β-cell regenerative efficacy of a polysaccharide isolated from methanolic extract of Tinospora cordifolia stem on streptozotocin -induced diabetic Wistar rats

Abstract

The use of herbal supplements either as extracts or plant-derived individual molecules has significantly increased in the process of drug discovery and development for their potential efficacy or reduced risk in treating human disorders. Tinospora cordifolia (T. cordifolia) is a widely used herbal source to treat various human ailments, including diabetes mellitus. The present study was aimed on evaluating the antidiabetic property of a novel polysaccharide isolated from the methanolic extract of T. cordifolia stem. Bioassay guided fractionation was followed to isolate a compound from the methanol extract. The compound was administered orally at a dose of 20 mg/kg.b.wt for 60 days to control and STZ-induced diabetic male Wistar rats. It was found that plasma glucose was significantly (p < 0.05) reduced compared to normal. Oral administration of the compound significantly decreased HBA1c, triglycerides and total cholesterol and at the same time markedly increased hemoglobin, tissue glycogen and HDL cholesterol. Also the compounds restored the altered carbohydrate metabolizing enzymes, insulin, C-peptide, 14C-glucose oxidation levels to near normal. In addition, the histological studies revealed that there was regeneration of β-cells in the pancreatic sections. The expression of Glut-4 mRNA and protein in the gasrtocnemius muscle were significantly enhanced after the compound treatment. These results confirm that the novel polysaccharide possesses hypoglycemic, glucose oxidizing, hypolipidemic and β-cell regenerative properties and hence it could be developed into potential oral hypoglycemic drug with lesser side effects.