Immunomodulatory Effects of a Low-Molecular Weight Polysaccharide from Enteromorpha prolifera on RAW 264.7 Macrophages and Cyclophosphamide- Induced Immunosuppression Mouse Models

Polysaccharides of Floccularia luteovirens regulate intestinal immune response, and oxidative stress activity through MAPK/Nrf2/Keap1 signaling pathway in immunosuppressive mice

This study explores the novel immunomodulatory effects of polysaccharides from the rare Floccularia luteovirens, a fungus with significant potential yet unexplored bioactive components, traditionally used in Tibetan medicine. This study employs a wide array of analytical techniques, including HPGPC, HPLC, western blotting, ELISA, and 16S rRNA gene sequencing, to comprehensively investigate FLP1's effects. The main structure of FLP1 was characterized by IF-TR and NMR spectrometry. The structural backbone of FLP1 was →3,6)-β-D-Glcp-(1 → and →2,3)-α-D-Manp-(1→. After immunosuppressed mice treated with FLP1, the findings demonstrated that FLP1 stimulated the production of secretory sIgA and secretion of cytokines (IL-4, TNF-α, and IFN-γ) in the intestine of Cy-treated mice, resulting in the activation of the MAPK pathway. Additionally, FLP1 protected oxidative stress by triggering Nrf2/Keap1 pathways and antioxidation enzymes (SOD, MDA, T-AOC, CAT, and GSH-Px). It also enhanced the intestinal barrier function by regulating the villous height ratio and expression of tight-junction protein. Furthermore, FLP1 remarkably reversed the gut microbiota dysbiosis in immunosuppressed mice by increasing the abundance of Oscilliospiraceae, and Lachnospiraceae, and altered the fecal metabolites by increasing LysoPE (0:0/18:0); 0:0/16:0; 18:1(11Z)/0:0, LysoPG (16:0/0:0), LysoPG 18:1 (2n) PE (14:0/20:1), echinenone, 2-(2-Nitroimidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl) acetamide, and suberic acid which is closely related to the immunity function. These results suggested that FLP1 may regulate the intestinal immune response by modulating the gut microbiota and fecal metabolites in immunosuppressed mice thereby activating the immune system.

Effect of Enteromorpha polysaccharides on gut-lung axis in mice infected with H5N1 influenza virus

Enteromorpha polysaccharides (EPPs) have been reported to have antiviral and anti-inflammatory properties. To explore the effect of EPPs on H5N1-infected mice, mice were pretreated with EPPs before being infected with the H5N1 influenza virus intranasally. H5N1 infection resulted in body-weight loss, pulmonary and intestinal damage, and an imbalance of gut microbiota in mice. As a result of the inclusion of EPPs, the body weight of mice recovered and pathological damage to the lung and intestine was reduced. EPPs also diminished inflammation by drastically lowering the expression of proinflammatory cytokines in lungs and intestines. H5N1 infection reduced bacterial diversity, and the abundance of pathogenic bacteria such as Desulfovibrio increased. However, the beneficial bacteria Alistipes rebounded in the groups which received EPPs before the infection. The modulation of the gut-lung axis may be related to the mechanism of EPPs in antiviral and anti-inflammatory responses. EPPs have shown potential in protecting the host from the influenza A virus infection.

Ganoderic acid C2 exerts the pharmacological effects against cyclophosphamide-induced immunosuppression: a study involving molecular docking and experimental validation

