Abstract

Malaria is a parasitic disease that is currently considered a major public health problem. The parasite responsible, Plasmodium falciparum, is increasingly resistant to current anti-malarial drugs. The objective of this study was to assess the in vitro anti-plasmodial potential of Scoparia dulcis Linn (Scrophulariaceae), a plant traditionally used to treat malaria in Niger. Organic and aqueous extracts were prepared from the leafy stems of S. dulcis Linn. Dichloromethane, methanol, and hydro-methanol were used for organic extraction, while an alkaloid extract was prepared through a specific extraction method. Aqueous extracts were prepared by boiling water. Chemical characterization was performed using tube assays and Thin Layer Chromatography (TLC). The in vitro anti-plasmodial activity of the extracts was assessed using the Lactate Dehydrogenase (p-LDH) technique on chloroquine-resistant K1 and chloroquine-sensitive 3D7 strains of P. falciparum. Phytochemical screening revealed the presence of various chemical groups, including flavonoids, sterols, triterpenes, sterol glycosides, saponins, coumarins, tannins, anthraquinones, carotenoids, and reducing compounds. The alkaloid extracts demonstrated significant antiplasmodial activity, with an inhibitory concentration 50 (IC50) of 1.58 µg/ml for 3D7 strains and 2.69 µg/ml for K1 strains. The dichloromethane extract showed IC50 values of 2.11 µg/ml for 3D7 and 2.23 µg/ml for K1. Methanol, aqueous, and hydro-methanol extracts were less active. S. dulcis shows potential as a candidate in the fight against malaria due to its rich phytochemical composition and anti-plasmodial activity.

Key words: Antiplasmodial activity, Plasmodium falciparum, Scoparia dulcis, Niger.