Protective effects of Ulva pertusa polysaccharide and polysaccharide‑iron (III) complex on cyclophosphamide induced immunosuppression in mice

Stability of oil-in-water emulsion and immunomodulating activity in S180 tumor-bearing mice

The stability and nutritional integrity of emulsions are susceptible to various factors including thermal treatment, solid-liquid ratio, and sterilization. In this study, the physicochemical stability and immunomodulatory activities of an oil-in-water emulsion containing immune peptides (TUFSE) were assessed through particle size, zeta potential, related cytokines, and so on. When the temperature was 70°C and a solid-liquid ratio of 1:4, the emulsion revealed stability at high-pressure homogenization, with the small particle size. The loss rates of vitamins were 8.57%-62.26% in 6 months at 25°C. After treatment with cyclophosphamide (CTX), lymphocyte proliferation activity in TUFSE-H group increased (p < 0.05), and immune globulin levels were notably elevated (p < 0.05) in TUFSE groups compared to model group. It confirms the parameters of the emulsion, suggesting its ability to be prepared with minimal vitamin loss while simultaneously improving the disease status in CTX-treated tumor-bearing mice. It shows potential as an immune-enhancing supplement with significant potential value. PRACTICAL APPLICATION: This study validated the parameters of the oil-in-water emulsion and showed that it can be stably prepared with minor vitamin loss while simultaneously improving the disease status in CTX-treated tumor-bearing mice. TUFSE-H group exhibited a notable increase in lymphocytes proliferation activity, whereas serum cytokines and immune globulin levels were elevated compared to MC group, indicating its potential as an immune-enhancing supplement with substantial value.

Interventional Effect of Donkey Bone Collagen Peptide Iron Chelate on Cyclophosphamide Induced Immunosuppressive Mice

Immunodeficiency can disrupt normal physiological activity and function. In this study, donkey bone collagen peptide (DP) and its iron chelate (DPI) were evaluated their potential as immunomodulators in cyclophosphamide (Cytoxan®, CTX)-induced Balb/c mice. The femoral tissue, lymphocytes, and serum from groups of mice were subjected to hematoxylin and eosin (H&E) staining, methylthiazolyldiphenyl-tetrazolium bromide (MTT) cell proliferation assays, and enzyme-linked immunosorbent assay (ELISA), respectively. Furthermore, a non-targeted metabolomics analysis based on UPLC-MS/MS and a reverse transcription polymerase chain reaction (RT-qPCR) technology were used to explore the specific metabolic pathways of DPI regulating immunocompromise. The results showed that CTX was able to significantly reduce the proliferative activity of mouse splenic lymphocytes and led to abnormal cytokine expression. After DP and DPI interventions, bone marrow tissue damage was significantly improved. In particular, DPI showed the ability to regulate the levels of immune factors more effectively than Fe2+ and DP. Furthermore, metabolomic analysis in both positive and negative ion modes showed that DPI and DP jointly regulated the levels of 20 plasma differential metabolites, while DPI and Fe2+ jointly regulated 14, and all 3 jointly regulated 10. Fe2+ and DP regulated energy metabolism and pyrimidine metabolism pathways, respectively. In contrast, DPI mainly modulated the purine salvage pathway and the JAK/STAT signaling pathway, which are the key to immune function. Therefore, DPI shows more effective immune regulation than Fe2+ and DP alone, and has good application potential in improving immunosuppression.

Anti-inflammatory potential of ulvan

Green seaweeds are a widespread group of marine macroalgae that could be regarded as biorenewable source of valuable compounds, in particular sulfated polysaccharides like ulvans with interesting biological properties. Among them, anti-inflammatory activity represents an interesting target, since ulvans could potentially avoid side effects of conventional therapies. However, a great variability in ulvan content, composition, structure and properties occurs depending on seaweed specie and growth and processing conditions. All these aspects should be carefully considered in order to have reproducible and well characterized products. This review presents some concise ideas on ulvan composition and general concepts on inflammation mechanisms. Then, the main focus is on the importance of adequate selection of extraction, depolymerization and purification technologies followed by an updated survey on anti-inflammatory properties of ulvans through modulation of different signaling pathways. The potential application in a number of diseases, with special emphasis on inflammaging, gut microbiota dysbiosis, wound repair, and metabolic diseases is also discussed. This multidisciplinary overview tries to present the potential of ulvans considering not only mechanistic, but also processing and applications aspects, trusting that it can aid in the development and application of this widely available and renewable resource as an efficient and versatile anti-inflammatory agent.

Advances in sulfonated modification and bioactivity of polysaccharides

Polysaccharides, as biological macromolecules, are widely found in plants, animals, fungi, and bacteria and exhibit various biological activities. However, many natural polysaccharides exhibit low or non-existent biological activities because of their high molecular weights and poor water solubility, limiting their application in many fields. Sulfonation is one of the most effective chemical modification methods to improve physicochemical properties and biological activities of natural polysaccharides or even impart natural polysaccharides with new biological activities. Therefore, sulfonated polysaccharides have attracted increasing attention because of their antioxidant, anticoagulant, antiviral, and immunomodulatory properties. This paper reviews the recent advances in the sulfonation of polysaccharides, including preparation, characterization, and biological activities of sulfonated polysaccharides, and provides a theoretical basis for wide applications of sulfonated polysaccharides.

Sea cucumber chondroitin sulfate polysaccharides attenuate OVA-induced food allergy in BALB/c mice associated with gut microbiota metabolism and Treg cell differentiation

Previous research studies have shown that sulfated polysaccharides can inhibit food allergy, but the detailed mechanism remains largely unknown. In this study, RBL-2H3 cells were used to compare the anti-allergic activities of four sulfated polysaccharides, and an ovalbumin (OVA)-sensitized allergic mouse experiment was used to explore their desensitization effect, with regard to the alteration in gut microbiota and immune cell differentiation. Compared with the shark, bovine and porcine chondroitin sulfate, sea cucumber chondroitin sulfate (SCCS) significantly inhibited the degranulation of RBL-2H3 cells. SCCS reduced allergic symptoms and protected the jejunum from injury in mice. Furthermore, SCCS increased the relative abundance of Lachnospiraceae NK4A136, decreased the relative proportion of Prevotellaceae NK3B31, and up-regulated the secretion of short chain fatty acids such as butyric acid in the feces, resulting in an increase in the mucin 2 (MUC2) secretion by goblet cells HT-29. Meanwhile, SCCS induced the differentiation of regulatory T cells in the mesenteric lymph nodes of mice. This study provides a deeper understanding of the functioning mechanism of SCCS in alleviating food allergy and may guide the development and production of anti-allergy active ingredients.

