Ascophyllum nodosum (Linnaeus) Le Jolis from Arctic: Its Biochemical Composition, Antiradical Potential, and Human Health Risk.

Ascophyllum nodosum is a brown seaweed common in Arctic tidal waters. We have collected A. nodosum samples from the Barents Sea (BS), Irminger Sea (IS), and Norwegian Sea (NS) in different reproductive stages and have evaluated their biochemical composition, radical scavenging potential, and health risks. The total content of dominating carbohydrates (fucoidan, mannitol, alginate, and laminaran) ranged from 347 mg/g DW in NS to 528 mg/g DW in BS. The proportion of two main structural monosaccharides of fucoidan (fucose and xylose) differed significantly between the seas and reproductive phase, reaching a maximum at the fertile phase in the BS sample. Polyphenols and flavonoids totals were highest in NS A. nodosum samples and increased on average in the following order: BS < IS < NS. A positive correlation of free radical scavenging activity for seaweed extracts with polyphenols content was observed. The concentration of elements in A. nodosum from the Arctic seas region was in the following order: Ca > Mg > Sr > Fe > Al > Zn > As total > Rb > Mn > Ba > Cu > Co. Seaweeds from BS had the lowest metal pollution index (MPI) of 38.4. A. nodosum from IS had the highest MPI of 83. According to the calculated target hazard quotient (THQ) and hazard index (HI) values, Arctic A. nodosum samples pose no carcinogenic risk to adult and child health and are safe for regular consumption. Our results suggest that the Arctic A. nodosum has a remarkable potential for food and pharmaceutical industries as an underestimated source of polysaccharides, polyphenols, and flavonoids.

Overlapping Local and Systemic Defense Induced by an Oomycete Fatty Acid MAMP and Brown Seaweed Extract in Tomato.

Eicosapolyenoic fatty acids are integral components of oomycete pathogens that can act as microbe-associated molecular patterns to induce disease resistance in plants. Defense-inducing eicosapolyenoic fatty acids include arachidonic acid (AA) and eicosapentaenoic acid and are strong elicitors in solanaceous plants, with bioactivity in other plant families. Similarly, extracts of a brown seaweed, Ascophyllum nodosum, used in sustainable agriculture as a biostimulant of plant growth, may also induce disease resistance. A. nodosum, similar to other macroalgae, is rich in eicosapolyenoic fatty acids, which comprise as much as 25% of total fatty acid composition. We investigated the response of roots and leaves from AA or a commercial A. nodosum extract (ANE) on root-treated tomatoes via RNA sequencing, phytohormone profiling, and disease assays. AA and ANE significantly altered transcriptional profiles relative to control plants, inducing numerous defense-related genes with both substantial overlap and differences in gene expression patterns. Root treatment with AA and, to a lesser extent, ANE also altered both salicylic acid and jasmonic acid levels while inducing local and systemic resistance to oomycete and bacterial pathogen challenge. Thus, our study highlights overlap in both local and systemic defense induced by AA and ANE, with potential for inducing broad-spectrum resistance against pathogens. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

The effect of foliar application of Ascophyllum nodosum (L.) Le Jol. seaweed extract on biochemical traits related to abiotic stresses in pistachio (Pistacia vera L. cv. Kaleh-Ghoochi).

