Bifunctional effects of fucoidan on the expression of inducible nitric oxide synthase

Immunopotentiating Activity of Fucoidans and Relevance to Cancer Immunotherapy

Fucoidans, discovered in 1913, are fucose-rich sulfated polysaccharides extracted mainly from brown seaweed. These versatile and nontoxic marine-origin heteropolysaccharides have a wide range of favorable biological activities, including antitumor, immunomodulatory, antiviral, antithrombotic, anticoagulant, antithrombotic, antioxidant, and lipid-lowering activities. In the early 1980s, fucoidans were first recognized for their role in supporting the immune response and later, in the 1990s, their effects on immune potentiation began to emerge. In recent years, the understanding of the immunomodulatory effects of fucoidan has expanded significantly. The ability of fucoidan(s) to activate CTL-mediated cytotoxicity against cancer cells, strong antitumor property, and robust safety profile make fucoidans desirable for effective cancer immunotherapy. This review focusses on current progress and understanding of the immunopotentiation activity of various fucoidans, emphasizing their relevance to cancer immunotherapy. Here, we will discuss the action of fucoidans in different immune cells and review how fucoidans can be used as adjuvants in conjunction with immunotherapeutic products to improve cancer treatment and clinical outcome. Some key rationales for the possible combination of fucoidans with immunotherapy will be discussed. An update is provided on human clinical studies and available registered cancer clinical trials using fucoidans while highlighting future prospects and challenges.

A fucoidan-gelatin wound dressing accelerates wound healing by enhancing antibacterial and anti-inflammatory activities

Microbial infections and the slow regression of inflammation are major impediments to wound healing. Herein, a tilapia fish skin gelatin-fucose gum-tannic acid (Gel&Fuc-TA) hydrogel wound dressing (Gel&Fuc-TA) was designed to promote wound healing by mixing and reacting tannic acid (TA) with tilapia fish skin gelatin (Gel) and fucoidan (Fuc). Gel&Fuc-TA hydrogel has a good network structure as well as swelling and release properties, and shows excellent antibacterial, antioxidant, cell compatibility, and hemostatic properties. Gel&Fuc-TA hydrogel can promote the expression of vascular endothelial growth factor (VEGF), platelet endothelial cell adhesion molecule-1 (CD-31), and alpha-smooth muscle actin (α-SMA), enhance collagen deposition, and accelerate wound repair. Gel&Fuc-TA hydrogel can change the wound microbiome, reduce wound microbiome colonization, and decrease the expression of microbiome-related proinflammatory factors, such as lipopolysaccharide (LPS), Toll-like receptor 2 (TLR2), and Toll-like receptor 4 (TLR4). Gel&Fuc-TA hydrogel effectively regulates the conversion of wound macrophages to the M2 (anti-inflammatory phenotype) phenotype, decreases the expression of interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-alpha (TNF-α), and increases the expression of arginase-1 (Arg-1), interleukin-10 (IL-10) and transforming growth factor-beta (TGF-β), thereby reducing the inflammatory response. In summary, Gel&Fuc-TA hydrogel prepared using a rational green cross-linking reaction can effectively accelerate wound healing.

Phytochemicals: A potential next generation agent for radioprotection

BACKGROUND

Radiation hazards are accountable for extensive damage in the biological system and acts as a public health burden. Owing to the rapid increasing in radiation technology, both Ionizing radiation (IR) from natural and man made source poses detrimental outcome to public health. IR releases free radicals which induces oxidative stress and deleterious biological damage by modulating radiation induced signalling intermediates. The efficacy of existing therapeutic approach and treatment strategy are limited owing to their toxicity and associated side effects. Indian system of traditional medicine is enriched with prospective phytochemicals with potential radioprotection ability.

PURPOSE

The present review elucidated and summarized the potential role of plant derived novel chemical compound with prospective radioprotective potential.

METHOD

So far as the traditional system of Indian medicine is concerned, plant kingdom is enriched with potential bioactive molecules with diverse pharmacological activities. We reviewed several compounds mostly secondary metabolites from plant origin using various search engines.

RESULTS

Both compounds from land plants and marine source exhibited antioxidant antiinflammatory, free radical scavenging ability. These compounds have tremendous potential in fine-tuning of several signalling intermediates, which are actively participated in the progression and development of a pathological condition associated with radiation stress.

CONCLUSION

Development and explore of an operational radioprotective agent from originated from plant source that can be used as a novel molecular tool to eliminate the widespread damage caused by space exploration, ionizing radiation, nuclear war and radiotherapy has been significantly appreciated. Through extensive literature search we highlighted several compounds from both land plant and marine origin can be implemented for a better therapeutic potential against radiation induced injury. Furthermore, extensive clinical trials must be carried out in near future for better therapeutic modality and clinical efficacy.

Degraded polysaccharides from Porphyra haitanensis: purification, physico-chemical properties, antioxidant and immunomodulatory activities

To explore effect of the structural properties of porphyra haitanensis polysaccharide on its biological activity, degraded porphyra polysaccharides were separated and purified by Cellulose DEAE-52 and Sephadex G-100 chromatography, obtaining three purified components (P1, P2 and P3). All the three components were sulfate polysaccharides containing the repeating units of → 3) β-D-galactose (1 → 4) 3,6-anhydro-α-L-galactose (1 →, and → 3) β-D-galactose (1 → 4) α-L-galactose-6-S (1 →, and → 3) 6-O-methyl-β-D-galactose (1 → 4) 3,6-anhydro-α-L-galactose (1 →. The molecular weight of the three fractions was measured to be 300.3, 130.4 and 115.1 kDa, respectively. Their antioxidant activity was investigated by the determination of the free radical scavenging effect and ferric reducing power. It was found that P1, P2 and P3 possessed marked antioxidant activity. It was also found that they appreciably enhanced the proliferation, phagocytic ability and nitric oxide secretion in RAW264.7 cells. Lower molecular weight and higher sulfate content were beneficial to bioactivities of P. haitanensis polysaccharides. Overall, P2 and P3 possess superior immuno-modulatory activity to that of P1 and PHP. Thus, the current work will provide the basis for the better utilization of P. haitanensis to develop the related functional foods.

