Anticoagulant Activity of Sulfated Ulvan Isolated from the Green Macroalga Ulva rigida

Exopolysaccharide from marine microalgae belonging to the Glossomastix genus: fragile gel behavior and suspension stability

With the aim to find new polysaccharides of rheological interest with innovated properties, rhamnofucans produced as exopolysaccharides (EPS) in a photobioreactor (PBR) and an airlift bioreactor (ABR) by the marine microalgae Glossomastix sp. RCC3707 and RCC3688 were fully studied. Chemical characterizations have been conducted (UHPLC - MS HR). Analyses by size-exclusion chromatography (SEC) coupled online with a multiangle light scattering detector (MALS) and a differential refractive index detector showed the presence of large structures with molar masses higher than 106 g.mol-1. The rheological studies of these EPS solutions, conducted at different concentrations and salinities, have evidenced interesting and rare behavior characteristic of weak and fragile hydrogels i.e. gel behavior with very low elastic moduli (between 10-2 and 10 Pa) and yield stresses (between 10-2 and 2 Pa) according to the EPS source, concentration, and salinity. These results were confirmed by diffusing wave spectroscopy. Finally, as one of potential application, solutions of EPS from Glossomastix sp. have evidenced very good properties as anti-settling stabilizers, using microcrystalline cellulose particles as model, studied by multiple light scattering (MLS) with utilization in cosmetic or food industry. Compared to alginate solution with same viscosity for which sedimentation is observed over few hours, microalgae EPS leads to a stable suspension over few days.

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.

Relationship between dietary fiber content and prebiotic potential of polysaccharides from the seaweeds of the North west coast of India

The macroalgae are a sustainable bioresource that can be harnessed for their functional food and nutraceutical applications. This study characterized the biochemical composition and bioactive potential of natural biological macromolecules, such as macroalgal polysaccharides extracted using a green, aqueous extraction process. The in-vitro antioxidant and antiglycemic activity of these polysaccharides were evaluated using model, free radical and antiglycemic compounds. The prebiotic potential of macroalgal polysaccharides were analysed based on their ability to promote the growth of two potential probiotic bacteria Lactobacillus acidophilus and L. bulgaricus and suppress the growth of enteric bacteria, Escherichia coli. Among the polysaccharides studied, the brown algal polysaccharide MPS8 MPS9 and MPS10 exhibited good antioxidant, antiglycemic and prebiotic activity. Based on infrared spectroscopy, the functional groups sulfation and carboxylation were identified in potential polysaccharides. The monosaccharide composition in the bioactive polysaccharides was determined using High Performance Anion Exchange Chromatography Pulse Amperometric detector (HPAEC-PAD). These bioactive polysaccharides were fractionated using ion exchange chromatography to purify it and further characterized using gel permeation chromatography and NMR spectroscopy. The results these polysaccharides are mainly composed of fucose and glucose which is due to the fucoidan and laminarin, respectively. Such macromolecules with high dietary fiber content and bioactivity are in global demand as functional food, nutraceutical and pharmaceutical formulations.

Anti-Inflammatory and Immunomodulatory Properties of a Crude Polysaccharide Derived from Green Seaweed Halimeda tuna: Computational and Experimental Evidences

In this study, we investigated for the first time the anti-inflammatory and immunomodulatory properties of crude polysaccharide (PSHT) extracted from green marine algae Halimeda tuna. PSHT exhibited anti-oxidant activity in vitro through scavenging 1, 1-diphenyl-2-picryl hydroxyl free radical, reducing Fe3+/ferricyanide complex, and inhibiting nitric oxide. PSHT maintained the erythrocyte membrane integrity and prevented hemolysis. Our results also showed that PSHT exerted a significant anti-edematic effect in vivo by decreasing advanced oxidation protein products and malondialdehyde levels and increasing the superoxide dismutase and glutathione peroxidase activities in rat's paw model and erythrocytes. Interestingly, PSHT increased the viability of murine RAW264.7 macrophages and exerted an anti-inflammatory effect on lipopolysaccharide-stimulated cells by decreasing pro-inflammatory molecule levels, including nitric oxide, granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor-alpha (TNF-α). Our findings indicate that PSHT could be used as a potential immunomodulatory, anti-inflammatory, anti-hemolytic, and anti-oxidant agent. These results could be explained by the computational findings showing that polysaccharide building blocks bound both cyclooxygenase-2 (COX-2) and TNF-α with acceptable affinities.

Anti-inflammatory potential of ulvan

Green seaweeds are a widespread group of marine macroalgae that could be regarded as biorenewable source of valuable compounds, in particular sulfated polysaccharides like ulvans with interesting biological properties. Among them, anti-inflammatory activity represents an interesting target, since ulvans could potentially avoid side effects of conventional therapies. However, a great variability in ulvan content, composition, structure and properties occurs depending on seaweed specie and growth and processing conditions. All these aspects should be carefully considered in order to have reproducible and well characterized products. This review presents some concise ideas on ulvan composition and general concepts on inflammation mechanisms. Then, the main focus is on the importance of adequate selection of extraction, depolymerization and purification technologies followed by an updated survey on anti-inflammatory properties of ulvans through modulation of different signaling pathways. The potential application in a number of diseases, with special emphasis on inflammaging, gut microbiota dysbiosis, wound repair, and metabolic diseases is also discussed. This multidisciplinary overview tries to present the potential of ulvans considering not only mechanistic, but also processing and applications aspects, trusting that it can aid in the development and application of this widely available and renewable resource as an efficient and versatile anti-inflammatory agent.

Understanding Macroalgae: A Comprehensive Exploration of Nutraceutical, Pharmaceutical, and Omics Dimensions

Driven by a surge in global interest in natural products, macroalgae or seaweed, has emerged as a prime source for nutraceuticals and pharmaceutical applications. Characterized by remarkable genetic diversity and a crucial role in marine ecosystems, these organisms offer not only substantial nutritional value in proteins, fibers, vitamins, and minerals, but also a diverse array of bioactive molecules with promising pharmaceutical properties. Furthermore, macroalgae produce approximately 80% of the oxygen in the atmosphere, highlighting their ecological significance. The unique combination of nutritional and bioactive attributes positions macroalgae as an ideal resource for food and medicine in various regions worldwide. This comprehensive review consolidates the latest advancements in the field, elucidating the potential applications of macroalgae in developing nutraceuticals and therapeutics. The review emphasizes the pivotal role of omics approaches in deepening our understanding of macroalgae's physiological and molecular characteristics. By highlighting the importance of omics, this review also advocates for continued exploration and utilization of these extraordinary marine organisms in diverse domains, including drug discovery, functional foods, and other industrial applications. The multifaceted potential of macroalgae warrants further research and development to unlock their full benefits and contribute to advancing global health and sustainable industries.

