A novel anticonvulsant modulates voltage‐gated sodium channel inactivation and prevents kindling‐induced seizures

Here, we explore the mechanism of action of isoxylitone (ISOX), a molecule discovered in the plant Delphinium denudatum, which has been shown to have anticonvulsant properties. Patch‐clamp electrophysiology assayed the activity of ISOX on voltage‐gated sodium channels (VGSCs) in both cultured neurons and brain slices isolated from controls and rats with experimental epilepsy (kindling model). Quantitative transcription polymerase chain reaction (qRT‐PCR) (QPCR) assessed brain‐derived neurotrophic factor (BDNF) mRNA expression in kindled rats, and kindled rats treated with ISOX. ISOX suppressed sodium current (INa) showing an IC50 value of 185 nM in cultured neurons. ISOX significantly slowed the recovery from inactivation (ISOX τ = 18.7 ms; Control τ = 9.4 ms; p