Anticonvulsant activity of acute and chronic treatment with a-asarone from Acorus gramineus in seizure models.

For centuries, extracts of Acorus gramineus have been used extensively in traditional Chinese medicine for the treatment, management, and/or control of human ailments, including central nervous system disorders such as convulsions and epilepsy. In the present study, we investigated the anticonvulsant activity of chronic treatment with the plant's major essential oil component (a-asarone, 50-200 mg/kg, per os (p.o.)) against maximal electroshock seizure (MES), pentylenetetrazole (PTZ)-induced seizures in mice, lithium-pilocarpine (LI-PILO)-induced status epilepticus (SE), and spontaneous recurrent seizures (SRSs) in rats and determined whether a single acute administration of a-asarone at various doses could produce anticonvulsant activity. As the standard antiepileptic drugs used, chronically administered a-asarone (50-200 mg/kg, p.o.) significantly delayed (p<0.05) the onset of, and antagonized maximal electroshock seizure and PTZ-induced seizures. Chronically administered a-asarone (50-200 mg/kg) also profoundly antagonized LI-PILO-induced seizures. The SE incidence, SE latency and seizure severity as well as mortality were significantly reduced after treatment with a-asarone at different doses. Higher doses of a-asarone (100-200 mg/kg) significantly reduced spontaneous recurrent seizure incidence, severity, and seizure frequency during treatment in LI-PILO-induced SRSs rats. On the other hand, a single acute administration of a-asarone (50-200 mg/kg) produced weak anticonvulsant activity in MES and PTZ-induced seizures. The results of this laboratory animal study indicate that chronically administered a-asarone possesses anticonvulsant activity in the mammalian experimental model used, and thus suggest that a-asarone may be used as a natural supplementary remedy in the management of convulsions and epilepsy.