Evaluation of In vivo Antitrypanosomal Activity of Aqueous and Methanol Leaf Extracts of Clutia abyssinica (Euphorbiaceae) against Trypanosoma congolense Field Isolate

Abstract

Aqueous and methanol leaf extracts of C. abyssinica were investigated for their in vivo activity against Trypanosoma congolence, the main causative agent of African animal trypanosomosis in Sub-Saharan Africa and Ethiopia. The in vivo antitrypanosomal efficacy of the aqueous and methanol extracts was evaluated in Swiss albino mice infected with T. congolense field isolate. The leaf extracts were administered 12 days post-infection at peak parasitaemia level of ~108 trypanosomes/ml at doses of 100, 200 and 400 mg/kg by intraperitoneal injection once daily for 7 days. Parasitaemia, packed cell volume (PCV), mean survival time and change in body weight were used as indices for monitoring the efficacy of the extracts by comparing with the positive control: 28 mg/kg dose of diminazene aceturate and negative control: 2% tween 80 treated groups. The extracts had a lethal dose greater than 2000 mg/kg and there were no evidences of acute toxicity at the doses tested. Highly significant (p<0.001) reduction in pre-treatment parasitaemia by 3.91% (7.38 ± 0.18), increase in PCV by 1.12% (48.66 ± 0.20), body weight improvement by 1.36% (22.34 ± 0.27) and mean survival time of 39.20 ± 0.37 days was observed in the group treated by 400 mg/kg methanol leaf extract of C. abyssinica. In general, the results obtained suggest ethno-pharmacological usefulness of the plant and necessitate further studies to be carried on isolated active substances from the plant.