Triterpenoids, as the main active ingredient of Ganoderma lucidum fermented extract, exert multiple pharmacological activities, including immunomodulatory properties. Our study aimed to reveal the pharmacological effects and potential mechanisms of Ganoderic acid C2 (GAC) against cyclophosphamide (CY)-associated immunosuppression. Target genes were collected from several public databases, including the DisGeNET, Comparative Toxicogenomics Database, GeneCards, and PharmMapper. STRING database was used to construct the protein-protein interaction of network. Subsequently, molecular docking was carried out to visualize the protein-GAC interactions. Experimental validations, including ELISA and qRT-PCR were performed to confirm the pharmacological activities of GAC on CY-induced immunosuppression model. A total of 56 GAC-related targets were identified to be closely associated with CY-induced immunosuppression. Enrichment analyses results revealed that these targets were mainly involved in immune and inflammatory response-related pathways. STAT3 and TNF were identified as the core targets of GAC. Molecular docking indicated that GAC combined well with STAT3 and TNF protein. In addition, animal experiments indicated that GAC improved immunity as well as STAT3 and TNF genes expression in CY-induced immunosuppression, which further verified the prediction through bioinformatics analysis and molecular docking. We successfully revealed the potential therapeutics mechanisms underlying the effect of GAC against CY-induced immunosuppression based on the combination of bioinformatics analysis, molecular docking, and animal experiments. Our findings lay a theoretical foundation for the in-depth development and utilization of Ganoderma lucidum fermentation product in the future, and also provide theoretical guidance for the development of innovative drugs that assist in improving immunity.

Immunomodulatory Effects of Microcin C7 in Cyclophosphamide-Induced Immunosuppressed Mice

Microcin C7 (McC) as a viable immunomodulator peptide can be a potential solution for pathogenic microbial infection in the post-antibiotic era and has gained substantial attention. This study was designed to evaluate the immunomodulatory activity of Microcin C7 in a cyclophosphamide (CTX)-induced immunodeficient mouse model. We show that Microcin C7 treatment significantly alleviated the CTX-caused body weight loss, improved the feed and water consumption to improve the state of the mice, and elevated the absolute number and proportion of peripheral blood lymphocytes as well as the level of hemoglobulin. We further aim to characterize the phenotypes of the immune function and intestinal health profiles. The results demonstrate that Microcin C7 treatment increased serum levels of immunoglobulin A (IgA), IgG, interleukin 6, and hemolysin, promoted splenic lymphocyte proliferation induced by concanavalin A and LPS, and enhanced the phagocytosis of peritoneal macrophages immunized by sheep red blood cells. Additionally, Microcin C7 treatment decreased levels of diamine oxidase and d-lactate, ameliorated CTX-induced intestinal morphological damage, and increased the levels of zonula occluden 1, occludin, claudin-1, mucin 2, and secretary IgA in the jejunum and colon. Moreover, Microcin C7 administration is sufficient to reverse CTX-induced intestinal microbiota dysbiosis by increasing the number of Lactobacillus and Bifidobacterium, decreasing the number of Escherichia coli in colonic contents. Collectively, our results demonstrate that Microcin C7 may have protective and immunomodulatory functions and could be a potential candidate used in animal feed, functional foods, and immunological regimens..

Regulatory Effects Mediated by Enteromorpha prolifera Polysaccharide and Its Zn(II) Complex on Hypoglycemic Activity in High-Sugar High-Fat Diet-Fed Mice

In order to investigate and develop functional foods of marine origin with hypoglycemic activity, Enteromorpha prolifera polysaccharide-Zn(II) (EZ) complex was first prepared by marine resourced E. prolifera polysaccharide (EP) and ZnSO4 and their anti-diabetes activities against high-sugar and high-fat-induced diabetic mice were evaluated. The detailed structural characterization of EZ was elucidated by UV-Vis spectroscopy, infrared spectroscopy, and monosaccharide composition determination. The pharmacological research suggests that EZ has a potent hypoglycemic effect on high-sugar and high-fat-induced diabetic mice by inhibiting insulin resistance, improving dyslipidemia, decreasing inflammatory status, repairing pancreas damage, as well as activating the IRS/PI3K/AKT signaling pathway and regulating GLUT2 gene expression. At the same time, microbiota analysis indicates that a high dose of EZ could enhance the abundance of dominant species, such as Staphylococcaceae, Planococcaceae, Muribaculaceae, Aerococcaceae, and Lacrobacillaceae, in intestinal microbiota distribution. Thus, EZ could be considered as a potential candidate for developing an ingredient of functional foods for Zn(II) supplements with hypoglycemic activity.

Pinellia ternata (Thunb.) Breit. Attenuates the allergic airway inflammation of cold asthma via inhibiting the activation of TLR4-medicated NF-kB and NLRP3 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Pinellia ternata (Thunb.) Breit. (PT) has been demonstrated to be effective against the allergic airway inflammation (AAI) in clinical practices, especially in cold asthma (CA). Until now, the active ingredients, protective effect, and possible mechanism of PT against CA remain unknown.

