Brown Seaweed Polysaccharides Research Articles

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.

Comparison of Chemical Composition and Bioactivities of Polysaccharides of Brown Seaweeds, the Red Sea, Egypt, Hurghada

Sulfated polysaccharides (SPs) from algae have been shown to be effective in a number of biological applications. Therefore, the chemical composition and different biological functions of various SPs were determined for three brown seaweed species from the Egyptian Red Sea: <i>Dictyopteris polypodioides, Polycladia myrica</i>, and <i>Turbinaria decurrens</i>. It has been found that the yield of crude SPs was higher than that of alginate and fucoidan with a range of 43.64% to 61.90%. Fucoidan, which has the maximum carbohydrate content of 56.89%, was found in <i>D. polypodioides.</i> The crude SPs of <i>P. myrica </i>had the greatest sulfate content of 22.44%. All functional groups of the examined samples were confirmed by the Fourier Transform Infrared spectrum (FTIR). Experimentally, three applicable assays were used to quantify the antioxidant activity of the extracted SPs depending on the method used, the type of polysaccharides, and algal species. The anti-diabetic activity of <i>T. decurrens</i>-crude SPs was highly active scoring 85.85% in the α-glucosidase assay. The anti-obesity activity showed the highest value (95.25%) for <i>T. decurrens</i>-fucoidan. Besides, <i>T. decurrens</i>-crude SPs showed the highest anti-arthritic activity (89.89%). In addition, a few positive records of antibacterial activity were detected. Furthermore, the most potent <i>T. decurrens</i>-crude SPs extract was tested for cytotoxicity against human liver cells and found to be safe. The activity of the isolated SPs and their chemical composition were shown to be correlated. Conclusively, the bioactivities recorded herein by the tested SPs pose promising medicinal applications towards developing a new therapeutic intervention.

Polysaccharides from brown seaweed: Physicochemical properties, absorption in the intestine, and beneficial effects on intestinal barrier

AbstractThe intestinal barrier is critical in maintaining gut homeostasis and host health. The intestinal barrier dysfunction contributes to intestinal and systemic diseases like inflammatory bowel disease, colorectal cancer, and metabolic syndromes. This review summarizes the physicochemical properties of three main kinds of brown seaweed polysaccharides (BSP), laminarin, fucoidan, and alginate, along with their absorption and metabolism in the intestine and their effects on the intestinal barrier. The physicochemical properties of BSP were closely related to their beneficial effects on intestinal health. BSP were not digested directly in the upper gastrointestinal tract but could be utilized through fermentation by the gut microbiota. BSP kept the integrity of intestinal epithelium by ameliorating intestinal oxidative stress through the nuclear factor erythroid 2‐related factor 2 signaling pathway. They also reduced tight junction dysfunction and intestinal permeability and increased the expression of mucins. Moreover, BSP regulated the composition and abundance of gut microbiota and promoted the production of beneficial metabolites such as short‐chain fatty acids. This review will help to understand the gut health‐promoting functions of the natural compounds derived from brown seaweed and offer a new perspective on intestinal disease prevention and therapy with high effectiveness and safety.

Alginate and its Two Components Acted Differently Against Dopaminergic Neuronal Loss in Parkinson's Disease Mice Model.

This study aims to investigate and compare the potentially neuroprotective effects and underlying mechanisms for brown seaweed polysaccharides (PS) of Alginate (Alg) and its two components, including polymannuronic acid (PM) and polyguluronic acid (PG), against Parkinson's disease (PD) pathogenesis. Model mice of PD are pretreated with Alg or PM or PG, separately via oral gavage once per day for four weeks. Our results found PM improved motor functions of PD mice, but Alg or PG did not. PM or PG, but not Alg, can prevent dopaminergic neuronal loss by increasing tyrosine hydroxylase (TH) expressions in midbrain of PD mice. The neuroprotective effects of PM rely on its anti-inflammation effects and its ability to improve striatal neurotransmitters (serotonin (5-HT) and 5-hydroxyindole acetic acid (5-HIAA)) levels in PD mice. PM inhibits inflammation, but PG or Alg induces inflammation in systemic circulation of PD mice. The neuroprotection provided by PG might be related to its ability to increase striatal neurotransmitter of 5-hydroxyindole acetic acid levels in PD mice. PM plays better than PG to provide neuroprotection, but Alg did not show any neuroprotection against PD. Alg and its two components acted differently in preventing dopaminergic neuronal loss in PD mice.

