Biodiversite vegetale et dynamique et reconstitution des jacheres post-culturales dans la foret classee d’Irobo (Sikensi, Cote d’Ivoire)

Nous analysons l’impact de l’agriculture traditionnelle sur la capacité de reconstitution dans une forêt dense humide sempervirente non soumise à  des perturbations naturelles majeures. Des relevés de surfaces complétés par des relevés itinérants ont permis d’inventorier 448 espèces, qui se  répartissent en 301 genres et 92 familles, dont les plus importantes étaient les Fabaceae, les Malvaceae, les Apocynaceae, les Euphorbiaceae, les Moraceae, les Rubiaceae, les Meliaceae et les Annonaceae. Parmi ces espèces, 32 (soit 7,14 % de l’effectif total) sont endémiques Ouest africaines et deux (2) d’entre elles sont endémiques ivoiriennes. La classification hiérarchique et l’ordination des 50 relevés de végétation a permis d’identifier cinq (5) groupes s’agençant le long d’un gradient de maturité forestière. Les stades pionniers, très variables, étaient dominés par une espèce  invasive : Chromolaena odorata (L.) R. King & H. Robinson. L’invasion précoce des champs par Chromolaena odorata. ne semble pas altérer  durablement la succession secondaire. Les plantations abandonnées se reconstituent pour atteindre le stade de forêt secondaire, proche de la forêt ancienne La forêt présente donc une bonne résilience. Mots clés : Biodiversité végétale, Successions secondaires, Forêt secondaire, Irobo, Côte d’Ivoire   English title:Plant biodiversity and dynamics of regeneration in tropical rain forest (Irobo, Coted d’Ivoire) This study aims at testing whether shifting cultivation contribute to plant diversity in tropical rain forest. For hundred forty species have been  recorded in Irobo forest (Côte d’Ivoire) during field investigations, distributed among 301 genera and 92 families, the most important being  Fabaceae, Malvaceae, Apocynaceae, Euphorbiaceae, Moraceae, Rubiaceae, Meliaceae and Annonaceae. Among those species, 33 (7.14%) are endemic from West Africa, among which only two are endemic from Côte d’Ivoire. The hierarchical classification of 50 vegetation releves helped to identify 5 groups along a gradient of maturity. Early-successional stages were dominated by the invasive species Chromolaena odorata (L.) R. King & H. Robinson. The early invasion by Chromolaena odorata did not does not appear to alter secondary succession. Species assembled themselves into plant communities along the successional gradient with respect to their light requirements, suggesting niche partitioning. The succession progressively leads to a secondary forest similar to the primary forest. This forest is highly resilient. Key-words: Plant biodiversity, Secondary successions, Secondary forest, Irobo, Côte d’Ivoir

Influence Of Mitragyna ciliate (Myta) On The Microsomal Activity Of ATPase Na+/K+ Dependent Extract On A Rabbit Heart.

Mitragyna ciliate (MYTA) (Rubiaceae) inhibits plasmodia activity. MYTA induces a cardiotonicity of the digitalic type on rat\'s isolated heart. In this work we studied the effect of MYTA on microsomal Na+/K+ - dependant ATPase (Na+, K+ ATPase) extracted from the heart of a rabbit since digitalics inhibit Na+, K+ ATPase. Our results revealed that the Na+/K+ ATPase has an optimum pH of 7.4 and temperature of 37oC respectively. There is a linear relationship between the organic phosphate formed and the incubation time over 25 mins incubation period. The ATP hydrolysis rate in the presence of MYTA was 0.775 μM/min. LINEWEAVER and BURK plots showed that MYTA did not alter KM (1.31 mM) but decreased VMAX. This study shows that MYTA exerts a non-competitive inhibition on the microsomal Na+/K+ ATPase extracted from rabbit heart with a Ci50 of 48 μg / ml. We conclude that the mechanism of action of MYTA is linked to the inhibition of the Na+/K+ ATPase like cardiotonics of the digitalic type. Keywords: Mitragyna ciliate; ATPase Na+/K+; inhibitors of ATPase Na+/K+.African Journal of Trad, Comp and Alternative Medicine Vol. 5 (3) 2008: pp.294-30

Effets de fertilisants organique et organomineral a base de dechets vegetaux et animaux sur la croissance et le rendement du soja (Glycine max (L.) Merrill) en zone de savane de Cote d’Ivoire

