A quantitative method to detect fucoidan in human plasma using a novel antibody

Orally administrated fucoidan and its low-molecular-weight derivatives are absorbed differentially to alleviate coagulation and thrombosis

Thrombosis is a serious threat to human health and life. Fucoidan, a sulfated polysaccharide from brown algae, could prevent coagulation and thrombus after intravenous administration. However, more efforts are still needed to develop its oral agent. In the present study, the absorption and excretion of fucoidan (90.8 kDa) and its degradation products, Dfuc1 (19.2 kDa) and Dfuc2 (5.5 kDa), were determined by HPLC-MS/MS after acid degradation and 1-phenyl-3-methyl-5-pyrazolone derivatization, and their anticoagulation and antithrombotic activities were evaluated in vivo after oral administration. Results showed that the maximum concentrations of fucoidan, Dfuc1 and Dfuc2 in rat plasma all achieved at 2 h after oral administration (150 mg/kg), and they were 41.1 ± 10.6 μg/mL, 45.3 ± 18.5 μg/mL and 59.3 ± 13.7 μg/mL, respectively. In addition, fucoidan, Dfuc1 and Dfuc2 could all prolong the activated partial thromboplastin time in vivo from 23.7 ± 2.7 s (blank control) to 25.1 ± 2.6 s, 27.1 ± 1.7 s and 29.4 ± 3.6 s, respectively. Moreover, fucoidan and its degradation products showed similar antithrombotic effect in carrageenan-induced thrombosis mice, and untargeted metabolomics analysis revealed that they all markedly regulated the carrageenan-induced metabolite disorders, especially the arachidonic acid metabolism. Thus, the degradation products of fucoidan with lower molecular weights are more attractive for the development of oral antithrombotic agents.

Diatom-derived mesoporous silica nanoparticles loaded with fucoidan for enhanced chemo-photodynamic therapy

Combination therapy merges chemical photodynamic therapy (CPDT) to improve cancer treatment. It synergizes chemotherapy with photodynamic therapy (PDT), using photosensitizers to produce reactive oxygen species (ROS) when exposed to light, effectively killing drug-resistant cancer cells. It is not affected by drug resistance, making it an attractive option for combination with chemotherapy. In this study, the focus was on the design of a combination therapy of chemotherapy and PDT. They synthesized diatomaceous earth mesoporous silica nanoparticles (dMSN) containing lanthanide metal ions in a PDT composition. These nanoparticles can generate ROS under near-infrared light irradiation and have MRI and fluorescence imaging capabilities, confirming their phototherapeutic effect on HCT116 cancer cells at a 200 μg/mL concentration. Fucoidan, derived from brown algae, was used as the chemotherapy component. The fucoidan extracted from Sargassum oligocystum in Pingtung Haikou showed the highest anticancer activity, with cell viability of 57.4 % at 200 μg/mL on HCT116 cancer cells. For combination therapy, fucoidan was loaded into nanoparticles (dMSN-EuGd@fucoidan). Cell viability experiments revealed that at 200 μg/mL, the cell survival rate of dMSN-EuGd@Fucoidan on HCT116 cancer cells was 47.7 %. Combination therapy demonstrated superior anticancer efficacy compared to PDT or chemotherapy alone, successfully synthesizing nanoparticles for combined chemotherapy and photodynamic therapy.

Unraveling the bioactive interplay: seaweed polysaccharide, polyphenol and their gut modulation effect

Seaweed is rich in many unique bioactive compounds such as polyphenols and sulfated polysaccharides that are not found in terrestrial plant. The discovery of numerous biological activities from seaweed has made seaweed an attractive functional food source with the potential to be exploited for human health benefits. During food processing and digestion, cell wall polysaccharide and polyphenols commonly interact, and this may influence the nutritional properties of food. Interactions between cell wall polysaccharide and polyphenols in plant-based system has been extensively studied. However, similar interactions in seaweed have received little attention despite the vast disparity between the structural and chemical composition of plant and seaweed cell wall. This poses a challenge in extracting seaweed bioactive compounds with intact biological properties. This review aims to summarize the cell wall polysaccharide and polyphenols present in brown, red and green seaweed, and current knowledge on their potential interactions. Moreover, this review gives an overview of the gut modulation effect of seaweed polysaccharide and polyphenol.

Novel Fucoidan Pharmaceutical Formulations and Their Potential Application in Oncology-A Review

Fucoidan belongs to the family of marine sulfated, L-fucose-rich polysaccharides found in the cell wall matrix of various brown algae species. In the last few years, sulfated polysaccharides have attracted the attention of researchers due to their broad biological activities such as anticoagulant, antithrombotic, antidiabetic, immunomodulatory, anticancer and antiproliferative effects. Recently the application of fucoidan in the field of pharmaceutical technology has been widely investigated. Due to its low toxicity, biocompatibility and biodegradability, fucoidan plays an important role as a drug carrier for the formulation of various drug delivery systems, especially as a biopolymer with anticancer activity, used for targeted delivery of chemotherapeutics in oncology. Furthermore, the presence of sulfate residues with negative charge in its structure enables fucoidan to form ionic complexes with oppositely charged molecules, providing relatively easy structure-forming properties in combination with other polymers. The aim of the present study was to overview essential fucoidan characteristics, related to its application in the development of pharmaceutical formulations as a single drug carrier or in combinations with other polymers. Special focus was placed on micro- and nanosized drug delivery systems with polysaccharides and their application in the field of oncology.

Purification and Characterization of the Enzyme Fucoidanase from Cobetia amphilecti Utilizing Fucoidan from Undaria pinnatifida

Fucoidanase is an unstable enzyme with high specificity that requires a large about of time to screen it from microorganisms. In this study, enzymatic hydrolysis was used to produce low-molecular-weight fucoidan from microorganisms via the degradation of high-molecular-weight fucoidan without damage to the sulfate esterification structure of oligosaccharide. The microbial strain HN-25 was isolated from sea mud and was made to undergo mutagenicity under ultraviolet light. Fucoidanase was extracted via ultrasonication and its enzymatic activity was improved via optimization of the ultrasonic conditions. The enzymatic properties and degradation efficiency of fucoidanase were characterized. The microbial strain HN-25 is a Gram-negative aerobic and rod-shaped-cell bacterium, and therefore was identified as Cobetia amphilecti via 16s rDNA. The results proved that fucoidanase is a hydrolytic enzyme with a molecular weight of 35 kDa and with high activity and stability at 30 °C and pH 8.0. The activity of fucoidanase was significantly enhanced by sodium and calcium ions and inhibited by a copper ion and ethylenediaminetetraacetate (EDTA). There was a significant decrease in the molecular weight of fucoidan after enzymatic hydrolysis. The low-molecular-weight fuicodan was divided into four fractions, mainly concentrated at F3 (20~10 kDa) and F4 (≤6 kDa). These consequences suggest that fucoidanase obtained from Cobetia amphilecti is stable and efficient and could be a good tool in the production of bioactive compounds.

