The increasing rise of resistance of malaria parasites to established antimalarial drugs have necessitated the continued search for new drug entities especially those with fresh modes of action. Caesalpinia pulcherrima is a plant with many pharmacological and medicinal properties. The leaf extract and fractions were studied for their antimalarial, ferric reducing antioxidant power and elemental composition.Various fractions of the leaf extracts were obtained using vacuum liquid chromatography (VLC). The in vivo antimalarial activity was evaluated against plasmodium berghei parasites. The required dose was given according to the weight of the animal two hours after inoculation of parasites on D1, then once daily for three more days (D2-D4). The antioxidant activity was carried out using UV-Visible spectrometer at 593 nm. The elemental analysis was done using Atomic Absorption Spectrophotometer. There was a dose dependent increase in percentage chemo-suppression of the parasites by the different groups with maximum effect at 800 mg/kg (61.57-34.86 % from day five (5)to day eight (8) respectively). The highest FRAP activity was observed in 100% ethyl acetate with 314.90 ± 3.94 mmol, while the lowest antioxidant power was observed in 50% ethyl acetate:50% n-hexane fraction with 48.50 ± 1.10. 90%methanol:10% distilled water fraction did not indicate any FRAP activity. The results obtained revealed that the phytochemicals with very potent antioxidant power are more present in the ethyl acetate fraction. Elemental compositions (ppm) in the powdered leaf of C. pulcherrima were, sodium (Na); 20.27 ± 0.12, iron (Fe); 13.50 ± 0.08, calcium (Ca); 9.0 ± 0.14, and copper (Cu); 0.30 ± 0.08. Lead (Pb) was not detected. This study has shown that Lead concentration was below detectable limit, while the concentrations of Fe and Cu were within established permissible limits. Appreciable amount of Na and Ca were also indicated. C. pulcherrima leaf extract and fractions contain biologically active principles that are relevant antimalarial and antioxidant agents with acceptable mineral compositions.

Oxidative stress has been shown to play an important role in the development of many diseases. Indeed, the increase in total antioxidant status is imperative in the recuperation from these diseases. The antioxidant activity, total phenolic and flavonoid contents of Caesalpinia pulcherrima leaves were determined in this study. The powdered dried leaves of C. pulcherrima were screened for their effect on 2,2-diphenyl-1-picrylhydrazyl radical (DPPH). Total phenolic and flavonoid contents of the extract and fractions were estimated using established methods. Concentrations of the plant extracts required for 50% inhibition of DPPH radical scavenging effect (IC50) were recorded as 3.20, 48.11, 33.12, 9.15, 27.26, 17.90, 272.18 and 55.51μg/ml for Ascorbic acid, 100% n-hexane, 50% n-hexane: 50% ethyl acetate, 100% ethyl acetate, 50% ethyl acetate:50% methanol, 100% methanol, 90% methanol:10% water fractions and crude extract, respectively. Total phenolic and flavonoid contents were highest for 100% ethyl acetate fraction. The leaf extract and fractions of C. pulcherrima exhibited notable radical scavenging activity and therefore corroborate its use as a natural plant antioxidant by preventing free radical damage.