Genistein has multiple biological activities in both humans and animals. However, a protective effect of genistein on Escherichia coli (E. coli)-induced intestinal mucosal barrier dysfunction remains unknown. In the present study, a total of 288 1-day-old male Arbor Acre broilers fed a corn-soybean basal diet unsupplemented or supplemented with 20 mg genistein/kg diet were subjected to E. coli serotype O78 (10⁸ cfu per bird) infection or equal volume of sodium chloride at 19 days of age. Sera and tissue samples were collected 2 days after E. coli infection. Growth performance, index of immune-related organs, intestinal barrier permeability, protein level of inflammatory cytokines, sIgA, tight junction protein, and mRNA level of apoptotic genes in jejunum were determined. Mortality rate at 7 days post infection was recorded. The results showed that E. coli challenge led to a reduced average daily gain, a decreased thymus index, and bursal index in broilers, an increase of fluorescein isothiocyanate (FITC)-dextran in serum, and a decreased sIgA in jejunum. These effects were abrogated by genistein administration. Western blot results showed that E. coli infection led to increased protein level of claudin-1 and zonula occludens (ZO)-1, which was largely abolished by genistein. Moreover, E. coli infection resulted increased protein level of TNF-α and IL-6, enhanced mRNA level of Bax and caspase-3, as well as decreased mRNA level of Bcl-2 were abrogated by genistein in jujunum of broilers. In conclusion, the results indicate that genistein supplementation improves intestinal mucosal barrier function which is associated with a regulatory effect on tight junction proteins, sIgA, apoptosis, and secretion of inflammatory cytokines in jejunum of E. coli-challenged broilers.

金雀异黄素在人和动物中都有多种生物活性。然而，金雀异黄素对大肠杆菌（E. coli）诱导的肠粘膜屏障功能障碍的保护作用仍然未知。在本研究中，共有288只1日龄雄性阿伯阿克肉鸡饲喂未补充或补充20毫克染料木黄酮/千克饲料的玉米-大豆基础日粮，对它们进行O78大肠杆菌血清型（每只禽10 ⁸ cfu） 19日龄感染或等量的氯化钠。大肠杆菌2天后收集血清和组织样本感染。测定生长性能，免疫相关器官的指数，肠屏障通透性，炎性细胞因子的蛋白水平，sIgA，紧密连接蛋白以及空肠中凋亡基因的mRNA水平。记录感染后7天的死亡率。结果表明，大肠杆菌攻击导致肉鸡平均日增重降低，胸腺指数和法氏囊指数降低，血清异硫氰酸荧光素（FITC）-葡聚糖增加，空肠中sIgA降低。通过染料木黄酮的施用消除了这些作用。蛋白质印迹结果表明，大肠杆菌感染导致claudin-1和zonula occludens（ZO）-1的蛋白质水平升高，但染料木黄酮已将其消除。此外，大肠杆菌感染可导致染料木黄酮消除肉仔鸡幼体中TNF-α和IL-6的蛋白水平升高，Bax和caspase-3的mRNA水平升高以及Bcl-2的mRNA水平降低。总之，结果表明，染料木黄酮补充剂可改善肠道粘膜屏障功能，这与对大肠杆菌感染的肉鸡空肠中紧密连接蛋白，sIgA，细胞凋亡和炎性细胞因子的分泌具有调节作用。