Activation of macrophages by polysaccharide isolated from Paecilomyces cicadae through toll-like receptor 4

Galactomannan inhibits Trichinella spiralis invasion of intestinal epithelium cells and enhances antibody-dependent cellular cytotoxicity related killing of larvae by driving macrophage polarization

Previous studies have shown that recombinant Trichinella spiralis galectin (rTsgal) is characterized by a carbohydrate recognition domain sequence motif binding to beta-galactoside, and that rTsgal promotes larval invasion of intestinal epithelial cells. Galactomannan is an immunostimulatory polysaccharide composed of a mannan backbone with galactose residues. The aim of this study was to investigate whether galactomannan inhibits larval intrusion of intestinal epithelial cells and enhances antibody-dependent cellular cytotoxicity (ADCC), killing newborn larvae by polarizing macrophages to the M1 phenotype. The results showed that galactomannan specially binds to rTsgal, and abrogated rTsgal facilitation of larval invasion of intestinal epithelial cells. The results of qPCR, Western blotting, and flow cytometry showed that galactomannan and rTsgal activated macrophage M1 polarization, as demonstrated by high expression of iNOS (M1 marker) and M1 related genes (IL-1β, IL-6, and TNF-α), and increased CD86+ macrophages. Galactomannan and rTsgal also increased NO production. The killing ability of macrophage-mediated ADCC on larvae was also significantly enhanced in galactomannan- and rTsgal-treated macrophages. The results demonstrated that Tsgal may be considered a potential vaccine target molecule against T. spiralis invasion, and galactomannan may be a novel adjuvant therapeutic agent and potential vaccine adjuvant against T. spiralis infection.

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.

Synthesis and biological evaluation of chromanone-based derivatives as potential anti-neuroinflammatory agents

As a privileged scaffold, chromanone has been extensively introduced in the design of drug leads with diverse pharmacological features, particularly in the area of inflammatory diseases. Herein, the preparation of chromanone-based derivatives (4a-4i) was smoothly achieved, and their structures were characterized using 1H NMR, 13C NMR, and ESI-HRMS spectroscopy techniques. Out of them, analogue 4e exhibited the most potent inhibitory capacity against the NO release and iNOS expression, without apparent cytotoxicity. Our observations showed that 4e could dramatically prevent the translocation of NF-κB from the cytoplasm to nucleus, and decrease the production of proinflammatory cytokines TNF-α, IL-6 and IL-1β in LPS-induced BV-2 cells. Mechanistically, 4e significantly deactivated NF-κB by disturbing TLR4-mediated TAK1/NF-κB and PI3K/Akt signaling cascades. Consistent with the in vitro study, 4e could effectively mitigate the inflammation response of hippocampal tissue in LPS-induced mouse model by inhibiting microglial activation. Collectively, these results revealed 4e as a prospective neuroprotective candidate for the therapy of neuroinflammation-related disorders.

Biotech Application of Exopolysaccharides from Curvularia brachyspora: Optimization of Production, Structural Characterization, and Biological Activity

C. brachyspora, a widespread dematiaceous fungus, was evaluated in this study to optimize the production of exopolysaccharides (CB-EPS). Optimization was performed using response surface methodology, and the best production yielded 75.05% of total sugar at pH 7.4, with 0.1% urea, after 197 h. The obtained CB-EPS showed typical signals of polysaccharides, which was confirmed by FT-IR and NMR. The HPSEC analysis indicated a polydisperse polymer, showing a non-uniform peak, with an average molar mass (M_w) of 24,470 g/mol. The major monosaccharide was glucose (63.9 Mol%), followed by mannose (19.7 Mol%), and galactose (16.4 Mol%). Methylation analysis encountered derivatives that indicated the presence of a β-d-glucan and a highly branched glucogalactomannan. CB-EPS was tested on murine macrophages to verify its immunoactivity, and the treated cells were able to produce TNF-α, IL-6, and IL-10. However, the cells did not produce superoxide anions or nitric oxide nor stimulated phagocytosis. The results demonstrated an indirect antimicrobial activity of macrophages by stimulating cytokines, showing another biotech applicability for the exopolysaccharides produced by C. brachyspora.

A New Galactoglucomannan from the Mycelium of the Medicinal Parasitic Fungus Cordyceps cicadae and Its Immunomodulatory Activity In Vitro and In Vivo

A new galactoglucomannan (C-0-1) was purified from the medicinal parasitic fungus of Cordyceps cicadae using an anion-exchange column and gel permeation column. The results of high-performance liquid chromatography and high-performance gel permeation chromatography indicated that C-0-1 consists of galactose, glucose, and mannose in a ratio of 5:1:4 and has a molecular weight of 23.3 kDa. The combined structural elucidation analysis methods including partial acid hydrolysis, methylation analysis, and NMR experiments revealed that C-0-1 was a comb-like polysaccharide with a core structure including (1→2)-α-D-Manp residues in the backbone and branches at O-6 of the main chain. (1→4)-α-D-Glcp, (1→2)-β-D-Galf, (1→2,6)-β-D-Galf, and terminal β-Galf were located at the side chains. An in vitro experiment using RAW 264.7 cells indicated that C-0-1 exhibits good immunomodulatory activity by enhancing inducible nitric oxide synthase secretion and the production of some major inflammatory cytokines. On inhibiting the cytokine production using anti-pattern recognition receptors antibodies, it was revealed that the activation of macrophages is mainly carried out by C-0-1 through the mannose receptor. Toll-like receptor 4 and Toll-like receptor 2 were also involved in this identification process. An in vivo experiment on immunosuppressive mice treated with cyclophosphamide indicated that C-0-1 improves the secretion of serum-related cytokines (IFN-γ, TNF-α, IL-2, IL-4, and IL-10) and affects the balance of T helper cells Th1/Th2. Given the structural and bioactivity similarity between Cordyceps cicadae and Cordyceps sinensis, we can conclude that Cordyceps cicadae could be used as an important medicinal fungus like Cordyceps sinensis.

