Antithrombotic activities of fucosylated chondroitin sulfates and their depolymerized fragments from two sea cucumbers

Intermediate molecular weight-fucosylated chondroitin sulfate from sea cucumber Cucumaria frondosa is a promising anticoagulant targeting intrinsic factor IXa

Thromboembolic diseases pose a serious risk to human health worldwide. Fucosylated chondroitin sulfate (FCS) is reported to have good anticoagulant activity with a low bleeding risk. Molecular weight plays a significant role in the anticoagulant activity of FCS, and FCS smaller than octasaccharide in size has no anticoagulant activity. Therefore, identifying the best candidate for developing novel anticoagulant FCS drugs is crucial. Herein, native FCS was isolated from sea cucumber Cucumaria frondosa (FCScf) and depolymerized into a series of lower molecular weights (FCScfs). A comprehensive assessment of the in vitro anticoagulant activity and in vivo bleeding risk of FCScfs with different molecule weights demonstrated that 10 kDa FCScf (FCScf-10 K) had a greater intrinsic anticoagulant activity than low molecular weight heparin (LMWH) without any bleeding risk. Using molecular modeling combined with experimental validation, we revealed that FCScf-10 K can specifically inhibit the formation of the Xase complex by binding the negatively charged sulfate group of FCScf-10 K to the positively charged side chain of arginine residues on the specific surface of factor IXa. Thus, these data demonstrate that the intermediate molecular weight FCScf-10 K is a promising candidate for the development of novel anticoagulant drugs.

Characterization and anti-aging activities of polysaccharide from Rana dybowskii Guenther

Introduction: Rana dybowskii Guenther (RDG), as a traditional Chinese medicine, has been shown to have antioxidant effects. However, studies on the anti-aging effect of RDG are still limited. Methods: In this study, we prepared polysaccharides from the skin of RDG (RDGP) by hot water extraction, alcohol precipitation, ion-exchange chromatography and gel chromatography. The proteins were removed using the Sevage method in combination with an enzymatic method. The structural features were analyzed using high-performance gel permeation chromatography, β-elimination reaction and Fourier transform infrared spectra. The anti-aging effect of RDGP was investigated by using D-Gal to establish an aging model in mice, and pathological changes in the hippocampus were observed under a microscope. Results: We obtained the crude polysaccharide DGP from the skin of RDG, with a yield of 61.8%. The free protein was then removed by the Sevage method to obtain DGPI and deproteinated by enzymatic hydrolysis combined with the Sevage method to further remove the bound protein to obtain the high-purity polysaccharide DGPII. Then, DGPIa (1.03 × 105 Da) and DGPIIa (8.42 × 104 Da) were obtained by gel chromatography, monosaccharide composition analysis showed that they were composed of Man, GlcA, GalNAc, Glc, Gal, Fuc with molar ratios of 1: 4.22 : 1.55: 0.18 : 8.05: 0.83 and 0.74 : 1.78: 1: 0.28: 5.37 : 0.36, respectively. The results of the β-elimination reaction indicated the presence of O-glycopeptide bonds in DGPIa. The Morris water maze test indicated that mice treated with DGPIIa exhibited a significantly shorter escape latency and increased time spent in the target quadrant as well as an increase in the number of times they traversed the platform. Pathologic damage to the hippocampus was alleviated in brain tissue stained with hematoxylin-eosin. In addition, DGPIIa enhanced the activities of SOD, CAT, and GSH-Px and inhibited the level of MDA in the serum and brain tissues of aging mice. Discussion: These results suggest that RDGP has potential as a natural antioxidant and provide useful scientific information for anti-aging research.

The Relationship between Preparation and Biological Activities of Animal-Derived Polysaccharides: A Comprehensive Review

Polysaccharides are biomolecules found in microorganisms, plants, and animals that constitute living organisms. Glycosaminoglycans, unique acidic polysaccharides in animal connective tissue, are often combined with proteins in the form of covalent bonds due to their potent biological activity, low toxicity, and minimal side effects, which have the potential to be utilized as nutrition healthcare and dietary supplements. Existing studies have demonstrated that the bioactivity of polysaccharides is closely dependent on their structure and chain conformation. The characteristic functional groups and primary structure directly determine the strength of activity. However, the relationship between structure and function is still unclear, and the target and mechanism of action are not fully understood, resulting in limited clinical applications. As a result, the clinical applications of these polysaccharides are currently limited. This review provides a comprehensive summary of the extraction methods, structures, and biological activities of animal-derived polysaccharides that have been discovered so far. The aim is to promote developments in animal active polysaccharide science and provide theoretical support for exploring other unknown natural products.

Sulfated polysaccharides in sea cucumbers and their biological properties: A review

Sea cucumbers contain a wide range of biomolecules, including sulfated polysaccharides (SPs), with immense therapeutic and nutraceutical potential. SPs in sea cucumbers are mainly fucosylated chondroitin sulfate (FCS) and fucan sulfate (FS) which exhibit a series of pharmacological effects, including anticoagulant activity, in several biological systems. FCS is a structurally distinct glycosaminoglycan in the sea cucumber body wall, and its biological properties mainly depend on the degree of sulfation, position of sulfate group, molecular weight, and distribution of branches along the backbone. So far, FCS and FS have been recognized for their antithrombotic, anti-inflammatory, anticancer, antidiabetic, anti-hyperlipidemic, anti-obesity, and antioxidant potential. However, the functions of these SPs are mainly dependent on the species, origins, harvesting season, and extraction methods applied. This review focuses on the SPs of sea cucumbers and how their structural diversities affect various biological activities. In addition, the mechanism of actions of SPs, chemical structures, factors affecting their bioactivities, and their extraction methods are also discussed.

