Structure characterization of a novel polysaccharide from Dictyophora indusiata and its macrophage immunomodulatory activities

Quantitative proteomic and metabolomic analysis of Dictyophora indusiata fruiting bodies during post-harvest morphological development

The differences in Dictyophora indusiata fruiting bodies between peach-shaped and mature stage during the postharvest were systematically investigated through quantitative proteomic and metabolomic analyses. A total of 951 differentially expressed proteins were identified, 571 upregulated and 380 downregulated in the mature fruiting body; additionally, 173 upregulated and 165 downregulated differential abundance metabolites were screened. Integrated proteome and metabolome analyses showed that, during the maturation of D. indusiata fruiting bodies, glycerophospholipids were hydrolyzed and drastically decreased, the degradation of glucan was upregulated, the degradation and synthesis of chitin were simultaneously enhanced, and proteins were dominated via catabolism. Along with vigorous material metabolism, energy production was enhanced through the upregulated TCA-cycles and oxidative phosphorylation. In addition, the synthesis of antioxidant substances and the decomposition of peroxides were enhanced in mature fruiting bodies. These omics analyses of D. indusiata provide high-throughput data and reveal the changes in the post-harvest morphological development.

Extraction, structural characterization, and immunobiological activity of ABP Ia polysaccharide from Agaricus bisporus

The extraction, purification, immunobiological activities, and structure of Agaricus bisporus polysaccharides (ABP) were investigated. Especially we purified and identified the polysaccharides with the highest in vitro immunobiological activity. The extraction conditions of ABP were optimized using single factor and orthogonal experiment. ABP Ia was screened after double purification with DEAE-52 and Sephadex G-200 and showed the best immunoregulatory activity. UV spectra analysis and high-performance gel permeation chromatography results indicated that the ABP Ia fraction did not contain any proteins or nucleotides and was a homogeneous polysaccharide with a relative molecular weight of 784 kDa. Gas chromatography mass spectroscopy results showed that ABP Ia was a heteropolysaccharide consisting of ribose, rhamnose, arabinose, xylose, mannose, glucose, and galactose at a molar ratio of 2.08:4.61:2.45:22.25:36.45:89.22:1.55. FT-IR and periodic acid oxidation analysis indicated that ABP Ia was an α-pyran polysaccharide composed of 1 → 2 and 1 → 4 glycosidic bonds, as well as a possible 1 → 3 glycosidic bond. Furthermore, atomic force microscopy revealed that ABP Ia polysaccharide chains twisted to form a rod-like architecture and, at a 5% concentration, aggregated into a tight structure similar to the shape of a stone forest. These findings identify ABP Ia as a potential functional food ingredient or pharmaceutical for immunoregulation.

Inhibition Effect of Dictyophora Polysaccharides on Human Hepatocellular Carcinoma Cell Line HCC-LM3

BACKGROUND It has been reported that polysaccharides have potential novel anti-cancer properties. Previously, we confirmed that Dictyophora polysaccharides could significantly inhibit liver transplantation tumors in mice. However, the mechanism of Dictyophora polysaccharide action on human liver cancer is unclear. Here, we aimed to clarify the mechanism of Dictyophora polysaccharide action on human hepatocellular carcinoma cells, namely the effect on cell proliferation, the cell cycle, and apoptosis, and on the apoptosis-related genes and proteins in vitro. MATERIAL AND METHODS The HCC-LM3 cell line was incubated with 2.5 mg/mL Dictyophora polysaccharides for 24, 48, and 72 h. The cell growth inhibition rate was evaluated using Cell Counting Kit-8. Cell cycle and apoptosis were measured with flow cytometry. The expression of apoptosis-related genes and proteins was measured using real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) and Western blotting, respectively. RESULTS The Dictyophora polysaccharides inhibited HCC-LM3 cell proliferation in a time- and dose-dependent manner and blocked the cell cycle in the G₂/M phase. In addition, Bax and caspase-3 expression were significantly increased after Dictyophora polysaccharides treatment. CONCLUSIONS To the best of our knowledge, this is the first published study on the mechanism of Dictyophora polysaccharide inhibition of HCC-LM3 cell proliferation.

