Structure, function and food applications of carboxymethylated polysaccharides: A comprehensive review

Distinctive activation of β-galactosidase by carboxymethylated β-glucan in vitro and mechanism study: Critical role of hydrophobic and electrostatic interactions

β-galactosidase (lactase) is commercially important as a dietary supplement to alleviate the symptoms of lactose intolerance. This work investigated a unique activation of CMP (carboxymethylated (1 → 3)-β-d-glucan) on lactase and its mechanism by comparing it with carboxymethyl chitosan (CMCS), an inhibitor of lactase. The results illustrated that the secondary and tertiary structures of lactase were altered and its active sites exposed after complexation with CMP, and dissociation of lactase aggregates was also observed. These changes favored better accessibility of the substrate to the active sites of lactase, resulting in a maximum increase of 60.5 % in lactase activity. Furthermore, the hydrophobic and electrostatic interactions with lactase caused by the carboxymethyl group of CMP were shown to be crucial for its activation ability. Thus, the improvement of lactase activity and stability by CMP shown here is important for the development of new products in the food and pharmaceutical industries.

Improvement of antibacterial activity of polysaccharides via chemical modification: A review

Antibiotic residue and bacterial resistance induced by antibiotic abuse have seriously threatened food safety and human healthiness. Thus, the development and application of safe, high-efficiency, and environmentally friendly antibiotic alternatives are urgently necessary. Apart from antitumor, antivirus, anti-inflammatory, gut microbiota regulation, immunity improvement, and growth promotion activities, polysaccharides also have antibacterial activity, but such activity is relatively low, which cannot satisfy the requirements of food preservation, clinical sterilization, livestock feeding, and agricultural cultivation. Chemical modification not only provides polysaccharides with better antibacterial activity, but also promotes easy operation and large-scale production. Herein, the enhancement of the antibacterial activity of polysaccharides via acetylation, sulfation, phosphorylation, carboxymethylation, selenation, amination, acid graft, and other chemical modifications is reviewed. Meanwhile, a new trend on the application of loading chemically modified polysaccharides into nanostructures is discussed. Furthermore, possible limitations and future recommendations for the development and application of chemically modified polysaccharides with better antibacterial activity are suggested.

Study on fermentation preparation, physicochemical properties and biological activity of carboxymethylpachymaran with different degrees of substitution

BACKGROUND

Carboxymethylpachymaran (CMP) is created by carboxymethylating pachyman (PM), which increases its water solubility and enhances a number of biological activities. Traditional polysaccharides modified by carboxymethylation employ strong chemical techniques. Carboxymethylcellulose (CMC) has been used previously for liquid fermentation to carboxymethyl modify bacterial polysaccharides. This theory can be applied to fungal polysaccharides because Poria cocos has the ability to naturally utilize cellulose.

RESULTS

CMC with different degrees of substitution (DS) (0.7, 0.9 and 1.2) were added to P. cocos fermentation medium, and CMPs with different DS (0.38, 0.56 and 0.78, respectively) were prepared by liquid fermentation. The physical and chemical properties and biological activities of the CMPs were determined. Their structures were confirmed by Fourier transform infrared (FTIR) spectroscopy and monosaccharide composition. With the increase of DS, the viscosity and viscosity-average molecular weight of CMPs decreased, whereas polysaccharide content and water solubility increased, although the triple helix structure was not affected. The results of bioactivity assay showed that the higher the DS of CMPs, the higher the 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability, and the stronger the bacterial inhibition ability.

CONCLUSION

The present study has developed a method for producing CMPs by P. cocos liquid fermentation. The results of the study confirm that enhancing the DS of CMP could effectively enhance its potential biological activity. The findings provide safe and reliable raw materials for creating CMP-related foods and encourage CMP application in the functional food industry. © 2024 Society of Chemical Industry.

In sight the behavior of natural Bletilla striata polysaccharide hydrocolloids by molecular dynamics method

Plant polysaccharides, distinguished by diverse glycosidic bonds and various cyclic sugar units, constitute a subclass of primary metabolites ubiquitously found in nature. Contrary to common understanding, plant polysaccharides typically form hydrocolloids upon dissolution in water, even though both excessively high and low temperatures impede this process. Bletilla striata polysaccharides (BSP), chosen for this kinetic study due to their regular repeating units, help elucidate the relationship between polysaccharide gelation and temperature. It is suggested that elevated temperatures enhance the mobility of BSP molecular chains, resulting in a notable acceleration of hydrogen bond breakage between BSP and water molecules and consequently, compromising the conformational stability of BSPs to some extent. This study unveils the unique relationship between polysaccharide dissolution processes and temperature from a kinetics perspective. Consequently, the conclusion provides a dynamical basis for comprehending the extraction and preparation of natural plant polysaccharide hydrocolloids, pharmaceuticals and related fields.

Carboxymethylated Desmodium styracifolium polysaccharide reduces the risk of calcium oxalate kidney stone formation by inhibiting crystal adhesion and promoting crystal endocytosis

The inhibition of cell surface crystal adhesion and an appropriate increase in crystal endocytosis contribute to the inhibition of kidney stone formation. In this study, we investigated the effects of different degrees of carboxymethylation on these processes. An injury model was established by treating human renal proximal tubular epithelial (HK-2) cells with 98.3 ± 8.1 nm calcium oxalate dihydrate (nanoCOD) crystals. The HK-2 cells were protected with carboxy (-COOH) Desmodium styracifolium polysaccharides at 1.17% (DSP0), 7.45% (CDSP1), 12.2% (CDSP2), and 17.7% (CDSP3). Changes in biochemical indexes and effects on nanoCOD adhesion and endocytosis were detected. The protection of HK-2 cells from nanoCOD-induced oxidative damage by carboxymethylated Desmodium styracifolium polysaccharides (CDSPs) is closely related to the protection of subcellular organelles, such as mitochondria. CDSPs can reduce crystal adhesion on the cell surface and maintain appropriate crystal endocytosis, thereby reducing the risk of kidney stone formation. CDSP2 with moderate -COOH content showed the strongest protective activity among the CDSPs.

Sulfated Polysaccharides with Anticoagulant Potential: A Review Focusing on Structure-Activity Relationship and Action Mechanism

Thromboembolism is the culprit of cardiovascular diseases, leading to the highest global mortality rate. Anticoagulation emerges as the primary approach for managing thrombotic conditions. Notably, sulfated polysaccharides exhibit favorable anticoagulant efficacy with reduced side effects. This review focuses on the structure-anticoagulant activity relationship of sulfated polysaccharides and the underlying action mechanisms. It is concluded that chlorosulfonicacid-pyridine method serves as the preferred technique to synthesize sulfated polysaccharides. The anticoagulant activity of sulfated polysaccharides is linked to the substitution site of sulfate groups, degree of substitution, molecular weight, main side chain structure, and glycosidic bond conformation. Moreover, sulfated polysaccharides exert anticoagulant activity via various pathways, including the inhibition of blood coagulation factors, activation of antithrombin III and heparin cofactor II, antiplatelet aggregation, and promotion of the fibrinolytic system.

