Immunomodulatory effect of a polysaccharide fraction on RAW 264.7 macrophages extracted from the wild Lactarius deliciosus

Chemical Structural Elucidation and Immunomodulatory Activity of a New Polysaccharide from Saposhnikoviae Radix

The chemical structure and immunomodulatory activity of a new homogeneous polysaccharide, SP4002501, isolated from Saposhnikoviae Radix (SR), were investigated. Purification of SP4002501 was performed by DEAE-Cellulose and Sepharose CL-6B column chromatography. The monosaccharidic constituents were identified as rhamnose (Rha), galacturonic acid (GalA), galactose (Gal), and arabinose (Ara) with a molar ratio of 3.7: 86.6: 2.7: 7.1. According to the methylation analysis, partial hydrolysis, FT-IR, and NMR analysis, SP4002501 had a backbone of polygalacturonic acid units with a small amount of galactose (Gal). Side chains are connected to C-3 of galactose (Gal) and consist of rhamnose (Rha), galacturonic acid (GalA), galactose (Gal), and arabinose (Ara), with arabinose (Ara) as terminal sugar. Biological activity assessment suggests that SP4002501 exhibits immunomodulatory activity through promoting macrophage proliferation and phagocytosis.

Polysaccharide fractions extracted from Lactarius quieticolor mushroom exhibit immune stimulatory activities on macrophages

Several beneficial properties have already been observed for mushrooms extracts containing polysaccharides, one of the main components present in these fungi. In order to obtain these extracts and clarify their composition, different extraction and characterization methods can be applied, contributing to understanding its biological effects. In this research, we evaluated three different crude fractions obtained through cold water, hot water, and alkaline solution, from the mushroom Lactarius quieticolor. Each sample was totally characterized by NMR (1H, 13C, HSQC-DEPT, COSY), GC-MS (monosaccharide composition and methylation analysis) and HPSEC (homogeneity and relative Mw). The results showed a mixture of different polysaccharides, including D-galactans and D-glucans in each fraction. All the extracts presented immunostimulant activity in murine RAW 264.7 macrophages, stimulating NO secretion and inducing morphological alterations that were typical of activated cells. These effects were more intense for alkaline fraction (EA), which have higher amounts of mannose and 3,6-di-O-substituted-Glcp units. The results obtained show that crude fractions can potentially stimulate immune cells, which indicates that the consumption of this edible mushroom can bring great benefits to health, being considered an excellent food due to its good biological properties.

Evaluation of Anticancer and Immunomodulatory Effects of Microwave-Extracted Polysaccharide from Ruditapes philippinarum

In recent years, research on active polysaccharides has progressed significantly, particularly regarding their anticancer and immunomodulatory properties. Among these, clam polysaccharides, a type of marine-derived polysaccharide, exhibit notable biological activities, including both anticancer effects and immune modulation. The aims of this study are to investigate the anticancer and immunomodulatory effects of microwave-extracted clam polysaccharide (MCP) in vitro. Cell experiments demonstrated that MCP significantly inhibited both colony formation and migration of HT-29 cells. Furthermore, treatment with MCP led to the downregulation of Bcl-2 gene expression, a reduction in mitochondrial membrane potential, activation of cytochrome C gene and caspase-3 gene, and, finally, the induction of apoptosis in HT-29 cells, implying the involvement of the mitochondrial pathway. Additionally, MCP was found to prompt a phenotypic shift in macrophages from M2 to M1 subtype and from M0 to M1 subtype. MCP also decreased reactive oxygen species (ROS) levels within the cancer cells, thereby augmenting anticancer efficacy through a dual mechanism of immune activation and antioxidant enhancement. These findings suggest that MCPs present significant potential as natural antitumor agents and immunomodulators, especially in the development of functional foods or drugs.

Structural characteristics and intestinal flora metabolism mediated immunoregulatory effects of Lactarius deliciosus polysaccharide

Lactarius deliciosus, a widely appreciated mushroom with delightful tastes and texture, has exhibited immunomodulatory activity in vitro, while the effects on intestinal flora metabolisms in vivo are ambiguous. In this study, a L. deliciosus polysaccharide (LDP) was extracted and purified, and the structural characteristics were evaluated, as well as the immunological enhancement on tumor-bearing mice through regulating intestinal flora metabolisms. Results showed that LDP was a heteropolysaccharide (average molecular weight of 1.44 × 107 Da) with a backbone of α-(1 → 6)-Manp and branches of α-(1 → 6)-Galp, α-(1 → 3)-Fucp, α-(1 → 6)-Glcp, α-(1 → 4)-Glcp. Animal experiments indicated that LDP could significantly protect immune organs of tumor-beraing mice and suppress solid tumors growth with inhibitory rate of 51.61 % (high-dose, 100 mg/kg), and improve the intestinal lactobacillus contents, promote adenine mediated zeatin biosynthesis, then competitively antagonize A2A receptor and enhance the activities of CD4+ T cells and CD8+ T cells, finally effectively facilitate the apoptosis and elimination of tumor cells. These results would provide powerful data supports for the further antitumor mechanisms development and practical applications of L. deliciosus polysaccharide in food and drug industries.

Synergetic effects and inhibition mechanisms of the polysaccharide-selenium nanoparticle complex in human hepatocarcinoma cell proliferation

BACKGROUND

Active components from natural fungal products have shown promising potential as anti-tumor therapeutic agents. In the search for anti-tumor agents, research to overcome the drawbacks of high molecular weight and low bioavailability of pure polysaccharides, polysaccharide-conjugated selenium nanoparticles (SeNPs) has attracted much attention.

RESULTS

A novel polysaccharide-selenium nanoparticle complex was produced, in which SeNPs were decorated with polysaccharide obtained from fermented mycelia broth of Lactarius deliciosus (FLDP). Transmission electron microscope, dynamic light scattering, and X-ray photoelectron spectroscopy were utilized to characterize the FLDP-SeNPs; and human hepatocarcinoma cell line (HepG2) was used to assess growth inhibition efficacy. The FLDP-SeNPs that were prepared had a spherical shape with the smallest mean diameter of 32 nm. The FLDP-SeNPs showed satisfactory dispersibility and stability after combination, demonstrating that a reliable consolidated structure had formed. The results revealed that FLDP-SeNPs had notable growth inhibition effects on HepG2 cells. They reduced the membrane potential of mitochondria significantly, increased the generation of reactive oxygen species, enhanced levels of both Caspase-3 and Caspase-9, and led to the nucleus in a wrinkled form.