Purification, characterization and anti-tumor activities of polysaccharides from Ecklonia kurome obtained by three different extraction methods

To investigate and compare the effects of different extraction methods on the structure and anti-tumor activity of Ecklonia kurome polysaccharides (EP), three techniques, namely hot water extraction (HW), ultrasonic-assisted extraction (UA) and enzyme-assisted extraction (EA), were used to extract EP, and three crude EPs were purified by DEAE-cellulose and gel filtration chromatography. The significant antitumor active components in each method were screened by MTT assay and named as HW-EP5, UA-EP4 and EA-EP3, respectively. The molecular weight, FT-IR assay and NMR showed that HW-EP5, UA-EP4 and EA-EP3 were pyran polysaccharides with a molecular weight of 14,466, 15,922 and 16,947 Da, respectively. HW-EP5 contained the most monosaccharides and the highest content of sulfate and uronic acid. HW-EP5 had an even and smooth sheet-like appearance, while UA-EP4 and EA-EP3 exhibited irregular and rough fragments. All three polysaccharides can inhibit the migration of human breast cancer cells (MCF-7) and promote its apoptosis. All three polysaccharides promoted caspase activity during apoptosis. HW-EP5 and UA-EP4 up-regulated the expression of proapoptotic proteins Bax and p53, while EA-EP3 only up-regulated the expression of p53. These experimental results indicate that Ecklonia kurome polysaccharides, especially HW-EP5, have great potential as a natural medicine for the treatment of breast cancer.

Polysaccharide from flammuliana velutipes improves colitis via regulation of colonic microbial dysbiosis and inflammatory responses

The aim of this study is to investigate whether Flammuliana Velutipes Polysaccharide (FVP) could aid in the prevention of colitis. Effect of FVP on colitis was evaluated using dextran sulfate sodium (DSS)-induced colitis in rats. Influence of FVP on the expression of inflammation related biomarkers and signal pathway element of TLR4\NF-κB were assessed. The composition and taxonomy of colonic microbiota were analyzed by 16S rDNA high throughput sequencing, and the concentrations of caecal short fatty chain acids were assessed by chromatography-mass spectrometry. Our results showed that FVP treatment could regulate the colonic microbial dysbiosis and promote the levels of caecal short fatty chain acids, leading to down-regulation of TLR4\NF-κB signal pathway, which finally ameliorate the colitis. Thus, the present study is the first attempt to elucidate the effect of FVP on colitis and support the potential application of FVP as a functional food ingredient or preventive drugs for colitis.

A novel polysaccharide isolated from Flammulina velutipes, characterization, macrophage immunomodulatory activities and its impact on gut microbiota in rats

The structural characteristics of a novel Flammulina velutipes polysaccharide (FVP2) were explored in this study. Besides, immunomodulatory activities of FVP2 on RAW 264.7 cell and its impact on gut microbiota in rats were investigated. FVP2 has a molecular weight of 18.3 kD, and its main components include galactose (19.96%), glucose (60.66%) and mannose (19.38%). By NMR analysis, the main-chain structure consisted of (1 → 3)-linked-β-D-Gal, (1 → 6) -linked-β-D-Gal, (1 → 6)-linked-α-D-Glc and (1 → 3,6)-linked-α-D-Man was identified. Results of the in vitro assays on RAW 264.7 murine macrophage cells showed FVP2 could significantly up-regulate the expression of NO, TNF-α and IL-6. FVP2 was intragastrically administered to rats for 2 weeks. Compared with the control group, two caecal short-chain fatty acids (SCFAs) concentration (isobutyric acid and butyric acid) and the abundance of beneficial microbiota of the FVP2-treated group were significantly increased (p < .05) respectively. The results demonstrated that FVP2 could effectively enhance the level of butyric acid and increase beneficial gut microbiota, which could improve the intestinal barrier function and maintain the intestinal mucosal integrity, suggesting that FVP2 could potentially be an immunomodulators or a functional food to promote intestinal health.