In vitro biological activities and in vivo hepatoprotective role of brown algae-isolated fucoidans

Brown seaweeds are rich in polysaccharides, such as fucoidan (FUC) which has shown beneficial effects in several medical conditions. The aim of the present study was to assess the antioxidant, anti-inflammatory, and hepatoprotective properties of Colpomenia sinuosa- and Sargassum prismaticum-isolated FUC in vitro and in vivo. The hot acid extraction method was used to isolate FUC from C. sinuosa (FCS) and S. prismaticum (FSP) species. The antioxidant, anticancer, as well as the effect on neurotransmitter-degrading enzyme and disaccharidase activities were measured using standard protocols. Moreover, the hepatoprotective effect of two FCS doses (100 and 200 mg/kg) on paracetamol-administered rats (one dose of 1 g/kg) were evaluated by measuring blood liver function markers, hepatic pro-oxidants as malondialdehyde (MDA) and nitric oxide (NO), antioxidants as glutathione (GSH) and glutathione peroxidase (GPx), proinflammatory markers as inducible nitric oxide synthase (iNOS), interleukin 1β (IL-1β), tumor necrosis factor-α (TNF-α), and liver histology. The crude fucoidan yield was 15.6% and 14.8% of C. sinuosa and S. prismaticum dry weights, respectively. The antioxidant effects and cytotoxic activity on hepatic cancer cell were higher for FCS than FSP. Moreover, in vivo data showed that FCS administration at both doses significantly improved liver functions and alleviated histological alterations, hepatic inflammation, and oxidative stress following paracetamol intake. In conclusion, fucoidan exerts anti-inflammatory, antidigestive enzyme activity, antioxidant, anticancer, and hepatoprotective effects.

Suppressive effects of sulfated polysaccharide ascophyllan isolated from Ascophyllum nodosum on the production of NO and ROS in LPS-stimulated RAW264.7 cells

In this study, we found that a sulfated polysaccharide isolated from the brown alga Ascophyllum nodosum, ascophyllan, showed suppressive effects on stimulated RAW264.7 cells. Ascophyllan significantly inhibited expression of inducible nitric oxide synthase mRNA and excessive production of nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells in a dose-dependent manner without affecting the viability of RAW264.7 cells. Ascophyllan also reduced the elevated level of intracellular reactive oxygen species (ROS) in LPS-stimulated RAW264.7 cells. Furthermore, preincubation with ascophyllan resulted in concentration-dependent decrease in ROS production in phorbol 12-myristate-13-acetate-stimulated RAW264.7 cells. Our results suggest that ascophyllan can exhibit anti-inflammatory effects on stimulated macrophages mainly through the attenuation of NO and ROS productions.

Structure and Biological Activity Analysis of Fucoidan Isolated from Sargassum siliquosum

Fucoidans are heterologous polysaccharides commonly seen in brown macroalgae and are known for their biological activity including anticancer, antiangiogenic, immunomodulation, and antiviral properties. The brown macroalga Sargassum siliquosum was used for the extraction and analysis of fucoidan in this study. The S. siliquosum fucoidan was indicated as a galactofucoidan composed of sugars, uronate, and sulfate at a ratio of 12:1:4 and its purity was 85% based on the abovementioned three major components. Structural analysis by electrospray ionization collision-induced dissociation tandem mass spectroscopy revealed that the purified fucoidan consisted of a carbohydrate chain composed of (1→3)-linked or (1→4)-linked l-fucose residues, with sulfate groups at C-2 and C-4 positions. Galactose residues with (1→4)-linkages function as the branch points and they are located at the C-3 or C-4 position of fucose residues. Galactose residues are sulfated mainly at C-4 and C-6, while some sulfation can also be seen at C-2. The fucoidan purified from S. siliquosum demonstrated antioxidant, anti-inflammatory, and antilipogenic activities.

Fucoidan protects against subacute diazinon-induced oxidative damage in cardiac, hepatic, and renal tissues

Fucoidans (FUC) are organic sulfated polysaccharides from natural seaweeds with multiple biological actions. The current study was performed to assess the chemoprotective, antioxidant, and anti-inflammatory effects of FUC from Laminaria japonicum against diazinon (DZN)-induced injuries to rat cardiac, hepatic, and renal tissues. Forty male Wistar rats were assigned into five groups, receiving saline, oral FUC 200 mg/kg/day, subcutaneous DZN 20 mg/kg/day, DZN plus FUC 100 mg/kg/day, or DZN plus FUC 200 mg/kg/day (each treatment was given daily for 4 weeks). Data analysis showed that DZN-intoxicated rats exhibited significantly higher (p < 0.05) serum levels of alanine transaminase, aspartate transaminase, alkaline phosphatase, urea, creatine, creatine kinase, creatine kinase-MB, lactate dehydrogenase, cholesterol, interleukin-6, and tumor necrosis factor-α, as well as lower levels of acetylcholinesterase, compared to control rats. In addition, DZN intoxication was associated with significantly higher (p < 0.05) cardiac, hepatic, and renal tissue concentrations of malondialdehyde and nitric oxide, as well as lower glutathione concentrations, and activities of glutathione peroxidase, superoxide dismutase, and catalase enzymes in comparison to control rats. Treatment with FUC (at 100 or 200 mg/kg/day) ameliorated all the aforementioned alterations in a dose-dependent manner. In conclusion, FUC from Laminaria japonicum ameliorated DZN-induced oxidative stress, pro-inflammatory effects, and injuries to the cardiac, hepatic, and renal tissues. These effects may be related to the antioxidant and anti-inflammatory effects of FUC.