A Dietary Supplement Containing Fucoidan Preserves Endothelial Glycocalyx through ERK/MAPK Signaling and Protects against Damage Induced by CKD Serum

(1) Damage to the endothelial glycocalyx (eGC), a protective layer lining the endothelial luminal surface, is associated with chronic kidney disease (CKD), which leads to a worsening of cardiovascular outcomes in these patients. Currently, there are no targeted therapeutic approaches. Whether the dietary supplement Endocalyx^TM (ECX) protects against endothelial damage caused by uremic toxins is unknown. (2) We addressed this question by performing atomic force microscopy measurements on living endothelial cells. We examined the effect of ECX on eGC thickness at baseline and with pooled serum from hemodialysis patients. ECX was also successfully administered in vivo in mice, in which eGC was assessed using perfused boundary region measurements by intravital microscopy of cremasteric vessels. (3) Both ECX and fucoidan significantly improved baseline eGC thickness. Our data indicate that these effects are dependent on ERK/MAPK and PI3K signaling. After incubation with eGC damaging serum from dialysis patients, ECX increased eGC height. Intravital microscopy in mice revealed a relevant increase in baseline eGC dimensions after feeding with ECX. (4) We identified a dietary supplement containing glycocalyx substrates and fucoidan as potential mediators of eGC preservation in vitro and in vivo. Our findings suggest that fucoidan may be an essential component responsible for protecting the eGC in acute settings. Moreover, ECX might contribute to both protection and rebuilding of the eGC in the context of CKD.

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.

Sulfated Galactofucans: An Outstanding Class of Fucoidans with Promising Bioactivities

Fucoidans encompass versatile and heterogeneous sulfated biopolysaccharides of marine origin, specifically brown algae and marine invertebrates. Their chemistry and bioactivities have been extensively investigated in the last few decades. The reported studies revealed diverse chemical skeletons in which l-fucose is the main sugar monomer. However, other sugars, i.e., galactose, mannose, etc., have been identified to be interspersed, forming several heteropolymers, including galactofucans/fucogalactans (G-fucoidans). Particularly, sulfated galactofucans are associated with rich chemistry contributing to more promising bioactivities than fucans and other marine polysaccharides. The previous reports in the last 20 years showed that G-fucoidans derived from Undaria pinnatifida were the most studied; 21 bioactivities were investigated, especially antitumor and antiviral activities, and unique biomedical applications compared to other marine polysaccharides were demonstrated. Hence, the current article specifically reviews the biogenic sources, chemistry, and outstanding bioactivities of G-fucoidans providing the opportunity to discover novel drug candidates.

Protective effects of fucoidan against kidney diseases: Pharmacological insights and future perspectives

Chronic kidney disease (CKD) is a major public health concern that costs millions of lives worldwide. Natural products are consistently being explored for the development of novel therapeutics in the management of CKD. Fucoidan is a sulfated polysaccharide predominantly extracted from brown seaweed, which has multiple pharmacological benefits against various kidney problems, including chronic renal failure and diabetic nephropathy. This review aimed at exploring literature to update the renoprotective effects of fucoidan, to get an understanding of pharmacological mechanisms, and to highlight the recent progress of fucoidan-based therapeutic development. Evidence shows that fucoidan is effective against inflammation, oxidative stress, and fibrosis in kidney. Fucoidan targets multiple signaling systems, including Nrf2/HO-1, NF-κB, ERK and p38 MAPK, TGF-β1, SIRT1, and GLP-1R signaling that are known to be associated with CKD pathobiology. Despite these pharmacological prospects, the application of fucoidan is limited by its larger molecular size. Notably, low molecular weight fucoidan has shown therapeutic promise in some recent studies. However, future research is warranted to translate the outcome of preclinical studies into clinical use in kidney patients.

Fucoidan Is Not Completely Dependent on Degradation to Fucose to Relieve Ulcerative Colitis

Recently, fucoidan has been proposed for use as a potential anti-inflammatory drug. The purpose of this study was to investigate the mechanism of fucoidan in the treatment of ulcerative colitis. We compared the anti-inflammatory effects of fucoidan and fucose induced by dextran sulfate sodium, and the effects of fucoidan and fucose on the gut microbiota of mice. Our results showed that low-dose fucoidan significantly improved weight loss, disease activity index scores, colonic shortening, colonic histopathological damage, intestinal fatty acid binding protein 2 levels, and the expression of Occludin, Claudin-4, and Claudin-1. However, both high-dose fucoidan and fucose did not perform as well as low-dose fucoidan as described above. In addition, 16S rDNA high-throughput sequencing showed that low-dose fucoidan significantly increased the abundance of Alloprevotella, and fucose significantly increased Ruminococcaceae, but neither significantly reversed the imbalance in the gut microbiota. Therefore, we inferred that the regulation of fucoidan on colitis has a unique and complex mechanism, and it is not completely dependent on degradation to fucose to relieve ulcerative colitis, nor is it achieved only by regulating the gut microbiota. The mechanism by which fucoidan treats colitis may also include reducing inflammatory cell infiltration and increasing intestinal barrier function.

Fucoidan Protects against Acute Sulfoxaflor-Induced Hematological/Biochemical Alterations and Oxidative Stress in Male Mice

Fucoidan is a sulfated polysaccharide which can be found among a number of macroalgea species. It has a broad spectrum of biological activities including anti-oxidant, anti-tumor, immunoregulation, anti-viral and anti-coagulant. The current study was performed to investigate possible protective effects of fucoidan for sulfoxaflor-induced hematological/biochemical alterations and oxidative stress in the blood of male Swiss albino mice. For this purpose, sulfoxaflor was administered at a dose of 15 mg/kg/day (1/50 oral LD₅₀), and fucoidan was administered at a dose of 50 mg/kg/day by oral gavage alone and combined for 24 h and 7 days. Hematological parameters (RBC, HGB, HCT, MCV, MCH, MCHC, Plt, WBC, Neu, Lym and Mon), serum biochemical parameters (AST, ALT, GGT, LDH, BUN, Cre and TBil), and serum oxidative stress/antioxidant markers (8-OHdG, MDA, POC and GSH) were analyzed. The results indicated that sulfoxaflor altered hematological and biochemical parameters and caused oxidative stress in mice; fucoidan ameliorated some hematological and biochemical parameters and exhibited a protective role as an antioxidant against sulfoxaflor-induced oxidative stress.

