1-Deoxynojirimycin modulates glucose homeostasis by regulating the combination of IR-GlUT4 and ADIPO-GLUT4 pathways in 3T3-L1 adipocytes.

1-Deoxynojirimycin (DNJ), the main alkaloid in mulberry leaves, was recognized to treat patients with type 2 diabetes mellitus (T2DM). However, the regulatory mechanism of DNJ on glucose homeostasis was still unclear. In the present study, a safe concentration of 0.1-10 μmol/L for DNJ was incubated with mature 3T3-L1 adipocytes. The results demonstrated that the genes/proteins expression of insulin receptor (IR), phosphatidylinositol-3-kinase (PI3K), protein kinase B (AKt/PkB), and adiponectin (ADIPO) increased with the increasing of DNJ concentration from 0.1-10 μmol/L. However the mRNA expression of adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK), glucose transporter 4 (GLUT4) and glucose absorption increased to the maximum at concentration of 5 μmol/L then decreased with further increase of DNJ concentration to 10 μmol/L. Both IR and ADIPO signaling pathways simultaneously affect the glucose homeostasis regulation effect of DNJ, whereas the key response target located in AMPK and its effect on subsequent GLUT4 mRNA expression.