Combined potentiating action of phytochemical(s) from Cinnamomum tamala and Aloe vera for their anti-diabetic and insulinomimetic effect using in vivo rat and in vitro NIH/3T3 cell culture system.

The present investigation was undertaken to analyze the ethanolic extracts of leaves of Cinnamomum tamala and Aloe vera for their anti-diabetic and insulinomimitic effect by determining the levels of blood sugar, glycosylated hemoglobin, and serum lipid profile (total cholesterol, triglycerides, high density lipoprotein (HDL), and low density lipoprotein (LDL)) after daily administration of each alone and in combined at 250 mg/kg in alloxan (ALX)-induced diabetic rats. Treatment of diabetic rats with the extracts restored the elevated biochemical parameters significantly. The anti-diabetic effect further potentiated the insulin signaling pathway by co-administration of both extracts. The molecular mechanisms of modulating gene expression and cellular signaling through the insulin receptor were also evaluated on specific targets of the insulin signaling pathway, including insulin receptor substrate (IRS), phosphatidylinositol 3-kinase (PI3-K), AKT, and the glucose transporter (GLUT4) on NIH/3T3 cell line by western blotting, ELISA, semiquantitative RT-PCR, and real-time PCR. The active principle of both extracts revealed insulin mimicking effect as indicated by increased expression of pIRS1 and pAKT in time-dependent manner. There was no significant difference in PI3-K content between unchallenged and challenged groups. Enhanced expression of GLUT-4 transcript further suggested that the Cinnamomum and Aloe phytochemicals could serve as a good adjuvant in the present armamentarium of anti-diabetic drugs by either mimicking or improving insulin action. This study reveals that ethanolic extracts of C. tamala and A. vera have potent therapeutic efficacy and prospect for the development of phytomedicine for diabetes mellitus.