Etude de l’activité antioxydante des extraits des feuilles de Vitex doniana (Verbenacea)

L’objectif de la présente étude était d’évaluer l’activité antioxydante des extraits des feuilles de Vitex doniana par spectrophotométrie en utilisant les méthodes de piégeage des radicaux libres 2,2-diphényl-1- picryl-hydrazyle (DPPH•) et acide 2,2’-azino-bis-(3-éthylbenzothiazoline-6-sulfonique) (ABTS+•). Une extraction éthanolique des feuilles de Vitex doniana a été effectuée au Soxhlet. L’extrait sec recueilli a été redissout dans de l’eau puis fractionné en utilisant successivement de l’hexane, du dichlorométhane et de l’acétate d’éthyle. Les propriétés antioxydantes de l’extrait éthanolique et celles de ses différentes fractions ont été évaluées aux concentrations de 2,5 ; 10 ; 100 et 200 μg/mL. Les pourcentages d’inhibition (PI) expriment l’effet antioxydant mesuré. L’extrait éthanolique et ses différentes fractions ont présenté une activité de piégeage des deux radicaux libres. Lors des tests d’inhibition de l’absorbance du radical DPPH•, les PI ont varié de (18,15±0,01)% pour la fraction hexanique (2,5 μg/mL) à (92,45±0,01)% pour la fraction d’acétate d’éthyle (100 μg/mL). Avec le radical ABTS+•, les PI ont varié de (52,76±0,05)% pour la fraction hexanique (2,5 μg/mL) à (98,27±0,12)% pour la fraction d’acétate d’éthyle (100 μg/mL). Ainsi, l’extrait éthanolique des feuilles de Vitex doniana et ses différentes fractions possèdent un pouvoir antioxydant significatif.Mots clés : Activité antioxydante, DPPH, ABTS, Vitex doniana

Development and validation of a simple and economical spectrofluorimetric method for estimation of quinine in pharmaceutical dosage forms

A new simple, sensitive, precise, economic and “green” spectrofluorimetric method for the determination of quinine both as a bulk drug and in tablet formulations was developed and validated using water as solvent. At a predetermined excitation wavelength (330 nm) and emission wavelength (380 nm), it was proved linear in the concentration range of 50-500 ng/mL, exhibited good correlation coefficient (R2= 0.999) and excellent mean recovery (97.5-103%). The results of the recovery studies showed that the method was not affected by the presence of common excipients. The method was applied for the analysis of the drug in the pure, tablet and injectable forms. The method was validated for precision, accuracy and recovery studies. Limit of Detection and Limit of Quantification for quinine were found to be 16.6 ng/mL and 19.8 ng/mL respectively. The method has been successfully applied for the analysis of marketed formulations available in Senegal. © 2013 International Formulae Group. All rights reserved.Keywords: Spectrofluorometric analysis, validation, quinine, green method

Generating demand and community support for sexual and reproductive health services for young people: A review of the Literature and Programs

BACKGROUND: This review investigates the effectiveness of interventions aimed at generating demand for and use of sexual and reproductive health (SRH) services by young people; and interventions aimed at generating wider community support for their use. METHODS: Reports and publications were found in the peer-reviewed and grey literature through academic search engines; web searches; the bibliographies of known conference proceedings and papers; and consultation with experts. The studies were reviewed against a set of inclusion criteria and those that met these were explored in more depth. RESULTS: The evidence-base for interventions aimed at both generating demand and community support for SRH services for young people was found under-developed and many available studies do not provide strong evidence. However, the potential of several methods to increase youth uptake has been demonstrated, this includes the linking of school education programs with youth friendly services, life skills approaches and social marketing and franchising. There is also evidence that the involvement of key community gatekeepers such as parents and religious leaders is vital to generating wider community support. In general a combined multi-component approach seems most promising with several success stories to build on. CONCLUSIONS: Many areas for further research have been highlighted and there is a great need for more rigorous evaluation of programmes in this area. In particular, further evaluation of individual components within a multi-component approach is needed to elucidate the most effective interventions

Innate immunity against HIV: a priority target for HIV prevention research

This review summarizes recent advances and current gaps in understanding of innate immunity to human immunodeficiency virus (HIV) infection, and identifies key scientific priorities to enable application of this knowledge to the development of novel prevention strategies (vaccines and microbicides). It builds on productive discussion and new data arising out of a workshop on innate immunity against HIV held at the European Commission in Brussels, together with recent observations from the literature