Structural characterization of a novel Lactarius volemus Fr. polysaccharide and its immunity activity in BALB/c mice

Lactarius volemus Fr. has been regarded as a great edible medicinal fungal resource in China. In this study, L. volemus Fr. polysaccharide (LVP) with an average molecular weight of 16.842 kDa was obtained by water extraction. The structure of LVP was characterized to be mannan, and the linkages in the mannan were found to comprise the Manp, (1→4)-α-Man and (1→4,6)-α-Man. Furthermore, intraperitoneal administration of LVP increased the thymus, spleen and liver indices, dose-dependently. Additionally, LVP enhanced the immune response and the phagocytic activities. Pathological evaluations showed that LVP in mice increased the proliferation of red medullary lymphocytes (60–70%). Collectively, these results indicated that LVP might be a potential resource of raw material for further investigations of functional foods.

Lactarius volemus Fr. has been regarded as a great edible medicinal fungal resource in China.

A study on the Fe3O4@Fructus mori L. polysaccharide particles with enhanced antioxidant activity and bioavailability

Molecular conformation is closely related to the functional properties of macromolecules.

The Chemistry, Pharmacology and Therapeutic Potential of the Edible Mushroom Dictyophora indusiata (Vent ex. Pers.) Fischer (Synn. Phallus indusiatus)

Dictyophora indusiata (Vent. Ex. Pers.) Fischer or Phallus indusiatus is an edible member of the higher mushroom phylum of Basidiomycetes. Known for its morphological elegance that gave it the names bridal veil fungus, veiled lady or queen of the mushrooms, it has numerous medicinal values that are beginning to be acknowledged through pharmacological efficacy studies. In an attempt to promote research on this valuable natural resource, the present communication aims to provide a comprehensive review of the chemistry, pharmacology and potential therapeutic applications of extracts and compounds isolated from D. indusiata. Of the bioactive compounds, the chemistry of the polysaccharides as major bioactive components primarily the β-(1 → 3)-D-glucan with side branches of β-(1 → 6)-glucosyl units are discussed, while small molecular weight compounds include terpenoids and alkaloids. Biochemical and cellular mechanisms of action from general antioxidant and anti-inflammatory to more specific signaling mechanisms are outlined along with potential applications in cancer and immunotherapy, neurodegenerative and chronic inflammatory diseases, etc. Further research areas and limitations of the current scientific data are also highlighted.

De novo transcriptome and proteome analysis of Dictyophora indusiata fruiting bodies provides insights into the changes during morphological development

De novo transcriptome assembly and shotgun proteome analysis of Dictyophora indusiata fruiting bodies were performed. A total of 19,704 unigenes were sequenced, and 4380 proteins were identified. Annotation and functional analysis of the identified proteins were significantly enriched in small molecule synthetic and metabolic processes, protein modification regulation (phosphorylation and ubiquitination), and vesicle transport. Furthermore, quantitative developmental transcriptome analysis was performed between the peach-shaped and mature fruiting bodies, and the results revealed that the metabolism and transport activities were upregulated in the mature stage, while protein translation was downregulated; this regulation is likely the main reason for the significant changes in the nutrients of fruiting bodies. Furthermore, the cell wall stress-dependent MAPK sub-pathway was activated in the mature stage, and fungal cell wall degradation-related genes were upregulated, which could promote reconstruction of the cell wall and might play a key role in the morphological development of D. indusiata fruiting bodies.

A fructan from Anemarrhena asphodeloides Bunge showing neuroprotective and immunoregulatory effects

A novel polysaccharide, AAP70-1, was isolated from Anemarrhena asphodeloides for the first time. The primary structural analysis revealed that AAP70-1 was composed of glucose and fructose, had an absolute molecular weight of 2720 Da, and contained a (2→6)-linked β-D-fructofuranose (Fruf) backbone and a (2→1,6)-linked β-D-Fruf side chain with an internal α-D-glucopyranose (Glcp) in the form of a neokestose. To explore the potential factors responsible for the medicinally relevant bioactivities of A. asphodeloides, a biological assay was performed. Using flow cytometry analysis, AAP70-1 was experimentally shown to have neuroprotective effects, and it can prevent and ameliorate neurological damage via reducing apoptosis. The immunomodulation assay further revealed that AAP70-1 can significantly improve immune function by promoting phagocytic capacity and the secretion of cytokines (IL-6, IL-1β and TNF-α) in RAW264.7 cells. These results suggest that AAP70-1 has potential as a therapeutic agent for central nervous system diseases or as an immunomodulatory agent.

