Delphinidin Induces Autolysosome As Well As Autophagosome Formation and Delphinidin-induced Autophagy Exerts a Cell Protective Role

Anthocyanidins, which are polyphenols that are believed to be effective for preventing cancer, are composed of a basic structure of the plant pigment anthocyanin. In this study, we investigated the biological activity of anthocyanidins, including delphinidin, against HeLa cells. The cytotoxicity observed in the anthocyanidins-treated cells was well correlated with the inhibitory effects of anthocyanidins on c-Jun-dependent transcriptional activity. Remarkably, anthocyanidin induced autophagosome formation but lacked the ability to induce apoptosis. Notably, delphinidin enhanced autolysosome formation as well as autophagosome formation. Delphinidin treatment resulted in the accumulation of the lipidated form of Map1lc3b protein in an Atg5-dependent manner in mouse embryonic fibroblasts. Finally, we revealed that the cytotoxicity induced by delphinidin was more severe in Atg5-deficient mouse embryonic fibroblasts than in wild-type cells. Taken together, these results indicate that the cytotoxicity induced by delphinidin was accompanied by autophagy and delphinidin-induced autophagy exerted a cell protective role.