Fucoidan prevent murine autoimmune diabetes via suppression TLR4-signaling pathways, regulation DC/Treg induced immune tolerance and improving gut microecology

Grafting of syringic acid onto fucoidan: Enhanced functional properties and therapeutic potential in histamine-induced liver injury

This study explores the grafting of syringic acid onto fucoidan and assesses the resultant graft's (FS) enhanced functional properties and therapeutic potential in a histamine-induced liver injury model. Utilizing a redox system of ascorbic acid and hydrogen peroxide, the grafting process achieved a grafting rate of 290.45 mg CAE/g, confirmed through UV-Vis spectroscopy, FT-IR spectroscopy, scanning electron microscopy, and thermogravimetric analysis. In vivo investigations using histamine-sensitive mice demonstrated that FS significantly mitigated histamine-induced damage, evidenced by improvements in body weight, organ index, and colon length. FS exhibited superior efficacy in restoring liver function indices (ALT, AST, ALP, GGT), enhancing antioxidant defenses (GSH, SOD), and reducing oxidative stress markers (MDA). Anti-inflammatory effects included reduced levels of pro-inflammatory cytokines (TNF-α, IL-6, IL-1β) and modulation of apoptosis-related proteins (BCl2, BAX). Additionally, FS upregulated key antioxidant genes in the Nrf2/KEAP1 pathway and downregulated inflammatory genes in the NF-κB pathway. Restoration of colonic tight junction proteins (ZO-1, Occludin, Claudin-1) and normalization of gut microbiota composition further underscored the therapeutic potential of FS. The study highlights the significant enhancement in functional properties of fucoidan through SA grafting, presenting FS as a promising candidate for developing functional foods and nutraceuticals aimed at preventing and mitigating liver damage and related disorders.

Fucoidan Supplementation Relieved Kidney Injury and Modulated Intestinal Homeostasis in Hyperuricemia Mice

Hyperuricemia is a metabolic disease characterized by an excessively increased level of uric acid (UA) in the blood, with an increasing prevalence and often associated with kidney damage. Gut microbiota and endotoxins of gut origin are key mediators in the gut-kidney axis that can cause renal impairment. The study was to reveal the protective effects of fucoidan on renal injury caused by hyperuricemia. The hyperuricemia model was established in C57BL/6J mice. After 10 weeks of fucoidan supplementation, we found that the levels of serum UA and creatinine were reduced, and the levels of renal tumor necrosis factor α, interleukin-18 (IL-18), IL-6, and interleukin-1β (IL-1β) were also decreased. Fucoidan inhibited the expressions of phosphorylated NF-κB p65, NLRP3, and activated caspase-1 in the kidneys. Fucoidan also regulated the expressions of Bcl-2 family proteins and decreased the activation of caspase-3, thereby exerting antiapoptotic effect. In addition, fucoidan could reduce the expressions of glucose transporter 9 (GLUT9) and urate transporter 1 (URAT1) proteins, thereby promoting the excretion of UA from the kidneys. Moreover, the protective effect of fucoidan on renal injury may be related to maintaining intestinal homeostasis. Fucoidan reduced serum lipopolysaccharide and improved the intestinal mucosal barrier function. Fucoidan decreased the abundances of Blautia, Muribaculaceae, and Dubosiella, and increased the abundances of Lactobacillus. High-dose fucoidan supplementation increased the content of butyric acid and enhanced the expression of ATP binding box transporter G2 (ABCG2) via the AMPK/AKT/CREB pathway in ileum. Conclusion: Fucoidan could protect against hyperuricemia-induced renal injury by inhibiting renal inflammation and apoptosis and modulating intestinal homeostasis in hyperuricemia mice.

Edible herbal source-derived polysaccharides as potential prebiotics: Composition, structure, gut microbiota regulation, and its related health effects

Recently, with changes in dietary patterns, there has been increased interest in the concept of food and medicine homology, which can help prevent disease development. This has led to a growing focus on the development of functional health foods derived from edible herbal sources. Polysaccharides, found in many edible herbal sources, are gaining popularity as natural ingredients in the production of functional food products. The gut microbiota can effectively utilize most edible herbal polysaccharides (EHPs) and produce beneficial metabolites; therefore, the prebiotic potential of EHPs is gradually being recognized. In this review, we comprehensively discuss the structural features and characterization of EHPs to promote gut microbiota regulation as well as the structure-activity relationship between EHPs and gut microbiota. As prebiotics, intestinal microbiota can use EHPs to indirectly produce metabolites such as short-chain fatty acids to promote overall health; on the other hand, different EHP structures possess some degree of selectivity on gut microbiota regulation. Moreover, we evaluate the functionality and mechanism underlying EHPs in terms of anticancer activity, antimetabolic diseases, anti-inflammatory activity, and anti-neuropsychiatric diseases.

