朝鲜蒲公英，学名Taraxacum coreanum Nakai（简写为TC），是一种产自韩国的蒲公英，长期被用作具有抗氧化和抗炎特性的草药。肠道炎症与肠道上皮屏障破裂密切相关，导致各种肠道疾病的进展。本研究旨在探讨TC提取物在脂多糖（LPS）刺激的Caco-2细胞中对炎症反应和肠道屏障功能紊乱的保护作用。通过Griess试剂和酶联免疫吸附测定法（ELISA）测定了TC对一氧化氮（NO）和促炎细胞因子产生的抑制作用，通过转上皮电阻（TEER）实验评估了上皮通透性，通过Western blotting分析了与炎症和紧密连接（TJ）有关的蛋白质表达。此外，通过使用UHPLC-ESI-MS和HPLC-DAD分析方法鉴定和定量了十种活性化合物。与仅接受LPS处理的组相比，TC处理显著减少了NO和促炎细胞因子（白细胞介素（IL）-6和肿瘤坏死因子（TNF）-α）的产生，尤其在100μg/mL浓度下。TC显著降低了TEER检测到的单层通透性。此外，经过TC处理后，荧光素异硫氰酸盐-葡聚糖4穿过屏障的传递减少。经TC处理后，与炎症相关的蛋白质（诱导型一氧化氮合酶、环氧合酶-2、TNF-α、IL-6和IL-1β）下调，与此相反，TC显著增加了TJ相关蛋白质claudin-5的水平。通过UHPLC-ESI-MS和HPLC-DAD分析方法，鉴定了十种植物化学物质（原儿茶酸、绿原酸、咖啡酸、香豆素、咖啡酸辣根酸、花叶糖苷、金酸脂苷、槐黄苷、苦豆糖苷和黄酮）。我们的研究结果表明，TC的乙醇提取物能够通过增加紧密连接蛋白、抑制炎症反应来减轻LPS诱导的肠道屏障功能紊乱。版权所有 © 2023 Elsevier B.V. 发表。

Taraxacum coreanum Nakai (TC) is a dandelion native to Korea that has long been used as a medicinal herb with antioxidant and anti-inflammatory properties. Intestinal inflammation is closely associated with intestinal epithelial barrier disruption, which leads to the progression of various intestinal diseases.The aim of this study was to investigate the protective effects of TC extract on inflammatory responses and intestinal barrier dysfunction in lipopolysaccharide (LPS)-stimulated Caco-2 cells.The inhibitory effect of TC on nitric oxide (NO) and pro-inflammatory cytokines production were determined by Griess reagent and enzyme-linked immunosorbent assay, respectively. The epithelial permeability was evaluated by transepithelial electrical resistance (TEER) assay and inflammation- and tight junction (TJ)-related protein expression were analyzed by Western blotting. In addition, the presence of ten active compounds was identified and quantified using UHPLC-ESI-MS and HPLC-DAD analyses.Treatment with TC significantly reduced NO production and pro-inflammatory cytokine production [interleukin (IL)-6 and tumor necrosis factor (TNF)-α] compared to the group treated with LPS only, particularly at 100 μg/mL. TC significantly decreased monolayer permeability as detected by TEER. In addition, the transmission of fluorescein isothiocyanate-dextran 4 across the barrier was decreased after treatment with TC. Inflammation-related proteins (inducible NO synthase, cyclooxygenase-2, TNF-α, IL-6, and IL-1β) were down-regulated after treatment with TC. In contrast, TC significantly increased the protein levels of the TJ-related protein, claudin-5. Ten phytochemicals (protocatechuic acid, chlorogenic acid, caffeic acid, scopoletin, chicoric acid, hyperoside, nicotiflorin, luteoloside, sophoricoside, and luteolin) were identified by UHPLC-ESI-MS and HPLC-DAD analysis.Our findings suggest that ethanolic extract of TC could attenuate the LPS-induced intestinal barrier dysfunction by increasing the tight junction protein and suppressing inflammatory responses.Copyright © 2023. Published by Elsevier B.V.