A heteropolysaccharide from Saccharina japonica with immunomodulatory effect on RAW 264.7 cells

Fucoidan from the cell wall of Silvetia siliquosa with immunomodulatory effect on RAW 264.7 cells

Silvetia siliquosa, the only species of the family Fucaceae in China, is used as a medicine food homology. Fucoidan from S. siliquosa was extracted by hot water twice thoroughly (13 % of total yield), and a purified fucoidan SSF with a molecular weight of 93 kD was obtained. Chemical composition analysis demonstrated that SSF was primarily composed of sulfate (21.68 wt%) and fucose (84 % of all neutral monosaccharides). IR, methylation analysis, NMR and ESI-MS results indicated SSF had the backbone of mainly (1 → 3)-α-L-fucopyranose and minor (1 → 4)-α-L-fucopyranose, with little 1,3 and 1,4 branched β-D-Xylp and β-D-Galp. The in vitro immunomodulatory test on RAW 264.7 cells showed that SSF could up-regulate the expression of immune related factors and proteins in a concentration-dependent manner, but the immunomodulatory effect disappeared from desulfated SSF. This research indicated that highly sulfated fucan possessed immunomodulatory effect and the importance of sulfate groups in the activity of SSF.

Structural, physicochemical, and immune-enhancing properties of edible insect protein isolates from Protaetia brevitarsis larvae

Edible insects are promising future food resources globally. Herein, the structural, physicochemical, and bio-functional properties of edible insect protein isolates (EPIs) extracted from Protaetia brevitarsis larvae were investigated. The results showed that EPIs have a high total essential amino acid content; moreover, β-sheet is the major secondary protein structure. The EPI protein solution was highly soluble and electrically stable and did not aggregate easily. In addition, EPIs exhibited immune-enhancing properties; EPI treatment of macrophages induced the activation of macrophages and consequently promoted the production of pro-inflammatory mediators (NO, TNF-α, and IL-1β). Moreover, macrophage activation of EPIs was confirmed to occur through the MAPK and NF-κB pathways. In conclusion, our results suggest that the isolated P. brevitarsis protein can be fully utilized as a functional food material and alternative protein source in the future food industry.

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

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

Compositional analysis and immunomodulatory activity of blue pigment fraction (BPF) from Laba garlic

Laba garlic is a kind of garlic (Allium sativum L.) product and blue pigment fraction (BPF) is the characteristic fraction of Laba garlic. The objective of the study was to isolate BPF from Laba garlic and explore its stability, composition, antioxidant activity, and immunomodulatory activity. The results suggested BPF was unstable under alkaline conditions. Twenty-four constituents including 9 peptides and 10 saponins were detected in BPF by Q Exactive HF LC/MS anlaysis. BPF showed antioxidant activity in a dose-dependent manner. It also showed effective immunomodulatory activity at a concentration of 5 μg/mL at the cellular level and the morphology of RAW 264.7 cells changed to a polygonal and dendritic-like structure. BPF could significantly increase NO production (P < 0.05), and up-regulate the mRNA levels of TNF-α, IL-6, iNOS and NF-κB in the RT-QPCR analysis. The present study systematically analyzed the compositions of BPF for the first time, and the results suggested that BPF might be a potential immunomodulator candidate, which is beneficial for the development and application of garlic products and natural pigments.

Polysaccharides from banana (Musa spp.) blossoms: Isolation, identification and anti-glycation effects

Musa spp. (banana) is consumed globally as a healthy fruit and improves the immune system. Banana blossoms are a by-product of banana harvesting rich in active substances such as polysaccharides and phenolic compounds; however, these blossoms are typically discarded as waste. In this report, a polysaccharide, MSBP11, was extracted, purified and identified from banana blossoms. MSBP11 is a neutral homogeneous polysaccharide with a molecular mass of ∼214.43 kDa and composed of arabinose and galactose at a ratio of 0.303:0.697. MSBP11 exhibited potent antioxidant and anti-glycation activities in a dose-dependent manner and can be used as a potential natural antioxidant and inhibitor of advanced glycosylation end products (AGEs). In addition, banana blossoms have been shown to decrease the levels of AGEs in chocolate brownies, which might possibly be developed as functional foods for diabetic patients. This study provides a scientific basis to further research the potential application of banana blossoms in functional foods.

