The thesis presents the results of ethnopharmacological, phytochemical and biological activities investigations on Opilia celtidifolia (Guill. & Perr.) Endl. ex Walp (Opiliaceae), Cola cordifolia (Cav.) R. Br. (Sterculiaceae), and Erythrina senegalensis DC (Fabaceae), three plants used in traditional medicine in Mali to cure various types of diseases.