Immunomodulation By Melatonin Of The Helicobacter Pylori-Induced Gastric Diseases

A large number of researches implicated that melatonin as an immunomodulatory compound modulates a wide range of physiological functions with pleiotropic effects on the immune system. But its immunoprotect mechanism of gastrointestinal diseases(GI diseases) caused by Helicobacter pylori infection remains unclear. In the present study, mice were intragastrically inoculated with SSI to acquire GI diseases, after use different concentrations(25mg/kg、50mg/kg、100mg/kg) of melatonin coeliac injected each group of mice within 2 、 4 、 6weeks, TGFβ1 concentration in plasma were measured by ELISA assay; Gastric mucosa damage level were observed by HE staining; the MT1 、 MT2 protein biding cites in stomach were determined by immunohistochemistry; protein levels of TGFβ1 in liver、Foxp3 in spleen、RORβin stomach were detected by Western Blot, respectively. All the mice were sacrificed and ELISA assay shows that TGFβ1 level in mice plasma were down-regulate in 2weeks group and upgrade in 4 and 6 weeks groups compared to the control group.Gastric tissues were checked by a urease test, which showed positive results, and stomach paraffin section and HE staining showed that inflammatory cells dispersed in mucosal layer and submucosa layer, which indicated that H.pylori colonization. IHC staining showed MT1、MT2 binding cites in stomach. Western blot result showed that protein level of Foxp3 in spleen decreased in 2 weeks group, but increased in 4 weeks group; RORβ were descend in 2weeks but ascend in 4 weeks group, yet ascend in 6weeks group; as well as TGFβ1 upgraded in both 2、4 and 6 weeks groups. This study provides novel insights into the therapeutic effect of melatonin against H.pylori induced gastrointestinal diseases, suggests its potential immunomodulation as an alternative therapy, and opens the way for further studies on melatonin immunoprotect effects.