Antiparasitic Effects of Sulfated Polysaccharides from Marine Hydrobionts

This review presents materials characterizing sulfated polysaccharides (SPS) of marine hydrobionts (algae and invertebrates) as potential means for the prevention and treatment of protozoa and helminthiasis. The authors have summarized the literature on the pathogenetic targets of protozoa on the host cells and on the antiparasitic potential of polysaccharides from red, brown and green algae as well as certain marine invertebrates. Information about the mechanisms of action of these unique compounds in diseases caused by protozoa has also been summarized. SPS is distinguished by high antiparasitic activity, good solubility and an almost complete absence of toxicity. In the long term, this allows for the consideration of these compounds as effective and attractive candidates on which to base drugs, biologically active food additives and functional food products with antiparasitic activity.

Marine Sulfated Polysaccharides: Preventive and Therapeutic Effects on Metabolic Syndrome: A Review

Metabolic syndrome is the pathological basis of cardiovascular and cerebrovascular diseases and type 2 diabetes. With the prevalence of modern lifestyles, the incidence of metabolic syndrome has risen rapidly. In recent years, marine sulfate polysaccharides (MSPs) have shown positive effects in the prevention and treatment of metabolic syndrome, and they mainly come from seaweeds and marine animals. MSPs are rich in sulfate and have stronger biological activity compared with terrestrial polysaccharides. MSPs can alleviate metabolic syndrome by regulating glucose metabolism and lipid metabolism. In addition, MSPs prevent and treat metabolic syndrome by interacting with gut microbiota. MSPs can be degraded by gut microbes to produce metabolites such as short chain fatty acids (SCFAs) and free sulfate and affect the composition of gut microbiota. The difference between MSPs and other polysaccharides lies in the sulfation pattern and sulfate content, therefore, which is very important for anti-metabolic syndrome activity of MSPs. This review summarizes the latest findings on effects of MSPs on metabolic syndrome, mechanisms of MSPs in treatment/prevention of metabolic syndrome, interactions between MSPs and gut microbiota, and the role of sulfate group and sulfation pattern in MSPs activity. However, more clinical trials are needed to confirm the potential preventive and therapeutic effects on human body. It may be a better choice to develop new functional foods containing MSPs for dietary intervention in metabolic syndrome.

Pharmacological Activities of Sulfated Fucose-Rich Polysaccharides after Oral Administration: Perspectives for the Development of New Carbohydrate-Based Drugs

Marine organisms are a source of active biomolecules with immense therapeutic and nutraceutical potential. Sulfated fucose-rich polysaccharides are present in large quantities in these organisms with important pharmacological effects in several biological systems. These polysaccharides include sulfated fucan (as fucoidan) and fucosylated chondroitin sulfate. The development of these polysaccharides as new drugs involves several important steps, among them, demonstration of the effectiveness of these compounds after oral administration. The oral route is the more practical, comfortable and preferred by patients for long-term treatments. In the past 20 years, reports of various pharmacological effects of these polysaccharides orally administered in several animal experimental models and some trials in humans have sparked the possibility for the development of drugs based on sulfated polysaccharides and/or the use of these marine organisms as functional food. This review focuses on the main pharmacological effects of sulfated fucose-rich polysaccharides, with an emphasis on the antidislipidemic, immunomodulatory, antitumor, hypoglycemic and hemostatic effects.

Fucoidan: a promising agent for brain injury and neurodegenerative disease intervention

Brain injury and neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis are urgent medical problems, which severely threaten the life quality of patients and their carers. However, there are currently no effective therapies. Fucoidan is a natural compound found in brown algae and some animals, which has multiple biological and pharmacological activities, such as antioxidant, anti-tumor, anti-coagulant, anti-thrombotic, immunoregulatory, anti-viral, and anti-inflammatory effects. A growing number of studies have shown that fucoidan also exerts a neuroprotective function. Particularly, recent findings have indicated that fucoidan could slow down the neurodegenerative processes and show protective effects against brain injury, which might be of therapeutic value for intervening in brain injury and neurodegenerative diseases. In this review, we have discussed the pharmacokinetics of fucoidan as well as the molecular mechanisms by which fucoidan exerts its neuroprotective effect on some neurological disorders. Along with this, we have also summarized the potential benefits of fucoidan in combination with other drugs in the treatment of neurodegenerative diseases and brain injury. Although the extraction process of fucoidan has been improved well, more efforts should be devoted to the translational research and clinical trials of fucoidan in the near future.

The Therapeutic Potential of the Anticancer Activity of Fucoidan: Current Advances and Hurdles

Several types of cancers share cellular and molecular behaviors. Although many chemotherapy drugs have been designed to weaken the defenses of cancer cells, these drugs may also have cytotoxic effects on healthy tissues. Fucoidan, a sulfated fucose-based polysaccharide from brown algae, has gained much attention as an antitumor drug owing to its anticancer effects against multiple cancer types. Among the anticancer mechanisms of fucoidan are cell cycle arrest, apoptosis evocation, and stimulation of cytotoxic natural killer cells and macrophages. Fucoidan also protects against toxicity associated with chemotherapeutic drugs and radiation-induced damage. The synergistic effect of fucoidan with existing anticancer drugs has prompted researchers to explore its therapeutic potential. This review compiles the mechanisms through which fucoidan slows tumor growth, kills cancer cells, and interacts with cancer chemotherapy drugs. The obstacles involved in developing fucoidan as an anticancer agent are also discussed in this review.

Present Status, Limitations and Future Directions of Treatment Strategies Using Fucoidan-Based Therapies in Bladder Cancer

Bladder cancer (BC) is a common urological cancer, with poor prognosis for advanced/metastatic stages. Various intensive treatments, including radical cystectomy, chemotherapy, immune therapy, and radiotherapy are commonly used for these patients. However, these treatments often cause complications and adverse events. Therefore, researchers are exploring the efficacy of natural product-based treatment strategies in BC patients. Fucoidan, derived from marine brown algae, is recognized as a multi-functional and safe substrate, and has been reported to have anti-cancer effects in various types of malignancies. Additionally, in vivo and in vitro studies have reported the protective effects of fucoidan against cancer-related cachexia and chemotherapeutic agent-induced adverse events. In this review, we have introduced the anti-cancer effects of fucoidan extracts in BC and highlighted its molecular mechanisms. We have also shown the anti-cancer effects of fucoidan therapy with conventional chemotherapeutic agents and new treatment strategies using fucoidan-based nanoparticles in various malignancies. Moreover, apart from the improvement of anti-cancer effects by fucoidan, its protective effects against cancer-related disorders and cisplatin-induced toxicities have been introduced. However, the available information is insufficient to conclude the clinical usefulness of fucoidan-based treatments in BC patients. Therefore, we have indicated the aspects that need to be considered regarding fucoidan-based treatments and future directions for the treatment of BC.

