In vitro and in vivo anti-inflammatory activities of a fucose-rich fucoidan isolated from Saccharina japonica

A critical review on pharmacological properties of sulfated polysaccharides from marine macroalgae

The marine ecosystem contains an assorted range of organisms, among which macroalgae stands out marine resources as an invaluable reservoir of structurally diverse bioactive compounds. Marine macroalgae are considered as primary consumers have gained more attention for their bioactive components. Sulfated polysaccharides (SPs) are complex polymers found in macroalgae that play a crucial role in their cell wall composition. This review consolidates high-tech methodologies employed in the extraction of macroalgal SPs, offering a valuable resource for researchers focuses in the pharmacological relevance of marine macromolecules. The pharmacological activities of SPs, focusing on their therapeutic action by encompassing diverse study models are summarized. Furthermore, in silico docking studies facilitates a comprehensive understanding of SPs interactions with their binding sites providing a valuable insight for future endeavors. The biological properties of algal SPs, along with a brief reference to mode of action based on different targets are presented. This review utilizes up-to-date research discoveries across various study models to elucidate the biological functions of SPs, focusing on their molecular-level mechanisms and offering insights for prospective investigations. Besides, the significance of SPs from seaweeds is highlighted, showcasing their potential beneficial applications in promoting human health. With promising biomedical prospects, this review explores the extensive uses and experimental evidence supporting the important roles of SPs in various fields.

Anti-inflammatory Fucoidan-ConA oral insulin nanosystems for smart blood glucose regulation

The smart oral administration Insulin device has the potential to improve glycemic management. It can reduce the risk of hypoglycemia associated with exogenous Insulin (INS) therapy while also avoiding many of the disadvantages associated with subcutaneous injections. Furthermore, diabetes mellitus (DM) is an endocrine illness characterized by inflammation, and it is critical to minimize the amount of inflammatory markers in diabetic patients while maintaining average blood glucose. In this study, a responsive nanosystem vitamin B12-Fucoidan-Concanavalin A (VB12-FU-ConA NPs) with anti-inflammatory action was developed for smart oral delivery of Insulin. Con A has high sensitivity and strong specificity as a glucose-responsive material. Fucoidan has anti-inflammatory, immunomodulatory, and hypoglycemic functions, and it can bind to Con A to form a reversible complex. Under high glucose conditions, free glucose competitively binds to Con A, which swells the nanocarrier and promotes Insulin release. Furthermore, in the low pH environment of the gastrointestinal tract, positively charged VB12 and anionic fucoidan bind tightly to protect the Insulin wrapped in the carrier, and VB12 can also bind to intestinal epithelial factors to improve transit rate, thereby promoting INS absorption. In vitro tests showed that the release of nanoparticles in hyperglycemic solutions was significantly higher than the drug release in normoglycemic conditions. Oral delivery of the nanosystems dramatically lowered blood glucose levels in type I diabetic mice (T1DM) during in vivo pharmacodynamics, minimizing the risk of hypoglycemia. Blood glucose levels reached a minimum of 8.1 ± 0.4 mmol/L after 8 h. Administering the nanosystem orally notably decreased the serum levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in diabetic mice. The nano delivery system can be degraded and metabolized in the intestinal tract after being taken orally, demonstrating good biodegradability and biosafety. In conclusion, the present study showed that VB12-FU-ConA nanocarriers are expected to be a novel system for rationalizing blood glucose.

Effect of Oligo-Fucoidan, Fucoxanthin, and L-Carnitine on Chronic Kidney Disease in Dogs: A Retrospective Study

Chronic kidney disease (CKD) commonly occurs in old dogs and cats. Oligo-fucoidan, fucoxanthin, and L-carnitine (OFL) compounds have a variety of reno-protective properties, including anti-inflammatory, anti-oxidative, and anti-fibrotic effects. Because their effects have not been investigated in naturally occurring canine CKD, we examined their reno-protective activities in dog patients with CKD. A total of 50 patients (OFL, n = 28; control, n = 22) were included in the analysis. A significant difference was identified in serum blood urea nitrogen and creatinine concentrations between the control and OFL groups at 6 months. No significant difference in electrolytes was found between the groups. A significant difference was identified in serum creatinine concentration between the control and OFL groups in azotemic (CKD IRIS stage 2-4) at 6 months. The OFL compounds showed a reno-protective effect, consistent with previous animal studies. The OFL combination can potentially delay the progression of canine CKD and be used as an adjuvant therapy.

DIAMMONIUM GLYCYRRHIZINATE INHIBITED INFLAMMATORY RESPONSE AND MODULATED SERUM METABOLISM IN POLY(I:C)-INDUCED PNEUMONIA MODEL MICE

ABSTRACT

Currently, the coronavirus disease 2019 (COVID-19) is becoming a serious threat to human health worldwide. Therefore, there is a great need to develop effective drugs against viral pneumonia. Diammonium glycyrrhizinate (DG), derived from Glycyrrhiza glabra L., has been demonstrated with significant anti-inflammatory properties. However, the therapeutic effects and mechanisms of DG on pneumonia require further clarification. In this study, mice received intratracheal injection of polyinosinic-polycytidylic acid (poly(I:C)) to induce pneumonia and were treated with DG. First, we evaluated the therapeutic potential of DG on poly(I:C)-induced pneumonia. Second, the anti-inflammatory and antioxidative activities and the impact of DG on the toll-like receptor 3 (TLR3) pathway were investigated. Third, the mechanism of DG was analyzed through untargeted metabolomics techniques. Our results revealed that DG intervention decreased permeability and reduced abnormal lung alterations in poly(I:C)-induced pneumonia model mice. DG intervention also downregulated cytokine levels in bronchoalveolar lavage fluid. Moreover, DG treatment inhibited the activation of TLR3 pathway. Furthermore, untargeted metabolomics analysis revealed that DG intervention could modulate serum metabolites involved in amino and nucleotide sugar metabolism, fructose and mannose metabolism, tyrosine metabolism, and phenylalanine, tyrosine, and tryptophan biosynthesis pathways. In conclusion, our study showed that DG could ameliorate poly(I:C)-induced pneumonia by inactivating the TLR3 pathway and affecting amino and nucleotide sugar, fructose and mannose metabolism, as well as tryptophan, phenylalanine, and tyrosine biosynthesis.

Effects of laminarin on growth performance and resistance against Pseudomonas plecoglossicida of large yellow croaker （Larimichthys crocea）

Laminarin (LAM) is widely used as an immunopotentiator in aquaculture, but its protective mechanism is still unclear. In this study, the effects of LAM on the growth performance and resistance against Pseudomonas plecoglossicida of large yellow croaker were studied in vitro and in vivo. The 42 d-feeding trial in large yellow croaker showed that dietary LAM could obviously promote the fish growth by improving the weight gain rate (WGR), specific growth rate (SGR), and feed conversion rate (FCR). Dietary LAM could also improve the survival rate of large yellow croakers subjected to P. plecoglossicida infection, and 500 mg/kg LAM produced the highest relative percent survival (RPS) of 35.00 %. LAM improved fish antioxidant level by enhancing serum total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activity, and reducing malondialdehyde (MDA) content. In addition, LAM also improved fish innate immunity by increasing serum acid phosphatase (ACP) and alkaline phosphatase (AKP) activities and complement 3 (C3) content under P. plecoglossicida infection. What is more, on 9 d post P. plecoglossicida challenge, LAM could significantly decrease the bacteria load in head kidneys, spleens and livers of fish, and the lowest bacterial load was found in 500 mg/kg LAM group. In vitro, LAM exerted a protective role against inactivated P. plecoglossicida-triggered inflammatory injury in primary head kidney macrophages (PKM) of large yellow croaker by recovering cell viability, suppressing NO production, and reversing pro-inflammatory cytokine expression (IL-1β, IL-6, and IL-8). All these findings therefore will provide insights into the protection mechanism of LAM in fish, facilitating its application in prevention and control of fish bacteriosis.

