Extraction, characterization and antimicrobial activity of sulfated polysaccharides from fish skins

Structural Elucidation of Glycosaminoglycans in the Tissue of Flounder and Isolation of Chondroitin Sulfate C

Glycosaminoglycans (GAGs) are valuable bioactive polysaccharides with promising biomedical and pharmaceutical applications. In this study, we analyzed GAGs using HPLC-MS/MS from the bone (B), muscle (M), skin (S), and viscera (V) of Scophthalmus maximus (SM), Paralichthysi (P), Limanda ferruginea (LF), Cleisthenes herzensteini (G), Platichthys bicoloratus (PB), Pleuronichthys cornutus (PC), and Cleisthenes herzensteini (CH). Unsaturated disaccharide products were obtained by enzymatic hydrolysis of the GAGs and subjected to compositional analysis of chondroitin sulfate (CS), heparin sulfate (HS), and hyaluronic acid (HA), including the sulfation degree of CS and HS, as well as the content of each GAG. The contents of GAGs in the tissues and the sulfation degree differed significantly among the fish. The bone of S. maximus contained more than 12 μg of CS per mg of dry tissue. Although the fish typically contained high levels of CSA (CS-4S), some fish bone tissue exhibited elevated levels of CSC (CS-6S). The HS content was found to range from 10-150 ug/g, primarily distributed in viscera, with a predominant non-sulfated structure (HS-0S). The structure of HA is well-defined without sulfation modification. These analytical results are independent of biological classification. We provide a high-throughput rapid detection method for tissue samples using HPLC-MS/MS to rapidly screen ideal sources of GAG. On this basis, four kinds of CS were prepared and purified from flounder bone, and their molecular weight was determined to be 23-28 kDa by HPGPC-MALLS, and the disaccharide component unit was dominated by CS-6S, which is a potential substitute for CSC derived from shark cartilage.

The Relationship between Preparation and Biological Activities of Animal-Derived Polysaccharides: A Comprehensive Review

Polysaccharides are biomolecules found in microorganisms, plants, and animals that constitute living organisms. Glycosaminoglycans, unique acidic polysaccharides in animal connective tissue, are often combined with proteins in the form of covalent bonds due to their potent biological activity, low toxicity, and minimal side effects, which have the potential to be utilized as nutrition healthcare and dietary supplements. Existing studies have demonstrated that the bioactivity of polysaccharides is closely dependent on their structure and chain conformation. The characteristic functional groups and primary structure directly determine the strength of activity. However, the relationship between structure and function is still unclear, and the target and mechanism of action are not fully understood, resulting in limited clinical applications. As a result, the clinical applications of these polysaccharides are currently limited. This review provides a comprehensive summary of the extraction methods, structures, and biological activities of animal-derived polysaccharides that have been discovered so far. The aim is to promote developments in animal active polysaccharide science and provide theoretical support for exploring other unknown natural products.

Mitigation of Hepatic Impairment with Polysaccharides from Red Alga Albidum corallinum Supplementation through Promoting the Lipid Profile and Liver Homeostasis in Tebuconazole-Exposed Rats

Sulfated polysaccharides from seaweed are highly active natural substances with valuable applications. In the present paper, attempts have been made to discuss the physicochemical and structural features of polysaccharides isolated from red marine alga Alsidium corallinum (ACPs) and their protective effect in hepatic impairments induced by tebuconazole (TEB) in male adult rats. Structural features were determined using high-performance liquid chromatography, Fourier-transformed infrared, and solid-state 1H and 13C-Nuclear magnetic resonance analysis. ACPs are found to be hetero-sulfated-anionic polysaccharides that contain carbohydrates, sulfate groups, and uronic acids. In vitro biological activities suggested the effective antioxidant and antimicrobial capacities of ACPs. For antioxidant testing in vivo, the biochemical analysis and plasma profiles displayed that oral administration of ACPs could mitigate blood lipid indicators, including total cholesterol, triglyceride, low and high-density lipoprotein cholesterol, and bilirubin. Liver function indexes involving alanine aminotransferase and aspartate aminotransferase showed that ACPs possessed prominent antioxidant activities. Additionally, the intervention of ACPs potentially inhibited lipid peroxidation, protein oxidation, key enzymes of lipid metabolism (<0.001), and improved antioxidant status (<0.05). Histomorphological observation confirmed that ACPs intervention could partially repair liver injuries caused by TEB. The computational results showed that A. corallinum monosaccharides bound 1JIJ, 1HD2, and 1WL4 receptors with acceptable affinities, which, together with deep embedding and molecular interactions, support the antioxidant, antimicrobial, and hypolipidemic outlined effects in the in vitro and in vivo findings. Given their prominent antioxidant effects, ACPs are promising candidates for liver diseases and must be considered in pharmaceutical applications.

