Fucoidan ingestion increases the expression of CXCR4 on human CD34+ cells

The STING-mediated antiviral effect of fucoidan from Durvillaea antarctica

Fucoidans have attracted increasing attention due to their minimal toxicity and various biological activities, such as antioxidant, anti-inflammatory, anti-tumor and immunomodulatory effects. In this study, the antiviral effect and mechanism of fucoidan (FU) derived from Durvillaea antarctica were explored in vitro. The results demonstrated that FU effectively inhibited the infection of both RNA virus (VSV) and DNA virus (HSV-1). The potential antiviral mechanism of FU is to trigger the production of type I IFN (IFN-I) and IFN-stimulated genes dependent on the cytoplasmic DNA adaptor STING (stimulator of interferon genes), and to enhance innate immune response via activating the STING-TBK1-IRF3 pathway. FU possesses the potential to be an antiviral and immunomodulatory agent in the future.

Prospects for the Use of Marine Sulfated Fucose-Rich Polysaccharides in Treatment and Prevention of COVID-19 and Post-COVID-19 Syndrome

Symptoms of the new coronavirus infection that appeared in 2019 (COVID-19) range from low fever and fatigue to acute pneumonia and multiple organ failure. The clinical picture of COVID-19 is heterogeneous and involves most physiological systems; therefore, drugs with a wide spectrum of mechanism of action are required. The choice of the treatment strategy for post-COVID-19 syndrome is still a challenge to be resolved. Polysaccharides with a high fucose content derived from seaweed and marine animals can form the basis for the subsequent development of promising agents for the treatment of COVID-19 and post-COVID-19 syndrome. This class of biopolymers is characterized by a variety of biological activities, including antiviral, antithrombotic, anticoagulant, hemo-stimulating, anti-inflammatory and immune-regulatory. Low molecular weight derivatives of these polysaccharides, as well as synthetic oligosaccharides with a sufficient amount and sulfation type may be considered as the most promising compounds due to their better bioavailability, which undoubtedly increases their therapeutic potential.

Combining mussel with fucoidan as a supplement for joint pain and prediabetes: Study protocol for a randomized, double-blinded, placebo-controlled trial

Introduction

Pharmaceutical drugs are beneficial to inflammatory conditions but with side effects, which led to the search for alternative therapies. Perna canaliculus, the New Zealand green-lipped mussel, have shown promise in placebo-controlled trials for inflammatory conditions. Fucoidan, an extract from seaweed Undaria pinnatifida, has been found to have beneficial effects on joint pain and insulin resistance. However, green-lipped mussel and fucoidan have never been combined.

Methods and analysis

A parallel, two-arm, double-blind, randomized, placebo-controlled trial will be conducted in New Zealand to determine whether a food product supplemented with green-lipped mussel and fucoidan improves joint pain and/or insulin resistance. Those who are ethnically Chinese, are aged over 30 years, have prediabetes and hip or knee joint pain will be eligible to participate. They will be randomized at 1:1 ratio to consume either dark chocolate supplemented with 1000 mg mussel powder and 1000 mg fucoidan or dark chocolate with no active substances daily for 100 days. The primary endpoints are change in insulin resistance and patient-reported joint pain. Secondary endpoints include anthropometry, fasting glucose and insulin, HbA1c, inflammatory markers, satiety, quality of life, physical function, pain intensity, and analgesic medication use. A sample size of 150 (75 per arm) will provide 90% power at an overall significance level of 5% (two-sided) to detect a standardized effect size of 0.625 on either of the two co-primary outcomes allowing for 10% loss.

Ethics and dissemination

The study was approved by the Health and Disability Ethics Committee (number: 20/STH/153). Results will be made available to participants, funders, and other researchers.

Discussion

This trial will provide data on the potential utility of a mussel-fucoidan supplement in reducing joint pain and/or insulin resistance, to inform the development of a supplemented food product suitable for the Chinese market.

Clinical trial registration

https://trialsearch.who.int/Trial2.aspx?TrialID=ACTRN12621000413820, ANZCTR Registration: ACTRN12621000413820, on 15 April 2021.

Structure and function of non-digestible carbohydrates in the gut microbiome

Together with proteins and fats, carbohydrates are one of the macronutrients in the human diet. Digestible carbohydrates, such as starch, starch-based products, sucrose, lactose, glucose and some sugar alcohols and unusual (and fairly rare) α-linked glucans, directly provide us with energy while other carbohydrates including high molecular weight polysaccharides, mainly from plant cell walls, provide us with dietary fibre. Carbohydrates which are efficiently digested in the small intestine are not available in appreciable quantities to act as substrates for gut bacteria. Some oligo- and polysaccharides, many of which are also dietary fibres, are resistant to digestion in the small intestines and enter the colon where they provide substrates for the complex bacterial ecosystem that resides there. This review will focus on these non-digestible carbohydrates (NDC) and examine their impact on the gut microbiota and their physiological impact. Of particular focus will be the potential of non-digestible carbohydrates to act as prebiotics, but the review will also evaluate direct effects of NDC on human cells and systems.

Brown Seaweed Food Supplementation: Effects on Allergy and Inflammation and Its Consequences

Multiple health benefits have been ascribed to brown seaweeds that are used traditionally as dietary component mostly in Asia. This systematic review summarizes information on the impact of brown seaweeds or components on inflammation, and inflammation-related pathologies, such as allergies, diabetes mellitus and obesity. We focus on oral supplementation thus intending the use of brown seaweeds as food additives. Despite the great diversity of experimental systems in which distinct species and compounds were tested for their effects on inflammation and immunity, a remarkably homogeneous picture arises. The predominant effects of consumption of brown seaweeds or compounds can be classified into three categories: (1) inhibition of reactive oxygen species, known to be important drivers of inflammation; (2) regulation, i.e., in most cases inhibition of proinflammatory NF-κB signaling; (3) modulation of adaptive immune responses, in particular by interfering with T-helper cell polarization. Over the last decades, several inflammation-related diseases have increased substantially. These include allergies and autoimmune diseases as well as morbidities associated with lifestyle and aging. In this light, further development of brown seaweeds and seaweed compounds as functional foods and nutriceuticals might contribute to combat these challenges.

Oral fucoidan improves muscle size and strength in mice

Fucoidan is a sulfated polysaccharide found in a range of brown algae species. Growing evidence supports the long-term supplementation of fucoidan as an ergogenic aid to improve skeletal muscle performance. The aim of this study was to investigate the effect of fucoidan on the skeletal muscle of mice. Male BL/6 mice (N = 8-10) were administered a novel fucoidan blend (FUC, 400 mg/kg/day) or vehicle (CON) for 4 weeks. Treatment and control experimental groups were further separated into exercise (CON+EX, FUC+EX) or no-exercise (CON, FUC) groups, where exercised groups performed 30 min of treadmill training three times per week. At the completion of the 4-week treatment period, there was a significant increase in cross-sectional area (CSA) of muscle fibers in fucoidan-treated extensor digitorum longus (EDL) and soleus fibers, which was accompanied by a significant increase in tibialis anterior (TA) muscle force production in fucoidan-treated groups. There were no significant changes in grip strength or treadmill time to fatigue, nor was there an effect of fucoidan or exercise on mass of TA, EDL, or soleus muscles. In gastrocnemius muscles, there was no change in mRNA expression of mitochondrial biogenesis markers PGC-1α and Nrf-2 in any experimental groups; however, there was a significant effect of fucoidan supplementation on myosin heavy chain (MHC)-2x, but not MHC-2a, mRNA expression. Overall, fucoidan increased muscle size and strength after 4 weeks of supplementation in both exercised and no-exercised mice suggesting an important influence of fucoidan on skeletal muscle physiology.

