(Euphorbiaceae) is used as a folk medicine for jaundice and other diseases in Malaysia and other countries. But, so far, no safety studies have been carried out on this plant with clear documentation, especially with those plants growing in Malaysia. So the aim of this study was to determine the toxic side effects of aqueous extract of leaves of P. amarus
(grown in Malaysia) following oral administration in rats. Acute admininstration of P. amarus
extract at a dose of 5 g/kg body weight did not produce any signs of toxicity or mortality. In the chronic study, no significant difference (P > 0.05) was observed between the control and P. amarus
extract administered (male and female) rats (at the doses of 100, 400 and 800 mg/kg body weight for 6 weeks) in the total body weight gain as well as in the liver marker enzymes analyzed in serum. The non-toxic nature of P. amarus
extract administration was confirmed by histological studies [light microscopy, proliferative cell nuclear antigen study and apoptotic study] i.e., no observable changes were found between control and P. amarus
extract administered rats. Therefore, acute oral administration of P. amarus
extract is non-toxic to the rat liver, even at a dose of 5 g /kg body weight and also the chronic toxicity studies of P. amarus
extracts administration showed the absence of cumulative toxicity as reflected by the non-significant change in the parameters studied as well as from the results of the histological studies.