Fucoidan inhibits smooth muscle cell proliferation and reduces mitogen-activated protein kinase activity

Co-immobilization of natural marine polysaccharides and bioactive peptides on ZE21B magnesium alloy to enhance hemocompatibility and cytocompatibility

Degradable magnesium alloy stents are considered to be ideal candidates to replace the traditional non-degradable stents for the treatment of cardiovascular diseases. However, bare magnesium alloy stents usually degrade too fast and show poor hemocompatibility and cytocompatibility, which seriously affects their clinical use. In this study, surface modification based on the MgF2 layer, polydopamine (PDA) coating, fucoidan and CAG peptides was performed on the Mg-Zn-Y-Nd (ZE21B) magnesium alloy with the purpose of improving its corrosion resistance, hemocompatibility and cytocompatibility for vascular stent application. After modification, the ZE21B alloy showed better corrosion resistance. Moreover, the lower hemolysis rate, platelet adhesion and activation, and fibrinogen adsorption and denaturation proved the improved hemocompatibility of modified ZE21B alloy in in vitro blood experiments. Furthermore, the co-immobilization of fucoidan and CAG peptides significantly promoted the adhesion, proliferation, migration and NO release of endothelial cells (ECs) on the modified ZE21B alloy, and meanwhile the modification with fucoidan and CAG peptides inhibited the adhesion and proliferation of smooth muscle cells (SMCs) and suppressed the expression of proinflammatory factors in the macrophages (MAs). The surface modification obviously enhanced the corrosion resistance, hemocompatibility and cytocompatibility of ZE21B alloy, and provided an effective strategy for the development of degradable vascular stents.

Recent Advances in the Fabrication and Performance Optimization of Polyvinyl Alcohol Based Vascular Grafts

Cardiovascular disease is one of the diseases with the highest morbidity and mortality rates worldwide, and coronary artery bypass grafting (CABG) is a fast and effective treatment. More researchers are investigating in artificial blood vessels due to the limitations of autologous blood vessels. Despite the availability of large-diameter vascular grafts (Ø > 6 mm) for clinical use, small-diameter vascular grafts (Ø < 6 mm) have been a challenge for researchers to overcome in recent years. Vascular grafts made of polyvinyl alcohol (PVA) and PVA-based composites have excellent biocompatibility and mechanical characteristics. In order to gain a clearer and more specific understanding of the progress in PVA vascular graft research, particularly regarding the preparation methods, principles, and functionality of PVA vascular graft, this article discusses the mechanical properties, biocompatibility, blood compatibility, and other properties of PVA vascular graft prepared or enhanced with different blends using various techniques that mimic natural blood vessels. The findings reveal the feasibility and promising potential of PVA or PVA-based composite materials as vascular grafts.

Fucoidan/chitosan hydrogels as carrier for sustained delivery of platelet-rich fibrin containing bioactive molecules

Platelet-rich fibrin (PRF), derived from human blood, rich in wound healing components, has drawbacks in direct injections, such as rapid matrix degradation and growth factor release. Marine polysaccharides, mimicking the human extracellular matrix, show promising potential in tissue engineering. In this study, we impregnated the self-assembled fucoidan/chitosan (FU_CS) hydrogels with PRF obtaining PRF/FU_CS hydrogels. Our objective was to analyze the properties of a hydrogel and the sustained release of growth factors from the hydrogel that incorporates PRF. The results of SEM and BET-BJH demonstrated the relatively porous nature of the FU_CS hydrogels. ELISA data showed that combining FU_CS hydrogel with PRF led to a gradual 7-day sustained release of growth factors (VEGF, EGF, IL-8, PDGF-BB, TGF-β1), compared to pure PRF. Histology confirmed ELISA data, demonstrating uniform PRF fibrin network distribution within the FU_CS hydrogel matrix. Furthermore, the FU_CS hydrogels revealed excellent cell viability. The results revealed that the PRF/FU_CS hydrogel has the potential to promote wound healing and tissue regeneration. This would be the first step in the search for improved growth factor release.

Marine-derived polysaccharides and their therapeutic potential in wound healing application - A review

Polysaccharides originating from marine sources have been studied as potential material for use in wound dressings because of their desirable characteristics of biocompatibility, biodegradability, and low toxicity. Marine-derived polysaccharides used as wound dressing, provide several benefits such as promoting wound healing by providing a moist environment that facilitates cell migration and proliferation. They can also act as a barrier against external contaminants and provide a protective layer to prevent further damage to the wound. Research studies have shown that marine-derived polysaccharides can be used to develop different types of wound dressings such as hydrogels, films, and fibres. These dressings can be personalised to meet specific requirements based on the type and severity of the wound. For instance, hydrogels can be used for deep wounds to provide a moist environment, while films can be used for superficial wounds to provide a protective barrier. Additionally, these polysaccharides can be modified to improve their properties, such as enhancing their mechanical strength or increasing their ability to release bioactive molecules that can promote wound healing. Overall, marine-derived polysaccharides show great promise for developing effective and safe wound dressings for various wound types.

