Dendrobium chrysotoxum Lindl. alleviates diabetic retinopathy by preventing retinal inflammation and tight junction protein decrease

Diabetic retinopathy (dr) is a serious complication of diabetes mellitus. this study aimed to observe the alleviation of the ethanol extract of dendrobium chrysotoxum lindl. (dc),a traditional chinese herbal medicine,on dr and its engaged mechanism. after dc (30 or 300 mg/kg) was orally administrated,the breakdown of blood retinal barrier (brb) in streptozotocin- (stz-) induced diabetic rats was attenuated by dc. decreased retinal mrna expression of tight junction proteins (including occludin and claudin-1) in diabetic rats was also reversed by dc. western blot analysis and retinal immunofluorescence staining results further confirmed that dc reversed the decreased expression of occludin and claudin-1 proteins in diabetic rats. dc reduced the increased retinal mrna expressions of intercellular adhesion molecule-1 (icam-1),tumor necrosis factor (tnf),interleukin- (il-) 6,and il-1β in diabetic rats. in addition,dc alleviated the increased 1 and phosphorylated p65,ib,and ib kinase (ikk) in diabetic rats. dc also reduced the increased serum levels of tnf,interferon-γ (ifn-γ),il-6,il-1β,il-8,il-12,il-2,il-3,and il-10 in diabetic rats. therefore,dc can alleviate dr by inhibiting retinal inflammation and preventing the decrease of tight junction proteins,such as occludin and claudin-1. © 2015 zengyang yu et al.