Berberine protects against esophageal mucosal damage in reflux esophagitis by suppressing proinflammatory cytokines

This study was performed to investigate the effects of berberine (BB) in a rat model of gastroesophageal reflux disease (GERD), induced by pylorus and forestomach ligation. We evaluated cytotoxicity and proinflammatory biomarkers (nitric oxide, interleukin (IL)-1β and prostaglandin E2) in RAW 264.7 cells in vitro and anti-inflammatory effects in vivo. A total of 54 Sprague Dawley rats were divided into six groups: intact control rats; reflux esophagitis (RE) control rats; RE rats treated with 20 mg/kg omeprazole and RE rats treated with BB at doses of 20, 40 and 60 mg/kg, respectively. All rats were fasted. RE was induced by pylorus and forestomach ligation one hour subsequent to the oral treatment. Six hours subsequent to the surgery, the rats were sacrificed, blood was collected from the abdominal vein and the esophagus and stomach were dissected. The gastric volume and the pH of the gastric juice were evaluated, prior to the esophagus being cut longitudinally and an inner mucosal area being imaged, to analyze mucosal damage indices. Proinflammatory biomarkers in the serum, including tumor necrosis factor (TNF)-α, IL-1β, IL-6 and monocyte chemoattractant protein (MCP)-1 were analyzed using an enzyme-linked immunosorbent assay (ELISA) kit, while the mRNA expression of TNF-α, IL-1β, IL-6 and plasminogen activator inhibitor (PAI)-1 was analyzed using a quantitative polymerase chain reaction (qPCR). Esophagic tissue damage in the BB groups was dose-dependently decreased compared with that in the RE control group. This result was consistent with significant reductions in the levels of proinflammatory biomarkers in the serum and in the expression of proinflammatory mRNA, specifically, TNF-α, IL-1β, IL-6 and PAI-1. The results suggest that the anti-inflammatory and protective effects of BB may attenuate the severity of RE and prevent esophageal mucosal damage, in addition to validating the use of BB as a pharmacological treatment for esophageal reflux disease.