Seaweed Ascophyllum Nodosum Research Articles

Microwave assisted extraction of sulfated polysaccharides (fucoidan) from Ascophyllum nodosum and its antioxidant activity

Sulfated polysaccharides (fucoidan) from brown seaweed Ascophyllum nodosum were extracted by microwave assisted extraction (MAE) technology. Different conditions of temperature (90–150°C), extraction time (5–30min) were evaluated and optimal fucoidan yield was 16.08%, obtained from 120°C for 15min's extraction. Compositional analysis, GPC, HPAEC and IR analysis were employed for characterization of extracted sulfated polysaccharides. Fucose was the main monosaccharide of fucoidan extracted at 90°C while glucuronic acid was the main monosaccharide of fucoidan extracted at 150°C. Both the molecular weight and sulfate content of extracted fucoidan increased with decreasing extraction temperature. All fucoidans exhibited antioxidant activities as measured by DPPH scavenging and reducing power, among which fucoidan extracted at 90°C was highest. This study shows that MAE is an efficient technology to extract sulfated polysaccharides from seaweed and Ascophyllum nodosum could potentially be a resource for natural antioxidants.

Anti-metastatic effects of the sulfated polysaccharide ascophyllan isolated from Ascophyllum nodosum on B16 melanoma

We previously found that ascophyllan, a sulfated polysaccharide isolated from brown seaweed Ascophyllum nodosum, exhibited antitumor activity in sarcoma-180 tumor-bearing mice. In this study, we found that ascophyllan inhibited the migration and adhesion of B16 melanoma cells by reducing the expression of N-cadherin and enhancing the expression of E-cadherin in a concentration-dependent manner. Transwell invasion assay revealed that ascophyllan suppressed the invasion ability of B16 cells. It also inhibited the expression of matrix metalloprotease-9 (MMP-9) mRNA and the secretion of MMP-9 protein in B16 cells, a process that may involve the extracellular signal-regulated kinase (ERK) signaling pathway. Furthermore, ascophyllan administered intraperitoneally at 25 mg/kg showed anti-metastatic activity in a mouse model of metastasis induced by intravenous injection of B16 cells, and the number of lung surface metastatic nodules in ascophyllan-treated mice was significantly reduced compared to that in the untreated control mice. Since splenic natural killer cell activity enhanced in the mice injected with ascophyllan intraperitoneally, we suggest that ascophyllan may exhibit in vivo anti-metastatic activity on B16 melanoma cells through activation of the host immune system in addition to a direct action on cancer cells.

Effect of ultrasound pre-treatment on the drying kinetics of brown seaweed Ascophyllum nodosum

The effect of ultrasound pre-treatment on the drying kinetics of brown seaweed Ascophyllum nodosum under hot-air convective drying was investigated. Pretreatments were carried out at ultrasound intensity levels ranging from 7.00 to 75.78Wcm−2 for 10min using an ultrasonic probe system. It was observed that ultrasound pre-treatments reduced the drying time required. The shortest drying times were obtained from samples pre-treated at 75.78Wcm−2. The fit quality of 6 thin-layer drying models was also evaluated using the determination of coefficient (R2), root means square error (RMSE), AIC (Akaike information criterion) and BIC (Bayesian information criterion). Drying kinetics were modelled using the Newton, Henderson and Pabis, Page, Wang and Singh, Midilli et al. and Weibull models. The Newton, Wang and Singh, and Midilli et al. models showed the best fit to the experimental drying data. Color of ultrasound pretreated dried seaweed samples were lighter compared to control samples. It was concluded that ultrasound pretreatment can be effectively used to reduce the energy cost and drying time for drying of A. nodosum.