A systematic review on phytochemicals for the treatment of dengue

Dengue fever is prevalent in subtopic regions, producing mortality and morbidity worldwide, which have been of major concern to different governments and World Health Organization. The search of new anti-dengue agents from phytochemicals was assumed to be highly emergent in past. The phytochemicals have been used in wide distribution of vector ailments such as malaria. The demand of the phytochemicals is based on the medicines which are mostly considered to be safer, less harmful than synthetic drugs and nontoxic. This review mentions majorly about the phytochemicals potentially inhibiting dengue fever around the world. The phytochemicals have been isolated from different species, have potential for the treatment of dengue. Different crude extracts and essential oils obtained from different species showed a broad activity against different phytochemicals. The current studies showed that natural products represent a rich source of medicines toward the dengue fever. Furthermore, ethnobotanical surveys and laboratory investigation established identified natural plants species in the development of drug discovery to control the dengue fever.

Seaweed's Bioactive Candidate Compounds to Food Industry and Global Food Security

The world population is continuously growing, so it is important to keep producing food in a sustainable way, especially in a way that is nutritious and in a sufficient quantity to overcome global needs. Seaweed grows, and can be cultivated, in seawater and generally does not compete for arable land and freshwater. Thus, the coastal areas of the planet are the most suitable for seaweed production, which can be an alternative to traditional agriculture and can thus contribute to a reduced carbon footprint. There are evolving studies that characterize seaweed's nutritional value and policies that recognize them as food, and identify the potential benefits and negative factors that may be produced or accumulated by seaweed, which are, or can be, dangerous for human health. Seaweeds have a high nutritional value along with a low caloric input and with the presence of fibers, proteins, omega 3 and 6 unsaturated fatty acids, vitamins, and minerals. Moreover, several seaweed sub-products have interesting features to the food industry. Therefore, the focus of this review is in the performance of seaweed as a potential alternative and as a safe food source. Here described is the nutritional value and concerns relating to seaweed consumption, and also how seaweed-derived compounds are already commercially explored and available in the food industry and the usage restrictions to safeguard them as safe food additives for human consumption.

Seaweeds as a Functional Ingredient for a Healthy Diet

Seaweeds have been used since ancient times as food, mainly by Asian countries, while in Western countries, their main application has been as gelling agents and colloids for the food, pharmaceuticals, and the cosmetic industry. Seaweeds are a good source of nutrients such as proteins, vitamins, minerals, and dietary fiber. Polyphenols, polysaccharides, and sterols, as well as other bioactive molecules, are mainly responsible for the healthy properties associated with seaweed. Antioxidant, anti-inflammatory, anti-cancer, and anti-diabetic properties are attributed to these compounds. If seaweeds are compared to terrestrial plants, they have a higher proportion of essential fatty acids as eicosapentaenoic (EPA) and docosahexaenoic (DHA) fatty acids. In addition, there are several secondary metabolites that are synthesized by algae such as terpenoids, oxylipins, phlorotannins, volatile hydrocarbons, and products of mixed biogenetic origin. Therefore, algae can be considered as a natural source of great interest, since they contain compounds with numerous biological activities and can be used as a functional ingredient in many technological applications to obtain functional foods.

Marine Seaweed Polysaccharides-Based Engineered Cues for the Modern Biomedical Sector

Seaweed-derived polysaccharides with unique structural and functional entities have gained special research attention in the current medical sector. Seaweed polysaccharides have been or being used to engineer novel cues with biomedical values to tackle in practice the limitations of counterparts which have become ineffective for 21st-century settings. The inherited features of seaweed polysaccharides, such as those of a biologically tunable, biocompatible, biodegradable, renewable, and non-toxic nature, urge researchers to use them to design therapeutically effective, efficient, controlled delivery, patient-compliant, and age-compliant drug delivery platforms. Based on their significant retention capabilities, tunable active units, swelling, and colloidal features, seaweed polysaccharides have appeared as highly useful materials for modulating drug-delivery and tissue-engineering systems. This paper presents a standard methodological approach to review the literature using inclusion-exclusion criteria, which is mostly ignored in the reported literature. Following that, numerous marine-based seaweed polysaccharides are discussed with suitable examples. For the applied perspectives, part of the review is focused on the biomedical values, i.e., targeted drug delivery, wound-curative potential, anticancer potentialities, tissue-engineering aspects, and ultraviolet (UV) protectant potential of seaweed polysaccharides based engineered cues. Finally, current challenges, gaps, and future perspectives have been included in this review.

Fucoidan from sea cucumber Holothuria polii: Structural elucidation and stimulation of hematopoietic activity

The structural elucidation of polysaccharides is essential for understanding their structure-bioactivity relationship and related drug development. In this study, fucoidan (Fuc_hp) was extracted and purified from sea cucumber Holothuria polii. Its sulfate content was 39.5 ± 1.4%, and the "weight-average" molecular mass was 103.1 ± 2.8 kDa. The primary structure of Fuc_hp was clarified using a combination of acid degradation, tandem mass spectrometry, and nuclear magnetic resonance spectroscopy analysis. As a result, Fuc_hp was found to be composed of a tetrafucose repeating unit [→3-α-l-Fucp-1 → 3-α-l-Fucp2(OSO₃^-)-1 → 3-α-l-Fucp2(OSO₃^-)-1 → 3-α-l-Fucp2,4(OSO₃^-)-1→]. The stimulating hematopoiesis was further evaluated in a mouse model induced by cyclophosphamide. Based on these findings, intraperitoneally administered Fuc_hp may accelerate the recovery of white blood cells and neutrophils, in which its activity exceeded that of recombinant human granulocyte colony-stimulating factor (rhG-CSF). Meanwhile, in the background of cyclophosphamide-induced immunosuppression, treatment with Fuc_hp reduces platelet aggregation caused by CTX, so it might have the effect of reducing the risk of thrombosis. Therefore, Fuc_hp can be exploited as potentially promising stimulator of hematopoiesis in the future.

Therapies from Fucoidan: New Developments

Since our last review in 2015, the study and use of fucoidan has extended in several research areas. Clinical use of fucoidan for the treatment of renal disease has become available and human safety studies have been undertaken on radiolabeled fucoidan for the purpose of imaging thrombi. Fucoidan has been incorporated into an increasing number of commercially available supplements and topical treatments. In addition, new measuring techniques are now available to assess the biologically relevant uptake of fucoidans and to assist in production. Microbiome modulation and anti-pathogenic effects are increasingly promising applications for fucoidans, due to the need for alternative approaches to antibiotic use in the food chain. This review outlines promising new developments in fucoidan research, including potential future therapeutic use.

