RITA OBIANUJU AGUBUEZE

The search for new therapeutic agents derived from natural sources has intensified due to the global rise in antimicrobial resistance (AMR). Medicinal plants remain a significant source of bioactive compounds with diverse pharmacological potentials. This study examined the phytochemical components and bacterial inhibitory property of the dichloromethane (DCM) fraction of the stem bark of Antiaris toxicaria var. africana, a plant widely used in African ethnomedicine for treating various infections. The stem bark was extracted using 70% ethanol and subsequently fractionated with DCM using column chromatography. High-Performance Liquid Chromatography (HPLC) and Gas Chromatography–Mass Spectrometry (GC–MS) were employed for chemical characterization. GC–MS analysis revealed the presence of bioactive compounds with known antibacterial and antioxidant properties, including 2,4-di-tert-butylphenol (18.86%), hexadecanoic acid (14.35%), benzoic acid (7.39%), and methyl stearate (6.66%). HPLC profiling confirmed the presence of important phytochemicals such as flavonoids (11.36 µg/mL), proanthocyanidins (13.99 µg/mL), flavanones (9.93 µg/mL), tannins (3.70 µg/mL), cardiac glycosides (5.53 µg/mL), sapogenins (7.96 µg/mL), and steroids (4.70 µg/mL), indicating a rich diversity of secondary metabolites. Antimicrobial testing showed that the extract exhibited inhibitory activity against Pseudomonas aeruginosa (19 mm), Bacillus subtilis (18 mm), Staphylococcus aureus (19 mm), Escherichia coli (20 mm), and Enterobacter cloacae (17 mm), but not against Bacillus cereus. Although the extract demonstrated lower activity than the positive control, ciprofloxacin, it displayed broad-spectrum antibacterial potential. Overall, the findings provide scientific validation for the traditional use of A. Toxicaria var. africana in treating bacterial infections.