Perception des producteurs et impact des facteurs socio-économiques sur la connaissance des mycotoxines du maïs en stockage au Bénin

Au Bénin, plusieurs technologies sont utilisées pour la conservation du maïs. Ces technologies utilisées ne contrôlent pas toujours les pertes fongiques enregistrées. L’objectif de l’étude est d’évaluer l’impact des facteurs socio-économiques des producteurs sur les technologies de prévention des pertes fongiques et leur niveau de connaissance des mycotoxines du maïs en stockage. Pour ce faire, une enquête a été réalisée dans sept zones agro-écologiques du Bénin. Au total, sept technologies de stockages du maïs ont été inventoriées (de A à G). La technologie B est non seulement présente dans toutes les zones parcourues mais aussi, elle est fortement représentée dans les zones III, IV et VIII avec des proportions respectives de 51,33%; 62,86% et 69,83%. La population agricole ayant un niveau secondaire (27%) et les alphabétisés (15%) ont la chance de connaître les mycotoxines. Les enquêtés (100%) ne connaissent pas le danger lié à la consommation du maïs contaminé et n’ont jamais reçu une formation sur les mycotoxines. L’observation de la couleur verte (61% des enquêtés) et la couleur noire (28% des enquêtés) témoigne bien de la persistance des mycotoxines dans le maïs en stock au Bénin.© 2016 International Formulae Group. All rights reserved.Mots clés: Technologie, conservation, céréales, contamination, moisissuresEnglish Title: Perception of maize producers in Benin and impact of the socio-economic factors on the knowledge of the mycotoxins of maize in storageEnglish AbstractIn Benin, various technologies are used for the conservation of the maize. Those technologies don't often control the recorded fungal losses. The objective of the study is to value the impact of the socioeconomic factors of producers on technologies of fungal loss prevention and their level of knowledge of mycotoxins of the maize in storage. A survey has been achieved in seven agro - ecological zones of Benin. Thus, a total of seven maize storage technologies were inventoried (A to G). The use of technology B is not only apparent in all the zones covered but it is also significantly used in zones III, IV and VIII in the respective proportions of51.33%; 62.86% and 69.83%. The agricultural population, i.e. those with secondary education (27%) and the literates (15%) happen to have some knowledge about mycotoxins. People investigated (100%) do not have knowledge of the danger associated with the consumption of contaminated maize and have never received training on mycotoxins. The observation of a green colour (by 61% of respondents) and black colour (by 28% of respondents) is testimony to the persistence of mycotoxins in maize under storage in Benin.© 2016 International Formulae Group. All rights reserved.Keywords: Technology, conservation, cereals, contamination, mould

HIGH PERFORMANCE LIQUID CHROMATOGRAPHY QUANTIFICATION OF OLEANOLIC ACID IN LAUNAEA TARAXACIFOLIA AND LARVICIDAL ACTIVITY AGAINST ANOPHELES GAMBIAE

Objective: One of the measures used to prevent malaria is the management of breeding sites. For preventive and ecologically profitable control, the use of bio-larvicides made from active plant extracts would be an asset for the control of malaria vectors, in particular Anopheles gambiae. Advances in pharmacognosy have revealed the benefits of several phytochemicals with very rich and varied therapeutic effects. Among the latter, oleanolic acid (OA) is quite remarkable because of its various and multiple properties, much of which is demonstrated with the leaves of Launaea taraxacifolia. Methods: After a liquid-liquid fractionation with different organic solvents of the hydro-methanolic extract of Launaea taraxacifolia, we obtained three fractions named Fhex (hexane fraction), FDCM (dichloromethane fraction) and FHM (hydro-methanolic fraction) which were tested on 3rd instar Anopheles gambiae larvae. Results: Fhex proved to be the most active with LC50 of 120.11 ppm and 69.50 ppm respectively in 24 and 48 hours of contact. We then developed a new method of Ultra-Violet High Performance Liquid Chromatography (HPLC / UV) method and determined the quantity of oleanolic acid in the Fhex and FDCM fractions to be respectively 0.46% and 0.23% . Conclusion: Launaea taraxacifolia has a larvicidal potential due to the presence of oleanolic acid whose inhibitory effect against Anopheles gambiae larvae

