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Natural products play an important role in the discovery and development of new pharmaceuticals. In the present study, we assessed the anthelmintic properties of medicinal plants used in Cote d'Ivoire. Ethanolic extracts from 50 medicinal plants were tested in vitro against trematodes (Echinostoma caproni, Schistosoma mansoni) and nematodes (Ancylostoma ceylanicum, Heligmosomoides bakeri, Trichuris muris). Active extracts were evaluated for their cytotoxicity and followed up in vivo in mice harbouring adult S. mansoni, E. caproni and T. muris at single oral doses of 400 or 800 mg/kg. All extracts tested were active against at least one helminths species. Ten of the 65 extracts tested (15.4%) in vitro revealed activity against all helminths tested. Of 65 extracts tested in vitro at a concentration of 2 mg/ml, all caused death of schistosomula and 34.4% and 39.1% were lethal against adult S. mansoni and E. caproni 72 h post-incubation, respectively. The highest activity against A. ceylanicum in vitro was observed with Sclerocarya birrea at 2 mg/ml, which resulted in death of adult worms and inhibition of activity of third-stage larvae (L3). Of the extracts, 41.5% completely inhibited movement of H. bakeri L3 at minimal lethal concentration (MLC) values of 20-200 μg/ml 48 h post-incubation, and 15.4% paralysed adult H. bakeri at 200 μg/ml 72 h after incubation. Of the extracts, 19% resulted in death of adult T. muris at MLC values of 10-100 μg/ml. In vivo, none of the extracts tested revealed activity against E. caproni. Olax subscorpioidea achieved total and female worm burden reductions of 60% and 84%, respectively in S. mansoni-infected mice. Combretum mucronatum was the most active extracts in vivo against T. muris with a worm burden reduction of 85.3%. In conclusion, several of the medicinal plants used in Côte d'Ivoire are active against different helminths, hence might play a role in the treatment of helminthiases. Further studies are necessary to isolate the active components from these extracts.

Based on the results of ethnomedical and ethnoveterinary surveys that we had carried out in northern Côte d'Ivoire during 1999-2001, 79 plant species belonging to 36 families were selected for in vitro anthelmintic screening. The activity of ethanol crude extracts was investigated using the nematode Haemonchus contortus Rudolphi (1803) as the test species. Of 115 extracts tested, 50 showed larvicidal activity and two were ovicidal. The most active came from Sclerocarya birrea (A. Rich) Hochst followed by Lannea kerstingii Engl. & K. Krause, Aframomum alboviolaceum (Ridely) K. Schum., Pericopsis laxiflora (Benth) van Meeuwen, Pseudocedrela kotschyi (Schweinf.) Harms, Securidaca longepedunculata Fres., Alchornea cordifolia (Schum. & Thonn.) Mü ll. Arg., Anthostema senegalense A. Juss, Ficus vallis-choudae Del., Ampelocissus grantii (Lour) Merrill, Vitellaria paradoxa C. F. Gaertn, and Hibiscus asper Hook f. The results supported the traditional uses of some of the tested plants in the treatment of intestinal helminthosis. As Haemonchus contortus is a pathogenic nematode in small ruminants, the active plant species could be a potential source of new lead anthelmintic agents.

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The genus Erythrina comprises more than 100 species, widely distributed in tropical and subtropical areas. In Africa, 31 wild species and 14 cultivated species have been described. In sub-Saharan Africa, Erythrina species are used to treat frequent parasitic and microbial diseases, inflammation, cancer, wounds. The rationale of these traditional uses in African traditional medicine was established by screening several species for biological activities. Promising activities were found against bacteria, parasites (Plasmodium), human and phytopathogenic fungi, some of which were multidrug resistant (MDR) micro organisms. Some species also exhibited antioxidant, anti-inflammatory activities and enzymes inhibitory properties. Most of the species chemically investigated were reported to contain flavanones, prenylated isoflavones, isoflavanones and pterocarpans. Some phytochemicals (vogelin B, vogelin C, isowightcone, abyssinin II, derrone) were the active principles as antibacterials, antifungals, antiplasmodials and inhibitors of enzyme borne diseases (PTP1B, HIV protease, DGAT). This review highlights the important role of Erythrina species as sources of lead compounds or new class of phytotherapeutic agents for fighting against major public health (MDR infections, cancer, diabetes, obesity) in sub-Saharan Africa.

The identification of new anthelmintic drugs becomes a priority because of the availability of a handful of drugs, cost of treatments, and recent emergence of drug resistance. Medicinal plants are a good source of bioactive compounds for development of drugs. In this study, in vivo efficacy of Anogeissus leiocarpus was assessed in sheep naturally infected with gastrointestinal nematodes. Fecal examination, serological analyses, and necropsy were carried out to determine the egg and worm-burden reduction. The administration of ethanolic extract (single oral dose of 80 mg/kg) of A. leiocarpus induced a moderate fecal egg reduction (81 %) and adult worm-burden reduction (87 %) against Haemonchus contortus and Trichostrongylus colubriformis (82 %). The plant exhibited high efficacy against adult Strongyloïdes papillosus (100 %), Gaigeria pachyscelis (90 %), Cooperia curticei (100 %), and Oesophagostomum columbianum (95 %) but low efficacy against Trichostrongylus axei (67 %) and Trichuris globulosa (79 %). All these helminthes were sensitive to fenbendazole, except O. columbianum which showed a decrease susceptibility (17 %). The plant extract also improved certain biological parameters by increasing bodyweight from 0.7 ± 2.9 to 3.3 ± 1.9 % and improving hematocrit of 6.9 ± 1.6 % 3-week posttreatment. It emerges from the results that the plant possesses significant effectiveness on diarrhea; all treated animals gave normal feces. This study has shown that A. leiocarpus could find an application in the control of multiparasitism in small ruminants.

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