In vitro antifungal activity of Shikonin against Candida albicans by inducing cellular apoptosis and necrosis

Abstract Our previous studies showed that Shikonin (SK) had a strong anti- Candida albicans ( C. albicans ) activity, especially against some fluconazole-resistant strains, which is probably due to the oxidative damage of SK to C. albicans . In this study, we further analyze the exact mechanism of SK against C. albicans . Through some experiments, such as detecting the apoptosis and necrosis rates of C. albicans SC5314 cells treated with different concentrations of SK by Annexin V-FITC / PI double staining, observing the ultrastructure of cells by transmission electron microscopy, testing mitochondrial cytochrome c oxidase activity, caspase activity, and caspase-related gene CaMCA1 expression level. We found that SK could induce a series of apoptosis characteristics, including phosphatidylserine (PS) externalization, chromatin condensation and fragmentation, decreased cytochrome c oxidase activity as well as caspase activation. In summary, this study highlighted the antifungal activity and mechanism of SK against C. albicans , providing a potential therapeutic strategy for C. albicans infection.