Marine polysaccharides: therapeutic efficacy and biomedical applications

Suaeda maritima polysaccharides attenuate LPS-induced inflammation of RAW264.7 cells and antioxidative activity

Our research focused on extracting polysaccharides from Suaeda maritima (SMP) to obtain crude polysaccharides (SMP-C), which were subsequently purified into SMP-F1 and SMP-F2. SMPs were evaluated for anti-inflammatory effects and SMP-F1 showed the highest inhibitory effects on nitric oxide (NO) production. The monosaccharide composition analysis of SMP-F1 (molecular weight of 112.2 × 103 g/mol) revealed predominant levels of glucose (45.4 %), arabinose (20.5 %), mannose (14.2 %), and galactose (12.7 %). The primary backbone of SMP-F1 consisted of (1 → 4)-D-glucopyranoside, (1 → 4,6)-D-glucopyranoside, (1 → 3)-D-mannopyranoside, (1 → 3,6)-D-mannopyranoside, and (1 → 5)-L-arabifuranoside. In addition, we hydrolysed SMP-F1 to SMP-H1, SMP-H2, and SMP-H3 and investigated their anti-inflammatory effects on RAW264.7 macrophages. Following SMP-F1 hydrolysis, SMP-H3 (molecular weight of 25.8 × 103 g/mol) exhibited superior anti-inflammatory properties compared to SMP-H1 and SMP-H2, demonstrating a significant decrease in NO production. SMP-H3 also demonstrated a remarkable reduction in the secretion of inflammatory mediators including NO, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2), and pro-inflammatory cytokines including tumour necrosis factor-alpha (TNF-α), interleukin (IL-1β and IL-6), while increasing IL-10 expression. Furthermore, SMP-H3 significantly inhibited LPS-stimulated cluster of differentiation (CD) 11b and CD40 expression. Our subsequent investigation unveiled the involvement of SMP-H3-activated macrophages in the nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways. Additionally, SMP-H3 exhibited antioxidant activity by scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide, and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) free radicals. These findings suggest the potential of SMP-H3 as an ingredient in the development of alternative drugs or functional foods.

Fucoidan-hybrid hydroxyapatite nanoparticles promote the osteogenic differentiation of human periodontal ligament stem cells under inflammatory condition

Inflammation-related bone defects often lead to poor osteogenesis. Therefore, it is crucial to reduce the inflammation response and promote the osteogenic differentiation of stem/progenitor cells to revitalize bone physiology. Here, a kind of hybrid nano-hydroxyapatite was prepared using the confined phosphate ion release method with the participation of fucoidan, a marine-sourced polysaccharide with anti-inflammation property. The physicochemical analyses confirmed that the fucoidan hybrid nano-hydroxyapatite (FC/n-HA) showed fine needle-like architectures. With a higher amount of fucoidan, the crystal size and crystallinity of the FC/n-HA reduced while the liquid dispersibility was improved. Cell experiences showed that FC/n-HA had an optimal cytocompatibility at concentration of 50 μg/mL. Moreover, the lipopolysaccharide-induced cellular inflammatory model with PDLSCs was established and used to evaluate the anti-inflammatory and osteogenic properties. For the 1%FC/n-HA group, the expression levels of TNF-α and IL-1β were significantly reduced at 24 h, while the expression of alkaline phosphatase of PDLSCs was significantly promoted at days 3 and 7, and calcium precipitates was enhanced at 21 days. In this study, the FC/n-HA particles showed effective anti-inflammatory properties and facilitated osteogenic differentiation of PDLSCs, indicating which has potential application in treating bone defects associated with inflammation, such as periodontitis.

Exploring the Regulatory Effect of Tegillarca granosa Polysaccharide on High-Fat Diet-Induced Non-Alcoholic Fatty Liver Disease in Mice Based on Intestinal Flora

To explore the potential mechanism of action of Tegillarca granosa polysaccharide (TGP) in treating nonalcoholic fatty liver disease (NAFLD), the study conducts in vivo experiments using male C57BL/6 mice fed a high-fat diet while administering TGP for 16 weeks. The study measures body weight, liver weight, serum biochemical markers, pathological histology, liver lipid accumulation, oxidative stress and inflammation-related factors, lipid synthesis and metabolism-related gene and protein expression, and the composition and abundance of intestinal flora. Additionally, short-chain fatty acid (SCFAs) content and the correlation between intestinal flora and environmental factors are measured. The results show that TGP effectively reduces excessive hepatic lipid accumulation, dyslipidemia, abnormal liver function, and steatosis in the mice with NAFLD. Moreover, TGP effectively regulates intestinal flora disorder, increases the diversity of intestinal flora, and affects the relative abundance of specific bacteria while also increasing the content of SCFAs. These findings provide a basis for exploring the regulatory effect of T. granosa polysaccharide on NAFLD based on intestinal flora and highlight its potential as a natural liver nutraceutical.

Marine algae: A treasure trove of bioactive anti-inflammatory compounds

This comprehensive review examines the diverse classes of pharmacologically active compounds found in marine algae and their promising anti-inflammatory effects. The review covers various classes of anti-inflammatory compounds sourced from marine algae, including phenolic compounds, flavonoids, terpenoids, caretenoids, alkaloids, phlorotannins, bromophenols, amino acids, peptides, proteins, polysaccharides, and fatty acids. The anti-inflammatory activities of marine algae-derived compounds have been extensively investigated using in vitro and in vivo models, demonstrating their ability to inhibit pro-inflammatory mediators, such as cytokines, chemokines, and enzymes involved in inflammation. Moreover, marine algae-derived compounds have exhibited immunomodulatory properties, regulating immune cell functions and attenuating inflammatory responses. Specific examples of compounds with notable anti-inflammatory activities are highlighted. This review provides valuable insights for researchers in the field of marine anti-inflammatory pharmacology and emphasizes the need for further research to harness the pharmacological benefits of marine algae-derived compounds for the development of effective and safe therapeutic agents.

Fucoidan-loaded electrospun Polyvinyl-alcohol/Chitosan nanofibers with enhanced antibacterial activity for skin tissue engineering

The polymeric nanofiber may interact and control certain regeneration processes at the molecular level to repair damaged tissues. This research focuses on the development of characterization and antibacterial capabilities of polyvinyl alcohol (PVA)/chitosan (CS) nanofibres containing fucoidan (FUC) for tissue engineering as a skin tissue substitute. A control group consisting of 13% PVA/(0.1)% CS nanofiber was prepared. To confer antibacterial properties to the nanofiber, 10, 20, and 30 mg of FUC were incorporated into this control group. The scanning electron microscope (SEM) proved the homogeneous and beadless structures of the nanofibers. The antibacterial activity of the 13% PVA/(0.1)% CS/(10, 20, 30) FUC was tested against the S.aureus and E.coli and the results showed that with FUC addition, the antibacterial activities of the nanofibers increased. The biocompatibility test was performed with a fibroblast cell line for 1, 3, and 7 days of incubation and the results demonstrated that FUC addition enhanced the bioactivity of the 13% PVA/(0.1)% CS nanofibers. In addition, the biocompatibility results showed that 13% PVA/(0.1)% CS/10 FUC had the highest viability value for all incubation periods compared to the others. In addition, the tensile test results showed that; the maximum tensile strength value was observed for 13% PVA/(0.1)% CS/10 FUC nanofibers.

