Characterized Polysaccharides from Green Tea Inhibited Starch Hydrolysis and Glucose Intestinal Uptake by Inducing Microstructural Changes of Wheat Starch.

The purpose of the current study was to investigate the effect of green tea ethanol extract (GTE) and polysaccharide fractions from green tea (PFGs) on the hydrolysis of wheat starch, microstructural changes, and intestinal transport of glucose. The amount of resistant starch (RS) was significantly lowered in the water-soluble polysaccharide (WSP), water-soluble polysaccharide-pectinase (WSP-P), and water-insoluble polysaccharide-alkali soluble (WISP-Alk-Soluble; p < 0.05). The microstructures of gelatinized wheat starch granules with WSP, WSP-P, and WISP-Alk-Soluble were spherical with small cracks. The amount of intestinal transported glucose from digested wheat starch was 2.12-3.50 times lower than the control group. The results from the current study suggest that water- and alkali-soluble PFGs could be potential ingredients to lower starch hydrolysis as well as to control the postprandial blood glucose level when foods that contain starch are consumed.

Application of X-ray diffraction and energy dispersive spectroscopy in the isolation of sulfated polysaccharide from Porphyra haitanensis and its antioxidant capacity under in vitro digestion.

BACKGROUND: The separation and purification of Porphyra haitanensis polysaccharide (PHP), and the determination of changes in molecular weight (Mw) and antioxidant capacity after in vitro digestion, were undertaken. RESULTS: Analysis of two polysaccharide fractions (PHP0.5-1-UF and PHP1.0-1-UF) by various techniques showed that they were very pure sulfated polysaccharides without pigment or protein. PHP0.5-1-UF was filamentous or 'tape-like' sheets, whereas PHP1.0-1-UF had some filaments and large numbers of rounded aggregates. The Mw of PHP, PHP0.5-1-UF and PHP1.0-1-UF was 2.06 × 106 (±2.02%), 6.68 × 106 (±3.17%), and 1.14 × 106 (±3.44%) (g mol-1 ), respectively. After in vitro digestion, the Mw of PHP, PHP0.5-1-UF, and PHP1.0-1-UF decreased. Their antioxidant capacities were markedly higher than before digestion, especially PHP0.5-1-UF and its digestion products, which might be related to the reductions in Mw. CONCLUSION: These findings provide a greater understanding of the separation and purification of sulfated polysaccharides and the influence of digestion on biological activity. They also contribute to the practical application of sulfated polysaccharides in functional foods. © 2021 Society of Chemical Industry.

Fractionation, structural characteristics and immunomodulatory activity of polysaccharide fractions from asparagus (Asparagus officinalis L.) skin.

The physicochemical properties, structural features and structure-immunomodulatory activity relationship of pectic polysaccharides from the white asparagus (Asparagus officinalis L.) skin were systematically studied. Using sequential ethanol precipitation, five sub-fractions namely WASP-40, WASP-50, WASP-60, WASP-70 and WASP-80 with distinct degree of esterification (DE) and molecular weight (Mw) were obtained. The Mw and DE values were decreased with the increase of the ethanol concentrations. Structurally, although 4-α-D-GalpA was the dominant sugar residue in all fractions, the molar ratios were decreased, whereas other sugar residues including arabinose- and mannose-based sugar residues overall increased with the increase of ethanol concentration. In addition, the effects of sub-fractions on the RAW 264.7 cells indicated that pectic polysaccharides with the higher DE value showed a stronger immunomodulatory activity. Moreover, the structure-activity relationship was also discussed in this study, which extends the value-added application of asparagus and its processing by-products.

