Abstract:
Ayurvedic and other 'traditional' medical practitioners in Sri Lanka use the mature leaves of the plant Osbeckia octandra for its hepatoprotective properties. In this study the effects of an aqueous extract of Osbeckia octandra against injury induced by D-galactosamine and tert-butyl hydroperoxide (TBH) were investigated in freshly isolated rat hepatocytes. The plant extract (500 micrograms/ml) significantly reduced the inhibition of protein synthesis (as assessed by the incorporation of 14C-leucine into protein) in hepatocytes incubated for 1 h with 10 mM galactosamine by a mean of 25.6 +/- 3.6% and decreased the release of cellular 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 from 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, respectively 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.