CONCLUSION

The FLDP-SeNPs could exert a synergetic toxicity reduction and inhibition enhancement effect on HepG2 cells by inducing early apoptosis, through mitochondria-mediated cytochrome C-Caspases and reactive oxygen species-induced DNA damage pathways. These results indicate that FLDP-SeNP treatment of HepG2 cells induced early apoptosis with synergetic efficacy, showing that FLDP-SeNPs can be useful as natural anti-tumor agents. © 2024 Society of Chemical Industry.

Structural and functional characteristics of pectins from three cultivars of apple (Malus pumila Mill.) pomaces

This study aimed to investigate the chemical composition, structural properties, and biological properties of pectin polysaccharides (AP-FS, AP-QG, and AP-HG) isolated from different varieties of apple pomace. Based on the methylation and nuclear magnetic resonance analyses, the structure of AP-FS was determined to be composed of an α-1,4-linked homogalacturonan backbone that exhibited high levels of O-6 methylation. All pectins exhibit potent inhibitory activity against human colon cancer and human liver cancer cells, along with immunostimulatory effects. Among them, AP-FS exhibited the highest activity level. Finally, we further investigated the underlying mechanism behind the effect of AP-FS on RAW 264.7 cells using proteomics analysis. Our findings revealed that AP-FS triggers RAW 264.7 macrophage activation via NOD-like receptor (NLR), NF-κB, and mitogen-activated protein kinase (MAPK) signaling pathways. Therefore, our research contributes to a better understanding of the structure-function relationship among apple pectins, and AP-FS has the potential to be applied to dietary supplements targeting immunomodulation.

Anti-Inflammatory and Immunomodulatory Properties of a Crude Polysaccharide Derived from Green Seaweed Halimeda tuna: Computational and Experimental Evidences

In this study, we investigated for the first time the anti-inflammatory and immunomodulatory properties of crude polysaccharide (PSHT) extracted from green marine algae Halimeda tuna. PSHT exhibited anti-oxidant activity in vitro through scavenging 1, 1-diphenyl-2-picryl hydroxyl free radical, reducing Fe3+/ferricyanide complex, and inhibiting nitric oxide. PSHT maintained the erythrocyte membrane integrity and prevented hemolysis. Our results also showed that PSHT exerted a significant anti-edematic effect in vivo by decreasing advanced oxidation protein products and malondialdehyde levels and increasing the superoxide dismutase and glutathione peroxidase activities in rat's paw model and erythrocytes. Interestingly, PSHT increased the viability of murine RAW264.7 macrophages and exerted an anti-inflammatory effect on lipopolysaccharide-stimulated cells by decreasing pro-inflammatory molecule levels, including nitric oxide, granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor-alpha (TNF-α). Our findings indicate that PSHT could be used as a potential immunomodulatory, anti-inflammatory, anti-hemolytic, and anti-oxidant agent. These results could be explained by the computational findings showing that polysaccharide building blocks bound both cyclooxygenase-2 (COX-2) and TNF-α with acceptable affinities.

Comprehensive studies of the anti-inflammatory effect of tetraprenyltoluquinone, a quinone from Garcinia cowa Roxb

ETHNOPHARMACOLOGICAL RELEVANCE

Garcinia cowa Roxb. is called asam kandis in West Sumatra. This plant contains several quinone compounds, including tetraprenyltoluquinone (TPTQ). The bioactivity of this compound has been tested as an anticancer agent. However, reports regarding its anti-inflammatory effects are still limited, especially against coronavirus disease (Covid-19).

AIM OF THE STUDY

This study explores the anti-inflammatory effect of TPTQ in silico, in vitro, and in vivo.

MATERIALS AND METHODS

In silico testing used the Gnina application, opened via Google Colab. The TPTQ structure was docked with the nuclear factor kappa B (NF-ĸB) protein (PDB: 2RAM). In vitro testing began with testing the cytotoxicity of TPTQ against Raw 264.7 cells, using the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) method. A phagocytic activity test was carried out using the neutral red uptake method, and interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) secretion tests were carried out using the enzyme-linked immunosorbent assay (ELISA) method. In vivo, tests were carried out on mice by determining cluster of differentiation 8+ (CD8+), natural killer cell (NK cell), and IL-6 parameters, using the ELISA method.

RESULTS

TPTQ has a lower binding energy than the native ligand and occupies the same active site as the native ligand. TPTQ decreased the phagocytosis index and secretion of IL-6 and TNF-α experimentally in vitro. TPTQ showed significant downregulation of CD8+ and slightly decreased NK cells and IL-6 secretion in vivo.

CONCLUSION

The potent inhibitory effect of TPTQ on the immune response suggests that TPTQ can be developed as an anti-inflammatory agent, especially in the treatment of Covid-19.

Characterization and anti-tumor activities of polysaccharide isolated from Brassica rapa L. via activation of macrophages through TLR2-and TLR4-Dependent pathways

We have previously shown the immunostimulatory effects by Nozawana (Brassica rapa L.). In this report, we determined the characteristics of Nozawana polysaccharide (NPS) and evaluated the immunomodulatory effects and anti-tumor activity of NPS mediated by macrophage activation. The molecular weight of NPS was determined by gel filtration chromatography with an average molecular weight of approximately 100.6 kDa. HPLC analysis showed that NPS contained glucose, galacturonic acid, galactose, and arabinose. NPS increased cytokine and nitric oxide (NO) production by macrophages in a Toll-like receptor (TLR)2 and TLR4-dependent manner. Furthermore, NPS induced apoptosis significantly against 4T1 murine breast cancer cells cultured in conditioned medium from NPS-treated macrophages through tumor necrosis factor-α. In tumor-bearing mouse model, tumor growth was significantly reduced in NPS-treated mice compared with control mice. These results support the potential use of NPS as an immunotherapeutic material found in health food products.

