Effect of anticoagulative sulfated polysaccharide purified from enzyme-assistant extract of a brown seaweed Ecklonia cava on Wistar rats

Seaweed in the Diet as a Source of Bioactive Metabolites and a Potential Natural Immunity Booster: A Comprehensive Review

Seaweed plays an essential role in the survival of marine life, provides habitats and helps in nutrient recycling. It is rich in valuable nutritious compounds such as pigments, proteins, polysaccharides, minerals, vitamins, omega-rich oils, secondary metabolites, fibers and sterols. Pigments like fucoxanthin and astaxanthin and polysaccharides like laminarin, fucoidan, galactan and ulvan possess immune-modulatory and immune-enhancing properties. Moreover, they show antioxidative, antidiabetic, anticancer, anti-inflammatory, antiproliferative, anti-obesity, antimicrobial, anticoagulation and anti-aging properties and can prevent diseases such as Alzheimer's and Parkinson's and cardiovascular diseases. Though seaweed is frequently consumed by Eastern Asian countries like China, Japan, and Korea and has gained the attention of Western countries in recent years due to its nutritional properties, its consumption on a global scale is very limited because of a lack of awareness. Thus, to incorporate seaweed into the global diet and to make it familiar as a functional food, issues such as large-scale cultivation, processing, consumer acceptance and the development of seaweed-based food products need to be addressed. This review is intended to give a brief overview of the present status of seaweed, its nutritional value and its bioactive metabolites as functional foods for human health and diseases owing to its immunity-boosting potential. Further, seaweed as a source of sustainable food and its prospects along with its issues are discussed in this review.

A Comparative Analysis of the Anti-Tumor Activity of Sixteen Polysaccharide Fractions from Three Large Brown Seaweed, Sargassum horneri, Scytosiphon lomentaria, and Undaria pinnatifida

Searching for natural products with anti-tumor activity is an important aspect of cancer research. Seaweed polysaccharides from brown seaweed have shown promising anti-tumor activity; however, their structure, composition, and biological activity vary considerably, depending on many factors. In this study, 16 polysaccharide fractions were extracted and purified from three large brown seaweed species (Sargassum horneri, Scytosiphon lomentaria, and Undaria pinnatifida). The chemical composition analysis revealed that the polysaccharide fractions have varying molecular weights ranging from 8.889 to 729.67 kDa, and sulfate contents ranging from 0.50% to 10.77%. Additionally, they exhibit different monosaccharide compositions and secondary structures. Subsequently, their anti-tumor activity was compared against five tumor cell lines (A549, B16, HeLa, HepG2, and SH-SY5Y). The results showed that different fractions exhibited distinct anti-tumor properties against tumor cells. Flow cytometry and cytoplasmic fluorescence staining (Hoechst/AO staining) further confirmed that these effective fractions significantly induce tumor cell apoptosis without cytotoxicity. qRT-RCR results demonstrated that the polysaccharide fractions up-regulated the expression of Caspase-3, Caspase-8, Caspase-9, and Bax while down-regulating the expression of Bcl-2 and CDK-2. This study comprehensively compared the anti-tumor activity of polysaccharide fractions from large brown seaweed, providing valuable insights into the potent combinations of brown seaweed polysaccharides as anti-tumor agents.

Sequential and enzyme-assisted extraction of algal bioproducts from Ecklonia maxima

Brown algae are gaining recognition as sources of bio-compounds with diverse properties and potential applications in the food, nutraceutical, and pharmaceutical industries. Compounds such as polyphenols, alginates and fucoidan possess multiple bioactivities, including antidiabetic, antioxidant, anticancer, anti-inflammatory, and antibacterial properties. Conventional extraction methods provide low yields, posing challenges for the industrial applications of biocompounds. However, innovations are rapidly emerging to address these challenges, and one such approach is enzyme-assisted extraction. Furthermore, extracting single compounds undervalues algal biomass as valuable compounds may remain in the waste. Therefore, the aim of our study was to develop a framework for the sequential and enzyme-assisted extraction of various bio-compounds using the same biomass in a biorefinery process. The Ecklonia maxima algal biomass was defatted, and polyphenols were extracted using solid-liquid extraction with aqueous ethanol. The remaining residue was treated with an enzyme combination (Cellic® Ctec 2 and Viscozyme L) to liberate carbohydrates into solution, where an alginate and fucoidan fraction were isolated. A second alginate fraction was harvested from the residue. The phenolic fraction yielded about 11% (dry weight of extract/dry weight of seaweed biomass), the alginate fraction 35% and the fucoidan fraction 18%. These were analysed using a variety of biochemical methods. Structural analyses, including FTIR, NMR and TGA, were performed to confirm the integrity of these compounds. This study demonstrated that a sequential extraction method for various algal bioproducts is possible, which can pave the way for a biorefinery approach. Furthermore, our study primarily employed environmentally and eco-friendly extraction technologies promoting an environmentally sustainable industrial approach. This approach enhances the feasibility and flexibility of biorefinery operations, contributing to the development of a circular bio-economy.

