In vitro antifungal activity of a new combination of essential oils against some filamentous fungi

The antifungal activities of essential oils and herbal extracts have been demonstrated against a range of filamentous fungi. In this study, in vitro antifungal activity of a combination of some essential oils (EO) extracted from the herbs (Thymus vulgaris, Salvia officinalis, Eucalyptus globulus and Mentha piperita) against some filamentous fungal strains (Metrhizium sp., Ophiostoma sp., Trichoderma sp. And enicillium expansum) was determined. The composition of oils was analyzed by gas chromatography (GC) and GC/mass spectrometry. The minimum inhibitory concentrations (MIC) and minimum fungicidal concentration (MFC) were determined by serial microdilution method. Based on the results, 1,8-cineol (21.37%), thymol (13.86%), camphor (7.92%), • -thujone (7.71%), menthon (6.8%) and menthol (6.2%) were the major constituents. The results indicated inhibitory effects of the combination of essential oils on the filamentous fungi tested. The MIC and MFC values were, respectively, 0.022 and 0.064 mg/ml for Metrhizium sp., 0.02 and 0.064 mg/ml for Ophiostoma sp., 0.018 and 0.048 mg/ml for Trichoderma sp. and 0.03 and 0.085 mg/ml for Penicillium expansum. Penicillium expansum showed the lowest inhibitory activity but was not significant (p>0.05). Also, Trichoderma sp. was the most sensitive species to this combination. According to this experiment, this combination was found to have a wide spectrum of activity against all filamentous fungi examined in this study and may be proposed for control of fungal diseases.