Characterization of Proteins Extracted from Ulva sp., Padina sp., and Laurencia sp. Macroalgae Using Green Technology: Effect of In Vitro Digestion on Antioxidant and ACE-I Inhibitory Activity

Macroalgal proteins were extracted from Ulva rigida (URPE) (green), Padina pavonica (PPPE) (brown), and Laurencia obtusa (LOPE) (red) using ultrasound-assisted enzymatic extraction, which is one of the green extraction technologies. Techno-functional, characteristic, and digestibility properties, and biological activities including antioxidant (AOA) and angiotensin-I converting enzyme (ACE-I) inhibitory activities were also investigated. According to the results, the extraction yield (EY) (94.74%) was detected in the extraction of L. obtusa, followed by U. rigida and P. pavonica. PPPE showed the highest ACE-I inhibitory activity before in vitro digestion. In contrast to PPPE, LOPE (20.90 ± 0.00%) and URPE (20.20 ± 0.00%) showed higher ACE-I inhibitory activity after in vitro digestion. The highest total phenolic content (TPC) (77.86 ± 1.00 mg GAE/g) was determined in LOPE. On the other hand, the highest AOACUPRAC (74.69 ± 1.78 mg TE/g) and AOAABTS (251.29 ± 5.0 mg TE/g) were detected in PPPE. After in vitro digestion, LOPE had the highest TPC (22.11 ± 2.18 mg GAE/g), AOACUPRAC (8.41 ± 0.06 mg TE/g), and AOAABTS (88.32 ± 0.65 mg TE/g) (p < 0.05). In vitro protein digestibility of three macroalgal protein extracts ranged from 84.35 ± 2.01% to 94.09 ± 0.00% (p < 0.05). Three macroalgae showed high oil holding capacity (OHC), especially PPPE (410.13 ± 16.37%) (p < 0.05), but they showed minimum foaming and emulsifying properties. The quality of the extracted macroalgal proteins was assessed using FTIR, SDS-PAGE, and DSC analyses. According to our findings, the method applied for macroalgal protein extraction could have a potential the promise of ultrasonication application as an environmentally friendly technology for food industry. Moreover, URPE, PPPE, and LOPE from sustainable sources may be attractive in terms of nourishment for people because of their digestibility, antioxidant properties, and ACE-I inhibitory activities.

Tropical Seaweeds as a Sustainable Resource Towards Circular Bioeconomy: Insights and Way Forward

Seaweeds are photosynthetic marine macroalgae known for their rapid biomass growth and their significant contributions to global food and feed production. Seaweeds play a crucial role in mitigating various environmental issues, including greenhouse gases, ocean acidification, hypoxia, and eutrophication. Tropical seaweeds are typically found in tropical and subtropical coastal zones with warmer water temperatures and abundant sunlight. These tropical seaweeds are rich sources of proteins, vitamins, minerals, fibers, polysaccharides, and bioactive compounds, contributing to their health-promoting properties and their diverse applications across a range of industries. The productivity, cultivability, nutritional quality, and edibility of tropical seaweeds have been well-documented. This review article begins with an introduction to the growth conditions of selected tropical seaweeds. Subsequently, the multifunctional properties of tropical seaweeds including antioxidant and anti-inflammatory, anti-coagulant, anti-carcinogenic and anti-proliferative, anti-viral, therapeutic and preventive properties were comprehensively evaluated. The potential application of tropical seaweeds as functional foods and feeds, as well as their contributions to sustainable cosmetics, bioenergy, and biofertilizer production were also highlighted. This review serves as a valuable resource for researchers involved in seaweed farming as it provides current knowledge and insights into the cultivation and utilization of seaweeds.

Rehashing Our Insight of Seaweeds as a Potential Source of Foods, Nutraceuticals, and Pharmaceuticals

In a few Southeast Asian nations, seaweeds have been a staple of the cuisine since prehistoric times. Seaweeds are currently becoming more and more popular around the world due to their superior nutritional value and medicinal properties. This is because of rising seaweed production on a global scale and substantial research on their composition and bioactivities over the past 20 years. By reviewing several articles in the literature, this review aimed to provide comprehensive information about the primary and secondary metabolites and various classes of bioactive compounds, such as polysaccharides, polyphenols, proteins, and essential fatty acids, along with their bioactivities, in a single article. This review also highlights the potential of seaweeds in the development of nutraceuticals, with a particular focus on their ability to enhance human health and overall well-being. In addition, we discuss the challenges and potential opportunities associated with the advancement of pharmaceuticals and nutraceuticals derived from seaweeds, as well as their incorporation into different industrial sectors. Furthermore, we find that many bioactive constituents found in seaweeds have demonstrated potential in terms of different therapeutic attributes, including antioxidative, anti-inflammatory, anticancer, and other properties. In conclusion, seaweed-based bioactive compounds have a huge potential to play an important role in the food, nutraceutical, and pharmaceutical sectors. However, future research should pay more attention to developing efficient techniques for the extraction and purification of compounds as well as their toxicity analysis, clinical efficacy, mode of action, and interactions with regular diets.

Multifaceted applications of ulvan polysaccharides: Insights on biopharmaceutical avenues

Ulvans are water-soluble sulfated polysaccharides predominantly found in the cell wall of green algae. They hold unique characteristics that are attributed to their 3D conformation, functional groups along with the presence of saccharides and sulfate ions. Traditionally, ulvans are widely used as food supplements and probiotics owing to the high content of carbohydrates. Despite their widespread usage in food industry, an in-depth understanding is required for extrapolating their potential application as a nutraceutical and medicinal agent which could be beneficial in promoting human health and well-being. This review emphasizes novel therapeutic avenues where ulvan polysaccharides can be used beyond their nutritional applications. A collection of literature points towards multifarious applications of ulvan in various biomedical fields. Structural aspects along with extraction and purification methods have been discussed. The underlying molecular mechanisms associated with its biomedical potential in different therapeutic fields like oncology, infectious diseases, inflammation, neuroprotection and tissue engineering, etc. have been unravelled. Challenges associated with clinical translation and future perspectives have been deliberated.

