Natural Polysaccharides and Their Derivates: A Promising Natural Adjuvant for Tumor Immunotherapy

Recognition on pharmacodynamic ingredients of natural products

Natural products (NPs) play an irreplaceable role in the intervention of various diseases and have been considered a critical source of drug development. Many new pharmacodynamic compounds with potential clinical applications have recently been derived from NPs. These compounds range from small molecules to polysaccharides, polypeptides, proteins, self-assembled nanoparticles, and extracellular vesicles. This review summarizes various active substances found in NPs. The investigation of active substances in NPs can potentiate new drug development and promote the in-depth comprehension of the mechanism of action of NPs that can be beneficial in the prevention and treatment of human diseases.

A randomized, double-blind, placebo-controlled study on immune improvement effects of ethanolic extract of Echinacea purpurea (L.) Moench in Korean adults

Echinacea purpurea (L.) Moench (EP), a medicinal plant native to North America, is now cultivated in various regions including Europe. With increasing popularity of Echinacea in Korea recently, a human clinical trial was conducted to evaluate immune-enhancing efficacy and safety of EP 60% ethanolic extract (EPE) in Koreans. Eighty volunteers were recruited for this randomized, double-blind, placebo-controlled clinical trial. They were randomly divided into two groups and given either a daily dose of 200 mg of EPE or a placebo. All participants underwent testing for Natural Killer (NK) cell cytotoxic activity, serum cytokine levels (IL-2, IL-6, IL-10, IL-12, IFN-γ, TNF-α), Wisconsin Upper Respiratory Symptom Survey-21 (WURSS-21), and Multidimensional Fatigue Scale (MFS) during this study to assess changes in outcomes. After 8 weeks of EPE consumption, a significant increase in NK cell cytotoxic activity compared to the placebo was observed. Additionally, serum cytokine levels of IL-2, IFN-γ, and TNF-α also significantly increased following EPE consumption. However, no significant changes were observed in WURSS-21 and MFS before and after EPE consumption. Throughout the 8-week study period, no adverse reactions were reported in relation to EPE consumption, and there were no clinically significant changes in diagnostic laboratory tests or vital signs in the EPE group. These results indicate that consumption of EPE could lead to immune improvement without any adverse effects. This clinical trial was the first to demonstrate beneficial effects of EPE consumption on immunity in Korean adults.

Steady-State Delivery and Chemical Modification of Food Nutrients to Improve Cancer Intervention Ability

Cancer is a crucial global health problem, and prevention is an important strategy to reduce the burden of the disease. Daily diet is the key modifiable risk factor for cancer, and an increasing body of evidence suggests that specific nutrients in foods may have a preventive effect against cancer. This review summarizes the current evidence on the role of nutrients from foods in cancer intervention. It discusses the potential mechanisms of action of various dietary components, including phytochemicals, vitamins, minerals, and fiber. The findings of epidemiological and clinical studies on their association with cancer risk are highlighted. The foods are rich in bioactive compounds such as carotenoids, flavonoids, and ω-3 fatty acids, which have been proven to have anticancer properties. The effects of steady-state delivery and chemical modification of these food's bioactive components on anticancer and intervention are summarized. Future research should focus on identifying the specific bioactive compounds in foods responsible for their intervention effects and exploring the potential synergistic effects of combining different nutrients in foods. Dietary interventions that incorporate multiple nutrients and whole foods may hold promise for reducing the risk of cancer and improving overall health.

Self-adjuvant Astragalus polysaccharide-based nanovaccines for enhanced tumor immunotherapy: a novel delivery system candidate for tumor vaccines

