Effets pharmacologiques d’un extrait aqueux de Bidens pilosa L. (Asteraceae) sur le système cardiovasculaire de mammifères

Pharmacological effects of an aqueous extract of Bidens pilosa L.(Asteraceae) on the cardiovascular system of mammalsThe crude aqueous extract of Bidens pilosa L. (Asteraceae), for concentrations ranging from 1x10-3 to 1.4x10-2 g/kg of body weight (b. w.) induced a transient dose dependant hypotension in the rabbit whereas the respiratory wide range and frequency were lessaffected. On the isolated heart of rat, this natural substance caused negative inotropic and chronotropic effects from the concentration of 10-10 mg/mL. These effects reached their maximum values at 10-8 mg/mL and then decreased at 10-6 mg/mL. At 10-4 mg/mL,no major changes were noticed in the recordings. These results suggest that the hypotension induced by Bidens pilosa L. could result, onthe one hand, from the relaxing effects observed by some authors on the vascular smooth muscle and on the other hand, from the cardiodepressant effects of the active principles contained in the plant.Three kinds of active principles were revealed in the presence of atropine, a muscarinic cholinoceptors antagonist. These are : 1) Muscarinic cholinomimetic active principles inhibited by atropine.2) Cardiodepressant principles insensible to atropine.3) Cardioactive principles acting at high doses of Bidens pilosa.At the dose of 1.3x10-1 g/kg of b.w., the crude extract of Bidens pilosa caused a deep hypotension followed by a respiratory arrest lethal for the rabbit. The results obtained justify the use of Bidens pilosa in traditional medicine to treat hypertension

Evolution des infections naturelles sur les mangues, les avocats et les bananes en Côte d’Ivoire et principaux champignons responsables

Objectif: Les altérations fongiques constituent une des causes majeures des pertes post récolte des fruits frais en Côte d’Ivoire. L’objectif de cette étude était d’analyser les infections naturelles qui apparaissent sur les fruits dans les principales zones de production du pays, et d’identifier les principaux agents pathogènes responsables.Méthodologie et résultats: L’étude a consisté à la collecte, de manière aléatoire, des fruits dans les zones Centre, Sud, Est et Nord du pays, à la notation quotidienne des infections naturelles apparues sur les fruits, sur une durée de 6 à 9 jours et à l’isolement ainsi que l’identification des champignons qui leur sont associés. Les résultats ont montré une évolution du taux cumulé des infections naturelles de tous les fruits et la présence de 16 groupes morphologiques dont les plus dominants sont ceux à thalle gris (93,75%) au niveau de la mangue, ceux à thalle noir cotonneux (73,53%) pour l’avocat et ceux à thalle rose (81,25%) pour la banane. L’identification a montré une diversité de champignons pathogènes dont les principaux genres sont : Colletotrichum, Fusarium, Aspergillus, Phoma, Penicillium, Curvularia, Botryodiplodia et Rhizoctonia.Conclusion et application des résultats: Les fruits frais subissent après récolte l’impact des champignons pathogènes par les infections qu’ils causent. Ces infections augmentent au fur et mesure que les fruits murissent. Ces résultats constituent une bonne base pour le renforcement des stratégies de lutte. Toutefois, des études complémentaires, notamment pathogéniques et moléculaires des principaux champignons, sont nécessaires pour mieux les connaître et envisager, ainsi, des méthodes intégrées de lutte plus inclusives.Mots clés: Fruits, post-récoltes, infections, champignons pathogènesEnglish AbstractObjective: Fungal alterations are one of the major causes of post-harvest losses of fresh fruit in Côte d'Ivoire. The objective of this study was to analyze the natural infections that appear on fruits produced in the main production areas of the country, and to identify the main pathogens.Methodology and results: The study consisted of random fruit collection in the main growing areas, daily recording of natural infections on the fruit over a period of 6 to 9 days and isolation of the associated fungi. The results showed an evolution of the cumulative rate of natural infections of all fruits and the presence of 16 morphological fungal groups of which the most dominant are those with grey thallus (93.75%) in mango, those with cottony black thallus (73.53%) for avocado and those with pink thallus (81.25%) for banana. Identification showed a diversity of pathogenic fungi including the genera Colletotrichum, Fusarium, Aspergillus, Phoma, Penicillium, Curvularia, Botryodiplodia and Rhizoctonia.Conclusion and application of results: Fresh fruits quality are influenced by pathogenic fungi through the infections they cause after harvest. These results provide a good basis for control strategy enhancement. However, additional studies, including pathogenic and molecular components of the main fungi, are needed to better understand them and thus consider more inclusive integrated control methodsKeywords: Fruits, post-harvest, infections, pathogenic fung