What doesn't kill you makes you stranger: Dipeptidyl peptidase-4 (CD26) proteolysis differentially modulates the activity of many peptide hormones and cytokines generating novel cryptic bioactive ligands

Dipeptidyl peptidase 4 (DPP4) is an exopeptidase found either on cell surfaces where it is highly regulated in terms of its expression and surface availability (CD26) or in a free/circulating soluble constitutively available and intrinsically active form. It is responsible for proteolytic cleavage of many peptide substrates. In this review we discuss the idea that DPP4-cleaved peptides are not necessarily inactivated, but rather can possess either a modified receptor selectivity, modified bioactivity, new antagonistic activity, or even a novel activity relative to the intact parent ligand. We examine in detail five different major DPP4 substrates: glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), peptide tyrosine-tyrosine (PYY), and neuropeptide Y (NPY), and stromal derived factor 1 (SDF-1 aka CXCL12). We note that discussion of the cleaved forms of these five peptides are underrepresented in the research literature, and are both poorly investigated and poorly understood, representing a serious research literature gap. We believe they are understudied and misinterpreted as inactive due to several factors. This includes lack of accurate and specific quantification methods, sample collection techniques that are inherently inaccurate and inappropriate, and a general perception that DPP4 cleavage inactivates its ligand substrates. Increasing evidence points towards many DPP4-cleaved ligands having their own bioactivity. For example, GLP-1 can work through a different receptor than GLP-1R, DPP4-cleaved GIP can function as a GIP receptor antagonist at high doses, and DPP4-cleaved PYY, NPY, and CXCL12 can have different receptor selectivity, or can bind novel, previously unrecognized receptors to their intact ligands, resulting in altered signaling and functionality. We believe that more rigorous research in this area could lead to a better understanding of DPP4's role and the biological importance of the generation of novel cryptic ligands. This will also significantly impact our understanding of the clinical effects and side effects of DPP4-inhibitors as a class of anti-diabetic drugs that potentially have an expanding clinical relevance. This will be specifically relevant in targeting DPP4 substrate ligands involved in a variety of other major clinical acute and chronic injury/disease areas including inflammation, immunology, cardiology, stroke, musculoskeletal disease and injury, as well as cancer biology and tissue maintenance in aging.

Trabecular Meshwork Regeneration - A Potential Treatment for Glaucoma

Purpose

In this review, we overview the pathophysiology of primary open-angle glaucoma as it relates to the trabecular meshwork (TM), exploring modes of TM dysfunction and regeneration via stem cell therapies.

Recent Findings

Stem cells from a variety of sources, including trabecular meshwork, mesenchymal, adipose and induced pluripotent stem cells, have shown the potential to differentiate into TM cells in vitro or in vivo and to regenerate the TM in vivo, lowering intraocular pressure (IOP) and reducing glaucomatous retinal ganglion cell damage.

Summary

Stem cell therapies for TM regeneration provide a robust and promising suite of treatments for eventual lowering of IOP and prevention of glaucomatous vision loss in humans in the future. Further investigation into stem cell homing mechanisms and the safety of introducing these cells into human anterior chamber, for instance, are required before clinical applications in treating glaucoma patients.

A promising oral fucoidan-based antithrombotic nanosystem: Development, activity and safety

Fucoidan-loaded nanoparticles emerge as great candidates to oral anticoagulant therapy, due to increasing of bioavailability and circulation time of this natural anticoagulant. Crosslink between chitosan chains are performed using glutaraldehyde to confer higher gastric pH resistance to nanoparticle matrices. In this work, chitosan-fucoidan nanoparticles, without (NpCF) and with glutaraldehyde crosslink (NpCF 1% and NpCF 2%), were prepared to evaluate their anticoagulant, antithrombotic and hemorrhagic profile. Nanoparticles were characterized by average diameter, polydispersity index, zeta potential, Fourier transform infrared spectroscopy and fucoidan in vitro release. Anticoagulant and antithrombotic activities were determined by in vitro and in vivo models, respectively. Hemorrhagic profile was in vivo evaluated by tail bleeding assay. Preparations showed nanometric and homogeneous average diameters. Zeta potentials of NpCF and NpCF 1% were stable over gastrointestinal pH range, which was confirmed by low fucoidan release in gastric and enteric media. In pH 7.4, NpCF and NpCF 1% demonstrated fucoidan release of 65.5% and 60.6%, respectively, within the first 24 hours. In comparison to fucoidan, NpCF and NpCF 1% showed increased in vitro anticoagulant activity. A significant difference on oral antithrombotic profile of NpCF 1% was found in comparison to fucoidan. Bleeding profile of NpCF and NpCF 1% showed no differences to control group, indicating the safety of these systems. Surprisingly, oral antithrombotic profile of commercially available fucoidan, from Fucus vesiculosus, has not been previously determined, which reveals new possibilities. In this work, significant advances were observed in anticoagulant and antithrombotic profiles of fucoidan through the preparation of NpCF 1%.

Fucoidan enhances the therapeutic potential of arsenic trioxide and all-trans retinoic acid in acute promyelocytic leukemia, in vitro and in vivo

The morbidity and mortality associated with current therapies for acute promyelocytic leukemia (APL) remain a significant clinical concern, despite improvements in patient survival. Consequently, the development of adjuvant therapies that increase efficacy while reducing morbidities is important. Reducing the concentration of the toxic drugs in adjuvant therapy has the potential to reduce unwanted side effects. Therefore, this study aimed to determine the synergistic effects of fucoidan, an anti-tumor agent, with current APL therapies.When the human APL cell line, NB4, was treated in vitro with fucoidan plus ATO and ATRA at therapeutic and sub-therapeutic doses, there was an increase in sub-G0/G1 cells, annexin V/PI-positive-apoptotic cells and DNA fragmentation. This reduction in proliferation and increase in apoptosis was accompanied by enhanced myeloid differentiation as indicated by an increased expression of CD11b. This was not observed with the AML cell line Kasumi-1, suggesting specificity for APL.In vivo treatment of APL-bearing mice with fucoidan+ATRA or fucoidan+ATO delayed tumor growth, induced differentiation and increased tumor volume doubling time. The differentiated APL cells derived from the excised tumor mass exhibited decreased CD44 expression in fucoidan+ATRA treated mice. This could translate to decreased cell migration in APL patients.Our findings provide evidence supporting the use of fucoidan as an adjuvant therapeutic agent in the treatment of APL.

[Antiviral action and pathogenetic targets for seaweed sulfated polysaccharides in herpesvirus infections]

The review summarizes results of studies of effects of sulfated polysaccharides from seaweed on herpesviruses and the course of herpesvirus infections. Importance of this problem is determined by the prevalence of herpesviruses that can persist in the human body and demonstrate a high degree of immune mimicry and resistance to antiviral agents. A wide range of physiological action of sulfated polysaccharides, receptor agonists of innate and adaptive immune cells, which possess potent antiviral, antioxidant and anti-inflammatory activities, open the possibility of their use for creation of new generation pharmacological substances and agents with associated activity for the treatment of herpesvirus infections.

