In this study, a HCl/ethanol-induced gastritis or pylorus ligation-induced ulcer rat model was utilized to reveal the protective effect of α-humulene and its related mechanism for mucus secretion, gastric acid secretion, oxidant/antioxidant balance, and mucosal stabilizing factors such as MUC5AC and MUC6 in vivo. This evidence concerns the gene MUC5AC and gastritis.