Fucoidan for cardiovascular application and the factors mediating its activities

Fucoidan is a sulfated polysaccharide with various bioactivities. The application of fucoidan in cancer treatment, wound healing, and food industry has been extensively studied. However, the therapeutic value of fucoidan in cardiovascular diseases has been less explored. Increasing number of investigations in the past years have demonstrated the effects of fucoidan on cardiovascular system. In this review, we will focus on the bioactivities related to cardiovascular applications, for example, the modulation functions of fucoidan on coagulation system, inflammation, and vascular cells. Factors mediating those activities will be discussed in detail. Current therapeutic strategies and future opportunities and challenges will be provided to inspire and guide further research.

Marine-derived drugs: Recent advances in cancer therapy and immune signaling

The marine environment is an enormous source of marine-derived natural products (MNPs), and future investigation into anticancer drug discovery. Current progress in anticancer drugs offers a rise in isolation and clinical validation of numerous innovative developments and advances in anticancer therapy. However, only a limited number of FDA-approved marine-derived anticancer drugs are available due to several challenges and limitations highlighted here. The use of chitosan in developing marine-derived drugs is promising in the nanotech sector projected for a prolific anticancer drug delivery system (DDS). The cGAS-STING-mediated immune signaling pathway is crucial, which has not been significantly investigated in anticancer therapy and needs further attention. Additionally, a small range of anticancer mediators is currently involved in regulating various JAK/STAT signaling pathways, such as immunity, cell death, and tumor formation. This review addressed critical features associated with MNPs, origin, and development of anticancer drugs. Moreover, recent advances in the nanotech delivery of anticancer drugs and understanding into cancer immunity are detailed for improved human health.

Current Research Landscape of Marine-Derived Anti-Atherosclerotic Substances

Atherosclerosis is a chronic disease characterized by lipid accumulation and chronic inflammation of the arterial wall, which is the pathological basis for coronary heart disease, cerebrovascular disease and thromboembolic disease. Currently, there is a lack of low-cost therapeutic agents that effectively slow the progression of atherosclerosis. Therefore, the development of new drugs is urgently needed. The research and development of marine-derived drugs have gained increasing interest from researchers across the world. Many marine organisms provide a rich material basis for the development of atherosclerotic drugs. This review focuses on the latest technological advances in the structures and mechanisms of action of marine-derived anti-atherosclerotic substances and the challenges of the application of these substances including marine polysaccharides, proteins and peptides, polyunsaturated fatty acids and small molecule compounds. Here, we describe the theoretical basis of marine biological resources in the treatment of atherosclerosis.

Fucoidan functionalization on poly(vinyl alcohol) hydrogels for improved endothelialization and hemocompatibility

The performance of clinical synthetic small diameter vascular grafts remains disappointing due to the fast occlusion caused by thrombosis and intimal hyperplasia formation. Poly(vinyl alcohol) (PVA) hydrogels have tunable mechanical properties and a low thrombogenic surface, which suggests its potential value as a small diameter vascular graft material. However, PVA does not support cell adhesion and thus requires surface modification to encourage endothelialization. This study presents a modification of PVA with fucoidan. Fucoidan is a sulfated polysaccharide with anticoagulant and antithrombotic properties, which was shown to potentially increase endothelial cell adhesion and proliferation. By mixing fucoidan with PVA and co-crosslinked by sodium trimetaphosphate (STMP), the modification was achieved without sacrificing mechanical properties. Endothelial cell adhesion and monolayer function were significantly enhanced by the fucoidan modification. In vitro and ex-vivo studies showed low platelet adhesion and activation and decreased thrombin generation with fucoidan modified PVA. The modification proved to be compatible with gamma sterilization. In vivo evaluation of fucoidan modified PVA grafts in rabbits exhibited increased patency rate, endothelialization, and reduced intimal hyperplasia formation. The fucoidan modification presented here benefited the development of PVA vascular grafts and can be adapted to other blood contacting surfaces.

Marine oligosaccharides originated from seaweeds: Source, preparation, structure, physiological activity and applications

Marine polysaccharides originated from seaweeds, including agar, alginate, carrageenan, and fucoidan, possess various kinds of physiological activities and have been widely used in food, agricultural and medical areas. However, the application has been greatly limited by their poor solubility and low bioavailability. Thus marine oligosaccharides, as the degradation products of those polysaccharides, have drawn increasing attentions due to their obvious biological activities, good solubility and excellent bioavailability. This review will summarize the recent advances on the source, molecular structure and physiological activity of marine oligosaccharides, emphasizing their application as functional food additives. Furthermore, the relationship between the structure and the physiological activity of marine oligosaccharides is also elucidated and highlighted. The review concludes with an outlook toward potential applications for preparing the functional oligosaccharides in food biotechnology and agriculture fields.

