Evaluation of Antimicrobial Activity of the Essential Oil of Myrtus communis L. and Its Formulation into Gum Paint

Abstract

Based on ethnopharmacological and taxonomic information, antimicrobial activity of the essential oil obtained from Myrtus communis L. was determined in vitro using agar well diffusion method against Staphylocccus aureus, Bacillus cerus, Escherichia coli, Pseudomonas aeruginosa, Streptococcus pyogens, Aspergillus niger and Candida albicans, at different concentrations. The oil showed activity against all test
bacteria and fungi with minimal activity against P. aeruginosa. Since the plant is traditionally used in the treatment of gingivitis, the oil was formulated as gum paint using glycerol and blend of surfactants (Tween 80 and Span 80). In vitro efficacy test of the formulation showed a promising activity having a mean zone of inhibition of 38 mm against S. auresus and E.coli, 43 mm against S. pyogens, 20 mm against B. cerus, 45 mm against A. niger and 40 mm against C. albicans. The gum paint formulation was found to be an oil-in-water emulsion with an optimal pseudoplastic viscosity (120 - 340 centpoises with 200 - 50 shear stress per min).

Keywords: essential oil, Myrtus communis, antimicrobial activity, formulation, gum paint

Ethiopian Pharmaceutical Journal Vol. 25 (1) 2007: pp. 72-76