Study On The Protection And Mechanism Mechanism Of Atractylodes Macrocephala Polysaccharides On Intestinal Mucosal Barrier Of Tail-suspended Rats

In the environment of weightlessness in space,the intestinal homeostasis of astronauts will be seriously damaged.Many studies have shown that atractylopolysaccharides have a good role in regulating intestinal homeostasis.Therefore,atractylopolysaccharides may be used as a protective agent for the imbalance of astronauts’ intestine.However,the mechanism of Atractylodes macrocephala polysaccharide on intestinal mucosal barrier and intestinal brain gut peptide is still unclear,which needs to be studied in detail.In this paper,a tail-hanging method was used to establish a simulated weightlessness model,and sixty Wistar rats were divided into five groups: ground group,tail suspension group,low dose group,medium dose group and high dose group.HE staining was used for intestinal histology and the expression of Occludin,Claudin-2,JAM-A and ZO-1 genes in duodenum and colon of rats were detected.The content of ET,D-lactic acid in plasma and intestinal s Ig A were determined by ELISA.16 S r DNA high-throughput sequencing was used to analyze the diversity of intestinal flora.The p H of feces,the number of goblet cells,lymphocytes and the gene expression level of NF-κB、TNF-α、IL-1β、IL-6 in duodenum and colon were measured.The gene expression level of VIP,SP,CCK and NT in duodenum and colon were also measured to study the protective effect of Atractylodes macrocephala polysaccharides on intestinal mucosal barrier and brain gut peptide in tail suspended rats.The results showed that:under simulated weightlessness,the morphology of duodenum and colon were damaged significantly,the gene expression levels of Occludin,Claudin-2,JAM-A and ZO-1 were changed significantly,the conte NT of ET and D-lactic acid in plasma were increased,and the intestinal permeability was increased.The intestinal p H of rats increased.The number of goblet cells in duodenum decreased by 70% and in colon decreased by 53%.The number of lymphocytes in duodenum decreased by 75% and in colon decreased by26%.The expression level of NF-κB、TNF-α、IL-1β、IL-6 gene increased significantly.And low,medium and high Atractylodes macrocephala polysaccharide have different degrees of regulation on the four barriers.The gene expression of VIP,SP and CCK in duodenum of rats in tail suspension group was significantly up-regulated,while the gene expression of low,medium and high dose groups was down regulated in varying degrees.The gene expression of VIP,SP and CCK in colon of tail suspension group was significantly up-regulated,while the gene expression of NT was significantly down regulated.The results showed that the intestinal barrier of rats was seriously damaged under simulated weightlessness,and VIP,SP,CCK and NT of duodenum and colon were out of balance.Atractylodes macrocephala polysaccharide had an important protective effect on the damage of intestinal mucosal barrier and the change of intestinal brain gut peptide in weightlessness rats.In summary,after simulated weightlessness,the rat’s intestinal mucosal barrier was damaged,and the expression of intestinal brain-gut peptides was changed.Atractylodes macrocephala can improve the rat’s intestinal mucosal barrier and regulate the content of brain-gut peptides,which can be used as an effective protective agent for astronauts to improve intestinal injury.