Optimization of ultrasound assisted extraction of bioactive components from brown seaweed Ascophyllum nodosum using response surface methodology

The objective of this study was to investigate the effect of key extraction parameters of extraction time (5–25min), acid concentration (0–0.06M HCl) and ultrasound amplitude (22.8–114μm) on yields of bioactive compounds (total phenolics, fucose and uronic acid) from Ascophyllumnodosum. Response surface methodology was employed to optimize the extraction variables for bioactive compounds’ yield. A second order polynomial model was fitted well to the extraction experimental data with (R2>0.79). Extraction yields of 143.12mgGAE/gdb, 87.06mg/gdb and 128.54mg/gdb were obtained for total phenolics, fucose and uronic acid respectively at optimized extraction conditions of extraction time (25min), acid concentration (0.03M HCl) and ultrasonic amplitude (114μm). Mass spectroscopy analysis of extracts show that ultrasound enhances the extraction of high molecular weight phenolic compounds from A. nodosum. This study demonstrates that ultrasound assisted extraction (UAE) can be employed to enhance extraction of bioactive compounds from seaweed.

EFFICIENCY OF NATURAL PRODUCTS IN THE CONTROL OF COLLETOTRICHUM ACUTATUM MONITORED BY REAL-TIME PCR

Strawberry anthracnose, caused by Colletotrichum acutatum J.H. Simmonds, has been reported from most areas of the world where strawberries are grown. The use of chemical phytosanitary products to control fungal diseases has been drastically reduced by EU legislation. For that reason, the development of non-chemical alternatives respectful with the environment and human health is urgent. This study tries to evaluate the effect of two natural products which previously showed a potential as plant defense inductors and in vitro biofungicide activity in the control of C. acutatum. Strawberry plants grown under temperature and humidity controlled conditions were treated with a biofungicide product containing seaweed (Ascophyllum nodosum) and cinnamon (Cinnamomum sp.) extracts (0.5%); a plant defense inductor based on quitosan (0.25%); a chemical fungicide (0.3% Chlorthalonil) as positive control, and water as negative control. 24 h after application of these products, plants were inoculated with a conidial suspension of C. acutatum. Non-treated and non-inoculated plants were used as control of natural occurring infection. The progress of C. acutatum infection was monitored by quantifying the amount of fungi at 24 h, 72 h, 7 days and 15 days after inoculation. A reliable, sensitive and fast TaqMan real-time PCR using dilutions of plant crude extracts, without the need of DNA extraction, was used to detect and quantify C. acutatum in the treated and then inoculated plants. Results demonstrated the efficiency of the assayed natural products in controlling the development of the fungus in the plant up to 15 days after treatment. This real-time PCR method based in the use of plant crude extract allows a rapid and sensitive detection and quantification of low amounts of fungus in the plant, even before the appearance of symptoms.

Ascophyllum nodosum in the diet of tilapia (Oreochromis niloticus) and its effect after inoculation of Aeromonas hydrophila

The objective of this study was to evaluate the effect of Ascophyllum nodosum brown seaweed meal (FAM) on the health of Nile tilapia submitted to inoculation with Aeromonas hydrophila. The experiment was conducted for a period of 40 days using 120 Nile tilapia fingerlings, with age of 40 days, distributed in 20 tanks. A diet including Ascophyllum nodosum seaweed meal at 20g.kg-1 and a control diet (without FAM) were provided which constituted the treatments. Thirty days after beginning the experiment, A. hydrophila was inoculated by bacterial inoculum diluted in sterile saline solution at a concentration of 10(6) CFU ml-1. Except for the width, which was greater for the treatment with the provision of FAM (P<0.05), there was no influence on the performance parameters of the fingerlings, but the occurrence of lesions in animals inoculated with A. hydrophila and fed with FAM was lower and they also exhibited a decline in the lesions in a shorter period of time than the control group. FAM prevents hepatopancreatic congestion in infected animals. Ascophyllum nodosum brown seaweed meal reduced the number of lesions in fish in a shorter time when compared to the control group.

Distribution of arsenic and risk assessment of activities on a golf course fertilised with arsenic-containing Ascophyllum nodosum seaweed

The use of seaweed fertilisers in sports green maintenance has become a common practice across the globe due to its image as an “eco-friendly” alternative to chemical fertilisers. The aim of this study was to characterise the risk of human exposure to arsenic (As), via dermal absorption, from golfing activities on a private golf course in the UK, where As contaminated seaweed fertiliser (~100mg/kg d.wt.) is applied. This was fulfilled by, 1) determining As concentrations in shallow soils with GIS geo-statistical analysis, 2) measuring As concentrations from an on-site borehole groundwater well, and (3) developing a risk assessment calculation for golfing activities based on field and questionnaire data. Total As concentrations in shallow soils were less than the UK threshold for domestic soils, however, frequent and sustained dermal contact between site-users and surface soil attributed to a maximum carcinogenic risk value of 2.75×10−4, which is in the upper limit of the acceptable risk range. Arsenic concentrations in underlying groundwater exceeded the WHO's permissible drinking water standard, demonstrating the risk of groundwater contamination following the application of seaweed fertiliser to golf course soils. This is the first risk study on dermal As absorption via the application of a seaweed fertiliser.