An Exopolysaccharide from Genistein-Stimulated Monascus Purpureus: Structural Characterization and Protective Effects against DSS-Induced Intestinal Barrier Injury Associated with the Gut Microbiota-Modulated Short-Chain Fatty Acid-TLR4/MAPK/NF-κB Cascade Response

Inflammatory bowel disease is a major health problem that can lead to prolonged damage to the digestive system. This study investigated the effects of an exopolysaccharide from genistein-stimulated Monascus purpureus (G-EMP) in a mouse model of colitis to clarify its molecular mechanisms and identified its structures. G-EMP (Mw = 56.4 kDa) was primarily consisted of → 4)-α-D-Galp-(1 →, → 2,6)-α-D-Glcp-(1→ and →2)-β-D-Manp-(1 → , with one of the branches being α-D-Manp-(1 →. G-EMP intervention reduced the loss of body weight, degree of colonic damage and shortening, disease activity index scores, and histopathology scores, while restoring goblet cell production and oxidative homeostasis, repairing colonic functions, and regulating inflammatory cytokines. RNA sequencing and Western blot analysis indicated that G-EMP exerts anti-inflammatory properties by suppressing the TLR4/MAPK/NF-κB inflammatory signaling pathway. G-EMP modulated the gut microbiota by improving its diversities, elevating the relative abundances of beneficial bacteria, declining the Firmicutes/Bacteroidota value, and regulating the level of short-chain fatty acids (SCFAs). Correlation analysis demonstrated strong links between SCFAs, gut microbiota, and the inflammatory response, indicating the potential of G-EMP to prevent colitis.

Plant polysaccharides extracted by high pressure: A review on yields, physicochemical, structure properties, and bioactivities

Polysaccharides are biologically essential macromolecules, widely exist in plants, which are used in food, medicine, bioactives' encapsulation, targeted delivery and other fields. Suitable extraction technology can not only improve the yield, but also regulate the physicochemical, improve the functional property, and is the basis for the research and application of polysaccharide. High pressure (HP) extraction (HPE) induces the breakage of raw material cells and tissues through rapid changes in pressure, increases extraction yield, reduces extraction time, and modifies structure of polysaccharides. However, thus far, literature review on the mechanism of extraction, improved yield and modified structure of HPE polysaccharide is lacking. Therefore, the present work reviews the mechanism of HPE polysaccharide, increasing extraction yield, regulating physicochemical and functional properties, modifying structure and improving activity. This review contributes to a full understanding of the HPE or development of polysaccharide production and modification methods and promotes the application of HP technology in polysaccharide production.

A thermostable xylanase hydrolyzes several polysaccharides from Bacillus altitudinis JYY-02 showing promise for industrial applications

Polysaccharides have attracted immense attention as the largest source of bioactive compounds. Its bioavailability and bioactivity can be improved by utilizing degradation enzymes to reduce their molecular weight and viscosity. In this study, a 654 bp gene encoding xylanase was screened from the genome of Bacillus altitudinis JYY-02 and overexpressed in Escherichia coli Rosetta (DE3). The recombinant xylanase with a molecular weight of 27.98 kDa was purified (11.7-fold) using Ni-NTA affinity chromatography, with a 43.6% final yield. Through molecular docking, Glu, Arg, Tyr, and Trp were found to be the main amino acids involved in the interaction between xylanase and xylobiose. The effects of pH, temperature, metal ions, and substrates on xylanase activity were determined, and the results showed that the highest catalytic activity was displayed at pH 6.5, 50 °C temperature, with Cu2+ as an activator and xylan as the substrate. The Km (substrate concentration that yields a half-maximal velocity) and Vmax (maximum velocity) of recombinant xylanase were 6.876 mg/mL and 10984.183 μmol/mg∙pr/min, respectively. The recombinant xylanase was thermostable, with 85% and 39% of the enzymatic activity retained after 1 h at 60 °C and 1 h at 90 °C, respectively. The recombinant xylanase demonstrated a significant clarifying effect on fruit juices.

Dandelion polysaccharides improve the emulsifying properties and antioxidant capacities of emulsions stabilized by whey protein isolate

In this study, the effects of dandelion polysaccharide (DP) and its carboxymethylated derivative (CMDP) on the emulsifying characteristics and antioxidant capacities of emulsions stabilized by whey protein isolate (WPI) were determined. The addition of both DP and CMDP reduced the particle size and zeta potential of the emulsions. Using 1.0 % WPI and 1.0 % CMDP as emulsifier, the emulsifying activity index (EAI) and emulsifying stability index (ESI) were 32.61 ± 0.11 m2/g and 42.58 ± 0.13 min, respectively, which were higher than the corresponding values of 27.19 ± 0.18 m2/g and 36.17 ± 0.15 min with 1.0 % WPI and 1.0 % DP. Fourier-transform infrared spectroscopy (FT-IR), far-ultraviolet circular dichroism (Far-UV CD), and fluorescence (FS) spectra analyses confirmed that the α-helix and β-sheet structures in WPI-polysaccharide complexes were reduced compared with those in pure WPI, whereas the random-coil content was enhanced by the addition of polysaccharides. Moreover, DP and CMDP effectively improved the antioxidant capacity and inhibited oxidation of the emulsions during storage. Therefore, DP and its carboxymethylated derivative exhibit great potential to be applied in the emulsion-based delivery system.

The function and application of edible fungal polysaccharides

Edible fungi, commonly known as mushrooms, are precious medicinal and edible homologous gifts from nature to us. Edible fungal polysaccharides (EFPs) are a variety of bioactive macromolecular which isolated from fruiting bodies, mycelia or fermentation broths of edible or medicinal fungus. Increasing researches have confirmed that EFPs possess multiple biological activities both in vitro and in vivo settings, including antioxidant, antiviral, anti-inflammatory, immunomodulatory, anti-tumor, hypoglycemic, hypolipidemic, and regulating intestinal flora activities. As a result, they have emerged as a prominent focus in the healthcare, pharmaceutical, and cosmetic industries. Fungal EFPs have safe, non-toxic, biodegradable, and biocompatible properties with low immunogenicity, bioadhesion ability, and antibacterial activities, presenting diverse potential applications in the food industries, cosmetic, biomedical, packaging, and new materials. Moreover, varying raw materials, extraction, purification, chemical modification methods, and culture conditions can result in variances in the structure and biological activities of EFPs. The purpose of this review is to provide comprehensively and systematically organized information on the structure, modification, biological activities, and potential applications of EFPs to support their therapeutic effects and health functions. This review provides new insights and a theoretical basis for prospective investigations and advancements in EFPs in fields such as medicine, food, and new materials.

