Costunolide inhibits inflammation in LPS-induced RAW264.7 cells and ameliorates gastric acid reflux-induced esophageal injury in rat model

As one of the gastroesophageal reflux disease (GERD), reflux esophagitis (RE) severely affects patients' daily lives. Costunolide (Cos), pertains to a sesquiterpene lactone, performs multiple pharmacological activities including inhibited acute liver injury, anti-inflammation and anti-oxidant. We carried out our study to investigate the anti-inflammatory effect and protective effects of Cos against esophageal tissue damage caused by gastric acid refluxing. The determination of anti-inflammatory effects of Cos were conducted using lipopolysaccharide (LPS)-induced RAW 264.7 cell inflammatory model. The ameliorative effects of Cos on RE were confirmed on RE controlled rats model. The results indicated that Cos reduced nitrite production and inhibited cellular inflammation via regulating the activation of NF-kappa B. In addition, gastric acid reflux increased expression levels of inflammatory proteins (COX-2, TNF-alpha and IL-1 beta) in esophageal tissues, while Cos treatment significantly downregulated the expression of these proteins by inhibiting activation of NF-kappa B. Furthermore, through observing histological stain, Cos significantly improved esophageal damage caused by gastric acid reflux. Therefore, we suggested that Cos has the potential to be a material of natural drug for the treatment of reflux esophagitis caused by acid reflux.