Abstract

Aim of the study: The present study was carried out to evaluate the safety of ethanolic extract of celtis timorensis (EECT) by acute and sub-acute toxicity studies. Materials and Methods: Acute toxicity study was conducted in mice by using OECD 425 guidelines whereas sub-acute toxicity study was carried out in rats by using OECD 407 guidelines. In the acute toxicity study, mice were administered a single dose of 2000 mg/kg and 5000 mg/kg orally and then observed individually for the first four hours, then over a period of 24 hours and at least once daily for 14 days. In the subacute toxicity studies, EECT was given orally at doses of 250 mg/kg, 500 mg/kg and 1000 mg/kg body weight daily for 28 days to male and female rats respectively. General behavior, adverse effects and mortality were observed throughout the experimental period. Food intake, water intake, body weight, organ weight, hematological and biochemical parameters, histopathological changes were evaluated. Results: The limit doses of 2000 mg/kg and 5000 mg/kg did not cause any mortality or signs of acute toxicity in the mice tested during the observation period. In sub-acute toxicity tests, the results did not show any treatment related abnormalities in terms of hematological and biochemical parameters. There were no significant differences in body weight and organ weight between the control and treated groups. No morphological changes were observed in the histopathological analysis of the major vital organs (liver, kidney, stomach, spleen, brain and heart) tested. Conclusion: These results concluded that the EECT did not cause any mortality and signs of toxicity in mice (acute toxicity study) and rats (sub-acute toxicity study). The oral lethal dose of ethanolic extract is more than 5000 mg/kg and noobserved- adverse-effect level (NOAEL) of the extract for both male and female rats is 1000 mg/kg per day for 28 days.