The prevention and treatment efficiency of ethanol-induced gastric epithelial injury are not satisfied. We have previously shown that AMP-activated protein kinase (AMPK) activation exerts a pro-survival function in human gastric epithelial cells (GECs). miroRNA-451 ("miR-451")'s inhibitor, antagomiR-451, can activate AMPK signaling. In the present study, we show that forced-expression of antagomiR-451 via a lentiviral vector depleted miR-451, leading to AMPK activation in established GES-1 cells and primary human GECs. AntagomiR-451 efficiently protected GES-1 cells and primary human GECs from ethanol-induced viability reduction and apoptosis. AMPK activation is required for antagomiR-451-induced GEC protection. AMPK alpha l knockdown (by targeted-shRNAs) or knockout (by CRISPR-Cas-9 KO plasmid) blocked antagomiR-451-induced AMPK activation, and GEC protection against ethanol. Further experimental results show that antagomiR-451 significantly attenuated ethanol-induced reactive oxygen species (ROS) production, lipid peroxidation and DNA damage. Collectively, antagomiR-451 protects human GECs from ethanol via activating AMPK signaling. (C) 2018 Elsevier Inc. All rights reserved.