The effect on blood clotting of some west African plants used against snakebite

Aqueous extracts of the bark of Schumanniophyton magnificum and the leaves of Mucuna pruriens var. utilis, Strophanthus gratus and Strophanthus hispidus show a dose related ability to prolong the time taken to clot for blood treated with a standardised dose of the venom of Echis carinatus. Strophanthus hispidus was shown to be the most potent of the plants tested. The dose-response profiles obtained showed that the increased clotting time was due to different processes for the different plant extracts.