茯砖茶对葡聚糖硫酸钠诱导UC小鼠炎症及肠道微生物的影响

Effects of Fu Brick Tea on Inflammation and Intestinal Microflora Diversity in Mice with DSS-induced Ulcerative Colitis

为研究茯砖茶对葡聚糖硫酸钠(Dextran sulfate sodium,DSS)诱导的溃疡性结肠炎(Ulcerative colitis,UC)小鼠的抗炎作用及肠道微生物多样性的影响,将60只C57BL/6雌性小鼠随机分成正常对照组、10 mg·kg^(-1) EGCG对照组、高剂量茯砖茶(300 mg·kg^(-1))对照组、DSS模型组、DSS+10 mg·kg^(-1) EGCG处理组、DSS+低剂量茯砖茶(100 mg·kg^(-1))处理组、DSS+中剂量茯砖茶(150 mg·kg^(-1))处理组、DSS+高剂量茯砖茶(300 mg·kg^(-1))处理组,对照组n=5,处理组n=9。DSS造模1周后,灌喂处理4周,试验5周后处死小鼠,观察小鼠结肠组织病理学变化,评估小鼠结肠炎疾病指数(Disease activity index,DAI),检测小鼠血清中IL-6、IL-8、IL-1β、TNF-α、IFN-γ等炎性因子水平及小鼠结肠组织中JAK2、STAT3基因表达水平,利用PCR-DGGE、克隆测序等技术分析小鼠肠道微生物菌群多样性。结果表明,与DSS模型组相比,灌喂EGCG和不同剂量茯砖茶后,小鼠生存质量、结肠组织形态明显改善,显著降低了小鼠血清中IL-6、IL-8、IL-1β、TNF-α、IFN-γ水平(P<0.05);显著降低JAK2、STAT3基因表达(P<0.05),抑制了JAK2/STAT3炎性信号通路;肠道微生物多样性增加、丰富度提高,不同处理组优势菌群发生变化。综上所述,茯砖茶可通过抑制JAK2/STAT3炎性信号通路以及调节小鼠肠道微生物多样性来改善DSS诱导的小鼠溃疡性结肠炎。

In this study,we investigated the effects of Fu brick tea on the anti-inflammation and intestinal microflora of ulcerative colitis(UC)mice induced by Dextran sulfate sodium(DSS).Sixty C57BL/6 female mice were randomly divided into the normal control group,10 mg·kg^(-1) EGCG control group,high dose brick tea(300 mg·kg^(-1),HBT)control group,DSS model group,DSS+10 mg·kg^(-1) EGCG group,DSS+low dose brick tea(100 mg·kg^(-1),LBT)group,DSS+middle dose brick tea(150 mg·kg^(-1),MBT)group and DSS+HBT group,with the control groups n=5 and the treatment groups n=9.After 1 week of DSS modeling,the mice were gavaged for 4 weeks.The mice were executed after 5 weeks of the treatments.The histopathological changes of mice colon were observed,and the disease activity index(DAI)of mice colitis was assessed.The levels of IL-6,IL-8,IL-1β,TNF-αand IFN-γinflammatory factors in mice serum and the expression levels of JAK2 and STAT3 genes in mice colon tissues were measured.The intestinal microflora of mice was analyzed by PCR-DGGE and clone sequencing techniques.The results show that compared with the DSS model group,the quality of survival and colonic tissue morphology of mice were significantly improved after feeding EGCG and different concentrations of brick tea,and the levels of inflammatory factors IL-6,IL-8,IL-1β,TNF-αand IFN-γin mice serum were significantly reduced(P<0.05).Moreover,the expressions of JAK2 and STAT3 genes were significantly reduced(P<0.05)JAK2/STAT3 inflammatory signaling pathway was inhibited;and intestinal microflora diversity and richness were increased significantly.The dominant bacterial flora in different treatment groups were changed as well.In conclusion,Fu brick tea can ameliorate DSS-induced UC injury by inhibiting JAK2/STAT3 inflammatory signaling pathway and modulating intestinal microflora diversity.