Application of bio-stimulator biocomplex 900 in producing tomato (Lycopersicon Essculentum Mill.) seedling

Applications of bio-stimulant Biocomplex 900 was studied in this paper in the production of tomato (Lycopersicon Essculentum Mill) seedling and the hybrid Belle was used. Indicators of growth and development were studied: mass of fresh root matter, stem and leaves, leaf area and the content of photosynthetic parameters in the leaf. A natural bio-stimulator was used in these studies as the ecological preparation, since it contains the seaweed Ascophyllum nodosum with high content of alginic acids, micro elements and amino acids. The application of this bio-stimulant showed very positive impact, compared to the control (untreated) variant and increased the values of almost all investigated parameters.

Prolonged administration of Ascophyllum nodosum to healthy human volunteers and cardiovascular risk

Introduction Edible algae, rich in biologically active components, may influence glycaemic control, lower blood lipids and increase antioxidant activities. The aim of this study was to evaluate the effect of prolonged supplementation with an extract of the brown edible seaweed Ascophyllum nodosum on anthropometric indexes and biomarkers of metabolic risk for cardiovascular disease in human volunteers.

Temporal dynamics of inducible anti-herbivory defenses in the brown seaweed Ascophyllum nodosum (Phaeophyceae)(1).

Anti-herbivory defenses support persistence of seaweeds. Little is known, however, about temporal dynamics in the induction of grazer-deterrent seaweed traits. In two induction experiments, consumption rates of the periwinkle Littorina obtusata (L.) on the brown seaweed Ascophyllum nodosum (L.) Le Jolis were measured in 3-d intervals. Changes in palatability of directly grazed A.nodosum were tested every 3d with feeding assays using fresh and reconstituted seaweed pieces. Likewise, assays with fresh A.nodosum assessed changes in seaweed palatability in response to water-borne cues from nearby grazed conspecifics. Consumption rates of L.obtusata varied significantly during the 27-d induction phase of each experiment. Direct grazing by L.obtusata lowered palatability of fresh and reconstituted A.nodosum pieces to conspecific grazers after 15d as well as after 6 and 12d, respectively. After 12, 18, and 24d, fresh A.nodosum located downstream of L.obtusata-grazed conspecifics was significantly less palatable than A.nodosum located downstream of ungrazed conspecifics. Changes in L.obtusata consumption rates and A.nodosum palatability during both induction experiments suggest temporal variation of grazer-deterrent responses, which may complicate experimental detection of inducible anti-herbivory defenses.

The effect of solvents on the antioxidant activity in Caco-2 cells of Irish brown seaweed extracts prepared using accelerated solvent extraction (ASE®)

The antioxidant activities of extracts from the Irish seaweed Ascophyllum nodosum (AN), Fucus vesiculosus (FV) and Fucus serratus (FS) prepared using different solvents were assessed in Caco-2 cells. The extracts were prepared using 100% H2O (AN100, FV100, FS100), 60% ethanol (AN60e, FV60e, FS60e), 80% ethanol (AN80e, FV80e, FS80e) or 60% methanol (AN60m, FV60m, FS60m) combined with an accelerated solvent extraction (ASE®) technique. The cellular antioxidant status was determined by measuring catalase (CAT) and superoxide dismutase (SOD) activity and glutathione (GSH) content. The protective effects of the extracts against H2O2 and tert-BOOH-induced DNA damage were assessed using the comet assay. AN100 and AN80e significantly protected (P<0.05) against H2O2-induced DNA damage. AN60e, AN80e, FS100, FS80e and FV60m protected against tert-BOOH-induced DNA damage. Extracts prepared from AN, particularly those prepared using 80% aqueous ethanol, appeared to have the greatest antioxidant potential, based on their ability to protect against oxidant-induced DNA damage.

