Antidiabetic activities of Abutilon indicum Sweet mediated by enhancement PPARγ and activation of the GLUT1 promoter

Abstract

Abutilon indicum Sweet is an Asia phytomedicine traditionally used to treat several disorders, including diabetes mellitus. However, molecular mechanisms supporting the antidiabetic effect of A. indicum Sweet remains unknown. Since a tremendous increase in the number of individuals with type 2 diabetes mellitus worldwide and insulin resistance is a major pathogenic factor for type 2 diabetes. The aim of this study was to evaluate whether extract of A. indicum Sweet improves insulin sensitivity. First, we observed the antidiabetic activity of aqueous extract of A. indicum on postprandial plasma glucose in diabetic rats. The subsequent experiments revealed that butanol fractions of the extract bind to PPARγ and activate 3T3‐L1 differentiation. To measure glucose uptake enhanced by insulin‐like activity, we used rat diaphragm incubated with various concentrations of the extract and found that the extract enhances glucose consumption in the incubated solution. Our data also indicate that the extract and the fractions did not affect the activity of kinases involved in Akt and GSK‐3β pathways; however, the reporter assay showed that the crude extract could activate glucose transporter 1 (GLUT1) promoter activity. These results suggest that the extract from A. indicum Sweet may be beneficial for reducing insulin resistance through its potency in regulating adipocyte differentiation through PPARγ agonist activity and increasing glucose utilization via GLUT1.