开心散联合氟西汀对慢性压力应激抑郁小鼠肠道菌群与机体致炎物质表达的影响

Effects of Kai-Xin-San Combined with Fluoxetine on Intestinal Flora and Expression of Inflammatory Factors in Chronic Unpredictable Mild Stress Depression Mice

目的评价开心散联合氟西汀对慢性压力应激(CUMS)抑郁小鼠肠道菌群与机体致炎物质表达的影响,探索其调控肠-脑轴抗抑郁作用机制。方法构建小鼠CUMS抑郁模型,通过检测糖水偏嗜率、悬尾不动时间与强迫游泳不动时间评价开心散联合氟西汀改善小鼠抑郁行为的效果。采用ELISA法测定受试动物大脑皮层、血清和小肠组织中致炎物质白介素6(IL-6)、白介素1β(IL-1β)、肿瘤坏死因子-α(TNF-α)与脂多糖(LPS)的表达。采用16S rRNA基因测序法对小鼠粪便中肠道菌群组成进行分析。采用Western blot法考察小鼠小肠组织中ZO-1、Occludin和Claudin 5等肠道屏障蛋白的表达情况。结果开心散联合氟西汀显著上调模型小鼠糖水偏嗜率(P<0.01),缩短悬尾不动时间与强迫游泳不动时间(P<0.05,P<0.01)。开心散与氟西汀中剂量联用的抗抑郁效用与单用氟西汀高剂量的趋势相似。联合用药还可显著抑制CUMS模型动物大脑皮层、血清和小肠致炎物质的上调(P<0.05,P<0.01)。肠道菌群分析显示,联合用药可改善模型动物肠道革兰氏阳性菌与阴性菌的比例,其对毛螺菌、双歧杆菌、瘤胃球菌、布劳特氏菌、优杆菌、丁酸肠杆菌、丹毒丝菌、另枝菌、脱硫弧菌、红椿菌-UCG-002等肠道菌相对丰度的改善与其缓解抑郁样行为与皮层致炎物质表达下调显著相关(P<0.05,P<0.01)。另外,联合用药还可显著上调肠道屏障蛋白表达(P<0.05,P<0.01)。结论开心散联合氟西汀可缓解CUMS模型动物的抑郁样行为并减少氟西汀单用的用量。两者连用调控肠道菌群组成,抑制肠道致炎物质表达,上调肠道屏障蛋白表达,从而减少血清与中枢的致炎物质的表达,可能是其调控肠-脑轴抗抑郁的作用环节。

OBJECTIVE To determine the effect of Kai-Xin-San(KXS)combined with fluoxetine on the intestinal flora and the expression of inflammatory factors in chronic unpredictable mild stress(CUMS)depression mice and to elucidate the antidepressant mechanism of regulating“intestine-brain”axis.METHODS CUMS depression mice model was established and the effect of combined medication on improving depression-like behaviors of mice was evaluated by determination of sucrose preference rate,immobile time of tail suspension and forced swimming.Additionally,the levels of inflammatory factors IL-6,IL-1β,TNF-αand LPS were determined in cortex,serum and intestine using the ELISA method.The composition of intestinal flora in mouse feces was analyzed by 16S rRNA sequence sequencing.Furthermore,Western blot assay was utilized to determine the expression levels of intestinal barrier proteins such as ZO-1,Occludin and Claudin-5.RESULTS The combination of KXS and fluoxetine resulted in a significant increase in sucrose preference rate(P<0.01)and decreased immobile time of tail suspension and forced swimming(P<0.05,P<0.01)in CUMS mice.The antidepressant effect of KXS combined with middle dose of fluoxetine was equivalent to that of high dose of fluoxetine alone.Meanwhile,the combination could significantly inhibit the up-regulation of inflammatory factors in the cortex,serum and small intestine of model animals(P<0.05,P<0.01).Intestinal flora analysis showed that the combination could improve the ratio of Gram-positive bacteria to negative bacteria in the intestinal tract of model animals,and the improvement of the relative abundance of intestinal bacteria Lachnospiraceae,Bifidobacterium,Ruminococcus,Blautia,Eubacterium,Intestinimonas,Erysipelotrichaceae,Alistipes,Desulfovibrionia and Coriobacteriaceae UCG-002 and so on in the model animals was significantly related to the alleviation of depression-like behavior and the down-regulation of cortical inflammatory factors(P<0.05,P<0.01).Furthermore,the combination treatment could significantly up-regulate the expression of intestinal barrier protein(P<0.01).CONCLUSION KXS combined with fluoxetine can alleviate depression-like behavior and reduce fluoxetine dosage in CUMS model animals.The combination of the two drugs may regulate the composition of intestinal flora,inhibit the expression of intestinal inflammatory factors,up-regulate intestinal barrier proteins,and thus reduce the expression of serum and central inflammatory factors,which may be the mechanism of their regulation of the gut brain axis in antidepressant action.