The effect of benzyl isothiocyanate on Candida albicans growth, cell size, morphogenesis, and ultrastructure

Candida albicans is a commensal yeast that may become pathogenic and even lethal to the host. Over the last few decades, antifungal resistance has increased, promoting screening of the antifungal potential of old and new substances. This study investigates the antifungal potential of isothiocyanates (ITCs) against C. albicans oral isolates. A preliminary susceptibility disk diffusion test (DD) was performed using allyl isothiocyanate (AITC), benzyl isothiocynanate (BITC) and phenyl ethyl isothiocyanate (PEITC) at a fixed concentration range (0.001-0.1 M). Because C. albicans isolates were more susceptible to BITC and PEITC, their effect on cell size and on germ tube formation (GTF) were tested. The most promising molecule, BITC, was further tested for effects on cell viability, oxidative stress and for ultrastructure. ITCs, especially the aromatic ones, had a significant type-, dose- and isolate-dependent anti-Candida activity. Although BITC and PEITC had similar activity against the yeast cells, BITC had a more pronounced effect on cell size and GTF. Furthermore, BITC appears to induce oxidative stress and promote changes in the cell ultrastructure, interfering with cell wall structure. Our work showed that aromatic ITCs have the potential to effect C. albicans cells in multiple ways, including size, shape and GTF (BITC and PEITC), oxidative stress, and ultrastructure (BITC). Overall, our results suggest that BITC may be effectively used against C. albicans to modulate its growth, and control or suppress its invasive potential.