Profilage phytochimique par chromatographie sur couche mince haute performance d'extraits de flavonoïdes totaux du Drepanoalpha® et évaluation de leur activité anti-drépanocytaire in vitro / In vitro evaluation of anti-sickling activity of crude flavonoid extracted from Drepanoalpha® and their phytochemical profiling by high performance thin layer chromatography

Contexte et objectif. Le défi le plus important dans la drépanocytose consiste à améliorer l'état de santé des patients dans les pays en développement. L'une des meilleures solutions est donc le développement de la phytomédecine basée sur la connaissance de la pharmacopée traditionnelle. L'objectif de la présente étude était d'évaluer les activités anti-drépanocytaires des flavonoïdes totaux extraits du phytomédicament Drépanoalpha® d'une part et déterminer leur profilage chimique par chromatographie sur couche mince haute performance d'autre part. Méthodes. Les flavonoïdes totaux ont été obtenus par fractionnement de l'extrait méthanolique par chromatographie flash (PURIFLASH COLUMN 30 SILICA HP - 12,0 g) et purifies à l'aide d'une cartouche (Polymeric Reversed Phase) puis caractérisés et dosés par chromatographie sur couche mince haute performance (CCMHP). L'activité anti-drépanocytaire a été mise en évidence grâce aux tests d'Emmel, de polymérisation, de rapport Fe2+/Fe3+, d'hémolyse et de la fragilité osmotique membranaire. Résultats. La poudre du Drépanoalpha® contenait une quantité de flavonoïdes totaux de 8,14 mg équivalent de quercétine/g d'extrait. Les flavonoïdes totaux extraits du Drépanoalpha® possèdent une activité antifalcémiante (avec le taux maximal de normalisation d'environ 90 % et une concentration minimale de normalisations de 11,4 µg/mL), un taux d'augmentation du rapport Fe2+/Fe3+ de 97,0 %, une activité anti-hémolytique avec une fragilité corpusculaire membranaire des érythrocytes (FCM) de 0,73 et un taux d'inhibition de la polymérisation de 77,5%. Conclusion. La pertinence des résultats de cette étude permet de confirmer les flavonoids comme phytomarqueur pour le contrôle de qualité et de standardisation de cet alicament.

Strategic establishment of an International Pharmacology Specialty Laboratory in a resource-limited setting

Background: A growing number of drug development studies that include pharmacokinetic evaluations are conducted in regions lacking a specialised pharmacology laboratory. This necessitated the development of an International Pharmacology Specialty Laboratory (IPSL) in Zimbabwe.Objectives: The aim of this article is to describe the development of an IPSL in Zimbabwe.Methods: The IPSL was developed collaboratively by the University of Zimbabwe and the University at Buffalo Center for Integrated Global Biomedical Sciences. Key stages included infrastructure development, establishment of quality management systems and collaborative mentorship in clinical pharmacology study design and chromatographic assay development and validation.Results: Two high performance liquid chromatography instruments were donated by an instrument manufacturer and a contract research organisation. Laboratory space was acquired through association with the Zimbabwe national drug regulatory authority. Operational policies, standard operating procedures and a document control system were established. Scientists and technicians were trained in aspects relevant to IPSL operations. A high performance liquid chromatography method for nevirapine was developed with the guidance of the Clinical Pharmacology Quality Assurance programme and approved by the assay method review programme. The University of Zimbabwe IPSL is engaged with the United States National Institute of Allergy and Infectious Diseases Division of AIDS research networks and is poised to begin drug assays and pharmacokinetic analyses.Conclusions: An IPSL has been successfully established in a resource-limited setting through the efforts of an external partnership providing technical guidance and motivated internal faculty and staff. Strategic partnerships were beneficial in navigating challenges leading to laboratory development and training new investigators. The IPSL is now engaged in clinical pharmacology research

Testing for Drugs of Abuse - Part 2

This is the second article in this series. The first looked at some of the commonly encountered drugs of abuse; discussed the range of samples on offer; established why urine is the preferred matrix; and addressed methods of sample adulteration. Part 2 briefly discusses immunoassay technology; the means to comment on the integrity of a sample and issues regarding cut-points and interpretations. The necessity for confirmatory testing of positive test results is discussed and the use of a mass spectrometric method is recommended for this purpose

Chromatographic and anti-motility studies on extracts of loranthus micranthus linn

The anti-motility properties of the leaves of African mistletoe; Loranthus micranthus (Linn); Loranthaceae harvested from Kola acuminatahost tree was studied by the charcoal meal test in mice. The intraperitoneal LD50 of the methanol extract was determined in mice by the Locke's method. The phytochemical constituents of the leaf extract were also determined. An attempt was also made to resolve the extracts into its components using thin layer chromatography (TLC). The leaves of L. micranthus were found to contain alkaloids; cyanogenetic glycosides; saponins; flavonoids; tannins; proteins and resins. The intraperitoneal LD50 of the methanol extract of the leaves in mice was calculated to be 5916 mg/kg. Among the chromatographic solvent systems tested; toluene: diethylamine (19:1) gave the best resolution in all the extracts. The highest number of spots was obtained with the ethanol extract. Result of the charcoal meal test revealed that the methanol extract had a significant dose-dependent anti-motility effect. At a dose of 200 mg/kg; the methanol extract produced a decrease in gastric transit time; which was significantly (P 0.05) higher than that of atropine (10 mg/kg)

Compatibility Studies on some Commercially Available Gentamicin Sulphate Injections with Commonly Co-Administered Parenterals

Compatibility of four brands of gentamicin sulphate injection with five parenteral drugs-dexamethasone; diazepam; hyoscine butylbromide; furosemide and promethazine were studied. These drugs are commonly used together in pre-anaesthetic or post-anaesthetic medications among others. For the different test situations; solutions of varying concentrations of gentamicin sulphate were prepared and mixed with the test drugs. After the test period; all the admixtures were evaluated for gentamicin potency; Ph changes; clarity and extent of interaction. Potency changes were determined by microbial assays while the extend of interaction was determined by chromatographic techniques. No significant changes in pH were observed in all the admixture studied. A significant reduction in potency was observed in all the admixtures of Gentarad. No significant interactions were observed based on the chromatographic studies

Chromatographie des acides amines urinaires chez l'enfant malnutri en Cote d'Ivoire

L'etude chromatographique des acides amines urinaires chez l'enfant malnutri a abouti aux constatations suivantes : le tryptophane pourrait etre considere comme un indicateur biologique de la malnutrition proteino-calorifique (M.P.C.); la triade tryptophane-isoleucine-arginine semble caracteriser les MPC et egalement les cas de deces dus a cette affection