Anticonvulsant property of Sutherlandia frutescens R. BR. (variety Incana E. MEY.) [Fabaceae] shoot aqueous extract

Aerial parts of Sutherlandia frutescens R. BR. [family: Fabaceae] are extensively used in South African traditional medicines for the treatment, management and/or control of an array of human ailments, including childhood convulsions and epilepsy. In this study, we examined the anticonvulsant property of the plant's shoot aqueous extract (SFE, 25-400 mg/kg i.p.) against pentylenetetrazole (PTZ)-, picrotoxin (PCT)- and bicuculline (BCL)-induced seizures in mice. Phenobarbitone and diazepam were used as reference anticonvulsant drugs for comparison. Like the reference antiseizure drugs used, S. frurescens shoot aqueous extract (SFE, 50-400 mg/kg i.p.) significantly delayed (p<0.05-0.001) the onset of, and antagonized, pentylenetetrazole (PTZ)-induced seizures. The plant's shoot aqueous extract (SFE, 50-400 mg/kg i.p.) also profoundly antagonized picrotoxin (PCT)-induced seizures, but only weakly antagonized bicuculline (BCL)-induced seizures. Although the data obtained in the present study do not provide conclusive evidence, it appears that S. frurescens shoot aqueous extract (SFE) produces its antiseizure effect directly by acting like GABA, or indirectly by enhancing GABAergic neurotransmission and/or action in the brain. The results of this laboratory animal study suggest that the herb may be used as a natural supplementary remedy in the management, control and/or treatment of childhood convulsions and epilepsy. In conclusion, the findings of this study indicate that S. frurescens shoot aqueous extract possesses anticonvulsant activity, and thus lend pharmacological credence to the suggested folkloric, ethnomedical uses of the herb in the management or treatment of childhood convulsions and epilepsy in some rural communities of South Africa.