Isolation and structural characterization of exopolysaccharide from the Cordyceps cicadae and the immunomodulatory activity on RAW264.7 cells

A new exopolysaccharide component named as PC-EPS was isolated from Cordyceps cicadae, and its structure was determined. PC-EPS was identified to be constituted of mannose, glucose, and galactose (28.84:1:19.42), with an average molecular weight of 3.72 × 106  Da, according to the results of monosaccharide composition, Fourier transform infrared, nuclear magnetic resonance, periodate oxidation and Smith degradation, and methylation studies. According to structural characterization, PC-EPS's connection type was made up of →6) -α-d-Manp (1→, →2) -β-d-Manp (1→, →4) -α-d-Manp (1→, →2) -α-d-Galf (1→, and →4) -α-d-Galp (1→. PC-EPS may significantly increase phagocytosis and RAW264.7 cell proliferation. Additionally, by boosting intracellular lysozyme, cellular acid phosphatase, and cellular superoxide dismutase enzyme concentrations, as well as by promoting the generation of cellular NO, it is the potential to regulate the immunological activity of RAW264.7 cells. Additionally, the effects of PC-EPS on RAW264.7 cells increased their capacities to create tumor necrosis factor-α and interleukin 6 cytokines, all of which suggested that PC-EPS had the potential to improve immunomodulatory activity.

Molecular Insights into the Macrophage Immunomodulatory Effects of Scrophulariae Radix Polysaccharides

Scrophulariae Radix (SR) has been widely used in Chinese herbal compound prescriptions, health care products and functional foods. The present study aimed to investigate the immunomodulatory activity of polysaccharides from SR (SRPs) in macrophages and explore the potential mechanisms. The results showed that four SRPs fractions (SRPs40, SRPs60, SRPs80 and SRPs100) had similar absorption peaks and monosaccharide compositions, but the intensities of absorption peaks and monosaccharide contents were distinguished. All SRPs fractions significantly enhanced the pinocytic activity, promoted the production of NO and TNF-α, increased the mRNA expressions of inflammatory factors (IL-1β, IL-6, TNF-α and PTGS2) and TLR2, and elevated the phosphorylation levels of p38, ERK, JNK, p65 and IκB. Moreover, the production of NO and TNF-α stimulated by SRPs was dramatically suppressed by anti-TLR2 antibody. These results indicated that SRPs activated macrophages through MAPK and NF-κB signaling pathways via recognition of TLR2.

In vitro immunomodulatory activity study of Garcinia cowa Roxb. fraction

OBJECTIVES

The objective of this study is to determine the activity of Garcinia cowa Roxb. n-hexane, ethyl acetate, and butanol fractions as an immunomodulator in vitro and obtain the fraction that has the potential as an immunomodulator.

METHODS

Raw 264.7 macrophages were used to asses G. cowa Roxb. immunomodulatory activity. The MTT assay was chosen to measure cell viability to evaluate the cytotoxic effect on cells. ELISA method was used to measure the concentration of Interleukin-6 (IL-6) and Tumor Necrosis Factor Alpha (TNF-α) secreted by cells after being treated with G. cowa Roxb. fraction. The neutral red uptake assay determined the effect of Garcinia cowa Roxb. on the phagocytic activity.

RESULTS

After Raw 264.7 macrophages were given the Hexan fraction (Hex) at concentrations of 12.5 and 25 μg/mL, there was a decrease in the concentration of IL-6, TNF-α, and the phagocytosis index of cells. Administration of the Ethyl Acetate fraction (EtOAc) at concentrations of 12.5 and 25 μg/mL on cells caused a decrease in IL-6 and TNF-α levels but did not affect the phagocytosis index. There was an increase in the level of TNF-α and the phagocytosis index after being given the Butanol fraction (BuOH) with concentrations of 12.5 and 25 μg/mL but there was a slight decrease in the level of IL-6.

CONCLUSIONS

Both Hex and EtOAc fractions could suppress immune responses through decreasing IL-6, TNF-α, and slightly decreased phagocytic activity. BuOH fraction could stimulate immunomodulatory activities through enhanced TNF-α levels and phagocytic index, but less potent in enhancing IL-6 production. The BuOH fraction could be developed as an immunostimulant.

Structural characterization and immunomodulatory activity of a polysaccharide from finger citron extracted by continuous phase-transition extraction

FCP-2-1, a water-soluble polysaccharide rich in galacturonic acid was isolated by continuous phase-transition extraction and purified with DEAE-52 cellulose and Sephadex G-100 column chromatography from finger citron with essential oil and flavonoids removed. The structural characterization and immunomodulatory activity of FCP-2-1 were further investigated in this work. FCP-2-1 with a M_w and M_n of 1.503 × 10⁴ g/mol and 1.125 × 10⁴ g/mol, respectively, was predominantly composed of galacturonic acid, galactose, and arabinose in a molar ratio of 0.685: 0.032: 0.283. The main linkage types of FCP-2-1 were proved to be →5)-α-L-Araf-(1→ and →4)-α-D-GalpA-(1→ based on methylation and NMR analysis. Moreover, FCP-2-1 was demonstrated to have significant immunomodulatory effects on macrophages in vitro by improving the cell viability, and enhancing phagocytic activity and secretion of NO and cytokines (IL-1β, IL-6, IL-10 and TNF-α), indicating that FCP-2-1 could be used as a natural agent in immunoregulation functional foods.

Theabrownin Isolated from Pu-Erh Tea Enhances the Innate Immune and Anti-Inflammatory Effects of RAW264.7 Macrophages via the TLR2/4-Mediated Signaling Pathway

Theabrownin (TB) is a tea pigment extracted from Pu-erh Tea. The effects of TB on innate immunity and inflammation are not well understood. Herein, the effects of TB on innate immunity are investigated using RAW264.7 macrophages. We found that TB promoted the proliferation of RAW264.7 macrophages, altered their morphology, enhanced their pinocytic and phagocytic ability, and significantly increased their secretion of nitric oxide (NO) and cytokines, all of which enhanced the immune response. Additionally, TB inhibited the release of inflammatory signals in RAW264.7 macrophages primed with lipopolysaccharide (LPS), implying that TB modulates the excessive inflammation induced by bacterial infection. A Western blot showed that TB could activate the toll-like receptor (TLR)2/4-mediated myeloid differentiation factor 88 (MyD88)-dependent mitogen activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling pathway and the TLR2-mediated phosphoinositide 3-kinase (PI3K)-AKT signaling pathway, enhancing the immune functions of RAW264.7 macrophages. TB also inhibited the phosphorylation of core proteins in the MAPK/NF-κB/PI3K-AKT signaling pathway induced by LPS. In addition, we analyzed the transcriptomes of RAW264.7 macrophages, and a Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis revealed that TB modulated thetoll-like receptor signal pathway. A gene ontology (GO) enrichment analysis indicated that TB treatment strongly modulated the immune response and inflammation. As a result, TB-enhanced innate immunity and modulated inflammation via the TLR2/4 signaling pathway.