Marine biomaterials in biomedical nano/micro-systems

Marine resources in unique marine environments provide abundant, cost-effective natural biomaterials with distinct structures, compositions, and biological activities compared to terrestrial species. These marine-derived raw materials, including polysaccharides, natural protein components, fatty acids, and marine minerals, etc., have shown great potential in preparing, stabilizing, or modifying multifunctional nano-/micro-systems and are widely applied in drug delivery, theragnostic, tissue engineering, etc. This review provides a comprehensive summary of the most current marine biomaterial-based nano-/micro-systems developed over the past three years, primarily focusing on therapeutic delivery studies and highlighting their potential to cure a variety of diseases. Specifically, we first provided a detailed introduction to the physicochemical characteristics and biological activities of natural marine biocomponents in their raw state. Furthermore, the assembly processes, potential functionalities of each building block, and a thorough evaluation of the pharmacokinetics and pharmacodynamics of advanced marine biomaterial-based systems and their effects on molecular pathophysiological processes were fully elucidated. Finally, a list of unresolved issues and pivotal challenges of marine-derived biomaterials applications, such as standardized distinction of raw materials, long-term biosafety in vivo, the feasibility of scale-up, etc., was presented. This review is expected to serve as a roadmap for fundamental research and facilitate the rational design of marine biomaterials for diverse emerging applications.

Curcumin-Encapsulated Nanomicelles Promote Tissue Regeneration in Zebrafish Eleutheroembryo

Regenerative medicine is an emerging field of research aiming to understand the wound healing mechanisms and to develop new therapeutic strategies. Nanocarriers are used to improve drug bioavailability, solubility, and therapeutic abilities. In this study, we used for the first time curcumin loaded oligo kappa-carrageenan-graft-polycaprolactone (oligoKC-g-PCL) nanomicelles to investigate their regenerative potential using a model of tail amputation in zebrafish eleutheroembryo. First, we showed that curcumin encapsulated oligoKC-g-PCL spherical micelles had a mean size of 92 ± 32 nm and that micelles were successfully loaded with curcumin. These micelles showed a slow and controlled drug release over 72 h. The toxicity of curcumin nanomicelles was then tested on zebrafish eleutheroembryo based on the survival rate after 24 h. At nontoxic concentration, curcumin nanomicelles improved tail regeneration within 3 days postamputation, compared with empty micelles or curcumin alone. Furthermore, we demonstrated that curcumin nanomicelles increased the recruitment of neutrophils and macrophages 6 h postlesion. Finally, our study highlights the efficiency of oligoKC-g-PCL nanomicelles for encapsulation of hydrophobic molecules such as curcumin. Indeed, our study demonstrates that curcumin nanomicelles can modulate inflammatory reactions in vivo and promote regenerative processes. However, further investigations will be required to better understand the mechanisms sustaining regeneration and to develop new therapeutics.

Deciphering the role of fucoidan from brown macroalgae in inhibiting SARS-CoV-2 by targeting its main protease and receptor binding domain: Invitro and insilico approach

The current study investigated the role of fucoidan from Padina tetrastromatica and Turbinaria conoides against 3-chymotrypsin like protease (3CLpro) and receptor binding domain (RBD) spike protein of SARS-CoV-2 using an invitro and computational approach. The 3CLpro and RBD genes were successfully cloned in pET28a vector, expressed in BL-21DE3 E. coli rosetta cells and purified by ion exchange affinity and size exclusion chromatography. Fucoidan extracted from both biomass using green approach, subcritical water, was found to inhibit 3CLpro of SARS-CoV-2 with an IC50 value of up to 0.35 mg mL-1. However, fucoidan was found to be inactive against the RBD protein. Molecular docking studies demonstrated that fucoidan binds to the active sites of 3CLpro with an affinity of -5.0 kcal mol-1. In addition, molecular dynamic simulations recorded stabilized interactions of protein-ligand complexes in terms of root mean square deviation, root mean square fluctuation, the radius of gyration, solvent accessible surface area and hydrogen bond interaction. The binding energy of fucoidan with 3CLpro was determined to be -101.821 ± 12.966 kJ mol-1 using Molecular Mechanic/Poisson-Bolt-Boltzmann Surface Area analysis. Fucoidan satisfies the Absorption, Distribution, Metabolism, and Excretion (ADME) properties, including Lipinski's rule of five, which play an essential role in drug design. According to the toxicity parameters, fucoidan does not exhibit skin sensitivity, hepatotoxicity, or AMES toxicity. Therefore, this work reveals that fucoidan from brown macroalgae could act as possible inhibitors in regulating the function of the 3CLpro protein, hence inhibiting viral replication and being effective against COVID-19.

Polysaccharide-based nanoassemblies: From synthesis methodologies and industrial applications to future prospects

Polysaccharides, due to their remarkable features, have gained significant prominence in the sustainable production of nanoparticles (NPs). High market demand and minimal production cost, compared to the chemically synthesised NPs, demonstrate a drive towards polysaccharide-based nanoparticles (PSNPs) benign to environment. Various approaches are used for the synthesis of PSNPs including cross-linking, polyelectrolyte complexation, and self-assembly. PSNPs have the potential to replace a wide diversity of chemical-based agents within the food, health, medical and pharmacy sectors. Nevertheless, the considerable challenges associated with optimising the characteristics of PSNPs to meet specific targeting applications are of utmost importance. This review provides a detailed compilation of recent accomplishments in the synthesis of PSNPs, the fundamental principles and critical factors that govern their rational fabrication, as well as various characterisation techniques. Noteworthy, the multiple use of PSNPs in different disciplines such as biomedical, cosmetics agrochemicals, energy storage, water detoxification, and food-related realms, is accounted in detail. Insights into the toxicological impacts of the PSNPs and their possible risks to human health are addressed, and efforts made in terms of PSNPs development and optimising strategies that allow for enhanced delivery are highlighted. Finally, limitations, potential drawbacks, market diffusion, economic viability and future possibilities for PSNPs to achieve widespread commercial use are also discussed.

A propitious role of marine sourced polysaccharides: Drug delivery and biomedical applications

Numerous compounds, with extensive applications in biomedical and biotechnological fields, are present in the oceans, which serve as a prime renewable source of natural substances, further promoting the development of novel medical systems and devices. Polysaccharides are present in the marine ecosystem in abundance, promoting minimal extraction costs, in addition to their solubility in extraction media, and an aqueous solvent, along with their interactions with biological compounds. Certain algae-derived polysaccharides include fucoidan, alginate, and carrageenan, while animal-derived polysaccharides comprise hyaluronan, chitosan and many others. Furthermore, these compounds can be modified to facilitate their processing into multiple shapes and sizes, as well as exhibit response dependence to external conditions like temperature and pH. All these properties have promoted the use of these biomaterials as raw materials for the development of drug delivery carrier systems (hydrogels, particles, capsules). The present review enlightens marine polysaccharides providing its sources, structures, biological properties, and its biomedical applications. In addition to this, their role as nanomaterials is also portrayed by the authors, along with the methods employed to develop them and associated biological and physicochemical properties designed to develop suitable drug delivery systems.

Extraction, Modification and Biomedical Application of Agarose Hydrogels: A Review

Numerous compounds present in the ocean are contributing to the development of the biomedical field. Agarose, a polysaccharide derived from marine red algae, plays a vital role in biomedical applications because of its reversible temperature-sensitive gelling behavior, excellent mechanical properties, and high biological activity. Natural agarose hydrogel has a single structural composition that prevents it from adapting to complex biological environments. Therefore, agarose can be developed into different forms through physical, biological, and chemical modifications, enabling it to perform optimally in different environments. Agarose biomaterials are being increasingly used for isolation, purification, drug delivery, and tissue engineering, but most are still far from clinical approval. This review classifies and discusses the preparation, modification, and biomedical applications of agarose, focusing on its applications in isolation and purification, wound dressings, drug delivery, tissue engineering, and 3D printing. In addition, it attempts to address the opportunities and challenges associated with the future development of agarose-based biomaterials in the biomedical field. It should help to rationalize the selection of the most suitable functionalized agarose hydrogels for specific applications in the biomedical industry.