Structure-activity relationships of bioactive polysaccharides extracted from macroalgae towards biomedical application: A review

Macroalgae are valuable and structurally diverse sources of bioactive compounds among marine resources. The cell walls of macroalgae are rich in polysaccharides which exhibit a wide range of biological activities, such as anticoagulant, antioxidant, antiviral, anti-inflammatory, immunomodulatory, and antitumor activities. Macroalgae polysaccharides (MPs) have been recognized as one of the most promising candidates in the biomedical field. However, the structure-activity relationships of bioactive polysaccharides extracted from macroalgae are complex and influenced by various factors. A clear understanding of these relationships is indeed critical in developing effective biomedical applications with MPs. In line with these challenges and knowledge gaps, this paper summarized the structural characteristics of marine MPs from different sources and relevant functional and bioactive properties and particularly highlighted those essential effects of the structure-bioactivity relationships presented in biomedical applications. This review not only focused on elucidating a particular action mechanism of MPs, but also intended to identify a novel or potential application of these valued compounds in the biomedical field in terms of their structural characteristics. In the last, the challenges and prospects of MPs in structure-bioactivity elucidation were further discussed and predicted, where they were emphasized on exploring modern biotechnology approaches potentially applied to expand their promising biomedical applications.

Antitumor and antioxidant activities of polysaccharides from the seaweed Durvillaea antarctica

The present study was carried out to determine the antitumor and antioxidant activities of the seaweed Durvillaea antarctica. Extraction and purification of polysaccharides from D. antarctica were performed. They were characterized by FT-IR and GC-MS, identifying isomers of arabinose, fucose, mannose, and galactose. The antioxidant capacity of polysaccharides was analyzed using the ABTS method (14.3 ± 0.5 μmol TE g-1 PS) and the DPPH method (21.82 ± 0.32 μmol TE g-1 PS). The antitumor capacity of polysaccharides was studied by MTT colorimetric assays in human leukemia, colon, breast, and lung cancer cell lines, obtaining the lowest IC50 in colon cancer (19.99 μg mL-1 ). In the line of healthy human gingival fibroblasts (HGF-1), an IC50 of 444.39 μg mL-1 was obtained. Flow cytometry in the HL60 cell line showed that polysaccharides at concentrations higher than IC50 inhibited cell proliferation, demonstrating a possible antitumor capacity in vitro. In the proteomic analysis with HGF-1, nine proteins involved in different biological processes were identified. In conclusion, polysaccharides from D. antarctica could be considered powerful nutraceuticals, mainly against colon cancer.

Optimization of fucoidan recovery by ultrasound-assisted enzymatic extraction from South African kelp, Ecklonia maxima

Fucoidan, a sulphated polysaccharide, is found exclusively in brown seaweeds and has been reported to possess a wide range of biological functionalities. Fucoidans are found within the cell wall of brown seaweeds, which is composed of recalcitrant cellulose and hemicellulose. This hampers the recovery of fucoidans. In addition, fucoidans are found within a network of viscous hydrocolloids, alginates, further complicating their recovery. Traditionally, the hot water extraction method is used to recover fucoidans from brown seaweed, however, this is characterized by low yields and long extraction time. To combat these issues, several novel extraction technologies have been introduced, these include ultrasound-assisted extraction and enzyme-assisted extraction. Thus, the main aim of this study was to investigate and optimize fucoidan recovery from Ecklonia maxima based on ultrasound-assisted enzymatic extraction. The impact of temperature (40-65 °C), ultrasound intensity (0-118 W·cm-2), enzyme dosage (0-0.05 ml·g-1) and pH (4.5-6) on total dissolved, total carbohydrates and inorganic sulphates yields was studied. The application of ultrasound-assisted enzymatic extraction mainly improved the extraction of total carbohydrates. Ultrasound significantly improves the kinetics and extraction of fucoidan, but there was no merit when it was applied with enzymes. Results reveal that at optimized conditions, the fucoidan extracted 79.13 mg⋅g-1 (7.9 % w/w) of algal dry weight. The present study provides insight into the extraction potentials of enzyme-assisted extraction, ultrasound-assisted extraction, and ultrasound-assisted enzymatic extraction.

Polysaccharides-Naturally Occurring Immune Modulators

The prevention of disease and infection requires immune systems that operate effectively. This is accomplished by the elimination of infections and abnormal cells. Immune or biological therapy treats disease by either stimulating or inhibiting the immune system, dependent upon the circumstances. In plants, animals, and microbes, polysaccharides are abundant biomacromolecules. Due to the intricacy of their structure, polysaccharides may interact with and impact the immune response; hence, they play a crucial role in the treatment of several human illnesses. There is an urgent need for the identification of natural biomolecules that may prevent infection and treat chronic disease. This article addresses some of the naturally occurring polysaccharides of known therapeutic potential that have already been identified. This article also discusses extraction methods and immunological modulatory capabilities.

