ANTIBACTERIAL ACTIVITY AND PHYTOCHEMICAL COMPOSITION OF Enantia chlorantha STEM BARK EXTRACTS AGAINST SELECTED PATHOGENIC BACTERIA

Abstract

Antimicrobial resistance has become a major global health concern, creating an urgent need for alternative antimicrobial agents. Enantia chlorantha (Annonaceae) is a medicinal plant widely used in African traditional medicine for the treatment of infectious diseases. This study investigated the antibacterial activity, phytochemical composition, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) of methanol stem bark extract and solvent fractions of E. chlorantha against selected pathogenic bacteria. Stem bark of E. chlorantha was extracted with methanol and partitioned into n-hexane, ethyl acetate, and aqueous fractions. Clinical isolates were identified using morphological, biochemical, and molecular techniques. Antibacterial activity was evaluated using the agar well diffusion method, while MIC and MBC were determined using broth dilution and sub-culturing methods. Quantitative phytochemical analysis was performed using standard spectrophotometric procedures. Molecular characterization confirmed the isolates as Escherichia coli, Pseudomonas aeruginosa, and Salmonella bongori. The methanol extract and aqueous fraction exhibited notable antibacterial activity against the test organisms, with inhibition zones ranging from 4.50 ± 0.50 to 15.90 ± 0.10 mm and 5.00 ± 1.00 to 19.50 ± 0.50 mm, respectively. MIC values ranged from 9.38 to 150 mg/mL. Phytochemical analysis revealed high concentrations of phenols (416.07 ± 0.07 mg/100 g), followed by saponins, tannins, and flavonoids. The findings demonstrate that E. chlorantha stem bark possesses significant antibacterial properties, likely due to its rich phytochemical constituents, and may serve as a promising source of novel antimicrobial agents.