Search Results (563)

While numerous extraction methods have been applied to the brown algae Saccharina latissima, a systematic evaluation of how individual extraction parameters influence the extraction of each target polysaccharide has not previously been reported. Accordingly, this study compared conventional and advanced techniques for extracting fucoidan, laminarin, and alginate from pre-treated biomass. Conventional methods employed diluted acid (0.01 M and 0.1 M HCl), diluted alkali (0.01 M and 0.1 M NaOH), and hot water (121 °C for 30/60 min) for extraction. Advanced techniques involved pressurized liquid extraction (PLE) using water and moderate electric field (MEF) extraction with conditions optimized by statistical experimental design. Pre-treatment with aqueous ethanol removed 30% ash and eliminated mannitol, improving extraction selectivity. The results demonstrated fucoidan yields of 31% with 0.01 M HCl and 46% with 0.1 M NaOH, while 0.01 M NaOH facilitated laminarin co-extraction (45%). Alginate, as a mannuronic acid polymer, was obtained at 9% yield with 0.1 M HCl, 42% yield with 0.1 M NaOH, and 27% with pressurized hot water for 30 min. High-temperature, short-duration PLE further improved alginate yield, while MEF showed limited gains due to high ionic content but demonstrated potential under optimized settings. The results support a cascading biorefinery approach in which different polysaccharide fractions can be sequentially obtained, contributing to more sustainable seaweed valorization. Full article

Background: Alginate is a naturally occurring anionic polysaccharide extracted from brown marine algae and widely explored for biomedical applications due to its biocompatibility and functional versatility. This study aims to extract and compare alginates from two Red Sea brown algae, Turbinaria ornata (TA) and Hormophysa cuneiformis (HA), and to evaluate how structural differences influence their therapeutic properties. Methods: Alginate was isolated by sequential acid–alkaline extraction and characterized using FTIR, XRD, TGA, elemental analysis, and HPLC. Biological activities were assessed through antioxidant, anti-inflammatory, antidiabetic, neuroprotective, and hepatoprotective assays, supported by molecular docking and gene ontology interaction analysis. Results: Distinct physicochemical variations were observed between HA and TA. TA exhibited stronger antioxidant (IC₅₀ = 25.89 µg/mL), anti-inflammatory (COX-1 IC₅₀ = 69.61 µg/mL), antidiabetic (α-amylase IC₅₀ = 45.14 µg/mL), and hepatoprotective activities (IC₅₀ = 118.21 µg/mL), whereas HA displayed superior neuroprotective potential through butyrylcholinesterase inhibition (IC₅₀ = 39.01 µg/mL). Molecular docking supported the in vitro findings by confirming interactions with key protein targets associated with oxidative stress and metabolic pathways. Conclusions: Structural variation between species-derived alginates directly impacts their biological activities. TA represents a promising candidate for metabolic and anti-inflammatory therapies, while HA may be more suitable for neuroprotective interventions. These results emphasize the importance of source-specific alginate selection for developing targeted pharmaceutical applications. Full article

Phlorotannin–alginate extracts from brown seaweeds offer promising natural solutions for food preservation. This study investigated the extraction, characterization, and application of phlorotannins and alginate from two brown seaweed species, Sargassum cristaefolium and Nizimuddinia zanardinii, for inhibiting melanosis and preserving quality in Pacific white shrimp during ice storage. Preliminary screening identified N. zanardinii methanol extract as superior, yielding the highest phlorotannin content (19.14 ± 0.65 mg Phloroglucinol/g) with potent antioxidant (98.95 ± 0.74% DPPH inhibition) and copper-chelating (73.44 ± 1.64%) activities. Consequently, N. zanardinii was selected for subsequent extraction and application studies. Alginate extraction efficiency was 4.73 ± 0.38 g/100 g seaweed, demonstrating moderate antioxidant properties. The extracts effectively inhibited shrimp polyphenol oxidase, with 2% phlorotannins + 1% alginate showing 84.51% inhibition. When applied to shrimp, this combination significantly delayed melanosis development, suppressed microbial growth, and maintained lower pH, total volatile basic nitrogen (TVB-N), and lipid oxidation values during 16 days of ice storage compared to untreated controls. Sensory evaluation confirmed better retention of quality attributes in treated shrimp. These findings demonstrate the potential of N. zanardinii phlorotannin–alginate extracts as effective natural preservatives for maintaining shrimp quality during cold storage, offering a sustainable alternative to synthetic additives in seafood processing. Full article