Advances in Genetic Tools and Their Application in Streptococcus thermophilus

Streptococcus thermophilus is a traditional starter. Nowadays, key aspects of S. thermophilus physiology have been revealed concerning the phenotypic traits relevant for industrial applications, including sugar metabolism, protein hydrolysis, and the production of important metabolites that affect the sensory properties of fermented foods as well as the original cooperation with Lactobacillus delbrueckii subsp. bulgaricus. Moreover, significant advances have been made in the synthetic biology toolbox of S. thermophilus based on technological advances in the genome and its sequencing and synthesis. In this review, we discuss the recently developed toolbox for S. thermophilus, including gene expression toolsets (promoters, terminators, plasmids, etc.) and genome editing tools. It can be used for both functionalized foods and therapeutic molecules for consumers. The availability of new molecular tools, including the genome editing toolbox, has facilitated the engineering of physiological studies of S. thermophilus and the generation of strains with improved technical and functional characteristics.

Ultrasonic-assisted enzymatic extraction of sulfated polysaccharide from Skipjack tuna by-products

The effect of ultrasound pretreatment on extraction efficiency of sulfate polysaccharides (SPs) using alcalase from different by-products of Skipjack tuna including head, bone and skin was evaluated. Structural, functional, antioxidant and antibacterial properties of the recovered SPs using the ultrasound-enzyme and enzymatic method were also investigated. Ultrasound pretreatment significantly increased the extraction yield of SPs from all the three by-products compared with the conventional enzymatic method. All extracted SPs showed high antioxidant potential in terms of ABTS, DPPH and ferrous chelating activities where the ultrasound treatment enhanced antioxidant activities of the SPs. The SPs exerted strong inhibiting activity against various Gram-positive and Gram-negative bacteria. The ultrasound treatment remarkably increased antibacterial activity of the SPs against L. monocytogenes but its effect on other bacteria was dependent on the source of the SPs. Altogether, the results suggest that ultrasound pretreatment during enzymatic extraction of SPs from tuna by-products can be a promising approach to improve extraction yield but also bioactivity of the extracted polysaccharides.

Antioxidant and antibacterial activities of a polysaccharide produced by Chaetomium globosum CGMCC 6882

In the present work, a Gynostemma pentaphyllum herb endophytic fungus of Chaetomium globosum CGMCC 6882 polysaccharide produced from tapioca starch (GCP-TS) with submerged fermentation was analyzed. GCP-TS contains rhamnose, glucosamine, galactose, glucose, mannose, and glucuronic acid in the molar ratio of 6.29: 0.55: 1.12: 22.93: 10.94: 3.54. Its weight-average molecular weight, number-average molecular weight and polydispersity were 4.73 × 10⁴ Da, 4.29 × 10⁴ Da and 1.103, respectively. Antioxidant results showed that GCP-TS had a concentration-dependent scavenging ability against DPPH radical, superoxide anion, hydroxyl radical, and ABTS radical. The corresponding scavenging capacities of GCP-TS aqueous solution at the concentration of 1.0 mg/mL were 45.11 ± 2.52, 43.58 ± 1.97, 36.27 ± 2.48, and 34.39 ± 2.06 %, respectively. Antibacterial activities of GCP-TS against Staphylococcus aureus and Escherichia coli were enhanced with the increase in its concentration, and its bacteriostatic activity against S. aureus was stronger than that against E. coli.

Effect of Saccharides Coating on Antibacterial Potential and Drug Loading and Releasing Capability of Plasma Treated Polylactic Acid Films

More than half of the hospital-associated infections worldwide are related to the adhesion of bacteria cells to biomedical devices and implants. To prevent these infections, it is crucial to modify biomaterial surfaces to develop the antibacterial property. In this study, chitosan (CS) and chondroitin sulfate (ChS) were chosen as antibacterial coating materials on polylactic acid (PLA) surfaces. Plasma-treated PLA surfaces were coated with CS either direct coating method or the carbodiimide coupling method. As a next step for the combined saccharide coating, CS grafted samples were immersed in ChS solution, which resulted in the polyelectrolyte complex (PEC) formation. Also in this experiment, to test the drug loading and releasing efficiency of the thin film coatings, CS grafted samples were immersed into lomefloxacin-containing ChS solution. The successful modifications were confirmed by elemental composition analysis (XPS), surface topography images (SEM), and hydrophilicity change (contact angle measurements). The carbodiimide coupling resulted in higher CS grafting on the PLA surface. The coatings with the PEC formation between CS-ChS showed improved activity against the bacteria strains than the separate coatings. Moreover, these interactions increased the lomefloxacin amount adhered to the film coatings and extended the drug release profile. Finally, the zone of inhibition test confirmed that the CS-ChS coating showed a contact killing mechanism while drug-loaded films have a dual killing mechanism, which includes contact, and release killing.

