The beneficial properties of marine polysaccharides in alleviation of allergic responses

Natural polysaccharides protect against diet-induced obesity by improving lipid metabolism and regulating the immune system

Unhealthy dietary patterns-induced obesity and obesity-related complications pose a great threat to human health all over the world. Accumulating evidence suggests that the pathophysiology of obesity and obesity-associated metabolic disorders is closely associated with dysregulation of lipid and energy metabolism, and metabolic inflammation. In this review, three potential anti-obesity mechanisms of natural polysaccharides are introduced. Firstly, natural polysaccharides protect against diet-induced obesity directly by improving lipid and cholesterol metabolism. Since the immunity also affects lipid and energy metabolism, natural polysaccharides improve lipid and energy metabolism by regulating host immunity. Moreover, diet-induced mitochondrial dysfunction, prolonged endoplasmic reticulum stress, defective autophagy and microbial dysbiosis can disrupt lipid and/or energy metabolism in a direct and/or inflammation-induced manner. Therefore, natural polysaccharides also improve lipid and energy metabolism and suppress inflammation by alleviating mitochondrial dysfunction and endoplasmic reticulum stress, promoting autophagy and regulating gut microbiota composition. Specifically, this review comprehensively summarizes underlying anti-obesity mechanisms of natural polysaccharides and provides a theoretical basis for the development of functional foods. For the first time, this review elucidates anti-obesity mechanisms of natural polysaccharides from the perspectives of their hypolipidemic, energy-regulating and immune-regulating mechanisms.

Microbial exopolysaccharide: Sources, stress conditions, properties and application in food and environment: A comprehensive review

Microbial glucan or exopolysaccharides (EPS) have caught an eye of researchers from decades. The unique characteristics of EPS make it suitable for various food and environmental applications. This review overviews the different types of exopolysaccharides, sources, stress conditions, properties, characterization techniques and applications in food and environment. The yield and production condition of EPS is a major factor affecting the cost and its applications. Stress conditions are very important as it stimulates the microorganism for enhanced EPS production and affects its properties. As far as application is concerned specific properties of EPS such as, hydrophilicity, less oil uptake behavior, film forming ability, adsorption potential have applications in both food and environment sector. Novel and improved method of production, feed stock and right choice of microorganisms with stress conditions are critical for desired functionality and yield of the EPS.

The Potential of Algae in the Nutricosmetic Sector

Seaweeds or algae are marine autotrophic organisms. They produce nutrients (e.g., proteins, carbohydrates, etc.) essential for the survival of living organisms as they participate in biochemical processes and non-nutritive molecules (such as dietary fibers and secondary metabolites), which can improve their physiological functions. Seaweed polysaccharides, fatty acids, peptides, terpenoids, pigments, and polyphenols have biological properties that can be used to develop food supplements and nutricosmetic products as they can act as antibacterial, antiviral, antioxidant, and anti-inflammatory compounds. This review examines the (primary and secondary) metabolites produced by algae, the most recent evidence of their effect on human health conditions, with particular attention to what concerns the skin and hair's well-being. It also evaluates the industrial potential of recovering these metabolites from biomass produced by algae used to clean wastewater. The results demonstrate that algae can be considered a natural source of bioactive molecules for well-being formulations. The primary and secondary metabolites' upcycling can be an exciting opportunity to safeguard the planet (promoting a circular economy) and, at the same time, obtain low-cost bioactive molecules for the food, cosmetic, and pharmaceutical industries from low-cost, raw, and renewable materials. Today's lack of methodologies for recovering bioactive molecules in large-scale processes limits practical realization.

An exploration of alginate oligosaccharides modulating intestinal inflammatory networks via gut microbiota

Alginate oligosaccharides (AOS) can be obtained by acidolysis and enzymatic hydrolysis. The products obtained by different methods have different structures and physiological functions. AOS have received increasing interest because of their many health-promoting properties. AOS have been reported to exert protective roles for intestinal homeostasis by modulating gut microbiota, which is closely associated with intestinal inflammation, gut barrier strength, bacterial infection, tissue injury, and biological activities. However, the roles of AOS in intestinal inflammation network remain not well understood. A review of published reports may help us to establish the linkage that AOS may improve intestinal inflammation network by affecting T helper type 1 (Th1) Th2, Th9, Th17, Th22 and regulatory T (Treg) cells, and their secreted cytokines [the hub genes of protein-protein interaction networks include interleukin-1 beta (IL-1β), IL-2, IL-4, IL-6, IL-10 and tumor necrosis factor alpha (TNF-α)] via the regulation of probiotics. The potential functional roles of molecular mechanisms are explored in this study. However, the exact mechanism for the direct interaction between AOS and probiotics or pathogenic bacteria is not yet fully understood. AOS receptors may be located on the plasma membrane of gut microbiota and will be a key solution to address such an important issue. The present paper provides a better understanding of the protecting functions of AOS on intestinal inflammation and immunity.

