Chemical, antifungal and cytotoxic evaluation of the essential oil of Thymus zygis subsp. sylvestris

Several Thymus species are used since olden times in traditional medicine, due to recognized therapeutic properties, namely the antimicrobial activity of their essential oils. In the present study we evaluated the composition and the antifungal activity (MIC and MLC) of four type oils obtained from Thymus zygis subsp. sylvestris, an Iberian endemic Lamiaceae, against yeasts, dermatophyte and Aspergillus strains. Moreover, we also assessed their cytotoxicity in skin dendritic cells at concentrations showing significant antifungal activity.The oils were investigated by GC and GC–MS, and four chemotypes were characterized: carvacrol (25.0%), thymol (23.8%), geranyl acetate/geraniol (20.8% and 19.8%) and linalool (30.0%).Assessment of cell viability was made by the MTT assay, and the results demonstrated that the oil with high amounts of carvacrol, which have stronger antifungal activity against dermatophyte strains, showed no cytotoxic effect, at concentrations ranging from 0.08 to 0.16 μL/mL, for as long as 24 h.In conclusion, it is possible to find appropriate doses of carvacrol type oil of T. zygis subsp sylvestris showing both antifungal activity and very low detrimental effect on mammalian cells. T. zygis with high content of carvacrol, could become a source of biologically active compounds for pharmaceutical industry.