This study investigated the year-round metabolomic variation in Fucus serratus (FS) and F. vesiculosus (FV) collected monthly from Danish coastal water around Aarhus Bay. Untargeted high-resolution liquid chromatography–mass spectrometry profiling (LC-HRMS), combined with multivariate data analysis and temporal clustering analysis, revealed that species identity was the primary driver of metabolic separation, followed by seasonal variation. FS showed higher levels of hydrolyzable tannins, flavonoid derivatives, aromatic amino acids, and glutamine-rich peptides, whereas FV was enriched in complex phlorotannins, tricarboxylic acid cycle intermediates, and carnitine derivatives. Temporal analysis identified recurring seasonal patterns across both species, including spring increases in amino acids, purine metabolites, and osmolytes; mid-summer peaks in mannitol and sulfated derivatives; and late-autumn elevations in phenolic compounds and betaine-type osmolytes. Despite apparent interspecific differences, several metabolite groups exhibited similar seasonal dynamics, suggesting shared physiological strategies associated with growth activation in spring, metabolic adjustment during summer to possible increased grazing pressure, and nutrient reallocation prior to winter. These findings provide a comprehensive, high-resolution view of seasonal metabolomic patterns in Fucus spp., offering new insights into their biochemical ecology and supporting the targeted utilization of these species for applications requiring specific metabolite profiles. Finally, this study contributes to the creation or expansion of metabolomic libraries for HRMS specific to Fucus seaweeds. Full article

The Portuguese Atlantic continental coast serves as a biogeographic transition zone where numerous macroalgal species reach their distribution limits, making it an especially intriguing area for studying shifts in species distribution. This region features sandy beaches and rocky outcrops that serve as habitats for a diverse range of organisms, including macroalgae. This illustrated guide aims to provide a simple and accessible overview of some of the most representative macroalgae species found along this coastline, specifically those designed for non-specialists in seaweed identification. Rather than offering a detailed identification key, the guide introduces key aspects of macroalgae—such as pigment composition, taxonomic classification, morphology, branching types, habitat on rocky shores, and potential human uses—in a clear and approachable format. Each species is accompanied by a photographic image, a general morphological description, and information about its typical habitat. Additionally, icons indicate whether a species has potential human applications or is considered non-indigenous. Species are categorized into green, brown, or red macroalgae based on their color and morphological characteristics. Full article

In recent years, seaweed-derived polysaccharides have gained recognition as renewed potent bioactive compounds with significant antibacterial and antiviral properties. These polysaccharides include carrageenan, agar, agarose, and porphyran from red seaweed; fucoidan, laminarin, and alginate (alginic acid) from brown seaweed; and ulvan from green seaweed. Their diverse and complex structures, shaped by sulfation patterns, glycosidic linkages, and monosaccharide composition, contribute to their broad-spectrum biological activities, including antimicrobial, immunomodulatory, and prebiotic functions. This review explores the structural characteristics of these marine polysaccharides, reported in vitro and in vivo antimicrobial activities, and the mechanisms underlying their antibacterial and antiviral effects. Additionally, the extraction, purification methods, and commercial applications of these bioactive polysaccharides are discussed. By integrating recent advances and highlighting their multifunctionality, this review underscores the translational promise of seaweed-derived polysaccharides as sustainable, natural agents in the global fight against antimicrobial resistance and infectious diseases. Full article

