Eugenol Affects the Germ Tube Formation and Cell Adhesion of Candida albicans

Candida albicans is the most common fungal pathogen in humans. Antimicrobial resistance in C. albicans is increasingly reported. The antifungal activity of eugenol against clinically relevant fungi including C. albicans has been recently described. In this study, the antifungal effects of eugenol on major virulence factors of C. albicans were evaluated. C. albicans isolates were exposed to sub-MIC of eugenol. The crystal violet-based method was used to quantify the germ tube formation. Extracellular enzymatic activity (proteinase, phospholipase, and lipase) was determined using the agar plate test. The adhesion to buccal epithelial cells was monitored microscopically. Our result showed that eugenol possesses fungicidal activity against C. albicans. At sub-inhibitory doses, eugenol significantly suppressed germ tube formation and cell adhesion of C. albicans (p<0.05). However, the enzymatic activity of yeast cells exposed to eugenol was slightly reduced. Our data indicate the inhibitory effect of eugenol on the growth and the pathogenicity of C. albicans in terms of germ tube formation and adhesion.