Fucoidan attenuates angiotensin II-induced abdominal aortic aneurysms through the inhibition of c-Jun N-terminal kinase and nuclear factor κB activation

BACKGROUND

Rupture of abdominal aortic aneurysm (AAA) is one of the leading causes of sudden death among the elderly. Most incidental AAAs are below the threshold for intervention at the time of detection; however, there is no evidence that commonly used cardiovascular drugs have clinical beneficial effects on AAA progression. Therefore, in addition to current cardiovascular risk-reducing treatments, an adjunctive medical therapy targeting the regulation of extracellular matrix metabolism is still required in the clinical setting. Fucoidan is an extract of brown seaweed and a sulfated polysaccharide. Emerging evidence suggests that fucoidan has potential cardiovascular applications. Numerous investigations of fucoidan in diseases of the cardiovascular system have mainly focused on its pleiotropic anti-inflammatory effects. Specifically, fucoidan has been shown to have matrix metalloproteinase (MMP)-reducing effects in several studies. We aimed to evaluate the beneficial effect of fucoidan on aneurysmal growth in a murine model of aortic aneurysm and further provide a rationale for using fucoidan as a medical adjunctive therapy.

METHODS

A murine model of angiotensin II (Ang II)-induced AAA was used to assess the therapeutic effects of fucoidan on AAA growth in vivo. The characteristics and quantification of AAAs were determined in situ. Human umbilical vein endothelial cells were used for studying the involved pathways in vitro. Western blotting was used to detect the involved signaling pathways both in vivo and in vitro.

RESULTS

Treatment with fucoidan significantly reduced the incidence of AAA formation. Administration of fucoidan significantly attenuated Ang II-induced aortic expansion from 1.56 ± 0.76 mm to 1.09 ± 0.30 mm. Administration of fucoidan significantly suppressed MMP-2 and MMP-9 activities and reduced the grade of elastin degradation in vivo. In vitro, we found that fucoidan could ameliorate the Ang II-induced phosphorylation of c-Jun N-terminal kinase and nuclear factor κB p65, and it further reduced MMP and reactive oxygen species production.

CONCLUSIONS

Fucoidan inhibits the progression of experimental AAA growth through the attenuation of proinflammatory nuclear factor κB and c-Jun N-terminal kinase activation. Fucoidan could be a potential medical adjunctive therapy for small AAAs.

Marine polysaccharides: therapeutic efficacy and biomedical applications

The ocean contains numerous marine organisms, including algae, animals, and plants, from which diverse marine polysaccharides with useful physicochemical and biological properties can be extracted. In particular, fucoidan, carrageenan, alginate, and chitosan have been extensively investigated in pharmaceutical and biomedical fields owing to their desirable characteristics, such as biocompatibility, biodegradability, and bioactivity. Various therapeutic efficacies of marine polysaccharides have been elucidated, including the inhibition of cancer, inflammation, and viral infection. The therapeutic activities of these polysaccharides have been demonstrated in various settings, from in vitro laboratory-scale experiments to clinical trials. In addition, marine polysaccharides have been exploited for tissue engineering, the immobilization of biomolecules, and stent coating. Their ability to detect and respond to external stimuli, such as pH, temperature, and electric fields, has enabled their use in the design of novel drug delivery systems. Thus, along with the promising characteristics of marine polysaccharides, this review will comprehensively detail their various therapeutic, biomedical, and miscellaneous applications.

Prospects for the therapeutic application of sulfated polysaccharides of brown algae in diseases of the cardiovascular system: review

CONTEXT

Fucoidans are water-soluble, highly sulfated, branched homo- and hetero-polysaccharides derived from the fibrillar cell walls and intercellular spaces of brown seaweeds of the class Phaeophyceae. Fucoidans possess mimetic properties of the natural ligands of protein receptors and regulate functions of biological systems via key signaling molecules.

OBJECTIVES

The aim of this review was to collect and combine all available scientific literature about the potential use of the fucoidans for diseases of cardiovascular system.

MATERIALS AND METHODS

The review has been compiled using references from major databases such as Web of Science, PubMed, Scopus, Elsevier, Springer and Google Scholar (up to September 2015). After obtaining all reports from database (a total number is about 580), the papers were carefully analyzed in order to find data related to the topic of this review (129 references).