Fucoidan alleviates microcystin-LR-induced hepatic, renal, and cardiac oxidative stress and inflammatory injuries in mice

Fucoidans (FUCs) are sulfated polysaccharides that have a wide range of bioactivities. The current study was designed to evaluate the antioxidant potential of FUC against microcystin-LR (MC-LR)-induced toxicity. Five mice groups (n = 8) were used. Group 1 received saline, Group 2 received oral FUC 100 mg/kg/day for 21 days, Group 3 received i.p. MC-LR 10 μg/kg/day for 14 days, Group 4 received MC-LR plus FUC 50 mg/kg/day, and Group 5 received MC-LR plus FUC 100 mg/kg/day. The present study showed that MC-LR administration was associated with significant increases (p < 0.01) in serum concentrations of hepatic (aspartate transferase, alanine transferase, and alkaline phosphatase), renal (urea and creatinine), and cardiac (creatine kinase and CK-MB) injury biomarkers, as well as serum lactate dehydrogenase, cholesterol, and pro-inflammatory cytokines (interleukins-1β and 6, and tumor necrosis factor-α), compared with the control group. Further, MC-LR-intoxicated mice exhibited significantly higher (p < 0.01) hepatic, renal, and cardiac tissue levels of malondialdehyde and nitric oxide, as well as lower tissue levels of reduced glutathione and activities of glutathione peroxidase, superoxide dismutase, and catalase enzymes in comparison with control mice. Treatment by FUC significantly ameliorated all the above-mentioned alterations in a dose-dependent manner with frequent restoration of the normal ranges in the FUC 100 mg/kg/day dose group. Moreover, treatment by FUC alone at 100 mg/kg/day was not associated with significant negative alterations in the assessed biochemical parameters, highlighting its safety at this dose. In conclusion, treatment by FUC significantly ameliorated organ injury, induced by MC-LR in mouse hepatic, renal, and cardiac tissues.

Production Inhibition and Excretion Promotion of Urate by Fucoidan from Laminaria japonica in Adenine-Induced Hyperuricemic Mice

This work aims to explore the amelioration of fucoidan on adenine-induced hyperuricemia and hepatorental damage. Adenine-induced hyperuricemic mice were administered with fucoidan, allopurinol and vehicle control respectively to compare the effects of the drugs. Serum uric acid, urea nitrogen, hepatorenal functions, activities of hepatic adenosine deaminase (ADA), xanthine oxidase (XOD), renal urate transporter 1 (URAT1) and NF-κB p65 were assessed. As the serum uric acid, urea nitrogen, creatinine, glutamic oxalacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) data demonstrated, the adenine not only mediated hepatorenal function disorders, but also induced hyperuricemia in mice. Meanwhile, activities of hepatic ADA and XOD were markedly augmented by adenine, and the expression of URAT1 was promoted, which was conducive to the reabsorption of urate. However, exposure to fucoidan completely reversed those adenine-induced negative alternations in mice, and the activities of hepatic ADA and XOD were recovered to the normal level. It was obvious that hepatic and renal functions were protected by fucoidan treatment. The expression of URAT1 was returned to normal, resulting in an increase of renal urate excretion and consequent healing of adenine-induced hyperuricemia in mice. Expression and activation of NF-κB p65 was promoted in kidneys of adenine treated mice, but suppressed in kidneys of mice exposed to fucoidan from Laminaria japonica or allopurinol. In conclusion, the fucoidan is a potential therapeutic agent for the treatment of hyperuricemia through dual regulatory roles on inhibition of hepatic metabolism and promotion of renal excretion of urate.

Pretreated fucoidan confers neuroprotection against transient global cerebral ischemic injury in the gerbil hippocampal CA1 area via reducing of glial cell activation and oxidative stress

Fucoidan is a sulfated polysaccharide derived from brown algae and possesses various beneficial activities, including antioxidant property. Previous studies have shown that fucoidan displays protective effect against ischemia-reperfusion injury in some organs. However, few studies have been reported regarding the protective effect of fucoidan against transient cerebral ischemic insults and its related mechanisms. Therefore, in this study, we examined the neuroprotective effect of fucoidan against transient global cerebral ischemia (tGCI), as well as underlying its mechanism using a gerbil model of tGCI which shows a loss of pyramidal neurons in the hippocampal cornu ammonis 1 (CA1) area after 5 min of tGCI. Fucoidan (25 and 50 mg/kg) was intraperitoneally administered once daily for 5 days before tGCI. Pretreatment with 50 mg/kg of fucoidan, not 25 mg/kg of fucoidan, attenuated tGCI-induced hyperactivity and protected CA1 pyramidal neurons from tGCI. In addition, pretreatment with 50 mg/kg of fucoidan inhibited activations of astrocytes and microglia in the ischemic CA1 area. Furthermore, pretreatment with 50 mg/kg of fucoidan significantly reduced the increased 4-hydroxy-2-noneal and superoxide anion radical production in the ischemic CA1 area and significantly increased expressions of SOD1 and SOD2 in the CA1 pyramidal neurons before and after tGCI. Additionally, treatment with diethyldithiocarbamate (an inhibitor of SODs) to the fucoidan-treated gerbils notably abolished the fucoidan-mediated neuroprotection. In brief, our present results indicate that fucoidan can effectively protect neurons from tGCI through attenuation of activated glial cells and reduction of oxidative stress via increase of SODs. Thus, we strongly suggest that fucoidan can be used as a useful preventive agent in cerebral ischemia.

The Sulfated Polysaccharides of Brown Algae and Products of Their Enzymatic Transformation as Potential Vaccine Adjuvants

The review is devoted to critical analysis of literature data, deal with effects and mechanisms of action of sulfated polysaccharides (PSs) – fucoidans from brown algae and products of their enzymatic transformation as potential adjuvants for enhancement of anti-infective and antitumor immune response. Numerous experimental data indicate that sulfated PSs demonstrate properties of vaccine adjuvants. Application perspectiveness of fucoidans as vaccine adjuvants is defined by their high biocompatibility, low-toxicity, safety and good tolerance by macroorganism, and also mechanisms of their immunomodulatory action. In particular, fucoidans are agonists of receptors of innate immunity and strong inducers of cellular and humoral immune response. At presenting the data of structural - functional interrelations, attention focused to the defining role of degree of sulfation, uronic acids and polyphenols contents, and also molecular mass in actions of fucoidans to innate and adaptive immunity cells. Insufficiency of literary data on studying of correlation of structure – physicochemical characteristics with adjuvanticities of the sulfated PSs, and also the problem of standardization of their active fractions are noted. Special attention is paid to the analysis of immunomodulatory and adjuvant activity of fucoidan oligosaccharides. Presented here results of experimental trial indicate that, despite the difficulties due to preparation of highly purified structurally characterized fractions and complex structure of fucoidans, these substances can be used as safe and effective adjuvants in vaccines against various pathogens including viruses, and also in antitumor vaccines.

