A report of a galactan from marine alga Gelidium crinale with in vivo anti-inflammatory and antinociceptive effects

Gut microbiome-based thiamine metabolism contributes to the protective effect of one acidic polysaccharide from Selaginella uncinata (Desv.) Spring against inflammatory bowel disease

Inflammatory bowel disease (IBD) is a serious disorder, and exploration of active compounds to treat it is necessary. An acidic polysaccharide named SUSP-4 was purified from Selaginella uncinata (Desv.) Spring, which contained galacturonic acid, galactose, xylose, arabinose, and rhamnose with the main chain structure of →4)-α-d-GalAp-(1→ and →6)-β-d-Galp-(1→ and the branched structure of →5)-α-l-Araf-(1→ . Animal experiments showed that compared with Model group, SUSP-4 significantly improved body weight status, disease activity index (DAI), colonic shortening, and histopathological damage, and elevated occludin and zonula occludens protein 1 (ZO-1) expression in mice induced by dextran sulfate sodium salt (DSS). 16S ribosomal RNA (rRNA) sequencing indicated that SUSP-4 markedly downregulated the level of Akkermansia and Alistipes. Metabolomics results confirmed that SUSP-4 obviously elevated thiamine levels compared with Model mice by adjusting thiamine metabolism, which was further confirmed by a targeted metabolism study. Fecal transplantation experiments showed that SUSP-4 exerted an anti-IBD effect by altering the intestinal flora in mice. A mechanistic study showed that SUSP-4 markedly inhibited macrophage activation by decreasing the levels of phospho-nuclear factor kappa-B (p-NF-κB) and cyclooxygenase-2 (COX-2) and elevating NF-E2-related factor 2 (Nrf2) levels compared with Model group. In conclusion, SUSP-4 affected thiamine metabolism by regulating Akkermania and inhibited macrophage activation to adjust NF-κB/Nrf2/COX-2-mediated inflammation and oxidative stress against IBD. This is the first time that plant polysaccharides have been shown to affect thiamine metabolism against IBD, showing great potential for in-depth research and development applications.

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.

Sulfation of furcellaran and its effect on hemocompatibility in vitro

In this study, furcellaran (FUR) obtained from Furcellaria lumbricalis was firstly employed for sulfation via various methods, including SO3-pyridine (SO3∙Py) complex in different aprotic solvents, chlorosulfonic acid and sulfuric acid with a "coupling" reagent N,N'-Dicyclohexylcarbodiimide. Structural characterization through FT-IR, GPC, XPS and elemental analyses confirmed the successful synthesis of 6-O-sulfated FUR derivates characterized by varying degrees of sulfation (DS) ranging from 0.15 to 0.91 and molecular weight (Mw) spanning from12.5 kDa to 2.7 kDa. In vitro clotting assays, partial thromboplastin time (aPTT), thrombin time (TT), and prothrombin time (PT) underscored the essential role of sulfate esters in conferring anticoagulant activity whereas FUR prepared via chlorosulfonic acid with DS of 0.91 reached 311.4 s in aPPT showing almost 4-fold higher anticoagulant activity than native FUR at the concentration 2 mg/mL. MTT test showed all tested samples decreased cell viability in a dose dependent manner while all of them are non-cytotoxic up to the concentration of 0.1 mg/mL. Furthermore, sulfated derivates deposited onto polyethylene terephthalate surface presented substantial decrease in platelet adhesion, as well as absence of the most activated platelet stages. These findings support the pivotal role of O-6 FUR sulfates in enhancing hemocompatibility and provide valuable insights for a comparative assessment of effective sulfating approaches.

Marine natural products and human immunity: novel biomedical resources for anti-infection of SARS-CoV-2 and related cardiovascular disease

