1.Chlorogenic Acid Decreases Retinal Vascular Hyperpermeability in Diabetic Rat Model.
Joo Young SHIN ; Joonhong SOHN ; Kyu Hyung PARK
Journal of Korean Medical Science 2013;28(4):608-613
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.
Animals
;
Blood-Retinal Barrier/*drug effects
;
Chlorogenic Acid/metabolism/*pharmacology
;
Claudin-5/metabolism
;
Dextrans/chemistry
;
Diabetes Mellitus, Experimental/complications/metabolism/*pathology
;
Diabetic Retinopathy/etiology/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