Fucoidans as Potential Therapeutics for Age-Related Macular Degeneration-Current Evidence from In Vitro Research

Age-related macular degeneration (AMD) is the major reason for blindness in the industrialized world with limited treatment options. Important pathogenic pathways in AMD include oxidative stress and vascular endothelial growth factor (VEGF) secretion. Due to their bioactivities, fucoidans have recently been suggested as potential therapeutics. This review gives an overview of the recent developments in this field. Recent studies have characterized several fucoidans from different species, with different molecular characteristics and different extraction methods, in regard to their ability to reduce oxidative stress and inhibit VEGF in AMD-relevant in vitro systems. As shown in these studies, fucoidans exhibit a species dependency in their bioactivity. Additionally, molecular properties such as molecular weight and fucose content are important issues. Fucoidans from Saccharina latissima and Laminaria hyperborea were identified as the most promising candidates for further development. Further research is warranted to establish fucoidans as potential therapeutics for AMD.

Pharmacokinetics of Marine-Derived Drugs

Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.

Immunomodulatory and Anti-Inflammatory Effects of Fucoidan: A Review

Inflammation is the initial response of the immune system to potentially harmful stimuli (e.g., injury, stress, and infections). The process involves activation of macrophages and neutrophils, which produce mediators, such as nitric oxide (NO), prostaglandin E2 (PGE2), pro-inflammatory and anti-inflammatory cytokines. The pro-inflammatory cytokines interleukin-1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor-α (TNF-α) are considered as biomarkers of inflammation. Even though it occurs as a physiological defense mechanism, its involvement in the pathogenesis of various diseases is reported. Rheumatoid arthritis, inflammatory bowel disease, Alzheimer's disease, and cardiovascular diseases are only a part of the diseases, in which pathogenesis the chronic inflammation is involved. Fucoidans are complex polysaccharides from brown seaweeds and some marine invertebrates, composed mainly of L-fucose and sulfate ester groups and minor amounts of neutral monosaccharides and uronic acids. Algae-derived fucoidans are studied intensively during the last years regarding their multiple biological activities and possible therapeutic potential. However, the source, species, molecular weight, composition, and structure of the polysaccharides, as well as the route of administration of fucoidans, could be crucial for their effects. Fucoidan is reported to act on different stages of the inflammatory process: (i) blocking of lymphocyte adhesion and invasion, (ii) inhibition of multiple enzymes, and (iii) induction of apoptosis. In this review, we focused on the immunemodulating and anti-inflammatory effects of fucoidans derived from macroalgae and the models used for their evaluation. Additional insights on the molecular structure of the compound are included.

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.

Therapeutic effects of an orally administered edible seaweed-derived polysaccharide preparation, ascophyllan HS, on a Streptococcus pneumoniae infection mouse model

Ascophyllan HS is a commercially available preparation of the edible brown alga Ascophyllum nodosum containing ascophyllan, a sulfated polysaccharide with diverse beneficial biological activities. In this study, the effects of ascophyllan HS were evaluated in a severe intranasal Streptococcus pneumoniae infection mouse model. The control untreated mice started to die on day 7 and 80% had died by day 14 post-infection. Continuous oral administration of ascophyllan HS before and after bacterial infection resulted in a remarkable increase in survival rate, with 90% of the low (167 mg/kg body weight/day) and 100% of the high (500 mg/kg body weight/day) dose ascophyllan HS-treated mice surviving at day 14 post-infection. Histopathological observation of the lungs of the infected mice revealed the induction of typical pneumonia features in the alveolar spaces of the untreated control mice, such as extensive infiltration of inflammatory cells, edema, and fibrin deposition. In contrast, notable levels of lung injuries or alterations were not observed in the ascophyllan HS-treated mice, and only a minor lesion was observed in one mouse. Furthermore, bacterial burdens in the lungs were significantly reduced in the ascophyllan HS-treated mice as compared to the control mice at day 4 post-infection. Significantly higher levels of IL-12 were detected in the serum of ascophyllan HS-treated mice than that of control mice measured at the end of the infection experiment (day 14). These results suggest that orally administered ascophyllan HS exerts a therapeutic effect on S. pneumoniae infection by activating the host defense systems. This is the first report of the therapeutic effect of an orally administered seaweed polysaccharide preparation on S. pneumoniae infection. Our findings suggest that ascophyllan HS has the potential to be developed as nutraceuticals and pharmaceuticals applicable for humans as well as a safe and promising therapeutic agent against S. pneumoniae infection.

The anti-cancer effects of fucoidan: a review of both in vivo and in vitro investigations

Fucoidan is a kind of the polysaccharide, which comes from brown algae and comprises of sulfated fucose residues. It has shown a large range of biological activities in basic researches, including many elements like anti-inflammatory, anti-cancer, anti-viral, anti-oxidation, anticoagulant, antithrombotic, anti-angiogenic and anti-Helicobacter pylori, etc. Cancer is a multifactorial disease of multiple causes. Most of the current chemotherapy drugs for cancer therapy are projected to eliminate the ordinary deregulation mechanisms in cancer cells. Plenty of wholesome tissues, however, are also influenced by these chemical cytotoxic effects. Existing researches have demonstrated that fucoidan can directly exert the anti-cancer actions through cell cycle arrest, induction of apoptosis, etc., and can also indirectly kill cancer cells by activating natural killer cells, macrophages, etc. Fucoidan is used as a new anti-tumor drug or as an adjuvant in combination with an anti-tumor drug because of its high biological activity, wide source, low resistance to drug resistance and low side effects. This paper reviews the mechanism by which fucoidan can eliminate tumor cells, delay tumor growth and synergize with anticancer chemotherapy drugs in vitro, in vivo and in clinical trials.