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.

Impact of advanced extraction technologies and characterization of freeze-dried brown seaweed polysaccharides

The main objective of the study is to evaluate the extraction efficiency methods followed by freeze-drying of bioactive brown seaweed polysaccharides (BSPs). Brown seaweeds such as Sargassum wightii, Spatoglossum asperum, Colpomenia sinuosa, Padina tetrastromatica were considered in this study. Conventional solvent extraction (CSE), and advanced extraction techniques such as microwave-aided (MAE), ultrasound-aided (UAE), and enzyme-aided extractions (EAE) were attempted. MAE (2.5 GHz, 15 min) and UAE (50–60 kHz, 30 min) require minimum time and found to be thermal effective compared to the CSE method. EAE exhibited the maximal extraction efficiency of BSPs and S. wightii shown high polysaccharide content (54.99%). The antioxidant activity of all the extracted polysaccharides was evaluated and found to be maximum with P. tetrastromatica. Prebiotic activity assays were attempted on all EAE polysaccharides. Based on antioxidant and prebiotic activity, enzyme-assisted P. tetrastromatica extract was chosen to study for its characteristics using sophisticated analytical techniques. This study signifies the intertwined characteristics of antioxidant properties and shelf life along with its prebiotic activity of freeze-dried bioactive compounds for its desired purpose as a functional ingredient.

Beneficial effects of three brown seaweed polysaccharides on gut microbiota and their structural characteristics: An overview

SummaryThe gut microbiota appears critical in the metabolic health and anti‐disease activity. In this review, we discuss three brown seaweed polysaccharides (alginate, laminarin, fucoidan) for their structural information, the digestive behaviour and the effects on gut microbiota. Bioactivities are associated with various physicochemical properties, like solubility, viscosity, hydration properties, molecular weight, monosaccharide composition, and so on. Brown seaweed polysaccharides can be completely utilised by microbes in the large bowel, and they can regulate the gut microbiota. The ultimate metabolite of these polysaccharides is mainly short‐chain fatty acids, which are able to regulate the ecology of the gut microbiota by increasing the growth of beneficial bacteria and inhibiting the growth of some harmful bacteria. In addition, this article also discusses the relationship between the structure and activity of modulating the gut microbiota. Results show that polysaccharides with low molecular weight are more conductive to modulate gut microbiota.

Prospects of brown seaweed polysaccharides (BSP) as prebiotics and potential immunomodulators

Prebiotics enhance immune response through the modulation of intestinal microbial activities, production of short chain fatty acids (SCFA), direct interaction with toll-like receptors and mucin production. These non-digestible food components are known to be resistant to enzymatic hydrolysis by digestive enzymes and are utilized as carbon source for the growth of beneficial bacteria population through the process of fermentation. Brown seaweed polysaccharides (BSP) have been described as emerging prebiotics due to their potential to stimulate gut microbiota activities at in vitro and in vivo stages. This review therefore examines evidence of the relationship between the prebiotic capacity of BSP, their structure, extraction, and possible mechanisms of immunomodulation. Practical applications Bio-functional ingredients have been widely explored for numerous health benefits. Of interest to this review are polysaccharides of brown seaweed which have great prebiotic prospects. Prebiotics are important bio-functional ingredients having the potential to improve immune health. An understanding of the prebiotic and immunomodulatory potential of BSP provides the food industry a novel alternative source of prebiotics. Excerpts from this review will provide background knowledge and advance scientific research into prospects of BSP as prebiotics and a possible commercialization of BSP products.

