Polysaccharide immunomodulators as therapeutic agents: structural aspects and biologic function

Research progress and future development potential of Flammulina velutipes polysaccharides in the preparation process, structure analysis, biology, and pharmacology: A review

In recent years, Flammulina velutipes (F. velutipes) has attracted consequential attention in various research fields due to its rich composition of proteins, vitamins, amino acids, polysaccharides, and polyphenols. F. velutipes polysaccharides (FVPs) are considered as key bioactive components of F. velutipes, demonstrating multiple physiological activities, including immunomodulatory, anti-inflammatory, and antibacterial properties. Moreover, they offer health benefits such as antioxidant and anti-aging properties, which have exceptionally valuable clinical applications. Polysaccharides derived from different sources exhibit a wide range of biomedical functions and distinct biological activities. The varied biological functions of polysaccharides, coupled with their extensive application in functional foods and clinical applications, have prompted a heightened focus on polysaccharide research. Additionally, the extraction, deproteinization, and purification of FVPs are fundamental to investigate the structure and biological activities of polysaccharides. Therefore, this review provides a comprehensive and systematic overview of the extraction, deproteinization, purification, characterization, and structural elucidation of FVPs. Furthermore, the biological activities and mechanisms of FVPs have been further explored through in vivo and in vitro experiments. This review aims to provide a theoretical foundation and guide future research and development of FVPs.

Functionality and Health-Promoting Properties of Polysaccharide and Plant-Derived Substances from Mesona chinensis

Mesona chinensis, in Thai called Chao Kuay and in Chinese Hsian-tsao, belongs to the Lamiaceae family. This herbal plant grows widely in Southern China, Taiwan (China), Malaysia, the Philippines, Indonesia, Vietnam, and Thailand. The Mesona plant is used to make functional products such as drinks and soft textured sweet treats, and also traditional medicine, to treat heat stroke, high blood pressure, heart attack, high blood sugar, hepatic diseases, colon diseases, inflammatory conditions, and to alleviate myalgia. The proximate composition of M. chinensis is a mixture of protein, fat, fiber, ash, and minerals. The main biological compounds in M. chinensis extracts are polysaccharides, terpenoids, flavonoids, and polyphenols, with wide-ranging pharmacological properties including antioxidant, antidiabetic, antilipidemic, carcinoma-inhibitory, renal-protective, antihypertensive, DNA damage-protective, and anti-inflammatory effects. This review investigated the proximate composition, polysaccharide type, and pharmacological properties of M. chinensis extracts. Phytochemical properties enhance the actions of the gut microbiota and improve health benefits. This review assessed the functional and medicinal activities of M. chinensis extracts. Future studies should further elucidate the in vitro/in vivo mechanisms of this plant extract and its impact on gut health.

Anti-inflammatory and immunomodulatory properties of polysaccharides in mushrooms

Mushrooms are distinguished as important food-containing polysaccharides possessing potent anti-inflammatory and immunomodulating properties. These compounds belong mostly to polysaccharides that are mostly β-D-glucans. Among them, β-1,3-glucan with β-1,6 side chains of glucose residues, has more important roles in their properties. In this review, we have introduced polysaccharides mainly from Lentinula edodes and Pleurotus citrinopileatus with anti-inflammatory and immunomodulating properties. In addition, the mechanisms of activation of their physiological properties and signal cascade are also reviewed.

Advanced nano-based strategies for mRNA tumor vaccine

Tumor vaccine is a promising strategy for cancer immunotherapy by introducing tumor antigens into the body to activate specific anti-tumor immune responses. Along with the technological breakthroughs in genetic engineering and delivery systems, messenger ribonucleic acid (mRNA) technology has achieved unprecedented development and application over the last few years, especially the emergency use authorizations of two mRNA vaccines during the COVID-19 pandemic, which has saved countless lives and makes the world witness the powerful efficacy of mRNA technology in vaccines. However, unlike infectious disease vaccines, which mainly induce humoral immunity, tumor vaccines also need to activate potent cellular immunity to control tumor growth, which creates a higher demand for mRNA delivery to the lymphatic organs and antigen-presenting cells (APCs). Here we review the existing bottlenecks of mRNA tumor vaccines and advanced nano-based strategies to overcome those challenges, as well as future considerations of mRNA tumor vaccines and their delivery systems.

Polysaccharides from Brassica rapa root: Extraction, purification, structural features, and biological activities. A review

Brassica rapa (B. rapa) roots are attracting increased attention from nutritionists and health-conscious customers because of their remarkable performance in supplying necessary nutrients. Polysaccharides are major biologically active substances in B. rapa roots, which come in a variety of monosaccharides with different molar ratios and glycosidic bond types. Depending on the source, extraction, separation, and purification methods of B. rapa roots polysaccharides (BRP); different structural features, and pharmacological activities are elucidated. Polysaccharides from B. rapa roots possess a range of nutritional, biological, and health-enhancing characteristics, including anti-hypoxic, antifatigue, immunomodulatory, hypoglycemic, anti-tumor, and antioxidant activities. This paper reviewed extraction and purification methods, structural features, and biological activities as well as correlations between the structural and functional characteristics of polysaccharides from the B. rapa roots. Ultimately, this work will serve as useful reference for understanding the connections between polysaccharide structure and biological activity and developing novel BRP-based functional foods.

Effect of Cyberlindnera jadinii yeast on growth performance, nutrient digestibility, and gut health of broiler chickens from 1 to 34 d of age

The effect of dietary graded levels of Cyberlindnera jadinii yeast (C. jadinii) on growth performance, nutrient digestibility, and gut health of broilers was evaluated from 1 to 34 d of age. A total of 360 male broiler chicks were randomly allocated to 1 of 4 dietary treatments (6 replicate pens each) consisting of a wheat-soybean meal-based pelleted diet (Control or CJ0), and 3 diets in which 10% (CJ10), 20% (CJ20), and 30% (CJ30) of the crude protein were supplied by C. jadinii, by gradually replacing protein-rich ingredients. Body weight and feed intake were measured at d 1, 11, 22, and 32. Pellet temperature, durability, and hardness increased linearly (P < 0.05) with C. jadinii inclusion, with highest (P < 0.05) values for CJ30. Up until d 22, feed conversion ratio (FCR) was similar between treatments (P = 0.169). Overall, increasing C. jadinii inclusion linearly increased (P = 0.047) feed intake but had no effect on weight gain or mortality. FCR increased (P < 0.05) linearly with increasing C. jadinii inclusion but only birds fed CJ30 had a significantly poorer FCR compared to the Control. Ileal digestibility was not affected by C. jadinii inclusion, however, there was a significant linear decrease in crude protein and phosphorus, and a tendency for a decrease in fat digestibility. Apparent metabolizable energy (AME) decreased (P < 0.001) quadratically with increasing C. jadinii and was significantly lower in CJ30 compared to the Control. Ileal concentrations of volatile fatty acids (VFAs) were not affected by C. jadinii inclusion, but butyric acid and total VFAs were linearly and quadratically increased and were significantly higher in cecal digesta of birds fed CJ20 and CJ30. Increasing C. jadinii inclusion was associated with an increase (P < 0.05) in the relative abundance of lactobacillus in the ileum and cecum. In conclusion, C. jadinii yeast can supply up to 20% of the total dietary protein without negatively affecting performance, digestibility, or gut health of broilers. The potential confounding role of feed processing and C. jadinii cell wall components on broiler performance is discussed.

