Abstract

Aim: The study evaluated the acute and sub acute toxicity of the aqueous leaf extract of Phyllathus amarus Schum. and Thonn using Wistar albino rat.

Methods: Sixty-one adult Wistar rats were grouped four groups with ten rats per group for acute study. Rats in group 2, 3 and 4 received 2000mg/kg, 4000mg/kg, and 8000mg/kg of the extract respectively. For sub acute study, rats were divided into three groups with seven per group. Rats in groups 2 and 3 received 2000mg/kg and 4000mg/kg of the extract respectively. Blood was obtained by cardiac puncture. The heart, liver and kidney of each rat were also excised, weighed and used for biochemical and histopathological analysis.

Results: The acute toxicity study revealed that the oral administration of the extract was safe up to the dose level of 8,000mg/kg. Besides the significant (P<0.05) ><0.05) reduction in plasma ALT and significant  (P<0.05) ><0.05)  increase in kidney AST 48hrs after acute exposure and significant reduction in plasma ALP in sub-acute exposure, no abnormality in plasma and tissue biochemical markers was observed. There was noneffect on the renal function indices but increase in WBC after sub-acute exposure. The gross and histopathological examination of the kidney and liver after both acute and sub acute study showed minor abnormalities.

Conclusion: Therefore, it can be concluded that P.amarus aqueous extract is safe, as oral administration has no adverse effect on rat liver and kidney.

Keywords: Acute, subacute toxicity, Phyllanthus amarus, Medicinal plant