Abstract

ABSTRACT
The safety of the ethanol stem bark extract of Dichaetanthera africana (EtOHDA) was evaluated. In the sub-chronic toxicity test, the plant extract was administered by daily gavage of 250–1000 mg/kg bw for 28 and 90 days respectively. Body weight, rectal temperature, food and water consumptions were recorded weekly. Hematological, biochemical and organ parameters were determined at the end of the 28 and 90-day administration. Histopathological examination of the liver and kidney of rats was done. No adverse effects or mortality were observed throughout the period of the acute toxicity experiment (LD50 ˃ 2000 mg/kg). In daily oral administration for 28 days, EtOHDA did not produce any mortality and there were no significant differences in the general condition between groups. For 90 days, EtOHDA caused dose-dependent general behaviour adverse effects. The no-observed adverse effect level of the extract was 1000 mg/kg bw. EtOHDA resulted significant changes in biochemical parameters at the dose of 500 and 1000 mg/kg bw. Liver histopathology revealed morphological alteration at these doses. The results suggested that EtOHDA is relatively non-toxic in daily oral administration for 28 days. However, it becomes toxic for 90 consecutive days at the doses of 500 and 1000 mg/kg bw.

Key words: Dichaetanthera africana, Melastomataceae, Ethanol stem bark extract, Oral acute toxicity, Oral subchronic toxicity.