A standardized extract of Echinacea purpurea containing higher chicoric acid content enhances immune function in murine macrophages and cyclophosphamide-induced immunosuppression mice

CONTEXT

Preparations of Echinacea have been used by herbalists to boost the immune system.

OBJECTIVE

In this study, Echinacea purpurea (L.) Moench (Asteraceae) extract with enriched chicoric acid content was investigated for immunomodulation.

MATERIALS AND METHODS

The standardized hydroalcoholic extract (4% chicoric acid) was prepared from the aerial parts of E. purpurea (SEP). The extract was screened for in vitro antioxidant activities, and immunomodulation in RAW 264.7 cells, at 200 and 400 µg/mL. Further, the male BALB/c mice (20-25 g) were divided into 4 groups (n = 6 per group). All the groups except control, were intraperitoneally injected with 70 mg/kg/day of cyclophosphamide (CTX) for 4 consecutive days. The treatment groups received SEP extract (100 and 200 mg/kg body weight) p.o. from day 5 to 14.

RESULTS

The SEP extract inhibited DPPH (IC50 = 106.7 µg/mL), ABTS+ (IC50 = 19.88 µg/mL) and nitric oxide (IC50 = 120.1 µg/mL). The SEP extract's ORAC (oxygen radical absorbance capacity) value was 1931.63 µM TE/g. In RAW 264.7 cells, SEP extract increased the nitric oxide production by 30.76- and 39.07-fold at 200 and 400 µg/mL, respectively, compared to the untreated cells. SEP extract significantly increased phagocytosis and cytokine release (TNF-α, IL-6, and IL-1β) in the cells. Further, the extract improved immune organ indices, lymphocyte proliferation and serum cytokine levels in CTX-induced mice. The extract at 200 mg/kg significantly increased the natural killer cell activity (24.6%) and phagocytic index (28.03%) of CTX mice.

CONCLUSION

Our results strongly support SEP extract with 4% chicoric acid as a functional ingredient for immunomodulation.

2-(Benzhydryl sulfinyl)-N-sec-butylacetamide) isolated from fig augmented trastuzumab-triggered phagocytic killing of cancer cells through interface with Fcγ receptor

The objective of the current study was to extract 2-(benzhydryl sulfinyl)-N-sec-butylacetamide), a novel compound from fig, and then determine its role in enhancing trastuzumab-triggered phagocytic killing of SKOV-3 cancer cells. In this study, Soxhlet was used to extract the compound from the mature and air-dried fig fruits. The production of the isolated extracts was enhanced by using polar and non-polar solvents. Several solvents, such as methanol, ethyl acetate, chloroform, and n-hexane, were used to isolate the effective compound 2-(benzhydryl sulfinyl)-N-sec-butylacetamide) from the organic layer. UV-spectroscopy, FT-IR, 1H-NMR, and 13C-NMR were applied to identify the purified compound. The in vitro and in vivo assays demonstrated that the 2-(benzhydryl sulfinyl)-N-sec-butylacetamide) can increase the activity of the phagocytic cells, via the interaction with FcY receptors, along with trastuzumab, and the pathway can use a model for the therapeutic strategy for effective treatment of ovarian cancer cells.

Cell-penetrating peptides predictors: A comparative analysis of methods and datasets

Cell-Penetrating Peptides (CPP) are emerging as an alternative to small-molecule drugs to expand the range of biomolecules that can be targeted for therapeutic purposes. Due to the importance of identifying and designing new CPP, a great variety of predictors have been developed to achieve these goals. To establish a ranking for these predictors, a couple of recent studies compared their performances on specific datasets, yet their conclusions cannot determine if the ranking obtained is due to the model, the set of descriptors or the datasets used to test the predictors. We present a systematic study of the influence of the peptide sequence's similarity of the datasets on the predictors' performance. The analysis reveals that the datasets used for training have a stronger influence on the predictors performance than the model or descriptors employed. We show that datasets with low sequence similarity between the positive and negative examples can be easily separated, and the tested classifiers showed good performance on them. On the other hand, a dataset with high sequence similarity between CPP and non-CPP will be a hard dataset, and it should be the one to be used for assessing the performance of new predictors.

A zinc-modified Anemarrhena asphodeloides polysaccharide complex enhances immune activity via the NF-κB and MAPK signaling pathways

Anemarrhena asphodeloides polysaccharide (AAP70-1) was reported to have immunomodulatory effects in our previous report. To further improve the immunomodulatory effects of AAP70-1, an A. asphodeloides polysaccharide-zinc complex (AAP-Zn) was synthesized using a ZnCl2 modification method, and the potential mechanisms by which AAP-Zn activates macrophages were investigated. The results showed that the structural features of AAP-Zn were similar to those of AAP70-1 with a Zn content of 0.2 %, confirming that Zn mainly interacted with AAP70-1 by forming ZnO coordination bonds and Zn…OH bonds. In addition, the administration of AAP70-1 and AAP-Zn effectively improved the immunomodulatory effects by enhancing phagocytosis and upregulating the mRNA expression of cytokines (TNF-α, IL-6, IL-1β, and IL-18), as well as increasing the production levels of nitric oxide (NO) and reactive oxygen species (ROS) in zebrafish embryos. The intracellular mechanism by which AAP-Zn activates macrophages was found to involve activation of the NF-κB and MAPK signaling pathways. Our findings suggested that AAP-Zn may be a potential immunopotentiator in the field of biomedicine or functional foods.