Ascophyllum nodosum Extract and Its Organic Fractions Stimulate Rhizobium Root Nodulation and Growth of Medicago sativa (Alfalfa)

The effects of the seaweed Ascophyllum nodosum extracts (ANE) on nitrogen (N)–fixing nodules and growth of alfalfa plants were studied under greenhouse conditions. The treatment of alfalfa roots increased the number of total nodules per plant with ANE (69%) and organic sub-fractions methanol (20%) and chloroform (35%) at 1 g L−1 concentration. The number of functional nodules was greater per plant in ANE (36%) and its organic sub-fraction chloroform (105%). Maximum increase in shoot length was observed in ANE-treated plants (42%) and chloroform-treated plants (42%). Root length was longer in the chloroform fraction (15%), whereas the shoot dry-weight accumulation was greater in plants treated with ANE (118%), methanol (85%), and chloroform (85%) than the control. Root dry-weight accumulation increased in plants treated with ANE (118%) and chloroform (69%) compared to the control. Further studies are under way to identify the chemical components in ANE and organic fractions.

Seasonal variations in concentrations of macro- and micronutrients in three species of brown seaweed

Abstract We studied variations through 1 year in concentrations of several macronutrients (C, N, P, Na, K, Ca, Mg, S) and micronutrients (Fe, Mn, Cu, Zn) and water content in tissues of the brown seaweeds Ascophyllum nodosum, Fucus vesiculosus and Fucus spiralis at two sites in a coastal embayment in northwest Spain. The annual mean concentrations of the nutrients in A. nodosum were very similar at both sampling locations. There were no significant differences between sites in the concentrations of N, P, Na, K, Ca, S, Fe, Mn or Cu, the C:N or N:P ratios or in the water content, whereas the chemical composition of this species was notably different at the site where it coexisted with F. vesiculosus (the only parameters that were not significantly different were concentrations of Ca, Cu and the N:P ratio). The C:N:P ratios and the clear seasonal variability in N in all species, with minimum values in summer, suggest limitation by this element. Along with N, K was the only other element that varied throughout the seasons in all of the species, and this was most notable in F. vesiculosus. Minimum concentrations of K were also observed in summer, which might indicate limitation by this element. Seasonal variations in C were only observed in the Fucus species; they followed a reverse trend from those of N and K, as the highest levels occurred in summer. The highest concentrations of P and Zn in F. vesiculosus were also observed in spring. No obvious seasonal trends were observed in the remaining minerals.

Transcriptional and metabolomic analysis of Ascophyllum nodosum mediated freezing tolerance in Arabidopsis thaliana.

BackgroundWe have previously shown that lipophilic components (LPC) of the brown seaweed Ascophyllum nodosum (ANE) improved freezing tolerance in Arabidopsis thaliana. However, the mechanism(s) of this induced freezing stress tolerance is largely unknown. Here, we investigated LPC induced changes in the transcriptome and metabolome of A. thaliana undergoing freezing stress.ResultsGene expression studies revealed that the accumulation of proline was mediated by an increase in the expression of the proline synthesis genes P5CS1 and P5CS2 and a marginal reduction in the expression of the proline dehydrogenase (ProDH) gene. Moreover, LPC application significantly increased the concentration of total soluble sugars in the cytosol in response to freezing stress. Arabidopsis sfr4 mutant plants, defective in the accumulation of free sugars, treated with LPC, exhibited freezing sensitivity similar to that of untreated controls. The 1H NMR metabolite profile of LPC-treated Arabidopsis plants exposed to freezing stress revealed a spectrum dominated by chemical shifts (δ) representing soluble sugars, sugar alcohols, organic acids and lipophilic components like fatty acids, as compared to control plants. Additionally, 2D NMR spectra suggested an increase in the degree of unsaturation of fatty acids in LPC treated plants under freezing stress. These results were supported by global transcriptome analysis. Transcriptome analysis revealed that LPC treatment altered the expression of 1113 genes (5%) in comparison with untreated plants. A total of 463 genes (2%) were up regulated while 650 genes (3%) were down regulated.ConclusionTaken together, the results of the experiments presented in this paper provide evidence to support LPC mediated freezing tolerance enhancement through a combination of the priming of plants for the increased accumulation of osmoprotectants and alteration of cellular fatty acid composition.

