Search Results (227)

Brown algae such as Ascophyllum nodosum (AN) and Fucus vesiculosus (FV) are gaining considerable attention as functional feed additives due to their health-beneficial properties. This study evaluated the antioxidant potential of AN and FV extracts in intestinal epithelial cells and the in vivo model Caenorhabditis elegans (C. elegans). Aqueous AN and FV extracts were characterized for total phenolic content (TPC), antioxidant capacity (TEAC, FRAP), and phlorotannin composition using LC-HRMS/MS. Antioxidant effects were assessed in vitro, measuring AAPH-induced ROS production in Caco-2 and IPEC-J2 cells via H₂DCF-DA, and in vivo, evaluating the effects of paraquat-induced oxidative stress and AN or FV treatment on worm motility, GST-4::GFP reporter expression, and gene expression in C. elegans. FV exhibited higher total phenolic content, antioxidant capacity (TEAC, FRAP), and a broader phlorotannin profile (degree of polymerization [DP] 2–9) than AN (DP 2–7), as determined by LC-HRMS/MS. Both extracts attenuated AAPH-induced oxidative stress in epithelial cells, with FV showing greater efficacy. In C. elegans, pre-treatment with AN and FV significantly mitigated a paraquat-induced motility decline by 22% and 11%, respectively, compared to PQ-stressed controls. Under unstressed conditions, both extracts enhanced nematode healthspan, with significant effects observed at 400 µg/g for AN and starting at 100 µg/g for FV. Gene expression analysis indicated that both extracts modulated antioxidant pathways in unstressed worms. Under oxidative stress, pre-treatment with AN and FV significantly reduced GST-4::GFP expression. In the nematode, AN was more protective under acute stress, whereas FV better supported physiological function in the absence of stressors. These findings demonstrate that AN and FV counteract oxidative stress in intestinal epithelial cells and in C. elegans, highlighting their potential as stress-reducing agents in animal feed. Full article

Background: Nowadays, to improve animal production sustainably, the zootechnical sector is exploring novel, functional ingredients, such as seaweed. This study investigated the functional properties of Fucus vesiculosus and their persistence after simulated digestion. Methods: F. vesiculosus was nutritionally characterized (AOAC methods) and digested in vitro through the INFOGEST protocol. The polyphenol, flavonoid, and phlorotannin contents of the samples were analyzed through colorimetric assays. The antioxidant properties were evaluated using ABTS assay and the growth inhibition capacity against Escherichia coli using the microdilution method. The cytotoxic activity and anti-inflammatory properties were evaluated on mouse peritoneal macrophages using crystal violet assay and the gene expression of IL-1β, IL-6, TNF-α, and iNOS. Results: F. vesiculosus demonstrated high levels of dietary fiber (47.36%) and protein (13.99%). Significant levels of polyphenols (6428.98 µg TAE/g), flavonoids (5171.31 µg CE/g), and phlorotannins (2.10 mg PGE/g) were detected. These bioactive compounds allowed for strong antioxidant activity (85.96% ABTS+ scavenging) and E. coli growth inhibition (17%). Simulated digestion minimally impacted the content of bioactive compounds and their associated functional properties. F. vesiculosus exhibited a protective effect against oxidative stress in macrophages, downregulating pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α). Conclusions: These findings support the potential of F. vesiculosus as a functional feed ingredient for livestock, maintaining its beneficial properties even after digestion. Full article

Chronic pain affects approximately 20% of the global adult population, posing significant healthcare and economic challenges. Effective management requires addressing both biological and psychosocial factors, with emerging therapies such as antioxidants and marine algae offering promising new treatment avenues. Marine algae synthesize bioactive compounds, including polyphenols, carotenoids, and sulfated polysaccharides, which modulate oxidative stress, inflammation, and neuroimmune signaling pathways implicated in pain. Both preclinical and clinical studies support their potential application in treating inflammatory, neuropathic, muscular, and chronic pain conditions. Notable constituents include polyphenols, carotenoids (such as fucoxanthin), vitamins, minerals, and sulfated polysaccharides. These compounds modulate oxidative stress and inflammatory pathways, particularly by reducing reactive oxygen species (ROS) and downregulating cytokines such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). Brown and red algae produce phlorotannins and fucoidans that alleviate pain and inflammation in preclinical models. Carotenoids like fucoxanthin demonstrate neuroprotective effects by influencing autophagy and inflammatory gene expression. Algal-derived vitamins (C and E) and minerals (magnesium, selenium, and zinc) contribute to immune regulation and pain modulation. Additionally, sulfated polysaccharides suppress microglial activation in the central nervous system (CNS). Marine algae represent a promising natural source of bioactive compounds with potential applications in pain management. Although current evidence, primarily derived from preclinical studies, indicates beneficial effects in various pain models, further research is necessary to confirm their efficacy, safety, and mechanisms in human populations. These findings advocate for the continued exploration of marine algae as complementary agents in future therapeutic strategies. Full article

