Fucoidan Isolated from Saccharina japonica Inhibits LPS-Induced Inflammation in Macrophages via Blocking NF-κB, MAPK and JAK-STAT Pathways

Extraction, purification, structural characterization, and anti-inflammatory activity of a polysaccharide from Lespedeza formosa

A new acidic polysaccharide was extracted from Lespedeza Formosa (LF) using microwave-assisted extraction. After a progressive purification, Lespedeza Formosa polysaccharide (LFP-1) with 96.14 % purity and moderate molecular weight was obtained. Subsequently, LFP-1's structural analysis and in vitro anti-inflammatory experiments were performed. LFP-1 is composed of nine monosaccharides, mainly including 39.7 % glucose, 29.1 % galactose, and 19.9 % arabinose, with three branched chains of its structure. The diverse monosaccharides and branched chains provided the essential conditions for the anti-inflammatory effects of LFP-1, which diminished the release of nitric oxide (NO) and reactive oxygen species (ROS). And they altered the release of internal inflammatory factors in lipopolysaccharide (LPS)-treated macrophages. LFP-1 exerted intracellularly anti-inflammatory effects through the nuclear factor kappa-B (NF-κB) signal pathway. The discovery of LFP-1 opens up a new possibility for natural anti-inflammatory medicine.

Algae-derived polysaccharides and polysaccharide-based nanoparticles: A natural frontier in breast cancer therapy

Breast cancer is the second leading cause of cancer-related mortality among women worldwide, with its progression closely tied to the tumor microenvironment. To address the limitations and adverse effects of conventional therapies, algal polysaccharides and their nanoparticle derivatives have emerged as promising and effective anti-breast cancer agents. These bioactive compounds, derived from algae, are distinguished by their natural origin, non-toxicity, and significant medical relevance. Notably, algal polysaccharide-based nanoparticles exhibit advantageous properties such as hydrophilicity, biodegradability, prolonged circulation, and selective accumulation in tumor tissues. This review explores the relationship between the structural attributes of algal polysaccharides and their therapeutic efficacy. It further highlights the advantages of algal polysaccharide-based nanoparticles as drug delivery systems, particularly their potential in tumor targeting and overcoming multidrug resistance, thereby providing a theoretical foundation for their application in breast cancer treatment.

Critical role of Oas1g and STAT1 pathways in neuroinflammation: insights for Alzheimer's disease therapeutics

BACKGROUND

Alzheimer's disease (AD) has a significant impact on an individual's health and places a heavy burden on society. Studies have emphasized the importance of microglia in the progression and development of AD. Interferon responses and Interferon-stimulated genes (ISGs) significantly function in neuroinflammatory and neurodegenerative diseases involving AD. Therefore, further exploration of the relationship among microglia, ISGs, and neuroinflammation in AD is warranted.

METHODS

Microglia datasets from the GEO database were retrieved, along with additional microglia RNA-seq data from laboratory mice. Weighted Correlation Network Analysis was used on the training dataset to identify gene co-expression networks. Genes from the black module were intersected with interferon-stimulated genes, and differentially expressed genes (DEGs) were identified. Machine learning algorithms were applied to DEGs, and genes selected by both methods were identified as hub genes, with ROC curves used to evaluate their diagnostic accuracy. Gene Set Enrichment Analysis was performed to reveal functional pathways closely relating to hub genes. Microglia cells were transfected with siRNAs targeting Oas1g and STAT1. Total RNA from microglia cells and mouse brain tissues was extracted, reverse-transcribed, and analyzed via qRT-PCR. Proteins were extracted from cells, quantified, separated by SDS-PAGE, transferred to PVDF membranes, and probed with antibodies. Microglia cells were fixed, permeabilized, blocked, and stained with antibodies for STAT1, then visualized and photographed.

RESULTS

Bioinformatics and machine learning algorithms revealed that Oas1g was identified as a hub gene, with an AUC of 0.812. Enrichment Analysis revealed that Oas1g is closely associated with interferon-related pathways. Expression of Oas1g was validated in AD mouse models, where it was significantly upregulated after microglial activation. Knockdown experiments suggested siOas1g attenuated the effect of siSTAT1, and the expressions of STAT1 and p-STAT1 were elevated. siOas1g could reverse the effect of siSTAT1, indicating that Oas1g potentially regulates the ISGs through the STAT1 pathway.

CONCLUSION

We demonstrated that Oas1g was identified as a hub ISG in AD and can downregulate the activation of IFN-β and STAT1, reducing the expression of ISGs in neuroinflammation. Oas1g might potentially be a beneficial candidate for both prevention and treatment of AD.

Baicalein antagonises Rhopilema esculentum toxin-induced oxidative stress and apoptosis by modulating ROS-MAPK-NF-κB and inhibiting PLA2 activity

The toxicity of jellyfish Rhopilema esculentum (R. esculentum), an edible jellyfish that releases venom, has been controversial. The aim of this comprehensive study was to investigate the toxic effects of jellyfish tentacle extract (TE), which was evaluated in vivo and in vitro using ICR mice and RAW264.7 cells respectively. A library of natural compounds was screened for their ability to antagonize phospholipase A2 (PLA2) activity to identify potential protective agents and mechanisms. Of the 20 natural compounds evaluated, baicalein was found to have the strongest PLA2 antagonistic and cytoprotective effects. In vivo, experiments showed that TE at a dose of 7.02 mg/kg only resulted in a 50% survival rate in mice. However, pretreatment with 30 mg/kg baicalein significantly increased the survival rate to 75%, while also attenuating TE-induced cardiac and hepatic injuries, and ameliorating TE-induced elevations in LDH, CK-MB, and AST levels. In vitro studies found that baicalein reduced cellular ROS and MDA levels, increased the expression of CAT, SOD, and GSH/GSSG to enhance cellular antioxidant defenses against TE-induced oxidative stress, and also inhibited TE-induced upregulation of TNF-α, IL-6, IL-1β, and CXCL10. Importantly, baicalein was found to modulate dysregulated MAPK and NF-κB signaling pathways disrupted by TE. Taken together, these findings suggest that baicalein can antagonize R. esculentum toxin-induced oxidative stress and apoptosis by modulating ROS/MAPK/NF-κB, which provides a viable therapeutic strategy to control the deleterious effects of jellyfish stings and associated inflammation.

