Metformin alleviates experimental colitis in mice by up-regulating TGF-β signaling

ABSTRACT

Ulcerative colitis is an inflammatory condition of the colon. Metformin, an antidiabetic drug, can suppress the inflammatory cascade. We investigated the effects of metformin on experimental colitis. Experimental colitis was induced in mice using dextran sulfate sodium. We used three groups of mice: untreated control, saline treated and metformin treated. We measured weight, disease activity index, colon length, levels of inflammatory cytokines, and we evaluated tissue histology. We found that metformin treatment decreased colon mucosal damage and preserved intestinal transit. We also found increased tissue levels of CD4+ Foxp3+ regulatory T cells (Treg), transforming growth factor-β1(TGF-β1) and pSmad2/3, and reduced expression of Th17 and IL-17. Metformin exhibited therapeutic potential for treating inflammatory conditions of the colon by targeting the immunoregulatory cytokine, TGF-β1.

KEYWORDS:

• Colitis
• inflammation
• metformin
• mice
• regulation
• TGF-β1
• ulcerative colitis

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

Our study was supported by a grant from the China Rehabilitation Research Center foundation (2019zx-05 to W.HF), Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction (KFKT2018011 to WHF) and the Nonprofit Industry Research Specific Fund of National Health and Family Planning Commission of China (201502018).