Abstract

Using Trypanosoma brucei as test organism, about two hundred extracts of varying polarities obtained from different parts of about forty tropical plants harvested from the savannah vegetational belt of Nigeria were evaluated for their in vitro trypanocidal activities at concentrations of 2 and 4 mg/ml. The proportion of petroleum ether, chloroform, methanol and aqueous extracts that eliminated motility within 60 min at the highest concentration tested were 77, 67, 50 and 47%, respectively, while 10, 11, 19 and 14% of these extracts were completely non-active under the test condition. Among the plants studied, extracts of Adenium obesum (stem bark), Afrormosia laxiflora (leaves and stem bark),Cochlospermum planchonii (stem bark), Prosopis africana (stem and root barks), Striga spp (leaves), Terminalia avicennioides (root and stem bark) andSwartzia madagascariensis (fruit pulp) exhibited the highest trypanocidal activity. These results suggest that tropical plants could be a very promising source of new generations of trypanocidal agents.

Key words: Medicinal plants, trypanocidal effects, in vitro assay, trypanosomiasis, Nigeria.