Antioxidant and Antibacterial Activities of a Purified Polysaccharide Extracted from Ceratonia siliqua L. and Its Involvement in the Enhancement Performance of Whipped Cream

The main objective discussed in this research was to determine the structural characteristics of carob kibble water-soluble polysaccharide (KWSP), extracted from Ceratonia siliqua L., and to assess its in vitro antioxidant activities, as well as its effect on whipped cream. The results obtained through 13C, 1H, and the hetero-nuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FT-IR) analysis indicated that KWSP had the characteristic bands of polysaccharides. Thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) suggested that KWSP is a hetero-polysaccharide composed of glucose and fructose, with an average molecular weight (Mw) amounting to 65 KDa. In addition, KWSP showed a good water holding capacity (WHC), a good oil holding capacity (OHC), and an emulsification stability, rated as 3.14 ± 0.05 g/g, 0.87 ± 0.02 g/g, and 71 ± 0.01%, respectively. The antioxidant activity of KWSP was investigated in vitro, demonstrating important DPPH and ABTS⋅+ radical scavenging activities and a good total antioxidant capacity. KWSP exhibited antibacterial activity against Listeria monocytogenes, Staphylococcus aureus, and Salmonella enterica. On the other hand, the incorporation of KWSP in whipped cream was investigated, to enhance its antioxidant capacity and consequently to extend its expiration date. Moreover, KWSP reduces the formation of conjugated dienes and trienes in cream fat.

Polysaccharides to combat viruses (Covid-19) and microbes: New updates

COVID-19, which is speedily distributed across the world and presents a significant challenge to public health, is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Following MERS coronavirus (MERS-CoV) and SARS, this is the third severe coronavirus outbreak in less than 20 years. To date, there are no exact agents and vaccines available for the treatment of COVID-19 that are clinically successful. Antimicrobial medications are effective in controlling infectious diseases. However, the extensive use of antibiotics makes microbes more resistant to drugs and demands novel bioactive agents' development. Polysaccharides are currently commonly used in the biomedical and pharmaceutical industries for their remarkable applications. Polysaccharides appear to have a wide range of anti-virus (anti-coronavirus) and antimicrobial applications. Polysaccharides are able to induce bacterial cell membrane disruption as they demonstrate potency in binding onto the surfaces of microbial cells. Here, the antiviral mechanisms of such polysaccharides and their success in the application of antiviral infections are reviewed. Additionally, this report provides a summary of current advancements of well-recognized polysaccharides as antimicrobial and anti-biofilm agents.

Selective in vitro cytotoxicity effect of Drimia calcarata bulb extracts against p53 mutant HT-29 and p53 wild-type Caco-2 colorectal cancer cells through STAT5B regulation

Colorectal cancer is the fourth leading cause of oncological-related deaths and the third most diagnosed malignancy, worldwide. The emergence of chemoresistance is a fundamental drawback of colorectal cancer therapies and there is an urgent need for novel plant-derived therapeutics. In this regard, other compounds are needed to improve the efficacy of treatment against colorectal cancer. Medicinal plants have been effectively used by traditional doctors for decades to treat various ailments with little to no side effects. Drimia calcarata (D. calcarata) is one of the plants used by Pedi people in South Africa to treat a plethora of ailments. However, the anticancer therapeutic use of D. calcarata is less understood. Thus, this study was aimed at evaluating the potential anticancer activities of D. calcarata extracts against human colorectal cancer cells. The phytochemical analysis and antioxidant activity were analysed using LC-MS, DPPH, and FRAP. The inhibitory effects and IC50 values of D. calcarata extracts were determined using the MTT assay. Induction of cellular apoptosis was assessed using fluorescence microscopy, the Muse® Cell Analyser, and gene expression analysis by Polymerase Chain Reaction (PCR). Water extract (WE) demonstrated high phenolic, tannin, and flavonoid contents than the methanol extract (ME). LC-MS data demonstrated strong differences between the ME and WE. Moreover, WE showed the best antioxidant activity than ME. The MTT data showed that both ME and WE had no significant activity against human embryonic kidney Hek 293 cell line that served as non-cancer control cells. Caco-2 cells demonstrated high sensitivity to the ME and demonstrated resistance toward the WE, while HT-29 cells exhibited sensitivity to both D. calcarata extracts. The expression of apoptosis regulatory genes assessed by PCR revealed an upregulation of p53 by ME, accompanied by downregulation of Bcl-2 and high expression of Bax after treatment with curcumin. The Bax gene was undetected in HT-29 cells. The methanol extract induced mitochondrial-mediated apoptosis in colorectal Caco-2 and HT-29 cells and WE induced the extrinsic apoptotic pathway in HT-29 cells. ME downregulated STAT1, 3, and 5B in HT-29 cells. The D. calcarata bulb extracts, therefore, contain potential anticancer agents that can be further targeted for cancer therapeutics.

