Search Results (546)

Macroalgae (seaweeds) produce unique bioactive metabolites that have enabled their survival for millions of years, offering significant potential for human benefits. In the Israeli Mediterranean Sea, no comprehensive systematic surveys of seaweeds have been published since the 1990s, and their chemical composition remains largely unexplored. This study presents an extensive survey of intertidal seaweed communities along the shallow Israeli coastline, documenting their spatial, temporal, and biochemical diversity. Of the 320 specimens collected, 55 seaweed species were identified: 29 red (Rhodophyta), 14 brown (Phaeophyceae), and 12 green (Chlorophyta). A significant shift in species abundance was documented, with a single dominant annual bloom occurring during spring, unlike previously reported biannual blooms. Chemical analysis of the dominant species revealed significant seasonal variations in compound levels, with higher protein content in winter and increased antioxidant capacity during spring. Phenolic and natural sunscreen compounds (mycosporine-like amino acids, MAAs) showed no general seasonal trend. These findings highlight the optimal environmental conditions for seaweed growth and underscore their potential for aquaculture and biotechnology. We hypothesize that the ecologically unique conditions of the Israeli Mediterranean Sea may foster resilient seaweed species enriched with distinctive chemical properties, suitable for nutritional, health, pharmaceutical, and nutraceutical applications, particularly as climate-adaptive bioresources. Full article

Background/Objectives: Estrogen deficiency contributes to dyslipidemia and visceral adiposity, increasing cardiovascular risk in postmenopausal women. Sargassum fulvellum (Sf), a brown seaweed rich in bioactive compounds, possesses lipid-regulating properties that may be enhanced by lactic acid bacteria fermentation. This study aimed to evaluate the effects of fermented S. fulvellum (SfLlLm), prepared using Lactococcus lactis and Leuconostoc mesenteroides, on lipid metabolism and adipose tissue remodeling in an ovariectomized (OVX) mouse model of estrogen deficiency. Methods: Female C57BL/6 mice underwent ovariectomy and were fed an AIN-76A diet supplemented with either unfermented Sf or SfLlLm for eight weeks. Sham-operated and 17β-estradiol-treated OVX groups served as controls. Serum lipid levels—total cholesterol, triglycerides, LDL-C, and HDL-C—were assessed, and histological analysis of visceral adipose tissue was conducted to evaluate adipocyte morphology. Results: OVX-induced estrogen deficiency led to increased total cholesterol, triglycerides, and LDL-C, along with hypertrophic changes in visceral adipocytes. Supplementation with fermented Sargassum fulvellum (SfLlLm) markedly improved these parameters, reducing total cholesterol by 6.7%, triglycerides by 9.3%, and LDL-C by 52.9%, while increasing HDL-C by 17.5% compared to the OVX controls. SfLlLm also normalized visceral adipocyte size and distribution. These effects were comparable to or exceeded those of 17β-estradiol treatment. Conclusions: Fermented SfLlLm ameliorated dyslipidemia and visceral adiposity under estrogen-deficient conditions. These findings support its potential as a functional dietary intervention for managing postmenopausal lipid disorders and associated metabolic complications. Full article

The marine seaweed Undaria pinnatifida belongs to the large group of brown macroalgae (Ochrophyta) and is valued both as a nutritious food and a source of pharmaceutical compounds. It has been widely consumed in East Asia as part of the traditional diet and is generally regarded as a “healthy longevity food.” Consequently, it represents one of the most promising natural sources of biomedicinal and bioactive products. This review aims to synthesize current scientific evidence on the pharmacologically active compounds of U. pinnatifida, emphasizing their mechanisms of action and therapeutic potential in neurodegenerative and chronic diseases. This narrative review is based on a comprehensive literature search of peer-reviewed articles from scientific databases, focusing on studies addressing the pharmacological properties of U. pinnatifida and its major bioactive constituents. Recent research highlights that compounds such as fucoxanthin (a carotenoid), fucosterol (a sterol), fucoidan (a polysaccharide), alginate, and dietary fiber found in U. pinnatifida possess significant potential for developing treatments for conditions including goitre, urinary diseases, scrofula, dropsy, stomach ailments, and hemorrhoids. Moreover, these compounds exhibit remarkable pharmacological properties, including immunomodulation, antitumor, antiviral, antioxidant, antidiabetic, anti-inflammatory, anticoagulant, antithrombotic, and antibacterial activities, all with low toxicity and minimal side effects. Additionally, U. pinnatifida shows promise in the treatment or prevention of neurodegenerative diseases such as Alzheimer’s and Parkinson’s, as well as neuropsychiatric conditions like depression, supported by its antioxidant effects against oxidative stress and neuroprotective activities. Numerous in vitro and in vivo studies have confirmed that U. pinnatifida polysaccharides (UPPs), particularly fucoidans, exhibit significant biological activities. Thus, accumulating evidence positions UPPs as promising therapeutic agents for a variety of diseases. Full article