Maize Fungal Growth Control with Scopoletin of Cassava Roots Produced in Benin

The chemical contamination of food is among the main public health issues in developing countries. With a view to find new natural bioactive products against fungi responsible for chemical contamination of staple food such as maize, the antifungal activity tests of scopoletin extracted from different components of the cassava root produced in Benin were carried out. The dosage of scopoletin from parts of the root (first skin, second skin, whole root, and flesh) was done by High Performance Liquid Chromatography. The scopoletin extract was used to assess the activity of 12 strains (11 strains of maize and a reference strain). The presence of scopoletin was revealed in all components of the cassava root. Scopoletin extracted from the first skin cassava root was the most active both as inhibition of sporulation (52.29 to 87.91%) and the mycelial growth (36.51–80.41%). Scopoletin extract from the cassava root skins showed significant inhibitory activity on the tested strains with fungicide concentration (MFC) between 0.0125 mg/mL and 0.1 mg/mL. The antifungal scopoletin extracted from the cassava root skins may be well beneficial for the fungal control of the storage of maize

Characterization of new vasorelaxant molecules : chemical-pharmacological studies of Carissa edulis, a medicinal species of the Beninese pharmacopoeia

Les maladies cardiovasculaires représentent la première cause de mortalité dans le monde et leur incidence est associée à plusieurs facteurs de risque majeurs dont l’hypertension (HTA). Au Bénin, plusieurs plantes sont utilisées en médecine traditionnelle pour traiter l’HTA. Trois d’entre elles ont été sélectionnées pour notre étude : Carissa edulis, Diodia scandens et Cleome gynandra. Ainsi, l’objectif principal de cette thèse est d’étudier le potentiel des extraits de ces plantes à moduler le tonus vasculaire et de déterminer les mécanismes sous-jacents. Pour cela, nous avons procédé ex vivo et in vivo à des tests de réactivité vasculaire, d’absorption des polyphénols et d’immunofluorescence de protéines cibles. Les résultats ont montré que l’extrait de Carissa edulis a été le plus actif des trois plantes. Il possède une importante activité vasorelaxante strictement dépendante de l’endothélium et médiée par le monoxyde d’azote (NO) et sa fraction butanolique (CEBF) a une activité encore plus prononcée. Le traitement de rats d'âge moyen avec l’extrait total de Carissa edulis pendant deux semaines a significativement amélioré la fonction endothéliale et restauré la relaxation médiée par le NO dans l'artère mésentérique principale et l’aorte thoracique. Il a aussi fortement réduit au niveau vasculaire le niveau d’expression d’ACE et AT1R impliqués dans la dysfonction endothéliale associée au vieillissement et à l’hypertension artérielle, et le stress oxydant. Une identification putative par métabolomique non ciblée des molécules de CEBF a révélé la présence des polyphénols, terpènes et alcaloïdes.Cardiovascular diseases represent the first cause of mortality in the world and their incidence is associated with several major risk factors including hypertension. In Benin, several plants are used in traditional medicine to treat hypertension. Three of them were selected for our study: Carissa edulis, Diodia scandens and Cleome gynandra. The objective of the thesis was to study the potential of these plant extracts to modulate vascular tone and to determine the underlying mechanisms. For this purpose, we did ex vivo and in vivo studies to study vascular reactivity, polyphenol uptake and immunofluorescence tests of target proteins. The results showed that Carissa edulis extract was the most active of the three plants. It induced pronounced and strictly endothelium-dependent vasorelaxant mediated by nitric oxide (NO), and its butanolic fraction (CEBF) was more active. Treatment of middle-aged rats with the total extract of Carissa edulis for two weeks significantly improved the endothelial function as indicated by restored NO-mediated relaxations in the main mesenteric artery and thoracic aorta. It also strongly reduced the vascular expression level of ACE and AT1R involved in endothelial dysfunction associated with aging and hypertension and reduced the level of oxidative stress. Putative identification by nontargeted metabolomics of CEBF molecules revealed the presence of polyphenols, terpenes, and alkaloids