Insights into the Edible and Biodegradable Ulvan-Based Films and Coatings for Food Packaging

Recently, edible films or coatings that are made from algal polysaccharides have become promising candidates for replacing plastic-based packaging materials for food storage due to their non-toxic, biodegradable, biocompatible, and bioactive characteristics. Ulvan, a significant biopolymer with unique functional properties derived from marine green algae, has been extensively used in various sectors. However, there are fewer commercial applications of this sugar in the food packaging industry compared to many other algae-derived polysaccharides, such as alginates, carrageenan, and agar. This article aims to review the unparalleled chemical composition/structure and physiochemical properties of ulvan and the latest developments in ulvan-based edible films and coatings, thus highlighting their potential applications in the food packaging industry.

An overview on the nutritional and bioactive components of green seaweeds

Green seaweed, as the most abundant species of macroseaweeds, is an important marine biological resource. It is a rich source of several amino acids, fatty acids, and dietary fibers, as well as polysaccharides, polyphenols, pigments, and other active substances, which have crucial roles in various biological processes such as antioxidant activity, immunoregulation, and anti-inflammatory response. In recent years, attention to marine resources has accelerated the exploration and utilization of green seaweeds for greater economic value. This paper elaborates on the main nutrients and active substances present in different green seaweeds and provides a review of their biological activities and their applications for high-value utilization.

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Sulfated polysaccharides as multi target molecules to fight COVID 19 and comorbidities

The majority of research to combat SARS-CoV-2 infection exploits the adaptive immune system, but innate immunity, the first line of defense against pathogenic microbes, is equally important in understanding and controlling infectious diseases. Various cellular mechanisms provide physiochemical barriers to microbe infection in mucosal membranes and epithelia, with extracellular polysaccharides, particularly sulfated polysaccharides, being among the most widespread and potent extracellular and secreted molecules blocking and deactivating bacteria, fungi, and viruses. New research reveals that a range of polysaccharides effectively inhibits COV-2 infection of mammalian cells in culture. This review provides an overview of sulfated polysaccharides nomenclature, its significance as immunomodulators, antioxidants, antitumors, anticoagulants, antibacterial, and as potent antivirals. It summarizes current research on various interactions of sulfated polysaccharide with a range of viruses, including SARS-CoV-2, and their application for potential treatments for COVID-19. These molecules interact with biochemical signaling in immune cell responses, by actions in oxidative reactions, cytokine signaling, receptor binding, and through antiviral and antibacterial toxicity. These properties provide the potential for the development of novel therapeutic treatments for SARS-CoV-2 and other infectious diseases from modified polysaccharides.

Partial characterization and anticoagulant activity of sulfated galactan from the green seaweed Halimeda opuntia

The number of deaths associated with cardiovascular diseases (CVD) increases every year, leading to an intense search for new compounds that may be employed as anticoagulants. One of the classes of bioprospected molecules comprises sulfated polysaccharides (SP) from seaweed, as heparin displays many adverse effects associated with its use. The present study aimed to characterize and evaluate the anticoagulant potential of SP extracted from the green algae Halimeda opuntia. Four PS-rich fractions, F23, F44, F60 and F75, were obtained by proteolytic digestion in papain followed by ethanol precipitation. The presence of SP was confirmed by agarose gel electrophoresis, revealing different populations in each fraction. The F44 fraction is noteworthy compared to the other fractions, presenting a 5% yield compared to the initial algae weight and anticoagulant activity revealed by the activated partial thromboplastin time (APTT) assay (intrinsic/common coagulation pathway). Surprisingly, F44 purification (SP peak P1F44) resulted in prothrombin time (PT) activity (extrinsic coagulation pathway) at a 160 µg/mL, in addition to enhanced APTT activity. The P1F44 anticoagulant activity mechanism was shown to be dependent on two coagulations factors, IIa and Xa, more potent via IIa. Future assessments will be performed to assess this fraction in the medical clinic.

Marine Biological Macromolecules and Chemically Modified Macromolecules; Potential Anticoagulants

Coagulation is a potential defense mechanism that involves activating a series of zymogens to convert soluble fibrinogen to insoluble fibrin clots to prevent bleeding and hemorrhagic complications. To prevent the extra formation and diffusion of clots, the counterbalance inhibitory mechanism is activated at levels of the coagulation pathway. Contrariwise, this system can evade normal control due to either inherited or acquired defects or aging which leads to unusual clots formation. The abnormal formations and deposition of excess fibrin trigger serious arterial and cardiovascular diseases. Although heparin and heparin-based anticoagulants are a widely prescribed class of anticoagulants, the clinical use of heparin has limitations due to the unpredictable anticoagulation, risk of bleeding, and other complications. Hence, significant interest has been established over the years to investigate alternative therapeutic anticoagulants from natural sources, especially from marine sources with good safety and potency due to their unique chemical structure and biological activity. This review summarizes the coagulation cascade and potential macromolecular anticoagulants derived from marine flora and fauna.

Sulfated Polysaccharide Extracted from the Green Algae Codium bernabei: Physicochemical Characterization and Antioxidant, Anticoagulant and Antitumor Activity

Codium bernabei is a green alga that grows on Chilean coasts. The composition of its structural polysaccharides is still unknown. Hence, the aim of this work is to isolate and characterize the hot water extracted polysaccharide fractions. For this purpose, the water extracts were further precipitated in alcohol (TPs) and acid media (APs), respectively. Both fractions were characterized using different physicochemical techniques such as GC-MS, GPC, FTIR, TGA, and SEM. It is confirmed that the extracted fractions are mainly made of sulfated galactan unit, with a degree of sulfation of 19.3% (TPs) and 17.4% (ATs) and a protein content of 3.5% in APs and 15.6% in TPs. Other neutral sugars such as xylose, glucose, galactose, fucose, mannose, and arabinose were found in a molar ratio (0.05:0.6:1.0:0.02:0.14:0.11) for TPs and (0.05:0.31:1.0:0.03:0.1:0.13) for ATs. The molecular weight of the polysaccharide samples was lower than 20 kDa. Both polysaccharides were thermally stable (Tonset > 190 °C) and showed antioxidant activity according to the ABTS•+ and DPPH tests, where TPs fractions had higher scavenging activity (35%) compared to the APs fractions. The PT and APTTS assays were used to measure the anticoagulant activity of the polysaccharide fractions. In general, the PT activity of the TPs and APs was not different from normal plasma values. The exception was the TPs treatment at 1000 µg mL−1 concentration. The APTTS test revealed that clotting time for both polysaccharides was prolonged regarding normal values at 1000 µg mL−1. Finally, the antitumor test in colorectal carcinoma (HTC-116) cell line, breast cancer (MCF-7) and human leukemia (HL-60) cell lines showed the cytotoxic effect of TPs and APs. Those results suggest the potential biotechnological application of sulfate galactan polysaccharides isolated from a Chilean marine resource.