Synthesis of spirulina loaded chitosan nanoparticles from prawn, Macrobrachium nipponense shell for extending the shelf life of pike-perch (Sander lucioperca) fillet during refrigerated storage

BACKGROUND

This study was aimed to synthesize polymeric chitosan nanoparticles (CSNPs) from Macrobrachium nipponense shells using sodium triphosphate (TPP) as a crosslinker that was incorporated with spirulina extract (SPE) to improve the shelf life of pike-perch during refrigerated storage (4 °C).

RESULTS

The encapsulation efficiency (EE) of SPE-loaded CSNPs decreased from 67% to 32%, and loading capacity (LC) was increased (10-14%) depending on their loaded SPE concentrations. The initial burst effect, followed by a slow-release at pH 7 (24 h), was observed. Free SPE and SPE incorporated CSNPs decreased microbial counts (total viable count, total psychotropic count, pseudomonas, and lactic acid bacteria) compared to control and unloaded CSNPs. Samples treated with free SPE or SPE-loaded CSNPs showed higher changes in odor, color, TVB-N (total volatile basic nitrogen), and TBA (thiobarbituric acid) compared with the unloaded CSNPs batch (P ≤ 0.05) until the tenth day of storage. However, fish fillets coated with SPE-loaded CSNPs had the highest overall consumer acceptability and the lowest values for TVB-N and TBA at the end of storage (14^th  day). Controlled release of bioactive compounds in batches treated with SPE-CSNPs could delay the microbial degradation and enhance chemical reactions (TBA and TVB-N) in comparison to pure SPE during storage time.

CONCLUSION

The incorporation of SPE in polymeric CSNPs can be considered as a promising material for controlled delivery of natural bioactive agents, and preservation of Pike perch quality during refrigerator storage. © 2022 Society of Chemical Industry.

Microalgal drugs: A promising therapeutic reserve for the future

Over the decades, a variety of chemically synthesized drugs are being used to cure existing diseases but often these drugs could not be effectively employed for the treatment of serious and newly emerging diseases. Fortunately, in nature there occurs immense treasure of plants and microorganisms which are living jewels with respect to their richness of medically important metabolites of high value. Hence, amongst the existing microorganism(s), the marine world offers a plethora of biological entities that can contribute to alleviate numerous human ailments. Algae are one such photosynthetic microorganism found in both marine as well as fresh water which are rich source of metabolites known for their nutrient content and health benefits. Various algal species like Haematococcus, Diatoms, Griffithsia, Chlorella, Spirulina, Ulva, etc. have been identified and isolated to produce biologically active and pharmaceutically important high value compounds like astaxanthin, fucoxanthin, sulphur polysaccharides mainly galactose, rhamnose, xylose, fucose etc., which show antimicrobial, antifungal, anti-cancer, and antiviral activities. However, the production of either of these bio compounds is favored under conditions of stress. This review gives detailed information on various nutraceutical metabolites extracted from algae. Additionally focus has been made on the role of these bio compounds extracted from algae especially sulphur polysaccharides to treat several diseases with prospective treatment for SARS-CoV-2. Lastly it covers the knowledge gaps and future perspectives in this area of research.

Promising bioactive compounds from the marine environment and their potential effects on various diseases

Background

The marine environment hosts a wide variety of species that have evolved to live in harsh and challenging conditions. Marine organisms are the focus of interest due to their capacity to produce biotechnologically useful compounds. They are promising biocatalysts for new and sustainable industrial processes because of their resistance to temperature, pH, salt, and contaminants, representing an opportunity for several biotechnological applications. Encouraged by the extensive and richness of the marine environment, marine organisms’ role in developing new therapeutic benefits is heading as an arable field.

