Cette étude porte sur la caractérisation structurale partielle et les activités biologiques d'une fraction polysaccharidique (GFC) isolée, par macération à chaud, de la gomme-résine de
Ferula ...communis
L. (Apiaceae) récoltée au Sahara. Le rendement massique de l'extrait était de 33,5 %. L'étude de la composition biochimique de cet extrait a révélé qu'il était constitué de 87,03 ± 0,01 % d'oses totaux (72,7 % d'oses neutres et 27,46 % d'oses acides) et de 5,29 ± 0,005 % de protéines. L'analyse de la composition monosaccharidique par chromatographie haute performance échangeuse d'anions après hydrolyse acide a permis d'identifier le galactose (69,31 %) comme espèce monosaccharidique majoritaire, et l'arabinose (12,34 %), l'acide glucuronique (5,50 %), l'acide galacturonique (1,99 %) et le rhamnose (7,36 %) comme espèces minoritaires. Ces résultats ont pu être confirmés par chromatographie en phase gazeuse après dérivatisation des monosaccharides issus de l'hydrolyse. La mesure de l'activité antihyperglycémiante de l'extrait mesuré par la détermination de son activité inhibitrice sur l'α-D-glucosidase a révélé son potentiel hypoglycémiant (IC
50
= 9 mg/ml). L'activité antiradicalaire a été évaluée par la mesure du pouvoir de piégeage du DPPH. La préparation a une IC
50
de 5,08 mg/ml.
Pseudomonas aeruginosa
et
Salmonella enterica
sont sensibles à l'extrait polysaccharidique avec une CMI de 0,5 mg/ml pour les deux souches bactériennes, alors qu'
Escherichia coli
et
Klebsiella pneumoniae
sont apparues comme moins sensibles avec une CMI de 2,5 et 1 mg/ml, tandis que
Listeria monocytogenes
était résistante.
The study focuses on a partial structural characterization and biological activities of a polysaccharide fraction (GFC) isolated after hot maceration of the gum resin of
Ferula communis
L. (Apiaceae) collected in the Sahara. The mass yield of the extract was 33.5%. The biochemical composition of this extract revealed that it was made up of 87.03 ± 0.01% of total oses (72.7% of neutral oses and 27.46% of uronic acids) and 5.29 ± 0.005% of proteins. The analysis of the monosaccharide composition by high-performance anions exchange chromatography after acid hydrolysis of the polysaccharide extracted made it possible to identify galactose (69.31%) as the major monosaccharide species and arabinose (12.34%), glucuronic acid (5.50%), galacturonic acid (1.99%) and rhamnose (7.36%) as minority ones. These results were confirmed by gas chromatography after derivatization of the monosaccharides resulting from acidic hydrolysis. Measurement of the antihyperglycaemic activity of the isolated extract by determining its inhibitory activity on α-D-glucosidase revealed its hypoglycaemic potential (IC
50
= 9 mg/ml). The anti-free radical activity was evaluated by measuring the scavenging power of DPPH at an IC
50
of 5.08 mg/ml.
Pseudomonas aeruginosa
and
Salmonella enterica
are sensitive to the polysaccharide extract exhibiting a MIC of 0.5 mg/ml for both bacterial strains.
Escherichia coli
and
Klebsiella pneumoniae
appeared to be less sensitive with MICs of 2.5 and 1 mg/ml respectively, whereas
Listeria monocytogenes
was resistant.
