Effects of Polymannuronic Acid on the Intestinal Microbiota in Mice after Long-Term Intragastric Administration.

Polymannuronic acid (PM) is an alginate oligosaccharide derived from brown algae with a characterized structure and excellent biological activities. Herein, mice were given different doses of PM through 30-day-long-term intragastric administration, and the contents of the jejunum, ileum, and colon were analyzed by 16S rRNA gene sequencing technology for microbial diversity, and relevant experiments were verified according to the analysis results so as to comprehensively evaluate the effects of PM on the intestinal flora. The PM (400 mg/kg and 100 mg/kg) could regulate the microflora balance at the phylum level and increase the microflora richness in the jejunum, ileum, and colon of the mice. The PM could induce more strains that are negatively correlated with Escherichia, thereby reducing the relative abundance of Escherichia. Analysis of bacterial function showed that high and low doses of PM could promote lipid metabolism in the bacterial communities. Moreover, the PM could reduce serum total cholesterol and cholesterol ester levels in a concentration-dependent manner. High-dose PM could lead to colonic intestinal inflammation by increasing the relative abundance of multiple bacterial groups in the jejunum, ileum, and colon. Moreover, high-dose PM could increase lipopolysaccharide-binding protein and interleukin-1ß levels. Therefore, the dose of PM plays an important role in its efficacy, and its biological activity is dosedifferent.

External inspection approaches and involvement of stakeholders' views in inspection following serious incidents - a qualitative mixed methods study from the perspectives of regulatory inspectors.

OBJECTIVE: The objective was to gain knowledge about how external inspections following serious incidents are played out in a Norwegian hospital context from the perspective of the inspectors, and whether stakeholders' views are involved in the inspection. METHODS: Based on a qualitative mixed methods design, 10 government bureaucrats and inspectors situated at the National Board of Health Supervision and three County Governors in Norway, were strategically recruited, and individual semi-structured interviews were conducted. Key official government documents were selected, collected, and thematically analyzed along with the interview data. RESULTS: Our findings overall demonstrate two overarching themes: Theme (1) Perspectives on different external inspection approaches of responding and involving stakeholders in external inspection following serious incidents, Theme (2) Inspectors' internal work practices versus external expectations. Documents and all participants reported a development towards new approaches in external inspection, with more policies and regulatory attention to sensible involvement of stakeholders. Involvement and interaction with patients and informal caregivers could potentially inform the case complexity and the inspector's decision-making process. However, stakeholder involvement was sometimes complex and challenging due to e.g., difficult communication and interaction with patients and/or informal caregivers, due to resource demands and/or the inspector's lack of experience and/or relevant competence, different perceptions of the principle of sound professional practice, quality, and safety. The inspectors considered balancing the formal objectives and expectations, with the expectations of the public and different stakeholders (i.e. hospitals, patients and/or informal caregivers) a challenging part of their job. This balance was seen as an important part of the continuous development of ensuring public trust and legitimacy in external inspection processes. CONCLUSIONS AND IMPLICATIONS: Our study suggests that the regulatory system of external inspection and its available approaches of responding to a serious incident in the Norwegian setting is currently not designed to accommodate the complexity of needs from stakeholders at the levels of hospital organizations, patients, and informal caregivers altogether. Further studies should direct attention to how the wider system of accountability structures may support the internal work practices in the regulatory system, to better algin its formal objectives with expectations of the public.

Using organic fertilizer to mitigate organic-inorganic fouling in agricultural saline wastewater irrigation systems.

