Cell wall-mediated maternal control of apical-basal patterning of the kelp Undaria pinnatifida.

The role of maternal tissue in embryogenesis remains enigmatic in many complex organisms. Here, we investigate the contribution of maternal tissue to apical-basal patterning in the kelp embryo. Focussing on Undaria pinnatifida, we studied the effects of detachment from the maternal tissue using microsurgery, staining of cell wall modifications, morphometric measurements, flow cytometry, genotyping and a modified kelp fertilisation protocol synchronising kelp embryogenesis. Detached embryos are rounder and often show aberrant morphologies. When a part of the oogonial cell wall remains attached to the zygote, the apical-basal patterning is rescued. Furthermore, the absence of contact with maternal tissue increases parthenogenesis, highlighting the critical role of maternal signals in the initial stages of development. These results show a key role for the connection to the maternal oogonial cell wall in apical-basal patterning in kelps. This observation is reminiscent of another brown alga, Fucus, where the cell wall directs the cell fate. Our findings suggest a conserved mechanism across phylogenetically distant oogamous lineages, where localised secretion of sulphated F2 fucans mediates the establishment of the apical-basal polarity. In this model, the maternal oogonial cell wall mediates basal cell fate determination by providing an extrinsic patterning cue to the future kelp embryo.

Neuromodulatory Effects Induced by the Association of Moringa oleifera Lam., Tribulus terrestris L., Rhodiola rosea Lam., and Undaria pinnatidifida Extracts in the Hypothalamus.

The present study investigated the role of a commercial formulation constituted by herbal extracts from Rhodiola rosea, Undaria pinnatifida, Tribulus terrestris, and Moringa oleifera. The formulation was analysed for determining the content in total phenols and flavonoids and scavenging/reducing properties. The formulation was also tested on isolated mouse hypothalamus in order to investigate effects on serotonin, dopamine, neuropeptide Y (NPY), and orexin A. The gene expression of gonadrotopin releasing hormone (GnRH) was also assayed. The formulation was able to reduce dopamine and serotonin turnover, and this could be related, albeit partially, to the capability of different phytochemicals, among which hyperoside and catechin to inhibit monoaminooxidases activity. In parallel, the formulation was effective in reducing the gene expression of NPY and orexin-A and to improve the gene expression of GnRH. In this context, the increased GnRH gene expression induced by the formulation may contribute not only to improve the resistance towards the stress related to ageing, but also to prevent the reduction of libido that could be related with a stimulation of the serotoninergic pathway. According to the in silico analysis, hyperoside could play a pivotal role in modulating the gene expression of GnRH. Regarding NPY and orexin A gene expression, no direct interactions between the formulation phytochemicals and these neuropeptides were anticipated; thus, suggesting that the pattern of gene expression observed following exposure of the hypothalamus to the formulation may be secondary to inhibitory effects of dopamine and serotonin turnover. Concluding, the present study demonstrated the efficacy of the formulation in exerting neuromodulatory effects at the hypothalamic level; thus, suggesting the potential to contrast stress and fatigue.

Characterization of l-fucose isomerase from Paenibacillus rhizosphaerae to produce l-fuculose from hydrolyzed fucoidan and commercial fucose.

AIMS: l-Fuculose is a valuable rare sugar that is used to treat a variety of ailments, including HIV, cancer, Hepatitis B, human lysosomal disease (fucosidosis), and cardio-protective medications. The enzymatic approach for the production of l-fuculose using l-fucose as a substrate would be an advantageous method with a wide range of industrial applications. The objective of this study is the characterization of recombinant l-fucose isomerase from Paenibacillus rhizosphaerae (Pa-LFI) for the production of l-fuculose from an inexpensive and natural source (fucoidan) as well as its comparison with commercial l-fucose (Sigma-Aldrich). METHODS AND RESULTS: Fucoidan, a fucose-containing polysaccharide (FPs), was isolated from Undaria pinnatifida, subsequently hydrolyzed, and characterized before the enzymatic production of l-fuculose. The results elaborate that FPs contain 35.9% of fucose along with other kinds of monosaccharides. The purified Pa-LFI exhibited a single band at 65 kDa and showed it as a hexamer with a native molecular mass of 396 kDa. The highest activity of 104.5 U mg-1 of Pa-LFI was perceived at a temperature of 50°C and pH 6.5 in the presence of 1 mM of Mn2+. The Pa-LFI revealed a melting temperature (Tm) of 75°C and a half-life of 12.6 h at 50°C. It exhibited that Pa-LFI with aldose substrate (l-fucose), has a stronger isomerizing activity, disclosing Km,kcat, and kcat/Km 86.2 mM, 32 831 min-1, and 335 min-1 mM-1, respectively. After reaching equilibrium, Pa-LFI efficiently catalyzed the reaction to convert l-fucose into l-fuculose and the conversion ratios of l-fuculose from 100 g L-1 of FPs and commercial fucose were around 6% (5.6 g L-1) and 30% (30.2 g L-1), respectively. CONCLUSIONS: According to the findings of the current study, the Pa-LFI will be useful in the manufacturing of l-fuculose using an effective and easy approach that produces no by-products.