Immune regulatory functions of biologically active proteins from edible fungi

Proteins from edible mushrooms have a variety of biological activities. Here, thirteen precious edible mushrooms such as Ophiocordyceps sinensis, Ganoderma lucidum, and Morchella esculenta and nine common edible mushrooms such as Flammulina velutipes, Pleurotus ostreatus, and Pleurotus eryngii, etc., from which their proteins were extracted, their composition analyzed and their immunomodulatory activity assessed. Rare mushrooms are a species of edible mushrooms with higher edible value and medicinal value than common edible mushrooms. The results showed that all the different edible mushroom crude proteins increased the proliferation and phagocytosis of mouse macrophages, and we found that these edible mushroom proteins affected the secretion of reactive oxygen species and nitric oxide by mouse macrophages. Further studies on cytokines secreted by mouse macrophages showed a significant increase in pro-inflammatory cytokines, suggesting that edible mushroom proteins promote the polarisation of macrophages into classical M1-type macrophages, further demonstrating that edible mushroom proteins enhance immunity. It was also found that the immunomodulatory activity of the precious edible mushroom proteins was significantly higher than that of the common edible mushroom proteins. These results have important implications for the processing and product development of edible mushroom proteins.

An Immunomodulatory Polysaccharide-Protein Complex Isolated from the Polypore Fungus Royoporus badius

Many wild edible polypore mushrooms have medicinal value. In this study, we investigate the potential medicinal properties of the wild polypore mushroom Royoporus badius collected from north-central British Columbia, Canada. Water extract from R. badius was found to exhibit potent immunomodulatory activity. The extract was purified using DEAE-Sephadex anion-exchange chromatography as well as Sephacryl S-500 and HPLC BioSEC5 size-exclusion chromatography, to yield a novel polysaccharide-protein complex (IMPP-Rb).IMPP-Rb has a peak maxima molecular weight (M_p) of 950 kDa. GC-MS analyses showed that IMPP-Rb is composed predominantly of glucose (49.2%), galactose (11.3%), mannose (10.8%), rhamnose (9.6%), and galacturonic acid (8.2%), with smaller amounts of xylose (5.2%), fucose (2.8%), N-acetyl glucosamine (1.8%), and arabinose (1.2%). IMPP-Rb has multiple linkages, with 4-Glcp, 4-Manp, 6-Manp, 3,4-Manp, 4-Xylp, and 2-Rhap being the most prominent. IMPP-Rb is capable of inducing many cytokines in vitro and the protein component is indispensable for its immunomodulatory activity. IMPP-Rb has potential application as an immuno-stimulatory agent with pharmaceutical value.

Isolation, purification, and structural elucidation of Stropharia rugosoannulata polysaccharides with hypolipidemic effect

Stropharia rugosoannulata is a widely grown edible mushroom with a high nutritional value. S. rugosoannulata polysaccharides is one of the most important bioactive components of S. rugosoannulata and has a wide range of activities. A S. rugosoannulata polysaccharides, named SRF-3, was derived from the S. rugosoannulata extraction by freeze-thaw combine with hot water extraction method, then prepareed with DEAE-cellulose column and Sephacryl S-200 HR gel column, and its hypolipidemic activity was determined. The structural characteristics of SRF-3 were analyzed by infrared spectral scanning (FT-IR), ultra-high performance liquid chromatography (UHPLC), acid hydrolysis, methylation analysis, nuclear magnetic resonance (NMR), and Gas Chromatography-Mass Spectrometer (GC-MS). SRF-3 is composed of mannose, galactose, methyl galactose and fructose with ratios of 16, 12, 58 and 12, respectively. In addition, the average relative molecular mass of SRF-3 is approximately 24 kDa. The main chain of SRF-3 is mainly composed of repeating α-D-1,6-Galp and α-D-1,6-Me-Galp units, with branches in the O-2 position of Gal. The structure is presumed to be a mannogalactan, with a small amount of t-β-D-Manp present as a side chain. Hypolipidemic activity assay showed that SRF-3 had good antioxidant and hypolipidemic effects in vitro, suggesting that SRF-3 have potential application in reducing liver fat accumulation.

Characterization of Novel Exopolysaccharides from Enterococcus hirae WEHI01 and Its Immunomodulatory Activity

Exopolysaccharide (EPS) from probiotic Enterococcus hirae WEHI01 was isolated and purified by anion exchange chromatography and gel chromatography, the results of which show that the EPS consists of four fractions, namely I01-1, I01-2, I01-3, and I01-4. As the main purification components, I01-2 and I01-4 were preliminarily characterized for their structure and their immunomodulatory activity was explored. The molecular weight of I01-2 was 2.28 × 104 Da, which consists mainly of galactose, and a few other sugars including glucose, arabinose, mannose, xylose, fucose, and rhamnose, while the I01-4 was composed of galactose only and has a molecular weight of 2.59 × 104 Da. Furthermore, the results of an evaluation of immunomodulatory activity revealed that I01-2 and I01-4 could improve the viability of macrophage cells, improve phagocytosis, boost NO generation, and encourage the release of cytokines including TNF-α and IL-6 in RAW 264.7 macrophages. These results imply that I01-2 and I01-4 could improve macrophage-mediated immune responses and might be useful in the production of functional food and medications.

The variation on structure and immunomodulatory activity of polysaccharide during the longan pulp fermentation

In the current study, the effects of fermentation manners on the structure and immunomodulatory activity of polysaccharide in longan wine or vinegar were investigated. Compared to longan polysaccharide (CP1), polysaccharide in longan wine (CP2) or vinegar (CP3 and CP4) had smaller molecular weights, and was consisted of more mannose, arabinose, rhamnose, galactose and less glucose. After purification, the major fraction (P1-P4) was obtained from CP1-CP4, respectively. The structures and immunoregulatory activities of P1-P4 were characterized. Fermentation and purification were favorable to increase the immunoregulatory activities of P2-P4, which were contributed to their different structural features. The structure-activity relationship analysis indicated that molecular weight, mannose, rhamnose, glucuronic acid, glucose and arabinose were significantly associated with the cytokines secretion. Compared with other polysaccharides, P3 displayed better immunomodulatory activity due to its lower molecular weight, lower contents of rhamnose and glucose, and higher levels of mannose and arabinose by activating MAPK and PI3K/Akt signaling pathways.

