Odile Germaine Nacoulma

Polyphenol Content and Antioxidant Activity of Fourteen Wild Edible Fruits from Burkina Faso

A total of fourteen (14) species of wild edible fruits from Burkina Faso were analyzed for their phenolic and flavonoid contents, and their antioxidant activities using the DPPH, FRAP and ABTS methods. The data obtained show that the total phenolic and total flavonoid levels were significantly higher in the acetone than in the methanol extracts. Detarium microcarpum fruit had the highest phenolic and the highest flavonoid content, followed by that of Adansonia digitata, Ziziphus mauritiana, Ximenia americana and Lannea microcarpa. Significant amounts of total phenolics were also detected in the other fruit species in the following order of decreasing levels: Tamarindus indica > Sclerocarya birrea > Dialium guineense > Gardenia erubescens > Diospyros mespiliformis > Parkia biglobosa > Ficus sycomorus > Vitellaria paradoxa. Detarium microcarpum fruit also showed the highest antioxidant activity using the three antioxidant assays. Fruits with high antioxidant activities were also found to possess high phenolic and flavonoid contents. There was a strong correlation between total phenolic and flavonoid levels and antioxidant activities.

Phytochemical Composition, Antioxidant and Xanthine Oxidase Inhibitory Activities of Amaranthus cruentus L. and Amaranthus hybridus L. Extracts

This paper describes a preliminary assessment of the nutraceutical value of Amaranthus cruentus (A. cruentus) and Amaranthus hybridus (A. hybridus), two food plant species found in Burkina Faso. Hydroacetonic (HAE), methanolic (ME), and aqueous extracts (AE) from the aerial parts were screened for in vitro antioxidant and xanthine oxidase inhibitory activities. Phytochemical analyses revealed the presence of polyphenols, tannins, flavonoids, steroids, terpenoids, saponins and betalains. Hydroacetonic extracts have shown the most diversity for secondary metabolites. The TLC analyses of flavonoids from HAE extracts showed the presence of rutin and other unidentified compounds. The phenolic compound contents of the HAE, ME and AE extracts were determined using the Folin–Ciocalteu method and ranged from 7.55 to 10.18 mg Gallic acid equivalent GAE/100 mg. Tannins, flavonoids, and flavonols ranged from 2.83 to 10.17 mg tannic acid equivalent (TAE)/100 mg, 0.37 to 7.06 mg quercetin equivalent (QE) /100 mg, and 0.09 to 1.31 mg QE/100 mg, respectively. The betacyanin contents were 40.42 and 6.35 mg Amaranthin Equivalent/100 g aerial parts (dry weight) in A. cruentus and A. hybridus, respectively. Free-radical scavenging activity expressed as IC50 (DPPH method) and iron reducing power (FRAP method) ranged from 56 to 423 µg/mL and from 2.26 to 2.56 mmol AAE/g, respectively. Xanthine oxidase inhibitory activities of extracts of A. cruentus and A. hybridus were 3.18% and 38.22%, respectively. The A. hybridus extract showed the best antioxidant and xanthine oxidase inhibition activities. The results indicated that the phytochemical contents of the two species justify their traditional uses as nutraceutical food plants.

Antimicrobial activity of polyphenol-rich fractions from Sida alba L. (Malvaceae) against co- trimoxazol-resistant bacteria strains

BackgroundThe increased resistance of microorganisms to the currently used antimicrobials has lead to the evaluation of other agents that might have antimicrobial activity. Medicinal plants are sources of phytochemicals which are able to initiate different biological activities including antimicrobialsMaterials and methodsIn vitro antibacterial (MIC, MBC and time-kill studies) of polyphenol-rich fractions from Sida alba L. (Malvaceae) was assessed using ten bacteria strains (Gram-negative and Gram-positive).ResultsAll test bacteria were susceptible to the polyphenol-rich fractions. Time-kill results showed that after 5 h exposition there was no viable microorganism in the initial inoculum and the effect of polyphenol-rich fractions was faster on Enterococcus faecalis (Gram-positive bacterium) comparatively to the other bacteria strains.ConclusionThe data analysis indicates that the tested of polyphenol-rich fractions has significant effects when compared with the standard antibiotic. These results therefore justify the traditional use of sida alba L., alone or in combination with other herbs to treat bacterial infections.

Mutagenic effect, antioxidant and anticancer activities of six medicinal plants from Burkina Faso

The antiproliferative activities of six medicinal plant extracts from Burkina Faso were evaluated in order to justify their traditional use for the treatment of cancer. The SOS chromotest method was used in vitro on Escherichia coli PQ37 to evaluate the mutagenic effect of the plant extracts. The DPPH method was used to evaluate the antioxidant activity of each plant. The antiproliferative activity was evaluated by MTS method on normal cells (Vero and MCR5) and cancer cells (KB) in contact with the extracts for 72 h. The results showed that the studied plants are not genotoxic. Lantana ukambensis and Acacia macrostachya induced a very significant antiproliferative effect against cancer cells with 94% and 95%, respectively. They also developed a strong antioxidant activity. The IC50 values were 5.96 ± 0.40 µg mL−1 for L. ukambensis and 4.30 ± 0.26 µg mL−1 for A. macrostachya. These two plants are therefore potential sources for isolating new antioxidant and anticancer molecules.

Cytotoxic pentacyclic triterpenes from Combretum nigricans.

A new pentacyclic triterpene, 11alpha-acetoxy-20,24-epoxy-25-hydroxy-dammar-3-one (1), has been isolated from the African tree Combretum nigricans, together with the known corresponding diol, 20,24-epoxy-11alpha, 25-dihydroxy-dammar-3-one (2). They are responsible, at least in part, for the cytotoxic activity of the methanolic extract of the plant.

