Polysaccharide from Pleurotus nebrodensis: Physicochemical, structural characterization and in vitro fermentation characteristics

Structural characteristics of a heteropolysaccharide from Ganoderma lucidum and its protective effect against Alzheimer's disease via modulating the microbiota-gut-metabolomics

Ganoderma lucidum is a traditional Chinese medicine used to treat Alzheimer's disease (AD), whose main active ingredient is polysaccharides. A heteropolysaccharide named GLPZ-1 was isolated from Ganoderma lucidum. GLPZ-1 (6.608 kDa) predominantly consisted of Glc and minor Gal. The results of GC-MS and NMR analyses indicated that the backbone of GLPZ-1 was mainly composed of 1,4-α-D-Glcp, 1,4,6-α-Glcp and a minor amount of 1,3,4-β-D-Glcp, which was substituted with complex side chains at C-6 of 1,4,6-α-D-Glcp and at C-3 of 1,3,4-β-D-Glcp. GLPZ-1 demonstrated a protective effect on AD rats by improving behavioral abnormalities, alleviating pathological damage and ameliorating levels of IL-6, IL-1β, TNF-α and Th17, which were associated with GLPZ-1 modulating the microbiota-gut-metabolomics of AD rats. GLPZ-1 regulated the gut microbiota in AD rats by increasing the abundance of Bacteroides, unclassified_Lachnospiraceae, Lactobacillus, Pediococcus, Oscillibacter, Lachnoclostridium and Bifidobacterium, while simultaneously reducing the abundance of Pseudomonas and Desulfovibrio. GLPZ-1 could regulate fecal metabolites in AD rats tending towards the normal levels. These regulated fecal metabolites belonged to fatty acid metabolism, cholesterol and bile acid metabolism, neurotransmitters and aromatic amino acid metabolism. These findings provide a preliminary research basis for the exploitation of GLPZ-1 as an effective drug to prevent and delay AD.

Functions and mechanisms of nonstarch polysaccharides in monogastric animal production

As natural active ingredients, polysaccharides are a class of biological macromolecules that are ubiquitous in living organisms and have antibacterial, antioxidant, antitumor and intestinal flora-regulating functions. Nonstarch polysaccharides (NSPs) are an important class of polysaccharides that include both soluble and insoluble nonstarch polysaccharides. As green feed additives, NSPs play important roles in promoting immunity and disease resistance in the body, regulating the intestinal microbial balance and improving the quality of animal products. NSPs regulate cell signal transduction mainly via interactions between short-chain fatty acids and G protein-coupled receptors and inhibiting the histone deacetylation pathway to protect the intestinal barrier in animals. In this paper, the composition, physiological functions, and molecular mechanisms of the gut protective effects of NSPs are reviewed to provide a reference for the application of NSPs in monogastric animal production.

Research progress in extraction, purification, structure of fruit and vegetable polysaccharides and their interaction with anthocyanins/starch

Fruits and vegetables contain polysaccharides, polyphenols, antioxidant enzymes, and various vitamins, etc. Fruits and vegetables polysaccharides (FVPs), as an important functional factor in health food, have various biological activities such as lowering blood sugar, blood lipids, blood pressure, inhibiting tumors, and delaying aging, etc. In addition, FVPs exhibit good physicochemical properties including low toxicity, biodegradability, biocompatibility. Increasing research has confirmed that FVPs could enhance the stability and biological activities of anthocyanins, affecting their bioavailability to improve food quality. Simultaneously, the addition of FVPs in natural starch suspension could improve the physicochemical properties of natural starch such as viscosity, gelling property, water binding capacity, and lotion stability. Hence, FVPs are widely used in the modification of natural anthocyanins/starch. A systematic review of the latest research progress and future development prospects of FVPs is very necessary to better understand them. This paper systematically reviews the latest progress in the extraction, purification, structure, and analysis techniques of FVPs. Moreover, the review also introduces the potential mechanisms, evaluation methods, and applications of the interaction between polysaccharides and anthocyanins/starch. The findings can provide important references for the further in-depth development and utilization of FVPs.