Production of monosaccharides and bio-active compounds derived from marine polysaccharides using subcritical water hydrolysis

Polysaccharides are the major components of brown seaweed, accounting for approximately 40–65% of the total mass. The majority of the brown seaweed polysaccharides consists of alginate (40% of dry matter), a linear hetero-polysaccharides commonly developed in fields. However, depolymerisation of alginate is required to recover high-value compounds. In this report, depolymerisation was performed using subcritical water hydrolysis (SWH) at 180–260°C, with a ratio of material to water of 1:25 (w/v) and 1% formic acid as a catalyst. Sugar recovery was higher at low temperatures in the presence of catalyst. The antioxidant properties of Saccharinajaponica showed the best activity at 180°C in the presence of a catalyst. The mass spectra produced using MALDI-TOF showed that polysaccharides and oligosaccharides were produced during hydrothermal treatment. Hydrolysis treatment at 180°C in the presence of a catalyst may be useful for modifying the structure of S. japonica and purified alginate.

Structure of a sulfated xylofucan from the brown alga Punctaria plantaginea

A polysaccharide composed of l-fucose, d-xylose, and sulfate in a molar proportion of about 5:2:3 was isolated from the brown alga Punctaria plantaginea. Polysaccharide structure was elucidated by methylation analysis, Smith degradation, as well as by 1D and 2D NMR spectroscopy. The polysaccharide was shown to contain a backbone of 3-linked α-l-fucopyranose residues, about two thirds of which are sulfated at O-2 forming trisaccharide repeating units →3)-α-l-Fucp2S-(1→3)-α-l-Fucp2S-(1→3)-α-l-Fucp-(1→. This structural regularity is masked by random distribution of non-sulfated β-d-Xylp residues attached to position 4 of the backbone. The polysaccharide is a new representative of a complex ‘fucoidan’ family of sulfated polysaccharides of brown seaweeds.

Microbacterium oxydans, a novel alginate- and laminarin-degrading bacterium for the reutilization of brown-seaweed waste

There is a growing demand for the efficient treatment of seaweed waste. We identified six bacterial strains from the marine environment for the reutilization of brown-seaweed waste, and the most potentially useful strain, Microbacterium oxydans, was chosen and further investigated. Plate assays indicated that this bacterial isolate possessed both alginate lyase and laminarinase activities. The optimal inoculum size, pH, temperature and substrate concentration for the degradation of brown-seaweed polysaccharides by the isolate were as follows: 20% (v v−1), pH 6.0, 37 °C, and 5 g L−1 for alginate and 20% (v v−1), pH 6.0, 30 °C, and 10 g L−1 for laminarin, respectively. During 6 d in culture under the optimal conditions, the isolate produced 0.17 g L−1 of reducing sugars from alginate with 11.0 U mL−1 of maximal alginate lyase activity, and 5.11 and 2.88 g L−1 of reducing sugars and glucose from laminarin, respectively. In particular, a fair amount of laminarin was degraded to glucose (28.8%) due to the isolate's exolytic laminarinase activity. As a result, the reutilization of brown-seaweed waste by this isolate appears to be possible for the production of reducing sugars as a valuable resource. This is the first study to directly demonstrate the ability of M. oxydans to degrade both alginate and laminarin.

The potential of bacteria isolated from ruminal contents of seaweed‐eating North Ronaldsay sheep to hydrolyse seaweed components and produce methane by anaerobic digestion in vitro

The production of methane biofuel from seaweeds is limited by the hydrolysis of polysaccharides. The rumen microbiota of seaweed-eating North Ronaldsay sheep was studied for polysaccharidic bacterial isolates degrading brown-seaweed polysaccharides. Only nine isolates out of 65 utilized > 90% of the polysaccharide they were isolated on. The nine isolates (eight Prevotella spp. and one Clostridium butyricum) utilized whole Laminaria hyperborea extract and a range of seaweed polysaccharides, including alginate (seven out of nine isolates), laminarin and carboxymethylcellulose (eight out of nine isolates); while two out of nine isolates additionally hydrolysed fucoidan to some extent. Crude enzyme extracts from three of the isolates studied further had diverse glycosidases and polysaccharidase activities; particularly against laminarin and alginate (two isolates were shown to have alginate lyase activity) and notably fucoidan and carageenan (one isolate). In serial culture rumen microbiota hydrolysed a range of seaweed polysaccharides (fucoidan to a notably lesser degree) and homogenates of L. hyperborea, mixed Fucus spp. and Ascophyllum nodosum to produce methane and acetate. The rumen microbiota and isolates represent potential adjunct organisms or enzymes which may improve hydrolysis of seaweed components and thus improve the efficiency of seaweed anaerobic digestion for methane biofuel production.