Advances on novel iron saccharide-iron (III) complexes as nutritional supplements

Iron deficiency is prevalent worldwide, and iron supplementation is a promising strategy to address iron needs of the body. However, traditional oral supplements such as ferrous sulfate, ferrous succinate, and ferrous gluconate are absorbed in the form of ferrous ions, leading to lipid peroxidation and side effects due to other reasons. In recent years, saccharide-iron (III) complexes (SICs) as novel iron supplements have aroused attention for the high iron absorption rate and no gastrointestinal irritation at oral doses. In addition, research on the biological activities of SICs revealed that they also exhibited good abilities in treating anemia, eliminating free radicals, and regulating the immune response. This review focused on the preparation, structural characterization, and bioactivities of these new iron supplements, as promising candidates for the prevention and treatment of iron deficiency.

Immunomodulatory activity of semen Ziziphi Spinosae protein: a potential plant protein functional food raw material

Semen Ziziphi Spinosae protein (SZSP) is a new plant protein resource with good food functional properties and health care function. However, the biological activity of SZSP has not been further studied, which greatly limits the development and utilization of SZSP in the food industry. The aim of this study was to investigate the protective effect of SZSP on immunosuppressed mice and its inhibitory effect on immune-stimulated RAW264.7 cells. The results demonstrated that SZSP remarkably improved the immunomodulatory secretion in serum (interleukin-2, tumor necrosis factor-α [TNF-α], interferon-γ, immunoglobulin-A, immunoglobulin-G, immunoglobulin-M) and primary macrophages (nitric oxide, interleukin-1β, TNF-α) and promoted the NK-cell killing activity of primary splenocytes in CTX-induced immunosuppression mice. Immunohistochemical analysis results indicated that the secretion of CD₄⁺ and CD₈⁺ in the spleen and thymus can be regulated by SZSP, leading to inhibition of the damage induced by cyclophosphamide in mice. Meanwhile, in order to clarify the immunomodulatory mechanism of SZSP, we showed that SZSP significantly inhibited the secretion of NO, interleukin-6, and TNF-α and reduced the phosphorylation expression of p-ERK, p-JNK, and p-IκBα in lipopolysaccharide-stimulated RAW264.7 cells. Therefore, the immunomodulatory effect of SZSP may be related to the activation of MAPKs and NF-κB signaling pathways. Based on the above studies, the preliminary purification of SZSP was continued, and S1F2G1 with immunomodulatory activity was obtained. Taken together, SZSP has an immunoregulatory effect in vivo and in vitro and may be a favorable candidate of functional food raw material for regulating immune responses.

Evaluating the Effect of Iron(III) in the Preparation of a Conductive Porous Composite Using a Biomass Waste-Based Starch Template

In this work, the effect of iron(III) in the preparation of a conductive porous composite using a biomass waste-based starch template was evaluated. Biopolymers are obtained from natural sources, for instance, starch from potato waste, and its conversion into value-added products is highly significant in a circular economy. The biomass starch-based conductive cryogel was polymerized via chemical oxidation of 3,4-ethylenedioxythiophene (EDOT) using iron(III) p-toluenesulfonate as a strategy to functionalize porous biopolymers. Thermal, spectrophotometric, physical, and chemical properties of the starch template, starch/iron(III), and the conductive polymer composites were evaluated. The impedance data of the conductive polymer deposited onto the starch template confirmed that at a longer soaking time, the electrical performance of the composite was improved, slightly modifying its microstructure. The functionalization of porous cryogels and aerogels using polysaccharides as raw materials is of great interest for applications in electronic, environmental, and biological fields.

Immunomodulatory effects and mechanisms of Tiepishihu Xiyangshen granules on cyclophosphamide induced immuno-suppression via TLR4/MAPKs and PI3K/AKT/FOXO3a signal pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Tiepishihu Xiyangshen granules (TXG) is a traditional Chinese medicine formula composed of Panax quinquefolius L, Dendrobium officinale Kimura & Migo and Ganoderma lucidum (Curtis) P. Karst. It has long been used as a nutritional supplement and an immune enhancer in China. However, the immunomodulatory effects and the underlying mechanisms of TXG have not been clarified.

AIM OF THE STUDY

This study aims to investigate the immunomodulatory effects of TXG and clarify the underlying mechanism.

MATERIALS AND METHOD

TXG was administered by gavage for 18 days. From the 15th day, the immunosuppression model was induced by intraperitoneally injecting 80 mg/kg CTX for 3 days. The immune regulatory effects of TXG on immune organs were verified by calculating the organ index and observing the spleen tissue structure through HE staining. The effects of TXG on immune cells were examined by recording the PBWC, the proliferation rate of lymphocyte and the T lymphocyte phenotype. The effects of TXG on immune molecules were measured by detecting serum hemolysin and the content of cytokines. In parallel, kit was utilized to detect its antioxidant capacity. RNA seq and Western blot were used to analyze the possible immune regulation mechanism of TXG. HPLC and UPLC-Q-TOF-MS were used to identify the chemical components in TXG.

RESULTS

At the level of immune organs, TXG effectively reduced the adverse reaction to the body and the substantial damage to the spleen after chemotherapy by improving the spleen damage. At the level of immune molecules, TXG upregulated the expression of cytokines and antibodies. At the level of immune cells, TXG antagonized bone marrow suppression by increasing the PBWC of immunosuppressed mice. Meanwhile, TXG upregulated the ratio of CD4⁺/CD8⁺ lymphocytes and ameliorated the proliferation of T and B lymphocytes. And the mechanism of TXG to improve immunity might be through TLR4/MAPKs and PI3K/AKT/FOXO3a signaling pathways.

CONCLUSION

The results of this study confirmed that TXG has prominent immunomodulatory activities, and the immunity regulations of TXG may be achieved by regulating TLR4/MAPKs and PI3K/AKT/FOXO3a signal pathways.

