Bright renoprotective properties of metformin: beyond blood glucose regulatory effects

Metformin, a biguanide drug, is widely prescribed to treat high blood glucose in individuals with type 2 diabetes mellitus. Type 2 diabetes mellitus is a troubling chronic disease and diabetic nephropathy is one of the most important complications of diabetes mellitus. Recent studies suggest that metformin, in addition to its efficacy in treating type 2 diabetes, may also have therapeutic efficacy in other conditions, including diabetic nephropathy or ameliorative property against tubular cell injury. Moreover, metformin significantly decreases albuminuria in patients with type 2 diabetes mellitus. However, the exact mechanisms beyond the effect of metformin on blood glucose are still unknown. Recent studies suggest that the therapeutic effect of metformin is mediated by its action on adenosine monophosphate-activated protein kinase in tissues. Various investigations show that metformin decreases intracellular reactive oxygen species. Metformin protects against tubular injury by restoring the biochemical alterations and regulation of oxidative stress on renal tubules. It also protects podocytes in nephropathy of diabetes. These findings can more strongly potentiate the clinical use of metformin in the prevention of nephropathy of diabetes. In this regard, to better understand the metformin nephroprotective properties, more experimental rat models and clinical studies are needed.