The technology of fucoidan extraction significantly affects its properties. This study aimed to evaluate the impact of dynamic maceration (DM) and ultrasound-assisted extraction (UAE) on the antioxidant and anticancer properties of fucoidan from Arctic brown algae. Fucus vesiculosus (Fv), Fucus serratus (Fs), Fucus distichus (Fd), and Ascophyllum nodosum (An) were collected from the Barents Sea. The average yield of fucoidan and uronic acid was higher (by 43.2% and 22.0%, respectively) after UAE, while phlorotannin content decreased by 53.7% compared with DM. The fucose level for all algae increased after UAE, while the molecular weight of fucoidans was lower. The highest antioxidant activity was noted for the fucoidan from An and Fv, which were obtained by DM and can be associated with the high concentrations of phlorotannins. The treatment of HeLa G-63 cells with all studied fucoidans for 48 h increased concentration-dependently the number of dead cells. The most promising were Fv and Fs fucoidans with high phlorotannins, low sulfates, and uronic acid extracted by DM. The co-administration of paclitaxel and fucoidan caused cell cycle arrest in the G2/M phase. The calculated for the first time combinatory effect showed that the simultaneous use of paclitaxel and fucoidan exposure leads to a synergistic interaction. Our results support the rationality of fucoidan use in complex chemotherapy to improve survival, quality of life and immunity in patients with cervical carcinoma. Full article

Phlorotannins, bioactive compounds isolated from brown seaweeds, have garnered significant attention in recent years for their wide-ranging therapeutic properties, particularly their anti-inflammatory effects. Recent studies have identified phlorotannins as potent inhibitors of inflammatory pathways such as NF-κB, MAPK, JAK/STAT3, and NLRP3. Specifically, phlorotannins derived from seaweeds like Ecklonia cava, Ishige okamurae, and Sargassum horneri have been shown to inhibit the gene and protein expression of pro-inflammatory cytokines and other inflammatory mediators in both in vivo and in vitro conditions. Despite these promising findings, no commercial drugs derived from seaweed phlorotannins have yet been developed to treat inflammatory diseases, and reports of clinical trials remain rare, even in the context of functional food applications for chronic inflammatory conditions. To address this knowledge gap, the authors reviewed peer-reviewed research articles published in 2020 or later, focusing on the anti-inflammatory potential of phlorotannins. The insights provided in this review are expected to be valuable for industries such as functional food research groups and others involved in developing anti-inflammatory therapeutics. Full article

Sargassum filipendula is a marine macroalgae, also known as brown algae. These species contain significant amounts of polysaccharides, such as alginates, and phenolic compounds, including phlorotannins, with excellent biological properties. This study evaluated the extraction of bioactive compounds from the residual biomass of Sargassum filipendula using deep eutectic solvents based on alkanol amines combined with polyols. The residual biomass presented a content of 7.36% protein, 1.11% lipids, 20.51% ash, 14.88% moisture, 50.25% total fibers, and 5.89% alginate. Preliminary screening identified N, N-(dimethylamino)-ethanol: benzyl alcohol (1.30:1) and N, N-(dimethylamino)-ethanol:1,3-propanediol (1.83:1) as the most efficient solvents for the extraction of bioactive compounds. The optimization process showed that the temperature and solid–liquid ratio significantly influenced (p < 0.05) the extraction of total phenolic compounds, phlorotannins, and the content of photosynthetic pigments. Intermediate temperatures (74.4 °C for N, N-(dimethylamino)-ethanol: benzyl alcohol (1.30:1) and 68.4 °C for N, N-(dimethylamino)-ethanol:1,3-propanediol (1.83:1), and a lower solid-to-liquid ratio (0.03) were optimal conditions to extract the low-pigment phlorotannins selectively. In contrast, higher temperatures (120 °C) maximized the extraction of phlorotannins and photosynthetic pigments. N, N-(dimethylamino)-ethanol: benzyl alcohol (1.30) extracted 110.64 mg PGE/g phlorotannins and 78.15 mg GAE/g phenolics, while N, N-(dimethylamino)-ethanol:1,3-propanediol (1.83:1) produced 21.57 mg PGE/g and 72.89 mg GAE/g, respectively. The extraction of photosynthetic pigments reached a maximum yield at 120 °C, using N, N-(dimethylamino)-ethanol: benzyl alcohol (1.30:1), with a content of 21.61 µg/g of chlorophylls and 38.11 µg/g of pheophytins, while N, N-(dimethylamino)-ethanol: 1,3-propanediol (1.83:1) provided content of 17.76 µg/g and 36.32 µg/g, respectively. The extracts exhibited antioxidant activity with 0.69 mg TE/mL in scavenging DPPH radicals, 24.42 mg TE/mL in scavenging ABTS radicals, and 2.26 mg TE/mL of iron-reducing antioxidant power. These results demonstrate the potential of DESs for the sustainable recovery of bioactive compounds from Sargassum filipendula residual biomass. Full article