Effect of Fucoidan on Anterior Cruciate Ligament Transection and Medial Meniscectomy Induced Osteoarthritis in High-Fat Diet-Induced Obese Rats

Osteoarthritis (OA) has become one of the most common disabilities among elders, especially in females. Obesity and mechanical injuries caused by OA are attributed to joint loading, cartilage disintegration, and bone loss, as well as inflammation. Pharmacological and non-pharmacological treatments can be used for OA. Fucoidan possesses several bioactivities such as antitumor, antiviral, anticoagulation, anti-obesity, and immunomodulation. This study aims to investigate the effect of fucoidan in surgery-induced OA on rats with diet-induced obesity. OA was induced by an anterior cruciate ligament transection and a partial medial meniscectomy (ACLT + MMx). The male SD rats were fed with a high-fat diet (HFD) for 4 weeks to induce obesity before causing ACLT + MMx to induce OA. The OA rats were administered with intragastric water or fucoidan in three different concentrations (32 mg/kg, 64 mg/kg, and 320 mg/kg) after the surgeries for 40 days with an HFD. We observed that the swelling in the knee joint was alleviated and the hind paw weight distribution was rectified after feeding them with fucoidan and that there was no significant effect on the weight gain and feed intake. Fucoidan administration indicated no significant variation on the high-density lipoprotein (HDL)-Cholesterol level, but it did indicate reduced plasma triglycerides and low-density lipoprotein (LDL)-Cholesterol levels. In addition, the weight-bearing tests showed an improvement in the fucoidan-treated group. Our results suggested that fucoidan may improve meniscal/ligamentous injury and obesity-induced OA.

Tilia tomentosa pectins exhibit dual mode of action on phagocytes as β-glucuronic acid monomers are abundant in their rhamnogalacturonans I

Silver linden flowers contain different pectins (PSI-PSIII) with immunomodulating properties. PSI is a low-esterified pectic polysaccharide with predominant homogalacturonan region, followed by rhamnogalacturonan I (RGI) with arabinogalactan II and RGII (traces) domains. PSII and PSIII are unusual glucuronidated RGI polymers. PSIII is a unique high molecular weight RGI, having almost completely O-3 glucuronidated GalA units with >30% O-3 acetylation at the Rha units. Linden pectins induced reactive oxygen species (ROS) and NO generation from non-stimulated whole blood phagocytes and macrophages, resp., but suppressed OZP-(opsonized zymosan particles)-activated ROS generation, LPS-induced iNOS expression and NO production. This dual mode of action suggests their anti-inflammatory activity, which is known for silver linden extracts. PSI expressed the highest complement fixation and macrophage-stimulating activities and was active on intestinal Peyer's patch cells. PSIII was active on non-stimulated neutrophils, as it induced ß₂-integrin expression, revealing that acetylated and highly glucuronidated RGI exhibits immunomodulating properties via phagocytes.

Renoprotective effect of low-molecular-weight sulfated polysaccharide from the seaweed Laminaria japonica on glycerol-induced acute kidney injury in rats

We investigated the renal protective effect of low-molecular-weight sulfated polysaccharide (LMWSP) fractions extracted from Laminaria japonica on glycerol-induced acute kidney injury (AKI) in rats. Glycerol treatment significantly increased serum creatinine (SCr) and blood urea nitrogen (BUN) levels. Intraperitoneal injection of LMWSP fractions markedly decreased SCr and BUN levels and reduced renal swelling. The fraction of 1.0M NaCl displayed the best renal protective effect of all fractions in attenuating AKI and maintaining blood glucose.

Anti-inflammatory activity of a sulfated polysaccharide isolated from an enzymatic digest of brown seaweed Sargassum horneri in RAW 264.7 cells

BACKGROUND/OBJECTIVES

Sargassum horneri is an edible brown alga that grows in the subtidal zone as an annual species along the coasts of South Korea, China, and Japan. Recently, an extreme amount of S. horneri moved into the coasts of Jeju Island from the east coast of China, which made huge economic and environmental loss to the Jeju Island. Thus, utilization of this biomass becomes a big issue with the local authorities. Therefore, the present study was performed to evaluate the anti-inflammatory potential of crude polysaccharides (CPs) extracted from S. horneri China strain in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells.

MATERIALS/METHODS

CPs were precipitated from S. horneri digests prepared by enzyme assistant extraction using four food-grade enzymes (AMG, Celluclast, Viscozyme, and Alcalase). The production levels of nitric oxide (NO) and pro-inflammatory cytokines, including tumor necrosis factor (TNF)-α and interleukin (IL)-1β were measured by Griess assay and enzyme-linked immunosorbent assay, respectively. The levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), nuclear factor (NF)-κB, and mitogen-activated protein kinases (MAPKs) were measured by using western blot. The IR spectrums of the CPs were recorded using a fourier transform infrared spectroscopy (FT-IR) spectrometer.

RESULTS

The polysaccharides from the Celluclast enzyme digest (CCP) showed the highest inhibition of NO production in LPS-stimulated RAW 264.7 cells (IC₅₀ value: 95.7 µg/mL). Also, CCP dose-dependently down-regulated the protein expression levels of iNOS and COX-2 as well as the production of inflammatory cytokines, including TNF-α and IL-1β, compared to the only LPS-treated cells. In addition, CCP inhibited the activation of NF-κB p50 and p65 and the phosphorylation of MAPKs, including p38 and extracellular signal-regulated kinase, in LPS-stimulated RAW 264.7 cells. Furthermore, FT-IR analysis showed that the FT-IR spectrum of CCP is similar to that of commercial fucoidan.

CONCLUSIONS

Our results suggest that CCP has anti-inflammatory activities and is a potential candidate for the formulation of a functional food ingredient or/and drug to treat inflammatory diseases.

Fucoidan reduces oxidative stress by regulating the gene expression of HO‑1 and SOD‑1 through the Nrf2/ERK signaling pathway in HaCaT cells

Fucoidan, a sulfated polysaccharide, is found in edible brown algae. In the present study, the molecular mechanisms of fucoidan against mild oxidative stress in human keratinocytes were investigated. The current study indicated that fucoidan significantly augmented the antioxidants heme oxygenase‑1 (HO‑1) and superoxide dismutase‑1 (SOD‑1) via the upregulation of nuclear factor erythroid 2‑related factor 2 (Nrf2) and markedly reduced the cytoplasmic stability of kelch‑like ECH‑associated protein 1. The upregulation of HO‑1 and SOD‑1 detected in the fucoidan‑treated cells may be responsible for the increased resistance to mild oxidative stress, indicating that fucoidan may augment the activities of antioxidant enzymes via stimulating Nrf2. This is the first report, to the best of our knowledge, to demonstrate that fucoidan attenuates oxidative stress by regulating the gene expression of SOD‑1 and HO‑1 via the Nrf2/extracellular signal‑regulated kinase signaling pathway.