La culture du soja, en Côte d’Ivoire, n’occupe pas la place qu’elle mérite malgré ses potentialités bénéfiques et les conditions favorables. Aussi, la fertilisation minérale, aux apports certains à la culture, demeure-t-elle coûteuse et inaccessible aux petits paysans. Cette étude vise à évaluer les effets de fertilisants organique et organo-minéral d’origines végétale et animale sur la croissance et le rendement du soja (Glycine max (L.) Merr). Le dispositif expérimental utilisé est un bloc de Fisher randomisé, avec quatre répétitions et quatre traitements que sont le témoin, la fumure minérale, la fumure organique et la fumure organo-minérale. La fumure minérale a été appliquée à des doses de 24 kg ha-1 N, 45 kg ha-1 P2O5 et 36 kg ha-1 K2O. La dose des fumures organique et organo-minérale était de 10 t ha-1. La fumure minérale a permis d’obtenir une meilleure croissance des plants durant les quarante-cinq premiers jours du cycle cultural. Pendant les quarante-cinq derniers jours du cycle, la fumure organo-minérale a eu les meilleurs effets. La fumure organique a, quant à elle, impacté favorablement le nombre de gousses (250) et la masse de 1000 graines (112,25 g). Cependant, le rendement en graines le plus élevé a été obtenu dans le traitement témoin (1,06 t ha-1). Ainsi, l’utilisation de fumure organo-minérale ne semble pas nécessaire pour la culture du soja, mais plutôt la fumure organique en cas de déficience du sol en matière organique, tout en comblant le déficit hydrique pendant la phase de production.Mots clés: fumure organique, fumure organo-minérale, croissance, rendement, soja, Côte d’IvoireEnglish Title: Effects of organic and organo-mineral fertilizers on soybean productivity in the savanna zone of Côte d’IvoireEnglish AbstractSoybean cultivation, in Côte d’Ivoire, is lagging despite its beneficial potential and favorable conditions. Also, the mineral fertilization remains expensive and inaccessible to small farmers. This study aims to evaluate the effects of organic and organo-mineral manure of vegetable and animal origins on the soybean growth and yield (Glycine max (L.) Merr). The experimental design used is a randomized Fisher block with four replicates and four treatments, namely control, mineral manure, organic manure and organo-mineral manure. The mineral manure was applied at doses of 24 kg ha-1 N, 45 kg ha-1 P2O5 and 36 kg ha-1 K2O. The dose of organic and organo-mineral manure was 10 t ha-1. The mineral manure allowed to obtain a better growth of plants during the first forty five days of the cultural cycle. During the last forty five days of the cycle, the organo-mineral manure had the best effects. The organic manure impacted favorably on the number of pods (250) and the mass of 1000 seeds (112,25 g). However, the highest seed yield was obtained in the control treatment (1.06 t ha-1). Thus, the use of organo-mineral manure does not seem necessary for the culture of the soybean, but  rather the organic manure in case of soil deficiency in organic matter, while covering the hydrous deficit during the production phase.Keywords: organic manure, organo-mineral manure, growth, yield, soybean, Côte d’Ivoire

Antibacterial activity of the aqueous extract of Thonningia sanguinea against Extended-Spectrum-b-Lactamases (ESBL) producing Escherichia coli and Klebsiella pneumoniae strains

Purpose: The aim of this study was to evaluate the antimicrobial activity of Thonningia sanguinea against two sensitive and two multi-drug resistant (ESBL) Enterobacteria strains namely Escherichia coli and Klebsiella pneumoniae. Method: The confirmation of the ESBL producing strains was done by the double-disc synergy tests and the broth dilution method was used for the determination of the antimicrobial parameters (MIC and MBC) on these sensitive and ESBL producing strains. Results: The two sensitive strains had the same MIC and MBC values respectively 3.125 mg /ml and 12.50 mg/ml. The ESBL producing strains also had the same MIC of 6.25 mg /ml and MBC values of 25 mg/ml. The extract was bactericidal for all tested strains. Conclusion: The results suggest that the flowers of T. sanguinea can be used in association with antibiotics for alternative therapy of diseases caused by ESBL producing E. coli, Klebsiella pneumoniae. Keywords: Antimicrobial activity, Thonningia sanguinea, ESBL producing strains; E. coli > Tropical Journal of Pharmaceutical Research Vol. 6 (3) 2007: pp. 779-78

Caracterisation des debits d’etiage dans un contexte de changements climatiques : Cas du bassin versant du N'zi (Cote d’Ivoire)

