© Georg Thieme Verlag Stuttgart · New York
Kavain Inhibits Non-Stereospecifically Veratridine-Activated Na+ Channels
04 January 2007 (online)
The action of the natural kava pyrone, (+)-kavain, and its synthetic racemate, (±)-kavain, on voltage-dependent Na+ channels was investigated, while considering their stereospecific properties, on veratridine-induced increases in cytosolic free Na+ and Ca2+ ([Na+]i, [Ca2+]i) and the release of endogenous glutamate from cerebrocortical synaptosomes. Both compounds dose-dependently suppressed the veratridine-induced increase in [Na+]i, [Ca2+]i and glutamate release with IC50 values (± S.D.) of 71 ± 22, 72 ± 7, 120 ± 37 µmol/l (+)-kavain and 77 ± 21, 90 ± 14, 92 ± 23 µmol/l (±)-kavain, respectively. As judged from the dose-dependency, IC50 values, velocity and time course of action, both kava pyrones were equally effective suggesting a non-stereospecific inhibition of veratridine-activated Na+ channels.