Composition and anti-inflammatory effect of polysaccharides from Sargassum horneri in RAW264.7 macrophages

Sulfated polysaccharides extracted from brown marine algae have been shown to possess a variety of biological activities. We assessed the potential activity of the sulfated polysaccharide from Sargassum horneri (SP) and its isolated two major components (fraction-1 (F1) and fraction-2 (F2)), on anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. In the present study, analysis of polysaccharide chemical composition found that the constituent ratios of sulfate ester and fucose in SP and F1 were 4.95% vs 7.6%, and 4.48% vs 55.9%, respectively, suggesting that F1 may be a major sulfated polysaccharide containing fucose. Meanwhile, our findings demonstrated that TNF-α secretion levels were significantly (P<0.05) decreased by SP and F1 treatments in LPS-stimulated RAW264.7 cells in a dose-dependent manner under the preventive and repair experimental models. Pro-/anti-inflammatory (TNF-α/IL-10) cytokines secretion ratios by LPS-stimulated RAW264.7 macrophages were significantly (P<0.05) inhibited by SP and F1 treatments, particularly by F1 (at high dose, 200μg/ml). Moreover, NO release and iNOS activity were significantly (P<0.05) inhibited by F1. Collectively, the present study suggested that purified component, F1 from SP, had strong anti-inflammatory effects on LPS-stimulated RAW264.7 macrophages in the preventive and repair manner through inhibiting TNF-α secretion levels and NO release.

Fucoidan alleviates high-fat diet-induced dyslipidemia and atherosclerosis in ApoE(shl) mice deficient in apolipoprotein E expression

Fucoidan, a sulfated polysaccharide extracted from brown seaweeds, possesses many biological activities including anti-inflammatory and antioxidant activities. We aimed to investigate the protective effects of fucoidan on dyslipidemia and atherosclerosis in apolipoprotein E-deficient mice (ApoE(shl) mice) and to elucidate its molecular targets in the liver by using a transcriptomic approach. For 12weeks, ApoE(shl) mice were fed a high-fat diet (HFD) supplemented with either 1% or 5% fucoidan. Fucoidan supplementation significantly reduced tissue weight (liver and white adipose tissue), blood lipid, total cholesterol (TC), triglyceride (TG), non-high-density lipoprotein cholesterol (non-HDL-C) and glucose levels in HFD-fed ApoE(shl) mice but increased plasma lipoprotein lipase (LPL) activity and HDL-C levels. Fucoidan also reduced hepatic steatosis levels (liver size, TC and TG levels, and lipid peroxidation) and increased white adipose tissue LPL activity. DNA microarray analysis and quantitative reverse transcription-polymerase chain reaction demonstrated differential expression of genes encoding proteins involved in lipid metabolism, energy homeostasis and insulin sensitivity, by activating Ppara and inactivating Srebf1. Fucoidan supplementation markedly reduced the thickness of the lipid-rich plaque, lipid peroxidation and foaming macrophage accumulation in the aorta in HFD-fed ApoE(shl) mice. Thus, fucoidan supplementation appears to have anti-dyslipidemic and anti-atherosclerotic effects by inducing LPL activity and inhibiting the effects of inflammation and oxidative stress in HFD-fed ApoE(shl) mice.

Antitumor activities and immunomodulatory of rice bran polysaccharides and its sulfates in vitro

Polysaccharides purified from rice bran show antitumor activity against tumor cells, yet the mechanism of this action remains poorly understood. To address this issue, our study evaluated the effect of rice bran polysaccharides on mouse melanoma cell line B16, and Raw264.7 macrophages. Rice bran polysaccharides (RBP) failed to inhibit B16 cell growth in vitro. However, Raw264.7 macrophages treated by RBP enhancement of cytotoxic effects. The cytotoxicity was confirmed by the stimulation of nitric oxide (NO) production and tumor necrosis factor-α (TNF-α) secretion on Raw264.7 macrophages in a dose-dependent manner. RBP2, a fraction of RBP, notably enhanced the inhibition of B16 cells and boosted the immunepotentiation effect compared with RBP. To further enhance the inhibition of B16 cell growth, sulfated polysaccharides (SRBP) was derived using the chlorosulfonic acid-pyridine method. SRBP2 was found to suppress B16 cell growth, reduce B16 cell survival and stimulate NO and TNF-α production. However, SRBP2 displayed a cytotoxic effect on Raw264.7 macrophages. These results suggest that the antitumor activity of RBP and RBP2 is mediated mainly through the activation of macrophages. SRBP2 exerts its antitumor activity by inducing apoptosis in tumor cells and the secretion of NO and TNF-α.

Sulfated Seaweed Polysaccharides as Multifunctional Materials in Drug Delivery Applications

In the last decades, the discovery of metabolites from marine resources showing biological activity has increased significantly. Among marine resources, seaweed is a valuable source of structurally diverse bioactive compounds. The cell walls of marine algae are rich in sulfated polysaccharides, including carrageenan in red algae, ulvan in green algae and fucoidan in brown algae. Sulfated polysaccharides have been increasingly studied over the years in the pharmaceutical field, given their potential usefulness in applications such as the design of drug delivery systems. The purpose of this review is to discuss potential applications of these polymers in drug delivery systems, with a focus on carrageenan, ulvan and fucoidan. General information regarding structure, extraction process and physicochemical properties is presented, along with a brief reference to reported biological activities. For each material, specific applications under the scope of drug delivery are described, addressing in privileged manner particulate carriers, as well as hydrogels and beads. A final section approaches the application of sulfated polysaccharides in targeted drug delivery, focusing with particular interest the capacity for macrophage targeting.

