Veronica Mantovani

Recent advances on separation and characterization of human milk oligosaccharides.

Free human milk oligosaccharides (HMOs) are unique due to their highly complex nature and important emerging biological and protective functions during early life such as prebiotic activity, pathogen deflection, and epithelial and immune cell modulation. Moreover, four genetically determined heterogeneous HMO secretory groups are known to be based on their structure and composition. Over the years, several analytical techniques have been applied to characterize and quantitate HMOs, including nuclear magnetic resonance spectroscopy, high‐performance liquid chromatography (HPLC), high pH anion‐exchange chromatography, off‐line and on‐line mass spectrometry (MS), and capillary electrophoresis (CE). Even if these techniques have proven to be efficient and simple, most glycans have no significant UV absorption and derivatization with fluorophore groups prior to separation usually results in higher sensitivity and an improved chromatographic/electrophoretic profile. Consequently, the analysis by HPLC/CE of derivatized milk oligosaccharides with different chromophoric active tags has been developed. However, UV or fluorescence detection does not provide specific structural information and this is a key point in particular related to the highly complex nature of the milk glycan mixtures. As a consequence, for a specific determination of complex mixtures of oligomers, analytical separation is usually required with evaluation by means of MS, which has been successfully applied to HMOs, resulting in efficient compositional analysis and profiling in various milk samples. This review aims to give an overview of the current state‐of‐the‐art techniques used in HMO analysis.

Human Milk Glycosaminoglycans Inhibit in vitro the Adhesion of Escherichia coli and Salmonella fyris to Human Intestinal Cells

Background:Breast-fed infants have a lower incidence of acute gastroenteritis due to the presence of several anti-infective factors in human milk. The aim of this work is to study the capacity of human milk glycosaminoglycans (GAGs) to inhibit the adhesion of some common pathogenic bacteria.Methods:GAGs were isolated from a pool of milk samples collected from different mothers during the first month of lactation. Experiments were carried out to study the ability of GAGs to inhibit the adhesion of two intestinal micro-organisms (enteropathogenic Escherichia coli serotype 0119 and Salmonella fyris) to Caco-2 and Int-407 cell lines.Results:The study showed that the GAGs had an anti-adhesive effect on the two pathogenic strains studied with different degrees of inhibition. In particular, in the presence of human milk GAGs, the adhesion of S. fyris to Caco-2 cells and to Int-407 cells of both tested strains was significantly reduced.Conclusion:Our results demonstrated that GAGs in human milk can be one of the important defensive factors against acute diarrheal infections in breast-fed infants.

Chondroitin Sulfate and Glucosamine as Disease Modifying Anti- Osteoarthritis Dru gs (DMOADs).

Osteoarthritis is a disabling affliction expected to increase in the coming decades, and disease- modifying osteoarthritis drugs (DMOADs) would be highly desirable adjuncts to symptomatic relief and structure reconstruction as they may delay the disease process. Chondroitin sulfate and glucosamine have been observed to exert beneficial effects on the metabolism of various cells involved in osteoarthritis as well as in animal models and clinical trials. Clinical trials have reported beneficial effects of both these biological agents, alone or in combination, on pain and functions as well as their structure-modifying capacity reported and analyzed in recent meta-analyses. Nonetheless, the effectiveness of these bioactive (macro)molecules as DMOADs reported from randomized trials is mismatched. Current studies with varying levels of evidence suggest that chondroitin sulfate and glucosamine can modify the disease progression but at the same time there are not absolute certainties on their efficacy in modifying the course of the disease. This comprehensive review aims to clarify the role of these compounds in the therapeutic molecules/ drugs useful to patients affected by osteoarthritis.