Kinetic Extraction of Fucoxanthin from Undaria pinnatifida Using Ethanol as a Solvent.

Fucoxanthin (Fx) has been proven to exert numerous biological properties, which makes it an interesting molecule with diverse industrial applications. In this study, the kinetic behavior of Fx was studied to optimize three variables: time (t-3 min to 7 days), temperature (T-5 to 85 °C), and concentration of ethanol in water (S-50 to 100%, v/v), in order to obtain the best Fx yield from Undaria pinnatifida using conventional heat extraction. The Fx content (Y1) was found through HPLC-DAD and expressed in µg Fx/g of algae sample dry weight (AS dw). Furthermore, extraction yield (Y2) was also found through dry weight analysis and was expressed in mg extract (E)/g AS dw. The purity of the extracts (Y3) was found and expressed in mg Fx/g E dw. The optimal conditions selected for Y1 were T = 45 °C, S = 70%, and t = 66 min, obtaining ~5.24 mg Fx/g AS; for Y2 were T = 65 °C, S = 60%, and t = ~10 min, obtaining ~450 mg E/g AS; and for Y3 were T = 45 °C, S = 70%, and t = 45 min, obtaining ~12.3 mg Fx/g E. In addition, for the selected optimums, a full screening of pigments was performed by HPLC-DAD, while phenolics and flavonoids were quantified by spectrophotometric techniques and several biological properties were evaluated (namely, antioxidant, antimicrobial, and cholinesterase inhibitory activity). These results could be of interest for future applications in the food, cosmetic, or pharmaceutical industries, as they show the Fx kinetic behavior and could help reduce costs associated with energy and solvent consumption while maximizing the extraction yields.

Valorisation of the Invasive Macroalgae Undaria pinnatifida (Harvey) Suringar for the Green Synthesis of Gold and Silver Nanoparticles with Antimicrobial and Antioxidant Potential.

Bacterial and fungal infections are a challenging global problem due to the reported increasing resistance of pathogenic microorganisms to conventional antimicrobials. Nanomaterials are a promising strategy to fight infections caused by multidrug-resistant microbes. In this work, gold (Au@UP) and silver (Ag@UP) nanoparticles were produced for the first time by green synthesis using an aqueous extract of the invasive macroalgae Undaria pinnatifida (UP). The nanoparticles were characterized by a wide range of physicochemical techniques. Au@UP and Ag@UP demonstrated to be spherical and crystalline with an average size of 6.8 ± 1.0 nm and 14.1 ± 2.8 nm, respectively. Carbohydrates and proteins of the UP extract may participate in the synthesis and capping of the nanoparticles. The UP extract, Ag@UP, and Au@UP were assessed for their antimicrobial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Candida auris. Ag@UP showed the highest antimicrobial activity with very low MIC and MBC values for all the tested bacteria, and Au@UP demonstrated to be very effective against biofilm-producing bacteria. The antifungal properties of both Ag@UP and Au@UP were remarkable, inhibiting hyphae formation. This study points towards a very promising biomedical exploitation of this invasive brown algae.

Releasing Bioactive Compounds from Brown Seaweed with Novel Cold-Adapted Alginate Lyase and Alcalase.

