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Potassium diformate (KDF) is a kind of formate, which possesses the advantages of antimicrobial activity, growth promotion and preventing diarrhea in weaned piglets. However, the researches of KDF in animal production mostly focused on apparent indexes such as growth performance and the mechanisms of KDF on intestinal health have not been reported. Thus, porcine small intestinal epithelial cells (IPEC-J2) infected with Enterohemorrhagic Escherichia coli (EHEC) was used to investigate the role of KDF on alleviating intestinal inflammation in this study. The 0.125 mg/mL KDF treated IPEC-J2 cells for 6 h and IPEC-J2 cells challenged with 5 × 107 CFU/mL EHEC for 4 h were confirmed as the optimum concentration and time for the following experiment. The subsequent experiment was divided into four groups: control group (CON), EHEC group, KDF group, KDF+EHEC group. The results showed that KDF increased the cell viability and the gene expression levels of SGLT3 and TGF-β , while decreased the content of IL-1β compared with the CON group. The cell viability and the gene expressions of SGLT1 , SGLT3 , GLUT2 , Claudin-1 , Occludin and TGF-β , and the protein expression of ZO-1 in EHEC group were lower than those in CON group, whereas the gene expressions of IL-1β , TNF , IL-8 and TLR4 , and the level of phosphorylation NF-кB protein were increased. Pretreatment with KDF reduced the content of IgM and IL-1β, the gene expressions of IL-1β , TNF , IL-8 and TLR4 and the level of phosphorylation NF-кB protein, and increased the gene expression of TGF-β and the protein expression of Occludin in IPEC-J2 cells infected EHEC. In conclusion, 0.125 mg/mL KDF on IPEC-J2 cells for 6 h had the beneficial effects on ameliorating the intestinal inflammation because of reduced pro-inflammatory cytokines and enhanced anti-inflammatory cytokines through regulating NF-кB signaling pathway under the EHEC challenge. • The mechanism of potassium diformate (KDF) alleviating intestinal injury caused by EHEC was elucidated. [ABSTRACT FROM AUTHOR]

The anti-inflammatory role of lutein has been widely recognized, however, the underlying mechanism is still not fully elucidated. Hence, the effects of lutein on the intestinal health and growth performance of broilers and the action of mechanism were investigated. 288 male yellow-feathered broilers (1-day old) were randomly allocated to 3 treatment groups with 8 replicates of 12 birds each, and the control group was fed a broken rice-soybean basal diet, while the test groups were fed a basal diet added with 20 mg/kg and 40 mg/kg of lutein (LU20, LU40), respectively. The feeding trial lasted for 21 d. The results showed that 40 mg/kg lutein supplementation tended to increase ADFI (P = 0.10) and ADG (P = 0.08) of broilers. Moreover, the addition of lutein caused a decreasing trend of gene expression and concentration of proinflammatory cytokines IL-1β (P = 0.08, P = 0.10, respectively) and IL-6 (P = 0.06, P = 0.06, respectively) and also tended to decrease the gene expression of TLR4 (P = 0.09) and MyD88 (P = 0.07) while increasing gene expression and concentration of anti-inflammatory cytokines IL-4 and IL-10 (P < 0.05) in the jejunum mucosa of broilers. Additionally, lutein supplementation increased the jejunal villi height of broilers (P < 0.05) and reduced villi damage. The experiment in vitro showed that lutein treatment reduced the gene expression of IL-1β, IL-6, and IFN-γ in chicken intestinal epithelial cells (P < 0.05). However, this effect was diminished after knock-down of TLR4 or MyD88 genes using RNAi technology. In conclusion, lutein can inhibit the expression and secretion of proinflammatory cytokines in the jejunum mucosa and promote intestinal development of broilers, and the anti-inflammatory effect may be achieved by regulating TLR4/MyD88 signaling pathway. [ABSTRACT FROM AUTHOR]

Broilers are frequently exposed to various immunological stresses, which lead to intestinal damage, weakened immunity, and even growth retardation. Lutein, as a kind of carotenoid, possesses antioxidant and immunomodulatory functions. Therefore, this study was conducted to investigate the effects of lutein on jejunal mucosal barrier function and inflammatory responses of yellow-feather broilers challenged with lipopolysaccharide (LPS). A total of two hundred eight-eight 1-day-old yellow-feather broilers were randomly allocated to 3 groups with 8 replicate cages containing 12 birds each. Birds were fed broken-rice-soybean basal diet containing 0, 20 and 40 mg/kg lutein (CON, LU20 and LU40) for 26 d. On days 21, 23, and 25 of the trial, broilers were intraperitoneally injected with LPS (1 mg/kg body weight). The results showed that, compared with CON group, LU40 supplementations significantly increased the average daily gain (ADG) of broilers at 1 to 21 and 22 to 26 d of age (P < 0.05), significantly decreased the ratio of feed to gain (F/G) of broilers at 22 to 26 d of age (P < 0.05). LU20 and LU40 supplementations increased goblet cell density in jejunum of broilers under LPS challenge, and LU20 supplementation elevated the villus area (P < 0.05). Scanning electron microscopy of jejunal mucosa revealed significant villi damage, while transmission electron microscopy demonstrated severe enterocyte damage and loss of cellular integrity in CON group. In particular, mitochondria were morphologically altered, appearing irregular or swollen. Apical junctional complexes between adjacent enterocytes were obviously shorter and saccular in CON group. LU20 and LU40 supplementations increased the mRNA expressions of Occludin, Claudin-1, and ZO-1 in the jejunal mucosa of broilers under LPS challenge (P < 0.05), restrained TLR4/MyD88/NF-κB pathway activation in the jejunal mucosa, decreased the mRNA expressions of IL-1β and IL-6, and strengthened the mRNA expressions of IL-4 and IL-10 (P < 0.05). Meanwhile, the protein expressions of p38 and JNK in LU40 group were lower than CON group (P < 0.05). It can be concluded that 40 mg/kg lutein supplementation improved LPS-induced jejunal mucosal barrier function and tamed inflammation of yellow-feather broilers. [ABSTRACT FROM AUTHOR]