Marine polysaccharides from algae with potential biomedical applications

There is a current tendency towards bioactive natural products with applications in various industries, such as pharmaceutical, biomedical, cosmetics and food. This has put some emphasis in research on marine organisms, including macroalgae and microalgae, among others. Polysaccharides with marine origin constitute one type of these biochemical compounds that have already proved to have several important properties, such as anticoagulant and/or antithrombotic, immunomodulatory ability, antitumor and cancer preventive, antilipidaemic and hypoglycaemic, antibiotics and anti-inflammatory and antioxidant, making them promising bioactive products and biomaterials with a wide range of applications. Their properties are mainly due to their structure and physicochemical characteristics, which depend on the organism they are produced by. In the biomedical field, the polysaccharides from algae can be used in controlled drug delivery, wound management, and regenerative medicine. This review will focus on the biomedical applications of marine polysaccharides from algae.

Intestinal absorption of fucoidan extracted from the brown seaweed, Cladosiphon okamuranus

The aim of this study was to examine the absorption of fucoidan through the intestinal tract. Fucoidan (0.1, 0.5, 1.0, 1.5 and 2.0 mg/mL) was added to Transwell inserts containing Caco-2 cells. The transport of fucoidan across Caco-2 cells increased in a dose-dependent manner up to 1.0 mg/mL. It reached a maximum after 1 h and then rapidly decreased. In another experiment, rats were fed standard chow containing 2% fucoidan for one or two weeks. Immunohistochemical staining revealed that fucoidan accumulated in jejunal epithelial cells, mononuclear cells in the jejunal lamina propria and sinusoidal non-parenchymal cells in the liver. Since we previously speculated that nitrosamine may enhance the intestinal absorption of fucoidan, its absorption was estimated in rats administered N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN) in their drinking water. Rats were fed 0.2% fucoidan chow (BBN + 0.2% fucoidan rats), 2% fucoidan chow (BBN + 2% fucoidan rats) and standard chow for eight weeks. The uptake of fucoidan through the intestinal tract seemed to be low, but was measurable by our ELISA method. Fucoidan-positive cells were abundant in the small intestinal mucosa of BBN + 2% fucoidan rats. Most fucoidan-positive cells also stained positive for ED1, suggesting that fucoidan was incorporated into intestinal macrophages. The uptake of fucoidan by Kupffer cells was observed in the livers of BBN + 2% fucoidan rats. In conclusion, the absorption of fucoidan through the small intestine was demonstrated both in vivo and in vitro.

Evaluation of adjuvant effects of fucoidan for improving vaccine efficacy

Fucoidan is a sulfated polysaccharide derived from brown seaweed, including Fucus vesiculosus. This compound is known to have immunostimulatory effects on various types of immune cells including macrophages and dendritic cells. A recent study described the application of fucoidan as a vaccine adjuvant. Vaccination is regarded as the most efficient prophylactic method for preventing harmful or epidemic diseases. To increase vaccine efficacy, effective adjuvants are needed. In the present study, we determined whether fucoidan can function as an adjuvant using vaccine antigens. Flow cytometric analysis revealed that fucoidan increases the expression of the activation markers major histocompatibility complex class II, cluster of differentiation (CD)25, and CD69 in spleen cells. In combination with Bordetella bronchiseptica antigen, fucoidan increased the viability and tumor necrosis factor-α production of spleen cells. Furthermore, fucoidan increased the in vivo production of antigen-specific antibodies in mice inoculated with Mycoplasma hyopneumoniae antigen. Overall, this study has provided valuable information about the use of fucoidan as a vaccine adjuvant.

Inhibitory activity of Sargassum hemiphyllum sulfated polysaccharide in arachidonic acid-induced animal models of inflammation

Sargassum hemiphyllum is a common plant found on the coasts of Taiwan; it has been used as an anti-inflammatory agent in traditional herbal medicine. This study aimed to evaluate the anti-inflammatory effects of S. hemiphyllum sulfated polysaccharide (SHSP) using two different mouse models. In both arachidonic acid-induced ear inflammatory gavage and paint models, SHSP decreased ear swelling and erythema. In addition, SHSP decreased the production of myeloperoxidase, nitric oxide, interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α in a dose-dependent manner. Histological examination results showed that SHSP reduced the area of neutrophilic infiltration in inflamed ears. The anti-inflammatory activity of SHSP has already been demonstrated in vitro. In this study, SHSP extracted from the same species of brown seaweed exhibited anti-inflammatory activity in both oral and topical applications in vivo. Therefore, SHSP may play a role in the treatment of inflammatory diseases.

Protective effect of polysaccharides from Sargassum horneri against oxidative stress in RAW264.7 cells

This study was designed to investigate chemical composition and the protective effects of polysaccharides isolated from Sargassum horneri against hydrogen peroxide (H2O2)-induced oxidative injury in RAW264.7 cells. Results showed that isolated polysaccharides (SHSc) and the major fractions (SHS1, SHS0.5) contained sulfate ester, and SHS1 was high fucose-containing sulfated polysaccharide. After preincubation with three isolated polysaccharides, RAW264.7 cells viability were significantly restored and decreased in cellular LDH release (P<0.05). SHS1 and SHS0.5 decreased intracellular ROS level, intracellular NO and malonic dialdehyde (MDA) level (P<0.05), restoring activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) (P<0.05), decreasing inducible nitric oxide synthase (iNOS) (P<0.05). Moreover, preincubation of SHS1 with RAW264.7 cells resulted in the increase of the gene expression level of endogenous antioxidant enzymes such as MnSOD and GSH-Px (P<0.05). These results clearly showed that SHSc and its fractions could attenuate H2O2-induced stress injury in RAW264.7 cells, and a similar efficiency in protecting RAW264.7 cells against H2O2-induced oxidative injury between SHS1 and Vitamin C. Taken together, our findings suggested that SHS1 can effectively protect RAW264.7 cells against oxidative stress by H2O2, which might be used as a potential natural antioxidant in the functional food and pharmaceutical industries.

Differential effects of fucoidans with low and high molecular weight on the viability and function of spleen cells

Fucoidan is an edible sulfated polysaccharide purified from brown algae that has multiple biological activities. However, the effects of fucoidans of different molecular weights on immune cells have not been determined. Thus, we treated spleen cells with low- and high-molecular-weight fucoidans (LMF and HMF, respectively). Viability assays demonstrated that HMF enhanced the viability and prevented the death of spleen cells. Furthermore, functional analysis revealed that HMF significantly increased the production of interferon-γ and nitric oxide. In contrast, LMF had low activity and was relatively toxic to spleen cells. Taken together, these results indicate that HMF makes the greatest contribution to the immunostimulatory activity of fucoidan mixtures. Additionally, fucoidans with different molecular weights may have different effects on the viability and function of immune cells. This study increases our understanding of fucoidans, and may broaden their use in the basic research and clinical fields.