Structural characterization and anti-inflammatory effects of Enteromorpha prolifera polysaccharide-Fe/Zn complexes

The structure of polysaccharide has a great influence on its biological functions, and the chelation with metal ions is an effective way to change polysaccharide structural configuration. Herein, the structure of Enteromorpha prolifera polysaccharide (EP)-Fe/Zn complexes were characterized and the results showed that the iron (III) existed in form of β-FeOOH in EP-Fe (III) complex and the zinc (II) existed in form of C-O-Zn in EP-Zn (II) complex. Besides, the chelation with iron (III) or zinc (II) completely changed the apparent forms, and improved the thermal stability of EP. Furthermore, the anti-inflammatory activities of EP, EP-Fe and EP-Zn were proved by a lipopolysaccharide (LPS)-induced RAW264.7 macrophages model. The results showed that EP, EP-Fe (III) and EP-Zn (II) could decrease the mitochondrial membrane potential and the secretion of NO and cytokines induced by LPS. One of the anti-inflammatory mechanisms of EP, EP-Fe (III) and EP-Zn (II) was that they could inhibit mitogen-activated protein kinase (MAPK) signaling pathway via increasing its inhibitor content in cells. Collectively, the research suggested that the chelation with iron (III) or zinc (II) could change the structure and improve the anti-inflammatory activities of EP.

Fucoidan's Molecular Targets: A Comprehensive Review of Its Unique and Multiple Targets Accounting for Promising Bioactivities Supported by In Silico Studies

Fucoidan is a class of multifunctional polysaccharides derived from marine organisms. Its unique and diversified physicochemical and chemical properties have qualified them for potential and promising pharmacological uses in human diseases, including inflammation, tumors, immunity disorders, kidney diseases, and diabetes. Physicochemical and chemical properties are the main contributors to these bioactivities. The previous literature has attributed such activities to its ability to target key enzymes and receptors involved in potential disease pathways, either directly or indirectly, where the anionic sulfate ester groups are mainly involved in these interactions. These findings also confirm the advantageous pharmacological uses of sulfated versus non-sulfated polysaccharides. The current review shall highlight the molecular targets of fucoidans, especially enzymes, and the subsequent responses via either the upregulation or downregulation of mediators' expression in various tissue abnormalities. In addition, in silico studies will be applied to support the previous findings and show the significant contributors. The current review may help in understanding the molecular mechanisms of fucoidan. Also, the findings of this review may be utilized in the design of specific oligomers inspired by fucoidan with the purpose of treating life-threatening human diseases effectively.

Investigating anti-inflammatory and apoptotic actions of fucoidan concentrating on computational and therapeutic applications

Fucoidan is linked to a variety of biological processes. Differences in algae species, extraction, seasons, and locations generate structural variability in fucoidan, affecting its bioactivities. Nothing is known about fucoidan from the brown alga Dictyota bartayresiana, its anti-inflammatory properties, or its inherent mechanism. This study aimed to investigate the anti-inflammatory properties of fucoidan isolated from D. bartayresiana against LPS-induced RAW 264.7 macrophages and to explore potential molecular pathways associated with this anti-inflammatory effects. Fucoidan was first isolated and purified from D. bartayresiana, and then, MTT assay was used to determine the effect of fucoidan on cell viability. Its effects on reactive oxygen species (ROS) formation and apoptosis were also studied using the ROS assay and acridine orange/ethidium bromide fluorescence labelling, respectively. Molecular docking and molecular dynamics simulation studies were performed on target proteins NF-κB and TNF-α to identify the route implicated in these inflammatory events. It was observed that fucoidan reduced LPS-induced inflammation in RAW 264.7 cells. Fucoidan also decreased the LPS-stimulated ROS surge and was found to induce apoptosis in the cells. Molecular docking and molecular dynamics simulation studies revealed that fucoidan's potent anti-inflammatory action was achieved by obstructing the NF-κB signalling pathway. These findings were particularly noteworthy and novel because fucoidan isolated from D. bartayresiana had not previously been shown to have anti-inflammatory properties in RAW 264.7 cells or to exert its activity by obstructing the NF-κB signalling pathway. Conclusively, these findings proposed fucoidan as a potential pharmaceutical drug for inflammation-related diseases.

In Vitro Anti-Inflammatory Activity and Structural Characteristics of Polysaccharides Extracted from Lobonema smithii Jellyfish

Crude polysaccharides were extracted from the white jellyfish (Lobonema smithii) using water extraction and fractionated using ion-exchange chromatography to obtain three different fractions (JF1, JF2, and JF3). The chemical characteristics of four polysaccharides were investigated, along with their anti-inflammatory effect in LPS-stimulated RAW264.7 cells. All samples mainly consisted of neutral sugars with minor contents of proteins and sulphates in various proportions. Glucose, galactose, and mannose were the main constituents of the monosaccharides. The molecular weights of the crude polysaccharides and the JF1, JF2, and JF3 fractions were 865.0, 477.6, 524.1, and 293.0 kDa, respectively. All polysaccharides were able to decrease NO production, especially JF3, which showed inhibitory activity. JF3 effectively suppressed iNOS, COX-2, IL-1β, IL-6, and TNF-α expression, while IL-10 expression was induced. JF3 could inhibit phosphorylated ERK, JNK, p38, and NF-κB p65. Furthermore, flow cytometry showed the impact of JF3 on inhibiting CD11b and CD40 expression. These results suggest that JF3 could inhibit NF-κB and MAPK-related inflammatory pathways. The structural characterisation revealed that (1→3)-linked glucopyranosyl, (1→3,6)-linked galactopyranosyl, and (1→3,6)-linked glucopyranosyl residues comprised the main backbone of JF3. Therefore, L. smithii polysaccharides exhibit good anti-inflammatory activity and could thus be applied as an alternative therapeutic agent against inflammation.

Anti-Inflammatory Activity of Fucan from Spatoglossum schröederi in a Murine Model of Generalized Inflammation Induced by Zymosan

Fucans from marine algae have been the object of many studies that demonstrated a broad spectrum of biological activities, including anti-inflammatory effects. The aim of this study was to verify the protective effects of a fucan extracted from the brown algae Spatoglossum schröederi in animals submitted to a generalized inflammation model induced by zymosan (ZIGI). BALB/c mice were first submitted to zymosan-induced peritonitis to evaluate the treatment dose capable of inhibiting the induced cellular migration in a simple model of inflammation. Mice were treated by the intravenous route with three doses (20, 10, and 5 mg/kg) of our fucan and, 1 h later, were inoculated with an intraperitoneal dose of zymosan (40 mg/kg). Peritoneal exudate was collected 24 h later for the evaluation of leukocyte migration. Doses of the fucan of Spatoglossum schröederi at 20 and 10 mg/kg reduced peritoneal cellular migration and were selected to perform ZIGI experiments. In the ZIGI model, treatment was administered 1 h before and 6 h after the zymosan inoculation (500 mg/kg). Treatments and challenges were administered via intravenous and intraperitoneal routes, respectively. Systemic toxicity was assessed 6 h after inoculation, based on three clinical signs (bristly hair, prostration, and diarrhea). The peritoneal exudate was collected to assess cellular migration and IL-6 levels, while blood samples were collected to determine IL-6, ALT, and AST levels. Liver tissue was collected for histopathological analysis. In another experimental series, weight loss was evaluated for 15 days after zymosan inoculation and fucan treatment. The fucan treatment did not present any effect on ZIGI systemic toxicity; however, a fucan dose of 20 mg/kg was capable of reducing the weight loss in treated mice. The treatment with both doses also reduced the cellular migration and reduced IL-6 levels in peritoneal exudate and serum in doses of 20 and 10 mg/kg, respectively. They also presented a protective effect in the liver, with a reduction in hepatic transaminase levels in both doses of treatment and attenuated histological damage in the liver at a dose of 10 mg/kg. Fucan from S. schröederi presented a promising pharmacological activity upon the murine model of ZIGI, with potential anti-inflammatory and hepatic protective effects, and should be the target of profound and elucidative studies.