Alga marinha marrom para alevinos de tilápia do nilo

Este trabalho avaliou os efeitos de níveis crescentes da farinha de alga marrom Ascophyllum nodosum (FAM) nas rações para alevinos de tilápia do Nilo Oreochromis niloticus. O experimento, com delineamento inteiramente casua-lizado, durou 42 dias. Foram utilizados alevinos de tilápia do Nilo (n= 75) com idade média de 30 dias e peso médio de 0,43 ± 0,02 g, distribuídos em 25 tanques plásticos submetidos à cinco tratamentos e cinco repetições. Os tratamentos foram níveis crescentes de farinha de alga marrom (5, 10, 15 e 20 g kg-1 de ração) e uma ração controle (sem FAM). Cada unidade experimental foi composta por um tanque plástico de 36 L com três alevinos. Foram estudados os parâmetros médios de peso final, percentagem de ganho de peso, taxa de conversão alimentar aparente, comprimento total e rendimento de carcaça, com e sem cabeça. As médias de peso final, percentagem de ganho de peso e comprimento total não foram influenciadas pelos tratamentos (p&gt;0,05). Os valores da taxa de conversão alimentar aparente melhoraram linearmente (p

Antioxidant, anti-inflammatory, and anti-senescence activities of a phlorotannin-rich natural extract from brown seaweed Ascophyllum nodosum.

Aging at the cellular level is characterized by oxidative stress, inflammation, and cell senescence. An extract of the brown seaweed Ascophyllum nodosum rich in phlorotannins has been studied for its inhibitory activity against oxidative stress, inflammation, and senescence. A. nodosum extract at 0.2 % prevented tBHP-induced reactive oxygen species production (evaluated using the H2DCF-DA test in cytofluorometry) in epithelial cells and LPS-induced TNF-α and IL-6 release (evaluated using ELISA technique) in macrophages. A. nodosum extract also increased nuclear SIRT1 activity in epithelial cells. Altogether, these beneficial cellular effects of phlorotannin-rich A. nodosum extract could be used in topical therapeutic formulations against aging.

Analysis of Seaweed Extract-induced Transcriptome Leads to Identification of a Negative Regulator of Salt Tolerance in Arabidopsis

Successful development of plants resistant to salinity stress is problematic as a result of the complex polygenic natures of salt tolerance. Previously, alkaline extracts of the brown seaweed Ascophyllum nodosum have shown promise in enhancing plant tolerance toward abiotic stresses. To understand the underlying molecular mechanisms, the whole genome transcriptome of Arabidopsis undergoing salt stress was analyzed by microarray analysis after treatment with the chemical components of A. nodosum extracts (ANE). Treatment with ANE induced many positive regulators of salt tolerance in addition to downregulating numerous other genes. Using T-DNA insertion mutants within these downregulated genes, we examined the potential for a novel source of enhanced NaCl tolerance through removal of negative regulators of NaCl stress responses within Arabidopsis. Several potential target mutations were identified with enhanced salt-tolerant phenotypes. A T-DNA insertion within the promoter of a putative Pectin Methyl Esterase Inhibitor (PMEI) gene (At1g62760) was found to be resistant to salinity stress and was further characterized. This T-DNA insertion mutant was designated as pmei1-1. The phenotype of pmei1-1 seedlings included increased primary root growth in vitro and improved biomass accumulation under NaCl stress. Additionally, modified transcript levels of dehydration-responsive genes, including RD29A, were observed in pmei1-1 plants. Taken together, these results suggest a role for PMEI as a negative regulator of NaCl resistance and that chemical stress-induced transcriptome analysis may lead to identification of additional novel regulators of abiotic stress tolerance in plants, the use of which would have significant implications for agriculture globally.

