Antioxidant properties of the essential oil of Eugenia caryophyllata and its antifungal activity against a large number of clinical Candida species

Many essential oils are known to possess an antioxidant activity and antifungal properties and therefore they potentially act as antimycotic agents. Essential oil of clove (Eugenia caryophyllata) was isolated by hydrodistillation. The chemical composition of the essential oil was analysed by gas chromatography and gas chromatography/mass spectroscopy. The antioxidant effect of the tested oil was evaluated by measuring its 2,2-diphenyl-l-1- picrylhydrazil radical scavenging ability and the antiradical dose required to cause a 50% inhibition (IC50) was recorded. The antifungal activity of essential oils was evaluated against 53 human pathogenic yeasts using a disc paper diffusion method. Our results show that the major components present in the clove bund oil were eugenol (88.6%), eugenyl acetate (5.6%), β-caryophyllene (1.4%) and 2-heptanone (0.9%). The tested essential oil exhibited a very strong radical scavenging activity (IC50 = 0.2 μg ml-1) when compared with the synthetic antioxidant (tert-butylated hydroxytoluene, IC50 = 11.5 μg ml-1). On the other hand, this species displayed an important antifungal effect against the tested strains. It is clear that clove oil shows powerful antifungal activity; and it can be used as an easily accessible source of natural antioxidants and in pharmaceutical applications. © 2007 The Authors.