Marine natural products (MNPs) and marine organisms include sea urchin, sea squirts or ascidians, sea cucumbers, sea snake, sponge, soft coral, marine algae, and microalgae. As vital biomedical resources for the discovery of marine drugs, bioactive molecules, and agents, these MNPs have bioactive potentials of antioxidant, anti-infection, anti-inflammatory, anticoagulant, anti-diabetic effects, cancer treatment, and improvement of human immunity. This article reviews the role of MNPs on anti-infection of coronavirus, SARS-CoV-2 and its major variants (such as Delta and Omicron) as well as tuberculosis, H. Pylori, and HIV infection, and as promising biomedical resources for infection related cardiovascular disease (irCVD), diabetes, and cancer. The anti-inflammatory mechanisms of current MNPs against SARS-CoV-2 infection are also discussed. Since the use of other chemical agents for COVID-19 treatment are associated with some adverse effects in cardiovascular system, MNPs have more therapeutic advantages. Herein, it's time to protect this ecosystem for better sustainable development in the new era of ocean economy. As huge, novel and promising biomedical resources for anti-infection of SARS-CoV-2 and irCVD, the novel potential mechanisms of MNPs may be through multiple targets and pathways regulating human immunity and inhibiting inflammation. In conclusion, MNPs are worthy of translational research for further clinical application.

Sulfated Galactans from Agarophytes: Review of Extraction Methods, Structural Features, and Biological Activities

Agarophytes are important seaweeds of the Rhodophyta type, which have been highly exploited for industrial use as sources of a widely consumed polysaccharide of agar. In addition to that, sulfated galactans (SGs) from agarophytes, which consist of various functional sulfate groups, have attracted the attention of scientists in current studies. SGs possess various biological activities, such as anti-tumor, anticoagulant, anti-inflammatory, antioxidant, anti-obesity, anti-diabetic, anti-microbial, anti-diarrhea, and gut microbiota regulation properties. Meanwhile, the taxonomy, ecological factors, i.e., environmental factors, and harvest period, as well as preparation methods, i.e., the pretreatment, extraction, and purification conditions, have been found to influence the chemical compositions and fine structures of SGs, which have, further, been shown to have an impact on their biological activities. However, the gaps in the knowledge of the properties of SGs due to the above complex factors have hindered their industrial application. The aim of this paper is to collect and systematically review the scientific evidence about SGs and, thus, to pave the way for broader and otherwise valuable industrial applications of agarophytes for human enterprise. In the future, this harvested biomass could be sustainably used not only as a source of agar production but also as natural materials in functional food and pharmaceutical industries.

Amelioration of atherosclerosis in ox-LDL induced HUVEC by sulfated polysaccharides from Gelidium crinale with antihypertensive activity

Red algal polysaccharide is a good potential medical resource. Different red algal polysaccharides have different structural characteristics and rich biological activities. Previous studies have identified some structural information of sulfated polysaccharide (GNP, 25.8 kDa) from red algae, Gelidium crinale and found that GNP has excellent anti-inflammatory, antioxidant and anti-tumor activities. On this basis, this study investigated the effect of GNP on atherosclerosis, which is closely related to antioxidant and anti-inflammatory mechanisms and usually coexists and interacts with hypertension. This study investigated the inhibitory activity of GNP on angiotensin-converting enzyme (ACE) and its mechanism on oxidized low-density lipoprotein (ox-LDL)-induced HUVEC atherosclerosis. The results showed that GNP inhibits the up-regulation of cell adhesion molecules and oxidized low-density lipoprotein receptor-1 (LOX-1). GNP can regulate mitogen-activated protein kinases (MAPK), nuclear factor kappa B (NF-κB) and PI3K/AKT signal pathways, inhibit apoptosis, invasion and migration. Meanwhile, GNP (IC₅₀ = 269.2 μg/mL) antagonizes ACE by competitive binding mode, and it can reduce systolic blood pressure (SBP) of spontaneously hypertensive rats (SHR). It provides a theoretical basis for GNP as a potential substance for the prevention and treatment of atherosclerosis.

Red Seaweed-Derived Compounds as a Potential New Approach for Acne Vulgaris Care

Acne vulgaris (AV) is a chronic skin disease of the pilosebaceous unit affecting both adolescents and adults. Its pathophysiology includes processes of inflammation, increased keratinization, sebum production, hormonal dysregulation, and bacterial Cutibacterium acnes proliferation. Common AV has been treated with antibiotics since the 1960s, but strain resistance has emerged and is of paramount concern. Macroalgae are known producers of substances with bioactive properties, including anti-viral, antibacterial, antioxidant, and anti-inflammatory properties, among several others. In particular, red algae are rich in bioactive compounds such as polysaccharides, phenolic compounds, lipids, sterols, alkaloids, and terpenoids, conferring them antioxidant, antimicrobial, and anti-inflammatory activities, among others. Thus, the exploration of compounds from marine resources can be an appealing approach to discover new treatment options against AV. The aim of this work is to provide an overview of the current knowledge of the potentialities of red macroalgae in the treatment of AV by reviewing the main therapeutic targets of this disease, and then the existence of compounds or extracts with bioactive properties against them.

