Lvguidingan inhibits Nav1.2 and epilepsy-associated SCN2A gain-of-function variants.

Voltage-gated sodium (Nav) channel Nav1.2, encoded by SCN2A, is a major determinant of neuronal excitability and an important contributor to epilepsy-associated hyperexcitability. However, small-molecule inhibitors with well-defined Nav1.2 pharmacology remain limited. Here, using an automated electrophysiological screening platform, we identified Lvguidingan (LV), an antiepileptic candidate that has entered phase II clinical evaluation in China, as a hit inhibitor of Nav1.2 and systematically characterized its pharmacological properties. Manual patch-clamp recordings showed that LV inhibited Nav1.2 and displayed differential inhibitory effects across other tested sodium channel subtypes. LV exhibited clear state- and use-dependent inhibition of Nav1.2 and shifted channel gating toward less available states. Molecular modeling and mutational analysis further identified key binding determinants underlying LV-mediated Nav1.2 inhibition. At the neuronal level, LV suppressed the firing of hippocampal neurons and reduced action potential amplitude. Importantly, LV also inhibited two epilepsy-associated SCN2A gain-of-function variants. Together, these results identify LV as a Nav1.2 inhibitor with defined biophysical and structural features and inhibitory activity against disease-associated SCN2A variants, providing new insight into the Nav1.2-related mechanism underlying the antiepileptic activity of LV.