Structural characterization and immune regulation of a novel polysaccharide from Maerkang Lactarius deliciosus Gray

The present study investigated the structural characterization and immune regulation of a novel polysaccharide from Maerkang Lactarius deliciosus Gray. Chemical methods, high performance gel permeation chromatography, fourier transform infrared spectroscopy, nuclear magnetic resonance spectrum and gas chromatography‑mass spectrometry were used to characterize the polysaccharide structure. The immunomodulatory abilities of the Maerkang L. deliciosus Gray polysaccharide (LDG‑M) were also investigated. LDG‑M was primarily composed of β‑D‑glucose and α‑D‑lyxose with the ratio of 2:1. The possible structure of LDG‑M had a backbone of 1,6‑linked‑β‑D‑glucose and 1,4,6‑linked‑β‑D‑glucose, with branches primarily composed of one (1→4)‑linked‑α‑D‑lyxose residue. The immunoregulatory activity results demonstrated that LDG‑M promoted the proliferation and phagocytosis of macrophages, and induced cytokine release. LDG‑M also promoted the proliferation of B cells by affecting the G0/G1, S and G2/M phases. The present study introduced LDG‑M as a valuable source with unique immunoregulatory properties.

Structure and in vitro hypoglycemic activity of a homogenous polysaccharide purified from Sargassum pallidum

This study aimed at investigating the structure, hypoglycemic activity and the underlying mechanism of a homogeneous polysaccharide (PSP-2) purified from Sargassum pallidum. Structural characterization revealed that PSP-2 with a molecular weight of 144.8 kDa was composed of fucose (21.6%), arabinose (2.5%), galactose (22.4%), glucose (2.2%), xylose (18.8%), mannose (1.2%), glucuronic acid (7.7%) and galacturonic acid (23.6%). The backbone chain of PSP-2 was composed of →1)-β-d-Xylp-(3→, →1,3)-β-l-Fucp-(4→, →1)-α-d-Galp-(6→, and →1)-α-d-GlcpNAc-(2→, and the side chains were composed of →1,3,6)-α-d-Galp-(2→, →3)-β-l-Fucp-(1,4→, β-d-GalpNAc-(1→, and α-d-Manp-(1→. In vitro hypoglycemic assays indicated that PSP-2 could significantly enhance glucose consumption, glycogen synthesis, and pyruvate kinase (PK) and hexokinase (HK) activities of insulin-resistant HepG2 cells. Furthermore, the underlying mechanistic studies revealed that PSP-2 could ameliorate insulin resistance by up-regulating the expression levels of insulin receptor substrate-1 (IRS-1), glycogen synthase (GS), phosphoinositide-3-kinase (PI3K) and glucose transporter-4 (GLUT4). These results suggested that PSP-2 may be a potential candidate for the prevention and treatment of Type 2 diabetes mellitus.

Quantitative Evaluation of Ultrasound-Assisted Extraction of 1,3-β-glucans from Dictyophora indusiata Using an Improved Fluorometric Assay

In the present study, an improved fluorometric assay based on aniline blue dye for the specific, accurate, and rapid quantification of 1,3-β-glucans in edible mushrooms was developed and fully validated. Furthermore, the improved method was successfully applied for the quantitative evaluation of water soluble 1,3-β-glucans extracted from Dictyophora indusiata by ultrasound-assisted extraction (UAE) with response surface methodology. Results showed that the improved method exhibited high specificity, accuracy, precision, repeatability, and stability, as well as a wide calibration range of 10-600 µg/mL (R2 > 99.9%). The maximum extraction yields of water soluble 1,3-β-glucans (1.20%) and total polysaccharides (5.41%) were achieved at the optimized extraction parameters as follows: ultrasound amplitude (56%), ultrasound extraction time (15 min), and ratio of liquid to raw material (22 mL/g). The results suggest that the improved fluorometric assay has great potential to be used as a routine method for the quantitative evaluation of 1,3-β-glucans in edible mushrooms and that the UAE method is effective for the extraction of 1,3-β-glucans from edible mushrooms.