Effects of fucoidan from Fucus vesiculosus in reducing symptoms of osteoarthritis: a randomized placebo-controlled trial

Purpose

Preliminary investigation of a fucoidan with demonstrated reduction in the symptoms of osteoarthritis (OA) of the hip and knee.

Patients and methods

A double-blind randomized controlled trial was carried out to determine the safety and efficacy of a 300 mg dose of a Fucus vesiculosus extract (85% fucoidan) over a 12-week period in a population (n=122) with mild-to-moderate OA of the hip and knee as measured by the validated instrument “Comprehensive Osteoarthritis Test.” Safety was measured by assessing cholesterol, liver function, renal function, and hematopoietic function, and closely monitoring adverse events.

Result

Ninety-six participants completed the study. The reduction in symptoms of OA was not significantly different from the placebo response. There were no changes in the blood measurements that were of any clinical significance during the course of the study.

Conclusion

The F. vesiculosus fucoidan extract was safe and well tolerated. At a dose of 300 mg, the extract showed no difference in reduction of OA symptoms from the placebo.

The sulfated polysaccharide fucoidan rescues senescence of endothelial colony-forming cells for ischemic repair

The efficacy of cell therapy using endothelial colony-forming cells (ECFCs) in the treatment of ischemia is limited by the replicative senescence of isolated ECFCs in vitro. Such senescence must therefore be overcome in order for such cell therapies to be clinically applicable. This study aimed to investigate the potential of sulfated polysaccharide fucoidan to rescue ECFCs from cellular senescence and to improve in vivo vascular repair by ECFCs. Fucoidan-preconditioning of senescent ECFCs was shown by flow cytometry to restore the expression of functional ECFC surface markers (CD34, c-Kit, VEGFR2, and CXCR4) and stimulate the in vitro tube formation capacity of ECFCs. Fucoidan also promoted the expression of cell cycle-associated proteins (cyclin E, Cdk2, cyclin D1, and Cdk4) in senescent ECFCs, significantly reversed cellular senescence, and increased the proliferation of ECFCs via the FAK, Akt, and ERK signaling pathways. Fucoidan was found to enhance the survival, proliferation, incorporation, and endothelial differentiation of senescent ECFCs transplanted in ischemic tissues in a murine hind limb ischemia model. Moreover, ECFC-induced functional recovery and limb salvage were markedly improved by fucoidan pretreatment of ECFCs. To our knowledge, the findings of our study are the first to demonstrate that fucoidan enhances the neovasculogenic potential of ECFCs by rescuing them from replicative cellular senescence. Pretreatment of ECFCs with fucoidan may thus provide a novel strategy for the application of senescent stem cells to therapeutic neovascularization.

Interference with the CXCL12/CXCR4 axis as potential antitumor strategy: superiority of a sulfated galactofucan from the brown alga Saccharina latissima and fucoidan over heparins

The present study demonstrates that fucose-containing sulfated polysaccharides (FCSP) from brown algae interfere with the CXCL12/CXCR4 axis in human Burkitt's lymphoma cells by binding CXCL12 and thereby blocking both CXCL12-induced CXCR4 receptor activation and downstream effects like migration and secretion of matrix metalloproteinase-9. This mode of action is currently considered as promising strategy for tumor therapy and may contribute to the known in vivo antitumor, antimetastatic and antiangiogenic activity of FCSP. In terms of the inhibition of the CXCR4 activation, FCSP from Saccharina latissima (S.l.-FCSP) proved to be more active than a commercial "Fucoidan" from Fucus vesiculosus, and both FCSP were superior to heparins by more than one order of magnitude. Fractionation of S.l.-FCSP revealed that its main fraction is composed of a homogeneous, higher sulfated galactofucan (S.l.-SGF) which consistently exhibited stronger activities and can therefore be considered as the active ingredient of S.l.-FCSP. By subjecting Fucoidan to the same fractionation procedure, the inhibitory activity of the obtained purified Fucoidan on the CXCL12/CXCR4 axis tended to be weaker and its antioxidant and antiproliferative effects were lost. This was probably due to the separation of contaminants including phenolic compounds, whose content additionally showed marked batch-to-batch variability. Regarding the need of standardized, well-characterized FCSP preparations for any potential medical application, our results indicate that S.l.-SGF is a promising candidate for further investigations and that S. latissima may be a more appropriate source of FCSP than F. vesiculosus or other algae species with high contents of co-extractable compounds.

Quantitative determination of fucoidan using polyion-sensitive membrane electrodes

The use of polyanion and polycation-sensitive membrane electrodes to detect five different preparations of fucoidan is described. Unlike linear polyanionic molecules previously measured with polymer membrane-based electrochemical sensors, fucoidans from marine brown algae are all highly branched, sulfated polysaccharides with varying charge densities and structures, depending on the species of seaweed, method of extraction used and extent of purification. When tridodecylmethylammonium (TDMA) was used as the ion-exchanger, a large, non-equilibrium EMF response was observed over a concentration range of 0.5-50 μg mL(-1) fucoidan. Fucoidan was also measured by titration with polycationic protamine, using a dinonylnaphthalene sulfonate (DNNS)-doped membrane electrode as the potentiometric endpoint detector. Potentiometric titration was used to determine the binding ratio between protamine and fucoidan at the neutralization endpoint for each fucoidan preparation. This binding ratio was then used to successfully determine the fucoidan content of commercially available nutritional supplements. Fucoidan was also measured in undiluted blood serum, demonstrating that this method may be applicable for measuring fucoidan for clinical applications.

Fucoidan and cancer: a multifunctional molecule with anti-tumor potential

There is a wide variety of cancer types yet, all share some common cellular and molecular behaviors. Most of the chemotherapeutic agents used in cancer treatment are designed to target common deregulated mechanisms within cancer cells. Many healthy tissues are also affected by the cytotoxic effects of these chemical agents. Fucoidan, a natural component of brown seaweed, has anti-cancer activity against various cancer types by targeting key apoptotic molecules. It also has beneficial effects as it can protect against toxicity associated with chemotherapeutic agents and radiation. Thus the synergistic effect of fucoidan with current anti-cancer agents is of considerable interest. This review discusses the mechanisms by which fucoidan retards tumor development, eradicates tumor cells and synergizes with anti-cancer chemotherapeutic agents. Challenges to the development of fucoidan as an anti-cancer agent will also be discussed.