RESULTS

An exhaustive survey of literature revealed that fucoidans possess a broad spectrum of biological activity, including anti-coagulant, hypolipidemic, anti-thrombotic, anti-inflammatory, immunomodulatory, anti-tumor, anti-adhesive and anti-hypertensive properties. Numerous investigations of fucoidans in diseases of the cardiovascular system mainly focus on pleiotropic anti-inflammatory effects. Fucoidans also possess pro-angiogenic and pro-vasculogenic properties.

CONCLUSION

A great number of investigations in the past years have demonstrated that fucoidans has great potential for in-depth investigation of their effects on cardiovascular system. Through this review, the authors hope to attract the attention of researchers to use fucoidan as mimetic of natural ligand receptor protein with the view of developing new formulations with an improved therapeutic value.

Fucoidan promotes early step of cardiac differentiation from human embryonic stem cells and long-term maintenance of beating areas

Somatic stem cells require specific niches and three-dimensional scaffolds provide ways to mimic this microenvironment. Here, we studied a scaffold based on Fucoidan, a sulfated polysaccharide known to influence morphogen gradients during embryonic development, to support human embryonic stem cells (hESCs) differentiation toward the cardiac lineage. A macroporous (pore 200 μm) Fucoidan scaffold was selected to support hESCs attachment and proliferation. Using a protocol based on the cardiogenic morphogen bone morphogenic protein 2 (BMP2) and transforming growth factor (TGFβ) followed by tumor necrosis factor (TNFα), an effector of cardiopoietic priming, we examined the cardiac differentiation in the scaffold compared to culture dishes and embryoid bodies (EBs). At day 8, Fucoidan scaffolds supported a significantly higher expression of the 3 genes encoding for transcription factors marking the early step of embryonic cardiac differentiation NKX2.5 (p<0.05), MEF2C (p<0.01), and GATA4 (p<0.01), confirmed by flow cytometry analysis for MEF2C and NKX2.5. The ability of Fucoidan scaffolds to locally concentrate and slowly release TGFβ and TNFα was confirmed by Luminex technology. We also found that Fucoidan scaffolds supported the late stage of embryonic cardiac differentiation marked by a significantly higher atrial natriuretic factor (ANF) expression (p<0.001), although only rare beating areas were observed. We postulated that absence of mechanical stress in the soft hydrogel impaired sarcomere formation, as confirmed by molecular analysis of the cardiac muscle myosin MYH6 and immunohistological staining of sarcomeric α-actinin. Nevertheless, Fucoidan scaffolds contributed to the development of thin filaments connecting beating areas through promotion of smooth muscle cells, thus enabling maintenance of beating areas for up to 6 months. In conclusion, Fucoidan scaffolds appear as a very promising biomaterial to control cardiac differentiation from hESCs that could be further combined with mechanical stress to promote sarcomere formation at terminal stages of differentiation.

Purification and Structure Study on Exopolysaccharides Produced by Lactobacillus paracasei KL1-Liu from Tibetan Kefir

To investigate the pure conditions of exopolysaccharides produced by Lactobacillus paracasei KL1-Liu from Tibetan Kefir, and to analyse the structure, we used Multi-level single-factor test to purify EPS by Sepharose CL-6B. And the purity of EPS was detected by UV scan and high performance liquid chromatogram (HPLC). EPS molecular weight and monosaccharide composition were determined by HPLC. Results: Adoption phosphate buffer gradient elution 0.02-0.10 mol/L, the velocity 0.25 mL/min, the sample concentration 1.0 mg/mL, the sample capacity 1.0 mL. Under this purification conditions, components EPSa and EPSb were obtained. The purities of EPSa and EPSb were 82.82% and 91.74% respectively, which were 1.4 and 1.5 times of the pre-purification. Purity Test results showed that EPSa and EPSb polysaccharide were single components, basically no nucleic acid and protein in them. Structural analysis revealed that the molecular weight of EPSa and EPSb were 4.60×104 Da and 2.12×104 Da detected by HPLC. EPSa monosaccharide components were glucose and rhamnose, and the molar ratio was 1:0.68. EPSb were composed of glucose, xylose and rhamnose, and the molar ratio was 1:0.77:0.69.

Structural characteristics and biological activity of Fucoidans from the brown algae Alaria sp. and Saccharina japonica of different reproductive status

Structural characteristics and the antitumor activity of fucoidans isolated from vegetative and reproductive tissue of the brown algae Alaria sp. and Saccharina japonica were studied. The reproductive status of the brown algae affected the yield of fucoidans and their structural characteristics. The fucoidan yield was 5.7% (w/w on the basis of the dried algae weight) for fertile and 3.8% for sterile Alaria sp. and 1.42 and 0.71% for fertile and sterile S. japonica, respectively. The fucoidans from fertile Alaria sp. and S. japonica had a slightly higher degree of sulfation and a somewhat more homogeneous monosaccharide composition, with predominate amounts of fucose and galactose, than those isolated from sterile algae tissue. The fucoidans from both the sterile and fertile brown algae tissue tested possessed selective cytotoxicity towards human breast cancer (T-47D) and melanoma (RPMI-7951) cell lines, but not to normal mouse epidermal cells (JB6 Cl41), and effectively inhibited the proliferation and colony formation of the breast cancer and melanoma cell lines. The fucoidans from reproductive tissue of brown algae possessed higher antitumor activity than those from vegetative plants.