Antihyperuricemic and Renal Protective Effect of Cordyceps chanhua (Ascomycetes) Fruiting Bodies in Acute Hyperuricemia and Chronic Gout Rodent Models

Cordyceps chanhua has been widely used in traditional Chinese medicine. The uric acid-lowering effect of artificially cultivated fruiting bodies of C. chanhua (FBCC) was studied using the acute hyperuricemia (AH) and chronic gout (CG) animal models. The AH mice and CG rats were randomly divided into 6 groups: the negative control group, model group, positive control group, low-dose group, medium-dose group, and high-dose group of FBCC, respectively. Serum uric acid, creatinine, urea nitrogen, and liver xanthine oxidase (XOD) activity were detected. Renal tubulointerstitial injury and urate crystals in CG rats were evaluated. The results showed that the uric acid content in AH mice with the high-dose FBCC group decreased statistically (P < 0.05). In the CG rats, the serum uric acid level in all FBCC groups and the serum creatinine value in the high-dose group exhibited a significant decrease (P < 0.05); the scores of renal tubulointerstitial damage and urate deposit were reduced in the high-dose group of FBCC. FBCC can reduce uric acid and improve renal function, demonstrating it as a beneficial supplement for uric acid-lowering and gout-relieving drugs.

Structural Characterization of Polysaccharide Derived from Gastrodia elata and Its Immunostimulatory Effect on RAW264.7 Cells

A polysaccharide from Gastrodia elata (named GEP-1) was isolated with a DEAE-52 column and Sephadex G-100 column. The structural characteristics showed that GEP-1 was mainly composed of glucose (92.04%), galactose (4.79%) and arabinose (2.19%) with a molecular weight of 76.444 kDa. The polydispersity (Mw/Mn) of GEP-1 was 1.25, indicating that the distribution of molar mass (Mw) was relatively narrow, which suggested that GEP-1 was a homogeneous polysaccharide. Moreover, the molecular conformation plot of the root mean square (RMS) radius (<rg2> 1/2) versus Mw yielded a line with a slope less than 0.33 (0.15 ± 0.02), displaying that GEP-1 is a compact and curly spherical molecule in NaNO3 aqueous solution. NMR and methylation analyses revealed that the main chain structure of GEP-1 was α-(1→4)-glucans. Furthermore, it was proven that GEP-1 possessed cytoproliferative and enhancing phagocytic activities and induced cytokine (TNF-α, IL1-β) and nitric oxide (NO) release in macrophages by upregulating the related gene expression. In addition, the RNA-seq results suggested that the GEP-1-induced immunomodulatory effect was mainly caused by activation of the NF-κB signaling pathway, which was further verified by NF-κB ELISA and pathway inhibition assays. As a result, GEP-1 exhibits the potential to be developed as a novel cheap immunostimulant without obvious toxicity.

Peptide nanotube loaded with a STING agonist, c-di-GMP, enhance cancer immunotherapy against melanoma

The activation of the stimulating factor of the interferon gene (STING) pathway can enhance the immune response within the tumor. Cyclic diguanylate monophosphate (c-di-GMP) is a negatively charged, hydrophilic STING agonist, however, its effectiveness is limited due to the poor membrane permeability and low bioavailability. Herein, we introduced KL-7 peptide derived from Aβ amyloid fibrils that can self-assemble to form nanotubes to load and deliver c-di-GMP, which significantly enhanced c-di-GMP's effectiveness and then exhibited a robust "in situ immunity" to kill melanoma cells. KL-7 peptide nanotube, also called PNT, was loaded with negatively charged c-di-GMP via electrostatic interaction, which prepared a nanocomposite named c-di-GMP-PNT. Treatment of RAW 264.7 cells (leukemia cells in mouse macrophage) with c-di-GMP-PNT markedly stimulated the secretion of IL-6 and INF-β along with phospho-STING (Ser365) protein expression, indicating the activation of the STING pathway. In the unilateral flank B16-F10 (murine melanoma cells) tumor-bearing mouse model, compared to PNT and c-di-GMP, c-di-GMP-PNT can promote the expression of INF-β, TNF-α, IL-6, and IL-1β. At the same time, up-regulated CD4 and CD8 active T cells kill tumors and enhance the immune response in tumor tissues, resulting in significant inhibition of tumor growth in tumor-bearing mice. More importantly, in a bilateral flank B16-F10 tumor model, both primary and distant tumor growth can also be significantly inhibited by c-di-GMP-PNT. Moreover, c-di-GMP-PNT demonstrated no obvious biological toxicity on the main organs (heart, liver, spleen, lung, and kidney) and biochemical indexes of mice. In summary, our study provides a strategy to overcome the barriers of free c-di-GMP in the tumor microenvironment and c-di-GMP-PNT may be an attractive nanomaterial for anti-tumor immunity.

Electronic Supplementary Material

Supplementary material (synthesis and characterization of KL-7 peptide; the encapsulation rate and cumulative release rate of c-di-GMP-PNT; cytotoxicity of PNT, c-di-GMP, and c-di-GMP-PNT; anti-tumor effect of c-di-GMP-PNT (equivalent to 1 and 5 µg c-di-GMP per mouse); representative immunofluorescence images; and biosafety analysis) is available in the online version of this article at 10.1007/s12274-022-5102-z.