Phytochemical and Potential Properties of Seaweeds and Their Recent Applications: A Review

Since ancient times, seaweeds have been employed as source of highly bioactive secondary metabolites that could act as key medicinal components. Furthermore, research into the biological activity of certain seaweed compounds has progressed significantly, with an emphasis on their composition and application for human and animal nutrition. Seaweeds have many uses: they are consumed as fodder, and have been used in medicines, cosmetics, energy, fertilizers, and industrial agar and alginate biosynthesis. The beneficial effects of seaweed are mostly due to the presence of minerals, vitamins, phenols, polysaccharides, and sterols, as well as several other bioactive compounds. These compounds seem to have antioxidant, anti-inflammatory, anti-cancer, antimicrobial, and anti-diabetic activities. Recent advances and limitations for seaweed bioactive as a nutraceutical in terms of bioavailability are explored in order to better comprehend their therapeutic development. To further understand the mechanism of action of seaweed chemicals, more research is needed as is an investigation into their potential usage in pharmaceutical companies and other applications, with the ultimate objective of developing sustainable and healthier products. The objective of this review is to collect information about the role of seaweeds on nutritional, pharmacological, industrial, and biochemical applications, as well as their impact on human health.

Preparation and characterization of fast dissolving ulvan microneedles for transdermal drug delivery system

Dissolving microneedles made from natural polymers recently have gained much attention as an efficient transdermal drug delivery system (TDDS). For the first time, ulvan, a sulfated polysaccharide extracted from Ulva lactuca, was applied to fabricate dissolving microneedles through a two-step casting method. The ulvan microneedles (UMNs) made from 4% ulvan solution were in a pyramidal shape with an average height of 655 μm and an aspect ratio of 2.63. The in vitro skin insertion study showed the UMNs could totally penetrate into the porcine skin to the dermis layer and rapidly dissolved as the needle height was reduced by 90.3% after post-insertion of only 2 min. The rapid dissolution of UMNs in situ thus could release the loaded model drugs of rhodamine 6G (R6G) and bovine serum albumin-fluorescein isothiocyanate conjugate (FITC-BSA) in the skin tissue. The in vitro drug release profiles through porcine skin revealed the UMNs markedly enhanced the cumulative release of FITC-BSA. In addition, the UMNs had good biocompatibility towards normal cells of HaCaT and NIH3T3. Briefly, this study demonstrates the rapidly dissolving UMNs could effectively carry the drug into skin and thus can be developed as a potential TDDS in the pharmaceutical and cosmeceutical fields.

Sulfated heteropolysaccharides from Undaria pinnatifida: Structural characterization and transcript-metabolite profiling of immunostimulatory effects on RAW264.7 cells

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UPP-3 showed significant effects on mRNA expression of iNOS, TNF-α, and IL-6.

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Transcript analysis illustrated the immunostimulatory effects of UPP-3.

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Metabolic profiling revealed the immunostimulatory effects of UPP-3.

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UPP-3 might affect the pathways in cancer of macrophage.

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Provided a molecular detail of the immunostimulatory effects of UPP-3.

Investigation of the polysaccharides from an edible marine brown algae Undaria pinnatifida has led to obtaining three fractional sulfated polysaccharides UPPs 1–3 with molecular weights of 7.212 kDa, 13.924 kDa, and 55.875 kDa, respectively. All UPPs are composed of galactose, xylose, glucose, mannose, glucuronic acid, and mannuronic acid, while UPP-3 also consisted of fucose, arabinose, and fructose. The immunostimulatory assay revealed that UPP-3 had important effects on cell viability, nitric oxide levels, and secretion of cytokines TNF-α and IL-6 in RAW264.7 cells. Furthermore, the transcript-metabolite data along with western blot and immunofluorescent staining revealed that UPP-3 could stimulate the Toll-like receptor (TLR4) associated with the nuclear factor kappa-B (NF-κB) p65 signaling pathway of RAW264.7 cells. These findings of the immunomodulatory sulfated polysaccharide will provide a basic understanding to further exploitation of U. pinnatifida polysaccharides.

Nutraceutical potentials of algal ulvan for healthy aging

Several theories for aging are constantly put forth to explain the underlying mechanisms. Oxidative stress, DNA dysfunction, inflammation, and mitochondrial dysfunction, along with the release of cytochrome c are some of these theories. Diseases such as type 2 diabetes mellitus, intestinal dysfunction, cardiovascular diseases, hepatic injury, and even cancer develop with age and eventually cause death. Ulva polysaccharides, owing to their special structures and various functions, have emerged as desirable materials for keeping healthy. These polysaccharide structures are found to be closely related to the extraction methods, seaweed strains, and culture conditions. Ulvan is a promising bioactive substance, a potential functional food, which can regulate immune cells to augment inflammation, control the activity of aging-related genes, promote tumor senescence, enhance mitochondrial function, maintain liver balance, and protect the gut microbiome from inflammatory attacks. Given the desirable physiochemical and gelling properties of ulvan, it would serve to improve the quality and shelf-life of food.

Chemical Structure and Anticoagulant Property of a Novel Sulfated Polysaccharide from the Green Alga Cladophora oligoclada

Marine macroalgae are efficient producers of sulfated polysaccharides. The algal sulfated polysaccharides possess diverse bioactivities and peculiar chemical structures, and represent a great potential source to be explored. In the present study, a heparinoid-active sulfated polysaccharide was isolated from the green alga Cladophora oligoclada. Results of chemical and spectroscopic analyses indicated that the sulfated polysaccharide was composed of →6)-β-d-Galp-(1→, β-d-Galp-(1→, →6)-α-d-Glcp-(1→ and →3)-β-d-Galp-(1→ units with sulfate esters at C-2/C-4 of →6)-β-d-Galp-(1→, C-6 of →3)-β-d-Galp-(1→ and C-3 of →6)-α-d-Glcp-(1→ units. The branches consisting of β-d-Galp-(1→ and →6)-β-d-Galp-(1→ units were located in C-3 of →6)-β-d-Galp-(1→ units. The sulfated polysaccharide exhibited potent anticoagulant activity in vitro and in vivo as evaluated by activated partial thromboplastin time (APTT), thrombin time, and the fibrinogen level. For the APTT, the signal for clotting time was more than 200 s at 100 μg/mL in vitro and at 15 mg/kg in vivo. The obvious thrombolytic activity of the sulfated polysaccharide in vitro was also found. The mechanism analysis of anticoagulant action demonstrated that the sulfated polysaccharide significantly inhibited the activities of all intrinsic coagulation factors, which were less than 1.0% at 50 μg/mL, but selectively inhibited common coagulation factors. Furthermore, the sulfated polysaccharide strongly stimulated the inhibition of thrombin by potentiating antithrombin-III (AT-III) or heparin cofactor-II, and it also largely promoted the inhibition of factor Xa mediated by AT-III. These results revealed that the sulfated polysaccharide from C. oligoclada had potential to become an anticoagulant agent for prevention and therapy of thrombotic diseases.