Low-molecular-weight fucoidan regulates myogenic differentiation through the mitogen-activated protein kinase pathway in C2C12 cells

Low-molecular-weight fucoidan (LMWF) has been broadly studied in recent years due to its numerous biological properties. Nevertheless, there have been no reports about the effects of LMWF on myogenic differentiation (MyoD). The objective of the present study was to demonstrate the impact of LMWF on myogenesis in C2C12 cells. The ultimate aim was to establish whether LMWF regulates myogenesis similar to heparin as a partial regulator of myogenesis. LMWF was prepared at a minimal size by ultra-filtration compared with crude fucoidan. We treated C2C12 cells with LMWF and/or heparin during MyoD. The data from the present study are the first to suggest that LMWF suppresses the expression of the myogenic regulatory factors and the myocyte enhancer factors as well as the morphological changes that occur during differentiation. Additionally, the expression of the mitogen-activated protein kinase (MAPK) family was significantly inhibited by LMWF when compared with controls. The LMWF-treated group showed significantly decreased expression of reactive oxygen species (ROS) enzymes compared with control cells. Heparin was used as a positive control because it has been reported to activate MyoD. Taken together, these results suggest that LMWF might regulate MyoD through the MAPK pathway and by regulating ROS activity in C2C12 cells.

Anticancer drugs from marine flora: an overview

Marine floras, such as bacteria, actinobacteria, cyanobacteria, fungi, microalgae, seaweeds, mangroves, and other halophytes are extremely important oceanic resources, constituting over 90% of the oceanic biomass. They are taxonomically diverse, largely productive, biologically active, and chemically unique offering a great scope for discovery of new anticancer drugs. The marine floras are rich in medicinally potent chemicals predominantly belonging to polyphenols and sulphated polysaccharides. The chemicals have displayed an array of pharmacological properties especially antioxidant, immunostimulatory, and antitumour activities. The phytochemicals possibly activate macrophages, induce apoptosis, and prevent oxidative damage of DNA, thereby controlling carcinogenesis. In spite of vast resources enriched with chemicals, the marine floras are largely unexplored for anticancer lead compounds. Hence, this paper reviews the works so far conducted on this aspect with a view to provide a baseline information for promoting the marine flora-based anticancer research in the present context of increasing cancer incidence, deprived of the cheaper, safer, and potent medicines to challenge the dreadful human disease.

Anticancer compounds from marine macroalgae and their application as medicinal foods

Cancer is one of the most challenging medical conditions that need a proper therapeutic approach for its proper management with fewer side effects. Until now, many of the phytochemicals from terrestrial origin have been assessed for their anticancer ability and few of them are in clinical trials too. However, marine environment also has been a greatest resource that harbors taxonomically diverse and a variety of life forms and serves as store house for several biologically beneficial metabolites. Hitherto, many metabolites have been isolated from marine biomasses that have exhibited excellent biological activities, especially as anticancer agents. In particular, marine macroalgae which are considered as dietary constituents in Pacific Asian region have become chief resources for their unparalleled and unique metabolites like sulfated polysaccharides (SPs), phlorotannins, and their ability in reducing the risk of cancer and its related diseases. In this chapter, we have discussed the anticancer activities of marine algae-derived SPs, phlorotannins, and carotenoids and the possibilities of marine algae as potential medicinal foods in the management of cancer.

Biological effects of fucoidan isolated from Fucus vesiculosus on thrombosis and vascular cells

Background

Fucoidan is a highly sulfated glycosaminoglycan, which has a molecular structure similar to that of heparin. The antithrombotic effects of fucoidan in vitro have been widely reported, but its antithrombotic effects in vivo as well as its other biological properties in vitro have not been well investigated.

Methods

This study investigated the effects and mechanism of fucoidan from Fucus vesiculosus on thrombosis both in vitro and in vivo. A ferric chloride-induced mouse carotid artery thrombosis model was used to determine the antithrombotic effects of fucoidan in vivo. Additionally, changes in the levels of proinflammatory cytokines and chemokines were examined in vascular cells treated with fucoidan.

Results

In vivo studies employing a ferric chloride-induced mouse carotid artery thrombosis model indicated that fucoidan had a stronger antithrombotic activity than heparin. Further, vascular cells treated with fucoidan demonstrated a decrease in proinflammatory cytokine and chemokine production as well as inhibition of proliferation.

