College of Food Science and Technology, Huazhong Agricultural University, Wuhan, China.
Key Laboratory of Environment Correlative Dietology (Huazhong Agricultural University), Ministry of Education, Wuhan 430070, China.
Food Funct. 2021 Nov 29;12(23):11956-11965. doi: 10.1039/d1fo01918j.
Procyanidins can alleviate small-intestine damage induced by acrylamide (ACR). However, little is known about whether procyanidins, after gastrointestinal digestion, can prevent ACR-induced intestinal barrier damage and the possible mechanism. Here, Caco-2 cells were differentiated into an intestinal epithelial cell monolayer membrane, which was stimulated with or without ACR in the presence or absence of procyanidin A (A) and its digestive products (D-A). Our findings show that both A and D-A significantly increased the transepithelial electrical resistance (TEER) value; decreased FITC-dextran 4 kDa (FITC-4 kDa) permeability, apoptosis and lactic dehydrogenase (LDH) release; and enhanced the expression of claudin-1, occludin and zonula occludens-1 (ZO-1) in ACR-induced Caco-2 cell monolayer membrane. In addition, A and D-A suppressed ACR-induced phosphorylation of mitogen-activated protein kinase (MAPK). Finally, A and D-A inhibited the myosin light chain kinase (MLCK) signaling pathway, thereby maintaining normal intestinal barrier functions, similar to the MLCK inhibitor in ACR-induced Caco-2 cell monolayer membrane. These findings indicate that A can alleviate ACR-induced intestinal barrier dysfunction inhibiting the MAPK/MLCK signaling pathway, and it still has excellent inhibitory effects after digestion.
原花青素可减轻丙烯酰胺（ACR）引起的小肠损伤。然而，关于原花青素在胃肠道消化后是否能预防 ACR 引起的肠道屏障损伤及其可能的机制，目前知之甚少。在这里，Caco-2 细胞被分化为肠上皮细胞单层膜，在存在或不存在原花青素 A（A）及其消化产物（D-A）的情况下，用或不用 ACR 刺激单层膜。我们的研究结果表明，A 和 D-A 均显著增加跨上皮电阻（TEER）值；降低 FITC-4 kDa（FITC-4 kDa）通透性、细胞凋亡和乳酸脱氢酶（LDH）释放；并增强 ACR 诱导的 Caco-2 细胞单层膜中 Claudin-1、Occludin 和 Zonula Occludens-1（ZO-1）的表达。此外，A 和 D-A 抑制了 ACR 诱导的丝裂原活化蛋白激酶（MAPK）磷酸化。最后，A 和 D-A 抑制肌球蛋白轻链激酶（MLCK）信号通路，从而维持正常的肠道屏障功能，类似于 ACR 诱导的 Caco-2 细胞单层膜中的 MLCK 抑制剂。这些发现表明，A 可通过抑制 MAPK/MLCK 信号通路来减轻 ACR 引起的肠道屏障功能障碍，并且在消化后仍具有出色的抑制作用。