Recycling saline wastewater for agricultural irrigation offer a promising solution to address both water scarcity and anthropogenic pollution. However, organic-inorganic fouling in saline wastewater irrigation systems (SWIS) poses significant technical and economic challenges. Traditional chemical biocides are currently insufficient for controlling composite organic-inorganic fouling and may pose environmental hazards. This study proposed a greener approach using organic acid (OA) fertilizers to alleviate organic-inorganic fouling in agricultural SWIS. The treatment performances were assessed employing four types of OA fertilizers (i.e., humic acid, alginic acid, nucleotide, and ammonia acid) and a negative control. Results showed that three types of OA, i.e., alginic acid, nucleotide, and ammonia acid, effectively reduced the total SWIS fouling content by 11.2%-57.4%, whereas humic acid exacerbated fouling by 11.2%-57.4%. Specifically, all types of OA significantly mitigated the content of inorganic fouling (precipitates and silicates) by 10.7%-42.3% by forming loosed and sparser structures. However, OA exhibited minimum effects on controlling silica fouling. Meanwhile, except the humic acid, other types of OA decreased the total content of organic fouling by 17.2%-39.5% by reducing the content of humic substances and building block fractions. In addition, the significant binary interactions of organic-inorganic fouling indicated the active role of calcium silica and biomineralization fouling. These findings provide insight into the development of appropriate and eco-friendly antifouling strategies for SWIS, with implications for recycling and reusing saline wastewater.

In situ formation of alginic acid-gold nanohybrids for application in cancer photothermal therapy.

Gold-based nanoparticles present excellent optical properties that propelled their widespread application in biomedicine, from bioimaging to photothermal applications. Nevertheless, commonly employed manufacturing methods for gold-based nanoparticles require long periods and laborious protocols that reduce cost-effectiveness and scalability. Herein, a novel methodology was used for producing gold-alginic acid nanohybrids (Au-Alg-NH) with photothermal capabilities. This was accomplished by promoting the in situ reduction and nucleation of gold ions throughout a matrix of alginic acid by using ascorbic acid. The results obtained reveal that the Au-Alg-NHs present a uniform size distribution and a spike-like shape. Moreover, the nanomaterials were capable to mediate a temperature increase of ≈11°C in response to the irradiation with a near-infrared region (NIR) laser (808 nm, 1.7 W cm-2 ). The in vitro assays showed that Au-Alg-NHs were able to perform a NIR light-triggered ablation of cancer cells (MCF-7), being observed a reduction in the cell viability to ≈27%. Therefore, the results demonstrate that this novel methodology holds the potential for producing Au-Alg-NH with photothermal capacity and higher translatability to the clinical practice, namely for cancer therapy.

Effects of Alginic Acid on the Porcine Granulosa Cells and Maturation of Porcine Oocytes.

SCOPE: Alginic acid (AA) from brown algae is a marine organic compound. There is extensive use of AA in the food industry and healthcare, suggesting a high probability of AA exposure. The present study investigates the effects of AA on porcine ovarian granulosa cells (GCs) and oocytes to explore its mechanism in female reproduction because of its adverse effects on reproduction. METHODS AND RESULTS: The study adds 20 µM AA to the porcine primary ovarian GCs medium and porcine oocyte in vitro maturation (IVM) medium. Estrogen and progesterone levels are downregulated in GCs. Reactive oxygen species are excessive, and the antioxidant capacity declines. Then mitochondria-mediated apoptosis pathway is involved in GCs apoptosis. In addition, scores of autophagosomes are found in the experimental cells. Furthermore, AA significantly inhibits the proliferation of GCs around cumulus-oocyte complexes (COCs) accompanied by abnormal spindle assembly, chromosome arrangement disorder, and aberrant cortical granules distribution in oocytes, leading to a decreased oocyte maturation rate. CONCLUSION: These findings suggest that 20 µM AA is toxic to sow reproduction by interfering with estrogen production, oxidative stress, mitochondria-mediated apoptosis, autophagy in GCs of sows, and oocyte maturation.

Cost-effectiveness of alginic acid in combination with proton pump inhibitor for the treatment of gastroesophageal reflux disease in systemic sclerosis patients.

