OBJECTIVEThis study investigated the acute and subacute toxicity of whole-plant aqueous extract of Vernonia mespilifolia Less. (AEVM) in rats for evaluating its safety profile.

METHODSAEVM for the acute (2000 and 5000 mg/kg) and subacute (200, 400 and 600 mg/kg) toxicity studies was administered orally to rats according the guidelines 425 and 407 of Organization for Economic Cooperation and Development, respectively. Food and water intake as well as body and organ weight of animals were recorded. Signs of toxicity were assessed, and hematological, biochemical and histopathological analyses were performed.

RESULTSIn the acute toxicity study, a single dose of the aqueous extract at 2000 or 5000 mg/kg caused no mortality in the animals, suggesting that the median lethal dose is greater than 5000 mg/kg. In the subacute toxicity study, administration of the extract for 28 d, at all doses, caused no significant changes in the body weights or organ weights of rats in the treated groups when compared with the control group. In addition, hematological and biochemical parameters also revealed no toxic effects of the extract on rats. Histological sections of the heart, liver and kidney from test animals showed no signs of degeneration.

CONCLUSIONThese results showed that AEVM at dosage levels up to 600 mg/kg is nontoxic and could also offer protection on some body tissues. AEVM could, therefore, be considered safe.