Dectin-1 multimerization and signaling depends on fungal β-glucan structure and exposure

Dectin-1A is a C-type lectin innate immunoreceptor that recognizes β-(1,3;1,6)-glucan, a structural component of Candida species cell walls. β-Glucans can adopt solution structures ranging from random coil to insoluble fiber due to tertiary (helical) and quaternary structure. Fungal β-glucans of medium and high molecular weight are highly structured, but low molecular weight glucan is much less structured. Despite similar affinity for Dectin-1, the ability of glucans to induce Dectin-1A-mediated signaling correlates with degree of structure. Glucan denaturation experiments showed that glucan structure determines agonistic potential, but not receptor binding affinity. We explored the impact of glucan structure on molecular aggregation of Dectin-1A. Stimulation with glucan signaling decreased Dectin-1A diffusion coefficient. Fluorescence measurements provided direct evidence of ligation-induced Dectin-1A aggregation, which positively correlated with increasing glucan structure content. In contrast, Dectin-1A is predominantly in a low aggregation state in resting cells. Molecular aggregates formed during interaction with highly structured, agonistic glucans did not exceed relatively small (<15 nm) clusters of a few engaged receptors. Finally, we observed increased molecular aggregation of Dectin-1A at fungal particle contact sites in a manner that positively correlated with the degree of exposed glucan on the particle surface. These results indicate that Dectin-1A senses the solution conformation of β-glucans through their varying ability to drive receptor dimer/oligomer formation and activation of membrane proximal signaling events.

Phytocompounds and their molecular targets in immunomodulation: a review

Immune cells are important for the healthy function of every organ. The homeostasis of the immune system is selfregulated by T-cells, B-cells, and natural killer cells. The immunomodulation process of immune cells is part of the immunotherapy. According to therapeutic methods of immune responses are categorized as inducing (immunostimulant), amplification (immune booster), attenuation (immunomodulation), and prevention (immunosuppressive) actions. The prevalence of chronic immunological diseases like viral infections, allergies, and cancer is mainly due to the over-activation of the immune system. Further, immunomodulators are reported to manage the severity of chronic immunological disorders. Moreover, these immunomodulator-acting proteins are identified as potential molecular targets for the regulation of the immune system. Moreover, natural compound like phytocompounds are known to bind these targets and modulates the immune system. The specialized phytocompounds like curcumin, quercetin, stilbenes, flavonoids, and lignans are shown the immunomodulatory actions and ameliorate the immunological disorders. The present scenario of a COVID-19 pandemic situation has taught us the need to focus on strengthening the immune system and the development of the most promising immunotherapeutics. This review is focused on an overview of various phytocompounds and their molecular targets for the management of immunological disorders via immunosuppressants and immunostimulants actions.

The antioxidant activity of polysaccharides: A structure-function relationship overview

Over the last years, polysaccharides have been linked to antioxidant effects using both in vitro chemical and biological models. The reported structures, claimed to act as antioxidants, comprise chitosan, pectic polysaccharides, glucans, mannoproteins, alginates, fucoidans, and many others of all type of biological sources. The structural features linked to the antioxidant action include the polysaccharide charge, molecular weight, and the occurrence of non-carbohydrate substituents. The establishment of structure/function relationships can be, however, biased by secondary phenomena that tailor polysaccharides behavior in antioxidant systems. In this sense, this review confronts some basic concepts of polysaccharides chemistry with the current claim of carbohydrates as antioxidants. It critically discusses how the fine structure and properties of polysaccharides can define polysaccharides as antioxidants. Polysaccharides antioxidant action is highly dependent on their solubility, sugar ring structure, molecular weight, occurrence of positive or negatively charged groups, protein moieties and covalently linked phenolic compounds. However, the occurrence of phenolic compounds and protein as contaminants leads to misleading results in methodologies often used for screening and characterization purposes, as well as in vivo models. Despite falling in the concept of antioxidants, the role of polysaccharides must be well defined according with the matrices where they are involved.

Natural-Product-Derived Adjunctive Treatments to Conventional Therapy and Their Immunoregulatory Activities in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is an invasive and persistent subtype of breast cancer that is likely to be resistant to conventional treatments. The rise in immunotherapy has created new modalities to treat cancer, but due to high costs and unreliable efficacy, adjunctive and complementary treatments have sparked interest in enhancing the efficacy of currently available treatments. Natural products, which are bioactive compounds derived from natural sources, have historically been used to treat or ameliorate inflammatory diseases and symptoms. As TNBC patients have shown little to no response to immunotherapy, the potential of natural products as candidates for adjuvant immunotherapy is being explored, as well as their immunomodulatory effects on cancer. Due to the complexity of TNBC and the ever-changing tumor microenvironment, there are challenges in determining the feasibility of using natural products to enhance the efficacy or counteract the toxicity of conventional treatments. In view of technological advances in molecular docking, pharmaceutical networking, and new drug delivery systems, natural products show promise as potential candidates in adjunctive therapy. In this article, we summarize the mechanisms of action of selected natural-product-based bioactive compounds and analyze their roles and applications in combination treatments and immune regulation.

Targeting NF-κB pathway for the anti-inflammatory potential of Bhadradarvadi kashayam on stimulated RAW 264.7 macrophages

Macrophage-arbitrated inflammation is associated with the regulation of rheumatoid arthritis (RA). Low risk and better efficiency are steered herbal drugs more credible than conventional medicines in RA management. Bhadradarvadi (BDK) concoction has been traditionally used for rheumatism in Ayurveda. However, the mechanisms at the molecular level are still elusive. This study was designed to inspect the process of immunomodulation and anti-inflammatory properties of BDK in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages for the first time. BDK concoction was prepared and evaluated with the stimulated murine macrophage-like RAW 264.7 cell lines. TNF-α, IL6, and PGE2 were quantified by ELISA. The normalization of the fold change in the expression of the target gene mRNA was done by comparing the values of the β-actin housekeeping gene using the 2-ΔΔCt comparative cycle threshold. The expression of TNF-α, IL6, iNOS, and COX-2 in the RAW 264.7 macrophage cells was analyzed using flow cytometry. Our results showed that BDK (150-350 μl/ml) treatment significantly decreased the inflammatory cytokines (TNF-α, and IL-6) and inflammatory mediators (PGE2) in LPS-stimulated RAW 264.7 macrophage cells. The pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) expression, inflammatory enzymes (iNOS and COX-2), and NF-κBp65 were significantly downregulated at transcriptome level in LPS-stimulated RAW 264.7 macrophage cells. The flow cytometry analysis revealed that BDK treatment diminished the TNF-α, IL-6, iNOS, and COX-2 expression at the proteome level, as well as obstruction of NF-κB-p65 nuclear translocation was observed by immunofluorescence analysis in LPS-stimulated RAW 264.7 macrophage cells. Collectively, BDK can intensely augment the anti-inflammatory activities via inhibiting the NF-κB signaling pathway trigger for treating autoimmune disorders including RA.