The study of tumor nanovaccines (NVs) has gained interest because they specifically recognize and eliminate tumor cells. However, the poor recognition and internalization by dendritic cells (DCs) and insufficient immunogenicity restricted the vaccine efficacy. Herein, we extracted two molecular-weight Astragalus polysaccharides (APS, 12.19 kD; APSHMw, 135.67 kD) from Radix Astragali and made them self-assemble with OVA257-264 directly forming OVA/APS integrated nanocomplexes through the microfluidic method. The nanocomplexes were wrapped with a sheddable calcium phosphate layer to improve stability. APS in the formed nanocomplexes served as drug carriers and immune adjuvants for potent tumor immunotherapy. The optimal APS-NVs were approximately 160 nm with uniform size distribution and could remain stable in physiological saline solution. The FITC-OVA in APS-NVs could be effectively taken up by DCs, and APS-NVs could stimulate the maturation of DCs, improving the antigen cross-presentation efficiency in vitro. The possible mechanism was that APS can induce DC activation via multiple receptors such as dectin-1 and Toll-like receptors 2 and 4. Enhanced accumulation of APS-NVs both in draining and distal lymph nodes were observed following s.c. injection. Smaller APS-NVs could easily access the lymph nodes. Furthermore, APS-NVs could markedly promote antigen delivery efficiency to DCs and activate cytotoxic T cells. In addition, APS-NVs achieve a better antitumor effect in established B16-OVA melanoma tumors compared with the OVA+Alum treatment group. The antitumor mechanism correlated with the increase in cytotoxic T cells in the tumor region. Subsequently, the poor tumor inhibitory effect of APS-NVs on the nude mouse model of melanoma also confirmed the participation of antitumor adaptive immune response induced by NVs. Therefore, this study developed a promising APS-based tumor NV that is an efficient tumor immunotherapy without systemic side effects.

Natural polysaccharides exert anti-tumor effects as dendritic cell immune enhancers

With the development of immunotherapy, the process of tumor treatment is also moving forward. Polysaccharides are biological response modifiers widely found in plants, animals, fungi, and algae and are mainly composed of monosaccharides covalently linked by glycosidic bonds. For a long time, polysaccharides have been widely used clinically to enhance the body's immunity. However, their mechanisms of action in tumor immunotherapy have not been thoroughly explored. Dendritic cells (DCs) are a heterogeneous population of antigen presenting cells (APCs) that play a crucial role in the regulation and maintenance of the immune response. There is growing evidence that polysaccharides can enhance the essential functions of DCs to intervene the immune response. This paper describes the research progress on the anti-tumor immune effects of natural polysaccharides on DCs. These studies show that polysaccharides can act on pattern recognition receptors (PRRs) on the surface of DCs and activate phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT), mitogen-activated protein kinase (MAPK), nuclear factor-κB (NF-κB), Dectin-1/Syk, and other signalling pathways, thereby promoting the main functions of DCs such as maturation, metabolism, antigen uptake and presentation, and activation of T cells, and then play an anti-tumor role. In addition, the application of polysaccharides as adjuvants for DC vaccines, in combination with adoptive immunotherapy and immune checkpoint inhibitors (ICIs), as well as their co-assembly with nanoparticles (NPs) into nano drug delivery systems is also introduced. These results reveal the biological effects of polysaccharides, provide a new perspective for the anti-tumor immunopharmacological research of natural polysaccharides, and provide helpful information for guiding polysaccharides as complementary medicines in cancer immunotherapy.

Discrimination of Radix Astragali from Different Growth Patterns, Origins, Species, and Growth Years by an H1-NMR Spectrogram of Polysaccharide Analysis Combined with Chemical Pattern Recognition and Determination of Its Polysaccharide Content and Immunological Activity

The fraud phenomenon is currently widespread in the traditional Chinese medicine Radix Astragali (RA) market, especially where high-quality RA is substituted with low-quality RA. In this case, focused on polysaccharides from RA, the classification models were established for discrimination of RA from different growth patterns, origins, species, and growth years. 1H Nuclear Magnetic Resonance (H1-NMR) was used to establish the spectroscopy of polysaccharides from RA, which were used to distinguish RA via chemical pattern recognition methods. Specifically, orthogonal partial least squares discriminant analysis (OPLS-DA) and linear discriminant analysis (LDA) were used to successfully establish the classification models for RA from different growth patterns, origins, species, and growth years. The satisfactory parameters and high accuracy of internal and external verification of each model exhibited the reliable and good prediction ability of the developed models. In addition, the polysaccharide content and immunological activity were also tested, which was evaluated by the phagocytic activity of RAW 264.7. And the result showed that growth patterns and origins significantly affected the quality of RA. However, there was no significant difference in the aspects of origins and growth years. Accordingly, the developed strategy combined with chemical information, biological activity, and multivariate statistical method can provide new insight for the quality evaluation of traditional Chinese medicine.