Recent advances in capillary electrophoresis separation of monosaccharides, oligosaccharides and polysaccharides

This article illustrates the basis and applications of methodologies for the analysis of simple and complex carbohydrates by means of CE. After a description of the most common and novel approaches useful for the analysis and characterization of carbohydrates, this review covers the recent advances in CE separation of monosaccharides, oligosaccharides, and polysaccharides. Various CE techniques are also illustrated for the study of carbohydrates derived from complex glyco‐derivatives such as glycoproteins and glycolipids, essential for biopharmaceutical and glycoproteomics applications as well as for biomarker detection. Most glycans have no significant UV absorption, and derivatization with fluorophore groups prior to separation usually results in higher sensitivity and an improved electrophoretic profile. We also discuss the recent applications and separations by CE of derivatized simple and more complex carbohydrates with different chromophoric active tags. Overall, this review aims to give an overview of the most recent state‐of‐the‐art techniques used in carbohydrate analysis by CE.

Purification, structural characterization and antiproliferative properties of chondroitin sulfate/dermatan sulfate from tunisian fish skins

Chondroitin sulfate/dermatan sulfate GAGs were extracted and purified from the skins of grey triggerfish (GTSG) and smooth hound (SHSG). The disaccharide composition produced by chondroitinase ABC treatment showed the presence of nonsulfated disaccharide, monosulfated disaccharides ΔDi6S and ΔDi4S, and disulfated disaccharides in different percentages. In particular, the nonsulfated disaccharide ΔDi0S of GTSG and SHSG were 3.5% and 5.5%, respectively, while monosulfated disaccharides ΔDi6S and ΔDi4S were evaluated to be 18.2%, 59% and 14.6%, 47.0%, respectively. Capillary elecrophoresis analysis of GTSG and SHSG contained 99.2% and 95.4% of chondroitin sulfate/dermatan sulfate, respectively. PAGE analysis showed a GTSG and SHSG having molecular masses with average values of 41.72KDa and 23.8KDa, respectively. HCT116 cell proliferation was inhibited (p<0.05) by 70.6% and 72.65% at 200μg/mL of GTSG and SHSG respectively. Both GTSG and SHSG demonstrated promising antiproliferative potential, which may be used as a novel, effective agent.

Studies on European eel skin sulfated glycosaminoglycans: Recovery, structural characterization and anticoagulant activity

Abstract The goal of the present work was the extraction and structural characterization of novel sulfated glycosaminoglycans from European eel skin. The recovered glycosaminoglycans were physicochemically characterized and the uronic acid and sulfate contents were 35.12 ± 2.13% and 16.32 ± 0.4%, respectively. Cellulose acetate electrophoresis for extracted glycosaminoglycans was also investigated. Molecular weight of these sulfated glycosaminoglycans was determined (~37 kDa) by the gradient PAGE. Glycosaminoglycans obtained from the European eel were composed of non-sulfated, mono- and disulfated disaccharides. These sulfated glycosaminoglycans were evaluated for their in vitro anticoagulant activity using activated partial thromboplastin time, thrombin time and prothrombin time tests. The result showed that the recovered glycosaminoglycans exhibited interestingly anticoagulant activity. These glycosaminoglycans did not show haemolytic activity towards human erythrocytes. Furthermore, these bioactive substances can be explored as a functional food with antithrombotic function or used as source of anticoagulant drugs.

Oral Bioavailability and Pharmacokinetics of Nonanimal Chondroitin Sulfate and Its Constituents in Healthy Male Volunteers

The pharmacokinetic profile of a new 800‐mg tablet of nonanimal chondroitin sulfate (CS) (Mythocondro®, 800‐mg tablets, Gnosis S.p.A., Italy) was investigated vs an animal CS in healthy volunteers for a total period of 48 hours. After a single 2400‐mg dose of the test and the reference formulation, total CS, the compositional disaccharides (ΔDi6S, ΔDi4S and ΔDi0S), and the overall charge density were quantified in plasma. The safety and tolerability profile after a single dose of this new nonanimal CS tablets was excellent. After baseline‐corrected concentrations, an overall greater plasma concentration was observed after 24 hours of ∼44% and after 48 hours of ∼45% from administration of nonanimal when compared to animal‐derived CS. Moreover, nonanimal CS increases the specific sulfation in the 6‐position of N‐acetyl‐galactosamine in human plasma CS and, as a consequence, the overall charge density, reaching double values (0.91), after 48 hours compared to bovine CS and to endogenous CS. In conclusion, nonanimal CS, possessing a lower molecular weight than an animal‐derived sample, produces a greater CS concentration for a more prolonged period of time in plasma and an increase in charge density and specific 6‐sulfation of endogenous plasma CS.