Extraction of high purity fucoidans from brown seaweeds using cellulases and alginate lyases

Fucoidans are fucose rich sulfated polysaccharides that are found in the cell wall of brown seaweeds and have been shown to have several beneficial bioactivities. In the present study, we report a new enzymatic extraction technique for the production of pure and intact fucoidans from the two brown seaweeds Saccharina latissima and Alaria esculenta. This new extraction protocol uses the commercial cellulase blend Cellic® CTec2 in combination with endo- and exo-acting thermophilic alginate lyases. The fucoidans obtained by this extraction technique are compared to traditionally extracted fucoidans in terms of chemical compositions and molecular weights and are shown to contain significantly higher amounts of fucose and sulfate, the main components of fucoidans, while cellulose, laminarin, and alginate contamination is low. Thus, by using this combination of enzymes, the extracted fucoidans do not undergo depolymerization during extraction and additional purification steps are not needed. The high purity fucoidans isolated by this new enzymatic extraction technique can be used to provide insight into the different fucoidan structures and biological activities.

Recent advances in industrial applications of seaweeds

Seaweeds have been generally utilized as food and alternative medicine in different countries. They are specifically used as a raw material for wine, cheese, soup, tea, noodles, etc. In addition, seaweeds are potentially good resources of protein, vitamins, minerals, carbohydrates, essential fatty acids and dietary fiber. The quality and quantity of biologically active compounds in seaweeds depend on season and harvesting period, seaweed geolocation as well as ecological factors. Seaweeds or their extracts have been studied as innovative sources for a variety of bioactive compounds such as polyunsaturated fatty acids, polyphenols, carrageenan, fucoidan, etc. These secondary metabolites have been shown to have antioxidant, antimicrobial, antiviral, anticancer, antidiabetic, anti-inflammatory, anti-aging, anti-obesity and anti-tumour properties. They have been used in pharmaceutical/medicine, and food industries since bioactive compounds from seaweeds are regarded as safe and natural. Therefore, this article provides up-to-date information on the applications of seaweed in different industries such as pharmaceutical, biomedical, cosmetics, dermatology and agriculture. Further studies on innovative extraction methods, safety issue and health-promoting properties should be reconsidered. Moreover, the details of the molecular mechanisms of seaweeds and their bioactive compounds for physiological activities are to be clearly elucidated.

Fucoidan for cardiovascular application and the factors mediating its activities

Fucoidan is a sulfated polysaccharide with various bioactivities. The application of fucoidan in cancer treatment, wound healing, and food industry has been extensively studied. However, the therapeutic value of fucoidan in cardiovascular diseases has been less explored. Increasing number of investigations in the past years have demonstrated the effects of fucoidan on cardiovascular system. In this review, we will focus on the bioactivities related to cardiovascular applications, for example, the modulation functions of fucoidan on coagulation system, inflammation, and vascular cells. Factors mediating those activities will be discussed in detail. Current therapeutic strategies and future opportunities and challenges will be provided to inspire and guide further research.

Structural characterization of fucose-containing disaccharides prepared from exopolysaccharides of Enterobacter sakazakii

Fucose-containing oligosaccharides (FCOs) have important applications in the food, medicine, and cosmetics industries owing to their unique biological activities. The degradation of microbial fucose-containing exopolysaccharide (FcEPS) is a promising strategy for obtaining FCOs, and bacteriophage-borne glycanase is a useful tool for degrading FcEPS. Here, we aimed to obtain FCOs using bacteriophage-borne glycanase to depolymerize FcEPS from Enterobacter sakazakii. The FcEPS was mainly composed of l-fucose (42.72 %), d-galactose (20.59 %), and d-glucose (21.81 %). Based on the results of nuclear magnetic resonance and mass spectrometry, the obtained FCOs were disaccharide fragments with backbones of β-d-Glcp-(1→4)-β-l-Fucp and α-d-Galp-(1→3)-β-l-Fucp, respectively. So far, few studies of disaccharides prepared from FcEPS have been reported. This study demonstrated that the FcEPS of E. sakazakii was a reliable fucose-containing disaccharide source and that bacteriophage-borne glycanase was an effective degradation tool for obtaining FCOs fragments from FcEPS.