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

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

Active Ingredients from Chinese Medicine for Combination Cancer Therapy

Combination therapy against cancer has gained increasing attention because it can help to target multiple pathways to tackle oncologic progression and improve the limited antitumor effect of single-agent therapy. Chinese medicine has been studied extensively in cancer therapy and proven to be efficacious in many cases due to its wide spectrum of anticancer activities. In this review, we aim to summarize the recent progress of active ingredients from Chinese medicine (AIFCM) in combination with various cancer therapeutic modalities, including chemotherapy, gene therapy, radiotherapy, phototherapy and immunotherapy. In addition to highlighting the potential contribution of AIFCM in combination cancer therapy, we also elucidate the underlying mechanisms behind their synergistic effect and improved anticancer efficacy, thereby encouraging the inclusion of these AIFCM as part of effective armamentarium in fighting intractable cancers. Finally, we present the challenges and future perspectives of AIFCM combination therapy as a feasible and promising strategy for the optimization of cancer treatment and better clinical outcomes.

Moringa oleifera leaf polysaccharides exert anti-lung cancer effects upon targeting TLR4 to reverse the tumor-associated macrophage phenotype and promote T-cell infiltration

Tumor-associated macrophages (TAMs) participate in tumorigenesis, growth, invasion as well as metastasis by facilitating an immunosuppressive tumor microenvironment. Reversing the pro-tumoral M2 phenotype of TAMs has become a hot spot in advancing cancer immunotherapy. In the current study, the content of Moringa oleifera leaf polysaccharides (MOLP) was determined and characterized, along with the anti-cancer mechanism of MOLP studied in a Lewis lung cancer (LLC) tumor-bearing mouse model and bone marrow-derived macrophages. The monosaccharide composition and gel permeation chromatography analyses show that MOLP are mainly composed of galactose, glucose, and arabinose, with approximately 17.35 kDa average molecular weight (Mw). In vivo studies demonstrate that MOLP convert TAMs from the immunosuppressive M2 phenotype to the antitumor M1 phenotype, thus inducing CXCL9 and CXCL10 expression and increasing T-cell infiltration in the tumor. Furthermore, macrophage depletion and T cell suppression demonstrated that the tumor suppressive effect of MOLP was reliant on reprogramming macrophage polarization and T cell infiltration. In vitro studies revealed that MOLP could induce the phenotypic switch from M2 macrophages to M1 by targeting TLR4. The current study highlights that MOLP are promising anticancer plant-derived polysaccharides with potential in modulating the immune microenvironment and have a bright application prospect in the immunotherapy of lung cancer.

β-Glucan produced by Lentinus edodes suppresses breast cancer progression via the inhibition of macrophage M2 polarization by integrating autophagy and inflammatory signals

BACKGROUND

β-Glucan from Lentinus edodes (LNT), an edible mushroom, possesses strong anticancer activity. However, the therapeutic effects of LNT during the occurrence and progression of breast cancer and their underlying molecular mechanisms have not been elucidated.

METHODS

Mouse mammary tumor virus-polyoma middle tumor-antigen (MMTV-PyMT) transgenic mice were used as a breast cancer mouse model. Hematoxylin and eosin, immunohistochemical, and immunofluorescence staining were performed for histopathological analysis. Moreover, we developed an inflammatory cell model using tumor necrosis factor-α (TNF-α). Macrophage polarization was assessed using western blot analysis and immunofluorescence.

RESULTS

Orphan nuclear receptor 77 (Nur77) and sequestosome-1 (p62) were highly expressed and positively correlated with each other in breast cancer tissues. LNT significantly inhibited tumor growth, ameliorated inflammatory cell infiltration, and induced tumor cell apoptosis in PyMT transgenic mice. Moreover, LNT attenuated the ability of tumors to metastasize to lung tissue. Mechanistically, LNT treatment restrained macrophage polarization from M1 to M2 phenotype and promoted autophagic cell death by inhibiting Nur77 expression, AKT/mTOR signaling, and inflammatory signals in breast tumor cells. However, LNT did not exhibit a direct pro-autophagic effect on tumor cell death, except for its inhibitory effect on Nur77 expression. LNT-mediated autophagic tumor cell death depends on M1 macrophage polarization. In in vitro experiments, LNT inhibited the upregulation of p62, autophagy activation, and inflammatory signaling pathways in Nur77 cells.

CONCLUSION

LNT inhibited macrophage M2 polarization and subsequently blocked the AKT/mTOR and inflammatory signaling axes in breast cancer cells, thereby promoting autophagic tumor cell death. Thus, LNT may be a promising therapeutic strategy for breast cancer.