Protective Effect of Anoectochilus formosanus Polysaccharide against Cyclophosphamide-Induced Immunosuppression in BALB/c Mice

In this study, Anoectochilus formosanus polysaccharide (AFP) was acquired a via water extraction and alcohol precipitation method. The immunoregulatory activity of AFP was first evaluated on cyclophosphamide (Cy)-treated mice. Galacturonic acid, glucose and galactose were confirmed to be the main components of AFP. AFP demonstrated the ability to stimulate the production of TNF-α and IL-6 in RAW 264.7 macrophages. Not surprisingly, the activation of the NF-κB signaling pathway by AFP was validated via Western blot analysis. Furthermore, AFP could alleviate Cy-induced immunosuppression, and significantly enhance the immunity of mice via increasing the thymus index and body weight, stimulating the production of cytokines (IgA, IgG, SIgA, IL-2, IL-6 and IFN-γ). The improvement in the intestinal morphology of immunosuppressed mice showed that AFP could alleviate Cy-induced immune toxicity. These results have raised the possibility that AFP may act as a natural immunomodulator. Overall, the study of AFP was innovative and of great significance for AFP's further application and utilization.

Effects of sheep whey protein combined with Fu brick tea polysaccharides and stachyose on immune function and intestinal metabolites of cyclophosphamide-treated mice

BACKGROUND

Sheep whey protein (SWP), Fu brick tea polysaccharides (FBTP) and stachyose (STA) have been shown to improve immunity, but little is known about the regulatory effect of SWP, FBTP, STA and their combined formula (CF) on immune function and intestinal metabolism of immunosuppressed mice induced by cyclophosphamide (CTX).

RESULTS

Administration of SWP, FBTP, STA or CF restored the levels of body weight, immune organ index, immune organ morphology, cytokines and immunoglobulins in CTX immunosuppressed mice. Interestingly, CF improved all the mentioned parameters more effective than administration of SWP, FBTP or STA alone. In addition, CF was more effective to increase the levels of intestinal immune-related gene expression than FBTP, SWP or STA alone in immunosuppressed mice, suggesting that CF exhibited excellent intestinal immune regulation function. CF also significantly improved cecal concentrations of short-chain fatty acids of CTX-treated mice. Furthermore, metabolomics analysis demonstrated that CF recovered the levels of 28 metabolites associated with the CTX treatment to the levels of normal mice.

CONCLUSION

Conclusively, these findings suggested that CF as a functional food combination of SWP, FBTP and STA could promote the immune function against human diseases, which providing theoretical support for the co-ingestion of SWP and functional sugars as a feasible strategy for improving the body immunity in the future. © 2023 Society of Chemical Industry.

Structural characterization and hepatoprotective activity of exopolysaccharide from Bacillus velezensis SN-1

BACKGROUND

Exopolysaccharide biopolymers produced by microorganisms are crucial to the environment. They contribute to areas such as the health and bionanotechnology sectors, food and cosmetic industries as gelling agents, and environmental sector as flocculants owing to their biodegradability and non-toxic nature. The current study aimed to isolate the fraction of released exopolysaccharide (rEPS) by Bacillus velezensis SN-1 from Chinese Da-Jiang.

RESULTS

The weighted average molecular weight of the major isolated component, rEPS-2, was 202 kDa, and its monosaccharide composition included mannose, glucose, and galactose at a molar ratio of 0.38:0.30:0.32. Further, the rEPS-2 was characterized using methylation analysis and one-dimensional/two-dimensional nuclear magnetic resonance (1D/2D NMR) spectroscopy. In vivo hepatoprotective effects indicated that rEPS-2 could alleviate carbon tetrachloride (CCl₄ )-induced liver injury in mice by lowering the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and the malondialdehyde (MDA) levels. Furthermore, rEPS-2 can increase the expression of antioxidant genes HO-1, GCLC and NQO1 in the Nrf2/ARE signaling pathway, thereby increasing the activity of antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and reduced catalase (CAT) in liver cells. Furthermore, the rEPS-2 can be used and modulate the gut microbiota of mice with liver injury caused by CCl₄ .

CONCLUSIONS

These results suggest that rEPS-2 has promising potential to serve as hepatoprotective agents. © 2022 Society of Chemical Industry.

Sulfated Polysaccharides from Macroalgae-A Simple Roadmap for Chemical Characterization

The marine environment presents itself as a treasure chest, full of a vast diversity of organisms yet to be explored. Among these organisms, macroalgae stand out as a major source of natural products due to their nature as primary producers and relevance in the sustainability of marine ecosystems. Sulfated polysaccharides (SPs) are a group of polymers biosynthesized by macroalgae, making up part of their cell wall composition. Such compounds are characterized by the presence of sulfate groups and a great structural diversity among the different classes of macroalgae, providing interesting biotechnological and therapeutical applications. However, due to the high complexity of these macromolecules, their chemical characterization is a huge challenge, driving the use of complementary physicochemical techniques to achieve an accurate structural elucidation. This review compiles the reports (2016-2021) of state-of-the-art methodologies used in the chemical characterization of macroalgae SPs aiming to provide, in a simple way, a key tool for researchers focused on the structural elucidation of these important marine macromolecules.

Effects of dietary Chinese yam polysaccharide copper complex on growth performance, immunity, and antioxidant capacity of broilers

