Synthesized oversulfated and acetylated derivatives of polysaccharide extracted from Enteromorpha linza and their potential antioxidant activity

Semisynthesis of new sulfated heterorhamnan derivatives obtained from green seaweed Gayralia brasiliensis and evaluation of their anticoagulant activity

Marine green algae produce sulfated polysaccharides with diverse structures and a wide range of biological activities. This study aimed to enhance the biotechnological potential of sulfated heterorhamnan (Gb1) from Gayralia brasiliensis by chemically modifying it for improved or new biological functions. Using controlled Smith Degradation (GBS) and O-alkylation with 3-chloropropylamine, we synthesized partially water-soluble amine derivatives. GBS modification increase sulfate groups (29.3 to 37.5 %) and α-l-rhamnose units (69.9 to 81.2 mol%), reducing xylose and glucose, compared to Gb1. The backbone featured predominantly 3- and 2-linked α-l-rhamnosyl and 2,3- linked α-l-rhamnosyl units as branching points. Infrared and NMR analyses confirmed the substitution of hydroxyl groups with aminoalkyl groups. The modified compounds, GBS-AHCs and GBS-AHK, exhibited altered anticoagulant properties. GBS-AHCs showed reduced effectiveness in the APTT assay, while GBS-AHK maintained a similar anticoagulant activity level to Gb1 and GBS. Increased nitrogen content and N-alkylation in GBS-AHCs compared to GBS-AHK may explain their structural differences. The chemical modification proposed did not enhance its anticoagulant activity, possibly due to the introduction of amino groups and a positive charge to the polymer. This characteristic presents new opportunities for investigating the potential of these polysaccharides in various biological applications, such as antimicrobial and antitumoral activities.

Anti-inflammatory potential of ulvan

Green seaweeds are a widespread group of marine macroalgae that could be regarded as biorenewable source of valuable compounds, in particular sulfated polysaccharides like ulvans with interesting biological properties. Among them, anti-inflammatory activity represents an interesting target, since ulvans could potentially avoid side effects of conventional therapies. However, a great variability in ulvan content, composition, structure and properties occurs depending on seaweed specie and growth and processing conditions. All these aspects should be carefully considered in order to have reproducible and well characterized products. This review presents some concise ideas on ulvan composition and general concepts on inflammation mechanisms. Then, the main focus is on the importance of adequate selection of extraction, depolymerization and purification technologies followed by an updated survey on anti-inflammatory properties of ulvans through modulation of different signaling pathways. The potential application in a number of diseases, with special emphasis on inflammaging, gut microbiota dysbiosis, wound repair, and metabolic diseases is also discussed. This multidisciplinary overview tries to present the potential of ulvans considering not only mechanistic, but also processing and applications aspects, trusting that it can aid in the development and application of this widely available and renewable resource as an efficient and versatile anti-inflammatory agent.

Rehashing Our Insight of Seaweeds as a Potential Source of Foods, Nutraceuticals, and Pharmaceuticals

In a few Southeast Asian nations, seaweeds have been a staple of the cuisine since prehistoric times. Seaweeds are currently becoming more and more popular around the world due to their superior nutritional value and medicinal properties. This is because of rising seaweed production on a global scale and substantial research on their composition and bioactivities over the past 20 years. By reviewing several articles in the literature, this review aimed to provide comprehensive information about the primary and secondary metabolites and various classes of bioactive compounds, such as polysaccharides, polyphenols, proteins, and essential fatty acids, along with their bioactivities, in a single article. This review also highlights the potential of seaweeds in the development of nutraceuticals, with a particular focus on their ability to enhance human health and overall well-being. In addition, we discuss the challenges and potential opportunities associated with the advancement of pharmaceuticals and nutraceuticals derived from seaweeds, as well as their incorporation into different industrial sectors. Furthermore, we find that many bioactive constituents found in seaweeds have demonstrated potential in terms of different therapeutic attributes, including antioxidative, anti-inflammatory, anticancer, and other properties. In conclusion, seaweed-based bioactive compounds have a huge potential to play an important role in the food, nutraceutical, and pharmaceutical sectors. However, future research should pay more attention to developing efficient techniques for the extraction and purification of compounds as well as their toxicity analysis, clinical efficacy, mode of action, and interactions with regular diets.

