Omeprazole preserves the RER in chief cells and enhances re-epithelialization of parietal cells with SOD and AQP-4 up-regulation in ethanol-induced gastritis rats

Gastric mucosal cells, particularly parietal and chief cells, are usually affected by exogenous, and endogenous stimuli-induced gastritis. The integrity of these cells and their alterations are involved in the pathogenesis of numerous gastric disorders. Omeprazole, a gastric acid secretion blocker, is commonly used for gastrointestinal diseases due to its antioxidative stress and anti-inflammatory properties. Little is known regarding how omeprazole modulates the re-epithelialized effect on gastric mucosal cells associated with gastrointestinal disorders. The present study aimed to determine whether omeprazole attenuates parietal and chief cell damage in association with its antioxidative property. An in vivo ethanol-induced gastritis rat model was used. Histopathological, scanning and transmission electron microscopic, and immunohistochemical studies were performed. The results revealed that omeprazole improved the gastric mucosal surface, and reduced the severity of mucosal inflammation and hemorrhaging. Notably, ethanol-induced gastritis caused dysmorphic rough endoplasmic reticulum (RER) in chief cells, which was accompanied by mitochondrial swelling. This alteration was modulated by omeprazole due to its antioxidant effect characterized by upregulation of superoxide dismutase in gastric mucosal cells. In addition, expression of aquaporin-4 was increased in the omeprazole treatment group, which may be due to the expansion of regenerative parietal cells and acid suppression. The results of the present study suggest that omeprazole preserves the RER in chief cells and enhances parietal cell regeneration through its antioxidative property by exerting anti-inflammatory effects.