基于糖皮质激素代谢组学的金丝桃素抗抑郁作用机制的研究

Hypericum perforatum L. (SJW) is the most widely used herbal antidepressant with high security and clinical efficacy. Hypericin is the main active ingredient of SJW. However, the specific mechanism remains elusive. Studies have shown that the glucocorticoid (GC) converting enzyme have a very close relationship with depression and Hypericin is difficult to enter the maincenter. The results of preliminary experiments showed that Hypericin could significantly reduce the concentrations of GC in rats, while there was no significant change in ACTH levels in normal rats. Therefore, we speculate that Hypericin interferes with depression by adjusting GC enzyme activities in peripheral tissues and reducing the concentrations of GC, rather than a direct effect on the central neurotransmitter. In the proposed study we intend to further reveal the changes of the GC metabolic profiling in the depression animal models before and after Hypericin treatment by GC metabolomics on the basis of preliminary studies. Pattern recognition technology will be used to filter out the molecular markers of depression and determine the target enzyme of Hypericin. The influence of Hypericin on target enzyme will be measured in vitro, and then the GC converting enzyme inhibitor will be used in animal models to inactivate the target enzyme, which will be expected to get negative results of Hypericin treatment. The anti-depression mechanism of Hypericin in rats will be further confirmed. Furthermore, the variation of the GC metabolic profiling in the urine of patients with depressive symptoms as well as drug treatment will be analysed to illuminate the mechanism of Hypericin. The project will study the anti-depression mechanism of Hypericin from a new approach, which provides new insights into the treatment of depression.

贯叶连翘是应用广泛的抗抑郁草药，疗效好，安全性高。金丝桃素是其主要活性成分，但具体作用机制不明。现有研究表明糖皮质激素(GC)转化酶与抑郁症关系密切，且金丝桃素难以进入中枢发挥作用。申请人前期研究结果表明金丝桃素显著性降低大鼠外周GC的含量，而对正常大鼠的ACTH含量没有显著影响。因此，金丝桃素可能通过调节外周GC转化酶的活性，降低GC浓度，干预抑郁症，而非直接作用于中枢神经递质。本项目拟在前期基础上采用GC代谢组学法揭示金丝桃素治疗前后抑郁动物模型GC代谢谱的变化，运用模式识别技术筛选出对抑郁症分类能力强的分子标记物，确定金丝桃素作用靶酶；体外试验确定金丝桃素对靶酶的调控，再在动物模型中采用转化酶抑制剂使靶酶失活，以期得到阴性结果，进一步证实其抗抑郁机制；分析抑郁患者尿液GC代谢谱随抑郁症及治疗的规律，明确作用机制。该项目从一个新途径揭示金丝桃素抗抑郁机制，为抑郁症的治疗提供新思路。

贯叶连翘是应用广泛的抗抑郁草药，疗效好，安全性高。金丝桃素是其主要活性成分，但具体作用机制不明。现有研究表明糖皮质激素(GC)转化酶与抑郁症关系密切，且金丝桃素难以进入中枢发挥作用。申请人前期研究结果表明金丝桃素显著性降低大鼠外周GC的含量，而对正常大鼠的ACTH含量没有显著影响。因此，金丝桃素可能通过调节外周GC转化酶的活性，降低GC浓度，干预抑郁症，而非直接作用于中枢神经递质。本研究中，通过行为学评估和尿液中代谢物的分析来研究金丝桃素和文拉法辛对于CUMS诱导的抑郁症状。通过慢性压力试验，测定食物消耗量、体重、肾上腺、胸腺和脾脏指数、行为学分数、糖水测试试验以及压力激素水平。结果表明，CUMS模型组和正常组的尿液代谢物有显著性差异。经典的行为学测试和药理的生物化学指标可以表明金丝桃素可以比文拉法辛可以在在更短时间内缓解抑郁症状。尿液中代谢物分析结果表明，金丝桃素和文拉法辛均可以影响兴奋性氨基酸和单胺类神经递质。金丝桃素还可以极大的提高尿液中缬氨酸的浓度。而人体慢性压力和主要的抑郁障碍和皮质醇代谢密切相关。11β-HSD1和 11β-HSD2这两个代谢酶调节着皮质醇(F)和皮质酮(E)之间的转化。同时，皮质醇和皮质酮还可以通过5α和5β还原酶四氢代谢灭活成为四氢皮质醇(THF)，异四氢皮质醇(5α-THF)和四氢可的松(THE)。为了深入研究，我们收集了12名健康男性受试者和12名未服药的男性抑郁患者（年龄20-50周岁）的晨尿，测定结果表明抑郁患者糖皮质激素代谢显著性的改变：抑郁患者的F/E比值和(THF+5α-THF)/THE比值，以及F 、THF浓度均比健康受试者显著性升高 (p < 0.05);5α-THF/F比值, 5α-THF/THF 比值以及5α-THF浓度均比健康受试者显著性降低 (p < 0.05). 该结果表明抑郁患者体内11β-HSD2活性降低从而导致5α-还原酶途径受损。同时，以氨基酸类神经递质的含量为分析指标，可以将抑郁患者和健康人体区分开，抑郁患者中酪胺的含量显著性高于健康人体。该项目从一个新途径揭示金丝桃素抗抑郁机制，为抑郁症的治疗提供新思路。