Algae-Derived Anti-Inflammatory Compounds against Particulate Matters-Induced Respiratory Diseases: A Systematic Review

Air pollution has recently become a subject of increasing concern in many parts of the world. The World Health Organization (WHO) estimated that nearly 4.2 million early deaths are due to exposure to fine particles in polluted air, which causes multiple respiratory diseases. Algae, as a natural product, can be an alternative treatment due to potential biofunctional properties and advantages. This systematic review aims to summarize and evaluate the evidence of metabolites derived from algae as potential anti-inflammatory agents against respiratory disorders induced by atmospheric particulate matter (PM). Databases such as Scopus, Web of Science, and PubMed were systematically searched for relevant published full articles from 2016 to 2020. The main key search terms were limited to "algae", "anti-inflammation", and "air pollutant". The search activity resulted in the retrieval of a total of 36 publications. Nine publications are eligible for inclusion in this systematic review. A total of four brown algae (Ecklonia cava, Ishige okamurae, Sargassum binderi and Sargassum horneri) with phytosterol, polysaccharides and polyphenols were reported in the nine studies. The review sheds light on the pathways of particulate matter travelling into respiratory systems and causing inflammation, and on the mechanisms of actions of algae in inhibiting inflammation. Limitations and future directions are also discussed. More research is needed to investigate the potential of algae as anti-inflammatory agents against PM in in vivo and in vitro experimental models, as well as clinically.

Effects of sulfated polysaccharides isolated from Codium fragile on inflammatory cytokine gene expression and Edwardsiella tarda infection in rockfish, Sebastes schlegelii

Sulfated polysaccharides (SPs) derived from Codium fragile (sponge seaweed) can regulate cytokine expression in mammalian macrophages, NK cell lines and olive flounder head kidney primary cells in vitro. In this study, we found that SPs from C. fragile exhibited anti-bacterial activities against fish pathogenic bacteria including Streptococcus parauberis, Lactococcus garvieae, Aeromonas salmonicida and Edwardsiella tarda at a minimum inhibitory concentration of 2 mg/mL, but not against S. iniae or Vibrio anguillarum. Immunostimulatory effects of SPs from C. fragile on rockfish (Sebastes schlegelii) were evaluated by analyzing mRNA expression levels of inflammatory cytokines (interleukin (IL)-1β, IL-8, IL-6 and tumor necrosis factor (TNF)-α) and anti-inflammatory cytokines (IL-10) both in vitro and in vivo. Results revealed that expression levels of all genes tested were upregulated in rockfish head kidney and spleen cells by SPs from C. fragile in a dose/time-dependent manner in vitro. By contrast, expression levels of these genes were significantly (p < 0.05) downregulated in the head kidney and spleen of rockfish in vivo at 1 and 3 days post intraperitoneal injection of SPs from C. fragile. In the liver, these genes were downregulated on day 1, but upregulated on day 3. Treatment with SPs downregulated the expression of these genes in spleen, but upregulated IL-10 gene expression in the intestine and liver. Meanwhile, when fish were fed with crude SPs for 4 weeks and challenged with E. tarda, infected fish started to die starting from 2 days after immune challenge. The cumulative mortality of the 0.1% group was significantly lower (p < 0.05) than that of the control group without feeding with SPs. Expression levels of IL-1β and IL-6 genes were significantly (p < 0.05) upregulated in head kidney of the 0.5% group on day 1 while IL-1β gene expression was downregulated on day 3 in the liver. These results indicate that SPs from C. fragile can regulate the immune gene expression in rockfish and that a diet containing 0.1% crude SPs can reduce the mortality of rockfish caused by E. tarda infection.

