Fucoidan stimulation induces a functional maturation of human monocyte-derived dendritic cells

Fucoidan from Durvillaea Antarctica enhances the anti-cancer effect of anti-PD-L1 antibody by activating dendritic cells and T cells

Immune checkpoint inhibitors are showing groundbreaking results in tumor immunotherapy. However, there are cases where treatment efficiency is insufficient due to limitations in immune activity, and various trials to overcome this are being studied. In this study, we investigated the immune activation ability of fucoidan extracted from Durvillaea antarctica (FDA) and whether it can enhance the anti-cancer effects of immune checkpoint inhibitors. FDA treatment resulted in an elevation of co-stimulator and major histocompatibility complex molecule expression, as well as the production of pro-inflammatory cytokines in bone marrow-derived and splenic dendritic cells (DCs). Administration of 50 mg/kg FDA increased the number of splenic CD8 T cells by >1.4-fold compared to PBS administration. Additionally, 50 mg/kg FDA increased the production of IFN-γ in CD4 and CD8 T cells by 4.3-fold and 7.2-fold, respectively, compared to the PBS control. FDA promoted immune cell activation was TLR4 dependent. Furthermore, anti-PD-L1 antibody administration inhibited CT-26 tumor growth by approximately 3-fold compared to the PBS control group, whereas combined treatment with FDA and anti-PD-L1 antibody showed an 8.4-fold tumor growth inhibition effect compared to the PBS control group. Therefore, FDA may be used to enhance the anti-cancer effects of immune checkpoint inhibitors.

Fucoidan may treat jellyfish dermatitis by inhibiting the inflammatory effect of jellyfish venom

Jellyfish dermatitis is a common medical problem caused by jellyfish stings. However, there are no targeted and effective medications for their treatment. Here, the biological activity of fucoidan for treatment of jellyfish dermatitis was investigated for the first time. 3 mg/mL Fucoidan attenuated the inflammatory effects of Nemopilema nomurai nematocyst venom (NnNV), including dermal toxicity and myotoxicity. Fucoidan may decrease the inflammatory effects of NnNV by downregulating MAPK and NF-κB pathways. This may be attributed to the inhibitory effect of fucoidan on metalloproteinases and phospholipase A2 (PLA2) in NnNV. 3 mg/mL fucoidan reduced the metalloproteinase activity in NnNV from 316.33 ± 20.84 U/mg to 177.33 ± 25.36 U/mg, while the inhibition of PLA2 activity in NnNV by 1 mg/mL fucoidan could reach 37.67 ± 3.42 %. Besides, external application of 3 mg/mL fucoidan can effectively alleviate the symptoms of jellyfish dermatitis. These observations suggest that fucoidan has considerable potential for treatment of jellyfish dermatitis and could be regarded as a novel medicine for jellyfish envenomation. This study provides new ideas for treatment of jellyfish envenomation and suggests evidence for the use of fucoidan in the treatment of jellyfish dermatitis as well as broadens the potential application of fucoidan in clinical practice.

Immunopotentiating Activity of Fucoidans and Relevance to Cancer Immunotherapy

Fucoidans, discovered in 1913, are fucose-rich sulfated polysaccharides extracted mainly from brown seaweed. These versatile and nontoxic marine-origin heteropolysaccharides have a wide range of favorable biological activities, including antitumor, immunomodulatory, antiviral, antithrombotic, anticoagulant, antithrombotic, antioxidant, and lipid-lowering activities. In the early 1980s, fucoidans were first recognized for their role in supporting the immune response and later, in the 1990s, their effects on immune potentiation began to emerge. In recent years, the understanding of the immunomodulatory effects of fucoidan has expanded significantly. The ability of fucoidan(s) to activate CTL-mediated cytotoxicity against cancer cells, strong antitumor property, and robust safety profile make fucoidans desirable for effective cancer immunotherapy. This review focusses on current progress and understanding of the immunopotentiation activity of various fucoidans, emphasizing their relevance to cancer immunotherapy. Here, we will discuss the action of fucoidans in different immune cells and review how fucoidans can be used as adjuvants in conjunction with immunotherapeutic products to improve cancer treatment and clinical outcome. Some key rationales for the possible combination of fucoidans with immunotherapy will be discussed. An update is provided on human clinical studies and available registered cancer clinical trials using fucoidans while highlighting future prospects and challenges.

A Review on Fucoidan Structure, Extraction Techniques, and Its Role as an Immunomodulatory Agent

Functional ingredients for human health have recently become the focus of research. One such potentially versatile therapeutic component is fucose-containing sulfated polysaccharides (FCSPs), referred to as fucoidans. The exploitation of marine brown algae provides a rich source of FCSPs because of their role as a structural component of the cell wall. Fucoidans are characterized by a sulfated fucose backbone. However, the structural characterization of FCSPs is impeded by their structural diversity, molecular weight, and complexity. The extraction and purification conditions significantly influence the yield and structural alterations. Inflammation is the preliminary response to potentially injurious inducements, and it is of the utmost importance for modulation in the proper direction. Improper manipulation and/or continuous stimuli could have detrimental effects in the long run. The web of immune responses mediated through multiple modulatory/cell signaling components can be addressed through functional ingredients, benefiting patients with no side effects. In this review, we attempted to address the involvement of FCSPs in the stimulation/downregulation of immune response cell signaling. The structural complexity and its foremost influential factor, extraction techniques, have also attracted attention, with concise details on the structural implications of bioactivity.

An ocean of possibilities: a review of marine organisms as sources of nanoparticles for cancer care

Seas and oceans have been explored for the last 70 years in search of new compounds that can support the battle against cancer. Marine polysaccharides can act as nanomaterials for medical applications and marine-derived bioactive compounds can be applied for the biosynthesis of metallic and nonmetallic nanoparticles. Nanooncology can be used in numerous fields including diagnostics, serving as drug carriers or acting as drugs. This review focuses on marine-derived nanoparticles with potential oncological applications. It classifies organisms used for nanoparticle production, explains the production process, presents different types of nanoparticles with prospective applications in oncology, describes the molecular pathways responsible for numerous nanomedicine applications, tags areas of nanoparticle implementation in oncology and speculates about future directions.

