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Foley SA, Szegezdi E, Mulloy B, Samali A, Tuohy MG. An unfractionated fucoidan from Ascophyllum nodosum: extraction, characterization, and apoptotic effects in vitro. J Nat Prod 2011; 74:1851-61. [PMID: 21875034 DOI: 10.1021/np200124m] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
An unfractionated fucoidan was extracted from the brown alga Ascophyllum nodosum. Extraction of fucoidan from seaweed was carried out using an innovative low-chemical process. A combinational approach involving compositional analysis, HPAEC, IR analysis, GPC, and NMR was employed to elucidate the composition and structure of an unfractionated fucoidan from A. nodosum. This fucoidan is composed mainly of fucose (52.1%), and also galactose (6.1%), glucose (21.3%), and xylose (16.5%). Sulfate content was determined to be 19%. GPC data indicated a polydisperse fucoidan containing two main size fractions (47 and 420 kDa). NMR analyses revealed a fucoidan displaying broad, complex signals as expected for such a high molecular weight and heterogeneous polymer with resonances consistent with a fucoidan isolated previously from A. nodosum. The effects of fucoidan on the apoptosis of human colon carcinoma cells and fucoidan-mediated signaling pathways were also investigated. Fucoidan decreased cell viability and induced apoptosis of HCT116 colon carcinoma cells. Fucoidan treatment of HCT116 cells induced activation of caspases-9 and -3 and the cleavage of PARP, led to apoptotic morphological changes, and altered mitochondrial membrane permeability. These results detail the structure and biological activity of an unfractionated fucoidan from A. nodosum.
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Affiliation(s)
- Sarah A Foley
- Department of Biochemistry, School of Natural Sciences, National University of Ireland, Galway, Ireland.
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102
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Audibert L, Fauchon M, Blanc N, Hauchard D, Gall EA. Phenolic compounds in the brown seaweed Ascophyllum nodosum: distribution and radical-scavenging activities. Phytochem Anal 2010; 21:399-405. [PMID: 20333652 DOI: 10.1002/pca.1210] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Accepted: 01/20/2010] [Indexed: 05/29/2023]
Abstract
INTRODUCTION Phenolic compounds are metabolites exhibited at high levels in Phaeophyceae. Although several studies have been conducted on total phenol contents, no one to our knowledge has dealt with the contents of phenolic compounds and antioxidant activities on purified fractions. OBJECTIVE The purpose of this study was the extraction and purification of phenolic compounds from the brown seaweed Ascophylllum nodosum, to determine both their distribution and their radical-scavenging activities, and to obtain a sufficiently purified oligophenolic fraction to perform an RP-HPLC analysis on molecules with a molecular weight (MW) < 2 kDa. METHODOLOGY Phenolic compounds were separated and purified by liquid-liquid extraction, tangential ultrafiltration and dialysis. Then, the contents of both phenolic compounds and radical-scavenging activities were measured by the Folin-Ciocalteu reagent, and DPPH and ABTS assays. NMR analysis was performed to validate the process. RP-HPLC with a C(18) column was performed on the oligophenolic fraction, using a novel method developed in this study. RESULTS Seven fractions were obtained as a function of polarity and molecular weight. Among them, the fraction containing phenolic compounds with a MW ≥ 50 kDa appeared to be the most active, correlated with the content of phenolic compounds. CONCLUSION This work constitutes a step forward in the separation and purification of bioactive phlorotannins and represents a prerequisite for further investigations into their structural characterisation and distribution in A. nodosum.
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Affiliation(s)
- Laetitia Audibert
- Laboratoire d'Ecophysiologie et de Biotechnologies des Halophytes et des Algues Marines, Europeen Institute of Marine Studies-University of West Brittany, Technopole Brest-Iroise, place Nicolas Copernic, 29280 Plouzané, Brittany, France.