Antiviral activity of a polysaccharide from Sargassum fusiforme against respiratory syncytial virus

This experiment examined the antiviral activity of polysaccharides from Sargassum fusiforme against respiratory syncytial virus (RSV) in vitro, including their mechanism of action and preliminary structural analysis. Four polysaccharides (SFP1, SFP2, SFP3, and SFP4) were purified from Sargassum fusiforme using a DEAE-52 cellulose column and an NW Super 150 gel column. CCK-8 and western blot were utilized to study the antiviral activities and mechanisms of the polysaccharides. Preliminary structural analysis was conducted using HPLC and NMR techniques. The findings suggest that SFP4 (120 kD) is an acidic chemical compound composed of 88.8 % total sugars, 0.13 % proteins, 10.8 % glucuronidic acids, and 21.1 % sulfates. It contains at least ten monosaccharides, primarily mannuronic acid and fucose. Among the four polysaccharides, SFP4 had the highest anti-RSV activity, with a therapeutic index (TI) exceeding 139. SFP4 exhibited noteworthy antiviral efficacy in both upper and lower respiratory cells that were infected, especially when administered as a prophylactic treatment 2 h in advance. Furthermore, SFP4 showed a dose-dependent antiviral effect, with the highest therapeutic index (TI > 320) observed at a concentration of 7.81 μg·mL-1 during the prophylactic phase. It was speculated that SFP4's antiviral effect is due to its ability to inhibit the attachment of G-proteins to cells.

Functions and mechanisms of nonstarch polysaccharides in monogastric animal production

As natural active ingredients, polysaccharides are a class of biological macromolecules that are ubiquitous in living organisms and have antibacterial, antioxidant, antitumor and intestinal flora-regulating functions. Nonstarch polysaccharides (NSPs) are an important class of polysaccharides that include both soluble and insoluble nonstarch polysaccharides. As green feed additives, NSPs play important roles in promoting immunity and disease resistance in the body, regulating the intestinal microbial balance and improving the quality of animal products. NSPs regulate cell signal transduction mainly via interactions between short-chain fatty acids and G protein-coupled receptors and inhibiting the histone deacetylation pathway to protect the intestinal barrier in animals. In this paper, the composition, physiological functions, and molecular mechanisms of the gut protective effects of NSPs are reviewed to provide a reference for the application of NSPs in monogastric animal production.

Fucoidan Improves D-Galactose-Induced Cognitive Dysfunction by Promoting Mitochondrial Biogenesis and Maintaining Gut Microbiome Homeostasis

Recent studies have indicated that fucoidan has the potential to improve cognitive impairment. The objective of this study was to demonstrate the protective effect and possible mechanisms of fucoidan in D-galactose (D-gal)-induced cognitive dysfunction. Sprague Dawley rats were injected with D-galactose (200 mg/kg, sc) and administrated with fucoidan (100 mg/kg or 200 mg/kg, ig) for 8 weeks. Our results suggested that fucoidan significantly ameliorated cognitive impairment in D-gal-exposed rats and reversed histopathological changes in the hippocampus. Fucoidan reduced D-gal-induced oxidative stress, declined the inflammation level and improved mitochondrial dysfunction in hippocampal. Fucoidan promoted mitochondrial biogenesis by regulating the PGC-1α/NRF1/TFAM pathway, thereby improving D-gal-induced mitochondrial dysfunction. The regulation effect of fucoidan on PGC-1α is linked to the upstream protein of APN/AMPK/SIRT1. Additionally, the neuroprotective action of fucoidan could be related to maintaining intestinal flora homeostasis with up-regulation of Bacteroidota, Muribaculaceae and Akkermansia and down-regulation of Firmicutes. In summary, fucoidan may be a natural, promising candidate active ingredient for age-related cognitive impairment interventions.

Therapeutic Potential of Fucoidan in Alleviating Histamine-Induced Liver Injury: Insights from Mice Studies

Histamine, a bioactive component in certain foods such as Huangjiu has been associated with liver injury and disrupted intestinal balance. This study explored the potential therapeutic effects of fucoidan (FCD) in mitigating histamine-induced imbalances in mice. We found that FCD mitigated liver injury, reducing transaminases, oxidative stress, and inflammation. Histological improvements included decreased cell infiltration and necrosis. FCD restored tight junction proteins and suppressed inflammation-related genes. Western blot analysis revealed FCD's impact on TGF-β1, p-AKT, AKT, CYP2E1, Grp78, NLRP3, Cas-1, and GSDMD. Gut LPS levels decreased with FCD. Gut microbiota analysis showed FCD's modulation effect, reducing Firmicutes and increasing Bacteroides. FCD demonstrates potential in alleviating histamine-induced liver injury, regulating inflammation, and influencing gut microbiota. Further research exploring higher dosages and additional parameters is warranted.