Regulation of immune cell metabolism in health and disease: Special focus on T and B cell subsets

Metabolism is a dynamic process and keeps changing from time to time according to the demand of a particular cell to meet its bio-energetic requirement. Different immune cells rely on distinct metabolic programs which allow the cell to balance its requirements for energy, molecular biosynthesis, and effector activity. In the aspect of infection and cancer immunology, effector T and B cells get exhausted and help tumor cells to evade immunosurveillance. On the other hand, T cells become hyperresponsive in the scenario of autoimmune diseases. In this article, we have explored the uniqueness and distinct metabolic features of key CD4⁺ T and B helper cell subsets, CD4⁺ T, B regulatory cell subsets and CD8⁺ T cells regarding health and disease. Th1 cells rely on glycolysis and glutaminolysis; inhibition of these metabolic pathways promotes Th1 cells in Treg population. However, Th2 cells are also dependent on glycolysis but an abundance of lactate within TME shifts their metabolic dependency to fatty acid metabolism. Th17 cells depend on HIF-1α mediated glycolysis, ablation of HIF-1α reduces Th17 cells but enhance Treg population. In contrast to effector T cells which are largely dependent on glycolysis for their differentiation and function, Treg cells mainly rely on FAO for their function. Therefore, it is of utmost importance to understand the metabolic fates of immune cells and how it facilitates their differentiation and function for different disease models. Targeting metabolic pathways to restore the functionality of immune cells in diseased conditions can lead to potent therapeutic measures.

Low molecular weight fucoidan alleviates cerebrovascular damage by promoting angiogenesis in type 2 diabetes mice

Diabetes leading to brain glucose metabolism disorders and cerebrovascular complications. Fucoidan is a kind of sulfated polysaccharides which found in brown algae, has multiply bioactivities and considered to be a promising therapeutic agent. Despite the increasing amount of evidence suggesting the diabetes protective role of fucoidans, the effect of fucoidan on brain abnormalities in type 2 diabetes mellitus patients remains unclear. In this study a low molecular weight fucoidan (LMWF) was obtained from Saccharina japonica and its effect on the cerebrovascular damage in db/db mice was investigated. Results were shown after LMWF treatment, the degree of cerebrovascular damage, the number of apoptotic neuronal cells and the inflammation were all decreased in db/db mice. Moreover, LMWF could up-regulates CD34 and VEGFA expression in db/db mice brain, and the subintestinal vessel angiogenesis in zebrafish was also promoted by LMWF. Moreover, the lumen formation of HUVEC endothelial cells was rescued by LMWF which was destroyed in high glucose treated endothelial cells. Further study found, LMWF alleviates vascular injury by up-regulating the expression level of phosphorylated PI3K and phosphorylated AKT. Our study indicates that LMWF has the potential to develop a cerebrovascular protection agent for type 2 diabetes patients.

In Vitro and In Vivo Dendritic Cell Immune Stimulation Effect of Low Molecular Weight Fucoidan from New Zealand Undaria pinnatifida

Low molecular weight fucoidan (LMWF) has been reported to have immunomodulation effects through the increase of the activation and function of macrophages. In this study, the regulating effect of LMWF from Undaria pinnatifida grown in New Zealand on dendritic cells (DCs) was investigated. We discovered that LMWF could stimulate DCs' maturation and migration, as well as CD4+ and CD8+ T cells' proliferation in vitro. We proved that this immune promoting activity is activated through TLR4 and its downstream MAPK and NF-κB signaling pathways. Further in vivo (mouse model) investigation showed that LMWF has a strong immunological boosting effect, such as facilitating the proliferation of immune cells and increasing the index of immune organs. These findings suggest that LMWF has a positive immunomodulatory effect and is a promising candidate to supplement cancer immunotherapy.

Low molecular weight fucoidan attenuating pulmonary fibrosis by relieving inflammatory reaction and progression of epithelial-mesenchymal transition

Diffuse alveolar injury and pulmonary fibrosis (PF) are the main causes of death of Covid-19 cases. In this study a low molecular weight fucoidan (LMWF) with unique structural was obtained from Laminaria japonica, and its anti- PF and anti-epithelial-mesenchymal transition (EMT) bioactivity were investigated both in vivo and in vitro. After LWMF treatment the fibrosis and inflammatory factors stimulated by Bleomycin (BLM) were in lung tissue. Immunohistochemical and Western-blot results found the expression of COL2A1, β-catenin, TGF-β, TNF-α and IL-6 were declined in mice lung tissue. Besides, the phosphorylation of PI3K and Akt were inhibited by LMWF. In addition, the progression of EMT induced by TGF-β1 was inhibited by LMWF through down-regulated both TGF-β/Smad and PI3K/AKT signaling pathways. These data indicate that unique LMWF can protect the lung from fibrosis by weakening the process of inflammation and EMT, and it is a promising therapeutic option for the treatment of PF.

Cancer-fighting potentials of algal polysaccharides as nutraceuticals

Cancer has been listed as one of the world's five incurable diseases by the World Health Organization and causes tens of thousands of deaths every year. Unfortunately, anticancer agents either show limited efficacy or show serious side effects. The algae possess high nutritional value and their polysaccharides have a variety of biological activities, especially anti-cancer and immunomodulatory properties. Algal polysaccharides exert anti-cancer effects by inducing apoptosis, cell cycle arrest, anti-angiogenesis, and regulating intestinal flora and immune function. Algal polysaccharides can be combined with nanoparticles and other drugs to reduce the side effects caused by chemotherapy and increase the anticancer effects. This review shows the signal pathways related to the anti-cancer mechanisms of algal polysaccharides, including their influence on intestinal flora and immune regulation, the application of nanoparticles, and the effects on combination therapy and clinical trials of cancer treatments.

The role of algal fucoidans in potential anti-allergic therapeutics

Allergic diseases are among the commonest causes of chronic ill-health and are rapidly rising the prevalence and complexity. Although the current drugs are efficacy for treatment of allergic diseases, however the extensive clinical use of these drugs has led to the diverse and undesirable side effects. Thus, the extensive studies of alternative anti-allergic agents from natural products are essential for a long-term purpose. Marine environment covers a huge source of extremely potential secondary metabolites for drug discovery. Among them, fucoidans from brown seaweeds have been evidenced to possess various biological activities and health benefit effects. Notably, a great deal of interest has been expressed regarding anti-allergic activity of fucoidans. Consequently, this contribution presents an overview of potential anti-allergic therapeutics of fucoidans from brown seaweeds to emphasize its functions in prevention as well as treatment of allergic diseases.