Carboxymethylated Abrus cantoniensis polysaccharide prevents CTX-induced immunosuppression and intestinal damage by regulating intestinal flora and butyric acid content

As a Chinese folk health product, Abrus cantoniensis exhibits good immunomodulatory activity because of its polysaccharide components (ACP), and carboxymethylation of polysaccharides can often further improve the biological activity of polysaccharides. In this study, we explored the impact of prophylactic administration of carboxymethylated Abrus cantoniensis polysaccharide (CM-ACP) on immunosuppression and intestinal damage induced by cyclophosphamide (CTX) in mice. Our findings demonstrated that CM-ACP exhibited a more potent immunomodulatory activity compared to ACP. Additionally, CM-ACP effectively enhanced the abundance of short-chain fatty acid (SCFA)-producing bacteria in immunosuppressed mice and regulated the gene expression of STAT6 and STAT3 mediated pathway signals. In order to further explore the relationship among polysaccharides, intestinal immunity and intestinal flora, we performed a pseudo-sterile mouse validation experiment and fecal microbiota transplantation (FMT) experiment. The findings suggest that CM-FMT and butyrate attenuate CTX-induced immunosuppression and intestinal injury. CM-FMT and butyrate show superior immunomodulatory ability, and may effectively regulate intestinal cell metabolism and repair the damaged intestine by activating STAT6 and STAT3-mediated pathways. These findings offer new insights into the mechanisms by which CM-ACP functions as functional food or drug, facilitating immune response regulation and maintaining intestinal health.

Structurally Modified Polysaccharides: Physicochemical Properties, Biological Activities, Structure-Activity Relationship, and Applications

Polysaccharides are an important class of biomolecules derived from several sources. However, the inherent structure of polysaccharides prevents them from exhibiting favorable physicochemical properties, which restricts their development in agriculture, industry, food, and biomedicine. This paper systematically summarizes the changes in the primary and advanced structures of modified polysaccharides, and focuses on the effects of various modification methods on the hydrophobicity, rheological properties, emulsifying properties, antioxidant activity, hypoglycemic, and hypolipidemic activities of polysaccharides. Then there is a list the applications of modified polysaccharides in treating heavy metal pollutants, purifying water resources, improving beverage stability and bread quality, and precisely delivering the drug. When summarized and reviewed, the information above can shed further light on the relationship between polysaccharide structure and function. Determining the structure-activity relationship provides a scientific basis for the direction of molecular modifications of polysaccharides.

Research on the application of Thelephora ganbajun exopolysaccharides in antioxidant, anti-inflammatory and spot-fading cosmetics

Thelephora ganbajun exopolysaccharides (TGEP) with a "coral-like" branched chain structure (main chain diameter ∼ 80 nm) were prepared by liquid fermentation and fractionated by ion-exchange chromatography. The main fraction (TGEP-2) with the highest in vitro antioxidant capacity was composed of Glc, Man, Gal, GalA, GlcA, Ara, Rha, GlcN, Fuc and Rib in a molar ratio of 465.43:420.43:219.14:188.43:37:35.14:31.43:19.43:11.14:1, with a molecular weight of 1.879 × 104 Da. The sequence of monosaccharide residue release revealed that Gal, Glc and Ara residues were more distributed in the side-branch chains and at their ends, whereas Man and GalA residues were more distributed in the main chains. TGEP-2 contained linear residues (mainly →4)-Glcp-(1 → and →4)-Manp-(1→), branch residues (→3,6)-Glcp-(1→, →4,6)-Glcp-(1 → and →3,6)-Galp-(1→) and terminal residues (Galp-(1→, Manp-(1 → and Glcp-(1→). TGEP-2 consisted of α- and β-glycosidically linked pyranosides, with a triple helical conformation and many long branches. Zebrafish oxidative stress and inflammation models found that TGEP-2 had antioxidant and anti-inflammatory activities. The zebrafish skin black spot assay showed that TGEP-2 inhibited melanin formation. Therefore, extracellular polysaccharides of T. ganbajun have strong application potential in anti-oxidant, anti-inflammatory and skin spot-fading functions cosmetics.

Effect of monosaccharide composition and proportion on the bioactivity of polysaccharides: A review

Polysaccharides have been widely used in pharmaceutical and food industries due to their diverse bioactivity, high safety, and few or no side effects. However, inability to quickly produce, screen, and synthesize bioactive polysaccharides is the limiting factor for their development and application. Structural features determine and influence the bioactivity of polysaccharides. Among them, monosaccharide is the basic unit of polysaccharide, which not only affects electrification, functional group, and bioactivity of polysaccharide but also is one of the simplest polysaccharide indexes to be detected. At present, effects of monosaccharide composition and proportion on anti-inflammatory, antioxidant, antitumor, immunomodulatory, antibacterial, and prebiotic activities of polysaccharides are reviewed. Further problems need to be considered during regulation and analysis of monosaccharide composition and proportion of polysaccharides. Overall, present work will provide help and reference for production, development, and structure-function investigation of polysaccharides based on their monosaccharide.

Solvent-less carboxymethylation-induced electrostatic crosslinking of chitosan

The successful N-carboxymethylation and concomitant crosslinking of solid chitosan upon heating its mixture with solid monochloroacetic acid, without the use of solvents or catalysts, is reported. The N-carboxymethylation was confirmed through the analysis of the partially depolymerized product using NMR spectroscopy, as well as a control reaction with lysine. This transformation was facilitated by the nucleophilic nature of the free amine group in the repeating unit of chitosan, which possesses lone pair of electrons capable of attacking the carbon center bearing the leaving group and displacing the leaving group in a concerted manner. The crosslinking, on the other hand, was established by the observed insolubility in aqueous acidic solutions, even when subjected to prolonged heating at 60 °C. This crosslinking occurs due to the electrostatic interactions between the carboxylate groups and the adjacent ammonium groups, as supported by evidence from FTIR spectroscopy and a control reaction involving ethyl chloroacetate. The resulting crosslinked carboxymethyl chitosan demonstrated its usefulness in the adsorption of methyl orange and fluorescein, as well as functioning as an organic catalyst for aza-Michael addition, Hantzsch reaction, and substituted perimidine synthesis.

Edible polysaccharide-based oleogels and novel emulsion gels as fat analogues: A review

Polysaccharide-based oleogels and emulsion gels have become novel strategies to replace solid fats due to safe and plentiful raw material, healthier fatty acid composition, controllable viscoelasticity, and more varied nutrition/flavor embedding. Recently, various oleogelation techniques and novel emulsion gels have been reported further to enrich the potential of polysaccharides in oil structuring, in which a crucial step is to promote the formation of polysaccharide networks determining gel properties through different media. Meanwhile, polysaccharide-based oleogels and emulsion gels have good oil holding, nutrient/flavor embedding, and 3D food printability, and their applications as fat substitutes have been explored in foods. This paper comprehensively reviews the types, preparation methods, and mechanisms of various polysaccharide-based oleogels and emulsion gels; meanwhile, the food applications and new trends of polysaccharide-based gels are discussed. Moreover, some viewpoints about potential developments and application challenges of polysaccharide-based gels are mentioned. In the future, polysaccharide-based gels may be flexible materials for customized nutritional foods and molecular gastronomy. However, it is still a challenge to select the appropriate oleogels or emulsion gels to meet the requirements of the products. Once this issue is addressed, oleogels and emulsion gels are anticipated to be used widely.