Fucoidan B (FucB) is a sulfated polysaccharide with recognized biological activity. In this study, FucB was chemically modified through redox conjugation with gallic acid (GA) to obtain FucB-GA, aiming to enhance its antioxidant properties. Structural characterization using FTIR, NMR, and electrophoresis confirmed the successful covalent binding of GA to FucB without major structural degradation. The conjugation increased the phenolic content and reduced crystallinity, as shown by XRD and SEM, indicating greater amorphous character, which can favor biological applications. Thermogravimetric analysis demonstrated enhanced thermal stability in FucB-GA. Antioxidant activity was evaluated through various in vitro assays. FucB-GA showed superoxide radical scavenging activity of 91.96%, copper chelating capacity of 43.2%, antioxidant capacity of 37 mg AEE/g, and reducing power of 94.22%, significantly higher results than FucB, while no sample chelated iron. Under the conditions analyzed, gallic acid alone showed minimal or no activity in most assays. These results suggest that conjugation with GA increases the antioxidant potential of FucB, while also improving the activity and bioavailability of GA, likely due to the increase in electron-donating and metal-binding groups. Overall, the study supports the development of FucB-GA as a promising antioxidant compound for pharmaceutical or nutraceutical applications. Full article

In recent years, insects have emerged as a nutritious and eco-sustainable alternative food source, with the house cricket (Acheta domesticus, AD) recently authorized by the European Commission as a novel food. However, the presence of harmful substances in insects poses potential health risks. This study investigated the content of potentially toxic elements (PTEs) such as cadmium (Cd), arsenic (As), lead (Pb), mercury (Hg), nickel (Ni), chromium (Cr), and aluminium (Al) in Acheta domesticus fed diets enriched with graded levels of the red seaweed Palmaria palmata or the brown seaweed Ascophyllum nodosum in two feeding trials. Chemical analyses were carried out by graphite furnace atomic absorption spectrophotometry for all elements except Hg, which was analyzed by thermal decomposition amalgamation atomic absorption spectrometry. The results showed that PTE content in the diets was below the legal limits for feed. The PTEs in AD ranged (mg kg⁻¹ dry matter) as follows: Cd (0.069 ± 0.005–0.127 ± 0.002), As (0.08 ± 0.01–0.36 ± 0.03), Pb (0.05 ± 0.01–0.12 ± 0.01), Hg (0.0065 ± 0.0002–0.0141 ± 0.0010), Ni (0.64 ± 0.06–1.20 ± 0.10), Cr (0.16 ± 0.02–0.58 ± 0.01), and Al (17 ± 2–61 ± 1). AD bioaccumulated As and Hg; however, the PTE levels remained below European Union food safety limits. The absence of non-carcinogenic risk for consumers suggests that AD fed seaweed-enriched diets are a safe, healthy, and low-chemical risk food for humans. Full article

This review focuses on five native Australian brown algae species—Cystophora torulosa, Durvillaea potatorum, Ecklonia radiata, Hormosira banksii, and Phyllospora comosa—evaluating their environmental adaptability, biochemical composition, bioactive compounds, and potential for commercial development. Species-specific differences in temperature and light tolerance influence their habitat distribution. Nutritional assessments reveal that these algae are rich in proteins, polysaccharides, polyunsaturated fatty acids, and essential trace elements. Bioactive compounds, including polyphenols and fucoidans, exhibit antioxidant, anti-inflammatory, and anti-diabetic properties. D. potatorum extracts have considerable economic value in agriculture by enhancing crop yield, improving nutritional value, and promoting root development. C. torulosa is predominantly found in cooler marine environments and is comparatively more thermally sensitive. In contrast, H. banksii has a higher heat tolerance of up to 40 °C and thrives in warmer environments. E. radiata is widely distributed, highly tolerant of environmental stresses, and exhibits notable disease-resistant activities. P. comosa, due to its high polysaccharide content, demonstrates strong potential for industrial applications. Consumer studies indicate growing acceptance of seaweed-based products in Australia, although knowledge gaps remain. This study highlights the need for continued research, optimized processing methods, and targeted education to support the sustainable development and utilization of Australia’s native brown algae resources. Full article