Multifunctional role of fucoidan, sulfated polysaccharides in human health and disease: A journey under the sea in pursuit of potent therapeutic agents

Fucoidan is a complex polysaccharide (molecular weight 10,000-100,000 Da) derived from brown algae which comprises of L-fucose and sulfate groups have potential as therapeutic diligences against several human diseases. The fucoidan has expanded a widespread range of pharmacological properties as an anti-inflammatory, anticoagulant, antiangiogenic, immunomodulatory, anti-adhesive, anticancer, antidiabetic, antiviral and anti-neurodegenerative agents owing to their diverse chemical conformation and potent antioxidant activity. The antioxidant and immunomodulatory activities of the fucoidan contribute towards their disease preventive potency through dynamic modulation of key intracellular signalling pathways, regulation of ROS accumulation, and maintenance of principal cell survival and death pathways. Additionally, it also reduces cancer-associated cachexia. Despite the wide range of therapeutic potency, the fucoidan is heavily regarded as an unexplored plethora of druggable entities in the current situation. The isolation, screening, biological application, pre-clinical, and clinical assessment along with large scale cost-effective production remain a foremost task to be assessed. Moreover, the chemical synthesis of the present bioactive drug with confirmational rearrangement for enhanced availability and bioactivity also need tenacious investigation. Hence, in the present review, we give attention to the source of isolation of fucoidan, their principle strategic deployment in disease prevention, and the mechanistic investigation of how it works to combat different diseases that can be used for future therapeutic intervention.

Current Designs and Developments of Fucoidan-based Formulations for Cancer Therapy

BACKGROUND

Natural nanostructure materials have been involved in antitumor drug delivery systems due to their biocompatibility, biodegradation, and bioactive properties.

METHODS

These materials have contributed to advanced drug delivery systems in the roles of both bioactive compounds and delivery nanocarriers. Fucoidan, a valuable ocean material used in drug delivery systems, has been exploited in research on cancer and a variety of other diseases.

RESULTS

Although the uniqueness, structure, properties, and health benefits of fucoidan have been mentioned in various prominent reviews, current developments and designs of fucoidan-based formulations still need to be assessed to further develop an effective anticancer therapy. In this review, current important formulations using fucoidan as a functional material and as an anticancer agent will be discussed. This article will also provide a brief principle of the methods that incorporate functional nanostructure materials in formulations exploiting fucoidan.

CONCLUSION

Current research and future perspectives on the use of fucoidan in anticancer therapy will advance innovative and important products for clinical uses.

Immunoadjuvant Activity of Fucoidans from the Brown Alga Fucus evanescens

Thе study presents the results of a comparative evaluation of the effect of structural modifications of fucoidans from the brown alga Fucus evanescens (native, highly purified рroduct of fucoidan enzymatic hydrolysis, a new regular 1→3;1→4-α-L-fucan, sulphated mainly at C2 and acetylated at C4 of the fucose residue) on the effector functions of innate and adaptive immunity cells in vitro and in vivo. Using flow cytometry, we found that all examined fucoidans induce the maturation of dendritic cells, enhance the ability of neutrophils to migrate and adhere, activate monocytes and enhance their antigen-presenting functions, and increase the cytotoxic potential of natural killers. Fucoidans increase the production of hepatitis B virus (HBs) specific IgG and cytokine Th1 (IFN-γ, TNF-α) and Th2 (IL-4) profiles in vivo. The data obtained suggest that in vitro and in vivo adjuvant effects of the products of fucoidan enzymatic hydrolysis with regular structural characteristics are comparable to those of the native fucoidan. Based on these data, the products of fucoidan enzymatic hydrolysis can be considered as an effective and safe candidate adjuvant to improve the efficacy of prophylactic and therapeutic vaccines.

Immune-modulating and anti-inflammatory marine compounds against cancer

The recent advances in cancer immunotherapy confirm the crucial role of the immune system in cancer progression and treatment. Chronic inflammation and reduced immune surveillance are both features of the tumor microenvironment. Strategies aimed at reverting pro-tumor inflammation and stimulating the antitumor immune components are being actively searched, and the anticancer effects of many candidate drugs have been linked to their ability to modulate the immune system. Marine organisms constitute a rich reservoir of new bioactive molecules; some of them have already been exploited for pharmaceutical use, whereas many others are undergoing clinical or preclinical investigations for the treatment of different diseases, including cancer. In this review, we will discuss the immune-modulatory properties of marine compounds for their potential use in cancer prevention and treatment and as possible tools in the context of cancer immunotherapy.

Fucoidan inhibits tooth movement by promoting restorative macrophage polarization through the STAT3 pathway

Retention after treatment and effective anchorage control are two essential factors in orthodontics. Our study aimed to explore the effects of fucoidan on orthodontic tooth movement (OTM) and the involvement of macrophages. We established a murine OTM model to test the effect of fucoidan administration. We found that mice injected with fucoidan had a deceleration in OTM and a higher bone mineral density. Moreover, fucoidan increased the proportion of F4/80⁺ CD206⁺ macrophages and promoted the messenger RNA expression of Arg-1, CD206, and IL-10 at both in vivo and in vitro levels. In addition, macrophages showed lower expression of TNF-α, IL-1β, and IL-6 and a decrease in F4/80⁺ CD11c⁺ cells. Mechanistically, the level of phosphorylated STAT3 was elevated in unpolarized and restorative macrophages after treatment with fucoidan. Taken together, our findings suggest that fucoidan treatment inhibits OTM and enhances the stability of teeth after movement by promoting restorative macrophages through the STAT3 pathway.

Translational Research Symposium-collaborative efforts as driving forces of healthcare innovation

The 5th Translational Research Symposium was organised at the annual meeting of the European Society for Biomaterials 2018, Maastricht, the Netherlands, with emphasis on the future of emerging and smart technologies for healthcare in Europe. Invited speakers from academia and industry highlighted the vision and expectations of healthcare in Europe beyond 2020 and the perspectives of innovation stakeholders, such as small and medium enterprises, large companies and Universities. The aim of the present article is to summarise and explain the main statements made during the symposium, with particular attention on the need to identify unmet clinical needs and their efficient translation into healthcare solutions through active collaborations between all the participants involved in the value chain.

