Antifungal activity of the clove essential oil from Syzygium aromaticum on Candida

J Med Microbiol. 2009 Jul 9. [Epub ahead of print]

Antifungal activity of the clove essential oil from Syzygium aromaticum (Eugenia caryophyllus) on Candida, Aspergillus and dermatophyte species.

Pinto E, Vale-Silva L, Cavaleiro C, Salgueiro L. Faculdade De Farmácia Da Universidade Do Porto;

The composition and the antifungal activity of clove essential oil, obtained from Syzygium aromaticum, were studied. Clove oil was obtained commercially and analysed by gas chromatography and by gas-chromatography-mass spectroscopy. The essential oil analysed showed high contents of eugenol (85.3 %). Minimal inhibitory concentration (MIC), determined according to CLSI (Clinical and Laboratory Standards Institute) protocols, and minimal fungicidal concentration (MFC) were used to evaluate the antifungal activity of the clove oil and its main component, eugenol, against Candida, Aspergillus, and dermatophyte clinical and ATCC (American Type Culture Collection) strains. The essential oil and eugenol showed inhibitory activity against all the tested strains. To clarify its mechanism of action on yeasts and filamentous fungi, flow cytometric and inhibition of ergosterol synthesis studies were performed. Propidium iodide (PI) rapidly penetrated the majority of the yeast cells when treated with concentrations just over the MICs, meaning that the fungicidal effect resulted from an extensive lesion of the cell membrane. Clove oil and eugenol caused also a considerable reduction of the quantity of ergosterol, a specific fungal cell membrane component. Germ tube formation by Candida albicans was completely or almost completely inhibited by concentrations below the MIC values, for the oil and eugenol. The present study indicates that clove oil and eugenol have a considerable antifungal activity against clinically relevant fungi, including fluconazole resistant strains, deserving further investigation for its clinical applications on the treatment of fungal infections.

PMID: 19589904 [PubMed - as supplied by publisher]