Exploring the Hypocholesterolemic Potential of a Fucus vesiculosus Extract: Omic Insights into Molecular Mechanisms at the Intestinal Level.

High blood cholesterol levels are a major risk factor for cardiovascular diseases. A purified aqueous extract of Fucus vesiculosus, rich in phlorotannins and peptides, has been described for its potential to inhibit cholesterol biosynthesis and intestinal absorption. In this work, the effect of this extract on intestinal cells' metabolites and proteins was analysed to gain a deeper understanding of its mode of action on lipids' metabolism, particularly concerning the absorption and transport of exogenous cholesterol. Caco-2 cells, differentiated into enterocytes, were exposed to the extract, and analysed by untargeted metabolomics and proteomics. The results of the metabolomic analysis showed statistically significant differences in glutathione content of cells exposed to the extract compared to control cells, along with an increased expression of fatty acid amides in exposed cells. A proteomic analysis showed an increased expression in cells exposed to the extract compared to control cells of FAB1 and NPC1, proteins known to be involved in lipid metabolism and transport. To the extent of our knowledge, this study is the first use of untargeted metabolomics and a proteomic analysis to investigate the effects of F. vesiculosus on differentiated Caco-2 cells, offering insights into the molecular mechanism of the extract's compounds on intestinal cells.

Algae-Based Supplements Claiming Weight Loss Properties: Authenticity Control and Scientific-Based Evidence on Their Effectiveness.

The worldwide prevalence of obesity impacts more than 600 million adults. Successfully managing weight is effective in reducing the risk of chronic diseases, but sustaining long-term weight loss remains a challenge. Although there are supplements based on algae that claim to aid in weight loss, there is a notable scarcity of scientific evidence supporting their effectiveness, and their regular consumption safety remains inadequately addressed. In this work, commercially available Arthrospira (Spirulina) platensis Gomont and/or Fucus vesiculosus L. supplements showed moderate capacity to inhibit the activity of carbohydrate-metabolizing enzymes, and to scavenge biologically relevant reactive species. IC25 values varying between 4.54 ± 0.81 and 66.73 ± 5.91 µg of dry extract/mL and between 53.74 ± 8.42 and 1737.96 ± 98.26 µg of dry extract/mL were obtained for α-glucosidase and aldose reductase, respectively. A weaker effect towards α-amylase activity was observed, with a maximum activity of the extracts not going beyond 33%, at the highest concentrations tested. Spirulina extracts showed generally better effects than those from F. vesiculosus. Similar results were observed concerning the antiradical capacity. In a general way, the extracts were able to intercept the in vitro-generated reactive species nitric oxide (•NO) and superoxide anion (O2•-) radicals, with better results for O2•-scavenging with the spirulina samples (IC25 values of 67.16 and 122.84 µg of dry extract/mL). Chemically, similar pigment profiles were observed between spirulina supplements and the authenticated counterpart. However, fucoxanthin, the chemotaxonomic marker of brown seaweeds, was not found in F. vesiculosus samples, pointing to the occurrence of a degradation phenomenon before, during, or after raw material processing. Our findings can contribute to providing data to allow regulatory entities (e.g., EFSA and FDA) to better rule these products in a way that can benefit society.

Fucus vesiculosus-Rich Extracts as Potential Functional Food Ingredients: A Holistic Extraction Approach.