Anxiolytic-like effects of hochuekkito in lipopolysaccharide-treated mice involve interleukin-6 inhibition

Hochuekkito (HET) is a Kampo medicine used to treat postoperative and post-illness general malaise and decreased motivation. HET is known to regulate immunity and modulate inflammation. However, the precise mechanism and effects of HET on inflammation-induced central nervous system disorders remain unclear. This study aimed to assess the effect of HET on inflammation-induced anxiety-like behavior and the mechanism underlying anxiety-like behavior induced by lipopolysaccharide (LPS). Institute of Cancer Research mice were treated with LPS (300 μg/kg, intraperitoneally), a bacterial endotoxin, to induce systemic inflammation. The mice were administered HET (1.0 g/kg, orally) once a day for 2 weeks before LPS treatment. The light-dark box test and the hole-board test were performed 24 h after the LPS injection to evaluate the effects of HET on anxiety-like behaviors. Serum samples were obtained at 2, 5, and 24 h after LPS injection, and interleukin-6 (IL-6) levels in serum were measured. Human and mouse macrophage cells (THP-1 and RAW264.7 cells, respectively) were used to investigate the effect of HET on LPS-induced IL-6 secretion. The repeated administration of HET prevented anxiety-like behavior and decreased serum IL-6 levels in LPS-treated mice. HET significantly suppressed LPS-induced IL-6 secretion in RAW264.7 and THP-1 cells. Similarly, glycyrrhizin, one of the chemical constituents of HET, suppressed LPS-induced anxiety-like behaviors. Our study revealed that HET ameliorated LPS-induced anxiety-like behavior and inhibited IL-6 release in vivo and in vitro. Therefore, we postulate that HET may be useful against inflammation-induced anxiety-like behavior.

Digestion behavior of a polysaccharide from Cyclina sinensis: An explanation for the discrepancy in its immunostimulatory activities in vitro and in vivo

Although numerous polysaccharides have demonstrated potential immunostimulatory activities in in vitro models, only a few of them successfully stimulate the immune system in vivo. In order to explore the possible reasons for the activity loss of polysaccharides in in vivo models, the immunostimulatory activities in vitro and in vivo and the digestion behavior of a polysaccharide from Cyclina sinensis (CSP) were investigated in the present study. CSP showed obvious immunostimulatory activity in a RAW 264.7 cell model. In in vitro experiment, CSP did not exhibit cytotoxicity at concentrations of ≤10 µg/ml, and significantly increased NO production at concentrations of 0.4-10 µg/ml, suggesting CSP processes immunostimulatory activity in vitro. Further investigation using simulated digestion model indicated that CSP could bind with the protein in the digestive fluids to form precipitate in both the stomach and small intestine, and it could be seriously degraded by amylase during the digestion in the small intestine. Furthermore, the in vivo immunostimulatory activity evaluation demonstrated CSP had no effect on immunosuppressed mice as indicated by the body weight, thymus and spleen indexes, and TNF-α, IL-1β, IL-6, and IL-10 mRNA expression. Thus, the present study indicates that the degradation and precipitation of CSP in the digestive tract are the possible reasons for the activity loss of CSP after digestion. PRACTICAL APPLICATION: Cyclina sinensis is the common aquatic shellfish in China and plays an important role in the marine aquaculture industry. Cyclina sinensis polysaccharide (CSP) is the main active component of C. sinensis. The structure characterization and immunostimulatory activity of a purified fraction of CSP (CSP-1) and the effect of digestion on CSP and its immunostimulatory activity were studied. The result of this study promotes the understanding of the nutritional function effects and provides a scientific reference for the rational development and high-value utilization of C. sinensis.

Supramolecular structure features and immunomodulatory effects of exopolysaccharide from Paecilomyces cicadae TJJ1213 in RAW264.7 cells through NF-κB/MAPK signaling pathways

This study investigated the supramolecular structure features and immunomodulatory effects of two exopolysaccharide fractions (EPS1 and EPS2) from Paecilomyces cicada TJJ1213 in vitro. AFM images revealed that EPS1 and EPS2 displayed different morphological features at different concentrations. Congo red and XRD assay further proved that EPS1 and EPS2 mainly exhibited amorphous structure with random coil conformation in solution. Furthermore, the immunomodulatory effect of EPSs was investigated on RAW264.7 cells. Results showed that EPS1 and EPS2 could enhance the phagocytic activity and induce the NO production and could also significantly up-regulate the mRNA expression of iNOS, TNF-α, IL-6, IL-1β, IFN-γ and IL-4. Western blot assay analysis demonstrated that EPSs increased protein expression of TLR4 and the nuclear translocation of NF-κB p50/p65. Additionally, the phosphorylation levels of MAPKs proteins (p38, ERK and JNK) were also remarkably increased. Thus, EPSs could active TLR4-NF-κB/MAPKs signaling pathways to exert the immunomodulatory effect on macrophages.

Immunomodulatory activity of Senegalia macrostachya (Reichenb. ex DC.) Kyal. & Boatwr seed polysaccharide fraction through the activation of the MAPK signaling pathway in RAW264.7 macrophages

Senegalia macrostachya (Reichenb. ex DC.) Kyal. & Boatwr seed (SMS) is a wild legume used as food and medicine in many African countries. In the current study, a novel polysaccharide (SMSP2) was extracted from SMS using hot water and purified with DEAE-52 cellulose. Its structure was characterized, and the immunomodulatory activity and possible molecular mechanism in murine macrophage RAW264.7 were explored. The results revealed that SMSP2 was a uronic acid-rich polysaccharide (51.6%, w/w) with a molecular weight of 52.07 kDa. The neutral sugars were mainly arabinose, xylose, mannose, and galactose at a molar ratio of 1.00 : 0.84 : 0.90 : 0.07. Interestingly, SMSP2 treatment markedly promoted macrophage proliferation and phagocytosis and induced the expression of inflammatory mediators, such as nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-10. SMSP2-induced macrophage stimulation occurs through the activation of the mitogen-activated protein kinase (MAPK) signaling pathway. Moreover, macrophage surface complement receptor 3 (CR3) might play an important role in SMSP2-induced macrophage activation. This study revealed that SMSP2 is a potent immunomodulator, which could be used as a functional food and a pharmaceutical adjuvant in treating immune-compromising diseases.

