Author(s): Abdullahi M Daskum, Chessed Godly, Muhammad A Qadeer and Lau Yee Ling

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.