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103
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Jiang Z, Okimura T, Yokose T, Yamasaki Y, Yamaguchi K, Oda T. Effects of sulfated fucan, ascophyllan, from the brown Alga Ascophyllum nodosum on various cell lines: a comparative study on ascophyllan and fucoidan. J Biosci Bioeng 2010; 110:113-7. [PMID: 20541128 DOI: 10.1016/j.jbiosc.2010.01.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Revised: 01/04/2010] [Accepted: 01/04/2010] [Indexed: 10/19/2022]
Abstract
The effects of fucose-containing sulfated polysaccharides, ascophyllan and fucoidan, isolated from the brown alga Ascophyllum nodosum, on the growth of various cell lines (MDCK, Vero, PtK(1), CHO, HeLa, and XC) were investigated. In a colony formation assay, ascophyllan and fucoidan showed potent cytotoxic effects on Vero and XC cells, while other cell lines were relatively resistant to these polysaccharides. Almost no significant effects of these polysaccharides were observed in the cell lines tested using the Alamar blue cytotoxicity assay over 48 h with varying initial cell densities (2500-20,000 cells/well) in growth medium. Interestingly, a significant growth promoting effect of ascophyllan on MDCK cells was observed, whereas treatment with fucoidan showed growth suppressive effects on this cell line under the same experimental conditions. These results suggest that ascophyllan is distinguishable from fucoidan in terms of their bioactivities. This is the first report of the growth promoting effects of a sulfated fucan on a mammalian cell line under normal growth conditions.
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Affiliation(s)
- Zedong Jiang
- Graduate School of Science and Technology, Nagasaki University, Nagasaki 852-8521, Japan
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104
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Abstract
Ascophyllum nodosum is a brown seaweed that grows abundantly in the Northeast coastal region. In this study, the potential of A. nodosum for type 2 diabetes management through antioxidant-mediated alpha-glucosidase and alpha-amylase inhibition was investigated. After the initial screening of 4 locally harvested seaweeds, A. nodosum was chosen for its highest phenolic content and was subjected to water extraction. Among extraction ratios of 50 g to 100 to 1000 mL at room temperature, 50 g/400 mL yielded the highest phenolic content of 4.5 mg/g wet weight. For evaluation of extraction temperature ranging from 20 to 80 degrees C, 50 g/400 mL was chosen as a minimum amount of extractant. Among temperatures studied, extraction at 80 degrees C resulted in the highest total phenolic contents (4.2 mg/g wet weight). All extracts had similar levels of antioxidant activity in the range of 60% to 70% in terms of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. The 80 degrees C extract had the highest alpha-glucosidase and alpha-amylase inhibitory activity with IC(50) of 0.24 and 1.34 microg phenolics, respectively, compared to the IC(50) of acarbose, reference inhibitor, being 0.37 and 0.68 microg. The results show that fresh A. nodosum has strong alpha-glucosidase and mild alpha-amylase inhibitory activities that correlated with phenolic contents. This study suggests a nutraceutical potential of A. nodosum based on phytochemical antioxidant and antihyperglycemia activities.
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Affiliation(s)
- E Apostolidis
- Dept. of Nutrition and Food Sciences, Food Science & Nutrition Research Center, Univ. of Rhode Island, Kingston, RI 02881, USA.
