Water-extractable phytochemicals from Phyllanthus niruri exhibit distinct in vitro antioxidant and in vivo hepatoprotective activity against paracetamol-induced liver damage in mice

The antioxidative and hepatoprotective potential of Phyllanthus niruri, a widely used medicinal plant in Brazil, were investigated. The aqueous extracts of leaves showed inhibition against thiobarbituric acid-reactive species (TBARS), induced by different pro-oxidants (10 μM FeSO4 and 5 μM sodium nitroprusside) in rat liver, brain and kidney homogenates. The extracts also lowered the formation of TBARS in phospholipids extracted from egg yolk. The plant exhibited strong antioxidant activity in the 2,2-diphenyl-1-picrylhydrazyl free radical (IC50, 43.4 ± 1.45 μg/ml) and iron chelation assay. The hepatoprotective activity of the extracts were also demonstrated in vivo against paracetamol-induced liver damage, as evidenced by the decrease in serum glutamate oxaloacetate transaminase (GOT), and glutamate pyruvate transaminase (GPT), and increased catalase activity in the liver in treatment groups, compared to the control. The results of the present study suggest the potential use of P. niruri in the treatment of various diseases, among which liver disease is the most important, due to its ability to act as an antioxidant. Furthermore, since the treatment of human intoxications with paracetamol is always limited to the administration of N-acetyl-cysteine, additional studies would be important to determine whether aqueous extracts of P. niruri could increase the efficacy of N-acetyl-cysteine against paracetamol acute hepatotoxicity.