Sub-Acute toxicological evaluation of the aqueous stem bark extract of <i>Brachystegia eurycoma</i> (harms

Abstract

Brachystegia eurycoma is a mainstay in the treatment of malaria, diabetes, hypertension, microbial infections and inflammatory conditions in folkloric medicine in Eastern Nigeria. Thus, the present study investigated the in vivo sub-acute toxicity of its aqueous stem bark extract. Toxicological evaluation was done using organ weight index, haematological, biochemical and histopathological parameters, following daily oral administration of 100, 400 and 800 mg/kg of the extract to albino Wistar rats for 14 days. The extract at all doses caused no significant changes in the organ weight index of selected organs except for 100 mg/kg which caused a significant (p < 0.05) increase in the weight of lungs compared to control. There was significant elevation of white blood cells and lymphocytes observed at all doses of extract tested. However, B. eurycoma caused mild periportal infiltrates of chronic inflammatory cells and Kupffer cell activation in the liver, lymphoid  aggregate activation in the lungs as well as activation of lymphoid follicle and sinus histiocyte in the spleen, thus indicating activation of the immune system. Overall, the results suggest that aqueous extract of B. eurycoma stem bark is not toxic in rats, although it has a tendency to activate the immune system.

Keywords: B. eurycoma, immunity, spleen, toxicity.