Characterization and macrophages immunomodulatory activity of two water-soluble polysaccharides from Abrus cantoniensis

The study aims to elucidate the physicochemical properties and immunomodulatory activity of two polysaccharides (ACP_t0 and ACP_t2) from Abrus cantoniensis. Results revealed that ACP_t0 with a molecular weight of 26.0 kDa, was mainly composed of glucose (83.1%) and galactose (6.1%), and that ACP_t2 with a molecular weight of 145.6/8.9 kDa, consisted of galactose (25.6%), galacturonic acid (22.2%), arabinos (16.6%) and galactose (11.0%) respectively. AFM and Congo red experiments suggested that ACP_t0 and ACP_t2 might be spherical particles with triple-helix conformation in aqueous solution. ACP_t0 and ACP_t2 exhibited immunomodulatory activity by promoting the proliferation, augmenting pinocytic and phagocytic capacities, releasing immunoactive molecules such as ROS, NO, iNOS, TNF-α, IL-6 and IL-1β, upregulation of the mRNA levels of corresponding cytokines in macrophages. Moreover, ACP_t0 and ACP_t2 were recognized by toll-like receptor 4 (TLR4) and exerted immunomodulatory effects via activating Myeloid differentiation factor 88 (MyD88), mitogen-activated protein kinases (MAPKs) and serine/threonine kinase (Akt) signaling pathways in macrophages. Notably, ACP_t2 had higher immunomodulatory activity than ACP_t0. Based on the present findings, ACP_t0 and ACP_t2 could be explored as an active component of immunomodulators in the food and pharmaceutical fields.

Gas chromatography (GC) fingerprinting and immunomodulatory activity of polysaccharide from the rhizome of Menispermum dauricum DC

This research aimed to establish the gas chromatography (GC) fingerprints and examine the immunomodulatory activity of the rhizome of Menispermum dauricum polysaccharides. In this study, the preparation conditions were optimized by the response surface method (RSM). GC is an effective and sensitive technique employed to measure the composition of monosaccharides; the GC fingerprints of total polysaccharides from 10 batches of the rhizome of M. dauricum (tMDP) were established, and chemometrics methods were adopted to examine the differences and similarities of tMDP from distinct regions. The similarity evaluation illustrated that the polysaccharides derived from the rhizome of M. dauricum from different origins were highly similar. The results of principal components analysis (PCA) illustrated that all the tMDPs may be integrated into one group within the 95% confidence interval, but the rhizome of M. dauricum from different origins could also be distinguished in the plot of PCA scores. Then, the major bioactive fraction MDP was purified and obtained by column chromatography. Our previous study showed that MDP exhibited significant immunomodulatory activity, but the mechanism of the in vitro immunomodulatory activity of MDP is unclear. The macrophage activation induced by MDP was abolished when Toll-like receptor 4 (TLR4) signaling was knocked down by the TLR4 inhibitor. Furthermore, western blot analysis illustrated that MDP activated RAW264.7 cells through MAPKs and NFκB pathways induced by TLR4. This research offers a theoretical foundation for quality control and additional study as a potential immunomodulator of MDP.

Peucedanum praeruptorum Dunn polysaccharides regulate macrophage inflammatory response through TLR2/TLR4-mediated MAPK and NF-κB pathways

The present study was to investigate the molecular mechanisms underlying macrophage inflammatory response to polysaccharides from Peucedanum praeruptorum Dunn (PPDs) and elucidate the receptors and signaling pathways associated with PPDs-mediated macrophage activation. MTT and Griess method were performed to investigate the effects of PPDs on cell viability and NO production. Neutral red and FITC-dextran were used to determine the pinocytic and phagocytic activity. RT-qPCR and ELISA were employed to analyze the mRNA expression of inflammatory factors and production of cytokines and chemokines. RNA-seq and bioinformatics analysis were conducted to determine the underlying molecules, regulators and pathways, which were further validated by pathway inhibition and neutralization assays. The results indicated that PPDs significantly enhanced pinocytic and phagocytic activity, promoted the expression and secretion of inflammatory factors and chemokines, and boosted the expression of accessory and costimulatory molecules. RNA-Seq analysis identified 1343 DEGs, 405 GO terms and 91 KEGG pathways. IL6 and TNF were identified as hubs of connectivity in PPDs-mediated macrophage activation. "Cytokine-cytokine receptor interaction", "TNF signaling pathway", "NF-kappa B signaling pathway", "JAK-STAT signaling pathway" and "MAPK signaling pathway" were the most significant pathways. The pathway inhibition assay revealed that MAPK and NF-κB pathways were essential to macrophage activation by PPDs. TLR2 and TLR4 were uncovered to be the functional receptors and involved in recognition of PPDs. These results indicated that PPDs modulated macrophage inflammatory response mainly through TLR2/TLR4-dependent MAPK and NF-κB pathways.

Structural and Potential Functional Properties of Alkali-Extracted Dietary Fiber From Antrodia camphorata

Antrodia camphorata is rich in a variety of bioactive ingredients; however, the utilization efficiency of the residue of A. camphorata is low, resulting in serious waste. It is necessary to deeply study the functional components of A. camphorata residues to achieve high-value utilization. In this study, the components, structural characteristics, and functional properties of alkali-extracted dietary fiber extracted from residues of A. camphorata (basswood and dish cultured fruiting body, respectively) were investigated. There were similar components and structural characteristics of ACA-DK (extract from basswood cultured) and ACA-DF (extract from dish cultured). The two alkali-extracted dietary fiber were composed of mainly cellulose and xylan. However, ACA-DK has better adsorption capacities than ACA-DF on lipophilic substances such as oil (12.09 g/g), cholesterol (20.99 mg/g), and bile salts (69.68 mg/g). In vitro immunomodulatory assays stated that ACA-DK had a good effect on promoting the proliferation of RAW 264.7 cells and can activate cell phagocytosis, NO synthesis, and other immune capabilities. The edible fungus A. camphorata is a good source of functional dietary fiber. The alkali-extracted dietary fiber of A. camphorata might be used as a functional ingredient in the medicine and food industry.

