| China is a large breeding country.In the modern breeding industry,livestock and poultry are faced with many diseases,which affect production performance and even lead to death.Diarrheal disease is one of them.Diarrhea can be caused by many reasons,such as bacterial or viral infection,stress and disturbance of intestinal flora,etc.All of the above reasons may lead to intestinal inflammation and cause diarrhea.At present,the main treatment is antibiotic treatment,but antibiotics can easily cause bacterial resistance,residues in meat and egg products and environmental pollution and other serious problems.Nowadays,the research and development of Chinese veterinary drug substitute anti products has become the heart of the majority of researchers.One of the major alkaloids extracted from Macleaya cordata plants,allocryptopine,belongs to isoquinoline alkaloids.In previous studies,most isoquinoline alkaloids have good anti-inflammatory activity.There are few studies on the anti-inflammatory activity of allocryptopine at home and abroad,but in fact it has high medicinal value.In this study,sodium dextran sulfate(DSS)was used to establish a mouse model of ulcerative colitis(UC),and ELISA,q PCR and other methods were used to study the anti-inflammatory effects of allocryptopine,so as to provide a new alternative for antibiotics.Bliss method was used to determine the oral LD50 value of allocryptopine in mice was524.2 mg/kg,and the 95% confidence limit was 450.8～618.4 mg/kg.Sixty male C57BL/6 mice were randomly divided into 5 groups after adaptive feeding for one week.They were blank control group(Con),model group(Mod),positive control group(Pos),allocryptopine low-dose group(ALL-L)and allocryptopine high-dose group(All-H),with 12 mice in each group.Mice in the Con group had free access to distilled water and gavage with 1% CMC-Na solution for 14 consecutive days.Mice in Mod group,Pos group,All-L group and All-H group were free to drink distilled water for the first 7 days and3% DSS solution for the second 7 days.For 14 consecutive days,1% CMC-NA solution,200 mg/kg allocryptopine suspension,25 mg/kg allocryptopine suspension and 50 mg/kg allocryptopine suspension were given intragastric administration.The clinical symptoms of the mice were observed and recorded daily during the experiment,and the DAI score was calculated.On the 15 th day,the mice were sacrificed,and blood samples were collected from the eyeballs.After dissection,the length of colon was measured,and colon tissue and intestinal contents were properly preserved.The levels of myeloperoxidase(MPO),malondialdehyde(MDA)and superoxide dismutase(SOD)in serum and colon tissues were detected by using related kits.The contents of anti-inflammatory factors IL-1β and IL-6 in serum were detected by enzyme-linked immunosorbent assay(ELISA).The m RNA expression levels of IL-1β,IL-6,IL-10,COX-2,i NOS,TLR4,MYD88,NLRP3,Occludin and ZO-1 in colon tissues were determined by real-time fluorescence quantitative PCR(q PCR).The protein expression of NF-κB and Occludin was detected by western blotting(WB).Cecal contents were sequenced by 16 S r DNA.The results showed that allocryptopine could significantly relieve the clinical symptoms of UC,reduce the infiltration of inflammatory cells in intestinal mucosa,and protect the integrity of goblet cell and crypt structure.It can also reduce the activity of MPO,inhibit the aggregation of neutrophil,increase the activity of SOD in serum,reduce the content of MDA,and relieve the oxidative stress of mice.Allocryptopine exerts its anti-inflammatory effect by inhibiting the expression of IL-1β and IL-6,blocking the transduction of TLR4/NF-κB/Myd88 signaling pathway,and protecting intestinal tight junction proteins Occludin and ZO-1.In addition,allocryptopine can regulate the composition of intestinal flora in UC mice,reduce inflammation and maintain intestinal health by maintaining the homeostasis of intestinal environment.After treatment with allocryptopine,the ratio of Firmicutes/Bacteroidetes in intestinal tract of UC mice increased,the number of pathogenic bacteria such as Escherichia-Shigellal decreased,and the number of beneficial bacteria such as Akkermansiaceae increased.These results provide a basis for the further study of the anti-inflammatory mechanism of allocryptopine and the development of its applied products. |
