Anti-Plasmodial Activity and Elemental Analysis of the Stem Bark Extract of Caesalpinia pulcherrima

The antiplasmodial activity of Caesalpinia pulcherrima (Pride of Barbados), a plant traditionally used in south-western Nigeria for the treatment of malaria, was investigated in the search for new antimalarial agents. Stem bark extracts and fractions were evaluated for in vivo antimalarial activity and elemental composition. Fractionation of the extracts was carried out using vacuum liquid chromatography (VLC), while elemental analysis was conducted using atomic absorption spectrophotometry (AAS). Antimalarial activity was assessed against Plasmodium berghei berghei in albino mice (20–30 g) using the 4-day suppressive test. Methanol–ethyl acetate stem bark extracts administered at doses of 200, 400, and 800 mg/kg produced dose-dependent chemo-suppression. The 200 mg/kg extract showed suppressive activities of 45.32%, 52.67%, 47.90%, and 24.17%; the 400 mg/kg extract showed 57.74%, 56.36%, 51.51%, and 30.35%; while the 800 mg/kg extract exhibited 63.29%, 62.09%, 54.24%, and 39.91%. These effects were lower than those of the standard drug chloroquine (5 mg/kg), which produced suppressive activities of 95.22%, 91.73%, 88.97%, and 86.22%. The results demonstrate that C. pulcherrima stem bark possesses significant antiplasmodial (suppressive) activity, supporting its traditional use in malaria treatment.