The purpose of this investigation is to contribute to the development of new anticonvulsant drugs to treat patients with refractory epilepsy. We applied a virtual screening protocol that involved the search into molecular databases of new compounds and known drugs to find small molecules that interact with the open conformation of the Nav1.2 pore. As the 3D structure of human Nav1.2 is not available, we first assembled 3D models of the target, in closed and open conformations. After the virtual screening, the resulting candidates were submitted to a second virtual filter, to find compounds with better chances of being effective for the treatment of P-glycoprotein (P-gp) mediated resistant epilepsy. Again, we built a model of the 3D structure of human P-gp, and we validated the docking methodology selected to propose the best candidates, which were experimentally tested on Nav1.2 channels by patch clamp techniques and in vivo by the maximal electroshock seizure (MES) test. Patch clamp studies allowed us to corroborate that our candidates, drugs used for the treatment of other pathologies like Ciprofloxacin, Losartan, and Valsartan, exhibit inhibitory effects on Nav1.2 channel activity. Additionally, a compound synthesized in our lab, N,N′-diphenethylsulfamide, interacts with the target and also triggers significant Na1.2 channel inhibitory action. Finally, in vivo studies confirmed the anticonvulsant action of Valsartan, Ciprofloxacin, and N,N′-diphenethylsulfamide.

中文翻译：

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寻找新的线索来治疗癫痫：基于目标的虚拟筛选发现抗惊厥药

这项研究的目的是有助于开发新的抗惊厥药来治疗难治性癫痫患者。我们应用了一种虚拟筛选方案，该方案涉及对新化合物和已知药物的分子数据库进行搜索，以发现与Nav1.2孔的开放构象相互作用的小分子。由于无法使用人类Nav1.2的3D结构，因此我们首先以封闭和开放的形式组装了目标的3D模型。在进行虚拟筛选后，将产生的候选物送至第二个虚拟过滤器，以查找更有可能有效治疗P-糖蛋白（P-gp）介导的抗药性癫痫的化合物。同样，我们建立了人类P-gp的3D结构模型，并验证了为提出最佳候选方案而选择的对接方法，通过膜片钳技术在Nav1.2通道上进行了实验性测试，并通过最大电休克发作（MES）测试在体内进行了测试。膜片钳研究使我们能够证实我们的候选药物（用于治疗环丙沙星，氯沙坦和缬沙坦等其他疾病的药物）对Nav1.2通道活性具有抑制作用。此外，在我们的实验室中合成的化合物N，N'-二苯乙基磺酰胺与靶标相互作用，并且还引发显着的Na1.2通道抑制作用。最后，体内研究证实了缬沙坦，环丙沙星和N，N'-二苯乙基磺酰胺具有抗惊厥作用。