Characterization of polysaccharides from different species of brown seaweed using saccharide mapping and chromatographic analysis

Brown seaweed polysaccharides (BSPs) are one of the primary active components from brown seaweed that has a range of pharmaceutical and biomedical applications. However, the quality control of BSPs is a challenge due to their complicated structure and macromolecule. In this study, saccharide mapping based on high-performance liquid chromatography (HPLC), multi-angle laser light scattering, viscometer, and refractive index detector (HPSEC-MALLS-Vis-RID), and Fourier transform infrared (FT-IR) were used to discriminate the polysaccharides from nine different species of brown algae (BA1-9). The results showed that BSPs were composed of β-D-glucans and β-1,3-1,4-glucan linkages. The molecular weight, radius of gyration, and intrinsic viscosity of BSPs were ranging from 1.718 × 10⁵ Da to 6.630 × 10⁵ Da, 30.2 nm to 51.5 nm, and 360.99 mL/g to 865.52 mL/g, respectively. Moreover, α values of BSPs were in the range of 0.635 to 0.971, which indicated a rigid rod chain conformation. The antioxidant activities of BSPs exhibited substantial radical scavenging activities against DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2, 2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid) radicals, which indicated that the use of BSPs might be a potential approach for antioxidant supplements. Thus, this study gives insights about the structure-function relationship of BSPs, which will be beneficial to improve the quality of polysaccharides derived from marine algae.

Bioassay-Guided Fractionation and Antimicrobial Activities of Padina australis Extracts

Background: Marine seaweeds synthesize different metabolites with various biological activities, including antimicrobial effects. Objectives: The main object of this study was to fractionate the seaweed Padina australis and analyze the antimicrobial activities of these fractions to isolate the bioactive compounds. Methods: Padina australis was collected from the Persian Gulf and extracted by maceration with methanol-ethyl acetate solvent. The extract was evaporated and partitioned by the Kupchan method to yield hexane, dichloromethane, water, and butanol partitions. Dichloromethane partition was further fractionated by MPLC, and antimicrobial activity of the crude extracts and all fractions were investigated using disc diffusion and agar plate count methods. The MIC values of hexane, dichloromethane, chloroform, and butanol partitions and all fractions were calculated. Results: Fraction numbers 11, 4, and 7 showed the highest inhibitory effect with MIC value of 87 µg/mL, 156 µg/mL, and 156 µg/mL against E. coli, P. aeruginosa, and S. aureus, respectively. Conclusions: This study reveals that different fractions of P. australis have antimicrobial activities against various microorganisms.

Effect of extraction procedures on the chemical structure, antitumor and anticoagulant properties of ulvan from Ulva lactuca of Tunisia coast

The effect of extraction procedures on chemical composition, structural, antitumor and anticoagulant properties of the sulphated polysaccharide 'ulvan' from the green seaweed Ulva lactuca were investigated. The structural features of ulvans were carried out by FTIR and by one- and two- dimensional ¹H and ¹³C NMR spectroscopic. The ulvans were mainly composed of rhamnose, xylose, and uronic acid. Chemical and spectroscopic analyses demonstrated that ulvans were constituted of (1→4)-β-glucuronic acid, (1→3,4)-α-L-rhamnose-3-sulphate and (1→4)-α-xylose. The extraction procedures effect were observed in chemical structure, Mw and biological activities. Cytotoxic activity of enzymatic-chemical extract on cervical cancer cells (HeLa) (IC₅₀ = 1000 μg/mL) was higher than on normal peripheral blood lymphocytes cells (PBL). Acid extracts promoted to reduce HeLa cells and to grow PBL cells. At high concentrations, acid extracts showed the highest APTT and TT clotting time. Antitumoral and anticoagulant activities of ulvans from Ulva lactuca promote their use as effective therapeutic agent.

Bioactive Polysaccharides from Seaweeds

Bioactive compounds with diverse chemical structures play a significant role in disease prevention and maintenance of physiological functions. Due to the increase in industrial demand for new biosourced molecules, several types of biomasses are being exploited for the identification of bioactive metabolites and techno-functional biomolecules that are suitable for the subsequent uses in cosmetic, food and pharmaceutical fields. Among the various biomasses available, macroalgae are gaining popularity because of their potential nutraceutical and health benefits. Such health effects are delivered by specific diterpenes, pigments (fucoxanthin, phycocyanin, and carotenoids), bioactive peptides and polysaccharides. Abundant and recent studies have identified valuable biological activities of native algae polysaccharides, but also of their derivatives, including oligosaccharides and (bio)chemically modified polysaccharides. However, only a few of them can be industrially developed and open up new markets of active molecules, extracts or ingredients. In this respect, the health and nutraceutical claims associated with marine algal bioactive polysaccharides are summarized and comprehensively discussed in this review.

