molecules Article Antifungal Activity of Thapsia villosa Essential Oil against Candida, Cryptococcus, Malassezia, Aspergillus and Dermatophyte Species Eugénia Pinto 1,2,* ID , Maria-José Gonçalves 3, Carlos Cavaleiro 3 and Lígia Salgueiro 3 1 Laboratory of Microbiology, Biological Sciences Department, Faculty of Pharmacy of University of Porto, Rua Jorge Viterbo Ferreira n◦ 228, 4050-313 Porto, Portugal 2 Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Terminal de Cruzeiros do Porto de Leixões Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal 3 CNC.IBILI, Faculty of Pharmacy, University of Coimbra, Azinhaga de S. Comba, 3000-354 Coimbra, Portugal;
[email protected] (M.-J.G.);
[email protected] (C.C.);
[email protected] (L.S.) * Correspondence:
[email protected]; Tel.: +351-220-428-585; Fax: +351-226-093-390 Received: 31 July 2017; Accepted: 20 September 2017; Published: 22 September 2017 Abstract: The composition of the essential oil (EO) of Thapsia villosa (Apiaceae), isolated by hydrodistillation from the plant’s aerial parts, was analysed by GC and GC-MS. Antifungal activity of the EO and its main components, limonene (57.5%) and methyleugenol (35.9%), were evaluated against clinically relevant yeasts (Candida spp., Cryptococcus neoformans and Malassezia furfur) and moulds (Aspergillus spp. and dermatophytes). Minimum inhibitory concentrations (MICs) were measured according to the broth macrodilution protocols by Clinical and Laboratory Standards Institute (CLSI). The EO, limonene and methyleugenol displayed low MIC and MFC (minimum fungicidal concentration) values against Candida spp., Cryptococcus neoformans, dermatophytes, and Aspergillus spp. Regarding Candida species, an inhibition of yeast–mycelium transition was demonstrated at sub-inhibitory concentrations of the EO (MIC/128; 0.01 µL/mL) and their major compounds in Candida albicans.