Chinese yam polysaccharide (CYP) has received attention in recent years owing to its positive nutritional and medicinal characteristics. Copper is an essential trace metal in animals, which plays an important role in iron absorption and hemoglobin synthesis. However, no published study has evaluated Chinese yam polysaccharide copper complex (CYP-Cu) as a dietary additive in broilers. This study was conducted to investigate the effects of dietary CYP-Cu on growth performance, immunity, and oxidative resistance in broilers. A total of 360 1-day-old 817 broiler chickens were randomly divided into 4 groups, with 3 replicates of 30 birds each and were fed a basal diet with the addition of 0 (control group), 0.02, 0.10, and 0.50 g/kg CYP-Cu. The feeding trial lasted 48 days. On day 28 and day 48, 6 broilers in each group were slaughtered, respectively. Then the parameters of growth and carcass, serum biochemistry, immunity, and antioxidation, and the expression level of hepatic antioxidative genes were investigated. The results showed that compared with the control group, the supplementation of dietary CYP-Cu could improve the indexes of the growth, carcass, serum biochemistry, immunity and oxidation resistance in broilers, such as average daily gain (ADG), the slaughter percentage (SP), semi-evisceration weight percentage (SEWP), eviscerated carcass weight percentage (EWP), breast muscle percentage (BMP), leg muscle percentage (LMP), serum albumin (ALB), high density lipoprotein (HDL), insulin-like growth factor I (IGF-I), triiodothyronine (T3), thyroxine (T4), growth hormone (GH), insulin (INS), immunoglobulin M (IgM), immunoglobulin G (IgG), immunoglobulin A (IgA), interleukin 2 (IL-2), interleukin 4 (IL-4), interleukin 6 (IL-6), complement 3 (C3), complement 4 (C4), total superoxide dismutase (T-SOD), total antioxidative capacity (T-AOC), glutathione peroxidase (GSH-Px), and glutathione s-transferase (GSH-ST); these parameters in the 0.10 g/kg CYP-Cu treated group were significantly increased (P < 0.05) in the total trial period, with the exceptions that feed conversion ratio (FCR) and serum low density lipoprotein (LDL), malondialdehyde (MDA) were decreased in the total trial period. In addition, the antioxidative gene mRNA expression of Nuclear factor E2-related factor 2 (Nrf ₂), Superoxide dismutase 1 (SOD ₁), Superoxide dismutase 2 (SOD ₂), and Catalase (CAT) were upregulated in the liver (P < 0.05). These results indicated that the supplementation of dietary CYP-Cu improved the growth, immunity, and oxidation resistance of broilers, and the addition of 0.10 g/kg CYP-Cu in broiler diets is recommended, which suggests that CYP-Cu may be a promising green feed additive in the poultry industry.

Enhancement of immune responses using ovalbumin-conjugated Eucommia ulmoides leaf polysaccharides encapsulated in a cubic liquid-crystalline phase delivery system

BACKGROUND

To improve the adjuvant activity of polysaccharides from Eucommia ulmoides leaves (PsEUL) in inducing an effective immune response against ovalbumin (OVA), PsEUL were conjugated to OVA using the N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) method. The synthesized PsEUL-OVA was encapsulated using phytantriol and F127 to produce PsEUL-OVA cubosomes (Cubs), a novel delivery system. The physicochemical properties and immune modulation effects of this novel delivery system were explored.

RESULTS

In vitro, PsEUL-OVA/Cubs carrying large amounts of OVA were rapidly phagocytized by macrophages and upregulated macrophage proliferation, thereby stimulating cytokine production (interleukin (IL)-6 and IL-4). In vivo, PsEUL-OVA/Cubs increased the titer of OVA-specific antibodies (immunoglobulin (Ig)G, IgG2b, IgG2a and IgG1) and cytokine levels (IL-2, IL-6, IL-4 and interferon-γ). In addition, the cubosomes promoted the differentiation of CD8⁺ and CD4⁺ T cells in the spleen and the maturation of dendritic cells (DCs). These results indicated that PsEUL-OVA/Cubs stimulated both cellular and humoral immune responses by enhancing the phagocytic activity of DCs and macrophages and increasing the antigen presentation efficiency.

CONCLUSION

Collectively, the findings demonstrate that PsEUL-antigen/Cubs can be a useful delivery vehicle with immune response-promoting effects. Therefore, this study lays the foundation for the development of novel adjuvant-antigen delivery systems with potential applications in vaccine design. © 2022 Society of Chemical Industry.

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.

Structural characterization and biological activities of polysaccharide iron complex synthesized by plant polysaccharides: A review

Iron deficiency anemia can lead to a variety of functional disorders, which is one of the highest incidence of nutrient deficiency diseases. The direct addition of iron to food will not only brings difficulties to the production of products, but also brings damages to human body. In recent years, international studies have shown that polysaccharide iron complex (PIC) not only has a variety of pharmacological activities of polysaccharide itself, but also has the function of supplementing iron, so it is a good iron supplement. With the advantages of good solubility, high iron content, low gastrointestinal irritation and high bioavailability, PIC is an effective iron supplement for iron deficiency anemia and has attracted more and more attention. In this paper, the different preparation methods, structural characterization, biological activities and clinical applications of PIC synthesized by natural polysaccharides from plant were reviewed, in order to provide theoretical basis for the development and application of PIC.

Immunomodulatory Activity In Vitro and In Vivo of a Sulfated Polysaccharide with Novel Structure from the Green Alga Ulvaconglobata Kjellman

Algae accumulate large amounts of polysaccharides in their cell walls or intercellular regions. Polysaccharides from algae possess high potential as promising candidates for marine drug development. In this study, a sulfated polysaccharide, UCP, from the green alga Ulva conglobata Kjellman was obtained by water extraction, anion-exchange, and size-exclusion chromatography purification, and its structure was characterized by a combination of chemical and spectroscopic methods. UCP mainly consisted of →4)-α/β-l-Rhap-(1→, →4)-β-d-Xylp-(1→ and →4)-β-d-GlcAp-(1→ residues. Sulfate ester groups were substituted mainly at C-3 of →4)-l-Rhap-(1→ and C-2 of →4)-β-d-Xylp-(1→. Partial glycosylation was at C-2 of →4)-α-l-Rhap-(1→ residues. UCP possessed a potent immunomodulatory effect in vitro, evaluated by the assays of lymphocyte proliferation and macrophage phagocytosis. The immunomodulatory activity of UCP in vivo was further investigated using immunosuppressive mice induced by cyclophosphamide. The results showed that UCP markedly increased the spleen and thymus indexes and ameliorated the cyclophosphamide-induced damage to the spleen and thymus. UCP could increase the levels of white blood cells, lymphocytes, and platelets, and improve the hematopoietic inhibition caused by cyclophosphamide. Moreover, UCP significantly promoted the secretions of the immunoglobulin (Ig)G, IgE, and IgM. The data demonstrated that UCP is a novel sulfated polysaccharide and may be a promising immunomodulatory agent.

Synthesis, Characterization, and Bioactivities of Polysaccharide Metal Complexes: A Review

Natural polysaccharides are critical to a wide range of fields (e.g., medicine, food production, and cosmetics) for their various remarkable physical properties and biological activities. However, the bioactivities of naturally acquired polysaccharides may be unsatisfactory and limit their further applications. It is generally known that the chemical structure exhibited by polysaccharides lays the material basis for their biological activities. Accordingly, possible structural modifications should be conducted on polysaccharides for their enhancement. Recently, polysaccharides complexed with metal ions (e.g., Fe, Zn, Mg, Cr, and Pt) have been reported to be possibly used to improve their bioactivities. Moreover, since the properties exhibited by metal ions are normally conserved, polysaccharides may be endowed with new applications. In this review, the synthesis methods, characterization methods, and bioactivities of polysaccharide metal complexes are summarized specifically. Then, the application prospects and limitations of these complexes are analyzed and discussed.