Fucoidan from Ericaria crinita Alleviates Inflammation in Rat Paw Edema, Downregulates Pro-Inflammatory Cytokine Levels, and Shows Antioxidant Activity

Fucoidans are sulfated polysaccharides detected mainly in the cell walls of brown seaweeds. Here, we examined the effects of single doses of fucoidan derived from Ericaria crinita (formerly Cystoseira crinita) on carrageenan-induced paw inflammation in rats. The serum levels of TNF-α, IL-1β, IL-6, and IL-10 of rats with LPS-induced systemic inflammation after 14 days of treatment were also evaluated. Subchronic treatment with fucoidan from E. crinita attenuated the inflammation during the late phase of the degraded carrageenan-induced paw edema (3rd to 5th hour after carrageenan injection) with peak activity at the 3rd hour after the application. Both doses of fucoidan from E. crinita (25 and 50 mg/kg bw) significantly decreased the levels of all tested pro-inflammatory cytokines (IL-1β, TNF-α, and IL-6) in the serum of rats with a model of system inflammation but had no effect on the anti-inflammatory cytokine IL-10. The results showed that the repeated application of fucoidan has a more prominent effect on the levels of some pro-inflammatory cytokines in serum in comparison to a single dose of the sulfated polysaccharide. This reveals the potential of E. crinita fucoidan as an anti-inflammatory agent. Furthermore, E. crinita fucoidan exhibited in vitro antioxidant capacity, determined by 2,2-diphenyl-1-picryl-hydrazyl radical scavenging and ferric reducing antioxidant power assays as follows: IC50 = 412 µg/mL and 118.72 μM Trolox equivalent/g, respectively.

In vitro anticancer potential of laminarin and fucoidan from Brown seaweeds

Marine seaweeds are rich source of polysaccharides present in their cell wall and are cultivated and consumed in China, Japan, Korea, and South Asian countries. Brown seaweeds (Phaeophyta) are rich source of polysaccharides such as Laminarin and Fucoidan. In present study, both the laminarin and fucoidan were isolated was yielded higher in PP (Padina pavonica) (4.36%) and STM (Stoechospermum marginatum) (2.32%), respectively. The carbohydrate content in laminarin and fucoidan was 86.91% and 87.36%, whereas the sulphate content in fucoidan was 20.68%. Glucose and mannose were the major monosaccharide units in laminarin (PP), however, fucose, galactose, and xylose in fucoidan (STM). FT-IR down peaks represent the carbohydrate of laminarin and fucoidan except, for 1219 cm-1, and 843 cm-1, illustrating the sulphate groups of fucoidan. The molecular weight of laminarin was 3-5 kDa, and the same for fucoidan was 2-6 kDa, respectively. Both the Fucoidan and Laminarin showed null cytotoxicity on Vero cells. Contrastingly, the fucoidan possess cytotoxic activity on human liver cancer cells (HepG2) (IC50-24.4 ± 1.5 µg/mL). Simultaneously, laminarin also shown cytotoxicity on human colon cancer cells (HT-29) (IC50-57 ± 1.2 µg/mL). The AO/EB (Acriding Orange/Ethidium Bromide) assay significantly resulted in apoptosis and necrosis upon laminarin and fucoidan treatments, respectively. The DNA fragmentation results support necrotic cancer cell death. Therefore, laminarin and fucoidan from PP and STM were potential bioactive compounds for anticancer therapy.

Physicochemical characterization and cosmetic application of kelp blanching water polysaccharides

Seaweeds account for half of global mariculture and have become a key player in bio-based industries. Seaweed process typically starts with hot water blanching that helps reduce postharvest quality deterioration but also generates large amounts of hydrothermal waste. This study aims to explore the feasibility of isolating water-soluble biopolymers from seaweed hydrothermal waste and their potential applications. Using Saccharina japonica (formerly Laminaria japonica) blanching water as example, 2.9 g/L of polymeric substances were efficiently isolated by ultrafiltration, implying biopolymer coproduction potential of ~5.8 kt from blanching wastewater of current kelp industry. Physicochemical characterizations revealed polysaccharidic nature of the biopolymers, with high contents of fucose, uronic acids and sulfate, showing distinct but also overlapping structural features with hot water-extracted kelp polysaccharides. The main fraction of the blanching water polymers after anion exchange chromatography was acidic polysaccharide, the major backbone residues of which were (1-4) linked mannopyranose, (1-4) linked gulopyranose and (1-2) linked fucopyranose while the branched residues were primarily 1,3,4-, 1,2,4- and 1,4,6-linked hexoses but also 1,3,4-fucopyranose. Furthermore, the polysaccharides were found to have a good compatibility in cosmetic creams with added cohesiveness and freshness, demonstrating the application potential of such natural biopolymers from currently underexplored seaweed blanching water.

Fucoidan from Saccharina japonica Alleviates Hyperuricemia-Induced Renal Fibrosis through Inhibiting the JAK2/STAT3 Signaling Pathway

Fucoidan is a native sulfated polysaccharide mainly isolated from brown seaweed, with diverse pharmacological activities, such as anti-inflammatory and antifibrosis. Hyperuricemia (HUA) is a common metabolic disease worldwide and mainly causes hyperuricemic nephropathy, including chronic kidney disease and end-stage renal fibrosis. The present study investigated the protective function of fucoidan in renal fibrosis and its pharmacological mechanism. The renal fibrotic model was established with the administration of potassium oxonate for 10 weeks. The protein levels of related factors were assessed in HUA mice by an enzyme-linked immunosorbent assay (ELISA) and western blotting. The results showed that fucoidan significantly reduced the levels of serum uric acid, blood urea nitrogen (BUN), α-smooth muscle actin (α-SMA), and collagen I, and improved kidney pathological changes. Furthermore, renal fibrosis had been remarkably elevated through the inhibition of the epithelial-to-mesenchymal transition (EMT) progression after fucoidan intervention, suppressing the Janus kinase 2 (JAK2) signal transducer and activator of transcription protein 3 (STAT3) signaling pathway activation. Together, this study provides experimental evidence that fucoidan may protect against hyperuricemia-induced renal fibrosis via downregulation of the JAK2/STAT3 signaling pathway.

Novel Fucoidan Pharmaceutical Formulations and Their Potential Application in Oncology-A Review

Fucoidan belongs to the family of marine sulfated, L-fucose-rich polysaccharides found in the cell wall matrix of various brown algae species. In the last few years, sulfated polysaccharides have attracted the attention of researchers due to their broad biological activities such as anticoagulant, antithrombotic, antidiabetic, immunomodulatory, anticancer and antiproliferative effects. Recently the application of fucoidan in the field of pharmaceutical technology has been widely investigated. Due to its low toxicity, biocompatibility and biodegradability, fucoidan plays an important role as a drug carrier for the formulation of various drug delivery systems, especially as a biopolymer with anticancer activity, used for targeted delivery of chemotherapeutics in oncology. Furthermore, the presence of sulfate residues with negative charge in its structure enables fucoidan to form ionic complexes with oppositely charged molecules, providing relatively easy structure-forming properties in combination with other polymers. The aim of the present study was to overview essential fucoidan characteristics, related to its application in the development of pharmaceutical formulations as a single drug carrier or in combinations with other polymers. Special focus was placed on micro- and nanosized drug delivery systems with polysaccharides and their application in the field of oncology.

