Effect of Senna occidentalis (Fabaceae) leaves extract on the formation of β-hematin and evaluation of in vitro antimalarial activity

Abstract

The search for antimalarials from plant sources has yield significant success in drug discovery approaches. The heme polymerization inhibitory activity as well as the antimalarial activity of Senna occidentalis, a local medicinal plant used for malaria therapy in Hausa folk medicine in Northern Nigeria was evaluated in in vitro assays. Results obtained revealed a good inhibition of 𝛽-hematin formation (83.08% and 83.97%) by the methanolic and aqueous leaves extracts of S. occidentalis at 500µg/mL as against the 54.92% inhibition exhibited by hexane extract at the same concentration. Findings of the in vitro antimalarial studies revealed a dose dependent suppression of plasmodium growth. At a concentration of 6.25 µg/ml, 73% suppression of parasite growth was observed for the hexane extract. This suppression of plasmodial growth attains 84.43% at 50 µg/ml with an IC50 of 3.47 µg/ml. Secondary metabolites such as anthraquinones, phenols, tannins, alkaloids and flavonoids were detected in S. occidentalis. This could be a responsible for the antimalarial activities observed.