| Objective:Through the 2,4,6-TNBS-induced inflammatory bowel disease model in young rats,we observed the level of Th17 cell related cytokine IL-17 A in the intestinal tissue of IBD young rats model after favage with Lactobacillus rhamnosus GG,then discussed the probiotics' regulative effects on Th17 cells.Methods:Thirty six four-weeks healthy male Sprague-Dswley rats were selected and divided into four groups,blank control group and LGG control group with 8 rats in each group,IBD group and IBD-LGG group with 10 rats in each group,every rats was fasted for 24 hours but drinking water normally:(1)blank control group: on the first day,gave0.9% normal saline enema,then gave normal diet,and fed drinking-water through gavage once a day;(2)LGG control group: on the first day,gave 0.9% normal saline enema,then fed LGG through gavage once a day;(3)IBD group: on the first day,gave 5% TNBS enema,established an IBD model,then gave normal diet,and fed drinking-water through gavage once a day;(4)IBD-LGG group: on the first day,gave 5% TNBS enema,established the IBD model,then fed LGG through gavage once a day.The weights,defecate characters and occult blood situations of all rats were observed every day in the same time.Also,we carried out the activity index score of disease according to the Cooper score method.On the seventh day,all rats were killed;the colon specimens were fixed,embedded and sectioned.We observed mucosal injury after HE staining and expression level of Th17 cell related cytokine IL-17 A that were detected after immunohistochemical process to tissue slice.Results:1.General situation: During the experiment,the rats of blank control group and LGG control group all had normal feeding,smooth body hair,normal stool,and had occult blood occult.The rats of IBD group and IBD-LGG group were poor eating,unresponsive,apathetic,fur loose and dull.Compared with the IBD group,IBD-LGG group were significantly relieved in the stool property and occult blood after treatment for three to four days.2.Body weight: After seven days,body weight of all rats increased compared to before,but there were no significant differences in all groups(P> 0.05).3.DAI scores:The DAI scores of the IBD group and the IBD-LGG group had no significant difference in the first 3 days,but higher than those in IBD-LGG groups on the 4th day,the difference was statistically significant(P <0.05).4.Gross Tissue and Pathological Section: There was no obvious abnormality in the gross structure and pathological section of the colon in the two control groups.Two groups of IBD rats showed significant intestinal inflammation changes,the general organization showed obvious congestion,edema,and even erosion and ulceration,a large number of infiltration of intestinal mucosa inflammatory cells could be seen,in part,inflammatory granuloma existed,the normal structure of the glands were destructed,but IBD-LGG group were light than IBD group.5.The expression of IL-17 A cytokines :The positive cells of IBD-LGG group of colon tissue were decreased significantly compared with IBD group,but a little in the blank control group and LGG control group.Comparing to blank control group,the level of IL-17 A in LGG control group was significantly lower(P <0.05)and obvious higher in IBD group,IBD-LGG group was lower than that in IBD group,and had significant difference(P <0.05).Conclusions:Probiotics treatment can reduce intestinal inflammation in IBD juvenile rats,the mechanism may be related to the inhibition of cytokine IL-17 A expression of Th17 cells. |
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