AIM OF THE STUDY

The aim of this investigation was to examine the therapeutic impact and elucidate the underlying mechanism of PT on the AAI of CA.

METHODS

The compositions of PT water extract were determined via the UPLC-Q-TOF-MS/MS. The ovalbumin (OVA) and cold-water baths were used to induce CA in female mice. Morphological characteristic observations, expectorant effect, bronchial hyperreactivity (BHR), excessive mucus secretion, and inflammatory factors were used to uncover the treatment effect of PT water extract. In addition, the mucin 5AC (MUC5AC) mRNA and protein levels and the aquaporin 5 (AQP5) mRNA and protein levels were detected via qRT-PCR, immunohistochemistry (IHC), and western blotting. Moreover, the protein expressions associated with the TLR4, NF-κB, and NLRP3 signaling pathway were monitored by western blot analysis.

RESULTS

Thirty-eight compounds were identified from PT water extract. PT showed significant therapeutic effects on mice with cold asthma in terms of expectorant activity, histopathological changes, airway inflammation, mucus secretion, and hyperreactivity. PT exhibited good anti-inflammatory effects in vitro and in vivo. The expression levels of MUC5AC mRNA and protein decreased significantly, while AQP5 expression levels increased significantly in the lung tissues of mice after administration with PT as compared to mice induced by CA. Furthermore, the protein expressions of TLR4, p-iκB, p-p65, IL-1β, IL-18, NLRP3, cleaved caspase-1, and ASC were markedly reduced following PT treatment.

CONCLUSIONS

PT attenuated the AAI of CA by modulating Th1- and Th2-type cytokines. PT could inhibit the TLR4-medicated NF-kB signaling pathway and activate the NLRP3 inflammasome to reduce CA. This study provides an alternative therapeutic agent of the AAI of CA after administration with PT.

An overview on the nutritional and bioactive components of green seaweeds

Green seaweed, as the most abundant species of macroseaweeds, is an important marine biological resource. It is a rich source of several amino acids, fatty acids, and dietary fibers, as well as polysaccharides, polyphenols, pigments, and other active substances, which have crucial roles in various biological processes such as antioxidant activity, immunoregulation, and anti-inflammatory response. In recent years, attention to marine resources has accelerated the exploration and utilization of green seaweeds for greater economic value. This paper elaborates on the main nutrients and active substances present in different green seaweeds and provides a review of their biological activities and their applications for high-value utilization.

Graphical abstract

Antitumor effects of polysaccharides from Tetrastigma hemsleyanum Diels et Gilg via regulation of intestinal flora and enhancing immunomodulatory effects in vivo

Tetrastigma hemsleyanum Diels et Gilg is a traditional Chinese herbal medicine with high medicinal value, and antitumor, antioxidant and anti-inflammatory biological activities. However, while several studies have focused on flavonoids in Tetrastigma hemsleyanum tubers, there are few studies on the enhanced immune effect of Tetrastigma hemsleyanum polysaccharides (THP). In this study, we evaluated the antitumor effect of THP in a lung tumor model and explored the mechanism of antitumor activity through intestinal flora. In addition, a cyclophosphamide (CTX)-induced immunosuppression model was used to declare the immunomodulatory effect of THP in the immunosuppressive state induced by antitumor drugs. The results showed that THP increased the content of ileum secreted immunoglobulin A (SIgA) and cecum short-chain fatty acids (SCFAs) and improved microbial community diversity, regulating the relative abundance of dominant microbiota flora from the phylum level to the genus level, and recovering the intestinal microflora disorder caused by tumors. Additionally, THP can increase the organ indices and improve immune organ atrophy. THP can upregulate routine blood counts and stimulate the production of the serum cytokines. THP also promoted the macrophage phagocytic index, NK-cell activation, and complement and immunoglobulin (IgG, IgA, IgM) levels. The detection of Splenic lymphocyte proliferation and T lymphocyte subsets also sideways reflects that THP can restore CTX-induced immune inhibition in mice. In conclusion, this study suggests that THP can effectively achieve the enhanced antitumor effects, regulate gut microbiota and improve the immunosuppression induced by antitumor drugs. Therefore, THP can enhance the immune capacity and provide novel immunomodulatory and antineoplastic adjuvant agents.

