Evaluation of Antifungal Activities of Myrtus communis L. by Bioautography Method

Myrtus communis L. is an evergreen perennial shrub belonging to the Myrtaceae family that is spontaneously growing throughout the Mediterranean area. Myrtle has demonstrated important antimicrobial and antifungal activities to treat bacterial and fungal diseases.

This study was aimed to develop a new method to evaluate the anti-fungal activity of hydroalcoholic extracts of Myrtle on dermatophytes by bioautography.

The species used for this study were: Microsporum canis, M. gypseum and Trichophyton mentagrophytes. The fungi were kept on Sabouraud dextrose agar (SDA) slants at 4°C and subcultured monthly throughout this study. Various fractions were prepared from hydroalcoholic extracts based on polarity. The antifungal assay of different solvent extracts was performed by agar disc diffusion method. A thin layer chromatography (TLC) method was developed to carry out bioautography TLC, the same solvent system as that of bioautography was used.

Ethyl acetate and total methanolic extracts respectively had the best antifungal effects against three tested genera of dermatophytes. The ethyl acetate extract and methanolic extract that had the most inhibitory effect compared with any other fractions, were separated by solvent system (trifluroacetic acid, ethyl acetate, methanol, water: 0.1: 10: 0.04: 0.04) by TLC method. The best antifungal effects of the three fungi extracts was obtained in Rf: 0 - 0.3.

The active compound may be a flavonoid. Existence of flavonoids in tested fractions could be the important medicinal properties of M. communis leaves. Further work is required to evaluate the exact effect of these biological compounds on animal model or human volunteers.