Tinospora Cordifolia Promotes Expression of Insulin Receptor and Proglucagon Genes in Streptozotocin Induced Diabetic Rats

The aim of the present study was to determine the effect of aqueous extract of Tinospora cordifolia (AQTC) on antihyperglycemia, in vitro and in vivo antioxidant, intestinal proglucagon and pancreatic insulin gene expression levels in streptozotocin induced diabetic rats. The AQTC (100, 200 and 400 mg/kg body weight) was administered orally once a daily for 28 days in STZ induced diabetic rats. Serum blood glucose levels, glycosylated hemoglobin (HbA1c), insulin were estimated. Antioxidant enzymes like superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) were estimated in the pancreas and liver homogenates. Finally the expression levels of pancreatic insulin receptor and intestinal proglucagon gene expression were estimated at the end of 28 days treatment period. The results of the study indicates a significant reduction in blood glucose, HbA1c levels with significant increase in serum insulin and total protein levels with AQTC treatment in diabetic rats and a significant reduction in MDA with elevated levels of SOD, CAT in the pancreas and liver homogenates of diabetic rats compared to normal rats. The expression levels of genes of pancreatic insulin receptor and intestinal proglucagon genes were increased significantly with AQTC treatment. This indicates AQTC has protective effects on expression of intestinal proglucagon, which is precursor for GLP- 1 synthesis and also shown to increase the effects of insulin receptor expression. The protective role of Tinospora cordifolia might be due to the presence of active principles