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.

Phytochemical analysis, antioxidant and anti-Candida albicans activities of Annona cherimola Mill. fruit pulp

Aims: The main objectives of the present study were to characterize the phytochemical profile of Annona cherimola Mill, to assess its antioxidant characteristics and its antifungal activity against Candida albicans. Methods and Material: Aqueous decoction, aqueous infusion, aqueous maceration, and methanolic maceration were screened for the presence of phytochemicals and to quantify content of phenolics, tannins, and flavonoids. Furthermore, antioxidant activity was assessed using DPPH and FRAP assays, as well the assessment of antifungal activity for the different extracts. Results: Results showed that phenols, tannins, flavonoids, and saponins were present in the four extracts. The aqueous maceration extract presented the highest total phenolic content (3.687 mg GAE/g of extract). Decoction extract showed the lowest phenolic content 2.504 mg GAE/g. Besides, infusion showed the most important total flavonoids content (2.567mg CE/g). The most relevant total antioxidant activity was found for decoction (lowest IC50 12.61 mg/ml AAE). The aqueous maceration exhibited the less antioxidant activity (IC50= 21.98 mg/ml AAE). The best scavenging activity was observed for decoction (IC50=7.27 mg/mL). All the extracts showed a reducing capacity. Infusion exhibited the best reducing power (EC50 = 11.29 mg/mL), compared to decoction (EC50 = 39.32 mg/mL). Regarding antifungal activity, at 100 and 200 µg/mL, decoction and methanolic maceration resulted in 6 and 9 mm inhibition zone, respectively. In addition, at higher doses (800 and 2000 µg/mL), inhibition zone increased in a dose dependent manner for all the extracts. Conclusions: Annona cherimola Mill. could be an important source of bioactive molecules with antioxidant and antifungal activities

Phytochemical Screening and Quantification of Flavonoids from Leaf Extract of Jatropha Curcas Linn

Background: The Jatropha curcas L.(Euphorbiaceae) herb is found in SouthWest; Nigeria and other parts of West Africa; and is claimed to possess anti-hypertensive property. Objective: The phytochemical screening and flavonoid quantification of the leaf extract of Jatropha curcas Linn were studied. Methods: The phytochemical screening of the methanolic leaf extract of J. curcas L. was carried using acceptable and standard methods. The flavonoid contents of the leaf extract of Jatropha curcas L. were determined using thin layer chromatography (TLC); infrared spectroscopy (IRS) and a reversed phase high performance liquid chromatography (HPLC). Results: The phytochemical screening of the methanolic extract of the leaves of the plant shows the presence of alkaloids; cardiac glycosides; cyanogenic glycosides; phlobatannins; tannins; flavonoids and saponins. To quantify the flavonoid contents of leaf extract of Jatropha curcas L ; extracts from the plant samples where examined in a C-18 column with UV detection and isocratic elution with acetonitrile; water (45:55). Levels of flavonoids (flavones) in leaves ranged from 6:90 to 8:85 mg / g dry weight. Conclusion : Results indicate that the methanolic extract of the leaves of Jatropha curcas L. contains useful active ingredients which may serve as potential drug for the treatment of diseases. In addition; a combination of TLC; IRS and HPLC can be used to analyse and quantify the flavonoids present in the leaves of Jatropha curcas L

Phytochemical Screening and Free Radical Scavenging Activities of the Fruits and Leaves of Allanblackia floribunda Oliv (Guttiferae)

Purpose: To compare the phytochemical constituents in the leaves and fruits of Allanblackia floribunda and determine their free radical scavenging activity. Methods: The fruit and leaves of AF collected from the uncultivated farmlands of Okeigbo; Ondo State; Nigeria; were dried; milled and extracted with methanol. Phytochemical screening was carried out according to standard procedures. Free radical scavenging activity was determined by measuring the decrease in the visible absorbance of 2;2-diphenyl-1 -picrylhydrazyl (DPPH) on addition of the plant extract. The mean inhibitory concentration (IC50); which is the concentration of extract needed to decrease the initial absorbance of DPPH by 50was determined graphically. Total phenolic; flavonoids and proanthocyanidin contents were determined by spectro-photometric methods. Results: Alkaloids; anthraquinones; tannins; saponins; steroids; terpenoids; flavonoids and cardiac glycosides were found to be present in both the fruits and leaves. Only AF fruit contained phlobatannins. IC50 values of 0.01; 0.02 and 0.1 mg/ml were recorded for Vitamin E; AF leaves and AF fruits respectively. Total phenolic; total flavonoid and proanthocyanidin contents were 65; 0.07 and 2.38 mg/g of powdered plant material for AF fruits; and 12; 51.35; 19.5 mg/g of powdered plant material for AF leaves as gallic acid; rutin and catechin equivalents respectively. Conclusion: AF leaves are five times more potent as a free radical scavenger compared to the fruits though the fruit was found to contain a higher phenolic content

Quercetin: a Versatile Flavonoid

Associative evidence from observational and intervention studies in human subjects shows that a diet including plant foods (particularly fruit and vegetables rich in antioxidants) conveys health benefits. There is no evidence that any particular nutrient or class of bioactive substances makes a special contribution to these benefits. Flavonoids occur naturally in fruits; vegetables and beverages such as tea and wine. Quercetin is the major flavonoid which belongs to the class called flavonols. Quercetin is found in many common foods including apples; tea; onions; nuts; berries; cauliflower; cabbage and many other foods. Quercetin provides many health promoting benefits; including improvement of cardiovascular health; eye diseases; allergic disorders; arthritis; reducing risk for cancers and many more. The main aim of this review is to obtain a further understanding of the reported beneficial health effects of Quercetin; its pharmacological effects; clinical application and also to evaluate its safety

Contribution a l'etude d'une plante utilisee traditionnellement comme poison d'epreuve au Gabon : le Strychnos icaja (Mbundu); Loganiacee

Le Strychnos icaja Baillon (Loganiacee) est une plante tropicale frequente dans les forets d'Afrique Centrale (Congo; Cameroun; Gabon.). Cette espece de Strychnos est aussi utilisee par les populations locales comme poison d'epreuve ou de fleches ou pour traiter les hemorroides mais elle est egalement utilisee par les tribus pygmees du Cameroun pour traiter le paludisme persistant. Elle est aussi employee pour ses proprietes magico-medicales. Les feuilles; les tiges et les racines renferment de nombreux alcaloides dont la Strychnine. Elle renferme en plus des tanins galliques dans les tiges et racines et des tanins catechiques dans les feuilles. On note egalement la presence de flavonoides; de sterols; de triterpenes et de saponosides dans toutes les parties etudiees