Immunomodulatory activity of a water-soluble polysaccharide extracted from mussel on cyclophosphamide-induced immunosuppressive mice models

This study aimed to investigate the protective effect of mussel polysaccharide (MP) on cyclophosphamide (Cy)-induced intestinal mucosal immunosuppression and microbial dysbiosis in mice. MP was shown to stimulate secretion of cytokines (SIgA, IL-2, IF-γ, IL-4, IL-10) and production of transcription factors (occludin, claudin-1, ZO-1, mucin-2, IL-2, IF-γ, IL-4, IL-10). Key proteins (p-IκB-α, p-p65) of the NF-κB pathway were upregulated after MP administration. SCFAs levels, which were decreased after the Cy treatment, were improved after treatment with MP. Furthermore, 16 S rRNA sequencing data of fecal samples revealed, through α-diversity and β-diversity analysis, that MP improved microbial community diversity and modulate the overall composition of gut microbiota. Taxonomic composition analysis showed that MP increased the abundance of probiotics species (Lactobacillus) and decreased the proportion of pathogenic species (Desulfovibrio). These findings suggested that MP has a potential immunomodulatory activity on the immunosuppressive mice.

Sulfated heteropolysaccharides from Undaria pinnatifida: Structural characterization and transcript-metabolite profiling of immunostimulatory effects on RAW264.7 cells

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UPP-3 showed significant effects on mRNA expression of iNOS, TNF-α, and IL-6.

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Transcript analysis illustrated the immunostimulatory effects of UPP-3.

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Metabolic profiling revealed the immunostimulatory effects of UPP-3.

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UPP-3 might affect the pathways in cancer of macrophage.

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Provided a molecular detail of the immunostimulatory effects of UPP-3.

Investigation of the polysaccharides from an edible marine brown algae Undaria pinnatifida has led to obtaining three fractional sulfated polysaccharides UPPs 1–3 with molecular weights of 7.212 kDa, 13.924 kDa, and 55.875 kDa, respectively. All UPPs are composed of galactose, xylose, glucose, mannose, glucuronic acid, and mannuronic acid, while UPP-3 also consisted of fucose, arabinose, and fructose. The immunostimulatory assay revealed that UPP-3 had important effects on cell viability, nitric oxide levels, and secretion of cytokines TNF-α and IL-6 in RAW264.7 cells. Furthermore, the transcript-metabolite data along with western blot and immunofluorescent staining revealed that UPP-3 could stimulate the Toll-like receptor (TLR4) associated with the nuclear factor kappa-B (NF-κB) p65 signaling pathway of RAW264.7 cells. These findings of the immunomodulatory sulfated polysaccharide will provide a basic understanding to further exploitation of U. pinnatifida polysaccharides.

Structural characteristics and immunomodulatory effects of sulfated polysaccharides derived from marine algae

Marine algae are becoming an important source of valuable candidates of functional food that remain unexplored. Compositional analysis showed that marine algae contain essential nutrients, such as carbohydrates, proteins, fats, and minerals, of which polysaccharides are the main bioactive component. Depending on the source, marine algae polysaccharides are sulfated, which have diverse structures and compositions that influence their biological activities. A growing body of evidence has demonstrated that sulfated polysaccharides derived from marine algae (SPs) exhibit various bioactivities, especially immunomodulation. This review aims at summarizing the structural characteristics of SPs, their immunomodulatory effects, and the structural-immunomodulatory activity relationships between them from articles in recent decade, in order to provide a theoretical basis for the further applications of SPs as promising food or feed additives and possible health products to modulate the immune response.

Polysaccharides from Spores of Cordyceps cicadae Protect against Cyclophosphamide-Induced Immunosuppression and Oxidative Stress in Mice

This study investigated the purification, preliminary structure and in vivo immunomodulatory activities of polysaccharides from the spores of Cordyceps cicadae (CCSP). The crude CCSP was purified by diethylaminoethyl (DEAE)-cellulose and Sephadex G-100 chromatography, affording CCSP-1, CCSP-2 and CCSP-3 with molecular weights of 1.79 × 10⁶, 5.74 × 10⁴ and 7.93 × 10³ Da, respectively. CCSP-2 consisted of mannose and glucose, while CCSP-1 and CCSP-3 are composed of three and four monosaccharides with different molar ratios, respectively. CCSP-2 exhibited its ameliorative effects in cyclophosphamide-induced immunosuppressed mice through significantly increasing spleen and thymus indices, enhancing macrophage phagocytic activity, stimulating splenocyte proliferation, improving natural killer (NK) cytotoxicity, improving bone marrow suppression, regulating the secretion of cytokines and immunoglobulins, and modulating antioxidant enzyme system. These results indicate that CCSP-2 might be exploited as a promising natural immunomodulator.

Structure characterization and lipid-lowering activity of a homogeneous heteropolysaccharide from sweet tea (Rubus Suavissmus S. Lee)

Sweet tea (Rubus Suavissmus S. Lee) is consumed as herbal tea in southwestern China, which has multiple functions such as relieving cough, alleviating allergic responses, and clearing away heat. Here we report the structure and lipid-lowering activity of a sweet tea polysaccharide (STP-60a). STP-60a is a homogeneous heteropolysaccharide with a molecular weight of 9.16 × 10⁴ Da, and composed of rhamnose, arabinose, glucose, galactose and glucuronic acid. The main backbone of STP-60a consists of β-L-Rhap-(1→, →3)-β-D-Galp-(1→, →4)-β-D-Glcp-UA-(1→, →3,6)-β-D-Galp-(1→, →6)-β-D-Galp-(1→, →3)-4-OAc-β-L-Arap-(1→, →3)-α-L-Araf-(1→ and the side chain are α-L-Araf-(1→ and →3)-α-D-Glcp-(1→. Using Caenorhabditis elegans (C. elegans) in a high-sugar diet as a model, we found that STP-60a significantly reduced the fat accumulation in the intestine of C. elegans, and extensively affected lipolysis, fatty acid synthesis and β-oxidation processes. In addition, sbp-1 and nhr-49 were essential for STP-60a to exert a lipid-lowering effect.