BACKGROUND: Systemic sclerosis (SSc) patients often become refractory to proton pump inhibitors (PPI)-a standard treatment for gastroesophageal reflux disease (GERD)-and intolerant to PPI in combination with domperidone. PPI with alginic acid is an alternative treatment option, but alginic acid is costly. OBJECTIVES: We compared the costs and effectiveness of alginic acid plus PPI versus standard treatments (PPI with/without antacids as needed and lifestyle modifications) for GERD in SSc patients unsuitable for, or intolerant to, domperidone. METHODS: An economic evaluation using the Markov model was conducted among SSc patients aged between 40 and 65 years with GERD, having a partial or non-response to 4 weeks of standard-dose omeprazole (40 mg/day) and being unsuitable for or intolerant to domperidone. Using a societal perspective, we computed the incremental cost-effectiveness ratios (ICERs) in terms of Thai baht (THB) per quality-adjusted life-year (QALY) between a combination of alginic acid plus PPI and standard treatment for GERD. The lifetime time horizon was used. RESULTS: The ICER for alginic acid plus PPI versus standard treatments was 377 101 THB/QALY. According to the one-way sensitivity analysis, the cost of alginic acid was the most impactful parameter. If the market prices of alginic acid plus PPI were reduced by 61%, this treatment option would become cost-effective at the willingness-to-pay threshold of 160 000 THB/QALY (34.68 THB/USD data on 25 May 2023). Furthermore, if alginic acid were included in the public health insurance program, the national budget would be increased by 66 313 THB per patient, resulting in an overall budget increase of 5 106 101 to 8 885 942 THB compared with the standard treatment. CONCLUSIONS: Alginic acid plus PPI does not represent good value for money compared with the standard treatment among such SSc patients in Thailand unless its price is reduced significantly.

The Protective Effects of Water-Soluble Alginic Acid on the N-Terminal of Thymopentin.

Thymopentin (TP5) has exhibited strong antitumor and immunomodulatory effects in vivo. However, the polypeptide is rapidly degraded by protease and aminopeptidase within a minute at the N-terminal of TP5, resulting in severe limitations for further practical applications. In this study, the protective effects of water-soluble alginic acid (WSAA) on the N-terminal of TP5 were investigated by establishing an H22 tumor-bearing mice model and determining thymus, spleen, and liver indices, immune cells activities, TNF-α, IFN-γ, IL-2, and IL-4 levels, and cell cycle distributions. The results demonstrated that WSAA+TP5 groups exhibited the obvious advantages of the individual treatments and showed superior antitumor effects on H22 tumor-bearing mice by effectively protecting the immune organs, activating CD4+ T cells and CD19+ B cells, and promoting immune-related cytokines secretions, finally resulting in the high apoptotic rates of H22 cells through arresting them in S phase. These data suggest that WSAA could effectively protect the N-terminal of TP5, thereby improving its antitumor and immunoregulatory activities, which indicates that WSAA has the potential to be applied in patients bearing cancer or immune deficiency diseases as a novel immunologic adjuvant.

Efficient adsorption of bulky reactive dyes from water using sustainably-derived mesoporous carbons.

Hazardous reactive dyes can cause serious environmental problems, as they are difficult to remove from water using conventional adsorbents due to their large molecular sizes and bulky structures. Sustainable mesoporous carbons derived from alginic acid demonstrated promising adsorbent capacity for several representative industrial bulky reactive dye molecules that account for almost 30% of the global textile dye market: Procion Yellow H-XEL (PY), Remazol Black (RB), Procion Crimson H-XEL (PC) and Procion Navy H-XEL (PN). These new adsorbents showed high mesoporosity (>90%) and large pore diameters (>20 nm) facilitating more straightforward and efficient adsorption and desorption processes when compared with predominately microporous activated carbon (AC), Norit, of similar surface chemistry, or with Silica gel (Sgel) that shows good mesoporosity but is hydrophilic. Their adsorption capacity was also significantly higher than that of both AC and Sgel, verifying suitability for bulky dye elimination from wastewater. Adsorption kinetic studies showed a best fit with the Elovich model, indicating a heterogeneous surface adsorption process. The adsorption isotherm data was best represented via the Toth model for almost all adsorbent/dye systems (R2 ≥ 0.98), validating the results of the Elovich model whereby the adsorbent is structurally heterogenous with multilayer dye coverage. From thermodynamic analysis, the derived parameters of ΔG (-11.6 âˆ¼ -6.2 kJ/mol), ΔH and ΔS demonstrate a spontaneous, enthalpy controlled adsorption process that was exothermic for RB (-10.0 kJ/mol) and PC (-23.9 kJ/mol) and endothermic for PY (3.9 kJ/mol) and PN (13.2 kJ/mol). Overall these alginic acid based mesoporous carbons are cost-effective, sustainable and efficient alternatives to current predominantly microporous adsorbent systems.