Polysaccharides as antioxidants and prooxidants in managing the double-edged sword of reactive oxygen species

Polysaccharides, a class of naturally occurring carbohydrates, were widely presented in animals, plants, and microorganisms. Recently, health benefits of polysaccharides have attracted much attention due to their unique characteristics in reactive oxygen species (ROS) management. ROS, by-products of aerobic metabolism linked to food consumption, exhibited a dual role in protecting cells and fostering pathogenesis collectively termed double-edged sword. Some interesting studies reported that polysaccharides could behave as prooxidants under certain conditions, besides antioxidant capacities. Potentiation of the bright side of ROS could contribute to the host defense that was vitally important for the polysaccharides acting as biological response modifiers. Correspondingly, disease prevention of polysaccharides linked to the management of ROS production was systematically described and discussed in this review. Furthermore, major challenges and future prospects were presented, aiming to provide new insight into applying polysaccharides as functional food ingredients and medicine.

Extraction Techniques, Biological Activities and Health Benefits of Marine Algae Enteromorpha prolifera Polysaccharide

There is increasing interest in the use of marine algae as functional food additives for improving human health. Enteromorpha (Ulva) prolifera (E. prolifera) is a seaweed green alga (Chlorophyta) that contains many bioactive compounds, of which polysaccharide is the main component. With the advancement of technology in the methods of extraction and analysis, recent studies in in vitro and animals model showed that polysaccharides derived from E. prolifera exert various biological activities, such as gut microbiota modulation, immunomodulation, antioxidant, antidiabetic, antimicrobial, and hypolipidemic. Research evidence has shown that methods of extraction and molecular modification, such as degradation, carboxymethylation, and sulfonation could alter the biological activities of polysaccharides. Therefore, in this review, we discussed the different extraction techniques, structural-activity relationship, and health benefits of sulfated polysaccharides derived from E. prolifera, and suggested future research avenues. This review helps to advance the extraction techniques and promote the application of marine algae polysaccharides as functional food and therapeutic agent.

Chemical structure of native and modified sulfated heterorhamnans from the green seaweed Gayralia brasiliensis and their cytotoxic effect on U87MG human glioma cells

A water-soluble sulfated heterorhamnan (Gb1) was isolated from the green seaweed Gayralia brasiliensis and purified by ultrafiltration, yielding a homogeneous polysaccharide (Gb1r). Both fractions contained rhamnose, xylose, galacturonic and glucuronic acids, galactose, and glucose. Chemical and spectroscopic methods allowed the determination of Gb1 and Gb1r chemical structure. Their backbones were constituted by 3-, 2-, and 2,3-linked rhamnosyl units (1:0.49:0.13 and 1:0.58:0.17, respectively), which are unsulfated (13.5 and 14.6%), disulfated (16.6 and 17.8%) or monosulfated at C-2 (8 and 8.6%) and C-4 (24.5 and 23.4%). Gb1 was oversulfated giving rise to Gb1-OS, which presented ~2.5-fold higher content of disulfated rhamnosyl units than Gb1, as determined by methylation analyses and NMR spectroscopy. Gb1 and Gb1-OS potently reduced the viability of U87MG human glioblastoma cells. Gb1 caused cell cycle arrest in the G₁ phase, increased annexin V-stained cells, and no DNA fragmentation, while Gb1-OS increased the percentage of cells in the S and G₂ phases and the levels of fragmented DNA and cells double-stained with annexin V/propidium iodide, suggesting an apoptosis mechanism. The results suggest that the different effects of Gb1 and Gb1-OS were related to differences in the sulfate content and position of these groups along the polysaccharide chains.