Seaweed is a sustainable ingredient that has been suggested to improve the nutritional aspects as well as the sensory properties of different food products. The objective of this study was to evaluate the flavor properties of extracts from brown seaweed (Ascophyllum nodosum) and sugar kelp (Saccharina latissimi) obtained at different temperatures. These varieties commonly grow in the Atlantic Ocean. The seaweed samples were extracted using water at three different temperatures (50 °C, 70 °C, and 90 °C). The volatile fraction of the extracts was extracted with headspace solid-phase microextraction and analyzed by gas chromatography–mass spectrometry. The headspace chemical composition varies significantly among seaweed extracts and at different extraction temperatures. Major classes of identified compounds were aldehydes, ketones, alcohols, hydrocarbons, and halogenated compounds. Extracts were also evaluated using temporal check-all-that-apply (with 84 untrained participants). The different temperatures had minimal impact on the flavour properties of the brown seaweed samples, but the extraction temperature did influence the properties of the sugar kelp samples. Increasing the extraction temperature seemed to lead to an increase in bitterness, savouriness, and earthy flavor, but future studies are needed to confirm this finding. This study continues the exploration of the flavor properties of seaweeds and identifies the dynamic flavor profile of brown seaweed and sugar kelp under different extraction conditions. Full article

Kombucha is a sweetened tea infusion fermented using a symbiotic culture of bacteria and yeast (SCOBY). Recently, kombucha has gained popularity due to its potential health benefits, attributed to its high antioxidant and probiotic properties. The aim of this research was to formulate a novel antioxidant-rich beverage with symbiotic benefits by utilizing ingredients such as Laminaria digitata (brown seaweed), cinnamon, and lavender adjuncts, alongside alternative substrates like acacia honey and conventionally used ingredients such as ginger (Zingiber officinale Roscoe). This study comprehensively evaluated parameters including pH levels, acidity, alcohol content, color, and antioxidant potential of the beverages. All kombucha beverages exhibited significantly high antioxidant potential levels, particularly in Honey Kombucha (HK) samples, which ranged between 164.44 and 164.78% 2,2-Diphenyl-1-picrylhydrazyl (DPPH) inhibition, and 155.44–155.29 µg Trolox Equivalent (TE)/mL for the Ferric-reducing antioxidant power (FRAP) assay on days 3 and 7. Sugar Kombucha Seaweed (SKS) and Sugar Kombucha Cinnamon (SKC) samples received the highest acceptability for flavor from the sensory panel, with scores of 87.5% and 70%, respectively. However, Honey Kombucha Ginger (HKG) received the lowest acceptability with only 12.5%. The added adjuncts and substrates significantly influenced the antioxidant potential compared to plain unfermented tea (PT). This research paper outlines well-characterized fermentation process for formulating health-promoting beverages utilizing locally sourced ingredients. Full article

Durvillaea incurvata, a Chilean brown seaweed, exhibits high antioxidant activity and polyphenol content, positioning it as a promising candidate for developing bioactive food ingredients. This study evaluated the anti-inflammatory activity of an ethanolic extract of Durvillaea incurvata, produced via ultrasound-assisted extraction, and its subsequent microencapsulation to obtain a functional food-grade ingredient. The extract’s anti-inflammatory capacity was assessed in vitro through hyaluronidase inhibition, and its cytotoxicity was evaluated using gastrointestinal cell models (HT-29 and Caco-2). Microencapsulation was performed by spray-drying with maltodextrin, and encapsulation efficiency (EE) was optimized using response surface methodology. Characterization included scanning electron microscopy, differential scanning calorimetry, and X-ray diffraction. The extract exhibited low cytotoxicity (cell viability > 75%). Optimal encapsulation conditions (inlet temperature: 198.28 °C, maltodextrin: 23.11 g/100 g) yielded an EE of 72.7% ± 1.2% and extract recovery (R) of 45.9% ± 2.4%. The microparticles (mean diameter, 2.75 µm) exhibited a uniform morphology, shell formation, glassy microstructure, and suitable physicochemical properties (moisture, 3.4 ± 0.1%; water activity, 0.193 ± 0.004; hygroscopicity, 30.3 ± 0.4 g/100 g) for food applications. These findings support the potential of microencapsulated Durvillaea incurvata extract as an anti-inflammatory ingredient for functional food development. Full article

