Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia.
Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia; Faculty of Science and Technology, Federation University, Ballarat, Victoria, Australia.
Int J Parasitol Drugs Drug Resist. 2019 Apr;9:59-71. doi: 10.1016/j.ijpddr.2018.12.007. Epub 2018 Dec 30.
In the present study, the anthelmintic activity of a human tyrosine kinase inhibitor, AG-1295, and 14 related tetrahydroquinoxaline analogues against Haemonchus contortus was explored. These compounds were screened against parasitic larvae - exsheathed third-stage (xL3) and fourth-stage (L4) - using a whole-organism screening assay. All compounds were shown to have inhibitory effects on larval motility, development and growth, and induced evisceration through the excretory pore in xL3s. The estimated IC values ranged from 3.5 to 52.0 μM for inhibition of larval motility or development. Cytotoxicity IC against human MCF10A cells was generally higher than 50 μM. Microscopic studies revealed that this eviscerated (Evi) phenotype occurs rapidly (<20 min) and relates to a protrusion of internal tissues and organs (evisceration) through the excretory pore in xL3s; severe pathological damage in L4s as well as a suppression of larval growth in both stages were also observed. Using a relatively low concentration (12.5 μM) of compound m10, it was established that the inhibitor has to be present for a relatively short time (between 30 h and 42 h) during in vitro development from xL3 to L4, to induce the Evi phenotype. Increasing external osmotic pressure prevented evisceration and moulting, and xL3s remained unaffected by the test compound. These results point to a mode of action involving a dysregulation of morphogenetic processes during a critical time-frame, in agreement with the expected behaviour of a tyrosine kinase inhibitor, and suggest potential for development of this compound class as nematocidal drugs.
在本研究中，研究了一种人源酪氨酸激酶抑制剂 AG-1295 及 14 种相关的四氢喹喔啉类似物对捻转血矛线虫的驱虫活性。使用全虫筛选试验，对寄生幼虫-刚蜕皮的第三期（xL3）和第四期（L4）幼虫进行了这些化合物的筛选。所有化合物均显示对幼虫运动、发育和生长有抑制作用，并通过 xL3 的排泄孔诱导内脏外翻。估计对幼虫运动或发育的抑制作用的 IC 值范围为 3.5 至 52.0 μM。对人 MCF10A 细胞的细胞毒性 IC 通常高于 50 μM。显微镜研究表明，这种内脏外翻（Evi）表型发生迅速（<20 分钟），与内部组织和器官的突起（内脏外翻）通过 xL3 的排泄孔有关；在 L4 中观察到严重的病理损伤以及在两个阶段中幼虫生长受到抑制。使用相对较低浓度（12.5 μM）的化合物 m10，确定抑制剂必须在从 xL3 到 L4 的体外发育过程中存在相对较短的时间（30 h 至 42 h 之间），才能诱导 Evi 表型。增加外部渗透压可防止内脏外翻和蜕皮，并且测试化合物对 xL3 没有影响。这些结果表明作用模式涉及在关键时间框架内形态发生过程的失调，与酪氨酸激酶抑制剂的预期行为一致，并表明该化合物类别的发展具有作为杀线虫药物的潜力。
