scholarly journals Effect of the molecular weight of water-soluble chitosan on its fat-/cholesterol-binding capacities and inhibitory activities to pancreatic lipase

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3279 ◽  
Author(s):  
Qiu Jin ◽  
Huahua Yu ◽  
Xueqin Wang ◽  
Kecheng Li ◽  
Pengcheng Li

BackgroundObesity has become a worldwide burden to public health in recent decades. Given that obesity is caused by an imbalance between caloric intake and expenditure, and that dietary fat is the most important energy source of all macronutrients (by providing the most calories), a valuable strategy for obesity treatment and prevention is to block fat absorption via the gastrointestinal pathway. In this study, the fat- and cholesterol-binding capacities and the inhibition of pancreatic lipase by water-soluble chitosan (WSC) with different weight-average molecular weight (Mw) were tested and comparedin vitro, in order to determine the anti-obesity effects of WSC and the influence of its Mw.MethodsIn this study, WSC with different Mw (∼1,000, ∼3,000, ∼5,000, ∼7,000 and ∼9,000 Da) were prepared by oxidative degradation assisted with microwave irradiation. A biopharmaceutical model of the digestive tract was used to determine the fat- and cholesterol-binding capacity of WSC samples. The pancreatic lipase assays were based on p-nitrophenyl derivatives.ResultsThe results showed that all of the WSC samples exhibit great fat- and cholesterol-binding capacities. Within the testing range, 1 g of WSC sample could absorb 2–8 g of peanut oil or 50–65 mg of cholesterol, which are both significantly higher than the ability of cellulose to do the same. Meanwhile, all the WSC samples were proven to be able to inhibit pancreatic lipase activity to some extent.DiscussionBased on the results, we suggest that there is a significant correlation between the binding capacity of WSC and its Mw, as WSC2 (∼3,000 Da) shows the highest fat- and cholesterol-binding capacities (7.08 g g−1and 63.48 mg g−1, respectively), and the binding ability of WSC declines as its Mw increases or decreases from 3,000 Da. We also suggest WSC as an excellent resource in the development of functional foods against obesity for its adsorption, electrostatic binding and entrapment of cholesterol, fat, sterols and triglycerides in the diet.

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1274 ◽  
Author(s):  
Céline M. A. Journot ◽  
Laura Nicolle ◽  
Yann Lavanchy ◽  
Sandrine Gerber-Lemaire

In the field of gene therapy, chitosan (CS) gained interest for its promise as a non-viral DNA vector. However, commercial sources of CS lack precise characterization and do not generally reach sufficient solubility in aqueous media for in vitro and in vivo evaluation. As low molecular weight CS showed improved solubility, we investigated the process of CS depolymerization by acidic hydrolysis, using either long time heating at 80 °C or short time microwave-enhanced heating. The resulting depolymerized chitosan (dCS) were analyzed by gel permeation chromatography (GPC) and 1H nuclear magnetic resonance (NMR) to determine their average molecular weight (Mn, Mp and Mw), polydispersity index (PD) and degree of deacetylation (DD). We emphasized the production of water-soluble CS (solubility > 5 mg/mL), obtained in reproducible yield and characteristics, and suitable for downstream functionalization. Optimal microwave-assisted conditions provided dCS with a molecular weight (MW) = 12.6 ± 0.6 kDa, PD = 1.41 ± 0.05 and DD = 85%. While almost never discussed in the literature, we observed the partial post-production aggregation of dCS when exposed to phase changes (from liquid to solid). Repeated cycles of freezing/thawing allowed the selection of dCS fractions which were exempt of crystalline particles formation upon solubilization from frozen samples.


1980 ◽  
Vol 29 (2) ◽  
pp. 376-382
Author(s):  
H. K. Kuramitsu ◽  
L. Wondrack ◽  
M. McGuinness

The Streptococcus mutans GS5 glucosyltransferase activities (both water-soluble and -insoluble glucan-synthesizing fractions) were inhibited by purified lipoteichoic acid. In vitro sucrose-dependent colonization of smooth surfaces by strain GS5 was also markedly reduced in the presence of the amphipathic molecules. The inhibition of soluble glucan synthesis by lipoteichoic acid appeared to be competitive with respect to both sucrose and primer dextran T10. These inhibitory effects were dependent on the presence of the fatty acid components of lipoteichoic acid since deacylated lipoteichoic acids did not inhibit glucosyltransferase activity. However, the deacylated molecules did interact with the enzymes since deacylated lipoteichoic acid partially protected the enzyme activity against heat inactivation and also induced the formation of high-molecular-weight enzyme complexes from the soluble glucan-synthesizing fraction. The presence of teichoic acid in high-molecular-weight aggregates of glucosyltransferase isolated from the culture fluids of strain GS5 was suggested by the detection of polyglycerophosphate in these fractions. In addition to strain GS5, two other organisms containing polyglycerophosphate teichoic acids, Lactobacillus casei and Lactobacillus fermentum , were demonstrated to bind glucosyltransferase activity. These results are discussed relative to the potential role of teichoic acid-glucosyltransferase interactions in enzyme binding to the cell surface of S. mutans and the formation of high-molecular-weight enzyme aggregates in the culture fluids of the organism.


1962 ◽  
Vol 40 (1) ◽  
pp. 1019-1024 ◽  
Author(s):  
Seiichi Yoshida

A water-soluble pigment excreted from Serratia marcescens has been purified by precipitation with ammonium sulphate, dialysis, and ultracentrifugation at different pH values. The purified pigment showed a single band in the ultracentrifuge and by electrophoretic analysis at several pH values. An average molecular weight of 5 × 106 was calculated from light-scattering measurements. This pigment is composed of carbohydrate and protein combined with prodigiosin, and several properties of the complex are described.


2021 ◽  
Author(s):  
Vinayak Uppin ◽  
Shylaja M Dharmesh ◽  
Sarada R

Polysaccharides from natural sources play a significant role in the management of different cancer types including gastric cancer. In this study, we reported the effect of spirulina polysaccharide (Sp) on galectin-3 modulatory activity on gastric cancer cells. The polysaccharide was isolated from the spirulina biomass, characterized, and the in silico, in vitro studies are carried out to assess the bioactivities. The isolated Sp possessed average molecular weight of 1457 kDa, and galactose (42%) as major sugar along with Rhamnose, Arabinose, Xylose, and Mannose. Further, characterization of Sp by FT-IR and NMR spectrum indicated the presence of (β1-4D) galactose sugar with galactoarabinorhamnoglycan backbone. Among the monosaccharides, galactose showed highest binding affinity with galectin-3 protein as evidenced by the in silico interaction study. The obtained Sp, inhibited the proliferation of AGS gastric cancer cells by 48 % without affecting normal NIH/3T3 cells as opposed to doxorubicin, a known anticancer drug. Also, Sp exhibited galectin-3 mediated haemagglutination inhibition with MIC of 9.37 μg/mL compared to galactose 6.25 μg/mL, sugar specific to galectin-3. The Sp treatment significantly (p<0.05) lowered the expression of galectin-3 by 32 % compared to untreated control cells. In addition, Sp exhibited the potent cytoprotection in RBCs, Buccal cells, and DNA exposed to oxidants. Thus, the findings suggest that the polysaccharide from spirulina offer a promising therapeutic strategy in the management of gastric cancer in addition to its currently known nutritional and pharmaceutical applications.


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