Hibicuslide C‐induced cell death in C andida albicans involves apoptosis mechanism

Aim To provide the observation that hibicuslide C‐induced cell death in yeast C andida albicans involves apoptosis mechanism. Methods and Results Hibicuslide C was isolated from A butilon 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. Casp ACE FITC ‐ VAD ‐ FMK staining using caspase inhibitor showed metacaspase activation. Also, the increase in intracellular Ca 2+ , which is a signal molecule of apoptosis, was detected by Fura‐2 AM and Rhod‐2 AM 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 . Conclusions Hibicuslide C exerts antifungal activity against C .  albicans through new mechanism inducing apoptosis. Significance and Impact of the Study C andida 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 .