Nutraceutical potentials of algal ulvan for healthy aging

Several theories for aging are constantly put forth to explain the underlying mechanisms. Oxidative stress, DNA dysfunction, inflammation, and mitochondrial dysfunction, along with the release of cytochrome c are some of these theories. Diseases such as type 2 diabetes mellitus, intestinal dysfunction, cardiovascular diseases, hepatic injury, and even cancer develop with age and eventually cause death. Ulva polysaccharides, owing to their special structures and various functions, have emerged as desirable materials for keeping healthy. These polysaccharide structures are found to be closely related to the extraction methods, seaweed strains, and culture conditions. Ulvan is a promising bioactive substance, a potential functional food, which can regulate immune cells to augment inflammation, control the activity of aging-related genes, promote tumor senescence, enhance mitochondrial function, maintain liver balance, and protect the gut microbiome from inflammatory attacks. Given the desirable physiochemical and gelling properties of ulvan, it would serve to improve the quality and shelf-life of food.

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

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

Fabrication of a Silk Sericin Hydrogel System Delivering Human Lactoferrin Using Genetically Engineered Silk with Improved Bioavailability to Alleviate Chemotherapy-Induced Immunosuppression

Chemotherapy is one of the main treatments for cancer; however, it usually causes severe atrophy of immune organs and self-immunity damage to patients. Human lactoferrin (hLF) is a multiple biofunctional protein in regulating the immune response and thus holds great promise to alleviate chemotherapy-caused immunosuppression. However, a sufficient hLF resource and efficient delivery of hLF remain a challenge. Here, we provide a useful strategy to simultaneously solve these two problems. A silk sericin hydrogel system delivering recombinant hLF (SSH-rhLF) was fabricated to alleviate the chemotherapeutic drug-caused side effects by rhLF-carrying silk cocoons, which were cost-effectively produced by a transgenic silkworm strain as the resource. SSH-rhLF with a uniform porous microstructural morphology, a dominant β-sheet internal structure, adjustable concentration and sustainable release of the rhLF, and non-cytotoxicity properties was demonstrated. Interestingly, the sericin hydrogel showed effective protection of the rhLF from degradation in the stomach and small intestine, thus prolonging the bioactivity and bioavailability of rhLF. As a result, the oral administration of SSH-rhLF with a low rhLF dose showed significant therapeutic effects on enhancing the immune organs of cyclophosphamide (CTX)-treated mice by protecting the splenic follicles, promoting the expression of immunoregulatory factors, and recovering the intestinal flora family from CTX-induced imbalance, which were similar to those achieved by oral administration of a high dose of free hLF in the solution form. The results suggest that the strategy of producing rhLF silk cocoons via feeding transgenic silkworms overcomes well the shortage of rhLF resources, improves the bioavailability of oral rhLF, and alleviates the side effects of chemotherapeutic drugs on immune organs. The oral SSH-rhLF will be promising for applications in cancer chemotherapy and immunity enhancement of patients.

Eucommia ulmoides Leaf Polysaccharide in Conjugation with Ovalbumin Act as Delivery System Can Improve Immune Response

In this investigation, to maximize the desired immunoenhancement effects of PsEUL and stimulate an efficient humoral and cellular immune response against an antigen, PsEUL and the model antigen ovalbumin (OVA) were coupled using the N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (EDC) reaction to yield a novel delivery system (PsEUL-OVA). The physicochemical characteristics and immune regulation effects of this new system were investigated. We found the yield of this EDC method to be 46.25%. In vitro, PsEUL-OVA (200 μg mL⁻¹) could enhance macrophage proliferation and increase their phagocytic efficiency. In vivo, PsEUL-OVA could significantly increase the levels of OVA-specific antibody (IgG, IgG1, IgG2a, and IgG2b) titers and cytokine (IL-2, IL-4, IL-6, IFN-γ) levels. Additionally, it could activate T lymphocytes and facilitate the maturation of dendritic cells (DCs). These findings collectively suggested that PsEUL-OVA induced humoral and cellular immune responses by promoting the phagocytic activity of macrophages and DCs. Taken together, these results revealed that PsEUL-OVA had the potential to improve immune responses and provide a promising theoretical basis for the design of a novel delivery system.

Structural modification and biological activities of carboxymethyl Pachymaran

Polysaccharides are good chelating agents for metal ions, which are often used to synthesize polysaccharide metal ion complexes. With carboxymethyl pachymaran (CMP) as the substrate, carboxymethyl pachymaran iron (CMPF), carboxymethyl pachymaran selenium (CMPS), and carboxymethyl pachymaran zinc (CMPZ) were synthesized by response surface methodology, and their biological characteristics were studied. The results showed that the CMP was a β-polysaccharide, and the degree of carboxymethylation was 0.6352. The polysaccharide metal ion complexes were characterized by physicochemical methods, scanning electron microscopy, Fourier transform infrared spectroscopy, circular dichroism spectroscopy, and nuclear magnetic resonance spectroscopy. All the polysaccharides and complexes possessed antioxidant activity in vitro with scavenging activities to ABTS, superoxide anions, and ferrous ions. CMPF, CMPS, and CMPZ caused significant inhibition of A2780 cell proliferation, promoted the production of reactive oxygen species, and induced apoptosis in a human ovarian cancer cell line (A2780 cells). These results suggest that the CMP complex may be an effective candidate drug for cancer treatment in the field of functional food and pharmacology.

The immunoenhancement effects of sea buckthorn pulp oil in cyclophosphamide-induced immunosuppressed mice

In this study, the immunomodulatory effect of sea buckthorn (SBT) pulp oil was elucidated in immunosuppressed Balb/c mice induced by cyclophosphamide (CTX). The results showed that SBT pulp oil could reverse the decreasing trend of body weight, thymus/spleen index and hematological parameters induced by CTX. Compared with immunosuppressive mice induced by CTX, SBT pulp oil could enhance NK cytotoxicity, macrophage phagocytosis, and T lymphocyte proliferation, and regulate the proportion of T cell subsets in mesenteric lymph nodes (MLN), and promote the production of secretory immunoglobulin A (sIgA), IFN-γ, IL-2, IL-4, IL-12 and TNF-α in the intestines. In addition, SBT pulp oil can promote the production of short fatty acids (SCFAs), increase the diversity of gut microbiota, improve the composition of intestinal flora, increase the abundance of Alistipes, Bacteroides, Anaerotruncus, Lactobacillus, ASF356, and Roseburia, while decreasing the abundance of Mucispirillum, Anaeroplasma, Pelagibacterium, Brevundimonas, Ochrobactrum, Acinetobacter, Ruminiclostridium, Blautia, Ruminiclostridium, Oscillibacter, and Faecalibaculum. This study shows that SBT pulp oil can regulate the diversity and composition of intestinal microflora in CTX-induced immunosuppressive Balb/c mice, thus enhancing the intestinal mucosa and systemic immune response. The results can provide a basis for understanding the function of SBT pulp oil and its application as a new probiotic and immunomodulator.