Influence of glycosyl composition on the immunological activity of pectin and pectin-derived oligosaccharide

Factors causing differences in immune activities between pectin and pectin-derived oligosaccharides have not been fully studied. In this article, four samples with different molecular weights and monosaccharide compositions, including polygalacturonic acid (poly-GA) and its oligosaccharide (oligo-GA), navel orange peel pectin (NP) and its oligosaccharide (oligo-NP), were used to compare their immunomodulatory properties on RAW264.7 cells. All samples had nontoxic effect on cells, oligo-GA and oligo-NP could increase the production of nitric oxide and cytokines to a much higher level than poly-GA and NP. The findings revealed that reducing the molecular weight and preserving the branched regions of pectin-derived samples could improve their immune-enhancing effects on macrophages. Interestingly, the addition of TAK-242 (TLR4 inhibitor) also demonstrated that the tested pectin oligosaccharides could stimulate the activation of macrophages through TLR4 signaling pathway. These results confirmed the potential value of pectin oligosaccharides, and provided theoretical support for their application in the pharmaceutical industry.

Comparative study of the immunomodulatory effects of different fucoidans from Saccharina japonica mediated by scavenger receptors on RAW 264.7 macrophages

Scavenger receptors (SRs) have been shown to participate in regulating the immune response of macrophages, and fucoidan from Fucus vesiculosus has been verified as a ligand of class A SRs (SR-A). However, the roles of SRs in the immunomodulatory activity of fucoidan from Saccharina japonica are not clear. Thus, we performed a comparative study of the immunomodulatory activities of six different fucoidans from S. japonica on RAW 264.7 macrophages, and the roles of SRs in the processes were studied. Six fucoidans (0.5 M FPS, 1 M FPS, 2 M FPS, 0.5 M DFPS, 1 M DFPS and 2 M FPS) had different molecular weights and chemical compositions. Griess reagent system, ELISA and RT-qPCR results showed that different fucoidans displayed different stimulation of macrophages to secrete NO, IL-6, IL-1β and TNF-α, as well as differences in the upregulation of their gene expressiones. Flow cytometric analysis of the protein expression level indicated the upregulation of TLR4 after treatment with all the fucoidans but different expressions of SRs. Furthermore, only 0.5 M DFPS and 1 M DFPS were confirmed to be ligands of SR-A through the competitive binding assay with Ac-LDL bound to the fluorescent probe DiI by flow cytometry. Our results revealed that fucoidans with low molecular weight and heterogeneity more easily bound to SRs and contributed to their immunomodulatory effects. This comparative study might promote the biological study of targeted SRs and the discovery of new pharmacological mechanisms of different fucoidans.

Immunoenhancement activity of Bletilla striata polysaccharide through MAPK and NF-κB signalling pathways in vivo and in vitro

Bletilla striata (Thunb.) Reichb.f., is a traditional Chinese medicine, and the Bletilla striata polysaccharide (BSP) is one of the principal components extracted from Bletilla striata with various biological activities. Previous studies have shown that many natural polysaccharides have significant immunomodulatory activities. However, as a plant polysaccharide, the research of BSP on immunomodulatory activities is limited. In this study, we aim to investigate the immunomodulatory effect of BSP in vivo and further explore its underlying mechanism in vitro. In vivo, a cyclophosphamide (CTX)-induced immunosuppression mice mode was established by intraperitoneal injection of CTX, and the immune-enhancing effect of BSP (25, 50 and 100 mg/kg) on immunosuppressed mice were evaluated. The result indicated that BSP could significantly improve the immune organ index and the content of immunoglobulin, TNF-α and IL-4 in serum. It was also found that BSP could clearly ameliorate the spleen damage induced by CTX. Meanwhile, the result showed that BSP could not only improve the proliferation of splenocytes, but also activate the lactate dehydrogenase (LDH) and acid phosphatase (ACP) in mouse spleen tissue. In vitro, potential mechanism was further revealed in macrophages. The result supported that BSP could activate macrophages with high phagocytic ability, and induce macrophages to secrete cytokines. Finally, it revealed that activation of NF-κB and MAPK signalling pathway should be the underlying mechanism of the immunoenhancment of BSP.