Ultrasound-assisted extraction of alginic acid from Sargassum angustifolium harvested from Persian Gulf shores using response surface methodology.

In this study, the extraction and characterization of alginic acid, the most abundant compound among brown algae were investigated. The used algae were Sargassum angustifolium from the family of brown algae native to the coasts of the Persian Gulf. The effect of temperature, time, algae mass to solvent volume ratio, and ultrasonic power on the extraction yield and ratio of monomers (M/G) was investigated using the central composite design method. Moreover, the effect of the mentioned parameters on the poly dispersity index and cytotoxic effects against breast cancer cells were also investigated. The maximum obtained extraction yield was 46 %, which was higher than those reported for algae in tropical climates. This shows the effectiveness of ultrasound in facilitating the extraction process. In addition, the minimum monomer ratio was 0.45, the minimum poly dispersity index was 2.5 and the maximum cytotoxicity for using the extract on breast cancer cell line (MCF-7) was 20.3 % (with alginic acid concentration of 250 micrograms per milliliter).

Gradient assembly of alginic acid/quaternary chitosan into biomimetic hidden nanoporous textiles for thermal management.

Hidden pores (including compact shell and porous core pores) occur naturally in polar animals' feathers/fur, and they show exceptional capability for thermal insulation. The facile implementation of such an architecture in macroscopic fibers is challenging. In this work, gradient assembly is developed to prepare biological hidden nanoporous fibers (average aperture, ~80 nm). Namely, a weak polyanion (alginic acid) and a polycation (quaternary chitosan) were dissolved in dimethyl sulphoxide (the anion charge of alginic acid was largely shielded) and then spun to ethanol/water/ammonia solution, whereby ammonia triggered the polymer assembly from the shell to the core. This presents an efficient process in 20 min, which is in stark contrast to tedious freeze-spinning or template methods. The as-prepared green textiles featuring much lower thermally conductivity (0.033 W m-1 K-1) compared with the conventional microporous/compact fibers, as well as robust mechanical strength and enhanced solar/electric-heat-harvesting properties, holding great potential to replace the unsustainable animal products.

Co-encapsulation of retinoic acid, curcumin and resveratrol by spray-drying of alginic acid sodium-based emulsions and ethyl cellulose-based solutions: Impact on the co-delivery profiles.

Co-encapsulation of retinoic acid (RA), curcumin and/or resveratrol into microparticles composed by alginic acid sodium and the ethyl cellulose + polyethylene glycol (EC + PEG) blend was proposed for the protection and co-delivery of these bioactive compounds. The final aim is to take benefit of combined therapeutic potential related to these molecules and use loaded microparticles obtained by spray-drying to improve the treatment of acute promyelocytic leukemia (APL). Alginic acid sodium-based emulsions were characterized regarding rheological properties (i.e. viscosity), stability and droplet size distribution. Biopolymer- and synthetic polymer-based microparticles loaded with RA, RA + curcumin, RA + resveratrol and RA + curcumin + resveratrol were produced with a product yield between 10 and 35 %. The obtained microparticles exhibited a variable form, a morphology that varied between a slightly and high rough surface and a mean diameter that ranged from 2.97 ± 0.04 and 88 ± 3 µm. Encapsulation efficiency was significantly influenced by the encapsulating agent(s) used in the microparticles formulations. The bioactive compounds that were co-encapsulated showed a similar release profile.

Double-interpenetrating nanostructured networks of marine polysaccharides possessing properties comparable to synthetic polymers.