Two Novel Polysaccharides From Clitocybe squamulosa: Their Isolation, Structures, and Bioactivities

The crude polysaccharides from the fruiting bodies of Clitocybe squamulosa (CSFP) were isolated by hot-water extraction. Two novel polysaccharides, CSFP1-β and CSFP2-α, were further purified by DEAE-52 anion exchange and Sephacryl S-400 gel filtration chromatography, and the purities reached 98.44 and 97.83%, respectively. The structural characteristics and bioactivities of CSFP, CSFP1-β, and CSFP2-α were identified by the combination of chemical and instrumental analysis. Results showed that CSFP was formed by the aggregation of honeycomb spherical materials; CSFP1-β and CSFP2-α were interwoven by reticular and fibrous structures, respectively. Purified components of both CSFP1-β and CSFP2-α showed typical infrared absorption peaks of polysaccharides, and contents of nucleic acid and protein decreased significantly. Simultaneously, CSFP with a molecular weight (Mw) of 1.948 × 10⁴ Da were composed mainly of glucose, mannose, galactose, and rhamnose. CSFP1-β was composed mainly of glucose, galactose, and mannose, while CSFP2-α was composed of glucose, and both their Mw distributions were uneven. Compared with CSFP, the antioxidant activities of CSFP1-β and CSFP2-α were significantly improved (p < 0.05), and they both showed good abilities to bind free cholesterol and bile acid salts in vitro. The binding abilities of the two compounds were found to be 68.62 and 64.43%, and 46.66 and 45.05 mg/g, respectively. CSFP, CSFP1-β, and CSFP2-α had good bacteriostatic effects with a linear increasing relationship to increasing concentration. In addition, CSFP promoted the growth of RAW264.7 cells and has potential immunomodulatory, anti-inflammatory, and anti-tumor activities.

Structural characterization and protective effect on PC12 cells against H2O2-induced oxidative damage of a polysaccharide extracted from mycelia of Lactarius deliciosus Gray

The crude polysaccharide LDP was extracted from mycelia of Lactarius deliciosus Gray and then purified by DEAE-52 cellulose and Sephadex G-200 to obtain a novel polysaccharide named LDP-CP. LDP-CP was mainly composed of mannose, glucose and galactose with an average molecular weight of 2.33 × 10³ kDa. The structure of LDP-CP was determined by FT-IR, methylation and NMR analysis, and the results showed that the sugar linkage units of LDP-CP were composed of (1 → 3)-linked β-D-Manp, (1 → 2,4)-linked α-D-Manp, (1→)-linked α-D-Manp, (1 → 4)-linked β-D-Glcp, (1 → 2)-linked β-D-Manp, (1 → 4,6)-linked α-D-Manp, (1 → 4)-linked α-D-Galp, (1 → 2,3)-linked α-D-Glcp and (1→)-linked α-D-Glcf. The protective effects of LDP and LDP-CP on PC12 cells against H₂O₂-induced oxidative injury were exhibited by enhancing cell viability and morphological protection. The improvement to the level of LDH, SOD and GSH further indicated that LDP and LDP-CP had ability to alleviate H₂O₂-induced oxidative damage on PC12 cells. The polysaccharides in Lactarius deliciosus Gray mycelia exhibited the great advantages in the management of oxidative toxicity, which indicated that the polysaccharides can be further developed in application of natural functional food source.

Immunomodulatory activity of egg yolk protein hydrolysates prepared by novel two-step hydrolysis: A study of mechanism and stability after in vitro digestion model

The aim of this study was to determine the immunomodulatory activity of 2-step egg yolk protein hydrolysates. A two-step hydrolysate of egg yolk protein was prepared using 2 enzymes sequentially, pancreatin and neutrase (EYPH-PN). Our results illustrated that EYPH-PN increased the expression of inducible nitric oxide synthase (iNOS) mRNA in macrophages, resulting in increased nitric oxide (NO) production. EYPH-PN could also enhance the production of tumor necrosis factor (TNF)-α and interleukin (IL)-6 at both the mRNA and protein levels in macrophages. In addition, treatment with EYPH-PN increased the phagocytic activity of macrophages. According to the evaluation with specific inhibitors, both p38 and JNK cell signaling pathways were involved in the activation of macrophages induced by EYPH-PN. As the TLR-2 receptor of macrophages was blocked, the NO production induced by EYPH-PN was decreased. These results suggest that EYPH-PN activates RAW 264.7 macrophages via the TLR-2/p38/JNK pathway to increase the production of NO, TNF-α, and IL-6, and increases phagocytic activity. Furthermore, the immunomodulatory activity of EYPH-PN was maintained even after applying the in vitro digestion model. Taken together, EYPH-PN could be used as a functional food ingredient with excellent immunomodulatory activity in the food industry. Therefore, this study suggests a new alternative method to effectively utilize egg yolk protein, a by-product of the poultry industry.

Mushroom extract of Lactarius deliciosus (L.) Sf. Gray as biopesticide: Antifungal activity and toxicological analysis

Monilinia fructicola (Wint.) Honey is a plant pathogenic fungus that infects stone fruits such as peach, nectarine and plum, which are high demand cultivars found in Brazil. This pathogen may remain latent in the host, showing no apparent signs of disease, and consequently may spread to different countries. The aim of this study was to evaluate the activity of hydroalcoholic extract (HydE) obtained from Lactarius deliciosus (L.) Sf. Gray a mushroom, against M. fructicola phytopathogenic-induced mycelial growth. In addition, the purpose of this study was to examine phytotoxicity attributed to HydE using Brassica oleracea seeds, as well as cytotoxic analysis of this extract on cells of mouse BALB/c monocyte macrophage cell line (J774A.1 cell line) (ATCC TIB-67). The L. deliciosus HydE inhibited fungal growth and reduced phytopathogen mycelial development at a concentration of 1.25 mg/ml. Our results demonstrated that the extract exhibited phytotoxicity as evidenced by (1) interference on germination percentage and rate index, (2) decreased root and initial growth measures, and (3) lower fresh weight of seedlings but no cytotoxicity in Vero cell lines. Data suggest that the use of the L. deliciosus extracts may be beneficial for fungal control without any apparent adverse actions on mouse BALB/c monocyte macrophage cell line (J774A.1 cell line) viability.