Brown macroalgae are rich sources of nutrients and health-promoting compounds. Nevertheless, their consumption is still limited by their strong organoleptic characteristics, thus requiring the development of extraction strategies to profit from their nutritional value. To fulfil this, two sequential extraction approaches were developed, differing in the solvent used in the first extraction step, water in approach 1 or food-grade ethanol in approach 2, to obtain economic and affordable extracts rich in specific compounds from Fucus vesiculosus. The use of water in the first step of extraction allowed us to recover water-soluble phlorotannins, laminarans and mannuronic-rich alginates, making the subsequent 70% ethanol extract richest in fucoxanthin (0.07% algae DW), and the hot water fractions purest in fucoidans and alginates with a lower mannuronic-to-guluronic (M/G) ratio (2.91). Conversely, when beginning extraction procedures with 96% ethanol, the recovered yields of phlorotannins increased (0.43 g PGE/100 g algae DW), but there was a concomitant seven-fold decrease in the recovery of fucoxanthin in the subsequent 70% ethanol extract. This approach also led to less pure hot water fractions containing fucoidans, laminarans and alginates with a higher M/G ratio (5.50). Overall, this work unveiled the potential of the first extraction steps in sustainable and holistic cascade strategies to modulate the composition of food-grade extracts, creating prospects of their application as tailored functional ingredients in food products.

Optimization of Extraction of Phlorotannins from the Arctic Fucus vesiculosus Using Natural Deep Eutectic Solvents and Their HPLC Profiling with Tandem High-Resolution Mass Spectrometry.

Phlorotannins are secondary metabolites produced mainly by brown seaweeds (Phaeophyceae) and belong to the class of polyphenolic compounds with diverse bioactivities. The key factors in the extraction of polyphenols are the selection of a suitable solvent, method of extraction and selection of optimal conditions. Ultrasonic-assisted extraction (UAE) is one of the advanced energy-saving methods suitable for the extraction of labile compounds. Methanol, acetone, ethanol and ethyl acetate are the most commonly used solvents for polyphenol extraction. As alternatives to toxic organic solvents, a new class of green solvents, natural deep eutectic solvents (NADES), has been proposed for the efficient extraction of a wide range of natural compounds including polyphenols. Several NADES were screened previously for the extraction of phlorotannins; however, the extraction conditions were not optimized and chemical profiling of NADES extract was not performed. The purpose of this work was to study the effect of selected extraction parameters on the phlorotannin content in NADES extract from Fucus vesiculosus, optimization of extraction conditions and chemical profiling of phlorotannins in the NADES extract. A fast and green NADES-UAE procedure was developed for the extraction of phlorotannins. Optimization was performed through an experimental design and showed that NADES (lactic acid:choline chloride; 3:1) provides a high yield (137.3 mg phloroglucinol equivalents per g dry weight of algae) of phlorotannins under the following extraction conditions: extraction time 23 min, 30.0% water concentration and 1:12 sample to solvent ratio. The antioxidant activity of the optimized NADES extract was equal to that of EtOH extract. In total, 32 phlorotannins have been identified (one trimer, two tetramers, six pentamers, four hexamers, six heptamers, six octamers and seven nonamers) in NADES extracts from arctic F. vesiculosus using the HPLC-HRMS and MS/MS technique. It was noted that all the above-mentioned phlorotannins were identified in both EtOH and NADES extracts. Our results suggest that NADES could be considered as an alternative to the conventional techniques for the effective extraction of phlorotannins from F. vesiculosus with high antioxidant potential.

Ascophyllum nodosum and Fucus vesiculosus Extracts Improved Lipid Metabolism and Inflammation in High-Energy Diet-Induced Hyperlipidemia Rats.

Ascophyllum nodosum and Fucus vesiculosus both contain unique polyphenols called phlorotannins. Phlorotannins reportedly possess various pharmacological activities. A previous study reported that the activity of phlorotannin is strongly correlated with the normalization of metabolic function, and phlorotannins are extremely promising nutrients for use in the treatment of metabolic syndrome. To date, no study has explored the antihyperlipidemic effects of phlorotannins from A. nodosum and F. vesiculosus in animal models. Therefore, in the present study, we investigated the effects of phlorotannins using a rat model of high-energy diet (HED)-induced hyperlipidemia. The results showed that the rats that were fed an HED and treated with phlorotannin-rich extract from A. nodosum and F. vesiculosus had significantly lower serum fasting blood sugar (FBS), aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol (TC), triacylglyceride (TG) and free fatty acids (FFAs) levels and hepatic TG level and had higher serum insulin, high-density lipoprotein cholesterol (HDL-C) levels and lipase activity in their fat tissues than in the case with the rats that were fed the HED alone. A histopathological analysis revealed that phlorotannin-rich extract could significantly reduce the size of adipocytes around the epididymis. In addition, the rats treated with phlorotannin-rich extract had significantly lowered interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) levels and increased superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities than did those in the HED group. These results suggested that the phlorotannin-rich extract stimulated lipid metabolism and may have promoted lipase activity in rats with HED-induced hyperlipidemia. Our results indicated that A. nodosum and F. vesiculosus, marine algae typically used as health foods, have strong antihyperlipidemic effects and may, therefore, be useful for preventing atherosclerosis. These algae may be incorporated into antihyperlipidemia pharmaceuticals and functional foods.

