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.

Peltophorum pterocarpum (family; Fabaceae) is an evergreen perennial crop grown in tropical gardens. Different parts of this tree are being used for the management of many diseases. This study investigated the acute toxicity, analgesic and anti-inflammatory potentials of n-hexane extract of P. pterocarpum stem bark. Acute oral toxicity of n-hexane extract of P. pterocarpum stem bark was investigated using standard method. Analgesic activity was investigated by using acetic acid-induced writhing model, using indomethacin as a reference drug. Antiinflammatory activity of n-hexane extract of P. pterocarpum stem bark was investigated by using formalin-induced paw licking model, using aspirin as standard drug. In the acute toxicity study, mortality was observed at 500 and 2500 mg/kg body weight. In the acetic acid induced writhing test, the n-hexane extract of P. pterocarpum (100 and 200 mg/kg body weight) showed a significant reduction in the number of writhing with 55.5 % and 60 % of inhibition respectively. In formalin-induced rat paw oedema test for acute inflammation, the n-hexane extract of P. pterocarpum in 50, 100 and 200 mg/kg body weight showed 26.00 %, 27.89 % and 32.27 % inhibition of oedema respectively after 4hours, which is comparable to that of standard drug-aspirin (33.59 %). These results validated that the extract of P. pterocarpum possesses significant analgesic and anti-inflammatory properties.

Malaria afflicts millions of people globally, particularly in tropical Africa; it is transmitted to humans through a bite of an Anopheles mosquito. Phytochemical, acute toxicity and in-vivo antiplasmodial activity of the leaves of Ageratum conyzoides were examined to study its effects on Mice that have been infected with the malaria parasite. Phytochemical screening of the methanol extract revealed the presence of secondary metabolites such as terpenoids, flavonoids, alkaloids, steroids and chromene. The LD50 was established at ˃ 1000 mg/kg body weight of mice. The methanol extract of A. conyzoides displayed intrinsic prophylactic and curative anti-malaria activity. At 200 mg/kg and 100 mg/kg body weight of mice, the extract revealed the highest percentage inhibition (83 and 61) for the prophylactic and curative study respectively. The acute toxicity study showed that A. conyzoides extract is relatively safe within the study administered doses. The methanol extract of the prophylactic study against Plasmodium berghei revealed an increase in the level of significance at administered portions of 100, 200 and 400 mg/kg in comparison with 0.2 ml distilled water and 10 mg/kg chloroquine. The methanol extract of the therapeutic study against Plasmodium berghei revealed a slight increase in the level of significance at administered doses of 100 and 200 mg/kg, however, no significant effect was observed for 400 mg/kg compared to the negative control and reference drug. The outcome implies that methanol leave extract of A. conyzoides possesses meaningful antiplasmodial activities and could be a promising source of novel antimalarial.Keywords: Malaria, Ageratum conyzoides, phytochemical screening, acute toxicity, Plasmodium berghei

Malaria is responsible for about a million deaths yearly. The fight against malaria is faced with the occurrence of widespread resistance of the malaria parasite, Plasmodium spp. The search for plant derived anti-malarial drugs has become greatly imperative. This study was aimed to isolate and investigate the In vivo anti-malarial activity of pulcherrimin A isolated from the stem bark of Caesalpinia pulcherrima. Ethyl acetate fraction of the stem bark extract was subjected to fractionation over silica gel column to obtain pure compound which was characterized as 3,5,6,7tetrahydroxy-19-vouacanoic acid;(3β,5α,6β,7β)-form,6,7-dibenzoyl (pulcherrimin A) a known compound using various spectroscopic techniques. Pulcherrimin A was evaluated for In vivo anti-malarial activity against P. berghe infected mice using the 4-day suppressive test. Different doses (50, 200 and 400 mg/kg/day) of pulcherrimin A were administered to the mice after parasite inoculation. A maximum parasitaemia suppression of 68.18% was observed for the middle dose (200 mg/kg/day) in contrast with 40.91% for the highest dose (400 mg/kg/day). The study therefore revealed that pulcherrimin A isolated from the stem bark of C. pulcherrima exhibited moderate-dose significant (p<0.05) inhibition of P. berghei parasite, thus authenticating the local usage of different parts of the plants in the treatment of malaria and other pyrexia-related infections.