Seaweeds are considered to be third-generation renewable biomasses, the comprehensive utilization of which has drawn increasing attention in recent years. A novel cold-active alginate lyase (VfAly7) was identified from Vibrio fortis and biochemically characterized for brown seaweed utilization. The alginate lyase gene was high-level expressed in Pichia pastoris, with an enzyme yield of 560 U/mL and a protein content of 9.8 mg/mL by high-cell density fermentation. The recombinant enzyme was most active at 30 °C and pH 7.5, respectively. VfAly7 was a bifunctional alginate lyase with both poly-guluronate and poly-mannuronate hydrolysis activities. On the basis of VfAly7, a bioconversion strategy for the utilization of brown seaweed (Undaria pinnatifida) was developed. The obtained AOSs showed stronger prebiotic activity towards tested probiotics when compared to that of commercial fructooligosaccharides (FOSs), while the obtained protein hydrolysates displayed strong xanthine oxidase inhibitory activity with IC50 of 3.3 mg/mL. This study provided a novel alginate lyase tool as well as a biotransformation route for the utilization of seaweeds.

Induction of Browning in White Adipocytes: Fucoidan Characterization and Gold Nanoparticle Synthesis from Undaria pinnatifida Sporophyll Extract.

Seaweed extracts and their specific polysaccharides are widely known for their ability to act as reducing and capping agents during nanoparticle synthesis. Their application is highly favored in green synthesis methods, owing to their eco-friendliness, cost-effectiveness, and remarkable time and energy efficiency. In this study, fucoidan extracted from Undaria pinnatifida sporophyll (UPS) is introduced as a polysaccharide that effectively serves as a dual-function reducing and capping agent for the synthesis of gold nanoparticles (AuNPs). Results from various analyses indicate that AuNPs derived from UPS extract display a uniform spherical shape with an average size of 28.34 ± 1.15 nm and a zeta potential of -37.49 ± 2.13 mV, conclusively confirming the presence of Au. The FT-IR spectra distinctly revealed the characteristic fucoidan bands on the stabilized UPS-AuNPs surface. A 1H-NMR analysis provided additional confirmation by revealing the presence of specific fucoidan protons on the UPS-AuNPs surface. To comprehensively evaluate the impact of UPS extract, UPS-AuNPs, and fucoidan on the biological properties of adipocytes, a rigorous comparative analysis of lipid droplet formation and morphology was conducted. Our findings revealed that adipocytes treated with UPS extract, fucoidan, and UPS-AuNPs, in that order, exhibited a reduction in the total lipid droplet surface area, maximum Ferret diameter, and overall Nile red staining intensity when compared to mature white adipocytes. Furthermore, our analysis of the effects of UPS extracts, UPS-AuNPs, and fucoidan on the expression of key markers associated with white adipose tissue browning, such as UCP1, PGC1a, and PRDM16, demonstrated increased mRNA and protein expression levels in the following order: UPS-AuNPs > fucoidan > UPS extracts. Notably, the production of active mitochondria, which play a crucial role in enhancing energy expenditure in beige adipocytes, also increased in the following order: UPS-AuNPs > fucoidan > UPS extract. These findings underscore the pivotal role of UPS extract, fucoidan, and UPS-AuNPs in promoting adipocyte browning and subsequently enhancing energy expenditure.

Emerging Technologies to Extract Fucoxanthin from Undaria pinnatifida: Microwave vs. Ultrasound Assisted Extractions.

Macroalgae are an extensive resource for the obtention of bioactive compounds, mainly phenolic compounds, phlorotannins, and pigments. Fucoxanthin (Fx) is the most abundant pigment present in brown algae and has shown several useful bioactivities that can be used to fortify products in the food and cosmetic industries. Nevertheless, to date, there is still insufficient literature reporting on the extraction yield of Fx from U. pinnatifida species from green technologies. In this regard, the present study aims to optimize the extraction conditions to obtain the highest Fx yield from U. pinnatifida through emerging techniques, namely microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE). These methods will be compared with the conventional methodologies of heat-assisted extraction (HAE) and Soxhlet-assisted extraction (SAE). According to our results, even though the extraction yield could be slightly higher when using MAE than UAE, the Fx concentration obtained from the alga was double when using UAE. Thus, the Fx ratio in the final extract reached values of 124.39 mg Fx/g E. However, the optimal conditions should also be considered since UAE needed 30 min to perform the extraction, whereas MAE was able to obtain 58.83 mg Fx/g E in only 3 min and 2 bar, meaning less energy expenditure and minimum cost function. To our knowledge, this study obtains the highest concentrations of Fx ever reported (58.83 mg Fx/g E for MAE and 124.39 mg Fx/g E for UAE), with low energy consumption and short times (3.00 min for MAE and 35.16 min for UAE). Any of these results could be selected for further experiments and proposed for industrial scaling-up.

