title: Human myeloperoxidase activity is inhibited in vitro by quercetin. Comparison with three related compounds.
abstract: Quercetin is an effective inhibitor of human myeloperoxidase (MPO) activity, both with purified enzyme (IC50 = 3.5 microM) and in a system using stimulated human neutrophils. Quercetin is significantly more potent than three other related compounds (rutin, rutin sulfate and troxerutin) and than methimazole, a previously-known myeloperoxidase inhibitor. The inhibitory activity of quercetin is of the competitive type. Moreover, quercetin is directly able to scavenge hypochlorous acid (HOCl), a chlorinated species generated by the MPO/H2O2/Cl- system.
authors.affiliation: Laboratoire de Biochimie et de Radiobiologie, Université de Liège, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Pincemail
authors.forename: C
authors.initials: C
authors.lastname: Deby
authors.forename: A
authors.initials: A
authors.lastname: Thirion
authors.forename: M
authors.initials: M
authors.lastname: de Bruyn-Dister
authors.forename: R
authors.initials: R
authors.lastname: Goutier
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D005419:Flavonoids / Q000494:pharmacology*; D006801:Humans; D006896:Hydroxyethylrutoside / Q000031:analogs & derivatives / Q000494:pharmacology; D006997:Hypochlorous Acid; D008713:Methimazole / Q000494:pharmacology; D009504:Neutrophils / Q000201:enzymology; D009195:Peroxidase / Q000037:antagonists & inhibitors*; D011794:Quercetin / Q000494:pharmacology*; D012431:Rutin / Q000031:analogs & derivatives / Q000494:pharmacology; D013053:Spectrophotometry
chemical_list: D005419:Flavonoids; D006896:Hydroxyethylrutoside; C056067:rutin sulfate; D008713:Methimazole; D012431:Rutin; D006997:Hypochlorous Acid; C005865:troxerutin; D011794:Quercetin; D009195:Peroxidase