Protective effects of aucuba japonica against carbon tetrachloride-induced liver damage

Abstract

Numerous plant preparations described in the oriental old medicinal books and folkloric remedies have been used for the purpose of liver protection or for the treatment of liver damage. But in most cases their effectiveness has never been proved. Among them, $\mbox{\underline{A}}$. $\mbox{\underline{japonica}}$ has been known to have protective effect against liver diseases. Our subject was to determine if extracts from $\mbox{\underline{A}}$. $\mbox{\underline{japonica}}$ protect $CCl_4$-induced liver damage. Leaves of the $\mbox{\underline{A}}$. $\mbox{\underline{japonica}}$ were extracted with methanol (90\%, v/v) for 6 hrs. This total methanol extract was again fractionated with various solvents such as methanol, water, petroleum ether, chloroform and n-butanol. Since water fraction of $\mbox{\underline{A}}$. $\mbox{\underline{japonica}}$ was most effective for protecting $CCl_4$-induced liver damage from a preliminary study (hexobarbital sleeping time), water fraction of $\mbox{\underline{A}}$. $\mbox{\underline{japonica}}$ was used in our experiment. When rats were pretreated twice with the extract 24 hr and 30 min before $CCl_4$ administration at 300, 600, 1,200 mg/kg dose, protective effects of the extract on increased plasma disappearance and decreased biliary excretion of BSP induced by $CCl_4$ were most effective at 600 mg/kg dose. But the extract treatment 30 min and 3 hr after $CCl_4$ administration showed partial protection on effects of $CCl_4$ on plasma disappearance and biliary excretion of BSP. Pretreatment with 600 mg/kg of the extract completely protected the increased SGPT activity and serum triglyceride and liver cell necrosis induced by $CCl_4$. But it did not affect cytechrome P-450 content and microsomal lipid peroxidation.