The HIV-1 Gp120/CXCR4 axis promotes CCR7 ligand-dependent CD4 T cell migration: CCR7 homo- and CCR7/CXCR4 hetero-oligomer formation as a possible mechanism for up-regulation of functional CCR7

During human immunodeficiency virus (HIV) infection, enhanced migration of infected cells to lymph nodes leads to efficient propagation of HIV-1. The selective chemokine receptors, including CXCR4 and CCR7, may play a role in this process, yet the viral factors regulating chemokine-dependent T cell migration remain relatively unclear. The functional cooperation between the CXCR4 ligand chemokine CXCL12 and the CCR7 ligand chemokines CCL19 and CCL21 enhances CCR7-dependent T cell motility in vitro as well as cell trafficking into the lymph nodes in vivo. In this study, we report that a recombinant form of a viral CXCR4 ligand, X4-tropic HIV-1 gp120, enhanced the CD4 T cell response to CCR7 ligands in a manner dependent on CXCR4 and CD4, and that this effect was recapitulated by HIV-1 virions. HIV-1 gp120 significantly enhanced CCR7-dependent CD4 T cell migration from the footpad of mice to the draining lymph nodes in in vivo transfer experiments. We also demonstrated that CXCR4 expression is required for stable CCR7 expression on the CD4 T cell surface, whereas CXCR4 signaling facilitated CCR7 ligand binding to the cell surface and increased the level of CCR7 homo- as well as CXCR4/CCR7 hetero-oligomers without affecting CCR7 expression levels. Our findings indicate that HIV-evoked CXCR4 signaling promotes CCR7-dependent CD4 T cell migration by up-regulating CCR7 function, which is likely to be induced by increased formation of CCR7 homo- and CXCR4/CCR7 hetero-oligomers on the surface of CD4 T cells.

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.

[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.

Fucoidan reduces secretion and expression of vascular endothelial growth factor in the retinal pigment epithelium and reduces angiogenesis in vitro

Fucoidan is a polysaccharide isolated from brown algae which is of current interest for anti-tumor therapy. In this study, we investigated the effect of fucoidan on the retinal pigment epithelium (RPE), looking at physiology, vascular endothelial growth factor (VEGF) secretion, and angiogenesis, thus investigating a potential use of fucoidan for the treatment of exudative age-related macular degeneration. For this study, human RPE cell line ARPE-19 and primary porcine RPE cells were used, as well as RPE/choroid perfusion organ cultures. The effect of fucoidan on RPE cells was investigated with methyl thiazolyl tetrazolium--assay, trypan blue exclusion assay, phagocytosis assay and a wound healing assay. VEGF expression was evaluated in immunocytochemistry and Western blot, VEGF secretion was evaluated in ELISA. The effect of fucoidan on angiogenesis was tested in a Matrigel assay using calcein-AM vital staining, evaluated by confocal laser scanning microcopy and quantitative image analysis. Fucoidan displays no toxicity and does not diminish proliferation or phagocytosis, but reduces wound healing in RPE cells. Fucoidan decreases VEGF secretion in RPE/choroid explants and RPE cells. Furthermore, it diminishes VEGF expression in RPE cells even when co-applied with bevacizumab. Furthermore, fucoidan reduces RPE-supernatant- and VEGF-induced angiogenesis of peripheral endothelial cells. In conclusion, fucoidan is a non-toxic agent that reduces VEGF expression and angiogenesis in vitro and may be of interest for further studies as a potential therapy against exudative age-related macular degeneration.

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.

Diabetes impairs mobilization of mouse bone marrow-derived Lin(-)/VEGF-R2(+) progenitor cells

Endothelial progenitor cells circulating in the peripheral blood (PB) contribute to vascular repair. This study aimed to evaluate the potential of a 'cocktail' consisting of erythropoietin, granulocyte colony-stimulating factor and tetrahydrobiopterin to mobilize hematopoietic lineage negative/vascular endothelial growth factor receptor 2 positive (Lin(-)/VEGF-R2(+)) cells from the bone marrow (BM) to PB in non-diabetic and diabetic mice. Diabetes was induced in mice by intraperitoneal injection of streptozotocin. Diabetic mice were studied after 16weeks of hyperglycemia. Half the mice in each group (non-diabetic and diabetic) received daily intraperitoneal injections of the cocktail for 6 consecutive days while the other half received vehicle buffer. Mobilization of Lin(-)/VEGF-R2(+) cells, which were expanded in MCP301 medium, was evaluated after isolating them from BM and PB and their phenotypic and morphological properties were studied. We found that 16weeks of diabetes affected neither the total number of BM mononucleated cells nor the number of Lin(-)/VEGF-R2(+) cells in BM compared with non-diabetic controls. In non-diabetic mice, cocktail treatment resulted in a significant decrease in BM Lin(-)/VEGF-R2(+) cells, paralleled by a significant increase of these cells in PB. Such changes in the number of Lin(-)/VEGF-R2(+) cells in BM and PB after the cocktail treatment were less marked in diabetic mice. In vitro studies of BM Lin(-)/VEGF-R2(+) cells from diabetic and non-diabetic mice did not reveal any differences in either phenotypes or colony forming potential. These findings indicate that diabetes impairs the mobilization of Lin(-)/VEGF-R2(+) cells from BM to PB. Impaired mobilization of BM Lin(-)/VEGF-R2(+) cells soon after the onset of diabetes may contribute to complications such as diabetic retinopathy.

Induction of apoptosis by low-molecular-weight fucoidan through calcium- and caspase-dependent mitochondrial pathways in MDA-MB-231 breast cancer cells

Fucoidan, a fucose-rich polysaccharide extracted from brown seaweed, has antitumor, anticoagulant, antiviral, anti-inflammatory, and antibacterial activities. Several studies have shown that a fucoidan treatment of cancer cells induced cytotoxicity and apoptosis and inhibited angiogenesis and invasion. We investigated in the present study the effect of low-molecular-weight fucoidan (LMWF) on apoptosis in estrogen receptor-negative MDA-MB-231 human breast cancer cells. The LMWF treatment of MDA-MB-231 cells was associated with the activation of caspases and mitochondrial dysfunction, including dissipation of the mitochondrial membrane potential (ΔΨm), alteration of Ca(2+) homeostasis, cytochrome c release, and decreased expression of antiapoptotic Bcl-2 family proteins. Understanding the molecular events that mediated LMWF-induced MDA-MB-231 cell death will contribute to a more rational approach to cancer chemotherapy.

Dietary algae and HIV/AIDS: proof of concept clinical data

Dietary algae have been reported to decrease HIV viral fusion/entry and replication and increase immune response, suggesting that regular consumption of algae by people in Japan, Korea, and Chad could be an important factor in their relatively low HIV/AIDS rates. Five antiretroviral-naïve people with HIV (three females, two males; five African Americans) living in Columbia SC participated in the phase I study of acute toxicity. Subjects were randomly assigned to 5 g day(-1) brown seaweed (Undaria pinnatifida), Spirulina (Arthrospira platensis), or a combination of both. Endpoints included HIV viral load, complete blood count (CBC), metabolic and lipid panel, and quality of life questionnaire data. When no short-term toxicities were observed, six additional subjects (four females, two males; five African Americans, one Latina) were recruited to further evaluate short- and long-term toxicities (phase II). No adverse effects were observed for the 11 subjects in the phase I trial, and quality of life indicators improved at 3 weeks. No significant changes were observed in CBC, metabolic or lipid panel analyses. CD4 cells (milliliters) and HIV-1 viral load remained stable over the first 3-month phase II study period. One subject continued in the study for 13 months and had clinically significant improvement in CD4 (>100 cells mL(-1)) and decreased HIV viral load of 0.5 log(10). Our pilot data suggest that Undaria, Spirulina, and a combination of both were nontoxic and over time may improve clinical endpoints of HIV/AIDS.