Importance of sulfate groups for the macrophage-stimulating activities of ascophyllan isolated from the brown alga Ascophyllum nodosum

To investigate the role of sulfate groups on the macrophage-stimulating activities of ascophyllan, we prepared desulfated ascophyllan, and its effects on RAW264.7 cells were compared with native ascophyllan. The chemical structural analysis revealed that nearly 21% of sulfate groups of ascophyllan were removed by desulfation reaction, while no significant changes in the molecular mass and monosaccharide composition occurred after desulfation. NO- and cytokine- (TNF-α and G-CSF) inducing activities of the desulfated ascophyllan on RAW264.7 cells were significantly decreased as compared to native ascophyllan. Furthermore, the activity of desulfated ascophyllan to induce reactive oxygen species (ROS) generation from RAW264.7 cells decreased to almost negligible level. Our results suggest that the level of sulfate groups of ascophyllan is an important structural element responsible for the macrophage-stimulating activities. Probably, even the limited removal of sulfate residues sensitive to desulfation reaction may result in significant decrease in the bioactivities of ascophyllan.

Low molecular weight fucoidan from the sporophyll of Undaria pinnatifida suppresses inflammation by promoting the inhibition of mitogen-activated protein kinases and oxidative stress in RAW264.7 cells

The suppression of MAPK and oxidative stress could be an important anti-inflammatory mechanism. Fucoidan regulates MAPK activity in several cell lines. However, the mechanism for the anti-inflammatory and oxidative stress effect of low molecular weight fucoidan (LMWF) is poorly understood in RAW264.7 cells. The objective of this study was to examine the critical role of LMWF during LPS-induced inflammation in RAW264.7 cells. To determine the potential role of LMWF, we analysed pro-inflammatory cytokine, transcription factor, inflammation-related and oxidative stress related protein expression in vitro during LPS-induced inflammation in RAW264.7 cells. In this study, we demonstrated the anti-inflammatory effects of LMWF on LPS-induced inflammation in macrophages through the regulation of signalling pathways, including its effect on the attenuation of inflammatory cytokines, such as IL-1β, IL-1 and TNF-α, and the degradation of phosphorylated p38 MAPK, ERK1/2 and JNK. This study also demonstrates that LMWF might block NO as well as the expression of reactive oxygen species (ROS), which subsequently inhibits the iNOS and COX-2 expression induced by LPS. Based on these findings, we suggest that LMWF might have great potential as an external pathogen prevention and intervention agent for inflammatory diseases.

The potent activity of sulfated polysaccharide, ascophyllan, isolated from Ascophyllum nodosum to induce nitric oxide and cytokine production from mouse macrophage RAW264.7 cells: Comparison between ascophyllan and fucoidan

Ascophyllan isolated from the brown alga Ascophyllum nodosum is a fucose-containing sulfated polysaccharide, which has similar but distinct characteristic monosaccharide composition and entire chemical structure to fucoidan. In this study, we examined the effects of ascophyllan, fucoidan isolated from A. nodosum (A-fucoidan), and fucoidan from Sigma (S-fucoidan) as a representative fucoidan derived from other source (Fucus vesiculosus) on mouse macrophage cell line RAW264.7 cells. No significant cytotoxic effects of ascophyllan and A-fucoidan on RAW264.7 cells were observed up to 1000μg/ml, while S-fucoidan showed cytotoxic effect in a concentration-dependent manner. Ascophyllan induced extremely higher level of nitric oxide (NO) production from RAW264.7 cells than those induced by fucoidans over the concentration range tested (0-200μg/ml). Reverse transcription polymerase chain reaction (RT-PCR) and western blot analysis revealed that expression level of inducible NO synthase (iNOS) in ascophyllan-treated RAW264.7 cells was much higher than the levels detected in the cells treated with fucoidans. Furthermore, the activities of ascophyllan to induce the secretion of tumor necrosis factor-α (TNF-α) and granulocyte colony-stimulating factor (G-CSF) from RAW264.7 cells were also greater than those induced by fucoidans especially at lower concentration range (3.1-50μg/ml). The activities of ascophyllan to induce NO and cytokine production in mouse peritoneal macrophages were also stronger than those of fucoidans. Electrophoretic mobility shift assay (EMSA) using infrared dye labeled nuclear factor-kappa B (NF-κB) and AP-1 consensus sequences suggested that ascophyllan can strongly activate these transcription factors. Marked increase in the nuclear translocation of p65, and the phosphorylation and degradation of IκB-α were also observed in ascophyllan-treated RAW264.7 cells. Analysis using mitogen-activated protein (MAP) kinase inhibitors and western blot analysis suggested that c-Jun N-terminal kinase (JNK) and p38 MAP kinase are mainly involved in ascophyllan-induced NO production.

Antiproliferative activity of fucoidan was associated with the induction of apoptosis and autophagy in AGS human gastric cancer cells

Fucoidan, a sulfated polysaccharide purified from brown algae, possesses a variety of pharmacologic effects, including antiinflammatory, antioxidant, and anticancer properties; however, the underlying action mechanisms are not completely understood. This study investigated the possible mechanisms through which fucoidan exerts its antiproliferative action in cultured AGS human gastric adenocarcinoma cells. We found that fucoidan effectively inhibits the growth of AGS cells by inducing autophagy, as well as apoptosis. Apoptosis by fucoidan treatment was associated with the downregulation of antiapoptotic Bcl-2 and Bcl-xL expression, loss of mitochondrial membrane potential, activation of caspases, and concomitant degradation of poly-(ADP-ribose) polymerase protein. In addition, the morphological study indicated a characteristic finding of autophagy, such as the formation of autophagosomes in fucoidan-treated AGS cells. Furthermore, markers of autophagy, namely, the conversion of microtubule-associated protein light chain 3 (LC3)-I to LC3-II and increased beclin-1 accumulation, were observed. Overall, the present data suggest that fucoidan induces apoptotic and autophagic cell death, and both apoptotic and autophagic mechanisms contribute to the fucoidan-induced AGS cell death.

