EFFECT OF A LIGNAN-ENRICHED FRUCTUS-SCHISANDRAE EXTRACT ON HEPATIC GLUTATHIONE STATUS IN RATS - PROTECTION AGAINST CARBON-TETRACHLORIDE TOXICITY

The effect of a lignan-enriched extract of the fruits of Schisandra ch inensis (FS) on hepatic glutathione (GSH) status was examined in both control and carbon tetrachloride (CCl4)-treated rats. FS treatment cau sed a dose-dependent enhancement in hepatic GSH status, as evidenced b y significant increases in hepatic GSH level and activities of hepatic glucose-6-phosphate and glutathione reductase (GRD), as well as a dec reased susceptibility of hepatic tissue homogenates to in vitro peroxi de-induced GSH depletion. The beneficial effect of FS treatment on hep atic GSH status became more evident after CCl4 challenge. Pretreating rats with FS extract at increasing daily doses ranged from 0.2 to 3.2 g/kg for 3 days caused a dose-dependent protection against the CCl4-in duced impairment in hepatic GSH status, The enhancement in hepatic GSH status was associated with corresponding decreases in tissue malondia ldehyde levels and plasma alanine aminotransferases activities, indica ting a significant reduction in the extent of oxidative hepatocellular damage. Our results indicate that the molecular mechanism of hepatopr otection afforded by FS pretreatment may involve the facilitation of G SH regeneration via the GRD-catalyzed and NADPH-mediated reaction.