Antioxidant and hepatoprotective effects of Anoectochilus formosanus and Gynostemma pentaphyllum

Anoectochilus formosanus Hay. and Gynostemma pentaphyllum Makino are popula r folk medicines that have been used for treating hepatitis, hypertension a nd cancer in Taiwan. Our previous studies showed that these crude drugs exe rt antiinflammatory activity and hepatoprotective activity against CCl4-ind uced liver damage. In this study, the antioxidant effect of these crude dru gs and their hepatoprotective activity on acetaminophen-induced liver injur y in rat was evaluated. Our results suggest that A. formosanus and G. penta phyllum do have antioxidant effects. On acetaminophen; intoxicated model, t he increased levels of aspartate aminotransferase (AST) and alanine aminotr ansferase (ALT) by acetaminophen administration were reduced by treatment w ith these two herbs. In histological observation, gross necrosis in the cen tribular area, sinusoidal congestion, infiltration of the lymphocytes and K upffer cells around the hepatic central vein, and loss of cell boundaries a nd ballooning degeneration were reduced with herbal treatment. However, the effect of A. formosanus and G. pentaphyllum is biphasic. Methanol extract (100 and 300 mg/kg) and water extract (300 and 500 mg/kg) of A formosanus a nd water extract (200, 300 and 500 mg/kg) of G. pentaphyllum enhanced the r ecovery of liver injury while treatment with 500 mg/kg of A. formosanus met hanol extract resulted in serious hepatic injury.