Development of a microplate-based novel toxicity bioassay using Chlorophyta and Phaeophyceae macroalgae.

Macroalgae are one of the main producers in marine environments. However, only a few toxicity test methods have been established that use reference strains of macroalgae to evaluate the effects of chemicals on the growth and reproduction of macroalgae to monitor water quality. We selected reference strains of Chlorophyta, Ulva aragoënsis; Phaeophyceae, Ectocarpus siliculosus; and wakame, Undaria pinnatifida, as test species to establish a microplate-based method to investigate the toxicity of potassium dichromate, 3,5-dichlorophenol, and two common herbicides (diuron and simazine). We determined the growth of the three macroalgae in their early life stages and during the sporangia formation stage in E. siliculosus under laboratory conditions. We observed that the growth and sporangia formation in these algae were impaired in a dose-dependent manner. Additionally, we investigated the sensitivity of these macroalgae by comparing the toxicity values of toxicants used in this study with those obtained from a database. Compared to other microalgae and plant species, macroalgae showed a relatively high sensitivity to organic compounds, including herbicides. Growth tests using U. aragoënsis and E. siliculosus produced reliable results at 0-32 and 25-32 practical salinity units (PSU), respectively. The tests established in this study could test the toxicity of chemical substances in macroalgae and are thus expected to contribute to a better understanding of the environmental risks of chemical substances on aquatic biota. The tests could be applied to all effluent toxicity tests used for the management of seawater and brackish water quality.

Proteins extracted from seaweed Undaria pinnatifida and their potential uses as foods and nutraceuticals.

Isolation and utilization of proteins from seaweeds have been a novel trend in the world at present due to the increasing demand for healthy non-animal proteins. The attention of scientific community has been paid on the protein derived from seaweed Undaria pinnatifida due to their high nutritional quality and bioactivity. This article aims to provide an integrated overview on methods of extraction, isolation and purification of U. pinnatifida-derived proteins and composition, nutritional value and potential nutraceutical and food applications with an interest to stimulate further research to optimize the utilization. Potential food applications of U. pinnatifida derived proteins are nutritional components in human diet, food ingredients and additives, alternative meat and meat analogues and animal and fish feed. Excellent antioxidant, antihypertension, anticoagulant, anti-diabetes, antimicrobial and anti-cancer activities possessed by proteins of U. pinnatifida enable the use of these proteins in various nutraceutical applications. A number of studies have been carried out on antioxidant and antihypertensive activities of U. pinnatifida proteins, whereas other bioactivites are yet to be further studied. Hence, more research works are crucial to be done in order to facilitate and promote the emerging novel foods and nutraceuticals, using proteins from seaweed U. pinnatifida.

In Vitro and In Vivo Dendritic Cell Immune Stimulation Effect of Low Molecular Weight Fucoidan from New Zealand Undaria pinnatifida.

Low molecular weight fucoidan (LMWF) has been reported to have immunomodulation effects through the increase of the activation and function of macrophages. In this study, the regulating effect of LMWF from Undaria pinnatifida grown in New Zealand on dendritic cells (DCs) was investigated. We discovered that LMWF could stimulate DCs' maturation and migration, as well as CD4+ and CD8+ T cells' proliferation in vitro. We proved that this immune promoting activity is activated through TLR4 and its downstream MAPK and NF-κB signaling pathways. Further in vivo (mouse model) investigation showed that LMWF has a strong immunological boosting effect, such as facilitating the proliferation of immune cells and increasing the index of immune organs. These findings suggest that LMWF has a positive immunomodulatory effect and is a promising candidate to supplement cancer immunotherapy.

