Abstract
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 α (TNFα), interleukin- (IL-) 6, and IL-1β in diabetic rats. In addition, DC alleviated the increased 1 and phosphorylated p65, IκB, and IκB kinase (IKK) in diabetic rats. DC also reduced the increased serum levels of TNFα, 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.
Highlights
Diabetic retinopathy (DR) is one of the most common and serious complications of diabetes mellitus (DM)
Our previous study showed that D. chrysotoxum alleviated retinal angiogenesis during the development of DR [14]
Our results in this study showed that Dendrobium chrysotoxum Lindl. (DC) did not affect body weight and blood glucose concentration of diabetic rats; 300 mg/kg DC alleviated retinal blood retinal barrier (BRB) breakdown in STZ-induced diabetic rats
Summary
Diabetic retinopathy (DR) is one of the most common and serious complications of diabetes mellitus (DM). With the improvement of people’s living standards, the incidence of diabetes has increased in developed and developing countries, including China [1]. Patients who suffer from diabetes for a long time likely experience chronic vascular injury caused by high blood sugar levels; these patients are at risk of DR when chronic vascular injury occurs in the retina [2, 3]. The pathogenesis of DR is generally divided into two stages, namely, nonproliferative DR (NPDR) and proliferative DR (PDR). In early NPDR stage, DR is characterized by retinal blood vessel permeability as a result of damaged blood retinal barrier (BRB); in PDR stage, retinal neoangiogenesis occurs [2, 3]. It is worth mentioning that, in the opinion of Adamis, DR is considered as an inflammatory disease [6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