Beneficial effects of seaweed-derived dietary fiber: Highlights of the sulfated polysaccharides

Seaweeds and their derivatives are important bioresources of natural bioactive compounds. Nutritional studies indicate that dietary fibers derived from seaweeds have great beneficial potentials in human health and can be developed as functional food. Moreover, sulfated polysaccharides are more likely to be the main bioactive components which are widely distributed in various species of seaweeds including Phaeophyceae, Rhodophyceae and Chlorophyceae. The catabolism by gut microbiota of the seaweeds-derived dietary fibers (DFs) may be one of the pivotal pathways of their physiological functions. Therefore, in this review, we summarized the latest results of the physiological characteristics of seaweed-derived dietary fiber and highlighted the roles of sulfated polysaccharides in the potential regulatory mechanisms against disorders. Meanwhile, the effects of different types of seaweed-derived dietary fiber on gut microbiota were discussed. The analysis of the structure-function correlations and gut microbiota related mechanisms and will contribute to further better applications in food and biotherapeutics.

Structure characterization of an arabinogalactan from Cynanchum atratum and its immune stimulatory activity on RAW264.7 cells

In the present study, a water-soluble neutral polysaccharide (CAPW-1) with an average molecular weight of 64 kDa was purified from the root of Cynanchum atratum Bunge (Apocynaceae). The monosaccharide residue analysis revealed that CAPW-1 was composed of arabinose and galactose with a relative molar ratio of 7: 3. The backbone of CAPW-1 was consisted of 1,3-Galp and 1,3,6-Galp, the branches were attached to the O-6 of 1,3-Galp, and the side chains contained 1,6-Galp, 1,3,6-Galp, 1,5-linked, 1,3-linked, 1,3,5-linked, and terminal-Araf, which was attached to the O-3 of side 1,6-Galp. The bioactivity study indicated CAPW-1 could stimulate the proliferation of RAW264.7 cells and promote the secretion of nitric oxide (NO), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) with no cytotoxicity. The results suggested a potential application of CAPW-1 as an immunostimulant for the treatment of diseases such as infection and tumor.

Enteromorpha prolifera polysaccharide-zinc complex modulates the immune response and alleviates LPS-induced intestinal inflammation via inhibiting the TLR4/NF-κB signaling pathway

Enteromorpha prolifera polysaccharide-zinc (EP-Zn), a kind of polysaccharide-zinc complex, has been shown to improve the immune response and reduce the inflammatory factors in weaned piglets. Yet, the molecular mechanism remains unclear. The present study was conducted to investigate the immunomodulating activity and anti-inflammatory mechanism of EP-Zn in mice. Different doses (350 mg kg^-1, 700 mg kg^-1, 1050 mg kg^-1 and 1400 mg kg^-1) of EP-Zn were administered to C57BL/6J mice for 28 days. The results showed that under physiological conditions, 350 mg kg^-1 EP-Zn stimulated cytokine (TNF-α, IL-1β, IL-6 and IL-10) secrection, regulated the intestinal microbiota, and reduced the levels of short-chain fatty acids (SCFAs) (acetic acid and propionic acid). In addition, in the LPS-induced inflammation model, EP-Zn pretreatment effectively alleviated LPS-induced shortening of colonic length and increased MPO and DAO contents, improved intestinal physical barrier function by modulating mucosal structure, and attenuated intestinal inflammation via inhibiting the TLR4/NF-κB signaling pathway. These findings suggested that EP-Zn exerted immunomodulatory and anti-inflammatory activities under physiological and inflammatory conditions, respectively.

Structural characterization and immunomodulatory activity of intracellular polysaccharide from the mycelium of Paecilomyces cicadae TJJ1213

Two intracellular polysaccharide fractions (IPS1 and IPS2) were obtained from the mycelium of Paecilomyces cicadae TJJ1213, and the structures were conducted. Results showed that they were homogenous with the average molecular weight of 2.40 × 10⁶ Da and 6.79 × 10⁵ Da. Two fractions were composed of mannose, glucose and galactose with molar ratios of 1.35: 6.93: 1.0 and 2.04: 1.0: 1.87, respectively. The backbone of IPS1 was → 4)-α-D-Glcp (1 → and → 3,4)-α-D-Manp (1 → residues with a side chain consisted of T-α-D-Galp. IPS2 was consisted of → 4)-α-D-Glcp-(1→, →3,4)-α-D-Manp-(1 → and → 2,6)-α-D-Manp-(1 → residues and the branches were also consisted of T-α-D-Galp. In addition, the scanning electron microscope and atomic force microscope images presented different features of IPS1 and IPS2, respectively. Furthermore, two fractions exhibited better immunomodulatory effects. They could markedly promote the proliferation of RAW264.7 cells and enhance phagocytosis, nitric oxide release and cytokines production. These results indicated that IPS1 and IPS2 had potential to enhance immune responses.

A polysaccharide extracted from alfalfa activates splenic B cells by TLR4 and acts primarily via the MAPK/p38 pathway

Alfalfa polysaccharide (APS) has been proposed to exhibit growth-promoting and immune-enhancing bodily functions in vivo. However, little is known about its downstream immunomodulatory and intrinsic molecular mechanisms. Herein, mouse splenic lymphocytes were isolated to characterize the immunomodulatory effects and molecular mechanisms of APS in vitro. The results demonstrated that APS selectively improved the cell viability and IgM production of B cells, but no effects on T cell viability or secretion of IL-2, IL-4 and IFN-γ were observed in vitro. The receptor blocking assay showed that TLR4 was the primary receptor involved in APS-mediated B cell activation, which was confirmed by the results obtained using C57BL/10ScNJ (TLR4 gene-deficient) mice. Moreover, APS activated the TLR4-MyD88 signaling pathway at the translational level by significantly increasing the protein expression of TLR4 and MyD88. Downstream pathway blocking assay demonstrated that both the MAPK and NF-κB pathways were involved in APS-induced B cell activation. Additionally, APS significantly enhanced the phosphorylation of p38, ERK, and JNK and activated the nuclear translocation of the NF-κB p65 subunit. Therefore, we concluded that APS specifically activates the immune functions of splenic B cells by TLR4, acting through the MAPK and NF-κB signaling pathways, and potently activates the p38 pathway.