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

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

Enzyme-Assisted Fucoidan Extraction from Brown Macroalgae Fucus distichus subsp. evanescens and Saccharina latissima

Fucoidans from brown macroalgae (brown seaweeds) have different structures and many interesting bioactivities. Fucoidans are classically extracted from brown seaweeds by hot acidic extraction. Here, we report a new targeted enzyme-assisted methodology for fucoidan extraction from brown seaweeds. This enzyme-assisted extraction protocol involves a one-step combined use of a commercial cellulase preparation (Cellic®CTec2) and an alginate lyase from Sphingomonas sp. (SALy), reaction at pH 6.0, 40 °C, removal of non-fucoidan polysaccharides by Ca2+ precipitation, and ethanol-precipitation of crude fucoidan. The workability of this method is demonstrated for fucoidan extraction from Fucus distichus subsp. evanescens (basionym Fucus evanescens) and Saccharina latissima as compared with mild acidic extraction. The crude fucoidans resulting directly from the enzyme-assisted method contained considerable amounts of low molecular weight alginate, but this residual alginate was effectively removed by an additional ion-exchange chromatographic step to yield pure fucoidans (as confirmed by 1H NMR). The fucoidan yields that were obtained by the enzymatic method were comparable to the chemically extracted yields for both F. evanescens and S. latissima, but the molecular sizes of the fucoidans were significantly larger with enzyme-assisted extraction. The molecular weight distribution of the fucoidan fractions was 400 to 800 kDa for F. evanescens and 300 to 800 kDa for S. latissima, whereas the molecular weights of the corresponding chemically extracted fucoidans from these seaweeds were 10-100 kDa and 50-100 kDa, respectively. Enzyme-assisted extraction represents a new gentle strategy for fucoidan extraction and it provides new opportunities for obtaining high yields of native fucoidan structures from brown macroalgae.

Partial Characterization, the Immune Modulation and Anticancer Activities of Sulfated Polysaccharides from Filamentous Microalgae Tribonema sp

Recently, Tribonema sp., a kind of filamentous microalgae, has been studied for biofuel production due to its accumulation of triacylglycerols. However, the polysaccharides of Tribonema sp. and their biological activities have rarely been reported. In this paper, we extracted sulfated polysaccharides from Tribonema sp. (TSP), characterized their chemical composition and structure, and determined their immunostimulation and anticancer activities on RAW264.7 macrophage cells and HepG2 cells. The results showed that TSP is a sulfated polysaccharide with a M_w of 197 kDa. TSP is a heteropolysaccharide that is composed mainly of galactose. It showed significant immune-modulatory activity by stimulating macrophage cells, such as upregulating interleukin 6 (IL-6), interleukin 10 (IL-10), and tumor necrosis factor α (TNF-α). In addition, TSP also showed significant dose-dependent anticancer activity (with an inhibition rate of up to 66.8% at 250 µg/mL) on HepG2 cells as determined by the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cycle analysis indicated that the anticancer activity of TSP is mainly the result of induced cell apoptosis rather than affecting the cell cycle and mitosis of HepG2 cells. These findings suggest that TSP might have potential as an anticancer resource, but further research is needed, especially in vivo experiments, to explore the anticancer mechanism of TSP.

Identification of polysaccharides extracted from pea pod by-products and evaluation of their biological and functional properties

A three-variable Box-Behnken design was employed to obtain the best possible combination of extraction time, ratio (raw material/water) and extraction temperature to allow maximum extraction yield of polysaccharides from pea pod (PPP). The preferred extraction conditions were: extraction time 195 min, extraction temperature 70 °C and ratio of raw material/water 1/40. Under these conditions, the experimental yield was 16.21 ± 1.12%, which is in close agreement with the value predicted by response surface methodology model yield (16.08 ± 0.95%). The molecular weight distribution of PPP showed two peaks with MW of 5217 kDa and 50 kDa, respectively. The main monosaccharides in PPP were galactose, xylose and arabinose, whereas the major functional groups identified from FT-IR spectrum included CO, OH and CH. In addition, PPP had high 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and a moderate reducing power. The antibacterial activity of PPP was also observed against the tested microorganisms and at 50 mg/mL PPP could inhibit the growth of the Gram-negative and Gram-positive bacteria. Generally, these results suggest that the PPP has significant antioxidant activity and good antibacterial activity and can potentially be used as additive in food, pharmaceutical and cosmetic preparations.

Bioactivity of fucoidan extracted from Laminaria japonica using a novel procedure with high yield

Due to antitumor and antioxidant activities, there has been increasing interest in fucoidans, sulfated polysaccharides, from brown algae. Currently, the classic hot water extraction and acid extraction are time-consuming, and can cause the partial cleavage of sulfate esters, leading to bioactivity loss. The present study developed a novel process for extracting fucoidans from Laminaria japonica with 0.5% ethylenediaminetetraacetic acid at 70 °C. Crude fucoidans (CFs) obtained with a yield (∼16%) was purified to different fractions of F1, F2 and F3. The fractions displayed similar anticancer activity against Hela cells. Due to the differences in sulfate content, molar ratio of sulfate to fucose and monosaccharide composition, F1 and F2 exhibited stronger antioxidant ability than CFs and F3. This novel extraction provides an efficient procedure for extracting fucoidans from brown seaweeds with high extraction yield and removing pigments with one single step.