Effects of Seaweed Polysaccharide on the Growth and Physiological Health of Largemouth Bass, Micropterus salmoides

A seven-week trial was designed to evaluate the effects of dietary seaweed polysaccharide (SP) supplementation on the growth performance and physiological health of largemouth bass. The results reveal that the 0.05SP group showed the best growth performance. The mRNA expression levels of tor, 4ebp1, and igf1 genes were remarkably down-regulated in the 0.15SP and 0.2SP groups compared to the control group. The CAT activities were significantly increased in the 0.05SP and 0.1SP groups, and the GSH-Px activity was increased in the 0.15SP group. The expression of the immune response-related gene nfκb was significantly down-regulated in the 0.1SP group, and those of tnfα and il-8 were at the maximum in the control group. Moreover, the expression of il-10 in the 0.15SP and 0.2SP groups was significantly down-regulated. Furthermore, endoplasmic reticulum stress (ERS)-related expression of atf6 was the highest in the control group. Furthermore, the chopα and bax expression levels in the 0.15SP and 0.2SP groups were significantly down-regulated compared with other groups. In addition, the highest expression level of bcl-xl was observed in the 0.15SP group. Finally, the quadratic regression analysis of antioxidant, immune, and ERS core parameters (CAT, nf-κb, and bcl-xl) determined 0.06-0.11% to be the optimal SP supplemental level in largemouth bass diets.

Acute Treatment with Fucoidan Ameliorates Traumatic Brain Injury-Induced Neurological Damages and Memory Deficits in Rats: Role of BBB Integrity, Microglial Activity, Neuroinflammation, and Oxidative Stress

There is no acquiesced remedy for the treatment of traumatic brain injury (TBI)-associated impairment, especially cognitive decline. The first 24 h after TBI is a golden time for preventing the progress of the impairments. The present study aimed to examine the acute effects of fucoidan on neurological outcomes and memory performance and investigate its potential mechanisms in rats with TBI. Fucoidan (25, 50, and 100 mg/kg, i.p.) was injected immediately after TBI induction. Veterinary coma scale (VCS), brain edema, blood-brain barrier (BBB) integrity, passive avoidance memory and spatial memory, neuroplasticity, myeloperoxidase (MPO) activity, oxidative stress, and histological alteration were evaluated after TBI induction and fucoidan treatment. The findings revealed that TBI resulted in an enhancement in brain water content and BBB permeability and diminished the performance of passive avoidance memory and spatial memory. These were accompanied by long-term potentiation (LTP) suppression in the hippocampus and the prevention of activities of SOD, catalase, and GPx and enhancement of MPO activity, TNF-α, IL-6, and lipid peroxidation levels in the hippocampus as well as hippocampal neuronal loss. Fascinatingly, acute treatment of TBI rats with fucoidan especially in the higher doses (50 and 100 mg/kg) significantly ameliorated (p < 0.05) neurological outcomes of VCS, cerebral edema, BBB integrity, passive avoidance memory, spatial memory, LTP impairment, and oxidative-antioxidative balance. Also, fucoidan significantly ameliorated hippocampal neuronal loss, TNF-α and IL-6 levels, and MPO activity as an indicator of microglial activation. These outcomes imply that fucoidan can be a hopeful remedy for TBI-associated neuronal impairments. However, further research is necessary to endorse this issue.

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.

Colon-targeted self-assembled nanoparticles loaded with berberine double salt ameliorate ulcerative colitis by improving intestinal mucosal barrier and gut microbiota

Ulcerative colitis (UC) is a chronic, recurrent inflammatory bowel disease marked by disturbances in intestinal mucosal barriers, persistent inflammation, oxidative stress, and dysbiosis of the intestinal microbiota. Traditional treatments often fail to adequately address these issues, primarily targeting inflammation. To address these limitations, this study developed an innovative approach using self-assembled nanoparticles for oral administration that target colonic inflammation. Berberine hydrochloride and ursodeoxycholic acid were combined to form a double salt (BeU), enhancing solubility and encapsulation. An amphiphilic polymer (FU-PA) was created by esterifying fucoidan with palmitic acid. FU-PA/BeU nanoparticles were prepared using the nanoprecipitation method and further encapsulated in acid-resistant sodium alginate microspheres (FU-PA/BeU NPs@MS) for targeted delivery to colonic lesions. The aggregation rate of nanoparticles with mucus was significantly reduced to 59 % of free berberine, while the apparent permeability coefficient increased by 2.4 times. In vitro, FU-PA/BeU NPs effectively targeted inflammatory macrophages, reducing IL-6 and NO levels while increasing IL-10 level (to 42.5 %, 26.8 %, and 539 % of the LPS-treated group, respectively). Additionally, the ABTS and DPPH radical scavenging capabilities of FU-PA/BeU NPs were 177.8 % and 151.7 % of BeU, respectively. In dextran sulphate sodium-induced UC mice, oral FU-PA/BeU NPs@MS significantly improved epithelial and mucosal barriers, restored gut microbiota diversity, reduced inflammation and oxidative stress. Remarkably, the mean colon length in the FU-PA/BeU NPs@MS group was 1.2 times longer than that in the sulfasalazine group. These dual-targeted FU-PA/BeU NPs@MS show great potential for UC treatment.