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.

Effects of polysaccharides from Yingshan Yunwu tea on free amino acids, flavor nucleotides and antioxidant abilities in chickens

Tea polysaccharides possess a variety of physiological activities including anti-oxidant, anti-cancer, anti-diabetic, immunomodulatory, hypolipidemic, and cation chelating ability, which have been proved a promising feed additive. Our study aimed to investigate the effects of polysaccharides from Yingshan Yunwu tea (GTPS) on free amino acids, flavor nucleotides and antioxidant ability in chickens. A total of 200 chickens were randomly divided into to 4 groups. Chickens were fed chicken basal diet with GTPS (200, 400 and 800 mg/kg). The results showed that GTPS increased body weight, average daily gain, and average daily feed intake in chickens. Moreover, GTPS increased the total amount of free amino acids of meat, and increased the content of histidine, leucine, serine, glutamic acid and alanine. GTPS also increased contents of inosine monophosphate and guanylic monophosphate, which improved the meat flavor of chickens. In addition, GTPS significantly increased (P < 0.05) contents of GSH-Px, SOD and T-AOC, and reduced content of MDA. It also increased Nrf2, NQO-1 and HO-1 mRNA expressions, and decreased Keap1expression. GTPS increased Nrf2 and HO-1 protein levels, and decreased Keap1 level. The above findings indicated that GTPS could be a promising natural feed additive in poultry industry.

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.

Network pharmacology combined with molecular docking to explore the potential mechanisms for the antioxidant activity of Rheum tanguticum seeds

Background

Rheum tanguticum (R. tanguticum) is an edible and medicinal plant that exhibits high antioxidant activity. The purpose of the present study was to investigate the bioactive components of its seeds and the potential mechanisms of antioxidant activity to provide a foundation for further developmental work on R. tanguticum seeds as a functional food.

Methods

In this study, the antioxidant activities of R. tanguticum seeds were measured using DPPH, ABTS and FRAP assays. LC-Q-TOF/MS was used to identify the active compounds in the seeds, and Swiss Target Prediction was used to identify their potential targets. The DisGENET, DrugBank, OMIM and GeneCard databases were used to search for antioxidant-related targets.

Results

The component–target–pathway network was constructed and included 5 compounds and 9 target genes. The hub genes included ESR1, APP, MAPK8, HSP90AA1, AKT1, MMP2, PTGS2, TGFB1 and JUN. The antioxidant activity signaling pathways of the compounds for the treatment of diseases were the cancer signaling pathway, estrogen signaling pathway, colorectal cancer signaling pathway, MAPK signaling pathway, etc. Molecular docking revealed that the compounds in R. tanguticum seeds could inhibit potential targets (AKT1, ESR1 and PTGS2).

Conclusion

Molecular docking studies revealed that the binding energy score between liriodenine and PTGS2 was the highest (8.16), followed by that of chrysophanol (7.10). This result supports the potential for PTGS2-targeted drug screening and design.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03611-3.

Ulva (Enteromorpha) Polysaccharides and Oligosaccharides: A Potential Functional Food Source from Green-Tide-Forming Macroalgae

The high-valued utilization of Ulva (previously known as Enteromorpha) bioresources has drawn increasing attention due to the periodic blooms of world-wide green tide. The polysaccharide is the main functional component of Ulva and exhibits various physiological activities. The Ulva oligosaccharide as the degradation product of polysaccharide not only possesses some obvious activities, but also possesses excellent solubility and bioavailability. Both Ulva polysaccharides and oligosaccharides hold promising potential in the food industry as new functional foods or food additives. Studies on Ulva polysaccharides and oligosaccharides are increasing and have been the focus of the marine bioresources field. However, the comprehensive review of this topic is still rare and do not cover the recent advances of the structure, isolation, preparation, activity and applications of Ulva polysaccharides and oligosaccharides. This review systematically summarizes and discusses the recent advances of chemical composition, extraction, purification, structure, and activity of Ulva polysaccharides as well as oligosaccharides. In addition, the potential applications as new functional food and food additives have also been considered, and these will definitely expand the applications of Ulva oligosaccharides in the food and medical fields.

