Argyreia Nervosa Facilitates GLUT4 Translocation to the Plasma Membrane by Promoting IRAP and VAMP-2 Genes in STZ-Induced Type 2 Diabetic Rats

Abstract

BackgroundArgyreia nervosa is a perennial vine which is originally found in the Indian subcontinent and was later introduced to various areas world wide such as Hawaii, Africa and the Caribbean. It is commonly called an elephant creeper. GLUT 4 mechanism is an example of cascade effect and is responsible for the control of blood sugar levels of a living organism. It mainly occurs in the skeletal muscles and adipose tissue. IRAP and VAMP-2 are the genes which are expressed in response to the GLUT-4 mechanism and are used to evaluate the blood glucose levels in an organism.

Aim and Objective

This study was aimed to determine if Argyreia nervosa facilitates GLUT4 translocation to the plasma membrane by promoting IRAP and VAMP-2  genes in STZ-induced diabetic rats.

Materials and Methods

The healthy male Wistar  albino rats were made to fast overnight and the next morning were injected with streptozotocin to induce diabetes in them. And then the plant extract was fed to them to check if it helped in reducing diabetes. The animals were grouped into 4 groups consisting of four rats in each group consisting of 6 animals. Group 1: Control; Group 2: STZ-induced diabetes; Group 3: Diabetes+A. Nervosa; Group 4: Control+A.nervosa for 30 days. At the end of the treatment period, animals were anesthetized, serum was collected, skeletal muscle was dissected out and used for the assessment of various parameters. Fasting blood glucose, serum insulin, mRNA expression of IRAP, VAMP-2 and GLUT 4 mRNA expression were carried out.The data were statistically analyzed using One-Way-ANOVA followed by Duncan’s multiple range test were used to check the statistical significance and considered at the levels of p<0.05.

Results: STZ-induced rats showed an increased fasting serum glucose and serum insulin level compared to normal control rats (p<0.05). However, type-2 diabetic rats treated with A.nervosa extract significantly reduced hyperglycemia and hyperinsulinemia effectively. mRNA expression of molecules involved in the GLUT4 translocation in the skeletal muscle were also studied by Real Time-PCR. Results of mRNA expression showed that GLUT4 mRNA expression was significantly reduced in STZ-induced rats. Similarly, IRAP and VAMP-2 mRNA levels were also found to be significantly reduced due to STZ-induced hyperglycemia. A. nervosa treatment brought back to the normal levels of GLUT4, IRAP and VAMP-2 effectively. 

Conclusion

It is concluded from the present findings that A. nervosa reduces diabetic complications  by facilitating the expression of molecules involved in the GLUT4 translocation such as IRAP, VAMP2 mRNA expression in the gastrocnemius muscle. Hence, A. nervosa could be used as a therapeutic drug candidate for the treatment of diabetes mellitus and associated complications.