Purification, Preliminary Characterization and Hepatoprotective Effects of Polysaccharides from Dandelion Root

In this study, purification, preliminary characterization and hepatoprotective effects of water-soluble polysaccharides from dandelion root (DRP) were investigated. Two polysaccharides, DRP1 and DRP2, were isolated from DRP. The two polysaccharides were α-type polysaccharides and didn't contain protein. DRP1, with a molecular weight of 5695 Da, was composed of glucose, galactose and arabinose, whereas DRP2, with molecular weight of 8882 Da, was composed of rhamnose, galacturonic acid, glucose, galactose and arabinose. The backbone of DRP1 was mainly composed of (1→6)-linked-α-d-Glc and (1→3,4)-linked-α-d-Glc. DRP2 was mainly composed of (1→)-linked-α-d-Ara and (1→)-linked-α-d-Glc. A proof-of-concept study was performed to assess the therapeutic potential of DRP1 and DRP2 in a mouse model that mimics acetaminophen (APAP) -induced liver injury (AILI) in humans. The present study shows DRP1 and DRP2 could protect the liver from APAP-induced hepatic injury by activating the Nrf2-Keap1 pathway. These conclusions demonstrate that the DRP1 and DRP2 might be suitable as functional foods and natural drugs in preventing APAP-induced liver injury.

Anti-inflammatory activity of a sulfated polysaccharide isolated from an enzymatic digest of brown seaweed Sargassum horneri in RAW 264.7 cells

BACKGROUND/OBJECTIVES

Sargassum horneri is an edible brown alga that grows in the subtidal zone as an annual species along the coasts of South Korea, China, and Japan. Recently, an extreme amount of S. horneri moved into the coasts of Jeju Island from the east coast of China, which made huge economic and environmental loss to the Jeju Island. Thus, utilization of this biomass becomes a big issue with the local authorities. Therefore, the present study was performed to evaluate the anti-inflammatory potential of crude polysaccharides (CPs) extracted from S. horneri China strain in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells.

MATERIALS/METHODS

CPs were precipitated from S. horneri digests prepared by enzyme assistant extraction using four food-grade enzymes (AMG, Celluclast, Viscozyme, and Alcalase). The production levels of nitric oxide (NO) and pro-inflammatory cytokines, including tumor necrosis factor (TNF)-α and interleukin (IL)-1β were measured by Griess assay and enzyme-linked immunosorbent assay, respectively. The levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), nuclear factor (NF)-κB, and mitogen-activated protein kinases (MAPKs) were measured by using western blot. The IR spectrums of the CPs were recorded using a fourier transform infrared spectroscopy (FT-IR) spectrometer.

RESULTS

The polysaccharides from the Celluclast enzyme digest (CCP) showed the highest inhibition of NO production in LPS-stimulated RAW 264.7 cells (IC₅₀ value: 95.7 µg/mL). Also, CCP dose-dependently down-regulated the protein expression levels of iNOS and COX-2 as well as the production of inflammatory cytokines, including TNF-α and IL-1β, compared to the only LPS-treated cells. In addition, CCP inhibited the activation of NF-κB p50 and p65 and the phosphorylation of MAPKs, including p38 and extracellular signal-regulated kinase, in LPS-stimulated RAW 264.7 cells. Furthermore, FT-IR analysis showed that the FT-IR spectrum of CCP is similar to that of commercial fucoidan.

CONCLUSIONS

Our results suggest that CCP has anti-inflammatory activities and is a potential candidate for the formulation of a functional food ingredient or/and drug to treat inflammatory diseases.

Algae as nutritional and functional food sources: revisiting our understanding

Global demand for macroalgal and microalgal foods is growing, and algae are increasingly being consumed for functional benefits beyond the traditional considerations of nutrition and health. There is substantial evidence for the health benefits of algal-derived food products, but there remain considerable challenges in quantifying these benefits, as well as possible adverse effects. First, there is a limited understanding of nutritional composition across algal species, geographical regions, and seasons, all of which can substantially affect their dietary value. The second issue is quantifying which fractions of algal foods are bioavailable to humans, and which factors influence how food constituents are released, ranging from food preparation through genetic differentiation in the gut microbiome. Third is understanding how algal nutritional and functional constituents interact in human metabolism. Superimposed considerations are the effects of harvesting, storage, and food processing techniques that can dramatically influence the potential nutritive value of algal-derived foods. We highlight this rapidly advancing area of algal science with a particular focus on the key research required to assess better the health benefits of an alga or algal product. There are rich opportunities for phycologists in this emerging field, requiring exciting new experimental and collaborative approaches.

Antimicrobial Action of Compounds from Marine Seaweed

Seaweed produces metabolites aiding in the protection against different environmental stresses. These compounds show antiviral, antiprotozoal, antifungal, and antibacterial properties. Macroalgae can be cultured in high volumes and would represent an attractive source of potential compounds useful for unconventional drugs able to control new diseases or multiresistant strains of pathogenic microorganisms. The substances isolated from green, brown and red algae showing potent antimicrobial activity belong to polysaccharides, fatty acids, phlorotannins, pigments, lectins, alkaloids, terpenoids and halogenated compounds. This review presents the major compounds found in macroalga showing antimicrobial activities and their most promising applications.

