Antidiabetic potential of mucilage fraction extracted from Astragalus gyzensis seeds

The objective of the current work is to extract a new mucilage fraction from Astragalus gyzensis Bunge. seeds, which are collected from the El-Oued province (septentrional Algerian Sahara) and evaluated for their antidiabetic potential. The mucilage fraction is obtained using hot water extraction followed by alcoholic precipitation of polysaccharides by cold ethanol (96%). The primary investigation was performed by describing the main structural features of the extract through colorimetric assays, Fourier-transform infrared spectroscopy and thin-layer chromatography analysis using two systems. Biological activity was also monitored by antidiabetic activity by testing the inhibition of α-amylase and α-glucosidase enzymes in vitro. The extraction yield was 20.69%. The chemical composition mainly consisted of 78.60±0.29% carbohydrates, among them 63.92±0.67% neutral sugar, 15.78±0.76% uronic acid, 8.08±0.04% proteins and 2.57±0.05% phenolic compounds. The results obtained by thin-layer chromatography analysis showed the dominance of mannose and galactose. Fourier-transform infrared spectrum showed characteristic bands expected galactomannans. The investigations highlighted the antihyperglycemic effect in a dose-dependent manner by the inhibition of the α-amylase enzyme (IC50=0.8±0.005 mg/mL). These factors make it suitable for the industrial application of dietary supplement fiber made for diabetic individuals. DOI: http://dx.doi.org/10.5281/zenodo.761853

Ethnic Medicine and Ethnobotany Concept to Identify and Characterize New Polysaccharide-Based Drug from Arid and Semi-Arid Lands

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A sulfated exopolysaccharide derived from Chlorella sp. exhibiting in vitro anti-α-d-Glucosidase activity

International audienceThere is a great scientific curiosity to discover all environments sheltering microalgae, especially those with exceptional characteristics from coldest to hottest ones, the purpose remains to explore the potential of the native microalgae flora and the research for new bioactive compounds. This study aimed to isolate a polysaccharide-producing microalga from an extreme ecosystem and to evaluate its capacity to inhibit the α- d - glucosidase enzyme. Chlorella strain is isolated from hypersaline Lake in the Algerian desert. The exopolysaccharide extraction was performed by the concentration of free-cell supernatant in a rotary evaporator. The infrared analysis showed a characteristic footprint of carbohydrates with particular functional groups, such as sulfate. Gas chromatography–mass spectrometry has revealed a hetero-exopolysaccharide composed of galactose 35.75%, glucose 21.13%, xylose 16.81%, fructose 6.96%, arabinose 5.10%, and glucuronic acid 2.68%. The evaluation of the anti-hyperglycemic activity demonstrated a significant α- d -glucosidase inhibition of 80.94 ± 0.01% at 10 mg mL −1 with IC 50 equal to 4.31 ± 0.20 mg mL −1 . This study opens a vast prospect to use exopolysaccharides as natural nutraceutical or food additive

Bioactivités, méthodes d’extraction et de purification des polysaccharides de produits naturels

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Mediterranean semi-arid plant Astragalus armatus as a source of bioactive galactomannan

International audienceA water-soluble polysaccharide fraction (WSPF) was extracted and purified from Astragalus armatus Lam. (Fabaceae), a spontaneous plant found in North Algerian Sahara. The structural features of WSPF were evaluated by colorimetric assays, Fourier transform infrared (FTIR) spectroscopy, high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) and gas chromatography coupled to mass spectrometry (GC/MS). WSPF was a galactomannan-rich fraction, with a β-(1,4)-d-manp backbone with α-(1,6)-d-galp branches, and a Man:Gal ratio of 1.13. Besides, the anti-complement activity and the antioxidant potential (DPPH and hydroxyl radicals) of WSPF were evaluated. The results exhibited an anti-complementary activity, with an IC50 value of 0.39 mg/mL of the fraction, better than for heparin (0.58 mg/mL). Moreover, WSPF possessed a notable antioxidant activity on DPPH radical with an IC50 of 330 µg/mL

CHEMICAL COMPOSITION AND BIOLOGICAL ACTIVITIES OF WATER-SOLUBLE POLYSACCHARIDES FROM Commiphora myrrha (Nees) Engl.GUM

International audienceMyrrha, the gum resin exudate from Commiphora myrrha (Nees) Engl. tree, has been extensively used in traditional medicine for their beneficial effects. In this work, we isolated and purified water-soluble polysaccharide fraction (WSP), which afforded a yield of 42%. The chemical composition of WSP was mainly consisted of 83.33±2.63% carbohydrates, among them 79.25±1.06% are neutral monosaccharides and 13.4± 2.18% proteins, with traces of polyphenols (3.82%): The majority components of monosaccharides were galactose (45%) and arabinose (44%), with low levels of xylose (6%), and mannose (5%): In order to evaluate the immunostimulatory effect of WSP, phagocytic activity of opsonized human leucocytes against opportunist pathogen yeast, Candida albicans, was assessed. WSP could significantly (p < 0.05) enhance phagocytic capacity at the dose of 150 μg/ml, which showed a phagocytic activity of 29%. Moreover, the antihyperglycemic activity of extract was determined by α-D-glucosidase inhibitory activity, in vitro. WSP displays a promising inhibitory activity with an IC50 value of 8.30±0.12 mg/mL. The results of this work provide new knowledge in the field of chemical composition and biological activities of polysaccharides of Commiphora myrrha gum and might play an important role in activating phagocytosis leucocytes cells, thus having contribution to antidiabetic activity

Chemical features and biological activities of water-soluble polysaccharides from Commiphora myrrha gum

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The prebiotic potential of a new galactomannan extracted from Astragalus gombo seeds

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Partial characterization and phagocytosis activity of water soluble polysaccharides from Plantago ciliata seeds

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Structural features and rheological behavior of a water-soluble polysaccharide extracted from the seeds of Plantago ciliata Desf.

International audienceA water-soluble polysaccharide (PSPC) was extracted from the seeds of Plantago ciliata Desf., a spontaneous Algerian Saharan plant by a hot aqueous extraction then purified by successive ethanolic precipitations. The final extraction yield for PSPC was close to 18.6% (w/v). PSPC was then investigated regarding its global composition, structural features and rheological properties. PSPC is a neutral arabinoxylan, composed of a β-(1,3)/β-(1,4)-D-xylan backbone with side chains of Xylp, and Araf residues attached in O-2 and O-3 positions. The macromolecular characteristics of PSPC in water was determined by SEC/MALLS, with a high molecular weight (Mw) of 700 kDa, a low polydispersity index (PDI) of 1.47 and an intrinsic viscosity [η] close to 157 mL/g. PSPC showed a pseudoplastic behavior in semi-dilute media and the critical overlay concentration (C*) was estimated around 0.32–0.37% (w/v). This current research has supplied original structural information on a new arabinoxylan which could be particularly useful as a novel source of soluble fiber belonging to psyllium