Preparation and characterization of carboxymethylated Aureobasidium pullulans β-(1 → 3, 1 → 6)-glucan and its in vitro antioxidant activity

Aureobasidium pullulans β-(1 → 3, 1 → 6)-glucan (APG) has a high degree of β-(1 → 6)-glucosyl branching and a regular triple helical structure similar to that of schizophyllan. In this study, APG was carboxymethylated to different degrees of substitution (DS = 0.51, 1.0, and 2.0, denoted CMAPG 1-3, respectively) using a heterogeneous reaction. With increasing DS, the triple-helix structure drastically decreased and converted to a random coil structure in CMAPG 3. Further, aqueous solutions of CMAPG changed from pseudoplastic fluids to perfect Newtonian liquids with increasing DS, indicating that the intra- and intermolecular hydrogen bonds had been cleaved by the substituents to form a random coil structure. In addition, APG and CMAPG solutions exhibited scavenging ability against hydroxyl, organic, and sulfate radicals. It was also found that the carboxymethylation of APG drastically enhanced the organic radical scavenging ability. On the basis of the relationship between the DS and radical scavenging ability of the CMAPG samples, we believe hydroxyl and organic radicals were preferably scavenged by the donation of hydrogen atoms from the glucose rings and the methylene moieties of the carboxymethyl groups, respectively. Considering the obtained results, CMAPG and APG are expected to have applications in pharmaceuticals, functional foods, and cosmetics as antioxidant polysaccharides.

Antitumor Activity of Carboxymethyl Pachymaran with Different Molecular Weights Based on Immunomodulatory and Gut Microbiota

Carboxymethyl pachymaran (CMP) was treated via high-temperature and cellulase hydrolysis to obtain HTCMP, HTEC-24, and HTEC-48. The chemical structure and in vivo antitumor activities of the four types of CMPs were investigated. Compared with CMP (787.9 kDa), the molecular weights of HTCMP, HTEC-24, and HTEC-48 were decreased to 429.8, 129.9, and 68.6 kDa, respectively. The viscosities and particle sizes of the CMPs could also decrease with the decline in the molecular weights. All the CMPs showed antitumor abilities, but HTEC-24 exhibited the best activity. In the animal study, when curing the spleen and thymus, CMPs displayed immunomodulatory effects by increasing the secretion of IFN-γ and IL2 in mice. The CMPs also exerted an antitumor ability by regulating the gut microbiota in tumor-bearing mice. Our results established a foundation to develop an antitumor drug with CMP.

Some new insights into the biological activities of carboxymethylated polysaccharides from Lasiodiplodia theobromae

BACKGROUND

Carboxymethylated Lasiodiplodan (LaEPS-C), Lasiodiplodia theobromae β-glucan exopolysaccharide derivative, has a well-known range of biological activities. Compared to LaEPS-C, its fractions, Linear (LLaEPS-C) and Branched (BLaEPS-C), have biological potentialities scarcely described in the literature. So, in this study, we investigate the immunomodulatory, antiviral, antiproliferative, and anticoagulant activities of LLaEPS-C and BLaEPS-C and compare them to the LaEPS-C.

METHODS

LaEPS was obtained from L. theobromae MMBJ. After carboxymethylation, LaEPS-C structural characteristics were confirmed by Elementary Composition Analysis by Energy Dispersive X-Ray Detector (EDS), Fourier Transform Infrared (FTIR), and Nuclear Magnetic Resonance (NMR). The immunomodulatory activity on cytokine secretion was evaluated in human monocyte-derived macrophage cultures. The antiviral activity was evaluated by Hep-2 cell viability in the presence or absence of hRSV (human respiratory syncytial virus). In vitro antiproliferative activity was tested by sulforhodamine B assay. The anticoagulant activity was determined by APTT (Activated Partial Thromboplastin Time) and PT (Prothrombin Time).

RESULTS

LaEPS-C showed low macrophage cell viability only at 100 µg/mL (52.84 ± 24.06, 48 h), and LLaEPS-C presented no effect. Conversely, BLaEPS-C showed cytotoxicity from 25 to 100 µg/mL (44.36 ± 20.16, 40.64 ± 25.55, 33.87 ± 25.16; 48 h). LaEPS-C and LLaEPS-C showed anti-inflammatory activity. LaEPS-C presented this at 100 µg/mL (36.75 ± 5.53, 48 h) for IL-10, and LLaEPS-C reduces TNF-α cytokine productions at 100 µg/mL (18.27 ± 5.80, 48 h). LLaEPS-C showed an anti-hRSV activity (0.7 µg/ml) plus a low cytotoxic activity for Hep-2 cells (1.4 µg/ml). LaEPS-C presented an antiproliferative activity for NCI-ADR/RES (GI50 65.3 µg/mL). A better PT was achieved for LLaEPS-C at 5.0 µg/mL (11.85 ± 0.87s).

CONCLUSIONS

These findings demonstrated that carboxymethylation effectively improves the biological potential of the LaEPS-C and their fractions. From those polysaccharides tested, LLaEPS provided the best results with low toxicity for anti-inflammatory, antiviral, and anticoagulant activities.

Recent advances in polysaccharide biomodification by microbial fermentation: production, properties, bioactivities, and mechanisms

Polysaccharides are natural chemical compounds that are extensively employed in the food and pharmaceutical industries. They exhibit a wide range of physical and biological properties. These properties are commonly improved by using chemical and physical methods. However, with the advancement of biotechnology and increased demand for green, clean, and safe products, polysaccharide modification via microbial fermentation has gained importance in improving their physicochemical and biological activities. The physicochemical and structural characteristics, biological activity, and modification mechanisms of microbially fermented polysaccharides were reviewed and summarized in this study. Polysaccharide modifications were categorized and discussed in terms of strains and fermentation techniques. The effects of microbial fermentation on the physicochemical characteristics of polysaccharides were highlighted. The impact of modification of polysaccharides on their antioxidant, immune, hypoglycemic, and other activities, as well as probiotic digestive enhancement, were also discussed. Finally, we investigated a potential enzyme-based process for polysaccharide modification via microbial fermentation. Modification of polysaccharides via microbial fermentation has significant value and application potential.

Exopolysaccharides from Genistein-Stimulated Monascus purpureus Ameliorate Cyclophosphamide-Induced Intestinal Injury via PI3K/AKT-MAPKs/NF-κB Pathways and Regulation of Gut Microbiota

Exopolysaccharides from genistein-stimulated Monascus purpureus (G-EMP) exhibited immunomodulatory potential in vitro, but whether it had immune-enhancing effects in vivo and its potential mechanism are not yet known. Here, the immunomodulatory effects of G-EMP were investigated by establishing an immunosuppressed mouse model treated with cyclophosphamide (Cy). The results suggested that G-EMP effectively alleviated the signs of weight reduction and diet reduction caused by Cy, increased fecal water content and splenic index, and decreased the oxidative stress of the liver. Simultaneously, G-EMP improved Cy-induced intestinal injury by restoring villus length, increasing the number of cupped cells, upregulating the expression of mucin and tight junction proteins, and downregulating the ratio of apoptotic proteins (Bax/Bcl-2). It also boosted the levels of mouse colonic cytokines, CD4+ and CD8+ T cells. Additionally, G-EMP markedly enhanced immunomodulation via the activation of PI3K/AKT-MAPKs/NF-κB signal pathways. Furthermore, G-EMP intervention displayed a positive association with most immunological indexes by elevating the levels of short-chain fatty acids, varying gut microbiota composition, and enhancing beneficial bacteria (Lactobacillaceae, Prevotellaceae, and S24-7). These findings demonstrated that G-EMP can strengthen immunity, repair intestinal mucosal damage, regulate gut microbiota, and be a potential source of prebiotics.