Anticoagulant sodium alginate sulfates and their mussel-inspired heparin-mimetic coatings

We synthesized novel sodium alginate sulfates (SASs) with different sulfation degrees. All the SASs, DA-g-SASs, and coated substrates had good anticoagulant properties and biocompatibilit.

Phlorotannins suppress adipogenesis in pre-adipocytes while enhancing osteoblastogenesis in pre-osteoblasts

Osteoporosis, a prevalent bone disease in an aging population, is considered to be closely related to osteoblastogenesis and adipogenesis. As a part of an ongoing trend to develop natural substances that attenuate osteoporotic conditions, edible brown algae E. cava and its bioactive constituents were tested for their effects on adipogenic differentiation in 3T3-L1 fibroblasts and osteoblast differentiation in MC3T3-E1 pre-osteoblasts. Following an activity-based isolation, three phlorotannin derivatives, triphlorethol-A (1), eckol (2) and dieckol (3), were isolated. Anti-adipogenesis effect of phlorotannins at the concentration of 20 µM was observed by reduced lipid accumulation and the suppressed expression of adipogenic differentiation markers. In addition, isolated phlorotannins successfully enhanced the osteoblast differentiation as indicated by increased alkaline phosphatase activity along with raised levels of osteoblastogenesis indicators and intracellular calcification at the concentration of 20 µM. In conclusion, E. cava is suggested as a source for functional food ingredients, especially phlorotannin derivatives that can be utilized for extenuating osteoporosis and obesity.

Characteristics and antioxidant of Ulva intestinalis sulphated polysaccharides extracted with different solvents

Ulva intestinalis, a tubular green seaweed, is a rich source of nutrient, especially sulphated polysaccharides. Sulphated polysaccharides from U. intestinalis were extracted with distilled water, 0.1N HCl, and 0.1N NaOH at 80°C for 1, 3, 6, 12, and 24h to study the effect of the extraction solvent and time on their chemical composition and antioxidant activity. Different types of solvents and extraction time had a significant influence on the chemical characteristics and antioxidant activity (p<0.05). Monosaccharide composition and FT-IR spectra analyses revealed that sulphated polysaccharides from all solvent extractions have a typical sugar backbone (glucose, rhamnose, and sulphate attached at C-2 or C-3 of rhamnose). Sulphated polysaccharides extracted with acid exhibited greater antioxidant activity than did those extracted with distilled water and alkali. The results indicated that solvent extraction could be an efficacious method for enhancing antioxidant activity by distinct molecular weight and chemical characteristic of sulphated polysaccharides.

Sulfated chitosan oligosaccharides suppress LPS-induced NO production via JNK and NF-κB inactivation

Various biological effects have been reported for sulfated chitosan oligosaccharides, but the molecular mechanisms of action of their anti-inflammatory effects are still unknown. This study aimed to evaluate the anti-inflammatory effects of sulfated chitosan oligosaccharides and to elucidate the possible mechanisms of action. The results showed that pretreated low molecular weight sulfated chitosan oligosaccharides inhibited the production of nitric oxide (NO) and inflammatory cytokines such as IL-6 and TNF-α in lipopolysaccharide (LPS)-activated RAW264.7 cells. The sulfated chitosan oligosaccharides also suppressed inducible nitric oxide synthase (iNOS), phosphorylation of JNK and translocation of p65, a subunit of NF-κB, into the nucleus by inhibiting degradation of IκB-α. Our investigation suggests sulfated chitosan oligosaccharides inhibit IL-6/TNF-α in LPS-induced macrophages, regulated by mitogen-activated protein kinases (MAPKs) pathways dependent on NF-κB activation.

Structural characterisation of algae Costaria costata fucoidan and its effects on CCl₄-induced liver injury

Fucoidan is a well-known natural product that is commonly found in brown algae and shows a variety of activities, including immunomodulation, antioxidation, and the combat of carcinogens. The fucoidan fractions of Costaria costata, a brown algae introduced from Japan and cultured in northern China, were studied. The fucoidan fractions were extracted, separated, and purified using a combinatorial procedure consisting of enzymolysis, ethanol precipitation, and DEAE and size-exclusion chromatographies. The fundamental characteristics of the four enriched fucoidan fractions (F1-F4), such as their sulphate content and monosaccharide composition, were investigated. FTIR and NMR spectroscopy were employed to further elucidate the structural features of the four fractions. It was found that the F1-F4 fractions all showed oxidative activity against hydroxyl radicals. The bioactive effects of the fucoidan fractions on CCl4-induced liver injury suggest their potential use as ingredients for functional foods or pharmaceuticals.

