PROTECTIVE EFFECTS OF OSBECKIA-OCTANDRA AGAINST GALACTOSAMINE AND TERT-BUTYL HYDROPEROXIDE-INDUCED HEPATOCYTE DAMAGE

Ayurvedic and other 'traditional' medical practitioners in Sri Lanka u se the mature leaves of the plant Osbeckia octandra for its hepatoprot ective properties. In this study the effects of an aqueous extract of Osbeckia octandra against injury induced by D-galactosamine and tert-b utyl hydroperoxide (TBH) were investigated in freshly isolated rat hep atocytes. The plant extract (500 mu g/ml) significantly reduced the in hibition of protein synthesis (as assessed by the incorporation of C-1 4-leucine into protein) in hepatocytes incubated for 1 h with 10 mM ga lactosamine by a mean of 25.6 +/- 3.6% and decreased the release of ce llular lactate dehydrogenase (LDH) and aspartate aminotransferase (AST ) enzyme activities into the medium by 55.3% and 32.8%, respectively. With TBH, the plant extract decreased lipid peroxidation (estimated fr om malondialdehyde formation) by a mean of 29.9 +/- 1.1% together with a 46.8% and 54.7% decrease in the release of LDH and AST, respectivel y into the incubation medium. Significant protection was also obtained when the Osbeckia extract was added to the incubation medium up to 30 min after pre-exposure of the hepatocytes to either galactosamine or, to a lesser extent, TBH. The results support the use of Osbeckia as a hepatoprotective agent.