A review of the therapeutic and biological effects of edible and wild mushrooms

Throughout history, mushrooms have occupied an inseparable part of the diet in many countries. Mushrooms are considered a rich source of phytonutrients such as polysaccharides, dietary fibers, and other micronutrients, in addition to various essential amino acids, which are building blocks of vital proteins. In general, mushrooms offer a wide range of health benefits with a large spectrum of pharmacological properties, including antidiabetic, antioxidative, antiviral, antibacterial, osteoprotective, nephroprotective, hepatoprotective, etc. Both wild edible and medicinal mushrooms possess strong therapeutic and biological activities, which are evident from their in vivo and in vitro assays. The multifunctional activities of the mushroom extracts and the targeted potential of each of the compounds in the extracts have a broad range of applications, especially in the healing and repair of various organs and cells in humans. Owing to the presence of the aforementioned properties and rich phytocomposition, mushrooms are being used in the production of nutraceuticals and pharmaceuticals. This review aims to provide a clear insight on the commercially cultivated, wild edible, and medicinal mushrooms with comprehensive information on their phytochemical constituents and properties as part of food and medicine for futuristic exploitation. Future outlook and prospective challenges associated with the cultivation and processing of these medicinal mushrooms as functional foods are also discussed.

Immune-Enhancing Effects of a Novel Glucan from Purple Sweet Potato Ipomoea batatas (L.) Lam on RAW264.7 Macrophage Cells via TLR2- and TLR4-Mediated Pathways

PSPP-1 was obtained from purple sweet potato, and the effects of PSPP-1 on the immune modulation on macrophage cells were investigated for the first time. PSPP-1 promoted RAW264.7 proliferation and increased the total cell percentage in DNA synthesis and mitosis phases, and the cell morphology changed in volume and appearance. Additionally, the RAW264.7 immune functions of phagocytic activity and nitric oxide, reactive oxygen species, and cytokine production were improved by PSPP-1. The western blot experiment showed that PSPP-1 could activate toll-like receptor 2 and toll-like receptor 4-mediated pathways, and the expressions of proteins in MyD88-dependent, mitogen-activated protein kinase (MAPK)-signaling, NF-κB-signaling, AP-1 signaling, and TRIF-dependent pathways were improved markedly. Molecular docking and Biolayer Interferometry study further indicated that PSPP-1 could recognize and bind TLR2 and TLR4 by targeting the binding sites with a strong affinity. It suggested that PSPP-1 could enhance immunity via TLR2- and TLR4-mediated pathways, and it could be explored as an immunomodulatory agent.

Characterization of a neutral polysaccharide from pumpkin (Cucurbita moschata Duch) with potential immunomodulatory activity

A neutral polysaccharide designated as CMDP-1a (molecular mass 9.263 kDa) was isolated from Cucurbita moschata Duch through hot water extraction, ethanol precipitation, and column chromatography. On the basis of methylation, fourier-transform infrared, monosaccharide composition, and one- and two-dimensional nuclear magnetic resonance spectroscopy analyses, the structure of CMDP-1a was determined to be a backbone composed of α-1,4 linked glucopyranosyl residues with α-Glcp residue linkage at backbone C-6. Atomic force microscopy and scanning electron microscopy analyses revealed that CMDP-1a had a spherical conformation in solution. In immunostimulation assays, CMDP-1a promoted the proliferation of RAW 264.7 macrophages and significantly enhanced their pinocytic and phagocytic capacity. Furthermore, CMDP-1a induced the M1 polarization of original macrophages and the conversion of macrophages from M2 to M1, thereby modulating the balance of M1/M2 macrophages. These results indicated that CMDP-1a might be a potential immunomodulator for food purposes.

A neutral polysaccharide with a triple helix structure from ginger: Characterization and immunomodulatory activity

A neutral ginger polysaccharide fraction (NGP) was isolated from ginger, and its primary structures and immunomodulatory activity were investigated. The results showed that NGP had a low molecular weight of 6305 Da. NGP principally consisted of glucose (93.88%) together with minor levels of galactose (3.27%) and arabinose (1.67%). Besides, results of methylation analysis and 1D/2D NMR spectroscopy demonstrated that NGP was α-glucan which had the main chain of 1,4-linked α-d-Glcp and α-d-Glcp residues branched at C-6 position which was different from the common triple helical β-glucans. NGP also displayed a remarkable immunological activity on the RAW264.7 cells in vitro. It could significantly enhance the proliferation of macrophages without cytotoxicity and increase the production of immune substances (NO, TNF-α, IL-1β and IL-6). The secretion at the concentration of 200 μg/mL was 29.41 μM, 1496.71, 44.30 and 1889.83 pg/mL for each substance, respectively. The results indicated that NGP could be a potential immune agent and might provide meaningful information for further chain conformation and immune mechanism research.

Effects of seleno-Sesbania canabina galactomannan on anti-oxidative and immune function of macrophage

Seleno-polysaccharides have become a major topic for research owing to their high anti-oxidative capacity and immune-enhancing activities. In this study, galactomannan (GM) was isolated from Sesbania cannabina, and next modified using HNO₃-Na₂SeO₃ method to obtain six varieties of seleno-galactomannans (SeGMs). FT-IR and GPC results showed the changes in chemical structure of SeGMs, indicating successful combination of selenium and GM. By measuring superoxide dismutase and malondialdehyde, the SeGMs showed a stronger protective effect against H₂O₂-induced oxidative damage in vitro than unmodified GM using macrophage RAW264.7 cell as a model, and the effect of SeGMs-14 was prominent. However, the selenylation modification did not show any obvious effect on the immunomodulatory activity of GM, as determined by the index of tumor necrosis factor-α, interleukin-6, and interleukin-1β. Overall, the prepared SeGMs from galactomannan could potentially serve as a dietary supplement of Se or an organic antioxidant.

Activation of RAW264.7 cells by PCp-I, a polysaccharide from Psoralea corylifolia L, through NF-κB/MAPK signalling pathway

PCp-I is a polysaccharide isolated and identified from the Psoralea corylifolia L. by our research group. In this study, the immunomodulatory effects of PCp-I on RAW264.7 cells was evaluated. PCp-I could enhance the level of NO along with up-regulation of iNOS mRNA in RAW264.7 cells. The PCp-I could significantly up-regulate the mRNA expression of TNF-α and IL-6 in RAW264.7 cells, and then the expression of TNF-α, IL-6, ROS and the phagocytic activity were increased. Additionally, PCp-I could significantly up-regulate the phosphorylation level of p65, p38, ERK and JNK proteins, which proved that PCp-I could activate the macrophages by MAPKs and NF-κB signalling pathway and the TLR4 may be one of the receptors of PCp-I regulate the RAW264.7 cells.

