Phytochemical Screening and Antibacterial Potency of Aspilia africana Leaves and Gardenia jasminoides Root Extracts

The increasing resistance of pathogenic bacteria to conventional antibiotics has necessitated the search for alternative antimicrobial agents, particularly from plants. This study investigates the phytochemical composition and antibacterial activity of ethanol and n-hexane extracts of Aspilia africana leaves and Gardenia jasminoides roots. Phytochemical screening was carried out using standard methods. The extracts were tested against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis using the disc diffusion method and Minimum Inhibitory Concentration (MIC) determination. The phytochemical screening revealed the presence of alkaloids, flavonoids, tannins, saponins, and terpenoids in varying concentrations across both plant extracts. The ethanol extract of Aspilia africana exhibited the highest flavonoid content (12.38%), while Gardenia jasminoides roots had a significantly higher tannin concentration (23.68%) in the ethanol extract compared to Aspilia africana (0.12%). Alkaloids and saponins were also abundant in Gardenia jasminoides roots (5.37% and 9.85%, respectively), particularly in the ethanol extract. Both plant extracts demonstrated significant antibacterial activity, with the ethanol extracts showing higher potency. The results of the antimicrobial analysis showed that the ethanol extracts of both plants demonstrated greater antimicrobial efficacy, particularly at higher concentrations. Gardenia jasminoides root extract showed inhibitory activity against all tested bacteria at 50mg/l and lower concentrations. Similarly, the n-hexane extract exhibited antibacterial activity, albeit less potent than the ethanol extract. In conclusion, the results indicate that both plant species possess potent antibacterial properties, particularly in ethanol extracts, supporting their traditional use in treating bacterial infections and justifying further research into their medicinal applications.