Main body of the abstract

There is currently much interest in biologically active compounds derived from natural resources, especially compounds that can efficiently act on molecular targets, which are involved in various diseases. Studies are focused on bacteria and fungi, isolated from sediments, seawater, fish, algae, and most marine invertebrates such as sponges, mollusks, tunicates, coelenterates, and crustaceans. In addition to marine macro-organisms, such as sponges, algae, or corals, marine bacteria and fungi have been shown to produce novel secondary metabolites (SMs) with specific and intricate chemical structures that may hold the key to the production of novel drugs or leads. The marine environment is known as a rich source of chemical structures with numerous beneficial health effects. Presently, several lines of studies have provided insight into biological activities and neuroprotective effects of marine algae, including antioxidant, anti-neuroinflammatory, cholinesterase inhibitory activity, and neuronal death inhibition.

Conclusion

The application of marine-derived bioactive compounds has gained importance because of their therapeutic uses in several diseases. Marine natural products (MNPs) display various pharmaceutically significant bioactivities, including antibiotic, antiviral, neurodegenerative, anticancer, or anti-inflammatory properties. The present review focuses on the importance of critical marine bioactive compounds and their role in different diseases and highlights their possible contribution to humanity.

Applying Seaweed Compounds in Cosmetics, Cosmeceuticals and Nutricosmetics

The interest in seaweeds for cosmetic, cosmeceutics, and nutricosmetics is increasing based on the demand for natural ingredients. Seaweeds offer advantages in relation to their renewable character, wide distribution, and the richness and versatility of their valuable bioactive compounds, which can be used as ingredients, as additives, and as active agents in the formulation of skin care products. Bioactive compounds, such as polyphenols, polysaccharides, proteins, peptides, amino acids, lipids, vitamins, and minerals, are responsible for the biological properties associated with seaweeds. Seaweed fractions can also offer technical features, such as thickening, gelling, emulsifying, texturizing, or moistening to develop cohesive matrices. Furthermore, the possibility of valorizing industrial waste streams and algal blooms makes them an attractive, low cost, raw and renewable material. This review presents an updated summary of the activities of different seaweed compounds and fractions based on scientific and patent literature.

Production of Low Molecular Weight Chitosan and Chitooligosaccharides (COS): A Review

Chitosan is a biopolymer with high added value, and its properties are related to its molecular weight. Thus, high molecular weight values provide low solubility of chitosan, presenting limitations in its use. Based on this, several studies have developed different hydrolysis methods to reduce the molecular weight of chitosan. Acid hydrolysis is still the most used method to obtain low molecular weight chitosan and chitooligosaccharides. However, the use of acids can generate environmental impacts. When different methods are combined, gamma radiation and microwave power intensity are the variables that most influence acid hydrolysis. Otherwise, in oxidative hydrolysis with hydrogen peroxide, a long time is the limiting factor. Thus, it was observed that the most efficient method is the association between the different hydrolysis methods mentioned. However, this alternative can increase the cost of the process. Enzymatic hydrolysis is the most studied method due to its environmental advantages and high specificity. However, hydrolysis time and process cost are factors that still limit industrial application. In addition, the enzymatic method has a limited association with other hydrolysis methods due to the sensitivity of the enzymes. Therefore, this article seeks to extensively review the variables that influence the main methods of hydrolysis: acid concentration, radiation intensity, potency, time, temperature, pH, and enzyme/substrate ratio, observing their influence on molecular weight, yield, and characteristic of the product.

Degraded Porphyra haitanensis sulfated polysaccharide relieves ovalbumin-induced food allergic response by restoring the balance of T helper cell differentiation

We previously described that Porphyra haitanensis sulfated polysaccharide (PHSP) maintains the balance of pro-inflammation and immunosuppression. However, it is unclear whether degraded PHSP (DPHSP) still shows the immunomodulatory activity. Here, we degraded PHSP by four different methods alone or combined in pairs, and the results showed that the molecular weight and viscosity of DPHSP were significantly decreased, while the main chemical bonds and functional structure were consistent with those of PHSP. We then investigated the immunomodulatory function of DPHSP in vitro and in vivo. Actually, DPHSP enhances the inhibitory effects on mast cell activation and improves the suppression activity of PHSP on the food anaphylactic response. In an ovalbumin-induced food allergy mouse model, the production of allergic mediators and cytokines (interleukin-4 and 13, and interferon-γ) was inhibited by DPHSP. Meanwhile, DPHSP had a stronger ability to up-regulate the differentiation of regulatory T (Treg) cells and its related cytokines. These results suggested that DPHSP showed a better anti-food allergic ability than PHSP by regulating T helper cell balance and promoting Treg cell differentiation, which indicates that DPHSP is a novel potential nutrient component against food allergy.

