Antiplasmodial and GABAA–benzodiazepine receptor binding activities of five plants used in traditional medicine in Mali, West Africa

Extracts of five medicinal plants: Boscia angustifolia, Cissus quadrangularis, Securidaca longipedunculata, Stylosanthes erecta and Trichilia emetica, used traditionally in Malian traditional medicine were screened for in vitro antiplasmodial activity and GABAA–benzodiazepine receptor binding activity. Four extracts showed significant antiplasmodial activities, with the dichloromethane extract of leaf of Securidaca longipedunculata being the most active (IC50 of 7 μg/ml [95% CI: 5–9]). The dichloromethane extract of leaf of Trichilia emetica, in addition to its antiplasmodial activity (IC50: 12 μg/ml [95% CI: 12–14]), exhibited a good binding activity to the GABAA–benzodiazepine receptor, while water and methanol extracts of the same plant did not show any activity. A strong GABAA-receptor complex binding activity was observed in the methanol extract of aerial part of Stylosanthes erecta. The results in this study justify some of the traditional indications of the plants investigated and may thus be candidates for Improved Traditional Medicines in Mali.