Veratridine
Veratridine is a steroid-derived alkaloid from plants in the Liliaceae family that functions as a neurotoxin by abolishing inactivation of sodium ion channels. It is primarily obtained from the herb Veratrum and sabadilla seeds. It binds to intramembrane receptor site 2 and increases intracellular Ca concentration. It acts by preferentially binding to activated Na channels causing persistent activation that leads to increased nerve excitability.