Encapsulation of polyphenols in pH-responsive micelles self-assembled from octenyl-succinylated curdlan oligosaccharide and its effect on the gut microbiota

An amphiphilic polymer based on octenyl succinic anhydride-modified curdlan oligosaccharide (MCOS) was synthesized. The critical micelle concentration of MCOS was 3.91 μg·mL-1. MCOS could self-assemble into spherical micelles with a particle size of 230.1 nm and a zeta potential of - 37.9 mV. When used for polyphenol encapsulation, the loading capacity of curcumin and quercetin-co-encapsulated micelles was higher than that of single-polyphenol encapsulated micelles. In vitro gastrointestinal release test showed that the MCOS micelle presented a pH-dependent release, released a little polyphenol in simulated gastric fluid, but presented sustained release in the simulated intestinal fluid. The gastrointestinal-digested polyphenol-loaded micelles exhibited excellent antioxidant ability. In vitro human fecal fermentation indicated that the MCOS carrier could promote the production of short-chain fatty acids by gut microbiota and exhibited the highest relative abundance of Megamonas. In addition, the supplementation of curcumin and quercetin-co-loaded MCOS micelles increased the relative abundance of Bifidobacterium and inhibited the growth of Escherichia_Shigella. These findings indicated that the MCOS carrier can be potentially used for the colon-targeted delivery of hydrophobic polyphenols due to its pH-responsive property.

Two Natural Flavonoid Substituted Polysaccharides from Tamarix chinensis: Structural Characterization and Anticomplement Activities

Two novel natural flavonoid substituted polysaccharides (MBAP-1 and MBAP-2) were obtained from Tamarix chinensis Lour. and characterized by HPGPC, methylation, ultra-high-performance liquid chromatography-ion trap tandem mass spectrometry (UPLC-IT-MSⁿ), and NMR analysis. The results showed that MBAP-1 was a homogenous heteropolysaccharide with a backbone of 4)-β-d-Glcp-(1→ and →3,4,6)-β-d-Glcp-(1→. MBAP-2 was also a homogenous polysaccharide which possessed a backbone of →3)-α-d-Glcp-(1→, →4)-β-d-Glcp-(1→ and →3,4)-β-d-Glcp-2-OMe-(1→. Both the two polysaccharides were substituted by quercetin and exhibited anticomplement activities in vitro. However, MBAP-1 (CH₅₀: 0.075 ± 0.004 mg/mL) was more potent than MBAP-2 (CH₅₀: 0.249 ± 0.006 mg/mL) and its reduced product, MBAP-1R (CH₅₀: 0.207 ± 0.008 mg/mL), indicating that multiple monosaccharides and uronic acids might contribute to the anticomplement activity of the flavonoid substituted polysaccharides of T. chinensis. Furthermore, the antioxidant activity of MBAP-1 was also more potent than that of MBAP-2. In conclusion, these two flavonoid substituted polysaccharides from T. chinensis were found to be potential oxidant and complement inhibitors.

Characterization of Alpinia officinarum Hance polysaccharide and its immune modulatory activity in mice

This study aimed to verify the regulating effect of a novel water-soluble polysaccharide (AOHP) extracted from Alpinia officinarum Hance on mouse immunity and to characterize its structure feature. The cellulose...