Conclusion

The major findings of this study showed that fucoidan has a stronger antithrombotic effect than heparin in vivo and that fucoidan has an inhibitory effect on proinflammatory cytokine production and proliferation of vascular cells.

A 4-week repeated oral dose toxicity study of fucoidan from the Sporophyll of Undaria pinnatifida in Sprague-Dawley rats

Fucoidan is extracted from brown seaweeds, which can have anti-coagulant, antithrombotic, antitumor, and antiviral activities. However, detailed studies on the toxicology of fucoidan have not been performed. Here we tested the toxicity of fucoidan in Sprague-Dawley rats. Fucoidan (1350mg/kg bw/day for 4 weeks) did not induce statistically significant differences in groups matched by gender with respect to body weight, ophthalmoscopy, urinalysis, hematology, and histopathology. Fucoidan did not change prothrombin time or activated partial thromboplastin time, indicating an inability to change blood clotting. This study demonstrated that fucoidan is not toxic under this administration paradigm.

Overexpression of CD39/nucleoside triphosphate diphosphohydrolase-1 decreases smooth muscle cell proliferation and prevents neointima formation after angioplasty

BACKGROUND

Growing evidence implicates the involvement of extracellular nucleotides in the regulation of platelet, leukocyte, endothelial cell (EC) and vascular smooth muscle cell (VSMC) phenotype and function. Within the quiescent vasculature, extracellular nucleotides are rapidly hydrolyzed by CD39, the dominant endothelial nucleoside triphosphate diphosphohydrolase (NTPDase-1). However, vascular CD39/NTPDase-1 activity is lost in EC activated by oxidative stress or proinflammatory mediators, and upon denudation of the endothelium following balloon injury. The consequent increase in extracellular nucleotide concentrations triggers signaling events leading to prothrombotic responses and increased VSMC proliferation.

OBJECTIVES

To investigate the effect of overexpressed CD39/NTPDase-1 in injured aorta.

METHODS

Using adenoviral-mediated gene transfer we expressed CD39/NTPDase-1 in mechanically denudated rat aortas. We measured intima formation by morphometry and VSMC proliferation by the [(3)H]-thymidine incorporation assay.

RESULTS

Targeted expression of CD39 in injured vessels increased NTPDase activity (from 2.91 +/- 0.31 to 22.07 +/- 6.7 nmols Pi mg(-1) protein, 4 days after exposure to the adenovirus) and prevented the formation of neointima. The thickness of the intimal layer in injured aortas exposed to Ad-CD39 was 26.2 +/- 3.9 microm vs. 51.8 +/- 6.1 microm and 64.4 +/- 22.2 microm (P < 0.001) in vessels treated with Ad-beta-gal and saline, respectively. Moreover, targeted expression of CD39/NTPDase-1 caused a 70% (P < 0.01) decrease in proliferation of VSMC isolated from transduced rat aortas as compared with VSMC derived from control vessels.

CONCLUSIONS

The presented data suggest that increasing CD39/NTPDase-1 activity in VSMC could represent a novel therapeutic approach for the prevention of stenosis associated with angioplasty and other occlusive vascular diseases.

The effect of polysaccharide extracted from the marine alga Capsosiphon fulvescens on ethanol administration

Seaweed extracts have recently been found to have antioxidant and antitumor activities. Capsosiphon fulvescens (Cf) is a green alga and nutrient-dense food source. In a previous study, we extracted polysaccharide from Cf (Cf-PS) and demonstrated its antitumor effect in gastric cancer cells. In this report, we describe the protective effect of Cf-PS against alcohol-induced gastric injury in rats and adenocarcinoma (AGS) cells. In vivo assay revealed stomach damage in rats treated with alcohol alone; however, the stomach condition of rats co-treated with Cf-PS and alcohol matched that of the control group. Cf-PS also inhibited alcohol-induced cell death in AGS cells. Compared with alcohol treatment alone, Cf-PS and alcohol co-treatment increased phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and Akt but inhibited poly-ADP-ribose polymerase (PARP) cleavage. Thus, ERK1/2 and Akt activation are instrumental in the protective effect of Cf-PS against alcohol-induced cell death in AGS cells. Moreover, Cf-PS treatment reduced the expressions of cyclooxygenase-2 (COX-2) and the inducible form of nitric oxide (iNOS), proteins related to ulcers. These results suggest that Cf-PS could help protect against alcohol-induced peptic ulcers.

Low Molecular Weight Fucoidan Prevents Neointimal Hyperplasia After Aortic Allografting

BACKGROUND

Fucoidan, a new low molecular weight sulfated polysaccharide (LMWF), has previously been shown to mobilize bone marrow-derived progenitors cells via stimulation of stromal derived factor (SDF)-1 release. Mobilized progenitor cells have been suggested to repair intimal lesions after immune-mediated endothelial injury and thus prevent intimal proliferation. The aim of this study was to evaluate the effect of LMWF treatment in a rat aortic allograft model of transplant arteriosclerosis (TA).

