Original article Antibacterial and anticandidal effects of the leaf extracts of Perseaamericana Mill.

Abstract

In this study, the antibacterial and anticandidal effects of the leaf extracts of Persea americana Mill. were examined against some pathogenic bacteria and some Candida species. Plant leaves were reduced to powder with liquid nitrogen. n-propanol, methanol, acetone, n-hexane, ethyl acetate, ethanol and boiling water as solvents were used for extraction. The agar well diffusion method is u sed for the a ntimicrobia l activities of extra cts. Test microorga nisms were 1 8 bacteria and 4 yeasts. Also, different antibiotic discs were used for comparison of the zone of inhibition. T he extra cts of the n-propa nol, a cetone, a nd ethanol of P. a me ric a na lea ves showed high activity as regards to other solvents, respectively. The extracts of the n-propanol and acetone of P. americana leaves inhibited S. aureus ATCC 25923, P. vulgaris ATCC 33420 and B. cereus ATCC 11778 and the inhibition zones ranged between 13-14 mm. Methanol and ethanol extracts of P. americana leaves demonstrated moderate antimicrobial effect against S. aureus ATCC 25923, P. vulgaris ATCC 33420, P. aeruginosa ATCC 35032, C. albicans ATCC 10231 and the inhibition zones ranged between 10-11 mm., while they inferred low effect (9 mm) on S. typhimurium ATCC 14028. The boiling water extract of P. americana leaves showed a high effect against P. aeruginosa ATCC 35032 and C. albicans ATCC 10231 and the inhibition zones ranged between 12-13 mm., while it indicated low effect (9 mm) on C. tropicalis. The ethyl acetate extract of P. americana leaves showed moderate effect (10 mm) on S.epidermidis ATCC 12228, C. xerosis ATCC 373, P. vulgaris ATCC 33420, while it demonstrated low effect (9 mm) on B. cereus ATCC 11778. However, hexane extract of P. americana leaves indicated no effect against tested microorganisms.

Inhibition of Bacterial Adhesion and Biofilm Formation by Seed-Derived Ethanol Extracts from Persea americana Mill

“…The avocado seeds have been traditionally used as remedies to treat asthma, inflammation, and mainly diarrhea and infectious diseases [ 16 , 17 ]. These effects have been mainly associated to the presence of secondary metabolites such as polyphenols [ 18 ]. In a previous study, we demonstrated that ethanol extracts from the seeds of P. americana growing in the Cuban eastern region showed a phytochemical composition rich in polyphenols such as catechins and neolignans derivatives as well as some fatty acids/alcohols as main [ 19 ].…”