Comparison of Physicochemical Characteristics and Macrophage Immunostimulatory Activities of Polysaccharides from Chlamys farreri

To address the structure-activity relationship of Chlamys farreri polysaccharides on their immunostimulatory efficacy, two polysaccharides (CFP-1 and CFP-2) were extracted from Chlamys farreri by hot water extraction, and separated through column chromatography. The isolated CFPs were chemically analyzed to clarify their physicochemical characteristics and cultured with murine macrophage RAW264.7 cells, in order to evaluate their immunostimulatory efficacy. Despite the fact that both CFP-1 and CFP-2 were mainly comprised of glucose lacking the triple-helix structure, as revealed through preliminary physicochemical analyses, obvious differences in regard to molecular weight (Mw), glucuronic acid content (GAc) and branching degree (BD) were observed between CFP-1 and CFP-2. In in vitro immunostimulatory assays for macrophage RAW264.7 cells, it was demonstrated that CFP-2 with larger Mw, more GAc and BD could evidently promote phagocytosis and increase the production of NO, IL-6, TNF-α and IL-1β secretion, by activating the expression of iNOS, IL-6, TNF-α and IL-1β genes, respectively. Hence, CFP-2 shows great promise as a potential immunostimulatory agent in the functional foods and nutraceutical industry, while CFP-1, with lower molecular weight, less GAc and BD, displays its weaker immunostimulatory efficacy, based on the indistinctive immunostimulatory parameters of CFP-1.

Can Cordyceps cicadae be used as an alternative to Cordyceps militaris and Cordyceps sinensis? - A review

ETHNOPHARMACOLOGICAL RELEVANCE

Cordyceps cicadae (Mig.) Massee is one of the oldest and well-known traditional Chinese medicine (TCM), with its uses recorded as far back as the 5th century A.D. For centuries, C. cicadae has been used as food, tonic and folk medicine to treat malaria, palpitations, cancer, fever, diabetes, eye diseases, dizziness, and chronic kidney diseases. Although C. cicadae has been used as TCM for over 1600 years, it is not the most popular amongst the Cordyceps family. Cordyceps Sinensis (C. sinensis) and Cordyceps militaris (C. militaris) are the most studied and widely used, with a number of commercially available products derived from these two Cordyceps species.

AIM OF THE REVIEW

This review seeks to look at the research that has been conducted on C. cicadae over the past 30 years, reporting on the biological activities, development and utilization. This information was compared to that focused on C. sinensis and C. militaris.

MATERIALS AND METHODS

A literature search was conducted on different scientific search engines including, but not limited to "Web of Science", "ScienceDirect" and "Google Scholar" to identify published data on C. cicadae, I. cicadae, P. cicadae, C. sinensis and C. militaris.

RESULTS

Research conducted on C. cicadae over the past two decades have shown that it poses similar biological properties and chemical composition as C. sinensis and C. militaris. C. cicadae has been reported to grow in many geographic locations, as compared to C. sinensis, and can be artificially cultivated via different methods.

CONCLUSION

There exists sufficient evidence that C. cicadae has medicinal benefits and contain bioactive compounds similar to those found on C. sinensis and C. militaris. However, more research and standardization methods are still needed to directly compare C. cicadae with C. sinensis and C. militaris, in order to ascertain the suitability of C. cicadae as an alternative source of Cordyceps products.

Antioxidant and anti-aging activities of polysaccharides from Cordyceps cicadae

Cordyceps cicadae is a traditional Chinese medicine with high nutritional value and biological activities. Previously, we reported on the antioxidant activity associated with the polysaccharides from Cordyceps cicadae (CP). To further explore which of the fraction of CP had the greatest potency, in here, the in vitro antioxidant and in vivo anti-aging activities of the fractions CP30-CP80 of CP were evaluated. The in vitro antioxidant activity results revealed that all the fractions (i.e. CP30-CP80) were potent with CP70 as the most potent. Notably, CP70 prolonged the lifespan of Drosophila (P < 0.05), increased the activities of catalase (CAT) and glutathione peroxidase (GSH-Px) (P < 0.01), and inhibited the formation of malondialdehyde (MDA) (P < 0.01). Additionally, CP70 upregulated the expression level of antioxidant-related genes CAT, SOD1 and MTH in Drosophila (P < 0.05). These results indicated that CP70 may prolong the lifespan of Drosophila through the up-regulation of the expression level of antioxidant-related genes CAT, SOD1 and MTH in Drosophila. Thus, polysaccharides from Cordyceps cicadae possess significant antioxidant and anti-aging activities, and could be explored as a new dietary supplement to slow down the aging process.

Activation of RAW264.7 macrophage by Exopolysaccharide from Aphanothece halaphytica (EPSAH) and the underlying mechanisms

Exopolysaccharide from Aphanothece halophytica (EPSAH), a potent antitumor agent and immunological adjuvant, was investigated for the activation effect on RAW264.7 macrophages and the underlying mechanisms. EPSAH could significantly enhance macrophage phagocytosis and the secretion of nitric oxide, increase the mRNA expression levels of the pro-inflammatory cytokines (IL-1β, IL-6, IL-12, and TNF-α), anti-inflammatory cytokine IL-10, and chemokines (MCP-1 and MIP-1α). When RAW264.7 cells were treated with EPSAH, the mRNA expression of TLR4 and its downstream molecules TRAF6 and MyD88 were upregulated. When TLR4 was blocked using a TLR4-specific neutralizing antibody, nitric oxide secretion from the macrophages was significantly inhibited. EPSAH was further shown to induce phosphorylation of the mitogen-activated protein kinases (MAPKs) ERK, JNK, and p38, and promote cytoplasmic IκB phosphorylation and increase nuclear NF-κB p65 levels remarkably in RAW264.7 cells. These data demonstrate the capacity of EPSAH to induce macrophage activation possibly via TLR4/MyD88 pathway, which leads to the activation of its main signaling downstream molecules MAPKs and NF-κB.