Dietary Supplementation with Low-Molecular-Weight Fucoidan Enhances Innate and Adaptive Immune Responses and Protects against Mycoplasma pneumoniae Antigen Stimulation

In this study, the low-molecular-weight (LMW) fucoidan, rich in fucose and sulfate, was extracted and purified from the edible brown seaweed, Laminaria japonica. In this study, we orally administered LMW fucoidan to mice for 6 weeks. We then examined fucoidan's effects on innate immunity, adaptive immunity, and Mycoplasma pneumoniae (MP)-antigen-stimulated immune responses. Our data showed that LMW fucoidan stimulated the innate immune system by increasing splenocyte proliferation, natural killer (NK) cell activity, and phagocytic activity. LMW fucoidan also increased interleukin (IL)-2, IL-4, and interferon (IFN)-γ secretion by splenocytes and immunoglobulin (Ig)-G and IgA content in serum, which help regulate adaptive immune cell functions, and decreased allergen-specific IgE. In MP-antigen-stimulated immune responses, the IgM and IgG content in the serum were significantly higher in the LMW fucoidan group after MP-antigen stimulation. Our study provides further information about the immunomodulatory effects of LMW fucoidan and highlights a potential role in preventing M. pneumoniae infection.

The effect of dietary fucoidan on growth, immune functions, blood characteristics and oxidative stress resistance of juvenile red sea bream, Pagrus major

We determined the supplementation effects of dietary fucoidan on growth, immune responses, blood characteristics, and oxidative stress resistance of juvenile red sea bream. A fishmeal (FM)-based basal diet supplemented with 0% (D1, control), 0.05% (D2), 0.1% (D3), 0.2% (D4), 0.4% (D5), and 0.8% (D6) mozuku fucoidan to formulate six experimental diets. Each diet was randomly allocated to triplicate groups of fish (3.8 g) for 60 days. Results showed that fish-fed diet D5 showed significantly higher (P < 0.05) growth performance compared to the control (D1). Diet groups D2 to D4 also showed intermediate values compared to D1. Feed conversion efficiency and protein efficiency ratio were significantly higher in diet group D5, which was not significantly different with D3. Fucoidan supplementation increased whole-body lipid, which was significantly higher in the D5 group. Condition factor (CF) was significantly higher in fish fed ≥ 0.2% fucoidan-supplemented diet groups. Diet group D5 and D4 showed significantly lower blood urea nitrogen (BUN) and aspartate aminotransferase (AST) level, respectively. Dietary fucoidan reduced the oxidative stress of fish. Among the measured nonspecific immune parameters, only peroxidase activity (PA) and total serum protein (TSP) were significantly influenced by dietary supplementation and it was higher in D4 group. Fucoidan supplementation reduces thiobarbituric acid reactive substance (TBARS) values numerically and it was lowest in fish-fed diet group D5. Under the present experimental condition, finally, we concluded that 0.3-0.4% dietary fucoidan supplementation enhanced the growth and health performance of red sea bream by increasing growth, immune response, blood characteristics, and oxidative stress resistance.

Fucoidan-Manganese Dioxide Nanoparticles Potentiate Radiation Therapy by Co-Targeting Tumor Hypoxia and Angiogenesis

Tumor hypoxia is a major mechanism of resistance to radiation therapy (RT), which is associated with poor prognosis in affected cancer patients. Various approaches to treat hypoxic and radioresistant cancers, including pancreatic cancer, have shown limited success. Fucoidan, a polysaccharide from brown seaweed, has antitumor and antiangiogenesis activities. Here, we discuss the development of fucoidan-coated manganese dioxide nanoparticles (Fuco-MnO₂-NPs) and testing of the therapeutic potential with RT using pancreatic cancer models. In vitro data showed that Fuco-MnO₂-NPs generated oxygen efficiently in the presence of H₂O₂ and substantially suppressed HIF-1 expression under a hypoxic condition in human pancreatic cancer cells. Fuco-MnO₂-NPs reversed hypoxia-induced radioresistance by decreasing clonogenic survival and increasing DNA damage and apoptotic cell death in response to RT. In a BxPC3 xenograft mouse model, the combination treatment with Fuco-MnO₂-NPs and RT resulted in a greater tumor growth delay than RT alone. Fucoidan-coated NPs, but not naked ones, further suppressed tumor angiogenesis, as judged by immunohistochemistry data with diminished expression of phosphorylated vascular endothelial growth factor receptor 2 (VEGFR2) and CD31. These data suggest that Fuco-MnO₂-NPs may potentiate the effects of RT via dual targeting of tumor hypoxia and angiogenesis, and they are of great clinical potential in the treatment of hypoxic, radioresistant pancreatic cancer.

Host-Directed Drug Therapies for Neglected Tropical Diseases Caused by Protozoan Parasites

The neglected tropical diseases (NTDs) caused by protozoan parasites are responsible for significant morbidity and mortality worldwide. Current treatments using anti-parasitic drugs are toxic and prolonged with poor patient compliance. In addition, emergence of drug-resistant parasites is increasing worldwide. Hence, there is a need for safer and better therapeutics for these infections. Host-directed therapy using drugs that target host pathways required for pathogen survival or its clearance is a promising approach for treating infections. This review will give a summary of the current status and advances of host-targeted therapies for treating NTDs caused by protozoa.

Laminarin promotes anti-cancer immunity by the maturation of dendritic cells

This research evaluates the effects of laminarin on the maturation of dendritic cells and on the in vivo activation of anti-cancer immunity. In vivo treatment of C56BL/6 mice with laminarin increased the expression levels of co-stimulatory molecules and the production of pro-inflammatory cytokines in spleen dendritic cells. Laminarin enhanced ovalbumin antigen presentation in spleen dendritic cells and promoted the proliferation of OT-I and OT-II T cells. Laminarin also induced the maturation of dendritic cells in tumor-draining lymph nodes and protected interferon-γ and tumor necrosis factor-α and proliferation of OT-I and OT-II T cells in tumors. The combination treatment of laminarin and ovalbumin inhibited B16-ovallbumin melanoma tumor growth and its liver metastasis by antigen-specific immune activation, including cytotoxic T lymphocyte activation and interferon-γ production. Thus, these data demonstrated the potential of laminarin as a new and useful immune stimulatory molecule for use in cancer immunotherapy.