Marine Sulfated Polysaccharide PMGS Synergizes with Paclitaxel in Inhibiting Cervical Cancer In Vitro

The incidence and mortality of cervical cancer in female malignancies are second only to breast cancer, which brings a heavy health and economic toll worldwide. Paclitaxel (PTX)-based regimens are the first-class choice; however, severe side effects, poor therapeutic effects, and difficulty in effectively preventing tumor recurrence or metastasis are unavoidable. Therefore, it is necessary to explore effective therapeutic interventions for cervical cancer. Our previous studies have shown that PMGS, a marine sulfated polysaccharide, exhibits promising anti-human papillomavirus (anti-HPV) effects through multiple molecular mechanisms. In this article, a continuous study identified that PMGS, as a novel sensitizer, combined with PTX exerted synergistic anti-tumor effects on cervical cancer associated with HPV in vitro. Both PMGS and PTX inhibited the proliferation of cervical cancer cells, and the combination of PMGS with PTX displayed significant synergistic effects on Hela cells. Mechanistically, PMGS synergizes with PTX by enhancing cytotoxicity, inducing cell apoptosis and inhibiting cell migration in Hela cells. Collectively, the combination of PTX and PMGS potentially provides a novel therapeutic strategy for cervical cancer.

Preparation and anti-tumor activity of selenium nanoparticles based on a polysaccharide from Paeonia lactiflora

The combination of selenium and polysaccharides is one of the significant ways to ameliorate the anti-cancer effects of polysaccharides. PLP50-1, a homogeneous polysaccharide purified from the aqueous extract of Paeonia lactiflora, had a molecular weight of 1.52 × 10⁴ Da and consisted of α-D-Glcp-(1→, →4)-α-D-Glcp-(1→, →6)-α-D-Glcp-(1→, →4,6)-α-D-Glcp-(1→, and →6)-β-D-Fruf-(2→. PLP50-1 showed weak anti-tumor effects against A549 cells. To ameliorate the activity of PLP50-1, the complex nanoparticles combining P. lactiflora polysaccharide with selenium were constructed successfully. Structural properties of the polysaccharide-based selenium nanoparticles (PLP-SeNPs) were clarified using various means. The results displayed that a kind of monodisperse spherical nanoparticles containing high selenium content (39.1 %) with controllable size was constructed and showed satisfactory stability. The cellular anti-tumor assay indicated that PLP-SeNPs had stronger antiproliferative activity against A549 cells than PLP50-1. Additionally, the zebrafish experiments displayed that PLP-SeNPs inhibited the proliferation and migration of A549 cells significantly and blocked the angiogenesis.

Polysaccharides from Phellinus linteus: A systematic review of their extractions, purifications, structures and functions

Phellinus linteus (P. linteus) is a famous Chinese medicine and has a long history in China. In recent years, P. linteus polysaccharides (PLPs) have attracted extensive attention because of their biological activities such as anti-bacteria, anti-aging, anti-oxidation, anti-inflammation, anti-tumor, hepatoprotective effect and hypoglycemic effect. In this review, we systemically summarized the advances in extractions, purifications and structural characterizations of PLPs, and also analyzed their biological functions and molecular mechanisms. Meanwhile, the structure-activity relationships of PLPs are closely related to their anti-oxidation and anti-tumor activities. So far, the applications of PLPs are still very limited, further exploring structure-activity relationships, biological functions and their mechanisms of PLPs will promote to develop functional foods.

Sulfated Polysaccharides from Macroalgae-A Simple Roadmap for Chemical Characterization

The marine environment presents itself as a treasure chest, full of a vast diversity of organisms yet to be explored. Among these organisms, macroalgae stand out as a major source of natural products due to their nature as primary producers and relevance in the sustainability of marine ecosystems. Sulfated polysaccharides (SPs) are a group of polymers biosynthesized by macroalgae, making up part of their cell wall composition. Such compounds are characterized by the presence of sulfate groups and a great structural diversity among the different classes of macroalgae, providing interesting biotechnological and therapeutical applications. However, due to the high complexity of these macromolecules, their chemical characterization is a huge challenge, driving the use of complementary physicochemical techniques to achieve an accurate structural elucidation. This review compiles the reports (2016-2021) of state-of-the-art methodologies used in the chemical characterization of macroalgae SPs aiming to provide, in a simple way, a key tool for researchers focused on the structural elucidation of these important marine macromolecules.

Fuc-S-A New Ultrasonic Degraded Sulfated α-l-Fucooligosaccharide-Alleviates DSS-Inflicted Colitis through Reshaping Gut Microbiota and Modulating Host-Microbe Tryptophan Metabolism

SCOPE

The dysbiosis of intestinal microecology plays an important pathogenic role in the development of inflammatory bowel disease.

METHODS AND RESULTS

A polysaccharide named Fuc-S, with a molecular weight of 156 kDa, was prepared by the ultrasonic degradation of fucoidan. Monosaccharide composition, FTIR, methylation, and NMR spectral analysis indicated that Fuc-S may have a backbone consisting of →3)-α-L-Fucp-(1→, →4)-α-L-Fucp-(1→ and →3, 4)-α-D-Glcp-(1→. Moreover, male C57BL/6 mice were fed three cycles of 1.8% dextran sulfate sodium (DSS) for 5 days and then water for 7 days to induce colitis. The longitudinal microbiome alterations were evaluated using 16S amplicon sequencing. In vivo assays showed that Fuc-S significantly improved clinical manifestations, colon shortening, colon injury, and colonic inflammatory cell infiltration associated with DSS-induced chronic colitis in mice. Further studies revealed that these beneficial effects were associated with the inhibition of Akt, p-38, ERK, and JNK phosphorylation in the colon tissues, regulating the structure and abundance of the gut microbiota, and modulating the host-microbe tryptophan metabolism of the mice with chronic colitis.

CONCLUSION

Our data confirmed the presence of glucose in the backbone of fucoidan and provided useful information that Fuc-S can be applied as an effective functional food and pharmaceutical candidate for IBD treatment.

Comparative analysis of proximate compositions, mineral and functional chemical groups of 15 different seaweed species

Seaweed is a popular edible source and is associated with many foods and pharmaceutical industries around the world. The current research aims to provide information on the chemical composition of 15 seaweed species, consisted of Chlorophyta, Ochrophyta/Phaeophyceae, and Rhodophyta macroalgae, collected from coastal areas of Sri Lanka. Seaweed samples were subjected to the analysis of lipids, proteins, ash and macro, micro, trace and ultra-trace elements. The highest protein content was recorded in the brown algae. Maximum dietary fiber and ash contents were recorded from green algae. The highest predominant fatty acids were observed from green seaweeds (Caulerpa racemosa); however, linoleic acid (C18:2n6) is the dominant fatty acid of all macroalgae. Mineral contents were highest in the red macroalga; however, copper, zinc and magnesium were also comparatively higher in green alga Ulva lactuca. In conclusion, 15 seaweed species belonging to the three different classes of seaweeds are investigated in details to obtain their biochemical, mineral and fatty acid compositions for the synthesis of novel therapeutic agents. In order to explore biorefinery processes for these seaweeds, as well as how they can potentially be cultivated, more extensive studies are required. Studying and determining the nutritional values of seaweeds will be beneficial with the potentials for future industrial uses and research.