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.

Ulvan mediated VE cadherin antibody and REDV peptide co-modification to improve endothelialization potential of bioprosthetic heart valves

An aging population and a rapid increase in the incidence of degenerative valve diseases have led to greater use of bioprosthetic heart valves (BHVs). The durability of glutaraldehyde cross-linked bioprostheses currently available for clinical use is poor due to calcification, coagulation, and degradation. Decellularization can partially reduce calcification by removal of xenogenic cells, but can also lead to thrombosis, which can be addressed by further surface modification. The natural sulfated polysaccharide ulvan possesses antithrombotic and anti-inflammatory properties, and can behave as a heparinoid to immobilize proteins through their heparin binding sites. VE-cadherin antibody and the Arg-Glu-Asp-Val (REDV) peptide can facilitate selective endothelial cell attachment, adhesion and proliferation. In this study, we functionalized decellularized porcine pericardium (DPP) with ulvan, REDV, and VE-cadherin antibody (U-R-VE). Ulvan was covalently modified to act as a protective coating and spacer for VE-cadherin antibody, and to immobilize REDV. In in vitro tests, we found that functionalization significantly and selectively promoted adhesion and growth of endothelial cells while reducing platelet adhesion, inflammation, and in vitro calcification of DPPs. In an in vivo subdermal implantation model, U-R-VE modified DPP exhibited greater endothelialization potential and biocompatibility compared with unmodified pericardium. Thus, U-R-VE modification provides a promising solution to the problem of preparing BHVs with enhanced endothelialization potential.

Semi-synthesis of hybrid ulvan-kappa-carrabiose polysaccharides and evaluation of their cytotoxic and anticoagulant effects

In this study we described the synthesis of a hybrid polysaccharide harboring moieties of ulvan and kappa-carrabiose. Alkylamines (1,3-diaminopropane and 1,6-diaminohexane) were selectively inserted into β-D-GlcAp and α-L-IdoAp units in the ulvan structure via an amide bond formation producing ulvan-amide derivatives F-DAP (N% = 1.77; M_w = 208 kg mol^-1) and F-DAH (N% = 1.77; M_w = 202 kg mol^-1), which were reacted with kappa-carrabiose via reductive amination to produce hybrid ulvan-kappa-carrabiose polysaccharides F-DAP-Kb (N% = 1.56; M_w = 206 kg mol^-1) and F-DAH-Kb (N% = 1.16; M_w = 200 kg mol^-1). All the ulvan derivatives were characterized by ¹H and ¹³C NMR spectroscopy and did not show cytotoxicity against human dermal fibroblasts (HDFa) at the concentrations of 25, 100, and 500 μg mL^-1, neither anticoagulant properties at the range of 10-150 μg mL^-1. Therefore, the ulvan-amide derivatives and the hybrid ulvan-kappa-carrabiose polysaccharides showed good biocompatibility in vitro, presenting as worthy candidates for tailoring scaffolds for biomedical applications.

Seaweed polysaccharides: Emerging extraction technologies, chemical modifications and bioactive properties

Nowadays, consumers are increasingly aware of the relationship between diet and health, showing a greater preference of products from natural origin. In the last decade, seaweeds have outlined as one of the natural sources with more potential to obtain bioactive carbohydrates. Numerous seaweed polysaccharides have aroused the interest of the scientific community, due to their biological activities and their high potential on biomedical, functional food and technological applications. To obtain polysaccharides from seaweeds, it is necessary to find methodologies that improve both yield and quality and that they are profitable. Nowadays, environmentally friendly extraction technologies are a viable alternative to conventional methods for obtaining these products, providing several advantages like reduced number of solvents, energy and time. On the other hand, chemical modification of their structure is a useful approach to improve their solubility and biological properties, and thus enhance the extent of their potential applications since some uses of polysaccharides are still limited. The present review aimed to compile current information about the most relevant seaweed polysaccharides, available extraction and modification methods, as well as a summary of their biological activities, to evaluate knowledge gaps and future trends for the industrial applications of these compounds.Key teaching pointsStructure and biological functions of main seaweed polysaccharides.Emerging extraction methods for sulfate polysaccharides.Chemical modification of seaweeds polysaccharides.Potential industrial applications of seaweed polysaccharides.Biological activities, knowledge gaps and future trends of seaweed polysaccharides.

A Comprehensive Review on Ulvan Based Hydrogel and Its Biomedical Applications

Ulvan is a natural sulfated polysaccharide obtained from marine green algae composed of 3-sulfated rhamnoglucuronan as the main component. It has a unique chemical structure that rich of L-rhamnosa, D-glucuronic acid, and L-iduronic acid. Ulvan has a similar structure to glycosaminoglycans (GAGs) in mammals including chondroitin sulfate, dermatan sulfate, and heparan sulfate that has broad range applications for many years. Here, we provide an overview of ulvan based hydrogels for biomedical applications. Hydrogels are one of ulvan advances in polymer science for application in drug delivery, tissue engineering, and wound healing. This review presented an overview about functional information of ulvan based hydrogels and the promising potential in biomedicals collected from published papers in Scopus, PubMed, and Google Scholar. Other important aspects concerning properties, hydrogel-forming mechanisms, and ulvan based hydrogel developments were reported as well. As conclusion, ulvan showed interesting properties in forming hydrogels and promising advances in biomedical applications.

