Anti-trypanosomal activity of the methanolic leaf extract of Pseudocedrela kotschyi (dry zone cedar) in mice infected with Trypanosoma brucei brucei

Abstract

Trypanosomiasis is a fatal disease placing both human and livestock at risk of infection if not treated. The aim of this study is to assess the effectiveness of Pseudocedrela kotschyi in the treatment of trypanosomiasis. This research work was carried out in the Animal House unit, University of Jos. Dry zone cedar (Pseudocedrela kotschyi) family: meliaceae, leaf powder was extracted using methanol, and the yield was 18.25 g (6.08%). A total of 32 mice used for the study were divided into 8 groups of 4 animals each. They were inoculated with 0.2 ml of the inoculums containing 1.2 x10⁷ trypanosome. The mice were treated daily with 0.2 ml dose of the extract and standard drug (Diminazene aceturate) and normal saline for 4 consecutive days. Mice in group one was not treated, groups two to four were treated with plant extract, Diminazene aceturate and extract/D. aceturate respectively 72 hours after innoculation, groups five and six were treated after two hours with extract and D. aceturate respectively, while group seven and eight were administered the extract and D. aceturate respectively and then inoculated after 72 hours. Thin Blood films were prepared and examined and the percentage parasitaemia were evaluated. The acute toxicity test indicated that the crude leaf extract caused no mortality in all the three doses (500 mg/kg, 1,000 mg/ kg and 1,500 mg/kg) tested within the 24 hours. Animals in group two had the highest mean parasitaemia of 40 followed by animals in group one and four which had 38.6 and 38 respectively. There was reduction in mean parasitaemia of mice in group five and seven with mean of 35 and 29 respectively. However reduction in mean parasitaemia was recorded progressively in those of Groups of 3, 6 and 8 tending towards zero parasitaemia. There is a significant difference (p<0.05) in parasitaemia within the groups. This study showed that the methanolic leaf extracts reduced trypanosomal load, with some animals lived longer than the control group. Therefore the plant should be explored for treatment of trypanosomiasis.

Keywords: Trypanosomiasis; mice; methanol leaf extract; Pseudocedrela kotschyi.