The leaf of Theobroma cacao L. is used in traditional medicine in Ghana for the treatment of malaria, yet, with no scientific evidence of its antimalarial property in animals. It was, therefore, studied to validate the antimalarial property in Plasmodium berghei-infected mice. Infected mice were treated with an aqueous extract of T. cacao leaf at different doses of 100, 200, and 400mg/kg daily for four days. Parasitaemia was determined before treatment and 24 hours following the last dose of extract. The reduction in parasitaemia and ED₅₀ and ED₉₀ of the extract were determined. Body weight, rectal temperature, and daily mortality of mice were also recorded. The extract had ED₅₀ and ED₉₀ of 242.2029.38 and 351.0029.52mg/kg/day, respectively. Percentage parasitaemia suppression was significant for all doses. The extract at the maximum dose of 400mg/kg body weight had the highest parasitaemia suppression of 79.19; mean survival time of 24.002.19 days and median survival of 23 days; body weight increase of 3.820.59; and the lowest body temperature reduction of 0.790.11C. T. cacao leaf extract showed an antimalarial property in P. berghei-infected mice. This reinforces the justification for the use of the plant material in treating malaria in Ghana.

Malaria is a public health challenge that requires prompt treatment for those infected to make a full recovery. Treatment of malaria infection is to be started as soon as a diagnosis is confirmed. Antimalarial medications are administered to prevent and also to treat malaria. The type of medication used and the duration of therapy is dependent on the type of malaria-causing plasmodium species, the severity of the symptoms, geographical area where malaria infection occurred and the medication used to prevent malaria and whether there is pregnancy. Treatment of malaria from public health perspective is to reduce transmission of the infection to others, by reducing the infectious reservoir and to prevent the emergence and spread of resistance to antimalarial medicines. Medications used in the treatment of malaria infection come from the following five groups of chemical compounds: quinolines and aryl amino alcohols, antifolate, artemisinin derivatives, hydroxynaphthoquinones and antibacterial agents. The treatment of malaria is not initiated until the diagnosis has been established through laboratory testing. Artemisinin-based Combination Therapy (ACTs) has been used for the treatment of uncomplicated malaria. ACTs are also to enhance treatment and protect against the development of drug resistance. IV artesunate is used in the treatment of severe malaria, regardless of infecting species.

Justiciaflava (Acanthaceae) is utilized in folk medicine for treating malaria, inflammatory conditions, and respiratory infections. In this study, the antiplasmodial and anti-inflammatory activities of the 70% hydroalcoholic leaf extract of J. flava (JFE) were investigated. The antiplasmodial activity was assessed by the suppressive test and Rane’s curative test. The carrageenan-induced paw oedema assay in chicks was used to assess the anti-inflammatory activity. In Rane’s curative test, JFE significantly suppressed the parasitaemia level ( < 0.0001) by 56.85%, 63.85%, and 77.85% at 30, 100, and 300 mg·kg⁻¹, respectively. The highest suppression of parasitaemia in the suppressive test was 51.31% at 300 mg·kg⁻¹. The extract prolonged the survival time of infected mice significantly and prevented weight loss and hypothermia which are cardinal signs of P. berghei-induced infection. JFE inhibited foot oedema in chicks with a maximum percentage inhibition of 54.00 ± 5.20%. Pharmacognostic characterization of J. flava revealed it to have simple, petiolate, oppositely arranged leaves which are broadly lanceolate in shape with entire to slightly crenate margins. Microscopy of the leaf showed wavy-walled epidermal cells, diallelocytic stomata, abundant clothing and secretory trichomes, pitted vessels, collateral conjoint vascular bundles, cystoliths, and prismatic calcium oxalate crystals. Flavonoids, tannins, phytosterols, triterpenoids, coumarins, alkaloids, and saponins were detected in the plant. This study has provided important parameters for the correct identification of J. flava and given the scientific credence to its antimalarial and anti-inflammatory effects in traditional medicine. J. flava is a potential source of new antimalarial and anti-inflammatory compounds.

Malaria is an acute infection caused by the Plasmodium parasites, namely, P. falciparum, P. ovale., P. vivax, P. malariae, and P. knowlesii, in humans. The disease is spread through the bite of a mosquito carrying the parasite, which typically bites at night and lives at elevations lower than 1500 meters. Symptoms of the disease include fever, general body weakness and pains, headache, shivering, and vomiting among others which start manifesting about 6–9 days after a mosquito carrying the parasite bites a person. Africa, Eastern Europe, Asia, Central and South America, and the South Pacific are among the regions where malaria is transmitted. There has not been any malaria in Europe since 2015. The strategies used for malaria control include vector (mosquito) control, the use of insecticide treated nets, indoor residual spraying, and the use of antimalarial drugs and vaccines among others. The screening of potential antimalarial drugs usually employs in vitro and in vivo assays which evaluates the levels of parasitaemia following infection and drug treatment. The in vitro assays include Schizont counting on thick films, DNA dye intercalation assays, isotopic assays, and quantification of parasite proteins. The in vivo assays include the Peter’s four-day suppressive and Rane’s curative assays.

Objective: This study aimed to evaluate the antimalarial activity of the extracts and isolated compounds from the stem of Phragmanthera capitata . Methods: Aqueous and methanol extracts were prepared from the stem of the plant. The methanol extract was purified via column chromatography to yield friedelin, friedelinol, β-sitosterol and daucosterol. The in vitro anti-plasmodial activity of the extracts and isolated compounds was evaluated against chloroquine-sensitive (3D7) and resistant (Dd2) strains of P. falciparum using the SYBR Green assay and, in vivo antimalarial activity via the Peters’ and Rane’s tests. Results: The methanol extract demonstrated superior activity over the aqueous extract, with IC ₅₀ values of 0.84 (3D7) and 1.92 µg/mL (Dd2) in the in vitro antiplasmodial assay. Similarly, daucosterol was the most active compound among the isolated compounds with IC ₅₀ values of 0.84 (3D7) and 2.05 μg/mL (Dd2). The aqueous and the methanol extracts showed comparable suppressive activities in the Peters’ assay with 88% and 89% parasitaemia suppression, respectively. The aqueous extract was more active in the Rane’s curative assay, with 89 % parasitaemia suppression. Friedelin and β-sitosterol displayed similar and remarkable curative potential in the Rane’s assay with % parasitaemia suppression of 85.66 and 86.49, respectively. Conclusion: This study validates the Phragmanthera capitata extracts and isolated compounds as antimalarial agents, rationalising the traditional use of the plant to treat malaria. Future work could consider development into antimalarial products, which would contribute to SDG 3 and the Universal Health coverage.