Optimization of Bioprocess Extraction of Poria cocos Polysaccharide (PCP) with Aspergillus niger β-Glucanase and the Evaluation of PCP Antioxidant Property

Poria cocos mushroom is widely used as a food and an herb in East Asian and other countries due to its high nutritional value. Research has demonstrated that Poria cocos polysaccharides (PCP) are the major bioactives and possess antioxidation, anti-inflammation, immunoregulation, and other health promoting properties. However, the efficient preparation of PCP has been a challenge, particularly in large scale for industry. Herein, we investigated the biotransformation of PCP from Poria cocos, catalyzed by β-glucanase from Aspergillus niger and focused on optimizing the most four influencing parameters: Temperature, time, pH, and enzyme dosage in this study. After numerous optimizations with the assistance of response surface optimization methodology, we have established that the optimal conditions for the biotransformation PCP preparation were as following: Enzymolysis temperature 60 °C, time 120 min, pH 5.0 and enzyme dose 20 mL. Under these conditions, the extraction yield of PCP reached as high as 12.8%. In addition, the antioxidant activities of PCP were evaluated by reducing power assay and 1,1-diphenyl-2-picryl-hydrazyl, superoxide anion, and hydroxyl radicals scavenging assays. Resulting data showed that PCP presented outstanding antioxidant capacity. Thus, these findings indicate that PCP could be produced as a natural antioxidant for further development.

DoRWA3 from Dendrobium officinale Plays an Essential Role in Acetylation of Polysaccharides

The acetylation or deacetylation of polysaccharides can influence their physical properties and biological activities. One main constituent of the edible medicinal orchid, Dendrobium officinale, is water-soluble polysaccharides (WSPs) with substituted O-acetyl groups. Both O-acetyl groups and WSPs show a similar trend in different organs, but the genes coding for enzymes that transfer acetyl groups to WSPs have not been identified. In this study, we report that REDUCED WALL ACETYLATION (RWA) proteins may act as acetyltransferases. Three DoRWA genes were identified, cloned, and sequenced. They were sensitive to abscisic acid (ABA), but there were no differences in germination rate and root length between wild type and 35S::DoRWA3 transgenic lines under ABA stress. Three DoRWA proteins were localized in the endoplasmic reticulum. DoRWA3 had relatively stronger transcript levels in organs where acetyl groups accumulated than DoRWA1 and DoRWA2, was co-expressed with polysaccharides synthetic genes, so it was considered as a candidate acetyltransferase gene. The level of acetylation of polysaccharides increased significantly in the seeds, leaves and stems of three 35S::DoRWA3 transgenic lines compared to wild type plants. These results indicate that DoRWA3 can transfer acetyl groups to polysaccharides and is a candidate protein to improve the biological activity of other edible and medicinal plants.

Sulfonamides-induced oxidative stress in freshwater microalga Chlorella vulgaris: Evaluation of growth, photosynthesis, antioxidants, ultrastructure, and nucleic acids

Sulfadiazine (SD), sulfamerazine (SM1), and sulfamethazine (SM2) are widely used and disorderly discharged into surface water, causing contamination of lakes and rivers. However, microalgae are regard as a potential resource to alleviate and degrade antibiotic pollution. The physiological changes of Chlorella vulgaris in the presence of three sulfonamides (SAs) with varying numbers of –CH₃ groups and its SA-removal efficiency were investigated following a 7-day exposure experiment. Our results showed that the growth inhibitory effect of SD (7.9–22.6%), SM1 (7.2–45.9%), and SM2 (10.3–44%) resulted in increased proteins and decreased soluble sugars. Oxidative stress caused an increase in superoxide dismutase and glutathione reductase levels but decreased catalase level. The antioxidant responses were insufficient to cope-up with reactive oxygen species (hydrogen peroxide and superoxide anion) levels and prevent oxidative damage (malondialdehyde level). The ultrastructure and DNA of SA-treated algal cells were affected, as evident from the considerable changes in the cell wall, chloroplast, and mitochondrion, and DNA migration. C. vulgaris-mediated was able to remove up to 29% of SD, 16% of SM1, and 15% of SM2. Our results suggest that certain concentrations of specific antibiotics may induce algal growth, and algal-mediated biodegradation process can accelerate the removal of antibiotic contamination.

