Sub-acute toxicological assessment of n-hexane fraction of Anogeissus leiocarpus stem bark extract in rats

Abstract

Anogeissus leiocarpus is traditionally used in Africa for treating diabetes and gastrointestinal disorders; and pharmacologically validated for its anti-inflammatory and antioxidant properties. However, data on the toxicological profile of its fractions remain limited. This study evaluated the acute toxicity of A. leiocarpus stem bark hydromethanolic extract (ALBHE) and subacute toxicity of its n-hexane fraction (n-hex). Acute toxicity was assessed by administering single oral doses of ALBHE (2000 and 5000 mg/kg body weight) to female rats (n = 5/group) and monitored for 14 days. For the subacute study, male and female rats (n = 10/group) received repeated oral doses of n-hex (40 or 80 mg/kg) for 28 days. The animals were sacrificed on day 29 following overnight fasting, and blood and essential organs (liver, kidney, heart, spleen, brain, uterus, and testes) were collected for haematological, biochemical, and histological assessments. Chemical profiling of n- hex was performed using high-performance liquid chromatography (HPLC), revealing 12 distinct compounds. No mortality or clinical signs of toxicity were observed in the course of acute toxicity. Haematological and biochemical parameters were not significantly altered (p > 0.05) compared to controls except for the mean corpuscular volume which was significantly decreased (p < 0.05) in male rats compared to control, and histological examination revealed well-preserved organ architecture. Taken together, the oral median lethal dose (LD50) of ALBHE was greater than 5000 mg/kg and the results indicate that both ALBHE and its n-hexane fraction are non-toxic at the tested doses and duration, supporting their potential safety in therapeutic applications.