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Human myeloperoxidase activity is inhibited in vitro by quercetin. Comparison with three related compounds
J Pincemail1, C Deby, A Thirion
1Laboratoire de Biochimie et de Radiobiologie, Université de Liège, Belgium.
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.
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