Fucoidan from Fucus vesiculosus Inhibits Inflammatory Response, Both In Vitro and In Vivo

Fucoidan has been reported to present diverse bioactivities, but each extract has specific features from which a particular biological activity, such as immunomodulation, must be confirmed. In this study a commercially available pharmaceutical-grade fucoidan extracted from Fucus vesiculosus, FE, was characterized and its anti-inflammatory potential was investigated. Fucose was the main monosaccharide (90 mol%) present in the studied FE, followed by uronic acids, galactose, and xylose that were present at similar values (3.8-2.4 mol%). FE showed a molecular weight of 70 kDa and a sulfate content of around 10%. The expression of cytokines by mouse bone-marrow-derived macrophages (BMDMs) revealed that the addition of FE upregulated the expression of CD206 and IL-10 by about 28 and 22 fold, respectively, in respect to control. This was corroborated in a stimulated pro-inflammatory situation, with the higher expression (60 fold) of iNOS being almost completely reversed by the addition of FE. FE was also capable of reverse LPS-caused inflammation in an in vivo mouse model, including by reducing macrophage activation by LPS from 41% of positive CD11C to 9% upon fucoidan injection. Taken together, the potential of FE as an anti-inflammatory agent was validated, both in vitro and in vivo.

Structural characterization and anti-inflammatory activity of polysaccharides from Astragalus membranaceus

In this study, two homogeneous polysaccharides (APS-A1 and APS-B1) were isolated from Astragalus membranaceus by DEAE-52 cellulose and Sephadex G-100 column chromatography. Their chemical structures were characterized by molecular weight distribution, monosaccharide composition, infrared spectrum, methylation analysis, and NMR. The results revealed that APS-A1 (2.62 × 10⁶ Da) was a 1,4-α-D-Glcp backbone with a 1,4,6-α-D-Glcp branch every ten residues. APS-B1 (4.95 × 10⁶ Da) was a heteropolysaccharide composed of glucose, galactose, and arabinose (75.24:17.27:19.35). Its backbone consisted of 1,4-α-D-Glcp, 1,4,6-α-D-Glcp, 1,5-α-L-Araf and the sidechains composed of 1,6-α-D-Galp and T-α/β-Glcp. Bioactivity assays showed that APS-A1 and APS-B1 had potential anti-inflammatory activity. They could inhibit the production of inflammatory factors (TNF-α, IL-6, and MCP-1) in LPS-stimulated RAW264.7 macrophages via NF-κB and MAPK (ERK, JNK) pathways. These results suggested that the two polysaccharides could be potential anti-inflammatory supplements.

Anti-inflammatory properties of antiangiogenic fucoidan in retinal pigment epithelium cells

Age-related macular degeneration (AMD) is a multifactorial disease in which angiogenesis, oxidative stress and inflammation are important contributing factors. In this study, we investigated the anti-inflammatory effects of a fucoidan from the brown algae Fucus vesiculosus (FV) in primary porcine RPE cells. Inflammation was induced by lipopolysaccharide (LPS), polyinosinic:polycytidylic acid (Poly I:C), Pam2CSK4 (Pam), or tumor necrosis factor alpha (TNF-α). Cell viability was tested with thiazolyl blue tetrazolium bromide (MTT) test, barrier function by measuring transepithelial electric resistance (TEER), interleukin 6 (IL-6) and interleukin 8 (IL-8) secretion in ELISA, retinal pigment epithelium-specific 65 kDa protein (RPE65) and protectin (CD59) expression in Western blot, gene expression with quantitative polymerase chain reaction (qPCR) (IL6, IL8, MERTK, PIK3CA), and phagocytotic activity in a microscopic assay. FV fucoidan did not influence RPE cell viability. FV fucoidan reduced the Poly I:C proinflammatory cytokine secretion of IL-6 and IL-8. In addition, it decreased the expression of IL-6 and IL-8 in RT-PCR. LPS and TNF-α reduced the expression of CD59 in Western blot, this reduction was lost under FV fucoidan treatment. Also, LPS and TNF-α reduced the expression of visual cycle protein RPE65, this reduction was again lost under FV fucoidan treatment. Furthermore, the significant reduction of barrier function after Poly I:C stimulation is ameliorated by FV fucoidan. Concerning phagocytosis, however, the inflammation-induced reduction was not improved by FV fucoidan. FV and proinflammatory milieu did not relevantly influence phagocytosis relevant gene expression either. In conclusion, we show that fucoidan from FV can reduce proinflammatory stimulation in RPE induced by toll-like receptor 3 (TLR-3) activation and is of high interest as a potential compound for early AMD treatment.

Relevance of the Extraction Stage on the Anti-Inflammatory Action of Fucoidans

The anti-inflammatory action of fucoidans is well known, based on both in vitro and some in vivo studies. The other biological properties of these compounds, their lack of toxicity, and the possibility of obtaining them from a widely distributed and renewable source, makes them attractive novel bioactives. However, fucoidans’ heterogeneity and variability in composition, structure, and properties depending on seaweed species, biotic and abiotic factors and processing conditions, especially during extraction and purification stages, make it difficult for standardization. A review of the available technologies, including those based on intensification strategies, and their influence on fucoidan composition, structure, and anti-inflammatory potential of crude extracts and fractions is presented.

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.

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.

Characterization and therapeutic effect of Sargassum coreanum fucoidan that inhibits lipopolysaccharide-induced inflammation in RAW 264.7 macrophages by blocking NF-κB signaling

Inflammation is a complex host-protective response against harmful stimuli involving macrophage activation that results in secretion of inflammatory mediators, like nitric oxide (NO), pro-inflammatory cytokines, and prostaglandin E2 (PGE2). In this study, we evaluated fucoidan isolated using Viscozyme-assisted enzymatic extraction of Sargassum coreanum extract against lipopolysaccharide (LPS)-stimulated inflammation in RAW 264.7 macrophages and zebrafish model. Among the fucoidan fractions isolated using ion exchange chromatography, SCVF5 showed the highest sulfate and fucose contents based on chemical composition and monosaccharide analysis. Fourier-transform infrared (FT-IR) spectroscopy confirmed the presence of sulfate esters by the stretching vibrations of the SO peak at 1240 cm-1. SCVF5 showed anti-inflammatory effects by inhibiting NO and PGE2 generation in LPS-stimulated RAW 264.7 macrophages by downregulating inducible NO synthase and cyclooxygenase-2 expression. Treatment with SCVF5 suppressed pro-inflammatory cytokine production, such as TNF-α, (IL)-1β, and IL-6 by modulating the nuclear factor-kappa B signaling cascade in LPS-induced RAW 264.7 cells. Furthermore, in vivo results showed that SCVF5 can potentially downregulate LPS-induced toxicity, cell death, and NO production in LPS-induced zebrafish model. Collectively, these results suggest that S. coreanum fucoidan has remarkable anti-inflammatory activity in vitro and in vivo and may have potential applications in the functional food, cosmetic, and pharmaceutical industries.