Microgravity and immune cells

The microgravity environment experienced during spaceflight severely impaired immune system, making astronauts vulnerable to various diseases that seriously threaten the health of astronauts. Immune cells are exceptionally sensitive to changes in gravity and the microgravity environment can affect multiple aspects of immune cells through different mechanisms. Previous reports have mainly summarized the role of microgravity in the classification of innate and adaptive immune cells, lacking an overall grasp of the laws that microgravity effects on immune cells at different stages of their entire developmental process, such as differentiation, activation, metabolism, as well as function, which are discussed and concluded in this review. The possible molecular mechanisms are also analysed to provide a clear understanding of the specific role of microgravity in the whole development process of immune cells. Furthermore, the existing methods by which to reverse the damage of immune cells caused by microgravity, such as the use of polysaccharides, flavonoids, other natural immune cell activators etc. to target cell proliferation, apoptosis and impaired function are summarized. This review will provide not only new directions and ideas for the study of immune cell function in the microgravity environment, but also an important theoretical basis for the development of immunosuppression prevention and treatment drugs for spaceflight.

[Molecular basis of biological activity of polysaccharides in COVID-19 associated conditions]

The review considers the main molecular biological features of the COVID-19 causative agent, the SARS-CoV-2 virus: life cycle, viral cell penetration strategies, interactions of viral proteins with human proteins, cytopathic effects. We also analyze pathological conditions that occur both during the course of the COVID-19 disease and after virus elimination. A brief review of the biological activities of polysaccharides isolated from various sources is given, and possible molecular biological mechanisms of these activities are considered. Data analysis shows that polysaccharides are a class of biological molecules with wide potential for use in the treatment of both acute conditions in COVID-19 and post-COVID syndrome.

Effects of Different Additives on Fermentation Quality, Microbial Communities, and Rumen Degradation of Alfalfa Silage

This study examined the effects of different additives on the fermentation quality, nutrient composition, microbial communities, and rumen degradation of ensiled alfalfa. Six treatments were employed in which additives were applied to alfalfa on a fresh weight basis: CK (no additive), FA (0.6% formic acid), CaO (3% calcium oxide and 3% urea), LB (1 × 106 cfu/g Lentilactobacillus buchneri), GLB (2% glucose and 1 × 106 cfu/g L. buchneri), and FLB (2% fucoidan and 1 × 106 cfu/g L. buchneri). After 60 days of ensiling, all treatments altered the bacterial communities, improved the fermentation quality, reduced dry matter (DM) and crude protein (CP) losses, and enhanced the rumen degradation of nutrients. The addition of LB increased the relative abundance of Lactobacillus spp. (p < 0.05), whereas GLB reduced (p < 0.05) the NH3-N:TN ratio and elevated (p < 0.05) the concentrations of Lactobacillus and lactic acid content. The FA treatment reduced (p < 0.05) the pH, as well as the DM and CP degradations, while the CaO treatment increased the degradations of DM, acid detergent fiber, and neutral detergent fiber. We concluded that FA, LB, GLB, and FLB had beneficial effects on alfalfa fermentation, and that CaO increased alfalfa silage rumen degradation.

Integrated biotechnology to mitigate green tides

Around the world, green tides are happening with increasing frequency because of the dual effects of increasingly intense human activity and climate change; this leads to significant impacts on marine ecology and economies. In the last decade, the world's largest green tide, which is formed by Ulva/Enteromorpha porifera, has become a recurrent phenomenon every year in the southern Yellow Sea (China), and it has been getting worse. To alleviate the impacts of such green tide outbreaks, multiple measures need to be developed. Among these approaches, biotechnology plays important roles in revealing the outbreak mechanism (e.g., molecular identification technology for algal genotypes), controlling and preventing outbreaks at the origin sites (e.g., technology to inhibit propagation), and utilizing valuable algal biomass. This review focuses on the various previously used biotechnological approaches that may be applicable to worldwide seaweed blooms that result from global climate change and environmental degradation.