Hot alkali-extracted antioxidative crude polysaccharide from a novel mushroom enhances immune response via TLR-mediated NF-κB activation: A strategy for full utilization of a neglected tribal food

Mushroom polysaccharides have been revered for decades as incredibly versatile compounds suitable for application in biomedical, pharmaceutical, food, and cosmetic industries. In that essence Russula alatoreticula, a traditionally appraised unique macrofungus, has earlier been explored to contain functional macromolecules elicited by hydrothermal and cold alkali systems. Remnants of that multistep extraction could further be utilized not only to isolate high-value components, but also to reduce waste material. With this in mind, we decided to recycle leftover residue of the tribal delicacy, rather than undervalue, by following heated NaOH reflux. Intriguingly, the effort resulted productive isolation of carbohydrate fraction (RualaHap) enriched in β-glucan that showed excellent antioxidant activity in terms of radical scavenging, chelating ability, and reducing power with EC₅₀ of 207-5000 μg/ml. Besides strong immune boosting prowess was also witnessed as exposure of RAW 264.7 cells to the metabolites influenced macrophage viability and phagocytosis in a time-dependent manner. Induction of intracellular NO and ROS generation was also enumerated along with aggrandized production of pseudopods representing hallmark of monocyte stimulation. Moreover, the treatment drastically triggered level of TLR-2, TLR-4, NF-κB, Iκ-Bα, iNOS, COX-2, TNF-α, IFN-γ, and IL-10 maintaining balance between M1 and M2 cytokines via TLR coordinated NF-κB pathway. Conclusively the research offers a roadmap for better utilization of a species boasted in traditional practice aiding future implementation of RualaHap as ingredients of nutraceuticals or functional foods. PRACTICAL APPLICATIONS: At present, macrofungal polysaccharides are regarded as an ideal resource for a range of safe uses encompassing direct contact or ingestion by human. In this context, RualaHap isolated from the wild edible mushroom, R. alatoreticula, could have a broad application prospect, particularly in development of natural therapeutics to ameliorate radical-induced ailment and immune-deficiency condition. The biopolymers could thus be utilized in functional diet or complementary medicine to improve health that in turn might raise local cost of the abandoned taxon boosting rural empowerment.

Natural bioactive substances for the control of food-borne viruses and contaminants in food

Abstract

Food-borne viruses and contaminants, as an important global food safety problem, are caused by chemical, microbiological, zoonotic, and other risk factors that represent a health hazard. Natural bioactive substances, originating from plants, animals, or microorganisms, might offer the possibility of preventing and controlling food-borne diseases. In this contribution, the common bioactive substances such as polyphenols, essential oils, proteins, and polysaccharides which are effective in the prevention and treatment of food-borne viruses and contaminants are discussed. Meanwhile, the preventive effects of natural bioactive substances and the possible mechanisms involved in food protection are discussed and detailed. The application and potential effects of natural bioactive substances in the adjuvant treatment for food-borne diseases is also described.