Potential Beneficial Actions of Fucoidan in Brain and Liver Injury, Disease, and Intoxication-Potential Implication of Sirtuins

Increased interest in natural antioxidants has brought to light the fucoidans (sulfated polysaccharides present in brown marine algae) as highly valued nutrients as well as effective and safe therapeutics against several diseases. Based on their satisfactory in vitro antioxidant potency, researchers have identified this molecule as an efficient remedy for neuropathological as well as metabolic disorders. Some of this therapeutic activity is accomplished by upregulation of cytoprotective molecular pathways capable of restoring the enzymatic antioxidant activity and normal mitochondrial functions. Sirtuin-3 has been discovered as a key player for achieving the neuroprotective role of fucoidan by managing these pathways, whose ultimate goal is retrieving the entirety of the antioxidant response and preventing apoptosis of neurons, thereby averting neurodegeneration and brain injuries. Another pathway whereby fucoidan exerts neuroprotective capabilities is by interactions with P-selectin on endothelial cells, thereby preventing macrophages from entering the brain proper. Furthermore, beneficial influences of fucoidan have been established in hepatocytes after xenobiotic induced liver injury by decreasing transaminase leakage and autophagy as well as obtaining optimal levels of intracellular fiber, which ultimately prevents fibrosis. The hepatoprotective role of this marine polysaccharide also includes a sirtuin, namely sirtuin-1 overexpression, which alleviates obesity and insulin resistance through suppression of hyperglycemia, reducing inflammation and stimulation of enzymatic antioxidant response. While fucoidan is very effective in animal models for brain injury and neuronal degeneration, in general, it is accepted that fucoidan shows somewhat limited potency in liver. Thus far, it has been used in large doses for treatment of acute liver injuries. Thus, it appears that further optimization of fucoidan derivatives may establish enhanced versatility for treatments of various disorders, in addition to brain injury and disease.

Is the transformation of fucoidans in human body possible?

Fucoidans are a group of homo-and hetero-polysaccharides, which necessarily contains residues of sulfated α-L-fucose. Fucoidans are found only in brown algae. These polysaccharides exhibit a wide spectrum of biological activity and have a great therapeutic potential. Enzymes capable of catalyzing the degradation of fucoidans are absent in the mammalian enzyme system. The question arises: is the transformation of fucoidan in mammals, particularly in human possible? Studies in vivo (in situ) and in vitro have demonstrated that high molecular weight fucoidans are absorbed across rat intestinal epithelial cells, accumulated by liver macrophages, and characterized by low levels in blood and urine. Using the example of the Okinawa Prefecture (Japan) residents, it was shown that Cladosiphon okamuranus alga is digested and the fucoidan contained in this alga is absorbed in the human body.

Isobolographic Analysis Demonstrates the Additive and Synergistic Effects of Gemcitabine Combined with Fucoidan in Uterine Sarcomas and Carcinosarcoma Cells

Background: Uterine sarcomas and carcinosarcoma are associated with unfavorable prognosis. The regimens that are used in chemotherapy are associated with high incidence of side effects and usually do not significantly increase patients’ survival rates. In this study we investigated the activity and interactions between gemcitabine and fucoidan, the natural compound known for its anti-tumor properties, in human sarcomas and carcinosarcoma cell models. Methods: SK-UT-1, SK-UT1-B (carcinosarcoma), MES-SA (leiomyosarcoma), and ESS-1 (endometrial stromal sarcoma) cell lines were used for the experiments. Cells were incubated in the presence of gemcitabine, fucoidan, and mixtures, after the incubation the MTT tests were performed. In order to assess the interactions between tested compounds isobolographic analysis was performed. Additional assessments of apoptosis and cell cycle were done. Results: Additive effect of combined treatment with gemcitabine and fucoidan was observed in ESS-1 and SK-UT-1 cell line. Although the supra-additive (synergistic) effect noticed in SK-UT-1B cell line. It was not possible to determine the interactions of fucoidan and gemcitabine in MES-SA cell line due to insufficient response to treatment. Addition of fucoidan to gemcitabine enhances its proapoptotic activity, what was observed especially in ESS-1 and SK-UT-1B cell lines. The arrest of cell cycle induced by mixture of gemcitabine and fucoidan, superior comparing gemcitabine alone was observed in SK-UT-1B. Conclusions: Obtained data showed that a combination of fucoidan and gemcitabine in uterine endometrial stromal sarcoma and carcinosarcoma cell lines has additive or even synergistic effect in decreasing cell viability. Furthermore, this drug combination induces apoptosis and arrest of cell cycle. The resistance of uterine leiomyosarcoma cell line, justifies searching for other drugs combinations to improve therapy efficacy.

Protective Effects of Fucoidan against Hydrogen Peroxide-Induced Oxidative Damage in Porcine Intestinal Epithelial Cells

Simple Summary

High levels of production in intensive farming systems make domestic animals like piglets particularly susceptible to oxidative stress, which is detrimental to intestinal homeostasis and function. It is of paramount importance to identify effective and reliable nutrients to counteract oxidative damage to the porcine intestinal epithelium, especially with the recent phasing out of the use of antibiotics in China. This study indicates that fucoidan could ameliorate hydrogen peroxide-induced oxidative stress in porcine intestinal epithelial cells, primarily owing to the action of fucoidan to facilitate nuclear factor-erythroid 2-related factor-2 signals and cellular antioxidant responses. These findings may provide useful implications for practical swine production.

Abstract

This study was conducted to evaluate the effectiveness of fucoidan in ameliorating hydrogen peroxide (H₂O₂)-induced oxidative stress to porcine intestinal epithelial cell line (IPEC-1). The cell viability test was initially performed to screen out appropriate concentrations of H₂O₂ and fucoidan. After that, cells were exposed to H₂O₂ in the presence or absence of pre-incubation with fucoidan. Hydrogen peroxide increased the apoptotic and necrotic rate, boosted reactive oxygen species (ROS) generation, and disturbed the transcriptional expression of genes associated with antioxidant defense and apoptosis in IPEC-1 cells. Pre-incubation with fucoidan inhibited the increases in necrosis and ROS accumulation induced by H₂O₂. Consistently, in the H₂O₂-treated IPEC-1 cells, fucoidan normalized the content of reduced glutathione as well as the mRNA abundance of NAD(P)H quinone dehydrogenase 1 and superoxide dismutase 1 while it prevented the overproduction of malondialdehyde. Moreover, H₂O₂ stimulated the translocation of nuclear factor-erythroid 2-related factor-2 to the nucleus of IPEC-1 cells, but this increase was further promoted by fucoidan pre-treatment. The results suggest that fucoidan is effective in protecting IPEC-1 cells against oxidative damage induced by H₂O₂, which may help in developing appropriate strategies for maintaining the intestinal health of young piglets.

The Pharmacokinetics of Fucoidan after Topical Application to Rats

Fucoidan, a fucose-rich polysaccharide from brown algae, has been used for transdermal formulations targeting inflammatory skin conditions, for the treatment of thrombosis, vascular permeability diseases, subcutaneous wounds, and burns. However, the pharmacokinetics of fucoidan after topical application has not been described. In this study, an ointment (OF) containing 15% fucoidan was topically applied to rats at the doses of 50–150 mg/g. The anti-Xa activity was selected as the biomarker, and the amidolytic assay method was validated and applied for pharmacokinetic studies of fucoidan. Fucoidan in OF penetrated the skin and distributed into the skin, striated muscle, and plasma with AUC_0–48 = 0.94 μg·h/g, 2.22 μg·h/g, and 1.92 µg·h/mL, respectively. The longest half-life for fucoidan was observed in plasma, then in striated muscle and skin. It was found that the pharmacokinetics of fucoidan after topical OF application was linear, in the range of 50–150 mg/kg. No accumulation of fucoidan in plasma was observed after repeated topical applications of 100 mg/kg during five days. Our results support the rationality of topical application of formulations with fucoidan.

