糖尿病性视网膜病变（DR）是一种导致成年人失明的神经血管疾病，也是糖尿病最严重和最常见的并发症。视网膜炎是DR的早期阶段，被认为在DR发展中起着重要作用。三七皂苷（PNS）是三七主根的主要活性成分，展现出多种生物活性，包括抗炎、抗氧化、神经保护和免疫调节功能。然而，PNS对DR的保护效应和潜在机制尚不清楚。本研究旨在研究PNS对DR的缓解效应及其所涉及的机制，并进一步探讨在体内发挥功效的主要成分。对Sprague Dawley大鼠腹腔注射链脲佐菌素后2个月，经口服PNS 1个月，通过苏木精-伊红（H&E）染色方法评估视网膜的形态结构和视网膜无细胞毛细血管。通过埃文斯蓝染料泄漏试验检测血视网膜屏障（BRB）的破坏，并通过荧光同仁卵白素A偶联凝集素标记试验实现视网膜白细胞粘附。进行免疫荧光染色和Western blot试验，检测视网膜中紧密连接蛋白、粘附分子和离子钙结合适配分子-1（Iba-1）的表达。通过酶联免疫吸附试验检测血清中肿瘤坏死因子（TNF）-α、白细胞介素（IL）-6和IL-1β的水平。此外，使用Western blot试验测定核因子（NF）-κB p65、磷酸化IKK（p-IKK）、磷酸化NF-κB抑制因子（p-IκB）和磷酸化NF-κB p65（p-p65）的蛋白表达水平。通过超高效液相色谱-串联质谱法确定正常和糖尿病大鼠中PNS的眼部组织分布。在人类穆勒细胞（MIO-M1）上评估PNS、三七皂苷（NGR1）、人参皂苷Rg1、Re、Rb1和Rd（GRg1、GRe、GRb1和GRd）的体外抗炎效应。PNS增强了视网膜内核层厚度的减少，减少了视网膜无细胞毛细血管的增加，并通过上调克劳丁-1和闭孔连接蛋白的蛋白表达下降，减轻了血视网膜屏障的破坏。此外，PNS显著抑制了小胶质细胞的激活，通过下调细胞间粘附分子-1和血管细胞粘附分子-1的蛋白表达上调了白细胞粘附的增加。此外，PNS减少了血清中TNF-α、IL-6和IL-1β的高水平，并抑制了p-IKK、p-IκB和p-p65的蛋白表达的增加，以及p65的核转位。组织分布结果显示，在眼部组织中检测到NGR1、GRg1、GRe、GRb1和GRd，其中GRg1和GRb1与其他成分相比表达水平最高。细胞实验结果显示，PNS、NGR1、GRg1、GRe、GRb1和GRd通过抑制MIO-M1细胞中NF-κB信号通路的激活，抑制了细胞炎症反应的发展，其抗炎作用相当。PNS通过抑制NF-κB信号通路的激活，抑制视网膜炎症，缓解DR。GRg1和GRb1可能是体内发挥抗炎作用的主要成分。版权©2023。由Elsevier B.V.发布。

Diabetic retinopathy (DR) is a neurovascular disease that causes blindness in adults and is the most serious and common complication of diabetes mellitus. Retinal inflammation is an early stage of DR, and it is believed to play a crucial role in the development of DR. Panax notoginseng saponins (PNS) are the major active constituent in the main root of P. notoginseng, and they exhibit various biological activities, including anti-inflammatory, antioxidant, neuroprotective, and immunomodulatory functions. However, the protective effects and underlying mechanisms of PNS against DR remain unclear.This study aimed to investigate the alleviation effects of PNS on DR and the mechanisms involved. Furthermore, it intended to explore the major components that exert efficacy in vivo.Streptozotocin (STZ) was administered intraperitoneally to Sprague Dawley rats, and PNS was administered orally for 1 month after 2 months of STZ injection. The morphological structure of the retina and retinal acellular capillaries were assessed via hematoxylin and eosin (H&E) staining assay. The disruption of the blood-retinal barrier (BRB) was detected through Evans blue dye leakage assay, and retinal leukocyte adhesion was achieved via fluorescein isothiocyanate-coupled concanavalin A lectin labeling assay. Immunofluorescence staining and Western blot assays were conducted to detect the expression of tight junction proteins, adhesion molecules, and the ionized calcium-binding adapter molecule-1 (Iba-1) in the retina. Enzyme-linked immunosorbent assay was performed to detect the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β in serum. In addition, the protein expression levels of nuclear factor (NF)-κB p65, phosphorylated IκB kinase (p-IKK), phosphorylated NF-κB inhibitor (p-IκB), and phosphorylated NF-κB p65 (p-p65) were measured using Western blot assay. The ocular tissue distribution of PNS in normal and diabetic rats was determined through ultra-performance liquid chromatography-tandem mass spectrometry. The in vitro anti-inflammatory effects of PNS, notoginsenoside (NGR1), ginsenoside Rg1, Re, Rb1, and Rd (GRg1, GRe, GRb1, and GRd) were evaluated on human Müller (MIO-M1) cells.PNS increased the reduction in retinal inner nuclear layer thickness, reduced the increase in retinal acellular capillaries, and attenuated elevated BRB disruption by upregulating the decrease in protein expression of claudin-1 and occludin. Furthermore, PNS significantly abrogated microglial cell activation and reversed the increase in leukocyte adhesion by downregulating the increase in the protein expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1. Moreover, PNS reduced the elevated levels of TNF-α, IL-6, and IL-1β in serum and inhibited the increased protein expression of p-IKK, p-IκB, and p-p65, and the nuclear translocation of p65. The tissue distribution results revealed that NGR1, GRg1, GRe, GRb1, and GRd were detected in the ocular tissue, while GRg1 and GRb1 were found at the highest levels compared with the other components. The cellular results showed that PNS, NGR1, GRg1, GRe, GRb1, and GRd suppressed the development of cellular inflammatory responses by inhibiting the activation of the NF-κB signaling pathway in MIO-M1 cells and that their anti-inflammatory effects were comparable.PNS suppressed retinal inflammation by inhibiting the activation of the NF-κB signaling pathway, alleviating DR. GRg1 and GRb1 may be the primary components that exert anti-inflammatory effects in vivo.Copyright © 2023. Published by Elsevier B.V.