Effects of co-fermented collagen peptide-jackfruit juice on the immune response and gut microbiota in immunosuppressed mice

Recently, the development of fermented foods for ameliorating immunity and gut microbiota has attracted extensive attention. In this study, co-fermented collagen peptide-jackfruit juice was used in immunosuppressed mice to evaluate the immune response and gut microbiota modulatoration. The results showed that co-fermented peptide-jackfruit juice (FPJ) increased anti-oxidant capacity and lactic acid content. FPJ significantly promoted the immune organ (spleen and thymus) indexes, alleviated the injuries of colon tissue and stimulated the secretion of cytokines and immunoglobulins (IgA, IgM, IgG) (P < 0.05). Moreover, FPJ significantly upregulated the gene expression of TNF-α, IL-4, IFN-γ, IL-2, IL-10, T-bet, Foxp3, RORγ and GATA3. Furthermore, FPJ improved gut microbiota composition and elevated the short-chain fatty acids (SCFAs) concentration. The relative abundances of pathogenic bacteria decreased while beneficial bacteria increased after administration FPJ. These findings suggested that FPJ could be developed as a promising functional food for immunomodulation.

Structure analysis and antioxidant activity of polysaccharide-iron (III) from Cordyceps militaris mycelia

Iron-enriched Cordyceps militaris was obtained by adding FeSO₄ solution to the mycelia for biotransformation. The polysaccharide-iron (III) was extracted by water extraction and alcohol precipitation. High performance liquid chromatography showed that the crude polysaccharide-iron (III) had three components. The second component was purified by Sephadex G-150 and named as CPS-iron-II. The average molecular weight of CPS-iron-II was 44.136 kDa. The content of iron was 2.73%. The monosaccharide composition analysis indicated that the CPS-iron-II was composed of rhamnose, arabinose, galactose, glucose, mannose, galacturonic acid with percentage ratio of 0.94:3.12:27.01:36.62:30.20:2.12. The results of methylation analysis revealed that the CPS-iron-II was made of →2)-β-D-Glcp-(1→, with →2, 4)-α-D-Glcp-(1→ highly branched. Congo-red test showed that CPS-iron-II can cause flocculation of Congo red solution. The anti-oxidative analysis showed that antioxidant activity of CPS-iron-II was almost equal to that of Vc. The manuscript provided a new way for the preparation of polysaccharide-iron(III) from Cordyceps militaris.

Konjac Glucomannan from Amorphophallus konjac enhances immunocompetence of the cyclophosphamide-induced immunosuppressed mice

This present study was designed to evaluate the immunomodulatory activity of Konjac glucomannan (KGM) on immunosuppressed mice induced by cyclophosphamide (CTX) treatment. The mice immunodeficiency model was established by CTX. KGM was used to modulate the activities of immunosuppressive mice. It was proved that KGM could promote the proliferation of lymphocyte, thymus, and spleen indices, and alleviate the atrophy of immune organs and weight loss. Besides, in mice serum, the levels of cytokines including TNF-α, IgG, IL-2, and the contents of hemolysin were also increased after treatment with KGM. Furtherly, in nonspecific immunity, KGM could enhance natural killer (NK) cell lethality and pinocytic activity of mouse peritoneal macrophages. Therefore, all of these results revealed that KGM could improve the reduced immunity of CTX-induced mice via modulation innate immunity and adaptive immunity.

Protein composites from silkworm cocoons as versatile biomaterials

Silk is a naturally occurring biopolymer formed into fibers composed primarily of fibroin and sericin proteins. The outstanding mechanical properties of silk fibroin (SF) provides numerous applications for silk-based biomaterials. However, the canonical approaches for fabricating silk-based biomaterials typically involve degumming to remove the silk sericin (SS) to avoid adverse biological effects. Meanwhile, sericin has multiple biological functions including outstanding hydrophilicity, promoting cell attachment that are useful to exploit in new materials, inspiring the use of sericin-based biomaterials for biomedical applications. However, compared to fibroin, sericin is not a structural protein, thus sericin-based materials do not provide robust mechanical properties. To address this problem, we report an effective method for fabricating silk fibroin-sericin protein (SS-SF) composites directly from whole cocoons, negating the traditional extraction step to remove the sericin. This approach combines the material features from both fibroin as a structural unit and sericin as a biological functional unit, to achieve advantages regarding processing and materials properties, not only simplifying processing and maintaining the mechanical properties of the fibroin by avoiding degumming, but also endowing these SS-SF composite materials with enhanced hydrophilicity and cell adhesion performance to promote cell growth and proliferation. In addition, these protein composites could be fabricated into a variety of materials formats (e.g. films, sponges, monoliths) to fit different biomedical applications.

Iron-Enriched Nutritional Supplements for the 2030 Pharmacy Shelves

Iron deficiency (ID) affects people of all ages in many countries. Due to intestinal blood loss and reduced iron absorption, ID is a threat to IBD patients, women, and children the most. Current therapies can efficiently recover normal serum transferrin saturation and hemoglobin concentration but may cause several side effects, including intestinal inflammation. ID patients may benefit from innovative nutritional supplements that may satisfy iron needs without side effects. There is a growing interest in new iron-rich superfoods, like algae and mushrooms, which combine antioxidant and anti-inflammatory properties with iron richness.

