In vivo efficacy and toxicity studies on Erythrina senegalensis and Khaya ivoriensis used as herbal remedies for malaria prevention in Cameroon

Aim: The study aimed at assessing the in vivo anti-plasmodial activity of aqueous extracts from Erythrina senegalensis and Khaya ivorensis, two plants used traditionally as bark decoctions in Cameroon to prevent and cure malaria. Methodology: The antiplasmodial activity of aqueous extracts of E. senegalensis and K. ivorensis was investigated using a murine malaria model (Plasmodium berghei / Anopheles stephensi / BALB/c mice), applying a protocol for assessing the prophylactic potential of the remedy. Treatments were administered orally to BALB/c mice for 9 days at doses of 200 and 400 mg/kg/day. Mice were challenged on day 3 of treatment by exposure to P. berghei infected mosquitoes. The impact on parasitaemia was assessed on thin blood smears prepared on day 7 after exposure to infective bites. The acute toxicity of the plant extracts was tested according to the guidelines of the Organization for Economic Co-operation and Development (OECD guidelines 423). Results: The plant extracts showed antiplasmodial activity, reducing parasitaemia by 40.4% to 56.3%, according to the extract. In particular, a combination of the two extracts at the dose of 100 mg/kg each provided a reduction of parasitaemia in treated mice by more than 50%, as compared to controls. The extract of E. senegalensis when used alone at 200 mg/kg/day reduced the parasitaemia by 40.3% +/- 7.2%, doubling the dosage increased parasite suppression to 56.3% +/- 5.1%. Toxicity studies yielded comforting results: up to a dosage of 2000 mg/kg no mortality occurred in treated mice. Also, animals treated during the antiplasmodial experiments did not reveal signs of toxicity and remained in good conditions up to the end of the experiments. Conclusion: The results suggest that the combination of E. senegalensis and K. ivorensis could be a valid plant combination for the preparation of a standardized, effective and affordable remedy against malaria, in particular for Cameroonian communities with limited access to modern drugs

Une analyse interdisciplinaire des vulnérabilités socioenvironnementales : le cas de falaises côtières urbanisées en Méditerranée

Cet article présente une recherche interdisciplinaire associant sociologie et géologie. L'analyse porte sur la vulnérabilité urbaine vis-à-vis de l'érosion des falaises côtières. Le terrain d'étude est la commune de Carry-le-Rouet dont le littoral est constitué de falaises calcaires associées parfois à de la calcarénite, en alternance avec des niveaux sableux et argileux moins consolidés, d'une hauteur maximale de 40 m. L'analyse révèle que certains des quartiers les plus luxueux de la commune sont les plus exposés au risque d'érosion, échappant au « classique » cumul des vulnérabilités sociales et environnementales. Les riverains n'ignorent pas le risque, mais, attachés à une culture anthropocentrée et techniciste, ils occultent leur trajectoire de vulnérabilité. En outre, la capacité d'action de ces populations aisées leur permet de capter à leur profit les bénéfices de la solidarité territoriale, par l'obtention de travaux de renforcement financés par la puissance publique, tout en revendiquant un entre-soi socialement et ethniquement sélectif

Khaya ivorensis - Alstonia booney, potential resource for the development of a standardized antimalarial plant remedy in Cameroon

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Hydroethanolic Extracts of Erigeron floribundus and Azadirachta indica Reduced Plasmodium berghei Parasitemia in Balb/c Mice

Malaria is one of the most important infectious diseases in Africa especially in Cameroon. The nonaccessibility to current treatments for poor people and the appearance of drug-resistant Plasmodium falciparum parasites stimulate the search for alternative treatments. The aim of this study was to evaluate the antimalarial activity and the safety of hydroethanolic extracts from Erigeron floribundus and Azadirachta indica. The crude hydroethanolic extracts of E. floribundus (HEEF) and A. indica (HEAI) were prepared via maceration of the whole plant powder of E. floribundus and the leaves of A. indica in 70% ethanol. The antimalarial activity was determined according to Peter’s 4-day suppressive test using the murine model Plasmodium berghei/Balb C mice, while the acute and subacute toxicity tests were assessed according to the OECD 425 and 407 guidelines, respectively. The results indicate a reduction of parasitemia ranging from 49.75 ± 3.64 to 69.28 ± 1.36% for HEAI and from 30.46 ± 4.30 to 62.36 ± 2.32% for HEEI. Overall, HEEF and HEAI at doses of 60, 120, and 240 mg/kg b.w. and 75, 150, and 300 mg/kg b.w., respectively, showed a significant (p≤0.001) parasitemia reduction on P. berghei infecting BALB/c mice. HEEF and HEAI caused a significant (p<0.001) attenuation of body temperature drop in mice compared to negative control, except for the 150 mg/kg b.w. dose in the female group. Moreover, there was no mice mortality observed with these extracts even at 5000 mg/kg, while the aspartate amino transferase (ASAT) level of mice treated with 300 mg/kg b.w. of HEAI extract increased when compared with the control. The results of this study support the traditional use of these plants species extracts against malaria infection in rural zones of Northern Cameroon, therefore confirming their potential as sources for the development of efficient phytomedicines for malaria-poverty disease alleviation

Antimalarial plant remedies from Burkina Faso: Their potential for prophylactic use.

Ethnopharmacological relevance: Saye, a combination remedy prepared from Cochlospermum planchonii Hook.f. (Cochlospermaceae), Cassia alata L. (Fabaceae) and Phyllanthus amarus Schumach. et Thonn. (Euphorbiaceae), N’Dribala, a Cochlospermum planchonii root decoction, and a fruit preparation of Azadirachta indica A. Juss. (Meliaceae) are plant remedies of the folk medicine in Burkina Faso and are commonly used by traditional healers for the treatment of malaria. Aim of the study: This study aimed at validating the antiplasmodial activity of the preparations and at estimating their potential for prophylaxis, using the murine malaria system Plasmodium berghei/Anopheles stephensi. Materials and methods: Aqueous extracts were orally administered to mice (6 animals per treatment group) at a daily dose of 200 mg/kg body weight for nine days, applying protocols that mimic as much as possible traditional recipes and treatment schemes. Results: Saye, N’Dribala and Azadirachta indica preparations revealed prophylactic activity, reducing parasitaemia in treated mice, with respect to controls, by 52.0% (CI95 46.1–57.9), 45.5% (CI95 44.5–46.5) and 45.0% (CI95 41.1–48.9), respectively. No evidence of transmission blocking effects was detected with any of the tested remedies. Conclusions: This study confirms, in the murine malaria system, the antiplasmodial properties of the examined remedies on the Plasmodium stages developing in the vertebrate host, thus encouraging studies aiming at identifying the active fractions and compounds responsible for the described activity and to develop standardized prophylactic remedies

Khaya ivorensis - Alstonia boonei, potential resource for the development of a standardized, antimalarial plant remedy in Cameroon

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Antimalarial plant remedies from Burkina Faso: Their potential for prophylactic use

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Potential of a Khaya ivorensis - Alstonia boonei extract combination as antimalarial prophylactic remedy

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