Structural characterization and anti-inflammatory activity of a polysaccharide from the lignified okra

The polysaccharide (AP1-b) of molecular weight 6.59 × 10⁵ Da was isolated from lignified okra (Abelmoschus esculentus (L.) Moench) by hot-water extraction, 40 % ethanol precipitation and purified by DEAE Cellulose chromatography, respectively. The structure and anti-inflammatory activity of AP1-b were investigated. AP1-b was composed of galactose, rhamnose, gluctose, arabinose and galacturonic acid in a molar ratio of 1.98:1.00:0.15:0.32:0.29. The structural features showed that the AP1-b consisted of →2)-α-d-Rhap-(1→, →4)-β-d-Galp-(1→, →4)-α-d-GalpA-(1→, →6)-β-d-Galp-(1→, β-d-Glcp-(1→ and α-l-Araf-(1→. AP1-b could observably improve the inflammatory injury of LPS-induced RAW 264.7 cells by inhibiting the secretion of NO and decreasing the levels of pro-inflammatory factors (IL-1β, iNOS and TNF-α). AP1-b also inhibited the phosphorylation levels of IκB and p65 proteins, manifesting the anti-inflammatory activity of AP1-b may associated with inhibition of NF-κB signaling pathway. Therefore, AP1-b had potential value in treating inflammatory injury.

Anti-inflammatory activity and structural identification of a sulfated polysaccharide CLGP4 from Caulerpa lentillifera

In the present study, the in vitro anti-inflammatory activity of four purified polysaccharides (CLGP1, CLGP2, CLGP3 and CLGP4) extracted from edible green algae Caulerpa lentillifera was evaluated. As a result, CLGP4 exhibited more effectively inhibitory effect on LPS-induced HT29 cells, including reducing the production of IL-1β, TNF-α, SIgA and mucin2, and decreasing the expression of IL-1β and TNF-α. According to the results, CLGP4 showed a better anti-inflammatory effect, might highly related to the presence of sulfate groups. Furthermore, the structure of CLGP4 was analyzed by methylation analysis, GC-MS and NMR spectroscopy. It was found that CLGP4 was a novel xylogalactomanan consisting of β-(1 → 4)-Man_p, →2,4)Man_p(1→, β-(1 → 2)-Man_p, β-(1 → 3)-Gal_p, β-(1 → 4)-Xyl_p, terminal β-Gal_p and terminal β-Xyl_p residues. Additionally, the sulfate groups were located on C-3 of →4)Xyl_p(1→, C-6 of →3)Gal_p(1→ and C-3 of →2)Man_p(1→. These results could enlarge the potential application of CLGP4 as functional ingredient to attenuate inflammation.

Macroalgal Polysaccharides in Biomimetic Nanodelivery Systems

BACKGROUND

Imitating nature in the design of bio-inspired drug delivery systems resulted in several success stories. However, the practical application of biomimicry is still largely unrealized owing to the fact that we tend to copy the shape more often than the whole biology. Interesting chemistry of polysaccharides provides endless possibilities for drug complex formation and creation of delivery systems with diverse morphological and surface properties. However, the type of biological response, which may be induced by these systems, remains largely unexploited.

METHODS

Considering the most current research for the given topic, in this review, we will try to present the integrative approaches for the design of biomimetic DDS's with improved therapeutic or theranostic effects based on different algal polysaccharides that exert multiple biological functions.

RESULTS

Algal polysaccharides may provide building blocks for bioinspired drug delivery systems capable of supporting the mechanical properties of nanomedicines and mimicking various biological processes by molecular interactions at the nanoscale. Numerous research studies demonstrate the efficacy and safety of multifunctional nanoparticles integrating several functions in one delivery system, composed of alginate, carrageenan, ulvan, fucoidan and their derivatives, intended to be used as bioartificial microenvironment or for diagnosis and therapy of different diseases.

CONCLUSION

Nanodimensional structure of polysaccharide DDS's shows substantial influence on the bioactive motifs potential availability for interaction with a variety of biomolecules and cells. Evaluation of the nano dimensional structure-activity relationship is crucial for unlocking the full potential of the future application of polysaccharide bio-mimicking DDS in modern diagnostic and therapeutic procedures.