Introduction Depuis la loi HPST, les pharmaciens d’officine sont impliqués dans l’accompagnement de patients atteints de maladie chronique. Le projet Diabétopharma visait à accompagner des ...pharmaciens d’officine dans la réalisation d’entretiens individuels avec des patients diabétiques. Les impacts des entretiens sur les habitudes de vie des patients et le ressenti des pharmaciens et des médecins traitants ont été évalués. Patients et méthodes Des focus groups patients, pharmaciens et médecins généralistes ont été réalisés pour déterminer les attentes. Douze pharmaciens du Nord-Pas-de-Calais ont été accompagnés, par un infirmier et un diététicien spécialisés en éducation thérapeutique, pour la réalisation d’entretiens individuels d’environ 30 minutes au sein de leurs officines. L’écoute empathique et la posture éducative ont guidé les entretiens de 70 patients. Les pharmaciens disposaient d’outils pédagogiques adaptés et ont été encouragés à informer les médecins traitants de la démarche et à leur transmettre un compte-rendu. Diabétopharma a été évalué au travers de questionnaires de satisfaction et d’échanges avec les pharmaciens, les patients et leurs médecins généralistes. Résultats Les pharmaciens rapportent que le programme leur a permis d’être sensibilisés et initiés à la posture éducative à adopter lors d’entretiens individuels et a renforcé leurs connaissances sur le diabète. 70 % des patients interrogés à 3 mois de l’entretien observent un impact positif sur leurs habitudes de vie (vigilance alimentaire, augmentation de l’activité physique) mais un test appréciant l’observance thérapeutique n’a pas été amélioré. 80 % des médecins généralistes interrogés apprécient l’initiative, instaurant un nouveau maillon dans le suivi des patients diabétiques. Ils encouragent le déploiement du projet à plus grande échelle. Conclusion Le pharmacien est un acteur du parcours de soins du patient diabétique. Cette étude démontre qu’un accompagnement par des professionnels experts en éducation ainsi que des outils spécifiques apportent aux pharmaciens les moyens d’acquérir les compétences nécessaires à la réalisation d’entretiens individuels. Un impact sur l’observance thérapeutique nécessitera une action dans la durée. Déclaration d’intérêt Les auteurs déclarent avoir un intérêt avec un organisme privé, industriel ou commercial en relation avec le sujet présenté. Étude sponsorisée par Sanofi France.
Probiotics and prebiotics play an important role in human nutrition. In recent years there has been a significant increase in research on the characterization and verification potential health ...benefits associated with the use of probiotic and prebiotic. The main effects attributed to selected probiotics/prebiotic products have been proved by clinical trials, while others have been acquired on the basis of in vitro tests which require in vivo transposition in order to be validated. The main clinical reports in the literature for the application of probiotic have been done for the treatment of infectious diseases including viral, bacterial or antibiotic associated diarrhoea, relief of chronic bowel inflammatory diseases, immuno-modulation, lowering of serum cholesterol, decreased risk of colon cancer, improve lactose digestion, reduce allergies, and effect on intestinal microbiota. Although the large investigation for the health benefits, information on probiotic species, a specific strain-therapeutic application, and sufficient dosages, is not sufficiently studied to allow practical and rational consumption. Moreover, prebiotic oligosaccharides although provided curative and nutritional values, they are poorly understood in regard to their origin, the processes employed to generate them, their fermentation profiles, and dosages required for health effects. The present review summarizes guidelines reported on the literature in regard to clinician or therapeutic trials of probiotic and prebiotic.
► Overview of prebiotic and probiotic. ► Prebiotic health benefits. ► Mains application of probiotic for inflammatory intestinal diseases. ► Probiotic interact with gut immune system and immuno-modulation. ► Probiotic provide health beneficial effects.
•Xanthan was successfully C-6 carboxylated by TEMPO/NaOCl/NaBr media system.•A new family of polyglucuronic acid called xanthouronan was generated.•Xanthouronan was a high molecular weight ...polysaccharide with antioxidant properties.•Xanthouronan was very resistant to various enzymatic treatments.
A xanthouronic acid sodium salt called xanthouronan was produced from xanthan by regioselective oxidation with NaOCl/NaBr using 2,2,6,6-tetramethylpiperidine-1-oxy radical (TEMPO) as catalyst. The efficiency of the one pot TEMPO-mediated oxidation was confirmed by HPAEC-PAD, 13C NMR, and FT-IR. The oxidation degree was close to 98% and the mass yield of this new polyglucuronic acid was higher than 90% (w/w). The macromolecular characterization of xanthouronan using SEC-MALLS showed a molecular size reduced by a third due to the oxidation treatment and the degree of polymerization (DP) of the xanthouronan form was about 665. The evaluation of the enzymatic degradation of this C-6 carboxylated xanthan by various polysaccharide hydrolases and one polysaccharide lyase showed its high resistant to biodegradation. The antioxidant activity of xanthouronan was also tested by using the 2,2′-diphenyl-1-picrylhydrazyle (DPPH) and hydroxyl radical procedures. At 1g/L, xanthouronan presented 75% of the ascorbic acid antioxidant activity.
Arabinogalactans (AGs) are plant heteropolysaccharides with complex structures occasionally attached to proteins (AGPs). AGs in cell matrix of different parts of plant are freely available or ...chemically bound to pectin rhamnogalactan. Type I with predominantly β-d-(1 → 4)-galactan and type II with β-d-(1 → 3) and/or (1 → 6)-galactan structural backbones construct the two main groups of AGs. In the current review, the chemical structure of AGs is firstly discussed focusing on non-traditional plant sources and not including well known industrial gums. After that, processes for their extraction and purification are considered and finally their techno-functional and biological properties are highlighted. The role of AG structure and function on health advantages such as anti-tumor, antioxidant, anti-ulcer- anti-diabetic and other activites and also the immunomodulatory effects on in-vivo model systems are overviewed.