BACKGROUND: Due to the important economic role of pistachio (Pistacia vera L.) the cultivation of this valuable crop has been extended. Various abiotic stresses harm the growth and performance of pistachio. Seaweed extract containing various substances such as pseudo-hormones that stimulate growth, nutritional elements, and anti-stress substances can cause more resistance to abiotic stresses, and increase the quantity and the quality of the fruit. The present study was conducted to evaluate the effect of foliar application of Ascophyllum nodosum (L.) Le Jol. seaweed extract on some biochemical traits related to abiotic stress in Pistacia vera L. cv. Kaleh-Ghoochi. The first factor of foliar spraying treatment included A. nodosum seaweed extract at four levels (0, 1, 2, and 3 g/L), and the second factor was the time of spraying solution which was done at three times (1- at the beginning of pistachio kernel growth period at the end of June, 2- at the stage of full kernel development at the end of August, and 3- Spraying in both late June and August). RESULTS: The results showed that all investigated traits were significant under the treatment of seaweed extract compared with the control. The seaweed extract concentrations had a significant effect on all traits except soluble carbohydrates, but the time of consumption of seaweed extract on soluble carbohydrates, protein, peroxidase, ascorbate peroxidase, and superoxide dismutase enzymes was significant, while had no significant effect on the rest of the traits. According to the interaction effect of time and concentration of consumption of seaweed extract, the highest values of the biochemical characters were as follows: total phenol content: 168.30 mg CAE/g DW, flavonoid content: mg CE/g DW, catalase: 12.66 µmol APX min- 1 mg- 1 protein, superoxide dismutase: 231.4 µmol APX min- 1 mg- 1 protein, and ascorbate peroxidase: 39.53 µmol APX min- 1 mg- 1 protein. CONCLUSIONS: Based on the results of this study, it seems that it is possible to use fertilizers containing A. nodosum seaweed extract with a concentration of 3 g/L in August to increase the tolerance of the pistachio cultivar "Kaleh-Ghoochi" to abiotic stresses.

Anti-Hyperlipidemic Effect of Fucoidan Fractions Prepared from Iceland Brown Algae Ascophyllum nodosum in an Hyperlipidemic Mice Model.

Ascophyllum nodosum, a brown algae abundantly found along the North Atlantic coast, is recognized for its high polysaccharide content. In this study, we investigated the anti-hyperlipidemic effect of fucoidans derived from A. nodosum, aiming to provide information for their potential application in anti-hyperlipidemic therapies and to explore comprehensive utilization of this Iceland brown seaweed. The crude fucoidan prepared from A. nodosum was separated using a diethylethanolamine column, resulting in two fucoidan fractions, AFC-1 and AFC-2. Both fractions were predominantly composed of fucose and xylose. AFC-1 exhibited a higher sulfate content of 27.8% compared to AFC-2 with 17.0%. AFC-2 was primarily sulfated at the hydroxy group of C2, whereas AFC-1 was sulfated at both the hydroxy groups of C2 and C4. To evaluate the anti-hyperlipidemic effect, a hyperlipidemia mouse model was established by feeding mice a high-fat diet. The effects of AFC-1, AFC-2, and the crude extract were investigated, with the drug atorvastatin used as a positive comparison. Among the different fucoidan fractions and doses, the high dose of AFC-2 administration demonstrated the most significant anti-hyperlipidemic effect across various aspects, including physiological parameters, blood glucose levels, lipid profile, histological analysis, and the activities of oxidative stress-related enzymes and lipoprotein-metabolism-related enzymes (p < 0.05 for the final body weight and p < 0.01 for the rest indicators, compared with the model group), and its effect is comparable to the atorvastatin administration. Furthermore, fucoidan administration resulted in a lower degree of loss in gut flora diversity compared to atorvastatin administration. These findings highlight the significant biomedical potential of fucoidans derived from A. nodosum as a promising therapeutic solution for hypolipidemia.

Effects of an Extract of the Brown Seaweed Ascophylum nodosum on Postprandial Glycaemic Control in Healthy Subjects: A Randomized Controlled Study.

The effects of the consumption of an extract of the brown seaweed Ascophyllum nodosum (BSW) on postprandial glucose and insulin responses to white bread were investigated in an acute, randomized, double-blind, three-arm, crossover, controlled trial in healthy, normoglycemic subjects. Sixteen subjects were administered either control white bread (50 g total digestible carbohydrates) or white bread with 500 mg or 1000 mg of BSW extract. Biochemical parameters were measured in venous blood over 3 h. Significant inter-individual variation in the glycaemic response to white bread was observed. Analysis of the responses of all subjects to either 500 mg or 1000 mg of BSW extract versus control revealed no significant effects of treatments. The variation in response to the control was used to classify individuals into glycaemic responders and non-responders. In the sub-cohort of 10 subjects with peak glucose levels after white bread above 1 mmol/L, we observed a significant decrease in maximum levels of plasma glucose after the intervention meal with 1000 mg of extract compared with the control. No adverse effects were reported. Further work is warranted to define all factors that determine "responders" to the effects of brown seaweed extracts and identify the cohort that would benefit the most from their consumption.

Effect of dietary seaweed (Ascophyllum nodosum) supplementation on milk mineral concentrations, transfer efficiency, and hematological parameters in lactating Holstein cows.