Potential anti-inflammatory natural products from marine algae

Inflammatory diseases have become one of the leading causes of health issue throughout the world, having a considerable influence on healthcare costs. With the emerging developments in natural product, synthetic and combinatorial chemistry, a notable success has been achieved in discovering natural products and their synthetic structural analogs with anti-inflammatory activity. However, many of these therapeutics have indicated detrimental side effects upon prolonged usage. Marine algae have been identified as an underexplored reservoir of unique anti-inflammatory compounds. These include polyphenols, sulfated polysaccharides, terpenes, fatty acids, proteins and several other bioactives. Consumption of these marine algae could provide defense against the pathophysiology of many chronic inflammatory diseases. With further investigation, algal anti-inflammatory phytochemicals have the potential to be used as therapeutics or in the synthesis of structural analogs with profound anti-inflammatory activity with reduced side effects. The current review summarizes the latest knowledge about the potential anti-inflammatory compounds discovered from marine algae.

Marine Non-Glycosaminoglycan Sulfated Glycans as Potential Pharmaceuticals

Sulfated fucans (SFs) and sulfated galactans (SGs) are currently the marine non-glycosaminoglycan (GAG) sulfated glycans most studied in glycomics. These compounds exhibit therapeutic effects in several pathophysiological systems such as blood coagulation, thrombosis, neovascularization, cancer, inflammation, and microbial infections. As analogs of the largely employed GAGs and due to some limitations of the GAG-based therapies, SFs and SGs comprise new carbohydrate-based therapeutics available for clinical studies. Here, the principal structural features and the major mechanisms of action of the SFs and SGs in the above-mentioned pathophysiological systems are presented. Discussion is also given on the current challenges and the future perspectives in drug development of these marine glycans.

Sensorial, structural and functional response of rats subjected to hind limb immobilization

AIMS

This study analyzed the sensorial, structural and functional response of rats subjected to paw immobilization.

MAIN METHODS

Animal pelvis, hip, knee and ankle were immobilized using waterproof tape during two weeks for assessment of sensorial response to thermal (hot plate test) and mechanical stimuli (Von Frey test), motor system structure (histology and radiography) and muscle function (soleus contractility).

KEY FINDINGS

Disuse animals became more responsive to thermal stimuli (49%), although less responsive to mechanical challenge (58%). Disuse animals showed local injuries such as reduction in muscle fiber diameter (16.7% in gastrocnemius, 5.7% in soleus), contractile activity (55% of the control maximal tonic contraction) and tibia cortical thickness (9.3%), besides increased nitrite:protein ratio, suggestive of protein degradation. Disuse also evoked systemic adaptations that include increase in serum lactate dehydrogenase (36.1%) and alkaline phosphatase (400%), but reduction in calcium (8.4%) and total serum protein (5.5%), especially albumin (34.2%).

SIGNIFICANCE

Two weeks of functional paw disuse leads to local and systemic harmful adaptive changes in sensorial and structural systems. This study brings new insights into nervous and motor system mechanism associated with therapeutic limb immobilization in muscle and skeletal pathological conditions.

Mechanisms involved in the anti-inflammatory action of a polysulfated fraction from Gracilaria cornea in rats

The anti-inflammatory mechanisms of the sulfated polysaccharidic fraction obtained from red marine alga Gracilaria cornea (Gc-FI) were investigated using a paw edema model induced in rats by different inflammatory agents (carrageenan, dextran, serotonin, bradykinin, compound 48/80 or L-arginine). Gc-FI at the doses of 3, 9 or 27 mg/kg, subcutaneously--s.c., significantly inhibited rat paw edema induced by carrageenan and dextran, as confirmed by myeloperoxidase and Evans' blue assessments, respectively. Gc-FI (9 mg/kg, s.c.) inhibited rat paw edema induced by histamine, compound 48/80 and L-arginine. Additionally, Gc-FI (9 mg/kg, s.c.) inhibited Cg-induced edema in animals with intact mast cells but did not inhibit that with degranulated mast cells by compound 48/80, revealing a protective role on mast cell membranes. Gc-FI down-regulated the IL-1β, TNF-α and COX-2 mRNA and protein levels compared with those of the carrageenan group, based on qRT-PCR and immunohistochemistry analyses. After inhibition with ZnPP IX, a specific heme oxygenase-1 (HO-1) inhibitor, the anti-inflammatory effect of Gc-FI was not observed in Cg-induced paw edema, suggesting that the anti-inflammatory effect of Gc-FI is, in part, dependent on the integrity of the HO-1 pathway. Gc-FI can target a combination of multiple points involved in inflammatory phenomena.

