Median lethal dose and sub-chronic toxicity profile of Azadirachta indica A. Juss. leaf hexane and ethyl acetate fractionated extracts on albino rats

Azadirachta indica A. Juss. (Neem) is a multipurpose medicinal plant, traditionally used in the treatment of various human ailments. This plant is tagged as having high toxicity profile, and the toxicity might be related to the polarity nature of the solvent used for extraction. Hence, this research was aimed at screening the toxicity profile of Azadirachta indica leaf fractionated extracts using Albino rats. A. indica leaf was collected, authenticated and extracted using 95 % methanol then fractionated with hexane and ethyl acetate. Median lethal dose (LD50) of each fraction was determined using single oral dose of 5,000 mg/kg body weight (b. wt.) to five (5) rats. For the sub-chronic toxicity screening, the fractions were administered to groups of rats at different concentrations. Group 1 served as control, groups 2-5 received 900, 1800, 2700 and 3600 mg/kg b. wt. respectively. After 28 days, biochemical indices of hepatic and renal functions as well as haematological and histopathological parameters were analyzed. LD50 of each of the fractions was greater-than 5000 mg/kg b. wt. All the extract fractions at the administered doses, significantly (P<0.05) altered the serum levels of some biochemical indices of the hepatic and renal functions, as well as the levels of some haematological parameters. For the histopathology, hepatic congestion, periportal inflammation, distortion, infiltration and haemorrhage were observed at 1800-3600 mg/kg b. wt. Hence, these results indicated that using hexane or ethyl acetate as solvent of extraction, A. indica leaf extracts might not be considered safe at the administered sub-chronic doses.