Comparative Acute Oral Toxicity of Landolphia owariensis P. beauv. Leaf Extracts in Wistar Rats

Landolphia owariensis is a liana used traditionally to treat malaria and other conditions in parts of sub-Saharan Africa. This study was aimed at comparing the acute oral toxicity of various leaf extracts of the plant in Wistar rats. Crude extracts of L. owariensis leaves were prepared by extracting successively with n-hexane, dichloromethane, ethylacetate, methanol, and water. In the acute toxicity test, a single dose of 2000 mg/kg body weight of each extract was administrated orally to groups of female Wistar rats. On day 14, blood samples and the organs (heart, lungs, liver, kidney, and spleen) of each animal were collected after they had been sacrificed. The effects of the various extracts on haematological parameters and organ histology were then evaluated. Data were analyzed using one-way ANOVA followed by Tukey’s test. The n-hexane extract significantly increased the leucocyte count (P < 0.05) compared with the control. It was further observed that treatment with the n-hexane, dichloromethane, and ethylacetate extracts of the plant produced significant changes (P<0.05) in platelet larger cell ratio (P-LCR), Haemoglobin (HGB) and haematocrit (HCT) respectively as compared with the control group. Histopathological examination of the organs revealed rhabdomyolysis in the heart and mild liver inflammation in the groups that received the n-hexane and dichloromethane extract of L. owariensis. The study revealed a median lethal dose (LD50) of greater than 2000 mg/kg body weight for all the extracts of L. owariensis since no mortality was observed at 2000 mg/kg. The n-hexane and dichloromethane extracts of the plant were found to be the most toxic.