Perspective on the Therapeutic Applications of Algal Polysaccharides

Abstract

Algae are an enormous source of polysaccharides and have gained much interest in human flourishing as organic drugs. Algal polysaccharides have aroused interest in the health sector owing to the various bioactivities namely anticancer, antiviral, immunoregulation, antidiabetic and antioxidant effects. The research community has comprehensively described the importance of algal polysaccharides regarding their extraction, purification, and potential use in various sectors. However, regardless of all the intriguing properties and potency in the health sector, these algal polysaccharides deserve detailed investigation. Hence, the present review emphasizes extensively on the previous and latest developments in the extraction, purification, structural properties and therapeutic bioactivities of algal polysaccharides to upgrade the knowledge for further advancement in this area of research. Moreover, the review also addresses the challenges, prospective research gaps and future perspective. We believe this review can provide a boost to upgrade the traditional methods of algal polysaccharide production for the development of efficacious drugs that will promote human welfare.

Graphic Abstract

Seaweed Components as Potential Modulators of the Gut Microbiota

Macroalgae, or seaweeds, are a rich source of components which may exert beneficial effects on the mammalian gut microbiota through the enhancement of bacterial diversity and abundance. An imbalance of gut bacteria has been linked to the development of disorders such as inflammatory bowel disease, immunodeficiency, hypertension, type-2-diabetes, obesity, and cancer. This review outlines current knowledge from in vitro and in vivo studies concerning the potential therapeutic application of seaweed-derived polysaccharides, polyphenols and peptides to modulate the gut microbiota through diet. Polysaccharides such as fucoidan, laminarin, alginate, ulvan and porphyran are unique to seaweeds. Several studies have shown their potential to act as prebiotics and to positively modulate the gut microbiota. Prebiotics enhance bacterial populations and often their production of short chain fatty acids, which are the energy source for gastrointestinal epithelial cells, provide protection against pathogens, influence immunomodulation, and induce apoptosis of colon cancer cells. The oral bioaccessibility and bioavailability of seaweed components is also discussed, including the advantages and limitations of static and dynamic in vitro gastrointestinal models versus ex vivo and in vivo methods. Seaweed bioactives show potential for use in prevention and, in some instances, treatment of human disease. However, it is also necessary to confirm these potential, therapeutic effects in large-scale clinical trials. Where possible, we have cited information concerning these trials.

The Potency of Seaweed Sulfated Polysaccharides for the Correction of Hemostasis Disorders in COVID-19

Hemostasis disorders play an important role in the pathogenesis, clinical manifestations, and outcome of COVID-19. First of all, the hemostasis system suffers due to a complicated and severe course of COVID-19. A significant number of COVID-19 patients develop signs of hypercoagulability, thrombocytopenia, and hyperfibrinolysis. Patients with severe COVID-19 have a tendency toward thrombotic complications in the venous and arterial systems, which is the leading cause of death in this disease. Despite the success achieved in the treatment of SARS-CoV-2, the search for new effective anticoagulants, thrombolytics, and fibrinolytics, as well as their optimal dose strategies, continues to be relevant. The wide therapeutic potential of seaweed sulfated polysaccharides (PSs), including anticoagulant, thrombolytic, and fibrinolytic activities, opens up new possibilities for their study in experimental and clinical trials. These natural compounds can be important complementary drugs for the recovery from hemostasis disorders due to their natural origin, safety, and low cost compared to synthetic drugs. In this review, the authors analyze possible pathophysiological mechanisms involved in the hemostasis disorders observed in the pathological progression of COVID-19, and also focus the attention of researchers on seaweed PSs as potential drugs aimed to correction these disorders in COVID-19 patients. Modern literature data on the anticoagulant, antithrombotic, and fibrinolytic activities of seaweed PSs are presented, depending on their structural features (content and position of sulfate groups on the main chain of PSs, molecular weight, monosaccharide composition and type of glycosidic bonds, the degree of PS chain branching, etc.). The mechanisms of PS action on the hemostasis system and the issues of oral bioavailability of PSs, important for their clinical use as oral anticoagulant and antithrombotic agents, are considered. The combination of the anticoagulant, thrombolytic, and fibrinolytic properties, along with low toxicity and relative cheapness of production, open up prospects for the clinical use of PSs as alternative sources of new anticoagulant and antithrombotic compounds. However, further investigation and clinical trials are needed to confirm their efficacy.

Poly- and Oligosaccharide Ulva sp. Fractions from Enzyme-Assisted Extraction Modulate the Metabolism of Extracellular Matrix in Human Skin Fibroblasts: Potential in Anti-Aging Dermo-Cosmetic Applications

Ulva sp. is known to be a source of bioactive compounds such as ulvans, but their biological activity on human dermal fibroblast extracellular matrix (ECM) is poorly reported. In this work, the regulation of ECM has been investigated for the first time at both proteomic and transcriptomic levels in normal human skin dermal fibroblasts, after 48 h of incubation with poly- and oligosaccharide fractions from Ulva sp. obtained after enzyme-assisted extraction and depolymerization. Cell proliferation enhancement (up to +68%) without exhibiting any cytotoxic effect on fibroblasts was demonstrated at 50 and 1000 µg/mL by both fractions. At the proteomic level, polysaccharide fractions at 1000 µg/mL enhanced the most the synthesis of glycosaminoglycans (GAGs, up to +57%), total collagen, especially types I (up to +217%) and III, as well as the synthesis and activity of MMP-1 (Matrix Metalloproteinase-1, up to +309%). In contrast, oligosaccharide fractions had no effect on GAGs synthesis but exhibited similarities for collagens and MMP-1 regulation. At the transcriptomic level, the decrease of COL1A1 and COL1A2 expression, and increase of COL3A1 and MMP-1 expression, confirmed the modulation of ECM metabolism by both fractions. Our research emphasizes that poly- and oligosaccharide Ulva sp. fractions exhibit interesting biological activities and supports their potential use in the area of skin renewal for anti-aging dermo-cosmetic applications.

Foliose Ulva Species Show Considerable Inter-Specific Genetic Diversity, Low Intra-Specific Genetic Variation, and the Rare Occurrence of Inter-Specific Hybrids in the Wild

Foliose Ulva spp. have become increasingly important worldwide for their environmental and financial impacts. A large number of such Ulva species have rapid reproduction and proliferation habits, which explains why they are responsible for Ulva blooms, known as "green tides", having dramatic negative effects on coastal ecosystems, but also making them attractive for aquaculture applications. Despite the increasing interest in the genus Ulva, particularly on the larger foliose species for aquaculture, their inter- and intra-specific genetic diversity is still poorly described. We compared the cytoplasmic genome (chloroplast and mitochondrion) of 110 strains of large distromatic foliose Ulva from Ireland, Brittany (France), the Netherlands and Portugal. We found six different species, with high levels of inter-specific genetic diversity, despite highly similar or overlapping morphologies. Genetic variation was as high as 82 SNPs/kb between Ulva pseudorotundata and U. laetevirens, indicating considerable genetic diversity. On the other hand, intra-specific genetic diversity was relatively low, with only 36 variant sites (0.03 SNPs/kb) in the mitochondrial genome of the 29 Ulva rigida individuals found in this study, despite different geographical origins. The use of next-generation sequencing allowed for the detection of a single inter-species hybrid between two genetically closely related species, U. laetevirens, and U. rigida, among the 110 strains analyzed in this study. Altogether, this study represents an important advance in our understanding of Ulva biology and provides genetic information for genomic selection of large foliose strains in aquaculture.

