Si-Miao-Yong-An Decoction for Diabetic Retinopathy: A Combined Network Pharmacological and In Vivo Approach

Abstract

Si-Miao-Yong-An decoction (SMYAD), a traditional Chinese medicine formula, is mainly used to clear away heat and detoxify and to promote blood circulation and relieve pain. Diabetic retinopathy (DR) is the most common type of microvascular complication caused by diabetes. This study is designed to examine the protective effect of SMYAD against DR and further to reveal the engaged mechanism via integrating network pharmacology and in vivo experimental evidence. Streptozotocin (STZ) was intraperitoneally injected into mice to induce diabetes. The dysfunction of the blood retina barrier (BRB) was observed by conducting Evan’s blue leakage assay, detecting tight junction (TJ) protein expression and counting the number of acellular capillaries in retinas. Our results showed that SMYAD alleviated BRB breakdown in vivo. Network pharmacology results demonstrated that regulating inflammation, immune responses, and angiogenesis might be associated with the efficacy of SMYAD in alleviating DR, in which the tumor necrosis factor (TNF) and hypoxia inducible factor 1 (HIF1) signal pathways were involved. Next, immunofluorescence staining results showed that SMYAD decreased microglia activation in retinas and reduced the enhanced adhesion of leukocytes into retinal vessels. SMYAD reduced the elevated serum TNFα content and retinal TNFα expression. SMYAD abrogated the activation of nuclear factor κB (NFκB) and HIF1α and consequently decreased the enhanced expression of some pro-inflammatory molecules and vascular endothelial growth factor (VEGF) in retinas. These results indicate that SMYAD attenuated DR development through suppressing retinal inflammation and angiogenesis via abrogating NFκB-TNFα and HIF1α-VEGF signal pathways.

Bie-Jia-Ruan-Mai-Tang, a Chinese Medicine Formula, Inhibits Retinal Neovascularization in Diabetic Mice Through Inducing the Apoptosis of Retinal Vascular Endothelial Cells

“…Since its onset occurs after many years of diabetes progression, there is an opportunity to take steps to prevent vision loss ( 23 ). Therefore, drugs that inhibit retinal vascular endothelial cell proliferation are expectedly used to prevent further deterioration of DR. PDR is closely associated with the formation of acellular capillaries, which is obviously promoted by VEGF ( 24 , 25 ). Additionally, hyperglycemia also impairs the expression of tight-junction protein zonula occludens-1 (ZO-1) in the retina, which will increase the permeability of retinal capillaries, leading to blood extravasation and deterioration of DR ( 26 ).…”

“…Human retinal capillary endothelial cells cultured in NG and HG were, respectively, seeded into 96-well plates (5 × 10 3 cells/well), incubated at 37 • C and 5% CO 2 for 24 h. The supernatant was discarded, and then the corresponding medium and different concentrations of BJ (10,25,50, 100, and 150 µg/mL) were added. After treatment with BJ for 24 h or 48 h, the supernatant was discarded, 100 µL of 10% CCK8 was added and incubated at 37 • C for 30 min, and the absorbance was measured at 450 nm using a microplate reader.…”

Effects of diabetes on microglial physiology: a systematic review of in vitro, preclinical and clinical studies

“…It has been reported that retinal microglia under physiological conditions reside in the inner and outer plexiform layers, but STZ-induced diabetes promotes microglial migration into the neuronal or photoreceptor layers [52]. Both mRNA and protein levels of Iba1 are increased in retinal microglia from diabetic mice [21,24,25,[102][103][104][105][106][107] and rats [25,38,[108][109][110][111][112][113][114][115][116][117]. Not only microglia numbers but also retinal microglia morphology is affected, showing fewer branches as well as fewer and shorter processes [117,118], while endpoints are reduced and the number of microglia in contact with acellular capillaries increases [117].…”

Integration of Network Pharmacology and Experimental Validation to Explore the Pharmacological Mechanisms of Zhuanggu Busui Formula Against Osteoporosis

“…To clarify the functional interactions among the screened potential proteins, they were all imported to the String database (https://string-db.org/) to construct Protein-Protein Interaction (PPI) network (31). Then the PPI network was inputted into Cytoscape 3.8 software, and key proteins were identified by CytoNCA software according to betweenness centrality (BC), closeness centrality (CC), degree centrality (DC), Eigenvector centrality (EC), local average connectivitybased method (LAC), and network centrality (NC), which were greater than or equal to the median value (32).…”