Antiplasmodial activity and toxicity of the leaves, stem and roots of Parinari robusta Oliv [CHRYSOBALANACEAE] in animal model

Abstract

Malaria continues to wreak havoc on various populations as a result of the mortality and economic burden associated with the disease. Progress made in the therapeutics of the disease is threatened by the emerging parasite resistance to currently used first line treatment drugs. This has prompted the search for new, effective, and safe antimalarial agents. Parinari robusta is one plant in use with inadequate evidence about its efficacy. This study therefore aimed to assess the in vivo and in vitro antimalarial potential, and the safety of the leaves, stem and roots of the plant. Acute toxicity was carried out according to OECD guidelines. In vivo antimalarial activity of the hydroethanolic extracts were assessed using the Peter's 4-day suppressive and Rane's curative tests. In vitro antiplasmodial activity of the hydroethanolic crude extracts were evaluated using the SYBR Green I fluorescence assay on the chloroquine sensitive (3D7) and chloroquine resistant (Dd2) strains of P. falciparum. P. robusta was safe with the lethal dose above 3000 mg/kg. All the extracts significantly (p < 0.001) suppressed parasitaemia in the Peter's suppressive and Rane's curative test in a dose dependent manner. The extracts showed highly to weakly active in vitro antiplasmodial activity with an IC50 between 2.629 μg/ml to 30.320 μg/ml against 3D7 and Dd2 strain of P. falciparum. Leaf and stem extract gave the most superior activity against the Dd2 and 3D7 P. falciparum strains. The findings of this study provide scientific evidence supporting the traditional use of P. robusta in the treatment of malaria.