PROTECTIVE EFFECTS OF OSBECKIA-OCTANDRA AGAINST PARACETAMOL-INDUCED LIVER-INJURY

1. Osbeckia octandra is a plant used in traditional medicine to treat jaundice and other liver disorders. In this study, the effects of Osbe ckia leaf extract on paracetamol-induced liver injury were investigate d both in vivo in mice and in rat hepatocytes in vitro. 2. Oral admini stration of Osbeckin extract (330 mg/kg) at the same time as paracetam ol (450 mg/kg) to mice, resulted in a significant protection (p < 0.05 ) against liver damage, as assessed by improvements in the blood Normo test (39.1 +/- 1.9 versus 46.3 +/- 2.0s), total liver glutathione (730 +/- 39 versus 574 +/- 27 mu g/250 mg liver), plasma aspartate aminotr ansferase level (916 +/- 225 versus 1965 +/- 291 iu/l), and liver hist opathology at 24 h after paracetamol administration. 3. In experiments to assess the direct effects of Osbeckia extract, significant protect ion was also found in freshly isolated rat hepatocytes against damage induced by 185 mu M 2,6-dimethyl N-acetyl p-quinoneimine (2,6-diMeNAPQ I, an analogue of NAPQI, the toxic metabolite of paracetamol) in vitro . When Osbeckia extract (500 mu g/ml) was added to the incubation medi um at the same time as 2,6-diMeNAPQI significant changes in cell viabi lity (78.4 +/- 3.3 versus 47.2 +/- 5.8% of control, p < 0.001), cell r educed glutathione (GSH) level (350 +/- 3.1 versus 23.8 +/- 1.5%, P = 0.009), and reduced release of lactate dehydrogenase (129.9 +/- 6.6 ve rsus 224.6 +/- 12.1%, P < 0.001) were demonstrated after 1 h incubatio n as compared with 2,6-diMeNAPQI alone. 4. Significant protection was still obtained against 2,6-diMeNAPQI in vitro when addition of Osbecki a extract was delayed by 20 min. These results indicate that Osbeckia extract can protect against paracetamol-induced liver injury.