The dominant Anopheles vectors of human malaria in Africa, Europe and the Middle East: occurrence data, distribution maps and bionomic précis

<p>Abstract</p> <p>Background</p> <p>This is the second in a series of three articles documenting the geographical distribution of 41 dominant vector species (DVS) of human malaria. The first paper addressed the DVS of the Americas and the third will consider those of the Asian Pacific Region. Here, the DVS of Africa, Europe and the Middle East are discussed. The continent of Africa experiences the bulk of the global malaria burden due in part to the presence of the <it>An. gambiae </it>complex. <it>Anopheles gambiae </it>is one of four DVS within the <it>An. gambiae </it>complex, the others being <it>An. arabiensis </it>and the coastal <it>An. merus </it>and <it>An. melas</it>. There are a further three, highly anthropophilic DVS in Africa, <it>An. funestus</it>, <it>An. moucheti </it>and <it>An. nili</it>. Conversely, across Europe and the Middle East, malaria transmission is low and frequently absent, despite the presence of six DVS. To help control malaria in Africa and the Middle East, or to identify the risk of its re-emergence in Europe, the contemporary distribution and bionomics of the relevant DVS are needed.</p> <p>Results</p> <p>A contemporary database of occurrence data, compiled from the formal literature and other relevant resources, resulted in the collation of information for seven DVS from 44 countries in Africa containing 4234 geo-referenced, independent sites. In Europe and the Middle East, six DVS were identified from 2784 geo-referenced sites across 49 countries. These occurrence data were combined with expert opinion ranges and a suite of environmental and climatic variables of relevance to anopheline ecology to produce predictive distribution maps using the Boosted Regression Tree (BRT) method.</p> <p>Conclusions</p> <p>The predicted geographic extent for the following DVS (or species/suspected species complex*) is provided for Africa: <it>Anopheles </it>(<it>Cellia</it>) <it>arabiensis</it>, <it>An. </it>(<it>Cel.</it>) <it>funestus*</it>, <it>An. </it>(<it>Cel.</it>) <it>gambiae</it>, <it>An. </it>(<it>Cel.</it>) <it>melas</it>, <it>An. </it>(<it>Cel.</it>) <it>merus</it>, <it>An. </it>(<it>Cel.</it>) <it>moucheti </it>and <it>An. </it>(<it>Cel.</it>) <it>nili*</it>, and in the European and Middle Eastern Region: <it>An. </it>(<it>Anopheles</it>) <it>atroparvus</it>, <it>An. </it>(<it>Ano.</it>) <it>labranchiae</it>, <it>An. </it>(<it>Ano.</it>) <it>messeae</it>, <it>An. </it>(<it>Ano.</it>) <it>sacharovi</it>, <it>An. </it>(<it>Cel.</it>) <it>sergentii </it>and <it>An. </it>(<it>Cel.</it>) <it>superpictus*</it>. These maps are presented alongside a bionomics summary for each species relevant to its control.</p

Aflatoxines dans les aliments : Recherche et dosage dans les huiles et les pâtes d’arachide de préparation artisanale

Les aflatoxines sont des mycotoxines produites par certaines souches de champignons (Aspergillus) qui se développent dans les graines d'arachide. L'arachide et ses produits de transformation tels que l'huile et la pâte étant très consommés au Sénégal, les risques d'intoxication par les aflatoxines sont potentiels. Ce travail a porté sur la déterminationdes niveaux de contamination par les aflatoxines des huiles artisanales et des pâtes d'arachide consommées au Sénégal. L'analyse par chromatographie liquide haute performance (CLHP) des différents échantillons a permis de constater une forte contamination en aflatoxine B1 (la plus redoutée) des huiles et pâtes artisanales vendues dans les marchés. Les pâtes industrielles et ménagères sont quant à elles, pour la plupart saines et propres à la consommation.Aflatoxines are mycotoxines produced by certain stumps of mushrooms (Aspergillus) which develop in the seeds of groundnut. The groundnut and its products of transformation such as the oil and the dough being very consummate in Senegal, risks of poisoning by aflatoxines are potential. This work concerned the determination of the levels of contagionby the aflatoxines of home-made oil and some peanut pastry consumed in Senegal. The analysis by high performance liquid chromatography (HPLC) of the various samples allowed to notice a strong contagion aflatoxine B1 (the most dreaded) of home-made oil and pastas sold in markets. Industrial and domestic pastry foods are as for them, for the greater part healthy and fit for consumption