Structural characterization and immuno-enhancing activity of a highly branched water-soluble β-glucan from the spores of Ganoderma lucidum

Structural characterization of β-glucan in Hericium erinaceus pretreated by steam explosion and its effects on human gut microbiota in vitro

To investigate the impact of steam explosion on the structure of β-glucan and its regulation human gut microbiota (GM), two polysaccharides were prepared from Hericium erinaceus fruit bodies treated by steam explosion and conventional crushing, respectively. Structural analysis indicated that both two fractions were identified as β-(1 → 3)-glucan with different branching ratios attached at O-6 position. Compared with W20E obtained by conventional crushing, Q5E obtained by steam explosion possessed lower molecular weight (Mw, 2.158 × 106 g/mol) and lower branching ratio of 2:7, which influenced its effects on the diversity and metabolites of GM. W20E (Mw, 6.944 × 106 g/mol, branching ratio of 1:3) could promote n-butyrate production by increasing the abundance of Prevotellaceae_NK3B31_group, Lachnospira and Faecalibacterium. Q5E tended to improve the abundance of Lactococcus, as well as the total production of short chain fatty acids, especially for acetic and propionic acids. These findings provide reference for further development of β-glucan in healthy food.

Innovative submerged directed fermentation: Producing high molecular weight polysaccharides from Ganoderma lucidum

Polysaccharides from Ganoderma lucidum (GLPs) exhibit unique bioactivity, but traditional cultivation yields low quantities and unstable quality, limiting their research and application. This study highlights how submerged fermentation processes enable the directed acquisition of structurally defined high molecular weight (MW) bioactive intracellular polysaccharides (IPS). The results showed that inoculation amount and fermentation scales had a significant effect on the content of high MW IPS. In the fermentor, by lowering the initial glucose concentration combined with fed-batch fermentation, the high MW IPS content was improved. The monosaccharide composition indicated that the high MW IPS obtained from different fermentation scales exhibited stability. This polysaccharide, which is a β-glucan with a β-1,3-Glcp backbone and β-1-Glcp attached at the O-6 position, demonstrated immunostimulatory effects in vitro. Overall, the consistent quality of GLPs during submerged fermentation underscores the feasibility of industrial-scale production, presenting a significant advancement over traditional cultivation methods and promising for biotechnological applications.

Prospects of Ganoderma polysaccharides: Structural features, structure-function relationships, and quality evaluation

Polysaccharides, the primary bioactive compounds found in Ganoderma, are responsible for a multitude of biological activities. The bioactivity of Ganoderma polysaccharides (GPs) closely correlates to their physicochemical properties. Consequently, the accurate characterization and quantification of GPs are essential for the quality control of these compounds. Regrettably, the complex structural features of GPs have limited research on the relationships between their structures and bioactivities. In addition, a lack of appropriate quality assessment methods has impeded the regulation and application of GPs and related products. Therefore, it is essential to conduct extensive studies to develop reliable for quality control methods based on their pharmacological activities. This review aims to comprehensively and systematically outline the structural features, structure-activity relationships and quality control methods of GPs, thereby supporting their potential value in pharmaceuticals and functional foods. The insights presented in this review will significantly contribute to the research and potential applications of GPs.

Role of Mushroom Polysaccharides in Modulation of GI Homeostasis and Protection of GI Barrier

Edible and medicinal mushroom polysaccharides (EMMPs) have been widely studied for their various biological activities. It has been shown that EMMPs could modulate microbiota in the large intestine and improve intestinal health. However, the role of EMMPs in protecting the gastric barrier, regulating gastric microbiota, and improving gastric health cannot be ignored. Hence, this review will elucidate the effect of EMMPs on gastric and intestinal barriers, with emphasis on the interaction of EMMPs with microbiota in maintaining overall gastrointestinal health. Additionally, this review highlights the gastroprotective effects and underlying mechanisms of EMMPs against gastric mucosa injury, gastritis, gastric ulcer, and gastric cancer. Furthermore, the effects of EMMPs on intestinal diseases, including inflammatory bowel disease, colorectal cancer, and intestinal infection, are also summarized. This review will also discuss the future perspective and challenges in the use of EMMPs as a dietary supplement or a nutraceutical in preventing and treating gastrointestinal diseases.

Selenium-Enriched Polysaccharides from Lentinula edodes Mycelium: Biosynthesis, Chemical Characterisation, and Assessment of Antioxidant Properties

Selenium-polysaccharides possess antioxidant properties, making them promising materials for functional foods, pharmaceuticals, and clinical applications. This study examines the incorporation of selenium into polysaccharides via mycelial biosynthesis and its effects on structure and antioxidant activity. Polysaccharides obtained from Lentinula edodes-submerged cultures grown in Se-supplemented and non-supplemented media were analysed for Se content (RP-HPLC/FLD), structure (FT-IR, HPLC, and HPGPC-ELSD), and antioxidant activity (DPPH scavenging, reducing power, and Fe2+ chelation). Two low-molecular-weight Se-heteropolysaccharides (Se-FE-1.1 and Se-FE-1.2) containing ~80 and 125 µg/g Se were isolated, primarily composed of glucose, mannose, and galactose with β-glycosidic linkages. Se incorporation into polysaccharides selectively enhanced their antioxidant activity in the DPPH radical scavenging assay, with minimal effects observed in iron chelation and reducing power assays. Crude Se-polysaccharides displayed the highest antioxidant activity, suggesting an additional contribution from protein components. Our findings demonstrate that Se is effectively incorporated into polysaccharides, altering monosaccharide composition while preserving glycosidic linkages. The selective enhancement of radical scavenging suggests that selenium plays a specific role in antioxidant activity, primarily influencing radical scavenging mechanisms rather than interactions with metal ions. Further research is needed to clarify the mechanisms of selenium incorporation, the nature of its bonding within the polysaccharide molecule, and its impact on biological activity.

Structure-function insights of natural Ganoderma polysaccharides: advances in biosynthesis and functional food applications

Ganoderma polysaccharides (GPs), derived from various species of the Ganoderma genus, exhibit diverse bioactivities, including immune modulation, anti-tumor effects, and gut microbiota regulation. These properties position GPs as dual-purpose agents for medicinal and functional food development. This review comprehensively explores the structural complexity of six key GPs and their specific mechanisms of action, such as TLR signaling in immune modulation, apoptosis pathways in anti-tumor activity, and their prebiotic effects on gut microbiota. Additionally, the structure-activity relationships (SARs) of GPs are highlighted to elucidate their biological efficacy. Advances in green extraction techniques, including ultrasonic-assisted and enzymatic methods, are discussed for their roles in enhancing yield and aligning with sustainable production principles. Furthermore, the review addresses biotechnological innovations in polysaccharide biosynthesis, improving production efficiency and making large-scale production feasible. These insights, combined with ongoing research into their bioactivity, provide a solid foundation for developing health-promoting functional food products that incorporate GPs. Furthermore, future research directions are suggested to optimize biosynthesis pathways and fully harness the health benefits of these polysaccharides.

Preparation, characterization, and prebiotic potential of resistant maltodextrin from the remaining starch in cassava pulp

This study aimed to produce a novel resistant maltodextrin (RMD) from the remaining starch in cassava pulp via pyrodextrinization and enzymatic hydrolysis. The optimum conditions involved a temperature of 180 °C, 0.5 % HCl, and a reaction time of 5 h, resulting in a significant RMD yield (18.6 %). In terms of its morphology, the RMD involved irregularly shaped sponge-like particles of multiple sizes, with XRD analysis indicating the loss of the original crystalline structure. The predominant relative molecular size of the product was DP 15-16 (70.9 %). Analysis of the monosaccharide composition revealed the presence of glucose (88.0 %), followed by hemicellulose-derived monosaccharides (11.1 %). Indigestible glycosidic linkages, including α-1,2, β-1,2, β-1,4, and β-1,6 linkages, were identified in the RMD using NMR spectroscopy. FTIR spectroscopy confirmed the presence of β-glycosidic linkages in the final product and revealed acetyl groups, consistent with the presence of hemicellulosic oligosaccharides, and in vitro digestibility tests revealed a highly digestion-resistant fraction of 91.7 %. Remarkably, the RMD demonstrated a potential prebiotic effect by promoting the growth of four probiotic species. These findings suggest that the starch remaining in cassava pulp is a viable source of RMD and could be utilized as a prebiotic.