Research Progress on the Mechanisms of Polysaccharides against Gastric Cancer

Gastric cancer is a common type of cancer that poses a serious threat to human health. Polysaccharides are important functional phytochemicals, and research shows that polysaccharides have good anti-gastric cancer effects. We collated all relevant literature published from 2000 to 2020 and found that more than 60 natural polysaccharides demonstrate anti-gastric cancer activity. At the present, the sources of these polysaccharides include fungi, algae, tea, Astragalus membranaceus, Caulis Dendrobii, and other foods and Chinese herbal medicines. By regulating various signaling pathways, including the PI3K/AKT, MAPK, Fas/FasL, Wnt/β-catenin, IGF-IR, and TGF-β signaling pathways, polysaccharides induce gastric cancer cell apoptosis, cause cell cycle arrest, and inhibit migration and invasion. In addition, polysaccharides can enhance the immune system and killing activity of immune cells in gastric cancer patients and rats. This comprehensive review covers the extraction, purification, structural characterization, and mechanism of plant and fungal polysaccharides against gastric cancer. We hope this review is helpful for researchers to design, research, and develop plant and fungal polysaccharides.

New opportunities for immunomodulation of the tumour microenvironment using chemical tools

Immunotherapy is recognised as an attractive method for the treatment of cancer, and numerous treatment strategies have emerged over recent years. Investigations of the tumour microenvironment (TME) have led to the identification of many potential therapeutic targets and methods. However, many recently applied immunotherapies are based on previously identified strategies, such as boosting the immune response by combining commonly used stimulators, and the release of drugs through changes in pH. Although methodological improvements such as structural optimisation and combining strategies can be undertaken, applying those novel targets and methods in immunotherapy remains an important goal. In this review, we summarise the latest research on the TME, and discuss how small molecules, immune cells, and their interactions with tumour cells can be regulated in the TME. Additionally, the techniques currently employed for delivery of these agents to the TME are also mentioned. Strategies to modulate cell phenotypes and interactions between immune cells and tumours are mainly discussed. We consider both modulatory and targeting methods aiming to bridge the gap between the TME and chemical modulation thereof.

Chemical Structure and Immune Activation of a Glucan From Rhizoma Acori Tatarinowii

Rhizoma Acori Tatarinowii is a traditional Chinese herb used to treat depression and coronary heart disease. Studies on its active components mainly focus on small molecular compounds such as asarone and other essential oil components, while the large molecular active components such as polysaccharides are ignored. In this study, we aimed to study the chemical structure and immune activation of polysaccharides from Rhizoma Acori Tatarinowii. In this study, a polysaccharide (RATAPW) was isolated and purified by DEAE-52 cellulose and Sephadex G-100 column chromatography from alkali extraction polysaccharide of Rhizoma Acori Tatarinowii. The average molecular weight of RATAPW was 2.51 × 10⁴ Da, and the total carbohydrate contents of RATAPW were 98.23 ± 0.29%. The monosaccharide composition, methylation, and nuclear magnetic resonance (NMR) analysis results displayed that the polysaccharide was α-1,4-glucan with short α-1,6 branches. Immunofluorescence assay and inhibitor neutralization assay indicated that RATAPW could promote the TNF-α production of RAW264.7 macrophage through the nuclear factor kappa B (NF-κB) molecular signaling pathway. Treatment with 200 μg/ml of RATAPW enhanced a 38.77% rise in the proliferation rate of spleen lymphocytes. RATAPW also enhances ConA-induced T cells and lipopolysaccharide (LPS)-induced B cell proliferation in a dose-dependent effect. Our study lays a foundation for the discovery of natural polysaccharide immune modulators or functional food from Rhizoma Acori Tatarinowii.

Astragalus polysaccharide: a review of its immunomodulatory effect

The Astragalus polysaccharide is an important bioactive component derived from the dry root of Astragalus membranaceus. This review aims to provide a comprehensive overview of the research progress on the immunomodulatory effect of Astragalus polysaccharide and provide valuable reference information. We review the immunomodulatory effect of Astragalus polysaccharide on central and peripheral immune organs, including bone marrow, thymus, lymph nodes, spleen, and mucosal tissues. Furthermore, the immunomodulatory effect of Astragalus polysaccharide on a variety of immune cells is summarized. Studies have shown that Astragalus polysaccharide can promote the activities of macrophages, natural killer cells, dendritic cells, T lymphocytes, B lymphocytes and microglia and induce the expression of a variety of cytokines and chemokines. The immunomodulatory effect of Astragalus polysaccharide makes it promising for the treatment of many diseases, including cancer, infection, type 1 diabetes, asthma, and autoimmune disease. Among them, the anticancer effect is the most prominent. In short, Astragalus polysaccharide is a valuable immunomodulatory medicine, but further high-quality studies are warranted to corroborate its clinical efficacy.

