Abstract：
Dihydromyricetin (DMY), a natural flavonoid compound, are believed to prevent inflammatory response, dealing with pathogens and repairing the intestinal barrier. The objective of this study was to investigate whether DMY supplementation could attenuate intestinal damage in the context of enterotoxigenic Escherichia coli K88 (ETEC F4+) infection. After weaning, different litters of pigs were randomly assigned to one of the following treatments: (1) non-challenged control (CON, fed with basal diet); (2) ETEC-challenged control (ECON, fed with basal diet); and (3) ETEC challenge + DMY treatment (EDMY, fed with basal diet plus 300 mg kg-1 DMY). We observed a significant reduction in fecal Escherichia coli shedding and diarrhea incidence, but an increase in ADG in pigs of EDMY group compared to the pigs of ECON group. Relative to the pigs of ECON group, dietary DMY treatment decreased (P < 0.05) concentrations of the serum D-xylose, D-lactate and diamine oxidase (DAO), but increased the abundance of zonula occludens-1 (ZO-1) in the jejunum of pigs. In addition, DMY also decreased (P < 0.05) the number of S-phase cells and the percentage of total apoptotic epithelial cells of jejunal epithelium in pigs of the EDMY group compared to the pigs of the ECON group. Furthermore, DMY decreased the mRNA expression levels of critical immune-associated genes TLR4, NFκB, Caspase3, Caspase9, IL-1β, IL-6, TNF-α and the protein p-NFκB and p-IκBα expressions of intestinal epithelium in pigs of the EDMY group compared to the pigs of the ECON group. Compared to the ECON group, DMY elevated (P < 0.05) the expression levels of β-defensins PBD1, PBD2, PBD3, PBD129, as well as the abundance of secreted IgA in intestinal mucosae of the EDMY group. Thus, our results indicate that DMY may relieve intestinal integrity damage due to Escherichia coli F4.
摘要：
二氢杨梅素（DMY），一种天然的黄酮类化合物，被认为可以预防炎症反应，处理病原体和修复肠道屏障。这项研究的目的是研究在肠产毒性大肠杆菌K88（ETECF4）感染的情况下，补充DMY是否可以减轻肠道损伤。断奶后,不同的窝猪被随机分配到以下处理之一：(1)非攻击对照(CON，用基础饮食喂养)；(2)ETEC挑战控制(ECON，以基础饮食喂养)；和(3)ETEC挑战+DMY治疗(EDMY，饲喂基础日粮加300mgkg-1DMY)。我们观察到粪便大肠杆菌脱落和腹泻发生率显着降低，但与ECON组相比，EDMY组的猪ADG增加。相对于ECON组的猪,饲粮DMY处理降低了血清D-木糖浓度(P<0.05),D-乳酸和二胺氧化酶（DAO），但增加了猪空肠中小带虫1（ZO-1）的丰度。此外,与ECON组的猪相比,DMY还降低(P<0.05)EDMY组的猪空肠上皮的S期细胞数量和总凋亡上皮细胞百分比。此外，DMY降低关键免疫相关基因TLR4、NFκB、Caspase3,Caspase9,IL-1β,与ECON组相比，EDMY组猪的肠上皮细胞IL-6，TNF-α以及蛋白p-NFκB和p-IκBα的表达。与ECON组相比，DMY提高了EDMY组肠粘膜β-防御素PBD1，PBD2，PBD3，PBD129的表达水平以及分泌的IgA的丰度（P<0.05）。因此，我们的结果表明，DMY可以减轻大肠杆菌F4引起的肠道完整性损伤。