Graphical abstract

Chondroitin/dermatan sulfate purified from corb (Sciaena umbra) skin and bone: In vivo assessment of anticoagulant activity

The present work deals with the extraction and purification of chondroitin sulfate/dermatan sulfate from skin (CSG) and bone (CBG) of corb (Sciaena umbra). Electrophoresis of these polymers in barium acetate buffer on cellulose acetate revealed two fractions similar to dermatan sulfate and chondroitin sulfate. The in vivo anticoagulant activity of both chondroitin sulfate/dermatan sulfate (CS/DS) were evaluated, at 25 and 75 mg kg^-1 of body weight (b.w), using activated partial thromboplastin time (aPTT), prothrombine time (TT) and thrombin time (PT) tests. Results showed that aPTT of CSG and CBG at 75 mg kg^-1 of b.w were prolonged by 1.59 and 1.48-fold respectively, compared with the control. Further, toxicity studies on liver performed by the catalytic activity of transaminases in plasma, oxidative stress markers and hepatic morphological changes demonstrated that CSG and CBG at both doses are not toxics. In summary, the higher activity and lower toxicity of both CS/DS, especially at 25 mg kg^-1 of b.w, recommended these compounds as a better drug candidate.

Poultry Shelf-Life Enhancing Potential of Nanofibers and Nanoparticles Containing Porphyra dioica Extracts

Aqueous extracts of commercially available red macroalgae Porphyra dioica were integrated as inner coatings of food-grade polypropylene (PP) films through use of electrospinning and electrospraying technologies. Two coating formulations (A = 5 wt% P. dioica extract and 7.5 wt% polyvinyl alcohol (PVA); B = 1 wt% P. dioica extract, 1 wt% PVA, and 17% gelatine) were evaluated as to their capacity to delay spoilage of minced chicken breasts, through monitoring of microbial growth (total mesophile aerobic colony counts), colour stability, lipid oxidation (thiobarbituric acid reactive substances (TBARS)), and sensory analysis over a 4-day refrigerated storage. Scanning electron microscopy (SEM) imaging revealed an increased nanofiber and nanoparticle density on extract-enriched fibers, without compromise to their morphology or the homogeneity of the coatings. Total microbial counts on coating B samples was significantly (p < 0.001) reduced compared to uncoated plastic wraps. The coated samples also exhibited fewer colour degradation, though the coatings did not differ substantially from uncoated plastic wrap. Sensory analysis test subjects successfully distinguished the raw samples based on their treatment and gave a positive approval rating (66.7%) to the extract-enriched coatings when asked about edibility post storage.

Sulfonated (1→6)-β-d-Glucan (Lasiodiplodan): Preparation, Characterization and Bioactive Properties

Sulfonated derivatives of lasiodiplodan (LAS-S) with different degrees of substitution (1.61, 1.42, 1.02 and 0.15) were obtained and characterized by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermal and solubility analyses. Antimicrobial, antioxidant and cytotoxic potential were also assessed. The sulfonation was confirmed by FTIR analysis with specific bands at 1250 cm-1 (S=O, strong asymmetrical stretching vibration) and at 810 cm-1 (C-O-S, symmetrical vibration associated with the C-O-SO3 group) in the sulfonated samples. SEM demonstrated that sulfonation promoted morphological changes on the surface of the biopolymer with heterogeneous fibrillary structures appearing along the surface following chemical modification. LAS-S showed high thermal stability, with mass loss due to oxidation at temperatures close to 460 °C. Sulfonation increased the solubility of LAS, and in addition, increased the antimicrobial activity, especially against Candida albicans (fungicidal) and Salmonella enterica Typhimurium (bacteriostatic). Native lasiodiplodan (LAS-N) showed higher OH˙ removal capacity, while LAS-S had higher ferric ion reducing antioxidant power (FRAP) potential. LAS-N and LAS-S did not demonstrate lethal cytotoxicity against wild and mutant strains of Saccharomyces cerevisiae. Samples with higher degree of substitution (1.42 and 1.61) showed lower potential to induce oxidative stress.

Purification, compositional analysis, and anticoagulant capacity of chondroitin sulfate/dermatan sulfate from bone of corb (Sciaena umbra)

Chondroitin sulfate/dermatan sulfate (CS/DS) were isolated and purified for the first time from the bone of corb (Sciaena umbra) (CBG) and their chemical composition and anticoagulant activity were assessed. Infrared spectrum and agarose-gel electrophoresis for extracted CS/DS were also investigated. The results showed that the purified CS/DS obtained at a yield of 10% contains about 31.28% sulfate and an average molecular mass of 23.35 kDa. Disaccharide analysis indicated that CBG was composed of monosulfated disaccharides in positions 6 and 4 of the N-acetylgalactosamine (8.6% and 40.0%, respectively) and disulfated disaccharides in different percentages. The charge density was 1.4 and the ratio of 4:6 sulfated residues was equal to 4.64. Chondroitinase AC showed that the purified CS/DS contained mainly 74% CS and 26% DS. Moreover, the new CS/DS extracted from bone of corb showed a strong anticoagulant effect through activated partial thrombosis time (aPTT), thrombin time (TT) and prothrombin time (PT). In fact, CBG prolonged significantly (p < 0.05), aPTT and PT about 2.62 and 1.26 fold, respectively, greater than that of the negative control at a concentration of 1000 μg/mL. However, TT assay of CBG was prolonged 3.53 fold compared with the control at 100 μg/mL. The purified CS/DS displayed a promising anticoagulant potential, which may be used as a novel and soothing drug.

