Teneurs en phénols totaux, activités antioxydantes des macérés et décocté des feuilles de Uvaria chamae P. Beauv. (Annonaceae)

Uvaria chamae est une plante de la biodiversité Ivoirienne utilisée en médecine traditionnelle. Malgré les vertus biologiques et thérapeutiques de cette plante, peu d’informations sur la teneur en phénols totaux et l’activité antioxydante existent. L’objectif de cette étude était d’évaluer la teneur en phénols totaux, l’activité antioxydante de macéré aqueux, de macéré éthanolique et de décocté aqueux des feuilles de Uvaria chamae. La teneur en phénols totaux a été effectuée par la méthode de Folin-Ciocalteu. L’activité antioxydante a été évaluée par la méthode de piégeage du DPPH (2,2-diphenyl-1-picrylhydrazyle) et d’ORAC (Oxygen Radical Absorbance Capacity). La teneur en phénols totaux était respectivement de 110,51 ± 7,18 µg GAE/mg d’extraits, de 86,34 ± 1,38 µg GAE/mg d’extrait et de 65,80 ± 0,13 µg GAE/mg d’extrait pour le macéré éthanolique, le décocté aqueux et le macéré aqueux de Uvaria chamae. Les différents macérés et décocté ont présenté une activité de piégeage des deux radicaux libres. S’agissant du radical DPPH, le macéré éthanolique de U. chamae exerce une forte activité antiradicalaire significative avec un CI50 de l’ordre de 0,08 ± 0,02 mg/ml. Avec la méthode ORAC, le macéré éthanolique de U. chamae (3,51 ± 0,15 µmol TE/µg d’extrait) et le décocté aqueux de U. chamae (3,36± 0,18 µmol TE/µg d’extrait) présentent des valeurs d’activités antioxydantes significatives. Par contre, les valeurs de l’activité  antioxydante du macéré aqueux de U. chamae (3,04 ± 0,20 µmol TE/µg d’extrait) et du témoin positif : extrait éthanolique de R.  officinalis (2,54 ± 0,06 µmol TE/µg d’extrait) ne sont pas significativement différentes (P ˃ 0,05). Ces résultats montrent l’existence d’une bonne corrélation linéaire entre la teneur en phénols totaux et le pouvoir antioxydant des différents macérés et décocté de cette plante. Cette plante Ivoirienne pourrait donc être considérée comme une source d’antioxydant naturel à des fins médicinales.Mots clés : Uvaria chamae, teneur en phénols totaux, antioxydant, Côte d’Ivoir

SUPERFICIAL ANTICANDIDOSIC ACTIVITY OF LEAVES OF COMBRETUM RACEMOSUM P. BEAUV. (COMBRETACEAE) EXTRACTS

This preliminary work consists in evaluating the superficial anticandidic activity of the leaves of Combretum racemosum P. Beauv in humans. To this end, we first demonstrated bioactive compounds of five (5) crude extracts (aqueous and hydro-organic 70%) from C. racemosum. Then, and finally, we have separately evaluated the superficial anticandidic activity of these extracts on Candida albicans, a species of genus Candida, mostly encountered in superficial human candidiasis. C. albicans was found to be sensitive to the five extracts tested. This partly justifies the use of C. racemosum in traditional medical practice against superficial microbial diseases. For these extracts, the Inhibitory Minimum Concentrations (MIC) recorded ranged from 7.8125 mg/mL to 62.550 mg/mL; While Fungicide Minimum Concentrations (CMF) range from 31.25 ± 0.00 mg/mL to 62.550 mg/mL. Concentrations for Fifty Percent Inhibition (IC50) range from 0.930 mg/mL to 3.861 mg/mL. The hydroethanolic macerated extract 70% (Eeth 70%) is the most active fraction on C. albicans (CMF = 7.8125 ± 0.00 mg/mL, IC50 = 0.941 ± 0.009 mg/mL) compared to the total of the five crude extracts tested. The preliminary phytochemical screening of the five crude extracts revealed the presence of alkaloids, saponins, terpenoids steroids and tannins (catechics and gallics) at various levels of concentration in our study. Eeth 70%, the most active extract in our work, contains in medium concentrations the same active ingredients cited above.  Finally, we note that the hydroethanolic macerated extract 70% is the most active fractions in this work. It may, however, subject to toxicological studies, be used in the treatment of theskin, the cutaneous appendages and the mucous membranes in humans. Keywords: Combretum racemosum, phytochemical screening, superficial anticandidi

Phytochemical screening, mineral analysis and evaluation of the diuretic effect of aqueous extract of Pericopsis laxiflora from male Sprague Dawley rats

Pericopsis laxiflora is among the medicinal plants used by the traditional practitioner in the treatment of many diseases. However, data on its diuretic power are lacking. Moreover, the effect of the preparation of traditional galenic formulations on the composition of phytocompounds and essential minerals and metals is unknown. The aim of this study was to show the effect of treatment on the phytocompounds   and minerals composition and to evaluate diuretic effect of Pericopsis laxiflora aqueous axtracts. The tube characterization reactions revealed flavonoids, sterols, terpenes, catechin tannins polyphenols and saponins in aqueous extracts. Gallic tannins  and quinones are absent, All compounds were generally present in same proportions in two aqueous extracts. Chemical analysis of all aqueous extracts by atomic absorption spectrometry (AAS) showed effect of model extraction on minerals. Copper (0.3116 mg / 100g), magnesium (260.7 mg /100 g), selenium (0.00904 mg /100 g), zinc (4.52 mg /100 g), manganese (75.029 mg /100g) are more concentrated in maceration than a   decoction. For decoction of same plant, the situation is reversed with sodium (58.6mg /100g), calcium (12670 mg/100g), iron (18.51mg/100g) and potassium (2781 mg /100g). For pharmacological investigation, 32 rats Sprague Dawley male weighing 385-433g are isolated each in metabolic cages from 6 pm to 8am  and treated with 100mg/kg of Pericopsis laxiflora aqueous extracts. From 8am to 2pm the animals received only tap water in metabolic cages. The volumes of water intake and urine were not significantly different in the two groups (treated and untreated).The diuretic effect was not observed with 100mg/kg (b/w) . In addition   polyphenols, flavonoids, saponins and minerals such as potassium, magnesium and selenium are indicators of the vasodilatory and cardioprotective functions of Pericopis laxiflora aqueous extracts. The prescription of these extracts in traditional medicine must take into account the toxicity of the plant associated with a calcium and manganese content. Keywords:  Pericopsis laxiflora, dueresis, decocted extract, macerated extract, minerals, Rats Sprague Dawele