Dans un contexte où les pressions exercées sur les milieux aquatiques et les besoins en eaux des populations ne cessent d’augmenter auquel s’ajoutent les impacts des changements globaux, la connaissance des débits d’étiage constitue un enjeu majeur. L’objectif de cette étude est de caractériser les débits d’étiage du bassin versant du N’zi-Bandama dans l’optique d’une meilleure gestion des ressources en eau de ce bassin. Des données de débits mensuels provenant de cinq stations hydrométriques du fleuve N’zi-Bandama (Fétékro, M’bahiakro, Bocanda, Dimbokro, N’zianouan) ont été utilisées et couvrent la période allant de 1960 à 2016. La méthodologie a consisté à calculer et analyser les seuils de sévérité d’étiage (seuil d’alerte ou QMNA-5, seuil de vigilance et seuil de crise). Les quantiles de débits d’étiage ont été déterminés à partir de la loi lognormale correspondant aux périodes de retour 2, 5, 10, 20 et 50 ans. Les principaux résultats obtenus ont montré que les débits de seuils de sévérité déterminés mettent en évidence la vulnérabilité à de sévères étiages du bassin versant du N’zi-Bandama avec une exposition à la vulnérabilité plus forte pour le sous-bassin versant d’exutoire Fétékro.Mots clés: Débits d’étiage ; QMNA ; Seuils de sévérité ; Bassin versant du N’zi ; Côte d’Ivoire

Antagonist potential of Trichoderma indigenous isolates for biological control of Phytophthora palmivora the causative agent of black pod disease on cocoa (Theobroma cacao L.) in Côte d’Ivoire

The biodiversity of Trichoderma isolates from cocoa rhizosphere in cocoa production areas of Côte d’Ivoire, and their antagonist potential with Phytophthora palmivora using in vitro assays and bioassays, were investigated and screened for field trials. A total of 135 isolates were analysed at the species level by using sequence analysis of ITS1 and 2 of the rRNA region and a fragment of translation elongation factor 1a (tef1) gene. Sixty-four isolates were identified as T. virens, 60 as T. harzianum, 7 as T. spirale, two as T. asperellum and two unidentified. Forty-three Trichoderma isolates were in vitro confronted with P. palmivora on agar plates, and their antagonist activity was further evaluated by the damages on leaf discs and detached pods. Twenty-five isolates reduced the mycelial growth of P. Palmivora more than 50%. The isolate T17 assigned to T .virens was the best to reduce mycelium growth upto 97.9%. All of Trichoderma isolates with the exception of isolate T39 reduced foliar sensitivity to P. palmivora. Tweenty-six Trichoderma isolates reduced the pod sensitivity to P. palmivora more than 50%. Based on the combined analysis, T. virens T7, T. harzianum T40, T. asperellum T54 and T. spirale T4 isolates were selected for field trials

Effet de l’engrais organique biojadi sur les populations d’insectes visitant le palmier a huile

Le palmier à huile est une culture oléagineuse importante à l’échelle mondiale en raison de son rendement élevé parfois dû à l’utilisation de fertilisants. Cependant, l’utilisation des engrais organiques peut influer sur les populations d’insectes visitant les plantations de palmier à huile. Cette étude vise à évaluer l’effet de l’engrais biojadi sur les populations d’insectes du palmier à huile. Le dispositif utilisé est un bloc de Fisher à quatre répétitions et trois traitements. L’inventaire de la faune entomologique réalisée dans les différents traitements a révélé la présence des insectes ravageurs, pollinisateurs et prédateurs. Le groupe des insectes pollinisateurs et ravageurs ont été présents de la même manière sur les parcelles T1, T2, T3 car aucune différence significative n’a été observée entre ces traitements. Cependant, le nombre d’insectes prédateurs a été plus élevé au niveau du traitement T3 qu’au niveau des traitements T1 et T2. La pullulation des prédateurs réduit considérablement l’abondance des pollinisateurs et ravageurs. L’engrais organique biojadi peut être recommandé. Cependant, l’application de cet engrais doit être faite de manière continue pour pouvoir maximiser son effet sur de long terme. Mot clés : Effet, engrais organique biojadi, insectes, palmier à huile  English Title: Effect of Biojadi organic fertilizer on insect populations visiting oil palm Oil palm is an important oilseed crop worldwide because of its high yield sometimes due to the use of fertilizers. However, the use of organic  fertilizers can affect insect populations visiting oil palm plantations. This study aims at evaluating the effect of biojadi fertilizer on oil palm insect populations. The device used is a Fisher block with four replicates and three treatments. The inventory of the entomological fauna carried out in the different treatments revealed the presence of insect pests, pollinators and predators. The group of pollinating insects and pests were present in the same way on plots T1, T2, T3 because no significant difference was observed between these treatments. However, the number of predatory insects was higher in the T3 treatment than in the treatments T1 and T2. The proliferation of predators significantly reduces the abundance of pollinators and pests. Biojadi organic fertilizer can be recommended. However, the application of this fertilizer must be done continuously to maximize its long-term effect. Keywords: Effect, biojadi organic fertilizer, insect populations, oil pal

