Role of Semisulcospira gottschei extract as medicinal food on reflux esophagitis in rats

Gastroesophageal reflux disease (GERD) is a globally prevalent disease and results from a reflux of gastric contents into the esophagus. Existing synthetic drug‐based treatments for GERD have various drawbacks including refractory symptoms, relapse, or resistance due to long‐term use or may result in mucosal degeneration, polyps, and osteoporosis. Semisulcospira gottschei (SE), a freshwater snail, has been generally consumed as a food source due to its excellent flavor and nutritional value in Korea and considered to have therapeutic properties for various diseases including dyspepsia, stomachache, and hepatic diseases. The present study aims to investigate whether Semisulcospira gottschei extract (SGE) has a protective effect on reflux esophagitis‐induced rat models. The anti‐inflammatory effects of SGE were evaluated via NO production in LPS‐induced Raw 264.7 macrophage. And the protection effects of SGE were analyzed by assessing the amelioration of mucosal damage and expression of inflammation‐associated proteins in reflux esophagitis (RE) rats. Our results indicate that SGE significantly suppressed NO production in LPS‐induced raw 264.7 cells without any cytotoxicity. We observed mucosal lesions and histological changes in the esophagus of RE control rats. However, SGE treatment markedly ameliorated mucosal lesion ratio indicated through histological changes. SGE administration suppressed the expression of proteins related to inflammation, such as p‐NF‐κB, p‐IκBα, COX‐2, and TNF‐α, in esophageal tissue. Moreover, SGE elevated the expression of claudin‐5, which is a tight junction protein, involved in barrier function of epithelium and endothelium. The results suggest that SGE is useful as a medicinal food in esophagitis and may be helpful in developing effective treatment protocols for GERD.