Poor solubility and bioavailability have limited the application of fucoxanthin and functional food processing. In order to encapsulate fucoxanthin in delivery systems, cellulose nanofibril-stabilized emulsion gels (CNFs) derived from industrial brown seaweed residue were developed to enhance fucoxanthin delivery. Cellulose nanofibrils (CNFs) were isolated using high-pressure homogenization at 105 MPa through 5, 10, and 15 cycles (denoted as C5, C10, and C15) and yielding reduced crystallinity down to 52.91 ± 2.13% (C15). The minimum particle size of the present CNFs is approximately 37 nm (C15). Moreover, single-factor and orthogonal experiments optimized the stability of the present emulsion. A 17.5 mg/mL CNFs 50% oil phase with coconut oil, 0.5 mg/mL fucoxanthin, and homogenization for 60 s were identified to be the optimal conditions for such emulsion gel. The present emulsions demonstrated a high storage stability at 4 °C versus 25 °C, which maintained minimal phase separation over 8 days. The release kinetics showed significant dependencies with fucoxanthin release increasing to 9.22 ± 0.62% at pH 8.0, 9.52 ± 0.58% under 1000 mM NaCl, and 8.25 ± 0.62% at 100 °C. In addition, the CNFs effectively preserved the antioxidant activity of the fucoxanthin under different pH values, salinities, and temperatures. The results establish seaweed-derived CNFs as effective stabilizers for fucoxanthin encapsulation, enhancing stability while preserving functionality against food-processing stresses. To our knowledge, no prior research has been reported on a fucoxanthin delivery system utilizing an emulsion gel stabilized by cellulose nanofibrils (CNFs). Such emulsions might provide a sustainable strategy for valorizing seaweed waste and advance functional food applications of marine bioactives. Full article

Inflammatory muscle loss results from excessive inflammatory responses, causing muscle damage and weakness. In the current investigation, we evaluated the protective effects of diphlorethohydroxycarmalol (DPHC) against tumor necrosis factor-alpha (TNF-α)-induced skeletal muscle inflammation and muscle loss and elucidated the underlying mechanisms. Furthermore, the effect of DPHC on swimming performance was confirmed under TNF-α-induced inflammatory muscle loss-conditioned zebrafish by assessing the swimming number, distance moved, time spent swimming, frequency of swimming zebrafishes in an upstream swim track (Zone A). In vivo behavioral endurance test results indicated that TNF-α treatment significantly decreased the number of swimming zebrafish and swimming distance in Zone A compared with the Control. Meanwhile, the DPHC treatment significantly increased the number of swimming zebrafish and swimming distance in Zone A compared to TNF-α-induced zebrafish. These findings indicate that DPHC treatment effectively improved the swimming performance of TNF-α-induced zebrafish. In an additional study, TNF-α significantly induced inflammatory muscle loss by upregulating nuclear factor kappa light chain enhancer of activated B cells (NF-κB) mitogen activated protein kinase (MAPK) associated proteins and MuRF-1 in the skeletal muscle tissues of TNF-α-induced zebrafish. However, DPHC administration significantly counteracted TNF-α-induced inflammation and muscle loss by downregulating NF-Κb and MAPK-associated proteins, as well as the muscle degradation-related proteins MuRF-1 and MAFbx, in the skeletal muscle tissues of TNF-α-induced zebrafish. In summary, our research findings demonstrated that DPHC from Ishige okamurae could be used for the development of nutraceuticals or functional foods targeting inflammatory muscle loss. Full article

The survival and efficacy of probiotic bacteria depend on their ability to grow under optimal conditions and withstand environmental stresses, and marine macroalgae are emerging as promising prebiotic sources that may enhance their viability. In this study the effect of Ascophyllum nodosum and Fucus vesiculosus supplementation (0.5% w/v) on Lactiplantibacillus plantarum was evaluated by assessing growth performance and stress resistance under different conditions, including temperatures (15, 25, 30, 37, 42 °C), pH levels (2.5, 3.5, 4.5, 6.5, 8.5), and enzymatic challenges (pepsin, trypsin, bile). Both algal supplements promoted faster initial growth between 25 and 42 °C, particularly at 37 °C, by reducing the lag phase and increasing the growth rate. Under acidic stress, survival exceeded 80% after 3 h, with significant improvements at pH 2.5 and 3.5 in the presence of seaweeds, while enzymatic assays demonstrated enhanced tolerance against pepsin, trypsin, and bile salts. Overall, supplementation with brown algal biomass provided modest but consistent benefits to L. plantarum growth and stress resistance, supporting the use of whole macroalgae as functional additives in probiotic formulations for both human and animal nutrition. Full article