METHODS

Aortic grafts were performed in Brown Norway (BN, donor) and Lewis (Lew, recipient) rats. The recipient rats were treated with LMWF (5 mg/kg/day) and sacrificed at 30 days. To determine the role of SDF-1 in mediating the effects of LMWF, a specific inhibitor of the SDF-1 receptor CXCR4, AMD 3100 (20 microg/kg/day), was used. The grafted segments were evaluated by morphometric (histochemical) analyses.

RESULTS

Untreated aortic allografts exhibited severe intimal proliferation, indicative of TA. In contrast, LMWF treatment significantly prevented allograft intimal proliferation as compared with controls (5.7+/-3 vs. 66.2+/-6 microm, P<0.01) and permitted a normalization of the intima/media ratio (0.1+/-0.1 vs. 1.7+/-0.3, P<0.01). Further, LMWF treatment stimulated allograft reendothelialization, as evidenced by strong intimal endothelial nitric oxide synthase antibody and CD31 signals. Unexpectedly, AMD treatment failed to prevent the protective effect of LMWF on intimal thickening and AMD treatment alone was found to reduced intimal proliferation in allografts.

CONCLUSIONS

We found that LMWF treatment reduced intimal thickness and induced the presence of an endothelial cell lining in the vascular graft at 30 days. Our findings may suggest a novel therapeutic strategy in the prevention of TA.

Fucoidan induces apoptosis of human HS-sultan cells accompanied by activation of caspase-3 and down-regulation of ERK pathways

Fucoidan, a sulfated polysaccharide in brown seaweed, was found to inhibit proliferation and induce apoptosis in human lymphoma HS-Sultan cell lines. Fucoidan-induced apoptosis was accompanied by the activation of caspase-3 and was partially prevented by pretreatment with a pan-caspase inhibitor, z-VAD-FMK. The mitochondrial potential in HS-Sultan cells was decreased 24 hr after treatment with fucoidan, indicating that fucoidan induced apoptosis through a mitochondrial pathway. When HS-Sultan was treated with 100 microg/mL fucoidan for 24 hr, phosphorylation of ERK and GSK markedly decreased. In contrast, phosphorylation of p38 and Akt was not altered by treatment with fucoidan. L-selectin and P-selectin are known to be receptors of fucoidan; however, as HS-Sultan does not express either of these selectins, it is unlikely that fucoidan induced apoptosis through them in HS-Sultan. The neutralizing antibody, Dreg56, against human L-selectin did not prevent the inhibitory effect of fucoidan on the proliferation of IM9 and MOLT4 cells, both of which express L-selectin; thus it is possible fucoidan induced apoptosis though different receptors. These results demonstrate that fucoidan has direct anti-cancer effects on human HS-Sultan cells through caspase and ERK pathways.

Fucoidan Modulates the Effect of Transforming Growth Factor (TGF)-.BETA.1 on Fibroblast Proliferation and Wound Repopulation in in Vitro Models of Dermal Wound Repair

Aberrant wound healing, either causing scarring or chronic wounds, is a significant cause of morbidity. There is therefore, considerable interest in agents which can modulate certain aspects of the wound healing process. Fucoidans, sulphated polyfucose polysaccharides which may be extracted from Fucus spp., have been shown to modulate the effects of a variety of growth factors through mechanisms thought to be similar to the action of heparin. We investigated the interaction between two commercial preparations of fucoidan and transforming growth factor (TGF)-beta(1). These preparations of fucoidan, as well as heparin, inhibited fibroblast proliferation at concentrations from 0.01 to 100 mg/ml. The anti-proliferative effects of 1 ng/ml TGF-beta(1) on dermal fibroblasts were abrogated by fucoidan preparation F7 when used at concentrations over 1 mg/ml. In a three dimensional in vitro model of wound repair, the fibroblast populated collagen lattice or "dermal equivalent", TGF-beta(1) reduced the rate of fibroblast repopulation of a wound defect created by punch biopsy. Addition of fucoidan to the model in the presence of TGF-beta(1) increased the rate of fibroblast repopulation of the wound and at 10 mg/ml of fucoidan the number of cells which had migrated into the wounded defect was similar to that of control cultures. These data suggest that fucoidan has properties which may be beneficial in the treatment of wound healing.