Hyaluronic Acid Modified Metal Nanoparticles and Their Derived Substituents for Cancer Therapy: A Review

The use of metal nanoparticles (M-NPs) in cancer therapy has gained significant consideration owing to their exceptional physical and chemical features. However, due to the limitations, such as specificity and toxicity towards healthy cells, their application in clinical translations has been restricted. Hyaluronic acid (HA), a biocompatible and biodegradable polysaccharide, has been extensively used as a targeting moiety, due to its ability to selectively bind to the CD44 receptors overexpressed on cancer cells. The HA-modified M-NPs have demonstrated promising results in improving specificity and efficacy in cancer therapy. This review discusses the significance of nanotechnology, the state of cancers, and the functions of HA-modified M-NPs, and other substituents in cancer therapy applications. Additionally, the role of various types of selected noble and non-noble M-NPs used in cancer therapy are described, along with the mechanisms involved in cancer targeting. Additionally, the purpose of HA, its sources and production processes, as well as its chemical and biological properties are described. In-depth explanations are provided about the contemporary applications of HA-modified noble and non-noble M-NPs and other substituents in cancer therapy. Furthermore, potential obstacles in optimizing HA-modified M-NPs, in terms of clinical translations, are discussed, followed by a conclusion and future prospects.

Intrinsically Disordered Synthetic Polymers in Biomedical Applications

In biology and medicine, intrinsically disordered synthetic polymers bio-mimicking intrinsically disordered proteins, which lack stable three-dimensional structures, possess high structural/conformational flexibility. They are prone to self-organization and can be extremely useful in various biomedical applications. Among such applications, intrinsically disordered synthetic polymers can have potential usage in drug delivery, organ transplantation, artificial organ design, and immune compatibility. The designing of new syntheses and characterization mechanisms is currently required to provide the lacking intrinsically disordered synthetic polymers for biomedical applications bio-mimicked using intrinsically disordered proteins. Here, we present our strategies for designing intrinsically disordered synthetic polymers for biomedical applications based on bio-mimicking intrinsically disordered proteins.

Biopharmaceutical applications of microbial polysaccharides as materials: A review

Biological characteristics of natural polymers make microbial polysaccharides an excellent choice for biopharmaceuticals. Due to its easy purifying procedure and high production efficiency, it is capable of resolving the existing application issues associated with some plant and animal polysaccharides. Furthermore, microbial polysaccharides are recognized as prospective substitutes for these polysaccharides based on the search for eco-friendly chemicals. In this review, the microstructure and properties of microbial polysaccharides are utilized to highlight their characteristics and potential medical applications. From the standpoint of pathogenic processes, in-depth explanations are provided on the effects of microbial polysaccharides as active ingredients in the treatment of human diseases, anti-aging, and drug delivery. In addition, the scholarly developments and commercial applications of microbial polysaccharides as medical raw materials are also discussed. The conclusion is that understanding the use of microbial polysaccharides in biopharmaceuticals is essential for the future development of pharmacology and therapeutic medicine.

The Antiviral Compound PSP Inhibits HIV-1 Entry via PKR-Dependent Activation in Monocytic Cells

Actin depolymerization factor (ADF) cofilin-1 is a key cytoskeleton component that serves to lessen cortical actin. HIV-1 manipulates cofilin-1 regulation as a pre- and post-entry requisite. Disruption of ADF signaling is associated with denial of entry. The unfolded protein response (UPR) marker Inositol-Requiring Enzyme-1α (IRE1α) and interferon-induced protein (IFN-IP) double-stranded RNA- activated protein kinase (PKR) are reported to overlap with actin components. In our published findings, Coriolus versicolor bioactive extract polysaccharide peptide (PSP) has demonstrated anti-HIV replicative properties in THP1 monocytic cells. However, its involvement towards viral infectivity has not been elucidated before. In the present study, we examined the roles of PKR and IRE1α in cofilin-1 phosphorylation and its HIV-1 restrictive roles in THP1. HIV-1 p24 antigen was measured through infected supernatant to determine PSP's restrictive potential. Quantitative proteomics was performed to analyze cytoskeletal and UPR regulators. PKR, IRE1α, and cofilin-1 biomarkers were measured through immunoblots. Validation of key proteome markers was done through RT-qPCR. PKR/IRE1α inhibitors were used to validate viral entry and cofilin-1 phosphorylation through Western blots. Our findings show that PSP treatment before infection leads to an overall lower infectivity. Additionally, PKR and IRE1α show to be key regulators in cofilin-1 phosphorylation and viral restriction.

The mycelium of the Trametes versicolor synn. Coriolus versicolor (Turkey tail mushroom) exhibit anti-melanoma activity in vitro

Melanoma is one of the most aggressive forms of skin cancer and is characterized by high metastatic potential. Despite improvements in early diagnosis and treatment, the mortality rate among metastatic melanoma patients continues to represent a significant clinical challenge. Therefore, it is imperative that we search for new forms of treatment. Trametes versicolor is a mushroom commonly used in Chinese traditional medicine due to its numerous beneficial properties. In the present work, we demonstrate T. versicolor fruiting body and mycelium ethanol extracts exhibit potent cytotoxic activity towards A375 (IC₅₀ = 663.3 and 114.5 µg/mL respectively) and SK-MEL-5 (IC₅₀ = 358.4 and 88.6 µg/mL respectively) human melanoma cell lines. Further studies revealed that T. versicolor mycelium extract induced apoptotic cell death and poly (ADP-ribose) polymerase cleavage, upregulated the expression of autophagy-associated marker LC3-II, increased the presentation of major histocompatibility complex II and expression of programmed death-ligand receptor, and inhibited cell migration in SK-MEL-5 cells. Therefore, our present findings highlight the therapeutic potential of T. versicolor mycelium extract for the treatment of melanoma and merit further study.

The Roles of Polysaccharides in Carp Farming: A Review

Carp is an important aquaculture species globally, and the production is expected to increase with the growing market demands. Despite that, disease outbreaks remain a major challenge, impeding the development of sustainable carp farming. Moreover, the application of antibiotics, a common prophylactic agent, can adversely impact public health and the environment. Therefore, polysaccharide has been recognized as a novel prophylactic agent in the health management of carp farming, as well as gaining consumers' confidence in carp farming products. In this review, the definition, sources, and main roles of polysaccharides in improving growth performance, stimulating the immune system, enhancing disease resistance, and alleviating abiotic stresses in carp farming are discussed and summarized. In addition, the use of polysaccharides in combination with other prophylactic agents to improve carp farming production is also highlighted. This review aims to highlight the roles of polysaccharides and provide valuable information on the benefits of polysaccharides in carp farming.

