基于糖链代谢转化的香附抗抑郁萜类配糖体体内活性次级糖苷及其分子机制研究

Scondary glycosides are obtained from natural terpenoid glycosides by enzymatic hydrolysis and display more potent pharmacological activity than the latter. The good effect increment of enzymatic hydrolysis experiment is the same as fermentation and aging of the traditional Chinese medicinal materials. Seven new glycosides from Cyperus rotundus acts well on antidepression and its antitdepressant mechanism is closely related to CREB and BDNF has been proved by integrated multi-model screening. Meanwhile, a new secodary glycoside rotunduside F1 was obtained by enzymatic hydrolysis from rotunduside F and its antitdepressant effect is superior to the positive control drug fluoxetine and rotunduside F. Rotunduside F1 are also found in the metabolite products of the rotunduside F. Basing on the previous study and new mechanisms of antidepressant, further research needs to be carried out. The antidepressant secondary glycosides in vivo obtained from enzymatic hydrolysis products of the seven new terpenoid glycosides from Cyperus rotundus and their mechanisms will be studied. The antidepressant secondary glycosides in vivo should be elucidated with the method of incubation, enzymatic conversion and characteristic fingerprint. Then, methods of rats model of chronically depressive stress, immunohistochemistry and radioimmunology will be adopted to analyze influences of the antidepressant secondary glycosides on neurotrophic factor and neuronic signaling transduction pathway. The research results of this project will establish a solid foundation for discovering antidepressant leading compounds, and provide some theoretical and experimental evidences for the development of a new antidepressant drug from the traditional Chinese medicine in the future.

天然存在的含多个糖基萜类配糖体经酶解脱糖产生次级糖苷，可以显著增强药效，与应用发酵、陈化等中药材加工方法达到增效原理相一致。前期多模型筛选证实香附7个新萜类配糖体具有明显的抗抑郁活性，其作用机制与CREB、BDNF神经营养因子密切相关。进一步研究发现，香附抗抑郁单体rotunduside F的糖苷酶转化产物次级糖苷rotunduside F1与其体内代谢产物相吻合，且抗抑郁活性优于酶解转化前和阳性药。我们将在此基础上，以香附抗抑郁萜类配糖体体内代谢的认识以及抗抑郁机制的新理论为指导，采用肠道菌群温孵、糖苷酶转化以及动态HPLC特征指纹图谱跟踪，系统研究香附抗抑郁萜类配糖体的体内活性次级糖苷；采用大鼠慢性应激抑郁模型、免疫组织化学、放射免疫学等研究方法，阐明活性次级糖苷对神经营养因子、神经信号转导通路的影响及分子机制。为发现治疗抑郁症药物先导化合物、开发新型抗抑郁中药新药提供理论和实验依据。

抑郁症是一种高患病率、高致残率以及高自杀率的严重精神性疾患。世界卫生组织的统计表明，世界上前十种致人残疾或丧失劳动能力的疾病中，抑郁症居第五位，并且具有逐步上升的趋势。目前抑郁症的治疗药物主要依靠化学合成，但是合成药物普遍存在抗抑郁谱窄、起效慢、副作用大的弊端，疗效并不理想。因此开发新型、高效、低毒副作用的天然抗抑郁药物具有重要的理论意义和实际应用价值。本项目研究了中药香附抗抑郁萜类配糖体的体内次级糖苷发现与制备、抗抑郁活性评价及其作用机制。采用肠道菌群温孵法和生物转化法，从香附抗抑郁萜类配糖体CyprotusideA-D等四个单体中发现15个体内次级糖苷，并建立了其制备工艺。采用小鼠强迫游泳实验、小鼠悬尾实验和空场实验，实施体内药效评价，获得6个强抗抑郁活性的体内次级糖苷。作用机制研究表明，香附体内次级糖苷抗抑郁机制与调控海马体cAMP、PKA、TrKB、ERK1/2、Ca2+、CaMKⅡ水平有关。本项目属于基础研究，为新药开发提供理论和实验依据，具有重要的理论研究意义和应用价值。