Action mechanism of metallo-allixin complexes as antidiabetic agents*

The metabolic syndrome is a group of factors associated with an increased risk of atherosclerosis and diabetes. Diabetes mellitus (DM) is classified into 2 major types—type 1 DM and type 2 DM—characterized by chronic hyperglycemia resulting from defects in insulin secretion and insulin action, respectively. Several synthetic pharmaceuticals have been developed and clinically used for treating DM; however, these pharmaceuticals continue to cause side effects. Recently, we proposed that oxovanadium(IV) (vanadyl) and zinc(II) (zinc) complexes are potent antidiabetic agents for both type 1 and type 2 DM therapy. This article reviews the vanadyland zinc-allixin and their related complexes that are being currently developed as novel types of antidiabetic metal complexes, focusing on their action mechanism in terms of regulation of the insulin signaling pathway and inhibition of lipolysis signaling in adipocyte cells.