Seaweeds as Nutraceutical Elements and Drugs for Diabetes Mellitus: Future Perspectives

Diabetes mellitus is a chronic metabolic condition marked by high blood glucose levels caused by inadequate insulin synthesis or poor insulin use. This condition affects millions of individuals worldwide and is linked to a variety of consequences, including cardiovascular disease, neuropathy, nephropathy, and retinopathy. Diabetes therapy now focuses on controlling blood glucose levels through lifestyle changes, oral medicines, and insulin injections. However, these therapies have limits and may not successfully prevent or treat diabetic problems. Several marine-derived chemicals have previously demonstrated promising findings as possible antidiabetic medicines in preclinical investigations. Peptides, polyphenols, and polysaccharides extracted from seaweeds, sponges, and other marine species are among them. As a result, marine natural products have the potential to be a rich source of innovative multitargeted medications for diabetes prevention and treatment, as well as associated complications. Future research should focus on the chemical variety of marine creatures as well as the mechanisms of action of marine-derived chemicals in order to find new antidiabetic medicines and maximize their therapeutic potential. Based on preclinical investigations, this review focuses on the next step for seaweed applications as potential multitargeted medicines for diabetes, highlighting the bioactivities of seaweeds in the prevention and treatment of this illness.

Fucoidan alleviated autoimmune diabetes in NOD mice by regulating pancreatic autophagy through the AMPK/mTOR1/TFEB pathway

Objectives

The present study investigated the effect and its underlying mechanisms of fucoidan on Type 1 diabetes mellitus (T1DM) in non-obese diabetic (NOD) mice.

Materials and Methods

Twenty 7-week-old NOD mice were used in this study, and randomly divided into two groups (10 mice in each group): the control group and the fucoidan treatment group (600 mg/kg. body weight). The weight gain, glucose tolerance, and fasting blood glucose level in NOD mice were detected to assess the development of diabetes. The intervention lasted for 5 weeks. The proportions of Th1/Th2 cells from spleen tissues were tested to determine the anti-inflammatory effect of fucoidan. Western blot was performed to investigate the expression levels of apoptotic markers and autophagic markers. Apoptotic cell staining was visualized through TdT-mediated dUTP nick-end labeling (TUNEL).

Results

The results suggested that fucoidan ameliorated T1DM, as evidenced by increased body weight and improved glycemic control of NOD mice. Fucoidan down-regulated the Th1/Th2 cells ratio and decreased Th1 type pro-inflammatory cytokines' level. Fucoidan enhanced the mitochondrial autophagy level of pancreatic cells and increased the expressions of Beclin-1 and LC3B II/LC3B I. The expression of p-AMPK was up-regulated and p-mTOR1 was inhibited, which promoted the nucleation of transcription factor EB (TFEB), leading to autophagy. Moreover, fucoidan induced apoptosis of pancreatic tissue cells. The levels of cleaved caspase-9, cleaved caspase-3, and Bax were up-regulated after fucoidan treatment.

Conclusion

Fucoidan could maintain pancreatic homeostasis and restore immune disorder through enhancing autophagy via the AMPK/mTOR1/TFEB pathway in pancreatic cells.

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.

Influence of intestinal microecology in the development of gout or hyperuricemia and the potential therapeutic targets

Gout and hyperuricemia are common metabolic diseases. Patients with purine metabolism disorder and/or decreased uric acid excretion showed increased uric acid levels in the blood. The increase of uric acid in the blood leads to the deposition of urate crystals in tissues, joints, and kidneys, and causes gout. Recent studies have revealed that imbalance of the intestinal microecology is closely related to the occurrence and development of hyperuricemia and gout. Disorder of the intestinal flora often occurs in patients with gout, and high purine and high fructose may induce the disorder of intestinal flora. Short-chain fatty acids and endotoxins produced by intestinal bacteria are closely related to the inflammatory response of gout. This article summarizes the characteristics of intestinal microecology in patients or animal models with hyperuricemia or gout, and explores the relationship between intestinal microecology and gout or hyperuricemia from the aspect of the intestinal barrier, intestinal microorganisms, intestinal metabolites, and intestinal immune system. We also review the current status of hyperuricemia treatment by targeting intestinal microecology.

