Anti-inflammatory And Mechanism Of Egg White Lysozyme On DSS-induced Ulcerative Colitis In Mice

Ulcerative colitis(UC)is a chronic non-specific inflammation.The pathogenesis is not yet clear,and the main triggers include genetic susceptibility,abnormal immunity of the intestinal mucosa,dietary factors,imbalance of intestinal flora and lifestyle changes and other factors.The World Health Organization(WHO)has listed ulcerative colitis as one of the refractory diseases.The current drug treatment not only cannot be cured,but also causes many side effects.Therefore,the application of natural ingredients that are derived from food and have health functions in medical treatment has gradually aroused the interest and favor of researchers.In this paper,the dietary protein derived from egg white-chicken egg white lysozyme is used as an intervention,using DSS-induced ulcerative colitis mice as a model to explore the antagonistic effect of HEL on ulcerative colitis and its possible underlying mechanism.Take freely drinking distilled water mice as the control group,freely drinking 3.5% DSS for one week and freely drinking distilled water for a week to relieve the induced UC in mice as a model.During the period,gavage mice with 5-ASA(75 mg/kg)200 ?L as the positive control During this period,200 ?L of egg white lysozyme(100 mg/kg,200 mg/kg,400mg/kg,800 mg/kg)was administered daily for intervention.During the experiment,the weight and fecal status of the mice were recorded daily,the fecal occult blood was tested,and the disease status of the mice was detected by DAI score.At the end of the experiment,the mice were dissected and the colon was taken to measure the length and weighed to check the macroscopic changes of the mouse colon tissue.The colon was segmented and fixed in10% formalin,and the pathological damage of the colon was examined by HE staining.The mouse orbital blood was centrifuged to collect serum,and ELISA was used to detect serum inflammatory factors.The orbital blood was collected and processed for white blood cells for labeling fluorescence,and the ratio of peripheral blood CD4 to CD8 T lymphocytes was detected by flow cytometry.Take the fragmented colon tissue to extract RNA for qRT-PCR to detect the mRNA expression of inflammatory mediators.The fragmented colon tissue was used to extract protein to quantitatively detect the expression of NF-?B inflammation pathway protein by Western blot.The colon tissue was taken,and frozen sections were made to detect the expression of phosphorylated NF-?B p65 protein by immunological fluorescence localization.The main research results and conclusions of this paper: The best effective dose of HEL(400 mg/kg·d)can improve the morphology of mouse colon mucosa,increase the number of goblet cells,and significantly reduce mouse DAI(p<0.01).The expression of cytokines IL-1?,TNF-?,and IL-6 were reduced(p<0.01)in serum.The mRNA expression of pro-inflammatory mediators IL-1?,TNF-?,IL-6,i NOS and COX-2 in colon tissue was down-regulated(p<0.01),and the expression of anti-inflammatory factor IL-10 was up-regulated(p<0.01).The expression of inflammatory pathway proteins NF-?B p65 and I?B-? in colon tissue were increased(p<0.01,p<0.05)),the expression of phosphorylated NF-?B p65 and phosphorylated I?B-? was reduced(p<0.01).It is suggested that HEL(400 mg/kg)has an antagonistic effect on DSS-induced UC in mice,which makes the DAI,colon tissue morphology,serum and colon cytokine levels in mice tend to be normal,and blood T lymphocyte subsets return to normal proportions.The expression of phosphorylated protein in inflammation pathway is down-regulated.It shows that HEL has a significant antagonistic effect on DSS-induced UC in mice.