Fucoidan Prolongs the Circulation Time of Dextran-Coated Iron Oxide Nanoparticles

The magnetic properties and safety of dextran-coated superparamagnetic iron oxide nanoparticles (SPIONs) have facilitated their clinical use as MRI contrast agents and stimulated research on applications for SPIONs in particle imaging and magnetic hyperthermia. The wider clinical potential of SPIONs, however, has been limited by their rapid removal from circulation via the reticuloendothelial system (RES). We explored the possibility of extending SPION circulatory time using fucoidan, a seaweed-derived food supplement, to inhibit RES uptake. The effects of fucoidan on SPION biodistribution were evaluated using ferucarbotran, which in its pharmaceutical formulation (Resovist) targets the RES. Ferucarbotran was radiolabeled at the iron oxide core with technetium-99m (99mTc; t1/2 = 6 h) or zirconium-89 (89Zr; t1/2 = 3.3 days). Results obtained with 99mTc-ferucarbotran demonstrated that administration of fucoidan led to a 4-fold increase in the circulatory half-life (t1/2 slow) from 37.4 to 150 min (n = 4; P < 0.0001). To investigate whether a longer circulatory half-life could lead to concomitant increased tumor uptake, the effects of fucoidan were tested with 89Zr-ferucarbotran in mice bearing syngeneic subcutaneous (GL261) tumors. In this model, the longer circulatory half-life achieved with fucoidan was associated with a doubling in tumor SPION uptake (n = 5; P < 0.001). Fucoidan was also effective in significantly increasing the circulatory half-life of perimag-COOH, a commercially available SPION with a larger hydrodynamic size (130 nm) than ferucarbotran (65 nm). These findings indicate successful diversion of SPIONs away from the hepatic RES and show realistic potential for future clinical applications.

Antiviral activity of a polysaccharide from Laminaria japonica against enterovirus 71

This in vitro study investigated the antiviral activity of an acidic polysaccharide from Laminaria japonica against enterovirus 71 (EV71) as well as its mechanism of action. The LJ04 polysaccharide was purified from Laminaria japonica by affinity chromatography. To investigate its antiviral activity, an MTT assay, q-PCR, immunofluorescent staining and western-blot analysis were performed. To define its mechanism of action, ELISA, q-PCR and flow cytometry were conducted. LJ04 had a low EC50, high CC50 and high SI. LJ04 inhibited not only JN200804, but also JN200803 in RD cells, and viral proliferation was strongly inhibited, whereas LJ04 suppressed viral-induced apoptosis as detected by flow cytometry. In conclusion, LJ04 was found to have robust antiviral activity by inhibiting apoptosis and inducing IFN-β expression. Our findings indicate that LJ04 is a good candidate for the treatment of EV71.

Fucoidan inhibits CCL22 production through NF-κB pathway in M2 macrophages: a potential therapeutic strategy for cancer

In tumor microenvironment, macrophages as a polarized M2 population promote tumor progression via releasing multiple cytokines and chemokines. A brown seaweed fucose-rich polysaccharide, fucoidan has antitumor activity and immune modulation through affecting tumor cells and lymphocytes. Here, we focused on the effect of fucoidan on macrophages especially M2 subtype. Our results demonstrated that fucoidan down-regulated partial cytokines and chemokines, especially a M2-type chemokine CCL22. Furthermore, fucoidan inhibited tumor cells migration and CD4⁺ T lymphocytes, especially Treg cells, recruitment induced by M2 macrophages conditioned medium through suppression of CCL22. Mechanismly, fucoidan inhibited CCL22 via suppressing p65-NF-κB phosphorylation and nuclear translocation. In addition, p38-MAPK and PI3K-AKT also affected the expression of CCL22 through differential modulation of NF-κB transcriptional activity. Taken together, we reveal an interesting result that fucoidan can inhibit tumor cell migration and lymphocytes recruitment by suppressing CCL22 in M2 macrophages via NF-κB-dependent transcription, which may be a novel and promising mechanism for tumor immunotherapy.

Fucoidans in Nanomedicine

Fucoidans are widespread cost-effective sulfated marine polysaccharides which have raised interest in the scientific community over last decades for their wide spectrum of bioactivities. Unsurprisingly, nanomedicine has grasped these compounds to develop innovative therapeutic and diagnostic nanosystems. The applications of fucoidans in nanomedicine as imaging agents, drug carriers or for their intrinsic properties are reviewed here after a short presentation of the main structural data and biological properties of fucoidans. The origin and the physicochemical specifications of fucoidans are summarized in order to discuss the strategy of fucoidan-containing nanosystems in Human health. Currently, there is a need for reproducible, well characterized fucoidan fractions to ensure significant progress.

Looking Beyond the Terrestrial: The Potential of Seaweed Derived Bioactives to Treat Non-Communicable Diseases

Seaweeds are a large and diverse group of marine organisms that are commonly found in the maritime regions of the world. They are an excellent source of biologically active secondary metabolites and have been shown to exhibit a wide range of therapeutic properties, including anti-cancer, anti-oxidant, anti-inflammatory and anti-diabetic activities. Several Asian cultures have a strong tradition of using different varieties of seaweed extensively in cooking as well as in herbal medicines preparations. As such, seaweeds have been used to treat a wide variety of health conditions such as cancer, digestive problems, and renal disorders. Today, increasing numbers of people are adopting a "westernised lifestyle" characterised by low levels of physical exercise and excessive calorific and saturated fat intake. This has led to an increase in numbers of chronic Non-communicable diseases (NCDs) such as cancer, cardiovascular disease, and diabetes mellitus, being reported. Recently, NCDs have replaced communicable infectious diseases as the number one cause of human mortality. Current medical treatments for NCDs rely mainly on drugs that have been obtained from the terrestrial regions of the world, with the oceans and seas remaining largely an untapped reservoir for exploration. This review focuses on the potential of using seaweed derived bioactives including polysaccharides, antioxidants and fatty acids, amongst others, to treat chronic NCDs such as cancer, cardiovascular disease and diabetes mellitus.

