| Ulcerative colitis(UC)is a chronic and nonspecific inflammatory bowel disease.In recent years,the number of UC patients was increasing.However,the pathogenesis is not clear,but the researches showed that the occurrence and development of UC are mainly related to immune,environment,genetic factors and changes in intestinal mucosal barrier.Today,the main treatments for UC were pharmacotherapy and surgery.Although the drugs had a certain alleviating effect on the symptoms of the disease,they could relapse after drugs withdrawal.And it had potent toxicity on the human body.Therefore,it was urgent to explore the pathogenesis of UC and find effective alternative drugs for the treatment of UC.Natural plants or fungi had the characteristics of natural health and effective safety,and had now become a hot topic in the research and treatment of UC.Armillariella tabescens is a kind of medicinal and edible mushrooms that was widely used in clinical treatment of cholecystitis,hepatitis,appendicitis,and other inflammatory diseases.Otherwise,it had anti-tumor,anti-inflammatory and immunity enhancement and other pharmacological functions.it had potential research value.However,the current research on A.tabescens mainly focused on the optimization of liquid fermentation process of mycelium,oral liquid of A.tabescens,polysaccharides and Armillarisin A and so on,while there were few reports on the activities of alcohol extracts of A.tabescens.In this study,a series of studies were carried out on the alcohol extract of A.tabescens to its protective effect on UC.The experiment consisted of normal group,model group and experimental group(positive drug group,and low,medium and high-dose alcohol extract of A.tabescens).Free drinking of 2.5% DSS solution induced a colitis animal model.The experimental group was given a corresponding volume of positive drug SASP and different concentrations of A.tabescens methanol extract(AME).The other groups were given 0.9% normal saline.During the experiment,the body weight was recorded every day,the stool status was observed,and the DAI index was evaluated.On the 10 th day of the experiment,the blood was taken from the eyeball and sacrificed,the colon and spleen were taken out,and the colon length and spleen weight were recorded.MPO activity in mouse colon tissue,LPS,TNF-α,IL-1β,1L-18 and IL-10 levels in serum were measured.H&E staining method was used to observe the pathological damage of mouse colon tissue.The expression of tight junction-related proteins ZO-1,Occludin and Claudin-1 in tissues was detected by immunohistochemistry.AB-PAS staining method was used to observe the distribution of goblet cells and mucous layer in the colon.Finally,the protein expressions of TLR4,p-p65,p-IκBα,NLRP3,ASC,Caspase-1 and IL-1β in colon tissues were quantitatively analyzed by western blotting.These results showed that the symptoms of mice were significantly improved after different doses of AME intervention,including weight loss,colon shortening,elevation of DAI index and spleen weight gain.The expression levels of LPS,TNF-α,IL-1β and1L-18 were inhibited,and the level of IL-10 was increased.In the DSS group,there were mucosal epithelial integrity destruction,crypt loss,goblet cell reduction and a large number of immune cell infiltration,which were significantly improved after AME intervention.Meanwhile,AME increased the expression of tight junction proteins ZO-1,Occludin and Claudin-1.AB-PAS results showed that goblet cells were significantly lost,crypt structure was destroyed and mucus layer was seriously damaged in the DSS group compared with the normal group.After AME intervention,crypt structure was recovered,goblet cells were significantly increased and mucus layer damage was significantly improved.These results showed that AME had obvious protective effect on colitis in mice.The mechanism of AME was further studied.WB results showed that after AME intervention,the expression of TLR4 protein was significantly decreased,the expression of NF-κB signaling pathway related proteins p-p65 and p-IκBα were inhibited,the NLRP3 inflammasome signaling pathway related proteins NLRP3,ASC,caspase-1 and IL-1β were also inhibited.Therefore,it is speculated that the mechanism of its action may be through inhibiting the activation of TLR4/NF-κB signaling pathway,regulating the balance of inflammatory factors,and then inhibiting the activation of NLRP3 inflammasome signaling pathway,so that the activation of IL-1β and IL-18 is inhibited,and play a protective role in the body.In conclusion,AME had a good protective effect on the inflammatory caused by UC,which could regulate the level of cytokines,improve the expression of tight junction protein,enhance the intestinal mucosal barrier function,inhibit the level of LPS,down-regulate the protein expression of downstream related signaling pathways,and play an anti-inflammatory effect.Finally,it can improved the disease symptoms and tissue damage of UC mice.This study indicated that AME may be used as a new alternative drug in the treatment of UC,which provided preference for future research. |
