Preliminary studies of acute and sub-chronic toxicity of the aqueous extract of Guibourtia tessmannii (Harms) J. Leonard stem barks (Caesalpiniaceae) in mice and rats

To investigate the toxicity of aqueous extract of Guibourtia tessmannii (Harms) J. Leonard (G. tessmannii) and evaluate its safety. NMRI mice were used to determine the acute toxicity of G. tessmannii. Increasing concentrations of the plant extracts were administered intraperitoneally or by force-feeding. General behavior and death were monitored and recorded daily for 7 days. In order to determine the sub-acute toxicity of the extract, several doses were administered by oral gavage daily for 28 days in adult Wistar rats. Different parameters were assessed including body weight, food and water intake, biochemical parameters and several vital organ weights. LD50 of 328.78 mg/kg was obtained by i.p. route and more than 5 000 mg/kg was obtained in acute toxicity by oral route. In sub-acute toxicity, no significant alteration was observed in body weight or vital organs, food and water intake, and biochemical parameters. The results showed that the aqueous extract of G. tessmannii has low toxicity intraperitoneally and no sub-acute toxicity via oral intake.