Sulfated polysaccharides of brown seaweeds are ligands of toll-like receptors

Sulfated polysaccharides of brown seaweeds are ligands of toll-like receptors

Sulfated polysaccharides of brown seaweeds--ligands of toll-like receptors

The interaction of sulfated polysaccharides--fucoidans from brown seaweeds Laminaria japonica, Laminaria cichorioides and Fucus evanescens with Toll-like receptors (TLRs) expressed on membranes of embryonic human kidney epithelial cells (HEK293-null, HEK293-TLR2/CD14, HEK293-hTLR4/CD14-MD2 and HEK293-hTLR2/6) was investigated. In vitro fucoidans specifically interacted with TLR-2, TLR-4, and the heterodimer TLR-2/6 resultated in activation of transcription nuclear factor NF-kappaB. Analysis of composition the hydrolyzed fucoidan from F. evanescens was carried out by gas-liquid chromatography and chromatography-mass spectrometry. Results indicated the absence of 3-3-hydroxytetradecanoic acid (3-OHC14), the basic component of lipopolysaccharides in the preparation. Thus, the obtained results suggested that fucoidans from brown seaweeds possessing immunotropic activity are independent ligands for TLRs, and are able to induce genetically determined biochemical processes of protection organisms against pathogenic microorganisms.

A Novel Antinociceptive Sulphated Polysaccharide of the Brown Marine Alga Spatoglossum Schroederi

Sulfated polysaccharides (SP) of brown algae (Phaeophyta) are composed mainly of alpha- L-fucose, being classified as fucans, with recognized role in inflammation but not in nociception, which was already described for SP obtained from red algae. Here the SP of the brown marine alga S. schroederi (named Ss-SP) was isolated and assayed for the antinociceptive effect. Ss-SP was isolated by DEAE-cellulose, analyzed by agarose gel electrophoresis and evaluated in nociception models (Formalin, Hot plate, Von Frey) using Swiss mice (20-25g). Anion exchange chromatography provided four major fractions being F1 (Ss-SP) that of highest metachromatic activity and sugar content. Ss-SP inhibited both phases of the formalin test. In the first phase the paw licking (55.2 +/- 8.07s) was reduced by 45% (30.5 +/- 6.51s) and 40% (32.85 +/- 8.66s) at 0.1 and 1 mg/kg, respectively. In the second phase, Ss-SP was also inhibitory about 39%, but only at 1 mg/kg (83.0 +/- 15.70s) compared to formalin (136.8 +/- 10.27s). This inhibitory effect suggests a mixed mechanism similar to morphine, which was not confirmed in the hot plate test, a model of pain associated with central neurotransmission. However, Ss-SP reduced the animal reaction in response to stimulation withVon Frey filament at the 2nd and 3rd h (20.8 +/- 6.86% versus carrageenan: 47.9 +/- 5.83%; 33.3 +/- 7.71% versus carrageenan: 62.5 +/- 9.83%). Accordingly, the paw edema induced by carrageenan (0.08 +/- 0.01g) was potently reduced in 45.35% by Ss-SP pre-treatment (0.02 +/- 0.003g), corroborating the anti-inflammatory activity demonstrated for brown seaweed polysaccharides. In conclusion our data revealed for the first time the antinociceptive effect of Ss-SP which could be used as a new source of analgesic substances.