Apoptotic effect of sulfated galactofucan from marine macroalga Turbinaria ornata on hepatocellular and ductal carcinoma cells

Tumor protein or cellular tumor antigen p53, is considered a critical transcriptional regulation factor, which can suppress the growth of tumor cells by activating other functional genes. The current study appraised the p53 activation pathways, which could be used as an alternative therapeutic strategy for the treatment of hepatocellular and ductal carcinoma. Algal polysaccharides have been used as emerging sources of bioactive natural pharmacophores. A sulfated galactofucan characterized as [→1)-O-4-sulfonato-α-fucopyranose-(3 → 1)-α-fucopyranose-(3→] as the main branch with [→1)-6-O-acetyl-β-galactopyranose-(4→] as side chain isolated from marine macroalga Turbinaria ornata exhibited prospective apoptosis on HepG2 (hepatocellular carcinoma) and MCF7 (ductal carcinoma) cells. Annexin V-fluorescein isothiocyanate-propidium iodide study displayed higher early apoptosis in MCF7 and HepG2 cell lines (56 and 24.2%, respectively) treated with TOP-3 (at IC50 concentration) than those administered with standard camptothecin. Upregulation of the p53 gene expression was perceived in TOP-3 treated HepG2 and MCF7 cells.

Marine polysaccharide laminarin embedded ZnO nanoparticles and their based chitosan capped ZnO nanocomposites: Synthesis, characterization and in vitro and in vivo toxicity assessment

In the current scenario where more and more products containing nanomaterials are on the technological or pharmaceutical market, it is crucial to have a thorough knowledge of their toxicity before proposing possible applications. A proper analysis of the toxicity of the nanoproducts should include both in vitro and in vivo biological approaches and should consider that the synthesis and purification methods of nanomaterials may affect such toxicity. In the current work, the green synthesis of laminarin embedded ZnO nanoparticles (Lm-ZnO NPs) and their based chitosan capped ZnO nanocomposites (Ch-Lm-ZnO NCmps) is described for the first time. Furthermore, the evaluation of their in vitro cytotoxicity, phytotoxicity, and in vivo (Zebrafish embryo) toxicity was described. First, the green synthesized Lm-ZnO NPs and Ch-Lm-ZnO NCmps were fully physicochemically characterized. Lm-ZnO NPs were greatly agglomerated and had a spindle morphology ranging from 100 to 350 nm, while Ch-Lm-ZnO NCmps had irregular rod shape with flake-like structure clusters randomly aggregated with diverse sizes ranging from 20 to 250 nm. The in vitro cytotoxicity assessment of the green synthesized Lm-ZnO NPs and Ch-Lm-ZnO NCmps was carried out in normal human dermal fibroblasts (HDF) cells and human colon cancer (HT-29) cells by MTT assay. Lm-ZnO NPs and Ch-Lm-ZnO NCmps (0.1-500 μg/mL), significantly inhibited the viability of both cell lines, revealing dose-dependent cytotoxicity. Besides, the Lm-ZnO NPs and Ch-Lm-ZnO NCmps significantly affected seed germination and roots and shoots length of mung (Vigna radiata). Moreover, the zebrafish embryo toxicity of Lm-ZnO NPs and Ch-Lm-ZnO NCmps among the various concentrations used (0.1-500 μg/mL) caused deformities, increased mortality and decreased the survival rate of zebrafish embryo dose-dependently.

Furcellaran Surface Deposition and Its Potential in Biomedical Applications

Surface coatings of materials by polysaccharide polymers are an acknowledged strategy to modulate interfacial biocompatibility. Polysaccharides from various algal species represent an attractive source of structurally diverse compounds that have found application in the biomedical field. Furcellaran obtained from the red algae Furcellaria lumbricalis is a potential candidate for biomedical applications due to its gelation properties and mechanical strength. In the present study, immobilization of furcellaran onto polyethylene terephthalate surfaces by a multistep approach was studied. In this approach, N-allylmethylamine was grafted onto a functionalized polyethylene terephthalate (PET) surface via air plasma treatment. Furcellaran, as a bioactive agent, was anchored on such substrates. Surface characteristics were measured by means of contact angle measurements, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Subsequently, samples were subjected to selected cell interaction assays, such as antibacterial activity, anticoagulant activity, fibroblasts and stem cell cytocompatibility, to investigate the Furcellaran potential in biomedical applications. Based on these results, furcellaran-coated PET films showed significantly improved embryonic stem cell (ESC) proliferation compared to the initial untreated material.

Multifaceted role of natural sources for COVID-19 pandemic as marine drugs

COVID-19, which is caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has quickly spread over the world, posing a global health concern. The ongoing epidemic has necessitated the development of novel drugs and potential therapies for patients infected with SARS-CoV-2. Advances in vaccination and medication development, no preventative vaccinations, or viable therapeutics against SARS-CoV-2 infection have been developed to date. As a result, additional research is needed in order to find a long-term solution to this devastating condition. Clinical studies are being conducted to determine the efficacy of bioactive compounds retrieved or synthesized from marine species starting material. The present study focuses on the anti-SARS-CoV-2 potential of marine-derived phytochemicals, which has been investigated utilizing in in silico, in vitro, and in vivo models to determine their effectiveness. Marine-derived biologically active substances, such as flavonoids, tannins, alkaloids, terpenoids, peptides, lectins, polysaccharides, and lipids, can affect SARS-CoV-2 during the viral particle's penetration and entry into the cell, replication of the viral nucleic acid, and virion release from the cell; they can also act on the host's cellular targets. COVID-19 has been proven to be resistant to several contaminants produced from marine resources. This paper gives an overview and summary of the various marine resources as marine drugs and their potential for treating SARS-CoV-2. We discussed at numerous natural compounds as marine drugs generated from natural sources for treating COVID-19 and controlling the current pandemic scenario.

Enteral Nutrition: Based on the Combination of Nutrison Fibre and TPF-DM with A Marine Biological-Based Active Polysaccharide Preparation

Good nutrition is essential for human growth, wound healing, and spiritual vitality. However, some individuals are unable to eat or experience gastrointestinal problems such as severe diarrhea, vomiting, gastric retention, and even gastrointestinal bleeding for a variety of causes. Therefore, it has important clinical significance to provide patients with required nutrients and maintain the integrity of the body’s tissues and organs through enteral nutrition. Based on this, this work uses a dual carrier of polylactic acid (PLA) and polyvinyl alcohol (PVA) to carry marine biopolysaccharides combined with sodium alginate (PSS) and successfully obtains the intestinal tract based on marine bioactive polysaccharides. Nutritional oral biological preparations (PSS-PLA/PVA) also cooperate with enteral nutritional suspension (diabetes) (TPF-DM) and Nutrison fibre to provide enteral nutritional support for critically ill patients. PSS-PLA/PVA has been shown in clinical studies to increase the effect of enteral nutrition support, the function of intestinal T lymphatic tissue, and the ability to control immunological function, indicating that it is worthy of further clinical development.

