Department of Biology, Animal Physiology and Neurobiology Section, KU Leuven, Naamsestraat 59, box 2465, 3000 Leuven, Belgium; Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Herestraat 49, box 921, 3000 Leuven, Belgium.
Department of Chemistry, Molecular Design and Synthesis, KU Leuven, Celestijnenlaan 200F, box 2404, 3000 Leuven, Belgium.
J Ethnopharmacol. 2018 Oct 5;224:421-428. doi: 10.1016/j.jep.2018.06.026. Epub 2018 Jun 19.
Semen Torreyae, the seeds of Torreya grandis Fortune ex Lindley (Cephalotaxaceae) is a well-known traditional Chinese medicinal plant recorded in the Chinese Pharmacopeia (2010 version). It is widely used for treating intestinal parasites in China, owing to its desirable efficacy and safety. However, the anthelmintic compounds in Semen Torreyae have not yet been identified.
This study aims to identify the compounds active against helminths from Semen Torreyae. In addition, we tested whether C. elegans strains resistant to currently-used anthelmintic drugs showed cross-resistance to these compounds.
A bioassay-guided isolation of anthelmintic compounds from Semen Torreyae was performed using a Caenorhabditis elegans (C. elegans) testing model. The structures of active compounds were elucidated by a combination of GC-MS, high resolution MS, and NMR. The median-effect method was employed to generate a combination index (CI) to evaluate the synergistic effect of the anthelmintic compounds. A panel of C. elegans mutant strains resistant against the major anthelmintic drug classes was used to study the cross-resistance to currently-used anthelmintic drugs. A panel of transient receptor potential (TRP) channel mutant strains was also tested to explore the possible mechanisms of action of the anthelmintic compounds.
The bioassay-guided isolation led to two active compounds, i.e. galangal acetate (IC: 58.5 ± 8.9 μM) and miogadial (IC: 25.1 ± 5.4 μM). The combination of galangal acetate and miogadial resulted in a synergistic effect at IC, IC, and IC levels (CIs < 1). Galangal acetate and miogadial demonstrated similar activity against drug-resistant C. elegans strains compared to the wild-type strain. In addition, none of the TRP mutants was significantly resistant to galangal acetate or miogadial compared to wild type worms.
We identified the bioactive compounds from Semen Torreyae responsible for its anthelmintic activity: galangal acetate and miogadial. The two anthelmintic compounds demonstrated a synergistic effect against C. elegans. Galangal acetate and miogadial are unlikely to act on the targets of currently-used anthelmintics (ivermectin, levamisole, benomyl and aldicarb), and an action on TRP channels appears to be ruled out as well. In summary, galangal acetate and miogadial are promising anthelmintic hits worth further investigation.
ETHNOPHARMACOLOGICAL 相关性：榧子，即红豆杉科（Cephalotaxaceae）的榧树（Torreya grandis Fortune ex Lindley）的种子，是《中国药典》（2010 年版）中记载的一种著名的传统中药。在中国，由于其良好的疗效和安全性，它被广泛用于治疗肠道寄生虫。然而，榧子中的驱虫化合物尚未被鉴定。
本研究旨在从榧子中鉴定出具有驱虫活性的化合物。此外，我们还测试了对目前使用的驱虫药物具有抗药性的秀丽隐杆线虫（Caenorhabditis elegans，C. elegans）菌株是否对这些化合物表现出交叉耐药性。
使用秀丽隐杆线虫（C. elegans）测试模型，对榧子中的驱虫化合物进行生物测定指导分离。通过 GC-MS、高分辨率 MS 和 NMR 的组合，阐明活性化合物的结构。采用中效法生成合并指数（CI），以评估驱虫化合物的协同作用。使用一组对主要驱虫药物类别具有抗药性的秀丽隐杆线虫突变株，研究对目前使用的驱虫药物的交叉耐药性。还测试了一组瞬时受体电位（TRP）通道突变株，以探讨驱虫化合物的可能作用机制。
生物测定指导分离得到两种活性化合物，即姜烯乙酸酯（IC：58.5±8.9 μM）和米奥加迪尔（IC：25.1±5.4 μM）。姜烯乙酸酯和米奥加迪尔在 IC、IC 和 IC 水平（CI<1）下表现出协同作用。姜烯乙酸酯和米奥加迪尔对耐药秀丽隐杆线虫菌株的活性与野生型菌株相似。此外，与野生型蠕虫相比，TRP 突变体中没有一个对姜烯乙酸酯或米奥加迪尔表现出明显的耐药性。
我们从榧子中鉴定出负责其驱虫活性的生物活性化合物：姜烯乙酸酯和米奥加迪尔。这两种驱虫化合物对秀丽隐杆线虫表现出协同作用。姜烯乙酸酯和米奥加迪尔不太可能作用于目前使用的驱虫药物（伊维菌素、左旋咪唑、苯菌灵和涕灭威）的靶点，并且似乎也排除了对 TRP 通道的作用。总之，姜烯乙酸酯和米奥加迪尔是有前途的驱虫化合物，值得进一步研究。