Caractérisation de nouvelles molécules vasorelaxantes : études chimico-pharmacologique de Carissa edulis, une espèce médicinale de la pharmacopée béninoise

Cardiovascular diseases represent the first cause of mortality in the world and their incidence is associated with several major risk factors including hypertension. In Benin, several plants are used in traditional medicine to treat hypertension. Three of them were selected for our study: Carissa edulis, Diodia scandens and Cleome gynandra. The objective of the thesis was to study the potential of these plant extracts to modulate vascular tone and to determine the underlying mechanisms. For this purpose, we did ex vivo and in vivo studies to study vascular reactivity, polyphenol uptake and immunofluorescence tests of target proteins. The results showed that Carissa edulis extract was the most active of the three plants. It induced pronounced and strictly endothelium-dependent vasorelaxant mediated by nitric oxide (NO), and its butanolic fraction (CEBF) was more active. Treatment of middle-aged rats with the total extract of Carissa edulis for two weeks significantly improved the endothelial function as indicated by restored NO-mediated relaxations in the main mesenteric artery and thoracic aorta. It also strongly reduced the vascular expression level of ACE and AT1R involved in endothelial dysfunction associated with aging and hypertension and reduced the level of oxidative stress. Putative identification by nontargeted metabolomics of CEBF molecules revealed the presence of polyphenols, terpenes, and alkaloids.Les maladies cardiovasculaires représentent la première cause de mortalité dans le monde et leur incidence est associée à plusieurs facteurs de risque majeurs dont l’hypertension (HTA). Au Bénin, plusieurs plantes sont utilisées en médecine traditionnelle pour traiter l’HTA. Trois d’entre elles ont été sélectionnées pour notre étude : Carissa edulis, Diodia scandens et Cleome gynandra. Ainsi, l’objectif principal de cette thèse est d’étudier le potentiel des extraits de ces plantes à moduler le tonus vasculaire et de déterminer les mécanismes sous-jacents. Pour cela, nous avons procédé ex vivo et in vivo à des tests de réactivité vasculaire, d’absorption des polyphénols et d’immunofluorescence de protéines cibles. Les résultats ont montré que l’extrait de Carissa edulis a été le plus actif des trois plantes. Il possède une importante activité vasorelaxante strictement dépendante de l’endothélium et médiée par le monoxyde d’azote (NO) et sa fraction butanolique (CEBF) a une activité encore plus prononcée. Le traitement de rats d'âge moyen avec l’extrait total de Carissa edulis pendant deux semaines a significativement amélioré la fonction endothéliale et restauré la relaxation médiée par le NO dans l'artère mésentérique principale et l’aorte thoracique. Il a aussi fortement réduit au niveau vasculaire le niveau d’expression d’ACE et AT1R impliqués dans la dysfonction endothéliale associée au vieillissement et à l’hypertension artérielle, et le stress oxydant. Une identification putative par métabolomique non ciblée des molécules de CEBF a révélé la présence des polyphénols, terpènes et alcaloïdes

Characterization of new vasorelaxant molecules : chemical-pharmacological studies of Carissa edulis, a medicinal species of the Beninese pharmacopoeia