Exopolysaccharide from Paecilomyces lilacinus modulates macrophage activities through the TLR4/NF‑κB/MAPK pathway

Multiple exopolysaccharides (EPSs) have been isolated from various organisms in extreme environments and have yielded a variety of activities. The present study evaluated the immunomodulatory capabilities of an EPS (termed PH‑EPS) derived from the fungus Paecilomyces lilacinus PH0016, which was isolated from a tropical and hyperhaline environment in southern China. The macrophage RAW 264.7 cell line was used to investigate the mechanism of PH‑EPS‑induced macrophage activation. The results indicated that RAW 264.7 macrophages were activated by PH‑EPS, in an effect slightly inferior to lipopolysaccharide (LPS), as evidenced by secretion of interleukin (IL)‑1β, tumor necrosis factor (TNF)‑α and nitric oxide (NO), and by significantly increased phagocytosis in the cells treated with PH‑EPS. Nuclear factor (NF)‑κB p65 was significantly translocated into the nucleus in the PH‑EPS‑treated cells. In addition, expression of inducible NO synthase (iNOS) and IκB‑α degradation were enhanced in PH‑EPS‑treated cells. The phosphorylation levels of p38, JNK and ERK were also significantly increased in the PH‑EPS‑treated cells. Furthermore, IL‑1β and TNF‑α production was markedly decreased in PH‑EPS‑treated cells when the mitogen‑activated protein kinase (MAPK) pathways were blocked by the inhibitor Dectin‑1 and by antibodies against Toll‑like receptor 4 (TLR4). The present results indicated that PH‑EPS from Paecilomyces lilacinus possessed the capability of activating RAW 264.7 cells via the TLR4/NF‑κB/MAPKs signaling pathway.

Binding of the polysaccharide from Acanthopanax giraldii Harms to toll-like receptor 4 activates macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese medicine, Acanthopanax giraldii Harms, is commonly used to treat arthralgia due to wind, cold and dampness, as well as weakness in the feet and knees. Its other reported effects include eliminating flatulence, strengthening muscles and bones, and delaying aging. The polysaccharides in A. giraldii Harms are the major bioactive substances that confer the herb's antioxidant properties as well as anticancer and antiviral effects.

AIMS OF THE STUDY

To elucidate the underlying mechanism and signaling cascade involved in the homogeneous A. giraldii Harms polysaccharide II (AHP-II)-mediated immunomodulation of mice macrophages.

MATERIALS AND METHODS

The phagocytosis of neutral red and the production of nitric oxide, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), were measured to determine AHP-II-induced macrophage activation. Confocal microscopy and flow cytometry were used to confirm the binding of AHP-II to macrophages. The involvement of Toll-like receptor (TLR) 4 in AHP-II-induced macrophage activation was demonstrated using antibody blocking and macrophages from C3H/HeJ TLR4-mutant mice. Western blotting was used to map AHP-II-induced downstream signaling pathways.

RESULTS

AHP-II increased the phagocytosis of macrophages and the release of nitric oxide, IL-6 and TNF-α cytokines. Direct, saturable and reversible binding of AHP-II to macrophages was observed, while it can be inhibited by the anti-TLR4 antibody. In addition, the presence of the anti-TLR4 antibody inhibited AHP-II-induced macrophage IL-6 and TNF-α production in the peritoneal macrophages of C3H/HeJ mice. Moreover, AHP-II-TLR4-stimulated macrophages activate the downstream intracellular ERK and JNK/nuclear factor (NF)-κB signaling pathways. In addition, the AHP-II-mediated regulation of IL-6 and TNF-α production from macrophages was greatly affected by specific ERK, JNK and NF-κB inhibitors.

CONCLUSION

Our study elucidated the immunomodulatory mechanism of AHP-II in macrophage activation and identified TLR4 as the main receptor coordinating AHP-II binding. Our findings suggest AHP-II may be used as a novel immunopotentiator for medical purposes.

A recombinant vaccine of Riemerella anatipestifer OmpA fused with duck IgY Fc and Schisandra chinensis polysaccharide adjuvant enhance protective immune response

Riemerella anatipestifer (R. anatipestifer) causes septicemia and infectious serositis in domestic ducks, leading to high mortality and great economic losses worldwide. Vaccination is currently considered the best strategy to prevent R. anatipestifer infection in ducklings. In this study, we fused the duck IgY Fc gene to the outer membrane protein A (ompA) of R. anatipestifer. The eukaryotic expression plasmid carrying the fusion gene was transformed into Pichia pastoris (P. pastoris) to express the recombinant ompA and ompA-Fc proteins. Then, the effects of fused Fc on the vitality and antigen processing efficiency of duck peritoneal macrophages (PMø) were evaluated in vitro, whereas their immunogenicity was evaluated in vivo. Furthermore, Schisandra chinensis polysaccharide (SCP) was used to evaluate its immune-conditioning effects on the activation of PMø. SCP was also used as adjuvant to investigate immunomodulation on immunoresponses induced by the fused ompA-Fc in ducklings. The conventional Freund's incomplete adjuvant served as the control of SCP. Notably, ompA-Fc promoted phagocytosis of PMø and significantly increased serum antibody titers, CD4⁺ and CD8⁺ T-lymphocyte counts, lymphocyte transformation rate, and serum levels of IL-2 and IL-4. In addition, ducklings injected with the ompA-Fc vaccine exhibited considerably greater resistance to the R. anatipestifer challenge than those that received vaccines based on standalone ompA. Of note, SCP was demonstrated to boost the secretion of nitric oxide (NO), IL-1β, IL-6, TNF-α, and IFN-β by duck macrophages. In addition, the supplementation of SCP adjuvant to the ompA-Fc vaccines led to the further enhancement of immune response and vaccine protection. The dose of 200 μg/mL showed the most pronounced effects. This study provided valuable insights into protective strategies against R. anatipestifer infection.