Porphyran and oligo-porphyran originating from red algae Porphyra: Preparation, biological activities, and potential applications

Porphyra is one of the most economically important red algae in the world. The functional components extracted from Porphyra such as porphyrans, proteins, lipids, and minerals have strong physiological activities. Porphyran, a sulfated galactan, is composed of alternating 1,4-linked α-l-galactopyranose-6-sulfate (L6S) and 1,3-linked β-d-galactopyranose (G). Porphyran and oligo-porphyran have a series of pharmacological and biological functions, such as antioxidation, anticancer, antiaging, antiallergic, immunomodulatory, hypoglycaemic, and hypolipidemic effects. Thus, red algae Porphyra-derived porphyran and oligo-porphyran have various potential applications in food, medicine, and cosmetic fields. For better application, this review introduces and summarizes the structure and source of porphyran as well as the preparation methods, biological activities, and potential applications of porphyran and oligo-porphyran. Moreover, the future research directions and emphasis of porphyran and oligo-porphyran preparation as well as their functional activities and applications are highlighted and prospected.

Nano-technological approaches for plant and marine-based polysaccharides for nano-encapsulations and their applications in food industry

Novel food preservation methods, along with preservatives have been employed to prevent food products from spoilage. There is an increasing demand to substitute synthetic preservatives with natural bioactive compounds since they are safe and environmentally friendly. Bioactive compounds with functional and therapeutic properties are found in foods and have also beneficial physiological and immunological health effects. However, there are some issues associated with bioactive compounds, such as low stability, solubility, and permeability. Encapsulation techniques, especially nano-encapsulation, are a promising technique to overcome these restrictions. A range of the plants' constituents can be converted into bio-nanomaterials. Major plant constituents are polysaccharides which have good biocompatibility properties and therapeutic activities, such as antioxidant, antiviral, anti-inflammatory, anti-allergic, and anti-tumor. Among plant and marine-based polysaccharides, cellulose, starch, alginates, chitosan, and carrageenans have been used as carrier materials to preserve core material. Moreover, many studies indicated that favorable sources such as plant and marine based polysaccharides are emerging. This chapter will cover plant and marine-based polysaccharides for nano-encapsulation and their application in the food industry.

Porphyran-capped silver nanoparticles as a promising antibacterial agent and electrode modifier for 5-fluorouracil electroanalysis

In the present work, the green synthesis of silver nanoparticles (AgNPs) using the sulfated polysaccharide porphyran (PFR) as capping agent and d-glucose as reducing agent is described. PFR was extracted from red seaweed and characterized by employing ¹³C NMR and determination of total sugar, protein, and sulfate contents. The obtained AgNPs-PFR were characterized by using UV-VIS spectroscopy, zeta potential determination, FESEM, and TEM, which demonstrated that PFR was effective at capping the AgNPs, yielding stable suspensions. The AgNPs-PFR presented good antimicrobial properties against Gram-positive and Gram-negative bacterial strains (Staphylococcus aureus and Escherichia coli, respectively). The AgNPs-PFR were also employed as the modifier of carbon paste electrodes, which were efficiently applied as electrochemical sensors for the determination of 5-fluorouracil (5-FU), an important anticancer drug, through square wave voltammetry (SWV). The AgNPs-PFR improved the electrochemical properties of the electrodes, and enhanced their electroanalytical performance. The developed sensing device presented detection and quantification limits equal to 10.7 and 35.8 μmol L-1, respectively, towards 5-FU determination. The proposed electrochemical sensor successfully quantified 5-FU in a real pharmaceutical formulation, confirming its potential as a new promising analytical detection tool for 5-FU quality control purposes.

Chitin and its derivatives: Structural properties and biomedical applications

Chitin, a polysaccharide that occurs abundantly in nature after cellulose, has attracted the interest of the scientific community due to its plenty of availability and low cost. Mostly, it is derived from the exoskeleton of insects and marine crustaceans. Often, it is insoluble in common solvents that limit its applications but its deacetylated product, named chitosan is found to be soluble in protonated aqueous medium and used widely in various biomedical fields. Indeed, the existence of the primary amino group on the backbone of chitosan provides it an important feature to modify it chemically into other derivatives easily. In the present review, we present the structural properties of chitin, and its derivatives and highlighted their biomedical implications including, tissue engineering, drug delivery, diagnosis, molecular imaging, antimicrobial activity, and wound healing. We further discussed the limitations and prospects of this versatile natural polysaccharide.