Rich d-Fructose-Containing Polysaccharide Isolated from Myxopyrum smilacifolium Roots toward a Superior Antioxidant Biomaterial

The presented study attempts to unveil and evaluate the antioxidant activity of a novel heteropolysaccharide separated from the roots of Myxopyrum smilacifolium (denoted as PS-MSR). The molecular weight of PS-MSR is found to be 1.88 × 10⁴ Da and contains two principal sugars, which are d-glucose and d-fructose, in the backbone. Decoding the structure of the obtained PS-MSR sample has disclosed a novel polysaccharide for the first time. Indeed, the PS-MSR is composed of (1 → 3)-linked glucosyl units and (2 → 3)-linked fructosyl units. In addition, the 1D and 2D NMR spectra of the PS-MSR sample display the repeating unit of the isolated polysaccharide, [→3)-α-d-Glcp-(1 → 3)-β-d-Frucf-(2 → 3)-β-d-Frucf-2 → 3)-)-β-d-Frucf-β-(2→] _n . Interestingly, the PS-MSR sample exhibits outstanding antioxidant activity, signifying the potential utilization of the explored polysaccharide for antioxidant-based material.

Immunomodulatory Effects of an Aqueous Extract of Black Radish on Mouse Macrophages via the TLR2/4-Mediated Signaling Pathway

Here, we determined the immunostimulatory effects of black radish (Raphanus sativus ver niger) hot water extract (BRHE) on a mouse macrophage cell line (RAW 264.7) and mouse peritoneal macrophages. We found that BRHE treatment increased cell proliferation, phagocytic activity, nitric oxide (NO) levels, cytokine production, and reactive oxygen species synthesis. Moreover, BRHE increased the expression of the following immunomodulators in RAW 264.7 cells and peritoneal macrophages: pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), iNOS, and COX-2. BRHE treatment significantly up-regulated the phosphorylation of components of the mitogen-activated protein kinase (MAPK), nuclear factor-κB (NF-κB), Akt, and STAT3 signaling pathways. Further, the effects of BRHE on macrophages were significantly diminished after the cells were treated with the TLR2 antagonist C29 or the TLR4 antagonist TAK-242. Therefore, BRHE-induced immunostimulatory phenotypes in mouse macrophages were reversed by multiple inhibitors, such as TLR antagonist, MAPK inhibitor, and Akt inhibitor indicating that BRHE induced macrophage activation through the TLR2/4-MAPK-NFκB-Akt-STAT3 signaling pathway. These results indicate that BRHE may serve as a potential immunomodulatory factor or functional food and provide the scientific basis for the comprehensive utilization and evaluation of black radish in future applications.

Microbial polysaccharides: An emerging family of natural biomaterials for cancer therapy and diagnostics

Microbial polysaccharides (MPs) offer immense diversity in structural and functional properties. They are extensively used in advance biomedical science owing to their superior biodegradability, hemocompatibility, and capability to imitate the natural extracellular matrix microenvironment. Ease in tailoring, inherent bio-activity, distinct mucoadhesiveness, ability to absorb hydrophobic drugs, and plentiful availability of MPs make them prolific green biomaterials to overcome the significant constraints of cancer chemotherapeutics. Many studies have demonstrated their application to obstruct tumor development and extend survival through immune activation, apoptosis induction, and cell cycle arrest by MPs. Synoptic investigations of MPs are compulsory to decode applied basics in recent inclinations towards cancer regimens. The current review focuses on the anticancer properties of commercially available and newly explored MPs, and outlines their direct and indirect mode of action. The review also highlights cutting-edge MPs-based drug delivery systems to augment the specificity and efficiency of available chemotherapeutics, as well as their emerging role in theranostics.

Dietary Polysaccharides as Modulators of the Gut Microbiota Ecosystem: An Update on Their Impact on Health

A polysaccharide is a macromolecule composed of more than ten monosaccharides with a wide distribution and high structural diversity and complexity in nature. Certain polysaccharides are immunomodulators and play key roles in the regulation of immune responses during the progression of some diseases. In addition to stimulating the growth of certain intestinal bacteria, polysaccharides may also promote health benefits by modulating the gut microbiota. In the last years, studies about the triad gut microbiota–polysaccharides–health have increased exponentially. In consequence, in the present review, we aim to summarize recent knowledge about the function of dietary polysaccharides on gut microbiota composition and how these effects affect host health.

Elderberry (Sambucus nigra L.) extracts promote anti-inflammatory and cellular antioxidant activity

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Extracts of Sambucus nigra berries have anti-inflammatory and antioxidant effects.

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Elderberries prevented the oxidative damage induced by tert-butyl-hydroperoxide.

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Elderberries protect HepG2 and Caco-2 cells from t-BOOH-induced oxidative stress.

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Elderberry extracts prevented GSH depletion, ROS production, and DNA fragmentation.

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Elderberries can be considered a functional food or a sources of nutraceuticals.

Despite the high value of Portuguese elderberries, recognized for decades by European markets, only a few studies address their beneficial effects at cellular level. Aiming to explore the anti-inflammatory and the cellular antioxidant potential characterized extracts from the three main Portuguese elderberry cultivars (Sabugueiro, Sabugueira, Bastardeira) were used. Lipopolysaccharide-stimulated RAW 264.7 cells pre-exposed to elderberry extracts exhibited dose-dependent inhibition of nitric oxide release, evidencing anti-inflammatory activity. Concerning cellular antioxidant protection, HepG2 and Caco-2 cells pre-exposure to elderberry extracts (50 µg/mL) prevented up-to 90 % of tert-butyl hydroperoxide (t-BOOH)-induced toxicity. In Caco-2 cells, elderberry extracts prevented glutathione depletion, reactive oxygen species production, abnormal morphological changes and DNA fragmentation, in response to t-BOOH oxidative insult. Results demonstrated that elderberries have high potential in reducing cellular oxidative stress as well as in preventing inflammatory processes. Thus, elderberries have high potential as health promoters, acting as functional foods or as sources of nutraceuticals.

