N-phenylmaleimide derivatives as mimetic agents of the pro-inflammatory process: myeloperoxidase activation.

Myeloperoxidase (MPO) is an important enzyme that catalyzes the reaction between hydrogen peroxide and chloride to generate hypochlorous acid, which oxidizes a range of biomolecules and has been associated with inflammatory diseases. The synthetic compounds N-phenylmaleimide (NFM) and 4-methyl-N-phenylmaleimide (Me-NFM) increased the MPO activity in vitro (of isolated enzyme and in isolated cells after animal treatment) and in vivo assays. MPO-induction may represent a good model system to investigate the molecular and cellular mechanisms of oxidative cell injury induced by activated neutrophils, and the interactions between damaging species involved in the respiratory burst.