Comprehensive evaluation of Flammulina velutipes residues polysaccharide based on in vitro digestion and human fecal fermentation

Flammulina velutipes residues (FVR) are the waste culture medium derived from the collection of Flammulina velutipes fruiting bodies, with an annual output that remains largely unexplored. The characteristics of digestion and fermentation of Flammulina velutipes residues polysaccharide (FVRP) are still relatively unknown. This study investigated the structure of the gut microbiota through 16 s rDNA gene sequencing and analyzed changes in short-chain fatty acid (SCFA) content via targeted metabolome analysis. The aim was to explore the prebiotic activity of FVRP based on a simulated digestion model combined with an in vitro anaerobic fermentation model. The results demonstrated that FVRP did not exhibit significant changes during in vitro digestion and fermentation but did enhance antioxidant activity. Furthermore, FVRP was found to rapidly reduce the pH value and increase SCFA production in the fermentation broth from lactic acid bacteria and human feces. Notably, FVRP altered the gut microbiota structure, significantly increasing the relative abundance of Firmicutes and Bacteroidota. Thus, FVRP could be considered a promising prebiotic food and feed additive that promotes the generation of short-chain fatty acids by modulating gut microbiota.

Bioactive Potential of Algae and Algae-Derived Compounds: Focus on Anti-Inflammatory, Antimicrobial, and Antioxidant Effects

Algae, both micro- and macroalgae, are recognized for their rich repository of bioactive compounds with potential therapeutic applications. These marine organisms produce a variety of secondary metabolites that exhibit significant anti-inflammatory, antioxidant, and antimicrobial properties, offering promising avenues for the development of new drugs and nutraceuticals. Algae-derived compounds, including polyphenols, carotenoids, lipids, and polysaccharides, have demonstrated efficacy in modulating key inflammatory pathways, reducing oxidative stress, and inhibiting microbial growth. At the molecular level, these compounds influence macrophage activity, suppress the production of pro-inflammatory cytokines, and regulate apoptotic processes. Studies have shown that algae extracts can inhibit inflammatory signaling pathways such as NF-κB and MAPK, reduce oxidative damage by activating Nrf2, and offer an alternative to traditional antibiotics by combatting bacterial infections. Furthermore, algae's therapeutic potential extends to addressing diseases such as cardiovascular disorders, neurodegenerative conditions, and cancer, with ongoing research exploring their efficacy in preclinical animal models. The pig model, due to its physiological similarities to humans, is highlighted as particularly suitable for validating the bioactivities of algal compounds in vivo. This review underscores the need for further investigation into the specific mechanisms of action and clinical applications of algae-derived biomolecules.

Structural analysis, anti-inflammatory activity of the main water-soluble acidic polysaccharides (AGBP-A3) from Panax quinquefolius L berry

Background

Panax quinquefolius L, widely recognized for its valuable contributions to medicine, has aroused considerable attention globally. Different from the extensive research has been dedicated to the root of P. quinquefolius, its berry has received relatively scant focus. Given its promising medicinal properties, this study was focused on the structural characterizations and anti-inflammatory potential of acidic polysaccharides from the P. quinquefolius berry.

Materials and methods

P. quinquefolius berry was extracted with hot water, precipitated by alcohol, separated by DEAE-52-cellulose column to give a series of fractions. One of these fractions was further purified via Sephadex G-200 column to give three fractions. Then, the main fraction named as AGBP-A3 was characterized by methylation analysis, NMR spectroscopy, etc. Its anti-inflammatory activity was assessed by RAW 264.7 cell model, zebrafish model and molecular docking.

Results

The main chain comprised of α-L-Rhap, α-D-GalAp and β-D-Galp, while the branch consisted mainly of α-L-Araf, β-D-Glcp, α-D-GalAp, β-D-Galp. The RAW264.7 cell assay results showed that the inhibition rates against IL-6 and IL-1β secretion at the concentration of 625 ng/mL were 24.83 %, 11.84 %, while the inhibition rate against IL-10 secretion was 70.17 % at the concentration of 312 ng/mL. In the zebrafish assay, the migrating neutrophils were significantly reduced in number, and their migration to inflammatory tissues was inhibited. Molecular docking predictions correlated well with the results of the anti-inflammatory assay.

Conclusion

The present study demonstrated the structure of acidic polysaccharides of P. quinquefolius berry and their effect on inflammation, providing a reference for screening anti-inflammatory drugs.

FGF21 Inhibits Hypoxia/Reoxygenation-induced Renal Tubular Epithelial Cell Injury by Regulating the PPARγ/NF-κB Signaling Pathway