Due to the adverse effects associated with synthetic cosmetic ingredients, global demand is increasingly shifting toward natural formulations that offer diverse benefits for enhancing skin health and overall beauty. Researchers around the world are extensively exploring a variety of unique natural secondary metabolites for cosmeceutical applications. Among the potential candidates, phlorotannins derived from brown seaweeds have shown significant potential as an active ingredient in cosmeceutical applications. The notable properties associated with phlorotannins include antioxidant, anti-aging, whitening, anti-wrinkling, anti-inflammatory, and hair health and growth-promoting effects, making them valuable in cosmeceutical formulations. However, to date, only a limited number of studies have critically reviewed the cosmeceutical applications of phlorotannins, and most are outdated. Thus, in the present review, primary attention is given to the collected scientific data published after 2020 about the bioactive properties of brown seaweed phlorotannins related to cosmeceutical applications. Full article

The brown seaweed Saccharina latissima is an abundant, although yet underutilized, source of natural bioactive compounds commonly found in western regions. In recent years, brown algae have garnered attention as promising sources of polyphenols, particularly phlorotannins. The recovery of these relevant components by eco-friendly and energy-efficient methods with solvents GRAS (Generally recognized as safe) contributes to minimizing environmental impact, and promotes sustainability. Pressurized liquid extraction (PLE) and microwave-assisted extraction (MAE) optimized by Box–Behnken design (BBD) were explored for this purpose. The methods were evaluated considering the process yield and the quality of the recovered extracts by phenolic and phlorotannin levels, and their antioxidant capacity was assessed by DPPH and ABTS assays. The optimized MAE techniques (80 °C, 2% EtOH/Water at 40 mL g⁻¹) and PLE2 (80 °C with water) showed the highest extract yields, with increases of 65.76% and 37.36%, respectively, compared to CRE. PLE2 also achieved higher TPC and antioxidant capacity (ABTS) values by 61.88% and 80.39%, respectively. MAE (optimized) increased TPC and ABTS by 53.90% and 36.42%, respectively. Regression analysis of MAE confirmed the accuracy of the models in assessing interaction parameters (adjustment p < 0.05 and adequacy R² > 0.86). Therefore, the study presents eco-efficient approaches for recovering phenolic compounds and antioxidants from brown algae, contributing to the valorization of these resources in the industry and enhancing their application. Full article

The rising demand for bioactive compounds from marine resources highlights the need for sustainable separation technologies. This study introduces an integrated process combining ultrasound-assisted extraction (USAE) and resin purification (RP) to isolate phlorotannins from Durvillaea incurvata, a brown seaweed with significant biomedical potential. Using a 32.5% ethanol–water solvent system for USAE followed by RP on Diaion HP-20 resin, phlorotannins were enriched 2.4-fold, with simultaneous removal of interfering compounds such as mannitol (~100%), which was demonstrated by FTIR and HPLC-IR analysis. Advanced characterization using UHPLC-QToF-MS/MS identified five novel phlorotannins with polymerization degrees of 3 to 8 phloroglucinol units in both USAE extracts and post-RP. Mass balance based on spectrophotometric measurements indicated a purification factor of ~2, confirming process effectiveness. RP streams showed distinct phlorotannin profiles, with one phlorotannin exceeding 70% relative abundance. However, MS/MS results showed significantly lower recoveries than spectrophotometric data, revealing a novel insight into RP purification. These findings highlight the critical role of comprehensive chemical characterization in optimizing sustainable phlorotannin extraction from seaweed. They propose a framework for scalable, eco-efficient technologies for achieving high-purity phlorotannin recovery. This approach facilitates the development of phlorotannin-based applications in the nutraceutical and pharmaceutical industries. Full article