Effet antihypertensif de BpF2, une fraction d\'extrait aqueux de feuilles de Bidens pilosa L. (Asteraceae) chez le lapin

Les feuilles de Bidens pilosa L. sont largement utilisées dans la pharmacopée traditionnelle. Nous avons cherché à mettre en évidence les effets antihypertensifs de ces feuilles. L'analyse phytochimique révèle que la fraction 2, dénommée BpF2, de l\'extrait aqueux des feuilles de Bidens pilosa L. (Asteraceae), contient des flavonoïdes, des polyphénols et des tanins catéchiques. Pour des doses comprises entre 1 et 25 mg/kg de poids corporel, cette fraction chromatographique induit une hypotension dose-dépendante chez le lapin. Cet effet explique le potentiel antihypertenseur de cette fraction. Ces effets ressemblent à ceux bien connus de l\'acétylcholine (ACh). Toutefois, alors que l\'atropine inhibe totalement l\'hypotension induite par l\'ACh, elle ne reverse que partiellement l\'hypotension provoquée par BpF2. Ces résultats suggèrent fortement la présence de deux types de principes actifs dans cette fraction active BpF2: - les principes actifs cholinomimétiques de type muscarinique, - les principes actifs non cholinomimétiques dont la nature reste à déterminer. La présence de ces substances dans la fraction active pourrait justifier, au moins en partie, l\'utilisation traditionnelle de Bidens pilosa L. contre l\'hypertension artérielle.The fraction 2, called BpF2, of the aqueous extract from Bidens pilosa L. (Asteraceae) leaves, contained flavonoids, polyphenols and catechic tannins. For doses ranging from 1 to 25 mg/kg of body weight, this chromatographic fraction induced a dose-dependent hypotension in the rabbit. This effect explained the antihypertensive potential of the fraction. These effects resembled those well-known of acetylcholine (ACh). However, whereas atropine completely inhibited the effect induced by ACh, its action remained partial on that caused by BpF2. These results suggested the presence of two types of active components in BpF2 fraction. - muscarinic and cholinomimetic activity, - non cholinomimetic activity to be clarified. The study showed at least two hypotensive activities in BpF2 fraction, justifying the traditional use of Bidens pilosa L. against hypertension. Keywords: Bidens pilosa L., acetylcholine, muscarinic cholinomimetic activity, non cholinomimetic activity.Sciences & Nature Vol. 5 (1) 2008: pp. 29-3

Effet D’un Extrait Aqueux De Pseudarthria Hookeri Wight & Arn. (Fabaceae) Sur La Glycemie Et Sur La Liberation Et Le Stockage Du Glucose Hepatique De Rats Diabetiques

Pseudarthria hookeri (Fabaceae) is a plant used in traditional medicine in Ivory Coast to treat diabetes. This study aims to evaluate the antidiabetic effects of the aqueous extract of Pseudarthria hookeri (EAPh) on the release and storage of hepatic glucose in alloxan induced diabetic rats. The administration of EAPh, at a dose of 1200 mg/kg body weight for 28 days, leads to a significant decrease of glycaemia in diabetic rats. The oral administration of EAPh, at doses of 800 mg/kg, 1000 mg/kg and 1200 mg/kg body weight, reduced for 60 min, in a dose-dependent manner, the release of hepatic glucose in normoglycemic rats. Moreover, for 90 days of treatment, EAPh significantly promotes the storage of hepatic glucose in diabetic rats. It appears that the aqueous extract of Pseudarthria hookeri has antidiabetic properties and acts by promoting the storage of hepatic glucose (glycogenesis), and by inhibiting the release of glucose from the liver (glycogenolysis). These results justify the use of Pseudarthria hookeri in traditional medicine to effectively treat diabetes