Konjac glucomannan-based hydrogels with health-promoting effects for potential edible electronics applications: A mini-review

Konjac glucomannan (KGM), a dietary fiber hydrocolloid polysaccharide isolated from Amorphophallus konjac tubers, has potential applications in various fields. However, the use of KGM-based hydrogels has mainly focused on the food, biomedical, and water treatment industries. KGM possesses several health benefits and could be a promising candidate for use in edible electronics. This paper presents the first review of KGM-based hydrogels as edible electronics and their potential health benefits. The paper initially focuses on the health-promoting effects of KGM-based hydrogels, such as prebiotic effects, antiobesity, antioxidant, and antibacterial properties. Then, it discusses the feasible design strategies for KGM-based hydrogels as edible electronics, considering their flexibility, mechanical properties, response to stimuli, degradability aspects, their role as electronic device components, and the retention period of the devices. Finally, this review outlines future directions for developing KGM-based hydrogels for use in edible electronics.

Carboxymethylated Rhizoma alismatis Polysaccharides Regulate Calcium Oxalate Crystals Growth and Reduce the Regulated Crystals' Cytotoxicity

OBJECTIVE

This study explored the effects of polysaccharides (RAPD) extracted from the traditional anti-stone Chinese medicine Rhizoma alismatis and their carboxymethylated derivatives (RAPs) on the crystal phase, morphology, and size of calcium oxalate (CaOx). It also determined the damaging ability of the regulated crystals on human renal tubular epithelial cells (HK-2).

METHODS

RAPD carboxymethylation with a carboxyl group (-COOH) content of 3.57% was carried out by the chloroacetic acid solvent method. The effects of -COOH content in RAPs and RAP concentration on the regulation of CaOx crystal growth were studied by controlling the variables. Cell experiments were conducted to explore the differences in the cytotoxicity of RAP-regulated crystals.

RESULTS

The -COOH contents of RAPD, RAP1, RAP2, and RAP3 were 3.57%, 7.79%, 10.84%, and 15.33%, respectively. RAPs can inhibit the growth of calcium oxalate monohydrate (COM) and induce the formation of calcium oxalate dihydrate (COD). When the -COOH content in RAPs was high, their ability to induce COD formation was enhanced. In the crystals induced by RAPs, a high COD content can lower the damage to cells. In particular, the cytotoxicity of the crystals induced by RAP3 was the lowest. When the concentration of RAP3 increased, the cytotoxicity gradually increased due to the reduced size of the formed COD crystals. An interaction was observed between RAPs and crystals, and the number of RAPs adsorbed in the crystals was positively correlated with the -COOH content in RAPs.

CONCLUSIONS

RAPs can reduce the damage of CaOx to HK-2 cells by regulating the crystallization of CaOx crystals and effectively reducing the risk of kidney stone formation. RAPs, especially RAP3 with a high carboxyl group content, has the potential to be developed as a novel green anti-stone drug.

Effects of degradation on the physicochemical and antioxidant properties of carboxymethyl pachymaran

Poria cocos (Schw.) Wolf is a well-known edible and medicinal fungus. The polysaccharide in the sclerotium of P. cocos was extracted and prepared into carboxymethyl pachymaran (CMP). Three different degradation treatments including high temperature (HT), high pressure (HP) and gamma irradiation (GI) were used to process CMP. The changes in physicochemical properties and antioxidant activities of CMP were then comparatively investigated. We found that the molecular weights of HT-CMP, HP-CMP, and GI-CMP decreased from 787.9 kDa to 429.8, 569.5 and 6.0 kDa, respectively. Degradation treatments had no effect on the main chains of →3-β-D-Glcp-(1 → while changed the branched sugar residues. The polysaccharide chains of CMP were depolymerized after high pressure and gamma irradiation treatments. The three degradation methods improved the stability of CMP solution while decreased the thermal stability of CMP. In addition, we found that the GI-CMP with lowest molecular weight had the best antioxidant activity. Our results suggest that gamma irradiation treatment could degrade CMP as functional foods with strong antioxidant activity.

Polysaccharide-Based Stimulus-Responsive Nanomedicines for Combination Cancer Immunotherapy

Cancer immunotherapy is a promising antitumor approach, whereas nontherapeutic side effects, tumor microenvironment (TME) intricacy, and low tumor immunogenicity limit its therapeutic efficacy. In recent years, combination immunotherapy with other therapies has been proven to considerably increase antitumor efficacy. However, achieving codelivery of the drugs to the tumor site remains a major challenge. Stimulus-responsive nanodelivery systems show controlled drug delivery and precise drug release. Polysaccharides, a family of potential biomaterials, are widely used in the development of stimulus-responsive nanomedicines due to their unique physicochemical properties, biocompatibility, and modifiability. Here, the antitumor activity of polysaccharides and several combined immunotherapy strategies (e.g., immunotherapy combined with chemotherapy, photodynamic therapy, or photothermal therapy) are summarized. More importantly, the recent progress of polysaccharide-based stimulus-responsive nanomedicines for combination cancer immunotherapy is discussed, with the focus on construction of nanomedicine, targeted delivery, drug release, and enhanced antitumor effects. Finally, the limitations and application prospects of this new field are discussed.

Preparation of biodegradable composite films based on carboxymethylated holocellulose from wheat straw

Holocellulose was extracted from wheat straw and catalytically transformed into carboxymethylated holocellulose (CMHCS) to prepare a biodegradable composite film. By changing the type and amount of catalyst, the carboxymethylation of the holocellulose was optimized with respect to the degree of substitution (DS). A high DS of 2.46 was achieved in the presence of a cocatalyst composed of polyethylene glycol and cetyltrimethylammonium bromide. The effect of DS on the properties of CMHCS-derived biodegradable composite films was further investigated. Compared to pristine holocellulose, the mechanical properties of the composite film were significantly improved and increased with increasing DS. The tensile strength, elongation at break, and Young's modulus increased from 6.58 MPa, 51.4 %, and 26.13 MPa for the unmodified holocellulose-based composite film to 14.81 MPa, 89.36 %, and 81.73 MPa for the film derived from the CMHCS with a DS of 2.46. The biodegradability of the composite film was assessed under soil burial biodisintegration conditions and reached 71.5 % degradation after 45 d. Additionally, a possible degradation process for the composite film was proposed. The results indicated that the CMHCS-derived composite film has good comprehensive performance, and CMHCS is expected to be applied in the field of biodegradable composite materials.

