Abstract：
Growing evidence showed the capacity of (poly)phenols to exert a protective role on intestinal health. Nevertheless, the existing findings are still heterogeneous and the underlying mechanisms remain unclear. This study investigated the potential benefits of a red raspberry (Rubus idaeus) powder on the integrity of the intestinal barrier, focusing on its ability to mitigate the effects of tumor necrosis factor-α (TNF-α)-induced intestinal permeability. Human colorectal adenocarcinoma cells (i.e., Caco-2 cells) were used as a model to assess the impact of red raspberry on intestinal permeability, tight junction expression, and oxidative stress. The Caco-2 cells were differentiated into polarized monolayers and treated with interferon-γ (IFN-γ) (10 ng mL-1) for 24 hours, followed by exposure to TNF-α (10 ng mL-1) in the presence or absence of red raspberry extract (1-5 mg mL-1). The integrity of the intestinal monolayer was evaluated using transepithelial electrical resistance (TEER) and fluorescein isothiocyanate-dextran (FITC-D) efflux assay. Markers of intestinal permeability (claudin-1, occludin, and zonula occludens-1 (ZO-1)) and oxidative stress (8-hydroxy-2-deoxyguanosine (8-OHdG) and protein carbonyl) were assessed using ELISA kits. Treatment with red raspberry resulted in a significant counteraction of TEER value loss (41%; p < 0.01) and a notable reduction in the efflux of FITC-D (-2.5 times; p < 0.01). Additionally, red raspberry attenuated the levels of 8-OHdG (-48.8%; p < 0.01), mitigating the detrimental effects induced by TNF-α. Moreover, red raspberry positively influenced the expression of the integral membrane protein claudin-1 (+18%; p < 0.01), an essential component of tight junctions. These findings contribute to the growing understanding of the beneficial effects of red raspberry in the context of the intestinal barrier. The effect of red raspberry against TNF-α-induced intestinal permeability observed in our in vitro model suggests, for the first time, its potential as a dietary strategy to promote gastrointestinal health.
摘要：
越来越多的证据表明（多）酚对肠道健康具有保护作用。然而，现有的研究结果仍然存在异质性,潜在机制仍不清楚.这项研究调查了红树莓（Rubusidaeus）粉末对肠屏障完整性的潜在益处，重点是减轻肿瘤坏死因子-α（TNF-α）诱导的肠通透性的能力。人结直肠腺癌细胞(即，Caco-2细胞）用作模型，以评估红树莓对肠道通透性的影响，紧密连接表达式，和氧化应激。将Caco-2细胞分化为极化单层，并用干扰素-γ（IFN-γ）（10ngmL-1）处理24小时，然后在存在或不存在红树莓提取物（1-5mgmL-1）的情况下暴露于TNF-α（10ngmL-1）。使用跨上皮电阻（TEER）和异硫氰酸荧光素-葡聚糖（FITC-D）外排测定来评估肠单层的完整性。肠通透性标志物(claudin-1，occludin，使用ELISA试剂盒评估闭塞带1（ZO-1）和氧化应激（8-羟基-2-脱氧鸟苷（8-OHdG）和蛋白羰基）。用红色树莓处理导致TEER值损失的显著抵消(41%;p<0.01)和FITC-D的流出的显著减少(~2.5倍;p<0.01)。此外,红树莓减弱了8-OHdG的水平（-48.8％；p<0.01），减轻TNF-α诱导的有害作用。此外，红树莓对整合膜蛋白claudin-1的表达有正向影响(+18%;p<0.01),紧密连接的重要组成部分。这些发现有助于人们越来越了解红树莓在肠道屏障方面的有益作用。在我们的体外模型中观察到的红树莓对TNF-α诱导的肠道通透性的影响表明，第一次,其作为促进胃肠道健康的饮食策略的潜力。