This study investigated the effect of feeding seaweed (Ascophyllum nodosum) to dairy cows on milk mineral concentrations, feed-to-milk mineral transfer efficiencies, and hematological parameters. Lactating Holstein cows (n = 46) were allocated to 1 of 2 diets (n = 23 each): (1) control (CON; without seaweed) and (2) seaweed (SWD; replacing 330 g/d of dried corn meal in CON with 330 g/d dried A. nodosum). All cows were fed the CON diet for 4 wk before the experiment (adaptation period), and animals were then fed the experimental diets for 9 wk. Samples included sequential 3-wk composite feed samples, a composite milk sample on the last day of each week, and a blood sample at the end of the study. Data were statistically analyzed using a linear mixed effects model with diet, week, and their interaction as fixed factors; cow (nested within diet) as a random factor; and data collected on the last day of the adaptation period as covariates. Feeding SWD increased milk concentrations of Mg (+6.6 mg/kg), P (+56 mg/kg), and I (+1,720 µg/kg). It also reduced transfer efficiency of Ca, Mg, P, K, Mn, and Zn, and increased transfer efficiency of Mo. Feeding SWD marginally reduced milk protein concentrations, whereas there was no effect of SWD feeding on cows' hematological parameters. Feeding A. nodosum increased milk I concentrations, which can be beneficial when feed I concentration is limited or in demographics or populations with increased risk of I deficiency (e.g., female adolescents, pregnant women, nursing mothers). However, care should also be taken when feeding SWD to dairy cows because, in the present study, milk I concentrations were particularly high and could result in I intakes that pose a health risk for children consuming milk.

Transcriptome, Biochemical and Phenotypic Analysis of the Effects of a Precision Engineered Biostimulant for Inducing Salinity Stress Tolerance in Tomato.

Salinity stress is a major problem affecting plant growth and crop productivity. While plant biostimulants have been reported to be an effective solution to tackle salinity stress in different crops, the key genes and metabolic pathways involved in these tolerance processes remain unclear. This study focused on integrating phenotypic, physiological, biochemical and transcriptome data obtained from different tissues of Solanum lycopersicum L. plants (cv. Micro-Tom) subjected to a saline irrigation water program for 61 days (EC: 5.8 dS/m) and treated with a combination of protein hydrolysate and Ascophyllum nodosum-derived biostimulant, namely PSI-475. The biostimulant application was associated with the maintenance of higher K+/Na+ ratios in both young leaf and root tissue and the overexpression of transporter genes related to ion homeostasis (e.g., NHX4, HKT1;2). A more efficient osmotic adjustment was characterized by a significant increase in relative water content (RWC), which most likely was associated with osmolyte accumulation and upregulation of genes related to aquaporins (e.g., PIP2.1, TIP2.1). A higher content of photosynthetic pigments (+19.8% to +27.5%), increased expression of genes involved in photosynthetic efficiency and chlorophyll biosynthesis (e.g., LHC, PORC) and enhanced primary carbon and nitrogen metabolic mechanisms were observed, leading to a higher fruit yield and fruit number (47.5% and 32.5%, respectively). Overall, it can be concluded that the precision engineered PSI-475 biostimulant can provide long-term protective effects on salinity stressed tomato plants through a well-defined mode of action in different plant tissues.

Fucoidans of Brown Algae: Comparison of Sulfated Polysaccharides from Fucus vesiculosus and Ascophyllum nodosum.

Preparations of sulfated polysaccharides obtained from brown algae are known as fucoidans. These biopolymers have attracted considerable attention due to many biological activities which may find practical applications. Two Atlantic representatives of Phaeophyceae, namely, Fucus vesiculosus and Ascophyllum nodosum, belonging to the same order Fucales, are popular sources of commercial fucoidans, which often regarded as very similar in chemical composition and biological actions. Nevertheless, these two fucoidan preparations are polysaccharide mixtures which differ considerably in amount and chemical nature of components, and hence, this circumstance should be taken into account in the investigation of their biological properties and structure-activity relationships. In spite of these differences, fractions with carefully characterized structures prepared from both fucoidans may have valuable applications in drug development.

