Protective effect of Oenanthe javanica on the hepatic lipid peroxidation in bromobenzene-treated rats and its bioactive component.

To investigate the detoxification of bromobenzene-induced hepatic lipid peroxidation by Oenanthe javanica DC, the hepatic lipid peroxide level and the activities of enzymes responsible for production and removal of epoxide were studied. The level of lipid peroxide elevated by bromobenzene was significantly reduced by the methanol extract (250 mg/kg) and persicarin (5 mg/kg). The methanol extract and persicarin administered daily over 4 weeks before intoxication with bromobenzene did not affect the activities of aminopyrine N-demethylase, aniline hydroxylase, and glutathione S-transferase. Epoxide hydrolase activity was decreased significantly by bromobenzene, which was restored to the control level by pretreatment with persicarin. However, the identical pretreatment with isorhamnetin and hyperoside did not change the enzyme activity or lipid peroxide level. The results suggest that the reduction of bromobenzene-induced hepatic lipid peroxidation by O. javanica under our experimental conditions is effected through enhancing the activity of epoxide hydrolase, an enzyme removing bromobenzene epoxide. In addition, the bioactive component of this plant responsible for the detoxification of bromobenzene, at least in part, is thought to be persicarin.