Production of a codonopsis polysaccharide iron complex and evaluation of its properties

A water extraction and alcohol precipitation method was applied to extract polysaccharides from Codonopsis pilosula (CPP), response surface methodology was used to optimize the extraction conditions and synthesis of C. pilosula polysaccharide iron (CPPI), and the properties of CPPI were evaluated. The optimum extraction conditions for CPP were as follows: liquid-solid ratio of 29.39 mL/g, time of 1.25 h and temperature of 62.84 °C. The optimum synthesis conditions for CPPI were pH 8.9, temperature 70.30 °C and the ratio of citric acid to CPP1 of 2.95. An HPSEC-MALLS-RID system, UV spectroscopy, FT-IR spectroscopy and NMR were used for characterization of the polysaccharide. CPPI exhibited antioxidant activity in vitro and a relatively strong inhibitory effect on A2780 cells growth. After CPPI treatment, the reactive oxygen species increased, the mitochondrial membrane potential decreased, and DNA damage was observed in A2780 cells. Therefore, CPPI should be explored as a potential antioxidant and an antitumor drug in a clinical setting.

Characterization of Low Molecular Weight Sulfate Ulva Polysaccharide and its Protective Effect against IBD in Mice

Inflammatory bowel disease (IBD) has been gradually considered a public health challenge worldwide. Sulfated polysaccharides, extracted from seaweed, have been shown to have an anti-inflammatory effect on the disease. In this study, LMW-ulvan, a unique sulfate Ulva polysaccharide with low molecular weight, was prepared using the enzymatic method. The structural characterization of LMW-ulvan and its protective effect on colitis induced by dextran sulfate sodium (DSS) were studied. The results showed that LMW-ulvan with molecular weight of 2.56 kDa consists of 57.23% rhamnose (Rha), 28.76% xylose (Xyl), 7.42% glucuronic acid (GlcA), and 1.77% glucose (Glc). Its backbone contains (1→3,4)-linked Rha, (1→4)-linked Xyl, and (1→4)-linked GlcA with small amounts of (1→4)-linked Rha residues; sulfate substitution was at C-3 of Rha. LMW-ulvan was found to reduce DSS-induced disease activity index, colon shortening, and colonic tissue damage, which were associated with decreased oxidative stresses and inflammation, thus improving the expression of tight junction proteins. These results indicate that LMW-ulvan is able to improve colitis and may be a promising application for IBD.

Hepatoprotection of pine nut polysaccharide via NRF2/ARE/MKP1/JNK signaling pathways against carbon tetrachloride-induced liver injury in mice

Previously, we obtained a purified polysaccharide (PNP40c-1) from Pinus koraiensis pine nut and reported its protective effect on carbon tetrachloride (CCl₄)-induced liver injury in vitro. The object of this study is to investigate its hepatoprotective activity in vivo and elucidate the mechanism underlying the hepatoprotection. PNP40c-1 effectively prevented the accumulation of serum liver injury biomarkers including alanine aminotransferase, aspartate aminotransferase, alkaline phpsphatase and total bilirubin stimulated by CCl₄. The pathological changes in PNP40c-1-treated mice livers were also markedly ameliorated. Results showed that PNP40c-1 suppressed the production of reactive oxygen species (ROS) and lipid peroxidation, upregulated Nrf2/ARE pathway and enhanced the antioxidant capacity of hepatocytes. Furthermore, the reaction between Nrf2 and ARE promoted the generation of Mkp1, which inhibited the activation of JNK induced by CCl₄, and suppressed hepatocytes apoptosis by regulating the protein expression of Bax, cleaved-Caspase-3 and Bcl2, exerting hepatoprotective activity. Taken together, upregulation of Nrf2/ARE pathway and suppression of JNK activation via Nrf2/ARE/Mkp1/JNK signaling pathways are the main mechanisms underlying the hepatoprotective effect of PNP40c-1 against CCl₄-induced mice liver injury. These results indicated that PNP40c-1 has potential to serve as a hepatoprotective agent against chemical induced hepatotoxicity.

Ulvan lyase assisted structural characterization of ulvan from Ulva pertusa and its antiviral activity against vesicular stomatitis virus

Marine green algae are valuable sources of diverse health-promoting bioactive components. Ulvan is suitable for biological applications due to its unique structure and numerous bioactivities. Here, the complex structure of ulvan from Ulva pertusa was analyzed using specific ulvan lyase degradation, MS, and NMR detection. Its structure mainly consists of →4)-β-d-GlcA-(1 → 4)-α-l-Rha3S-(1 → and →4)-β-d-Xyl-(1 → 4)-α-l-Rha3S-(1 → repeating units. Small amounts of →4)-α-l-IdoA-(1 → 4)-α-l-Rha3S-(1 → unit also exist. In addition, a minor number of branches, a single GlcA, and a long branch containing GlcA-Glc were linked to Rha3S. The antiviral activity of the ulvan and its degraded fragments were further investigated. Ulvan (1068.2 kDa) and ulvan-F1 (38.5 kDa) with relatively high molecular weight showed potency of inhibiting the infection and replication of vesicular stomatitis virus (VSV) at 100 μg/mL, the inhibition rate of VSV replication was 40.75% and 40.13%, respectively. These results indicated that ulvan has potential as a functional agent.

Physicochemical properties of polysaccharide fractions from Sargassum fusiforme and their hypoglycemic and hypolipidemic activities in type 2 diabetic rats

Two polysaccharide fractions (SFPs, designated as respectively SFP-1 and SFP-2) were acquired from Sargassum fusiforme by ultrasound-assisted enzymatic extraction, and their physicochemical properties and hypoglycemic and hypolipidemic effects were investigated. Structural analysis indicated that SFPs were obvious different in the zeta potential, molecular weight distribution, characteristic organic group, microstructure and the contents of total sugar, uronic acid, sulfate and moisture. SFPs consisted of fucose, mannose, rhamnose, glucose, galactose and glucuronic acid with different molar ratios. Congo red test explained that SFPs had no triple-helix structure. SFP-1 exhibited lower viscosity due to its lower molecular weight. Regarding to hypoglycemic and hypolipidemic effects, oral administration of SFPs prominently restrained loss of body weight and increase of water intake, and also significantly controlled the increase of levels of fasting blood glucose, triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), uric acid (UA), urea nitrogen (BUN), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) of diabetic rats, and SFP-2 showed better effects in controlling fasting blood glucose, ALT, UA and BUN levels. Intervention of SFP-2 reduced the levels of insulin, FFA and TBA of diabetic rats. Histomorphological observation further demonstrated that SFPs could attenuate liver and kidney damage caused by hyperglycemia and hyperlipidemia. Data indicated that SFPs, especially SFP-2, significantly improved hyperglycemia, hyperlipidemia and liver and kidney function of diabetic rats.