Metformin-d6 is intended for use as an internal standard for the quantification of metformin by GC- or LC-MS. Metformin is a biguanide with diverse biological activities. Metformin (250 mg/kg, i.p.) increases hepatic AMPK activity and reduces blood glucose by more than 50% in a liver kinase B1-dependent manner in mice fed normal and high-fat diets, respectively, and reduces blood glucose by 40% in ob/ob mice. It reduces weight gain, hepatic lipid droplet content, and total cholesterol, LDL cholesterol, and triglyceride levels in the plasma of diet-induced obese mice when administered at doses of 10 or 50 mg/kg per day. It also reverses increased hepatic triglyceride and apolipoprotein A5 levels, as well as hepatic steatosis, in a dose-dependent manner in an ob/ob mouse model of non-alcoholic fatty liver disease (NAFLD). Metformin (250 mg/kg) reduces tumor growth in an HCT116 p53-\- human colon cancer mouse xenograft model, but has no effect on HCT116 p53-\- tumors overexpressing recombinant S. cerevisiae Ndi1 NADH dehydrogenase, a single-subunit ortholog of the multi-subunit mammalian mitochondrial complex I. Formulations containing metformin have been used in the treatment of type 2 diabetes.