Background/Objectives: Brown algae, particularly Eisenia bicyclis, produce various bioactive chemicals with significant application potential in the food, cosmetics, and pharmaceutical industries. This study aimed to evaluate the antibacterial, antibiofilm, and antivirulence properties of the ethyl acetate fraction (EA) of E. bicyclis and its synthesized gold nanoparticles (EA-AuNPs), with a focus on their potential applications against both Gram-positive and Gram-negative bacteria. Methods: The bioactive component in the ethyl acetate fraction was identified using a gas chromatography-mass spectroscopy (GC-MS) device and a liquid chromatography-mass spectrometer/mass spectrometry (LC-MS) system. The crystal violet method was utilized to evaluate the biofilm inhibition experiments. Several instruments, including dynamic light scattering, Fourier transform infrared, X-ray diffraction, field emission transmission electron microscopy, and energy-dispersive spectroscopy, were employed to completely characterize the produced EA-AuNPs. The cytotoxicity of the EA-AuNPs was determined using the MTT assay, and the expression of genes linked with biofilm and virulence in Pseudomonas aeruginosa and Staphylococcus aureus was investigated using real-time polymerase chain reaction (RT-PCR). Results: Various bioactive compounds were identified from the EA using GC-MS and LC-MS, including fatty acids and phlorotannins such as eckol, dieckol, 6,6’-bieckol, and phlorofucofuroeckol in high amounts, highlighting EA as a phlorotannin-rich fraction. The EA also demonstrated significant antibiofilm activity, with 79.86% inhibition at 512 μg/mL against P. aeruginosa and 87.00% at 64 μg/mL against S. aureus. EA was then used in the synthesis of gold nanoparticles (AuNPs) to improve their stability and safety. The synthesized EA-AuNPs were determined to have an average size of 165.04 nm, with a zeta potential of −29.86 mV, indicating good stability. In antibiofilm activity assays, EA-AuNPs demonstrated 45.76% inhibition against P. aeruginosa at 1024 μg/mL and 44.64% inhibition against S. aureus at 128 μg/mL. At sub-MIC levels, EA-AuNPs significantly inhibited biofilm formation and virulence factors, including the motility of P. aeruginosa and staphyloxanthin synthesis in S. aureus. The RT-PCR analysis revealed the downregulation of key genes involved in biofilm formation and virulence in P. aeruginosa and S. aureus. Conclusions: These findings highlight the potential of E. bicyclis solvent-soluble extracts and EA-AuNPs as effective antibacterial, antibiofilm, and antivirulence agents, with significant application potential in the pharmaceutical and food industries. To the best of our knowledge, this is the first report of antibiofilm activity against both Gram-positive and Gram-negative bacteria using EA-AuNPs. Full article

In recent years, the exploration of bioactive molecules derived from natural sources has gained interest in several application fields. Among these, macroalgae have garnered significant attention due to their functional properties, which make them interesting in therapeutic applications, including cancer treatment. Cancer constitutes a significant global health burden, and the side effects of existing treatment modalities underscore the necessity for the exploration of novel therapeutic models that, in line with the goal of reducing drug treatments, take advantage of natural compounds. This review explores the anticancer properties of macroalgae, focusing on their bioactive compounds and mechanisms of action. The key findings suggest that macroalgae possess a rich array of bioactive compounds, including polysaccharides (e.g., fucoidans and alginates), polyphenols (e.g., phlorotannins), and terpenoids, which exhibit diverse anticancer activities, such as the inhibition of cell proliferation, angiogenesis, induction of apoptosis, and modulation of the immune system. This review provides an overview of the current understanding of macroalgae’s anticancer potential, highlighting the most promising compounds and their mechanisms of action. While preclinical studies have shown promising results, further research is necessary to translate these findings into effective clinical applications. Full article

Ishige okamurae (I. okamuare), an edible brown alga, is rich in isophloroglucin A (IPA) phlorotannin compounds and is effective in preventing diseases, including diabetes. We evaluated its anti-glycation ability, intracellular reactive oxygen species scavenging activity, inhibitory effect on the accumulation of intracellular MGO/MGO-derived advanced glycation end products (AGE), and regulation of downstream signaling pathways related to the AGE–receptor for AGEs (RAGE) interaction. IPA (0.2, 1, and 5 μM) demonstrated anti-glycation ability by inhibiting the formation of glucose-fructose-BSA-derived AGEs by up to 54.63% compared to the untreated control, reducing the formation of irreversible cross-links between MGO-derived AGEs and collagen by 67.68% and the breaking down of existing cross-links by approximately 91% (p < 0.001). IPA protected cells from MGO-induced oxidative stress by inhibiting intracellular MGO accumulation (untreated cells: 1.62 μg/mL, MGO treated cells: 25.27 μg/mL, and IPA 5 μM: 11.23 μg/mL) (p < 0.001) and AGE generation and inhibited MGO-induced renal cell damage via the downregulation of MGO-induced RAGE protein expression (relative protein expression levels of MGO treated cells: 9.37 and IPA 5 μM:1.74) (p < 0.001). Overall, these results suggest that IPA has the potential to be utilized as a useful natural agent for the prevention and management of AGE-related diabetic nephropathy, owing to its strong anti-glycation activity. Full article