Role of macrophages in tumor progression and therapy (Review)

The number and phenotype of macrophages are closely related to tumor growth and prognosis. Macrophages are recruited to (and polarized at) the tumor site thereby promoting tumor growth, stimulating tumor angiogenesis, facilitating tumor cell migration, and creating a favorable environment for subsequent colonization by (and survival of) tumor cells. These phenomena contribute to the formation of an immunosuppressive tumor microenvironment (TME) and therefore speed up tumor cell proliferation and metastasis and reduce the efficacy of antitumor factors and therapies. The ability of macrophages to remodel the TME through interactions with other cells and corresponding changes in their number, activity, and phenotype during conventional therapies, as well as the association between these changes and drug resistance, make tumor-associated macrophages a new target for antitumor therapies. In this review, advantages and limitations of the existing antitumor strategies targeting macrophages in Traditional Chinese and Western medicine were analyzed, starting with the effect of macrophages on tumors and their interactions with other cells and then the role of macrophages in conventional treatments was explored. Possible directions of future developments in this field from an all-around multitarget standpoint were also examined.

Comparative Analysis of Metabolic Compositions and Trace Elements of Inonotus hispidus Mushroom Grown on Five Different Tree Species

Inonotus hispidus is a popular edible and medicinal mushroom widely used in China. I. hispidus mushroom mainly grows on five different tree species (Morus alba L., Ulmus macrocarpa Hance, Fraxinus mandshurica Rupr., Ziziphus jujuba Mill., and Malus pumila Mill.), and their fruiting bodies were all separately used in the market. However, there is no holistic insight to elucidate the molecular basis of the differentiated usage. This study aimed to investigate and compare the metabolite compositions and trace elements in I. hispidus grown on five different tree species. The metabolomic data, 8 kinds of principal components and 12 kinds of trace elements, were analyzed in this study. The results showed that the same 1353 metabolites were identified in I. hispidus grown on five different tree species, but the relative abundance was different. The principal components and trace elements contents are different, for example, polysaccharides, phenol metabolites, Ca, Na, Mg, Fe, and Mn were enriched in I. hispidus grown on M. alba, the flavonoids were enriched in Z. jujuba samples, and the steroids, terpenoids, and Zn were enriched in M. pumila samples. Further, the KEGG enrichment pathway and metabolic models were established. These findings provide a molecular basis for the unique use of the I. hispidus mushroom grown on different tree species.

Achyranthes bidentata Polysaccharide Activates Nuclear Factor-Kappa B and Promotes Cytokine Production in J774A.1 Cells Through TLR4/MyD88 Signaling Pathway

Achyranthes bidentata Blume, a traditional Chinese medicine, is widely acknowledged for its function of invigorating the liver and kidneys and as a stranguria-relieving diuretic and used in the treatment of edema, gonorrhea, and other diseases. Polysaccharide (ABPS), isolated from Achyranthes bidentata Blume, has been demonstrated to have multiple biological activities including immunomodulatory effects. However, the mechanisms underlying the effects of ABPS have not been fully investigated. The present study is conducted to explore the underlying mechanism of immunomodulatory activities of ABPS. Results showed that ABPS significantly increased the secretion of IL-1β and TNF-α in J744 A.1 cells. Nitric oxide (NO) also significantly increased after ABPS treatment. The special antibodies (Toll-like receptor 4 (TLR4) antibody and CD14/TLR4 antibody) significantly decreased the activation, while the Toll-like receptor 2 (TLR2) antibody could not abolish this activation. Meanwhile, pyrrolidine dithiocarbamate (PDTC), a specific inhibitor of NF-κB, remarkably inhibited the secretion of IL-1β and TNF-α induced by ABPS in J744 A.1 cells. Western blotting (WB) and confocal laser scanning microscopy (CLSM) showed that ABPS promoted NF-κB translocation into the nucleus. Furthermore, the mRNA and protein expression of TLR4 and MyD88 were significantly increased after ABPS treatment. Taken together, these findings suggested that the immunomodulatory mechanism of ABPS was associated with the secretion of cytokines by stimulating the NF-κB pathway through TLR4/MyD88 signaling.