Enteromorpha prolifera oligomers relieve pancreatic injury in streptozotocin (STZ)-induced diabetic mice

The polysaccharides of Enteromorpha prolifera (PEP) displayed various bioactivities such as anti-viral, anti-inflammatory and immune-regulative effects. However, no studies were performed on the biological effect of Enteromorpha prolifera oligomers (EPO). In this study, we prepared EPO and evaluated their anti-diabetic effect. By enzymatic degradation, EPO were produced from PEP, and the average molecular weight was identified to be 44.1 kDa by Gel Permeation Chromatography (GPC) analysis. The major monosaccharide units of EPO were measured to be rhamnose, glucuronic acid, glucose, xylose and galactose by capillary electrophoresis assay. Based on the in vitro studies, EPO presented potent reducing power and antioxidant effect such as the scavenging of 1, 1-diphenyl-2-picrylhydrazyl (DPPH), superoxide and NO radicals. The in vivo studies show that EPO relieved the symptoms of polydipsia, polyphagia, emaciation and hyperglycemia in streptozotocin (STZ)-induced diabetic mice to a certain extent. Further, by using the quantitative real-time PCR (qPCR) assay and immunofluorescence staining, EPO was proved to promote the insulin secretion by reducing pancreatic inflammation and apoptosis in diabetic mice. In summary, our results indicate that the mitigation of EPO on pancreatic damage might be an effective way to ameliorate the diabetes mellitus.

Acetylation Modification Improves Immunoregulatory Effect of Polysaccharide from Seeds of Plantago asiatica L

The current study was conducted to investigate effects of acetylated Plantago asiatica L. polysaccharides (Ac-PLCPs) on their immunoregulatory activities in bone-marrow-derived dendritic cells (DCs) model. Influences of natural Plantago asiatica L. crude polysaccharide (PLCP) and Ac-PLCPs on inducing phenotypic and functional maturation on DCs were determined. The results showed that Ac-PLCPs with degree of substitution (DS) from 0.06 to 0.1 could not only stimulate the expression of surface molecules major histocompatibility complex class II (MHC II), cluster of differentiation 86 (CD86), and CD80 on DCs (P<0.01) but also increase the secretion of cytokine IL-12p70 (P<0.01). The endocytosis activity of DCs was attenuated by Ac-PLCPs treatment (P<0.01), while the mRNA expressions of chemokine receptors CCR7 and CXCR4 in DCs were significantly increased (P<0.01). Besides, DCs treated with the Ac-PLCPs showed extremely strong T cell proliferation stimulating activity (P<0.01). These data showed that Ac-PLCPs had higher maturation-stimulating activity on DCs than PLCP, which indicated that acetylation modification improved the immunoregulatory effect of PLCP.

Isolation, characterization and bioactive potential of sulfated galactans from Spyridia hypnoides (Bory) Papenfuss

The sulfated galactans (SG) of mass 16 kDa was purified from S.hypnoides through anion exchange and gel permeation chromatography. The biochemical properties of SG including carbohydrate, 3,6 anhydrogalactose, sulfate, uronic acid, moisture, ash, carbon, hydrogen, nitrogen contents were estimated. In the purified SG, the presence of major sugars such as galactose and glucose were identified through HPLC and it was further structurally characterised through FT-IR and NMR spectroscopy. Anticoagulant activity of SG was estimated as 25.36 & 2.46 IU at 25 μg/ml (aPTT & PT). SG also showed potential dose dependent antioxidant activity against free radicals such as DPPH (56.41% at 2 mg/ml), hydroxyl radicals (65.58% at 3 mg/ml) and superoxide radicals (73.12% at 0.6 mg/ml). The maximum metal chelating and total antioxidant property (76.42%, 66.81%) was exhibited at 1 mg/ml. The results indicate that the SG from red seaweed represents a good source of polysaccharide with significant anticoagulant and antioxidant properties.