Avaliação in vitro e in vivo do potencial imunomodulador de frações polissacarídicas extraídas do chuchu / In vitro and in vivo evaluation of the immunomodulatory potential of polysaccharide fractions extracted from chayote

Os polissacarídeos não amido constituem importante parcela das fibras dietéticas, e podem ser considerados modificadores de resposta biológica (MRBs), uma vez que são capazes de interagir com o sistema imune, e suas características estruturais estão atreladas aos efeitos biológicos gerados. O potencial imunomodulador dos polissacarídeos do chuchu já foi demonstrado, entretanto, informações sobre suas características estruturais e sua relação com o perfil imunológico são limitadas a ensaios in vitro, não havendo, até o momento, estudos in vivo. Assim, o objetivo do estudo foi avaliar, in vitro e in vivo, o perfil imunomodulador de frações isoladas do polissacarídeo do chuchu. Por meio da filtração tangencial foram obtidas as frações de estudo, SeRI<50 e SeSE<50, respectivamente as frações isoladas do polissacarídeo do chuchu extraídas do resíduo insolúvel e do sobrenadante pós-tratamento enzimático para retirada do amido com peso molecular menor que 50 kDa. A caracterização por meio da determinação da composição monossacarídica e da análise de ligação apontou que ambas as frações são formadas por galacturonanos, arabinanos, arabinogalactanos e glicomananos. A SeRI<50 é menos ramificada e, provavelmente, composta por galactanos, enquanto SeSE<50 é mais ramificada e, provavelmente, composta por galactuglucomananos. Essas frações foram capazes de estimular os macrófagos murinos RAW 264.7 e as células mononucleares do baço, do sangue e do intestino delgado de camundongos Balb/c, sugerindo um perfil de ação mais pró-inflamatório, com base nos efeitos produzidos pelas espécies reativas de oxigênio, citocinas e pelos marcadores de ativação de linfócitos. Ambas as amostras, SeRI<50 e SeSE<50, mostraram ser eficientes em ativar a cascata imunológica, não sendo citotóxicas mesmo com a maior concentração testada no ensaio in vitro

Non-starch polysaccharides are important components of dietary fibers, and they may be considered biological response modifiers (MRBs), as they may interact with the immune system, depending on their structural characteristics. The immunomodulatory potential of chayote polysaccharides has already been demonstrated, however, information on their structural characteristics and their relationship with the immunological profile are limited to in vitro assays, with no reports on in vivo studies. Thus, the objective of the study was to evaluate, in vitro and in vivo, the immunomodulatory profile of polysaccharide from chayote. Through tangential filtration two fractions, SeRI <50 and SeSE <50, were obtained, respectively the fraction isolated from the chayote polysaccharide extracted from the insoluble residue and the fraction from the enzymatic post-treatment supernatant to remove starch, both under molecular weight 50 kDa. The monosaccharide composition and linkage analysis showed that both fractions are formed by galacturonans, arabinans, arabinogalactans and glycomanans. SeRI <50 is less branched and probably composed of galactans, while SeSE <50 is more branched and probably composed of galactuglucomannans. These fractions were able to stimulate murine macrophages RAW 264.7 and mononuclear cells of the spleen, blood and small intestine of Balb / c mice, suggesting a more proinflammatory action profile, based on the reactive oxygen species production, cytokines and lymphocyte activation markers. Both samples, SeRI <50 and SeSE <50, were able to efficiently activate the immunological cascade, not being cytotoxic even at the highest concentration tested in the in vitro assay

Prebiotic properties of different polysaccharide fractions from Artemisia sphaerocephala Krasch seeds evaluated by simulated digestion and in vitro fermentation by human fecal microbiota.