Aqueous Extract of Rauwolfia Vomitoria Afzel (Apocynaceae) Roots Effect on Blood Glucose Level of Normoglycemic and Hyperglycemic Rats

At 500, 700 and 1000 mg/ kg B.W., EARv causes, like glibenclamide at 10 mg/kg B.W., a reduction of blood glucose level of treated normoglycemic rats. In addition, EARv at 1000 mg/kg B.W. reducedand quickly nullifies the glucose tolerance in rats that is induced by oral administration of glucose (4 g/kg B.W.). This effect is also observed with glibenclamide (10 mg/kg B.W.). The phytochemical screening shows that EARv contains alkaloids, flavonoids, and antrhones and anthraquinones, catechin tannins, saponins and monoterpenoids. This study shows that the aqueous extract of Rauwolfia vomitoria has hypoglycemic and some antihyperglycemic properties, that justify its use in the treatment of diabetic hyperglycemia in traditional medicine.This study aims to assess the pharmacological effects of an aqueous extract roots of Rauwolfia vomitoria (EARv), a plant used in traditional medicine in the Ivory Coast to treat diabetes, on blood glucose normoglycemic rats and on glucose tolerance in rats by administration of glucose. The acute toxicity, as well as the phytochemicals present in this extract are also determined. During the experience, fives groups of rats received respectively distilled water, EARv at doses of 500, 700 and 1000 mg/kg of body weight and 10 mg/kg of glibenclamide. Then the blood glucose level of each rat was measured using a glucometer. Hyperglycemia was induced in rats by oral administration of glucose at dose of 4 g/kg. The rats were pretreated or post-treated of the same doses of tests substances and blood glucose level of each rat was measured. Acute toxicity by oral administration was studied in mice and phytochemical screening was performed by thin layer chromatography. The results show that EARv administered orally at doses up to 5000 mg/kg B.W., does not cause the death of the treated mice.

Propriétés Antidiarrhéiques de L’extrait Aqueux de Solanum Torvum (Solanaceae) chez le Rat de Souche Wistar

En Afrique, particulièrement en Côte d’Ivoire, Solanum torvum (Solanaceae) est couramment utilisé en médecine traditionnelle pour le traitement de plusieurs pathologies, entre autre la diarrhée. En vue de contribuer à la valorisation des plantes médicinales par l’établissement de bases scientifiques justifiant leurs utilisations en médecine traditionnelle, cette étude est menée sur Solanum torvum (Solanaceae). La diarrhée est une pathologie mortelle, considérée par l’OMS comme un problème de santé publique. Le but de cette étude est principalement d’évaluer, chez des rats, le potentiel antidiarrhéique d’un extrait aqueux de feuilles de Solanum torvum (EASt). Pour cela, des rats sont prétraités avec l’EASt avant de recevoir par voie orale de l’huile de ricin, puis leurs crottes diarrhéiques sont comptées. Leur intestin est isolé et vidé pour déterminer le volume du contenu intestinal. La durée du transit intestinal est aussi mesurée grâce au charbon actif utilisé comme marqueur. Cette étude montre que, sur des rats rendus diarrhéique, l’EASt administré par voie orale aux doses de 150 et 250 mg/kg PC réduit de façon dose-dépendante l’apparition et le nombre de crottes diarrhéiques et, ainsi, baisse la sévérité de la diarrhée. L’EASt entraîne aussi chez ces rats une diminution du volume du contenu intestinal et une réduction de la mobilité intestinale par rapport aux témoins diarrhéiques. Ces effets de l’EASt sont similaires à ceux du lopéramide sur les crottes diarrhéiques et sur le volume du contenu intestinal de rats rendus diarrhéiques. Ces effets sont aussi semblables à celui du sulfate d’atropine sur la mobilité gastro-intestinale de rats rendus diarrhéiques. Ces actions de l’EASt indiquent que cet extrait a des propriétés antidiarrhéiques. Ces propriétés antidiarrhéiques de l’extrait aqueux de Solanum torvum justifient l’utilisation traditionnelle de cette plante contre la diarrhée. Cet extrait pourrait donc être préconisé dans le traitement de cette pathologie. In Africa, particularly in Côte d'Ivoire, Solanum torvum (Solanaceae) is commonly used in traditional medicine for the treatment of several pathologies, including diarrhea. In order to contribute to the promotion of medicinal plants by establishing scientific bases justifying their uses in traditionalmedicine, this study is conducted on Solanumtorvum(Solanaceae). Diarrhea is a deadly disease, considered by WHO to be a public health problem. The aim of this study is mainly to assess, in rats, the antidiarrheal potential of an aqueous extract of Solanum torvum leaves (EASt). For this, rats are pretreated with EASt before receiving castor oil by mouth, then their diarrheal droppings are counted. Their gut is isolated and emptied to determine the volume of intestinal contents. The duration of intestinal transit is also measured using activated charcoal used as a marker. This study shows that, in rats rendered diarrheal, EASt administered orally at doses of 150 and 250 mg / kg bw dose-dependent reduced the appearance and the number of droppings of diarrhea and, thus, reduced the severity diarrhea. In these rats, EASt also causes a decrease in the volume of intestinal contents and a reduction in intestinal mobility compared to the diarrheal controls. These effects of EASt are similar to those of loperamide on diarrheal droppings and on the volume of the intestinal contents of rats rendered diarrheal. These effects are also similar to that of atropine sulfate on the gastrointestinal mobility of rats with diarrhea. These EASt actions indicate that this extract has anti-diarrheal properties. These anti-diarrheal properties of the aqueous extract of Solanum torvum justify the traditional use of this plant against diarrhea. This extract could therefore be recommended in the treatment of this pathology