A Nutraceutical Formulation Containing Brown Algae Reduces Hepatic Lipid Accumulation by Modulating Lipid Metabolism and Inflammation in Experimental Models of NAFLD and NASH.

Recently, some preclinical and clinical studies have demonstrated the ability of brown seaweeds in reducing the risk factors for metabolic syndrome. Here, we analyzed the beneficial effect of a nutraceutical formulation containing a phytocomplex extracted from seaweeds and chromium picolinate in animal models of liver steatosis of differing severities (rats with non-alcoholic fatty liver disease (NAFLD) and its complication, non-alcoholic steatohepatitis (NASH)). This treatment led to a significant drop in hepatic fat deposition in both models (p < 0.01 vs. untreated animals), accompanied by a reduction in plasma inflammatory cytokines, such as interleukin 6, tumor necrosis factor α, and C reactive protein, and myeloperoxidase expression in liver tissue. Furthermore, a modulation of the molecular pathways involved in lipid metabolism and storage was demonstrated, since we observed the significant reduction of the mRNA levels of fatty acid synthase, diacylglycerol acyltransferases, the sterol-binding protein SREBP-1, and the lipid transporter perilipin-2, in both treated NAFLD and NASH rats in comparison to untreated ones. In conclusion, this nutraceutical product was effective in reducing liver steatosis and showed further beneficial effects on hepatic inflammation and glycemic control, which were particularly evident in rats characterized by a more severe condition, thus representing a therapeutic option for the treatment of NAFLD and NASH patients.

Added Value of Ascophyllum nodosum Side Stream Utilization during Seaweed Meal Processing.

Ascophyllum nodosum contains many valuable compounds, including polyphenols, peptides, and carotenoids that have been shown to exhibit biological activities. These compounds are not a priority ingredient in seaweed meal products for the current users. Hence, the aim of the study was to investigate the chemical and bioactive characteristics of A. nodosum as affected by seasonal variation and evaluate the potential benefits of alternative processing and the utilization of side streams for product development. The analysis of raw materials, press liquid, and press cake from alternative processing and the commercial seaweed meal at different harvesting periods indicated that the chemical composition is linked to the reproductive state of the algae. Phenolic content and ORAC activity increased following the seaweed's fertile period, making alternative processing more promising in July and October compared to June. Several valuable ingredients were obtained in the press liquid, including polyphenols, which can be used in the development of new high-value bioactive products. The suggested alternative processing does not have a negative effect on the composition and quality of the current seaweed meal products. Hence, the extraction of valuable ingredients from the fresh biomass during the processing of seaweed meal could be a feasible option to increase the value and sustainability of seaweed processing.

Sulfated polysaccharide ascophyllan prevents amyloid fibril formation of human insulin and inhibits amyloid-induced hemolysis and cytotoxicity in PC12 cells.

We found that ascophyllan significantly inhibited the fibrillation of human insulin and was the most effective among the sulfated polysaccharides tested. Gel-filtration analysis suggested that ascophyllan was capable of forming a complex with insulin through a weak interaction. Secondary structure transition from native α-helix to ß-sheet predominant structure of insulin under the fibrillation conditions was suppressed in the presence of ascophyllan. Interestingly, ascophyllan attenuated insulin fibril-induced hemolysis of human erythrocytes. Moreover, ascophyllan attenuated insulin amyloid-induced cytotoxicity on rat pheochromocytoma PC12 cells and reduced the level of intracellular reactive oxygen species. This is the first report indicating that a sulfated polysaccharide, ascophyllan, can suppress the insulin amyloid fibril formation and inhibit the fibril-induced detrimental bioactivities.

Evaluation of the Antibacterial and Prebiotic Potential of Ascophyllum nodosum and Its Extracts Using Selected Bacterial Members of the Pig Gastrointestinal Microbiota.