Effect of Sulfated Chitooligosaccharides on Wheat Seedlings (Triticum aestivum L.) under Salt Stress

In this study, sulfated chitooligosaccharide (SCOS) was applied to wheat seedlings to investigate its effect on the plants' defense response under salt stress. The antioxidant enzyme activities, chlorophyll contents, and fluorescence characters of wheat seedlings were determined at a certain time. The results showed that treatment with exogenous SCOS could decrease the content of malondialdehyde, increase the chlorophyll contents, and modulate fluorescence characters in wheat seedlings under salt stress. In addition, SCOS was able to regulate the activities of antioxidant enzymes containing superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, glutathione reductase, and dehydroascorbate reductase. Similarly, the mRNA expression levels of several antioxidant enzymes were efficiently modulated by SCOS. The results indicated that SCOS could alleviate the damage of salt stress by adjusting the antioxidant enzyme activities of plant. The effect of SCOS on the photochemical efficiency of wheat seedlings was associated with its enhanced capacity for antioxidant enzymes, which prevented structure degradation of the photosynthetic apparatus under NaCl stress. Furthermore, the effective activities of alleviating salt stress indicated the activities of SCOS were closely related with the sulfate group.

Purification and characterization of polysaccharides degradases produced by Alteromonas sp. A321

Two different degradases from Alteromonas sp. A321 for polysaccharides from Enteromorpha prolifera (DPE-L and DPE-P) were purified to homogeneity. The molecular weights of purified DPE-L and DPE-P were 75.2 and 102.5 kDa, respectively, and their internal sequences were analysed by LC-MS-MS. The enzymes exhibited an optimum temperature of 30-40 °C (DPE-L) and 35-45 °C (DPE-P), an optimum pH of 7.0 (DPE-L) and 6.0 (DPE-P). DPE-P was highly stable in the presence of EDTA and 1,10-phenanthroline while DPE-L was inhibited by 1,10-phenanthroline. The Km values of DPE-L and DPE-P were 2.93 mg/ml and 0.31 mg/ml and the Vmax values were 6.11 μmol/min/ml and 2.88 μmol/min/ml, respectively. Results of HPLC and ESI-MS analyses showed that enzymatic products were: Rha1(SO3H)1, Rha1(SO3H)1Gluc1, Rha2(SO3H)2Gluc1, and Rha3(SO3H)3Gluc1Xyl1 by DPE-L, and Glu2, Glu3, plus Glu4 by DPE-P, respectively. Thus DPE-L and DPE-P can be used to produce oligosaccharides which potentially revealed more of structure of polysaccharides from E. prolifera.

Marine polysaccharides from algae with potential biomedical applications

There is a current tendency towards bioactive natural products with applications in various industries, such as pharmaceutical, biomedical, cosmetics and food. This has put some emphasis in research on marine organisms, including macroalgae and microalgae, among others. Polysaccharides with marine origin constitute one type of these biochemical compounds that have already proved to have several important properties, such as anticoagulant and/or antithrombotic, immunomodulatory ability, antitumor and cancer preventive, antilipidaemic and hypoglycaemic, antibiotics and anti-inflammatory and antioxidant, making them promising bioactive products and biomaterials with a wide range of applications. Their properties are mainly due to their structure and physicochemical characteristics, which depend on the organism they are produced by. In the biomedical field, the polysaccharides from algae can be used in controlled drug delivery, wound management, and regenerative medicine. This review will focus on the biomedical applications of marine polysaccharides from algae.