Anti-inflammatory effects of fucoidan through inhibition of NF-κB, MAPK and Akt activation in lipopolysaccharide-induced BV2 microglia cells

Fucoidan, a sulfated polysaccharide extracted from brown seaweed, displays a wide variety of internal biological activities; however, the cellular and molecular mechanisms underlying fucoidan's anti-inflammatory activity remain poorly understood. In this study, we investigated the inhibitory effects of fucoidan on production of lipopolysaccharide (LPS)-induced pro-inflammatory mediators in BV2 microglia. Our data indicated that fucoidan treatment significantly inhibited excessive production of nitric oxide (NO) and prostaglandin E₂ (PGE₂) in LPS-stimulated BV2 microglia. It also attenuated expression of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, monocyte chemoattractant protein-1 (MCP-1), and pro-inflammatory cytokines, including interleukin-1β (IL-1β) and tumor necrosis factor (TNF)-α. Moreover, fucoidan exhibited anti-inflammatory properties by suppression of nuclear factor-kappa B (NF-κB) activation and down-regulation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), and AKT pathways. These finding suggest that fucoidan may offer substantial therapeutic potential for treatment of neurodegenerative diseases that are accompanied by microglial activation.

Suppression by fucoidan of liver fibrogenesis via the TGF-β/Smad pathway in protecting against oxidative stress

Fucoidan, a sulfated polysaccharide extracted from various types of brown seaweed, possesses a wide range of pharmacological properties. We investigated the protective effect of fucoidan on dimethylnitrosamine-induced liver fibrogenesis in rats and its mechanism. Liver fibrosis was induced by injecting DMN (10 mg/kg, 3 times per week, I.P.) for 4 weeks, and fucoidan was simultaneously administered (100 mg/kg, 3 times per week, P.O.). The anti-oxidative and anti-inflammatory effects of fucoidan were observed by relative mediators. Fucoidan improved liver fibrosis by inhibiting the expression of transforming growth factor beta 1 (TGF-β(1))/Smad3 and the tissue inhibitor of metalloproteinase 1 (TIMP-1), and increasing the expression of metalloproteinase-9 (MMP-9). Fucoidan also significantly decreased the accumulation of the extracellular matrix (ECM) and collagen. These results suggest that fucoidan had an anti-fibrotic effect, which was exerted by inhibiting the TGF-β/Smad pathway, as well as anti-oxidative and anti-inflammatory effects.

Inhibition of Lipopolysaccharide (LPS)-induced inflammatory responses by Sargassum hemiphyllum sulfated polysaccharide extract in RAW 264.7 macrophage cells

Sargassum hemiphyllum , a kind of brown seaweed generally found along coastlines in East Asia, has long served as a traditional Chinese medicine. S. hemiphyllum has shown an anti-inflammatory effect; however, its mechanism has not been elucidated clearly. This study explored S. hemiphyllum for its biomedical effects. S. hemiphyllum sulfated polysaccharide extract (SHSP) was first prepared; the mouse macrophage cell line (RAW 264.7) activated by lipopolysaccharide (LPS) was used as a model system. The secretion profiles of pro-inflammatory cytokines, including IL-1β, IL-6, TNF-α, and NO, were found significantly to be reduced in 1-5 mg/mL dose ranges of SHSP treatments. RT-PCR analysis suggested SHSP inhibits the LPS-induced mRNA expressions of IL-β, iNOS, and COX-2 in a dose-dependent manner. At protein levels, Western blot analysis demonstrated a similar result for NF-κB (p65) in cytosol/nuclear. Taken together, the anti-inflammatory properties of SHSP may be attributed to the down-regulation of NF-κB in nucleus.

Chemical structures and bioactivities of sulfated polysaccharides from marine algae

Sulfated polysaccharides and their lower molecular weight oligosaccharide derivatives from marine macroalgae have been shown to possess a variety of biological activities. The present paper will review the recent progress in research on the structural chemistry and the bioactivities of these marine algal biomaterials. In particular, it will provide an update on the structural chemistry of the major sulfated polysaccharides synthesized by seaweeds including the galactans (e.g., agarans and carrageenans), ulvans, and fucans. It will then review the recent findings on the anticoagulant/antithrombotic, antiviral, immuno-inflammatory, antilipidemic and antioxidant activities of sulfated polysaccharides and their potential for therapeutic application.

In vivo anti-inflammatory effect of a sulfated polysaccharide isolated from the marine brown algae Lobophora variegata

CONTEXT

Lobophora variegata J.V. Lamouroux (Dictyotaceae) is a brown marine alga widely encountered in the Brazilian sea coast that presents high content of fucans. Anti-inflammatory effects of fucans are reported mostly in models in vitro, but little is known about its effects in vivo.

OBJECTIVE

To investigate vascular and cellular effects of a sulfated polysaccharide from the brown marine algae L. variegata (SP-Lv) in acute inflammatory models.

MATERIALS AND METHODS

SP-Lv was isolated by DEAE-cellulose and analyzed by agarose gel electrophoresis and evaluated for its inhibitory effect on paw edema, vascular permeability, leukocyte migration and peritoneal nitrite content induced by zymosan in Wistar rats. Anticoagulant activities and possible systemic toxicity were also evaluated.

RESULTS

SP-Lv inhibited the paw edema (120 min: 1.42 ± 0.11 vs. 0.95 ± 0.05 mL), plasma exudation (21.53 ± 0.62 vs. 11.96 ± 0.68 μg/g), nitrite content (4.42 ± 0.33 vs. 2.86 ± 0.003 μM) and leukocyte migration (5.15 ± 1.21 vs. 1.99 ± 0.16 cells/10(3) mL) induced by zymosan. SP-Lv and L-NAME reduced the paw edema (60-120 min) elicited by L-arginine. However, at 180 min SP-Lv effect was more accentuated and sustained until 240 min, while that of L-NAME was abolished. Similarly to indomethacin, SP-Lv inhibited the entire edema time-course induced by phospholipase A(2), except for the time of 60 min.

DISCUSSION AND CONCLUSION

The anti-edematogenic effect of SP-Lv seems to occur via inhibition of nitric oxide synthase and cyclooxygenase activities. These results suggest a potential applicability of polysaccharides from alga origin in acute inflammatory conditions.