Artesunate antagonizes antiplasmodial activity of Vernonia amygdalina methanol leaf extract in murine model of malaria.

Abstract

Context: Malaria is a life-threatening disease in sub-Saharan Africa. Vernonia amygdalina (VAM), a popular Nigeria vegetable is commonly consumed by patients on antimalarial therapy, as a means of curbing resistance posed by Plasmodium species to conventional antimalarial drugs. Objective: This study was designed to evaluate the effect of Artemisinin Combination Based Therapy (ACT), ART/Amodiaquine (A/A) on the antimalarial efficacy of VAM leaf extract. Materials and Methods: Plasmodium berghi infected mice were randomized into six groups as follows; Group 1 (untreated control), group 2 (ART/VAM, 35.14/125 mg/kg), group 3 (ART, 35.14 mg/kg), group 4 (ART/A, 35.14/105 mg/kg), group 5 (VAM, 125 mg/kg) and group 6 (ART/VAM, 2.86/125 mg/kg). Administration lasted for three consecutive days and antiplasmodial activity was assessed using Rane’s curative test. Result: Parasitemia clearance of 98.8 and 52.83% were recorded for VAM (125 mg/kg) and ART (35.14 mg/kg) respectively. However, lower parasitemia clearance of 97.05 and 80.49% were produced by the combinations of VAM/ART (125/2.86 mg/kg) and VAM/ART (125 mg/kg/35.14 mg/kg) respectively when compared to that of VAM, 125 mg/kg. A/A, (35.14/105 mg/kg) produced a parasite clearance of 89.69%. Conclusion: ART produced dose dependent antagonism on the antimalarial efficacy of VAM. Combination of higher dose of ART and VAM should be discouraged, while the combination of low dose of ART and VAM could be encouraged for malaria patients.