ABSTRACT
BACKGROUND: One of the most dangerous Plasmodium species is Plasmodium falciparum. Hence, it causes a higher rate of mortality. The resistance of Plasmodium falciparum to the ACT (Artemisinin-based Combination Therapies) has led to the search for new antimalarial drugs. The purpose of this research was to assess the in vivo antiplasmodial activity of Entandrophragma cylindricum ethyl acetate extract to provide a scientific basis for the use of this medicinal plant to treat malaria. METHODS: Entandrophragma cylindricum stem bark powder was macerated in ethyl acetate to obtain the extract. The extract liquid filtrate was concentrated, evaporated and dry using a Rotavapor. The Peter and Rane test were used for the suppressive and curative antiplasmodial activities at different doses (125, 250 and 500 mg/kg). A positive and negative control groups were administered chloroquine (5 mg/kg) and 10% hypromelose, respectively. To assess the parasitemia of the mice a thin blood smear was made. RESULTS: The ethyl acetate extract completely (100%) inhibited the development of P. berghei in the suppressive test at the dose of 500 mg/kg while that of the curative test was inhibited at 95%. The extract-treated group (500 mg/kg) and (Chloroquine (5 mg/kg) group all survived. The negative control group recorded a 100% mortality rate. CONCLUSION: The present study provides scientific confirmation on the use of E. cylindricum stem bark as an antiplasmodial remedy. However, the identification of the mode of action and the purification of the active compounds are necessary for further studies.
ABSTRACT
BACKGROUND: Malaria is one of the most critical diseases causing about 219 million cases worldwide in developing countries. The spread and development of resistance against chemical antimalarial drugs is one of the major problems associated with malaria control. The present study was to investigate the antimalarial efficacy of ethyl acetate extract and one fraction of Bidens pilosa in vivo in order to support the usage of this plant by traditional healers to treat malaria. METHODS: The extracts were prepared by maceration of B. pilosa leaf powder in ethyl acetate. The liquid filtrate of the extract and the best in vitro antiplasmodial fraction using HPLC were concentrated and evaporated using a rotavapor under vacuum to dryness. The antimalarial activity of B. pilosa plant products were evaluated in vivo against Plasmodium berghei infected mice according to the Peter and Rane test. The antimalarial efficacy of the a selected crude extract (ethyl acetate extract) was evaluated at 125, 250, and 500 mg/kg, while a selected fraction from ethyl acetate extract (fraction 12) was evaluated at 62.5 and 125 mg/kg. Blood from experimental animals was collected to assess hematological parameters. RESULTS: The crude extract of ethyl acetate and fraction 12 demonstrated 100% in vivo parasite suppressive activity at doses of 500 mg/kg and 125 mg/kg, respectively, for the crude extract and fraction 12. The mice treated with 250 and 500 mg/kg had their parasitemia (intraerythrocytic phase of P. Berghei) drop considerably, disappearing by the 8th day in mice receiving 500 mg/kg. The ethyl acetate extract of B. pilosa, fraction 12 showed an even higher antiplasmodial activity. By the 5th day of the experiment, the treatment led to a modification of hematological parameters in mice. The chloroquine (5 mg/kg), fraction 12 (125 mg/kg), and the crude extract (500 mg/kg) groups all survived the 30 days of the experiment, while the negative control group registered 100% of the deaths. CONCLUSION: This study scientifically supports the use of Bidens pilosa leaves in the traditional treatment of malaria. However, the mode of action and in vivo toxicity of the plant still need to be assessed.