Beneficial Effects of Holothuria leucospilota Polysaccharides on Fermentability In Vivo and In Vitro

This work aimed to investigate the in-vitro and in-vivo fermentation behaviors of Holothuria leucospilota Polysaccharides (HLP) and the impact on mouse liver antioxidant activity. HLP showed excellent fermentability during in vitro experiments, which was characterized by increased levels of total sugar consumption and short-chain fatty acids (SCFAs). During in vitro fecal fermentation, the fucose contents in the HLP fermentation products (0.174 mg/mL) were higher than those of xylose and galactosamine during the first three hours, and fucose disappeared after 24 h. The concentrations of the generated SCFAs increased to 111.13 mmol/mL after in-vitro fermentation at 48 h. After 28 days of oral administration, the SCFA contents that were detected in the feces of mice treated with high HLP doses were significantly higher than those in the feces of mice treated with lower doses and the normal group. In addition, histological observations demonstrated that HLP increased the number of goblet cells without causing hepatocellular injury. Moreover, the increased glutathione peroxidase (GSH-Px) and superoxidase dismutase (SOD) activities and decreased malondialdehyde (MDA) contents in the mouse livers treated with HLP suggested the good performance of HLP with respect to liver antioxidants.

Comparative study of structural properties and biological activities of polysaccharides extracted from Chroogomphus rutilus by four different approaches

Extraction processes significantly alter the structural and functional properties of polysaccharides. In this study, we extracted polysaccharides from Chroogomphis rutilus fruiting bodies (designated as CRP) using four methods, including hot water, ultrasound, microwave and sequential ultrasound-microwave, and designated these polysaccharides as CRP-H, CRP-M, CRP-U and CRP-UM, respectively. All CRPs were heteropolysaccharides with semblable monosaccharide types of glucose, mannose and galactose, mainly constituted of α-d-glucopyranosyl-(1 → 4). The extraction processes significantly affected the molecular weights, monosaccharide proportions, glycosidic bond ratios, branching degrees, triple-helix conformation and surface morphology of the CRPs. Among them, CRP-UM showed the highest yield and most potent antioxidative capacity in vitro and in HL-7702 cells, but the weakest activation of immunostimulatory response in RAW264.7 cells. In contrast, CRP-H exhibited the lowest yield but strongest immunostimulatory activity. Overall, microwave extraction could be utilized as a general and practical CRP extraction approach, based on its relatively high yield and bioactivities.

Structural characterization of two novel polysaccharides from Gastrodia elata and their effects on Akkermansia muciniphila

Two homogeneous polysaccharides, GEP-3 and GEP-4, were purified from Gastrodia elata, a precious traditional Chinese medicine. Their structural characteristics were obtained using HPGPC, PMP-HPLC, LC/MS, FT-IR, NMR, and SEM methods. GEP-3 was 1,4-glucan with molecular weight of 20 kDa. Interestingly, GEP-4 comprised of a backbone of →[4)-α-Glcp-(1]₁₀→[4)-α-Glcp-(1→]₅[6)-β-Glcp-(1]₁₁→6)-α-Glcp-(3→ and two branches of β-Glcp and p-hydroxybenzyl alcohol citrate, with repeating p-hydroxybenzyl alcohol attached to the backbone chain at O-6 position of →4,6)-α-Glcp-(1→ and O-1 position of →3,6)-α-Glcp-(1→. GEP-4 is a novel polysaccharide obtained and characterized for the first time. Bioactivity test indicated that both of them significantly promote the growth of Akkermansia muciniphila (Akk. muciniphila). Furthermore, GEP-3 and GEP-4 promoted the growth of Akk. muciniphila from high-fat diet (HFD) fecal microbiota. These results indicated that GEP-3 and GEP-4 were potential Akk. muciniphila growth promoters.

Isolation and Purification of Fucoxanthin from Brown Seaweed Sargassum horneri Using Open ODS Column Chromatography and Ethanol Precipitation

As an abundant marine xanthophyll, fucoxanthin (FX) exhibits a broad range of biological activities. The preparation of high-purity FX is in great demand, however, most of the available methods require organic solvents which cannot meet the green chemistry standard. In the present study, a simple and efficient purification approach for the purification of FX from the brown seaweed Sargassum horneri was carried out. The FX-rich ethanol extract was isolated by octadecylsilyl (ODS) column chromatography using ethanol-water solvent as a gradient eluent. The overwhelming majority of FX was successfully eluted by the ethanol-water mixture (9:1, v/v), with a recovery rate of 95.36%. A parametric study was performed to optimize the aqueous ethanol precipitation process by investigating the effects on the purity and recovery of FX. Under the optimal conditions, the purity of FX was 91.07%, and the recovery rate was 74.98%. Collectively, the eco-friendly method was cost-efficient for the purification of FX. The developed method provides a potential approach for the large-scale production of fucoxanthin from the brown seaweed Sargassum horneri.