Pomegranate peel polyphenols inhibits inflammation in LPS-induced RAW264.7 macrophages via the suppression of TLR4/NF-κB pathway activation

BACKGROUNDS

Inflammatory response mediated by activated immune cells is a vital process in host defense system while responding to various stresses. Our previous studies have indicated that pomegranate peel polyphenols (PPPs) and their main components punicalagin (PC) and ellagic acid (EA) decreased pro-inflammatory cytokines and inflammatory mediators by regulating the mitogen-activated protein kinases (MAPKs) pathway, but whether these tested polyphenols play an important role in NF-κB signaling pathway, another crucial pathway of inflammation, remains unclear.

OBJECTIVE

In this study, we analyzed the anti-inflammatory effect of these polyphenols via TLR4-NF-κB pathway in lipopolysaccharide (LPS)-induced RAW264.7 macrophages.

METHODS

Different concentrations of PPPs, PC, and EA were pre-incubated with RAW264.7 macrophages and then stimulated with LPS (1 μg/mL), and the effects of reactive oxygen species and TLR4 were investigated. Moreover, NF-κB p65 nuclear translocation and phosphorylation, and degradation of IκB were measured by Western blot. Furthermore, the influence of pro-inflammatory cytokines was detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Our data showed that PPPs, PC, and EA inhibited LPS-induced intracellular ROS production and suppressed the mRNA and protein expression levels of TLR4 in a dose-dependent manner. Moreover, the anti-inflammatory mechanism was involved in blocking LPS-induced phosphorylation, degradation of IκB, and nuclear translocation of p65. Additionally, PPPs and PC exhibited a stronger anti-inflammatory effect than that of EA.

CONCLUSION

The results indicated that PPPs possess potent anti-inflammatory effect, and PC was the main effective component in PPPs, which provided new insights into the utilization of PPPs to prevent inflammation-associated disorders.

Purification, structural analysis and mechanism of murine macrophage cell activation by sulfated polysaccharides from Cystoseira indica

Sulfated polysaccharides were isolated and purified from the water extract of Cystoseira indica using DEAE Sepharose Fast Flow column to evaluate their structure and macrophage stimulating capacity. Crude and fractionated polysaccharides, CIF1 and CIF2, were mostly composed of neutral sugars (73.1%-78.6%) with relatively lower amounts of acidic sugars (1.3%-9.0%) and sulfate esters (6.9%-9.7%). The polymer chains of polysaccharides were mainly built of different levels of glucose (2.1%-30.8%), fucose (17.2%-24.4%), mannose (17.8%-20.6%) and galactose (16.7%-17.3%). The weight average molecular weight (Mw) of polysaccharides varied between 573.1 × 103 g/mol to 1146.6 × 103 g/mol. The CIF2 polysaccharide, as the most immunostimulating polysaccharide, remarkably induced the release of nitric oxide and inflammatory cytokines including TNF-α, IL-1β, IL-6 and IL-10 from RAW264.7 murine macrophage cells through NF-κB and PAMKs transduction signaling pathways via cell surface TLR4. The interconnections of sugars in CIF2 polysaccharide were complex with (1→3)-fucopyranose, (1→2,3,4)-glucopyranose, (→1)-galactopyranose, (→1)-xylopyranose, (1→2)-rhamnopyranose and (1→2,3)-mannopyranose units being the most predominant residues.

Polysaccharide from alfalfa activates RAW 264.7 macrophages through MAPK and NF-κB signaling pathways

Alfalfa polysaccharide (APS), a bioactive compound extracted from alfalfa, has been proposed to exhibit potential growth-promoting and immune-enhancing functions. But, little is known about the cellular immunomodulatory and intrinsic molecular mechanisms. Here we extracted the APS, and performed in vitro experiments to characterize the immunomodulatory functions as well as the molecular mechanisms of APS on RAW 264.7 macrophages cells. Chemical analyses showed that APS was mainly composed of fucose, arabinose, galactose, glucose, xylose, mannose, galacturonic acid and glucuronic acid. The results of in vitro assays demonstrated that 50 and 100 μg/mL APS increased the cell viability of RAW 264.7 cells. The secretion and gene expression of NO/iNOS, IL-6 and TNF-α in APS-induced macrophage cell were significantly enhanced. However, APS-induced TNF-α production was decreased by blocking the MAPK or NF-κB signaling pathways, especially for the blockade of p38. Moreover, APS enhanced the phosphorylation of p38, ERK, and JNK, promoted the degradation of IκBα, and increased the nuclear translocation of NF-κB p65 subunit. Therefore, we demonstrated that APS could improve the immune functions of RAW 264.7 macrophages cells by promoting the cell viability and increasing secretion and gene expressions of NO/iNOS, IL-6 and TNF-α through the MAPK and NF-κB signaling pathways.

Potential therapeutic effects of Cordyceps cicadae and Paecilomyces cicadae on adenine-induced chronic renal failure in rats and their phytochemical analysis

Background

Natural Cordyceps cicadae (C. cicadae) has been utilized extensively in traditional Chinese medicine to treat chronic renal diseases, heart palpitations, infantile convulsions, and dizziness. However, given its slow growth and immoderate exploitation, C. cicadae resources have been severely depleted. By contrast, Paecilomyces cicadae (P. cicadae), as the anamorph stage of C. cicadae, is easy to cultivate, and this kind of cultivated P. cicadae has good and controllable quality.

Purpose

This study aimed to compare the therapeutic effects of C. cicadae and P. cicadae on adenine-induced chronic renal failure (CRF) rats. In accordance with the aforementioned studies, our work subsequently analyzed the intrinsic relationships between the efficacy and pharmacodynamic substances of C. cicadae and P. cicadae to conclude whether or not P. cicadae could be used as an alternative to C. cicadae in treating CRF.

Methods

Rats were administered with C. cicadae (1.0 g/kg) or P. cicadae (1.0 g/kg) by gavage for 4 weeks. Furthermore, we applied Fourier transform infrared spectroscopy, gas chromatography–mass spectrometry, liquid chromatography–tandem mass spectrometry, and ultraviolet spectrophotometry to comprehensively detect and analyze the chemical constituent differences from ten batches each of C. cicadae and P. cicadae.

