Abstract

BACKGROUND
The target of the treatment of metabolic syndrome and diabetes is an improvement of insulin resistance. D-chiro-inositol (DCI) plays a role in a phospholipid mediating intracellular insulin action. In the previous studies, the urine level of DCI were decreased in the diabetic animal with insulin resistance. Some clinical studies showed that DCI improved a glucose level and HbA1c. Therefore we studied the relationship between DCI and glucose metabolism, especially insulin resistance. METHODS: To investigate the mechanism of DCI affecting the glucose metabolism, we examined the effects of DCI on 2-deoxyglucose uptake, gene expression of adipocytokines and AMPK pathway by using RT-PCR and western blot in 3T3-L1 cells. RESULTS: Insulin-stimulated 2-deoxyglucose uptake increased in DCI-treated cells by about 1.2-fold (relative to the control) and was inhibited by phosphoinositide 3-kinase (PI3 Kinase) inhibitors (Wortmanin, LY294002) and AMPK inhibitor (STO-609). In Western blot analysis, it didn't show the difference of phosphorylation of Akt and AMPK between DCI-treated group and control in 3T3-L1 cells. However, DCI decreased the gene expression of resistin in 3T3-L1 cells. CONCLUSION: DCI may involve other pathway of insulin signaling, but not PI3 Kinase and AMPK signaling pathways and it may be useful in managing metabolic syndrome by improving insulin resistance through increasing glucose uptake and decreasing resistin relevant to insulin resistance.

• Keywords: Adipocytokine;Diabetes;D-Chiro-Inositol;Insulin resistance;Metabolic syndrome