title: Inhibition of arachidonic acid 5-lipoxygenase of human polymorphonuclear leukocytes by esculetin.
abstract: Esculetin (6,7-dihydroxycoumarin) inhibits arachidonic acid 5-lipoxygenase of human polymorphonuclear leukocytes (HPMNL). Complete inhibition of the biosynthesis of 5-HETE, 5,12-DHETE and LTB4 was observed at a concentration of 100 microM (IC50 = = 0.4 microM, 6.0 microM and 0.1 microM, respectively). At these concentrations the formation of the cyclooxygenase product, 12-HHT, is increased. Upon stimulation of the cells with calcium ionophore A-23187, the inhibitory action of esculetin is revealed at the higher concentrations.
mesh_terms: D001095:Arachidonic Acids / Q000096:biosynthesis*; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D066298:In Vitro Techniques; D007975:Leukotriene B4 / Q000096:biosynthesis; D016859:Lipoxygenase Inhibitors; D009504:Neutrophils / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D014468:Umbelliferones / Q000494:pharmacology*
chemical_list: D001095:Arachidonic Acids; D016859:Lipoxygenase Inhibitors; D014468:Umbelliferones; D007975:Leukotriene B4; C007628:esculetin