INS and diabetes mellitus: As stated earlier, we chose the metformin dosage according to Sun et al. who found 100 mg/kg metformin to be effective in lowering blood sugar in STZ-induced diabetic rats with hyperinsulinemia, labeled as VET2D by us [46]; but clearly the effect of metformin as an insulin sensitizer should depend on the stage of diabetes in terms of insulin levels in the body.