Effects of Laminaria japonica polysaccharides on airway inflammation of lungs in an asthma mouse model

Background

Asthma is a serious chronic inflammatory disease affecting 300 million people worldwide. This aim of this study to investigate the anti-inflammatory and anti-asthmatic effects of Laminaria japonica extract in the ovalbumin (OVA)-induced mouse asthma model.

Methods

A mouse asthma model was established in SPF Kunming mice by OVA-sensitization followed by inhalation of aerosol allergen for two weeks. Laminaria japonica polysaccharides (LJPS) were given by gavage feeding at 50 mg/kg/day during OVA inhalation challenge period, and their effect on asthma was compared with the standard treatment of Budesonide inhalation. The total inflammatory cells and eosinophils in bronchoalveolar lavage fluid (BALF) were determined. Histopathological changes in lung tissue were studied and scored to determine the degree of inflammation. Levels of IL-12, IL-13, and TGF-β1 in BALF as well as serum levels of IgE were measured. Expressions of IL-12, IL-13, and TGF-β1 in lung tissues were assessed.

Results

Highly inflammatory lungs infiltrated with significant increased eosinophils were observed in OVA-induced asthmatic mice. The OVA treated mice presented with a lower level of IL-12 and higher levels of IL-13 and TGF-β1 in BALF and lung tissues, as well as an increased level of the serum IgE. Treatment with LJPS (Group B) significantly decreased the numbers of eosinophils in the BALF (P < 0.05) and alleviated lung inflammation compared to the untreated asthma mice (Group A). It also reduced the serum IgE levels, increased expression of IL-12, and decreased the expression of IL-13 and TGF-β1 in BALF and lung (Both P < 0.05) compared with the group A.

Conclusions

LJPS can significantly inhibit airway inflammation of asthmatic mice, adjust the balance of cytokines, and improve the pulmonary histopathological condition. Our data suggested that LJPS might be a potential therapeutic reagent for allergic asthma.

The adjuvant effects of high-molecule-weight polysaccharides purified from Antrodia cinnamomea on dendritic cell function and DNA vaccines

The biological activity of the edible basidiomycete Antrodia cinnamomea (AC) has been studied extensively. Many effects, such as anti-cancer, anti-inflammatory, and antioxidant activities, have been reported from either crude extracts or compounds isolated from AC. However, research addressing the function of AC in enhancing immunity is rare. The aim of the present study is to investigate the active components and the mechanism involved in the immunostimulatory effect of AC. We found that polysaccharides (PS) in the water extract of AC played a major role in dendritic cell (DC) activation, which is a critical leukocyte in initiating immune responses. We further size purified and identified that the high-molecular weight PS fraction (greater than 100 kDa) exhibited the activating effect. The AC high-molecular weight PSs (AC hmwPSs) promoted pro-inflammatory cytokine production by DCs and the maturation of DCs. In addition, DC-induced antigen-specific T cell activation and Th1 differentiation were increased by AC hmwPSs. In studying the molecular mechanism, we confirmed the activation of the MAPK and NF-κB pathways in DCs after AC hmwPSs treatment. Furthermore, we demonstrated that TLR2 and TLR4 are required for the stimulatory activity of AC hmwPSs on DCs. In a mouse tumor model, we demonstrated that AC hmwPSs enhanced the anti-tumor efficacy of the HER-2/neu DNA vaccine by facilitating specific Th1 responses. Thus, we conclude that hmwPSs are the major components of AC that stimulate DCs via the TLR2/TLR4 and NF-κB/MAPK signaling pathways. The AC hmwPSs have potential to be applied as adjuvants.

Fucoidan from Macrocystis pyrifera has powerful immune-modulatory effects compared to three other fucoidans

Fucoidan, a sulfated polysaccharide purified from brown algae, has a variety of immune-modulation effects, such as promoting activation of dendritic cells (DCs), natural killer (NK) cells and T cells, and enhancing anti-viral and anti-tumor responses. However, the immune-modulatory effect of fucoidan from different seaweed extracts has not been thoroughly analyzed and compared. We analyzed fucoidans obtained from Ascophyllum nodosum (A. nodosum), Macrocystis pyrifera (M. pyrifera), Undaria pinnatifida (U. pinnatifida) and Fucus vesiculosus (F. vesiculosus) for their effect on the apoptosis of human neutrophils, activation of mouse NK cells, maturation of spleen DCs, proliferation and activation of T cells, and the adjuvant effect in vivo. Fucoidans from M. pyrifera and U. pinnatifida strongly delayed human neutrophil apoptosis at low concentration, whereas fucoidans from A. nodosum and F. vesiculosus delayed human neutrophil apoptosis at higher concentration. Moreover, fucoidan from M. pyrifera promoted NK cell activation and cytotoxic activity against YAC-1 cells. In addition, M. pyrifera fucoidan induced the strongest activation of spleen DCs and T cells and ovalbumin (OVA) specific immune responses compared to other fucoidans. These data suggest that fucoidan from M. pyrifera can be potentially useful as a therapeutic agent for infectious diseases, cancer and an effective adjuvant for vaccine.

Evaluation of adjuvant effects of fucoidan for improving vaccine efficacy

Fucoidan is a sulfated polysaccharide derived from brown seaweed, including Fucus vesiculosus. This compound is known to have immunostimulatory effects on various types of immune cells including macrophages and dendritic cells. A recent study described the application of fucoidan as a vaccine adjuvant. Vaccination is regarded as the most efficient prophylactic method for preventing harmful or epidemic diseases. To increase vaccine efficacy, effective adjuvants are needed. In the present study, we determined whether fucoidan can function as an adjuvant using vaccine antigens. Flow cytometric analysis revealed that fucoidan increases the expression of the activation markers major histocompatibility complex class II, cluster of differentiation (CD)25, and CD69 in spleen cells. In combination with Bordetella bronchiseptica antigen, fucoidan increased the viability and tumor necrosis factor-α production of spleen cells. Furthermore, fucoidan increased the in vivo production of antigen-specific antibodies in mice inoculated with Mycoplasma hyopneumoniae antigen. Overall, this study has provided valuable information about the use of fucoidan as a vaccine adjuvant.