Sulfated Oligomers of Tyrosol: Toward a New Class of Bioinspired Nonsaccharidic Anticoagulants

Sulfated phenolic polymers have extensively been investigated as anticoagulant agents in view of their higher bioavailability and resistance to degradation compared to heparins, allowing for increased half-lives. In this frame, we report herein the preparation of sulfated derivatives of tyrosol, one of the most representative phenolic constituents of extra virgin olive oil, by different approaches. Mild sulfation of OligoTyr, a mixture of tyrosol oligomers, that has been reported to possess antioxidant properties and osteogenic activity, afforded OligoTyrS I in good yields. Elemental analysis, NMR, and MALDI-MS investigation provided evidence for an almost complete sulfation at the OH on the phenylethyl chain, leaving the phenolic OH free. Peroxidase/H₂O₂ oxidation of tyrosol sulfated at the alcoholic group (TyrS) also provided sulfated tyrosol oligomers (OligoTyrS II) that showed on structural analysis highly varied structural features arising likely from the addition of oxygen, derived from water or hydrogen peroxide, to the intermediate quinone methides and substantial involvement of the phenolic OH group in the oligomerization. In line with these characteristics, OligoTyrS I proved to be more active than OligoTyrS II as antioxidant in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) assays and as anticoagulant in the classical clotting times, mainly in prolonging the activated partial thromboplastin time (APTT). After intraperitoneal administration in mice, OligoTyrS I was also able to significantly decrease the weight of an induced thrombus. Data from chromogenic coagulation assays showed that the anticoagulant effect of OligoTyrS I was not dependent on antithrombin or factor Xa and thrombin direct inhibition. These results clearly highlight how some structural facets of even closely related phenol polymers may be critical in dictating the anticoagulant activity, providing the key for the rationale design of active synthetic nonsaccharidic anticoagulant agents alternative to heparin.

Structural characterization and transcript-metabolite correlation network of immunostimulatory effects of sulfated polysaccharides from green alga Ulva pertusa

Three water-soluble polysaccharides (UPPs 1-3) were obtained from edible green alga Ulva pertusa. The chemico-physical analyses indicated that UPPs 1-3 possessed molecular weights of 376.7 kDa, 57.21 kDa, and 131.13 kDa, with sulfate contents of 26.01 ± 8.13%, 9.86 ± 3.24%, and 13.32 ± 6.56%, respectively, and composed of arabinose, galactose, glucose, xylose, galacturonic acid, glucuronic acid, and mannuronic acid, with different ratios. The in vitro studies revealed that UPP-1 showed significant effects on the proliferation and phagocytic activity of macrophage, release of nitric oxide, and secretion of cytokines (TNF-α and IL-6). The transcript-metabolite analysis of UPP-1 treated macrophage revealed 4747 differential genes (2416 up-regulated and 2331 down-regulated) and 94 differential metabolites (77 up-regulated and 17 down-regulated) that significantly co-mapped a transcript-metabolite correlation network of biosynthesis of amino acids, glycerophospholipid metabolism, and carbon metabolism. Thus, these findings provide a valuable foundation for the potential application of U. pertusa polysaccharides.

Therapeutic Uses of Red Macroalgae

Red Seaweed “Rhodophyta” are an important group of macroalgae that include approximately 7000 species. They are a rich source of structurally diverse bioactive constituents, including protein, sulfated polysaccharides, pigments, polyunsaturated fatty acids, vitamins, minerals, and phenolic compounds with nutritional, medical, and industrial importance. Polysaccharides are the main components in the cell wall of red algae and represent about 40–50% of the dry weight, which are extensively utilized in industry and pharmaceutical compounds, due to their thickening and gelling properties. The hydrocolloids galactans carrageenans and agars are the main red seaweed cell wall polysaccharides, which had broad-spectrum therapeutic characters. Generally, the chemical contents of seaweed are different according to the algal species, growth stage, environment, and external conditions, e.g., the temperature of the water, light intensity, nutrient concentrations in the ecosystem. Economically, they can be recommended as a substitute source for natural ingredients that contribute to a broad range of bioactivities like cancer therapy, anti-inflammatory agents, and acetylcholinesterase inhibitory. This review touches on the main points of the pharmaceutical applications of red seaweed, as well as the exploitation of their specific compounds and secondary metabolites with vital roles.

The Potential of Sulfated Polysaccharides Isolated from the Brown Seaweed Ecklonia maxima in Cosmetics: Antioxidant, Anti-melanogenesis, and Photoprotective Activities

Sulfated polysaccharides prepared from marine algae are potential ingredients in nutraceutical, pharmaceutical, and cosmeceutical industries. In the present study, the antioxidant, anti-melanogenesis, and photoprotective effects of sulfated polysaccharides obtained from Ecklonia maxima (EMC) were investigated to evaluate their potential in cosmetic. EMC was successfully prepared through Celluclast-assisted extraction and ethanol precipitation, and it contained 79.88% of sulfated polysaccharides that with 69.37% carbohydrates and 10.51% sulfate. EMC effectively suppressed 2,2-azobis(2-amidinopropane) hydrochloride (AAPH)-induced oxidative stress in vitro in Vero cells and in vivo in zebrafish. Furthermore, EMC significantly inhibited mushroom tyrosinase and reduced melanin synthesis in alpha-melanocyte-stimulating hormone-stimulated B16F10 cells. In addition, EMC remarkably attenuated photodamage induced by UVB irradiation in vitro in human keratinocytes (HaCaT cells) and in vivo in zebrafish. Furthermore, EMC effectively inhibited wrinkle-related enzymes and improved collagen synthesis in UVB-irradiated human dermal fibroblasts (HDF cells). These results indicate that EMC possesses strong antioxidant, anti-melanogenesis, and photoprotective activities, and suggest that EMC may be an ideal ingredient in the pharmaceutical and cosmeceutical industries.