Construction and Performance Evaluation of Nicandra physalodes (Linn.) Gaertn. Polysaccharide-Based Nanogel

The nanogels made from these polysaccharides and their derivatives are often used to construct drug delivery systems owing to their biocompatible, biodegradable, non-toxic, water-soluble, and bioactive characteristics. In this work, a novel pectin with unique gelling properties was extracted from the seed of Nicandra physalodes (NPGP). The structural research indicated that NPGP was a low methoxyl pectin with a high content of galacturonic acid. NPGP-based nanogels (NGs) were accomplished employing the water in oil (W/O) nano-emulsion method. The cysteamine containing reduction-responsive bond and integrin-targeting RGD peptide were also grafted onto NPGP. The anti-tumor drug doxorubicin hydrochloride (DOX) was loaded during the formation of NGs, and the performance of DOX delivery was studied. The NGs were characterized by UV-vis, DLS, TEM, FT-IR, and XPS. The results showed that the prepared NGs were nanosized (167.6 ± 53.86 nm), had excellent encapsulation efficiency (91.61 ± 0.85%), and possessed a fine drug loading capacity (8.40 ± 0.16%). The drug release experiment showed that DOX@NPGP-SS-RGD had good redox-responsive performance. Furthermore, the results of cell experiments revealed good biocompatibility of prepared NGs, along with selective absorption by HCT-116 cells through integrin receptor-mediated endocytosis to play an anti-tumor effect. These studies indicated the potential application of NPGP-based NGs as targeted drug delivery systems.

Fucosylated Chondroitin Sulfate against Parkinson's Disease through Inhibiting Inflammation Induced by Gut Dysbiosis

Growing evidence for the importance of the gut-brain axis in Parkinson's disease (PD) has attracted researchers' interest in the possible application of microbiota-based treatment approaches. Using a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model, we looked into the prospect of treating PD with fucosylated chondroitin sulfate obtained from sea cucumbers Isostichopus badionotus (fCS-Ib). We showed that giving fCS-Ib polysaccharide orally greatly reduced the motor deficits, dopamine depletion, and alpha-synuclein increase caused by MPTP in the substantia nigra (SN). It appears that the anti-PD action of fCS-Ib polysaccharide could be attained by squelching inflammation. Glial cell hyperactivation in SN and overproduction of proinflammatory substances in serum could both be suppressed by fCS-Ib polysaccharide injection. The bacterial DNA in fresh colonic feces was submitted to 16S rRNA and untargeted metabolic analyses to confirm the participation of the microbiota-gut-brain axis in the aforementioned interpretation. The findings showed that the MPTP treatment-induced decrease in norank_f_Muribaculaceae and the increase in Staphylococcus were reversed by the administration of fCS-Ib polysaccharide. The NF-κB signaling pathway was shown to be involved in the fCS-Ib polysaccharide-induced anti-inflammation. In conclusion, our research demonstrated for the first time how fCS-Ib polysaccharide combats PD by reducing inflammation caused by gut microbial dysbiosis.

Structure and hypoglycemic effect of a neutral polysaccharide isolated from sea cucumber Stichopus japonicus

In addition to its high nutritious value, sea cucumber has been recognized by folk medicine for a long time. This study investigated the structure and hyperglycemic activity of a neutral polysaccharide (NPsj) from sea cucumber Stichopus japonicus, whose molecular weight was determined as 301.75 kDa by HPGPC method. Monosaccharide composition analysis indicated that NPsj is a glucan. The structure of NPsj was obtained by combining the analysis of methylation analysis, FTIR, NMR, periodate oxidation, Smith degradation and ESI-MS, which is mainly composed of (1 → 4)-α-d-glucoses with β-d-glucose(1→) branches substituted at O-6 every 7-9 of 1,4 linked glucoses. An in vitro insulin resistance Hep G2 cells model and a 3 T3-L1 cells model were established, and the NPsj has significant effect to increase glucose consumption with no toxicity at 10-100 μg/mL. Furthermore, NPsj upregulates the phosphorylation of Akt1 and down-regulated GSK3β, and then reduces the phosphorylation of GS, indicating its mechanism of ameliorating insulin resistance via Akt/GSK3β/GS signaling pathway.

