Studies on the Toxicological Properties of Ethanol Stem-Bark Extract of Newbouldia laevis (P. Beauv) Seem in Rats

Abstract

This research aimed at evaluating the toxicological profile of ethanol stem-bark extract of N. laevis in Wistar rats. Repeated oral dose toxicity studies (28 and 90 days) were carried out with 32 rats for 28-day study and 40 rats for 90-day study. The rats were divided into 4 groups (A, B, C and D) of six rats per group and were treated with 250, 500 and 1,000 mg/kg body-weight of the extract for 28 and 90 days respectively. Blood samples were collected at the end of the experiment and were used for Biochemical and Haematological investigations, organs were also collected for histological examination. There was significant (p ≤ 0.05) reduction in WBCs following 28-day treatment and a significant (p ≤ 0.05) increase after 90-day treatment. The RBCs, haemoglobin and haematocrit increased significantly (p ≤ 0.05) at 1,000 mg/kg following 28-day treatment and at all doses for RBCs and haemoglobin after 90-day treatment. A significant (p ≤ 0.05) increase in HDL and a decrease in LDL was observed after 28-day treatment, the 90 days treatment showed significant (p ≤ 0.05) decrease in HDL and an increase in LDL. The AST level also increased significantly (p ≤ 0.05) after 28-day treatment. Histological-examination revealed pathological abnormalities in kidney and liver of the treated rats at all doses. This study showed that extract of N. laevis stem-bark was toxic when used at high doses and for a long period of time in the treated rats.