IRENE OSEGHALE

Persea americana (avocado) leaves are reported to exhibit antimicrobial properties. As herbal products become increasingly popular, it is crucial to investigate whether formulation excipients affect the antimicrobial efficacy of plant extracts such as avocado leaves. This study investigates the antimicrobial efficacy of Persea americana leaf extract formulated into balms, comparing its effectiveness to that of the crude n-hexane extract. Fresh leaves of Persea americana were harvesteddried, pulverized and macerated in n- hexane.The extract obtained was subjected to phytochemical screening, then formulated into balms (0,100 and 200 mg/mL) and tested against clinical strains of Staphylococcus aureus Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Bacillussubtilis using the ditch method. Ciprofloxacin was used as a positive control. Statistical significance was determined using a One Way ANOVA, with a significance level set at p≤ 0.05.The hexane extract contained alkaloids, triterpenoids, steroids, phenolics, and proteins. At 100 mg/mL, the balm exhibited antimicrobial activity against Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus,while the hexane extract showed no activity. At 200 mg/mL, the extract showed broader antimicrobial activity against the five test organisms compared to the balm.The balm containing no extract showed no activity against any of the test organisms.The crude n-hexane extract exhibited dose-dependent antibacterial activity, producing inhibition zones of 17–20 mm at 200 mg/mL and 22–24 mm at 400 mg/mL, corresponding to approximately 50–77% of ciprofloxacin (4 mg/mL) activity.When formulated into a balm, antimicrobial potency of the extract decreased slightly, indicating possible interactions between the plant extract and the components of the balm. Formulating the n-hexane extract of Persea americana leaves into balm reduced the extract's antimicrobial activity. This suggests that excipient-extract interactions are essential factors to consider in the development of herbal formulations.