Background/Objectives: Cancer remains one of the leading causes of mortality worldwide, while natural antioxidants have emerged as promising therapeutic agents in cancer treatment. Although fucoidan from brown algae shows anticancer potential, its efficacy is limited by bioavailability challenges, and the synergistic effects of combining it with gold nanoparticles remain unexplored. Methods: Fucoidan was extracted from Sargassum cinereum and Turbinaria decurrens. F-AuNPs were produced utilizing fucoidan as both a reducing and stabilizing agent. The nanoparticles were analyzed by UV-Vis spectroscopy, FTIR, TEM, XRD, DLS, TAG, and zeta potential evaluation. The antioxidant activity was evaluated by DPPH and FRAP tests. Cytotoxicity was determined against HepG2, THP-1, and BNL cells, utilizing MTT and SRB tests. Flow cytometry was utilized to assess the cell cycle, while molecular docking was carried out to examine binding to oncogenic proteins. Results: T. decurrens produced higher polysaccharides rich in fucoidan content (235.9 mg/g dry weight) and stated higher antioxidant activity (FRAP: 9.21 μg TE mg⁻¹; DPPH: 4.48 μg TE mg⁻¹) in comparison to S. cinereum. F-AuNPs showed potent cytotoxicity toward HepG2 cells, with IC₅₀ values and cytotoxicity toward HepG2 cells, with IC₅₀ values of 377.6 μg/mL for S. cinereum and 449.5 μg mL⁻¹ for T. decurrens. Molecular docking revealed robust binding of fucoidan to COX-2 (−7.1 kcal mol⁻¹) and TERT (−5.4 kcal mol⁻¹). Conclusions: Fucoidan and F-AuNPs reveal remarkable antioxidant and anticancer properties. Nanoparticle formulation greatly improves bioactivity, underscoring its promise as a synergistic approach for cancer treatment by influencing oxidative stress and cancer-associated pathways. Full article

Background/Objectives: Brown seaweeds, such as Himanthalia elongata, are a promising source of dietary fiber. However, in vivo evidence regarding the effects of H. elongata intake on the human gut microbiota remains limited. This study aimed to evaluate the impact of daily H. elongata consumption on the gut microbiota composition and short-chain fatty acid production in overweight adults. Methods: A randomized, double-blind, placebo-controlled trial was conducted in which 10 overweight adult participants consumed 2 g/day of whole H. elongata for 30 days. Fecal samples were collected before and after the intervention for 16S rRNA sequencing and short-chain fatty acid analysis. Dietary intake was evaluated using a 24 h recall and a 3-day dietary record. Nutritional assessment was performed to determine habitual macronutrient consumption. Results: Baseline dietary analysis revealed an imbalanced macronutrient profile characterized by high intakes of total and saturated fats and protein, along with low carbohydrate and fiber consumption. In addition, 50% of the participants were obese, and 50% were overweight based on the BMI. Notable changes in the gut microbiota composition were observed after the intervention, including increases in short-chain fatty acid-producing species, such as Parabacteroides distasonis, Bacteroides eggerthii, Bacteroides uniformis, and Bacteroides obeum. Conclusions: This study provides the first clinical evidence in humans that whole H. elongata can beneficially modulate the gut microbiota composition. These results support the potential use of this seaweed as a functional prebiotic ingredient in dietary strategies aimed at enhancing gut health. Full article