One-Step Preparative Separation of Fucoxanthin from Three Edible Brown Algae by Elution-Extrusion Countercurrent Chromatography.

A method for batch preparation of fucoxanthin from brown algae was established, which possessed the advantages of high yield and high purity. The ultrasonic-assisted extraction method was used to obtain a crude extract from Sargassum fusiforme as the separation sample. Then the crude extract was separated by elution-extrusion countercurrent chromatography. The optimum preparation conditions of fucoxanthin were determined as follows: n-hexane-ethanol-water (20:9:11, v:v:v) as a two-phase solvent system, the mobile phase flow rate was 5 mL min-1, the revolution speed was 800 r min-1, the loading capacity was 60 mg 10 mL-1 and the temperature was 25 °C. By this method, 12.8 mg fucoxanthin with a purity of 94.72% was obtained from the crude extract of Sargassum fusiforme. In addition, when the loading capacity was 50 mg 10 mL-1, the purity of fucoxanthin reached 96.01%. Two types of by-products, chlorophyll and pheophytin, could also be obtained during the process of separation. This optimal method was further applied to separate fucoxanthin from Laminaria japonica and Undaria pinnatifida, and 6.0 mg and 9.7 mg fucoxanthin with a purity of 96.24% and 92.62% were acquired, respectively. Therefore, it was demonstrated that the preparation method of fucoxanthin established in this study had an applicability to brown algae, which improved the utilization value of raw materials.

[Instant drinks based on extracts of Japan sea brown algae and fruit and berry juices as functional products].

Nowadays, there is a need to create functional drinks that not only normalize the water-electrolyte balance, but also correct and optimize the chemical structure of the diet. The basis for the production of dry drinks can be fruit and berry juices, extracts of herbal raw materials, including algae, etc. The aim of the study was to develop dry drinks based on dry extracts of brown algae (Costaria costata and Undaria pinnatifida) and concentrated fruit and berry juices and to evaluate the content of biologically active substances in them, as well as the antioxidant properties of the resulting drinks. Material and methods. Brown algae of the Far Eastern region Costaria costata and Undaria pinnatifida were used as objects, from which dry hydrothermal extracts were obtained, as well as dry drinks based on these extracts (21-26%) and concentrated fruit and berry juices of black currant and blueberry (31-37%). The content of iodine was determined by titrimetric method, fucoidan, the sum of phenolic compounds, flavonoids, catechins - by spectrophotometric method, vitamin C - titrimetrically, anthocyanins - by pH-differential spectrophotometry. Identification of phenolic compounds was carried out by HPLC. The antiradical properties of beverages were evaluated by the ability to interact with the stable 2.2-diphenyl-1-picrylhydrazyl free radical in vitro spectrophotometrically. Results. Dry hydrothermal extracts of C. costata and U. pinnatifida brown algae are characterized by a high content of bioactive substances, the main of which are fucoidan and iodine. The fucoidan content in C. costata extract was 1.7 g/100 g, in U. pinnatifida extract - 0.5 g/100 g; the iodine content was 0.0036 and 0.0028 g/100 g, respectively. The content of phenolic compounds was at least 205 mg of tannic acid per 1 g, the main compounds were syringic acid and epicatechin, salicylic and coumaric acids, as well as chlorogenic, caffeic, 2.5-dihydroxybenzoic, ferulic acid and gallates of epigallocatechin and epicatechin. The developed drinks based on dry extracts of C. costata and U. pinnatifida brown algae (21-26%) and concentrated blueberry and blackcurrant juices (31-37%) (the rest is powdered sugar) are a food system enriched with bioactive substances. The content per 1 serving of drinks (10 g per 200 ml) of iodine was high and amounted to 70-75 mcg, phenolic compounds - about 250 mg, vitamin C level was maximum in a drink with black currant (41-44 mg), fucoidan content ranged from 79 to 84 mg. The resulting dry drinks satisfy the daily physiological requirement in iodine by at least 40%, in vitamin C - by at least 30% when consuming 1 serving. The radical binding activity of all the studied beverages was quite high and amounted to 91.1-96.5%. The drink with blueberry juice and C. costata extract showed maximum antiradical properties. Conclusion. The developed dry soft drinks based on dry extracts of C. costata and U. pinnatifida brown algae and concentrated juices of black currant or blueberry contain a wide range of bioactive compounds. They can be attributed to functional products due to the high degree of satisfaction of the daily physiological requirement of the human body in vitamin C and iodine and are characterized by high antiradical properties.

