Screening of plants used in southern Africa for epilepsy and convulsions in the GABAA-benzodiazepine receptor assay.

A number of plants are traditionally used to treat mental diseases in South Africa. Aqueous and ethanol extracts of 43 plants that are traditionally used to treat against epilepsy and convulsions, were tested in the GABAA-benzodiazepine receptor binding assay, where the binding of 3H-Ro 15-1788 (flumazenil) to the benzodiazepine site is measured. The GABAA-benzodiazepine receptor complex is involved in epilepsy and convulsions. Out of the 118 extracts tested, one aqueous and 18 ethanol extracts showed activity. The most active extracts were the ethanolic leaf extracts of Rhus tridentata, Rhus rehmanniana and Hoslundia opposita and the ethanolic corm extract of Hypoxis colchicifolia, which all showed good dose-dependent activity.