FIGURE 4.

Metformin inhibited TGF‐β1/Smad3 signalling. (A) Western blot showing the expression of TGF‐β1 in NIH‐3T3 cells treated with metformin at different concentrations. Treatment with 10 mmol/L metformin significantly reduced TGF‐β1 levels. *, P < .05. (B) Western blot showing the expression of TGF‐β1 at different time‐points in NIH‐3T3 cells treated with metformin. TGF‐β1 was significantly reduced after metformin treatment for 48 hours. **, P < .01. (C) Metformin inhibited the phosphorylation of Smad3 in NIH‐3T3 cells. *, P < .05. (D) SRI‐011381 (Smad3 agonist) mitigated the effects of metformin on the expression of fibronectin in NIH‐3T3 cells. *, P < .05