Techno-functional properties and immunomodulatory potential of exopolysaccharide from Lactiplantibacillus plantarum MM89 isolated from human breast milk

An exopolysaccharide, designated as MM89-EPS, was isolated from Lactiplantibacillus plantarum MM89. It was comprised of glucose and mannose molecules with an average molecular weight of 138 kDa. FTIR and NMR spectra showed that MM89-EPS had characteristic polysaccharide functional groups. MM89-EPS displayed excellent water solubility and capacities to retain water and oil due to its porous structure. MM89-EPS exhibited no significant cytotoxicity on RAW264.7 cells and showed strong immunomodulatory activity by increasing phagocytosis, acid phosphatase activity, and cytokine production in RAW264.7 cells. Furthermore, an in vivo study revealed that splenic indices, intestinal IgA levels, serum cytokine levels, and lymphocyte proliferation were increased in an MM89-EPS-treated cyclophosphamide-induced immunosuppressed mouse model. To summarize, our results indicate that MM89-EPS can efficiently enhance the immunostimulatory activity of immune cells and an immunosuppressed mouse model. Hence, MM89-EPS may be use as a potential source of immunomodulatory agent in various food products.

Structural characterization and immunomodulatory activity of a mannan from Helvella leucopus

A new polysaccharide fraction HLP-1 (2.55 × 10⁵ Da) was obtained from the fruiting bodies of Helvella leucopus. Structural characterization of HLP-1 was elucidated by infrared spectroscopy, monosaccharide composition analysis, methylation analysis, nuclear magnetic resonance spectroscopy, scanning electron microscopy and Congo red assay. HLP-1 was a mannan with a backbone of →6)-α-D-Manp(1 → 4)- α-D-Manp(1 → 6)-α-D-Manp(1 → 3)-α-D-Manp(1 → 4)-α-D-Manp(1 → 3)-α-D-Manp(1→, which branched at the O-6 position and terminated with T-β-D-Manp. Moreover, HLP-1 could significantly improve the proliferation and neutral red phagocytosis of RAW264.7. Besides, HLP-1 could stimulate the production of nitric oxide (NO), ROS, tumor necrosis factor-α (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6). HLP-1 induced macrophage activation via NF-κB signal pathway. These findings indicated that HLP-1 was a potential immune enhancement agent applied in functional foods.

Anti-Inflammatory Effects of Gynura procumbens on RAW264.7 Cells via Regulation of the PI3K/Akt and MAPK Signaling Pathways

Gynura procumbens is a traditional herb and food extensively cultivated in China and Southeast Asian countries. In this work, the crude extract (CE) of G. procumbens was purified with macroporous resin to obtain the refined fraction, and its anti-inflammatory activity was compared with that of CE. Moreover, the detailed mechanisms of anti-inflammatory activity were also investigated for the first time. The results indicated that CE was more effective in anti-inflammatory activity and it could reduce the secretion of NO, TNF-α, and PGE2 via decreasing the iNOS, TNF-α, and COX-2 genes transcription and related proteins translation, which were associated with the inhibition of AP-1 and NF-κB nuclear translocation and downregulation of PI3K/Akt and MAPK signaling pathways. In conclusion, the extract of G. procumbens has a promising potential in inflammation-related disorders alleviation, and these findings could provide the basis for the comprehensive utilization of G. procumbens and the new functional food development.

Structures and immunomodulatory activity of one galactose- and arabinose-rich polysaccharide from Sambucus adnata

One galactose- and arabinose-rich polysaccharide isolated from Sambucus adnata was named SPS-1, which had an average molecular weight 138.52 kDa, and was composed of L-rhamnose, D-glucuronic acid, D-galacturonic acid, D-galactose, and L-arabinose in a molar ratio of 0.6:0.4:0.1:4.9:4.0. The primary structure of SPS-1 was further analyzed through methylation and NMR spectroscopy. The results showed that SPS-1 had the structural characteristics of AG-II pectin. The immunoactivity test showed that SPS-1 activated the phosphorylation of MAPKs-related proteins and further elevated the expression levels of related nuclear transcription factors (IκBα and NF-κB p65) in the cells through the TLR2 and MyD88/TRAF6-dependent pathway, thereby significantly enhancing the phagocytosis of macrophages and stimulating the secretion of NO, IL-1β, IL-6, and TNF-α, which activated the RAW264.7 cells. Therefore, SPS-1, acting as an immunomodulator, is a potential drug for immunological diseases.