De-starched Panax ginseng polysaccharide: Preparation, in vitro digestion, fermentation properties and the activating effect of the resultant products on RAW264.7 cells

Panax ginseng C. A. Meyer (ginseng) neutral polysaccharides have been proven to be an immune enhancer, but their digestion and fermentation characteristics are unclear. This study aimed to prepare a de-starched polysaccharide (DGPN) from ginseng and investigate its degradation rules and the changes in immune activity by using an in vitro digestion and fermentation model. Results showed that in digestion process, the molecular weight of DGPN decreased from 4.72 × 104 to 4.04 × 104 Da, reducing sugar (CR) content increased from 0.0539 ± 0.0037 to 0.0919 ± 0.0015 mg/mL. During the fecal fermentation process, a significant decrease in total carbohydrate content and molecular weight, a significant increase in CR and change in the proportion of monosaccharide composition can be observed, indicating that DGPN was mainly degraded during fermentation process. DGPN modulated the microbial composition via increasing the relative abundance of beneficial bacteria including Bacteroides, [Eubacterium]_nodatum_group, Ligilactobacillus, Enterococcus and reducing harmful bacteria such as Escherichia_Shigela. DGPN also promoted the production of short chain fatty acids. Cell experiments results showed that fermentation product DGPN-F48 activated RAW264.7 cells via TLR4/Myd88/NF-κB signaling pathway and the activity was significantly enhanced after fermentation process. This study confirmed DGPN is beneficial for enhancing gut health and has prebiotic potential.

A glucomannan from defatted Ganoderma lucidum spores: structural characterization and immunomodulatory activity via activating TLR4/MyD88/NF-κB signaling pathway

Ganoderma lucidum spores are tiny mature germ cells ejected from the abaxial side of the pileus and were responsible for multiple pharmacological properties. The defatted G. lucidum spores are the byproducts after the extraction of G. lucidum spores oil by supercritical fluid extraction technology, which have not been given sufficient attention. In order to fully utilize the resources of G. lucidum spores, a glucomannan (SGL90-1, 6.4 kDa) was isolated from the defatted G. lucidum spores. SGL90-1 was composed of mannose, glucose, galactose, and fucose in a molar ratio of 23.9:28.7:9.0:1.0. The backbone of SGL90-1 was consisted of →2,4)-α-D-Manp-(1→, →6)-β-D-Manp-(1→, →2,6)-α-D-Manp-(1→, →2)-α-D-Glcp-(1→, and →3,6)-β-D-Glcp-(1→ with seven side chains, and terminated with β-D-Manp-(1→, β-D-Glcp-(1→, α-L-Fucp-(1→, and β-D-Galf-(1→. Moreover, SGL90-1 could significantly elevate the phagocytic capability of RAW264.7 macrophages and promote the levels of nitric oxide (NO), tumor necrosis factor-α (TNF-α), and interlrukin-6 (IL-6) through activating the TLR4/MyD88/NF-κB signaling pathway. Collectively, these findings demonstrated the potential of SGL90-1 as a natural functional food with strong immune-enhancing effect.

Structural Characterization and Anti-Gouty Nephropathy Potential of Polysaccharides from Atractylodes chinensis

Polysaccharides derived from Atractylodes chinensis (DC.) Koidz. (ACP), a traditional Chinese medicine, were extracted and analyzed for their structural characteristics and anti-gouty nephropathy (GN) activity. Sprague-Dawley (SD) rats were divided into six groups: control, model, positive control, and three treatment groups (ACP-60-L, ACP-60-M, and ACP-60-H). Treatment significantly reduced inflammatory responses and renal damage, as evidenced by decreased levels of uric acid (UA), creatinine (Cr), and blood urea nitrogen (BUN), alongside modulation of NOD-like receptor protein 3 (NLRP3) expression in renal tissues. ACP-60 was fractionated into three polysaccharides, including ACP-60-A (Mw 9.18 kDa), ACP-60-B (Mw 58.21 kDa), and ACP-60-C (Mw 109.01 kDa) using DEAE-52 cellulose column chromatography. Monosaccharide analysis revealed that ACP-60-A predominantly comprised fructose (Fru) and glucose (Glc), ACP-60-B contained rhamnose (Rha), galactose (Gal), Fru, and mannose (Man), and ACP-60-C included Man, Gal, Rha and xylose (Xyl). In vitro studies using HK-2 cells confirmed the anti-GN activity of all three fractions, with ACP-60-A demonstrating the highest efficacy. Structural elucidation of ACP-60-A identified its main glycosidic linkages as a →1)-β-Fruf-(2→ backbone with α-Glcp-(1→ and β-Fruf-(2→ branches. The underlying mechanism of ACP-60-A's anti-GN activity is associated with inhibition of the NLRP3 inflammasome signaling pathway, suppression of downstream inflammatory factor release, and downregulation of NLRP3, ASC, and Caspase-1 protein expression. Further studies demonstrated that the superior activity of ACP-60-A is attributable to its lower molecular weight, specific monosaccharide composition, and unique glycosidic bond arrangement. ACP-60-A shows potential for increased anti-GN efficacy through purification or modification, laying the groundwork for developing novel therapeutic agents for GN.

Harnessing β-glucan conjugated quercetin nanocomplex to function as a promising anti-inflammatory agent via macrophage-targeted delivery

Quercetin, a promising anti-inflammatory agent, faces challenges related to poor bioavailability and limited practical applications. β-glucan, a natural polysaccharide, can be specifically recognized by macrophages, making it an ideal targeting carrier to enhance therapeutic efficacy for macrophage-related dysfunctions. In this study, β-glucan conjugated quercetin nano-complexes (CM-Cur@QT) were developed to target macrophage and alleviate pro-inflammatory response in M1-like macrophages. The results demonstrated that CM-Cur@QT exhibited a spheric shape with an average diameter around 200 nm. FT-IR, 1H NMR, XRD and XPS analyses confirmed the complexation of CM-Cur@QT. This complex showed excellent stability during stimulated digestion, protecting QT from degradation while maintaining favorable antioxidant activity. After complexation, CM-Cur@QT displayed sustained uptake kinetics and enhanced accumulation in macrophages, with a 61.88 % increase compared to individual quercetin after 5 h of incubation. Meanwhile, CM-Cur@QT administration induced evidently cell cycle phases transitions and altered phagocytotic activity in M1-like macrophages. Furthermore, CM-Cur@QT reduced intracellular ROS accumulation, achieving a ROS scavenging rate of up to 49.92 %, compared to 25.59 % in quercetin group. This complex also effectively modulated TNF-a, IL-6 and TGF-β secretion profiles in pro-inflammatory macrophages, outperforming individual QT treatment. Notably, CM-Cur@QT facilitated anti-inflammatory effects while minimizing impacts on inactivated M0 macrophages. These findings underscore the potential of CM-Cur@QT as a promising agent for mitigating inflammatory disorders.

Structure-activity relationship of synthesized glucans from Ganoderma lucidum with in vitro hypoglycemic activity

The synthetic polysaccharides, which have precise structure, can be used to design new drugs by comparing structure-activity relationships (SAR). Improved protein stability may be due to the interaction between the polysaccharides and protein, which includes covalent and noncovalent interactions. It is critical to investigate the SAR of polysaccharides with a precise structure from the perspective of protein stability. Glucans-insulin interaction may be a useful stratagy to solve this problem. This study reports the SAR of the synthesized glucan GLSWA-1 and its substructures 2-4 on insulin secretion and discusses its mechanism. The results showed that although GLSWA-1 and its substructures 2-4 bind insulin to varying degrees, compound 2 improves insulin secretion in a dose-dependent manner. Further research found that compound 2 maintains the thermal stability of insulin better than GLSWA-1 through stronger hydrogen bonding, and molecular dynamics simulations demonstrated that compound 2 can form a "groove-binding model" with insulin. This study considerably improves the research on the SAR of glucan based on insulin thermostability and indicates that compound 2, its linear structure, appropriate chain flexibility ((1 → 6)-glucoside bonds), low molecular weight, and smaller steric hindrance is a potential hypoglycemic agent.

