Anticonvulsant activities of the FS-1 subfraction isolated from roots of Delphinium denudatum.

Delphinium denudatum Wall. (Ranunculaceae) is a medicinal herb used for the treatment of epilepsy in the subcontinent. The present study reports the anticonvulsant activities in the maximal electroshock test (MEST) and subcutaneous pentylenetetrazole (PTZ), bicuculline (BIC), picrotoxin (PIC)-induced seizures of the FS-1 subfraction (FS-1) that was obtained by purification of an aqueous fraction isolated from the roots of D. denudatum. In CF 1 mice, FS-1 (600 mg/kg i.p.) exhibited very potent anticonvulsant activity that was comparable to the effects of the well-known antiepileptic drug phenytoin (20 mg/kg) in MEST and protected 100% animals from hind limb tonic extension phase of this model. FS-1 also suppressed PTZ-induced threshold seizure and the loss of the righting reflex with tonic fore and hind limb extension by 100%, similar to the antiepileptic drug valproic acid (350 mg/kg). BIC-induced seizures were suppressed in 80% of the animals. FS-1 exhibited weak anticonvulsant effect on PIC-induced seizures, however, it significantly reduced mortality and delayed the onset of seizures. FS-1 had no effect on strychnine (STN)-induced extensor seizures. The results demonstrate the broad and potent anticonvulsant activity of the compounds in FS-1 of D. denudatum.