Mobilization of mesenchymal stem cells by stromal cell-derived factor-1 released from chitosan/tripolyphosphate/fucoidan nanoparticles

Stromal cell-derived factor 1 (SDF-1) is an important chemokine in stem cell mobilization, and plays a critical role in the biological and physiological functions of mesenchymal stem cells (MSC). However, the use of SDF-1 in tissue regeneration is limited by two drawbacks, which are its short half-life and ready degradation by enzymes. This study investigates the release of SDF-1 from chitosan-based nanoparticles (NP) and evaluates the effect of released SDF-1 on the migration of MSC. Among the prepared chitosan-based NP a chitosan/tripolyphosphate/fucoidan (CS/TPP/F) NP is the most effective carrier for SDF-1 release. CS/TPP/F NP are spherical and effectively encapsulate SDF-1. The CS/TPP/F NP protected SDF-1 against proteolysis and heat treatment and controlled its release for up to 7 days. The concentration of released SDF-1 reached 23 ng ml(-1). According to in vitro experiments on cells the released SDF-1 retained its mitogenic activity, promoted the migration of MSC and enhanced PI3K expression. Biocompatible CS/TPP/F NP may be effective as carriers for the delivery and controlled release of SDF-1 to mobilize stem cells in tissue engineering applications.

Therapies from fucoidan; multifunctional marine polymers

Published research on fucoidans increased three fold between 2000 and 2010. These algal derived marine carbohydrate polymers present numerous valuable bioactivities. This review discusses the role for fucoidan in the control of acute and chronic inflammation via selectin blockade, enzyme inhibition and inhibiting the complement cascade. The recent data on toxicology and uptake of fucoidan is detailed together with a discussion on the comparative activities of fractions of fucoidan from different sources. Recent in vivo, in vitro and clinical research related to diverse clinical needs is discussed. Targets include osteoarthritis, kidney and liver disease, neglected infectious diseases, hemopoietic stem cell modulation, protection from radiation damage and treatments for snake envenomation. In recent years, the production of well characterized reproducible fucoidan fractions on a commercial scale has become possible making therapies from fucoidan a realizable goal.

Antioxidant bioavailability and rapid immune-modulating effects after consumption of a single acute dose of a high-metabolite yeast immunogen: results of a placebo-controlled double-blinded crossover pilot study

The objective of this pilot study was to investigate the acute effects on circulating lymphocyte subsets, antioxidant status, and cytokine profile after consumption of EpiCor(®) (EP) (Embria Health Sciences, Ankeny, IA, USA), a dried fermentate produced from Saccharomyces cerevisiae, using a placebo-controlled randomized crossover study design with 12 healthy adult human subjects. EP contains high levels of bioavailable antioxidants and strongly activates natural killer (NK) cells in vitro. EP consumption has been shown to increase erythrocyte hematocrit levels, boost mucosal immune protection, reduce cold/flu symptoms, reduce seasonal allergy symptoms and the need for rescue medication, and increase salivary secretory immunoglobulin A levels. This warranted further study on immune effects in humans. A within-subject analysis of data collected before and at 1 and 2 hours after consumption of a single dose of 500 mg of EP versus placebo was performed. A transient reduction in circulating T and NK cell numbers was observed 2 hours post-consumption, suggesting that homing and recirculation of these cells, as part of healthy immune surveillance, were supported by EP. The increased expression of activation markers on the CD3(-) CD56(+) NK cell population was significant for CD69 at 1 hour post-consumption (CD25, P<.07; CD69, P<.05), whereas for CD25 it was significant at 2 hours after consumption (CD25, P<.03; CD69, P<.15). A rapid increase in serum interferon-γ was observed at 1 hour post-consumption (P<.07; after removal of two outlying data sets, P<.05) and may have contributed to the effects seen on NK and T cell subsets. Significant increase in serum antioxidant protection was seen 2 hours after consumption (P<.04). Thus consumption of a single 500 mg dose of EP provides a rapid and transient effect on the trafficking and activation status of specific lymphocyte subsets, as well as increased antioxidant protection.

Radiolabeled fucoidan as a p-selectin targeting agent for in vivo imaging of platelet-rich thrombus and endothelial activation

P-selectin expression is involved in the pathophysiology of biologically active arterial thrombus and endothelial activation after a transient ischemic event. Fucoidan is a polysaccharidic ligand of P-selectin, with a nanomolar affinity. In the present study, we propose a new approach of P-selectin molecular imaging based on radiolabeled fucoidan.

METHODS

Two kinds of experimental models were selected to evaluate the ability of radiolabeled fucoidan to detect P-selectin expression: platelet-rich arterial thrombi (vegetations of infective endocarditis and arterial mural thrombus) and myocardial ischemia-reperfusion. These 2 settings were chosen because they were clinically relevant, and both were associated with an important overexpression of platelet and endothelial P-selectin, respectively.

RESULTS

(99m)Tc-fucoidan SPECT was able to detect the presence of platelet-rich arterial thrombi in all animals, with a median target-to-background ratio of 5.2 in vegetations of endocarditis and 3.6 in mural aneurysmal thrombus, and to detect a persistent endothelial activation at 2 h after reperfusion. In this latter model, the magnitude of the signal was correlated with the extent of myocardium that underwent transient ischemia. The sensitivity of selectivity of the uptake and retention of (99m)Tc-fucoidan in both settings was excellent.

CONCLUSION

This study supports (99m)Tc-fucoidan as a relevant imaging agent for in vivo detection of biologic activities associated with P-selectin overexpression, such as arterial thrombus and ischemic memory. Given the reported wide availability at a low cost, and its low toxicity, fucoidan seems to overcome some of the limitations of previous P-selectin-targeted imaging agents.

Antioxidant bioavailability and rapid immune-modulating effects after consumption of a single acute dose of a high-metabolite yeast immunogen: results of a placebo-controlled double-blinded crossover pilot study

The objective of this pilot study was to investigate the acute effects on circulating lymphocyte subsets, antioxidant status, and cytokine profile after consumption of EpiCor(®) (EP) (Embria Health Sciences, Ankeny, IA, USA), a dried fermentate produced from Saccharomyces cerevisiae, using a placebo-controlled randomized crossover study design with 12 healthy adult human subjects. EP contains high levels of bioavailable antioxidants and strongly activates natural killer (NK) cells in vitro. EP consumption has been shown to increase erythrocyte hematocrit levels, boost mucosal immune protection, reduce cold/flu symptoms, reduce seasonal allergy symptoms and the need for rescue medication, and increase salivary secretory immunoglobulin A levels. This warranted further study on immune effects in humans. A within-subject analysis of data collected before and at 1 and 2 hours after consumption of a single dose of 500 mg of EP versus placebo was performed. A transient reduction in circulating T and NK cell numbers was observed 2 hours post-consumption, suggesting that homing and recirculation of these cells, as part of healthy immune surveillance, were supported by EP. The increased expression of activation markers on the CD3(-) CD56(+) NK cell population was significant for CD69 at 1 hour post-consumption (CD25, P<.07; CD69, P<.05), whereas for CD25 it was significant at 2 hours after consumption (CD25, P<.03; CD69, P<.15). A rapid increase in serum interferon-γ was observed at 1 hour post-consumption (P<.07; after removal of two outlying data sets, P<.05) and may have contributed to the effects seen on NK and T cell subsets. Significant increase in serum antioxidant protection was seen 2 hours after consumption (P<.04). Thus consumption of a single 500 mg dose of EP provides a rapid and transient effect on the trafficking and activation status of specific lymphocyte subsets, as well as increased antioxidant protection.