Using Commercial Bio-Functional Fungal Polysaccharides to Construct Emulsion Systems by Associating with SPI

Fungi polysaccharides are nutraceutical-rich compounds with bioactive properties, offering promising applications in food formulation. This study examined the non-covalent complexation of commercial polysaccharides derived from the fruiting bodies of Auricularia auricula-judae (AA) and Ganoderma lucidum (GL) and soy protein isolate to enhance emulsifying properties. Complexes were examined across protein-to-polysaccharide ratios (0:1 to 1:0), pH levels (3 to 7), and heat treatment conditions. Results indicated a maximum insoluble association at pH 4 for both SPI-AAP and SPI-GLP complexes, with SPI-AAP complexes remaining soluble at pH 3, while SPI-GLP complexes exhibited insolubility. Heat treatment had a limited effect on electrostatically driven complexation but resulted in larger particles through a protein-denaturation-induced increase of hydrophobic interactions. In terms of emulsifying properties, individual GLPs demonstrated superior performance compared to individual AAPs. The GLPs engaged in competitive adsorption at the oil-water interface alongside SPI, resulting in larger emulsion droplet sizes compared to either component alone. The association of either AAPs or GLPs with SPI enhanced the emulsion stability against coalescence and Ostwald ripening. Commercial fungal polysaccharides demonstrate substantial potential for incorporation into manufactured food products, particularly in colloidal formulations.

Metabolomics analysis of anaphylactoid reactions induced by Xueshuantong injection in normal and immunocompromised mice

Background

Xueshuantong injection (Lyophilized) (XSTI) is widely used to treat cardiovascular and cerebrovascular diseases. However, anaphylactoid reactions (ARs) are frequently reported as one of its side effects, and the mechanisms of ARs and their relationship with the different immune status are still not well understood.

Purpose

This article aims to examine the sensitizing effect of XSTI, explore the impact of normal and immunocompromised states on ARs, and analyze AR-related metabolic pathways by metabolomics.

Methods

An immunocompromised mouse model was established through intraperitoneal injection of cyclophosphamide (CTX). Normal and immunocompromised mice were then treated with normal saline (NS), histamine (HIS), and XSTI, respectively. Behavioral responses, auricle blue staining, and Evans blue (EB) exudation were used as indices to evaluate the sensitization of XSTI on both normal and immunocompromised mice. Subsequently, ARs models with different immune statuses were established, and validated by measuring four serum indicators using enzyme-linked immunosorbent assay (ELISA). Finally, LC-MS metabolomics analysis was performed on mouse serum to evaluate the metabolic pathways.

Results

The intensity of ARs induced by XSTI in mice was found to increase with the administered dose, with normal mice exhibiting higher AR intensities compared to immunocompromised mice. Metabolomic analysis revealed significant metabolic changes in XSTI-treated mice. The metabolic pathways predicted from these different metabolites include biotin metabolism, histidine metabolism, glycerolipid metabolism, bile secretion, arachidonic acid metabolism, sphingolipid metabolism, niacin and nicotinamide metabolism, tryptophan metabolism, steroid biosynthesis, and arginine and proline metabolism.

Conclusion

Research indicated that the sensitization of XSTI is dose-dependent, and mice with weakened immune functions exhibit lower sensitivity. Through metabolomics research, the differential metabolites in mice were analyzed, and the metabolic pathways inducing ARs were predicted. This study offers guidance on safe medication from the perspective of organism susceptibility and lays a foundation for research on the potential mechanisms of ARs.

Targeted isolation and AI-based analysis of edible fungal polysaccharides: Emphasizing tumor immunological mechanisms and future prospects as mycomedicines

Edible fungal polysaccharides have emerged as significant bioactive compounds with diverse therapeutic potentials, including notable anti-tumor effects. Derived from various fungal sources, these polysaccharides exhibit complex biological activities such as antioxidant, immune-modulatory, anti-inflammatory, and anti-obesity properties. In cancer therapy, members of this family show promise in inhibiting tumor growth and metastasis through mechanisms like apoptosis induction and modulation of the immune system. This review provides a detailed examination of contemporary techniques for the targeted isolation and structural elucidation of edible fungal polysaccharides. Additionally, the review highlights the application of advanced artificial intelligence (AI) methodologies to facilitate efficient and accurate structural analysis of these polysaccharides. It also explores their interactions with immune cells within the tumor microenvironment and their role in modulating gut microbiota, which can enhance overall immune function and potentially reduce cancer risks. Clinical studies further demonstrate their efficacy in various cancer treatments. Overall, edible fungal polysaccharides represent a promising frontier in cancer therapy, leveraging their natural origins and minimal toxicity to offer novel strategies for comprehensive cancer management.

Preparation, characterization and cytotoxic activity of selenium nanoparticles stabilized with a heteropolysaccharide isolated from Sanghuangporus vaninii residue

Selenium nanoparticles (SeNPs) possess unique features with excellent bioavailability and bioactivity, but the poor stability limits its application. A combination of polysaccharides and SeNPs is an effective strategy to overcome the limitation. Herein, a heteropolysaccharide (SVL-3) with an average molecular weight of 2.428 × 104 Da was purified from the fruiting body residue of Sanghuangporus vaninii after soaking in sorghum wine, which was composed of fucose, galactose, glucose, fructose and 3-O-methyl-galactose. The main chain of SVL-3 was composed of →6)-α-3-MeO-Galp-(1→, →4)-α-D-Galp-(1→, →2,6)-β-D-Glcp-(1 → and →3)-α-D-Glcp-(1→, and the branched chain was composed of →4)-α-D-Xylp-(1 → and α-L-Fucp-(1→. For enhancing bioactivity of SVL-3 and stability of SeNPs, SVL-3-functionalized SeNPs (SVL-3-SeNPs) was prepared, which contained 45.31 % polysaccharide and 48.49 % selenium. SVL-3-SeNPs maintained an emphatic stability over 28 days at 4 °C and pH 6-8, and exhibited a higher cytotoxic effect on MCF-7 cells than SVL-3 and SeNPs. The inhibitory effect of SVL-3-SeNPs on the cancer cells may be associated with the mechanisms by inducing S-phase arrest, triggering apoptosis and elevating the protein levels of Cytochrome c, Caspases and cleaved caspases 3 and 9. These results indicated that SeNPs modified by S. vaninii polysaccharides can be utilized as a potential material for targeted antitumor drugs.

Anti-colorectal cancer activity of mannatide from spent brewer's yeast by regulating immune cells and immune function in the tumor microenvironment

Chemotherapy and radiotherapy are generally accompanied by adverse effects, which reduce tolerance to cancer therapies. Immunonutrition improves the clinical outcomes of cancer patients. Hence, natural immunomodulator is therefore considered as a favorable alternative. This study aimed to elucidate the anti-colorectal cancer (CRC) effect of mannatide (MTE) from the immunostimulatory perspective. MTE (concentrations≥1200 μg/mL) significantly inhibited HT-29 cells viabilities compared with the 5-fluorouracil (5-FU) group and all predetermined concentrations of MTE promoted the proliferation of RAW264.7 (p < 0.01). Moreover, MTE treatment suppressed tumor growth, decreased leukocyte and platelet count, and regulated immune organ indexes compared with the model group. In comparison of Model and 5-FU groups, MTE treatment reshaped tumor-associated macrophages (TAMs) from alternatively activated macrophages (M2)-like into classical activated macrophages (M1)-like phenotype. Also, it increased the proportion of CD8+ and CD4+ T cells accompanied by secreting pro-inflammatory cytokines (interferon (IFN)-γ and tumor necrosis factor (TNF)-α) and decreasing pro-inflammatory cytokines (interleukin (IL)-4, interleukin (IL)-6, arginine (Arg)-1, and cyclooxygenase (COX)-2) to reduce immunosuppression. Moreover, MTE-administrated alleviated intestinal mucositis and improved the prognostic indexes compared with the 5-FU group. Notably, the ability of low-dose MTE to regulate immune cells and the function of the tumor microenvironment was higher than that of high-dose. Generally, MTE as an immunomodulator presents great potential to strengthen anti-CRC activity.