Inhibitory effects of fucoidan on NMDA receptors and l-type Ca2+ channels regulating the Ca2+ responses in rat neurons

CONTEXT

Fucoidan, a sulphated polysaccharide extracted from brown algae [Fucus vesiculosus Linn. (Fucaceae)], has multiple biological activities.

OBJECTIVE

The effects of fucoidan on Ca²⁺ responses of rat neurons and its probable mechanisms with focus on glutamate receptors were examined.

MATERIALS AND METHODS

The neurons isolated from the cortex and hippocampi of Wistar rats in postnatal day 1 were employed. The intracellular Ca²⁺ responses triggered by various stimuli were measured in vitro by Fura-2/AM. Fucoidan at 0.5 mg/mL or 1.5 mg/mL was applied for 3 min to determine its effects on Ca²⁺ responses. RT-PCR was used to determine the mRNA expression of neuron receptors treated with fucoidan at 0.5 mg/mL for 3 h.

RESULTS

The Ca²⁺ responses induced by NMDA were 100% suppressed by fucoidan, and those induced by Bay K8644 90% in the cortical neurons. However, fucoidan has no significant effect on the Ca²⁺ responses of cortical neurons induced by AMPA or quisqualate. Meanwhile, the Ca²⁺ responses of hippocampal neurons induced by glutamate, ACPD or adrenaline, showed only a slight decrease following fucoidan treatment. RT-PCR assays of cortical and hippocampal neurons showed that fucoidan treatment significantly decreased the mRNA expression of NMDA-NR1 receptor and the primer pair for l-type Ca²⁺ channels, PR1/PR2.

DISCUSSION AND CONCLUSIONS

Our data indicate that fucoidan suppresses the intracellular Ca²⁺ responses by selectively inhibiting NMDA receptors in cortical neurons and l-type Ca²⁺ channels in hippocampal neurons. A wide spectrum of fucoidan binding to cell membrane may be useful for designing a general purpose drug in future.

Evaluation of the Immunomodulatory Effects of Fucoidan Derived from Cladosiphon Okamuranus Tokida in Mice

Okinawa mozuku (Cladosiphon okamuranus Tokida) is an edible seaweed classified as brown algae and is a native species of the Ryukyu Islands in Japan. In recent years, the genomic decoding of Okinawa mozuku has been completed. Previous studies on the anti-inflammatory, antiviral, and antitumor properties of Okinawa mozuku have suggested that it affects the regulation of cellular and humoral immunity. The aim of the present study was to examine the immunoregulatory effect of fucoidan derived from Okinawa mozuku in mice. A product containing fucoidan (purity, 88.3%; molecular weight, 49.8 kDa) was developed from Okinawa mozuku and tested for its immunoregulatory effects in mice. The experimental animals were 8-week-old female BALB/c mice to which fucoidan (0, 102.5, 205.0, 410.0, and 1025.0 mg/kg) was administered orally continuously for six weeks. Immune cell proliferation, cytokine production, macrophage phagocytosis, and serum antibody concentration were measured. We found that immune cell proliferation, interleukin (IL)-2, macrophage phagocytes, and serum antibodies (IgM, -G, -A) increased significantly, but IL-4, -5, and IgE decreased significantly. These results indicated that fucoidan modulated cellular and humoral immunity.

Therapeutic Effects of Fucoidan: A Review on Recent Studies

Fucoidan is a polysaccharide largely made up of l-fucose and sulfate groups. Fucoidan is favorable worldwide, especially amongst the food and pharmaceutical industry as a consequence of its promising therapeutic effects. Its applaudable biological functions are ascribed to its unique biological structure. Classical bioactivities associated with fucoidan include anti-oxidant, anti-tumor, anti-coagulant, anti-thrombotic, immunoregulatory, anti-viral and anti-inflammatory effects. More recently, a variety of in vitro and in vivo studies have been carried out to further highlight its therapeutic potentials. This review focuses on the progress towards understanding fucoidan and its biological activities, which may be beneficial as a future therapy. Hence, we have summarized in vitro and in vivo studies that were done within the current decade. We expect this review and a variety of others can contribute as a theoretical basis for understanding and inspire further product development of fucoidan.

Selective Suppression of Cell Growth and Programmed Cell Death-Ligand 1 Expression in HT1080 Fibrosarcoma Cells by Low Molecular Weight Fucoidan Extract

Low molecular weight fucoidan extract (LMF), prepared by an abalone glycosidase digestion of a crude fucoidan extracted from Cladosiphon novae-caledoniae Kylin, exhibits various biological activities, including anticancer effect. Various cancers express programmed cell death-ligand 1 (PD-L1), which is known to play a significant role in evasion of the host immune surveillance system. PD-L1 is also expressed in many types of normal cells for self-protection. Previous research has revealed that selective inhibition of PD-L1 expressed in cancer cells is critical for successful cancer eradication. In the present study, we analyzed whether LMF could regulate PD-L1 expression in HT1080 fibrosarcoma cells. Our results demonstrated that LMF suppressed PD-L1/PD-L2 expression and the growth of HT1080 cancer cells and had no effect on the growth of normal TIG-1 cells. Thus, LMF differentially regulates PD-L1 expression in normal and cancer cells and could serve as an alternative complementary agent for treatment of cancers with high PD-L1 expression.

Metabolites of Seaweeds as Potential Agents for the Prevention and Therapy of Influenza Infection

CONTEXT

Seaweed metabolites (fucoidans, carrageenans, ulvans, lectins, and polyphenols) are biologically active compounds that target proteins or genes of the influenza virus and host components that are necessary for replication and reproduction of the virus.

OBJECTIVE

This review gathers the information available in the literature regarding to the useful properties of seaweeds metabolites as potential agents for the prevention and therapy of influenza infection.

MATERIALS AND METHODS

The sources of scientific literature were found in various electronic databases (i.e., PubMed, Web of Science, and ScienceDirect) and library search. The retrospective search depth is 25 years.