Advances in Research on Immunoregulation of Macrophages by Plant Polysaccharides

Polysaccharides are among the most important members of the biopolymer family. They are natural macromolecules composed of monosaccharides. To date, more than 300 kinds of natural polysaccharide compounds have been identified. They are present in plants, animals, and microorganisms, and they engage in a variety of physiological functions. In the 1950s, due to the discovery of their immunoregulatory and anti-tumor activities, polysaccharides became a popular topic of research in pharmacology, especially in immunopharmacology. Plants are an important source of natural polysaccharides. Pharmacological and clinical studies have shown that plant polysaccharides have many functions, such as immune regulation, anti-tumor activity, anti-inflammatory activity, anti-viral functions, anti-radiation functions, and a hypoglycaemic effect. The immunomodulatory effects of plant polysaccharides have received much attention. Polysaccharides with these effects are also referred to as biological response modifiers (BRMs), and research on them is one of the most active areas of polysaccharide research. Thus, we summarize immunomodulatory effects of botanical polysaccharides isolated from different species of plants on the macrophage. The primary effect of botanical polysaccharides is to enhance and/or activate macrophage immune responses, including increasing reactive oxygen species (ROS) production, and enhancing secretion of cytokines and chemokines. Therefore, it is believed that botanical polysaccharides have significant therapeutic potential, and represent a new method for discovery and development of novel immunomodulatory medicine.

Anti-hyperlipidemic, antioxidant and organic protection effects of acidic-extractable polysaccharides from Dictyophora indusiata

In the present work, we investigated the anti-hyperlipidemic, antioxidant and organic protection effects of acidic-extractable Dictyophora indusiata polysaccharides (Ac-DPS) on hyperlipidemic mice induced by high-fat emulsion. The results demonstrated that Ac-DPS had impressive abilities to mitigate oxidative stress by increasing the activities of antioxidant enzyme and reducing the contents of lipid peroxide. Moreover, lipid levels in serum were returned to normal status. Besides, Ac-DPS exhibited potential hepatic and renal protection effects reflected by decreasing serum enzyme activities, lowering TBIL, UREA and CREA levels and increasing ALB content. At the same time, histopathological observations proved protective effects of Ac-DPS on organs. Subsequently, the physical properties of polysaccharide were also investigated by HPGPC and FT-IR. The above consequences confirmed the important role of Ac-DPS as a functional food and natural medicine in the fight against oxidative stress and the prevention of hyperlipidemia.

Effects of Atmospheric and Room Temperature Plasma (ARTP) Mutagenesis on Physicochemical Characteristics and Immune Activity In Vitro of Hericium erinaceus Polysaccharides

The polysaccharide is the main active substance contained in Hericium erinaceus and is commonly used in the treatment of neurasthenia, tumors, and digestive diseases. Six intracellular polysaccharide components were obtained from H. erinaceus fruiting bodies cultivated by ARTP (atmospheric and room temperature plasma) mutagenic strain (321) and the original strain (0605), respectively. This study was designed to investigate the physicochemical characteristics of these polysaccharide components and their potential immunomodulatory activities on RAW264.7 macrophages. The results showed that the yield of fruiting body cultivated by mutated strain increased by 22% and the polysaccharide content improved by 16% compared with the original one owing to ARTP mutagenesis. The molecular weight distribution and the monosaccharide compositions of polysaccharide components from H. erinaceus induced by ARTP mutagenesis were significantly different from that of the original one. The NO, IL-6, IL-10, IL-1β, and TNF-α production activities of macrophages were enhanced by stimulation of 20% ethanol precipitated polysaccharides from H. erinaceus induced by ARTP mutagenesis. These results indicated that ARTP is an efficient and practical method for high polysaccharide content breeding of the H. erinaceus strain and this provided a reference for obtaining high quality resources and healthy product development from H. erinaceus.