Comparing the antioxidation and bioavailability of polysaccharides from extruded and unextruded Baijiu vinasses via in vitro digestion and fecal fermentation

Extrusion has been proven to be a novel approach for modifying the physicochemical characteristic of Baijiu vinasses (BV) to extract polysaccharides, contributing to the sustainable development of brewing industry. However, the comparison of the bioactivity and bioavailability of extruded (EX) and unextruded (UE) BV polysaccharides was unclear, which impended the determination of the efficacy of extrusion in BV resourcing. In this study, in vitro digestion and fecal fermentation experiments were conducted to investigate the bioavailability, and the results showed that EX exhibited less variation in the monosaccharide composition and molecular weight, while exhibiting a stronger antioxidant capacity compared to UE. Moreover, during fermentation EX increased the abundance of Parasutterella and Lachnospiraceae, while UE promoted the proliferation of Bacteroides, Faecalibacterium, and Dialister, resulting in variation in short-chain fatty acids. These findings indicate that extrusion can enhance the capacity of antioxidants and bioavailability of BV polysaccharides.

Insights into dynamic evolution of glucuronofucogalactoglucan from water extract of Agrocybe cylindracea during maturation

This study explored the physicochemical properties and structural characteristics of Agrocybe cylindracea polysaccharides at four developmental stages, as well as their dynamic evolution during maturation. Results showed that the polysaccharides from A. cylindracea water extract exhibited similar structural characteristics across all four maturity stages, despite a significant reduction in yields. Four water-soluble heteroglycans, including one high molecular weight (ACPM-Et50-I) and three low molecular weight (ACPM-Et50-II, ACPM-Et60, ACPM-Et80), were isolated from A. cylindracea at each maturity stage. ACPM-Et50-I was identified as branched heterogalactans, while ACPM-Et60 and ACPM-Et80 were branched heteroglucans. However, ACPM-Et50-II was characterized as a branched glucuronofucogalactoglucan at the tide-turning stage but a glucuronofucoglucogalactan at the pileus expansion stage due to the increase of its α-(1 → 6)-D-Galp. In general, although the structural skeletons of most A. cylindracea heteroglycans were similar during maturation as shown by their highly consistent glycosyl linkages, there were still differences in the distribution of some heteroglucans. This work has for the first time reported a glucuronofucogalactoglucan in A. cylindracea and its dynamic evolution during maturation, which may facilitate the potential application of A. cylindracea in food and biomedicine industries.

Role of autonomic nervous system in BDE-209 maternal exposure induced immunotoxicity in female offspring

Decabrominated diphenyl ether (BDE-209) is a typical persistent organic pollutant that can cross the placental barrier, increasing the exposure risk for offspring. Norepinephrine (NE) from nerve terminals and acetylcholine (Ach) can bind to specific receptors on immune cells, inhibit the immune function of the body then cause immunotoxicity. However, whether maternal exposure to BDE-209 could lead to immunotoxicity in the offspring by acting on the sympathetic and parasympathetic nervous systems remains unclear. In view of this, the pregnancy and lactation rat BDE-209 exposure model was established and the results demonstrated that pregnancy and lactation BDE-209 exposure could induce immunotoxicity to female offspring via affecting immunopathology (hematological and biochemical parameters, organ indices, and spleen histopathological), decreasing humoral immunity (serum hemolysin, immunoglobulins, and cytokine productions), damaging cellular immunity (splenic lymphocytes and spleen cytokine productions), and restraining nonspecific immunity. Moreover, a dramatically significant correlation was observed between spleen nerve indices and immunity indices. Additionally, the mechanism revealed that maternal BDE-209 exposure caused offspring immunotoxicity through (1) activating MHC/PKCθ/NF-κB pathway; (2) promoting sympathetic nervous pathway, by upregulating the expression of β2AR protein, which in turn elevating cAMP, following activate PKA and phosphorylate CREB, ultimately leading to immunotoxicity;(3) activating parasympathetic nerve pathway by reducing the binding with Ach and α7nAchR, upregulating the expression of JAK2 and phosphorylating STAT3, induced immunotoxicity of female offspring.

A Review of Ganoderma lucidum Polysaccharide: Preparations, Structures, Physicochemical Properties and Application

Ganoderma lucidum (GL) is a kind of edible fungus with various functions and a precious medicinal material with a long history. Ganoderma lucidum polysaccharide (GLP) is one of the main bioactive substances in GL, with anti-tumor, anti-oxidation, anti-cancer, and other biological activities. GLP is closely related to human health, and the research on GLP is getting deeper. This paper reviewed the extraction and purification methods of GLP, the relationship between structure and activity, and the qualitative and quantitative methods. This review provides solutions for the analysis and application of GLP. At the same time, some new methods for extraction, purification and analysis of GLP, the relationship between advanced structures and activity, and future applications of and research into GLP were emphasized. As a kind of bioactive macromolecule, GLP has unique functional properties. Through the comprehensive summary of the extraction, purification, and analysis of GLP and its future prospects, we hope that this review can provide valuable reference for the further study of GLP.

Interactions between Gut Microbiota and Natural Bioactive Polysaccharides in Metabolic Diseases: Review

The gut microbiota constitutes a complex ecosystem, comprising trillions of microbes that have co-evolved with their host over hundreds of millions of years. Over the past decade, a growing body of knowledge has underscored the intricate connections among diet, gut microbiota, and human health. Bioactive polysaccharides (BPs) from natural sources like medicinal plants, seaweeds, and fungi have diverse biological functions including antioxidant, immunoregulatory, and metabolic activities. Their effects are closely tied to the gut microbiota, which metabolizes BPs into health-influencing compounds. Understanding how BPs and gut microbiota interact is critical for harnessing their potential health benefits. This review provides an overview of the human gut microbiota, focusing on its role in metabolic diseases like obesity, type II diabetes mellitus, non-alcoholic fatty liver disease, and cardiovascular diseases. It explores the basic characteristics of several BPs and their impact on gut microbiota. Given their significance for human health, we summarize the biological functions of these BPs, particularly in terms of immunoregulatory activities, blood sugar, and hypolipidemic effect, thus providing a valuable reference for understanding the potential benefits of natural BPs in treating metabolic diseases. These properties make BPs promising agents for preventing and treating metabolic diseases. The comprehensive understanding of the mechanisms by which BPs exert their effects through gut microbiota opens new avenues for developing targeted therapies to improve metabolic health.

Unveiling the structural properties and induced resistance activity in rice of Chitin/Chitosan-Glucan Complex of Rhizoctonia solani AG1 IA inner cell wall

Phytopathogen cell wall polysaccharides have important physiological functions. In this study, we isolated and characterized the alkali-insoluble residue on the inner layers of the Rhizoctonia solani AG1 IA cell wall (RsCW-AIR). Through chemical composition and structural analysis, RsCW-AIR was mainly identified as a complex of chitin/chitosan and glucan (ChCsGC), with glucose and glucosamine were present in a molar ratio of 2.7:1.0. The predominant glycosidic bond linkage of glucan in ChCsGC was β-1,3-linked Glcp, both the α and β-polymorphic forms of chitin were presented in it by IR, XRD, and solid-state NMR, and the ChCsGC exhibited a degree of deacetylation measuring 67.08 %. RsCW-AIR pretreatment effectively reduced the incidence of rice sheath blight, and its induced resistance activity in rice was evaluated, such as inducing a reactive oxygen species (ROS) burst, leading to the accumulation of salicylic acid (SA) and the up-regulation of SA-related gene expression. The recognition of RsCW-AIR in rice is partially dependent on CERK1.

