FMN upregulated GLUT4 and AMPK expression. FMN significantly upregulated GLUT4 (A), and AMPK (B) expression in diabetic mice. Mice were fed with HFD for 9 weeks followed by two low doses of STZ injection (40 mg/kg), after diabetes was confirmed, mice were treated with 20 mg/kg FMN or 200 mg/kg metformin for 28 days, mice were then sacrificed, and soleus muscle was isolated and homogenized before western blotting performed. One-way ANOVA followed by Tukey post hoc, **<0.01, ***<0.001. VC; vehicle control.