The toxic effects of copper (Cu) excess in brown macroalgae have been well characterized. However, the interactive effects of increased temperatures, associated with climate change, and Cu stress on these macrophytes remain almost unexplored. In this study, we exposed the model brown seaweed Ectocarpus to different Cu concentrations (0, 0.8, 1.6, and 3.2 μM) at two different temperatures (15 and 25 °C). Relative growth rates decreased at 25 °C for the two highest Cu concentrations after 8 days of exposure, but a contrasting pattern was observed in the photosynthetic maximum quantum yield (F_v/F_m) and photosynthetic efficiency (α), where reductions were observed at 15 °C for the same Cu concentrations. Although no differences among treatments were observed for chlorophyll a (Chla) and chlorophyll c (Chlc), a reduction in concentration of the accessory pigment fucoxanthin (Fx) was only observed at 15 °C in all Cu treatments. Interestingly, at 25 °C, 20.1% less total Cu (intracellular + extracellularly bound) accumulated compared to 15 °C upon exposure to 3.2 μM Cu. Likewise, 33.1 and 23.8% less Cu accumulated intracellularly at 25 °C after exposure to 1.6 μM and 3.2 μM Cu, respectively. Additionally, at 25 °C about half of the Cu ions accumulated intracellularly and half extracellularly compared to 15 °C, where Cu accumulated mostly intracellularly at the two highest Cu concentrations. The results presented here provide valuable information to better understand the interactive effects of increased temperature and excess Cu in the stress response of Ectocarpus, suggesting that increased temperature helps to offset the negative impacts of exposure to high Cu concentrations. Full article

Sargassum thunbergii is a dominant seaweed species in the intertidal zone along the coast of China. It provides various ecological services, such as primary productivity, marine carbon sequestration, and water purification. To investigate the population structure characteristics of Sargassum thunbergii, the Hegyi competition model was employed to quantify intraspecific competition within populations in the intertidal zone of Luhua Island, China. The results showed that the competition intensity decreased as a power function (y = 1.93x^−0.89, R² = 0.28) with increasing seaweed height. Intraspecific competition had minimal effects on seaweeds taller than 50 cm. Seaweeds at lower population levels exhibited more stable competition indices. Therefore, the model can reliably predict intraspecific competition intensity in Sargassum thunbergii. The sample circle method was applied to identify an optimal intraspecific competitive range of 50 cm for intertidal populations of Sargassum thunbergii. This study provides scientific guidance for seaweed spacing and rational harvesting during ecological restoration. Moreover, it offers valuable insight for conserving other macroalgae, such as Sargassum fusiforme, and restoring seaweed beds ecologically. Full article

This study presents a sustainable, environmentally friendly synthetic route for the production of key intermediates in losartan using palladium nanoparticles (PdNPs) derived from a brown seaweed, Sargassum incisifolium, as a recyclable nanocatalyst. A key intermediate, biaryl, was synthesized with an excellent yield (98%) via Suzuki–Miyaura coupling between 2-bromobenzonitrile and 4-methylphenylboronic acid, catalyzed using bio-derived PdNPs under mild conditions. Subsequent bromination using N-bromosuccinimide (NBS) under LED light, followed by imidazole coupling and tetrazole ring formation, allowed for the production of losartan with an overall yield of 27%. The PdNP catalyst exhibited high stability and recyclability, as well as strong catalytic activity, even at lower loadings, and nitrosamine formation was not detected. While the overall yield was lower than that of traditional industrial methods, this was due to the deliberate avoidance of the use of toxic reagents, hazardous solvents, and protection/deprotection steps commonly used in conventional routes. This trade-off marks a shift in pharmaceutical process development, where environmental and safety considerations are increasingly prioritized in line with green chemistry and regulatory frameworks. This study provides a foundation for green scaling up strategies, incorporating sustainability principles into drug synthesis. Full article

Fucus vesiculosus is a brown seaweed known for its strong antioxidant properties, mainly attributed to its high polyphenolic content. This study aimed to evaluate the antioxidant protective effect of an optimised F. vesiculosus extract in an experimental model of intestinal ischemia/reperfusion (I/R) injury, considering the intestine as particularly vulnerable to this pathology. Seventy-two male Wistar albino rats were randomly divided into twelve groups: Sham, I/R groups (3 and 24 h reperfusion), I/R plus vehicle groups (three application times, 3 h reperfusion), and I/R plus F. vesiculosus extract groups (three application times, 3 and 24 h reperfusion). Intestinal injury was assessed through biochemical markers (malondialdehyde [MDA], superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GPx], and mieloperoxidase [MPO]), inflammatory cytokines (interleukin 1 β [IL-1β] and interleukin [IL-10]), and histological analysis. Results demonstrated that treatment with F. vesiculosus significantly reduced oxidative stress and inflammation caused by I/R injury (p < 0.05), restoring analysed parameters (MDA, SOD, CAT, IL-10) to levels comparable to the Sham group. Histological examination confirmed the preservation of intestinal mucosal integrity following F. vesiculosus administration. These findings suggest that the antioxidant extract from F. vesiculosus effectively protects against intestinal I/R injury, highlighting its potential for clinical use in preventing and managing this pathological condition, particularly in surgical contexts. Full article

