title: Rhein: an anthraquinone that modulates superoxide anion production from human neutrophils.
abstract: Rhein (4,5-dihydroxyanthraquinone-2-carboxylic acid), the active metabolite of diacetylrhein, which has been reported as an effective antirheumatic drug in man, inhibited superoxide anion production from human neutrophils challenged with N-formylmethionyl-leucyl-phenylalanine (FMLP: IC50, 2 x 10(-5) M) and A23186 (IC50, 10(-5) M), but not with phorbol myristate acetate. In the same concentration range (10(-6)-10(-3) M), the drug did not affect oxy-radical production by a cell-free hypoxanthine-xanthine oxidase system and exerted weak inhibitory effects on FMLP-evoked lysosomal enzyme release. Rhein inhibitory effects on neutrophil functioning may contribute to the overall therapeutic activity of the parent drug, diacetylrhein.
mesh_terms: D000328:Adult; D000880:Anthraquinones / Q000494:pharmacology*; D000001:Calcimycin / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009247:NADH, NADPH Oxidoreductases / Q000037:antagonists & inhibitors*; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D013481:Superoxides / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D000880:Anthraquinones; D013481:Superoxides; D000001:Calcimycin; D009240:N-Formylmethionine Leucyl-Phenylalanine; D009247:NADH, NADPH Oxidoreductases; D013755:Tetradecanoylphorbol Acetate; C020491:rhein