Antithrombotic Activity of Heparinoid G2 and Its Derivatives from the Clam Coelomactra antiquata

Clam heparinoid G2 (60.25 kDa) and its depolymerized derivatives DG1 (24.48 kDa) and DG2 (6.75 kDa) prepared from Coelomactra antiquata have been documented to have excellent fibrinolytic and anticoagulant activity. In this study, to further explore the antithrombotic activity of G2, DG1 and DG2, azure A, sheep plasma, and clot lytic rate assays were used to determine their anticoagulant and thrombolytic activity in vitro. The results indicated that the anticoagulant titer of G2 was approximately 70% that of heparin and the thrombolytic activity of DG2 was greater than G2, DG1, and heparin activities. Moreover, in a carrageenan-induced venous thrombosis model, oral administration of G2 and DG1 each at 20 mg/kg and 40 mg/kg for 7 days significantly reduced blacktail thrombus formation, increased tissue-type plasminogen activator, fibrin degradation products, and D-dimer levels, decreased von Willebrand factor and thromboxane B2 levels, and restored phylum and genus abundance changes of intestinal bacteria. DG2 had no antithrombotic effect. At 20 mg/kg, G2, DG1, and heparin had comparable antithrombotic activities, and DG1 at 40 mg/kg had more muscular antithrombotic activity than G2. Thus, DG1 could be an antithrombotic oral agent owing to its more robust antithrombotic activity and lower molecular weight.

Holothurian fucosylated chondroitin sulfates and their potential benefits for human health: Structures and biological activities

Fucosylated chondroitin sulfates (FCS) are a sulfated polysaccharide exclusively existing in the body wall of sea cucumber. FCS possesses a mammalian chondroitin sulfate like backbone, namely repeating disaccharides units composed of GlcA and GalNAc, with fucosyl branches linked to GlcA and/or GalNAc residues. It is found that FCS can prevent unhealthy dietary pattern-induced metabolic syndromes, including insulin resistance and β-cell function improvement, anti-inflammation, anti-hyperlipidemia, and anti-adipogenesis. Further studies show that those activities of FCS might be achieved through positively modulating gut microbiota composition. Besides, FCS also show therapeutic efficacy in cancer, HIV infection, and side effects of cyclophosphamide. Furthermore, bioactivities of FCS are closely affected by their molecular weights, sulfation pattern of the fucosyl branches, and chain conformations. This review summarizes the recent 20 years studies to provide references for the future studies and applications of FCS in functional foods or drugs.

Semisynthetic Isomers of Fucosylated Chondroitin Sulfate Polysaccharides with Fucosyl Branches at a Non-Natural Site

The several interesting activities detected for fucosylated chondroitin sulfate (fCS) have fueled in the last years several efforts toward the obtainment of fCS oligosaccharides and low molecular weight (LMW) polysaccharides with a well-defined structure, in order to avoid the problems associated with the potential employment of native, sea cucumber sourced fCSs as a drug. Total synthesis and controlled depolymerization of the natural fCS polysaccharides are the main approaches to this aim; nonetheless, they present some limitations. These could be circumvented by semisynthesis, a strategy relying upon the regioselective fucosylation and sulfation of a microbial sourced polysaccharide sharing the same chondroitin backbone of fCS but devoid of any fucose (Fuc) and sulfate decoration on it. This approach is highly versatile, as it could open access also to fCS isomers carrying Fuc and sulfate groups at non-natural sites. Here we prepare for the first time some structurally homogeneous fCS isomers through a multistep procedure with a glycosylation reaction between a LMW polysaccharide acceptor and three different Fuc donors as key step. The obtained products were subjected to a detailed structural characterization by 2D-NMR. The conformational behavior was also investigated by NMR and molecular dynamics simulation methods and compared with data reported for natural fCS.

Effect of Oligochitosan on Experimental Venous Thrombosis in Guinea Pigs

Oligochitosan Сh10/85 with a molecular weight of 10 kDa and a deacetylation degree of 85% prevented the development of experimental venous thrombosis in guinea pigs after intravenous administration in a dose of 30 mg/kg. In a concentration of 0.005-0.5 mg/ml, oligochitosan Ch10/85 did not provoke hemolysis of human red blood cells in in vitro experiments. The antithrombotic effect of oligochitosan Ch10/85 that exhibits low anticoagulant activity (by two orders of magnitude lower than that of unfractionated heparin) can be associated with inhibition of platelet aggregation.

Marine Natural Products and Coronary Artery Disease

Coronary artery disease is the major cause of mortality worldwide, especially in low- and middle-income earners. To not only reduce angina symptoms and exercise-induced ischemia but also prevent cardiovascular events, pharmacological intervention strategies, including antiplatelet drugs, anticoagulant drugs, statins, and other lipid-lowering drugs, and renin-angiotensin-aldosterone system blockers, are conducted. However, the existing drugs for coronary artery disease are incomprehensive and have some adverse reactions. Thus, it is necessary to look for new drug research and development. Marine natural products have been considered a valuable source for drug discovery because of their chemical diversity and biological activities. The experiments and investigations indicated that several marine natural products, such as organic small molecules, polysaccharides, proteins, and bioactive peptides, and lipids were effective for treating coronary artery disease. Here, we particularly discussed the functions and mechanisms of active substances in coronary artery disease, including antiplatelet, anticoagulant, lipid-lowering, anti-inflammatory, and antioxidant activities.

