Background. Terminalia mantaly is used in Cameroon traditional medicine to treat malaria and related symptoms. However, its antiplasmodial efficacy is still to be established. Objectives. The present study is aimed at evaluating the in vitro and in vivo antiplasmodial activity and the oral acute toxicity of the Terminalia mantaly extracts. Materials and Methods. Extracts were prepared from leaves and stem bark of T. mantaly, by maceration in distilled water, methanol, ethanol, dichloromethane (DCM), and hexane. All extracts were initially screened in vitro against the chloroquine-resistant strain W2 of P. falciparum to confirm its in vitro activity, and the most potent one was assessed in malaria mouse model at three concentrations (100, 200, and 400 mg/kg/bw). Biochemical, hematological, and histological parameters were also determined. Results. Overall, 7 extracts showed in vitro antiplasmodial activity with IC50 ranging from 0.809 μg/mL to 5.886 μg/mL. The aqueous extract from the stem bark of T. mantaly (Tmsbw) was the most potent (IC50=0.809 μg/mL) and was further assessed for acute toxicity and efficacy in Plasmodium berghei-infected mice. Tmsbw was safe in mice with a median lethal dose (LD50) higher than 2000 mg/kg of body weight. It also exerted a good antimalarial efficacy in vivo with ED50 of 69.50 mg/kg and had no significant effect on biochemical, hematological, and histological parameters. Conclusion. The results suggest that the stem bark extract of T. mantaly possesses antimalarial activity.

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Ripe figs, barks, and wood of Ficus vallis-choudae are used in traditional medicine against several conditions including nausea and malaria. However, its use is still to be scientifically documented and validated. Hence, the aim of the present work was to evaluate the antiplasmodial activity of the dichloromethane-methanol (DCM-MeOH (1:1)) crude extract, their hexane, dichloromethane, ethyl acetate, and methanoli fractions, as well as the isolated chemical constituents. The chemical study of the DCM-MeOH (1:1) crude extract of F. vallis-choudae figs led to the isolation of fifteen (15) known compounds identified based on their spectroscopic data [one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR), mass spectrometry] and by comparison of these data with those reported in the literature. Some of the isolated compounds were assessed in vitro for their antiplasmodial activity against Plasmodium falciparum chloroquine-sensitive 3D7 ( Pf 3D7) and multidrug-resistant Dd2 strains. The dichloromethane fraction exhibited very good antiplasmodial activity against both strains with IC 50 values of 13.86 μg/mL and 8.18 μg/mL, respectively. Among the tested compounds, wighteone ( 2 ) was the most active against P. falciparum 3D7 (IC 50 = 24.6 ± 1.5 μM) and Dd2 (IC 50 = 11.9 ± 2.4 μM) strains. The obtained results could justify the traditional uses of F. vallis-choudae against malaria. Wighteone appears to be the most active ingredient. However, further consideration of this compound as starting point for antimalarial drug discovery will depend upon its selectivity of action towards Plasmodium parasites. Highlights • 15 (fifteen) compounds were isolated from the dichloromethane-methanol extract of Ficus vallis-choudae. • Their structures were determined on the basis of their spectroscopic data. • The dichloromethane fraction showed promising activities on the Pf 3D7 and Pf Dd2 strains with IC 50 values of 13.86 and 8.18 µg/mL, respectively. • Wighteone was the most active compound against Pf Dd2 (IC 50 = 11.9 ± 2.4 μM). Graphical abstract Supplementary Information The online version contains supplementary material available at 10.1007/s00436-022-07540-5.

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Entandrophragma angolense plant was harvested at Dschang, Menoua Division (West Region, Cameroon) in June 2016. Plant parts such as stem bark were collected and authenticated by Mr Nana Victor, a botanist at the National Herbarium of Cameroon where a voucher specimen of the plant has been deposited under the number 29933/HNC. Experimental animal Eight weeks old female mice Balb/c weighing between 22 to 25 g were used for experimentation. ABSTRACT Background: Research for new antimalarial drugs remains a permanent quest for the control of malaria. Objective: The present study investigates the effects of the aqueous extract of Entandrophragma angolense bark on P. berghei-induced malaria in mice. Methods: Eight weeks old mice, were intraperitoneally infested with 200 μl of blood, containing 1x10 6 P. berghei-infected-erythrocytes. Parasitaemia was determined using a 10% giemsa stained blood smear read under optical microscope (x100). The infected animals were randomized into 5 groups of 10 animals each and daily treated for 5 days with the plant extract at 125, 250 and 500 mg/kg. The normal control and malaria control received water while the chloroquine control was treated with 10 mg/kg of chloroquine. Body weight, parasitaemia and survival time were monitored daily during treatment and follow up periods. Five animals from each group were sacrificed under anaesthesia at the end of treatment (d8) and after the follow up period (d28). Venous blood was used for haematological and biochemical tests. Organs (liver, kidneys and spleen) were also collected for biochemical and histological analyses. Results: Administration of the aqueous extract of E. angolense bark to infected mice significantly inhibited parasite development (p <0.001) with ED 50 estimated at 25.32 mg/kg. The extract prevented animal from death, body weight loss, anaemia, leucocytosis, high transaminases (ALT and AST), high bilirubin, creatinine and MDA levels, oxidative stress and anatomical alteration in organs as compared to the malaria control. Conclusion: The E. angolense bark possesses antimalarial properties, supporting its use in traditional medicine to treat malaria.