Sustainable use of agro-industrial wastes as potential feedstocks for exopolysaccharide production by selected Halomonas strains

Large quantities of waste biomass are generated annually worldwide by many industries and are vastly underutilized. However, these wastes contain sugars and other dissolved organic matter and therefore can be exploited to produce microbial biopolymers. In this study, four selected Halomonas strains, namely, Halomonas caseinilytica K1, Halomonas elongata K4, Halomonas smyrnensis S3, and Halomonas halophila S4, were investigated for the production of exopolysaccharides (EPS) using low-cost agro-industrial wastes as the sole carbon source: cheese whey, grape pomace, and glycerol. Interestingly, both yield and monosaccharide composition of EPS were affected by the carbon source. Glucose, mannose, galactose, and rhamnose were the predominant monomers, but their relative molar ratio was different. Similarly, the average molecular weight of the synthesized EPS was affected, ranging from 54.5 to 4480 kDa. The highest EPS concentration (446 mg/L) was obtained for H. caseinilytica K1 grown on cheese whey that produced an EPS composed mostly of galactose, rhamnose, glucose, and mannose, with lower contents of galacturonic acid, ribose, and arabinose and with a molecular weight of 54.5 kDa. Henceforth, the ability of Halomonas strains to use cost-effective substrates, especially cheese whey, is a promising approach for the production of EPS with distinct physicochemical properties suitable for various applications.

Effects of Exopolysaccharides from Lactiplantibacillus plantarum JLAU103 on Intestinal Immune Response, Oxidative Stress, and Microbial Communities in Cyclophosphamide-Induced Immunosuppressed Mice

This study investigated the effects of the exopolysaccharide from Lactiplantibacillus plantarum JLAU103 (EPS103) on the intestinal immune response, oxidative stress, intestinal mucosal barrier, and microbial community in cyclophosphamide-induced immune-suppressed mice. The results showed that EPS103 promoted the secretion of cytokines and the generation of secretory immunoglobulin A and mucin-2 in the small intestine of mice, which might be related to the activation of the MAPK pathway. Additionally, EPS103 protected against oxidative stress by activating antioxidation enzymes and Nrf2/Keap1 pathways. It also improved the intestinal physical barrier functions via regulating the ratio of villous height to crypt depth and upregulating the expression of tight-junction proteins. Meanwhile, EPS103 promoted the generation of short-chain fatty acids (SCFAs) and modulated the constituents of gut microbiota. These results suggested that EPS103 may modulate the intestinal immunoresponse relying on the regulation of SCFA production and gut microbiota in immunosuppressed mice, resulting in the activation of systemic immunity.

Understanding immune-modulatory efficacy in vitro

Boosting or suppressing our immune system represents an attractive adjunct in the treatment of infections including SARS-CoV-2, cancer, AIDS, malnutrition, age related problems and some inflammatory disorders. Thus, there has been a growing interest in exploring and developing novel drugs, natural or synthetic, that can manipulate our defence mechanism. Many of such studies, reported till date, have been designed to explore effect of the therapeutic on function of macrophages, being a key component in innate immune system. Indeed, RAW264.7, J774A.1, THP-1 and U937 cell lines act as ideal model systems for preliminary investigation and selection of dose for in vivo studies. Several bioassays have been standardized so far where many techniques require high throughput instruments, cost effective reagents and technical assistance that may hinder many scholars to perform a method demanding compilation of available protocols. In this review, we have taken an attempt for the first time to congregate commonly used in vitro immune-modulating techniques explaining their principles. The study detected that among about 40 different assays and more than 150 sets of primers, the methods of cell proliferation by MTT, phagocytosis by neutral red, NO detection by Griess reaction and estimation of expression of TLRs, COX-2, iNOS, TNF-α, IL-6 and IL-1β by PCR have been the most widely used to screen the therapeutics under investigation.

