1,25-Dihydroxy vitamin D3 treatment reduces the levels of pro-inflammatory cytokines in reflux esophagitis in rats

Abstract Gastroesophageal reflux disease (GERD) is the most common upper gastrointestinal (GI) disorder with a considerably high prevalence across the world. Reflux of gastric acid into the esophagus can cause irritation and inflammation of the esophagus and progress into reflux esophagitis (RE). Vitamin D has anti-inflammatory effects and plays an important regulatory role in adaptability and innate immunity. Therefore, we hypothesized that VitD3 may play a protective role in RE. A total of 70 male Sprague–Dawley rats were used to surgically induce acute RE(n = 35) or chronic RE (n = 35), and to examine effects of different doses of 1,25-dihydroxy vitamin D3(VitD3) on morphological changes and alteration of pro-inflammatory cytokine levels. Macrographic and histopathological examinations revealed various degrees of esophageal impairment in rats following surgical induction of acute or chronic RE, whereas morphologic grading of esophageal mucosa showed no significant difference between groups. The protein expression of IL-1β, IL-6, and IL-8 was significantly increased in the rats with acute or chronic RE compared with rats that received sham-surgery. Vit D3 treatment significantly reduced the levels of these pro-inflammatory cytokines in both the low-dose and high-dose VitD3 groups compared with the control group in acute RE. Although no morphologic and histopathologic changes were observed, these novel findings suggest a potential protective role of VitD3 in RE at an early stage.