Preparation, Characterization, and Anti-Adhesive Activity of Sulfate Polysaccharide from Caulerpa lentillifera against Helicobacter pylori

In the gastric mucosa, chronic inflammation due to Helicobacter pylori infection promotes gastrocarcinogenesis. Polysaccharides of Caulerpa lentillifera are well-characterized by broad antimicrobial activity and anti-inflammatory potentials. The present study was undertaken to investigate whether the low molecular sulfate polysaccharides of C. lentillifera (CLCP) exhibit any anti-adhesive activity against H. pylori. After a hot water extraction and purification process, two purified polysaccharide fractions (CLCP-1 and CLCP2) were studied based on structural characterization and bioactivity determination. The results implied that except for the molar ratio, CLCP-1 and CLCP-2 contain high sulfate, mannose, galactose, xylose, glucose levels, and low protein levels. The molecular weight and Fourier transform infrared spectroscopy (FT-IR) assays confirmed that CLCP-1 and CLCP-2 are sulfate polysaccharides with an average molecular weight (Mw) of 963.15 and 648.42 kDa, respectively. In addition, CLCP-1 and CLCP-2 exhibited stronger antibacterial activity against H. pylori. CLCP-1 and CLCP-2 could significantly promote macrophage proliferation and decrease the production of nitric oxide (NO) through downregulated expression of inducible nitric oxide synthase (iNOS). Meanwhile, CLCP-1 and CLCP-2 in this study showed efficiently protected gastric adenocarcinoma (AGS) cells against H. pylori with the inhibition of the IL-8/NF-κB axis. These findings suggested the effect of Caulerpa lentillifera polysaccharides on H. pylori adhesion, a potential supply of nutrients for eradication therapy through the reduction of cell count and inflammation.

Structural Characterization and In Vivo Anti-Inflammatory Activity of Fucoidan from Cystoseira crinita (Desf.) Borry

The aim of this study was to evaluate the effects of fucoidan isolated from C. crinita on histamine-induced paw inflammation in rats, and on the serum levels of TNF-α, IL-1β, IL-6, and IL-10 in rats during systemic inflammation response. The levels of TNF-α in a model of acute peritonitis in rats were also investigated. The isolated crude fucoidan was identified as a sulfated xylogalactofucan with high, medium, and low molecular weight fractions and a content of fucose of 39.74%, xylose of 20.75%, and galactose of 15.51%. Fucoidan from C. crinita showed better anti-inflammatory effects in the rat paw edema model, and this effect was present during all stages of the experiment. When compared to controls, a commercial fucoidan from F. vesiculosus, the results also displayed anti-inflammatory activity on the 60th, 90th, and 120th minute of the experiment. A significant decrease in serum levels of IL-1β in rats treated with both doses of C. crinita fucoidan was observed in comparison to controls, whereas TNF-α concentrations were reduced only in the group treated with fucoidan from C. crinita at the dose of 25 mg/kg bw. In the model of carrageenan-induced peritonitis, we observed a tendency of decrease in the levels of the pro-inflammatory cytokine TNF-α in peritoneal fluid after a single dose of C. crinita fucoidan, but this did not reach the statistical significance margin. Single doses of C. crinita fucoidan did not alter serum levels of the anti-inflammatory cytokine IL-10 in animals with lipopolysaccharide-induced systemic inflammation.

Prospects for the Use of Marine Sulfated Fucose-Rich Polysaccharides in Treatment and Prevention of COVID-19 and Post-COVID-19 Syndrome

Symptoms of the new coronavirus infection that appeared in 2019 (COVID-19) range from low fever and fatigue to acute pneumonia and multiple organ failure. The clinical picture of COVID-19 is heterogeneous and involves most physiological systems; therefore, drugs with a wide spectrum of mechanism of action are required. The choice of the treatment strategy for post-COVID-19 syndrome is still a challenge to be resolved. Polysaccharides with a high fucose content derived from seaweed and marine animals can form the basis for the subsequent development of promising agents for the treatment of COVID-19 and post-COVID-19 syndrome. This class of biopolymers is characterized by a variety of biological activities, including antiviral, antithrombotic, anticoagulant, hemo-stimulating, anti-inflammatory and immune-regulatory. Low molecular weight derivatives of these polysaccharides, as well as synthetic oligosaccharides with a sufficient amount and sulfation type may be considered as the most promising compounds due to their better bioavailability, which undoubtedly increases their therapeutic potential.

The effects of fucoidan as a dairy substitute on diarrhea rate and intestinal barrier function of the large intestine in weaned lambs

This paper explores the effects of fucoidan on the frequency of diarrhea, colon morphology, colon antioxidant status, cytokine content, short-chain fatty acids, and microflora of cecal contents in early weaned lambs in order to provide a reference for the intestinal health of young ruminants. Fucoidan is a natural active polysaccharide extracted from kelp and other large brown algae. It has many biological effects, such as improving immunity, nourishing the stomach and intestines, and anti-tumor properties. This study investigated the effects of fucoidan supplementation in milk replacer on the large intestine's ability to act as an intestinal barrier in weaned lambs. With six duplicate pens and one lamb per pen, a total of 24 weaned lambs (average starting body weight of 7.32 ± 0.37 kg) were randomly assigned to one of four milk replacer treatments. Four concentrations of fucoidan supplementation (0, 0.1, 0.3, and 0.6% dry matter intake) were employed to investigate the effects of fucoidan on cecal fermentation and colon microbial organization. The test period lasted 37 days (1 week before the test and 1 month after the test), and lamb cecal contents and colon organization were collected for examination. In addition, the fecal status of all lambs was observed and recorded daily, allowing us to calculate the incidence of diarrhea in weaned lambs. The findings demonstrated that fucoidan may significantly increase the concentration of short-chain fatty acids (propionic acid and butyric acid) in the cecal digesta of weaned lambs. In weaned lambs, 16S rDNA testing showed that fucoidan at 0.3-0.6% (dry matter intake) was beneficial for boosting the variety of the intestinal bacteria and modifying the relative abundance of a few bacterial strains. In addition, fucoidan enhanced colon antioxidant and immune functions and decreased the diarrhea rate to relieve weaning stress. This result demonstrates that milk replacer supplementation with fucoidan contributes to the improvement in the large intestinal health of weaned lambs.

High Molecular Weight Fucoidan Restores Intestinal Integrity by Regulating Inflammation and Tight Junction Loss Induced by Methylglyoxal-Derived Hydroimidazolone-1

Fucoidan from brown seaweeds has several biological effects, including preserving intestinal integrity. To investigate the intestinal protective properties of high molecular weight fucoidan (HMWF) from Undaria pinnatifida on intestinal integrity dysfunction caused by methylglyoxal-derived hydroimidazolone-1 (MG-H1), one of the dietary advanced-glycation end products (dAGEs) in the human-colon carcinoma-cell line (Caco-2) cells and ICR mice. According to research, dAGEs may damage the intestinal barrier by increasing gut permeability. The findings of the study showed that HMWF + MG-H1 treatment reduced by 16.8% the amount of reactive oxygen species generated by MG-H1 treatment alone. Furthermore, HMWF + MGH-1 treatment reduced MG-H1-induced monolayer integrity disruption, as measured by alterations in transepithelial electrical resistance (135% vs. 75.5%) and fluorescein isothiocyanate incorporation (1.40 × 10^-6 cm/s vs. 3.80 cm/s). HMWF treatment prevented the MG-H1-induced expression of tight junction markers, including zonula occludens-1, occludin, and claudin-1 in Caco-2 cells and mouse colon tissues at the mRNA and protein level. Also, in Caco-2 and MG-H1-treated mice, HMWF plays an important role in preventing receptor for AGEs (RAGE)-mediated intestinal damage. In addition, HMWF inhibited the nuclear factor kappa B activation and its target genes leading to intestinal inflammation. These findings suggest that HMWF with price competitiveness could play an important role in preventing AGEs-induced intestinal barrier dysfunction.