Brassica napus Growth is Promoted by Ascophyllum nodosum (L.) Le Jol. Seaweed Extract: Microarray Analysis and Physiological Characterization of N, C, and S Metabolisms

Despite its high capacity to take up nitrate from soil, winter rapeseed (Brassica napus) is characterized by a low N recovery in seeds. Thus, to maintain yield, rapeseed requires a high fertilization rate. Increasing nutrient use efficiency in rapeseed by addition of a biostimulant could help improve its agroenvironmental balance. The effects of marine brown seaweed Ascophyllum nodosum on plant growth have been well described physiologically. However, to our knowledge, no study has focused on transcriptomic analyses to determine metabolic targets of these extracts. A preliminary screening of different extracts revealed a significant effect of one of them (AZAL5) on rapeseed root (+102 %) and shoot (+23 %) growth. Microarray analysis was then used on AZAL5-treated or nontreated plants to characterize changes in gene expression that were further supported by physiological evidence. Stimulation of nitrogen uptake (+21 and +115 % in shoots and roots, respectively) and assimilation was increased in a similar manner to growth, whereas sulfate content (+63 and +133 % in shoots and roots, respectively) was more strongly stimulated leading to sulfate accumulation. Among the identified genes whose expression was affected by AZAL5, MinE, a plastid division regulator, was the most strongly affected. Its effect was supported by microscopic analysis showing an enhancement of chloroplast number per cell and starch content but without a significant difference in net photosynthetic rate. In conclusion, it is suggested that AZAL5, which promotes plant growth and nutrient uptake, could be used as a supplementary tool to improve rapeseed agroenvironmental balance.

Marginal populations under pressure: spatial and temporal heterogeneity of Ascophyllum nodosum and associated assemblages affected by human trampling in Portugal

Anthropogenic disturbances are major threats to coastal biodiversity and may exert drastic effects on natural populations occurring at the borders of the geographical distribution of species, which are thus already experiencing sub-optimal environmental conditions. In this paper, we examined the effects of experimental intensities of human trampling on temporal and spa - tial variance of the brown seaweed Ascophyllum nodosum and associated organisms in north Por tugal. This is the southernmost population of A. nodosum in Europe and shows morphological and demographic traits that are different from those of populations from more central locations within its range of distribution. Results indicated that high trampling intensity reduced the small- scale spatial heterogeneity in the abundance of A. nodosum, whose cover was stabilized around relatively low values, and of the associated red algae Polysiphonia lanosa and Rhodothamniella floridula; however, it increased the spatial variance of limpets and green foliose macroalgae of the genus Ulva. Idiosyncratic responses in temporal patterns were also documented, with high tram- pling intensity causing relatively larger fluctuations in the structure of whole A. nodosum associ- ated assemblages and in the abundance of Ulva spp., and smaller fluctuations in the cover of Fucus vesiculosus. The present findings are key to predicting the relatively unstudied responses of coastal populations of A. nodosum to increasing anthropogenic disturbance and have important implications for the management and conservation of the examined population, which represents a relevant component of the biodiversity of European rocky shores.

Bait worm packaging as a potential vector of invasive species

Invasive species have become an increasingly greater concern for the ecological health of coastal ecosystems, yet vectors of these introductions often are unclear. This project evaluated the potential for the brown seaweed Ascophyllum nodosum ecad scorpiodes (Hauck) Reinke, packaged with bait worms (Nereis virens) harvested from the coast of Maine (USA), as a vector of invasive marine fauna and flora. Often, the seaweed and contents of the bait boxes are discarded into the water by recreational fishermen after using the bait worms, and any included non-native species may then be introduced. Bait boxes were purchased from several commercial vendors in Connecticut and New York over a two-year period. Subsamples of the seaweed were placed in laboratory culture and the growth of associated macro- and microalgae was monitored. Marine invertebrate species present in the samples were also identified and quantified. Results indicated 13 species of macroalgae and 23 species of invertebrates were associated with baitboxes. Among the highly diverse microbial assemblage detected, two species of potentially toxic marine microalgae, Alexandrium fundyense Balech and Pseudonitzschia multiseries (Hasle) Hasle, were found both prior to and after incubation at various temperatures, indicating these harmful algae are brought to and can survive in receiving waters. These findings highlight the need to consider alternative choices of bait box packaging materials or appropriate disposal methods of the seaweed in order to minimize the transport of species which are not native to the receiving coastal waters.