Background/Objectives: Desiccation profoundly influences the distribution and abundance of intertidal seaweeds, necessitating robust molecular adaptations. Sargassum muticum is a brown seaweed inhabiting intertidal rocky substrates. During low tides, this species undergoes periodic aerial exposure. Such environmental conditions necessitate robust physiological mechanisms to mitigate desiccation stress. Yet, the molecular basis of this adaptation remains poorly understood. Methods: To investigate desiccation-responsive genes and elucidate the underlying mechanisms of adaptation, we exposed S. muticum to 6 h of controlled desiccation stress in sterilized ceramic trays, simulating natural tidal conditions, and performed comparative transcriptome analysis using RNA-seq on the Illumina NovaSeq 6000 platform. Results: High-quality sequencing identified 66,192 unigenes, with 1990 differentially expressed genes (1399 upregulated and 591 downregulated). These differentially expressed genes (DEGs) were categorized into regulatory genes—including mitogen-activated protein kinase (MAPK), calmodulin, elongation factor, and serine/threonine-protein kinase—and functional genes, such as heat shock protein family members (HSP20, HSP40, and HSP70), tubulin (TUBA and TUBB), and endoplasmic reticulum homeostasis-related genes (protein disulfide-isomerase A6, calreticulin, and calnexin). Gene Ontology (GO) enrichment highlighted upregulated DEGs in metabolic processes like glutathione metabolism, critical for oxidative stress mitigation, while downregulated genes were linked to transport functions, such as ammonium transport, suggesting reduced nutrient uptake during dehydration. KEGG pathway analysis revealed significant enrichment in “protein processing in endoplasmic reticulum” and “MAPK signaling pathway-plant”, implicating endoplasmic reticulum stress response and conserved signaling cascades in desiccation adaptation. Validation via qRT-PCR confirmed consistent expression trends for key genes, reinforcing the reliability of transcriptomic data. Conclusions: These findings suggest that S. muticum undergoes extensive biological adjustments to mitigate desiccation stress, highlighting candidate pathways for future investigations into recovery and tolerance mechanisms. Full article

The extraction of bioactive compounds from marine natural products has gained increasing attention due to their diverse applications, such as in pharmaceuticals, nutraceuticals, and cosmetics. Yet, low extraction yields and toxicity associated with common solvents are a major bottleneck. Deep eutectic solvents (DESs) and natural deep eutectic solvents (NADESs) have emerged as promising green alternatives to conventional organic solvents, offering advantages such as biodegradability, greater environmental and economic sustainability, low toxicity, and enhanced extraction selectivity. This review provides a comprehensive analysis of the principles, physicochemical properties, and applications of DESs/NADESs to obtain bioactive compounds from marine organisms. Among the most recent works, it is possible to verify the success of NADESs to extract carrageenan from the seaweed Kappaphycus alvarezii; pigments from Palmaria palmata; and polyphenols and proteins from different brown seaweeds. NADESs have also shown high potential to extract other valuable compounds from marine by-products, such as chitin from crabs and shrimp shells, and also lipids and proteins from different fish species and protein rich extracts from tilapia viscera. The challenges for DESs/NADESs use at industrial scale are also discussed, and success cases are revealed, highlighting their potential as game changers for extracting bioactive compounds from marine organisms and driving the development of innovative biotechnological products. Full article

Algae are the group that has managed to generate the largest number of compounds and secondary metabolites with different properties, many of them only present in the aquatic kingdom. Among them, brown algae are one of the main producers within marine ecosystems. Furthermore, one of the main groups of secondary metabolites studied are sesquiterpenes due to the great variety of properties observed, largely due to the great structural variability of these compounds. Many studies have been carried out to isolate and characterize compounds with a sesquiterpene structure from different species of brown algae. This article reviews the natural occurrence of sesquiterpene and derivatives in brown algae. A total of 51 sesquiterpenes isolated from brown algae, having monocyclic, bicyclic, or tricyclic skeletons, as well as 23 sesquiterpenoids with various chemical structures, are depicted. Moreover, there are at least eleven publications focused on the study of the profiles on volatile organic compounds (VOCs) within brown algae, derived using several analytic and extraction techniques, and in the finding of a large variety of structures of sesquiterpenes. Full article