Antihypertensive and anticoagulant properties of glycosaminoglycans extracted from the sturgeon (Acipenser persicus) cartilage

Large amounts of valuable waste are produced during sea food processing. This has a great potential for conversion to biologically active proteins and polysaccharides. Among these compounds, sulfated polysaccharides have been considered due to their many biological properties.

The present work was conducted to study anticoagulant activities and angiotensin-I converting enzyme (ACE) inhibitory effects of glycosaminoglycans (GAGs) extracted from the cartilage of sturgeon (Acipenser persicus). The enzymatic extraction of sturgeon cartilage was performed in the presence of cetylpyridinium chloride salt. The structure was characterized via electron microscope and Fourier transform infrared spectroscopy (FTIR) analysis. Herein, ACE inhibitory and anticoagulant properties of extracted GAGs were determined.

The amount of GAGs was 6.8±1.3% of cartilage dry weight. GAGs showed good activity in ACE inhibitory – with a highest level of 85.7%. The derived anticoagulant activity indexes, APPT (activated partial thromboplastin time) and TT (Thrombin time) of the extracted polysaccharide showed a prolonging of clotting time, compare to control.

The results of this study revealed that the cartilage extracted GAGs possess promising ACE inhibitory properties and anticoagulant effects. Thus, the product can be substituted for blood reducing drugs and antithrombotic agents at least in laboratory conditions.

Protective activities of polysaccharides from Cipangopaludina chinensis against high-fat-diet-induced atherosclerosis via regulating gut microbiota in ApoE-deficient mice

The supplementation of sulfated polysaccharides extracted from C. chinensis slows down the development of atherosclerosis caused by high-fat-diet-induced AS via regulating gut microbiota.

A Polysaccharide Purified from Morchella conica Pers. Prevents Oxidative Stress Induced by H₂O₂ in Human Embryonic Kidney (HEK) 293T Cells

Morchella conica Pers. (M. conica) has been used both as a medical and edible mushroom and possesses antimicrobial properties and antioxidant activities. However, the antioxidant properties of polysaccharides purified from M. conica have not been studied. The aim of this study was to investigate the in vitro antioxidant properties of a polysaccharide NMCP-2 (neutral M. conica polysaccharides-2) purified from M. conica, as determined by radical scavenging assay and H₂O₂-induced oxidative stress in HEK 293T cells. Results showed that NMCP-2 with an average molecular weight of 48.3 kDa possessed a much stronger chelating ability on ferrous ions and a higher ability to scavenge radical scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) than the other purified fraction of NMCP-1 from M. conica. Moreover, 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetra-zolium bromide (MTT) assay showed that NMCP-2 dose-dependently preserved cell viability of H₂O₂-induced cells. The NMCP-2 pretreated group reduced the generation of reactive oxygen species (ROS) content and increased the mitochondria membrane potential (MMP) levels. In addition, Hoechst 33342 staining revealed cells treated with NMCP-2 declined nuclear condensation. Ultrastructural observation revealed that NMCP-2 pretreatment alleviated the ruptured mitochondria when exposed to H₂O₂. Furthermore, western blot analysis showed that NMCP-2 prevented significant downregulation of the protein expression of Bax, cleaved caspases 3, and upregulated Bcl-2 levels. These results suggest the protective effects of NMCP-2 against H₂O₂-induced injury in HEK 293T cells. NMCP-2 could be used as a natural antioxidant of functional foods and natural drugs.