Unsweetened Natural Cocoa Powder: A Potent Nutraceutical in Perspective

Unsweetened natural cocoa powder is a pulverized high-grade powder of compressed solid blocks which remains after extraction and removal of the cocoa butter. The authors determined the elementary composition of UNCP, investigated its effect on nitric oxide levels, toxicity, and its protective effect on the heart, kidney, and liver during simultaneous administration with high dose (HD) artemether/lumefantrine (A/L). Macro- and microelements in UNCP were analyzed with energy dispersive x-ray fluorescence spectroscopy (EDXRF). Adult male guinea pigs were administered various doses of UNCP alone and also simultaneously with A/L. Phytochemical analysis of UNCP showed the presence of saponins, flavonoids, tannins, cardiac glycosides, and 38 macro- and microelements. Histopathological analysis showed no toxic effect on the heart, liver, kidney, lungs, testis, and spleen. Administration of various doses of UNCP increased white blood cell counts and lymphocyte count (p > 0.05) compared with the controls. Additionally, UNCP and A/L combination caused an increase in nitric oxide levels when compared with the control group and restores some hematological disorders induced by the 3-day HD A/L administration. Even though UNCP appears to be relatively safe, care should be taken due to the high content of copper element to avoid the possibility of intestinal lining erosion

Hepatoprotective and antioxidant activities of Hibiscus sabdariffa petal extracts in Wistar rats

Background: Hibiscus sabdariffa is a medicinal plant rich in phytochemical compounds, which is the source of its biological properties. This study on the aqueous extract of H. sabdariffa (AEHS) was conducted to assess its hepatoprotective and antioxidant properties.Methods: It was carried out with 25 Wistar rats divided into five groups. Two groups were treated with a solution of NaCl 0.9%. One group was treated with silymarin at a dose of 25 mg/kg body weight (BW). Two other groups were treated with the AEHS at different doses (100 and 200 mg/kg BW). The treatments were carried out via oral route and at single dose for 7 days. After injection of 2,4-dinitrophenylhydrazine (DNPH), blood samples were collected for the carrying out of biochemical analyses of oxidative stress markers (thiobarbituric acid reactive substances, ferric reduction antioxidant parameter, and 2,2-diphenyl-1-picrylhydrazyl) and hepatotoxicity (albumin, total and direct bilirubin, alanine transaminase, aspartate aminotransferase, and lactate dehydrogenase).Results: Three major results were obtained. The hepatotoxicity of DNPH expressed by the rats of Group 1 was significantly different (p<0.05) from those of the other groups (control, 2-4) for both hepatotoxicity and oxidative stress markers. The hepatoprotective and antioxidant properties of the AEHS and confirmation of those of silymarin through the rats of Groups 2-4 were statistically identical (p<0.05) to the control group for markers of hepatotoxicity and oxidative stress.Conclusion: These results confirm and reinforce certain therapeutic virtues of H. sabdariffa

Long-term continuous administration of a hydro-ethanolic extract of Synedrella nodiflora (L) Gaertn in male Sprague-Dawley rats: biochemical, haematological and histopathological changes

Background: Conflicting reports about the toxicity of Synedrella nodiflora (L) Gaertn (family Asteraceae), a plant traditionally used in Ghana for the management of epilepsy, abound in literature. The present study evaluates the effect of a 90-day continuous oral administration of a hydro-ethanolic whole plant extract of Synedrella nodiflora (SNE) in male Sprague-Dawley rats.Methods: The toxicological evaluation of the extract (100, 300 and 1000 mgkg-1) was focused on haematological, serum biochemical parameters and histopathological changes of some isolated organs.Results: The extract produced no mortality in the rats treated during the study period. Only SNE 100 mgkg-1 produced significant decrease in white blood cell and neutrophil counts and an increase in albumin, globulin, total bilirubin, total protein and potassium levels. The higher doses (SNE 300 and 1000 mgkg-1) had no significant effect on all the haematological and biochemical parameters measured. Histopathological assessment of the liver, kidney and heart revealed no abnormalities in rats treated with the extracts. Only the SNE 1000 mgkg-1 produced distortions of the branching arrangements of the myocardial fibres and a congested vessel which indicates a healed infarction.Conclusions: The findings suggest hydro-ethanolic extract of Synedrella nodiflora (L) Gaertn generally has a low toxicity profile following a 90-day continuous oral administration in male Sprague-Dawley rats under the present laboratory conditions. However patients with renal or cardiac problems should use the plant with caution.Funding: Jointly supported by the International Foundation for Science, Stockholm, Sweden, through a grant (# F/5191-1) to Dr. Patrick Amoateng and the Office of Research, Innovation and Development (ORID), University of Ghana, Accra, Ghana, grant awarded to Dr. Patrick Amoateng (reference number: URF/6/ILG-002/2012-2013)Keywords: : Synedrella nodiflora, Sprague-Dawley rats, histopathological, haematologica