Characterization of Alpinia officinarum Hance polysaccharide and its immune modulatory activity in mice

This study aimed to verify the regulating effect of a novel water-soluble polysaccharide (AOHP) extracted from Alpinia officinarum Hance on mouse immunity and to characterize its structure feature. The cellulose...

Dietary Enteromorpha Polysaccharide Enhances Intestinal Immune Response, Integrity, and Caecal Microbial Activity of Broiler Chickens

Marine algae polysaccharides have been shown to regulate various biological activities, such as immune modulation, antioxidant, antidiabetic, and hypolipidemic. However, litter is known about the interaction of these polysaccharides with the gut microbiota. This study aimed to evaluate the effects of marine algae Enteromorpha (Ulva) prolifera polysaccharide (EP) supplementation on growth performance, immune response, and caecal microbiota of broiler chickens. A total of 200 1-day-old Ross-308 broiler chickens were randomly divided into two treatment groups with ten replications of ten chickens in each replication. The dietary treatments consisted of the control group (fed basal diet), and EP group (received diet supplemented with 400 mg EP/kg diet). Results showed that chickens fed EP exhibited significantly higher (P < 0.05) body weight and average daily gain than the chicken-fed basal diet. In addition, significantly longer villus height, shorter crypt depth, and higher villus height to crypt depth ratio were observed in the jejunal and ileal tissues of chickens fed EP. EP supplementation upregulated the mRNA expression of NF-κB, TLR4, MyD88, IL-2, IFN-α, and IL-1β in the ileal and jejunal tissues (P < 0.05). Besides, we observed significantly higher (P < 0.05) short-chain volatile fatty acids (SCFAs) levels in the caecal contents of the EP group than in the control group. Furthermore, 16S-rRNA analysis revealed that EP supplementation altered gut microbiota and caused an abundance shift at the phylum and genus level in broiler chicken. Interestingly, we observed an association between microbiota and SCFAs production. Overall, this study demonstrated that supplementation of diet with EP promotes growth performance, improves intestinal immune response and integrity, and modulates the caecal microbiota of broiler chickens. This study highlighted the application of marine algae polysaccharides as an antibiotic alternative for chickens. Furthermore, it provides insight to develop marine algae polysaccharide-based functional food and therapeutic agent.

TLR4-IN-C34 Inhibits Lipopolysaccharide-Stimulated Inflammatory Responses via Downregulating TLR4/MyD88/NF-κB/NLRP3 Signaling Pathway and Reducing ROS Generation in BV2 Cells

TLR4 signal activated by lipopolysaccharide (LPS) is involved in the pathological process of the central nervous system (CNS) diseases and the suppression of TLR4 signal may become an effective treatment. TLR4-IN-C34, a TLR4 inhibitor, is expected to become a candidate compound with anti-neuroinflammatory response. In the present study, the anti-neuroinflammatory effects and possible mechanism of TLR4-IN-C34 were investigated in BV2 microglia cells stimulated by LPS. The results showed that TLR4-IN-C34 decreased the levels of pro-inflammatory factors and chemokines including NO, TNF-α, IL-1β, IL-6, and MCP-1 in the supernatant of LPS-stimulated BV2 cells. Further research indicated that TLR4-IN-C34 suppressed the expression or phosphorylation levels of inflammatory proteins regarding TLR4/MyD88/NF-κB/NLRP3 signaling pathway. In addition, TLR4-IN-C34 reduced ROS production in BV2 cells after LPS treatment. In conclusion, our findings suggest that anti-neuroinflammatory activity of TLR4-IN-C34 may be interrelated to the inhibition of TLR4/MyD88/NF-κB/NLRP3 signaling pathway and reduction of ROS generation.