Ascophyllum nodosum and its extracts are promising antibacterial and prebiotic dietary supplements for pigs. The objectives of this study were to evaluate the effects of the increasing concentrations of: (1) two whole biomass samples of A. nodosum with different harvest seasons, February (ANWB-F) and November (ANWB-N), in a weaned pig faecal batch fermentation assay, and (2) A. nodosum extracts produced using four different extraction conditions of a hydrothermal-assisted extraction methodology (ANE1-4) and conventional extraction methods with water (ANWE) and ethanol (ANEE) as solvent in individual pure culture growth assays using a panel of beneficial and pathogenic bacterial strains. In the batch fermentation assay, ANWB-F reduced Bifidobacterium spp. counts (p < 0.05) while ANWB-N increased total bacterial counts and reduced Bifidobacterium spp. and Enterobacteriaceae counts (p < 0.05). Of the ANE1-4, produced from ANWB-F, ANWE and ANEE that were evaluated in the pure culture growth assays, the most interesting extracts were the ANE1 that reduced Salmonella Typhimurium, enterotoxigenic Escherichia coli and B. thermophilum counts and the ANE4 that stimulated B. thermophilum growth (p < 0.05). In conclusion, the extraction method and conditions influenced the bioactivities of the A. nodosum extracts with ANE1 and ANE4 exhibiting distinct antibacterial and prebiotic properties in vitro, respectively, that merit further exploration.

Anti-Inflammatory Activity of Fucoidan Extracts In Vitro.

Fucoidans are sulfated, complex, fucose-rich polymers found in brown seaweeds. Fucoidans have been shown to have multiple bioactivities, including anti-inflammatory effects, and are known to inhibit inflammatory processes via a number of pathways such as selectin blockade and enzyme inhibition, and have demonstrated inhibition of inflammatory pathologies in vivo. In this current investigation, fucoidan extracts from Undaria pinnatifida, Fucus vesiculosus, Macrocystis pyrifera, Ascophyllum nodosum, and Laminaria japonica were assessed for modulation of pro-inflammatory cytokine production (TNF-α, IL-1ß, and IL-6) by human peripheral blood mononuclear cells (PBMCs) and in a human macrophage line (THP-1). Fucoidan extracts exhibited no signs of cytotoxicity in THP-1 cells after incubation of 48 h. Additionally, all fucoidan extracts reduced cytokine production in LPS stimulated PBMCs and human THP-1 cells in a dose-dependent fashion. Notably, the 5-30 kDa subfraction from Macrocystis pyrifera was a highly effective inhibitor at lower concentrations. Fucoidan extracts from all species had significant anti-inflammatory effects, but the lowest molecular weight subfractions had maximal effects at low concentrations. These observations on various fucoidan extracts offer insight into strategies that improve their efficacy against inflammation-related pathology. Further studies should be conducted to elucidate the mechanism of action of these extracts.

Milk supplemented with dried seaweed affects the systemic innate immune response in preweaning dairy calves.

Intact seaweed or seaweed extracts are used as feed supplements to improve the gut microbiome in young animals. Seaweeds provide functional polysaccharides, and they are a good source of vitamins, minerals, and phenolic compounds, all of which are relevant for immune system development. However, literature on the effects of dried seaweed supplementation on immune system development is limited, especially in calves. This experiment aimed to study the effect of feeding milk supplemented with Ulva lactuca, Ascophyllum nodosum, or Saccharina latissima on the systemic immune status of preweaning dairy calves. Forty male Holstein calves with birth body weight 41 ± 4 kg and plasma Brix percentage ≥8.7% at d 2 after birth were used in this study. Calves were fed 4 L of cow milk twice a day (total 8 L/d). From d 2 to d 28, calves in the control group (n = 10) received milk without seaweed supplementation. Over the same period, experimental calves received milk supplemented with Ulva lactuca (SW1; n = 10), Ascophyllum nodosum (SW2; n = 10), or Saccharina latissima (SW3, n = 10). Dried and ground seaweeds were offered at a daily allowance of 50 g/8 L of milk (i.e., approximately 5% inclusion rate on a dry matter basis). Blood samples were collected from a jugular vein on d 2, 4, 7, 14, 21, and 28 after birth. Plasma concentrations of total protein, albumin, immunoglobulins, and acute-phase proteins (i.e., serum amyloid A, fibrinogen, and haptoglobin) were measured. We detected no differences in average daily gain, plasma immunoglobulins, albumin, or total protein. However, the contrast analysis revealed that plasma concentrations of fibrinogen (SW1 and SW2) and serum amyloid A (SW2 and SW3) were significantly higher in the seaweed groups compared with the control group. We also found a tendency for high plasma haptoglobin in the seaweed groups (SW1 and SW2) compared with the control group. Differences in acute-phase protein concentrations could be partially explained by the large differences in micromineral intake between control and seaweed-supplemented calves. Feeding milk supplemented with dried seaweed increased plasma concentrations of variables related to the innate immune response in preweaning dairy calves.

