Inhibition Of Intestinal Inflammation Caused By Shigella Flexneri By Tannic Acid

Shigella is a major pathogen causing bacterial diarrhea in humans and animals.In recent years,with the large-scale application of antibiotics in the treatment of bacillary dysentery,the drug resistance of Shigella has also increased year by year,mainly resistant to cephalosporins and quinolones.Traditional Chinese medicine has gradually become a research hotspot due to its low cost,difficulty in forming drug resistance,and ease of drug properties.Shigella mainly colonizes colon tissue to cause mucosal damage and mucous bloody diarrhea.Tannic acid(TA)is the main component of Chinese medicine Galla japonica.Although previous reports have always used tannic acid as an anti-nutritional factor,in recent years,with the in-depth study of tannic acid,its bactericidal and bacteriostatic effects have been gradually discovered.Adding tannic acid to animal diet production can improve bacterial diarrhea and have antioxidant,anticancer,and antiviral properties.In this study,Shigella flexneri(S.flex)cell permeability test,drug resistance gene test,and mouse colon inflammation test were used to explore the antibacterial mechanism of tannic acid against Shigella flexneri,Drug resistance mechanisms and anti-inflammatory effects.In exploring the effect of tannic acid on the cell permeability of Shigella flexneri.In this study,fresh feces of sick goose were collected from a breeding base in Daqing City,and Shigella flexneri was isolated.Subsequently,the minimum inhibitory concentration of bacteria was detected;the detection of alkaline phosphatase activity;the determination of DNA,RNA leakage and the change of bacterial cell fluid conductivity.The test results showed that the alkaline phosphatase activity,DNA,RNA leakage,and bacterial cell fluid conductivity were significantly higher than those in the blank control group after the action of tannic acid.After the bacteria reacted with tannic acid,propidium iodide solution was added,and the entry of propidium iodide into the cells was observed under a fluorescent inverted microscope.The test results showed that the permeability of bacteria changed after the action of tannic acid,and propidium iodide passed through the cell membrane and entered the interior of the bacteria.Changes in the expression of soluble protein were detected by PAGE electrophoresis test.The results showed that bacterial soluble protein expression was inhibited after 6 hours of tannic acid exposure to bacteria.The changes of cell morphology and cell damage were observed by scanning electron microscope and transmission electron microscope.The results showed that the morphology of most bacteria changed from rod-shaped to spherical after the interaction of bacteria with tannic acid.To explore the effect of tannic acid on drug resistance genes carried by Shigella flexneri plasmids.In this study,the resistance of Shigella flexneri to common antibiotics was detected by drug susceptibility testing.The results showed that Shigella flexneri was resistant to cephalosporins,quinolones,sulfonamides,etc.,but the sensitivity of Shigella flexneri to some cephalosporins was enhanced after the action of Tannic acid.PCR results showed that Shigella flexneri contained TEM,CTX-M,qnr S,cat,int I1 and trb C genes,and the expression of CTX-M-14 gene was inhibited after the interaction with tannic acid.Inhibition of tannic acid in mice colonic inflammation induced by Shigella flexneri.In this study,30 C57 male 6-week-old mice weighing 19-20 g were used to establish a colonic inflammation model.The mice were divided into blank control group,model group,and administration group.The administration group was divided into 3 administration concentrations of 20 mg/kg,40 mg/kg,and 60 mg/kg,a total of 5 groups with 6 in each group.Only.After the7-day adaptation period,the administration groups were given different concentrations of tannic acid by gavage,and the model group and the blank control group were given the same amount of normal saline for 7 days.After 7 days of administration,the model group and the administration group were given 1×10~9 CFU/m L by gavage at a dose of 0.1 m L each.The blank control group was given an equal volume of normal saline.After administration of bacteria,mice were anesthetized and sacrificed on the third day,and the expression levels of IL-6,IL-8,TNF-αin serum and colon tissue,and the pathological changes of colon tissue were detected.The test results showed that the expression of inflammatory factors in blood and tissue was significantly higher in the model group than in the other four groups(P<0.05).With the increase of drug concentration,the expression of inflammatory factors in the administration group decreased significantly(P<0.05),but both were significantly higher than those in the blank control group(P<0.05).Pathological section results showed that the model group had obvious inflammatory factor infiltration and epithelial cell damage.There was no significant change in the administration group.In conclusion,tannic acid destroys the integrity of the cell membrane of Shigella flexneri,inhibits the expression of soluble protein in Shigella flexneri,reduces the expression of drug resistance genes,improves antibiotic sensitivity,and alleviates the colon inflammation in mice caused by Shigella flexneri.