Sustainable circular economy requires materials that possess a property profile comparable to synthetic polymers and, additionally, processing and sourcing of raw materials that have a small environmental footprint. Here, we present a paradigm for processing marine biopolymers into materials that possess both elastic and plastic behavior within a single system involving a double-interpenetrating polymer network comprising the elastic phase of dynamic physical cross-links and stress-dissipating ionically cross-linked domains. As a proof of principle, films possessing more than twofold higher elastic modulus, ultimate tensile strength, and yield stress than those of polylactic acid were realized by blending two water-soluble marine polysaccharides, namely alginic acid (Alg) with physically cross-linkable carboxylated agarose (CA) followed by ionic cross-linking with a divalent cation. Dried CAAlg films showed homogeneous nano-micro-scale domains, with yield stress and size of the domains scaling inversely with calcium concentration. Through surface activation/cross-linking using calcium, CAAlg films could be further processed using wet bonding to yield laminated structures with interfacial failure loads (13.2 ± 0.81 N) similar to the ultimate loads of unlaminated films (10.09 ± 1.47 N). Toward the engineering of wood-marine biopolymer composites, an array of lines of CAAlg were printed on wood veneers (panels), dried, and then bonded following activation with calcium to yield fully bonded wood two-ply laminate. The system presented herein provides a blueprint for the adoption of marine algae-derived polysaccharides in the development of sustainable high-performance materials.

In-Depth Understanding of Ecklonia stolonifera Okamura: A Review of Its Bioactivities and Bioactive Compounds.

Ecklonia stolonifera Okamura (ES) is mainly distributed in the coastal areas of the middle Pacific, around Korea and Japan, and has a long-standing edible value. It is rich in various compounds, such as polysaccharides, fatty acids, alginic acid, fucoxanthin, and phlorotannins, among which the polyphenol compound phlorotannins are the main active ingredients. Studies have shown that the extracts and active components of ES exhibit anti-cancer, antioxidant, anti-obesity, anti-diabetic, antibacterial, cardioprotective, immunomodulatory, and other pharmacological properties in vivo and in vitro. Although ES contains a variety of bioactive compounds, it is not widely known and has not been extensively studied. Based on its potential health benefits, it is expected to play an important role in improving the nutritional value of food both economically and medically. Therefore, ES needs to be better understood and developed so that it can be utilized in the development and application of marine medicines, functional foods, bioactive substances, and in many other fields. This review provides a comprehensive overview of the bioactivities and bioactive compounds of ES to promote in-depth research and a reference for the comprehensive utilization of ES in the future.

Insight on updates in polysaccharides for ocular drug delivery.

Ocular drug delivery is a significantly challenging task due to the presence of various anatomical and physiological barriers in the eye. Naturally available polysaccharides, when used as drug vehicles provide increased retention time, bioavailability, and penetration due to their unique mucoadhesive and charge-possessing nature. This review discusses the polysaccharide-based drug delivery system for the eye. Polysaccharides like alginic acid, cellulose derivatives, chitosan, pectin, xanthan gum, gellan gum, and hyaluronic acid are reviewed in this report. Additionally, emphasis is given to some of the recently investigated polymers such as sugarcane bagasse cellulose, a polysaccharide extracted from the seeds of Manilkara zapota, and Tremella fuciformis polysaccharide as drug vehicles for effective ocular drug delivery. This review also provides insight on clinical status and FDA-approved polysaccharides for ophthalmic delivery of therapeutics.

Alginate ester: New moisture-scavenging excipients for direct compressible pharmaceutical tableting.

The objective of this work is to evaluate methyl ester alginates and alginic acid (AA) as moisture-scavenging excipients for the formulation of aspirin tablets obtained by direct compression. The tablets were stored at accelerated conditions (40 °C/75 % RH) and assessed for changes in tensile strength, mass, thickness and disintegration time. While moisture caused a reduction in the hardness of MCC and AA tablets, hardness of the tablets made from methylated materials was virtually unaffected. The physical stability of alginate ester tablets was found to be related to their increased plastic deformation leading to extended interparticle contact with less impact on tablet porosity. Finally, the combination of higher moisture affinity and lower water dissociation exhibited by alginates esters resulted in tablets with the lowest aspirin degradation. These findings suggest that excipients with high water retention can act as moisture-scavengers without losing their functional properties and reducing the degradation of moisture-sensitive drugs.

