Ameliorating Effects of Geranium koreanum Kom on Esophageal Damage in Reflux Esophagitis via Nuclear Factor‑κB Signaling‑Mediated Anti‑Inflammatory Activities

Objective: In the present study, we wanted to demonstrate the anti‑inflammatory effects of G. koreanum extracts on esophagus damage in acute reflux esophagitis (RE)‑induced rats. Materials and Methods: The anti‑inflammatory effects of G. koreanum measured in nitric oxide (NO) production and inducible NO synthase (iNOS) protein expression on lipopolysaccharide (LPS)‑induced Raw 264.7 macrophages. To evaluate the improvement in RE, rats were per orally treated with G. koreanum 100 and 200 mg/kg 90 min before RE induction surgery. After 5 h, the rats were sacrificed to confirm the degree of esophageal injury. The esophageal mucosal ulcer ratio and histological changes were examined using Image J program and hematoxylin and eosin (H and E) staining of the rat esophagus, respectively. In addition, expression levels of pro‑inflammatory proteins on esophagus in RE rat were measured by western blotting. Results: G. koreanum exhibited anti‑inflammatory effects against LPS‑stimulated cells by significantly inhibiting NO production and iNOS protein expression. In addition, the LPS‑induced morphological transformation of cells was recovered following pretreatment with G. koreanum. In vivo, the result show that G. koreanum 200 mg/ kg extract‑treated group was ameliorated esophageal damage on histological analysis. The inflammatory mechanism (nuclear factor‑κB and mitogen‑activated protein kinases signaling pathways) involved in the esophageal damage was investigated by using western blotting with esophageal tissue, and G. koreanum clearly inhibited the inflammatory response in esophagitis‑induced rats. Conclusions: This study showed that G. koreanum has anti‑inflammatory and ameliorating effects in acute RE.