Natural products targeting FcεRI receptor for anti-allergic therapeutics

Mast cells and basophils are important contributors for development of allergic reactions. The activation of these cells via cross-linking of IgE bound to FcεRI by allergen causes the generation of allergic mediators and the reaction of immediate hypersensitivity. Obviously, FcεRI is considered as a key trigger of acute allergic responses. Consequently, FcεRI is regarded as a potential target for downregulation of allergic diseases. So far, numerous synthetic agents have been reported for inhibition of FcεRI expression and FcεRI-IgE interaction. Meanwhile, natural products have received much attention due to their efficacy and safety. Recently, numerous anti-allergic agents from natural products have been revealed as promising inhibitors of allergic reactions via inhibiting the expression of FcεRI subunits as well as blocking FcεRI activation. Thus, the present contribution is mainly focused to describe natural products targeting FcεRI receptor and to emphasize their applicable potential as anti-allergic foods. PRACTICAL APPLICATIONS: Phlorotannins, epigallocatechin-3-gallate, peptides, chitooligosaccharides, and other natural products have been revealed as potential inhibitors of allergic responses. These bioactive agents target to FcεRI receptor by inhibiting expression of FcεRI and blocking interaction of FcεRI-IgE. Hence, these compounds could be applied as functional ingredients of anti-allergic foods.

The Role of Fucoidans Isolated from the Sporophylls of Undaria pinnatifida against Particulate-Matter-Induced Allergic Airway Inflammation: Evidence of the Attenuation of Oxidative Stress and Inflammatory Responses

Ambient particulate matter (PM) is a critical environment pollutant that promotes the onset and aggravation of respiratory diseases such as asthma through airway inflammation and hypersecretion of mucus. In this study, we aimed to identify the effects of fucoidans isolated from sporophylls of Undaria pinnatifida on asthma symptoms such as the inflammatory response and mucus secretion using a mouse model. Balb/c mice, intraperitoneally sensitized with ovalbumin (OVA, 10 μg) dissolved in 200 µL saline and 2 mg Al(OH)3, were exposed to PM (5 mg/m3) for 7 consecutive days. In parallel, along with PM exposure, we orally administrated fucoidans (100, 400 mg/Kg) or prednisone (5 mg/Kg), an anti-inflammatory drug. We found that oral administration of fucoidans significantly attenuated PM-induced lipid peroxidation and infiltration of inflammatory cells like F4/80+ macrophages, Gr-1+ granulocytes, and CD4+ T lymphocytes. Fucoidans also attenuated the level of PM-exacerbated IL-4, a primitive cytokine released in Th2 mediated eosinophilic asthma. This further suppressed mast cell activation, degranulation and IgE synthesis of PM exposed mice. Interestingly, fucoidans attenuated PM-exacerbated mucus hypersecretion and goblet cell hyperplasia. Therefore, our results suggest that fucoidans are effective at alleviating PM-exacerbated allergic asthma symptoms by attenuating the airway inflammatory response and mucus hypersecretion.

Marine Biocompounds for Neuroprotection-A Review

While terrestrial organisms are the primary source of natural products, recent years have witnessed a considerable shift towards marine-sourced biocompounds. They have achieved a great scientific interest due to the plethora of compounds with structural and chemical properties generally not found in terrestrial products, exhibiting significant bioactivity ten times higher than terrestrial-sourced molecules. In addition to the antioxidant, anti-thrombotic, anti-coagulant, anti-inflammatory, anti-proliferative, anti-hypertensive, anti-diabetic, and cardio-protection properties, marine-sourced biocompounds have been investigated for their neuroprotective potential. Thus, this review aims to describe the recent findings regarding the neuroprotective effects of the significant marine-sourced biocompounds.

Nasal epithelial barrier dysfunction increases sensitization and mast cell degranulation in the absence of allergic inflammation

BACKGROUND

Increased epithelial permeability has been reported in allergic rhinitis, with histamine and type-2 inflammation being responsible for tight junction dysfunction. The impact of an epithelial barrier defect on allergic sensitization and mast cell (MC) degranulation remains speculative.