Multifunctional Enzyme with Endoglucanase and Alginase/Glucuronan Lyase Activities from Bacterium Cellulophaga lytica.

Cellulophaga lytica is a Gram-negative aerobic bacterium in the genome of which there are many genes encoding polysaccharide degrading enzymes. One of the enzymes named ClGP contains a glycoside hydrolase domain from the GH5 family and a polysaccharide lyase domain from the PL31 family. The enzyme also contains the TAT signaling peptide and the TIGR04183 domain that indicates extracellular nature of the enzyme. Phylogenetic analysis has shown that the enzymes most closely related to ClGP and containing all four domains (TAT, GH5, PL31, TIGR04183) are widespread among bacterial species belonging to the Flavobacteriaceae family. ClGP produced by the recombinant strain of E. coli was purified and characterized. ClGP exhibited activity of endoglucanase (EC 3.2.1.4) and catalyzed hydrolysis of ß-D-glucan, carboxymethyl cellulose sodium salt (CMC-Na), and amorphous cellulose, but failed to hydrolyze microcrystalline cellulose and xylan. Products of CMC hydrolysis were cellobiose and cellotriose, whereas ß-D-glucan was hydrolyzed to glucose, cellobiose, cellotetraose, and cellopentaose. ClGP was more active against the poly-ß-D-mannuronate blocks than against the poly-α-L-glucuronate blocks of alginic acid. This indicates that the enzyme is a polyM lyase (EC 4.2.2.3). ClGP was active against polyglucuronic acid, so it displayed a glucuronan lyase (EC 4.2.2.14) activity. The enzyme had a neutral pH-optimum, was stable in the pH range 6.0-8.0, and displayed moderate thermal stability. ClGP effectively saccharified two species of brown algae, Saccharina latissima and Laminaria digitata, that suggests its potential for use in the production of biofuel from macroalgae.

3D printing of alginate/thymoquinone/halloysite nanotube bio-scaffolds for cartilage repairs: experimental and numerical study.

One of the newest advances in 3D printing is the printing process of bio-scaffolds. The 3D printing of true materials for cartilage repairs accelerates cell growth and proliferation. In this study, a novel biomaterial was developed for the 3D printing of cartilage scaffolds composed of alginate, thymoquinone and halloysite nanotube. Calcium chloride was used as a cross-linker to form hydrogels. Experimental and numerical studies such as scanning electron microscopy, experimental tensile tests, and compression tests, chondrocyte cell seed, and MTT assay were also done. According to the results, alginate and halloysite nanotube increased the printing quality and mechanical performance of biomaterials. Tensile strength in bio-ink with the 30 mg/ml of alginate, 40 mg/ml of halloysite nanotube with 5% of thymoquinone increased up to 372 ± 42 kPa, while compressive stress reached 894 ± 39 kPa. Numerical results indicated that tensile and compressive properties of the scaffold structure depend on the space between printed rows. The best structure was obtained when the distance of rows was chosen at 0.4 mm, and the nozzle diameter was 0.3 mm. Finally, the biomaterial with the 30 mg/ml of alginate, 40 mg/ml of halloysite nanotube with 5% of thymoquinone showed a high mechanical and biological performance, compared to pure alginate bio-scaffolds. Biomaterials included alginic acid sodium salt/thymoquinone/halloysite nanotube mixed and 3D printed in high technology bioprinter, then mechanical and biological properties of printed bio-scaffolds obtained by different experimental tests.

Mussel-inspired nanocomposite hydrogel based on alginate and antimicrobial peptide for infected wound repair.