Water soluble sulfated-fucans with immune-enhancing properties from Ecklonia cava

Water-soluble sulfated fucans isolated from Ecklonia cava were fractionated using an anion-exchange chromatography to investigate their molecular characteristics and immunomodulating activities. The crude fucoidan extract and purified fractions (EF1, EF2, and EF3) consisted mostly of different ratios of neutral sugars, proteins, sulfates, uronic acids, and their monosaccharide compositions were also significantly different. The backbone of the most immunoenhancing fraction, EF2, was mainly linked by (1→3)-linked fucopyranosyl and (1→4)-linked mannopyranosyl residues with sulfates at C-4 of fucopyranosyl units. The molecular weights of the crude fucoidan extract and purified fractions ranged from 8.3×10(3) to 442.6×10(3)g/mol. The crude extract, EF1 and EF2 stimulated RAW264.7 cells to produce considerable amounts of nitric oxide and cytokines. The treatment of cells with the sulfated fucans induced the degradation of Iκ-B and the phosphorylation of MAPK in RAW264.7 cells, implying that they might stimulate RAW264.7 cells through the activation of NF-κB and MAPK pathways.

Chemical characterization, antioxidant and antitumor activity of sulfated polysaccharide from Sargassum horneri

Three water-soluble polysaccharide fractions (SHP30, SHP60, and SHP80) extracted from the Sargassum horneri were obtained by water extraction and radial flow chromatography. The high-performance gel-permeation chromatography analysis showed that the average molecular weight (Mw) of three polysaccharides were approximately 1.58×10(3), 1.92×10(3) and 11.2KDa, respectively. Their in vitro antioxidant activities, antitumor activities were investigated and compared. Among these three polysaccharides, SHP30 with the highest sulfate content and intermediate molecular weight exhibited excellent antioxidant and antitumor activities in the superoxide radical assay, hydroxyl radical assay, reducing power assay, and MTT assay. Then, flow cytometry assay and quantitative real-time reverse transcription-PCR analysis suggested that the accumulation of cells in G0/G1 and S phase effecting apoptosis-associated gene expressions such as Bcl-2 and Bax might account for the growth inhibition of DLD cells by SHP30. Based on these results, we have inferred that sulfate content and molecular weight were the factors influencing antioxidant and antitumor activities.

A comparative study of the anticoagulant activities of eleven fucoidans

Seven fucoidans that differed only with respect to the average molecular weight and four fucoidans that differed with respect to both the molar ratio of fucose to galactose and the average molecular weight were obtained. The anticoagulant activities of these fucoidans were determined in order to understand the effects of the average molecular weight and the content of galactose. Fucoidans Y5-Y11, with the average molecular weight in the range of 50.1-8.4 kDa, showed decreasing activity at three concentrations and dose-dependent activity in the APTT and TT assays. Y1-Y4, which differed with respect to the average molecular weight and the molar ratio of fucose to galactose, exhibited complicated results in the APTT and TT assays. It was shown that not only the average molecular weight but also the molar ratio of fucose to galactose affected the anticoagulant activity of fucoidans.

Therapeutic importance of sulfated polysaccharides from seaweeds: updating the recent findings

Seaweeds, being prolific sources of bioactive components have garnered unprecedented interest in recent times. The complex polysaccharides from the brown, red and green seaweeds possess broad spectrum therapeutic properties. Especially, the sulfated polysaccharides, viz. fucans, carrageenans and ulvans have exhibited strong antioxidant, antitumor, immunostimulatory, anti-inflammatory, pulmonary fibrosis anticoagulant/antithrombotic, lipid lowering, antiviral, antibacterial, antiprotozoan, hyperplasia prevention, gastrointestinal, regenerative and nano medicine applications. Considering the immense biomedical prospects of sulfated polysaccharides, the profound and emerging functional properties published in recent times will be discussed here with experimental evidences. The limitations of the seaweed-derived sulfated polysaccharides in healthcare will be summarized. Strategies to maximize extraction and bioavailability will be pondered.

Structure and antioxidant activities of sulfated guar gum: homogeneous reaction using DMAP/DCC catalyst

It was essential to understand the chemical structure of polysaccharides for further research and biochemical or medical application of this natural biopolymer. In the present study, sulfated derivatives of guar gum with high degree of sulfation (DS) were synthesized using 4-dimethylaminopyridine (DMAP)/dimethylcyclohexylcarbodiimide (DCC) as catalyst in homogeneous conditions. The effects of the ratio of chlorosulfuric acid to pyridine, the content of catalyst and reaction temperature were investigated. Results of FT-IR, (1)H and (13)C NMR indicated that C-6 substitution was predominant in sulfated polysaccharide. In the sulfation reaction, a sharp decrease in M(W) was observed. The enhanced antioxidant activities of sulfated polysaccharides were not a function of a single factor but a combination of high DS and low molecule weight.