Protective Effect Of Selenomethionine On Chicken Lipopolysaccharides Induced Enteritis

Lipopolysaccharides are components of the outer wall of the cell wall of gram-negative bacteria,and as endotoxins,they can induce inflammatory reactions in the body,resulting in symptoms such as fever,endotoxemia,hypotension,and shock.Selenomethionine can significantly improve the immunity,production performance,antioxidant and antitoxin functions of livestock and poultry.Based on the establishment of the model of polysaccharide enteritis in laying hens,this study analyzed the protective effect of selenomethionine on lipopolysaccharide-induced enteritis in chickens from the aspects of histomorphology,oxidative stress,programmed necrosis and inflammatory factors,in order to provide basic data for the study of the biological function of selenomethionine.1.A total of 100 46-week-old Isa brown laying hens were randomly and evenly divided into control group(Con group)and selenomethionine feed addition group(SeMet group),and the selenium content in the feed was 0.5 mg/kg.After 60 days of rearing,50 laying hens were randomly selected from the two groups,each of which was intraperitoneally injected with 200μg/kg lipopolysaccharide,and the remaining laying hens were injected with the same amount of normal saline.It was divided into 4 groups,namely Con group,SeMet group,LPS group and SeMet+LPS group.After 10 h,the laying hens were sacrificed,jejunal tissue samples were collected,and after pathological section staining of their epithelial tissues,it was found that the intestinal epithelial tissue cell structure of the Con group and the SeMet group was clear and complete,and there were no obvious lesions.The jejunal tissue of laying hens in the LPS group showed sparse villi,rupture,jejunal epithelial cell necrosis,and a large number of inflammatory infiltrates.The jejunal tissue of laying hens in the SeMet+LPS group was only infiltrated with a small amount of inflammatory cells,which significantly reduced the tissue damage compared with that of laying hens in the LPS group.The results showed that SeMet could relieve the inflammatory damage of jejunum tissue in chicken lipopolysaccharide enteritis.2.The results of oxidative stress related indicators showed that compared with the indicators of Con group laying hens,the indicators of SeMet group had no significant changes,the MDA content of in LPS group increased significantly(p<0.05),T-AOC level,CAT,GPx,SOD activity,and GSH content were significantly reduced(p<0.05).However,the antioxidant enzyme activity and GSH and MDA contents of laying hens in the SeMet+LPS group were between the index values in the LPS group and the Con group.The results showed that SeMet could relieve oxidative stress of chicken intestinal tissue in laying hens with lipopolysaccharide enteritis.3.In the study of programmed necrosis and inflammation of jejunal tissue in laying hens,the indicators in the SeMet group were good compared with those of layer hens in the Con group.In the LPS group,the expression of RIPK1,RIPK3,MLKL,TNF-α,IL-1β,IL-6 and TGF-β in laying hens increased to varying degrees,while the expression of IFN-γ and IL-2 decreased,indicating that lipopolysaccharides could induce programmed necrosis and inflammation of laying hens jejunal tissues,while the expression of that in the SeMet+LPS group was inhibited except IFN-γand IL-2.The results indicated that selenomethionine could antagonize the expression of toxicitymediated programmed necrosis and inflammation-related factors in lipopolysaccharide enteritis of laying hens,thereby reducing intestinal damage.4.The results of the detection of intestinal permeability of laying hens showed that compared with the Con group,the indicators of layer hens in SeMet group did not change significantly,and the expression of Claudin3,AQP3,Occludin and TJP1 in LPS group decreased significantly(p<0.05),while the expression of that in the SeMet+LPS group was between the indicators in the LPS group and the Con group.These results suggest that selenomethionine can repair jejunum damage caused by lipopolysaccharide enteritis in laying hens.In conclusion,selenomethionine antagonizes lipopolysaccharide-induced enteritis in laying hens by alleviating oxidative stress,programmed necrosis,and the expression of intestinal tight junction protein and inflammatory factors.These results provide basic data for the application of selenomethionine in animal production to alleviate inflammation and injury.