S-phase accumulation of Candida albicans by anticandidal effect of amentoflavone isolated from Selaginella tamariscina.

Amentoflavone, which is a biflavone derived from various plants, has been known to possess various biological activities including anti-tumor and anti-inflammatory activity. In the previous study, we reported antifungal effect of amentoflavone isolated from an ethyl acetate extract of Selaginella tamariscina on human pathogenic fungi. Amentoflavone significantly inhibited the growth of fungal cells without hemolysis of human erythrocytes. In the present study, we investigated antifungal acting mode of amentoflavone in human pathogenic yeast Candida albicans. Anticandidal activity was exerted in an energy-independent manner presented by an antifungal assay in the presence of NaN(3), which is ATP-depleting agent as a metabolic inhibitor. To investigate the effects of amentoflavone on cellular physiology in C. albicans, we performed cell cycle analysis, and the analysis showed that amentoflavone significantly arrested cell cycles during the S-phase. These results demonstrated that amentoflavone has potent anticandidal activity with significant physiological changes inducing S-phase arrest in intracellular environment. Therefore, amentoflavone may be applied to a lead compound for the development of therapeutic agents, which can treat candidiasis resulted from candidal infections.