Acute and Subchronic Oral Toxicity Assessment of the Ethanolic Extract of the root of Oncoba spinosa (Flacourtiaceae) in Rodents

Purpose: To investigate the toxicological profile of the ethanol extract of Oncoba spinosa (EEOS) after acute and sub-chronic administration to rodents. Methods: In the acute toxicity study, a single administration of the extract at doses of 2000 and 5000 mg/kg, respectively, was given to the mice. Mice were observed for general behavioural changes, adverse effects and mortality up to 14 days post-treatment. In sub-acute toxicity studies, EEOS was given orally to male and female rats at doses of 250 mg/kg, 500 mg/kg and 1000 mg/kg for 28 days. Body weight, food intake and water intake were monitored throughout the experimental period; hematological parameters, biochemical parameters of the blood and histopathology of various organs were also evaluated at the end of the experiment. Results: In the acute toxicity study, both the doses used did not cause any mortality or significant behavioural changes. Daily oral administration of EEOS for 28 days, in the sub-chronic toxicity study, did not show any treatment-related abnormalities with regard to hematological and biochemical parameters. There were no significant differences in body weight and organ weight between the control and treated groups (p < 0.05). Histological analysis did not show any morphological changes in the major vital organs (liver, kidney, stomach, spleen, brain and heart) tested. Conclusion: These results demonstrate that the extract may not have any single dose toxicity. The LD50 value is greater than 5000 mg/kg. The no-observed adverse effects level (NOAEL) was considered to be 1000 mg/kg for male and female rats, respectively.