Effect of Astragalus polysaccharide and its sulfated derivative on growth performance and immune condition of lipopolysaccharide-treated broilers

This study evaluates the immunomodulating activities of Astragalus polysaccharide (APS) and sulfated APS (SAPS) in LPS-infected broiler chicks. SAPS was derived using the classic chlorosulfonic acid-pyridine method. On day 16, the birds were injected intramuscularly with 0.5 mL of either saline, APS (4 or 8 mg/kg of body weight (BW), shorten as APS-4 or APS-8) or SAPS (4 or 8 mg/kg of BW, shorten as SAPS-4 or SAPS-8) once a day for three successive days. On days 19 and 20, the birds were intraperitoneally injected with 0.5 mL of LPS (1mg/kg of BW). Saline was used as blank control. Compared with the blank control, LPS-treated birds showed lower daily body weight gain (BWG), average daily feed intake (ADFI), villus height and intraepithelial lymphocytes (IEL) number in jejunum, and higher feed conversion ratio (FCR, feed:gain), spleen index, plasma NO concentration, blood heterophil:lymphocyte (H:L) ratio, and the production of NO in the blood T lymphocytes. Compared with the LPS group, birds in APS-4, SAPS-4 and SAPS-8 groups showed decreased FCR (P<0.05). Moreover, SAPS increased BWG and jejunal villus height (P<0.05) at 8 mg/kg BW. Plasma NO concentration was lower in APS-8 group than that in LPS group (P<0.05). Both APS-8 and SAPS-8 treatments elevated the number of jejunal IEL (P<0.05), and decreased blood H:L ratio (P<0.05), respectively. Administration of APS or SAPS did not affect the ADFI, immune organ index, crypt depth and mucosal thickness of the jejunum, and the number of goblet cell. Our findings suggested that APS and SAPS possessed dose-dependent growth-promoting and immunomodulating effect, and was a potential development direction for immunomodulator under early LPS stimulation condition.

Overview on biological activities and molecular characteristics of sulfated polysaccharides from marine green algae in recent years

Among the three main divisions of marine macroalgae (Chlorophyta, Phaeophyta and Rhodophyta), marine green algae are valuable sources of structurally diverse bioactive compounds and remain largely unexploited in nutraceutical and pharmaceutical areas. Recently, a great deal of interest has been developed to isolate novel sulfated polysaccharides (SPs) from marine green algae because of their numerous health beneficial effects. Green seaweeds are known to synthesize large quantities of SPs and are well established sources of these particularly interesting molecules such as ulvans from Ulva and Enteromorpha, sulfated rhamnans from Monostroma, sulfated arabinogalactans from Codium, sulfated galacotans from Caulerpa, and some special sulfated mannans from different species. These SPs exhibit many beneficial biological activities such as anticoagulant, antiviral, antioxidative, antitumor, immunomodulating, antihyperlipidemic and antihepatotoxic activities. Therefore, marine algae derived SPs have great potential for further development as healthy food and medical products. The present review focuses on SPs derived from marine green algae and presents an overview of the recent progress of determinations of their structural types and biological activities, especially their potential health benefits.

First norovirus outbreaks associated with consumption of green seaweed (Enteromorpha spp.) in South Korea

In February 2012, an outbreak of gastroenteritis was reported in school A; a successive outbreak was reported at school B. A retrospective cohort study conducted in school A showed that seasoned green seaweed with radishes (relative risk 7·9, 95% confidence interval 1·1-56·2) was significantly associated with illness. Similarly, a case-control study of students at school B showed that cases were 5·1 (95% confidence interval 1·1-24·8) times more likely to have eaten seasoned green seaweed with pears. Multiple norovirus genotypes were detected in samples from students in schools A and B. Norovirus GII.6 isolated from schools A and B were phylogenetically indistinguishable. Green seaweed was supplied by company X, and norovirus GII.4 was isolated from samples of green seaweed. Green seaweed was assumed to be linked to these outbreaks. To our knowledge, this is the first reported norovirus outbreak associated with green seaweed.