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105
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Rayirath P, Benkel B, Mark Hodges D, Allan-Wojtas P, Mackinnon S, Critchley AT, Prithiviraj B. Lipophilic components of the brown seaweed, Ascophyllum nodosum, enhance freezing tolerance in Arabidopsis thaliana. Planta 2009; 230:135-47. [PMID: 19363684 DOI: 10.1007/s00425-009-0920-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Accepted: 03/05/2009] [Indexed: 05/08/2023]
Abstract
Extracts of the brown seaweed Ascophyllum nodosum enhance plant tolerance against environmental stresses such as drought, salinity, and frost. However, the molecular mechanisms underlying this improved stress tolerance and the nature of the bioactive compounds present in the seaweed extracts that elicits stress tolerance remain largely unknown. We investigated the effect of A. nodosum extracts and its organic sub-fractions on freezing tolerance of Arabidopsis thaliana. Ascophyllum nodosum extracts and its lipophilic fraction significantly increased tolerance to freezing temperatures in in vitro and in vivo assays. Untreated plants exhibited severe chlorosis, tissue damage, and failed to recover from freezing treatments while the extract-treated plants recovered from freezing temperature of -7.5 degrees C in in vitro and -5.5 degrees C in in vivo assays. Electrolyte leakage measurements revealed that the LT(50) value was lowered by 3 degrees C while cell viability staining demonstrated a 30-40% reduction in area of damaged tissue in extract treated plants as compared to water controls. Moreover, histological observations of leaf sections revealed that extracts have a significant effect on maintaining membrane integrity during freezing stress. Treated plants exhibited 70% less chlorophyll damage during freezing recovery as compared to the controls, and this correlated with reduced expression of the chlorphyllase genes AtCHL1 and AtCHL2. Further, the A. nodosum extract treatment modulated the expression of the cold response genes, COR15A, RD29A, and CBF3, resulting in enhanced tolerance to freezing temperatures. More than 2.6-fold increase in expression of RD29A, 1.8-fold increase of CBF3 and two-fold increase in the transcript level of COR15A was observed in plants treated with lipophilic fraction of A. nodosum at -2 degrees C. Taken together, the results suggest that chemical components in A. nodosum extracts protect membrane integrity and affect the expression of stress response genes leading to freezing stress tolerance in A. thaliana.
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Affiliation(s)
- Prasanth Rayirath
- Department of Plant and Animal Sciences, Nova Scotia Agricultural College, 58 River Road, P.O. Box 550, Truro, NS B2N5E3, Canada
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106
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Nakayasu S, Soegima R, Yamaguchi K, Oda T. Biological activities of fucose-containing polysaccharide ascophyllan isolated from the brown alga Ascophyllum nodosum. Biosci Biotechnol Biochem 2009; 73:961-4. [PMID: 19352011 DOI: 10.1271/bbb.80845] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A fucose-containing, sulfated polysaccharide ascophyllan was isolated from the brown alga Ascophyllum nodosum. Composition analysis demonstrated that ascophyllan mainly contains uronic acid, xylose, fucose, and sulfate half ester in approximately equimolecular proportions, which are evidently distinct from those of alginate and fucoidan. Ascophyllan inhibited the proliferation of U937 cells in a concentration-dependent manner, and DNA-fragmentation and typical apoptotic nuclear morphological changes were observed in the ascophyllan-treated cells. Furthermore, ascophyllan induced the secretion of tumor necrosis factor-alpha (TNF-alpha) and granulocyte colony-stimulating factor (G-CSF) from mouse macrophage cell line RAW264.7.
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Affiliation(s)
- Seiichirou Nakayasu
- Research and Development Division, Hayashikane Sangyo Co., Ltd., Shimonoseki, Yamaguti 750-8608, Japan
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107
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Morrison L, Baumann HA, Stengel DB. An assessment of metal contamination along the Irish coast using the seaweed Ascophyllum nodosum (Fucales, Phaeophyceae). Environ Pollut 2008; 152:293-303. [PMID: 17949868 DOI: 10.1016/j.envpol.2007.06.052] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2006] [Revised: 06/12/2007] [Accepted: 06/14/2007] [Indexed: 05/25/2023]
Abstract
The relative abundance and variation of Cr, Co, Cd and Pb in Ascophyllum nodosum and intertidal surface sediments from six locations around the coast were assessed over six seasons. Higher Cd and Pb levels in Galway Docks and Cork Harbour were attributed to localised inputs of these metals from municipal and domestic waste, while at a reference site (Ballyconneely), high algal Cr concentrations were considered a function of geological setting rather than anthropogenic loading. Little seasonal variation was observed, with the exception of higher Co levels in plants in winter, associated with growth dynamics and increased fluvial inputs. In comparison with previously published data for metals in A. nodosum from the North Atlantic, with the exception of localised hot spots, the Irish coastline is still a relatively pristine environment. A. nodosum may be successfully and easily used as a biomonitor of metal contamination in coastal waters.
