Naringin inhibited robust ER-stress-mediated autophagy in colorectal mucosal cells. (A) Electron microscopy analyzed the ultrastructures of ER, indicating ER expansion with double-membrane structures. Naringin attenuated ER expansion. (B) Electron microscopy showed double membrane autophagy vesicles in colorectal mucosal epithelial cells. Autophagy vesicles were reduced in naringin-treated mice. (C) AOM/DSS induced robust ER stress as evidenced by high expressions of GRP78, IRE1α, PERK and ATF6α. Naringin inhibited the expression of GRP78, IRE1α, PERK and ATF6α in colorectal mucosal cells. (D) Naringin prevented the formation of robust ER stress induced-ATG16L1 complex in colorectal mucosal cells. (E) Naringin reduced ER stress-induced high level of LC3B and Bcelin-1 in colorectal mucosal cells.