It's all in the milk: chondroitin sulfate as potential preventative therapy for necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a devastating condition affecting up to 5% of neonatal intensive care unit (NICU) admissions. Risk factors include preterm delivery, low birth weight, and antibiotic use. The pathogenesis is characterized by a combination of intestinal ischemia, necrosis of the bowel, reperfusion injury, and sepsis typically resulting in surgical resection of afflicted bowel. Targeted medical therapy remains elusive. Chondroitin sulfate (CS) holds the potential to prevent the onset of NEC through its anti-inflammatory properties and protective effect on the gut microbiome. The purpose of this review is to outline the many properties of CS to highlight its potential use in high-risk infants and attenuate the severity of NEC. The purpose of this review is to (1) discuss the interaction of CS with the infant microbiome, (2) review the anti-inflammatory properties of CS, and (3) postulate on the potential role of CS in preventing NEC. IMPACT: NEC is a costly medical burden in the United States. Breast milk is the best preventative measure for NEC, but not all infants in the NICU have access to breast milk. Novel therapies and diagnostic tools are needed for NEC. CS may be a potential therapy for NEC due to its potent anti-inflammatory properties. CS could be added to the formula in an attempt to mitigate breast milk disparities.

A Review on Molecular Mechanisms and Patents of Marine-derived Anti-thrombotic Agents

Thrombosis is a condition of major concern worldwide as it is associated with life-threatening diseases related to the cardiovascular system. The condition affects 1 in 1000 adults annually, whereas 1 in 4 dies due to thrombosis, and this increases as the age group increases. The major outcomes are considered to be a recurrence, bleeding due to commercially available anti-coagulants, and deaths. The side effects associated with available anti-thrombotic drugs are a point of concern. Therefore, it is necessary to discover and develop an improvised benefit-risk profile drug, therefore, in search of alternative therapy for the treatment of thrombosis, marine sources have been used as promising treatment agents. They have shown the presence of sulfated fucans/galactans, fibrinolytic proteases, diterpenes, glycosaminoglycan, glycoside, peptides, amino acids, sterols, polysaccharides, polyphenols, vitamins, and minerals. Out of these marine sources, many chemicals were found to have anti-thrombotic activities. This review focuses on the recent discovery of anti-thrombotic agents obtained from marine algae, sponges, mussels, and sea cucumber, along with their mechanism of action and patents on its extraction process, preparation methods, and their applications. Further, the article concludes with the author's insight related to marine drugs, which have a promising future.

Fucosylated Chondroitin Sulfates from the Sea Cucumbers Paracaudina chilensis and Holothuria hilla: Structures and Anticoagulant Activity

Fucosylated chondroitin sulfates (FCSs) PC and HH were isolated from the sea cucumbers Paracaudina chilensis and Holothuria hilla, respectively. The purification of the polysaccharides was carried out by anion-exchange chromatography on a DEAE-Sephacel column. The structural characterization of the polysaccharides was performed in terms of monosaccharide and sulfate content, as well as using a series of nondestructive NMR spectroscopic methods. Both polysaccharides were shown to contain a chondroitin core [→3)-β-d-GalNAc (N-acethyl galactosamine)-(1→4)-β-d-GlcA (glucuronic acid)-(1→]_n, bearing sulfated fucosyl branches at O-3 of every GlcA residue in the chain. These fucosyl residues were different in their pattern of sulfation: PC contained Fuc2S4S and Fuc4S in a ratio of 2:1, whereas HH included Fuc2S4S, Fuc3S4S, and Fuc4S in a ratio of 1.5:1:1. Moreover, some GalNAc residues in HH were found to contain an unusual disaccharide branch Fuc4S-(1→2)-Fuc3S4S-(1→ at O-6. Sulfated GalNAc4S6S and GalNAc4S units were found in a ratio of 3:2 in PC and 2:1 in HH. Both polysaccharides demonstrated significant anticoagulant activity in a clotting time assay, which is connected with the ability of these FCSs to potentiate the inhibition of thrombin and factor Xa in the presence of anti-thrombin III (ATIII) and with the direct inhibition of thrombin in the absence of any cofactors.

Marine Antithrombotics

Thrombosis remains a prime reason of mortality worldwide. With the available antithrombotic drugs, bleeding remains the major downside of current treatments. This raises a clinical concern for all patients undergoing antithrombotic therapy. Novel antithrombotics from marine sources offer a promising therapeutic alternative to this pathology. However, for any potential new molecule to be introduced as a real alternative to existing drugs, the exhibition of comparable anticoagulant potential with minimal off-target effects must be achieved. The relevance of marine antithrombotics, particularly sulfated polysaccharides, is largely due to their unique mechanisms of action and lack of bleeding. There have been many investigations in the field and, in recent years, results have confirmed the role of potential marine molecules as alternative antithrombotics. Nonetheless, further clinical studies are required. This review covers the core of the data available so far regarding the science of marine molecules with potential medical applications to treat thrombosis. After a general discussion about the major biochemical steps involved in this pathology, we discuss the key structural and biomedical aspects of marine molecules of both low and high molecular weight endowed with antithrombotic/anticoagulant properties.

(Semi)-Synthetic Fucosylated Chondroitin Sulfate Oligo- and Polysaccharides

Fucosylated chondroitin sulfate (fCS) is a glycosaminoglycan (GAG) polysaccharide with a unique structure, displaying a backbone composed of alternating N-acetyl-d-galactosamine (GalNAc) and d-glucuronic acid (GlcA) units on which l-fucose (Fuc) branches are installed. fCS shows several potential biomedical applications, with the anticoagulant activity standing as the most promising and widely investigated one. Natural fCS polysaccharides extracted from marine organisms (Echinoidea, Holothuroidea) present some advantages over a largely employed antithrombotic drug such as heparin, but some adverse effects as well as a frequently found structural heterogeneity hamper its development as a new drug. To circumvent these drawbacks, several efforts have been made in the last decade to obtain synthetic and semi-synthetic fCS oligosaccharides and low molecular weight polysaccharides. In this Review we have for the first time collected these reports together, dividing them in two topics: (i) total syntheses of fCS oligosaccharides and (ii) semi-synthetic approaches to fCS oligosaccharides and low molecular weight polysaccharides as well as glycoclusters displaying multiple copies of fCS species.

