Yang Runqiang, Hui Qianru, Jiang Qian, Liu Shangxi, Zhang Hua, Wu Jiandong, Lin Francis, O Karmin, Yang Chengbo
College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.
Department of Animal Science, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
Antioxidants (Basel). 2019 Jul 28;8(8):250. doi: 10.3390/antiox8080250.
Red-osier dogwood, a native species of flowering plant in North America, has been reported to have anti-oxidative properties because of abundant phenolic compounds; this could be promising as a functional food or a feed additive. In the present study, an oxidative damage model using 1.0 mM hydrogen peroxide (HO) in Caco-2 cells was established to evaluate the antioxidative effects of red-osier dogwood extracts (RDE). The results showed that 1.0 mM HO pre-exposure for 3 h significantly decreased cell viability, and increased interleukin 8 (IL-8) secretion and the intracellular reactive oxygen species (ROS) level. Caco-2 cells were treated with 100 µg/mL RDE for 24 h after pre-exposure to HO. It was found that the decreased cell viability caused by HO was significantly restored by a subsequent 100 µg/mL RDE treatment. Furthermore, the IL-8 secretion and ROS level were significantly blocked by RDE, accompanied by the enhanced gene expression of hemeoxygenase-1 (HO-1), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px), and the enhanced protein expression of the nuclear factor (erythroid-derived 2)-like 2 (Nrf-2). Moreover, RDE improved barrier functions in Caco-2 cells. Using RDE reduced the diffusion of fluorescein isothiocyanate (FITC)-dextran and increased the transepithelial resistance (TEER) value. The relative mRNA level of tight junction claudin-1, claudin-3, and occludin was elevated by RDE. These extracts also repaired the integrity of zonula occludens-1 (ZO-1) damaged by HO and increased the protein expressions of ZO-1 and claudin-3 in the HO-pretreated cells. These results illustrated that RDE reduced the ROS level and enhanced the barrier function in oxidative-damaged epithelial cells.
红枝山茱萸是北美本土的一种开花植物，据报道，由于其富含酚类化合物，具有抗氧化特性；这有望成为一种功能性食品或饲料添加剂。在本研究中，建立了一种在Caco-2细胞中使用1.0 mM过氧化氢（H₂O₂）的氧化损伤模型，以评估红枝山茱萸提取物（RDE）的抗氧化作用。结果表明，1.0 mM H₂O₂预暴露3小时显著降低了细胞活力，并增加了白细胞介素8（IL-8）的分泌和细胞内活性氧（ROS）水平。在预暴露于H₂O₂后，用100 µg/mL RDE处理Caco-2细胞24小时。结果发现，随后100 µg/mL RDE处理显著恢复了由H₂O₂引起的细胞活力下降。此外，RDE显著阻断了IL-8的分泌和ROS水平，同时血红素加氧酶-1（HO-1）、超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH-Px）的基因表达增强，核因子（红系衍生2）样2（Nrf-2）的蛋白表达增强。此外，RDE改善了Caco-2细胞的屏障功能。使用RDE减少了异硫氰酸荧光素（FITC）-葡聚糖的扩散，并增加了跨上皮电阻（TEER）值。RDE提高了紧密连接蛋白claudin-1、claudin-3和闭合蛋白的相对mRNA水平。这些提取物还修复了被H₂O₂破坏的闭合小带-1（ZO-1）的完整性，并增加了HO预处理细胞中ZO-1和claudin-3的蛋白表达。这些结果表明，RDE降低了氧化损伤上皮细胞中的ROS水平，并增强了屏障功能。