Engineered macromolecular Toll-like receptor agents and assemblies

Macromolecular Toll-like receptor (TLR) agents have been utilized as agonists and inhibitors in preclinical and clinical settings. These agents interface with the TLR class of innate immune receptors which recognize macromolecular ligands that are characteristic of pathogenic material. As such, many agents that have been historically investigated are derived from the natural macromolecules which activate or inhibit TLRs. This review covers recent research and clinically available TLR agents that are macromolecular or polymeric. Synthetic materials that have been found to interface with TLRs are also discussed. Assemblies of these materials are investigated in the context of improving stability or efficacy of ligands. Attention is given to strategies which modify or enhance the current agents and to future outlooks on the development of these agents.

Beneficial effects of seaweed-derived components on metabolic syndrome via gut microbiota modulation

Metabolic syndrome comprises a group of conditions that collectively increase the risk of abdominal obesity, diabetes, atherosclerosis, cardiovascular diseases, and cancer. Gut microbiota is involved in the pathogenesis of metabolic syndrome, and microbial diversity and function are strongly affected by diet. In recent years, epidemiological evidence has shown that the dietary intake of seaweed can prevent metabolic syndrome via gut microbiota modulation. In this review, we summarize the current in vivo studies that have reported the prevention and treatment of metabolic syndrome via seaweed-derived components by regulating the gut microbiota and the production of short-chain fatty acids. Among the surveyed related articles, animal studies revealed that these bioactive components mainly modulate the gut microbiota by reversing the Firmicutes/Bacteroidetes ratio, increasing the relative abundance of beneficial bacteria, such as Bacteroides, Akkermansia, Lactobacillus, or decreasing the abundance of harmful bacteria, such as Lachnospiraceae, Desulfovibrio, Lachnoclostridium. The regulated microbiota is thought to affect host health by improving gut barrier functions, reducing LPS-induced inflammation or oxidative stress, and increasing bile acid production. Furthermore, these compounds increase the production of short-chain fatty acids and influence glucose and lipid metabolism. Thus, the interaction between the gut microbiota and seaweed-derived bioactive components plays a critical regulatory role in human health, and these compounds have the potential to be used for drug development. However, further animal studies and human clinical trials are required to confirm the functional roles and mechanisms of these components in balancing the gut microbiota and managing host health.

Establishment of specific age-related macular degeneration relevant gene expression panels using porcine retinal pigment epithelium for assessing fucoidan bioactivity

PURPOSE

Age-related macular degeneration (AMD) is the leading cause of severe vision loss in industrialized nations. Important factors in pathogenesis are oxidative stress, inflammation, and, in the wet form of AMD, angiogenesis. Fucoidans, sulfated polysaccharides from brown algae, may have antioxidant, anti-inflammatory, and antiangiogenic effects. In this study, we established specific gene expression panels for inflammation, oxidative stress and angiogenesis in porcine retinal pigment epithelium (RPE), and investigated the effect of fucoidans on gene expression under different noxious agents.

METHODS

Primary porcine RPE cells cultured for at least 14 days were used. Using viability assays with tetrazolium bromide and real-time polymerase chain reaction of marker genes, positive controls were established for appropriate concentrations and exposure times of selected noxious agents (lipopolysaccharide (LPS), H₂O₂, CoCl₂). Three different AMD relevant gene panels specific for porcine RPE for inflammation, oxidative stress, and angiogenesis were established, and the influence of fucoidans (mainly Fucus vesiculosus; FV) on gene expression was investigated.

RESULTS

The following was shown by gene expression analyses: (1) Inflammation panel: Expression of 18 genes was affected under LPS (three days). Among them, LPS increased genes for interleukin 1 receptor 2, interleukin 8, cyclooxygenase-2 and vascular cell adhesion protein 1 expression which were diminished when FV was present. (2) Oxidative stress panel: Under stimulation of H₂O₂ (one day) and LPS (one day), expression of a total of 15 genes was affected. LPS induced increase in genes for superoxide dismutase-1, C-X-C motif chemokine 10, and CC chemokine ligand-5 expression was not detected when FV was present. (3) Angiogenesis panel: Under stimulation with CoCl₂ (three days) expression of six genes was affected, with the increase of genes for angiopoietin 2, vascular endothelial growth factor receptor-1, and follistatin being diminished when FV was present.

CONCLUSION

Three specific gene expression panels for porcine RPE that map genes for three of the major pathological factors of AMD, inflammation, oxidative stress, and angiogenesis, were established. Further, we demonstrated that fucoidans can reduce stress related gene activation in all of these three major pathogenic pathways. This study is another indication that fucoidans can act on different pathomechanisms of AMD simultaneously, which provides further evidence for fucoidans as a possible drug for treatment and prevention of AMD.

Bidirectional association between NAFLD and gallstone disease: a systematic review and meta-analysis of observational studies

BACKGROUND

Growing evidence indicates an association between NAFLD and gallstone disease (GD), while some does not support this. The aim of this meta-analysis was to evaluate the bidirectional association between NAFLD and GD.

