Abstract:
Traditional herbal medicines are potentially rich sources of new drugs against malaria and other infectious diseases. However, phytochemicals extracted from a medicinal plant is strongly dependent on the nature of the extracting solvent. This study therefore aimed to investigate the antimalarial activity of three plants traditionally used to treat malaria using solvents of different polarities as solvents of extraction. The leaves of Lawsonia inermis, Tithonia diversifolia, and stem barks of Nauclea latifolia were extracted with water, n-hexane, ethanol and dichloromethane: methanol (1:1). The extracts were thereafter investigated for their antiplasmodial activity against Plasmodium berghei in infected mice using Peter’s 4-days suppressive test. In N. latifolia stem bark, the aqueous extract showed the highest percentage chemosuppression (79.04%) followed by the dichloromethane: methanol (1:1), ethanolic and hexane extracts with percentage chemosuppressions of 74.66%, 61.47% and 8.81% respectively. The dichloromethane: methanol (1:1) extract of T. diversifolia leaves exhibited moderate antiplasmodial activity with percentage chemosuppression of 43.90% while its other extracts showed weak activity. Only dichloromethane: methanol (1:1) extract of L. inermis showed good antiplasmodial activity with percentage chemosuppression of 61.57% while the other extracts had between weak to inactivity. The antimalarial activity exhibited by these plants, most especially N. latifolia and L. inermis, against P. berghei suggests that these plants have active principles against malarial as claimed by the folklore, and further work is necessary to isolate, identify and characterize the active components of the plants.