A combined Phase I and II open-label study on the immunomodulatory effects of seaweed extract nutrient complex

Background:

Isolated fucoidans from brown marine algae have been shown to have a range of immune-modulating effects. This exploratory study aimed to determine whether a seaweed nutrient complex containing a blend of extracts from three different species of brown algae plus nutrients is safe to administer and has biological potential as an immune modulator. The study was undertaken as an open-label combined Phase I and II study.

Methods:

Participants (n = 10) were randomized to receive the study medication at either a 100 mg (n = 5) or 1000 mg (n = 5) dose over 4 weeks. The primary outcome measurement was in vivo changes in lymphocyte subsets. The secondary outcome measures were ex vivo changes in T-lymphocyte (CD4 and CD8) activation, phagocytosis of granulocytes and monocytes, T helper 1/T helper 2 cytokines, and serum oxygen radical absorbance capacity.

Results:

The preparation was found to be safe over the 4 weeks at both doses tested. There were no clinically relevant changes to blood measurements of hemopoietic, hepatic, or renal function. Immunomodulatory measurements showed no dose response between the two doses. The combined results from the two doses demonstrated a significant increase in cytotoxic T cell numbers and phagocytic capacity in monocytes, and a significant decrease in levels of the inflammatory cytokine interleukin 6. A separate analysis of the 100 mg dose (n = 5) alone showed a significant linear component over time (P < 0.05) for phagocytosis by both granulocytes and monocytes.

Conclusion:

The seaweed nutrient complex was safe to use when taken orally over 4 weeks. The preparation was demonstrated to have potential as an immune modulator, and this bioactivity deserves further exploration.

Fucoidan cures infection with both antimony-susceptible and -resistant strains of Leishmania donovani through Th1 response and macrophage-derived oxidants

OBJECTIVES

The aim of this study was to evaluate and characterize the antileishmanial efficacy of fucoidan, a polyanionic sulphated polysaccharide from brown algae, in experimental infections of BALB/c mice with antimony-susceptible (AG83) and -resistant (GE18ER) Leishmania donovani.

METHODS

The effect of fucoidan was assessed against intracellular parasites in cultured macrophages and in suppressing splenic and liver parasite burdens in a BALB/c mouse model of visceral leishmaniasis by microscopic evaluation of surviving intracellular amastigotes stained with Giemsa. To evaluate the type of immunological responses, real-time PCR and ELISA were performed for various Th1 and Th2 cytokines in both in vitro and in vivo infected conditions. To determine the effector mechanism, reactive oxygen species (ROS) and NO were measured in fucoidan-treated animals by H(2)DCFDA-based fluorometric analysis and Griess reaction, respectively.

RESULTS

In addition to having appreciable inhibitory effect on amastigote multiplication within macrophages (>93% inhibition at 50 μg/mL), complete elimination of liver and spleen parasite burden was achieved by fucoidan at a dose of 200 mg/kg/day given orally, 3 times weekly, in a 6-week mouse model of both antimony-susceptible and -resistant strains. This curative effect is associated with switching of T cell differentiation from Th2 to Th1 mode. Further, splenocytes of fucoidan-treated infected (AG83 and GE18FR) mice generated significantly enhanced levels of superoxide and NO. Not only was this treatment curative when administered orally 15 days post-infection, but it also imparted resistance to reinfection.

CONCLUSIONS

These results suggest the effectiveness of fucoidan as potent immunomodulator for controlling both antimony-susceptible and -resistant visceral leishmaniasis.

Immunomodulatory dietary polysaccharides: a systematic review of the literature

BACKGROUND

A large body of literature suggests that certain polysaccharides affect immune system function. Much of this literature, however, consists of in vitro studies or studies in which polysaccharides were injected. Their immunologic effects following oral administration is less clear. The purpose of this systematic review was to consolidate and evaluate the available data regarding the specific immunologic effects of dietary polysaccharides.

METHODS

Studies were identified by conducting PubMed and Google Scholar electronic searches and through reviews of polysaccharide article bibliographies. Only articles published in English were included in this review. Two researchers reviewed data on study design, control, sample size, results, and nature of outcome measures. Subsequent searches were conducted to gather information about polysaccharide safety, structure and composition, and disposition.

RESULTS

We found 62 publications reporting statistically significant effects of orally ingested glucans, pectins, heteroglycans, glucomannans, fucoidans, galactomannans, arabinogalactans and mixed polysaccharide products in rodents. Fifteen controlled human studies reported that oral glucans, arabinogalactans, heteroglycans, and fucoidans exerted significant effects. Although some studies investigated anti-inflammatory effects, most studies investigated the ability of oral polysaccharides to stimulate the immune system. These studies, as well as safety and toxicity studies, suggest that these polysaccharide products appear to be largely well-tolerated.

CONCLUSIONS

Taken as a whole, the oral polysaccharide literature is highly heterogenous and is not sufficient to support broad product structure/function generalizations. Numerous dietary polysaccharides, particularly glucans, appear to elicit diverse immunomodulatory effects in numerous animal tissues, including the blood, GI tract and spleen. Glucan extracts from the Trametes versicolor mushroom improved survival and immune function in human RCTs of cancer patients; glucans, arabinogalactans and fucoidans elicited immunomodulatory effects in controlled studies of healthy adults and patients with canker sores and seasonal allergies. This review provides a foundation that can serve to guide future research on immune modulation by well-characterized polysaccharide compounds.

The differential effect of high and low molecular weight fucoidans on the severity of collagen-induced arthritis in mice

Fucoidans have been extensively studied for their various biological activities but the exact role of fucoidans on the inflammatory processes associated with arthritic disease has not been studied. The effect of the treatment of high, medium and low molecular weight fucoidans (HMWF, MMWF and LMWF, respectively) on the progression of collagen-induced arthritis (CIA) was tested. A daily oral administration of HMWF enhanced the severity of arthritis, inflammatory responses in the joint cartilage and the levels of collagen-specific antibodies, while LMWF reduced the severity of arthritis and the levels of Th1-dependent collagen-specific IgG(2a). Further in vitro analyses, using macrophage cell lines, revealed that the HMWF induced the expression of various inflammatory mediators, and enhanced the cellular migration of macrophages. These stimulatory effects of fucoidan decreased in fucoidans with lower molecular weights and LMWF did not exhibit any pro-inflammatory effects. Interestingly, the oral administration of HMWF enhanced the production of IFN-gamma, one of the Th1 cytokines, in collagen-stimulated spleen cells that had been isolated from CIA mice, while LMWF had the opposite effect. These results indicate that HMWF enhances arthritis through enhancing the inflammatory activation of macrophages while LMWF reduces arthritis through the suppression of Th1-mediated Immune reactions.