RESEARCH DESIGN AND METHODS

Five electronic databases were searched from inception to May 2022. The association was analyzed based on the odds ratio (OR) and 95% confidence interval (CI) with Reviewer Manager 5.3.

RESULTS

Ten studies involving 284,512 participants met the criteria for GD predicting the onset of NAFLD. GD patients had a higher incidence of NAFLD (OR:1.48, CI:1.32-1.65, p < 0.00001), especially the incidence of moderate-to-severe NAFLD (OR:1.63; CI:1.40-1.79), with females at a higher risk (OR: 1.84; CI: 1.48-2.29). The inverse association was explored in eight studies involving 326,922 participants. The GD incidence in NAFLD patients was higher (OR:1.71, CI:1.63-1.79, p < 0.00001) and may increase due to female sex (OR: 4.18; CI: 1.21-14.37) and high BMI (OR: 1.80; CI: 1.36-2.56), compared with the non-NAFLD group. Besides, this bidirectional association was also confirmed in the Chinese population.

CONCLUSIONS

The findings supported positive concurrent and bidirectional relationships between NAFLD and GD. Therefore, clinicians may alert the possibility of NAFLD in patients with GD and vice versa.

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

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

Fucoidan in Pharmaceutical Formulations: A Comprehensive Review for Smart Drug Delivery Systems

Fucoidan is a heterogeneous group of polysaccharides isolated from marine organisms, including brown algae and marine invertebrates. The physicochemical characteristics and potential bioactivities of fucoidan have attracted substantial interest in pharmaceutical industries in the past few decades. These polysaccharides are characterized by possessing sulfate ester groups that impart negatively charged surfaces, low/high molecular weight, and water solubility. In addition, various promising bioactivities have been reported, such as antitumor, immunomodulatory, and antiviral effects. Hence, the formulation of fucoidan has been investigated in the past few years in diverse pharmaceutical dosage forms to be able to reach their site of action effectively. Moreover, they can act as carriers for various drugs in value-added drug delivery systems. The current work highlights the attractive biopharmaceutical properties of fucoidan being formulated in oral, inhalable, topical, injectable, and other advanced formulations treating life-quality-affecting diseases. Therefore, the present work points out the current status of fucoidan pharmaceutical formulations for future research transferring their application from in vitro and in vivo studies to clinical application and market availability.

Bioactivity of crude fucoidan extracted from Sargassum ilicifolium (Turner) C. Agardh

Fucoidan derived from brown algae has been shown to exhibit antitumor and antioxidant effects, so research on sulfated polysaccharides is increasing. The purpose of this study was to evaluate the characteristics and biological activity of fucoidan that was extracted at two temperatures (65 and 80 °C) from Sargassum ilicifolium (Turner) C. Agardh from five regions of Taiwan. The data show that there are significant differences in the yield, sulfate and total sugar content of Sargassum ilicifolium (Turner) C. Agardh grown in different locations in the same sea area. HPLC was used to determine the monosaccharide compositions of the fucoidan, which contains fucose, mannose, mannose, glucose and galactose and have a low molecular weight of less than 5 kDa, and then we will select the algae collected in Fugang, Taitung, for further biological activity research. The sampled Sargassum ilicifolium (Turner) C. Agardh at all five locations has a good polyphenol content, and it shows great DPPH radical scavenging activity, ABTS radical scavenging activity, Ferrous ion-chelating activity and Reducing power. The Sargassum ilicifolium (Turner) C. Agardh that was collected from Taitung Fugang is not toxic to L929 normal cells, but for A549 cancer cells and HCT116 cancer cells, it is known from the results that it has good cytotoxicity for A549 cancer cells. Thus, this study found that the Sargassum ilicifolium (Turner) C. Agardh that was collected from Taitung Fugang has significant antioxidant and anticancer properties.

Preclinical insights into fucoidan as a nutraceutical compound against perfluorooctanoic acid-associated obesity via targeting endoplasmic reticulum stress

