Chlorogenic acid decreases retinal vascular hyperpermeability in diabetic rat model

J Korean Med Sci. 2013 Apr;28(4):608-13. doi: 10.3346/jkms.2013.28.4.608. Epub 2013 Mar 27.


To evaluate the effect of chlorogenic acid (CGA), a polyphenol abundant in coffee, on retinal vascular leakage in the rat model of diabetic retinopathy, Sprague-Dawley rats were divided into four groups: controls, streptozotocin-induced diabetic rats, and diabetic rats treated with 10 and 20 mg/kg chlorogenic acid intraperitoneally daily for 14 days, respectively. Blood-retinal barrier (BRB) breakdown was evaluated using FITC-dextran. Vascular endothelial growth factor (VEGF) distribution and expression level was evaluated with immunohistochemistry and Western blot analysis. Expression of tight junction proteins, occludin and claudin-5, and zonula occludens protein, ZO-1 was also evaluated with immunohistochemistry and Western blot analysis. BRB breakdown and increased vascular leakage was found in diabetic rats, with increased VEGF expression and down-regulation of occludin, claudin-5, and ZO-1. CGA treatment effectively preserved the expression of occludin, and decreased VEGF levels, leading to less BRB breakdown and less vascular leakage. CGA may have a preventive role in BRB breakdown in diabetic retinopathy by preserving tight junction protein levels and low VEGF levels.

Keywords: Blood-Retinal Barrier; Chlorogenic Acid; Diabetes Rat Model; Diabetic Retinopathy; Vascular Endothelial Growth Factor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blood-Retinal Barrier / drug effects*
  • Chlorogenic Acid / metabolism
  • Chlorogenic Acid / pharmacology*
  • Claudin-5 / metabolism
  • Dextrans / chemistry
  • Diabetes Mellitus, Experimental / complications
  • Diabetes Mellitus, Experimental / metabolism
  • Diabetes Mellitus, Experimental / pathology*
  • Diabetic Retinopathy / etiology
  • Diabetic Retinopathy / prevention & control
  • Down-Regulation
  • Fluorescein-5-isothiocyanate / chemistry
  • Male
  • Occludin / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Retina / metabolism*
  • Tight Junction Proteins / metabolism
  • Vascular Endothelial Growth Factor A / metabolism
  • Zonula Occludens-1 Protein / metabolism


  • Claudin-5
  • Dextrans
  • Occludin
  • Tight Junction Proteins
  • Tjp1 protein, rat
  • Vascular Endothelial Growth Factor A
  • Zonula Occludens-1 Protein
  • Chlorogenic Acid
  • Fluorescein-5-isothiocyanate