Results

This study revealed that both C. cicadae and P. cicadae exerted obvious therapeutic effects on CRF and were more consistent with their chemical compositions.

Conclusion

P. cicadae can be used as an alternative to C. cicadae for treating CRF to cater to market demands.

A 3-O-methylated heterogalactan from Pleurotus eryngii activates macrophages

Mushroom-derived polysaccharides exhibit various biological activities owing to their diverse structural features. Here, we purified a 3-O-methylated heterogalactan (WPEP-N-b, Mw 21.4 kDa) from the fruiting bodies of Pleurotus eryngii. WPEP-N-b is composed primarily of galactose (43.8%), mannose (39.3%), methyl-galactose (11.7%) and glucose (9.2%) residues, with the main chain being composed of α-1,6-linked D-Galp and 3-O-Me-D-Galp, branched at O-2 with single t-β-D-Manp as major the side chain. β-1,6-D-Glcp residues are present as minor components either in side-chains or backbone. WPEP-N-b increases macrophage phagocytosis and secretion of NO, TNF-α, IL-6 and IL-1β. Mechanistic studies demonstrate that WPEP-N-b promotes the degradation of IκB-α, and enhances phosphorylation of MAPKs and the NF-κB p65 subunit. Our results also indicate that this polysaccharide activates RAW264.7 cells via MAPK and NF-κB signaling pathways and the Toll-like receptor 2(TLR2). These results increase our understanding as to how mushroom-derived polysaccharides modulate the immunologic process.

Neutrophil extracellular traps promote lipopolysaccharide-induced airway inflammation and mucus hypersecretion in mice

Bacterial lipopolysaccharide (LPS) contributes to airway inflammation and mucus hypersecretion in chronic airway inflammatory diseases, such as chronic obstructive pulmonary disease (COPD) and cystic fibrosis (CF). Neutrophil extracellular traps (NETs) are extracellular meshworks composed of DNA fibers and antimicrobial proteins. Although NET formation has been detected in COPD and CF patients, how NETs contribute to these diseases is poorly understood. This study was performed to clarify the effects and mechanisms of action of NETs in airway inflammation and mucus hypersecretion. We created a murine model of LPS-induced airway inflammation and mucus hypersecretion, and found that LPS-induced NET formation was degraded by aerosolized DNase I treatment in mice. Degradation of NETs by aerosolized DNase I reduced LPS-induced airway inflammation and mucus hypersecretion in mice, this reduction correlated with suppression of TLR4/NF-κB signaling pathway. More importantly, NETs promoted LPS-induced production of IL-1β, IL-6 and TNF-α in macrophages. These results suggest NET degradation using aerosolized DNase I is a potential new therapeutic strategy for treating COPD and CF.

Purification, Preliminary Characterization, and Immunological Activity of Polysaccharides from Crude Drugs of Sijunzi Formula

Sijunzi Decoction (SJZD) is a conventional prescription for curing spleen deficiency in Traditional Chinese Medicine and polysaccharide is its main ingredient. In order to explore the effective ingredients contributing to the immunological activity of SJZD, we isolated and purified seven homogeneous polysaccharides from Radix Ginseng (RS-3-1 and RS-3-2), Rhizoma Atractylodis Macrocephalae (BZ-3-1, BZ-3-2, and BZ-3-3), Poria (FL-3-1), and Radix Glycyrrhizae (GC-3-1) decoctions, respectively. The molecular weight of seven homogeneous polysaccharides ranged from 5.42 × 10⁴ to 5.65 × 10⁴ Da. Monosaccharide composition determined by GC-MS analysis showed that these polysaccharides were primarily composed of Rha, Ara, Xyl, Man, Glc, and Gal with various ratios. Immunological activity assay revealed that polysaccharides from four crude drug components of SJZD displayed inhibitory effects on the complement system. RS-3-1, BZ-3-1, FL-3-1, and GC-3-1 could significantly enhance the phagocytosis and increase the NO production and tumor necrosis factor (TNF-α) level in RAW 264.7 cells (p < 0.05). These results demonstrated the immunological activities of these polysaccharides from the four crude drugs. This study supports the therapeutic effect of SJZD in clinical use and is essential for further identification the immunopolysaccharide from SJZD decoction.

Okanin, effective constituent of the flower tea Coreopsis tinctoria, attenuates LPS-induced microglial activation through inhibition of the TLR4/NF-κB signaling pathways

The EtOAc extract of Coreopsis tinctoria Nutt. significantly inhibited LPS-induced nitric oxide (NO) production, as judged by the Griess reaction, and attenuated the LPS-induced elevation in iNOS, COX-2, IL-1β, IL-6 and TNF-α mRNA levels, as determined by quantitative real-time PCR, when incubated with BV-2 microglial cells. Immunohistochemical results showed that the EtOAc extract significantly decreased the number of Iba-1-positive cells in the hippocampal region of LPS-treated mouse brains. The major effective constituent of the EtOAc extract, okanin, was further investigated. Okanin significantly suppressed LPS-induced iNOS expression and also inhibited IL-6 and TNF-α production and mRNA expression in LPS-stimulated BV-2 cells. Western blot analysis indicated that okanin suppressed LPS-induced activation of the NF-κB signaling pathway by inhibiting the phosphorylation of IκBα and decreasing the level of nuclear NF-κB p65 after LPS treatment. Immunofluorescence staining results showed that okanin inhibited the translocation of the NF-κB p65 subunit from the cytosol to the nucleus. Moreover, okanin significantly inhibited LPS-induced TLR4 expression in BV-2 cells. In summary, okanin attenuates LPS-induced activation of microglia. This effect may be associated with its capacity to inhibit the TLR4/NF-κB signaling pathways. These results suggest that okanin may have potential as a nutritional preventive strategy for neurodegenerative disorders.