Obesity is a growing global health problem; it has been forecasted that over half of the global population will be obese by 2030. Obesity is complicated with many diseases, such as diabetes and cardiovascular diseases, leading to an economic impact on society. Other than diet, exposure to environmental pollutants is considered a risk factor for obesity. Exposure to perfluorooctanoic acid (PFOA) was found to impair hepatic lipid metabolism, resulting in obesity. In this study, we applied network pharmacology and systematic bioinformatics analysis, such as gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, together with molecular docking, to investigate the targets of fucoidan for treating PFOA-associated obesity through the regulation of endoplasmic reticulum stress (ERS). Our results identified ten targets of fucoidan, such as glucosylceramidase beta (GBA), glutathione-disulfide reductase (GSR), melanocortin 4 receptor (MC4R), matrix metallopeptidase (MMP)2, MMP9, nuclear factor kappa B subunit 1 (NFKB1), RELA Proto-Oncogene, NF-KB Subunit (RELA), nuclear receptor subfamily 1 group I member 2 (NR1I2), proliferation-activated receptor delta (PPARD), and cellular retinoic acid binding protein 2 (CRABP2). GO and KEGG enrichment analyses highlighted their involvement in the pathogenesis of obesity, such as lipid and fat metabolisms. More importantly, the gene cluster is responsible for obesity-associated diseases and disorders, such as insulin resistance (IR), non-alcoholic fatty liver disease, and diabetic cardiomyopathy, via the control of signaling pathways. The findings of this report provide evidence that fucoidan is a potential nutraceutical product against PFOA-associated obesity through the regulation of ERS.

Beneficial effects of seaweed-derived dietary fiber: Highlights of the sulfated polysaccharides

Seaweeds and their derivatives are important bioresources of natural bioactive compounds. Nutritional studies indicate that dietary fibers derived from seaweeds have great beneficial potentials in human health and can be developed as functional food. Moreover, sulfated polysaccharides are more likely to be the main bioactive components which are widely distributed in various species of seaweeds including Phaeophyceae, Rhodophyceae and Chlorophyceae. The catabolism by gut microbiota of the seaweeds-derived dietary fibers (DFs) may be one of the pivotal pathways of their physiological functions. Therefore, in this review, we summarized the latest results of the physiological characteristics of seaweed-derived dietary fiber and highlighted the roles of sulfated polysaccharides in the potential regulatory mechanisms against disorders. Meanwhile, the effects of different types of seaweed-derived dietary fiber on gut microbiota were discussed. The analysis of the structure-function correlations and gut microbiota related mechanisms and will contribute to further better applications in food and biotherapeutics.

Understanding the mechanism underlying the anti-diabetic effect of dietary component: a focus on gut microbiota

Diabetes has become one of the biggest non-communicable diseases and threatens human health worldwide. The management of diabetes is a complex and multifaceted process including drug therapy and lifestyle interventions. Dietary components are essential for both diabetes management and health and survival of trillions of the gut microbiota (GM). Herein, we will discuss the relationship between diets and GM, the mechanism linking diabetes and gut dysbiosis, and the effects of dietary components (nutrients, phytochemicals, probiotics, food additives, etc.) on diabetes from the perspective of modulating GM. The GM of diabetic patients differs from that of health individuals and GM disorder contributes to the onset and maintenance of diabetes. Studies in humans and animal models consolidate that dietary component is a key regulator of diabetes and increasing evidence suggests that the alteration of GM plays a salient role in dietary interventions for diabetes. Given that diabetes is a major public health issue, especially that diabetes is linked with a high risk of mortality from COVID-19, this review provides compelling evidence for that targeting GM by dietary components is a promising strategy, and offers new insights into potential preventive or therapeutic approaches (dietary and pharmacological intervention) for the clinical management of diabetes.

Algal polysaccharides and derivatives as potential therapeutics for obesity and related metabolic diseases

The potential and challenges of algal polysaccharides and their derivatives as potential therapeutic agents for obesity and its related metabolic diseases.

Immunomodulatory effects of polysaccharides from marine algae for treating cancer, infectious disease, and inflammation

A significant rise in the occurrence and severity of adverse reactions to several synthetic drugs has fueled considerable interest in natural product-based therapeutics. In humans and animals, polysaccharides from marine microalgae and seaweeds have immunomodulatory effects. In addition, these polysaccharides may possess antiviral, anticancer, hypoglycemic, anticoagulant, and antioxidant properties. During inflammatory diseases, such as autoimmune diseases and sepsis, immunosuppressive molecules can serve as therapeutic agents. Similarly, molecules that participate in immune activation can induce immune responses against cancer and infectious diseases. We aim to discuss the chemical composition of the algal polysaccharides, namely alginate, fucoidan, ascophyllan, and porphyran. We also summarize their applications in the treatment of cancer, infectious disease, and inflammation. Recent applications of nanoparticles that are based on algal polysaccharides for the treatment of cancer and inflammatory diseases have also been addressed. In conclusion, these applications of marine algal polysaccharides could provide novel therapeutic alternatives for several diseases.