•High yield polysaccharides extraction from Cereus triangularis cladodes.•Arabinogalactan from Cereus triangularis cladodes with Araf/Galp=0.67 ratio.•High molecular weight mucilage from Cereus ...triangularis cladodes.•Antioxidant properties of arabinogalactan.
Cereus triangularis (Cactaceae) is a cactus used in food decoction as a traditional medicine in the North region of Madagascar to reduce stomach ache and intestinal diseases. Hydrocolloids were sequentially extracted from its cladodes with a yield of 24% (240mg/g based on dried cladodes powder). Structural analyses has revealed that this polysaccharide with a molecular mass of 8430,000g/mol was mainly composed of a galactan backbone of a (1→4) linked β-d-Galp residues probably substituted at position 3 by l-arabinofuranosyl residues. In vitro antioxidant activity of this arabinogalactan-rich fraction was detected and quantified by radical DPPH scavenging, hydroxyl radical scavenging, radical anion superoxide scavenging and reducing power method.
ABSTRACT
We present the Global Rapid Advanced Network Devoted to the Multi-messenger Addicts (GRANDMA). The network consists of 21 telescopes with both photometric and spectroscopic facilities. They ...are connected together thanks to a dedicated infrastructure. The network aims at coordinating the observations of large sky position estimates of transient events to enhance their follow-up and reduce the delay between the initial detection and optical confirmation. The GRANDMA programme mainly focuses on follow-up of gravitational-wave alerts to find and characterize the electromagnetic counterpart during the third observational campaign of the Advanced LIGO and Advanced Virgo detectors. But it allows for follow-up of any transient alerts involving neutrinos or gamma-ray bursts, even those with poor spatial localization. We present the different facilities, tools, and methods we developed for this network and show its efficiency using observations of LIGO/Virgo S190425z, a binary neutron star merger candidate. We furthermore report on all GRANDMA follow-up observations performed during the first six months of the LIGO–Virgo observational campaign, and we derive constraints on the kilonova properties assuming that the events’ locations were imaged by our telescopes.
Single cell analysis circumvents the need to average data from large populations by observing each cell individually, thus enabling the analysis of cell-to-cell variability. The ability to work on ...this scale presents many new opportunities for the life sciences and biomedical applications. Microfluidics has become a tool of choice for such studies and electrowetting on dielectric (EWOD) technology is well adapted for samples with reduced size and biological studies at the single cell level. In the present manuscript, for the first time, we present an integrated and automated system based on EWOD that can process the complete workflow on a single device, from the isolation of a single cell to mRNA purification and gene expression analysis.
The N=52Ga83β decay was studied at ALTO. The radioactive 83Ga beam was produced through the ISOL photofission technique and collected on a movable tape for the measurement of γ-ray emission following ...β decay. While β-delayed neutron emission has been measured to be 56–85% of the decay path, in this experiment an unexpected high-energy 5–9 MeV γ-ray yield of 16(4)% was observed, coming from states several MeVs above the neutron separation threshold. This result is compared with cutting-edge QRPA calculations, which show that when neutrons deeply bound in the core of the nucleus decay into protons via a Gamow–Teller transition, they give rise to a dipolar oscillation of nuclear matter in the nucleus. This leads to large electromagnetic transition probabilities which can compete with neutron emission, thus affecting the β-decay path. This process is enhanced by an excess of neutrons on the nuclear surface and may thus be a common feature for very neutron-rich isotopes, challenging the present understanding of decay properties of exotic nuclei.
Totally unknown at the beginning of the nineties, polyglucuronic acids have aroused the interest of scientific community working with polysaccharides. These polyuronides, initially isolated from ...microorganisms, have been later identified in some complex cell walls such as those of green algae. The recent progresses in the regioselective oxidation of neutral glucans permits them to be obtained on a large scale under relatively mild conditions. At the same time, new enzymes able to degrade these polysaccharides have been identified leading notably to the description of a new polysaccharide lyase family. The different forms of polyglucuronic acids such as those of low molecular weight obtained after enzymatic degradation of β-(1,4)-polyglucuronic acids have been tested for biological activities with success. So, several industrial applications associated with these compounds have been patented. This review focuses on this class of polyuronides and the enzymes capable of cleaving them.
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