Development of the 1,2,4-triazole-based anticonvulsant drug candidates acting on the voltage-gated sodium channels. Insights from in-vivo, in-vitro, and in-silico studies.

The treatment of epilepsy remains difficult mostly since almost 30% of patients suffer from pharmacoresistant forms of the disease. Therefore, there is an urgent need to search for new antiepileptic drug candidates. Previously, it has been shown that 4-alkyl-5-substituted-1,2,4-triazole-3-thione derivativatives possessed strong anticonvulsant activity in a maximal electroshock-induced seizure model of epilepsy. In this work, we examined the effect of the chemical structure of the 1,2,4-triazole-3-thione-based molecules on the anticonvulsant activity and the binding to voltage-gated sodium channels (VGSCs) and GABA_A receptors. Docking simulations allowed us to determine the mode of interactions between the investigated compounds and binding cavity of the human VGSC. Selected compounds were also investigated in a panel of ADME-Tox assays, including parallel artificial membrane permeability assay (PAMPA), single cell gel electrophoresis (SCGE) and cytotoxicity evaluation in HepG2 cells. The obtained results indicated that unbranched alkyl chains, from butyl to hexyl, attached to 1,2,4-triazole core are essential both for good anticonvulsant activity and strong interactions with VGSCs. The combined in-vivo, in-vitro and in-silico studies emphasize 4-alkyl-5-substituted-1,2,4-triazole-3-thiones as promising agents in the development of new anticonvulsants.