METHODS

Transepithelial passage of allergens was evaluated on primary human nasal epithelial cell cultures. Active sensitization was attempted by repeated intranasal ovalbumin (OVA) applications in Naïve mice. In a passive sensitization model, mice were injected with IgE to Dermatophagoides pteronyssinus (rDer p)2 and then exposed intranasally to the allergen. Chitosan was used to disrupt nasal epithelial integrity in vitro and in vivo.

RESULTS

Chitosan strongly reduced transepithelial electrical resistance and facilitated transepithelial allergen passage in cultured primary nasal epithelial cells. In vivo, intranasal chitosan affected occludin expression and facilitated allergen passage. After epithelial barrier disruption, intranasal OVA application induced higher OVA-specific IgG1 and total IgE in serum, and increased eosinophilia and interleukin-5 in bronchoalveolar lavage (BAL) compared to sham-OVA mice. Chitosan exposure, prior to rDer p2 allergen challenge in passively sensitized mice, resulted in increased β-hexosaminidase levels in serum and BAL compared to sham-rDer p2 mice. Intranasal treatment with the synthetic glucocorticoid fluticasone propionate prevented chitosan-induced barrier dysfunction, allergic sensitization, and MC degranulation.

CONCLUSION

Epithelial barrier dysfunction facilitates transepithelial allergen passage, allergic sensitization, and allergen-induced MC degranulation even in the absence of inflammatory environment. These results emphasize the crucial role of an intact epithelial barrier in prevention of allergy.

Structure and Bioactivities of Porphyrans and Oligoporphyrans

BACKGROUND

Pyropia (Porphyra), commonly known as nori or laver, is an important food source in many parts of the world. Edible dried Pyropia contains numerous nutrients and biofunctional components, including proteins, vitamins, eicosapentaenoic acid, minerals, carotenoids, mycosporine-like amino acids, and carbohydrate, and one of the compounds which we are interested in is porphyran, a sulfated polysaccharide comprising the hot-water-soluble portion of Pyropia cell walls. Researchers have performed a large number of in-depth studies on the biological activity and potential therapeutic applications of porphyrans and oligoporphyrans.

METHODS

This mini review aims to provide comprehensive and update overview on the source, extraction, structure, biological activities and structure-activity relationships of porphyrans and oligoporphyrans based on the studies in the past 30 years which were included in Web of Science.

RESULTS

The structure of porphyran has been basically determined given that its straight chain is relatively simple, and the skeleton structure has been described. The extraction methods were simplified continuously, but different extraction methods and post- processing methods still had great influence on the structure and composition of porphyran, so there was no standardized extraction process which can achieve quality control until now. In order to obtain oligoporphyrans, there are a variety of degradation methods, including chemical method, physical method and enzymatic method, but it is worth mentioning that specific degradation enzyme is still unavailable. Studies on the biological and pharmacology properties include antioxidant, anti-tumor, anti-inflammatory, immunomodulation, anti-cardiovascular and cerebrovascular diseases and drug delivery.

CONCLUSION

Owing to the therapeutic potential and drug delivery applications, porphyran and oligoporphyrans are expected to be further developed as a medicine against human diseases, as well as a supplement in cosmetics and health products.

Oral Administration of Fucoidan Can Exert Anti-Allergic Activity after Allergen Sensitization by Enhancement of Galectin-9 Secretion in Blood

A previous study revealed that fucoidan inhibited mast cell degranulation through the upregulation of galectin-9 in blood. The purpose of this study is to elucidate its mechanism using ovalbumin (OVA) induced anaphylaxis model mice (BALB/c, Female, 5-week-old) and mast cell line (RBL-2H3 cells). Oral administration of fucoidan after sensitization with OVA/Al(OH)₃ inhibited reduction of rectal temperature induced by activation of mast cells. Fucoidan increased galectin-9 mRNA expression only in colonic epithelial cells. These results suggested that fucoidan could suppress the allergic symptoms in sensitized mice by inducing galectin-9 production from colonic epithelial cells. In addition, to check the influence of galectin 9 on the degranulation of mast cells, RBL-2H3 cell lines were treated directly with recombinant galectin-9. As expected, galectin-9 inhibited degranulation of RBL-2H3 cells pre-bound with IgE. Moreover, the residual amounts of IgE on RBL-2H3 cells were decreased by an addition of galectin-9. It was demonstrated that galectin-9 could remove IgE even if IgE was already bound to mast cells and suppress the mast cells degranulation induced by antigen. This study shows that fucoidan might become an effective therapeutic agent for patients already developed type I allergic diseases.