In vitro activities of kappa-carrageenan isolated from red marine alga Hypnea musciformis: Antimicrobial, anticancer and neuroprotective potential

This study assessed the antioxidant, antimicrobial, anticancer and neuroprotective activities of the kappa(k)-carrageenan isolated from the red alga Hypnea musciformis (Hm-SP). The chemical spectrum of the k-carrageenan from Hm-SP was confirmed by Fourier transform infrared (FT-IR) spectroscopy. Hm-SP revealed an antibacterial and antifungal action against Staphylococcus aureus and Candida albicans, respectively. Hm-SP did not promoted cytotoxic effects against Human breast cancer (MCF-7) and Human neuroblastoma (SH-SY5Y) cell-lines. However, it was observed a significant reduction of the cellular proliferation capacity in these cancer cells in presence of the Hm-SP. Furthermore, Hm-SP showed neuroprotective activity in 6-hydroxydopamine-induced neurotoxicity on SH-SY5Y cells by modulation of the mitochondria transmembrane potential and reducing Caspase 3 activity. In addition, Hm-SP demonstrates low antioxidant potential and did not induce significant cytotoxic effects or changes in the cell proliferation on Balb/c 3T3 mouse fibroblast cell-line. In summary, our data suggest that Hm-SP shows antimicrobial, anticancer and neuprotective activities.

Fish bone peptide promotes osteogenic differentiation of MC3T3-E1 pre-osteoblasts through upregulation of MAPKs and Smad pathways activated BMP-2 receptor

Fish bone, a by-product of fishery processing, is composed of protein, calcium, and other minerals. The objective of this study was to investigate the effects of a bioactive peptide isolated from the bone of the marine fish, Johnius belengerii, on the osteoblastic differentiation of MC3T3-E1 pre-osteoblasts. Post consecutive purification by liquid chromatography, a potent osteogenic peptide, composed of 3 amino acids, Lys-Ser-Ala (KSA, MW: 304.17 Da), was identified. The purified peptide promoted cell proliferation, alkaline phosphatase activity, mineral deposition, and expression levels of phenotypic markers of osteoblastic differentiation in MC3T3-E1 pre-osteoblast. The purified peptide induced phosphorylation of mitogen-activated protein kinases, including p38 mitogen-activated protein kinase, extracellular regulated kinase, and c-Jun N-terminal kinase as well as Smads. As attested by molecular modelling study, the purified peptide interacted with the core interface residues in bone morphogenetic protein receptors with high affinity. Thus, the purified peptide could serve as a potential pharmacological substance for controlling bone metabolism.

Purification and structural elucidation of chondroitin sulfate/dermatan sulfate from Atlantic bluefin tuna (Thunnus thynnus) skins and their anticoagulant and ACE inhibitory activities

Chondroitin sulfate/dermatan sulfate (CS/DS) was extracted from Atlantic bluefin tuna (Thunnus thynnus) skin (SGAT) and was purified and characterized. SGAT was characterized by acetate cellulose electrophoresis, FTIR spectroscopy, ¹³C NMR spectroscopy and SAX-HPLC. According to the results obtained for specific chondroitinases (ABC and AC) and the SAX-HPLC separation of generated unsaturated repeating disaccharides, the polymer was found to contain a disaccharide monosulfated in positions 6 and 4 of GalNAc and disulfated disaccharides in different percentages. These results were confirmed by ¹³C NMR experiments. The average molecular mass was 24.07 kDa, as determined by PAGE analysis. SGAT was evaluated for its in vitro anticoagulant activity via activated partial thromboplastin time, thrombin time and prothrombin time tests. The polymer showed strong inhibitory activity against angiotensin I-converting enzyme (IC₅₀ = 0.25 mg mL⁻¹). Overall, the results suggest that this newly extracted CS/DS can be useful for pharmacological applications.

Chondroitin sulfate/dermatan sulfate (CS/DS) was extracted from Atlantic bluefin tuna (Thunnus thynnus) skin (SGAT) and was purified and characterized.

Sulphated polysaccharide isolated from Sargassum vulgare: Characterization and hypolipidemic effects

A sulphated polysaccharide from brown algae Sargassum vulgare (SVSP) was extracted and examined with respect to chemical, structural characterization and hypolipidemic effects. SVSP consisted mainly of sulphate and total sugars with low levels of lipids and proteins. Its structure was studied by nuclear magnetic resonance (RMN), gas chromatography-mass spectrometry (GC-MS), infra-red spectroscopic, differential scanning calorimetry and X-ray diffraction analysis. Allowing us therefore to revealed that SVSP was composed of glucose, rhamnose, xylose, galactose, mannose and arabinose with XRD pattern that was typical for a semi-crystalline polymer and complexities of the spectra reflected its homogeneous structure. The administration of SVSP to obese rats is effective in lowering the body weight and inhibiting the lipase activity leading to notable regulation of lipid profile, increasing the activities of antioxidant enzymes, limiting lipid peroxidation; and protects liver-kidney functions proved by a decrease in the levels of toxicity parameters in blood, confirmed by histological study.