Undaria pinnatifida extract feeding increases exercise endurance and skeletal muscle mass by promoting oxidative muscle remodeling in mice.

Dietary habits can alter the skeletal muscle performance and mass, and Undaria pinnatifida extracts are considered a potent candidate for improving the muscle mass and function. Therefore, in this study, we aimed to assess the effect of U pinnatifida extracts on exercise endurance and skeletal muscle mass. C57BL/6 mice were fed a 0.25% U pinnatifida extract-containing diet for 8 weeks. U pinnatifida extract-fed mice showed increased running distance, total running time, and extensor digitorum longus and gastrocnemius muscle weights. U pinnatifida extract supplementation upregulated the expression of myocyte enhancer factor 2C, oxidative muscle fiber markers such as myosin heavy chain 1 (MHC1), and oxidative biomarkers in the gastrocnemius muscles. Compared to the controls, U pinnatifida extract-fed mice showed larger mitochondria and increased gene and protein expression of molecules involved in mitochondrial biogenesis and oxidative phosphorylation, including nuclear respiratory factor 2 and mitochondrial transcription factor A. U pinnatifida extract supplementation also increased the mRNA expression of angiogenesis markers, including VEGFa, VEGFb, FGF1, angiopoietin 1, and angiopoietin 2, in the gastrocnemius muscles. Importantly, U pinnatifida extracts upregulated the estrogen-related receptor γ and peroxisome proliferator-activated receptor gamma co-activator 1-alpha (PGC-1α)/AMP-activated protein kinase (AMPK)/sirtuin 1 (SIRT1) networks, which are partially increased by fucoxanthin, hesperetin, and caffeic acid treatments. Collectively, U pinnatifida extracts enhance mitochondrial biogenesis, increase oxidative muscle fiber, and promote angiogenesis in skeletal muscles, resulting in improved exercise capacity and skeletal muscle mass. These effects are attributable to fucoxanthin, hesperetin, and caffeic acid, bioactive components of U pinnatifida extracts.

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.

Undaria pinnatifida improves obesity-related outcomes in association with gut microbiota and metabolomics modulation in high-fat diet-fed mice.

Dietary fiber has beneficial effects on obesity-related diseases and gut microbiota, contributing a key role in the interaction between dietary metabolism and host metabolism. Our objective was to investigate the cause of the improvement in multiple types of physiological states with seaweed Undaria pinnatifida treatment on high-fat diet-fed mice and to evaluate whether its consequent anti-adiposity and anti-hyperlipidemic effects are associated with gut microbiota and its metabolomics regulation. U. pinnatifida administration in our experiment was shown to significantly decrease high-fat diet-induced body weight gain, as well as epididymal and abdominal adiposity. U. pinnatifida intake also significantly reduced liver weight and serum triacylglycerol accumulation. We also found that improving effects of U. pinnatifida on high-fat diet-induced metabolic dysfunctions were associated with significant increase in specific bacteria, such as Bacteroides acidifaciens and Bacteroides ovatus, as well as metabolites, including short-chain fatty acids and tricarboxylic acid cycle intermediates. Our result provides a cheap dietary strategy to host metabolism improvement and obesity management. KEY POINTS: • U. pinnatifida improved adipose accumulation and lipid metabolism. • B. acidifaciens and B. ovatus contributed to the beneficial effects of U. pinnatifida. • SCFAs and TCA cycle intermediates were critical to the metabolic outcomes. • Our study provides a cheap dietary strategy for obesity management.

Oral Fucoidan Attenuates Lung Pathology and Clinical Signs in a Severe Influenza a Mouse Model.

Fucoidans are known to be effective inhibitors of inflammation, and of virus binding and cellular entry. Undaria pinnatifida-derived fucoidan (UPF) was assessed in a severe influenza A (H1N1, PR8) infection model in mice. Initially, UPF was gavaged at 3.52 mg daily in a treatment model. Gross lung pathology (consolidation) was significantly reduced as compared to controls. UPF was then presented as a feed supplement at a rate of either nil, 3.52 mg/day or 7.04 mg/day in a prophylactic model, dosed three days before infection. A significant improvement was observed in the clinical signs of ill-health, as well as a reduction in gross lung pathology in animals treated with the higher dose, although there was no significant reduction in lung viral titres.