Carboxymethylation modification, characterization of dandelion root polysaccharide and its effects on gel properties and microstructure of whey protein isolate

In the present study, a native polysaccharide (DP) with sugar content of 87.54 ± 2.01 % was isolated from dandelion roots. DP was chemically modified to obtain a carboxymethylated polysaccharide (CMDP) with DS of 0.42 ± 0.07. DP and CMDP were composed of the same six monosaccharides including mannose, rhamnose, galacturonic acid, glucose, galactose, and arabinose. The molecular weights of DP and CMDP were 108,200 and 69,800 Da, respectively. CMDP exhibited more stable thermal performance and better gelling properties than DP. The effects of DP and CMDP on the strength, water holding capacity (WHC), microstructure, and rheological properties of whey protein isolate (WPI) gels were investigated. Results showed that CMDP-WPI gels had higher strength and WHC than DP-WPI gels. With the addition of 1.5 % CMDP, WPI gel had a good three-dimensional network structure. The apparent viscosities, loss modulus (G"), and storage modulus (G') of WPI gels were increased with the polysaccharide addition, the influence of CMDP was remarkable compared to DP at the same concentration. These findings suggest that CMDP may be used as a functional ingredient in protein-containing food products.

Ultrasound-assisted extraction and analysis of maidenhairtree polysaccharides

The maidenhairtree polysaccharides (MTPs) have important application prospects. So, the extraction, purification, structure, derivatization and biological activities of polysaccharides from leaves, fruits, and testae of maidenhairtree were disscussed. Polysaccharides were extracted by collaborative extraction methods such as ultrasound-assisted extraction and microwave-assisted extraction. The ultrasound-assisted extraction had higher content and higher efficiency. The structural characteristics and structure-activity relationship of maidenhairtree polysaccharides were studied in order to provide theoretical basis and technical support for the further development and utilization of maidenhairtree polysaccharides.

Application of carboxymethyl chitosan-based coating in fresh-cut apple preservation: Incorporation of guava leaf flavonoids and their noncovalent interaction study

Carboxymethyl chitosan (CMCS) has antibacterial activity and coating-forming ability. Under the impact of noncovalent interactions, the bioactivity and functionality of CMCS may be positively affected by the coexistence of flavonoids. This study investigated the effect of a CMCS coating incorporated with flavonoids from guava (Psidium guajava L. cv. Carmine) leaf (GLF) on the refrigeration of fresh-cut apples for preservation. Compared with the CMCS group, apples treated with the CMCS-GLF coating showed better quality (weight loss, browning index, firmness), nutritional value (ascorbic acid and total phenolic content), and microbial safety during storage. The mechanism study indicated that the hydrogen bonding, electrostatic, and hydrophobic interactions between CMCS and GLF (the carboxymethyl moiety of CMCS had the highest response priority and binding strength of the interaction with -C-O of GLF) changed the surface charge distribution and microstructure of CMCS, and increased its molecular weight, particle size, viscosity, and hydrophobicity. Thus, the CMCS-GLF coating exerted better bioactivities (antibacterial and antioxidant activity), and its film showed better mechanical and barrier properties. These results revealed that the noncovalent interaction with GLF could modify the physiochemical properties of CMCS, which was beneficial to improve its bioactivity and application value in fresh fruit preservation.

A pH-sensitive hydrogel based on carboxymethylated konjac glucomannan crosslinked by sodium trimetaphosphate: Synthesis, characterization, swelling behavior and controlled drug release

The pH-sensitive hydrogel consisting of carboxymethylated konjac glucomannan (CMKGM) and sodium trimetaphosphate (STMP) was prepared for a potential intestinal targeted delivery system. Both the CMKGM and the CMKGM hydrogel were characterized by FT-IR spectra, X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The Congo red and atomic force microscope (AFM) results showed a coil-to-helix transition of CMKGM in alkaline conditions with the degree of substitution (DS) increased from 0.20 to 0.49. Rheological measurements indicated that the DS and the STMP content collectively influence the mechanical stiffness and swelling properties of the obtained hydrogels. In addition, the swelling behavior of the hydrogels revealed that they were sensitive to pH value changes and were following a Korsmeyer-Peppas gastrointestinal release behavior, indicating that the release was controlled by non-Fickian diffusion. Furthermore, all the results suggested that the prepared pH-sensitive hydrogel may serve as a potential biomaterial for the intestine-targeted delivery system.

HPMC films functionalized by zein/carboxymethyl tamarind gum stabilized Pickering emulsions: Influence of carboxymethylation degree

Pickering emulsions are promising systems to act as carriers of active hydrophobic components, and to improve compatibility and the water vapor barrier properties of bio-based films. This study aimed to investigated the effects of cinnamon essential oil Pickering emulsions (CEOEs) using zein/carboxymethyl tamarind gum as stabilizers on the mechanical, barrier, antibacterial and antioxidant properties of Hydroxypropyl methyl cellulose (HPMC) films, and assessed the influence of carboxymethylation degree. In addition, the effect of the packaging was studied on the shelf life of cherry tomatoes. Results showed that the droplet size reduced approximately from 93.03 to 10.59 μm with the increasing degree of substitution (DS), greatly facilitating the droplet uniform distribution in film matrix. Moreover, with the addition of CEOEs, significant increase was observed with the tensile strength from 8.46 to 25.41 MPa, and the water vapor permeability decreased from 6.18 × 10^-10 to 4.24 × 10^-10 g·m^-1·s^-1·Pa^-1. The films exhibited good UV barrier properties without sacrificing the transparency after adding CEO. Furthermore, the antibacterial and antioxidant activities of the prepared films have also been greatly improved. Consequently, the CEOEs was an ideal alternative for incorporation with HPMC based films for increasing the shelf life of cherry tomatoes.

Structure, Merits, Gel Formation, Gel Preparation and Functions of Konjac Glucomannan and Its Application in Aquatic Food Preservation

Konjac glucomannan (KGM) is a natural polysaccharide extracted from konjac tubers that has a topological structure composed of glucose and mannose. KGM can be used as a gel carrier to load active molecules in food preservation. The three-dimensional gel network structure based on KGM provides good protection for the loaded active molecules and allows for sustained release, thus enhancing the antioxidant and antimicrobial activities of these molecules. KGM loaded with various active molecules has been used in aquatic foods preservation, with great potential for different food preservation applications. This review summarizes recent advances in KGM, including: (i) structural characterization, (ii) the formation mechanism, (iii) preparation methods, (iv) functional properties and (v) the preservation of aquatic food.

Effect of ultrasonic degradation on the structural feature, physicochemical property and bioactivity of plant and microbial polysaccharides: A review

With the bioactivities of antioxidant, anti-bacteria, anti-inflammation, immune regulation, antitumor and anti-coagulation, plant and microbial polysaccharides have been widely used in foods, medicine and cosmetics. However, how structure features affect the physicochemical property and bioactivity of plant and microbial polysaccharides is still unclear. Ultrasonic degradation usually degrades or modifies plant and microbial polysaccharides with different physicochemical properties and bioactivities by affecting their chemical or spatial structures via mechanical bond breaking and cavitation effects. Therefore, ultrasonic degradation might be an effective strategy for producing bioactive plant and microbial polysaccharides and analyzing their structure-function relationship. Present review summarized the influence of ultrasonic degradation on structural feature, physicochemical property and bioactivity of plant and microbial polysaccharides. Moreover, further problems need to be paid attention to during the application of ultrasonication for plant and microbial polysaccharides degradation are also recommended. Overall, present review will provide an efficient method for producing enhanced bioactive plant and microbial polysaccharides and analyzing their structure-activity relationship based on ultrasonic degradation.

