The Effect of Curcumin on GLUT4 Gene Expression as a Diabetic Resistance Marker in C2C12 Myoblast Cells

Objective: Adipocyte and skeletal muscle are important tissues which contribute the development and progression of metabolic disorder. Insulin has a major regulatory function on glucose metabolism in these tissues by redistributing glucose transporter (GLUT4) from intracellular vesicles to the cell surface. Today, due to the side effects of chemical medications attendance to herbal medicines is growing. In this study, the effect of Curcumin extract as main polyphenols in Turmeric on gene expression of GLUT4 was evaluated. Materials and Methods: Curcumin was extracted using alcohol and chloroform from turmeric powder.TLC chromatography was used to confirm purity of Curcumin extracted. Mouse C2C12 myoblasts were grown in Dulbecco’s Modified Eagle Medium (DMEM 1.5 g/l glucose) supplemented with 10% fetal bovine serum, 50 U/ml penicillin, and 50 μg/ml streptomycin. After differentiating of C2C12 cells during 4 days to myotubes, cells were treated separately in the presence of insulin (100 nM), Curcumin (25 µM) and co-treatment for 24h.RNA extraction from C2C12 cells was performed and GLUT4 expression levels were examined by semi-quantitative RT-PCR. Results: The results showed a significant increase in the GLUT4expression in Curcumin treatment group, in compare with negative control but less than insulin as a positive control. The synergistic effect of Curcumin and insulin was lower in comparison with insulin as a positive control. Conclusion: Curcumin could increase the gene expression but synergistic effects of Curcumin and insulin is more powerful than Insulin which can be due to the competitive action of insulin and Curcumin in activation of gene expression pathway.