Comparative Studies of Therapeutic Effect of Leaves, Stem Bark and Root Bark Extracts of Afzelia africana (Smith) in Mice Challenged with Trypanosoma brucei brucei

Background: Traditional and complimentary health care is inarguably the system most close to homes, accessible and affordable. It is also culturally acceptable and trusted by large numbers of people. The affordability of most traditional medicines makes them all the more attractive at a time of soaring health-care costs, neglect of orphaned/non profitable diseases and nearly universal austerity.

Aim: Aqueous leaf, stem bark and root bark extracts were evaluated for their anti trypanosomal effect in experimental trypanosomiasis with a view to come up with a phytomedicine that is efficacious, available, accessible and non-toxic to both humans and animals.

Study Design: Complete randomized clinical trial design was used in the experiment.

Methodology: Ninety five (95) mice were grouped into three (I, II, III) of thirty mice each (with sub groups A, B, C, D, E, and F consisting of five mice each) to which the leaf, stem bark and root bark extracts were administered at a dose of 100, 200, 300, 400 mg/Kgbw, while the remaining five mice served as the control for all the groups.

Results: The aqueous leaves extract at doses of 100, 200 and 300 mg/Kg bw portrayed very low activities except for the 400 mg/Kg bw that displayed a sustained Trypanostatic effect. The aqueous stem bark extract, at doses of 100 and 200 mg/Kg bw portrayed trypanostatic effect while doses of 300 and 400 mg/Kg bw effectively cleared the parasites from circulation on the 13th and 17th days into the treatment respectively. Three and two of treated mice survived and remained apparasitaemic for up to 120 days and beyond in the group treated with 300 and 400 mg/kg bw respectively. In the group treated with the root bark extract, the mice on a dose of 100 mg/Kg bw died some few days into the experiment (6th day) while the dose of 200 mg/Kgbw sustained the animals until the 19th day. Doses of 300 and 400 mg/Kg bw were observed to clear the parasites in circulation after sustained administration for 23 and 16 days respectively.

Conclusion: This study has demonstrated the potency of the stem bark and root bark crude extracts of Afzelia africana in treating experimental trypanosomiasis and can thus be further purified and packaged as phytomedicine against this dreaded but neglected disease.