Haemostatic Properties of Chrysophyllum Caïnito L. (Sapotaceae) in Wistar Rat

The measure of certain blood parameters makes it possible to detect certain pathologies such as the hemophilia and leukemia among patients. Indeed, the aggregating and antiaggreganting activity of certain substances are known. It is a question in this work of checking the effect of the aqueous extract of Chrysophyllum cainito (AECc) on blood. It is a comparative study between AECc and two products of synthesis known for purpose which are the dicynone and the aspirin in vivo in the rats wistar specie Rattus norvegicus. The time of bleeding (TB), the number of blood plates, the red blood corpuscle rate, of hemoglobin, the hematocrit and the sedimentation test (TS) were evaluated. During the first week, the evolution of the time of bleeding (TB) is not significant for all the animals. The second week and until the end of the treatment, the TB drops for the animals treated with EACc in an amount-dependant way. Thus the fall is of 4% for the amounts of 300 mg/kg b.w, 17.4% for the amounts of 500 mg/kg b.w and 30.43% for the amounts of 1000 mg/kg b.w at the end of the treatment. In the animals treated with the dicynone, the fall reaches 41.55% at the end of the thirty days of treatment. On the other hand, in the rats treated with the aspirin, the TB increases as from the second week and reached the rise of 17.40% at the end of the thirty days. On the blood plates, AECc varies their number of manner proportions dependant as of the first week on treatment. The number of blood plates increases by 07.69% and 15.38% for the amount of AECc of 300 mg/kg b.w, 15th and 30th day. The amount of 500 mg/kg b.w of AECc makes increase the number of plates of 09.89%, 21.97%, and 25.16%, respectively 5th, 15th and 30th day.The concentration of AECc of 1000 mg/kg b.w involves an increase in the plates of 22.31%, 27.36% and 33.07%, respectively with 5th, 15th and 30th day of treatment. The dicynone is managed with the rats with the amount of 500 mg/kg b.w the number of blood plates passes thus from 910±85.83 to 915±88.0, 918±87.0 then 920±92.0; 5th, 15th and 30th days of treatment is 0.55%, 0.88% and 1.09%. This variation is nonsignificant. On the other hand the aspirin managed with the rats with the amount of 500 mg/kg b.w cause a drop in the number of blood plates as of the 5th days with 900±88.2 then with 889±82.2 15th and 750±80.6 the 30th. These drops successive represent rates by -1%,-2.30% and -17.58%. The other factors such as the number of red blood corpuscles the rate of hemoglobin, the hematocrit and also the sedimentation test do not vary significantly before and during the treatment