As a predominant trigger of acute kidney injury, renal ischemia-reperfusion injury can cause permanent renal impairment, and the effective therapies are lacking. Fibroblast growth factor 21 (FGF21) plays a critical regulatory role in a variety of biological activities. This study was conducted to explore the functional of FGF21 in renal ischemia-reperfusion injury and to discuss the hidden reaction mechanism. To simulate renal ischemia-reperfusion injury in vitro, HK2 cells were induced by hypoxia/reoxygenation (H/R). The effects of FGF21 on H/R-induced HK2 cell viability were evaluated utilizing cell counting kit-8 (CCK-8). The levels of lactate dehydrogenase (LDH) and inflammatory cytokines in H/R-induced HK2 cells were assessed by means of LDH assay and enzyme-linked immunosorbent assay (ELISA). The levels of oxidative stress markers were appraised with corresponding assay kits and western blot was applied to estimate the expressions of oxidative stress-related proteins. The apoptosis of H/R-induced HK2 cells was assessed by virtue of flow cytometry. The expressions of apoptosis- and PPARγ/NF-κB signaling pathway-related proteins were evaluated with western blot. To discuss the reaction mechanism of PPARγ/NF-κB pathway in H/R-induced HK2 cells, PPARγ inhibitor GW9662 was employed to treat cells and the above experiments were then conducted again. This study found that FGF21 treatment inhibited the inflammatory response, oxidative stress and apoptosis in H/R-induced HK2 cells. Moreover, FGF21 regulated PPARγ/NF-κB signaling pathway and GW9662 partially reversed the impacts of FGF21 on the inflammatory response, oxidative stress and apoptosis in H/R-exposed HK2 cells. Collectively, FGF21 protected against H/R-induced renal tubular epithelial cell injury by regulating the PPARγ/NF-κB signaling pathway.

Green (Ulva fenestrata) and Brown (Saccharina latissima) Macroalgae Similarly Modulate Inflammatory Signaling by Activating NF-κB and Dampening IRF in Human Macrophage-Like Cells

Macroalgae are considered healthy food ingredients due to their content in numerous bioactive compounds, and the traditional use of whole macroalgae in Asian cuisine suggests a contribution to longevity. Although much information is available about the bioactivity of pure algal compounds, such as different polyphenols and polysaccharides, documentation of potential effects of whole macroalgae as part of Western diets is limited. Lifestyle- and age-related diseases, which have a high impact on population health, are closely connected to underlying chronic inflammation. Therefore, we have studied crude extracts of green (Ulva fenestrata) and brown (Saccharina latissima) macroalgae, as two of the most promising food macroalgae in the Nordic countries for their effect on inflammation in vitro. Human macrophage-like reporter THP-1 cells were treated with macroalgae extracts and stimulated with lipopolysaccharide (LPS) to induce inflammatory signalling. Effects of the macroalgae extracts were assessed on transcription factor activity of NF-κB and IRF as well as secretion and/or expression of the cytokines TNF-α and IFN-β and chemokines IL-8 and CXCL10. The crude macroalgae extracts were further separated into polyphenol-enriched and polysaccharide-enriched fractions, which were also tested for their effect on transcription factor activity. Interestingly, we observed a selective activation of NF-κB, when cells were treated with macroalgae extracts. On the other hand, pretreatment with macroalgae extracts selectively repressed IRF activation when inflammatory signaling was subsequently induced by LPS. This effect was consistent for both tested species as well as for polyphenol- and polysaccharide-enriched fractions, of which the latter had more pronounced effects. Overall, this is the first indication of how macroalgae could modulate inflammatory signaling by selective activation and subsequent repression of different pathways. Further in vitro and in vivo studies of this mechanism would be needed to understand how macroalgae consumption could influence the prevention of noncommunicable, lifestyle- and age-related diseases that are highly related to unbalanced inflammatory processes.

The Ocean's Pharmacy: Health Discoveries in Marine Algae

Non-communicable diseases (NCDs) represent a global health challenge, constituting a major cause of mortality and disease burden in the 21st century. Addressing the prevention and management of NCDs is crucial for improving global public health, emphasizing the need for comprehensive strategies, early interventions, and innovative therapeutic approaches to mitigate their far-reaching consequences. Marine organisms, mainly algae, produce diverse marine natural products with significant therapeutic potential. Harnessing the largely untapped potential of algae could revolutionize drug development and contribute to combating NCDs, marking a crucial step toward natural and targeted therapeutic approaches. This review examines bioactive extracts, compounds, and commercial products derived from macro- and microalgae, exploring their protective properties against oxidative stress, inflammation, cardiovascular, gastrointestinal, metabolic diseases, and cancer across in vitro, cell-based, in vivo, and clinical studies. Most research focuses on macroalgae, demonstrating antioxidant, anti-inflammatory, cardioprotective, gut health modulation, metabolic health promotion, and anti-cancer effects. Microalgae products also exhibit anti-inflammatory, cardioprotective, and anti-cancer properties. Although studies mainly investigated extracts and fractions, isolated compounds from algae have also been explored. Notably, polysaccharides, phlorotannins, carotenoids, and terpenes emerge as prominent compounds, collectively representing 42.4% of the investigated compounds.

Biomedical potency and mechanisms of marine polysaccharides and oligosaccharides: A review

Derived from bountiful marine organisms (predominantly algae, fauna, and microorganisms), marine polysaccharides and marine oligosaccharides are intricate macromolecules that play a significant role in the growth and development of marine life. Recently, considerable attention has been paid to marine polysaccharides and marine oligosaccharides as auspicious natural products due to their promising biological attributes. Herein, we provide an overview of recent advances in the miscellaneous biological activities of marine polysaccharides and marine oligosaccharides that encompasses their anti-cancer, anti-inflammatory, antibacterial, antiviral, antioxidant, anti-diabetes mellitus, and anticoagulant properties. Furthermore, we furnish a concise summary of the underlying mechanisms governing the behavior of these biological macromolecules. We hope that this review inspires research on marine polysaccharides and marine oligosaccharides in medicinal applications while offering fresh perspectives on their broader facets.