Sulfated modification enhances the modulatory effect of yam polysaccharide on gut microbiota in cyclophosphamide-treated mice

Our previous study has demonstrated that sulfated yam polysaccharide (SCYP) had a stronger immunomodulatory activity than yam polysaccharide (CYP). In order to investigate how the sulfated modification influence the immunological activity of CYP, this research was mainly focused on the study of gut microbiotal. The results showed that SCYP treatment could increase the digestive enzyme activities of colon contents and restore the production of short-chain fatty acids (SCFAs) in mice that were decreased by cyclophosphamide (Cy) treatment. Furthermore, SCYP treatment could modulate the structure of the gut microbiota, which was mainly manifest in the result of an increased abundances of Lactobacillus, Bacteroidetes and Akkermansia, and the decrease of the proportion of Proteobacteria and Verrucomicrobia in the microbial community. Diversity and overall structure of microbial community were also improved by SCYP treatment based on alpha-diversity and beta-diversity analysis results. The biomarkers of the gut microbial that were regulated by SCYP have been identified by linear discriminant analysis (LDA) effect size (LEfSe). These findings further indicate that there is great potential for SCYP to be developed into prebiotics or functional foods.

Health benefits of edible mushroom polysaccharides and associated gut microbiota regulation

Edible mushrooms have been an important part of the human diet for thousands of years, and over 100 varieties have been cultivated for their potential human health benefits. In recent years, edible mushroom polysaccharides (EMPs) have been studied for their activities against obesity, inflammatory bowel disease (IBD), and cancer. Particularly, accumulating evidence on the exact causality between these health risks and specific gut microbiota species has been revealed and characterized, and most of the beneficial health effects of EMPs have been associated with its reversal impacts on gut microbiota dysbiosis. This demonstrates the key role of EMPs in decreasing health risks through gut microbiota modulation effects. This review article compiles and summarizes the latest studies that focus on the health benefits and underlying functional mechanisms of gut microbiota regulation via EMPs. We conclude that EMPs can be considered a dietary source for the improvement and prevention of several health risks, and this review provides the theoretical basis and technical guidance for the development of novel functional foods with the utilization of edible mushrooms.

Hydrogen Peroxide Effects on Natural-Sourced Polysacchrides: Free Radical Formation/Production, Degradation Process, and Reaction Mechanism-A Critical Synopsis

Numerous reactive oxygen species (ROS) entities exist, and hydrogen peroxide (H2O2) is very key among them as it is well known to possess a stable but poor reactivity capable of generating free radicals. Considered among reactive atoms, molecules, and compounds with electron-rich sites, free radicals emerging from metabolic reactions during cellular respirations can induce oxidative stress and cause cellular structure damage, resulting in diverse life-threatening diseases when produced in excess. Therefore, an antioxidant is needed to curb the overproduction of free radicals especially in biological systems (in vivo and in vitro). Despite the inherent properties limiting its bioactivities, polysaccharides from natural sources increasingly gain research attention given their position as a functional ingredient. Improving the functionality and bioactivity of polysaccharides have been established through degradation of their molecular integrity. In this critical synopsis; we articulate the effects of H2O2 on the degradation of polysaccharides from natural sources. Specifically, the synopsis focused on free radical formation/production, polysaccharide degradation processes with H2O2, the effects of polysaccharide degradation on the structural characteristics; physicochemical properties; and bioactivities; in addition to the antioxidant capability. The degradation mechanisms involving polysaccharide's antioxidative property; with some examples and their respective sources are briefly summarised.