Fucoidan with three functions extracted from Sargassum aquifolium integrated rice-husk synthesis dual-imaging mesoporous silica nanoparticle

In this study, we used the nanoparticle delivery system to reduce the side effect of conventional cancer treatment- radiation therapy and chemotherapy. We used rice husk silicon source mesoporous silica nanoparticle doped in Eu3+ and Gd3+ as the carrier in the delivery system and to enable fluorescence and MRI dual-imaging functions for follow-up therapy. In addition, we choose a popular seaweed extract-fucoidan was extracted from the same brown algae-Sargassum aquifolium collected from Taiwan-Pingtung-Kenting-Chuanfan Rock. In this research, we used acid hydrolysis to prepared two different molecular weight fucoidan, the small molecular fucoidan (Fus) as drug, and the molecular weight approximately 1 kDa fucoidan (Ful) as the nanoparticle gatekeeper, and as targeting molecule for overexpressed P-selectin on the surface of the metastatic tumors. The results of the cell cytotoxicity experiment showed that HCT116 cancer cells have a survival rate of approximately 58.12% when treated with 200 μg/mL fucoidan. Dual-imaging rice husk mesoporous silica nanoparticles (rMSN-EuGd) were modified with 1 kDa fucoidan (Ful) as the gatekeeper and target, and the small molecule fucoidan (Fus) was loaded into nanoparticles (Ful-Fus@rMSN-EuGd) at a concentration of 200 μg/mL. The HCT116 cancer cells had a survival rate of approximately 55.56%. The cell cytotoxicity experiment results show that Ful-Fus@rMSN-EuGd can improve the anticancer effect of fucoidan, and the nanoparticle drug delivery system using fucoidan as a drug, target, and gatekeeper was successfully synthesized.

Biocompatibility and immunostimulatory properties of fish collagen and shrimp chitosan towards peripheral blood mononuclear cells (PBMCs)

Several naturally occurring biopolymers are commercially produced from livestock and farmed animals processing wastes, including aquatic organisms. These wastes are considered valuable coproducts of fishery processing industry, from which biopolymers may be recovered and exploited for their bioactive potential. The aim of this work was to prepare polymeric films from collagen and chitosan solutions, extracted from fishery discards, and investigate the cytotoxicity and immunomodulatory activity towards human peripheral blood mononuclear cells (PBMCs). PBMCs were isolated from healthy donors and treated with Chitosan, Collagen, Chitosan+Collagen solutions and Chitosan+Collagen film in order to measure the changes in cell viability, cytosolic calcium concentration ([Ca²⁺]cyt), mitochondrial membrane potential (ΔΨm), reactive oxygen species (ROS) levels, differentiation and activation of T CD8⁺ and CD4⁺ lymphocytes, and cytokine production. Results showed that collagen and chitosan preparations did not show cytotoxic effect, while cellular IL-6, IL-10, and TNF-α release was observed. Chitosan and collagen were able to promote non-cytotoxic PBMCs activation through cytosolic and mitochondrial ROS production. There was a noteworthy phenotyping of lymphocytes T CD8⁺ and CD4⁺ counting and an increase of [Ca²⁺] cyt and ΔΨm levels. These results suggest that chitosan/collagen-based biomaterials produce immunostimulatory effects on PBMC with potential to biomedical approaches.

Advances in Research on Antiviral Activities of Sulfated Polysaccharides from Seaweeds

In recent years, various viral diseases have suddenly erupted, resulting in widespread infection and death. A variety of biological activities from marine natural products have gradually attracted the attention of people. Seaweeds have a wide range of sources, huge output, and high economic benefits. This is very promising in the pharmaceutical industry. In particular, sulfated polysaccharides derived from seaweeds, considered a potential source of bioactive compounds for drug development, have shown antiviral activity against a broad spectrum of viruses, mainly including common DNA viruses and RNA viruses. In addition, sulfated polysaccharides can also improve the body’s immunity. This review focuses on recent advances in antiviral research on the sulfated polysaccharides from seaweeds, including carrageenan, galactan, fucoidan, alginate, ulvan, p-KG03, naviculan, and calcium spirulan. We hope that this review will provide new ideas for the development of COVID-19 therapeutics and vaccines.

Current Advances in Multifunctional Nanocarriers Based on Marine Polysaccharides for Colon Delivery of Food Polyphenols

Inflammatory bowel disease (IBD) has been considered as a chronic disease that is difficult to cure and needs lifelong treatment. Marine polysaccharides with good biocompatibility and biodegradability, mucoadhesion, sensitivity to external stimuli, and targeting ability can be used as wall materials for oral colon-targeted delivery of polyphenols in nutrition intervention of IBD. This manuscript reviewed the latest progress in the design, preparation, and characterization of marine polysaccharides-derived multifunctional nanocarriers for polyphenol colon delivery. Chitosan, sodium alginate, chondroitin sulfate, and hyaluronic acid were discussed in the preparation of polyphenol delivery systems. The design strategy, synthesis methods, and structure characterization of multifunctional polyphenol carriers including stimuli-responsive nanocarriers, mucoadhesive and mucus-penetrating nanocarriers, colon targeted nanocarriers, and bioactive compounds codelivery nanocarriers were reviewed in the alleviation of IBD. The research perspectives in the preparation and characterization of delivery carriers using marine polysaccharide as materials were proposed for their potential application in food bioactive components.

Bioactive Properties of Peptides and Polysaccharides Derived from Peanut Worms: A Review

Peanut worms (Sipunculids) are unsegmented marine worms that usually inhabit shallow waters. Peanut worms are good source of bioactive compounds including peptides and polysaccharides. Many recent studies have investigated the bioactive properties of peptides and polysaccharides derived from peanut worms in order to enhance their applications in food and pharmaceutical industries. The peptides and polysaccharides isolated from peanut worms have been reported to possess anti-hypertensive, anti-oxidant, immunomodulatory, anti-inflammatory, anti-cancer, anti-hypoxia and wound healing activities through the modulation of various molecular mechanisms. Most researchers used in vitro, cell culture and animal models for the determination of bioactivities of peanut worm derived compounds. However, studies in humans have not been performed considerably. Therefore, it is important to conduct more human studies for better utilization of marine bioactive compounds (peptides and polysaccharides) derived from peanut worms. This review mainly focuses on the bioactive properties of peptides and polysaccharides of peanut worms and their molecular mechanisms.

Can algae contribute to the war with Covid-19?

The world at large is facing a new threat with the emergence of the Coronavirus Disease 2019 (COVID-19) pandemic. Though imperceptible by the naked eye, the medical, sociological and economical implications caused by this newly discovered virus have been and will continue to be a great impediment to our lives. This health threat has already caused over two million deaths worldwide in the span of a year and its mortality rate is projected to continue rising. In this review, the potential of algae in combating the spread of COVID-19 is investigated since algal compounds have been tested against viruses and algal anti-inflammatory compounds have the potential to treat the severe symptoms of COVID-19. The possible utilization of algae in producing value-added products such as serological test kits, vaccines, and supplements that would either mitigate or hinder the continued health risks caused by the virus is prominent. Many of the characteristics in algae can provide insights on the development of microalgae to fight against SARS-CoV-2 or other viruses and contribute in manufacturing various green and high-value products.