Two Ascophyllum nodosum Fucoidans with Different Molecular Weights Inhibit Inflammation via Blocking of TLR/NF-κB Signaling Pathway Discriminately

The present study aimed to clarify the potential mechanism of fucoidans found in Ascophyllum nodosum on anti-inflammation and to further explore the relationship between their structures and anti-inflammation. Two novel fucoidans named ANP-6 and ANP-7 and found in A. nodosum, were separated and purified and their structures were elucidated by HPGPC, HPLC, GC-MS, FT-IR, NMR, and by the Congo red test. They both possessed a backbone constructed of →2)-α-L-Fucp4S-(1→, →3)-α-L-Fucp2S4S-(1→, →6)-β-D-Galp-(1→, and →3,6)-β-D-Galp4S-(1→ with branches of →2)-α-L-Fucp4S-(1→ and →3)-β-D-Galp-(1→. Moreover, ANP-6 and ANP-7 could prevent the inflammation of the LPS-stimulated macrophages by suppressing the NO production and by regulating the expressions of iNOS, COX-2, TNF-α, IL-1β, IL-6, and IL-10. Their inhibitory effects on the TLR-2 and TLR-4 levels suggest that they inhibit the inflammation process via the blocking of the TLR/NF-κB signal transduction. In addition, ANP-6, with a molecular weight (63.2 kDa), exhibited stronger anti-inflammatory capabilities than ANP-7 (124.5 kDa), thereby indicating that the molecular weight has an influence on the anti-inflammatory effects of fucoidans.

Depolymerization of fucoidan with endo-fucoidanase changes bioactivity in processes relevant for bone regeneration

Fucoidans are polysaccharides from brown macroalgae, showing multiple bioactivities important for bone regeneration and bone health. However, the use of fucoidans in medical applications remains sparse due to the heterogeneity in their chemical properties and unclear structure-function relationships. Innovations in extraction techniques and post processing steps are needed to produce homogeneous fucoidan molecules with tailorable bioactivities. Here, we applied enzyme-assisted extraction coupled with enzymatic hydrolysis by Fhf1 fucoidanase to generate low (LMW) and medium molecular weight (MMW) fucoidans from Fucus evanescens. In contrast to the anti-angiogenic properties of the high molecular weight fucoidan, LMW and MMW no longer suppressed the production of pro-angiogenic molecules by bone stem cells, nor impaired the formation of prevascular structures in vitro. In contrast to LMW, a pro-inflammatory response of OEC was observed after treatment with high concentrations of MMW. Thus, fucoidanase hydrolysis could be a useful tool to tailor the bioactivity of fucoidans.

Anti-Inflammatory Effect of Sulfated Polysaccharides Isolated from Codium fragile In Vitro in RAW 264.7 Macrophages and In Vivo in Zebrafish

In this study, the anti-inflammatory activity of sulfated polysaccharides isolated from the green seaweed Codium fragile (CFCE-PS) was investigated in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and zebrafish. The results demonstrated that CFCE-PS significantly increased the viability of LPS-induced RAW 264.7 cells in a concentration-dependent manner. CFCE-PS remarkably and concentration-dependently reduced the levels of inflammatory molecules including prostaglandin E₂, nitric oxide (NO), interleukin-1 beta, tumor necrosis factor-alpha, and interleukin-6 in LPS-stimulated RAW 264.7 cells. In addition, in vivo test results indicated that CFCE-PS effectively reduced reactive oxygen species, cell death, and NO levels in LPS-stimulated zebrafish. Thus, these results indicate that CFCE-PS possesses in vitro and in vivo anti-inflammatory activities and suggest it is a potential ingredient in the functional food and pharmaceutical industries.

Protective effects of fucoidan against kidney diseases: Pharmacological insights and future perspectives

Chronic kidney disease (CKD) is a major public health concern that costs millions of lives worldwide. Natural products are consistently being explored for the development of novel therapeutics in the management of CKD. Fucoidan is a sulfated polysaccharide predominantly extracted from brown seaweed, which has multiple pharmacological benefits against various kidney problems, including chronic renal failure and diabetic nephropathy. This review aimed at exploring literature to update the renoprotective effects of fucoidan, to get an understanding of pharmacological mechanisms, and to highlight the recent progress of fucoidan-based therapeutic development. Evidence shows that fucoidan is effective against inflammation, oxidative stress, and fibrosis in kidney. Fucoidan targets multiple signaling systems, including Nrf2/HO-1, NF-κB, ERK and p38 MAPK, TGF-β1, SIRT1, and GLP-1R signaling that are known to be associated with CKD pathobiology. Despite these pharmacological prospects, the application of fucoidan is limited by its larger molecular size. Notably, low molecular weight fucoidan has shown therapeutic promise in some recent studies. However, future research is warranted to translate the outcome of preclinical studies into clinical use in kidney patients.

A new polysaccharide from Caulerpa chemnitzia induces molecular shifts of immunomodulation on macrophages RAW264.7

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CCP showed significant immunomodulatory effects.

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CCP raising the level of NO, TNF-α, and IL-6 of macrophages RAW264.7.

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Investigation on the metabolites and genes changes in CCP-induced RAW264.7.

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Potential immunostimulatory mechanism of CCP on RAW264.7 was elucidated.

Investigation on Caulerpa chemnitzia polysaccharides led to the finding of a new polysaccharide (CCP). The basic components of CCP were the total sugar (59.18% ± 0.57%), the uronic acids (36.75% ± 0.28%) and the sulfate (42.50% ± 0.42%), in total content. The physicochemical analysis revealed that CCP was a heteropolysaccharide with a molecular weight of 321.6 KDa, and composed of arabinose, fucose, glucose, mannose, galactose, xylose, fructose, ribose, glucuronic acid and galacturonic acid. The immunomodulatory assay showed that CCP played an important role in activating cell viability, the nitric oxide product and cytokines (IL-6 and TNF-α) secretion. Furthermore, the transcript-metabolic analysis displayed a total of 7692 differentially expressed genes (DEGs) and 95 differentially accumulated metabolites (DAMs), and revealed that CCP may play an immunomodulatory effect by activating NF-κB signaling pathway and arachidonic acid metabolism pathway. These findings will provide a basic understanding to further investigation of Caulerpa polysaccharides.

Application of fucoidan as treatment for cardiovascular and cerebrovascular diseases

Fucoidan is a marine polysaccharide. In recent years, fucoidan has attracted wide-scale attention from the pharmaceutical industries due to its diverse biological activities such as lipid-lowering, anti-atherosclerosis, and anticoagulation. This review clarifies the pharmacological effects of fucoidan in the treatment of human cardiovascular and cerebrovascular diseases. Fucoidan exerts a hypolipidemic effect by increasing the reverse transport of cholesterol, inhibiting lipid synthesis, reducing lipid accumulation, and increasing lipid metabolism. Inflammation, anti-oxidation, and so on have a regulatory effect in the process of atherosclerosis endothelial cells, macrophages, smooth muscle cells, and so on; fucoidan can not only prevent thrombosis through anticoagulation and regulate platelet activation, but also promote the dissolution of formed thrombi. Fucoidan has a neuroprotective effect, and also has a positive effect on the prognosis of the cardiovascular and cerebrovascular. The prospects of applying fucoidan in cardio-cerebrovascular diseases are reviewed to provide some theoretical bases and inspirations for its full-scale development and utilization.

Structural characterisation and bioactivity of polysaccharides isolated from fermented Dendrobium officinale

BACKGROUND

A polysaccharide was purified in this study, which was acquired from the fermentation broth of Dendrobium officinale Kimura et Migo. We aimed to investigate the structural features and bioactivity of this polysaccharide.