Artemisia sphaerocephala Krasch polysaccharide (ASKP) and its two fractions-60P (branched xylan) and 60S (branched glucomannan), were subjected to simulated gastrointestinal digestion and in vitro fermentation by human fecal microbiota. The results showed that all polysaccharide fractions could transit through gastrointestinal tract without dramatic degradation and be utilized by gut microbiota. ASKP exhibited the highest depletion rate and highest capability to decrease the pH than its fractions. Meanwhile, 60S showed the stronger capability to increase the production of propionic acid and reduce the ratio of acetic acid to propionic acid. At the phylum level, all polysaccharides efficiently reduced the Firmicutes/Bacteroidetes ratio and relative abundance of Proteobacteria, with ASKP being the most capable to suppress the proliferation of Proteobacteria. At the genus level, ASKP and 60P markedly promoted the growth of Bacteroidetes, and 60S promoted the growth of Parabacteroides and Collinsella. Prediction on metabolic function revealed that polysaccharide administration could dramatically change the metabolic profile of bacteria compared with fructooligosaccharides. Besides, all the polysaccharides dramatically promoted the bile acid metabolism. Compared with 60S, ASKP and 60P showed stronger ability to suppress the metabolisms on carbohydrate and amino acid. In summary, both ASKP and its two fractions showed the prebiotic potentials.

Immunomodulatory Activity in vitro and in vivo of Polysaccharides from Kabuli Chickpea (Cicer arietinum L.) Hull.

RESEARCH BACKGROUND: Polysaccharides isolated from plants, fungi and bacteria are associated with immunomodulatory effects. Chickpea hull, which is regarded as food industrial waste, contains considerable amount of antioxidants and bioactive compounds. EXPERIMENTAL APPROACH: In the present study, we investigated the immunomodulatory activity of polysaccharides from kabuli chickpea (Cicer arietinum L.) hull (CHPS). In vitro study was conducted with RAW264.7 cell line while in vivo study was carried out using specific pathogen-free BALB/c mouse animal model. RESULTS AND DISCUSSION: In in vitro test with RAW264.7 murine macrophage cells, the three purified fractions of chickpea hull polysaccharides showed potent immunomodulatory activity. Sample CHPS-3 showed stronger effect on cell viability, promoted the phagocytosis index to a greater extent and had the best effect on acid phosphatase activity. Moreover, it was found that CHPS-3 significantly (p<0.05) enhanced the secretion of nitrogen monoxide and cytokine (interleukins IL-6, IL-1ß and tumor necrosis factor-alpha (TNF-α)) levels. In in vivo study, CHPS-3 improved thymus and spleen indices in cyclophosphamide-induced immunodeficient mice. Increased activities of lysozyme, catalase, superoxide dismutase and glutathione peroxidase, serum haemolysin content and total antioxidant capacity were observed, while the amount of malondialdehyde in the liver decreased. NOVELTY AND SCIENTIFIC CONTRIBUTION: The results suggest that chickpea hull polysaccharides enhanced the immune activity and could be developed as the ingredient of functional foods.

Toll-like receptor 4/nuclear factor-kappa B pathway is involved in activating microphages by polysaccharides isolated from Fagopyrum esculentum.

Buckwheat polysaccharide fractions (BPFs) isolated from seeds of Fagopyrum esculentum have shown extensive immunomodulatory activities including activation of immune system. In this study, the immuno-modulation effects of BPFs on microphages were investigated. The obtained results show that BPFs can activate microphages as indicated by significant increases in the activity of inducible nitric oxide synthase (12.6 ± 1.30 U/mg prot), nuclear factor-kappa B (NF-κB) protein levels, and secretion of nitric oxide (NO) (21.5 ± 1.20 µmol/ml) and tumor necrosis factor-alpha (TNF-α) (71.2 ± 18.20 pg/ml). Moreover, blocking toll-like receptor 4 (TLR4)/NF-κB pathway using a specific antibody to TLR4 or inhibitor of NF-κB led to the significant inhibitory immuno-modulation effect on microphages as indicated by the decrease in the secretion level of NO and TNF-α. It is demonstrated that BPFs can activate microphages and TLR4/NF-κB pathway is involved in the induction of NO and TNF-α in macrophages by BPFs.

In Vitro Digestion and Fermentation of Three Polysaccharide Fractions from Laminaria japonica and Their Impact on Lipid Metabolism-Associated Human Gut Microbiota.