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.

Structural characteristics and immune-enhancing activity of fractionated polysaccharides from Athyrium Multidentatum (Doll.) Ching

Polysaccharides coded as CP were extracted from Athyrium Multidentatum (Doll.) Ching and then fractionated into five fractions (FP-1, FP-2, FP-3, FP-4 and FP-5). A purified polysaccharide designated as FP-3-4 was prepared from FP-3 by Sephadex G-100 column chromatography. Chemical analysis disclosed that CP and these fractions were heteropolysaccharides and mainly composed of glucose, galactose, arabinose, mannose, rhamnose, xylose, fucose, ribose and uronic acid with different molar ratios. They presented different images of SEM. FP-3-4 was highly branched polymers with sixteen types of linkages. The in vitro immunomodulatory results stated that CP and these fractions could promote macrophage proliferation, enhance macrophage phagocytosis and increase the production of NO, TNF-α, IFN-γ, IL-1β, IL-6, IL-10 and IL-2, indicating remarkable immune enhancement activities. RNA sequencing analysis revealed that CP and FP-3 induced macrophage activation mainly through MAPK and alternative NF-κΒ signaling pathways via CD14/TLR4 and Dectin-2 receptors, which were verified by RT-qPCR and western blot.

Structural characterization of a water-soluble polysaccharide from Angelica dahurica and its antitumor activity in H22 tumor-bearing mice

A novel Angelica dahurica polysaccharide (ADP) with Mw of 6.09 × 10³ Da was isolated. The contents of total sugar and uronic acid in ADP were 91.04% and 12.69%. The structure characteristics indicated that ADP was an acidic polysaccharide consisting of rhamnose, arabinose, galactose, glucose, mannose, glucuronic acid and galacturonic acid (0.09: 0.61: 1.88: 1: 0.14: 0.63: 0.03). Moreover, there were →3)-Manp-(1→, →4, 6)-Galp-(1→, →4)-Galp-(1→, →3)-Glcp-(1→, →5)-Araf-(1→, →2)-Galp-(1→ in ADP with relative molar ratios of 0.32:0.57:0.29:0.95:0.71:0.26. In vivo experiments suggested that ADP significantly inhibited the tumor growth of mice, increased the activities of spleen lymphocytes and natural killer (NK) cells, improved the cytokine level (IL-2 and TNF-α) and the proportions of lymphocyte subsets in the peripheral blood. The tumor cell progression was arrested in the G₁ phase, and the apoptosis rate of tumor cells were 7.54% and 19.32% at the dose of 100 and 200 mg/kg, which was consistent with the results of pathological observation. In summary, the study might provide a theoretical basis for the application on functional foods containing Angelica dahurica polysaccharides.

Optimization of the composite enzyme extraction of polysaccharide from Erythronium sibiricum bulb and its immunoregulatory activities

An efficient compound enzyme extraction process was developed and optimized to extract the polysaccharide from Erythronium sibiricum bulb via response surface methodology. The polysaccharide E2P was obtained. Then, the preliminary characteristics of E2P were determined via colorimetry and chromatography. Additionally, the immunoregulatory activities of E2P and another polysaccharide (ESBP, extracted using the hot water method) were compared. The optimized extraction results were as follows: temperature (54.56 °C), time (2.52 h), pH (6.53), and enzyme concentration ratio (0.5% cellulase:1.5% amylase). The yield (64.18% ± 2.91%) obtained under the aforementioned conditions was considerably higher than the yield of ESBP (37.25% ± 0.17%). The total sugar, uronic acid, starch, and protein contents of E2P were 81.77% ± 2.84%, 3.31% ± 0.45%, 3.29% ± 0.01%, and 0.24% ± 0.02%, respectively. The HPLC result suggested that the predominant monosaccharides of E2P included glucose, galactose, and arabinose, with a molar ratio of 543.2:1:1.8. The in vitro tests in RAW264.7 cells indicated that ESBP exhibited better immunomodulatory activities than E2P. In particular, ESBP can promote the proliferation, phagocytosis, and cytokine secretion abilities of cytokines, such as nitric oxide, tumor necrosis factor-α, and interleukin (IL)-1β of RAW264.6 cells. By contrast, E2P can only promote phagocytosis ability and the secretion of IL-1β.

