This study evaluates the composition, antifungal activity and mechanism of action of the essential oil of Ferulago capillaris (Link ex Spreng.) Cout. and its main components, limonene and α-pinene, against clinically relevant yeasts and moulds. Essential oil from the plant's aerial parts was obtained by hydrodistillation and analysed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS). Essential oil showed high contents of limonene (30.9%) and α-pinene (35.8%). Minimum inhibitory concentrations (MICs) were measured according to the reference Clinical and Laboratory Standards Institute (CLSI) broth macrodilution protocols. Cell suspensions were subcultured in solid medium and the minimum fungicidal concentrations (MFCs) were rendered. The effect of essential oil on germ tube formation, mitochondrial function and ergosterol biosynthesis was investigated. Essential oil and α-pinene displayed low and similar MIC and MFC values against tested organisms (0.08 to 5.0 μL/mL), while limonene showed a weaker activity (0.32 to 20 μL/mL). Essential oil inhibited germ tube formation at sub-inhibitory concentrations on Candida albicans. The exposure of C. albicans to the essential oil resulted in impairment of mitochondrial functions in a dose-dependent manner. No difference in ergosterol content was observed in essential oil-treated C. albicans. F. capillaris and α-pinene display a broad fungicidal activity. The fungicidal activity of F. capillaris on C. albicans can be related to an induced oxidative stress which affects enzymes activity and the membrane potential of mitochondria. The essential oil of F. capillaris was shown to have potential for use in the development of clinically useful therapeutic preparations, particularly for topical application in the management of superficial mycoses.

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The composition and antifungal activity of the essential oil (EO) of Angelica major and its main components α-pinene and cis-β-ocimene against clinically relevant yeasts and moulds were evaluated. EO from the plant's aerial parts was obtained by hydrodistillation and analysed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The oil showed high contents of α-pinene (21.8 %) and cis-β-ocimene (30.4 %). Minimum inhibitory concentrations (MICs) were measured according to the broth macrodilution protocols by the Clinical and Laboratory Standards Institute (CLSI). The EO, α-pinene and cis-β-ocimene displayed low MICs and minimum fungicidal concentrations (MFCs) against dermatophytes and Cryptococcus neoformans, with α-pinene being the most active. Regarding Candida species, the EO susceptibility profiles seem to be diverse and not correlated with fluconazole susceptibility patterns. Moreover, an inhibition of yeast-mycelium transition was demonstrated at sub-inhibitory concentrations of the EO, α-pinene and cis-β-ocimene in C. albicans. In addition, their haemolytic activity was low. The activity displayed by A. major EO and its main components associated with low cytotoxic activity confirms their potential as an antifungal agent against fungal species frequently implicated in human mycoses, particularly cryptococcosis and dermatophytosis. The association with commercial antifungal compounds could bring benefits, by the effect on germ tube formation, and be used in mucocutaneous candidiasis treatment.