Polysaccharides as antioxidants and prooxidants in managing the double-edged sword of reactive oxygen species

Polysaccharides, a class of naturally occurring carbohydrates, were widely presented in animals, plants, and microorganisms. Recently, health benefits of polysaccharides have attracted much attention due to their unique characteristics in reactive oxygen species (ROS) management. ROS, by-products of aerobic metabolism linked to food consumption, exhibited a dual role in protecting cells and fostering pathogenesis collectively termed double-edged sword. Some interesting studies reported that polysaccharides could behave as prooxidants under certain conditions, besides antioxidant capacities. Potentiation of the bright side of ROS could contribute to the host defense that was vitally important for the polysaccharides acting as biological response modifiers. Correspondingly, disease prevention of polysaccharides linked to the management of ROS production was systematically described and discussed in this review. Furthermore, major challenges and future prospects were presented, aiming to provide new insight into applying polysaccharides as functional food ingredients and medicine.

Characterization of a processive inulosucrase from Lactobacillus mulieris for efficient biosynthesis of high-molecular-weight inulin

Inulin has been determined to have many exceptional properties and functions and has been used in the food and pharmaceutical fields. Recently, microbial high-molecular-weight inulin synthesized from sucrose by inulosucrase attracted much attention. In this study, a novel inulosucrase from Lactobacillus mulieris was constructed, overexpressed, purified, and identified. The recombinant enzyme displayed the maximum activity at pH 6.0 and 55 °C, and it exhibited high thermostability below 45 °C. After optimizing the production conditions, the conversion rate from 100 g/L sucrose to inulin reached 31 %, meanwhile, the maximum molecular weight of produced inulin reached 3.21 × 10⁶ g/mol. The truncated IS showed a "processive" transfructosylation process, only synthesizing a small number of short-chain oligosaccharides with polymerization degrees below 6, which was in favor of the accumulation of high-molecular-weight inulin. Given this, L. mulieris inulosucrase might be a good potential candidate for the industrial production of high-molecular-weight inulin.

Carboxymethyl Cellulose-Based Polymers as Promising Matrices for Ficin Immobilization

The present work is devoted to research on the interaction between carboxymethyl cellulose sodium salt and its derivatives (graft copolymer of carboxymethyl cellulose sodium salt and N,N-dimethyl aminoethyl methacrylate) with cysteine protease (ficin). The interaction was studied by FTIR and by flexible molecular docking, which have shown the conjugates' formation with both matrices. The proteolytic activity assay performed with azocasein demonstrated that the specific activities of all immobilized ficin samples are higher in comparison with those of the native enzyme. This is due to the modulation of the conformation of ficin globule and of the enzyme active site by weak physical interactions involving catalytically valuable amino acids. The results obtained can extend the practical use of ficin in biomedicine and biotechnology.

Molecular mechanism of epicatechin gallate binding with carboxymethyl β-glucan and its effect on antibacterial activity

The non-covalent binding between flavanols and polysaccharides has impacts on their bioactivities, but the binding mechanism is less understood. This work aimed to unveil the non-covalent interactions between epicatechin gallate (ECG) and anionic carboxymethyl Poria cocos polysaccharide (CMP_N) at the structural and molecular level based on the synergistic antibacterial effect between them. The results suggested that there was hydrogen bonding, hydrophobic and electrostatic interaction between ECG and CMP_N, which was also supported by the results of molecular dynamics simulations. The resulting changes in physicochemical properties enhanced the antibacterial activity of the ECG-CMP_N mixture. More specifically, through two-dimensional Fourier transform infrared correlation spectrum (2D-FT-IR) and nuclear magnetic resonance spectroscopy (NMR) analysis, COO^- in CMP_N carboxymethyl and CO in ECG galloyl had the highest response priority and binding strength in the interaction, allowing us to conclude the critical functional groups that affect the non-covalent interactions of polysaccharide and flavanols and their bioactivities.

Enhancement of functional activity and biosynthesis of exopolysaccharides in Monascus purpureus by genistein treatments

The exopolysaccharides (EPS) produced by the edible medicinal fungus Monascus purpureus (EMP) become the center of growing interest due to their techno-functional properties and their numerous applications in the food industries; however, the low EPS yields limit its application. In this study, the effect of genistein supplementation on the production, rheological and antioxidant properties of EPS by M. purpureus and its biosynthesis mechanism were explored. The results indicated that the addition of genistein (3 g/L) generated a 110% and 59% increase in the maximum mycelial biomass and EPS yield, respectively. The genistein supplementation group (G-EMP) had higher molar percentages of Xyl and Man, and significantly decreased molecule weight and particle size of EPS, which resulted in stronger antioxidant effect and cell growth promotion. Rheological analysis showed that both EMP and G-EMP demonstrated pseudoplastic fluid behavior and G-EMP exhibited strong gel-like elastic behavior (G' > G"). Furthermore, genistein not only facilitated the production of EPS by regulating cell membrane permeability, enhancing cellular respiratory metabolism and monosaccharide precursor synthesis pathways, and enhancing antioxidant enzyme activity to reduce oxidative stress damage, but also affected the composition of the monosaccharides by increasing enzyme activity in the underlying synthesis pathways. These findings expand the application of M. purpureus resources and provide a paradigm for future study of the structural and functional characteristics of EPS.

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Genistein (3 g/L) significantly stimulate yield of biomass and exopolysaccharides (EPS) from M. purpureus.

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The physicochemical and rheological properties of EPS were significantly changed.

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Their antioxidant and cytoprotective effect were compared.

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A possible mechanism for the response of genistein to increase EPS yield is proposed.

Emerging Food Packaging Applications of Cellulose Nanocomposites: A Review

Cellulose is the most abundant biopolymer on Earth, which is synthesized by plants, bacteria, and animals, with source-dependent properties. Cellulose containing β-1,4-linked D-glucoses further assembles into hierarchical structures in microfibrils, which can be processed to nanocellulose with length or width in the nanoscale after a variety of pretreatments including enzymatic hydrolysis, TEMPO-oxidation, and carboxymethylation. Nanocellulose can be mainly categorized into cellulose nanocrystal (CNC) produced by acid hydrolysis, cellulose nanofibrils (CNF) prepared by refining, homogenization, microfluidization, sonification, ball milling, and the aqueous counter collision (ACC) method, and bacterial cellulose (BC) biosynthesized by the Acetobacter species. Due to nontoxicity, good biodegradability and biocompatibility, high aspect ratio, low thermal expansion coefficient, excellent mechanical strength, and unique optical properties, nanocellulose is utilized to develop various cellulose nanocomposites through solution casting, Layer-by-Layer (LBL) assembly, extrusion, coating, gel-forming, spray drying, electrostatic spinning, adsorption, nanoemulsion, and other techniques, and has been widely used as food packaging material with excellent barrier and mechanical properties, antibacterial activity, and stimuli-responsive performance to improve the food quality and shelf life. Under the driving force of the increasing green food packaging market, nanocellulose production has gradually developed from lab-scale to pilot- or even industrial-scale, mainly in Europe, Africa, and Asia, though developing cost-effective preparation techniques and precisely tuning the physicochemical properties are key to the commercialization. We expect this review to summarise the recent literature in the nanocellulose-based food packaging field and provide the readers with the state-of-the-art of this research area.

