Étude in vitro de l’effet antifalcémiant des globules rouges et de l’activité antioxydante d’extraits de la poudre de racines de Maytenus senegalensis Lam (Celestraceae)

La drépanocytose est une hémoglobinopathie largement répandue chez les populations africaines noires. Actuellement, très peu de traitements conventionnels existent sur le marché, d’où le recours à la médecine traditionnelle. Maytenus senegalensis est une plante prescrite par les tradipraticiens dans la prise en charge de la drépanocytose. L’activité antifalcémiante des extraits de la poudre de racines de Maytenus senegalensis a été étudiée dans ce travail. Après obtention de l’extrait hexanique par extraction à l’aide d’un Soxhlet, le marc est macéré dans de l’acétate d’éthyle puis dans du méthanol pour donner les extraits correspondants. L’activité des fractions a été évaluée sur des drépanocytes de type SS. Les activités antifalcémiantes les plus importantes ont été observées pour les fractions polaires du méthanol et de l’acétate d’éthyle avec des taux d’inversion de la falciformation respectivement de 77% et de 65% à 10 mg/mL. Les activités antioxydantes de M. senegalensis (CI50 = 0,195 ± 0,004 mg/mL) et de l’acide ascorbique (CI50 = 0,078 ± 0,002 mg/mL) ont été déterminées. Les pouvoirs antioxydants (PA) montrent que l’activité antiradicalaire de l’acide ascorbique (PA = 12,85) est 2,5 fois meilleure que celle de M. senegalensis (PA = 5,14). Les résultats de l’étude justifient l’utilisation traditionnelle des racines de Maytenus senegalensis dans la prise en charge de la drépanocytose.Mots clés : Hémoglobine, drépanocytose, Maytenus senegalensis, activité antifalcémiante, stress oxydant, radicaux libres, activité antioxydante

TIMES-WAPP, a Long-Term Prospective Model for the West African Power System

International audienc

Scoping study on building resilient groundnut and millet value chains in Senegal

The cultivation of groundnuts and millet, which has historically been the cornerstone of Senegal's agricultural economy, continues to be an essential component in the nation's efforts to lift its rural population out of poverty. However, increased climatic variability, extreme weather events and market risk has resulted in increased vulnerability of the groundnut and millet value chains impacting the rural livelihoods adversely. As part of the AICCRA project this scoping aims analyses the current situation of the groundnut and millet value chains in terms of performance, access to technologies, climate information delivery and vulnerability and resilience. It also attempts to map the value chain stakeholders and their functions. This report is groundwork to undertake further research to build and assess dynamic value chain model to inform policy makers, stakeholders and development agencies in creating favourable frameworks and design interventions that can promote resilience, farmers’ profitability, efficiency, competitive businesses, sustainable development, poverty alleviation and environmental protection in targeted regions

Antioxidant and antiglycation properties of two mango (Mangifera indica L.) cultivars from Senegal

Objective: To evaluate the total phenolic contents, antioxidant and antiglycation activities of leaves, barks, roots and kernels from two cultivars of Mangifera indica (Anacardiaceae). Methods: Total phenolic contents were determined by using Folin-Ciocalteu's method. The antioxidant activities were assessed by three different protocols including DPPH, oxygen radical absorbance capacity and iron (II) chelation assays. In addition, in vitro bovine serum albumin/D-ribose assay was chosen to evaluate the antiglycation properties of the extracts. Results: All the investigated extracts were found to contain high level of total phenols as well as potent antioxidant activities. Kernel extracts showed the highest total phenol contents and DPPH radical scavenging activities whereas higher oxygen radical absorbance capacity values were observed for leave, root and bark extracts. Besides, extracts from leaves, roots and barks from both cultivars exhibited potent inhibitory effects against the formation of advanced glycation end products, with IC50 values lower than the standard positive control aminoguanidine. Conclusions: The potent antiglycation and antioxidative activities of these two Mangifera indica cultivars suggest a possible role in targeting aging, diabetic complications and oxidative stress related diseases

Chemical Constituents and Antimicrobial and Antioxidant Activities of Essential Oil from Dried Seeds of Xylopia aethiopica

The study aimed to investigate the chemical composition and antimicrobial and antioxidant activities of the essential oil from dried seeds of Xylopia aethiopica. The essential oil was obtained by hydrodistillation and analyzed by GC/FID and GC/MS. The essential oil yield was 1.35%. Forty-nine compounds were identified in the essential oil with 1,8-cineole (16.3%), β-pinene (14.8%), trans-pinocarveol (9.1%), myrtenol (8.3%), α-pinene (5.9%), and terpinen-4-ol (5.6%) as major components. The antimicrobial activity of this essential oil was studied using disk diffusion and broth microdilution methods on four bacteria (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa) and one fungus (Candida albicans). The essential oil exhibited excellent activity against S. aureus, E. faecalis, and C. albicans and moderate activity against E. coli. Among all strains tested, C. albicans showed the best sensitivity with a MIC of 50 mg/mL. The antioxidant activity was examined using a DPPH-free radical scavenging assay. The essential oil of X. aethiopica showed low antioxidant activity (IC50 = 784.604 ± 0.320 mg/mL) compared to that of ascorbic acid and the reference compound (IC50 = 0.163 ± 0.003 mg/mL). The results indicate that consumption of X. aethiopica seeds can reduce the virulence of food-borne pathogens and their resistance to antibiotics

Evaluation of antibacterial and antifungal activities of N-benzylthienopyrimidinone derivatives

This study is part of the biological investigation of the chemical library of molecules already described by the Laboratory of Organic Chemistry and Therapeutic Chemistry of the University of Bordeaux. The main objective was to explore the contribution of a thienyl moiety attached to the pyrimidinone nucleus, in the expression of an antimicrobial activity. The structural modifications mainly concerned the conservation or not of  the  benzo fragment attached to the thienyl, the saturation or not in position-1,2 of the pyrimidinone ring, the substitution on N-benzyl with more or less lipophilic units, the modification of the orientation of the thienyl fragment with, on  the one hand, the compounds in which the sulfur is located near the N1 nitrogen (series of thieno[2,3-d]pyrimidin-4-ones) and on the other hand, compounds in which the sulfur is located near the ketone group (series of thieno[3,2-d]pyrimidin-4-ones). In general, thienyl fragment with sulfur located near the ketone group and the unsaturated pyrimidinone nucleus in the 1,2-position, seem to promote a broad spectrum of antibacterial activity, with compound 9c which is active on both Gram + bacteria and Gram – bacteria studied. The same pattern was observed for antifungal activity, which is maximum with the compounds of the thieno[3,2-d]pyrimidin-4-ones series for an MIC of 31.25 μg/ml on the strains of Candida albicans and Candida kruzei studied. Keywords: Thienopyrimidinones, antibacterial activity, antifungal activity