Immunoceuticals: Harnessing Their Immunomodulatory Potential to Promote Health and Wellness

Knowledge that certain nutraceuticals can modulate the immune system is not new. These naturally occurring compounds are known as immunoceuticals, which is a novel term that refers to products and systems that naturally improve an individual’s immuno-competence. Examples of immunoceuticals include vitamin D3, mushroom glycans, flavonols, quercetin, omega-3 fatty acids, carotenoids, and micronutrients (e.g., zinc and selenium), to name a few. The immune system is a complex and highly intricate system comprising molecules, cells, tissues, and organs that are regulated by many different genetic and environmental factors. There are instances, such as pathological conditions, in which a normal immune response is suboptimal or inappropriate and thus augmentation or tuning of the immune response by immunoceuticals may be desired. With infectious diseases, cancers, autoimmune disorders, inflammatory conditions, and allergies on the rise in both humans and animals, the importance of the use of immunoceuticals to prevent, treat, or augment the treatment of these conditions is becoming more evident as a natural and often economical approach to support wellness. The global nutraceuticals market, which includes immunoceuticals, is a multi-billion-dollar industry, with a market size value of USD 454.55 billion in 2021, which is expected to reach USD 991.09 billion by 2030. This review will provide an overview of the immune system, the importance of immunomodulation, and defining and testing for immunocompetence, followed by a discussion of several key immunoceuticals with clinically proven and evidence-based immunomodulatory properties.

Effectiveness of immunization with multi-component bacterial immunomodulator in foals at 35th day of life

The aim of the study was to investigate the mechanisms leading to immunization through the use of a multicomponent bacterial immunomodulator and to find out the relationship between the TLR 4 receptor with selected parameters of innate immunity and to acquire immunity. The study was conducted on 18 Polish Pony Horses foals divided into two study groups: control (n = 9) and experimental (n = 9). Foals from the experimental group received intramuscular duplicate injection of 5 ml of multi-component bacterial immunomodular at 35 and 40 days of age. RNA isolated from venous blood was used to evaluate the expression of TLR4 genes using RT-PCR. Concentration of Il-6, IL-10, IgM and IgG2 was determined by the ELISA method in blood plasma. Immunostimulation had a significant impact on the level of genes expression for TLR4 expression and IL-6 concentration. No effect of stimulation on IgM and IgG2 concentrations was found. The expression of TLR4 genes as well as the levels of interleukins could be modulated by stimulation with a pharmacological agent multi-component bacterial immunomodulator. The experiment demonstrated a strong positive correlation between TLR4 gene expression and IL-6 concentration and between TLR4 gene expression and IgM concentration.

Synthesis of bioactive (1→6)-β-glucose branched poly-amido-saccharides that stimulate and induce M1 polarization in macrophages

β-Glucans are of significant interest due to their potent antitumor and immunomodulatory activities. Nevertheless, the difficulty in purification, structural heterogenicity, and limited solubility impede the development of structure-property relationships and translation to therapeutic applications. Here, we report the synthesis of a new class of (1→6)-β-glucose-branched poly-amido-saccharides (PASs) as β-glucan mimetics by ring-opening polymerization of a gentiobiose-based disaccharide β-lactam and its copolymerization with a glucose-based β-lactam, followed by post-polymerization deprotection. The molecular weight (Mn) and frequency of branching (FB) of PASs is readily tuned by adjusting monomer-to-initiator ratio and mole fraction of gentiobiose-lactam in copolymerization. Branched PASs stimulate mouse macrophages, and enhance production of pro-inflammatory cytokines in a FB-, dose-, and Mn-dependent manner. The stimulation proceeds via the activation of NF-κB/AP-1 pathway in a Dectin-1-dependent manner, similar to natural β-glucans. The lead PAS significantly polarizes primary human macrophages towards M1 phenotype compared to other β-glucans such as lentinan, laminarin, and curdlan.

Low molecular-weight polyguluronate phosphate: An immunostimulant by activating splenocyte/macrophage invitro and improving immune response invivo

The substituents and backbones are two main factors affecting immune activities of polysaccharides. In the present study, we firstly evaluated the immunostimulating effects of phosphorylated, sulfated, H-phosphonated and nitrated derivatives of low-molecular-weight polymannuronate (LPM) and polyguluronate (LPG) on splenocytes and peritoneal macrophages in vitro. The results showed that the phosphate group was the best substituent to enhance the immune activities, and LPG phosphate (LPGP) had much better activity than LPM phosphate (LPMP). Further studies showed that LPGP not only promoted the proliferation of mouse splenocytes in the presence of either LPS or Con A, but also acted as an excellent peritoneal macrophage activator to enhance the cell phagocytosis, energy metabolism, cytokines release and activities of intracellular enzymes. The studies in RAW264.7 cells revealed that LPGP activated the TBK1-IκBα-NF-κB and the TBK1-IRF3 pathway. Moreover, LPGP rescued the immune response in the Cyclophosphamide-treated mice in vivo. In conclusion, LPGP is a potential alginate-based biological response modifier (BRM).

Immunoenhancement Effects of the Herbal Formula Hemomine on Cyclophosphamide-Induced Immunosuppression in Mice

Hemomine is an herbal blend comprising Angelicae Gigantis Radix and other herbs known to have immunomodulatory effects. We examined the immunopotentiating effect of this herbal blend on cyclophosphamide (CPA)-induced immunosuppression. Male mice were assigned to one of six groups: the intact control and five CPA treatment groups (one control, one reference (β-glucan), and three with the application of hemomine at different concentrations; 4, 2, or 1 mL/kg; n = 10 per group). Mice were injected with CPA to induce myelosuppression and immunosuppression, after which they received one of the experimental treatments. In immunosuppressed mice, hemomine treatment alleviated the noticeable reductions in body, spleen, and submandibular lymph node weights caused by CPA; caused changes in hematological markers; induced the reduced levels of serum IFN-γ and spleen TNF-α, IL-1β, and IL-10 by CPA; improved natural killer cell activities in the spleen and peritoneal cavity; and also improved lymphoid organ atrophy in a dose-dependent manner. We demonstrate that hemomine, a mixture of six immunomodulatory herbs, is an effective immunomodulatory agent, with the potential to enhance immunity.

Clarification of the structural features of Rhamnogalacturonan-I type polysaccharide purified from radish leaves

Determining the structure of REPI, an immunostimulatory polysaccharide fraction from radish leaves, is an important health objective. Herein, we show that REP-I contains nine different monosaccharides, including GalA (22.2%), Gal (32.6%), Ara (27.5%), and Rha (10.2%) as main sugars. REP-I was also reacted with β-glucosyl Yariv reagent (29.8%), suggesting the presence of the arabino-β-3,6-galactan. Furthermore, methylated-product analysis revealed that REP-I contains 13 different glycosyl linkages, including 4-linked GalpA (21.0%), 2,4-linked Rhap (7.0%), 4-linked Galp (5.8%), 5-linked Araf (10.1%), and 3,6-linked Galp (7.9%), which are characteristic of RG-I. Microstructural information was obtained by sequential degradation using four linkage-specific glycosylases and β-elimination, with fragments analyzed on the basis of sugar composition, methylation, and MS/MS spectra. The results show that the immunostimulatory activity of REP-I is possibly due to the structure of RG-I, which is composed of a main chain with repeating [→2)-Rhap-(1 → 4)-GalpA-(1→] linkage units and three side-chains: a branched α(1 → 5)arabinan, a β(1 → 4)galactan, and arabino-β-3,6-galactan, which are branched at the C(O)4 position of each Rha residue in the REP-I main chain.