Efficacy of marine bioactive compound fucoidan for bone regeneration and implant fixation in sheep

The need for a substitute for allograft and autograft is rising as bone graft surgeries exceed available supplies. We investigated the efficacy of the low-molecular weight marine bioactive compound fucoidan (FUC) on bone regeneration and implant fixation in seven female sheep, as FUC has shown great promise as a bone substitute. Titanium implants were inserted bilaterally in the distal femurs to test three hydroxyapatite/fucoidan (HA/FUC) groups and compared to allograft. The HA was coated with either 500 or 1500 μg of FUC, obtained by microwave-assisted chemical extraction, or 500 μg of FUC obtained by an enzyme-assisted extraction method. The concentric 2-mm gap around the implant was filled with either one of the HA/FUCs or allograft from the donor sheep. After 12 weeks, implant-bone blocks were harvested and divided into three parts for mechanical push-out testing, immunohistochemistry, and micro-CT and histomorphometry. Pronounced bone formations were observed by micro-CT and histomorphometry in all groups, but higher bone volume fractions were seen in the allograft group compared to the three HA/FUC groups. The trabecular thickness, trabecular separation, and architectural anisotropy were all significantly higher in the allograft group compared to the three HA/FUC groups. In conclusion, adequate bone formation was observed in all groups, although the bone formation was significantly greater in the allograft group. Also, no significant differences existed in the shear mechanical properties between groups, suggesting that the combination of HA and FUC can achieve a similar fixation strength to allograft in this model.

Development and Characterization of Ulvan Polysaccharides-Based Hydrogel Films for Potential Wound Dressing Applications

Background

Ulvan is a natural polymer and type of sulfated polysaccharides from green seaweed that could have potential as a candidate for wound dressing material based on the support of its biopolymer characteristics such as antioxidant and antimicrobial activities.

Objective

In this study, we developed and prepared three different hydrogel films to explore the potency of ulvan for wound dressing application.

Methods

Ulvan hydrogel films were prepared by the facile method through ionic crosslinking with boric acid and added glycerol as a plasticizer. The films were evaluated in regard to swelling degree, water vapor transmission (WVTR), Fourier transform infrared (FTIR), powder x-ray diffractometry (P-XRD), scanning electron microscopy (SEM), mechanical properties, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), antimicrobial, and antioxidant activity.

Results

The hydrogel films showed that the different concentration of ulvan in the formula affects the characteristics of the hydrogel film. The higher the concentration of ulvan in UHF, the higher the value of viscosity (201±13.45 to 689±62.23 cps for UHF5 to UHF10), swelling degree (82% to 130% for UHF5 to UHF10 at 1 h), moisture content (24%±1.94% to 18.4%±0.51 for UHF5 to UHF10), and the WVTR were obtained in the range 1856–2590g/m²/24h. Meanwhile, the SEM showed porous hydrogel film. Besides, all hydrogel films can reduce hydroxyl radicals and inhibit gram-positive and negative bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Streptococcus epidermidis).

Conclusion

The swelling behavior and WVTR of these films are great and could have potential as a wound dressing biomaterial, supported by their antimicrobial and antioxidant properties.

Exploring the therapeutic potential of marine-derived bioactive compounds against COVID-19

The ocean is the most biodiverse habitat of various organisms. The organisms surviving in the harsh conditions of the ocean consist of several spectacular properties and produce bioactive compounds of pharmacological importance. These compounds are effective even in small quantities with various immunomodulatory qualities such as antioxidant and anti-inflammatory properties. Though the vaccines for COVID-19 are developed, and drug development is also in progress, but till now no effective drug is available for this deadly virus. Researchers are mining the huge data of bioactive compounds to develop the specific drug for COVID-19. The use of the repurposed drugs is challenging against the rapidly mutating virus with variable symptoms and mode of transmission. This review is an attempt to compile all the spattered data of marine-derived bioactive compounds with antiviral properties and to explore their therapeutic potential against COVID-19.

Applying Seaweed Compounds in Cosmetics, Cosmeceuticals and Nutricosmetics

The interest in seaweeds for cosmetic, cosmeceutics, and nutricosmetics is increasing based on the demand for natural ingredients. Seaweeds offer advantages in relation to their renewable character, wide distribution, and the richness and versatility of their valuable bioactive compounds, which can be used as ingredients, as additives, and as active agents in the formulation of skin care products. Bioactive compounds, such as polyphenols, polysaccharides, proteins, peptides, amino acids, lipids, vitamins, and minerals, are responsible for the biological properties associated with seaweeds. Seaweed fractions can also offer technical features, such as thickening, gelling, emulsifying, texturizing, or moistening to develop cohesive matrices. Furthermore, the possibility of valorizing industrial waste streams and algal blooms makes them an attractive, low cost, raw and renewable material. This review presents an updated summary of the activities of different seaweed compounds and fractions based on scientific and patent literature.

Polygalacto-fucopyranose from marine alga as a prospective antihypertensive lead

Consumption of marine alga-based polysaccharides as additional functional foods can endow with health benefits by diminishing the risk of chronic diseases. A polygalacto-fucopyranose characterized as [→1)-2, 4-SO3-α-Fucp-(3 → 1)-{2-SO3-α-Fucp-(3→}] with [(4 → 1)-6-OAc-β-Galp-(4→] side chain isolated from marine alga Sargassum wightii exhibited potential antihypertensive activity. Upon treatment with studied polygalactofucan (50 mg/kg BW), serum hypertension biomarkers troponin-T (1.3 pg/mL), troponin-I (1.2 μg/dL) and angiotensin-II converting enzyme (0.18 pg/mL) were significantly recovered in hypertensive rats compared to disease control. Serum cardiovascular risk indices of diseased rats were significantly decreased (< 10%, p < 0.05) after administration of the studied galactofucan (50 mg/kg BW) related to hypertension group (> 17%), and were comparable with standard antihypertensive agent telmisartan (8.3-10.2% at 2 mg/kg BW). The studied compound was safe for consumption as obvious from the high LD50 value (>5 g/kg), and could be developed as a prospective functional food ingredient attenuating the pathophysiological attributes causing hypertension-related conditions.

Exocellular polysaccharides extracted from mangrove fungus Paecilomyces Lilacinuson present anti-HSV-1 activity in mice

This study examined the anti-HSV-1 activity of EPS extracts isolated from mangrove fungus Paecilomyces Lilacinuson after intraperitoneal administration in mice. Mice were experimentally infected with HSV-1 intracranially and treated intraperitoneally with three different doses of EPS extract (6 g/Kg, 8 g/Kg, and 10 g/Kg) for 7 days. One group of 15 mice was infected with HSV-1 but did not receive any treatment, while another group of 15 mice was mock-infected to remain a control group. Animals were observed twice a day for 14 days after virus infection, searching for clinical signs of weight loss, piloerection, isolation, or retardation movement. Compared with the mock-infected group, mortality was significantly increased (p < 0.05) in the virus-infected group and the groups that received 6 g/Kg and 8 g/Kg EPS extract. Interestingly, no significant differences in mortality were found between the 10 g/Kg EPS extract and the mock-infected group. Mortality in the 10 g/Kg EPS extract group was substantially improved compared with virus-infected(p < 0.05). Additionally, EPS extracts inhibited HSV-1 replication in the mice brain in a dose-dependent manner. Furthermore, the extracts decreased NF-κB protein and mRNA expression and the production of TNF-α in HSV-1-infected mice brain tissue. These effects were also dose-dependent. Our findings suggest that the EPS extract may be a potential candidate for developing an antiviral drug against HSV-1.

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

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

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.

