bioRxiv preprint doi: https://doi.org/10.1101/2020.04.24.059188; this version posted August 14, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY 4.0 International license. 1 Inhibitory effect of eslicarbazepine acetate and S-licarbazepine on 2 Nav1.5 channels 3 Theresa K. Leslie1, Lotte Brückner 1, Sangeeta Chawla1,2, William J. Brackenbury1,2* 4 1Department of Biology, University of York, Heslington, York, YO10 5DD, UK 5 2York Biomedical Research Institute, University of York, Heslington, York, YO10 5DD, UK 6 * Correspondence: Dr William J. Brackenbury, Department of Biology and York Biomedical 7 Research Institute, University of York, Wentworth Way, Heslington, York YO10 5DD, UK. Email: 8
[email protected]. Tel: +44 1904 328284. 9 Keywords: Anticonvulsant, cancer, epilepsy, eslicarbazepine acetate, Nav1.5, S-licarbazepine, 10 voltage-gated Na+ channel. 11 Abstract 12 Eslicarbazepine acetate (ESL) is a dibenzazepine anticonvulsant approved as adjunctive treatment for 13 partial-onset epileptic seizures. Following first pass hydrolysis of ESL, S-licarbazepine (S-Lic) 14 represents around 95 % of circulating active metabolites. S-Lic is the main enantiomer responsible 15 for anticonvulsant activity and this is proposed to be through the blockade of voltage-gated Na+ 16 channels (VGSCs). ESL and S-Lic both have a voltage-dependent inhibitory effect on the Na+ current 17 in N1E-115 neuroblastoma cells expressing neuronal VGSC subtypes including Nav1.1, Nav1.2, 18 Nav1.3, Nav1.6 and Nav1.7.