Priming with a Seaweed Extract Strongly Improves Drought Tolerance in Arabidopsis.

Drought represents a major threat to plants in natural ecosystems and agricultural settings. The biostimulant Super Fifty (SF), produced from the brown alga Ascophyllum nodosum, enables ecologically friendly stress mitigation. We investigated the physiological and whole-genome transcriptome responses of Arabidopsis thaliana to drought stress after a treatment with SF. SF strongly decreased drought-induced damage. Accumulation of reactive oxygen species (ROS), which typically stifle plant growth during drought, was reduced in SF-primed plants. Relative water content remained high in SF-treated plants, whilst ion leakage, a measure of cell damage, was reduced compared to controls. Plant growth requires a functional shoot apical meristem (SAM). Expression of a stress-responsive negative growth regulator, RESPONSIVE TO DESICCATION 26 (RD26), was repressed by SF treatment at the SAM, consistent with the model that SF priming maintains the function of the SAM during drought stress. Accordingly, expression of the cell cycle marker gene HISTONE H4 (HIS4) was maintained at the SAMs of SF-primed plants, revealing active cell cycle progression after SF priming during drought. In accordance with this, CYCP2;1, which promotes meristem cell division, was repressed by drought but enhanced by SF. SF also positively affected stomatal behavior to support the tolerance to drought stress. Collectively, our data show that SF priming mitigates multiple cellular processes that otherwise impair plant growth under drought stress, thereby providing a knowledge basis for future research on crops.

Clinical Efficacy of Brown Seaweeds Ascophyllum nodosum and Fucus vesiculosus in the Prevention or Delay Progression of the Metabolic Syndrome: A Review of Clinical Trials.

Metabolic syndrome (MetS) is a global public health problem affecting nearly 25.9% of the world population characterised by a cluster of disorders dominated by abdominal obesity, high blood pressure, high fasting plasma glucose, hypertriacylglycerolaemia and low HDL-cholesterol. In recent years, marine organisms, especially seaweeds, have been highlighted as potential natural sources of bioactive compounds and useful metabolites, with many biological and physiological activities to be used in functional foods or in human nutraceuticals for the management of MetS and related disorders. Of the three groups of seaweeds, brown seaweeds are known to contain more bioactive components than either red and green seaweeds. Among the different brown seaweed species, Ascophyllum nodosum and Fucus vesiculosus have the highest antioxidant values and highest total phenolic content. However, the evidence base relies mainly on cell line and small animal models, with few studies to date involving humans. This review intends to provide an overview of the potential of brown seaweed extracts Ascophyllum nodosum and Fucus vesiculosus for the management and prevention of MetS and related conditions, based on the available evidence obtained from clinical trials.

Inhibition of the lemon brown rot causal agent Phytophthora citrophthora by low-toxicity compounds.

BACKGROUND: Phytophthora spp., soil-borne oomycetes, cause brown rot (BR) on postharvest lemons. The management of this disease is based on cultural practices and chemical control using inorganic salts of limited efficacy. In the search for new alternatives, the aim of this work was to evaluate the effect of low-toxicity compounds to inhibit the growth of P. citrophthora and to control BR disease on lemons. Sodium bicarbonate, potassium sorbate, polyhexamethylene guanidine, Ascophyllum nodosum extract and a formulation containing phosphite salts plus A. nodosum (P+An) were evaluated. RESULTS: All tested products inhibited mycelial growth, sporangia formation and zoospore germination of P. citrophthora in vitro. In postharvest applications on artificially inoculated lemons, only P+An exhibited a BR curative effect, with incidence reduction of around 60%. When this formulation was applied in field treatments, BR incidence was reduced by 40% on lemons harvested and inoculated up to 30 days post application. CONCLUSION: Our results demonstrate the in vitro direct anti-oomycete effect of low-toxicity compounds and the in vivo efficacy of P+An formulation to control BR, encouraging the incorporation of the latter in the management of citrus BR. © 2020 Society of Chemical Industry.

