Hepatoprotective effects of Mimic of Manganese superoxide dismutase against carbon tetrachloride-induced hepatic injury.

The aim of this study was to investigate the protective effects of Mimic of Manganese superoxide dismutase (MnSODm) against carbon tetrachloride (CCl(4))-induced hepatic injury in mice. Bifendate or MnSODm was intragastrically administered per day for 7 days. On the 8th day, all mice except the normal group were given 0.5% CCl(4)/peanut oil to induce hepatic injury model by intraperitoneal injection. Mice were sacrificed 24 h after CCl(4) treatment. Compared with the CCl(4) group, MnSODm significantly decreased the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the serum and increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the serum and liver. Moreover, the contents of hepatic and serum malondialdehyde (MDA) and nitric oxide (NO) with inducible nitric oxide synthase (iNOS) activities were reduced. Histological findings also confirmed the antihepatotoxic characterization. In addition, MnSODm inhibited the pro-inflammatory mediators, such as prostaglandin E(2) (PGE(2)), cyclooxygenase-2 (COX-2), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Further investigation showed that the inhibitory effect of MnSODm on the pro-inflammatory cytokines was associated with the down-regulation of nuclear factor-kappa B (NF-κB). In brief, our results show that the protective effect of MnSODm against CCl(4)-induced hepatic injury may rely on its ability to reduce oxidative stress and suppress inflammatory responses.