Antibacterial and Antioxidant Activities of the Essential Oil and Methanolic Leaf Extract of Persea americana

This study attempted to find out if the essential oils and methanolic crude extract of the leaves of Persea americana (PA) had potent antibacterial and antioxidant properties. The essential oil was extracted using steam distillation and subsequently subjected to gas chromatography –mass spectroscopy (GC-MS) analysis. The crude extract was obtained using methanol as the solvent. Subsequently, the antimicrobial activity of the essential oil and crude extract against pathogens were evaluated using standardized assays while the antioxidant activity of the essential oil and crude extract was evaluated using DPPH and FRAP assay. The GC-MS showed 1R-α-pinene, terpinolene, caryophyllene, camphene, isopulegol, longiverbenone, isoaromadendrene and humulene as the main constituents in Persea americana respectively which are constituents on the leaf’s extract. The crude extract showed higher inhibitory activity (15.00±1.23 mm) on S. aureus compared to the essential oil (11.00±1.11 mm). The same applies for P. aeruginosa where the crude extract and essential oil inhibited the enzyme by 23.00±1.02 mm and 19.00±1.12 mm respectively, also Salmonella typhi where the crude extract and essential oil inhibited the enzyme by 24.00±1.24 mm and 18.00±1.32 mm respectively. P. americana volatile oil demonstrated significant ability to scavenge free with an IC50 value of 72.22 μg/mL in the DPPH assay. Additionally, the FRAP assay revealed that the P. americana volatile oil possessed notable reducing power of 4.42 μg/g further highlighting its antioxidant capacity.