Antagonistic effects of some commonly used herbs on the efficacy of Artemisinin derivatives in the treatment of malaria in experimental mice

Abstract

Abstract Background The use of herbs in combination with drugs in treatment of malaria is increasing, and this necessitated research on the possible antagonistic, additive, potentiation or synergistic properties of commonly used plants with standard drugs in treatment of malaria. In this study, extracts of Morindamorindiodes (Mm) root, Morindalucida (ML) leaf and Vernonia amygdalina (Va) leaf were combined with artesunate (Ar) and assessed for anti-malarial activities against established Plasmodium berghei NK65 infection in 45 experimental mice randomly distributed into 9 groups and treated at a graded dose of 100 mg/kg for the herbs and herbs–drugs combination, while chloroquine and artesunate was administered at 10 mg/kg Results At the end the sixth day, Mm root extract, ML and Va leaf extract reduced parasitaemia by 86.83%, 84.20% and 48.10%, respectively (p < 0.05). A total parasite clearance (100% chemosuppression) was observed in the group treated with artesunate and chloroquine. However, the combination of each extracts of M. lucida, M. morindiodes and V. amygdalina with artesunate significantly reduced the chemosuppression to 89.93%, 89.43% and 86.93%, respectively. Conclusion This study showed that though the extracts of Morinda morindiodes and Morinda lucida possess convincing antiplasmodial effect when administered singly, the combination of these extracts with artesunate could not produce total parasite clearance. There is need to enlighten the public on the possible setback associated with combined use of antimalarial plants with antimalaria drugs.