In vitro Antibacterial Activity of Organic Extracts from North-West Moroccan Medicinal Plant Myrtus communis (L.)

Abstract

Aims: This study was designed to evaluate the antibacterial activity of methanol, ethanol, ethyl acetate and n-hexane extract from the leaves of Myrtus communis (L.) growing in North-West of Morocco. Study Design: In vitro evaluating of antibacterial activity and determination of total phenols and flavonoids content of extracts. Place and Duration of Study: Department of Biology (Faculty of Sciences), between July 2015 and November 2015. Methodology: The total phenol content and flavonoids content of methanol, ethanol, ethyl-acetate and n-hexane extracts were determined using Folin-Ciocalteu method and Aluminum chloride (AlCl3) colorimetric method respectively. The antibacterial activity of extracts was tested against five reference strains, Escherichia coli K12 MBLA, Staphylococcus aureus CECT 976, Listeria monocytogenes serovar 4b CECT 4032 and Pseudomonas aeruginosa IH using the agar well diffusion method and the micro-dilution assays. Results: The amount of the total phenolic content and total flavonoid content ranged between 86,31-137,46 gallic acid equivalents (GAE mg/g) and 14,31±1,09–31,24 quercetin equivalents (QE mg/g) of dry weight of extract, respectively. All extracts had a significant antibacterial activity against the tested bacterial strains. The biggest zones of inhibition were observed against two positive bacteria (L. monocytogenes, S. aureus). While, Gram negative bacteria (E. coli K12,               P. aeruginosa) had showed to be resistant toward extracts. Conclusion: Considering these results, M. communis leaves can be used as a source of novel antimicrobial and antioxidant compounds.