Protective Effect And Its Mechanism Of Chebulia Extract On Intestinal Mucosal Injury Induced By LPS In Mice

Intestinal tract is not only an important organ for digestion and absorption,but also the largest immune organ in the body,it plays an important role in the body’s non-specific anti-infection defense system.Intestinal mucosa can monitor and remove intestinal bacteria,toxins,potentially harmful biopeptides and food antigens,to ensure the integrity of the body.Intact intestinal mucosal barrier is the basis for the normal maintenance of multiple intestinal functions.Intestinal mucosal barrier mainly consists of biological barrier,chemical barrier,mechanical barrier and immune barrier.Among them,the synergistic effect between mechanical barrier and immune barrier is the core of maintaining intestinal homeostasis.In trauma,burns,severe infections,endotoxin pathological conditions,damage to intestinal mucosal barrier function,lead to intestinal barrier dysfunction,the integrity of the intestinal mucosal barrier is broken,intestinal mucous membrane permeability increased,making a large number of bacteria endotoxin and the portal vein and lymphatic system go into the systemic circulation,causing enterogenic infection,and can stimulate the inflammatory cells cascade to cause systemic inflammatory response syndrome,lead to the disease aggravating,induce the body injury,eventually develop into multiple organ dysfunction syndrome.Therefore,the protection of intestinal mucosal barrier function is of vital importance,and the protection of intestinal mucosa with natural drugs has become a hot topic of current research.Chebulia is the dried ripe fruit of the Terminalia chebula Retz.or Terminalia chebula Retz.Var.tomentella Kurt.Taste Bitter,acid,acerbity and flat.The main effect of it is anti-cough and anti-diarrheal.The previous studies of this research group showed that the ethyl acetate part of Chebulia could effectively treat diarrhea in mice.Combined with the histological results,it was found that the ethyl acetate part of Chebulia had a certain protective effect on intestinal mucosa,but the protective mechanism of the ethyl acetate part of Chebulia on intestinal mucosa was not clear.Therefore,healthy male BALB/c mice were selected to establish the LPSs-induced intestinal mucosal injury model in this study.Intestinal mucosal injury model was used to evaluate the protective effect of the ethyl acetate part of Chebulia on intestinal mucosa.Further,the RNA-seq transcriptome method was used to investigate the possible molecular mechanism of Chebulia extract to protect intestinal mucosa from LPS.According to transcriptome results,q PCR was used to elucidated the mechanism of protecting intestinal mucosa by Chebulia from the perspective of regulating PPARα/NF-κB signaling pathway.First,the mental state of mice,small intestineexamination,body weight change rate,HE staining,plasma DAO and D-lactate levels were observed to evaluate the intestinal mucosal injury model in mice and the protective effect of Chebulia extract on mice.The results showed that after LPS treatment,the mice showed varying degrees of mental depression,intestinal gas accumulation,intestinal wall thinning,intestinal mucosal structure destruction,loss of small intestinal villous epithelial cells,weight loss,and increased plasma DAO and d-lactate levels,and the degree of injury was dose-dependent on LPS concentration.In the LPS+HZ group,the intestinal mucosa structure was basically intact,only a small number of small intestinal villous epithelial cells were shed,and the plasma DAO and D-lactate levels in mice could be reduced.The above results showed that the position of Chebulia ethyl acetate had an obvious protective effect on LPS-induced intestinal mucosa injury in mice.On this basis,the RNA-seq transcriptome study method for sequencing,result shows that exist between the blank group and LPS model 345 differentially expressed genes,including quantity increase of genes expressed in 238 and 107 genes expression quantity downgrade,the enrichment of differentially expressed genes in KEGG pathways mainly includes: PPAR signaling pathway,ECM-receptor interaction,Complement and coagulation cascades and Cell adhesion molecules,etc.Compared with the LPS+HZ treatment group,there were 756 differentially expressed genes in the LPS model group,including 323 up-regulated genes and 433 down-regulated genes.The pathways enriched by differentially expressed genes in KEGG mainly include Non-alcoholic fatty liver disease,PPAR signaling pathway,sulfur metabolism,RIG-I-like receptor signaling pathway and p53 signaling pathway.Combining the transcriptome test results with the literature analysis,we concluded that the PPAR signaling pathway may be the key pathway for the protective effect of Chebulia extract on intestinal mucosa.Finally,in order to study the protective mechanism of Chebulia extract on LPS-induced intestinal mucosal injury in mice,expression of IL-1β,IL-6,TNF-α,NF-κB and PPARα were detected by ELISA and fluorescence quantitative PCR.The results showed that LPS+HZ group could significantly alleviate the intestinal mucosa injury induced by LPS in mice,reduce the levels of IL-1β,IL-6,TNF-α,and NF-κB,and significantly increase the expression of PPARα,which further revealed the protective effect of Chebulia extract on intestinal mucosa through the PPARα/NF-κB signaling pathway.