Sulphation and Hydrolysis Improvements of Bioactivities, and Immuno-Modulatory Properties of Edible Amanita hemibapha Subspecies javanica (Corner and Bas) Mucilage Polysaccharide as a Potential in Personalized Functional Foods

In this study, the mucilage polysaccharide (MP) from Amanita hemibapha subspecies javanica was prepared by hot water extraction and ethanol precipitation and then fractionated using anion-exchange chromatography equipped with a DEAE Sepharose fast flow column. The most immune-enhancing polysaccharide fraction 2 (MPF2) was subjected to a structural modification such as hydrolysis or over-sulphation. The sulphate and molecular weight (Mw) of over-sulphated (OS1-3) and hydrolysed (HS1-3) derivatives of MPF2 differed between 9.85% and 14.2% and 32.8 and 88.1 × 103 g/mol, respectively. Further, the immune-enhancing properties of MPF2 and its derivatives were tested on RAW264.7 and NK cells through various in vitro assays. Interestingly, a low molecular weight of HS1-3 significantly increased the nitric oxide (NO) production (p < 0.05) more than MPF2, indicating that Mw is a major factor in RAW264.7 cell stimulation. In addition, RAW264.7 cells produced various cytokines by up-regulating mRNA expression levels and the activation of nuclear factor kappa-B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. On the other hand, OS1-3-treated natural killer (NK) cells induced cytotoxicity in HepG2 cells through the expression of IFN-γ, Grandzyme-B, perforin, NKp30, and FasL. These results demonstrated that sulphate derivatives play an important role in NK cell activation. Further, this study also explores how polysaccharide binds to RAW264.7 and NK cells. MPF2 and HS3 may activate RAW264.7 cells via binding to TLR4 receptors, and OS2 could be activated through the CR3 signalling pathways.

Extraction Techniques, Biological Activities and Health Benefits of Marine Algae Enteromorpha prolifera Polysaccharide

There is increasing interest in the use of marine algae as functional food additives for improving human health. Enteromorpha (Ulva) prolifera (E. prolifera) is a seaweed green alga (Chlorophyta) that contains many bioactive compounds, of which polysaccharide is the main component. With the advancement of technology in the methods of extraction and analysis, recent studies in in vitro and animals model showed that polysaccharides derived from E. prolifera exert various biological activities, such as gut microbiota modulation, immunomodulation, antioxidant, antidiabetic, antimicrobial, and hypolipidemic. Research evidence has shown that methods of extraction and molecular modification, such as degradation, carboxymethylation, and sulfonation could alter the biological activities of polysaccharides. Therefore, in this review, we discussed the different extraction techniques, structural-activity relationship, and health benefits of sulfated polysaccharides derived from E. prolifera, and suggested future research avenues. This review helps to advance the extraction techniques and promote the application of marine algae polysaccharides as functional food and therapeutic agent.

The immunomodulatory effects of Carapax Trionycis ultrafine powder on cyclophosphamide-induced immunosuppression in Balb/c mice

BACKGROUND

There are abundant resources of Carapax Trionycis from soft-shelled turtle processing wastes each year in China. Our preliminary work showed that Carapax Trionycis ultrafine powder (CTUP) obtained using ball-milling with a particle size of 2.24 μm (D0.025) contained more active ingredients. The CTUP D0.025 has a good bioaccessibility, but there has been no report about the immunomodulatory function of CTUP. Therefore, using a cyclophosphamide-induced immunosuppression mice model, we investigated the immunomodulatory effects of CTUP D0.025.

RESULTS

The results indicated that CTUP D0.025 administration significantly improved the immune organ (bone marrow, thymus and spleen) indices, ameliorated spleen tissue morphology and increased the capacity of splenocyte proliferation and the activity of macrophage phagocytosis. CTUP D0.025 also significantly promoted the secretion of cytokines (IL-2, IL-4, IL-10, IFN-γ and TNF-α), improved the related mRNA expression levels of IL2, IFN-γ, T-bet and GATA3 in immunosuppressed mice and increased the production of serum hemolysin and the levels of IgG, IgM as well as complement C₃ . Moreover, CTUP D0.025 administration enhanced the antioxidant capacity of mice, exhibited a moderating effect on the damage of bone and skeletal muscle and improved the recovery of bone mineral density and calcium metabolism.

CONCLUSIONS

These findings demonstrated that CTUP D0.025 had an effective immune-enhancing function in immunosuppressive Balb/c mice and also exhibited anti-osteoporosis properties. © 2020 Society of Chemical Industry.