Therapeutic potential of non-starch polysaccharides on type 2 diabetes: from hypoglycemic mechanism to clinical trials

Non-starch polysaccharides (NSPs) have been reported to exert therapeutic potential on managing type 2 diabetes mellitus (T2DM). Various mechanisms have been proposed; however, several studies have not considered the correlations between the anti-T2DM activity of NSPs and their molecular structure. Moreover, the current understanding of the role of NSPs in T2DM treatment is mainly based on in vitro and in vivo data, and more human clinical trials are required to verify the actual efficacy in treating T2DM. The related anti-T2DM mechanisms of NSPs, including regulating insulin action, promoting glucose metabolism and regulating postprandial blood glucose level, anti-inflammatory and regulating gut microbiota (GM), are reviewed. The structure-function relationships are summarized, and the relationships between NSPs structure and anti-T2DM activity from clinical trials are highlighted. The development of anti-T2DM medication or dietary supplements of NSPs could be promoted with an in-depth understanding of the multiple regulatory effects in the treatment/intervention of T2DM.

Extraction, isolation, structural characterization, and antioxidant activity of polysaccharides from elderberry fruit

The isolation, purification, and antioxidant activity of polysaccharides extracted from elderberry fruits were studied. Two neutral polysaccharides (EFP-0 and EFP-1) and three acidic polysaccharides (EFP-2, EFP-3, and EFP-4) were isolated from elderberry. EFP-0, EFP-1, EFP-2, EFP-3, and EFP-4 all contain arabinose, galactose, glucose, and mannose, with molecular weights of 1.7981 × 10⁶, 7.0523 × 10⁶, 7.7638 × 10⁶, 4.3855 × 10⁵, and 7.3173 × 10⁵ Da, respectively. Structural characterization showed that the backbone of EFP-2 consisted of →4)-Manp (1→4)-β-D-Glcp (1→ and →4)-β-D-Glcp (1→5)-α-L-Araf (1→units, and T-α-L-Araf (1→ and T-β-D-Galp (1→ residues were detected by methylation analysis and NMR analysis. In addition, the MTT assay and zebrafish oxidative damage assay showed that EFP-2 had a protective effect on H₂O₂-damaged RAW264.7 cells in a dose-dependent manner, and zebrafish with the addition of EFP-2 would have low levels of ROS in vivo which showed significant antioxidant activity. Therefore, the results showed that the elderberry polysaccharides have antioxidant activity and can be used as potential antioxidants in functional foods.

Anticancer effects of carboxymethylated (1→3)(1→6)-β-D-glucan (botryosphaeran) on multicellular tumor spheroids of MCF-7 cells as a model of breast cancer

Breast cancer is the most common cancer worldwide among the female population. The fungal exopolysaccharide botryosphaeran is a (1→3)(1→6)-β-D-glucan with limited solubility in water that can be promoted through carboxymethylation. Thus, the aim of this study was to examine in-vitro anticancer effects of carboxymethylated-botryosphaeran (CM-BOT) on breast cancer MCF-7 cells cultivated in multicellular tumor spheroids (MCTS). CM-BOT (≥ 600 µ/ml) decreased the viability (resazurin assay) of MCF-7 grown in monolayers after 24 hr incubation. Although CM-BOT did not markedly alter viability of MCTS in the resazurin assay after 24, 48 or 72 hr, CM-BOT ≥ 600 µg/ml produced cell-death by apoptosis after 72 hr utilizing the triple staining assay and labeling dead cells with propidium iodide, which can also be visualized on the architecture of MCTS. CM-BOT (1000 µg/ml) inhibited cell proliferation, which resulted in MCTSs with smaller diameters than controls. CM-BOT at all concentrations examined decreased the ability of MCF-7 to form colonies and to migrate in the extracellular matrix. This is the first report using MCTS-architecture to study anti-tumor effects of β-glucans. Our findings are important in the search for compounds for use in breast cancer therapy, or as adjuvants in reducing the adverse effects of mammary tumor chemotherapy.

Bioactive polysaccharides and oligosaccharides from garlic (Allium sativum L.): Production, physicochemical and biological properties, and structure-function relationships

Garlic is a common food, and many of its biological functions are attributed to its components including functional carbohydrates. Garlic polysaccharides and oligosaccharides as main components are understudied but have future value due to the growing demand for bioactive polysaccharides/oligosaccharides from natural sources. Garlic polysaccharides have molecular weights of 1 × 10³ to 2 × 10⁶  Da, containing small amounts of pectins and fructooligosaccharides and large amounts of inulin-type fructans ((2→1)-linked β-d-Fruf backbones alone or with attached (2→6)-linked β-d-Fruf branched chains). This article provides a detailed review of research progress and identifies knowledge gaps in extraction, production, composition, molecular characteristics, structural features, physicochemical properties, bioactivities, and structure-function relationships of garlic polysaccharides/oligosaccharides. Whether the extraction processes, synthesis approaches, and modification methods established for other non-garlic polysaccharides are also effective for garlic polysaccharides/oligosaccharides (to preserve their desired molecular structures and bioactivities) requires verification. The metabolic processes of ingested garlic polysaccharides/oligosaccharides (as food ingredients/dietary supplements), their modes of action in healthy humans or populations with chronic conditions, and molecular/chain organization-bioactivity relationships remain unclear. Future research directions related to garlic polysaccharides/oligosaccharides are discussed.

Preparation, characterization and immunoregulatory activity of derivatives of polysaccharide from Atractylodes lancea (Thunb.) DC

A polysaccharide (ALP-1) extracted from Atractylodes lancea (Thunb.) DC. was carboxymethylated (C-ALP-1), phosphorylated (P-ALP-1) and acetylated (A-ALP-1) to improve its physicochemical properties and bioactivities. The solubility of all derivatives was increased, and the solubility of A-ALP-1 increased to 137.5 mg/mL, which was much higher than the solubility of ALP-1 (15.0 mg/mL). The results of HPSEC-MALLS-RID showed that the molecular weight of polysaccharides was slightly increased after the modification, and the root mean square radius of rotation (Rz) and morphology of polysaccharides in solution were also changed. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) results confirmed that the surface morphology of ALP-1 changed dramatically and the crystallinity decreased after structural modification. From thermal analysis results, the T₅₀ of ALP-1, C-ALP-1, P-ALP-1 and A-ALP-1 were 281.34, 292.14, 333.75 and 298.70 °C, which showed that derivatives had stronger thermal stability than ALP-1. The immunomodulatory activity studies displayed that P-ALP-1 showed the best ability to stimulate RAW264.7 macrophages to release NO, and A-ALP-1 showed the best capacity to stimulate TNF-α and IL-6 releasing. These results indicated that chemical modification could enhance the solubility, the thermal stability and immunomodulatory activity of polysaccharides, which is beneficial for the development and utilization of natural polysaccharides.