Marine sulfated polysaccharides as potential antiviral drug candidates to treat Corona Virus disease (COVID-19)

The viral infection caused by SARS-CoV-2 has increased the mortality rate and engaged several adverse effects on the affected individuals. Currently available antiviral drugs have found to be unsuccessful in the treatment of COVID-19 patients. The demand for efficient antiviral drugs has created a huge burden on physicians and health workers. Plasma therapy seems to be less accomplishable due to insufficient donors to donate plasma and low recovery rate from viral infection. Repurposing of antivirals has been evolved as a suitable strategy in the current treatment and preventive measures. The concept of drug repurposing represents new experimental approaches for effective therapeutic benefits. Besides, SARS-CoV-2 exhibits several complications such as lung damage, blood clot formation, respiratory illness and organ failures in most of the patients. Based on the accumulation of data, sulfated marine polysaccharides have exerted successful inhibition of virus entry, attachment and replication with known or unknown possible mechanisms against deadly animal and human viruses so far. Since the virus entry into the host cells is the key process, the prevention of such entry mechanism makes any antiviral strategy effective. Enveloped viruses are more sensitive to polyanions than non-enveloped viruses. Besides, the viral infection caused by RNA virus types embarks severe oxidative stress in the human body that leads to malfunction of tissues and organs. In this context, polysaccharides play a very significant role in providing shielding effect against the virus due to their polyanionic rich features and a molecular weight that hinders their reactive surface glycoproteins. Significantly the functional groups especially sulfate, sulfate pattern and addition, uronic acids, monosaccharides, glycosidic linkage and high molecular weight have greater influence in the antiviral activity. Moreover, they are very good antioxidants that can reduce the free radical generation and provokes intracellular antioxidant enzymes. Additionally, polysaccharides enable a host-virus immune response, activate phagocytosis and stimulate interferon systems. Therefore, polysaccharides can be used as candidate drugs, adjuvants in vaccines or combination with other antivirals, antioxidants and immune-activating nutritional supplements and antiviral materials in healthcare products to prevent SARS-CoV-2 infection.

Marine Macroalgal Polygalactan-Built Nanoparticle Construct for Osteogenesis

Naturally derived polysaccharide biopolymer-based nanoparticles with their size and drug release potentials have appeared as promising biomaterials for osteogenic differentiation. A metallic nanoparticle (GS-AgNP) prepared from a sulfated polygalactan characterized as →3)-2-O-methyl-O-6-sulfonato-β-d-galactopyranosyl-(1 → 4)-2-O-methyl-3,6-anhydro-α-d-galactopyranose-(1→ isolated from the marine macroalga Gracilaria salicornia exhibited a prospective osteogenic effect. Upon treatment with the studied GS-AgNP, alkaline phosphatase activity (88.9 mU/mg) was significantly elevated in human mesenchymal osteoblast stem cells (hMSCs) compared to that in the normal control (33.7 mU/mg). A mineralization study of GS-AgNPs demonstrated an intense mineralized nodule formation on the hMSC surface. A fluorescence-activated cell sorting study of osteocalcin and bone morphogenic protein-2 (BMP-2) expression resulted in an increased population of osteocalcin (78.64%) and BMP-2-positive cells (46.10%) after treatment with GS-AgNPs (250 μg/mL) on M2 macrophages. A time-dependent cell viability study of GS-AgNPs exhibited its non-cytotoxic nature. The studied polygalactan-built nanoparticle could be developed as a promising bioactive pharmacophore against metabolic bone disorder and the treatment for osteogenesis therapy.

Seaweed Polysaccharide Based Products and Materials: An Assessment on Their Production from a Sustainability Point of View

Among the various natural polymers, polysaccharides are one of the oldest biopolymers present on the Earth. They play a very crucial role in the survival of both animals and plants. Due to the presence of hydroxyl functional groups in most of the polysaccharides, it is easy to prepare their chemical derivatives. Several polysaccharide derivatives are widely used in a number of industrial applications. The polysaccharides such as cellulose, starch, chitosan, etc., have several applications but due to some distinguished characteristic properties, seaweed polysaccharides are preferred in a number of applications. This review covers published literature on the seaweed polysaccharides, their origin, and extraction from seaweeds, application, and chemical modification. Derivatization of the polysaccharides to impart new functionalities by chemical modification such as esterification, amidation, amination, C-N bond formation, sulphation, acetylation, phosphorylation, and graft copolymerization is discussed. The suitability of extraction of seaweed polysaccharides such as agar, carrageenan, and alginate using ionic solvent systems from a sustainability point of view and future prospects for efficient extraction and functionalization of seaweed polysaccharides is also included in this review article.

Antiviral Cyanometabolites-A Review

Global processes, such as climate change, frequent and distant travelling and population growth, increase the risk of viral infection spread. Unfortunately, the number of effective and accessible medicines for the prevention and treatment of these infections is limited. Therefore, in recent years, efforts have been intensified to develop new antiviral medicines or vaccines. In this review article, the structure and activity of the most promising antiviral cyanobacterial products are presented. The antiviral cyanometabolites are mainly active against the human immunodeficiency virus (HIV) and other enveloped viruses such as herpes simplex virus (HSV), Ebola or the influenza viruses. The majority of the metabolites are classified as lectins, monomeric or dimeric proteins with unique amino acid sequences. They all show activity at the nanomolar range but differ in carbohydrate specificity and recognize a different epitope on high mannose oligosaccharides. The cyanobacterial lectins include cyanovirin-N (CV-N), scytovirin (SVN), microvirin (MVN), Microcystisviridis lectin (MVL), and Oscillatoria agardhii agglutinin (OAA). Cyanobacterial polysaccharides, peptides, and other metabolites also have potential to be used as antiviral drugs. The sulfated polysaccharide, calcium spirulan (CA-SP), inhibited infection by enveloped viruses, stimulated the immune system’s response, and showed antitumor activity. Microginins, the linear peptides, inhibit angiotensin-converting enzyme (ACE), therefore, their use in the treatment of COVID-19 patients with injury of the ACE2 expressing organs is considered. In addition, many cyanobacterial extracts were revealed to have antiviral activities, but the active agents have not been identified. This fact provides a good basis for further studies on the therapeutic potential of these microorganisms.

Underscoring the immense potential of chitosan in fighting a wide spectrum of viruses: A plausible molecule against SARS-CoV-2?

Chitosan is a deacetylated polycationic polysaccharide derived from chitin. It is structurally constituted of N-acetyl-D-glucosamine and β-(1-4)-linked D-glucosamine where acetyl groups are randomly distributed across the polymer. The parameters of deacetylation and depolymerization process greatly influence various physico-chemical properties of chitosan and thus, offer a great degree of manipulation to synthesize chitosan of interest for various industrial and biomedical applications. Chitosan and its various derivatives have been a potential molecule of investigation in the area of anti-microbials especially anti-fungal, anti-bacterial and antiviral. The current review predominantly highlights and discusses about the antiviral activities of chitosan and its various substituted derivatives against a wide spectrum of human, animal, plants and bacteriophage viruses. The extrinsic and intrinsic factors that affect antiviral efficacy of chitosan have also been talked about. With the rapid unfolding of COVID-19 pandemic across the globe, we look for chitosan as a plausible potent antiviral molecule for fighting this disease. Through this review, we present enough literature data supporting role of chitosan against different strains of SARS viruses and also chitosan targeting CD147 receptors, a novel route for invasion of SARS-CoV-2 into host cells. We speculate the possibility of using chitosan as potential molecule against SARS-CoV-2 virus.

