Essential oils and their components in combating fungal pathogens of animal and human skin

The most common problems of modern medicine include fungal infections of the skin and its appendages caused by dermatomycetes, yeast-like fungi and moulds. Due to toxicity of pharmacological fungicides and promotion of ecology, natural substances with high antifungal properties are sought. Essential oils and their components show potential in this regard.

Fourteen commercial essential oils were tested for antifungal activity. The study were carried out by agar dilution method against the following fungal species: Microsporum gypseum, Microsporum canis, Trichophyton mentagrophytes, Trichophyton violaceum, Aspergillus niger, Scopulariopsis brevicaulis and (IZ 1) dog skin isolate. The minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) values were determined for all tested oils and individual components of oils with the highest activity against the tested fungi. GC-MS analysis was performed for the most active oils.

Cinnamon, thyme, clove, geranium and manuka oils were most active against the test fungi. The MIC values in the tested oils were in the range of 0.5->10μg/μl and the MFC amounted to 1.25->10μg/μl. Activity of individual components against the tested fungi strains was selective and clearly higher against dermatomycetes fungi and IZ 1 isolate. The strongest effect on dermatomycetes fungi was of cinnamaldehyde, thymol and carvacrol-with the values of 0.039-1.25μg/μl (MIC) and 0.078-1.25μg/μl (MFC). In turn, the highest activity against IZ 1 isolate was of cinnamaldehyde, eugenol, carvacrol, geraniol and thymol. Their MIC and MFC was 0.313-1.25μg/μl.

The results prove the applicability of selected oils and their components as alternatives to synthetic agents in combating fungal dermatoses in animals and humans.