Molecular Mechanism of Anti-Inflammatory Activities of a Novel Sulfated Galactofucan from Saccharina japonica

Seaweed of Saccharina japonica is the most abundantly cultured brown seaweed in the world, and has been consumed in the food industry due to its nutrition and the unique properties of its polysaccharides. In this study, fucoidan (LJNF3), purified from S. japonica, was found to be a novel sulfated galactofucan, with the monosaccharide of only fucose and galactose in a ratio of 79.22:20.78, and with an 11.36% content of sulfate groups. NMR spectroscopy showed that LJNF3 consists of (1→3)-α-l-fucopyranosyl-4-SO₃ residues and (1→6)-β-d-galactopyranose units. The molecular mechanism of the anti-inflammatory effect in RAW264.7 demonstrated that LJNF3 reduced the production of nitric oxide (NO), and down-regulated the expression of MAPK (including p38, ENK and JNK) and NF-κB (including p65 and IKKα/IKKβ) signaling pathways. In a zebrafish experiment assay, LJNF3 showed a significantly protective effect, by reducing the cell death rate, inhibiting NO to 59.43%, and decreasing about 40% of reactive oxygen species. This study indicated that LJNF3, which only consisted of fucose and galactose, had the potential to be developed in the biomedical, food and cosmetic industries.

Structural characterization of novel arabinoxylan and galactoarabinan from citron with potential antitumor and immunostimulatory activities

This study aimed to extract polysaccharides from citron and analyze their structures and potential bioactivities. Two novel polysaccharides CM-1 and CM-2 were purified from citron by DEAE-Sepharose Fast Flow and Sephadex G-100 column chromatography. Monosaccharide composition, linkage and NMR data were used to infer their sugar chains composition. The anti-breast cancer cells and immunoregulatory activities of CM-1 and CM-2 were investigated. Results indicated that CM-1 (Mw = 21,520 Da), composed of arabinose, xylose, mannose and glucose in a molar ratio of 10.78:11.53:1.00:1.70, was arabinoxylan (AX) with (1 → 4)-linked β-d-Xylp skeleton monosubstituted with α-l-Araf units at O-3 position. While CM-2 (Mw = 22,303 Da), composed of arabinose, mannose, glucose and galactose in a molar ratio of 25.46:1.45:1.00:6.57, was galactoarabinan (GA) with (1 → 5)-linked α-l-Araf backbone substituted by β-d-Galp units at O-2 and/or O-3 positions. Both polysaccharides exhibited potential inhibiting cancer and immunostimulatory activities in vitro, especially CM-1. These results provide a basis for further research on citron polysaccharides.

A Sulfated Polysaccharide from Saccharina japonica Suppresses LPS-Induced Inflammation Both in a Macrophage Cell Model via Blocking MAPK/NF-κB Signal Pathways In Vitro and a Zebrafish Model of Embryos and Larvae In Vivo

Inflammation is a complicated host-protective response to stimuli and toxic conditions, and is considered as a double-edged sword. A sulfated Saccharinajaponica polysaccharide (LJPS) with a sulfate content of 9.07% showed significant inhibitory effects against lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophage cells and zebrafish. Its chemical and structural properties were investigated via HPLC, GC, FTIR, and NMR spectroscopy. In vitro experiments demonstrated that LJPS significantly inhibited the generation of nitric oxide (NO) and prostaglandin E2 (PGE2) via the downregulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression and suppressed pro-inflammatory cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-1β production via the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signal pathways in LPS-induced RAW 264.7 cells. Moreover, LJPS showed strong protective effects against LPS-induced inflammatory responses in zebrafish, increasing the survival rate, reducing the heart rate and yolk sac edema size, and inhibiting cell death and the production of intracellular reactive oxygen species (ROS) and NO. Its convenience for large-scale production and significant anti-inflammatory activity indicated the potential application of LJPS in functional foods, cosmetics, and pharmaceutical industries.