Chondroitin sulfate/dermatan sulfate from corb ( Sciaena umbra ) skin: Purification, structural analysis and anticoagulant effect

In this study, chondroitin sulfate/dermatan sulfate was isolated and purified from the skin of corb (Sciaena umbra) (CSG) with a yield of 6.2%. Chemical and structural analysis showed that CSG consisted of high sulfate content 28.74% and an average molecular weight of 15.46 KDa. The separation of CSG by agarose-gel electrophoresis revealed the presence of DS and CS. Structural analysis of the purified CS/DS by means of SAX-HPLC after treatment with specific chondroitinases showed that this polymer was composed of nonsulfated disaccharide, monosulfated disaccharides and disulfated disaccharides in various percentages. The results also suggest that the percentage of CS and DS recovred in CSG were 24% and 76%, respectively. Anticoagulant activity in vitro was measured in plasma using classical anticoagulation tests: activated partial thromboplastin time (aPTT), thrombin time (TT) and prothrombine time (PT) tests. The findings thus indicated that the purified CS/DS exhibits a remarkably high anticoagulant effect.

Isolation, Purification and Structural Characterestics of Chondroitin Sulfate from Smooth hound Cartilage: In vitro Anticoagulant and Antiproliferative Properties

Chondroitin sulfate was extracted from the cartilage of smooth hound (CSSH) and then purified by anion exchange chromatography. The structual characteristic of CSSH was evaluated by acetate cellulose electrophoresis, FTIR, 13C NMR and SAX-HPLC. Molecular weight of CSSH was average 68.78 KDa. Disaccharide analysis indicated that CSSH was predominately composed of monosulfated disaccharides in position 6 and 4 of the N-acetylgalactosamine (45.34% and 32.49%, respectively). CSSH was tested for in vitro anticoagulant activity using the three classical coagulation assays (activated partial thromboplastin time (aPTT), prothrombine time (TT) and thrombin time (PT) tests). The finding showed that CSSH prolonged significatively (p < 0.05), aPTT, TT and PT about 1.4, 3.44 and 1.21 fold, respectively, greater than that of the negative control at a concentration of 100 μg/ml. The CSSH caused a significant antiproliferative activity against HCT116 cell, which was 79% of cell proliferation inhibition at the concentration of 1000 μg/ml. Further, CSSH presented no toxicity against the normal cells and no hemolysis towards bovine erythrocytes for all concentrations tested. CSSH demonstrated hopeful antiproliferative and anticoagulant potential, which may be used as a novel and effective drug.

Composition and structure of glycosaminoglycans in DBS from 2-3-day-old newborns for the diagnosis of mucopolysaccharidosis

Dried blood spot (DBS) technology is a cheap and easy method largely applied in newborn screening. Mucopolysaccharidoses (MPS) are characterized by the deficit of enzymes that degrade glycosaminoglycans (GAGs) characterized by progressive worsening of the conditions. For a possible early diagnosis of MPS, we developed a method of uronic acid (UA)-GAGs determination in DBS of 600 healthy newborns and from a small group of MPS subjects matched for age. Spotted blood UA-GAGs of the normal newborns are composed of 67.2% chondroitin sulfate (CS), 28.6% heparan sulfate (HS) and 4.4% hyaluronic acid with a CS/HS ratio of 2.35 and a total GAGs content of 0.43 μg/DBS. A chemical evaluation of CS and HS structure was performed by measuring their disaccharide composition, sulfation and the overall charge density. The DBS of four different MPS types presented an increase of total or single UA-GAGs content and/or modifications of the CS and HS disaccharide composition as well as chemical signature also related to the MPS enzymatic defect. The modifications of the UA-GAGs composition, parameters and structure of healthy newborns determined in DBS would be useful for a possible early diagnosis of various MPS types.