Impacts of preparation technologies on biological activities of edible mushroom polysaccharides - novel insights for personalized nutrition achievement

Edible mushroom polysaccharides (EMPs) as a natural macromolecular carbohydrate have a very complex structure and composition. EMPs are considered ideal candidates for developing healthy products and functional foods and have received significant research attention due to their unique physiological activities such as immunomodulatory, anti-inflammatory, anti-tumor/cancer, gut microbiota regulation, metabolism improvement, and nervous system protection. The structure and monosaccharide composition of edible mushroom polysaccharides have an unknown relationship with their functional activity, which has not been widely studied. Therefore, we summarized the preparation techniques of EMPs and discussed the association between functional activity, preparation methods, structure and composition of EMPs, laying a theoretical foundation for the personalized nutritional achievements of EMP. We also establish the foundation for the further investigation and application of EMPs as novel functional foods and healthy products.

Structural variety of glucans from Ganoderma lucidum fruiting bodies

Ganoderma lucidum, widely used in traditional medicine, has several biological properties. Polysaccharides, mainly glucans, are known as one of its main bioactive compounds. Consequently, the achievement and chemical investigation of such molecules are of pharmaceutical interest. Herein, we obtained water-insoluble and water-soluble polysaccharides from G. lucidum by alkaline extraction. Fractionation process yielded three fractions (GLC-1, GLC-2, and GLC-3). All samples showed to be composed mainly of glucans. GLC-1 is a linear (1 → 3)-linked β-glucan; GLC-2 is a mixture of three different linear polysaccharides: (1 → 3)-β-glucan, (1 → 3)-α-glucan, and (1 → 4)-α-mannan; while GLC-3 is a branched β-glucan with a (1 → 4)-linked main chain, which is branched at O-3 or O-6 by (1 → 3)- or (1 → 6)-linked side chains. This research reports the variability of glucans in Ganoderma lucidum fruiting bodies and applicable methodologies to obtain such molecules. These polysaccharides can be further applied in biological studies aiming to investigate how their chemical differences may affect their biological properties.

Structural characterization and anti-oxidative activity for a glycopeptide from Ganoderma lucidum fruiting body

A water-soluble glycopeptide (named GL-PWQ3) with a molecular weight (Mw) of 2.40 × 104 g/mol was isolated from Ganoderma lucidum fruiting body by hot water extraction, membrane ultrafiltration, and gel column chromatography, which mainly consisted of glucose and galactose. Based on the methylation, FT-IR, 1D, and 2D NMR analysis, the polysaccharide portion of GL-PWQ3 was identified as a glucogalactan, which was comprised of unsubstituted (1,6-α-Galp, 1,6-β-Glcp, 1,4-β-Glcp) and monosubstituted (1,2,6-α-Galp and 1,3,6-β-Glcp) in the backbone and possible branches that at the O-3 position of 1,3-Glcp and T-Glcp, and the O-2 position of T-Fucp, T-Manp or T-Glcp. The chain conformational study by SEC-MALLS-RI and AFM revealed that GL-PWQ3 was identified as a highly branched polysaccharide with a polydispersity index of 1.25, and might have compact sphere structures caused by stacked multiple chains. Moreover, the GL-PWQ3 shows strong anti-oxidative activity in NRK-52E cells. This study provides a theoretical basis for further elucidating the structure-functionality relationships of GL-PWQ3 and its potential application as a natural antioxidant in pharmacotherapy as well as functional food additives.

Exploring the anti-cancer potential of Ganoderma lucidum polysaccharides (GLPs) and their versatile role in enhancing drug delivery systems: a multifaceted approach to combat cancer

There has been a growing global interest in the potential health benefits of edible natural bioactive products in recent years. Ganoderma lucidum, a medicinal mushroom, has gained attention for its decadent array of therapeutic and pharmaceutical compounds. Notably, G. lucidum exhibits significant anti-cancer effects against various cancer types. Polysaccharides, a prominent component in G. lucidum, are pivotal in conferring its diverse biological and medicinal properties. The primary focus of this study was to investigate the anti-cancer activities of G. lucidum polysaccharides (GLPs), with particular attention to their potential to mitigate chemotherapy-associated toxicity and enhance targeted drug delivery. Our findings reveal that GLPs exhibit anti-cancer effects through diverse mechanisms, including cytotoxicity, antioxidative properties, apoptosis induction, reactive oxygen species (ROS) generation, and anti-proliferative effects. Furthermore, the potential of GLPs-based nanoparticles (NPs) as delivery vehicles for bioactive constituents was explored. These GLPs-based NPs are designed to target various cancer tissues, enhancing the biological activity of encapsulated compounds. As such, GLPs derived from G. lucidum represent a promising avenue for inhibiting cancer progression, minimizing chemotherapy-related side effects, and supporting their utilization in combination therapies as natural adjuncts.

One-Pot Assembly of the Highly Branched Tetradecasaccharide from Ganoderma lucidum Glycan GLSWA-1 with Immune-Enhancing Activities

The highly branched tetradecasaccharide repeating unit and shorter sequences of GLSWA-1 with immune-enhancing activities from Ganoderma lucidum have been prepared via a one-pot glycan assembly strategy. The synthetic route features (1) orthogonal one-pot glycosylation on the basis of PVB glycosylation to streamline glycan synthesis avoiding such issues as aglycone transfer, (2) one-pot assembly of oligosaccharides with up to four different glycosyl linkages, and (3) modular and convergent [4+5+5] one-pot assembly of the highly branched tetradecasaccharide.

Pharmacological Activities and Safety of Ganoderma lucidum Spores: A Systematic Review

Ganoderma lucidum is traditionally used to prevent and treat some diseases such as liver disorders, hypertension, insomnia, diabetes, and cancer. G. lucidum spore extracts are also reported to share similar bioactivities as extracts from its other parts. However, there is no systematic review that elucidates its pharmacological effect. Our aim is to comprehensively summarise current evidence of G. lucidum spore extracts to clarify its benefits to be applied in further studies. We searched five primary databases: PubMed, Virtual Health Library (VHL), Global Health Library (GHL), System for Information on Grey Literature in Europe (SIGLE), and Google Scholar on September 13, 2021. Articles were selected according to inclusion and exclusion criteria. A manual search was applied to find more relevant articles. Ninety studies that reported the pharmacological effects and/or safety of G. lucidum spores were included in this review. The review found that G. lucidum spore extracts showed quite similar effects as other parts of this medicinal plant including anti-tumor, anti-inflammatory, antioxidant effects, and immunomodulation. G. lucidum sporoderm-broken extract demonstrated higher efficiency than unbroken spore extract. G. lucidum extracts also showed their effects on some genes responsible for the body's metabolism, which implied the benefits in metabolic diseases. The safety of G. lucidum should be investigated in depth as high doses of the extract could increase levels of cancer antigen (CA)72-4, despite no harmful effect shown on body organs. Generally, there is a lot of potential in the studies of compounds with pharmacological effects and new treatments. Sporoderm breaking technique could contribute to the production of extracts with more effective prevention and treatment of diseases. High doses of G. lucidum spore extract should be used with caution as there was a concern about the increase in CA.

Recent Advances in the Preparation, Structure, and Biological Activities of β-Glucan from Ganoderma Species: A Review

Ganoderma has served as a valuable food supplement and medicinal ingredient with outstanding active compounds that are essential for human protection against chronic diseases. Modern pharmacology studies have proven that Ganoderma β-d-glucan exhibits versatile biological activities, such as immunomodulatory, antitumor, antioxidant, and antiviral properties, as well as gut microbiota regulation. As a promising polysaccharide, β-d-glucan is widely used in the prevention and treatment of various diseases. In recent years, the extraction, purification, structural characterization, and pharmacological activities of polysaccharides from the fruiting bodies, mycelia, spores, and fermentation broth of Ganoderma species have received wide attention from scholars globally. Unfortunately, comprehensive studies on the preparation, structure and bioactivity, toxicology, and utilization of β-d-glucans from Ganoderma species still need to be further explored, which may result in limitations in future sustainable industrial applications of β-d-glucans. Thus, this review summarizes the research progress in recent years on the physicochemical properties, structural characteristics, and bioactivity mechanisms of Ganoderma β-d-glucan, as well as its toxicological assessment and applications. This review is intended to provide a theoretical basis and reference for the development and application of β-d-glucan in the fields of pharmaceuticals, functional foods, and cosmetics.