Foliar Application of Boron during Flowering Promotes Tolerance to Cocoa (Theobroma cacao L.) Swollen Shoot Viral Disease

Boron nutrition is known to reduce the effect of some viral and fungal diseases on plant fitness. This study investigated the potential of boron application to improve yield and tolerance of cacao trees naturally infected by virulent cocoa swollen shoot virus (CSSV) strains and determined the effective dose and time of application. Foliar sprays of a commercial product containing 20.5% of boron were performed either at the onset of flowering’s peak of the little milking (early in November) or four weeks later (early in December) with four doses of boron (0, 31.25, 41.67, and 83.27 g/ha) in a randomized complete block design with four replications. We found that boron application improved foliar density and induced production of pods of normal shape meanwhile reducing the appearance of this misshapenness due to CSSV. Boron also increased the number of emitted flowers, cherelles and pods subsequently. Moreover, weight and size of fresh cocoa beans per pod were positively correlated to boron dosage. Interestingly, foliar sprays performed early in November resulted in less flat cocoa beans. Finally, the optimal dose of boron that reduced the adverse effects of the most virulent form of cocoa swollen shoot viral disease is 41.67 g/ha

EFFETS HYPOGLYCEMIQUE ET ANTI-HYPERGLYCEMIQUE DE L’EXTRAIT ETHANOLIQUE 70 % DE RACINES DE RAUVOLFIA VOMITORIA AFZEL (APOCYNACEAE)

Rauwolfia vomitoria Afzel. (Apocynaceae) is a plant used in traditional medicine in the Ivory Coast for the treatment of several illnesses such as malaria, diarrhea, rheumatism, high blood pressure, and diabetes. This study aims to determine the level of toxicity of a 70 % ethanol extract of the root of that plant (HARv) and to evaluate its hypoglycemic and anti-hyperglicemic activities. It occurs that HARv shows no toxicity when administered orally to rats up to a concentration of 5000 mg/kg of body weight. However, doses of 500, 700 and 1000 mg/kg of body weight lead to hypoglycemia when HARv is administered via the oral route. Similar to the effect of glibenclamide (in a concentration of 10 mg/kg of body weight), concentrations of 700 and 1000 mg/kg of body weight of HARv significantly reduce hyperglycemia induced by the administration of 4 g/kg of body weight of glucose. The presence of saponins, flavonoids, and tannoids in the extract may cause the observed hypoglycemic and anti-hyperglycemic effects. We infer from this study that 70 % ethanol extract of the roots of Rauwolfia vomitoria is not toxic when administered orally to rats. In addition, HARv shows hypoglycemic and anti-hyperglycemic effects, explaining its use in traditional medicine for the treatment of diabetes

Antibacterial Properties of an Aqueous Extract of Solanum torvum (Solanaceae) on a Few Multidrug Resistant Bacterial Strains to Common Antibiotics

This study aimed to evaluate the antibacterial activity of the aqueous extract of Solanum torvum leaves (EASt) on multidrug-resistant bacterial strains to common antibiotics. This plant is used in traditional medicine against diarrhoea. Solid agar diffusion and liquid dilution methods were respectively used to assess the sensitivity of bacterial strains to EASt and to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Tests performed on ten (10) bacterial strains, isolated from various biological products, showed that Staphylococcus aureus 234 UB/17 and Escherichia coli 135 UB/17, were significantly sensitive to EASt, with a higher sensitivity for the latter strain. This sensitivity was shown by an inhibition of bacterial growth in solid agar and liquid medium, by a decrease in turbidity caused by EASt sensitive germs growth as the concentration of this plant extract increased (25 to 100 mg/ml). This demonstrate that EASt is an antibacterial substance. Thus, treated with EASt at a dose of 100 mg/ml, the MICs of S. aureus 234 UB/17 and E. coli 135 UB/17 were 6.25 and 12.5 mg/ml respectively, and the MBCs were 25 and 50 mg/ml respectively. The ratio of these bactericidal parameters (MBC/MIC) equaled to four (4) for these two bacterial strains, indicating that EASt is bactericidal for these bacterial strains. The antibacterial and bactericidal properties of EASt on multiple antibiotic resistant germs could justify the use of this plant in traditional medicine for the treatment of some bacterial infections causing diarrhoea