Low molecular weight fucoidan fraction LF2 improves metabolic syndrome via up-regulating PI3K-AKT-mTOR axis and increasing the abundance of Akkermansia muciniphila in the gut microbiota

Metabolic syndrome (MetS) is a pathological condition of a variety of metabolic abnormalities, which requires more urgent treatment and intervention. Fucoidan has been recommended as a supplement for health enhancement and disease management. Here, we first propose that the beneficial effect of low molecular weight fucoidan fraction LF2 in regulating metabolic syndrome induced by high-fat diet is similar to that of metformin, in terms of molecular mechanism and gut microbiota. The study found that LF2 significantly reduces fasting blood glucose, enhances insulin sensitivity and restores insulin homeostasis and lipid homeostasis. Moreover, LF2 reduced liver oxidative stress and inflammation, and improved hepatocyte steatosis. To decipher the mechanism behind this therapeutic effect, both the molecular mechanisms and gut microbiota were further analyzed. LF2 inhibited the activation of PI3K-Akt-mTOR axis and decreased the expression of SREBP-1c and PPARγ in liver. Interestingly, we found that LF2 and metformin have similar effects on gut microbiota, increasing the proportion of Verrucomicrobia and enriching the abundance of Akkermansia muciniphila, which is beneficial to host health. Collectively, our research clarifies the new application of fucoidan as a functional food for anti-MetS, and provides a new insight for fucoidan to exert systemic therapeutic effects from the perspective of molecular mechanism and gut microbiota.

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.

Metabolic regulation mechanism of fucoidan via intestinal microecology in diseases

The intestinal microecology is an extremely complex ecosystem consisting of gut microbiota, intestinal mucosa and the intestinal immune system. The intestinal microecology performs several important functions and is considered to be an essential 'organ' because it plays an important role in regulating human metabolism. Fucoidan contains a large amount of fucose and galactose residues, as well as various other neutral and acidic monosaccharides. Fucoidan particularly effects tumors, inflammatory bowel disease, diabetes and obesity by repairing intestinal mucosal damage and improving the intestinal microecological environment. It has been proposed that fucoidan could be used as a prebiotic agent for pharmaceutical and functional foods. In this review, we elucidate the potential mechanisms of the metabolic regulation of fucoidan with respect to the intestinal microecology of diseases. © 2021 Society of Chemical Industry.

Overview of key molecular and pharmacological targets for diabetes and associated diseases

Diabetes epidemiological quantities are demonstrating one of the most important communities' health worries. The essential diabetic difficulties are including cardiomyopathy, nephropathy, inflammation, and retinopathy. Despite developments in glucose decreasing treatments and drugs, these diabetic complications are still ineffectively reversed or prohibited. Several signaling and molecular pathways are vital targets in the new therapies of diabetes. This review assesses the newest researches about the key molecules and signaling pathways as targets of molecular pharmacology in diabetes and diseases related to it for better treatment based on molecular sciences. The disease is not cured by current pharmacological strategies for type 2 diabetes. While several drug combinations are accessible that can efficiently modulate glycemia and mitigate long-term complications, these agents do not reverse pathogenesis, and in practice, they are not established to modify the patient's specific molecular profiling. Therapeutic companies have benefited from human genetics. Genome exploration, which is agnostic to the information that exists, has revealed tens of loci that impact glycemic modulation. The physiological report has begun to examine subtypes of diseases, illustrate heterogeneity and propose biochemical therapeutic pathways.

Fucoidans and Bowel Health

Fucoidans are cell wall polysaccharides found in various species of brown seaweeds. They are fucose-containing sulfated polysaccharides (FCSPs) and comprise 5-20% of the algal dry weight. Fucoidans possess multiple bioactivities, including antioxidant, anticoagulant, antithrombotic, anti-inflammatory, antiviral, anti-lipidemic, anti-metastatic, anti-diabetic and anti-cancer effects. Dietary fucoidans provide small but constant amounts of FCSPs to the intestinal tract, which can reorganize the composition of commensal microbiota altered by FCSPs, and consequently control inflammation symptoms in the intestine. Although the bioactivities of fucoidans have been well described, there is limited evidence to implicate their effect on gut microbiota and bowel health. In this review, we summarize the recent studies that introduce the fundamental characteristics of various kinds of fucoidans and discuss their potential in altering commensal microorganisms and influencing intestinal diseases.

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.