L-fucose and fucoidan alleviate high-salt diet-promoted acute inflammation

Excessive salt intake is a widespread health issue observed in almost every country around the world. A high salt diet (HSD) has a strong correlation with numerous diseases, including hypertension, chronic kidney disease, and autoimmune disorders. However, the mechanisms underlying HSD-promotion of inflammation and exacerbation of these diseases are not fully understood. In this study, we observed that HSD consumption reduced the abundance of the gut microbial metabolite L-fucose, leading to a more substantial inflammatory response in mice. A HSD led to increased peritonitis incidence in mice, as evidenced by the increased accumulation of inflammatory cells and elevated levels of inflammatory cytokines, such as tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and monocyte chemotactic protein-1 (MCP-1, also known as C-C motif chemokine ligand 2 or CCL2), in peritoneal lavage fluid. Following the administration of broad-spectrum antibiotics, HSD-induced inflammation was abolished, indicating that the proinflammatory effects of HSD were not due to the direct effect of sodium, but rather to HSD-induced alterations in the composition of the gut microbiota. By using untargeted metabolomics techniques, we determined that the levels of the gut microbial metabolite L-fucose were reduced by a HSD. Moreover, the administration of L-fucose or fucoidan, a compound derived from brown that is rich in L-fucose, normalized the level of inflammation in mice following HSD induction. In addition, both L-fucose and fucoidan inhibited LPS-induced macrophage activation in vitro. In summary, our research showed that reduced L-fucose levels in the gut contributed to HSD-exacerbated acute inflammation in mice; these results indicate that L-fucose and fucoidan could interfere with HSD-promotion of the inflammatory response.

Effect of monosaccharide composition and proportion on the bioactivity of polysaccharides: A review

Polysaccharides have been widely used in pharmaceutical and food industries due to their diverse bioactivity, high safety, and few or no side effects. However, inability to quickly produce, screen, and synthesize bioactive polysaccharides is the limiting factor for their development and application. Structural features determine and influence the bioactivity of polysaccharides. Among them, monosaccharide is the basic unit of polysaccharide, which not only affects electrification, functional group, and bioactivity of polysaccharide but also is one of the simplest polysaccharide indexes to be detected. At present, effects of monosaccharide composition and proportion on anti-inflammatory, antioxidant, antitumor, immunomodulatory, antibacterial, and prebiotic activities of polysaccharides are reviewed. Further problems need to be considered during regulation and analysis of monosaccharide composition and proportion of polysaccharides. Overall, present work will provide help and reference for production, development, and structure-function investigation of polysaccharides based on their monosaccharide.

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.

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-functionalized gelatin methacryloyl microspheres ameliorate intervertebral disc degeneration by restoring redox and matrix homeostasis of nucleus pulposus

Loss of extracellular matrix (ECM) and dehydration of the nucleus pulposus (NP) are major pathological characteristics of intervertebral disc degeneration (IVDD), the leading cause of low back pain. Excessive reactive oxygen species (ROS) induced by proinflammatory cytokines substantially contribute to IVDD pathogenesis. This study aimed to examine the potential of fucoidan in protecting the matrix metabolism of NP cells and its therapeutic efficacy in the prevention of IVDD. In an inflammatory environment induced by interleukin (IL)-1β, fucoidan treatments demonstrated a dose-dependent enhancement of ECM production in NP cells, while concurrently reducing the expression of matrix degradation enzymes. The protective effect of fucoidan was mediated through the activation of nuclear factor erythroid 2-related factor 2 (NRF2) and subsequent induction of antioxidant enzymes, whereas silencing Nrf2 abrogated the protection of fucoidan on NP cells against IL-1β-induced oxidative stress. Moreover, a novel fucoidan-functionalized gelatin methacryloyl microsphere (Fu@GelMA-MS) was synthesized. The in vivo application of Fu@GelMA-MS via in situ injection in a rat caudal IVD model effectively conserved the ECM components and maintained the hydration of the NP tissue, thereby preventing IVDD caused by puncture. Collectively, fucoidan-functionalized hydrogel microspheres represent a promising strategy for the regeneration of NP and the treatment of IVDD.

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.

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.

Comparison of Fucoidans from Saccharina latissima Regarding Age-Related Macular Degeneration Relevant Pathomechanisms in Retinal Pigment Epithelium

Fucoidans from brown algae are described as anti-inflammatory, antioxidative, and antiangiogenic. We tested two Saccharina latissima fucoidans (SL-FRO and SL-NOR) regarding their potential biological effects against age-related macular degeneration (AMD). Primary porcine retinal pigment epithelium (RPE), human RPE cell line ARPE-19, and human uveal melanoma cell line OMM-1 were used. Cell survival was assessed in tetrazolium assay (MTT). Oxidative stress assays were induced with erastin or H2O2. Supernatants were harvested to assess secreted vascular endothelial growth factor A (VEGF-A) in ELISA. Barrier function was assessed by measurement of trans-epithelial electrical resistance (TEER). Protectin (CD59) and retinal pigment epithelium-specific 65 kDa protein (RPE65) were evaluated in western blot. Polymorphonuclear elastase and complement inhibition assays were performed. Phagocytosis of photoreceptor outer segments was tested in a fluorescence assay. Secretion and expression of proinflammatory cytokines were assessed with ELISA and real-time PCR. Fucoidans were chemically analyzed. Neither toxic nor antioxidative effects were detected in ARPE-19 or OMM-1. Interleukin 8 gene expression was slightly reduced by SL-NOR but induced by SL-FRO in RPE. VEGF secretion was reduced in ARPE-19 by SL-FRO and in RPE by both fucoidans. Polyinosinic:polycytidylic acid induced interleukin 6 and interleukin 8 secretion was reduced by both fucoidans in RPE. CD59 expression was positively influenced by fucoidans, and they exhibited a complement and elastase inhibitory effect in cell-free assay. RPE65 expression was reduced by SL-NOR in RPE. Barrier function of RPE was transiently reduced. Phagocytosis ability was slightly reduced by both fucoidans in primary RPE but not in ARPE-19. Fucoidans from Saccharina latissima, especially SL-FRO, are promising agents against AMD, as they reduce angiogenic cytokines and show anti-inflammatory and complement inhibiting properties; however, potential effects on gene expression and RPE functions need to be considered for further research.