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Affiliation(s)
- Liam Morrison
- Department of Botany, Martin Ryan Institute and Environmental Change Institute, National University of Ireland, Galway, Ireland.
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108
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Parys S, Rosenbaum A, Kehraus S, Reher G, Glombitza KW, König GM. Evaluation of quantitative methods for the determination of polyphenols in algal extracts. J Nat Prod 2007; 70:1865-70. [PMID: 18052031 DOI: 10.1021/np070302f] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Marine brown algae such as Ascophyllum nodosum and Fucus vesiculosus accumulate polyphenols composed of phloroglucinol units. These compounds are of ecological importance and, due to their antioxidative activity, of pharmacological value as well. In this study four methods for the quantitative determination of phlorotannins are compared: spectrophotometric determinations using Folin-Ciocalteu's phenol reagent or 2,4-dimethoxybenzaldehyde (DMBA), quantitative (1)H NMR spectroscopy (qHNMR), and gravimetrical measurements. On the basis of the relative standard deviation and the F-test, the determination using Folin-Ciocalteu's phenol reagent and qHNMR proved to be the most reliable and precise methods.
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Affiliation(s)
- Sabine Parys
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, D-53115, Bonn, Germany
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109
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Zhang J, Tiller C, Shen J, Wang C, Girouard GS, Dennis D, Barrow CJ, Miao M, Ewart HS. Antidiabetic properties of polysaccharide- and polyphenolic-enriched fractions from the brown seaweed Ascophyllum nodosum. Can J Physiol Pharmacol 2007; 85:1116-23. [PMID: 18066114 DOI: 10.1139/y07-105] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We screened seaweed species from Atlantic Canada for antidiabetic activity by testing extracts for alpha-glucosidase inhibitory effect and glucose uptake stimulatory activity. An aqueous ethanolic extract of Ascophyllum nodosum was found to be active in both assays, inhibiting rat intestinal alpha-glucosidase (IC50 = 77 microg/mL) and stimulating basal glucose uptake into 3T3-L1 adipocytes during a 20-minute incubation by about 3-fold (at 400 microg/mL extract). Bioassay-guided fractionation of the A. nodosum extract showed that alpha-glucosidase inhibition was associated with polyphenolic components in the extract. These polyphenolics, along with other constituents appeared to be responsible for the stimulatory activity on glucose uptake. However, attempts to further concentrate this activity through fractionation techniques were unsuccessful. A crude polyphenol extract (PPE), an enriched polyphenolic fraction (PPE-F1) and a polysaccharide extract (PSE) were prepared from commercial A. nodosum powder and administered to streptozotocin-diabetic mice for up to 4-weeks by daily gavage at 200 mg/kg body mass. PPE and PPE-F1 improved fasting serum glucose level in diabetic mice; however, the effect was only statistically significant at day 14. In addition, PPE-F1 was shown to blunt the rise in blood glucose after an oral sucrose tolerance test in diabetic mice. Mice treated with PPE and PPE-F1 had decreased blood total cholesterol and glycated serum protein levels compared with untreated diabetic mice, whereas PPE also normalized the reduction in liver glycogen level that occurred in diabetic animals. All 3 A. nodosum preparations improved blood antioxidant capacity.