Immunomodulatory Activity of Polysaccharide from Trametes gibbosa (Pers.) Fr (Basidiomycota, Fungi) Mediated by TLR4 Signaling Pathway

Background

Trametes species possess remarkable immunomodulatory and anticancer effects which are mainly related to the activation of innate immune receptors by their polysaccharide constituents. In this study, we investigate the effect of Trametes gibbosa (Pers.) Fr. polysaccharide fraction (TGP) on activation of TLR-4 receptor and subsequent release of IL-8 in HEK-Blue™ hTLR4 cells.

Materials and Methods

The polysaccharide fraction was purified using ethanol precipitation and dialysis methods. The total sugar content and monosaccharide composition were analyzed by phenol-sulfuric acid and chromatographic methods. FT-IR spectroscopy was also performed for structure characterization of the polysaccharide. The activation of TLR4 was determined by measuring the secreted embryonic alkaline phosphatase in the culture media.

Results

The results indicated that the total sugar content of TGP was about 90%, which glucose was the major constituents. FT-IR analysis showed the characteristic bands of polysaccharides. TGP was able to activate the TLR-4 signaling pathway in a dose-dependent manner. Moreover, the significant increase of IL-8 was observed in cells treating with TGP. The HEK-Blue Null2™ reporter cells lacking TLR4, did not respond to LPS and TGP.

Conclusion

The results suggest that TLR4 signaling cascade serve as targets for immunomodulatory activity of T. gibbosa which could address the anticancer properties of Trametes species.

Ganoderma lucidum: Novel Insight into Hepatoprotective Potential with Mechanisms of Action

Ganoderma lucidum (G. lucidum) has been widely used for its health benefits as an edible and traditional medicinal mushroom for thousands of years in Asian countries. It is currently used as a nutraceutical and functional food owing to its major bioactive compounds, polysaccharides and triterpenoids. G. lucidum exhibits a broad range of hepatoprotective impacts in various liver disorders, such as hepatic cancer, nonalcoholic fatty liver disease (NAFLD), alcohol-induced liver disease, hepatitis B, hepatic fibrosis, and liver injury induced by carbon tetrachloride (CCl4) and α-amanitin. G. lucidum protects the liver through a broad range of mechanisms that include the modulation of liver Phase I and II enzymes, the suppression of β-glucuronidase, antifibrotic and antiviral actions, the regulation of the production of nitric oxide (NO), the maintenance of hepatocellular calcium homeostasis, immunomodulatory activity, and scavenging free radicals. G. lucidum could signify an encouraging approach for the management of various chronic hepatopathies, and its potential mechanisms make it a distinctive agent when used alone or with other drugs and applied as a functional food, nutraceutical supplement, or adjuvant to modern medicine. This review summarizes the hepatoprotective properties of G. lucidum with its various mechanisms of action on different liver ailments. Biologically active substances derived from G. lucidum are still being studied for their potential benefits in treating different liver ailments.

Structural characterization of Euglena gracilis polysaccharide and its in vitro hypoglycemic effects by alleviating insulin resistance

Diabetes mellitus, characterized by hyperglycemia and insulin resistance, is a disorder of the endocrine metabolic system which has emerged as a common chronic disease worldwide. Euglena gracilis polysaccharides have ideal development potential in the treatment of diabetes. However, their structure and bioactivity are largely unclear. A novel purified water-soluble polysaccharide (EGP-2A-2A) from E. gracilis with a molecular weight of 130.8 kDa consisted of xylose, rhamnose, galactose, fucose, glucose, arabinose, and glucosamine hydrochloride. The SEM image for EGP-2A-2A suggested a rough surface with the presence of globule-like protrusions. Methylation and NMR spectral analyses revealed that EGP-2A-2A was mainly composed of →6)-β-D-Galp-(1 → 2)-α-D-Glcp-(1 → 2)-α-L-Rhap-(1 → 3)-α-L-Araf-(1 → 6)-β-D-Galp-(1 → 3)-α-D-Araf-(1 → 3)-α-L-Rhap-(1 → 4)-β-D-Xylp-(1 → 6)-β-D-Galp-(1 → with complex branching structure. EGP-2A-2A significantly increased glucose consumption and glycogen content in IR-HeoG2 cells and modulates glucose metabolism disorders by regulating PI3K, AKT, and GLUT4 signaling pathways. EGP-2A-2A significantly suppressed TC, TG, and LDL-c levels, and enhanced that of HDL-c. EGP-2A-2A ameliorated abnormalities caused by disorders of glucose metabolism and the hypoglycemic activity of EGP-2A-2A may be mainly positively related to its high glucose content and the β-configuration in the main chain. These results suggested that EGP-2A-2A played an important role in alleviating disorders of glucose metabolism through insulin resistance and has the potential for development as a novel functional food with nutritional and health benefits.

Ganoderma lucidum polysaccharide inhibits HSC activation and liver fibrosis via targeting inflammation, apoptosis, cell cycle, and ECM-receptor interaction mediated by TGF-β/Smad signaling

BACKGROUND

Ganoderma lucidum polysaccharide (GLP) has many biological properties, however, the anti-fibrosis effect of GLP is unknown at present.

PURPOSE

This study aimed to examine the anti-fibrogenic effect of GLP and its underlying molecular mechanisms in vivo and in vitro.

STUDY DESIGN

Both CCl₄-induced mouse and TGF-β1-induced HSC-T6 cellular models of fibrosis were established to examine the anti-fibrogenic effect of a water-soluble GLP (25 kDa) extracted from the sporoderm-removed spores of G. lucidum..

METHOD

Serum markers of liver injury, histology and fibrosis of liver tissues, and collagen formation were examined using an automatic biochemical analyzer, H&E staining, Sirius red staining, immunohistochemistry, immunofluorescence, ELISA, Western blotting, and qRT-PCR. RNA-sequencing, enrichment pathway analysis, Western blotting, qRT-PCR, and flow cytometry were employed to identify the potential molecular targets and signaling pathways that are responsible for the anti-fibrotic effect of GLP.

RESULTS

We showed that GLP (150 and 300 mg/kg) significantly inhibited hepatic fibrogenesis and inflammation in CCl₄-treated mice as mediated by the TLR4/NF-κB/MyD88 signaling pathway. We further demonstrated that GLP significantly inhibited hepatic stellate cell (HSCs) activation in mice and in TGF-β1-induced HSC-T6 cells as manifested by reduced collagen I and a-SMA expressions. RNA-sequencing uncovered inflammation, apoptosis, cell cycle, ECM-receptor interaction, TLR4/NF-κB, and TGF-β/Smad signalings as major pathways suppressed by GLP administration. Further studies demonstrated that GLP elicits anti-fibrotic actions that are associated with a novel dual effect on apoptosis in vivo (inhibit) or in vitro (promote), suppression of cell cycle in vivo, induction of S phase arrest in vitro, and attenuation of ECM-receptor interaction-associated molecule expressions including integrins ITGA6 and ITGA8. Furthermore, GLP significantly inhibited the TGF-β/Smad signaling in mice, and reduced TGF-β1 or its agonist SRI-011381-induced Smad2 and Smad3 phosphorylations, but increased Samd7 expression in HSC-T6 cells.

CONCLUSION

This study provides the first evidence that GLP could be a promising dietary strategy for treating liver fibrosis, which protects against liver fibrosis and HSC activation through targeting inflammation, apoptosis, cell cycle, and ECM-receptor interactions that are mediated by TGF-β/Smad signaling.

