Protective effects of Mn(III)tetrakis (4-benzoic acid) porphyrin (MnTBAP),a superoxide dismutase mimetic, in paw oedema induced by carrageenan in the rat

In the present study we investigated thr therapeutic efficacy of Mn(III)tet rakis (4-benzoic acid) porphyrin (MnTBAP), a superoxide dismutase mimetic w hich possesses peroxynitrite scavenging effects, in rats subjected to carra geenan-induced paw oedema. Local administration of MnTBAP (5, 25, and 50 mu g/paw) significantly and dose dependently reduced carrageenan-induced paw oedema at all time points. MnTBAP also caused a significant dose-dependent reduction in paw myeloperoxidase activity and lipid peroxidation, as well a s preventing histological injury. Immunohistochemical analysis for nitrotyr osine revealed a positive staining in paw from carrageenan-treated rats. No positive nitrotyrosine staining was found in the paws of the carrageenan-t reated rats that received MnTBAP. Our study demonstrates that MnTBAP exerts protective effects in carrageenan-induced paw oedema. Part of these anti-i nflammatory effects may be related to: 1) reduction of superoxide formation due to the superoxide dismutase-like activity of the compound; and 2) scav enging of peroxynitrite. BIOCHEM PHARMACOL 58;1:171-176, 1999. (C) 1999 Els evier Science Inc.