Inhibitory effect of fucoidan on the activities of crotaline snake venom myotoxic phospholipases A(2)

Myotoxic phospholipases A(2) account for most of the muscle necrosis that results from envenenomation by crotaline snakes. In this study, we investigated the protective effect of fucoidan, a natural sulfated polysaccharide obtained from the brown seaweed Fucus vesiculosus, against the cytotoxic and myotoxic activities of a group of phospholipase A(2) myotoxins from crotaline snake venoms: Bothrops asper myotoxins I, II, III, and IV, Cerrophidion godmani myotoxins I and II, Atropoides nummifer myotoxins I and II, and Bothriechis schlegelii myotoxin I. All of the toxins tested were efficiently inhibited by fucoidan, in both their cytotoxic and myotoxic effects. The basis for this inhibition appears to be the rapid formation of complexes between fucoidan and myotoxins, as evidenced by turbidimetric analysis. The possible binding site of fucoidan on the myotoxins was investigated using short synthetic peptides that represent the membrane-damaging region (residues 115-129) for three of these toxins. Fucoidan clearly inhibited the cytolytic activity of the peptides, indicating its ability to interact with the C-terminal myotoxic region of these phospholipases A(2). Fucoidan significantly inhibited muscle damage in mice, when administered locally, immediately after experimental envenomation with crude venom from B. asper. These results encourage further studies of sulfated fucans as compounds of potential use to improve the treatment of envenomations by crotaline snakes.

Low-molecular-weight fucoidan promotes therapeutic revascularization in a rat model of critical hindlimb ischemia

The therapeutic potential of low-molecular-weight (LMW) fucoidan, a sulfated polysaccharide extracted from brown seaweed devoid of direct antithrombin effect, was investigated in vitro and in a model of critical hindlimb ischemia in rat. In vitro results showed that LMW fucoidan enhanced fibroblast growth factor (FGF)-2-induced [(3)H]thymidine incorporation in cultured rat smooth muscle cells. Intravenous injection in rats of LMW fucoidan significantly increased the stromal-derived factor (SDF)-1 level from 1.2 +/- 0.1 to 6.5 +/- 0.35 ng/ml in plasma. The therapeutic effect of LMW fucoidan (5 mg/kg/day), FGF-2 (1 micro g/kg/day), and LMW fucoidan combined with FGF-2 was assessed 14 days after induction of ischemia by 1) clinical evaluation of claudication, 2) tissue blood flow analysis, 3) histoenzymology of muscle metabolic activity, and 4) quantification of capillary density. Both LMW fucoidan and FGF-2 similarly improved residual muscle blood flow (62.5 +/- 6.5 and 64.5 +/- 4.5%, respectively) compared with the control group (42 +/- 3.5%, p < 0.0001). The combination of FGF-2 and LMW fucoidan showed further significant improvement in tissue blood flow (90.5 +/- 3%, p < 0.0001). These results were confirmed by phosphorylase activity, showing muscle regeneration in rats treated with the combination of FGF-2 and LMW fucoidan. Capillary density count increased from 9.6 +/- 0.7 capillaries/muscle section in untreated ischemic controls to 14.3 +/- 0.9 with LMW fucoidan, 14.5 +/- 0.9 with FGF-2, and 19.1 +/- 0.9 in combination (p < 0.001). Thus, LMW fucoidan potentiates FGF-2 activity, mobilizes SDF-1, and facilitates angiogenesis in a rat model. This natural compound could be of interest as an alternative for conventional treatment in critical ischemia.

Low molecular weight fucoidan prevents neointimal hyperplasia in rabbit iliac artery in-stent restenosis model

OBJECTIVE

Smooth muscle cell (SMC) proliferation within the intima is regulated by heparan sulfates. We studied a low molecular weight (LMW) fucoidan (sulfated polysaccharide from brown seaweed) on SMC proliferation in vitro and intimal hyperplasia in vivo.

METHODS AND RESULTS

In vitro study revealed that LMW fucoidan reduces rabbit SMC proliferation and is internalized in SMC perinuclear vesicles. On rabbit iliac arteries perfused in vivo with fluorolabeled LMW fucoidan after angioplasty, the labeling was mainly located on sites of injury. Pharmacokinetic studies showed that LMW fucoidan exhibited in rats an elimination half-life of 56+/-25 minutes (n=8) after intravenous administration and a constant plasma rate for > or =6 hours after intramuscular administration. After stent implantation in their iliac arteries, rabbits were also treated with LMW fucoidan (5 mg/kg IM twice a day). Histomorphometric analysis at day 14 indicated that LMW fucoidan reduced intimal hyperplasia by 59% (1.79+/-0.4 versus 0.73+/-0.2 mm2, P<0.0001) and luminal cross-sectional area narrowing by 58% (0.38+/-0.08 versus 0.16+/-0.04, P<0.0001). Blood samples showed no anticoagulant activity due to LMW fucoidan.

CONCLUSIONS

This natural polysaccharide with high affinity for SMCs and sustained plasma concentration markedly reduced intimal hyperplasia, suggesting its use for the prevention of human in-stent restenosis.