Purpurogallin protects both ventricular myocytes and aortic endothelial cells of rats against oxyradical damage.
Rat ventricular myocytes have been isolated and cultured by two separate procedures. Using phase-contrast and electron microscopies, we illustrate that (a) definitive cell damage is produced when myocytes are exposed to xanthine oxidase--hypoxanthine and (b) purpurogallin between 0.25 and 1.0 mM prolongs survival of both myocyte preparations in a dose-dependent manner. The cytoprotection produced by 1 mM purpurogallin exceeds that given by 2 mM each of ascorbate, Trolox, and mannitol, or 24,200 IU superoxide dismutase/L and (or) 92,000 IU catalase/L. Furthermore, we noted, for the first time, that purpurogallin markedly protects rat aortic endothelial cells, a key target of free radical generation and attack. In contrast, Trolox has a negligible effect here. Mechanistically, we showed that purpurogallin inhibits urate formation by xanthine oxidase more potently than allopurinol. Also, the compound diminishes formation of superoxide-reduced cytochrome c. Therefore, purpurogallin is a potent protector of ventricular myocytes and aortic endothelial cells, both of which are important cells in the cardiovascular system.
Wu
T W
TW
Department of Clinical Biochemistry, University of Toronto, Ont., Canada.
Wu
J
J
Carey
D
D
Zeng
L H
LH
D000818:Animals; D001011:Aorta / Q000166:cytology / Q000187:drug effects; D001567:Benzocycloheptenes / Q000494:pharmacology*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects*; D016166:Free Radical Scavengers; D005609:Free Radicals; D006321:Heart / Q000187:drug effects*; D006352:Heart Ventricles / Q000166:cytology / Q000187:drug effects; D008297:Male; D008854:Microscopy, Electron; D010100:Oxygen / Q000037:antagonists & inhibitors*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors*
D001567:Benzocycloheptenes; D016166:Free Radical Scavengers; D005609:Free Radicals; D014969:Xanthine Oxidase; C026133:purpurogallin; D010100:Oxygen