Proteoglycan from Bacillus sp. BS11 Inhibits the Inflammatory Response by Suppressing the MAPK and NF-κB Pathways in Lipopolysaccharide-Induced RAW264.7 Macrophages

Inflammation is involved in the pathogenesis of many debilitating diseases. Proteoglycan isolated from marine Bacillus sp. BS11 (EPS11) was shown to have anticancer activity, but its anti-inflammatory potential remains elusive. In the present study, the anti-inflammatory effects and mechanism of EPS11 were evaluated using a lipopolysaccharide (LPS)-induced RAW264.7 macrophage model. Biochemical characterization showed that the total sugar content and protein content of EPS11 were 49.5% and 30.2% respectively. EPS11 was composed of mannose, glucosamine, galactosamine, glucose, galactose, rhamnose, and glucuronic acid. Its molecular weight was determined to be 3.06 × 10⁵ Da. The protein determination of EPS11 was also performed. EPS11 displayed a strong anti-inflammatory effect on LPS-stimulated RAW264.7 macrophages in vitro, which significantly suppressed inflammatory cytokines and mediators (such as NO, TNF-α, IL-6 and IL-1β, and COX-2). Western blot analysis indicated that EPS11 could downregulate the expression of many key proteins in mitogen-activated protein kinases (MAPKs) and transcription factor nuclear factor-κB (NF-κB) signaling pathways. In particular, EPS11 almost completely inhibited the expression of NF-κB P65, which indicated that EPS11 acted primarily on the NF-κB pathways. These findings offer new insights into the molecular mechanism underlying the anti-inflammatory effect of EPS11.

In vitro and in vivo anti-inflammatory activities of a fucose-rich fucoidan isolated from Saccharina japonica

A fucoidan (LJSF4) purified from Saccharina japonica was found to show a strong anti-inflammatory effect via activity assay in lipopolysaccharide (LPS) induced RAW 264.7 macrophage cells and zebrafish. Chemical and structural analysis indicated that LJSF4 with a sulfate content of 30.72% was composed of fucose, galactose, rhamnose, xylose and mannose with molar ratio percentages of 79.49%, 16.76%, 0.82%, 1.08% and 1.84%. NMR spectroscopy showed that LJSF4 is a polysaccharide with a backbone of alternating 1 → 3 linked α-l-fucopyranosyl and →4-α-l-fucopyranosyl with sulfate groups mainly at C-4 and partially at C-2 positions. Moreover, it also contained branches in the form of β-d-Galp-(1 → 4) units. The results of anti-inflammatory effect in vitro demonstrated that LJSF4 decreased the production of nitric oxide (NO) and cytokines, including TNF-α, IL-1β and IL-6. The mechanism revealed to be associated with the down-regulated expression of signal pathways including MAPK and NF-κB. By in vivo assay, LJSF4 showed a significantly protective effect by reducing the cell death rate, and the production of NO and ROS on LPS exposed zebrafish. Our results indicated that LJSF4 has the potential to be developed as an anti-inflammatory agent applied in functional food and cosmetic industries.

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

The water-soluble polysaccharide EP2, from Enteromorpha prolifera, belongs to the group of polysaccharides known as glucuronoxylorhamnan, which mainly contains glucuronic acid (GlcA), xylose (Xyl), and rhamnose (Rha). The aim of this study was to detect the immunomodulatory effects of EP2 on RAW 264.7 macrophages and cyclophosphamide (CYP)-induced immunosuppression mouse models. The cells were treated with EP2 for different time periods (0, 0.5, 1, 3, and 6 h). The results showed that EP2 promoted nitric oxide production and up-regulated the expression of pro-inflammatory cytokines, such as IL-1β, IL-6, and TNF-α, in a time-dependent manner. Furthermore, we found that EP2-activated iNOS, COX2, and NLRP3 inflammasomes, and the TLR4/MAPK/NF-κB signaling pathway played an important role. Moreover, EP2 significantly increased the body weight, spleen index, thymus index, inflammatory cell counts, and the levels of IL-1β, IL-6, and TNF-α in CYP-induced immunosuppression mouse models. These results indicate that EP2 might be a potential immunomodulatory drug and provide the scientific basis for the comprehensive utilization and evaluation of E. prolifera in future applications.