Comparison of anti-tumor activities and underlying mechanisms of glucuronomannan oligosaccharides and its sulfated derivatives on the hepatocarcinoma Huh7.5 cells

Hepatocellular carcinoma (HCC) is an aggressive tumor triggered by various factors such as virus infection and alcohol abuse. Glucuronomannan polysaccharide (Gx) is a subtype of fucoidans that possesses many bioactivities, but its anti-tumor activities in HCC have not been reported. In this paper, the anti-tumor effects of glucuronomannan oligosaccharides (Gx) and its sulfated derivatives (GxSy) on hepatocarcinoma Huh7.5 cells were investigated. The anti-proliferation, anti-metastasis activities, and underlying mechanism of Gx and GxSy on Huh7.5 cells were analyzed and compared by MTT, wound healing, transwell, and western blotting assays, respectively. Results showed that the best anti-proliferation effects were G4S1 and G4S2 among 13 drugs, which were 38.67% and 30.14%, respectively. The cell migration rates were significantly inhibited by G2S1, G4S2, G6S2, and unsulfated Gn. In addition, cell invasion effects treated with G4S1, G4S2, and G6S1 decreased to 48.62%, 36.26%, and 42.86%, respectively. Furthermore, sulfated G4 regulated the expression of (p-) FAK and MAPK pathway, and sulfated G6 down-regulated the MAPK signaling pathway while activating the PI3K/AKT pathway. On the contrary, sulfated G2 and unsulfated Gx had no inhibited effects on the FAK-mTOR pathway. These results indicated that sulfated Gx derivatives have better anti-tumor activities than unsulfated Gx in cell proliferation and metastasis process in vitro, and those properties depend on the sulfation group levels. Moreover, degrees of polymerization of Gx also played a vital role in mechanisms and bioactivities. This finding shows the structure-activity relationship for developing and applying the marine oligosaccharide candidates.

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.

Anti-Proliferative and Pro-Apoptotic vLMW Fucoidan Formulas Decrease PD-L1 Surface Expression in EBV Latency III and DLBCL Tumoral B-Cells by Decreasing Actin Network

Epstein-Barr virus (EBV) infects 95% of the world's population and persists latently in the body. It immortalizes B-cells and is associated with lymphomas. LCLs (lymphoblastoid cell lines, EBV latency III B-cells) inhibit anti-tumoral T-cell response following PD-L1 overexpression (programmed death-ligand 1 immune checkpoint). Many cancer cells, including some DLBCLs (diffuse large B-cell lymphomas), also overexpress PD-L1. Immunotherapies are based on inhibition of PD-L1/PD-1 interactions but present some dose-dependent toxicities. We aim to find new strategies to improve their efficiency by decreasing PD-L1 expression. Fucoidan, a polysaccharide extracted from brown seaweed, exhibits immunomodulatory and anti-tumor activities depending on its polymerization degree, but data are scarce on lymphoma cells or immune checkpoints. LCLs and DLBCLs cells were treated with native fucoidan (Fucus vesiculosus) or original very-low-molecular-weight fucoidan formulas (vLMW-F). We observed cell proliferation decrease and apoptosis induction increase with vLMW-F and no toxicity on normal B- and T-cells. We highlighted a decrease in transcriptional and PD-L1 surface expression, even more efficient for vLMW than native fucoidan. This can be explained by actin network alteration, suggesting lower fusion of secretory vesicles carrying PD-L1 with the plasma membrane. We propose vLMW-F as potential adjuvants to immunotherapy due to their anti-proliferative and proapoptotic effects and ability to decrease PD-L1 membrane expression.

Anti-inflammatory effect of fucoidan isolated from fermented Sargassum fusiforme in in vitro and in vivo models

Fucoidans possess potent anti-inflammatory effects. In the present study, the anti-inflammatory effect of the fucoidan (SFF-PS-F5) isolated from fermented Sargassum fusiforme was evaluated in vitro in RAW 264.7 macrophages and in vivo in zebrafish. The in vitro test results demonstrate that SFF-PS-F5 effectively inhibited nitric oxide (NO) production induced by lipopolysaccharides (LPS) in RAW 264.7 cells. SFF-PS-F5 effectively and concentration-dependently improved the viability of LPS-stimulated RAW 264.7 cells, and reduced the level of prostaglandin E2, interleukin-1 beta, tumor necrosis factor-alpha, and interleukin-6. Further results display that these effects were actioned by suppressing the expression of inducible nitric oxide synthase and cyclooxygenase-2 via regulating the nuclear factor kappa-B signaling pathway. The in vivo test results indicate that SFF-PS-F5 remarkably reduced reactive oxygen species, cell death, and NO levels in LPS-treated zebrafish. These results indicate that SFF-PS-F5 could inhibit both in vitro and in vivo inflammatory responses and suggest it is a functional ingredient in the functional food and cosmetic industries.

