Methyl helicterate protects against CCl4-induced liver injury in rats by inhibiting oxidative stress, NF-κB activation, Fas/FasL pathway and cytochrome P4502E1 level.

This study was designed to investigate the protective effects of the methyl helicterate (MH) isolated from Helicteres angustifolia L. against CCl4-induced hepatotoxicities in rats. Liver injury was induced in rats by the administration of CCl4 twice a week for 8 weeks. Compared with the CCl4 group, MH significantly decreased the activities of ALT, AST and ALP in the serum and increased the activities of SOD, GSH-Px and GSH-Rd in the liver. Moreover, the content of hepatic MDA was reduced. Histological findings also confirmed the anti-hepatotoxic characterisation. In addition, MH significantly inhibited the proinflammatory mediators, such as PGE2, iNOS, COX-2, IL-6, TNF-α and myeloperoxidase (MPO). Further investigation showed that the inhibitory effect of MH on the proinflammatory cytokines was associated with the downregulation of NF-κB. Besides, MH also markedly decreased the levels of Fas/FasL protein expression and the activities of caspase-3/8, as well as the activity of cytochrome P4502E1 (CYP2E1). In brief, the protective effect of MH against CCl4-induced hepatic injury may rely on its ability to reduce oxidative stress, suppress inflammatory responses, protect against Fas/FasL-mediated apoptosis and block CYP2El-mediated CCl4 bioactivation.