PHYTOCHEMICAL AND ANTIBACTERIAL ANALYSIS OF DIALIUM GUINEENSE (CHEKU LEAVES) AGAINST STAPHYLOCOCCUS AUREUS AND ESCHERICHIA COLI

ABSTRACT This study investigated the phytochemical constituents and antibacterial activity of Dialium guineense (Cheku leaves) against Staphylococcus aureus and Escherichia coli. The study was carried out to determine the presence of important bioactive compounds in the leaves and to evaluate their inhibitory effects on selected pathogenic bacteria commonly associated with human infections. Fresh leaves of Dialium guineense were collected, identified, air-dried, and pulverized into powder. The powdered leaves were extracted using ethanol by the maceration method. Qualitative phytochemical screening of the extract was carried out using standard laboratory procedures to detect the presence of alkaloids, flavonoids, tannins, saponins, glycosides, terpenoids, steroids, and phenols. The antibacterial activity of the extract was determined against Staphylococcus aureus and Escherichia coli using the agar well diffusion method at different concentrations of 100 mg/mL, 50 mg/mL, 25 mg/mL, and 12.5 mg/mL. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the extract were also determined using standard broth dilution and sub-culture methods. The result of the phytochemical screening revealed the presence of alkaloids, flavonoids, tannins, saponins, glycosides, terpenoids, steroids, and phenols in the leaf extract of Dialium guineense. The antibacterial susceptibility test showed that the extract exhibited inhibitory activity against both test organisms, with zones of inhibition increasing as the concentration of the extract increased. At 100 mg/mL, the highest zones of inhibition recorded were 21.0 mm against Staphylococcus aureus and 17.0 mm against Escherichia coli. The MIC values were 12.5 mg/mL for Staphylococcus aureus and 25.0 mg/mL for Escherichia coli, while the MBC values were 25.0 mg/mL and 50.0 mg/mL, respectively. The findings indicated that Staphylococcus aureus was more susceptible to the extract than Escherichia coli.