Optimization of Porphyran Extraction from Pyropia yezoensis by Response Surface Methodology and Its Lipid-Lowering Effects

Macroalgae polysaccharides are phytochemicals that are beneficial to human health. In this study, response surface methodology was applied to optimize the extraction procedure of Pyropia yezoensis porphyran (PYP). The optimum extraction parameters were: 100 °C (temperature), 120 min (time), and 29.32 mL/g (liquid-solid ratio), and the maximum yield of PYP was 22.15 ± 0.55%. The physicochemical characteristics of PPYP, purified from PYP, were analyzed, along with its lipid-lowering effect, using HepG2 cells and Drosophila melanogaster larvae. PPYP was a β-type sulfated hetero-rhamno-galactan-pyranose with a molecular weight of 151.6 kDa and a rhamnose-to-galactose molar ratio of 1:5.3. The results demonstrated that PPYP significantly reduced the triglyceride content in palmitic acid (PA)-induced HepG2 cells and high-sucrose-fed D. melanogaster larvae by regulating the expression of lipid metabolism-related genes, reducing lipogenesis and increasing fatty acid β-oxidation. To summarize, PPYP can lower lipid levels in HepG2 cells and larval fat body (the functional homolog tissue of the human liver), suggesting that PPYP may be administered as a potential marine lipid-lowering drug.

Antiviral activity of sulfated polysaccharides from marine algae and its application in combating COVID-19: Mini review

Marine-derived sulfated polysaccharides possess various antiviral activities against a broad range of enveloped and non-enveloped viruses. It has become the potential source of antiviral drugs for pharmaceutical development. In this review, we will discuss the different types of sulfated polysaccharides and their structural classification. Some of the major sulfated polysaccharides with potent antiviral activity, including carrageenan, agar, ulvan, fucoidan, and alginates, are considered in this review. The mechanism of these sulfated polysaccharides in inhibiting the different stages of the viral infection process inside the host cell is also demonstrated. It involves blocking the initial entry of the virus or inhibiting its transcription and translation by modulating the immune response of the host cell. In addition, we explore the potential of sulfated polysaccharides as antiviral agents in preventing recent Corona Virus Disease-2019 (COVID-19).

Application prospect of polysaccharides in the development of anti-novel coronavirus drugs and vaccines

Since the outbreak of the novel coronavirus disease COVID-19, caused by the SARS-CoV-2 virus, it has spread rapidly worldwide and poses a great threat to public health. This is the third serious coronavirus outbreak in <20 years, following SARS in 2002-2003 and MERS in 2012. So far, there are almost no specific clinically effective drugs and vaccines available for COVID-19. Polysaccharides with good safety, immune regulation and antiviral activity have broad application prospects in anti-virus, especially in anti-coronavirus applications. Here, we reviewed the antiviral mechanisms of some polysaccharides, such as glycosaminoglycans, marine polysaccharides, traditional Chinese medicine polysaccharides, and their application progress in anti-coronavirus. In particular, the application prospects of polysaccharide-based vaccine adjuvants, nanomaterials and drug delivery systems in the fight against novel coronavirus were also analyzed and summarized. Additionally, we speculate the possible mechanisms of polysaccharides anti-SARS-CoV-2, and propose the strategy of loading S or N protein from coronavirus onto polysaccharide capped gold nanoparticles vaccine for COVID-19 treatment. This review may provide a new approach for the development of COVID-19 therapeutic agents and vaccines.

Biocompatibility analysis of high molecular weight chitosan obtained from Pleoticus muelleri shrimps. Evaluation in prokaryotic and eukaryotic cells

The search for the exploitation and recycling of biomaterials is increasing for reducing the use of non-renewable resources and minimizing environmental pollution caused by synthetic materials. In this context, Chitosan (CS) being a naturally occurring biopolymer becomes relevant. The aim of the present work was to explore the effects of High Molecular Weight CS (H-CS) from Argentinean shrimp's wastes in prokaryotic and eukaryotic in vitro cell cultures. Ultrastructure of H-CS was analysed by SEM and TEM. In vitro studies were performed in prokaryotic (Lactobacillus casei BL23) and eukaryotic (Caco-2, ARPE-19, EA.hy926 and 3T3-L1) culture cells. High performance microscopic techniques were applied to examine culture cells. No changes in morphology were found in any of the cell types. In addition, fluorescent-dyed H-CS revealed that eukaryotic cells could internalize it optimally. Viability was maintained and proliferation rate even increased for Caco-2, ARPE-19 and 3T3-L1 cells under H-CS treatment. Besides, viability was neither altered in L. casei nor in EA.hy926 cells after H-CS exposure. In conclusion, H-CS could be a suitable biopolymer to be exploited for biomedical or food industry applications.

Human Peripheral Blood Dendritic Cell and T Cell Activation by Codium fragile Polysaccharide

Natural polysaccharides exhibit an immunostimulatory effect with low toxicity in humans and animals. It has shown that polysaccharide extracted from Codium fragile (CFP) induces anti-cancer immunity by dendritic cell (DC) activation, while the effect of CFP has not examined in the human immune cells. In this study, we found that CFP promoted the upregulation of CD80, CD83 and CD86 and major histocompatibility complex (MHC) class I and II in human monocyte-derived dendritic cells (MDDCs). In addition, CFP induced the production of proinflammatory cytokines in MDDCs. Moreover, CFP directly induced the activation of Blood Dendritic Cell Antigen (BDCA)1⁺ and BDCA3⁺ subsets of human peripheral blood DCs (PBDCs). The CFP-stimulated BDCA1⁺ PBDCs further promoted activation and proliferation of syngeneic CD4 T cells. The CFP-activated BDCA3⁺ PBDCs activated syngeneic CD8 T cells, which produced cytotoxic mediators, namely, cytotoxic T lymphocytes. These results suggest that CFP may be a candidate molecule for enhancing immune activation in humans.

Immunomodulatory effects of fucosylated chondroitin sulfate from Stichopus chloronotus on RAW 264.7 cells

Sea cucumbers were nutritional food and traditional Chinese medicine. In this study, fucosylated chondroitin sulfate from sea cucumber Stichopus chloronotus (fCS-Sc), a potential anticoagulant agent and immunological adjuvant, was investigated for its immune activation effects on RAW 264.7 macrophage for the first time. The results indicated that fCS-Sc could significantly promote the proliferation, the pinocytic activity of RAW 264.7 cells, and the production of NO, TNF-α, IL-1β, and IL-6. The fluorescence labeling assay indicated that fCS-Sc could bind to the macrophage. Moreover, the specific pattern recognition receptor inhibition assays showed that toll-like receptor 4 (TLR4) and TLR2 were involved in the recognition of fCS-Sc. Western blot assays indicated that fCS-Sc could induce degradation of cytoplasm IκB-α, and promotion of NF-κB p65 subunit translocation to nucleus, leading to a functional improvement of macrophage through NF-κB pathway. The results suggested that fCS-Sc might served as a promising candidate of immunomodulator.

Inhibition of glucuronomannan hexamer on the proliferation of lung cancer through binding with immunoglobulin G

The anti-lung cancer activity of oligosaccharides derived from glucuronomannan was investigated. The inhibition of A549 cell proliferation by glucuronomannan (Gn) and its oligomers (dimer (G2), tetramer (G4) and hexamer (G6)) were concentration dependent. In vivo activities on the A549-derived tumor xenografts showed the tumor inhibition of G2, G4 and G6 were 17 %, 40 % and 46 %, respectively. Organ coefficients in nude mice showed an increase in the kidney with G4, the brain with G6, and the spleen with G6. An advanced tandem mass tag labeled proteomics approach was performed. A significant differential expression was found in 59 out of the 4371 proteins, which involved the immune system. Surface plasmon resonance (SPR) studies revealed G6 was strongly bound to immunoglobulin G. This suggests that glucuronomannan hexamer inhibits the proliferation of lung cancer through its binding to immunoglobulin.