Anti-diabetic effects of emodin involved in the activation of PPARγ on high-fat diet-fed and low dose of streptozotocin-induced diabetic mice

Rheum palmatum unit has been widely applied in the clinical treatment of diabetes mellitus It has been found that emodin as the major bioactive component of R palmatum L exhibits the competency to activate peroxisomal proliferator-activated receptor-gamma (PPAR gamma) in vitro So the aim of this study was to evaluate the anti-diabetic effects of emodin through the activation of PPAR gamma on high-fat diet-fed and low dose of streptozotocin (STZ)-induced diabetic mice The diabetic mice were intraperitoneally injected with emodin for three weeks No changes of food consumption and the body weight in emodin-treated mice were monitored daily during the entire experiment At the end of experiment. the levels of blood glucose, triglyceride and total cholesterol in serum were significantly decreased after emodin treatment. However, serum high-density lipoprotein cholesterol (HDLc) concentration was significantly elevated The glucose tolerance and insulin sensitivity in emodin-treated group were significantly improved Furthermore, the results of quantitative RT-PCR analysis showed that emodin significantly elevated the mRNA expression level of PPAR gamma and regulated the mRNA expressions of LPL. FAT/CD36, resistin and FABPs (ap2) in liver and adipocyte tissues. No effects on the mRNA expressions of PPAR alpha and PPAR alpha-target genes were observed Taken together, the results suggested that the activation of PPAR gamma and the modulation of metabolism-related genes were likely involved in the anti-diabetic effects of emodin (C) 2009 Elsevier B V All rights reserved