Hibicuslide C-induced cell death in Candida albicans involves apoptosis mechanism

To provide the observation that hibicuslide C‐induced cell death in yeast Candida albicans involves apoptosis mechanism. Hibicuslide C was isolated from Abutilon theophrasti by column chromatography. In reactive oxygen species (ROS) assay, C. albicans treated with hibicuslide C showed increase in ROS, and its accumulation induced fungal cell death. In particular, hydroxyl radicals were a large part of the ROS. Mitochondrial dysfunction including mitochondrial depolarization and release of cytochrome c, which is a pro‐apoptotic factor, was detected by JC‐1 assay and Western blot. CaspACE FITC‐VAD‐FMK staining using caspase inhibitor showed metacaspase activation. Also, the increase in intracellular Ca2+, which is a signal molecule of apoptosis, was detected by Fura‐2AM and Rhod‐2AM assays. Finally, annexin V‐FITC and PI double staining and TUNEL assay confirmed that hibicuslide C induces early apoptosis followed by secondary necrosis in C. albicans. Hibicuslide C exerts antifungal activity against C. albicans through new mechanism inducing apoptosis. Candida albicans is the common cause of nosocomial infections with high mortality. Our findings provide that hibicuslide C can be a model molecule that induces apoptosis in C. albicans.