A Polysaccharide Isolated from Dictyophora indusiata Promotes Recovery from Antibiotic-Driven Intestinal Dysbiosis and Improves Gut Epithelial Barrier Function in a Mouse Model

Despite the tremendous biological activity of polysaccharides from the mushroom Dictyophora indusiata, its role in the restoration of gut microbiota has not yet been explored. The present study aimed to investigate whether D. indusiata polysaccharide (DIP) could modulate the recovery of gut microbiota composition and intestinal barrier function after broad-spectrum antibiotic-driven dysbiosis. Alteration and restoration in the microbial communities were elucidated by the Illumina MiSeq platform. Colon histology, expression of tight-junction associated proteins, and serum/tissue endotoxin and cytokine levels were evaluated. Two-week daily oral administration of clindamycin and metronidazole resulted in reduced bacterial diversity and richness, and perturbed the microbial flora at various taxonomic levels (altered Firmicutes/Bacteroidetes ratio and increased relative abundance of harmful flora (Proteobacteria, Enterococcus, and Bacteroides)), whereas DIP administration reversed the dysbiosis and increased beneficial flora, including Lactobacillaceae (lactic acid-producing bacteria), and Ruminococaceae (butyrate-producing bacteria). In addition, it resulted in the reduction of endotoxemia (through lipopolysaccharides (LPSs)) and pro-inflammatory cytokine (tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and interleukin 1β (IL-1β)) levels, with the increased expression of tight-junction associated proteins (claudin-1, occludin, and zonula occludens-1). These findings not only suggested a comprehensive understanding of the protective effects of a DIP in the restoration of gut microbiota but also highlighted its role in the enhancement of gut barrier integrity, reduction of inflammation and lowering of endotoxin levels in mice.

Structural characteristics and bioactive properties of a novel polysaccharide from Flammulina velutipes

A new water-soluble polysaccharide (FVP1) was extracted from Flammulina velutipes by traditional method "water extraction and alcohol precipitation" and purified by column chromatography. Physicochemical characterization showed that FVP1 was a homogeneous polysaccharide with a relative molecular weight of 54.78 kDa. It is composed of mannose (7.74%), glucose (70.41%), and galactose (16.38%). FVP1 (1000 mg/mL) possessed significant immune activity by increasing the secretion of nitric oxide (NO), tumour necrosis factor-α (TNF-α) (3183 ± 133.84 pg/mL), interleukin (IL)-6 (1133.21 ± 39.05 pg/mL), and IL-12 (579.96 ± 74.53 pg/mL) in macrophages. Furthermore, FVP1 showed significant hepatitis B surface antibody (anti-HBV) activity through reducing the expression of hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg) and hepatitis B virus (HBV) DNA replication. These results suggest a novel role for FVP1 to be applied as an immunomodulators in dietary supplements to prevent HBV infection.

Purification, characterization and immunomodulatory activity of polysaccharides from stem lettuce

Stem lettuce has a long history of cultivation in China and possesses high nutritional and medicinal value. In our previous studies, extraction optimization, characterization, and bioactivities of stem lettuce polysaccharides (SLP) were investigated. In this study, SLP were further separated into two purified polysaccharides, SLP-1 and SLP-2, by anion exchange chromatography followed by size exclusion chromatography. SLP-1, with a molecular weight of 90 KDa, was mainly composed of galacturonic acid, galactose and arabinose in a molar ratio of 17.6:41.7:33.9. SLP-2, with a molecular weight of 44 KDa, was mainly composed of mannose, galacturonic acid, galactose and arabinose in a molar ratio of 11.5:69.5:9.3:8.2. In addition, both purified polysaccharides contain sulphate radicals, have triple helical structures and can promote macrophage proliferation without cytotoxicity. SLP-2 was better able to stimulate phagocytic and nitric oxide production than SLP-1. The results suggest that polysaccharides from stem lettuce could be explored as immunomodulatory agents in the field of pharmaceuticals and functional foods.