Bioactive and thermostable sulphated polysaccharide from Sargassum swartzii with drug delivery applications

Sulphated Polysaccharides (SP) were extracted from a brown seaweed Sargassum swartzii by two extraction methods using hydrochloric acid and hot water. The sulphated polysaccharide yield using the hot water extraction method was found to be higher and hence used for further study. The extracted polysaccharide was characterized using UV, FT-IR, biochemical and thin layer chromatography analyses. Further, the purity of the extracted polysaccharide was ascertained by HPLC analysis. The sugars present in the sulphated polysaccharide were revealed by acid hydrolysis. The structure of the extracted SP was revealed as fucoidan using the NMR spectrum. Thermal stability of the sulphated polysaccharide was assessed using Thermogravimetric analysis and polymer was found to be stable up to 700 °C. Anti-oxidant and anti-inflammatory activities were evaluated using phosphomolybdenum and BSA assay, respectively. Cell proliferation analysis using MTT assay against normal cell lines revealed that the polysaccharide is biocompatible while with cancer cell lines, the compound exhibited potential anti-proliferative activity. Application of this sulphated polysaccharide as a carrier for drug delivery with rutin as a model drug was explored. The drug release kinetics was modeled and the stability of the rutin encapsulated SP nano formulation was studied.

Anticoagulant-active sulfated arabinogalactan from Chaetomorpha linum: Structural characterization and action on coagulation factors

A sulfated polysaccharide from the green alga Chaetomorpha linum, designated CLS4, was isolated by water extraction, anion-exchange and size-exclusion chromatography. Chemical and spectroscopic analyses demonstrated that CLS4 was a sulfated arabinogalactan, which was constituted by (1→6)-β-d-galactopyranose and (1→5)-α-l-arabinofuranose residues with sulfate groups at C-2/ C-3 of (1→5)-α-l-arabinofuranose and C-2/C-4 of (1→6)-β-d-galactopyranose. CLS4 possessed strong anticoagulant activity in vitro or in vivo as evaluated by activated partial thromboplastin time and thrombin time assays. CLS4 largely inhibited the activities of the coagulation factors XII, XI, IX and VIII. CLS4 was a potent thrombin inhibitor mediated by antithrombin III (ATIII) or heparin cofactor II, and it also effectively stimulated the factor Xa inhibition by potentiating ATIII. Moreover, CLS4 had a high thrombolytic activity in vitro as assessed by clot lytic rate assay. The results suggested that CLS4 could be a promising source of anticoagulant agent.

Characterization of Bioactive Components in Edible Algae

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Isolation and Characterization of a Heparin-Like Compound with Potent Anticoagulant and Fibrinolytic Activity from the Clam Coelomactra antiquata

Heparin from mollusks with unique sulfated glycosaminoglycan exhibits strong anti-thrombotic activities. This study reports on a purified heparinoid from Coelomactra antiquata, which shows potent anticoagulant and fibrinolytic abilities. Its structure was characterized by infrared spectroscopy, high-performance liquid chromatography, and one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy. Its fibrinolytic activity was determined in vitro and in vivo. Its anticoagulant activity was determined by activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT). The results indicated that clam heparinoid was a homogeneous glycosaminoglycan with a molecular weight of 30.99 kDa, mainly composed of →4)-α-IdoA2S-(1→4)-α-GlcNS3S6S (or GlcNS6S)-(1→4)-β-GlcA-(1→4)-α-GlcNS6S (or GlcNAC)-(1→. Furthermore, this heparinoid showed a highly anticoagulant titer and fibrinolytic value of 149.63 IU/mg and 1.96 IU/mg, respectively. In summary, clam heparinoid shows great potential for application in the clinic and antithrombotic drugs industry.

Production of Active Poly- and Oligosaccharidic Fractions from Ulva sp. by Combining Enzyme-Assisted Extraction (EAE) and Depolymerization

Data on fractionation and depolymerization of the matrix ulvan polysaccharides, and studies on the biological activities on skin cells, are very scarce. In this work, crude ulvans were produced by using EAE (enzyme-assisted extraction) and compared to maceration (an established procedure). After different fractionation procedures-ethanolic precipitation, dialysis, or ammonium sulfate precipitation-the biochemical composition showed that EAE led to an increased content in ulvans. Coupling EAE to sulfate ammonium precipitation led to protein enrichment. Oligosaccharides were obtained by using radical depolymerization by H₂O₂ and ion-exchange resin depolymerization. Sulfate groups were partially cleaved during these chemical treatments. The potential bioactivity of the fractions was assessed using a lipoxygenase inhibition assay for anti-inflammatory activity and a WST-1 assay for human dermal fibroblast viability and proliferation. All ulvans extracts, poly- and oligosaccharidic fractions from EAE, expanded the fibroblast proliferation rate up to 62%. Our research emphasizes the potential use of poly- and oligosaccharidic fractions of Ulva sp. for further development in cosmetic applications.

Anti-ageing and antioxidant effects of sulfate oligosaccharides from green algae Ulva lactuca and Enteromorpha prolifera in SAMP8 mice

Oligosaccharides from green algae Ulva lactuca (ULO) and Enteromorpha prolifera (EPO) were used for investigation of anti-ageing effects and the underlying mechanism in SAMP8 mice. The structural properties of ULO and EPO were analyzed by fourier-transform infrared spectroscopy, gas chromatography-mass spectrometry, and agarose gel electrophoresis. These oligosaccharides enhanced the glutathione, superoxide dismutase, catalase, and telomerase levels and total antioxidant capicity, and decreased the levels of malondialdehyde and advanced glycation end products. After ULO and EPO treatment, the levels of inflammatory factors, including IFN-γ, TNF-α, and IL-6, decreased; the BDNF and ChAT levels increased; and hippocampal neurons were protected. Downregulation of the p53 and FOXO1 genes and upregulation of the Sirt1 gene indicated that ULO and EPO have potential therapeutic effects in the prevention of ageing in SAMP8 mice. By 16S rRNA gene high-throughput sequencing, the abundance of Desulfovibrio was discovered to be markedly different in mice treated with ULO and EPO. The abundances of Verrucomicrobiaceae, Odoribacteraceae, Mogibacteriaceae, Planococcaceae, and Coriobacteriaceae were positively correlated with age-related indicators. These results demonstrated that oligosaccharides from U. lactuca and E. prolifera are ideal candidate compounds that can be used in functional foods and pharmaceuticals to prevent ageing.