SPASMOLYTIC EFFECTS OF AQUEOUS EXTRACT OF MIXTURE FROM AFRAMOMUMUM MELEGUETA (K SCHUM) – CITRUS AURANTIFOLIA (CHRISTM AND PANZER) ON ISOLATED TRACHEA FROM RAT

The spasmolytic properties of the aqueous extract of Aframomum melegueta (K Schum) and Citrus aurantifolia (Christm and Panzer) (AMCA) mixture were tested on isolated rat trachea. Inhibition of the contraction was observed the in presence of the AMCA (EC 50 = 1.80 ± 0.48 mg/mL) after a pre contraction of the trachea by acetylcholine (10 -5 M). With propranolol (10 -6 M), the spasmolytic activity of the mixture was inhibited and the concentration-response curve shifted to the right. The EC50 value was then 2.60 ± 0.41 mg/mL. AMCA also inhibited contraction induced by KCl (4.10 -2 M) with EC50 value = 1.86 ± 0.65 mg/mL. These results clearly show the relaxing effect of the aqueous extract on the isolated rat trachea. This effect involved some β-adrenergic receptor inhibition

Composition Chimique Et Influence De Différents Tweens Sur Le Pouvoir Antimicrobien Des Huiles Essentielles De Ocimum Gratissimum, Ocimum Basilicum, Laurus Nobilis Et Melaleuca Quinquenervia

This study aimed firstly to determine the chemical composition, Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of essential oils extracted from Ocimum gratissimum, Ocimum basilicum, Laurus nobilis and Melaleuca quinquenervia collected from Benin (West Africa) on five oral microorganisms (Micrococcus luteus ATCC 10240, Staphylococcus aureus ATCC 29213, Proteus mirabilis ATCC 24974, Pseudomonas aeruginosa ATCC 27853 and Candida albicans IP 4872), and secondly to assess the influence of different tweens on antimicrobial potential of four oils against previous microorganisms. Using Clevenger apparatus, oil extraction was performed by steam distillation and the chemical compositions was determined by chromatography. The antimicrobial activity of different oils was evaluated according to microdilution method using ELISA microplates. From this study, Tween 60 proved best to others tweens (20, 40 and 80) by ensuring proper dispersion and distribution of oils. With tween 60, O. brasilicum essential oil proved the most effective of the four oils with the lowest MIC (0.078 mg/ml) and CMB (0.078 mg/ml) and is effective on all oral germs tested. Chemical screening of these species revealed the presence of several compounds among which thymol (30.62%), para-cymene (25.25%) and gamma-terpinolene (24.24%) (O. gratissimum); methyl-chavicol (85.92%) (O. basilicum); eugenol (42.50%), myrcene (28.09%) (L. nobilis) and beta-ocimene (29.62%), alphapinene (12.11%) and viridiflorol (11.85%) (M. quinquenervia)

HPLC quantification of two isomeric triterpenic acids isolated from Mitracarpus scaber and antimicrobial activity on Dermatophilus congolensis

Oleanolic (OA) and ursolic acids (UA) were isolated for the first time from the alcoholic extract of Mitracarpus scaber possessing antimicrobial effects on Dermatophilus congolensis. These two triterpenic acids were also active (MIC 15 microg/ml) on this causative agent of dermatophilosis in African animals. To quantify OA and UA in M. scaber, a new, simple and rapid high-performance liquid chromatography (HPLC) method compatible with MS detection was developed and validated. The mobile phase acetonitrile:H2O (85:15, v/v) was pumped through a C18 octadecylsilyl silica column at a flow rate of 0.6 ml/min and the eluate was monitored at 215 nm. The calibration curves constructed between 0.5 and 10 microg/ml showed linear relationships with good R2 values. The developed method was precise and reproducible with relative standard deviations (RSD) for these two active constituents between 0.22-2.06% (intraday) and 1.61-3.72% (interday) for concentrations from 0.5 to 6 microg/ml. Limits of detection and quantification were, respectively, 0.2 and 0.5 microg/ml

Chemical characterization and origin of dyes used in the manufacture of Beninese cultural heritage objects

International audienceSix objects of Beninese cultural heritage provided by African and Confluences museums of Lyon (France) were the focus of this study. The characterization of colored compounds was achieved using: microchemical tests, Fourier transform infrared spectroscopy and liquid chromatography coupled to a photodiode array detector. The main results reflect the presence of organic compounds like indigotin, 2-hydroxynaphthoquinone, and mineral ions such as Al 3+ , S 2− , Na + , and Fe 3+. Dyes were identified from Philenoptera cyanescens (Yoruba indigo) and Lawsonia inermis L. (henna); pigments were identified as laundry blue, Prussian blue, and iron oxides. All of these data therefore make possible the conservation and the restoration of these objects while maintaining their visual and functional integrity

Développement et validation d’une méthode quantitative de dosage par Chromatographie Liquide à Haute Performance Ultra-violet (CLHP-UV) de l’artémisinine dans Artemisia annua cultivé au Bénin

Artemisia annua, espèce de la famille des asteraceae est une plante dont les feuilles contiennent une lactone sesquiterpénique appelée artémisinine qui est efficace contre toutes les souches de parasites responsables du paludisme. Cette étude nous a permis de développer et de valider une méthode de Chromatographie : la méthode de Chromatographie Liquide à Haute Performance (CLHP), dans le but de quantifier l’artémisinine dans les poudres de feuilles d’Artemisia annua cultivé au Bénin. La méthode de Chromatographie Liquide à Haute Performance développée, est validée pour les quantités en artémisinine de 200 à 1200 ng. Les analyses fournissent une bonne : exactitude, reproductibilité, et sélectivité pour l'analyse quantitative de l'artémisinine. La courbe de calibration est linéaire avec un coefficient de corrélation R2 = 0,9988. Les coefficients de variations (CV) intra-jour ou répétabilité et inter-jours ou fidélité intermédiaire sont inférieurs à 5% pour toutes les séries de quantités en artémisinine. Les taux de récupération de l’artémisinine par la méthode d’extraction au soxhlet sont d’environ 98%. Les limites de détection et de quantification ont été déterminées : elles sont respectivement inférieures à 2,4 et 8 ng. La teneur en artémisinine est d’environ 0,3% pour la poudre de feuilles d’artemisia annua cultivé au Bénin