RESULTS

The polysaccharide was purified and the main polysaccharide fraction (i.e., DOP-1) was obtained. High-performance gel permeation chromatography (HPGPC) revealed that the molecular weight of DOP-1 was 447.48 kDa. Galactose, glucose and mannose were found to be present in DOP-1 via monosaccharide composition analysis, at a ratio of 1:1.79:6.71. Methylation and nuclear magnetic resonance spectroscopic analysis indicated that the backbone of DOP-1 was →4)-α-d-Glcp-(1 → 4)-α-d-Manp-(1 → 4)-α-d-Manp-(1 → 4,6)-α-d-Manp-(1→, and its repeating units were also preliminarily established. In vitro tests proved that DOP-1 not only protects RAW264.7 macrophages from the cytotoxic effect induced by lipopolysaccharide (LPS), but also inhibits cytokines (i.e., interleukin-6 and tumour necrosis factor-α) induced by LPS. DOP-1 demonstrated good scavenging activity in vitro toward 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals, as well as good metal chelating activity. Therefore, DOP-1 has potential antioxidant applications.

CONCLUSION

The structural characteristics of DOP-1 support its favourable biological activities and lay a strong foundation for further exploration of its structure-activity relationships and activity development, providing experimental data for the development and utilisation of fermentation broth of D. officinale. © 2021 Society of Chemical Industry.

Fucoidan from Sargassum hemiphyllum inhibits infection and inflammation of Helicobacter pylori

Having infected by Helicobacter pylori, the infection often leads to gastritis, gastric ulcer, or even gastric cancer. The disease is typically treated with antibiotics as they used to effectively inhibit or kill H. pylori, thus reducing the incidence of gastric adenoma and cancer to significant extent. H. pylori, however, has developed drug resistance to many clinically used antibiotics over the years, highlighting the crisis of antibiotic failure during the H. pylori treatment. We report here that the fucoidan from Sargassum hemiphyllum can significantly reduce the infection of H. pylori without developing to drug resistance. Fucoidan appears to be a strong anti-inflammation agent as manifested by the RAW264.7 cell model examination. Fucoidan can prohibit H. pylori adhesion to host cells, thereby reducing the infection rate by 60%, especially in post treatment in the AGS cell model assay. Mechanistically, fucoidan intervenes the adhesion of BabA and AlpA of H. pylori significantly lowering the total count of H. pylori and the level of IL-6 and TNF-α in vivo. These results all converge on the same fact that fucoidan is an effective agent in a position to protect the stomach from the H. pylori infection by reducing both the total count and induced inflammation.

Recent Advancements and Future Perspectives of Microalgae-Derived Pharmaceuticals

Microalgal cells serve as solar-powered factories that produce pharmaceuticals, recombinant proteins (vaccines and drugs), and valuable natural byproducts that possess medicinal properties. The main advantages of microalgae as cell factories can be summarized as follows: they are fueled by photosynthesis, are carbon dioxide-neutral, have rapid growth rates, are robust, have low-cost cultivation, are easily scalable, pose no risk of human pathogenic contamination, and their valuable natural byproducts can be further processed. Despite their potential, there are many technical hurdles that need to be overcome before the commercial production of microalgal pharmaceuticals, and extensive studies regarding their impact on human health must still be conducted and the results evaluated. Clearly, much work remains to be done before microalgae can be used in the large-scale commercial production of pharmaceuticals. This review focuses on recent advancements in microalgal biotechnology and its future perspectives.

Anti-Inflammatory Activity of Fucoidan Extracts In Vitro

Fucoidans are sulfated, complex, fucose-rich polymers found in brown seaweeds. Fucoidans have been shown to have multiple bioactivities, including anti-inflammatory effects, and are known to inhibit inflammatory processes via a number of pathways such as selectin blockade and enzyme inhibition, and have demonstrated inhibition of inflammatory pathologies in vivo. In this current investigation, fucoidan extracts from Undaria pinnatifida, Fucus vesiculosus, Macrocystis pyrifera, Ascophyllum nodosum, and Laminaria japonica were assessed for modulation of pro-inflammatory cytokine production (TNF-α, IL-1β, and IL-6) by human peripheral blood mononuclear cells (PBMCs) and in a human macrophage line (THP-1). Fucoidan extracts exhibited no signs of cytotoxicity in THP-1 cells after incubation of 48 h. Additionally, all fucoidan extracts reduced cytokine production in LPS stimulated PBMCs and human THP-1 cells in a dose-dependent fashion. Notably, the 5-30 kDa subfraction from Macrocystis pyrifera was a highly effective inhibitor at lower concentrations. Fucoidan extracts from all species had significant anti-inflammatory effects, but the lowest molecular weight subfractions had maximal effects at low concentrations. These observations on various fucoidan extracts offer insight into strategies that improve their efficacy against inflammation-related pathology. Further studies should be conducted to elucidate the mechanism of action of these extracts.

Therapeutic Potential of Selected Medicinal Plants Against Carrageenan Induced Inflammation in Rats

The current study was aimed to analyze the therapeutic effect of selected medicinal plants, that is, Curcuma longa, Zingiber officinale, Trigonella graceum-foenum, Nigella sativa, and Syzygium aromaticum against carrageenan-induced oxidative stress and inflammation in rats. Phytochemical analysis revealed the presence of diverse range of bioactives. IC₅₀ values for antioxidant assays including DPPH (2,2-diphenyl-1-picrylhydrazyl), metal chelating, ABTS scavenging (2, 2^′-Azino-Bis-3-Ethylbenzothiazoline-6-Sulfonic Acid), β-carotene bleaching, and H₂O₂ (hydrogen peroxide) scavenging ranged from 37-294, 71-243.4, 69.66-191.8, 98.92-228.5, and 82-234.9 μg/mL, respectively. All tested plants extract were found active against tested pathogenic microorganisms with lowest minimum inhibitory concentrations. Oral administration of tested plants extracts in different doses (250, 500, and 1000 mg/kg b. w) did not exhibit any toxicological effects on hemato-biochemical profile of treated rats in comparison to control group rats. Further, plants extract exhibited considerable anti-inflammatory activity in rats paw inflammation and decreased cellular infiltration to inflammatory site in dose dependent manner. Pretreatment of animals with tested plants extract (100, 200, and 400 mg/kg b. w.) caused significant alteration in total antioxidants, oxidants, and enzymes activities in paw tissue homogenate and the effect was more pronounced at higher concentration (400 mg/kg b. w.). Results showed that tested plants extract are rich source of diverse classes of phenolics and have therapeutic potential against oxidative stress and inflammation.

Structural diversity of fucoidans and their radioprotective effect

Fucoidans are biologically active sulfated polysaccharides of brown algae. They have a great structural diversity and a wide spectrum of biological activity. This review is intended to outline what is currently known about the structures of fucoidans and their radioprotective effect. We classified fucoidans according to their composition and structure, examined the structure of fucoidans of individual representatives of algae, summarized the available data on changes in the yields and compositions of fucoidans during algae development, and focused on information about underexplored radioprotective effect of these polysaccharides. Based on the presented in the review data, it is possible to select algae, which are the sources of fucoidans of desired structures and to determine the best time to harvest them. The use of high purified polysaccharides with established structures increase the value of studies of their biological effects and the determination of the dependence "structure - biological effect".

