Abstract

Kigelia africana (Sausage tree) is traditionally acclaimed in African herbal medicine for its therapeutic effects, particularly in treating infections and inflammatory conditions. This study scientifically investigated the antioxidant, antimicrobial, phytochemical, and toxicity properties of methanol leaf extract of Kigelia africana in male albino rats. Phytochemical screening revealed the presence of alkaloids, flavonoids, tannins, glycosides and phenolic compounds—bioactive constituents often linked to medicinal benefits. Antioxidant activity was evaluated by analyzing Glutathione Peroxidase (GPx), Catalase (CAT), Superoxide Dismutase (SOD), and Malondialdehyde (MDA) levels. A dose-dependent enhancement in GPx activity was observed, while CAT, SOD, and MDA remained statistically unchanged. Antimicrobial testing demonstrated greater inhibition against Staphylococcus aureus (zone of inhibition: 16.2 mm; MIC: 2.5 mg/mL) compared to Pseudomonas aeruginosa. Acute toxicity assessment revealed no signs of toxicity or mortality at 5000 mg/kg, suggesting an LD₅₀ above this threshold. However, sub-acute toxicity tests indicated reduced body weight and significant hematological alterations at higher doses, including decreased white blood cell and platelet counts, as well as variations in mean corpuscular hemoglobin concentration (MCHC) and volume (MCV). These findings support the traditional use of Kigelia africana for its antioxidant and antimicrobial effects but also highlight the need for caution due to possible hematotoxic effects at high doses. Further studies are recommended to isolate the active compounds and assess their pharmacological and safety profiles.

Key words: Kigelia africana, Antioxidant, Antimicrobial, Toxicity, Staphylococcus aureus, Pseudomonas aeruginosa, LD₅₀.