Fucoidan reduces the toxicities of chemotherapy for patients with unresectable advanced or recurrent colorectal cancer

Combination chemotherapy with oxaliplatin plus 5-fluorouracil/leucovorin (FOLFOX) or irinotecan plus 5-fluorouracil/leucovorin (FOLFIRI) has become a standard regimen for advanced or recurrent colorectal cancer. Numerous studies have reported that long-term use of FOLFOX or FOLFIRI leads to better survival for these patients. Thus, control of the toxicity of these drugs may be crucial to prolonging survival. Fucoidan is one of the major sulfated polysaccharides of brown seaweeds and exhibits a wide range of biological activities. In the present study, we analyzed the effect of fucoidan on suppressing the toxicity of anti-cancer drugs. A total of 20 patients with unresectable advanced or recurrent colorectal cancer scheduled to undergo treatment with FOLFOX or FOLFIRI were randomly allocated into a fucoidan treatment group (n=10) and a control group without fucoidan treatment (n=10). Results showed that fucoidan regulated the occurrence of fatigue during chemotherapy. Chemotherapy with fucoidan was continued for a longer period than chemotherapy without fucoidan. Additionally, the survival of patients with fucoidan treatment was longer than that of patients without fucoidan, although the difference was not significant. Thus, fucoidan may enable the continuous administration of chemotherapeutic drugs for patients with unresectable advanced or recurrent colorectal cancer, and as a result, the prognosis of such patients is prolonged.

Synthesis, NMR and Conformational Studies of Fucoidan Fragments, 8: Convergent Synthesis of Branched and Linear Oligosaccharides

The brown seaweed polysaccharides fucoidans inhibit microbial adhesion, angiogenesis, P- and L-selectin-mediated inflammation, and blood coagulation. In this communication we report on the efficient highly stereoselective blockwise synthesis of linear and branched fucoidan chains related oligosaccharides α-L-Fucp-(1→3)-[α-L-Fucp-(1→3)] n -α-L-Fucp-OPr (n = 2, 4, 6), α-L-Fucp-( 1→)-[α-L-Fucp-(1→3)-oi-L-Fucp-(1→4)] n -α-L-Fucp-OPr (n = 1, 2), α-L-Fucp-(1→3)-α-L-Fucp-(1→3)-[α-L-Fucp-(1→2)]-α-L-Fucp-OPr and their derivatives bearing sulfonato groups at 02 or at 04 of fucose residues. [2+2], [2+4], and [4+4] Carbohydrate skeleton assembling strategies were applied for the synthesis oftetra-, hexa-, and octasaccharides, respectively. The target oligosaccharides are regarded as model compounds to assess the structure of fucoidan fragments responsible for their biological activity.

Digestive capabilities reflect the major food sources in three species of talitrid amphipods

Digestive enzyme activities of three talitrid amphipods were examined to investigate the relationship between their digestive capabilities and diet. Laminarinase, cellobiase, carboxymethyl-cellulase, xylanase, α- and β-glucosidase and lipase were detected in all three species suggesting talitrid amphipods can readily digest dietary carbohydrate and lipid, including complex polysaccharides. Relatively high specific enzyme activity (Units (mg −1 digestive tract protein) −1) of laminarinase and lipase was detected in Talorchestia marmorata, a supralittoral kelp feeder which is coherent with the digestion of lipid-esters and β-glucans (laminarin) which are the main lipid and storage polysaccharides of brown seaweeds. Talorchestia sp., a low shore intertidal feeder, had high enzymatic activity of α- and β-glucosidase, cellobiase and xylanase, which is consistent with the digestion of diatoms. Keratroides vulgaris, a forest litter feeder had a relatively low specific activity of all enzymes. It is possible that leaf litter is partially digested prior to ingestion by bacteria and fungi present in the rotting vegetation, with bacterial and fungal enzymes contributing to this species' ability to hydrolyse its diet. This study provides the first quantitative data on digestive capacity in these three talitrid amphipods and confirms the relationship between dietary preference and digestive enzyme complement.

Polysaccharides of brown seaweeds X. The structure of the side chains of the pelvecyan molecule

The compositions and structures of some oligosaccharides isolated by the partial acid hydrolysis and acetolysis of pelvecyan have been established. It has been shown that the side chains of the pelvecyan molecule consist of residues of fucose, xylose, and galactose connected with one another in various sequences and by various types of glycosidic bonds.

Polysaccharides of brown seaweeds VIII. The structure of the side chains of the sargassan molecule

Polysaccharides of brown seaweeds VIII. The structure of the side chains of the sargassan molecule