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Affiliation(s)
- Junzeng Zhang
- Ocean Nutrition Canada Limited, 101 Research Drive, Dartmouth, NS B2Y 4T6, Canada
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110
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Daniel R, Chevolot L, Carrascal M, Tissot B, Mourão PAS, Abian J. Electrospray ionization mass spectrometry of oligosaccharides derived from fucoidan of Ascophyllum nodosum. Carbohydr Res 2007; 342:826-34. [PMID: 17280652 DOI: 10.1016/j.carres.2007.01.009] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2006] [Revised: 01/08/2007] [Accepted: 01/10/2007] [Indexed: 10/23/2022]
Abstract
Algal fucoidan is a complex sulfated polysaccharide whose structural characterization requires powerful spectroscopic methodologies. While most of the structural investigations reported so far have been performed using NMR as the main spectroscopic method, we report herein data obtained by negative electrospray ionization mass spectrometry. MS analysis has been carried out on oligosaccharides obtained by partial hydrolysis of fucoidan from the brown algae Ascophyllum nodosum. Oligosaccharide mixtures were fractionated by size exclusion chromatography, which allowed the analysis of oligomers ranging from monosaccharide to pentasaccharide. Monosaccharides were detected as monosulfated as well as disulfated forms. Besides, part of the oligosaccharides exhibited a high content of sulfate, evidencing that fucoidan contains disulfated fucosyl units. Fragmentation experiments yielded characteristic fragment ions indicating that the fucose units are mainly 2-O-sulfated. This study demonstrates that highly sulfated oligosaccharides from fucoidan can be analyzed by ESIMS which gives additional information about the structure of this highly complex polysaccharide.
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Affiliation(s)
- Régis Daniel
- CNRS, UMR 8587, Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement, Université d'Evry Val d'Essonne, F-91025 Evry, France.
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111
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Coleman RA, Ramchunder SJ, Davis KM, Davies KM, Moody AJ, Foggo A. Herbivore-induced infochemicals influence foraging behaviour in two intertidal predators. Oecologia 2007; 151:454-63. [PMID: 17106720 DOI: 10.1007/s00442-006-0601-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2005] [Accepted: 10/20/2006] [Indexed: 10/23/2022]
Abstract
Herbivore-induced defences appear ubiquitous across most biomes and habitats. Yet the direct correlation between induced changes in host plant chemistry and the population dynamics of the herbivore remain untested in many systems. In plant-herbivore interactions in the terrestrial environment, indirect or tritrophic interactions appear a successful way in which changes in the host plant chemistry induced by prior herbivory can impact on herbivore populations via increased success of natural enemies. This set of interactions remains untested in the marine system. Here, we present work from experiments using orthogonal contrasts of plants with different prior treatments (control, mechanical damage or herbivory) and the presence or absence of herbivores on the foraging behaviour of a crab, Carcinus maenas, and a fish, Lipophrys pholis. These experiments were carried out using a novel flow-through flume, i.e. as a choice chamber supplied by turbulent water from independent cue sources. Our results show that in the Ascophyllum nodosum (plant)-Littorina obtusata (herbivore) system infochemicals from induced plants can directly influence predator foraging behaviour. L. pholis was attracted to the presence of a feeding L. obtusata, but was also more attracted to odours from herbivore-induced tissue than odours from mechanically damaged or naïve A. nodosum. C. maenas was more attracted to odours from herbivore-induced tissue compared to naïve tissue, regardless of the presence of L. obtusata. This is the first demonstration of such behavioural consequences of herbivore-induced changes in plants for marine systems.
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Affiliation(s)
- Ross A Coleman
- Marine Biology and Ecology Research Centre, School of Biological Sciences, University of Plymouth, Plymouth, PL4 8AA, UK.
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112
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Oliver LR, Perkins WT, Mudge SM. Detection of technetium-99 in Ascophyllum nodosum from around the Welsh coast. Chemosphere 2006; 65:2297-303. [PMID: 16808960 DOI: 10.1016/j.chemosphere.2006.05.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2005] [Revised: 05/08/2006] [Accepted: 05/09/2006] [Indexed: 05/10/2023]
Abstract
The presence of the radionuclide (99)Tc in the marine environment is of concern to environmental scientists because of its conservative nature and high concentration factor in commercially valuable species. The brown seaweed Ascophyllum nodosum (Linnaeus) Le Jolis was used to biomonitor the spatial distribution of (99)Tc around the Welsh coast, an area relatively unstudied with respect to this isotope. Over the course of a year an inverse relationship was observed between the (99)Tc concentration in A. nodosum samples and approximate straight-line distance from Sellafield. These data show that detectable levels of a Sellafield derived radionuclide are reaching the Welsh coast despite the overall northward movement of the Sellafield plume.