Effects of dietary fucoidan on the blood constituents, anti-oxidation and innate immunity of juvenile yellow catfish (Pelteobagrus fulvidraco)

This experiment was conducted to investigate the effects of fucoidan on the blood constituents, anti-oxidation and innate immunity of juvenile yellow catfish, Pelteobagrus fulvidraco. Totally 420 individuals of juvenile yellow catfish were randomly allocated to 7 groups with 3 replicates per group and 20 fishes per replicate. The same experimental fish were randomly subjected to one of the following 7 treatments for 12 weeks: The basal diet was applied as control group, the experimental groups were fed on fucoidan extracted from Sargassum horneri (SF) and commodity fucoidan purchased from the market (MF), and the effective dosages were 0.05%, 0.1% and 0.2% per kilogram feed (the groups were respectively marked as SF1, SF2, SF3, MF1, MF2 and MF3). The capabilities of anti-oxidation and innate immunity were detected by the blood characters, serum enzyme activities, serum MDA content, respiratory burst activity and phagocytic index of head-kidney macrophages. Challenge test was conducted also. The results indicated that the triglyceride (TG) and total cholesterol (TC) values of the yellow catfish were significantly decreased when dietary with SF and MF, while there was no significant difference between the MF1 and the control group. Fish fed on SF and MF diets had a lower high density lipoprotein-cholesterol (HDL-C) level than those fed on basal diet except SF2 group. The low density lipoprotein-cholesterol (LDL-C) and glucose (GUL) levels of the fish were significantly decreased at the 0.2% dietary fucoidan level, and there were no significant differences between the other groups. The activities of serum superoxide dismutase (SOD) significantly increased and the contents of malondialdehyde (MDA) significantly decreased when the fish fed dietary SF and MF. The CAT activities of SF groups were higher than that of control groups, while these values were not significantly changed in MF1 and MF3 groups. The maximum of catalase (CAT) activities of the fish fed on two kind fucoidan were obtained in the SF2 and MF2 groups (fucoidan = 0.1%) respectively. The serum lysozyme (LZM) activities of the yellow catfish fed on SF and MF were significantly higher than the control ones except SF3, MF2 and MF3 group. Phagocytosis index (PI) and the respiratory burst (RB) activity of head-kidney were significantly influenced by dietary fucoidan, PI values of the fish fed on SF2, MF1 and MF2 were higher than those fed on basal diet. RB activity of the yellow catfishes were significantly increased when they were fed on fucoidan except the SF3 and MF3 groups. The challenge experiment with Aeromonas hydrophilalala revealed that the fish fed on fucoidan had no significant effect on mortality rate of the yellow catfish. These results suggested that fucoidan significantly influences the blood characters, antioxidant status, non-specific immune responses in juvenile yellow catfish.

[Effect of sulfated polysaccharides from brown seaweed Laminaria japonica on the morfology of lymfoid organs and functional characteristics of immunocompetent cells]

The effect of sulfated polysaccharide fucoidan from the brown alga Laminaria japonica on morphological characteristics of mouse lymphoid organs, subpopulations of spleen mononuclear leukocytes, cytokine production and cytotoxic activity of splenocytes has been investigated. Fucoidan promoted activation and proliferation of lymphoid hematopoietic cells in primary and secondary immunogenesis bodies, increased expression of markers CD19, NK, NKT, CD25, MHC II, TCR, TLR2 and TLR4, the cytotoxic activity of splenocytes and production of immunoregulatory and proinflammatory cytokines (IL- 2, IL-12, IFN-g, TNF-a, IL-6). This suggests activation of effector mechanisms of innate immunity and adaptive immune responses via the Th-1 type.

Ascophyllan purified from Ascophyllum nodosum induces Th1 and Tc1 immune responses by promoting dendritic cell maturation

Marine-derived sulfated polysaccharides have been shown to possess certain anti-virus, anti-tumor, anti-inflammatory and anti-coagulant activities. However, the in vivo immunomodulatory effects of marine-derived pure compounds have been less well characterized. In this study, we investigated the effect of ascophyllan, a sulfated polysaccharide purified from Ascophyllum nodosum, on the maturation of mouse dendritic cells (DCs) in vitro and in vivo. Ascophyllan induced up-regulation of co-stimulatory molecules and production of pro-inflammatory cytokines in bone marrow-derived DCs (BMDCs). Moreover, in vivo administration of ascophyllan promotes up-regulation of CD40, CD80, CD86, MHC class I and MHC class II and production of IL-6, IL-12 and TNF-α in spleen cDCs. Interestingly, ascophyllan induced a higher degree of co-stimulatory molecule up-regulation and pro-inflammatory cytokine production than fucoidan, a marine-derived polysaccharide with well-defined effect for promoting DC maturation. Ascophyllan also promoted the generation of IFN-γ-producing Th1 and Tc1 cells in the presence of DCs in an IL-12-dependent manner. Finally, myeloid differentiation primary response 88 (MyD88) signaling pathway was essential for DC maturation induced by ascophyllan. Taken together, these results demonstrate that ascophyllan induces DC maturation, and consequently enhances Th1 and Tc1 responses in vivo. This knowledge could facilitate the development of novel therapeutic strategies to combat infectious diseases and cancer.

Fucoidan can function as an adjuvant in vivo to enhance dendritic cell maturation and function and promote antigen-specific T cell immune responses

Fucoidan, a sulfated polysaccharide purified from brown algae, has a variety of immune-modulation effects, including promoting antigen uptake and enhancing anti-viral and anti-tumor effects. However, the effect of fucoidan in vivo, especially its adjuvant effect on in vivo anti-tumor immune responses, was not fully investigated. In this study, we investigated the effect of fucoidan on the function of spleen dendritic cells (DCs) and its adjuvant effect in vivo. Systemic administration of fucoidan induced up-regulation of CD40, CD80 and CD86 expression and production of IL-6, IL-12 and TNF-α in spleen cDCs. Fucoidan also promoted the generation of IFN-γ-producing Th1 and Tc1 cells in an IL-12-dependent manner. When used as an adjuvant in vivo with ovalbumin (OVA) antigen, fucoidan promoted OVA-specific antibody production and primed IFN-γ production in OVA-specific T cells. Moreover, fucoidan enhanced OVA-induced up-regulation of MHC class I and II on spleen cDCs and strongly prompted the proliferation of OVA-specific CD4 and CD8 T cells. Finally, OVA immunization with fucoidan as adjuvant protected mice from the challenge with B16-OVA tumor cells. Taken together, these results suggest that fucoidan can function as an adjuvant to induce Th1 immune response and CTL activation, which may be useful in tumor vaccine development.