This review explores the pharmacological potential of chondroitin sulfate and fucoidan as immunomodulatory agents targeting N-acetylgalactosaminidase (nagalase) to normalize immune responses. Nagalase, an enzyme produced by tumor and virus-infected cells, contributes to immune suppression by deactivating macrophage-activating factor. Both chondroitin sulfate and fucoidan, as representatives of glycosaminoglycans and heteropolysaccharides, exhibit significant potential in inhibiting nagalase activity, thereby restoring immune functionality. Chondroitin sulfate, a key component of the extracellular matrix, demonstrates anti-inflammatory and tissue-regenerative properties by modulating nuclear factor (NF)-κB pathways and cytokine expression. Fucoidan, a sulfated polysaccharide derived from brown seaweed, enhances immune responses through macrophage and natural killer cell activation, while also exhibiting antiviral and anticancer activities. This dual action positions these compounds as promising agents for therapeutic interventions in chronic inflammatory conditions, cancer, and infectious diseases. The synergistic effects of chondroitin sulfate and fucoidan highlight their potential to address the root causes of immune dysregulation. This review aims to elucidate the underlying mechanisms of action and explore the clinical applications of these compounds within the framework of innovative immunotherapeutic strategies. However, current evidence is limited by the predominance of preclinical studies and variability in experimental models. Well-designed clinical trials are needed to validate their efficacy for therapeutic use. Full article

Grapes are one of the most preferred fruit species in the world. Increasing yield and quality in table grape production has always been the top priority for producers. Producers’ interest in biostimulants from sustainable agricultural practices for quality and yield increase is increasing day by day. Seaweed extracts (SWEs), which are among the most preferred biostimulants, are shown as an organic input due to their ecological safety and harmlessness. In this study, Ecklonia maxima (Em), Macrocystis integrifolia (Mi) and Ascophyllum nodosum (An), which are brown SWEs, were applied to the Alphonse Lavallée (AL) grape variety four times via the leaves. As a result of the applications, yield, quality and physiological parameters were examined. As a result of the study, all SWE applied increased yield per vine between 28% and 47%. SWEs improved cluster and berry characteristics and increased phenolic content and antioxidant activity compared to the control. They also contributed to physiological characteristics of the grapevine, such as photosynthetic activity and stomatal conductance. It is thought that SWEs, which are among the sustainable agricultural practices, will improve the yield and quality of grapes not only in organic farming but in all agricultural practices. Full article

In response to the growing demand for sustainable biomaterials in tissue engineering, we investigated the potential of structurally intact brown seaweed scaffolds derived from Laminaria digitata (L.D.) and Laminaria saccharina (L.S.), produced by a detergent-free, visible-light decellularization process aimed at preserving structural integrity. Blades were submerged in cold flow-through and aerated water with red (620 nm) and blue (470 nm) light exposure for 4 weeks. Histology, scanning electron microscopy (SEM), and micro-computed tomography (micro-CT) analyses demonstrated that the light decellularization process removed cells/debris, maintained essential structural features, and significantly increased scaffold porosity. Mechanical property analysis through tensile testing revealed a substantial increase in tensile strength post decellularization, with L.D. scaffolds increasing from 3.4 MPa to 8.7 MPa and L.S. scaffolds from 2.1 MPa to 6.6 MPa. Chemical analysis indicated notable alterations in polysaccharide and protein composition following decellularization. Additionally, scaffolds retained high swelling and fluid absorption capacities, critical for biomedical uses. These findings underscore that the decellularized L.D. and L.S. scaffolds preserved structural integrity and exhibited enhanced mechanical properties, interconnected porous structures, and significant liquid retention capabilities, establishing them as promising biomaterial candidates for soft-tissue reinforcement, wound care, and broader applications in regenerative medicine. Full article