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

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

Brown Algae Fucus vesiculosus in Pasta: Effects on Textural Quality, Cooking Properties, and Sensorial Traits.

Fucus vesiculosus is a brown seaweed rich in iodine, fucoxanthin, and phlorotannins, all known to be bioactive compounds associated with health-promoting events. The enrichment of a staple food such as pasta with seaweed flour, could convey health benefits without changing eating habits. In this work, F. vesiculosus flour (FVF) was incorporated into durum wheat pasta at 1, 5.5, and 10% gradient levels. The pasta enriched with FVF needed additional water during dough formation and required more cooking time, resulting in higher weight gain but also increased cooking loss (observed with 5.5 and 10%). The fracturability of raw pasta decreased for all the FVF pasta, though the cooked firmness and hardness were only affected with the inclusion of 10% FVF. The substitution of wheat semolina with FVF at a 10% level caused an increase in the pasta's fiber content, which resulted in a more discontinuous protein-matrix structure, as observed at the microscopic level. Untrained consumers were very positive about the overall sensory traits of the pasta with low supplementation levels (1 and 5.5%). About 72% of panelists selected the 1% FVF pasta as their favorite sample. The utilization of FVF in pasta should be targeted at low inclusion levels to cope with the expected texture quality and prevent the impairment of the sensory traits.

The Impact of Natural Deep Eutectic Solvents and Extraction Method on the Co-Extraction of Trace Metals from Fucus vesiculosus.

In recent years, natural deep eutectic solvents (NADES) have been widely investigated for the extraction of food and medicinal plants as well as seaweeds. However, the ability of NADES for trace elements co-extraction from natural sources is not well investigated. The aim of this study was to investigate the ability of common NADES for trace elements co-extraction from Fucus vesiculosus. All of the tested NADES did not recover As and Co (concentration

Effect of Extraction Temperature on Pressurized Liquid Extraction of Bioactive Compounds from Fucus vesiculosus.

This study was aimed at investigating the effect of low polarity water (LPW) on the extraction of bioactive compounds from Fucus vesiculosus and to examine the influence of temperature on the extraction yield, total phenolic content, crude alginate, fucoidan content, and antioxidant activity. The extractions were performed at the temperature range of 120-200 °C with 10 °C increments, and the extraction yield increased linearly with the increasing extraction temperature, with the highest yields at 170-200 °C and with the maximum extraction yield (25.99 ± 2.22%) at 190 °C. The total phenolic content also increased with increasing temperature. The extracts showed a high antioxidant activity, measured with DPPH (2,2-Diphenyl-1-picrylhydrazyl) radicals scavenging and metal-chelating activities of 0.14 mg/mL and 1.39 mg/mL, respectively. The highest yield of alginate and crude fucoidan were found at 140 °C and 160 °C, respectively. The alginate and crude fucoidan contents of the extract were 2.13% and 22.3%, respectively. This study showed that the extraction of bioactive compounds from seaweed could be selectively maximized by controlling the polarity of an environmentally friendly solvent.

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.

RP-HPLC-DAD determination of the differences in the polyphenol content of Fucus vesiculosus extracts with similar antioxidant activity.