Recent Developments in Molecular Characterization, Bioactivity, and Application of Arabinoxylans from Different Sources

Arabinoxylan (AX) is a polysaccharide composed of arabinose, xylose, and a small number of other carbohydrates. AX comes from a wide range of sources, and its physicochemical properties and physiological functions are closely related to its molecular characterization, such as branched chains, relative molecular masses, and substituents. In addition, AX also has antioxidant, hypoglycemic, antitumor, and proliferative abilities for intestinal probiotic flora, among other biological activities. AXs of various origins have different molecular characterizations in terms of molecular weight, degree of branching, and structure, with varying structures leading to diverse effects of the biological activity of AX. Therefore, this report describes the physical properties, biological activities, and applications of AX in diverse plants, aiming to provide a theoretical basis for future research on AX as well as provide more options for crop breeding.

Structural elucidation and anti-inflammatory activity of a proteoglycan from spent substrate of Lentinula edodes

A proteoglycan LEPS1 was firstly isolated and purified from the spent substrate of Lentinula edodes, an agricultural waste that may cause environmental pollution. The average molecular weight of LEPS1 was 1.18 × 10⁴ g/mol, and carbohydrate moiety (88.9 %) was composed of glucose, arabinose, galactose, xylose and mannose at a molar ratio of 1.2:1.2:1.0:2.3:1.1. The protein moiety (8.5 %) of LEPS1 was bonded to the polysaccharide chain via O-glycosidic linkage. LEPS1 could significantly improve the inflammatory injury of LPS stimulated RAW264.7 macrophages by inhibiting the secretion of NO and decreasing the levels of pro-inflammatory factors (TNF-α, IL-1β and IL-6). LEPS1 inhibited JAK-STAT1 and p38 MAPK signaling pathway via modulating JAK expression, phosphorylation of STAT1 and phosphorylation of p38, respectively. Moreover, LEPS1 could promote the expression of CD 206 and IL-10 which were the markers for repairing macrophages. Overall, LEPS1 had anti-inflammatory activity and can potentially treat as a novel anti-inflammation agent. This work could provide scientific basis and valuable information for the highly efficient utilization of spent L. edodes substrates as the by-product in mushroom industries.

Effects of ultrasound-assisted H2O2 on the solubilization and antioxidant activity of yeast β-glucan

Yeast β-glucan (YG) possess an extensive range of biological activities, such as the inhibition of oxidation, but the poor water solubility of macromolecular YG limits its application. In this study, through the combined degradation of ultrasonic waves and H₂O₂, and the optimization of the main process parameters for solubilizing YG by response surface methodology (RSM), a new product of YG_UH was generated. The molecular weight, structural characteristics and degradation kinetics before and after solubilization were evaluated. The results showed that the optimal solubilization conditions were reaction time: 4 h, ultrasonic power: 3 W/mL, H₂O₂ concentration: 24 %. Under these conditions, ultrasound-assisted H₂O₂ increased the solubility (from 13.60 % to 70.00 %) and reduced molecular weight (from 6.73 × 10⁶ Da to 1.22 × 10⁶ Da). Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), Congo red (CR), scanning electron microscopy (SEM) revealed that ultrasound-assisted H₂O₂ increased the conformation's flexibility greatly, without changing the main structure of YG. More importantly, solubilization of YG improved free radical scavenging activity with YG_UH exhibiting the highest levels of DPPH and ABTS⁺ free radical scavenging activity. These results revealed that ultrasound-assisted H₂O₂ degradation could be a suitable way to increase the solubility of YG for producing value-added YG.

Microwave-assisted degradation of β-D-glucan from Ganoderma lucidum and the structural and immunoregulatory properties of oligosaccharide fractions

Microwave-assisted degradation of β-(1 → 3,1 → 6)-D-glucan from Ganoderma lucidum and correlated immunoregulatory activities were investigated in this study. The optimal temperature and degradation time for microwave hydrothermal hydrolysis were 140 °C and 40 min, respectively. Under these conditions, a high yield of degradation rate (98.4 %) and abundant β-oligosaccharide products (GLOS) with different degrees of polymerization (DP 2-24) were obtained. Four fractions including F1 (DP 2-8), F2 (DP 6-19), F3 (DP 8-24) and F4 (high DPs) with different average ratios of β-(1 → 3) to β-(1 → 6)-linked glucose units were isolated from GLOS. The structures of oligosaccharides with DP (2-6) in F1 were identified as linear β-(1 → 3)-linked glucooligosaccharides without or with β-(1 → 6)-linked glucose residues based on MS/MS analysis. The immunoregulation activity of β-glucooligosaccharides was correlated with their DPs and the average ratios of β-(1 → 3) to β-(1 → 6)-linked glucose units. F4 fraction with high DPs and ratio of 3.29:1 exhibited higher immunoenhancing activity on inducing NF-κB activation through binding to dectin-1. Surface plasmon resonance (SPR) analysis indicated that β-glucooligosaccharides could bind to Dectin-1 directly and the binding affinity increased with the increase of DPs and the ratios of β-(1 → 3)-linked glucose.

Recent advances in qualitative and quantitative analysis of polysaccharides in natural medicines: A critical review

Polysaccharides from natural medicines, being safe and effective natural mixtures, show great potential to be developed into botanical drugs. However, there is yet one polysaccharide-based case that has fulfilled the Botanical Guidance definition of a botanical drug product. One of the reasons is the analytical methods commonly used for qualitative and quantitative analysis of polysaccharides fall far behind the quality control criteria of botanical drugs. Here we systemically reviewed the recent advances in analytical methods. A critical evaluation of the strength and weaknesses of these methods was provided, together with possible solutions to the difficulties. Mass spectrometry with or without robust chromatographic separation was increasingly employed. And scientists have made significant progress in simplifying polysaccharide quantification by depolymerizing it into oligosaccharides. This oligosaccharides-based strategy is promising for qualitative and quantitative analysis of polysaccharides. And continuous efforts are still needed to develop a standardized quality control method that is specific, accurate, repeatable, and applicable for analyzing individual components in natural medicine formulas.

Ganoderma spp. polysaccharides are potential prebiotics: a review

The gut microbiota (GM) is a complex ecosystem that is closely linked to host health. Ganoderma spp. polysaccharides (GPs), a major bioactive component of the fungal genus Ganoderma, can modulate the GM, exhibiting various health effects and prebiotic potential. This review comprehensively concluded the structural features and extraction method of GPs. The mechanism of GPs for anti-obesity, anti-diabetes, anti-inflammatory, and anti-cancer were further evaluated. The simulated gastrointestinal digestion of GPs and the utilization mechanism of host microorganisms were discussed. It was found that the physicochemical properties and biological activities of GPs depend on their structural characteristics (molecular weight, monosaccharide composition, glycosidic bonds, etc.). Their extraction method also affects the structure and bioactivities of polysaccharides. GPs supplementation could increase the relative abundance of beneficial bacteria (e.g. Bacteroides, Parabacteroides, Akkermansia, and Bifidobacterium), while reducing that of pathogenic bacteria (e.g. Aerococcus, Ruminococcus), thus promoting health. Moreover, GPs are resistant to digestion in the stomach and small intestine but are digested in the large intestine. Therefore, GPs can be considered as potential prebiotics. However, further studies should investigate how GPs as prebiotics regulate GM and improve host health.

Influence of ultrasound assisted metal-free Fenton reaction on the structural characteristic and immunostimulatory activity of a β-D-glucan isolated from Dictyophora indusiata

The present study aimed to evaluate the influence of ultrasound assisted H₂O₂/ascorbic acid reaction on the structural characteristic and immunostimulatory activity of a β-D-glucan isolated from D. indusiata, so as to reveal its potential structure-immunostimulatory activity relationship. A purified β-D-glucan, named as DP, was quickly isolated from D. indusiata, and further identified as a 1,3-β-D-glucan with 1,6-β-D-Glcp as branched chains, which exhibited a rigid rod chain conformation in 0.9 % (w/v) of NaCl solution. Furthermore, results showed that the primary structure of DP was overall stable after the degradation by ultrasound assisted H₂O₂/ascorbic acid reaction. However, the molar mass and chain conformation of DP obviously changed. In addition, DP and its degraded products exerted remarkable immunostimulatory activity in vitro and in vivo, which could activate the nuclear factor-κB (NF-κB) signaling pathway through toll-like receptor 4 (TLR4). Indeed, the immunostimulatory activity of DP was closely-correlated to its molar mass and chain conformation. An appropriate degradation of molar mass could promote its immunostimulatory activity. While the transformation of chain conformation from rigid rod to random coil could cause the significant decrease of its immunostimulatory activity. These findings are beneficial to better understanding the structure-immunostimulatory activity relationship of β-D-glucans from edible mushrooms.