Isolation, purification and structural characterization of two pectin-type polysaccharides from Coreopsis tinctoria Nutt. and their proliferation activities on RAW264.7 cells

Coreopsis tinctoria Nutt. (C.tinctoria) is an annual herb of the Compositae family with many health benefits, such as clearing heat, antioxidant and anticancer activity. In this paper, two polysaccharides were isolated from C.tinctoria, named CTAP-1 and CTAP-2, respectively. Structure of CTAP-1and CTAP-2 were elucidated by high-performance gel permeation chromatography, chemical derivative analyses, GC-MS and NMR techniques. Results reveal that they both CTAP-1 and CTAP-2 consisted of predominant amounts of galacturonic acid residues along with small amounts of arabinose, rhamnose and galactose.Both them contain homogalacturonan and rhammnogalcturan I regions in different ratio, suggesting their pectin-type features. The proliferation activities of CTAP-1 and CTAP-2 on RAW264.7 cells in vitro were detected. Results show both them have the significant proliferation effect on RAW264.7 cells when the concentration from 40 to 200 µg/mL. Given their structural characteristics and proliferation activities, the pectins are expected to be potential natural immune modulators, which need further study.

Immunomodulatory and Antioxidant Activities of a Polysaccharide from Ligustrum vicaryi L. Fruit

Ligustrum vicaryi L. is a hybrid of Ligustrum ovalifolium Hassk. var. aureo-marginatum and Ligustrum vulgale L., belonging to the Oleaceae family. It is often used as an ornamental shrub due to its golden leaves. However, its medical value is yet to be discovered. Recently, plant polysaccharides have attracted comprehensive attention owing to their biological properties, including immunomodulatory and antioxidant activities. This study aimed to extract, purify, and characterize the polysaccharide from the Ligustrum vicaryi L. fruit and investigate its immunomodulatory and antioxidant activities. The Ligustrum vicaryi L. fruit polysaccharide (LVFP) was obtained by ultrasonic extraction, ethanol precipitation, macroporous resin separation, and dialysis bag purification. The physicochemical properties of the LVFP were elucidated using Fourier-transform infrared spectrometry, high-performance ion chromatography, and high-performance gel filtration chromatography. The results indicated that the LVFP consisted of rhamnose, arabinose, galactose, and glucose in a ratio of 1.79 : 7.55 : 4.58 : 1.54, and its molecular weight was 88,949 Da. The immunomodulatory and antioxidant activities of the LVFP were investigated using a cyclophosphamide- (Cy-) induced immunosuppressed mouse model. The results demonstrated that the LVFP significantly increased spleen and thymus indexes, enhanced the phagocytic function of neutrophils, activated B and T lymphocytes, and upregulated serum levels of IL-10 and TNF-α. Moreover, we observed that the LVFP relieved Cy-induced liver damage by increasing superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) levels. These results suggested that the LVFP has the immunomodulatory and antioxidant activities, therefore laying a foundation for the application of the LVFP in the pharmaceutical and functional food industries.

Designing selenium polysaccharides-based nanoparticles to improve immune activity of Hericium erinaceus

In previous researches, the results showed that selenium Hericium erinaceus polysaccharide and Hericium erinaceus polysaccharide-loaded poly (lactic-co-glycolic acid) nanoparticles enhanced immune responses. In order to further enhance the immune adjuvant activity and phagocytosis of the nanoparticles, two way of combination (selenium-HEP loaded PLGA nanoparticles and selenium modified HEP-PLGA nanoparticles) were prepared to investigate the effects on macrophages in vitro. After treatment with the nanoparticles, the effects of phagocytosis, co-stimulatory molecules expression, nitric oxide (NO), and cytokines secretion were evaluated. The results showed that the particle size, PDI and zeta potential of the selenium-HEP loaded PLGA nanoparticles (Se-HEP-PLGA) and selenium modifified HEP-PLGA nanoparticles (HEP-PLGA-Se) were presented. Se-HEP-PLGA and HEP-PLGA-Se nanoparticles significantly stimulated phagocytic activity, CD40 and CD86 expression of macrophages. In addition, the levels of NO, TNF-α, IL-1β and IL-6 were enhanced in the peritoneal macrophages by stimulation with Se-HEP-PLGA and HEP-PLGA-Se nanoparticles. Among them, Se-HEP-PLGA showed the best effects on the expression of co-stimulatory molecules, secretions of NO and cytokines. These results indicated that Se-HEP-PLGA could enhance the activation of macrophages, and it could be potentially used as an HEP delivery system for the induction of strong immune responses.

Study on immunostimulatory activity and extraction process optimization of polysaccharides from Caulerpa lentillifera

The process of extracting polysaccharides from the green algae Caulerpa lentillifera was studied by single factor experiments and response surface methodology. Additionally, the immunostimulatory activity of Caulerpa lentillifera polysaccharides (CLP) on RAW264.7 mouse macrophage was evaluated by in vitro cell experiments. The results showed that the optimal extraction conditions consisted of ultrasonification for 30 min, extraction time of 9 h, extraction temperature of 100 °C, and a ratio of water to raw material of 40:1. RAW264.7 macrophage exhibited enhanced phagocytosis with no toxic effects after treatment with CLP. In addition, CLP effectively increased the synthesis and secretion of cytokines (IL-6, TNF-α, IL-1β, and NO), whereby the secretion levels of IL-6, TNF-α, and IL-1β were 1,840.32 ± 21.03 pg/mL (50 μg/mL), 197.17 ± 3.13 ng/mL (50 μg/mL), and 1,178.35 ± 78.82 pg/mL (25 μg/mL), respectively. The polysaccharides contained in Caulerpa lentillifera have potential value for further development due to their immunological activity.

Polysaccharides of mushroom Pleurotus spp.: New extraction techniques, biological activities and development of new technologies

The biodiversity of mushrooms Pleurotus spp. is impressive due to its complexity and diversity related to the composition of chemical structures such as polysaccharides, glycoproteins and secondary metabolites such as alkaloids, flavonoids and betalains. Recent studies of polysaccharides and their structural elucidation have helped to direct research and development of technologies related to pharmacological action, production of bioactive foods and application of new, more sophisticated extraction tools. The diversity of bioactivities related to these biopolymers, their mechanisms and routes of action are constant focus of researches. The elucidation of bioactivities has helped to formulate new vaccines and targeted drugs. In this context, in terms of polysaccharides and the diversity of mushrooms Pleurotus spp., this review seeks to revisit the genus, making an updated approach on the recent discoveries of polysaccharides, new extraction techniques and bioactivities, emphasising on their mechanisms and routes in order to update the reader on the recent technologies related to these polymers.

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.