Chloroform-induced oxidative stress in rat liver: Implication of metallothionein

Current studies evaluated the effect of acute and subacute exposure to chloroform (CHCl3) on rat liver and the implication of oxidative stress. For this purpose, different doses of CHCl3 (150, 300 and 450 mg/kg bw) were administered intraperitoneally (ip) to male Wistar rats. Malondialdehyde (MDA), glutathione (GSH), reduced cytochrome c and metallothioneins (MTs) levels as well as the activities of catalase (CAT) and glutathione peroxidase (GPx) and the activities of the biochemical markers of hepatic injury (alanine transaminase [ALT] and aspartate transaminase [AST]) were determined. CHCl3 did not cause a significant increase in hepatic lipid peroxidation. However, dose-dependant and/or time dependant effects of CHCl3 were demonstrated on most of the oxidative stress parameters measured, namely the GSH depletion and the superoxide anion production. Acute exposure CHCl3 increased the aminotransferase and GPx activities and reduced cytochrome c levels in a dose-dependant pattern. A well-combined dose-dependent and time-dependent effect of CHCl3 on MT levels after acute and subacute exposure was noticed. Moreover, the increase of MT levels seems to be associated with the GSH depletion, indicating a possible role of the latter in MT synthesis. In conclusion, the superoxide anion production and the GSH depletion could be implicated in the mechanism of hepatotoxity of CHCl3 and MTs seem to be a part of the antioxidant defense system against the oxidative damage caused by CHCl3 in liver.