Protective Effect of a Fucose-Rich Fucoidan Isolated from Saccharina japonica against Ultraviolet B-Induced Photodamage In Vitro in Human Keratinocytes and In Vivo in Zebrafish

A fucose-rich fucoidan was purified from brown seaweed Saccharina japonica, of which the UVB protective effect was investigated in vitro in keratinocytes of HaCaT cells and in vivo in zebrafish. The intracellular reactive oxygen species levels and the viability of UVB-irradiated HaCaT cells were determined. The results indicate that the purified fucoidan significantly reduced the intracellular reactive oxygen species levels and improved the viability of UVB-irradiated HaCaT cells. Furthermore, the purified fucoidan remarkably decreased the apoptosis by regulating the expressions of Bax/Bcl-xL and cleaved caspase-3 in UVB-irradiated HaCaT cells in a dose-dependent manner. In addition, the in vivo UV protective effect of the purified fucoidan was investigated using a zebrafish model. It significantly reduced the intracellular reactive oxygen species level, the cell death, the NO production, and the lipid peroxidation in UVB-irradiated zebrafish in a dose-dependent manner. These results suggest that purified fucoidan has a great potential to be developed as a natural anti-UVB agent applied in the cosmetic industry.

Immunostimulatory Effect of Sulfated Galactans from the Green Seaweed Caulerpa cupressoides var. flabellata

Sulfated polysaccharides (SPs) obtained from green seaweeds are structurally heterogeneous molecules with multifunctional bioactivities. In this work, two sulfated and pyruvated galactans were purified from Caulerpa cupressoides var. flabellata (named SP1 and SP2), and their immunostimulatory effect was evaluated using cultured murine macrophage cells. Both SPs equally increased the production of nitric oxide, reactive oxygen species, and the proinflammatory cytokines TNF-α and IL-6. NMR spectroscopy revealed that both galactans were composed primarily of 3)-β-d-Galp-(1→3) units. Pyruvate groups were also found, forming five-membered cyclic ketals as 4,6-O-(1'carboxy)-ethylidene-β-d-Galp residues. Some galactoses are sulfated at C-2. In addition, only SP2 showed some galactose units sulfated at C-4, indicating that sulfation at this position is not essential for the immunomodulatory activity of these galactans. Overall, the data showed that the galactans of C. cupressoides exhibited immunostimulating activity with potential therapeutic applications, which can be used in the development of new biomedical products.

Designing selenium polysaccharides-based nanoparticles to improve immune activity of Hericium erinaceus

In previous researches, the results showed that selenium Hericium erinaceus polysaccharide and Hericium erinaceus polysaccharide-loaded poly (lactic-co-glycolic acid) nanoparticles enhanced immune responses. In order to further enhance the immune adjuvant activity and phagocytosis of the nanoparticles, two way of combination (selenium-HEP loaded PLGA nanoparticles and selenium modified HEP-PLGA nanoparticles) were prepared to investigate the effects on macrophages in vitro. After treatment with the nanoparticles, the effects of phagocytosis, co-stimulatory molecules expression, nitric oxide (NO), and cytokines secretion were evaluated. The results showed that the particle size, PDI and zeta potential of the selenium-HEP loaded PLGA nanoparticles (Se-HEP-PLGA) and selenium modifified HEP-PLGA nanoparticles (HEP-PLGA-Se) were presented. Se-HEP-PLGA and HEP-PLGA-Se nanoparticles significantly stimulated phagocytic activity, CD40 and CD86 expression of macrophages. In addition, the levels of NO, TNF-α, IL-1β and IL-6 were enhanced in the peritoneal macrophages by stimulation with Se-HEP-PLGA and HEP-PLGA-Se nanoparticles. Among them, Se-HEP-PLGA showed the best effects on the expression of co-stimulatory molecules, secretions of NO and cytokines. These results indicated that Se-HEP-PLGA could enhance the activation of macrophages, and it could be potentially used as an HEP delivery system for the induction of strong immune responses.