Rapid toxicity assessment of six antifouling booster biocides using a microplate-based chlorophyll fluorescence in Undaria pinnatifida gametophytes.

Biocides of antifouling agents can cause problems in marine ecosystems by damaging to non-target algal species. Aquatic bioassays are important means of assessing the quality of water containing mixtures of contaminants and of providing a safety standard for water management in an ecological context. In this study, a rapid, sensitive and inexpensive test method was developed using free-living male and female gametophytes of the brown macroalga Undaria pinnatifida. A conventional fluorometer was employed to evaluate the acute (48 h) toxic effects of six antifouling biocides: 4,5-Dichloro-2-octyl-isothiazolone (DCOIT), diuron, irgarol, medetomidine, tolylfluanid, zinc pyrithione (ZnPT). The decreasing toxicity in male and female gametophytes as estimated by EC50 (effective concentration at which 50% inhibition occurs) values was: diuron (0.037 and 0.128 mg l-1, respectively) > irgarol (0.096 and 0.172 mg l-1, respectively) > tolylfluanid (0.238 and 1.028 mg l-1, respectively) > DCOIT (1.015 and 0.890 mg l-1, respectively) > medetomidine (12.032 and 12.763 mg l-1, respectively). For ZnPT, 50% fluorescence inhibition of U. pinnatifida gametophytes occurred at concentrations above 0.4 mg l-1. The Undaria method is rapid, simple, practical, and cost-effective for the detection of photosynthesis-inhibiting biocides, thus making a useful tool for testing the toxicity of antifouling agents in marine environments.

Protective Effects of Fucoidan Isolated from Celluclast-Assisted Extract of Undaria pinnatifida Sporophylls against AAPH-Induced Oxidative Stress In Vitro and In Vivo Zebrafish Model.

Fucoidan is a fucose-enriched polysaccharide, obtained from brown algae, with demonstrated antioxidant properties. However, traditional extraction methods using water or chemical-based extraction methods have reduced yield and produced hazardous by-products. In this study, we isolated fucoidan at a high yield using enzyme-assisted extraction; the Celluclast enzyme assisted extract of Undaria pinnatifida sporophylls (FCUS). To examine the antioxidant properties of FCUS, oxidative stress was induced with 2,2'-azobis (2-methylpropionamidine) dihydrochloride (AAPH) in Vero cells and zebrafish model. FCUS was composed of 30.4% sulfate and 52.3% fucose. Pre-treatment of Vero cells with FCUS dose dependently inhibited AAPH-induced reactive oxygen species (ROS) production. Moreover, FCUS remarkably reduced cell death, ROS generation, and lipid peroxidation production in zebrafish larvae. Overall, these findings indicate that the sulfate-rich fucoidan of FCUS, obtained with an eco-friendly process, could be implemented as a beneficial antioxidant agent in the functional food industry.

Brown Seaweeds for the Management of Metabolic Syndrome and Associated Diseases.

Metabolic syndrome is characterized by the coexistence of different metabolic disorders which increase the risk of developing type 2 diabetes mellitus and cardiovascular diseases. Therefore, metabolic syndrome leads to a reduction in patients' quality of life as well as to an increase in morbidity and mortality. In the last few decades, it has been demonstrated that seaweeds exert multiple beneficial effects by virtue of their micro- and macronutrient content, which could help in the management of cardiovascular and metabolic diseases. This review aims to provide an updated overview on the potential of brown seaweeds for the prevention and management of metabolic syndrome and its associated diseases, based on the most recent evidence obtained from in vitro and in vivo preclinical and clinical studies. Owing to their great potential for health benefits, brown seaweeds are successfully used in some nutraceuticals and functional foods for treating metabolic syndrome comorbidities. However, some issues still need to be tackled and deepened to improve the knowledge of their ADME/Tox profile in humans, in particular by finding validated indexes of their absorption and obtaining reliable information on their efficacy and long-term safety.