Effects of Rhamnolipids on Growth Performance, Immune Function, and Cecal Microflora in Linnan Yellow Broilers Challenged with Lipopolysaccharides

This present study aimed to investigate the effects of rhamnolipids (RLS) on the growth performance, intestinal morphology, immune function, short-chain fatty acid content, and microflora community in broiler chickens challenged with lipopolysaccharides (LPS). A total of 450 broiler chickens were randomly allocated into three groups: basal diet with no supplement (NCO), basal diet with bacitracin (ANT), and basal diet with rhamnolipids (RLS). After 56 d of feeding, 20 healthy broilers were selected from each group, with half being intraperitoneally injected with lipopolysaccharides (LPS) and the other half with normal saline. Treatments with LPS were labelled LPS-NCO, LPS-ANT, and LPS-RLS, whereas treatments with normal saline were labelled NS-NCO, NS-ANT, and NS-RLS. LPS-challenged birds had lower jejunal villus height and higher crypt depth than unchallenged birds. LPS-RLS broilers had increased jejunal villus height and villus height/crypt depth ratio (V/C) but lower crypt depth than LPS-NCO. Dietary supplementation with RLS reduced the LPS-induced immunological stress. Compared with LPS-NCO, birds in LPS-RLS had lower concentrations of IL-1β, IL-6, and TNF-α. In LPS-challenged broilers, RLS and ANT increased the concentrations of IgA, IgM, and IgY compared with LPS-NCO. In LPS treatments, RLS enhanced the contents of acetic acid, butyrate, isobutyric acid, isovalerate, and valerate more than LPS-NCO birds. High-throughput sequencing indicated that RLS supplementation led to changes in the cecal microbial community of broilers. At the species level, Clostridium-sp-Marseille-p3244 was more abundant in NS-RLS than in NS-NCO broilers. In summary, RLS improved the growth performance and relative abundance of cecal microbiota and reduced the LPS-induced immunological stress in broiler chickens.

Effect of fucoidan on ethanol-induced liver injury and steatosis in mice and the underlying mechanism

BACKGROUND

Alcoholic liver disease is caused as a result of chronic alcohol consumption. In this study, we used an alcoholic liver injury mouse model to investigate the effect of fucoidan on ethanol-induced liver injury and steatosis and the underlying mechanisms.

METHODS

All mice were randomly divided into four groups: 1) control group, 2) model group, 3) diammonium glycyrrhizinate treatment group (200 mg/kg body weight), and 4) fucoidan treatment group (300 mg/kg body weight). Administration of ethanol for 8 weeks induced liver injury and steatosis in mice.

RESULTS

Fucoidan treatment decreased serum alanine aminotransferase activity, serum total cholesterol levels, and hepatic triglyceride levels, and improved the morphology of hepatic cells. Fucoidan treatment upregulated the expression of AMPKα1, SIRT1, and PGC-1α and inhibited the expression of ChREBP and HNF-1α. The levels of hepatic IL-6 and IL-18 were significantly decreased in the fucoidan group. Further, the levels of cytochrome P450-2E1 (CYP2E1), glucose-regulated protein (GRP) 78, and 3-nitrotyrosine (3-NT) in hepatic tissues were reduced in the fucoidan group as compared to the model group. Fucoidan significantly reversed the reduction of ileac Farnesoid X receptor (FXR) and fibroblast growth factor 15 (FGF15) levels induced by alcohol-feeding and reduced CYP7A1 (cholesterol 7α-hydroxylase) expression and total bile acid levels in the liver tissue. In addition, fucoidan regulated the structure of gut flora, with increased abundance of Prevotella and decreased abundance of Paraprevotella and Romboutsia as detected by 16S rDNA high-throughput sequencing.

CONCLUSION

Fucoidan inhibited alcohol-induced steatosis and disorders of bile acid metabolism in mice through the AMPKα1/SIRT1 pathway and the gut microbiota-bile acid-liver axis and protected against alcohol-induced liver injury in vivo.

Effects of Low Molecular Weight Fucoidan on the Proliferation and Apoptosis of Dysplastic Oral Keratinocyte and Oral Squamous Cell Carcinoma Cells

Oral squamous cell carcinoma (OSCC) is one of the most common malignant tumors with high incidence, rapid progress, and high mortality. There are still some defects in the treatments of OSCC, which seriously affect the quality of patients’ life. Therefore, it is urgent to find a safer and more effective treatment for OSCC. Low molecular weight fucoidan (LMWF) has various biological activities, such as antitumor, anti-inflammatory, and antithrombotic, and has no obvious side effects, but the effect of LMWF on OSCC has not been reported. In this study, the effects of LMWF on dysplastic oral keratinocyte (DOK) and OSCC cells SCC-9 and SCC-25 were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, TUNEL, colony formation, and wound healing assay, and the expression levels of Notch-1 and Jagged-1 treated with LMWF were detected by RT-qPCR. The results showed that LMWF could inhibit the proliferation and migration of DOK and SCC-9, and promote apoptosis. Low molecular weight fucoidan upregulated the expression of Notch-1 and Jagged-1 in DOK and SCC-9 cells. It indicated that LMWF might promote the apoptosis of DOK and SCC-9 by upregulating the Notch signal pathway, thereby inhibiting cell proliferation and playing an antitumor role. It provided theoretical basis to develop LMWF as a novel therapeutic drug for oral cancer.