Effects of Laminaria Japonica Polysaccharides on the Survival of Non-Small-Cell Lung Cancer A549 Cells

Objective. To investigate the effect of Laminaria japonica polysaccharides (LJP) on the survival of non-small-cell lung cancer (NSCLC) A549 cells and its mechanism. Methods. In vitro: the cells were randomly divided into control group, LJP (5 mg/ml) group, LJP (10 mg/ml) group, and LJP (20 mg/ml) group. After corresponding treatment, the survival rate and the expression of proteins related to proliferation, apoptosis, epithelial-mesenchymal transition (EMT), and signaling pathway were detected by CCK8 assay and Western blot, respectively. In vivo: a xenograft model was established to detect the tumor volume and mass and the expression of the above pathway proteins. Results. Compared with the control group, LJP decreased the survival rate of A549 cells (P<0.05), inhibited the protein expression of Ki67 and PCNA (P<0.05), downregulated the expression of Bcl-2 while upregulated the expression of Bax, cl-caspase-3, and cl-caspase-9 (P<0.05), upregulated the expression of E-cadherin, downregulated the expression of vascular endothelial growth factor (VEGF) and N-cadherin (P<0.05), and downregulated β-catenin, transcription factor-4 (TCF4), and c-Myc protein expression levels (P<0.05). In vivo: LJP decreased the volume and mass of the xenograft tumors and downregulated β-catenin, TCF4, and c-Myc protein expression levels compared with the control group (P<0.05). Conclusion. LJP can inhibit the survival of non-small-cell lung cancer A549 cells in vitro, and its mechanism is related to the inhibition of activation of β-catenin/TCF4 pathway activation.

Structural characterization and immunostimulatory activity of a novel polysaccharide from green alga Caulerpa racemosa var peltata

A novel water-soluble polysaccharide (named CRVP-1) was successfully obtained from Caulerpa racemosa var peltata by hot-water extraction, ethanol precipitation, and column chromatography. The structure of CRVP-1 was characterized by HPGPC, HPAEC-PAD, FT-IR, GC-MS and NMR. The structural analysis indicated that CRVP-1 possessed a sulfate content of 25.8%±0.7% and was a heteropolysaccharide with an average molecular weight of 29.68kDa, and composed of mannose, galactose, glucose, galacturonic acid, and glucuronic acid with rates of 92.1%, 2.9%, 1.8%, 1.7% and 1.2%, respectively, owning a backbone structure of (1→6)-linked α-D-Manp residues with (1→4)-linked α-D-Manp and (1→2)-linked α-D-Manp residues and side chain that was consisted of (1→4)-linked β-D-Galp residues. The immunostimulatory assay revealed that CRVP-1 had significant effects on the proliferation of macrophage, production of NO and secretion of cytokines (TNF-α, IL-1β and IL-6). These findings provide a scientific basis for further utilization of polysaccharides from C. racemosa var peltata.

Caulerpa Cupressoides Var. Flabellata

Green seaweeds are rich sources of sulfated polysaccharides (SPs) with potential biomedical and nutraceutical applications. The aim of this work was to evaluate the immunostimulatory activity of SPs from the seaweed, Caulerpa cupressoides var. flabellata on murine RAW 264.7 macrophages. SPs were evaluated for their ability to modify cell viability and to stimulate the production of inflammatory mediators, such as nitric oxide (NO), intracellular reactive oxygen species (ROS), and cytokines. Additionally, their effect on inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) gene expression was investigated. The results showed that SPs were not cytotoxic and were able to increase in the production of NO, ROS and the cytokines, tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6). It was also observed that treatment with SPs increased iNOS and COX-2 gene expression. Together, these results indicate that C. cupressoides var. flabellata SPs have strong immunostimulatory activity, with potential biomedical applications.