ABSTRACT
Background:Malaria is one of the most important infectious diseases in Nigeria and in Africa at large as everyone is at risk of the infection. Objectives: This study was carried out to evaluate the antiplasmodial activity of Alchornea laxiflora leaf extracts against Plasmodium berghei infected mice. Materials and Methods:In vivoantimalarial assay on chloroquine-sensitive P. berghei-infected mice was carried out by oral administration of graded doses (200mg/kg, 400mg/kg and 600mg/kg) of methanolic and chloroform extracts using chloroquine and distilled water as positive and negative control respectively. Prophylactic potential in residual infection and curative assay against established infectionwere tested in P. berghei-infected mice. The assay was performed using 4-day suppressive standard test. Results:The prophylactic efficacy of methanolic and chloroform leaf extacts showed percentage chemosuppression of 72.37% and 66.32% respectively at oral dose of 600mg/kg. The methanol leaf extract of A. laxifloradisplayed the highest curative activity of percentage chemosuppression of 98.36% at oral dose of 600mg/kg. The extracts displayed dose-dependent significant (p ≤ 0.05 antiplasmodial activity as compared to the control. Haematological analysis revealed an increase in packed cell volume, red blood cell, haemoglobin and white blood cell counts on dose-dependent manner in the treated mice compared to the negative control mice. Conclusion:The high suppressive values obtained in this study show that the tested leaf extracts of Alchornea laxiflora might be a good alternative drug for the treatment of malaria infection in Nigeria.