Northern Sea Cucumber (Cucumaria frondosa): A Potential Candidate for Functional Food, Nutraceutical, and Pharmaceutical Sector

Sea cucumber (Cucumaria frondosa) is the most abundant and widely distributed species in the cold waters of North Atlantic Ocean. C. frondosa contains a wide range of bioactive compounds, mainly collagen, cerebrosides, glycosaminoglycan, chondroitin sulfate, saponins, phenols, and mucopolysaccharides, which demonstrate unique biological and pharmacological properties. In particular, the body wall of this marine invertebrate is the major edible part and contains most of the active constituents, mainly polysaccharides and collagen, which exhibit numerous biological activities, including anticancer, anti-hypertensive, anti-angiogenic, anti-inflammatory, antidiabetic, anti-coagulation, antimicrobial, antioxidation, and anti- osteoclastogenic properties. In particular, triterpene glycosides (frondoside A and other) are the most researched group of compounds due to their potential anticancer activity. This review summarizes the latest information on C. frondosa, mainly geographical distribution, landings specific to Canadian coastlines, processing, commercial products, trade market, bioactive compounds, and potential health benefits in the context of functional foods and nutraceuticals.

The Antithrombotic Effects of Low Molecular Weight Fragment from Enzymatically Modified of Laminaria Japonica Polysaccharide

BACKGROUND Laminaria japonica polysaccharide (LJP), a fucose enriched sulfated polysaccharide has been demonstrated to have excellent anticoagulant and antithrombotic activities. However, the antithrombotic effect of low molecular weight polysaccharide from enzymatically modified of LJP (LMWEP) remains unknown. MATERIAL AND METHODS LMWEP was prepared by fucoidanase enzymatic hydrolysis, and the antithrombotic and anticoagulant activities, and the underlying mechanism were investigated thoroughly. Rats were randomly divided into 6 groups (8 rats in each group): the blank control group, the blank control group treated with LMWEP (20 mg/kg), the model group, the model group treated with heparin (2 mg/kg), the model group treated with LJP (20 mg/kg), and the model group treated with LMWEP (20 mg/kg). After 7 days of intravenous administration, blood was collected for biochemical parameters examinations. RESULTS LMWEP increased the activated partial thromboplastin time (APTT), thrombin time (TT), prothrombin time (PT), 6-keto prostaglandin F1alpha (6-Keto-PGF1alpha), and endothelial nitric oxide synthase (eNOS). In addition, LMWEP decreased fibrinogen (FIB), endothelin-1 (ET-1), thromboxane B2 (TXB2), erythrocyte sedimentation rate (ESR), and hematocrit (HCT). CONCLUSIONS LMWEP, an enzymatically modified fragment with a molecular weight of 25.8 kDa, is a potential antithrombotic candidate for treatment of thrombosis related diseases.

Two different fucosylated chondroitin sulfates: Structural elucidation, stimulating hematopoiesis and immune-enhancing effects

Two fucosylated chondroitin sulfates FCS_hp and FCS_ht were isolated from the sea cucumber Holothuria polii and Holothuria tubulosa, respectively. The NMR spectroscopy and HILIC-FTMS methods were applied for their detailed structural characterization. Chemical analysis indicated that the two FCSs all contained a chondroitin sulfate backbone chondroitin sulfate-like core and fucosyl branches of α-L-Fuc2,4S, α-L-Fuc4S or α-L-Fuc3,4S linked to O-3 of glucuronic acid residues. The main branches of FCS_hp and FCS_ht were monofucose, and the small amounts of di-, tri- and tetrafucose with α-1,3-linkage type were also detected. Finally, we investigated the immunomodulatory function of FCS_hp and FCS_ht in cyclophosphamide (CTX)-induced immunosuppressed mouse models. The results showed that FCS_hp and FCS_ht had beneficial effects on hematopoietic function recovery in CTX-induced bone marrow suppression mice. Notably, the α-L-Fuc2,4S was more important to the activity than α-L-Fuc3,4S. These results provided basis for developing the drugs to reduce side effects of chemotherapy.

Bottom-up analysis using liquid chromatography-Fourier transform mass spectrometry to characterize fucosylated chondroitin sulfates from sea cucumbers

Fucosylated chondroitin sulfates (FCSs) from sea cucumbers have repetitive structures that exhibit minor structural differences based on the organism from which they are recovered. A detailed characterization of FCSs and their derivatives is important to establish their structure-activity relationship in the development of new anticoagulant drugs. In the current study, online hydrophilic interaction chromatography-Fourier transform mass spectrometry (FTMS) was applied to analyze the FCS oligosaccharides generated by selective degradation from four species of sea cucumbers, Isostichopus badionotus, Pearsonothuria graeffei, Holothuria mexicana and Acaudina molpadioides. These depolymerized FCS fragments were quantified and compared using the glycomics software package, GlycReSoft. The quantified fragments mainly had trisaccharide-repeating compositions and showed significant differences in fucosylation (including its sulfation) among different species of sea cucumbers. Detailed analysis of FTMS ion peaks and top-down nuclear magnetic resonance spectroscopy of native FCS polysaccharides verified the accuracy of this method. Thus, a new structural model for FCS chains from these different sea cucumbers was defined. This bottom-up approach provides rich detailed structural analysis and provides quantitative information with high accuracy and reproducibility and should be suitable for the quality control in FCSs as well as their oligosaccharides.