Fucoidan as a marine anticancer agent in preclinical development

Fucoidan is a fucose-containing sulfated polysaccharide derived from brown seaweeds, crude extracts of which are commercially available as nutritional supplements. Recent studies have demonstrated antiproliferative, antiangiogenic, and anticancer properties of fucoidan in vitro. Accordingly, the anticancer effects of fucoidan have been shown to vary depending on its structure, while it can target multiple receptors or signaling molecules in various cell types, including tumor cells and immune cells. Low toxicity and the in vitro effects of fucoidan mentioned above make it a suitable agent for cancer prevention or treatment. However, preclinical development of natural marine products requires in vivo examination of purified compounds in animal tumor models. This review discusses the effects of systemic and local administration of fucoidan on tumor growth, angiogenesis, and immune reaction and whether in vivo and in vitro results are likely applicable to the development of fucoidan as a marine anticancer drug.

Anticancer and cancer preventive properties of marine polysaccharides: some results and prospects

Many marine-derived polysaccharides and their analogues have been reported as showing anticancer and cancer preventive properties. These compounds demonstrate interesting activities and special modes of action, differing from each other in both structure and toxicity profile. Herein, literature data concerning anticancer and cancer preventive marine polysaccharides are reviewed. The structural diversity, the biological activities, and the molecular mechanisms of their action are discussed.

Structural analysis of heteropolysaccharide from Saccharina japonica and its derived oligosaccharides

Degraded fucoidan (F1) was desulfated by DMSO-MeOH. And anion exchange chromatography was performed to fractionate desulfated F1 (ds-F1) into five fractions. Electrospray ionization mass spectrometry (ESI-MS) showed that each fraction contained at least one set of neutral and/or sulfated fucooligosaccharides in the form of methyl glycosides. And the structures of oligomeric fragments were characterized by ESI-CID-MS/MS and ESI-CID-MS/MS/MS. In addition, more structural features were shown by NMR. Therefore, it was concluded that LF1 contained a backbone of (1→3)-linked fucopyranose residues sulfated at C-4 and branched at C-2 by fucopyranose residues and fucoglucuronomannan, fucoglucuronan, galactan and xylan were found in LF-5. Finally, it was concluded that F1 was the middle component, which contained the information of both F0.5 and F2, indicating that the differences between F1 and F0.5, F2 might be derived primarily from the different needs of algae itself.

The Pseudomonas aeruginosa Mannose Sensitive Hamemagglutination Strain (PA-MSHA) Induces a Th1-Polarizing Phenotype by Promoting Human Dendritic Cells Maturation

Pseudomonas aeruginosa mannose sensitive hamemagglutination strain (PA-MSHA) is a kind of peritrichous P. aeruginosa strain with MSHA fimbriae and has been shown to activate kinds of immunocytes. Dendritic cells (DCs) are specialized antigen-presenting cells required for the stimulating and priming CD4(+) T cells toward the T helper cell type 1 (Th1), Th2 and other different phenotypes. PA-MSHA effecting on Th1 remains an important missing link. Here we demonstrated that PA-MSHA augmented monocytes derived-dendritic cells (Mo-DCs) expression of HLA-DR, co-stimulatory and adhesion molecules, and induced Th1-promoting interleukin-12 and tumor necrosis factor α secretion, in addition, PA-MSHA treated Mo-DCs displayed lesser endocytic capacity. Furthermore, in mixed lymphocyte reactions, allostimulatory capacity of Mo-DCs was enhanced by PA-MSHA, CD4(+) T cells stimulated by PA-MSHA -activated Mo-DCs showed a Th1-polarized cytokine production, increasing secretion of IFN-γ and decreasing secretion of IL-10 and IL-4. Our findings identified PA-MSHA as an important exogenous factor that induced DCs maturation toward a Th1-promoting phenotype.

Fucoidan inhibits the growth of hepatocellular carcinoma independent of angiogenesis

Some sulphated polysaccharides can bind bFGF but are unable to present bFGF to its high-affinity receptors. Fucoidan, a sulphated polysaccharide purified from brown algae, which has been used as an anticancer drug in traditional Chinese medicine for hundreds of years, exhibits a variety of anticancer effects, including the induction of the apoptosis and autophagy of cancer cells, the inhibition of the growth of cancer cells, the induction of angiogenesis, and the improvement of antitumour immunity. Our research shows that fucoidan dose not inhibit the expressions of VEGF, bFGF, IL-8, and heparanase in HCC cells and/or tumour tissues. Moreover, fucoidan exhibited low affinity for bFGF and could not block the binding of bFGF to heparan sulphated. Although fucoidan had no effect on angiogenesis and apoptosis in vivo, this drug significantly inhibited the tumour growth and the expression of PCNA. These results suggest that fucoidan exhibits an anticancer effect in vivo at least partly through inhibition of the proliferation of HCC cells, although it is unable to suppress the angiogenesis induced by HCC.

Effects of oral administration of fucoidan extracted from Cladosiphon okamuranus on tumor growth and survival time in a tumor-bearing mouse model

We evaluated the anti-tumor activities of the oral administration of fucoidan extracted from Cladosiphon okamuranus using a tumor (colon 26)-bearing mouse model. The materials used included low-molecular-weight fucoidan (LMWF: 6.5-40 kDa), intermediate-molecular-weight fucoidan (IMWF: 110-138 kDa) and high-molecular-weight fucoidan (HMWF: 300-330 kDa). The IMWF group showed significantly suppressed tumor growth. The LMWF and HMWF groups showed significantly increased survival times compared with that observed in the control group (mice fed a fucoidan-free diet). The median survival times in the control, LMWF, IMWF and HMWF groups were 23, 46, 40 and 43 days, respectively. It was also found that oral administration of fucoidan increased the population of natural killer cells in the spleen. Furthermore, from the results of the experiment using Myd-88 knockout mice, it was found that these effects are related to gut immunity. These results suggest that fucoidan is a candidate anti-tumor functional food.