THERAPEUTIC ANTITRYPANOSOMAL ACTIVITY OF ALCHORNEA LAXIFLORA LEAVES EXTRACT IN RATS EXPERIMENTALLY INFECTED WITH TRYPANOSOMA BRUCEI BRUCEI.

Catherine O. Durojaye* and Innocent B. Osho

ABSTRACT

African trypanosomoses has been estimated to render 50 million people and 48 million cattle at risk leading to low productivity and death. The disease is responsible for major health and economic problems in rural sub-Saharan Africa. Caused mainly by extracellular protozoa of the genus, Trypanosoma with specie such as Trypanosoma brucei brucei. This study was carried out to evaluate the antitrypanosomal activities of Alchornea laxiflora leaf extracts in rats experimentally infected with Trypanosoma brucei brucei. Invitro antitrypanosomal analysis was carried out at varied concentrations of 2.5mg/ml, 5mg/ml and 10mg/ml with five different solvent extracts (ethanolic, ethyl acetate, n-hexane, chloroform and aqueous) using diminazine aceturate and normal saline as positive and negative controls respectively. The invivo assay was carried out by intraperitoneal administration of ethyl acetate and chloroform extracts of the plant at graded doses of 200, 400 and 600 mg/kg for three consecutive days. The chloroform, n-hexane and ethyl acetate extracts yielded high percentage DPPH free radical scavenging activity of 86.03, 84. 16 and 76.10 respectively. All extracts tested invitro showed decrease in motility of the parasites at different times. The responses were concentration dependent positively. Complete cessation of motility was recorded at 35 and 45 minutes at 10mg/ml concentration of chloroform and ethyl acetate extracts respectively. Two extracts (ethyl acetate and chloroform extracts) showed the best invitro responses and were subjected to invivo analysis. Both extracts caused decrease in trypanosome parasitemia and prolongation of mean survival days of the rats to 15days as compared with 7days in the negative control group. The extracts displayed dose-dependent significant (p ≤ 0.05) antitrypanosomal activity as compared to the control. The antitrypanosomal values obtained in this study show that the tested leaf extracts of Alchornea laxiflora might be a good alternative drug for the treatment of trypanosomoses in Nigeria. Further fractionation, purification and isolation should be done to confirm the active components in Alchornea laxiflora leaves responsible for the antitrypanosomal activities recorded.

Keywords: Alchornea laxiflora, antitrypanosomal activities, Trypanosoma brucei brucei,