Inhibitors of Cyclic Adenosine Monophosphate Phosphodiesterase in Polygala tenuifolid

Abstract

Cyclic adenosine monophosphate (AMP) phosphodiesterase inhibitors contained in Polygala tenuifolia WILLD. were identified as saponins and oleic acid. The concentrations of onjisaponins E, F and G required to give 50% inhibition (IC 50) were of the sameor der as that of papaverine. A kinetic study revealed that onjisaponin F acts non-competitively against cyclic AMP phosphodiesterase, like papaverine. Onjisaponin F exhibited a prolongation effect on hexobarbital sleeping time in mice.