FMN reduced glucose level during IPGTT. 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 fasted overnight before injection with 0.5 g/kg glucose intraperitoneally, and glucose level determined at 0, 30, 60, and 120 min. Two-way ANOVA followed by Tukey post hoc, ***<0.001. VC; vehicle control.