Synthesis and Properties of Functional Glycomimetics through Click Grafting of Fucose onto Chondroitin Sulfates

Fucosylated chondroitin sulfate (fCS), a representative marine polysaccharide isolated from sea cucumber, possesses diverse biological functions especially as a promising anticoagulant. However, its supply suffers from the challenges of high-cost materials, different species, and batch-to-batch variability. In the present study, we designed a concise route for the synthesis of functional glycomimetics by natural fCS as a template. 4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride-mediated amidation was applied on chondroitin sulfates for site-selective alkynylation with controllable ratios between 0.15 and 0.78. A small library of 12 fCS glycomimetics with specific sulfation patterns and fucose branches was prepared through copper-catalyzed azide-alkyne cycloaddition, which was fully characterized by nuclear magnetic resonance spectroscopy and size-exclusion chromatography with multiangle light scattering and refractive index. Through screening of their biological activities, CSE-F1 and CSE-SF1 exhibited anticoagulant activities through intrinsic pathway and inhibition of factor Xa by antithrombin III. The concise approach developed herein supplies novel glycopolymers to mimic the distinct functions of natural polysaccharides and promote the development of marine carbohydrate-based drugs.

Chondroitin: a natural biomarker with immense biomedical applications

Naturally extracted glycosaminoglycan chondroitin sulphate is the reactive product of N-acetylgalactosamine and d-glucuronic acid. Chondroitin sulfate (CS) extracted from Scophthalmus maximus, H. scabra, E. fraudatrix, M. magnum, and H. mexicana has shown remarkable anticoagulant, articular cartilage repair, corneal lesion healing, antidiabetic, and antiproliferative effects. Also, platinum and strontium nanoparticles of chondroitin sulfate are effective in osteoarthritis and exert anti-HSV2 and anti-angiogenic properties. A combination of chondroitin sulfate and RNA lipolexes demonstrates gene silencing effects in liver fibrosis. Chondroitin sulfate has also been used as a carrier for loxoprofen hydrogel preparation. Oligosaccharides of chondroitin sulfate showed effective inhibition of bovine testicular hyaluronidase enzyme as an antibacterial agent during pregnancy. Monoclonal antibody-recognized chondroitin sulfate A was effectively used to treat ameloblastoma. Selenium-chondroitin sulfate nanoparticles demonstrated positive effects in therapy of Kashin-Beck disease (KBD) and osteoarthritis.

Extraction, isolation and structural characterization of a novel polysaccharide from Cyclocarya paliurus

A water soluble polysaccharide CP-III was extracted and purified from Cyclocarya paliurus. CP-III is identified as a novel pectin-like polysaccharide with molecular weight (Mw) of 72.7 kDa. The structural features of CP-III were characterized by methylation and nuclear magnetic resonance (NMR) spectroscopy. Its depolymerized fragments were analyzed by hydrophilic interaction chromatography-Fourier transform mass spectrometry (HILIC-FTMS). The main chain of CP-III is composed of →4)GalA_p(α1 → and →2)Rha_p(α1 → 4)GalA_p(α1→, repeatedly. The residue of →4)Gal_p(β1 → and →5)Ara_f(α1 → alternately exists on the O-4 of partial →2)Rha_p(α1 → residues as side chains. On the O-3 of sectional →5)Ara_f(α1 → residues is a secondary branch assembled by →3)Ara_f(α1→. Moreover, on the non-reducing terminus of →4)Gal_p(β1 → occasionally have an →5)Ara_f(α1 → chain. Surprisingly, a sub-branch constructed by →6)Hex_p(β1 → with a galacturonate or methyl galacturonate exists on the O-3 of certain →4)Gal_p(β1 → residues in the non-reducing terminus. In addition, a terminal Xyl is located on the O-3 of fractional →4)GalA_p(β1 → residue. The highly branched polysaccharide CP-III with high water solubility can be used as food supplement and medicinal carrier in the future.

Antithrombotics from the Sea: Polysaccharides and Beyond

Marine organisms exhibit some advantages as a renewable source of potential drugs, far beyond chemotherapics. Particularly, the number of marine natural products with antithrombotic activity has increased in the last few years, and reports show a wide diversity in scaffolds, beyond the polysaccharide framework. While there are several reviews highlighting the anticoagulant and antithrombotic activities of marine-derived sulfated polysaccharides, reports including other molecules are sparse. Therefore, the present paper provides an update of the recent progress in marine-derived sulfated polysaccharides and quotes other scaffolds that are being considered for investigation due to their antithrombotic effect.

