Treatment of T2DM rats with low dose of metformin (150 mg/kg) for 8 weeks only significantly decreased the levels of LDL-C, TC, and BUN (P < 0.05) but not BG, HbA1c, and INS, whereas higher doses of metformin (300, 500 mg/kg) obviously restored all measured biochemical parameters after 8 weeks (P < 0.05) as compared with group DM (Figure 1). Here, INS is linked to type 2 diabetes mellitus.