Modulation of neural cell membrane conductance by the herbal anxiolytic and antiepileptic drug aswal

To evaluate the effects of aswal on ionic fluxes and neuronal excitation, w e performed extracellular and whole cell patch clamp recordings on CA1 pyra midal neurons of guinea pigs and Long-Evans rats. Aswal (100-250 mg/l) was administered systemically, and its effects on the rate of synchronized extr acellular field potentials (EFP), membrane parameters, action potentials an d postsynaptic potentials were recorded. The extracellular results obtained are consistent with calcium antagonistic properties. Intracellular recordi ngs suggest that a direct sodium antagonistic effect as seen in many antiep ileptic drugs plays no significant role. Further effects on ligand gated io n channels are discussed controversially. In summary, the cellular action o f aswal appears heterogeneous with calcium antagonism playing a prominent r ole in counteracting excitation which may be a common feature in epilepsy a nd different psychiatric conditions as mood and anxiety disorder. Copyright (C) 2000 S. Karger AG, Basel.