Anti-diabetic effects of cinnamaldehyde and berberine and their impacts on retinol-binding protein 4 expression in rats with type 2 diabetes mellitus

Wei Zhang, Yan Cheng Xu, Fang Jian Guo, Ye Meng, Ming Li Li

Research output: Contribution to journalArticle

61 Scopus citations


Background: Retinol binding protein 4 (RBP4), as an adipocyte secreted cytokine, was recently found to be inversely correlated with expression of glucose transporter 4 (GLUT4) in insulin resistance (IR) state and to have an intimate relationship with IR and type 2 diabetes mellitus (T2DM). The present study aimed to evaluate the anti-diabetic efficacy of cinnamaldehyde (Cin), berberine (Ber), and metformin (Met) as well as their impacts on the RBP4-GLUT4 system. Methods: Rat models of T2DM were established by combination of intraperitoneal injection of low-dose streptozotocin and high fat diet induction. Rats were divided into five groups: the control group, the diabetes group, the diabetes+Ber group, the diabetes+Cin group, and the diabetes+Met group. Western blotting was used to detect the serum or tissue RBP4 and GLUT4 protein levels. Results: After treatment for four weeks, both Cin and Ber displayed significant hypolipidemic, hypoglycemic, and insulin sensitizing functions (P <0.01) compared with the control group. Their effects on lowering fasting plasma glucose (FPG), low density lipoprotein-cholesterol (LDL-C) and homeostasis model assessment of insulin resistance (HOMA-IR) seem even better than that of Met. Cin and Ber markedly lowered serum RBP4 levels and up-regulated the expression of tissue GLUT4 protein, and Cin seemed more notable in affecting these two proteins. Conclusions: Both Cin and Ber display an exciting anti-diabetic efficacy in this study and may be of great value for the treatment of type 2 diabetes. Their mechanisms involve the RBP4-GLUT4 system, during which the serum RBP4 levels are lowered and the expression of tissue GLUT4 protein is up-regulated.

Original languageEnglish (US)
Pages (from-to)2124-2128
Number of pages5
JournalChinese Medical Journal
Issue number21
StatePublished - Nov 5 2008
Externally publishedYes



  • Berberine
  • Cinnamaldehyde
  • Glucose transporter 4
  • Insulin resistance
  • Retinol binding protein 4
  • Type 2 diabetes mellitus

ASJC Scopus subject areas

  • Medicine(all)

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