J H Hwang1, H Choi, A R Kim, J W Yun, R Yu, E-R Woo, D G Lee. 1. School of Life Sciences, BK 21 Plus KNU Creative BioResearch Group, College of Natural Sciences, Kyungpook National University, Daegu, Korea.
Abstract
AIM: To provide the observation that hibicuslide C-induced cell death in yeast Candida albicans involves apoptosis mechanism. METHODS AND RESULTS: 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 Ca(2+), 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. CONCLUSIONS: Hibicuslide C exerts antifungal activity against C. albicans through new mechanism inducing apoptosis. SIGNIFICANCE AND IMPACT OF THE STUDY: 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.
AIM: To provide the observation that hibicuslide C-induced cell death in yeastCandida albicans involves apoptosis mechanism. METHODS AND RESULTS: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 Ca(2+), 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. CONCLUSIONS:Hibicuslide C exerts antifungal activity against C. albicans through new mechanism inducing apoptosis. SIGNIFICANCE AND IMPACT OF THE STUDY: 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.