(+)-Medioresinol leads to intracellular ROS accumulation and mitochondria-mediated apoptotic cell death in Candida albicans

The phytochemical (+)-Medioresinol, a furofuran type lignan identification and isolation on the stem bark of Sambucus williamsii, which is a folk medicinal plant used in traditional medicine. (+)-Medioresinol is known to possess a lesishmanicidal activity and Cardiovascular Disease risk reduction but its Antifungal effects have not yet been identified. In this study, to confirm (+)-Medioresinol's Antifungal properties and mode of action, we observed morphological and physiological change in Candida albicans. In cells exposed to (+)-Medioresinol, arrested the cell cycle and intracellular Reactive Oxygen Species (ROS) which is a major cause of Apoptosis were increased. The increase of ROS induced oxidative stress and the mitochondria dysfunction which causes release of pro-apoptotic factors. We investigated a series of characteristic cellular changes of Apoptosis by using various Apoptosis detection methods. We report here for the first time that (+)-Medioresinol has effects on mitochondria and induced the accumulation of ROS in C. albicans cells. We demonstrated that one of the important features of Apoptosis, mitochondrial membrane depolarization is caused by ROS. Substantially, we investigated the release of cytochrome c, which is one of the factors of metacaspase activity. We also show that the effects of (+)-Medioresinol are mediated at an early stage in Apoptosis acting on the plasma membrane phosphatidylserine externalization. In addition, (+)-Medioresinol induced apoptotic morphological changes, showing the reduced cell size (low FSC) and enhanced intracellular density (high SSC). In late stage of confirmation of diagnostic markers in yeast Apoptosis include the effects of nucleus morphological change, DNA fragmentation and condensation by influence of oxidative stress. These apoptotic phenomena represent that oxidative stress and mitochondria dysfunctions by inducing the phytochemical (+)-Medioresinol must be an important factors of the apoptotic process in C. albicans. These results support the elucidation of the underlying Antifungal mechanisms of (+)-Medioresinol.