Purpose: The purpose of the present study was to evaluate the acute and subacute toxicity of the aqueous leaf extract of Combretum molle.

Methods: The acute toxicity of the extract was evaluated in rats. The animals were orally administered with doses ranging from 2000 to 8000 mg/kg and observed continuously for the first 4 h, then  hourly for the next 24 h, and finally, 6-hourly for 72 h. Control animals received orally normal saline. The rats were observed carefully for mortality, pain as well as respiratory movements. For subacute toxicity, 6 groups of 6 rats (3 male and 3 female) each received intraperitoneally, normal saline (control), 400, 600, 800, 1000 and 1200 mg/kg of the extract, respectively, thrice daily for 15 days. At the end of the treatment period, the animals were sacrificed and their organs (liver, heart and kidney) removed for macroscopic examination.

Results: For the acute toxicit test, no death and signs of poisoning were observed in the treated groups. In the subacute tstudy, LD₅₀ in the rats after intraperitoneal administration was 700 mg/kg (456 - 896, 95 % confidence interval). The clinical signs of poisoning (motor difficulties, decreased respiratory rate, and tremor preceding death) were observed, suggesting overt toxicity throughout the neuromuscular system. However, histological examination of vital organs showed normal architecture suggesting no morphological abnormalities in the heart, kidney and liver.

Conclusion: The results show that the aqueous leaf extract of C. molle is moderately toxic when given intraperitoneally.