A Review on Fucoidan Structure, Extraction Techniques, and Its Role as an Immunomodulatory Agent

Functional ingredients for human health have recently become the focus of research. One such potentially versatile therapeutic component is fucose-containing sulfated polysaccharides (FCSPs), referred to as fucoidans. The exploitation of marine brown algae provides a rich source of FCSPs because of their role as a structural component of the cell wall. Fucoidans are characterized by a sulfated fucose backbone. However, the structural characterization of FCSPs is impeded by their structural diversity, molecular weight, and complexity. The extraction and purification conditions significantly influence the yield and structural alterations. Inflammation is the preliminary response to potentially injurious inducements, and it is of the utmost importance for modulation in the proper direction. Improper manipulation and/or continuous stimuli could have detrimental effects in the long run. The web of immune responses mediated through multiple modulatory/cell signaling components can be addressed through functional ingredients, benefiting patients with no side effects. In this review, we attempted to address the involvement of FCSPs in the stimulation/downregulation of immune response cell signaling. The structural complexity and its foremost influential factor, extraction techniques, have also attracted attention, with concise details on the structural implications of bioactivity.

Comparative study of the immunomodulatory effects of different fucoidans from Saccharina japonica mediated by scavenger receptors on RAW 264.7 macrophages

Scavenger receptors (SRs) have been shown to participate in regulating the immune response of macrophages, and fucoidan from Fucus vesiculosus has been verified as a ligand of class A SRs (SR-A). However, the roles of SRs in the immunomodulatory activity of fucoidan from Saccharina japonica are not clear. Thus, we performed a comparative study of the immunomodulatory activities of six different fucoidans from S. japonica on RAW 264.7 macrophages, and the roles of SRs in the processes were studied. Six fucoidans (0.5 M FPS, 1 M FPS, 2 M FPS, 0.5 M DFPS, 1 M DFPS and 2 M FPS) had different molecular weights and chemical compositions. Griess reagent system, ELISA and RT-qPCR results showed that different fucoidans displayed different stimulation of macrophages to secrete NO, IL-6, IL-1β and TNF-α, as well as differences in the upregulation of their gene expressiones. Flow cytometric analysis of the protein expression level indicated the upregulation of TLR4 after treatment with all the fucoidans but different expressions of SRs. Furthermore, only 0.5 M DFPS and 1 M DFPS were confirmed to be ligands of SR-A through the competitive binding assay with Ac-LDL bound to the fluorescent probe DiI by flow cytometry. Our results revealed that fucoidans with low molecular weight and heterogeneity more easily bound to SRs and contributed to their immunomodulatory effects. This comparative study might promote the biological study of targeted SRs and the discovery of new pharmacological mechanisms of different fucoidans.

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.

Magnoliae flos Downregulated Lipopolysaccharide-Induced Inflammatory Responses via NF-κB/ERK-JNK MAPK/STAT3 Pathways

Background. Magnoliae flos is the dried flower bud of Magnolia biondii and related plants. It has been used as a medicinal herb for the treatment of rhinitis, sinusitis, and sinus headaches. Nevertheless, the effects of Magnoliae flos in microbial infection or sepsis remain unclear. In this study, we investigated the anti-inflammatory effects of Magnoliae flos water extract (MF) in lipopolysaccharide- (LPS-) induced septic mice and LPS-stimulated RAW264.7 macrophages. Results. We found that MF reduced the mortality of LPS-challenged mice. Enzyme immunoassays and reverse transcription polymerase chain reaction analysis revealed that MF administration attenuated mRNA expression and protein production of proinflammatory mediators, including cyclooxygenase 2, inducible nitric oxide synthase, tumor necrosis factor-α, and interleukin-6. In parallel to these results in mice, pretreatment with MF suppressed the LPS-induced production of proinflammatory mediators in RAW264.7 macrophages. In addition, we found that MF exerted its suppressive effects by inhibiting the activation of the mitogen-activated protein kinase, nuclear factor-κB, and signal transducer and activator of transcription pathways at the protein level. Conclusion. MF could be a potential therapeutic agent for regulating excessive inflammatory responses in sepsis.

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.

Oct4 downregulation-induced inflammation increases the migration and invasion rate of oral squamous cell carcinoma

Inflammatory changes are involved in tumor cell proliferation, migration, and invasion. Tumor necrosis factor-α (TNF-α) and lipopolysaccharide (LPS) play important roles in inflammatory regulation during tumor development. Oct4 acts as a transcription factor that modulates inflammatory changes in mesenchymal stem cells. In this study, we explored the role of Oct4 in the invasion and migration of oral squamous cell carcinoma (OSCC) cells. LPS and TNF-α were used to treat the OSCC cell lines HN4 and CAL27 to induce inflammation. The generation of inflammatory cytokines, including TNF-α, interleukin (IL)-1β, and IL-6, was evaluated by enzyme-linked immunosorbent assay and real-time quantitative PCR. Western blot analysis was employed to detect the expression and phosphorylation of JNK1, p65, and STAT3, which are key modulators of inflammation. Wound scratch healing and transwell invasion assays were further used to determine the role of inflammation in the invasion and migration of OSCC cells. Robust inflammation was observed in HN4 and CAL27 cells treated with LPS and TNF-α. A marked increase in JNK1, p65, and STAT3 phosphorylation levels in OSCC cells was also detected after LPS and TNF-α treatment. The migration and invasion of HN4 and CAL27 cells were significantly boosted by stimulation with LPS and TNF-α. Furthermore, Oct4 mRNA and protein levels were significantly upregulated by stimulation with LPS and TNF-α. Silencing of Oct4 led to reduced inflammation and decreased levels of phosphorylated JNK1, p65, and STAT3 and impaired invasion and migration in LPS- and TNF-α-stimulated OSCC cells. Overall, LPS- and TNF-α-induced inflammation suppressed the migration and invasion of OSCC cells by upregulating Oct4 expression.

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.

