Anticonvulsant activity of Hypericum scabrum L.; possible mechanism involved.

Objectives: Hypericum (H.) spp. has been used in traditional medicine for their anticonvulsant effect for many years. In spite of many works on this genus, little is known about H. scabrum. In this work, anticonvulsant activity of H. scabrum was investigated.
Materials and Methods: Anticonvulsant activity of aqueous extract was evaluated by pentylenetetrazole (PTZ) induced convulsion and picrotoxin induced convulsion. Also, nitric oxide radical scavenging was investigated as a possible mechanism involved.
Results: Extract (125-500 mg kg-1, i.p.) significantly delayed the onset of PTZ induced convulsion. At 500 mg kg-1, 100% protection against mortality was observed. At this dose, it significantly prolonged the onset of picrotoxin induced convulsion in mice, too. It showed significant nitric oxide radical scavenging activity.
Conclusions: Mechanism of anticonvulsant activity may be through GABA and/or nitric oxide pathway.