DECREASE OF HYPOCHLOROUS ACID AND HYDROXYL RADICAL GENERATED BY STIMULATED HUMAN NEUTROPHILS - COMPARISON IN-VITRO OF SOME THIOL-CONTAININGDRUGS

Among reactive oxygen species generated by human neutrophils during in flammatory disorders, hypochlorous acid and hydrohyl radical are espec ially involved in many diseases such as arteriosclerosis ol emphysema. It was shown in vitro that two thiol-containing drugs, mesna and N-ac etylcysteine, have antioxidant properties towards these oxidants. The 50% inhibitory concentrations (IC(50)s) of mesna and N-acetylcysteine for hypochlorous acid production by stimulated neutrophils were 29 and 30 mcM, respectively, and for hydroxyl radical production, IC(50)s we re 520 and 480 mcM, respectively. With this in vitro demonstrated effe ctiveness, both mesna and N-acetylcysteine have been considered as the rapeutic antioxidants to decrease tissue damage inflicted by an excess of activated neutrophils by scavenging hypochlorous acid and hydroxyl radical.