Timely hemostasis, antibacterial activity, and good adhesion are essential for wound healing. Here, we report about a novel nanocomposite hydrogel with hemostatic, antibacterial, and adhesive properties constructed with a mussel-inspired strategy. Oxidized alginic acid, dopamine, and antimicrobial peptide ε-polylysine were used to prepare a nanocomposite (ODP), and then further cross-linked with acrylamide to fabricate a nanocomposite hydrogel (ODPA). ODPA hydrogel can adhere to the surface of bleeding organs and arrest bleeding within 30 s. It can also be stretched to 12 times its original length and withstand a compression strain of 40 %, and shows effective inhibition on gram-positive and gram-negative bacteria. Compared with commercial alginate sponge, ODPA hydrogel can accelerate the healing of infected full-thickness wound by reducing inflammation, promoting angiogenesis, and collagen deposition. Therefore, the nanocomposite hydrogel is expected to be a multifunctional dressing for promoting healing of infected wounds.

Immunomulation effect of alginic acid and chitooligosaccharides in silver carp (Hypophthalmichthys molitrix).

Individual and combined efficacy of chitooligosaccharides (COS) and alginic acid (AA) at 1 g, 2 g, and 3 g per kg diet was assessed on growth and disease resistance in silver carp (Hypophthalmichthys molitrix) against Edwardsiella ictaluri. Growth parameters including specific growth rate (SGR), weight gain (WG), and feed conversion rate (FCR) were significant in fish fed 2 g and 3 g kg-1 of COS or AA, and fish fed combined COS + AA at 1, 2 and 3 kg-1 diet. In all groups, the survival rate (SR) was recorded 100%, except in group fed 2 g kg-1 AA diet. All the hematological and biochemical profiles significantly increased in groups fed 2 g and 3 g kg-1 of COS, AA, and COS + AA diets. Lipase and amylase enzyme activities and superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GPx) antioxidant enzyme activities were significantly increased in fish fed 2 g and 3 g kg-1 of COS, AA, and COS + AA diet. Respiratory burst (RB), lysozyme (Lyz), reactive oxygen species (ROS) activities, and immunoglobuline (Ig) level were enhanced significantly in fish fed 2 g kg-1 of COS or COS + AA and all 3 g kg-1 diets, whereas nitric acid (NO) production and serum AP activity were improved in 2 g kg-1 COS + AA and 3 g kg-1 COS or COS + AA diets. Pro-inflammatory cytokine such as IL-8 mRNA transcriptions was significant in 2 g kg-1 COS + AA diet and all 3 g kg-1 diet. The IL-10 anti-inflammatory cytokine mRNA transcriptions were significant in 3 g kg-1 COS or COS + AA diets. This study was confirmed that H. molitrix fed with 3 g kg-1 COS or COS + AA diets were better activity when compared to other diet.

Fluorescent Labeling of Polymannuronic Acid and Its Distribution in Mice by Tail Vein Injection.

Polymannuronic acid (PM) possesses more pharmacological activities than sodium alginate, but there have been few studies on its absorption mechanism, tissue distribution, and pharmacokinetics. Studies of pharmacokinetics and tissue distribution are necessary to elucidate the pharmacological effects of PM. Thus, we used fluorescein isothiocyanate (FITC) to produce fluorescently labeled PM (FITC-PM) and detected the distribution and pharmacokinetics of PM in vivo via tail vein injection. The results demonstrate that the FITC-PM showed high stability in different pH solutions. After the tail vein injection, FITC-PM tended to be distributed in the kidney, followed by the liver and in the heart, spleen, and lungs at lower concentrations. Pharmacokinetic analysis showed that the elimination rate constant of FITC-PM was 0.24, the half-life time was 2.85 h, the peak concentration was 235.17 µg/mL, the area under the curve was 631.48 µg/mL·h, the area under the curve by statistical moment was 1843.15 µg/mL·h2, the mean residence time was 2.92 h, and the clearance rate was 79.18 mL/h. These results indicate that FITC-PM could be used for PM distribution and pharmacokinetic studies, and the studies of pharmacokinetics and tissue distribution provided basic information that can be used to further clarify PM pharmacodynamic mechanisms.