基于肠黏膜通透性的四逆散治疗肝郁型抑郁症的机制研究

In TCM theory, Sini San is a classical prescription for soothing the liver qi and has significant effect on depression with liver-qi stagnation syndrome. However, current mechanism research focus on the central nervous system, which is very limited. Modern medical research indicates that the increased intestinal mucosal permeability has a close relationship with depression. Our previous study has established a method to discriminate the model of depression with liver-qi stagnation syndrome, and proved that Sini San can improved the model’s depressive behavior and the accompanying intestinal and liver lesions. Tight junction is an important factor to regulate the intestinal permeability. The results of previous animal experiment on the antidepressant mechanism, network pharmacology’s target prediction of Sini San and multiple other research indicates that the Sini San has the function of regulating tight junction. So we put forward the hypothesis: Sini San can regulate the intestinal permeability by tight junction, hence improve the depressive symptoms. Based on this, our study intends to detect the related factors of tight junction in intestinal mucosa, intestinal mucosal permeability, and indicators for depression. If our hypothesis is verified, it will be an important supplement for Sini San’s antidepressive mechanism and will provide more powerful support for Sini San’s soothing liver qi effect to treat depression in TCM theory.

四逆散是中医疏肝祖方，临床治疗肝郁型抑郁症疗效显著，但目前机制研究切入点以中枢神经生物学指标为主，结果局限。现代医学显示肠黏膜通透性增加与抑郁症的发生发展密切相关。课题组前期已建立大鼠肝郁型抑郁症判别方法，并证明四逆散能够改善模型大鼠抑郁行为以及伴发的肠、肝病变。紧密连接是调节肠黏膜通透性的重要因素。本课题前期对四逆散的抗抑郁机制实验研究和通过网络药理学对四逆散的靶点预测以及现代多项实验研究结果均提示四逆散具有调节肠黏膜紧密连接的作用。因此我们提出假说：四逆散可通过紧密连接对肠黏膜通透性进行调控，从而对肝郁型抑郁症大鼠起到治疗作用。基于此，本课题拟对肠黏膜紧密连接相关因子、肠黏膜通透性进行检测，并与抑郁症相关指标进行相关性研究。如果本课题假说得到验证，将为四逆散的抗抑郁机制做出重要补充，也将为四逆散疏肝治疗抑郁症提供更为重要的支撑和依据。

四逆散是中医疏肝祖方，是临床治疗肝郁型抑郁症的核心方剂，但目前机制研究并不清楚。现代医学研究显示肠黏膜通透性增加导致的机体系统炎症反应与抑郁症的发生发展密切相关。课题组前期已建立大鼠肝郁型抑郁症判别方法，并证明四逆散能够改善模型大鼠抑郁行为及伴发的肠、肝病变。本课题采用尤斯灌流技术、酶联免疫技术分别对空肠粘膜通透性、总体的肠粘膜通透性（LPS, Zonulin）以及血液炎症因子（IL-1β、IL-6、TNF-α）进行了检测，结果显示，四逆散可以有效改善肝郁型抑郁症大鼠的行为学和微观指标改变，显著改善大鼠总体的肠粘膜通透性及血清IL-1β增高的现象，提示四逆散通过改善肠粘膜通透性增高引发的炎症反应，可能是四逆散发挥抗抑郁的机制之一。紧密连接是调节肠黏膜通透性的重要因素。故本课题采用透射电镜、免疫组化、酶联免疫、RT-PCR等技术对空肠粘膜的紧密连接及其相关调控蛋白（claudin-1、 claudin-5、claudin-8、occludin、ZO-1、β-catenin、PP2A等）进行了检测研究，但未发现显著差异，未来可能需要对其他部位肠粘膜进行研究。在原课题基础上，本课题进行了拓展研究：采用16SrDNA测序分析技术以及紫外-乳酸脱氢酶法对大鼠的肠道菌群及肝功能进行了研究，结果显示四逆散可以有效改善肠道菌群的拟杆菌属(Bacteroides)、副杆菌属（Parabacteroides）、另枝菌属(Alistipes)等菌群，显著改善抑郁大鼠血清AST、ALT增高的现象，这些发现也将为未来的研究方向提供新的思路。