Methane alleviates infammation and apoptosis of dextran sulfate sodium-induced inflammatory bowel diseases by inhibiting tolllike receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)/nuclear translocation of nuclear factor-κB (NF-κB) and endoplasmic reticulum stress pathways in mice

Background: Inflammatory bowel diseases (IBDs) are chronic idiopathic diseases with increased occurrence and recurrence rates. The aim of this study was to explore whether methane-rich saline (MRS) would be beneficial to IBD. Material/Methods: Dextran sulfate sodium (DSS) was utilized to establish an IBD model. Male C57BL/6J mice were randomly grouped as follows: the control group, the DSS+NS group, the DSS+5-ASA group, the DSS+MRS (1) and DSS+MRS (10) groups. Seven days after model induction, blood and colon tissues were collected to assess the treatment effects. Results: The DSS+MRS (10) group showed obviously reduced weight loss, disease activity index, and spleen index. The isolated colon samples had a notably longer length, less thickness and weight, and better macroscopic score with MRS treatment compared with the DSS+NS group. Additionally, assessment of morphological impairment revealed a milder and lower microscopic score in the DSS+MRS (10) group, consistent with the myeloperoxidase (MPO) results. The inflammation-related molecules levels were dramatically reduced by MRS. MRS also significantly reduced oxidative stress related proteins. In addition, apoptotic cells were visually decreased in the DSS+MRS (10) group, in which the pro-apoptotic molecules Bax and cleaved caspase-3 were reduced, whereas the level of Bcl-2 was increased. Furthermore, MRS markedly decreased the TLR4, MyD88, p-NF-kB p65, p-IKKab, and p-IkBa, and increased IL-10, p-JAK1, and p-STAT3 expression levels. Proteins involved in endoplasmic reticulum stress (ERS) were also notably reduced under MRS treatment. Conclusions: MRS exerts protective effects on DSS-induced IBD via inhibiting inflammatory reaction, promoting anti-inflammatory capacity, suppressing oxidative stress, and ameliorating apoptosis.