Extraction, purification, structural characterization, and gut microbiota relationship of polysaccharides: A review

Intestinal dysbiosis is one of the major causes of the occurrence of metabolic syndromes, such as obesity, diabetes, nonalcoholic fatty liver disease, and cardiovascular diseases. Polysaccharide-based microbial therapeutic strategies have excellent potential in the treatment of metabolic syndromes, but the underlying regulatory mechanisms remain elusive. Identification of the internal regulatory mechanism of the gut microbiome and the interaction mechanisms involving bacteria and the host are essential to achieve precise control of the gut microbiome and obtain valuable clinical data. Polysaccharides cannot be directly digested; the behavior in the intestinal tract is considered a "bridge" between microbiota and host communication. To provide a relatively comprehensive reference for researchers in the field, we will discuss the polysaccharide extraction and purification processes and chemical and structural characteristics, focusing on the polysaccharides in gut microbiota through the immune system, gut-liver axis, gut-brain axis, energy axis interactions, and potential applications.

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.

Mycelium polysaccharides of Macrolepiota procera alleviate reproductive impairments induced by nonylphenol

Nonylphenol (NP) exposure has become a crucial inducement of male reproductive disorders in the world. Therefore, it is urgent to seek solutions to alleviate the toxicity of NP. This study was oriented toward studying the protective effects of Macrolepiota procera mycelium polysaccharides (MMP) on NP-induced reproductive impairments. After NP administration, declined sperm amounts and testis index, increased the deformity rate of sperms, aberrant hormone secretion and testicular pathological injury were observed, corporately leading to reproductive capacity attenuation. Importantly, MMP significantly reversed the foregoing changes in NP-treated mice. Notably, it has been observed that the MMP therapy remarkably improved oxidative stress, apoptosis, autophagy and inflammatory responses, and suppressed the Akt/mTOR signaling pathway in testicular tissues. These results manifested that MMP might be a promising treatment strategy for ameliorating the biotoxicity of NP.

Structure of water-soluble polysaccharides in spore of Ganoderma lucidum and their anti-inflammatory activity

Ganoderma lucidum spore is widely accepted as functional food. Polysaccharides are the predominant bioactive components in G. lucidum spore and contribute much to its health benefits. However, their structural characteristics remain unclear. In this work, water-soluble polysaccharides (GLSP) were obtained by hot water extraction. Three monosaccharides, including arabinose (Ara), glucose (Glc) and galactose (Gal), were presented in GLSP. 1D and 2D NMR data revealed that GLSP were composed mainly by two polysaccharides, β-glucan and arabinogalactan. The arabinogalactan had a backbone of galactan with Araf in the side chain. β-Glucan was the dominant polysaccharide in G. lucidum spore. The molecular weight was measured. GLSP could induce IEC-6 cells proliferation in a concentration-dependent manner. Moreover, GLSP possessed a strong anti-inflammatory activity through inhibiting the overproduction of NO and pro-inflammatory cytokines, like interleukin-6 (IL-6) and interleukin-1β (IL-1β) induced by LPS. These results implied the potential of GLSP on gut barrier protection.

Extraction, Structural Characterization, and Immunomodulatory Activity of a High Molecular Weight Polysaccharide From Ganoderma lucidum

Ganoderma lucidum polysaccharides (GLP) exhibited excellent immunomodulatory activity. Unfortunately, the structure and immunomodulatory activity of GLP are still unclear. GLP was separated into two fractions [high Mw Restriction Fragment Length Polymorphism (RGLP) and low Mw EGLP] using 10 kDa cut-off ultrafiltration membrane. Although the RGLP content was low in GLP, the immunomodulatory activity in RGLP was significantly higher than that of EGLP. Moreover, RGLP was further separated via the Sephacryl column to obtain RGLP-1 showed the best immunomodulatory activity in the macrophage RAW264.7 model. Structural analysis revealed that RGLP-1 was 3,978 kDa and mainly consisted of glucose. Periodate oxidation, Smith degradation, and methylation results indicated that RGLP-1 is a β-pyran polysaccharide mainly with 1→3, 1→4, 1→6, and 1→3, 6 glycosyl bonds at a molar ratio of 40.08: 8.11: 5.62: 17.81. Scanning electron microscopy, atomic force microscopy, and Congo red experiments revealed that RGLP-1 intertwined with each other to form circular aggregates and might possess a globular structure with triple-helix conformation in water. Overall, these results provide RGLP-1 as a potential functional food ingredient or pharmaceutical for immunomodulatory.

Structural characterization and hepatoprotective activity of an acidic polysaccharide from Ganoderma lucidum

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Ganoderma lucidum crude polysaccharide (GLP) exhibited protective effect on liver damage in mice caused by restraint stress through improving oxidative status.

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Two polysaccharides, including a neutral β-glucan and an acidic β-glucan containing glucuronic acid were purified from GLP by anion-exchange chromatography (AEC) and gel filtration.

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Acidic polysaccharide demonstrated stronger hepatoprotective effect in vitro compared to neutral polysaccharide.

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Anion-exchange chromatography (AEC) is an effective technique for separate β-glucan into neutral and ionic fractions by different ionic strength buffer.

In this study, Ganoderma lucidum crude polysaccharide (GLP) was found to have protective effect on liver damage in mice caused by restraint stress through improving oxidative status. Two polysaccharides, including a neutral β-glucan (GLPB2) and an acidic β-glucan (GLPC2) were purified from GLP through anion-exchange chromatography (AEC) combined with gel permeation. GLPC2, with an average molecular weight of 20.56 kDa, exhibited stronger hepatoprotective effect against H₂O₂-induced liver injury in HepG2 cells compared to GLPB2. Glycosidic residues and NMR analysis comprehensively revealed that GLPC2 contained d-Glcp-(1→, →3)-d-Glcp-(1→, →4)-d-Glcp-(1→, →6)-d-Glcp-(1→, →3, 6)-d-Glcp-(1 → and → 4)-d-GlcpA-(1 → . AEC can be an effective technique for separating β-glucans into neutral and acidic fractions by different ionic strength buffer. The findings provided a theoretical basis for the potential application of G. lucidum polysaccharides as a hepatoprotective in food and pharmaceutical industry.

Structure identification of a polysaccharide in mushroom Lingzhi spore and its immunomodulatory activity

Ganoderma lucidum spore serves as a well-known immunomodulatory functional food in Asia. The polysaccharides in G. lucidum spore are responsible for the claimed immunomodulatory activity. However, the structural information of polysaccharides remains unclear. In this work, the leading water-soluble polysaccharide in G. lucidum spore (GLSP-I) with a molecular weight of 128.0 kDa was isolated and purified. The monosaccharide composition analysed by gas chromatography indicated that GLSP-I was a glucan. Three side chains, including Glc-(1 → 3)-Glc-(1 → 3)-Glc-(1 → 6)-Glc, Glc-(1 → 6)-Glc-(1 → 6)-Glc-(1 → 6)-Glc and Glc-(1 → 3)-Glc-(1 → 3)-Glc-(1 → 3)-Glc-(1 → 3)-Glc, were identified by UPLC-MS/MS. The structural characteristics were further identified by NMR spectra. The results indicated that the backbone of GLSP-I was (1 → 3)-β-D-glucan, with side chains linking at O-6. The proposed structure was drawn as below. The immunomodulatory activity assay indicated that GLSP-I could activate macrophages in a dose-dependent manner.