Protective effects of caffeic acid phenethyl ester and thymoquinone on toluene induced liver toxicity.

Toluene is an organic solvent that is toxic to humans. Caffeic acid phenethyl ester (CAPE) and thymoquinone (TQ) exhibit antioxidant and antitoxic effects. We investigated the protective effects of CAPE and TQ on toluene induced hepatotoxicity. Wistar albino rats were divided into seven groups of eight. The animals were injected intraperitoneally (i.p.) with 0.1 ml/10 g/day corn oil (control I), 0.1 ml/10 g/day corn oil + 2 ml/kg/day 10% ethanol (control II), 20 mg/kg/day TQ dissolved in 0.1 ml/10 g corn oil (TQ), 10 µmol/kg/day CAPE dissolved in 10% ethanol (CAPE), 500 mg/kg/day toluene (T), toluene and TQ together (T + TQ), or toluene and CAPE together (T + CAPE). All rats were sacrificed on day 15. Liver samples were obtained for histological analysis. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were measured to evaluate liver function. Liver sections from the control I and TQ groups exhibited normal histology. Sections from the T group exhibited sinusoid dilation, hemorrhage, vacuolization and necrosis. TQ and CAPE protected against toluene induced histopathological changes. AST and ALT levels were increased significantly in T group compared to both control groups. CAPE decreased significantly the toluene induced increase in AST and ALT levels, while TQ did not. CAPE and TQ exhibited some antitoxic and hepato-protective effects on toluene induced liver damage.