Our previous study has proved that the three polysaccharide fractions from L. japonica (LP-A4, LP-A6, and LP-A8) had significantly different structure characterization. Herein, we conducted in vitro simulated digestion and fermentation to study the digestive mechanism of LP-As. The results of gastrointestinal digestion indicated that LP-A6 and LP-A8 would be easier to trap the enzyme molecules for their denser interconnected macromolecule network compared with LP-A4. Fermentation of LP-As by human gut microbiota, especially for LP-A8, generated a large amount of short-chain fatty acids (SCFAs), which could upregulate the abundance of Firmicutes ( Lachnoclostridium and Eubacterium). The high content of sulfate and highly branched sugar residue of LP-A8 might help it be easily used by Firmicutes in gut microbiota of hyperlipidemic patients. Functional analysis revealed that the increased metabolic activities of glycerophospholipid metabolism, ether lipid metabolism, and fatty acid metabolism induced by LP-A8 treatment were closely associated with metabolic syndromes and hyperlipidemia.

Polysaccharide fractions from Fortunella margarita affect proliferation of Bifidobacterium adolescentis ATCC 15703 and undergo structural changes following fermentation.

In this study, the relationships between the proliferation effect of polysaccharide fractions from the citrus shrub Fortunella margarita on Bifidobacterium adolescentis ATCC 15703 and their resulting structural changes were investigated. Four polysaccharide fractions, FP20, FP40, FP60, and FP80, were obtained by graded precipitation at ethanol concentrations of 20%, 40%, 60% and 80%, respectively. The results showed that polysaccharide fractions, especially FP20, FP40, and FP60, enhanced the proliferation of B. adolescentis ATCC 15703 and their effects were better than those of FP80, inulin or glucose. Moreover, acetic acid was mainly produced during fermentation. After fermentation, the molecular weight of polysaccharide fractions decreased and the tightly structural chain conformations of FP20, FP40, and FP60 changed to highly branched structures. The prebiotic effect of these polysaccharide fractions might be related to their molecular weight and chain conformation. Thus, these polysaccharides could be used as potential prebiotics.

Physicochemical properties of polysaccharides from Dendrobium officinale by fractional precipitation and their preliminary antioxidant and anti-HepG2 cells activities in vitro.

BACKGROUND: Dendrobium officinale as a precious traditional Chinese herb is widely used in medicines and health supplements. Thus the extraction, purification and biological activities of polysaccharides from the stem of Dendrobium officinale have significant meaning on theory and application value. METHODS: The crude Dendrobium officinale polysaccharide (DOP) was obtained by hot water extraction- ethanol precipitation method, and four new polysaccharide fractions (DOP-40, DOP-50, DOP-60, and DOP-70) were further obtained from the crude DOP by fractional precipitation with ethanol method, then four fractions were further purified by Toyopearl-H65F gel resin. The molecular weight and monosaccharide composition of four purified fractions were determined by high performance anion exchange chromatography and high performance liquid chromatography. The antioxidant activities of them were evaluated by the reducing power assay, and the superoxide anion, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and hydroxyl free radicals scavenging assays, respectively. Finally, the anticancer activities of them were investigated via the MTT assay and the western blot analysis using HepG2 cells. RESULTS: Among these four purified fractions were mainly composed of D-mannose and D-glucose with different molar ratios, and their average molecular weights were 999, 657, 243 and 50.3 kDa, respectively. What's more, DOP-70 always exhibited the strongest antioxidant and anticancer activities, while DOP-40 and DOP-60 showed very close antioxidant and anticancer activities which were better than that of DOP-50. The western blotting analysis also showed that DOP-40, DOP-60, and DOP-70 induced apoptosis in HepG2 human liver cancer cells through the Bcl-2 and Bax-dependent pathway. CONCLUSIONS: Fractional precipitation with ethanol could successfully apply to extract four new polysaccharide fractions from Dendrobium officinale stems, and the polysaccharide fractions possessed efficient antioxidant and anticancer activities, especially DOP-70.

Extraction optimization, preliminary characterization and antioxidant activities of polysaccharides from Glycine soja.

