Evaluation of the acute and sub acute toxicity of Annona senegalensis root bark extracts

Abstract

Objective: To investigate the safety profile of Annona senegalensis (A. senegalensis).

Methods: Dried powdered root-bark of A. senegalensis was prepared by Sohxlet extraction using methanol-methylene chloride (1:1) solution and concentrated to obtain the methanol-methylene chloride extract (MME). MME was fractionated to obtain the n-hexane (HF), ethylacetate (EF) and methanol (MF) fractions. Acute toxicity (LD(50)) test was performed with MME, HF, EF and MF in mice by oral route. The sub acute toxicity studies were performed in rats after 14 days of MME administration while haematological and biochemical parameters were monitored.

Results: Medium lethal (LD(50)) values of 1,296, 3,808, 1,265 and 2,154 mg/kg were obtained for the MME, MF, HF and EF, respectively. The sub-acute toxicity studies indicated a significant (P<0.05) increase in the body weight of both the treated rats and the control. The haematological tests indicated no change in the packed cell volume values but a significant (P<0.05) increase in the total WBC count at 100 and 400 mg/kg doses. The differential analysis showed a decrease in the nutrophils and a non-significant increase in the lymphocyte counts. The liver transaminase enzymes, alanin transaminase and aspartate transaminase showed no significant increase compared to the control. Histopathological examination of the liver sections also indicted no obvious signs of hepatotoxicity except with the 400 mg/kg dose that showed degeneration and necrosis of the hepatocytes.

Conclusions: These results indicated that the root bark extracts of A. Senegalensis are safe at the lower doses tested, and calls for caution in use at higher doses in treatment.