Purification, structural characterization and antiproliferative properties of chondroitin sulfate/dermatan sulfate from tunisian fish skins

Chondroitin sulfate/dermatan sulfate GAGs were extracted and purified from the skins of grey triggerfish (GTSG) and smooth hound (SHSG). The disaccharide composition produced by chondroitinase ABC treatment showed the presence of nonsulfated disaccharide, monosulfated disaccharides ΔDi6S and ΔDi4S, and disulfated disaccharides in different percentages. In particular, the nonsulfated disaccharide ΔDi0S of GTSG and SHSG were 3.5% and 5.5%, respectively, while monosulfated disaccharides ΔDi6S and ΔDi4S were evaluated to be 18.2%, 59% and 14.6%, 47.0%, respectively. Capillary elecrophoresis analysis of GTSG and SHSG contained 99.2% and 95.4% of chondroitin sulfate/dermatan sulfate, respectively. PAGE analysis showed a GTSG and SHSG having molecular masses with average values of 41.72KDa and 23.8KDa, respectively. HCT116 cell proliferation was inhibited (p<0.05) by 70.6% and 72.65% at 200μg/mL of GTSG and SHSG respectively. Both GTSG and SHSG demonstrated promising antiproliferative potential, which may be used as a novel, effective agent.

Effects of dietary oxidized konjac glucomannan sulfates (OKGMS) and acidolysis-oxidized konjac glucomannan (A-OKGM) on the immunity and expression of immune-related genes of Schizothorax prenanti

In the present study, konjac glucomannan (KGM) was degraded by H2O2, and then used trisulfonated sodium amine and HCl, individually, to obtain two kinds of derivatives: oxidized konjac glucomannan sulfates (OKGMS) and acidolysis-oxidized konjac glucomannan (A-OKGM). The effects of two OKGM modified products on the immune parameters and expressions of toll-like receptor 22 (TLR22), myeloid differentiation factor 88 (MyD88) and interferon regulatory factors 7 (IRF7) genes in Schizothorax prenanti were determined. The alternative haemolytic complement (ACH50) activity was found to be significantly increased by the OKGMS diets. The immunoglobulin M (IgM) level was significantly enhanced by the OKGMS diets. The lysozyme activity was significantly increased by both OKGMS and A-OKGM diets. The superoxide dismutase (T-SOD) activity in fish fed with all doses of OKGMS diets was significantly higher than that in fish fed with basal diet. The glutathione peroxidase (GSH-PX) activity in fish fed with 0.8% and 1.6% A-OKGM diets was significantly higher than control group. The malondialdehyde (MDA) level was significantly decreased by both OKGMS and A-OKGM diets. The 0.8% A-OKGM diet significantly up-regulated TLR22 gene expression in the head kidney and spleen. TLR22 gene expression was significantly promoted by all OKGMS diets in the mesonephros and liver. The MyD88 mRNA level in 1.6% A-OKGM group significantly increased in the head kidney. The low dose of OKGMS significantly induced the MyD88 gene expression in the mesonephros, gut and liver, while 0.8% A-OKGM group also showed a significantly enhanced MyD88 mRNA expression in the gut. High dose of OKGMS significantly increased the IRF7 mRNA expression in the mesonephros and spleen. Fish fed with low dose of A-OKGM showed significantly higher expression of IRF7 in the gut and liver. Present study suggested that OKGMS and A-OKGM can act as immunostimulant to improve the immune indexes and up-regulate the immune-related gene expressions.

Physicochemical characteristics and bioactivities of the exopolysaccharide and its sulphated polymer from Streptococcus thermophilus GST-6

Exopolysaccharide (EPS) produced by Streptococcus thermophilus GST-6 in skim milk was extracted and purified. The EPS was composed of glucose and galactose in a molar ratio of 1.80:1.03 with identical primary structure to the EPS from S. thermophilus ST1 reported previously. The purified EPS was sulphated at a sulphonation degree of 0.26±0.03, and presence of sulphate groups in the sulphated EPS (SEPS) was confirmed. Microstructural studies demonstrated a porous web with coarse surface for the EPS while the SEPS appeared as stacked flakes with relatively uniform shapes. Sulphonation of the EPS slightly decreased its degrading temperature from 234.6°C to 232.5°C. The DPPH, superoxide and hydroxyl radicals scavenging activities of the EPS were significantly (P<0.05) improved after sulphonation. The SEPS also showed stronger inhibitory activity than the EPS against Eschericia coli, Salmonella typhimurium and Staphylococcus aureus.