Red Algae Sulfated Polysaccharides Effervescent Tablets Attenuated Ovalbumin-Induced Anaphylaxis by Upregulating Regulatory T cells in Mouse Models

Red algae sulfated polysaccharides (RASP) were extracted from Porphyra haitanensis and Gracilaria lemaneiformis. RASP were applied to effervescent tablets to develop a type of functional food, termed red algae sulfated polysaccharide effervescent tablets (RASPET), based on the antiallergic activities of RASP. The antiallergic activities and the mechanisms of RASPET were investigated in an ovalbumin (OVA)-induced mouse model of food allergy. The results revealed that RASPET alleviated intestinal villi injury by scanning electron microscopy and anaphylactic symptoms; reduced OVA-specific immunoglobulin E, histamine, and mast cell protease-1 levels in the serum; reduced the level of serum interleukin-4; increased serum interferon-γ level; and decreased B cell and mast cell populations. Remarkably, RASPET increased the levels of serum interleukin-10, transforming growth factor-β, and upregulated splenic CD4⁺foxp3⁺ T cell populations (15.28, 16.82, and 17.58%, respectively) compared to the OVA group (13.17%). In conclusion, RASPET attenuated OVA-induced anaphylaxis via the upregulation of regulatory T cells.

Chitosan Oligosaccharide Exerts Anti-Allergic Effect against Shrimp Tropomyosin-Induced Food Allergy by Affecting Th1 and Th2 Cytokines

BACKGROUND

Shrimp-derived allergen has a serious impact on people's health. Chitosan oligosaccharide (COS) has anti-allergic action but its function on shrimp allergen-induced allergy and related molecular mechanisms remain unclear.

METHODS

COS and its degrees of polymerization (DP) were selected to interact with shrimp tropomyosin (TM) and IgE was measured. A mouse model of food allergy was established by receiving shrimp TM intraperitoneally. The models were treated with different concentrations of COS. Fecal and serum histamine, serum IgE, IgG1 and IgG2a, and inflammatory cytokines were measured.

RESULTS

The main products for COS were DP2-6 with the contents of 6, 40, 26, 16, and 4%, respectively, and reacted with shrimp TM increasingly when COS DP was increased. Severe symptoms of food allergy were observed in the TM group (diarrhea, anaphylactic response, and rectal temperature). In contrast, COS treatment improved these symptoms significantly (p < 0.05). The sensitized mice were desensitized after they were treated with 1 mg/kg COS. COS treatment significantly reduced serum IgE and IgG1 levels, and increased IgG2a levels (p < 0.05). COS consumption decreased fecal and serum histamine. COS treatment reduced Th2 cytokine (IL-4, IL-5, and IL-13) levels and increased the Th1 cytokine (IFN-γ) level (p < 0.05).

CONCLUSIONS

COS showed anti-allergy properties by regulating the levels of Th1 and Th2 cytokines.

Purification and Characterization of A New Cold-Adapted and Thermo-Tolerant Chitosanase from Marine Bacterium Pseudoalteromonas sp. SY39

Chitosanases play an important role in chitosan degradation, forming enzymatic degradation products with several biological activities. Although many chitosanases have been discovered and studied, the enzymes with special characteristics are still rather rare. In this study, a new chitosanase, CsnM, with an apparent molecular weight of 28 kDa was purified from the marine bacterium Pseudoalteromonas sp. SY39. CsnM is a cold-adapted enzyme, which shows highest activity at 40 °C and exhibits 30.6% and 49.4% of its maximal activity at 10 and 15 °C, respectively. CsnM is also a thermo-tolerant enzyme that recovers 95.2%, 89.1% and 88.1% of its initial activity after boiling for 5, 10 and 20 min, respectively. Additionally, CsnM is an endo-type chitosanase that yields chitodisaccharide as the main product (69.9% of the total product). It’s cold-adaptation, thermo-tolerance and high chitodisaccharide yield make CsnM a superior candidate for biotechnological application to produce chitooligosaccharides.