Anti-Inflammatory Mechanisms of Fucoidans to Treat Inflammatory Diseases: A Review

Fucoidans are sulfated heteropolysaccharides found in the cell walls of brown seaweeds (Phaeophyceae) and in some marine invertebrates. Generally, fucoidans are composed of significant amounts of L-fucose and sulfate groups, and lesser amounts of arabinose, galactose, glucose, glucuronic acid, mannose, rhamnose, and xylose. In recent years, fucoidans isolated from brown seaweeds have gained considerable attention owing to their promising bioactive properties such as antioxidant, immunomodulatory, anti-inflammatory, antiobesity, antidiabetic, and anticancer properties. Inflammation is a complex immune response that protects the organs from infection and tissue injury. While controlled inflammatory responses are beneficial to the host, leading to the removal of immunostimulants from the host tissues and restoration of structural and physiological functions in the host tissues, chronic inflammatory responses are often associated with the pathogenesis of tumor development, arthritis, cardiovascular diseases, diabetes, obesity, and neurodegenerative diseases. In this review, the authors mainly discuss the studies since 2016 that have reported anti-inflammatory properties of fucoidans isolated from various brown seaweeds, and their potential as a novel functional material for the treatment of inflammatory diseases.

Brown Algae Carbohydrates: Structures, Pharmaceutical Properties, and Research Challenges

Brown algae (Phaeophyceae) have been consumed by humans for hundreds of years. Current studies have shown that brown algae are rich sources of bioactive compounds with excellent nutritional value, and are considered functional foods with health benefits. Polysaccharides are the main constituents of brown algae; their diverse structures allow many unique physical and chemical properties that help to moderate a wide range of biological activities, including immunomodulation, antibacterial, antioxidant, prebiotic, antihypertensive, antidiabetic, antitumor, and anticoagulant activities. In this review, we focus on the major polysaccharide components in brown algae: the alginate, laminarin, and fucoidan. We explore how their structure leads to their health benefits, and their application prospects in functional foods and pharmaceuticals. Finally, we summarize the latest developments in applied research on brown algae polysaccharides.

Feeding Marine Polysaccharides to Alleviate the Negative Effects Associated with Weaning in Pigs

In young pigs, the challenge of weaning frequently leads to dysbiosis. This predisposes pigs to intestinal infection such as post-weaning diarrhoea (PWD). Dietary interventions to reduce PWD have centred on dietary inclusion of antibiotic growth promoters (AGP) and antimicrobials in pig diets, or high concentrations of zinc oxide. These interventions are under scrutiny because of their role in promoting multidrug resistant bacteria and the accumulation of minerals in the environment. There are significant efforts being made to identify natural alternatives. Marine polysaccharides, such as laminarin and fucoidan from macroalgae and chitosan and chito-oligosaccharides from chitin, are an interesting group of marine dietary supplements, due to their prebiotic, antibacterial, anti-oxidant, and immunomodulatory activities. However, natural variability exists in the quantity, structure, and bioactivity of these polysaccharides between different macroalgae species and harvest seasons, while the wide range of available extraction methodologies and conditions results in further variation. This review will discuss the development of the gastrointestinal tract in the pig during the post-weaning period and how feeding marine polysaccharides in both the maternal and the post-weaned pig diet, can be used to alleviate the negative effects associated with weaning.

Brown Seaweed Food Supplementation: Effects on Allergy and Inflammation and Its Consequences

Multiple health benefits have been ascribed to brown seaweeds that are used traditionally as dietary component mostly in Asia. This systematic review summarizes information on the impact of brown seaweeds or components on inflammation, and inflammation-related pathologies, such as allergies, diabetes mellitus and obesity. We focus on oral supplementation thus intending the use of brown seaweeds as food additives. Despite the great diversity of experimental systems in which distinct species and compounds were tested for their effects on inflammation and immunity, a remarkably homogeneous picture arises. The predominant effects of consumption of brown seaweeds or compounds can be classified into three categories: (1) inhibition of reactive oxygen species, known to be important drivers of inflammation; (2) regulation, i.e., in most cases inhibition of proinflammatory NF-κB signaling; (3) modulation of adaptive immune responses, in particular by interfering with T-helper cell polarization. Over the last decades, several inflammation-related diseases have increased substantially. These include allergies and autoimmune diseases as well as morbidities associated with lifestyle and aging. In this light, further development of brown seaweeds and seaweed compounds as functional foods and nutriceuticals might contribute to combat these challenges.

Molecular Mechanism of Anti-Inflammatory Activities of a Novel Sulfated Galactofucan from Saccharina japonica

Seaweed of Saccharina japonica is the most abundantly cultured brown seaweed in the world, and has been consumed in the food industry due to its nutrition and the unique properties of its polysaccharides. In this study, fucoidan (LJNF3), purified from S. japonica, was found to be a novel sulfated galactofucan, with the monosaccharide of only fucose and galactose in a ratio of 79.22:20.78, and with an 11.36% content of sulfate groups. NMR spectroscopy showed that LJNF3 consists of (1→3)-α-l-fucopyranosyl-4-SO₃ residues and (1→6)-β-d-galactopyranose units. The molecular mechanism of the anti-inflammatory effect in RAW264.7 demonstrated that LJNF3 reduced the production of nitric oxide (NO), and down-regulated the expression of MAPK (including p38, ENK and JNK) and NF-κB (including p65 and IKKα/IKKβ) signaling pathways. In a zebrafish experiment assay, LJNF3 showed a significantly protective effect, by reducing the cell death rate, inhibiting NO to 59.43%, and decreasing about 40% of reactive oxygen species. This study indicated that LJNF3, which only consisted of fucose and galactose, had the potential to be developed in the biomedical, food and cosmetic industries.

Recent development in zebrafish model for bioactivity and safety evaluation of natural products

The zebrafish is a species of freshwater fish, popular in aquariums and laboratories. Several advantageous features have facilitated zebrafish to be extensively utilized as a valuable vertebrate model in the lab. It has been well-recognized that natural products possess multiple health benefits for humans. With the increasing demand for natural products in the development of functional foods, nutraceuticals, and natural cosmetics, the zebrafish has emerged as an unprecedented tool for rapidly and economically screening and identifying safe and effective substances from natural products. This review first summarized the key factors for the management of zebrafish in the laboratory, followed by highlighting the current progress on the establishment and applications of zebrafish models in the bioactivity evaluation of natural products. In addition, the zebrafish models used for assessing the potential toxicity or health risks of natural products were involved as well. Overall, this review indicates that zebrafish are promising animal models for the bioactivity and safety evaluation of natural products, and zebrafish models can accelerate the discovery of novel natural products with potential health functions.

Purification and Structural Characterization of Sulfated Polysaccharides Derived from Brown Algae, Sargassum binderi: Inhibitory Mechanism of iNOS and COX-2 Pathway Interaction

Among the components derived from brown algae, anionic sulfated polysaccharides, which contain sulfated fucose as the major monosaccharide, exert significant biological activities. In this study, we purified and structurally characterized sulfated polysaccharides from brown algae, Sargassum binderi (S. binderi; SBPs), and evaluated their biological activity in vitro and in vivo. The SBPs were separated based on their charges and their biophysical properties were investigated according to their functional groups, structural features, and molecular weights using FTIR, NMR, and MALS. Among all the SBPs, Fraction 4 (SBP-F4), with an average molecular weight of 2.867 × 10⁵ g/mol, had the highest polysaccharide and sulfate contents (75.15 ± 0.25% and 24.08 ± 0.18%, respectively). The biological activities of SBP-F4 were investigated further in vitro and in vivo. Our results showed that SBP-F4 significantly suppressed the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins in LPS-activated macrophages. Moreover, in the LPS-treated zebrafish model, a significant decrease in cell death and NO production was observed. Collectively, these results show that SBPs not only exert protective effects against LPS-induced cytotoxicity but also inhibit the activation and anti-inflammatory activity of macrophages. Therefore, polysaccharides derived from S. binderi are potential anti-inflammatory agents for use in clinical settings.