Fucus vesiculosus and Ascophyllum nodosum Ameliorate Liver Function by Reducing Diet-Induced Steatosis in Rats.

The Asian coastal communities have used the brown seaweeds Fucus vesiculosus and Ascophyllum nodosum since ancient times. Recently, some in vitro and in vivo studies have demonstrated their abilities in reducing risk factors for metabolic syndrome. Here, we analyzed the protective effect of a phytocomplex extracted from these seaweeds on the deposition of fat in the liver after the administration of a high-fat diet (HFD) to rats for five weeks. The administration of F. vesiculosus and A. nodosum led to significant reductions in microvescicular steatosis and plasma biochemical and lipid parameters, such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total and conjugated bilirubin, and triglycerides. Furthermore, the postprandial glycemic peak was delayed and significantly reduced (p < 0.01) by the algal extract administration. In conclusion, this extract is effective in reducing microvescicular steatosis and improving glycemic control, thereby lowering the risk of nonalcoholic fatty liver disease, obesity, and diabetes, diseases related to the consumption of fat and sugar-enriched diets.

Fucoidan from Ascophyllum nodosum Suppresses Postprandial Hyperglycemia by Inhibiting Na+/Glucose Cotransporter 1 Activity.

We previously demonstrated that fucoidan with a type II structure inhibited postprandial hyperglycemia by suppressing glucose uptake, but the mechanism remains elusive. Here, we aimed to assess whether the effect of glucose absorption inhibition was related to the basic structure of fucoidans and preliminarily clarified the underlying mechanism. Fucoidans with type II structure and type I structure were prepared from Ascophyllumnodosum (AnF) or Laminariajaponica (LjF) and Kjellmaniellacrassifolia (KcF), respectively. The effects of various fucoidans on suppressing postprandial hyperglycemia were investigated using in vitro (Caco-2 monolayer model), semi-in vivo (everted gut sac model), and in vivo (oral glucose tolerance test, OGTT) assays. The results showed that only AnF with a type II structure, but not LjF or KcF with type I structure, could inhibit the glucose transport in the Caco-2 monolayer and everted gut sac models. A similar result was seen in the OGTT of Kunming mice and leptin receptor-deficient (db/db) mice, where only AnF could effectively inhibit glucose transport into the bloodstream. Furthermore, AnF (400 mg/kg/d) treatment decreased the fasting blood glucose, HbA1c, and fasting insulin levels, while increasing the serum glucagon-like peptide-1 (GLP-1) level in obese leptin receptor-deficient (db/db) mice. Furthermore, surface plasmon resonance (SPR) analysis revealed the specific binding of AnF to Na+/glucose cotransporter 1 (SGLT1), which indicated the effect of AnF on postprandial hyperglycemia could be due to its suppression on SGLT1 activity. Taken together, this study suggests that AnF with a type II structure can be a promising candidate for hyperglycemia treatment.

A Biostimulant Obtained from the Seaweed Ascophyllum nodosum Protects Arabidopsis thaliana from Severe Oxidative Stress.

Abiotic stresses cause oxidative damage in plants. Here, we demonstrate that foliar application of an extract from the seaweed Ascophyllum nodosum, SuperFifty (SF), largely prevents paraquat (PQ)-induced oxidative stress in Arabidopsis thaliana. While PQ-stressed plants develop necrotic lesions, plants pre-treated with SF (i.e., primed plants) were unaffected by PQ. Transcriptome analysis revealed induction of reactive oxygen species (ROS) marker genes, genes involved in ROS-induced programmed cell death, and autophagy-related genes after PQ treatment. These changes did not occur in PQ-stressed plants primed with SF. In contrast, upregulation of several carbohydrate metabolism genes, growth, and hormone signaling as well as antioxidant-related genes were specific to SF-primed plants. Metabolomic analyses revealed accumulation of the stress-protective metabolite maltose and the tricarboxylic acid cycle intermediates fumarate and malate in SF-primed plants. Lipidome analysis indicated that those lipids associated with oxidative stress-induced cell death and chloroplast degradation, such as triacylglycerols (TAGs), declined upon SF priming. Our study demonstrated that SF confers tolerance to PQ-induced oxidative stress in A. thaliana, an effect achieved by modulating a range of processes at the transcriptomic, metabolic, and lipid levels.