Single-factor experiment and Central Composite Design (CCD) was applied to optimize the ultrasound-assisted extraction (UAE) conditions of polysaccharides from Glycine soja (CGPS), and a preliminary characterization of three polysaccharide fractions (CGPS, GPS-1, and GPS-2) and their antioxidant activities were investigated. Under the optimal conditions: ratio of liquid to solid 42.7mL/g, extraction power 293.7W, extraction temperature 68.9°C, and extraction time 34.7min, the experimental CGPS yield was 6.04mg/g. CGPS was further purified by DEAE-cellulose and Sephadex-100 chromatography to obtain two fractions (GPS-1 and GPS-2), and their monosaccharides compositions were characterized by HPLC. Fourier-transform infrared spectra (FT-IR) indicated the chemical structures of them. Moreover, they exhibited high antioxidant activities in a concentration-dependent manner in vitro. In summary, the present study suggested that UAE was a very effective method to extract polysaccharides from Glycine soja and the polysaccharides could be explored as potential antioxidant agents for medicine and function food.

Characterization and mesenteric lymph node cells-mediated immunomodulatory activity of litchi pulp polysaccharide fractions.

Three water-soluble hetero-polysaccharides, designated LP1-3, were isolated from litchi pulp. Their structures, solution properties and immunomodulatory activities were evaluated. LP1 contained (1→4,6)-ß-d-Glc and (1→4)-α-l-Gal, while LP2 contained (1→3)-α-l-Ara and (l→2)-ß-d-Gal, and LP3 contained α-l-Ara and (l→4)-ß-Rha. Their molecular weights ranged from 105,880 to 986,470g/mol. LP1 had a spherical conformation with hyper-branched structure and LP2 was semi-flexible chain, while the polysaccharide chains of LP3 were cross linked to form network-like conformation in solution. In addition, all fractions strongly stimulated mesenteric lymph node cell proliferation, IFN-γ and IL-6 secretion in the dose range of 25-100µg/mL compared with untreated control group (p<0.05). LP1 exhibited the strongest stimulation of mesenteric lymph node cell proliferation and cytokine secretion, which may be attributed to its unique chemical structure and chain conformation. This is the first report on the solution properties and intestinal immunity activities of polysaccharides from litchi pulp.

Molecular Structural Characteristics of Polysaccharide Fractions from Canarium album (Lour.) Raeusch and Their Antioxidant Activities.

UNLABELLED: The objective of this study was to investigate the multiple relations between the preliminary molecular structural characteristics and antioxidant activities of polysaccharides from Canarium album (Lour.) Raeusch (CPS). Three polysaccharide fractions, CPS1, CPS2, and CPS3, were isolated from CPS by column chromatography. CPS1 and CPS3 were mainly composed of neutral polysaccharides linked by α- and ß-glycosidic linkages while CPS2 was pectin polysaccharides mainly linked by ß-glycosidic linkages. According to the SEC-MALLS-RI system, the molecular weight of CPS1 was greater compared to CPS2 and CPS3, and the molecular weight and radius of CPS did not display positive correlation. The chain conformation analysis indicated CPS1 and CPS2 were typical highly branched polysaccharides while CPS3 existed as a globular shape in aqueous. Furthermore, the antioxidant activity of CPS2 was better than that of CPS3, while that of CPS1 was the weakest. The antioxidant activities of polysaccharide fractions were affected by their monosaccharide composition, glycosidic linkage, molecular weight, and chain conformation. This functional property was a result of a combination of multiple molecular structural factors. CPS2 was the major antioxidant component of CPS and it could be exploited as a valued antioxidant product. PRACTICAL APPLICATION: The molecular structural characteristics, antioxidant activities, and structure-function relationships of polysaccharide fractions from Canarium album were first investigated in this study. The results provided background and practical knowledge for the deep-processed products of C. album with high added value. CPS2 was the major antioxidant component of CPS, which could be exploited as a valued antioxidant ingredient in food and pharmaceutical industries.