RESULTS

Influenza is a serious medical and social problem for humanity. Recently developed drugs are quite effective against currently circulating influenza virus strains, but their use can lead to the selection of resistant viral strains. In this regard, new therapeutic approaches and drugs with a broad spectrum of activity are needed. Metabolites of seaweeds fulfill these requirements. This review presents the results of in vitro and in vivo experimental and clinical studies about the effectiveness of these compounds in combating influenza infection and explains the necessity of their use as a potential basis for the creation of new drugs with a broad spectrum of activity.

Fucoidan from Undaria pinnatifida has anti-diabetic effects by stimulation of glucose uptake and reduction of basal lipolysis in 3T3-L1 adipocytes

Fucoidan, a sulfated polysaccharide derived from brown seaweeds, has been shown to reduce blood glucose levels and improve insulin sensitivity in mice. We investigated the effects of fucoidan on lipid accumulation, lipolysis, and glucose uptake in 3T3-L1 cells to test the hypothesis that fucoidan exerts an anti-diabetic function by acting directly on adipocytes. The 3T3-L1 cells were treated with 10, 50, 100, and 200 μg/mL of fucoidan from Undaria pinnatifida. Oil Red O staining and AdipoRed assay were used to determine lipid accumulation during adipocyte differentiation. Fucoidan was shown to reduce lipid accumulation and glycerol-3-phosphate dehydrogenase (GPDH) activity in a dose-dependent manner (P < .01). The expression of peroxisome proliferator-activated receptor γ (PPARγ), a major transcription factor associated with adipocyte differentiation, was also suppressed upon treatment with fucoidan. Treatment with fucoidan stimulated glucose uptake in normal adipocytes and restored insulin-stimulated glucose uptake in obesity-induced insulin resistant adipocytes, which were made by incubating hypertrophied 3T3-L1 cells with the conditioned media of RAW 264.7 macrophages (RAW-CM) (P < .01). In the presence of RAW-CM, fucoidan enhanced epinephrine-stimulated lipolysis but reduced basal lipolysis, as determined by non-esterified fatty acid into the culture medium (P < .001). These results suggest that fucoidan may have anti-diabetic effects by improving insulin-stimulated glucose uptake and inhibiting basal lipolysis in adipocytes without inducing adipogenesis.

Fucoidan Structure and Activity in Relation to Anti-Cancer Mechanisms

Fucoidan is a natural derived compound found in different species of brown algae and in some animals, that has gained attention for its anticancer properties. However, the exact mechanism of action is currently unknown. Therefore, this review will address fucoidans structure, the bioavailability, and all known different pathways affected by fucoidan, in order to formulate fucoidans structure and activity in relation to its anti-cancer mechanisms. The general bioactivity of fucoidan is difficult to establish due to factors like species-related structural diversity, growth conditions, and the extraction method. The main pathways influenced by fucoidan are the PI3K/AKT, the MAPK pathway, and the caspase pathway. PTEN seems to be important in the fucoidan-mediated effect on the AKT pathway. Furthermore, the interaction with VEGF, BMP, TGF-β, and estrogen receptors are discussed. Also, fucoidan as an adjunct seems to have beneficial effects, for both the enhanced effectiveness of chemotherapy and reduced toxicity in healthy cells. In conclusion, the multipotent character of fucoidan is promising in future anti-cancer treatment. However, there is a need for more specified studies of the structure⁻activity relationship of fucoidan from the most promising seaweed species.

Pretreated fucoidan confers neuroprotection against transient global cerebral ischemic injury in the gerbil hippocampal CA1 area via reducing of glial cell activation and oxidative stress

Fucoidan is a sulfated polysaccharide derived from brown algae and possesses various beneficial activities, including antioxidant property. Previous studies have shown that fucoidan displays protective effect against ischemia-reperfusion injury in some organs. However, few studies have been reported regarding the protective effect of fucoidan against transient cerebral ischemic insults and its related mechanisms. Therefore, in this study, we examined the neuroprotective effect of fucoidan against transient global cerebral ischemia (tGCI), as well as underlying its mechanism using a gerbil model of tGCI which shows a loss of pyramidal neurons in the hippocampal cornu ammonis 1 (CA1) area after 5 min of tGCI. Fucoidan (25 and 50 mg/kg) was intraperitoneally administered once daily for 5 days before tGCI. Pretreatment with 50 mg/kg of fucoidan, not 25 mg/kg of fucoidan, attenuated tGCI-induced hyperactivity and protected CA1 pyramidal neurons from tGCI. In addition, pretreatment with 50 mg/kg of fucoidan inhibited activations of astrocytes and microglia in the ischemic CA1 area. Furthermore, pretreatment with 50 mg/kg of fucoidan significantly reduced the increased 4-hydroxy-2-noneal and superoxide anion radical production in the ischemic CA1 area and significantly increased expressions of SOD1 and SOD2 in the CA1 pyramidal neurons before and after tGCI. Additionally, treatment with diethyldithiocarbamate (an inhibitor of SODs) to the fucoidan-treated gerbils notably abolished the fucoidan-mediated neuroprotection. In brief, our present results indicate that fucoidan can effectively protect neurons from tGCI through attenuation of activated glial cells and reduction of oxidative stress via increase of SODs. Thus, we strongly suggest that fucoidan can be used as a useful preventive agent in cerebral ischemia.

The Sulfated Polysaccharides of Brown Algae and Products of Their Enzymatic Transformation as Potential Vaccine Adjuvants

The review is devoted to critical analysis of literature data, deal with effects and mechanisms of action of sulfated polysaccharides (PSs) – fucoidans from brown algae and products of their enzymatic transformation as potential adjuvants for enhancement of anti-infective and antitumor immune response. Numerous experimental data indicate that sulfated PSs demonstrate properties of vaccine adjuvants. Application perspectiveness of fucoidans as vaccine adjuvants is defined by their high biocompatibility, low-toxicity, safety and good tolerance by macroorganism, and also mechanisms of their immunomodulatory action. In particular, fucoidans are agonists of receptors of innate immunity and strong inducers of cellular and humoral immune response. At presenting the data of structural - functional interrelations, attention focused to the defining role of degree of sulfation, uronic acids and polyphenols contents, and also molecular mass in actions of fucoidans to innate and adaptive immunity cells. Insufficiency of literary data on studying of correlation of structure – physicochemical characteristics with adjuvanticities of the sulfated PSs, and also the problem of standardization of their active fractions are noted. Special attention is paid to the analysis of immunomodulatory and adjuvant activity of fucoidan oligosaccharides. Presented here results of experimental trial indicate that, despite the difficulties due to preparation of highly purified structurally characterized fractions and complex structure of fucoidans, these substances can be used as safe and effective adjuvants in vaccines against various pathogens including viruses, and also in antitumor vaccines.