Volatile Oil of Platycladus Orientalis (L.) Franco Leaves Exerts Strong Anti-inflammatory Effects via Inhibiting the IκB/NF-κB Pathway

This study was designed to investigate the anti-inflammatory effects of volatile oil of Platycladus orientalis (L.) Franco leaves (VOPF) and the underlying molecular mechanisms by using the non-infectious inflammation rat models and infectious inflammation mouse models. Ear swelling and intraperitoneal capillary permeability in mice, and carrageenan-induced toe swelling and cotton ball-induced granuloma in rats were used to reveal anti-inflammatory effects of VOPF. Moreover, the lipopolysaccharide (LPS)-induced mouse model of acute lung injury was used to explore the anti-inflammatory mechanism of VOPF. The results showed that VOPF could significantly inhibit auricular swelling, intraperitoneal capillary permeability in mice, and reduce granuloma swelling and paw swelling in rats. Furthermore, it significantly alleviated the pathological damage of the lung tissue. In addition, VOPF could reduce the contents of IL-1β and TNF-α and increase the content of IL-10 in the serum. It had little effect on the expression of p65 but reduced the phosphorylation level of p65 and IκB in NF-κB pathway. In conclusion, VOPF has anti-inflammatory effects and the mechanisms involve the down-regulation of the phosphorylation levels of p65 and IκB and blockage of the NF-κB signaling pathway.

Present Status, Limitations and Future Directions of Treatment Strategies Using Fucoidan-Based Therapies in Bladder Cancer

Bladder cancer (BC) is a common urological cancer, with poor prognosis for advanced/metastatic stages. Various intensive treatments, including radical cystectomy, chemotherapy, immune therapy, and radiotherapy are commonly used for these patients. However, these treatments often cause complications and adverse events. Therefore, researchers are exploring the efficacy of natural product-based treatment strategies in BC patients. Fucoidan, derived from marine brown algae, is recognized as a multi-functional and safe substrate, and has been reported to have anti-cancer effects in various types of malignancies. Additionally, in vivo and in vitro studies have reported the protective effects of fucoidan against cancer-related cachexia and chemotherapeutic agent-induced adverse events. In this review, we have introduced the anti-cancer effects of fucoidan extracts in BC and highlighted its molecular mechanisms. We have also shown the anti-cancer effects of fucoidan therapy with conventional chemotherapeutic agents and new treatment strategies using fucoidan-based nanoparticles in various malignancies. Moreover, apart from the improvement of anti-cancer effects by fucoidan, its protective effects against cancer-related disorders and cisplatin-induced toxicities have been introduced. However, the available information is insufficient to conclude the clinical usefulness of fucoidan-based treatments in BC patients. Therefore, we have indicated the aspects that need to be considered regarding fucoidan-based treatments and future directions for the treatment of BC.

Fucoidans as Potential Therapeutics for Age-Related Macular Degeneration-Current Evidence from In Vitro Research

Age-related macular degeneration (AMD) is the major reason for blindness in the industrialized world with limited treatment options. Important pathogenic pathways in AMD include oxidative stress and vascular endothelial growth factor (VEGF) secretion. Due to their bioactivities, fucoidans have recently been suggested as potential therapeutics. This review gives an overview of the recent developments in this field. Recent studies have characterized several fucoidans from different species, with different molecular characteristics and different extraction methods, in regard to their ability to reduce oxidative stress and inhibit VEGF in AMD-relevant in vitro systems. As shown in these studies, fucoidans exhibit a species dependency in their bioactivity. Additionally, molecular properties such as molecular weight and fucose content are important issues. Fucoidans from Saccharina latissima and Laminaria hyperborea were identified as the most promising candidates for further development. Further research is warranted to establish fucoidans as potential therapeutics for AMD.

A Sulfated Polysaccharide from Saccharina japonica Suppresses LPS-Induced Inflammation Both in a Macrophage Cell Model via Blocking MAPK/NF-κB Signal Pathways In Vitro and a Zebrafish Model of Embryos and Larvae In Vivo

Inflammation is a complicated host-protective response to stimuli and toxic conditions, and is considered as a double-edged sword. A sulfated Saccharinajaponica polysaccharide (LJPS) with a sulfate content of 9.07% showed significant inhibitory effects against lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophage cells and zebrafish. Its chemical and structural properties were investigated via HPLC, GC, FTIR, and NMR spectroscopy. In vitro experiments demonstrated that LJPS significantly inhibited the generation of nitric oxide (NO) and prostaglandin E2 (PGE2) via the downregulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression and suppressed pro-inflammatory cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-1β production via the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signal pathways in LPS-induced RAW 264.7 cells. Moreover, LJPS showed strong protective effects against LPS-induced inflammatory responses in zebrafish, increasing the survival rate, reducing the heart rate and yolk sac edema size, and inhibiting cell death and the production of intracellular reactive oxygen species (ROS) and NO. Its convenience for large-scale production and significant anti-inflammatory activity indicated the potential application of LJPS in functional foods, cosmetics, and pharmaceutical industries.

Production, Characterization and Immunomodulatory Activity of an Extracellular Polysaccharide from Rhodotorula mucilaginosa YL-1 Isolated from Sea Salt Field

A novel exopolysaccharide from marine-derived red yeast Rhodotorula mucilaginosa strain YL-1 was produced and characterized. The highest yield of polysaccharide reached 15.1 g/L after medium and culture parameter optimization. This exopolysaccharide, composed of four neural monosaccharides including glucose, mannose, galactose and fucose, had an average molecular weight of 1200 KDa. It had good immunomodulatory activity on RAW256.7 cell lines. ELISA (enzyme linked immunosorbent assay) and Q-PCR (quantitative real-time PCR) results showed that the cell was stimulated to express more IL-6, IL-18, IL-1β and TNFα cytokines than the control group. This is the first report of an exopolysaccharide with immunomodulatory activity from marine-derived Rhodotorula mucilaginosa.