Les maladies cardiovasculaires représentent la première cause de mortalité dans le monde et leur incidence est associée à plusieurs facteurs de risque majeurs dont l’hypertension (HTA). Au Bénin, plusieurs plantes sont utilisées en médecine traditionnelle pour traiter l’HTA. Trois d’entre elles ont été sélectionnées pour notre étude : Carissa edulis, Diodia scandens et Cleome gynandra. Ainsi, l’objectif principal de cette thèse est d’étudier le potentiel des extraits de ces plantes à moduler le tonus vasculaire et de déterminer les mécanismes sous-jacents. Pour cela, nous avons procédé ex vivo et in vivo à des tests de réactivité vasculaire, d’absorption des polyphénols et d’immunofluorescence de protéines cibles. Les résultats ont montré que l’extrait de Carissa edulis a été le plus actif des trois plantes. Il possède une importante activité vasorelaxante strictement dépendante de l’endothélium et médiée par le monoxyde d’azote (NO) et sa fraction butanolique (CEBF) a une activité encore plus prononcée. Le traitement de rats d'âge moyen avec l’extrait total de Carissa edulis pendant deux semaines a significativement amélioré la fonction endothéliale et restauré la relaxation médiée par le NO dans l'artère mésentérique principale et l’aorte thoracique. Il a aussi fortement réduit au niveau vasculaire le niveau d’expression d’ACE et AT1R impliqués dans la dysfonction endothéliale associée au vieillissement et à l’hypertension artérielle, et le stress oxydant. Une identification putative par métabolomique non ciblée des molécules de CEBF a révélé la présence des polyphénols, terpènes et alcaloïdes.Cardiovascular diseases represent the first cause of mortality in the world and their incidence is associated with several major risk factors including hypertension. In Benin, several plants are used in traditional medicine to treat hypertension. Three of them were selected for our study: Carissa edulis, Diodia scandens and Cleome gynandra. The objective of the thesis was to study the potential of these plant extracts to modulate vascular tone and to determine the underlying mechanisms. For this purpose, we did ex vivo and in vivo studies to study vascular reactivity, polyphenol uptake and immunofluorescence tests of target proteins. The results showed that Carissa edulis extract was the most active of the three plants. It induced pronounced and strictly endothelium-dependent vasorelaxant mediated by nitric oxide (NO), and its butanolic fraction (CEBF) was more active. Treatment of middle-aged rats with the total extract of Carissa edulis for two weeks significantly improved the endothelial function as indicated by restored NO-mediated relaxations in the main mesenteric artery and thoracic aorta. It also strongly reduced the vascular expression level of ACE and AT1R involved in endothelial dysfunction associated with aging and hypertension and reduced the level of oxidative stress. Putative identification by nontargeted metabolomics of CEBF molecules revealed the presence of polyphenols, terpenes, and alkaloids

EPA:DHA 6:1 is a superior omega-3 PUFAs formulation attenuating platelets-induced contractile responses in porcine coronary and human internal mammary artery by targeting the serotonin pathway via an increased endothelial formation of nitric oxide

International audienceAt arterial sites of endothelial denudation and dysfunction, activated platelets contribute to vascular injury through the release of potent contracting factors such as serotonin (5-HT). This study evaluated whether omega-3 polyunsaturated fatty acids (PUFAs), known to protect the vascular system, are able to prevent platelets-induced contractile responses in isolated arteries and, if so, to investigate the underlying mechanism and the importance of the omega-3 PUFAs formulation. Porcine coronary arteries (PCA), human internal mammary arteries (IMA) and washed human platelets were prepared and vascular reactivity was studied in organ chambers. In PCA rings, aggregating platelets caused concentration-dependent contractions that were significantly inhibited by the 5-HT2A receptor antagonist ketanserin, and by EPA:DHA 6:1 but not EPA:DHA 1:1 at 0.4% v/v. EPA:DHA 6:1 also prevented the 5-HT-induced contractions but affected only slightly those to the thromboxane A2 analogue U46619. The inhibitory effect of EPA:DHA 6:1 on platelets-induced contractions was not observed in rings without endothelium, and prevented by an eNOS inhibitor but not by inhibitors of endothelium-dependent hyperpolarization. In IMA rings, EPA:DHA 6:1 but not EPA:DHA 1:1 at 0.4% v/v significantly prevented the 5-HT-induced contraction, and induced greater endothelium-dependent relaxations than bradykinin and acetylcholine sensitive to an eNOS inhibitor. EPA:DHA 6:1 strongly inhibits platelets- and 5-HT-induced contractions in PCA rings and those to 5-HT in IMA rings most likely through an increased endothelial formation of NO. These findings suggest that the omega-3 PUFAs EPA:DHA 6:1 formulation may be of interest to prevent platelets-induced vascular injury at arterial sites of endothelial dysfunction

Intake of coated EPA:DHA 6:1 nanoparticles improves age-related endothelial dysfunction by restoring the endothelial formation of NO and improving oxidative stress: Role of the local angiotensin system

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Empagliflozin prevents angiotensin II-induced hypertension related micro and macrovascular endothelial cell activation and diastolic dysfunction in rats despite persistent hypertension: Role of endothelial SGLT1 and 2

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