Absorption Study of Mozuku Fucoidan in Japanese Volunteers

We performed an oral administration study of fucoidan in 396 Japanese volunteers and investigated significant factors concerning the absorption of fucoidan. Urine samples were collected at 0, 3, 6, and 9 h after ingestion of 3 g of fucoidan. Fucoidan was detected in urine after ingestion in 385 out of 396 subjects. The maximum value (mean ± standard deviation (SD)) of urinary fucoidan was 332.3 ± 357.6 μg/gCr in subjects living in Okinawa prefecture, compared with 240.1 ± 302.4 μg/gCr in subjects living outside Okinawa. Compared with the estimated urinary excretion of fucoidan by place of residence, those of subjects living in Okinawa prefecture were significantly higher than those living outside Okinawa prefecture (p < 0.01). In addition, subjects living in Okinawa prefecture consumed significantly greater amounts of mozuku compared with those living outside Okinawa prefecture (p < 0.01). Multiple regression analysis showed that having Okinawa prefecture as a place of residence was a significant factor (p < 0.01) contributing to the estimated urinary excretion of fucoidan. Because the habit of eating mozuku was significantly higher (p < 0.01) in subjects living in Okinawa prefecture than in those living outside Okinawa prefecture, the habit of eating mozuku was speculated to be a factor in the absorption of fucoidan.

Pharmacokinetic and Tissue Distribution of Fucoidan from Fucus vesiculosus after Oral Administration to Rats

Fucus vesiculosus L., known as bladderwrack, belongs to the brown seaweeds, which are widely distributed throughout northern Russia, Atlantic shores of Europe, the Baltic Sea, Greenland, the Azores, the Canary Islands, and shores of the Pacific Ocean. Fucoidan is a major fucose-rich sulfated polysaccharide found in Fucus (F.) vesiculosus. The pharmacokinetic profiling of active compounds is essential for drug development and approval. The aim of the study was to evaluate the pharmacokinetics and tissue distribution of fucoidan in rats after a single-dose oral administration. Fucoidan was isolated from F. vesiculosus. The method of measuring anti-activated factor X (anti-Xa) activity by amidolytic assay was used to analyze the plasma and tissue concentrations of fucoidan. The tissue distribution of fucoidan after intragastric administration to the rats was characterized, and it exhibited considerable heterogeneity. Fucoidan preferentially accumulates in the kidneys (AUC0–t = 10.74 µg·h/g; Cmax = 1.23 µg/g after 5 h), spleen (AUC0–t = 6.89 µg·h/g; Cmax = 0.78 µg/g after 3 h), and liver (AUC0–t = 3.26 µg·h/g; Cmax = 0.53 µg/g after 2 h) and shows a relatively long absorption time and extended circulation in the blood, with a mean residence time (MRT) = 6.79 h. The outcome of this study provides additional scientific data for traditional use of fucoidan-containing plants and offers tangible support for the continued development of new effective pharmaceuticals using fucoidan.

The Effect of Undaria pinnatifida Fucoidan on the Pharmacokinetics of Letrozole and Tamoxifen in Patients With Breast Cancer

BACKGROUND

Although the use of complementary and alternative medicines is widespread in cancer patients, clinical evidence of their benefits is sparse. Furthermore, while they are often assumed to be safe with regard to concurrent use of anticancer therapies, few studies have been carried out to investigate possible interactions. Fucoidans are a group of sulfated carbohydrates, derived from marine brown algae, which have long been used as dietary supplements due to their reported medicinal properties, including anticancer activity. The aim of this study was to investigate the effect of co-administration of fucoidan, derived from Undaria pinnatifida, on the pharmacokinetics of 2 commonly used hormonal therapies, letrozole and tamoxifen, in patients with breast cancer.

METHODS

This was an open label non-crossover study in patients with active malignancy taking letrozole or tamoxifen (n = 10 for each group). Patients took oral fucoidan, given in the form of Maritech extract, for a 3-week period (500 mg twice daily). Trough plasma concentrations of letrozole, tamoxifen, 4-hydroxytamoxifen, and endoxifen were measured using HPLC-CAD (high-performance liquid chromatography charged aerosol detector), at baseline and after concomitant administration with fucoidan.

RESULTS

No significant changes in steady-state plasma concentrations of letrozole, tamoxifen, or tamoxifen metabolites were detected after co-administration with fucoidan. In addition, no adverse effects of fucoidan were reported, and toxicity monitoring showed no significant differences in all parameters measured over the study period.

CONCLUSIONS

Administration of Undaria pinnatifida fucoidan had no significant effect on the steady-state trough concentrations of letrozole or tamoxifen and was well tolerated. These results suggest that fucoidan in the studied form and dosage could be taken concomitantly with letrozole and tamoxifen without the risk of clinically significant interactions.

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%.

Preclinical Evaluation of Safety of Fucoidan Extracts From Undaria pinnatifida and Fucus vesiculosus for Use in Cancer Treatment

OBJECTIVES

To evaluate potential hepatic metabolism-mediated drug interactions with fucoidan from Undaria pinnatifida (UPF) or Fucus vesiculosus (FVF) and potential growth inhibition activity with either fucoidan alone or with chemotherapy. In vivo studies were done to confirm safety and investigate fucoidan-mediated immune modulation.

METHODS

Cytochrome P450 (CYP450) 3A4, 2C8, 2C9, and 2D6 inhibition experiments were conducted in vitro followed by an ex vivo human hepatocytes model to evaluate the CYP450 induction potential of each fucoidan at highest theoretical concentrations. Four hepatic metabolism phase II pathways-glutathione S transferase (GST), quinone oxidoreductase (QOR), catechol-O-methyltransferases (COMT), and uridine di-phosphate (UDP)-glucuronosyltransferase (UGT)-were evaluated with validated immunoassays. Growth inhibition assays were performed with each fucoidan alone and in combination with chemotherapy agents in a panel of human cancer cell lines. In vivo studies evaluated safety and immune modualtion.

RESULTS

CYP450 inhibition was observed with FVF. The GST, QOR, and UGT pathways had no changes. UPF and FVF both interacted with COMT. No growth inhibitory activity in cancer cell lines was observed. UPF and FVF had synergistic activity with paclitaxel or tamoxifen and additive activity with topotecan. In vivo, FVF decreased HeLa human cervical tumor growth and both FVF and UPF decreased TOV-112D human ovarian tumor growth. Otherwise, no significant change in tumor growth was observed. FVF immune modulation of IgG and IL-6 was observed (p<0.03).

CONCLUSION

At higher doses, UPF and FVF may have limited potential for drug-supplement interactions, with either CYP450 or COMT hepatic metabolism pathways. Additional studies are warranted to evaluate to confirm findings of fucoidans in combination with chemotherapy.