Antiacetylcholinesterase and antioxidant activity of essential oils from six medicinal plants from Burkina Faso

In this investigation, we evaluated essential oils from six medicinal plants from Burkina Faso for their antiacetylcholinesterase and antioxidant abilities. The chemotype of most active were also determined. The best antiacetylcholinesterase activities were recorded for the essential oils of Eucalyptus camaldulensis (IC50 18.98 µ g/mL) and Ocimum canum (IC50 36.16 µ g/mL). Their chemotype have been related to the 1,8-cineole one. Both essential oils demonstrated a linear mixed non competitive inhibition. The essential oil of Ocimum basilicum which belong to the linalool-eugenol chemotype exhibited the best radical scavenging activity (IC50 3.82 µ g/mL) and reducing power (531.75 mg AAE/g). In comparison with gallic and ascorbic acids, O. basilicum essential oil evidenced interesting antioxidant activities. The antiacetylcholinesterase and antioxidant activities of essential oils were discussed in regard with their chemical composition.

Antioxidant and Anti-Inflammatory Effects of Scoparia dulcis L.

Different extracts were obtained from Scoparia dulcis L. (Scrophulariaceae) by successive extraction with hexane, chloroform, and methanol. These extracts exhibited significant antioxidant capacity in various antioxidant models mediated (xantine oxidase and lipoxygenase) or not mediated (2,2-diphenyl-picrylhydrazyl, ferric-reducing antioxidant power, β-carotene bleaching, lipid peroxidation) by enzymes. The antioxidant activity of the extracts was related to their phytochemical composition in terms of polyphenol and carotenoid contents. The chloroform extract was richest in phytochemicals and had the highest antioxidant activity in the different antioxidant systems. All the extracts exhibited less than 50% inhibition on xanthine oxidase but more than 50% inhibition on lipid peroxidation and lipoxygenase. The extracts strongly inhibited lipid peroxidation mediated by lipoxygenase.

IND-6, a Highly Divergent IND-Type Metallo-β-Lactamase from Chryseobacterium indologenes Strain 597 Isolated in Burkina Faso

ABSTRACT The genus Chryseobacterium and other genera belonging to the family Flavobacteriaceae include organisms that can behave as human pathogens and are known to cause different kinds of infections. Several species of Flavobacteriaceae, including Chryseobacterium indologenes, are naturally resistant to β-lactam antibiotics (including carbapenems), due to the production of a resident metallo-β-lactamase. Although C. indologenes presently constitutes a limited clinical threat, the incidence of infections caused by this organism is increasing in some settings, where isolates that exhibit multidrug resistance phenotypes (including resistance to aminoglycosides and quinolones) have been detected. Here, we report the identification and characterization of a new IND-type variant from a C. indologenes isolate from Burkina Faso that is resistant to β-lactams and aminoglycosides. The levels of sequence identity of the new variant to other IND-type metallo-β-lactamases range between 72 and 90% (for IND-4 and IND-5, respectively). The purified enzyme exhibited N-terminal heterogeneity and a posttranslational modification consisting of the presence of a pyroglutamate residue at the N terminus. IND-6 shows a broad substrate profile, with overall higher turnover rates than IND-5 and higher activities than IND-2 and IND-5 against ceftazidime and cefepime.

Antioxidant, diuretic activities and polyphenol content of Stereospermum kunthianum Cham. (Bignoniaceae)

Stereospermum kunthianum was used for biological and phytochemical investigations. In biological studies, antioxidant activities were investigated with water, methanol and aqueous acetone extracts. Furthermore, the xanthine oxidase inhibitory activity and the diuretic activity of an aqueous acetone extract were evaluated. In the phytochemical investigations, the flavonoids and polyphenols were quantified spectrophotometrically in all extracts followed by high-performance liquid chromatography-mass spectrometry (HPLC–MS) analysis of an aqueous acetone extract. The 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing/antioxidant power (FRAP) and 2,2′-azinobis (3-ethylbenzoline-6-sulphonate (ABTS) methods have shown that the aqueous acetone extract presents the best antioxidant activities. This aqueous acetone extract was further proven to have interesting xanthine oxidase inhibitory activity, but only a weak diuretic activity. This aqueous acetone extract also possessed the highest phenolic and flavonoid contents. HPLC–MS analysis allowed identifying and quantifying, rutin, isoquercitrin, quercetin, hyperoside, quercitrin and luteolin and the glycosides of ferulic, sinapic p-coumaric acids and kaempferol, apigenin in aqueous-acetone extract.

Identification and quantification of phenolic compounds from Balanites aegyptiaca (L) Del (Balanitaceae) galls and leaves by HPLC–MS

Balanites aegyptiaca is a tropical plant which is widely used for medicinal purposes in several African countries, including Burkina Faso. Despite its widespread use, little is known about its phenolic content. This study sought to carry out a screening of the polyphenols from the leaves and galls of B. aegyptiaca. A high-performance liquid chromatography–mass spectrometry method was used to investigate the phenolic content in the parts of the plant studied here. The phenolic acid profile showed the presence of gentisic, p-coumaric, caffeic, ferulic and sinapic acids in the crude and hydrolysed extracts. The flavonoids pattern showed hyperoside, isoquercitrin, rutoside and quercitrin in the crude extract of leaves. Myricetol, quercetol and kaempferol were found after acid hydrolysis of the leaves extract. Ferulic acid, isoquercitrin, rutoside and quercitrin were identified as major phenolic compounds in this study.