Shellfish: Nutritive Value, Health Benefits, and Consumer Safety

Shellfish is a major component of global seafood production. Specific items include shrimp, lobsters, oysters, mussels, scallops, clams, crabs, krill, crayfish, squid, cuttlefish, snails, abalone, and others. Shellfish, in general, contain appreciable quantities of digestible proteins, essential amino acids, bioactive peptides, long-chain polyunsaturated fatty acids, astaxanthin and other carotenoids, vitamin B₁₂ and other vitamins, minerals, including copper, zinc, inorganic phosphate, sodium, potassium, selenium, iodine, and also other nutrients, which offer a variety of health benefits to the consumer. Although shellfish are generally safe for consumption, their exposure to diverse habitats, the filter feeding nature of shellfish such as oysters, clams, and mussels, and unhealthy farming and handling practices may occasionally entail health risks because of possible presence of various hazards. These hazards include pathogenic organisms, parasites, biotoxins, industrial and environmental pollutants, heavy metals, process-related additives such as antibiotics and bisulfite, and also presence of allergy-causing compounds in their bodies. Most of the hazards can be addressed by appropriate preventive measures at various stages of harvesting, farming, processing, storage, distribution, and consumption. Furthermore, consumer safety of shellfish and other seafood items is strictly monitored by international, governmental, and local public health organizations. This article highlights the nutritional value and health benefits of shellfish items and points out the various control measures to safeguard consumer safety with respect to the products.

F-fucoidan from Saccharina japonica is a novel inducer of galectin-9 and exhibits anti-allergic activity

Fucoidan is a sulfated polysaccharide from brown sea algae. In the present study, it was demonstrated that oral administration of F-fucoidan from Saccharina japonica possessed anti-allergic effects using the passive cutaneous anaphylaxis reaction, but not by intraperitoneal administration. The inhibitory mechanism was dependent on galectin-9, which belongs to a soluble lectin family that recognizes β-galactoside and prevents IgE binding to mast cells. The anti-allergy properties of F-fucoidan were cancelled by an intravenous dose of anti-galectin-9 antibody or lactose, which bind competitively with galectin-9 before the passive cutaneous anaphylaxis reaction. F-fucoidan increased the expression level of galectin-9 mRNA in intestinal epithelial cells and serum galectin-9 levels. Oral treatment with F-fucoidan suppressed allergic symptoms through the induction of galectin-9. This is the first report that F-fucoidan can induce the secretion of galectin-9.

Purification and identification of a polysaccharide from medicinal mushroom Amauroderma rude with immunomodulatory activity and inhibitory effect on tumor growth

Medicinal mushrooms in recent years have been the subject of many experiments searching for anticancer properties. We previously screened thirteen mushrooms for their potential in inhibiting tumor growth, and found that the water extract of Amauroderma rude exerted the highest activity. Previous studies have shown that the polysaccharides contained in the water extract were responsible for the anticancer properties. This study was designed to explore the potential effects of the polysaccharides on immune regulation and tumor growth. Using the crude Amauroderma rude extract, in vitro experiments showed that the capacities of spleen lymphocytes, macrophages, and natural killer cells were all increased. In vivo experiments showed that the extract increased macrophage metabolism, lymphocyte proliferation, and antibody production. In addition, the partially purified product stimulated the secretion of cytokines in vitro, and in vivo. Overall, the extract decreased tumor growth rates. Lastly, the active compound was purified and identified as polysaccharide F212. Most importantly, the purified polysaccharide had the highest activity in increasing lymphocyte proliferation. In summary, this molecule may serve as a lead compound for drug development.

Polysaccharides from the Marine Environment with Pharmacological, Cosmeceutical and Nutraceutical Potential

Carbohydrates, also called saccharides, are molecules composed of carbon, hydrogen, and oxygen. They are the most abundant biomolecules and essential components of many natural products and have attracted the attention of researchers because of their numerous human health benefits. Among carbohydrates the polysaccharides represent some of the most abundant bioactive substances in marine organisms. In fact, many marine macro- and microorganisms are good resources of carbohydrates with diverse applications due to their biofunctional properties. By acting on cell proliferation and cycle, and by modulating different metabolic pathways, marine polysaccharides (including mainly chitin, chitosan, fucoidan, carrageenan and alginate) also have numerous pharmaceutical activities, such as antioxidative, antibacterial, antiviral, immuno-stimulatory, anticoagulant and anticancer effects. Moreover, these polysaccharides have many general beneficial effects for human health, and have therefore been developed into potential cosmeceuticals and nutraceuticals. In this review we describe current advances in the development of marine polysaccharides for nutraceutical, cosmeceutical and pharmacological applications. Research in this field is opening new doors for harnessing the potential of marine natural products.