The mechanism of fucoidan-induced apoptosis in leukemic cells: involvement of ERK1/2, JNK, glutathione, and nitric oxide

Fucoidan, a sulfated polysaccharide in brown seaweed, has various biological activities including anti-tumor activity. We investigated the effects of fucoidan on the apoptosis of human promyeloid leukemic cells and fucoidan-mediated signaling pathways. Fucoidan induced apoptosis of HL-60, NB4, and THP-1 cells, but not K562 cells. Fucoidan treatment of HL-60 cells induced activation of caspases-8, -9, and -3, the cleavage of Bid, and changed mitochondrial membrane permeability. Fucoidan-induced apoptosis, cleavage of procaspases, and changes in the mitochondrial membrane permeability were efficiently blocked by depletion of mitogen-activated protein kinase (MAPK) kinase kinase 1 (MEKK1), and inhibitors of MAPK kinase 1 (MEK1) and c Jun NH2-terminal kinase (JNK). The phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and JNK was increased in fucoidan-treated HL-60, NB4, and THP-1 cells, but not K562 cells. ERK1/2 activation occurred at earlier times than JNK activation and JNK activation was blocked by MEK1 inhibitor. In addition, fucoidan-induced apoptosis was inhibited by addition of glutathione and/or L-NAME, and fucoidan decreased intracellular glutathione concentrations and stimulated nitric oxide (NO) production. Buthionine-[R,S]-sulfoximine rendered HL-60 cells more sensitive to fucoidan. Depletion of MEKK1 and inhibition of MEK1 restored the intracellular glutathione content and abrogated NO production, whereas inhibition of JNK activation by SP600125 restored intracellular glutathione content but failed to inhibit NO production in fucoidan-treated HL-60 cells. These results suggest that activation of MEKK1, MEK1, ERK1/2, and JNK, depletion of glutathione, and production of NO are important mediators in fucoidan-induced apoptosis of human leukemic cells.

A combined phase I and II open label study on the effects of a seaweed extract nutrient complex on osteoarthritis

Background:

Isolated fucoidans from brown marine algae have been shown to have a range of anti-inflammatory effects.

Purpose:

This present study tested a Maritech^® extract formulation, containing a blend of extracts from three different species of brown algae, plus nutrients in an open label combined phase I and II pilot scale study to determine both acute safety and efficacy in osteoarthritis of the knee.

Patients and methods:

Participants (n = 12, five females [mean age, 62 ± 11.06 years] and seven males [mean age, 57.14 ± 9.20 years]) with a confirmed diagnosis of osteoarthritis of the knee were randomized to either 100 mg (n = 5) or 1000 mg (n = 7) of a Maritech^® extract formulation per day. The formulation contained Maritech^® seaweed extract containing Fucus vesiculosis (85% w/w), Macrocystis pyrifera (10% w/w) and Laminaria japonica (5% w/w) plus vitamin B6, zinc and manganese. Primary outcome was the average comprehensive arthritis test (COAT) score which is comprised of four sub-scales: pain, stiffness, difficulty with physical activity and overall symptom severity measured weekly. Safety measures included full blood count, serum lipids, liver function tests, urea, creatinine and electrolytes determined at baseline and week 12. All adverse events were recorded.

Results:

Eleven participants completed 12 weeks and one completed 10 weeks of the study. Using a multilevel linear model, the average COAT score was reduced by 18% for the 100 mg treatment and 52% for the 1000 mg dose at the end of the study. There was a clear dose response effect seen between the two treatments (P ≤ 0.0005) on the average COAT score and each of the four COAT subscales (pain, stiffness, difficulty with physical activity and overall symptom severity) (P ≤ 0.05). The preparation was well tolerated and the few adverse events were unlikely to be related to the study medication. There were no changes in blood parameters measured over the course of the study with the exception of an increase in serum albumin which was not clinically significant.

Conclusion:

The seaweed extract nutrient complex when taken orally over twelve weeks decreased the symptoms of osteoarthritis in a dose-dependent manner. It was demonstrated to be safe to use over the study period at the doses tested. The efficacy of the preparation now needs to be demonstrated in a phase III randomized controlled trial (RCT).

Australian and New Zealand Clinical Trials Register:

ACTRN12607000229471.

Effect of fucoidan on aspirin-induced stomach ulceration in rats

In this study, the effects of fucoidan on aspirin-induced ulcers in rats were evaluated: both biochemical and immunological parameters were taken into consideration. The status of stomach tissue glycogen storage and histological changes were also examined. Examination of basic biochemical parameters showed significant (p<0.01) alterations in aspartate (AST) and alanine (ALT) transaminases in ulcer-induced rats. Also, moderate alterations (p<0.05) were observed in the levels of cholesterol and blood urea nitrogen (BUN). Histopathological examination showed neutrophil infiltration and inflammation in oxyntic cells with altered glycogen storage. Analysis of serum cytokines of aspirin-induced rats showed a moderate decrease in interleukin-10 (IL-10) with considerable increase of interleukin-6 (IL-6) and interferon-gamma (INF-gamma) when compared with control. Administration of fucoidan showed considerable (p<0.05) protection against ulceration by inhibiting the acute alterations of AST, ALT, cytokines and stomach glycogen. However, aggravated serum INF-gamma was observed in the fucoidan-pretreated group. These findings suggest that the anti-ulcer property of fucoidan might contribute in protecting the inflammatory cytokine-mediated oxidative damage to gastric mucosa.

Inhibitory effect of fucoidan on Huh7 hepatoma cells through downregulation of CXCL12

The aim of this study is to assess whether fucoidan modulates the expression of chemokine ligand 12 (CXCL12)/chemokine receptor 4 (CXCR4) and exerts antitumor activity toward Huh7 hepatoma cells. According to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, fucoidan inhibited the growth of Huh7 cells and HepG2 cells in a dose-dependent manner, with a 50% inhibition of cell growth (IC50) of 2.0 and 4.0 mg/ml, respectively. alpha-fetoprotein levels in medium collected from fucoidan-treated cells were significantly decreased in Huh7 cells but not in HepG2 cells. Western blotting revealed that the amount of alpha-fetoprotein was decreased by 1.0 mg/ml of fucoidan in Huh7 cells, whereas it was unchanged in HepG2 cells. In Huh7 cells, CXCL12 mRNA expression was significantly downregulated by 1.0 mg/ml of fucoidan, whereas CXCR4 mRNA expression was unchanged by fucoidan. CXCL12 and CXCR4 mRNA were barely expressed in HepG2 cells. In addition, 1.0 mg/ml of fucoidan mildly arrested the cell cycle and induced apoptosis in Huh7 cells. The findings suggest that fucoidan exhibits antitumor activity toward Huh7 cells through the downregulation of CXCL12 expression.