Next-generation probiotics - do they open new therapeutic strategies for cancer patients?

Gut microbiota and its association with cancer development/treatment has been intensively studied during the past several years. Currently, there is a growing interest toward next-generation probiotics (NGPs) as therapeutic agents that alter gut microbiota and impact on cancer development. In the present review we focus on three emerging NGPs, namely Faecalibacterium prausnitzii, Akkermansia muciniphila, and Bacteroides fragilis as their presence in the digestive tract can have an impact on cancer incidence. These NGPs enhance gastrointestinal immunity, maintain intestinal barrier integrity, produce beneficial metabolites, act against pathogens, improve immunotherapy efficacy, and reduce complications associated with chemotherapy and radiotherapy. Notably, the use of NGPs in cancer patients does not have a long history and, although their safety remains relatively undefined, recently published data has shown that they are non-toxigenic. Notwithstanding, A. muciniphila may promote colitis whereas enterotoxigenic B. fragilis stimulates chronic inflammation and participates in colorectal carcinogenesis. Nevertheless, the majority of B. fragilis strains provide a beneficial effect to the host, are non-toxigenic and considered as the best current NGP candidate. Overall, emerging studies indicate a beneficial role of these NGPs in the prevention of carcinogenesis and open new promising therapeutic options for cancer patients.

Immunomodulatory activity of β-glucan polysaccharides isolated from different species of mushroom - A potential treatment for inflammatory lung conditions

Acute respiratory distress syndrome (ARDS) is the most common form of acute severe hypoxemic respiratory failure in the critically ill with a hospital mortality of 40%. Alveolar inflammation is one of the hallmarks for this disease. β-Glucans are polysaccharides isolated from a variety of natural sources including mushrooms, with documented immune modulating properties. To investigate the immunomodulatory activity of β-glucans and their potential as a treatment for ARDS, we isolated and measured glucan-rich polysaccharides from seven species of mushrooms. We used three models of in-vitro injury in THP-1 macrophages, Peripheral blood mononuclear cells (CD14+) (PMBCs) isolated from healthy volunteers and lung epithelial cell lines. We observed variance between β-glucan content in extracts isolated from seven mushroom species. The extracts with the highest β-glucan content found was Lentinus edodes which contained 70% w/w and Hypsizygus tessellatus which contained 80% w/w with low levels of α-glucan. The extracts had the ability to induce secretion of up to 4000 pg/mL of the inflammatory cytokine IL-6, and up to 5000 pg/mL and 500 pg/mL of the anti-inflammatory cytokines IL-22 and IL-10, respectively, at a concentration of 1 mg/mL in THP-1 macrophages. In the presence of cytokine injury, IL-8 was reduced from 15,000 pg/mL to as low as 10,000 pg/mL in THP-1 macrophages. After insult with LPS, phagocytosis dropped from 70-90% to as low 10% in CD14+ PBMCs. After LPS insult CCL8 relative gene expression was reduced, and IL-10 relative gene expression increased from 50 to 250-fold in THP-1 macrophages. In lung epithelial cells, both A549 and BEAS-2B after IL-1β insult, IL-8 levels dropped from 10,000 pg/mL to as low as 6000 pg/mL. TNF-α levels dropped 10-fold from 100 pg/mL to just below 10 pg/mL. These results demonstrate the therapeutic potential of β-glucans in inflammatory lung conditions. Findings also advance bio-based research that connects green innovation with One Health applications for the betterment of society.

Polysaccharide hydrogels: Functionalization, construction and served as scaffold for tissue engineering

Polysaccharide hydrogels have been widely utilized in tissue engineering. They interact with the organismal environments, modulating the cargos release and realizing of long-term survival and activations of living cells. In this review, the potential strategies for modification of polysaccharides were introduced firstly. It is not only used to functionalize the polysaccharides for the consequent formation of hydrogels, but also used to introduce versatile side groups for the regulation of cell behavior. Then, techniques and underlying mechanisms in inducing the formation of hydrogels by polysaccharides or their derivatives are briefly summarized. Finally, the applications of polysaccharide hydrogels in vivo, mainly focus on the performance for alleviation of foreign-body response (FBR) and as cell scaffolds for tissue regeneration, are exemplified. In addition, the perspectives and challenges for further research are addressed. It aims to provide a comprehensive framework about the potentials and challenges that the polysaccharide hydrogels confronting in tissue engineering.

Exopolysaccharides Produced by Lactic Acid Bacteria: From Biosynthesis to Health-Promoting Properties

The production of exopolysaccharides (EPS) by lactic acid bacteria (LAB) has attracted particular interest in the food industry. EPS can be considered as natural biothickeners as they are produced in situ by LAB and improve the rheological properties of fermented foods. Moreover, much research has been conducted on the beneficial effects of EPS produced by LAB on modulating the gut microbiome and promoting health. The EPS, which varies widely in composition and structure, may have diverse health effects, such as glycemic control, calcium and magnesium absorption, cholesterol-lowering, anticarcinogenic, immunomodulatory, and antioxidant effects. In this article, the latest advances on structure, biosynthesis, and physicochemical properties of LAB-derived EPS are described in detail. This is followed by a summary of up-to-date methods used to detect, characterize and elucidate the structure of EPS produced by LAB. In addition, current strategies on the use of LAB-produced EPS in food products have been discussed, focusing on beneficial applications in dairy products, gluten-free bakery products, and low-fat meat products, as they positively influence the consistency, stability, and quality of the final product. Highlighting is also placed on reports of health-promoting effects, with particular emphasis on prebiotic, immunomodulatory, antioxidant, cholesterol-lowering, anti-biofilm, antimicrobial, anticancer, and drug-delivery activities.