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Affiliation(s)
- Lucie R Oliver
- Institute of Geography and Earth Sciences, University of Wales, Aberystwyth, UK.
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113
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Alhakawati MS, Banks CJ. Removal of copper from aqueous solution by Ascophyllum nodosum immobilised in hydrophilic polyurethane foam. J Environ Manage 2004; 72:195-204. [PMID: 15294352 DOI: 10.1016/j.jenvman.2004.04.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2003] [Revised: 04/07/2004] [Accepted: 04/15/2004] [Indexed: 05/24/2023]
Abstract
The seaweed Ascophyllum nodosum was pre-treated by successive washes in distilled water and dilute acid, dried, and pulverised to produce particles of <150 microm. These were immobilised during the manufacturing process of Hypol 2002 polymer to form a biomass/polymer matrix that was stable and easy to handle. In making the composite a mixing speed of 360 rpm for 20-30 s with 2% (w/w) addition of surfactant to pre-polymer was found to be ideal. The average pore sizes for different water polymer mixes (expressed as volume ratios) were 1.66 mm +/- 0.98 (ratio 0.75:1), 1.58 mm +/- 0.76 (ratio 1:1), 1.64 mm +/- 0.6 (ratio 1.5:1) and 1.11 mm +/- 0.615 (ratio 2:1). The biomass/polymer was used alongside free native biomass in an initial adsorption experiment using a 0.0315 mmol dm(-3) Cu (II) solution and gave a copper uptake capacity (q)(max) of 0.037 mmol Cu g(-1) dry weight seaweed in both cases which represented approximately 85% of total initially available copper. In later adsorption isotherm experiments using Cu concentrations between 0.0315 and 0.944 mmol dm(-3) at pH 5.0 and immobilized biomass over five consecutive adsorption/desorption cycles the biomass/polymer showed an initial lowering of adsorption capacity but stabilised at 0.23 mmol g(-1) dry weight by the third re-use. The q(max) of the immobilised biomass decreased from 0.55 and 0.416 mmol of Cu g(-1) dry weight when pH was lowered from 4.0 to 3.0, and increased from 0.576 mmol g(-1) dry weight (biomass) at 283 K to 0.636 mmol g(-1)(biomass) at 303 K.
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Affiliation(s)
- M S Alhakawati
- Department of Civil and Environmental Engineering, University of Southampton, Southampton, SO17 1BJ, UK
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114
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Borell EM, Foggo A, Coleman RA. Induced resistance in intertidal macroalgae modifies feeding behaviour of herbivorous snails. Oecologia 2004; 140:328-34. [PMID: 15148602 DOI: 10.1007/s00442-004-1589-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2003] [Accepted: 04/14/2004] [Indexed: 11/25/2022]
Abstract
Herbivory in terrestrial and marine systems can induce changes in plant chemistry affecting the foraging behaviour of herbivores. A model based on terrestrial plant-herbivore interactions predicts herbivory-induced changes in leaf chemistry to be manifested in (1) increased herbivore mobility, (2) increased feeding dispersal and (3) reduced tissue consumption by herbivores. This study is the first to demonstrate that herbivory-induced changes in the tissue chemistry of the brown seaweed Ascophyllum nodosum elicit the same response in the feeding behaviour of the gastropod Littorina obtusata as predicted for herbivorous insects, providing good evidence for the model's validity across different ecosystems. The potential benefit of increased feeding dispersal to terrestrial plants as suggested by the model is the prevention of concentrated damage to apical tissues thereby preserving the plant's ability to compete for light; A. nodosum does not conform to these predictions. Increased dispersal of feeding damage on A. nodosum away from primary frond tissues would reduce the likelihood of frond breakage implying a fitness benefit of induced resistance.
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Affiliation(s)
- Esther M Borell
- Marine Biology and Ecology Research Group, School of Biological Sciences, University of Plymouth, Plymouth, PL4 8AA, UK
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