurine and hypotaurine on silica-induced lipid peroxidation was evaluated using linoleic acid as a model lipid. Hypotaurine, but not taurine, caused a significant inhibition of silica-induced lipid peroxidation. The results show that hypotaurine is an excellent antioxidant and appears to have the potential for being a therapeutic agent against silica-induced lung injury.
Shi
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X
Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, WV 26505, USA.
Flynn
D C
DC
Porter
D W
DW
Leonard
S S
SS
Vallyathan
V
V
Castranova
V
V
D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism; D002857:Chromium / Q000378:metabolism; D003497:Cyclic N-Oxides / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers / Q000378:metabolism*; D005609:Free Radicals / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D017665:Hydroxyl Radical / Q000378:metabolism*; D007501:Iron / Q000378:metabolism; D007700:Kinetics; D015227:Lipid Peroxidation / Q000187:drug effects*; D012822:Silicon Dioxide / Q000494:pharmacology*; D013113:Spin Labels; D013654:Taurine / Q000031:analogs & derivatives* / Q000378:metabolism* / Q000494:pharmacology; D017962:alpha-Linolenic Acid / Q000378:metabolism
D000975:Antioxidants; D003497:Cyclic N-Oxides; C045076:Fenton's reagent; D016166:Free Radical Scavengers; D005609:Free Radicals; D013113:Spin Labels; D002857:Chromium; D017962:alpha-Linolenic Acid; D013654:Taurine; D017665:Hydroxyl Radical; C003949:hypotaurine; C017245:5,5-dimethyl-1-pyrroline-1-oxide; D012822:Silicon Dioxide; D006861:Hydrogen Peroxide; D007501:Iron