The optimization of bioactive compound extraction from Fucus vesiculosus using ultrasound-assisted extraction (UAE) via sonotrode was investigated to maximize phenolic recovery and antioxidant activity while promoting a sustainable process. Optimal conditions (40% v/v ethanol in water, 38 min, 36% amplitude) were selected to maximize phenolic recovery while considering environmental and energy sustainability by optimizing extraction efficiency and minimizing solvent and energy usage. HPLC-ESI-QTOF-MS analysis tentatively identified 25 phenolic compounds, including sulfated phenolic acids, phlorotannins, flavonoids, and halophenols, with some reported for the first time in F. vesiculosus, underscoring the complexity of this alga’s metabolome. The antioxidant activity of the optimized extract was evaluated through FRAP (143.7 µmol TE/g), DPPH (EC₅₀ 105.6 µg/mL), and TEAC (189.1 µmol Trolox/g) assays. The optimized process highlights F. vesiculosus as a valuable source of natural antioxidants, with potential applications in biotechnology, cosmetics, and food industries. Full article

Type 2 diabetes mellitus (T2DM), a serious metabolic disorder, is a worldwide health problem due to the alarming rise in prevalence and elevated morbidity and mortality. Chronic hyperglycemia, insulin resistance, and ineffective insulin effect and secretion are hallmarks of T2DM, leading to many serious secondary complications. These include, in particular, cardiovascular disorders, diabetic neuropathy, nephropathy and retinopathy, diabetic foot, osteoporosis, liver damage, susceptibility to infections and some cancers. Polyphenols such as flavonoids, phenolic acids, stilbenes, tannins, and lignans constitute an extensive and heterogeneous group of phytochemicals in fresh fruits, vegetables and their products. Various in vitro studies, animal model studies and available clinical trials revealed that flavonoids (e.g., quercetin, kaempferol, rutin, epicatechin, genistein, daidzein, anthocyanins), phenolic acids (e.g., chlorogenic, caffeic, ellagic, gallic acids, curcumin), stilbenes (e.g., resveratrol), tannins (e.g., procyanidin B2, seaweed phlorotannins), lignans (e.g., pinoresinol) have the ability to lower hyperglycemia, enhance insulin sensitivity and improve insulin secretion, scavenge reactive oxygen species, reduce chronic inflammation, modulate gut microbiota, and alleviate secondary complications of T2DM. The interaction between polyphenols and conventional antidiabetic drugs offers a promising strategy in the management and treatment of T2DM, especially in advanced disease stages. Synergistic effects of polyphenols with antidiabetic drugs have been documented, but also antagonistic interactions that may impair drug efficacy. Therefore, additional research is required to clarify mutual interactions in order to use the knowledge in clinical applications. Nevertheless, dietary polyphenols can be successfully applied as part of supportive treatment for T2DM, as they reduce both obvious clinical symptoms and secondary complications. Full article

This study focuses on developing innovative and eco-friendly purification methods for the isolation of bioactive compounds derived from Padina pavonica, a brown abundant macroalga in Djibouti. Three distinct fractions, obtained via liquid-liquid extraction (LLE_FAE), solid-phase extraction (SPE_WE50), and flash chromatography (FC_EtOH20), were selected based on their high phenolic content and antioxidant activities. All fractions were also evaluated for their anti-ageing potential by assessing their ability to inhibit two vital skin-ageing enzymes, tyrosinase and elastase. Structural analysis by ¹H-¹³C HMBC NMR and LC-MS revealed a selectivity of phlorotannins depending on the purification methods. The LLE_FAE fraction exhibited greater structural complexity, including compounds such as phloroglucinol, diphlorethol/difucol, fucophlorethol and bifuhalol, which likely contribute to its enhanced bioactivity compared to the fractions obtained by FC_EtOH20 and SPE_WE50, which were also active and enriched only in phloroglucinol and fucophlorethol. These findings highlight the impact of purification techniques on the selective enrichment of specific bioactive compounds and demonstrated the interest of FC or SPE in producing active phlorotannin-enriched fractions. These two purification methods hold strong potential for innovative cosmeceutical applications. Results are discussed regarding the use of P. pavonica as a promising marine resource in Djibouti to be used for the development of cosmetic industry. Full article