Extraction, Characterization and Antioxidant Activity in vitro of Proteins from Semen Allii Fistulosi

Semen Allii Fistulosi (PSAF) is the seed of Allium fistulosum L. of the Liliaceae family. The purpose of this study was to extract, characterize, and evaluate the antioxidant activity in vitro of proteins. Using single factor and orthogonal design, the optimum conditions of extraction were determined to be as follows: extraction time 150 min, pH 8.5, temperature 60 °C, and ratio (v/w, mL/g) of extraction solvent to raw material 35. The isoelectric point of the pH was determined to be about 4.4 and 10.2, by measuring the protein content of PSAF solutions at different pH values. The amino acid composition of PSAF was determined by high performance liquid chromatography (HPLC), and the results suggested that the species of amino acids contained in the PSAF was complete. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS–PAGE) analysis showed the molecular weight was mainly between 40 and 55 kDa, and Fourier-transform infrared spectroscopy (FTIR) characterized prevalent protein absorption peaks. PSAF exhibited potent scavenging activities against DPPH assays, via targeting of hydroxyl and superoxide radicals, while chelating Fe²⁺ activity and demonstrating weak reducing power. This work revealed that PSAF possessed potential antioxidant activity in vitro, suggesting potential for use of PSAF as a natural antioxidant.

Glycosaminoglycans from a Sea Snake (Lapemis curtus): Extraction, Structural Characterization and Antioxidant Activity

Sea snakes have wide application prospects in medicine, health food and other fields. Several novel polysaccharides were successfully obtained from the skin and the meat of a sea snake (Lapemis curtus). The structures of polysaccharides LSP3 and LMP3, which were extracted and purified from Lapemis curtus, were determined to be new and highly heterogenic glycosaminoglycans (GAGs) by means of FT-IR, ESI-MS/MS and NMR. LSP3 is a hybrid dermatan sulfate (DS) and composed of 48% 4-sulfated disaccharides (Di4S), 42% 6-sulfated disaccharides (Di6S) and 5% disulfated disaccharides (Di2,6S), while LMP3 is a hybrid chondroitin sulfate (CS) and composed of 70% Di4S, 20% Di6S, and 8% Di2,6S. More importantly, LSP3 and LMP3 showed a strong scavenging ability of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, iron (Fe²⁺) chelating activity and total antioxidant capacity in vitro, especially LSP3, with high contents of uronic acid and sulfate, which possessed a higher scavenging ability of DPPH radicals than other fractions. These data suggested that the sea snake polysaccharides could be promising candidates for natural antioxidant ingredients.

Marine polysaccharides attenuate metabolic syndrome by fermentation products and altering gut microbiota: An overview

Marine polysaccharides (MPs), including plant, animal, and microbial-derived polysaccharides, can alleviate metabolic syndrome (MetS) by different regulation mechanisms. MPs and their derivatives can attenuate MetS by vary cellular signal pathways, such as peroxisome proliferator-activated receptor, 5' adenosine monophosphate-activated protein kinase, and CCAAT/enhancer binding protein-α. Also, most of MPs cannot be degraded by human innate enzymes, but they can be degraded and fermented by human gut microbiota. The final metabolic products of these polysaccharides are usually short-chain fatty acids (SCFAs), which can change the gut microbiota ecology by altering the existing percentage of special microorganisms. In addition, the SCFAs and changed gut microbiota can regulate enteroendocrine hormone secretion, blood glucose, lipid metabolism levels, and other MetS symptoms. Here, we summarize the up-to-date findings on the effects of MPs, particularly marine microbial-derived polysaccharides, and their metabolites on attenuating MetS.

Pharmacological Potential of Sea Cucumbers

This review presents a detailed analysis of published research data focused on the pharmacological activity exerted by biologically active compounds isolated from sea cucumbers belonging to the class of Holothuroidea, phylum Echinodermata. The review contains descriptions of the structure, physico-chemical properties and pharmacological effects of these active substances. Particular attention is given to compounds with anticoagulant, antithrombotic, antioxidant, anticancer, anti-infectious, immune-stimulating and anti-ACE (angiotensin converting enzyme) activities as well as to the substances exerting a regulating influence on lipid and carbohydrate metabolism. All these compounds may be considered as prototypes for development of new pharmaceutical substances and medicines.

Heparin mimetics with anticoagulant activity

Heparin, a sulfated polysaccharide belonging to the glycosaminoglycan family, has been widely used as an anticoagulant drug for decades and remains the most commonly used parenteral anticoagulant in adults and children. However, heparin has important clinical limitations and is derived from animal sources which pose significant safety and supply problems. The ever growing shortage of the raw material for heparin manufacturing may become a very significant issue in the future. These global limitations have prompted much research, especially following the recent well-publicized contamination scandal, into the development of alternative anticoagulants derived from non-animal and/or totally synthetic sources that mimic the structural features and properties of heparin. Such compounds, termed heparin mimetics, are also needed as anticoagulant materials for use in biomedical applications (e.g., stents, grafts, implants etc.). This review encompasses the development of heparin mimetics of various structural classes, including synthetic polymers and non-carbohydrate small molecules as well as sulfated oligo- and polysaccharides, and fondaparinux derivatives and conjugates, with a focus on developments in the past 10 years.

