Abstract

The acute toxicity of aqueous leaf extract of Newbouldia laevis was evaluated in Swiss albino mice. For the first phase, the mice were divided into four groups of three animals each at random. The aqueous leaf extract of Newbouldia laevis was administered both orally and intraperitoneally to the groups in doses of 0, 10, 100, and 1000 mg/kg body weight, respectively. The animals were separated into four groups of three animals each for the second phase of administration, and single doses of the extract at 0, 1600, 2900, and 5000 mg/kg body weight were administered. Animals in both phases were closely monitored for 24 hours and 14 days, respectively. For the animals that got the extract through the oral route, no death was recorded in any of the groups in both phase. The LD50 of the aqueous leaf extract of Newbouldia laevis when administered orally was calculated to be up to 5000 mg/kg. The results indicate that the extract may be safe to be used at high doses through the oral route. For the intraperitoneal administration, no death was recorded in any of the groups in phase I, however, all the animals that got the extract in phase II died within 24 hours after intraperitoneal administration. The LD50 of the aqueous leaf extract of Newbouldia laevis when administered intraperitoneally was calculated to be 1264.9 mg/kg. The results indicate that the extract may be toxic at a high dose in short-term exposure and non-toxic when taken at low doses through the intraperitoneal route.