Antioxidant activity of carboxymethyl (1→3)-β-d-glucan (from the sclerotium of Poria cocos) sulfate (in vitro)

(1→3)-β-d-glucan derived from Poria cocos hardly exhibits bioactivities. To extend its use, three types of (1→3)-β-d-glucan derivatives, which were sulfated (1→3)-β-d-glucan (S-P), carboxymethyl (1→3)-β-d-glucan (CMP) and carboxylmethyl (1→3)-β-d-glucan sulfate (S-CMP), were synthesized. Potential antioxidant activities of S-P, CMP and S-CMP were evaluated in vitro. The experiments of scavenging abilities of free radicals were carried out, such as 1,1-diphenyl-2-picrylhydrazyl (DPPH), superoxide anion and hydroxyl. Deeply study of the derivatives' inhibitory effect for lipid peroxidation, DNA oxidative damage, erythrocyte hemolysis, and malondialdehyde (MDA) production were determined. And S-CMP significantly (P<0.01) increased the antioxidant activity of β-glucan. These results showed that multiple modifications of polysaccharides may bring the derivatives with excellent properties and various applications.

Sulfated Astragalus polysaccharide can regulate the inflammatory reaction induced by LPS in Caco2 cells

This study evaluates the effect of sulfated Astragalus polysaccharide (SAPS) on inflammatory reaction induced by LPS in Caco2 cells. Sulfated modification was conducted using the chlorosulfonic acid-pyridine method. Caco2 cells were cultured with 25, 50 and 100 μg/mL SAPS or 100 μg/mL Astragalus polysaccharide (APS) for 24 h. Then, 1 μg/mL LPS was added for the next 24 h to trigger an inflammatory response. DMEM culture medium was used as a blank control. In present study, LPS stimulation significantly increased the mRNA expression of TNF-α, IL-1β, IL-8 and TLR4, and reduced the expression of ZO-1 and occludin. Compared with the LPS control group, APS (100 μg/mL) or SAPS (100 μg/mL) administration decreased the expression of TNF-α, IL-1β and IL-8. Moreover, 25 μg/mL and 50 μg/mL SAPS down-regulated TNF-α and IL-1β expression. APS administration (100 μg/mL) up-regulated occludin expression, but did not affect ZO-1 expression. However, the expression of ZO-1 and occludin was up-regulated by lower dose SAPS administration (25 μg/mL and 50 μg/mL). Compared with the other groups, the expression of TLR4 was lower in the SAPS group at all concentrations of SAPS. These results suggest that SAPS was to be a more effective anti-inflammatory agent than APS in vitro.

The immunological and antioxidant activities of polysaccharides extracted from Enteromorpha linza

Polysaccharides extracted with water and alkali from Enteromorpha linza were a group of hetero polysaccharides, and their immunological and antioxidant activities were investigated employing various established in vitro systems. The structural analysis showed that they were composed of rhamnose, mannose, xylose, glucose, and galactose with different molar ratio. Available data obtained with in vitro models suggested that the two kinds of polysaccharide showed significant inhibitory effects on radical and could increase the capability of T and B lymphocytes proliferation. These results clearly establish the possibility that these polysaccharides extracted from E. linza could be effectively employed as ingredient in health or functional food, to all eviate oxidative stress. However, comprehensive studies need to be conducted in experimental animal models.

Separation and scavenging superoxide radical activity of chitooligomers with degree of polymerization 6-16

The separation of chitooligomers (COS) with well-defined degree of polymerization (DP) is of interest to further study their bioactivity. However, there has been no report on separation of chitooligomers with DP>6 and the activity of these oligomers is unknown. This paper focuses on separating COS with DP>6 and five fractions were separated from the prepared fully deacetylated chitooligomers mixture by CM Sepharose Fast Flow column and analyzed by HPLC, which mainly contained glucosamine oligomers with DP6-7 (41.31%, 50.22%), DP7-8 (22.47%, 70.13%), DP9-10 (53.06%, 27.99%), DP10-12 (18.45%, 49.36%, 22.31%), and DP>12, respectively. The superoxide radical scavenging activity of each fraction was investigated. The oligomers with DP ranging from 10 to 12 exhibited higher scavenging activity than other fractions and in combination with the DP distribution of fractions, it was further concluded that the chitooligomers with DP11 was likely to be optimal for scavenging superoxide radical activity.