A novel structural fucosylated chondroitin sulfate from Holothuria Mexicana and its effects on growth factors binding and anticoagulation

Fucosylated chondroitin sulfate (FCS), a structurally distinct glycosaminoglycan from the body wall of sea cucumber, possesses many biological properties and pharmacology functions. The refined structure of FCS isolated from sea cucumber Holothuria Mexicana (FCS_hm) was characterized by NMR spectra and HILIC-FTMS, which demonstrated four types of branches in FCS_hm. Among these, two branches were α-L-Fuc-2S4S (where Fuc is fucose and S is sulfo) and α-L-Fuc-4S linked to O-3 of glucuronic acid residues, while others were identified as α-L-Fuc-4S and α-L-Fuc-3S4S attached to O-6 of N-acetylgalactosamine residue. Furthermore, the fucosyl branches were α-1,3-linked with different degree of polymerization from 1 to 5. FCS_hm exhibited high affinity to fibroblast growth factor 1 and 2, growth factors involved in neovascularization. Moreover, FCS_hm displayed intrinsic anticoagulant activity and inhibited thrombin and factor Xa activation by antithrombin III. Our results proposed a novel structural FCS and demonstrated its favorable application prospects in anti-angiogenesis and anticoagulation.

Molecular size is important for the safety and selective inhibition of intrinsic factor Xase for fucosylated chondroitin sulfate

Fucosylated chondroitin sulfate from sea cucumber Isostichopus badionotus (FCS-Ib) showed potent anticoagulant activities without selectivity. The present study focused on developing safe FCS-Ib oligomers showing selective inhibition of intrinsic factor Xase (anti-FXase) prepared through partial N-deacetylation-deaminative cleavage. The N-deacetylation degree was regulated by reaction time, controlling the resulting oligomer distribution. Structure analysis confirmed the selectivity of degradation, and 12 high purity fractions with trisaccharide-repeating units were separated. In vitro anticoagulant assays indicated a decrease in molecular weight (Mw) dramatically reduced activated partial thromboplastin time (APTT), thrombin time (TT), AT-dependent anti-FIIa and anti-FXa activities, while the oligomers retained potent anti-FXase activity until they fell below 3kDa. Meanwhile, human FXII activation and platelet aggregation were markedly reduced with decreasing Mw and were moderate when under 12.0kDa. Thus, fragments of 3-12.0kDa should be safe and effective as selective inhibitors of intrinsic tenase complex for application as clinical anticoagulants.

Glycosaminoglycans from marine sources as therapeutic agents

Glycosaminoglycans (GAGs) in marine animals are different to those of terrestrial organisms, mainly in terms of molecular weight and sulfation. The therapeutic properties of GAGs are related to their ability to interact with proteins, which is very much influenced by sulfation position and patterns. Since currently GAGs cannot be chemically synthesized, they are sourced from natural products, with high intra- but also inter-species variability, in terms of chain length, disaccharide composition and sulfation pattern. Consequently, sulfated GAGs are the most interesting molecules in the marine environment and constitute the focus of the present review. In particular, chondroitin sulfate (CS) appears as the most promising compound. CS-E chains [GlcA-GalNAc(4S,6S)] extracted from squid possess antiviral and anti-metastatic activities and seem to impart signalling properties and improve the mechanical performance of cartilage engineering constructs; Squid CS-E and octopus CS-K [GlcA(3S)-GalNAc(4S)], dermatan sulfate (DS) from sea squirts [-iK units, IdoA(3S)-GalNAc(4S)] and sea urchins [-iE units, IdoA-GalNAc(4S,6S)] and hybrids CS/DS from sharks (-B/iB [GlcA/IdoA(2S)-GalNAc(4S)], -D/iD [GlcA/IdoA(2S)-GalNAc(6S)] and -E/iE units [GlcA/IdoA-GalNAc(4S,6S)]) promote neurite outgrowth and could be valuable materials for nerve regeneration. Also displaying antiviral and anti-metastatic properties, a rare CS with fucosylated branches isolated from sea cucumbers is an anticoagulant and anti-inflammatory agent. In this same line, marine heparin extracted from shrimp and sea squirt has proven anti-inflammatory properties, with the added advantage of decreased risk of bleeding because of its low anticoagulant activity.

A highly regular fucosylated chondroitin sulfate from the sea cucumber Massinium magnum: Structure and effects on coagulation

A fucosylated chondroitin sulfate MM was isolated from the sea cucumber Massinium magnum. Structure of this polysaccharide was determined using chemical and NMR spectroscopic methods. The backbone of MM was shown to consist mainly of chondroitin sulfate E units with a small portion (about 10%) of chondroitin sulfate A fragments. Practically one type of branches Fuc3S4S attached to O-3 of GlcA residues was found in the polysaccharide molecules. The main repeating units of MM are →4)-[α-l-Fuc3S4S-(1→3)]-β-d-GlcA-(1→3)-β-d-GalNAc4S6S-(1→, whereas the minor repeating units are →4)-[α-l-Fuc3S4S-(1→3)]-β-d-GlcA-(1→3)-β-d-GalNAc4S-(1→. Anticoagulant activity of MM determined in APTT and TT tests was shown to be lower than that of heparin, but higher than that of enoxaparin. In the experiments with purified proteins MM effectively potentiated inhibition of thrombin and factor Xa by ATIII. Besides, MM did not induce platelets aggregation in platelets rich plasma.