Yeast β-Glucan Altered Intestinal Microbiome and Metabolome in Older Hens

The prebiotics- and probiotics-mediated positive modulation of the gut microbiota composition is considered a useful approach to improve gut health and food safety in chickens. This study explored the effects of yeast β-glucan (YG) supplementation on intestinal microbiome and metabolites profiles as well as mucosal immunity in older hens. A total of 256 43-week-old hens were randomly assigned to two treatments, with 0 and 200 mg/kg of YG. Results revealed YG-induced downregulation of toll-like receptors (TLRs) and cytokine gene expression in the ileum without any effect on the intestinal barrier. 16S rRNA analysis claimed that YG altered α- and β-diversity and enriched the relative abundance of class Bacilli, orders Lactobacillales and Enterobacteriales, families Lactobacillaceae and Enterobacteriaceae, genera Lactobacillus and Escherichia–Shigella, and species uncultured bacterium-Lactobacillus. Significant downregulation of cutin and suberin, wax biosynthesis, atrazine degradation, vitamin B6 metabolism, phosphotransferase system (PTS), steroid degradation, biosynthesis of unsaturated fatty acids, aminobenzoate degradation and quorum sensing and upregulation of ascorbate and aldarate metabolism, C5-branched dibasic acid metabolism, glyoxylate and dicarboxylate metabolism, pentose and glucuronate interconversions, steroid biosynthesis, carotenoid biosynthesis, porphyrin and chlorophyll metabolism, sesquiterpenoid and triterpenoid biosynthesis, lysine degradation, and ubiquinone and other terpenoid-quinone biosyntheses were observed in YG-treated hens, as substantiated by the findings of untargeted metabolomics analysis. Overall, YG manifests prebiotic properties by altering gut microbiome and metabolite profiles and can downregulate the intestinal mucosal immune response of breeder hens.

β-Glucans Could Be Adjuvants for SARS-CoV-2 Virus Vaccines (COVID-19)

Waiting for an effective treatment against the SARS-CoV-2 virus (the cause of COVID-19), the current alternatives include prevention and the use of vaccines. At the moment, vaccination is the most effective strategy in the fight against pandemic. Vaccines can be administered with different natural biological products (adjuvants) with immunomodulating properties. Adjuvants can be taken orally, complementing vaccine action. Adjuvant compounds could play a key role in alleviating the symptoms of the disease, as well as in enhancing vaccine action. Adjuvants also contribute to an effective immune response and can enhance the protective effect of vaccines in immunocompromised individuals such as the elderly. Adjuvants must not produce adverse effects, toxicity, or any other symptoms that could alter immune system function. Vaccine adjuvants are substances of wide varying chemical structure that are used to boost the immune response against a simultaneously administered antigen. Glucans could work as adjuvants due to their immunomodulatory biological activity. In this respect, β-(1,3)-(1,6) glucans are considered the most effective and safe according to the list issued by the European Commission. Only glucans with a β-(1,3) bond linked to a β-(1,6) are considered modulators of certain biological responses. The aim of this review is to present the possible effects of β-glucans as adjuvants in the efficacy of vaccines against SARS-CoV-2 virus.

Structural Elucidation and Immunostimulatory Activities of Quinoa Non-starch Polysaccharide Before and After Deproteinization

Non-starch polysaccharides derived from natural resources play a significant role in the field of food science and human health due to their extensive distribution in nature and less toxicity. In this order, the immunostimulatory activity of a non-starch polysaccharide (CQNP) from Chenopodium quinoa was examined before and after deproteination in murine macrophage RAW 264.7 cells. The chemical composition of CQNP and deproteinated-CQNP (D-CQNP) were spectrometrically analysed that revealed the presence of carbohydrate (22.7 ± 0.8% and 39.5 ± 0.8%), protein (41.4 ± 0.5% and 20.8 ± 0.5%) and uronic acid (8.7 ± 0.3% and 6.7 ± 0.2%). The monosaccharide composition results exposed that CQNP possesses a high amount of arabinose (34.5 ± 0.3) followed by galactose (26.5 ± 0.2), glucose (21.9 ± 0.3), rhamnose (7.0 ± 0.1), mannose (6.0 ± 0.1) and xylose (4.2 ± 0.2). However, after deproteination, a difference was found in the order of the monosaccharide components, with galactose (41.1 ± 0.5) as a major unit followed by arabinose (34.7 ± 0.5), rhamnose (10.9 ± 0.2), glucose (6.6 ± 0.2), mannose (3.4 ± 0.2) and xylose (3.2 ± 0.2). Further, D-CQNP potentially stimulate the RAW 264.7 cells through the production of nitric oxide (NO), upregulating inducible nitric oxide synthase (iNOS) and various pro-inflammatory cytokines including interleukin (IL)-1β, IL-6, IL-10, and tumor necrosis factor-alpha (TNF-α). Moreover, stimulation of RAW 264.7 cells by D-CQNP takes place along the NF-κB and the MAPKs signaling pathways through the expression of cluster of differentiation 40 (CD40). This results demonstrate that RAW 264.7 cells are effectively stimulated after removal of the protein content in C. quinoa non-starch polysaccharides, which could be useful for develop a new immunostimulant agent.

The succinoglycan riclin restores beta cell function through the regulation of macrophages on Th1 and Th2 differentiation in type 1 diabetic mice

Bacterial succinoglycan is found suitable as a viscosifying and emulsifying agent in the food industry. Riclin is a de-succinyl succinoglycan from an Agrobacterium isolate. Our previous study has revealed that riclin exerts special anti-inflammatory effects in vitro and in vivo. This study aims to determine the effects of riclin on preventing against immunological injury of beta cells in a type 1 diabetic model. We found that orally riclin effectively restores beta-cell function and improves the complications of streptozotocin (STZ)-induced diabetes. Riclin also reduces STZ-induced liver and kidney damage, and balances the inappropriate ratio of T helper type 1 cell (Th1)/type 2 cell (Th2) in the spleen and pancreatic draining lymph nodes of the STZ-induced diabetic mice. In a co-culture system with the islet β cell MIN6 and macrophage RAW 264.7, riclin reduces the levels of IFN-γ and IL-1β, protecting against STZ-caused MIN6 cell injury. We identified that riclin specifically binds to the membrane of macrophages and regulates the ratio of IL-10 and IL-12, thereby inhibiting the macrophage-mediated polarization of Th1 cells and promoting the differentiation of Th2 cells, which depends on the dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) receptor. Moreover, orally riclin significantly decreases the incidence of STZ-induced hyperglycemia (7.1% in riclin vs. 92.9% in STZ), and prevents autoimmune diabetes in non-obese diabetic (NOD) mice, with 87.5% of mice free of diabetes compared to 46.6% of the control mice. These results suggest that riclin has potential to be a functional food to prevent and improve autoimmune diabetes and related diseases.