Sulfated glycans in inflammation

Sulfated glycans such as glycosaminoglycans on proteoglycans are key players in both molecular and cellular events of inflammation. They participate in leukocyte rolling along the endothelial surface of inflamed sites; chemokine regulation and its consequential functions in leukocyte guidance, migration and activation; leukocyte transendothelial migration; and structural assembly of the subendothelial basement membrane responsible to control tissue entry of cells. Due to these and other functions, exogenous sulfated glycans of various structures and origins can be used to interventionally down-regulate inflammation processes. In this review article, discussion is given primarily on the anti-inflammatory functions of mammalian heparins, heparan sulfate, chondroitin sulfate, dermatan sulfate and related compounds as well as the holothurian fucosylated chondroitin sulfate and the brown algal fucoidans. Understanding the underlying mechanisms of action of these sulfated glycans in inflammation, helps research programs involved in developing new carbohydrate-based drugs aimed to combat acute and chronic inflammatory disorders.

Phytol, a diterpene alcohol, inhibits the inflammatory response by reducing cytokine production and oxidative stress

Studies have shown that diterpenes have anti-inflammatory and redox-protective pharmacological activities. The present study aimed to investigate the anti-inflammatory properties of phytol, a diterpene alcohol, in a mouse model of acute inflammation, and phytol effect on leukocyte recruitment, cytokines levels, and oxidative stress. The anti-inflammatory activities of phytol were assessed by measuring paw edema induced by different inflammatory agents (e.g., λ-carrageenan, compound 48/80, histamine, serotonin, bradykinin, and prostaglandin E2 [PGE2 ]), myeloperoxidase (MPO) activity, peritonitis model and cytokine levels. Further, oxidative stress was evaluated by determining glutathione (GSH) levels and malondialdehyde (MDA) concentration. The results showed that phytol (7.5, 25, 50, and 75 mg/kg) significantly reduced carrageenan-induced paw edema, in a dose-dependent manner. In addition, phytol (75 mg/kg) inhibited compound 48/80-, histamine-, serotonin-, bradykinin- and PGE2 -induced paw edema. It also inhibited the recruitment of total leukocytes and neutrophils; decreased MPO activity, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) levels, and MDA concentration; and increased GSH levels during carrageenan-induced acute inflammation. These results suggest that phytol attenuates the inflammatory response by inhibiting neutrophil migration that is partly caused by reduction in IL-1β and TNF-α levels and oxidative stress.

Marine algal natural products with anti-oxidative, anti-inflammatory, and anti-cancer properties

For their various bioactivities, biomaterials derived from marine algae are important ingredients in many products, such as cosmetics and drugs for treating cancer and other diseases. This mini-review comprehensively compares the bioactivities and biological functions of biomaterials from red, green, brown, and blue-green algae. The anti-oxidative effects and bioactivities of several different crude extracts of algae have been evaluated both in vitro and in vivo. Natural products derived from marine algae protect cells by modulating the effects of oxidative stress. Because oxidative stress plays important roles in inflammatory reactions and in carcinogenesis, marine algal natural products have potential for use in anti-cancer and anti-inflammatory drugs.

Therapeutic importance of sulfated polysaccharides from seaweeds: updating the recent findings

Seaweeds, being prolific sources of bioactive components have garnered unprecedented interest in recent times. The complex polysaccharides from the brown, red and green seaweeds possess broad spectrum therapeutic properties. Especially, the sulfated polysaccharides, viz. fucans, carrageenans and ulvans have exhibited strong antioxidant, antitumor, immunostimulatory, anti-inflammatory, pulmonary fibrosis anticoagulant/antithrombotic, lipid lowering, antiviral, antibacterial, antiprotozoan, hyperplasia prevention, gastrointestinal, regenerative and nano medicine applications. Considering the immense biomedical prospects of sulfated polysaccharides, the profound and emerging functional properties published in recent times will be discussed here with experimental evidences. The limitations of the seaweed-derived sulfated polysaccharides in healthcare will be summarized. Strategies to maximize extraction and bioavailability will be pondered.