Significant quantities of bioactive compounds have been found in the chemical composition of seaweeds. This source of natural antioxidants such as polyphenols appears to attenuate lipid peroxidation caused by oxidative stress, preventing the harmful effects of a number of injuries including ischemia-reperfusion (I/R). Conventional extraction (CE) has been used for years as a traditional method for obtaining bioactive components from seaweeds. However, recent studies highlight ultrasonic-assisted extraction (UAE) as an alternative and more eco-friendly technique. Therefore, the two methods were optimised and compared to obtain a Fucus vesiculosus extract (FVE) with high antioxidant activity and polyphenol content. The highest antioxidant activity was obtained after 1 h at 25 °C for conventional extraction, and after 5 min at 35 °C for ultrasonic-assisted extraction. Higher concentrations of polyphenols were obtained with the optimal conditions in conventional extraction (13.61 mg PGE/g seaweed), but no significant differences were observed between the antioxidant activity obtained with UAE (89.33%) and CE (89.74%). The characterization of the polyphenols present in both optimised extracts was carried out and compared with reverse-phase high-performance liquid chromatography coupled to a diode array detector (HPLC-DAD). The following compounds were identified: phloroglucinol, gallic acid, catechin, vanillic acid, epicatechin, protocatechuic acid, rutin, gentisic acid, chlorogenic acid, caffeic acid, coumaric acid and ferulic acid. RP-HPLC-DAD results also showed higher concentrations of polyphenols in optimised extracts with CE. Consequently, CE was found to be more effective than UAE in providing extracts with higher concentrations of polyphenols, but UAE constitutes an efficient and more eco-friendly methodology for obtaining a FVE with the highest antioxidant activity.

Hypertriglyceridemia treated with Fucus vesiculosus - A case series.

Hypertriglyceridemia is an independent risk factor of coronary heart disease (as established through various previously conducted studies) and it's rising incidence is creating a need for the immediate attention of it's management. Instead of focusing on the controversies involving the toxicity caused due to the long-term use of statin therapy in conventional mode of treatment, opting for a safer alternative system of treatment seems important. Five cases of diagnosed HTG, with triglyceride levels above 200 were treated with homoeopathic medicine - Fucus vesiculosus, in mother tincture form. The primary outcome measure was to evaluate the reduction in the blood triglyceride levels. All the five cases showed a reduction in triglyceride levels to normal range within 4 months of starting the treatment with the Fucus vesiculosus mother tincture. Also, it was observed that the borderline cholesterol levels and high LDL levels in 2 cases were found to reduce to normal. Treatment involving Fucus vesiculosus in cases diagnosed with HTG showed significant reduction in triglyceride levels along with other parameters of lipid profile. Further authentication of results with significant sample sizes may be taken up.

Antitumor Activity of Fucus vesiculosus-Derived Phlorotannins through Activation of Apoptotic Signals in Gastric and Colorectal Tumor Cell Lines.

Seaweeds are one of the largest producers of biomass in the marine environment and a source of multiple bioactive metabolites with valuable health benefits. Among these, phlorotannins have been widely recognized for their promising bioactive properties. The potential antitumor capacity of Fucus vesiculosus-derived phlorotannins remains, however, poorly explored, especially in gastrointestinal tract-related tumors. Therefore, this work aimed to evaluate the cytotoxic properties and possible mechanisms by which F. vesiculosus crude extract (CRD), phlorotannin-rich extract (EtOAc), and further phlorotannin-purified fractions (F1-F9) trigger cell death on different tumor cell lines of the gastrointestinal tract, using flow cytometry. The results indicate that F. vesiculosus samples exert specific cytotoxicity against tumor cell lines without affecting the viability of normal cells. Moreover, it was found that, among the nine different phlorotannin fractions tested, F5 was the most active against both Caco-2 colorectal and MKN-28 gastric cancer cells, inducing death via activation of both apoptosis and necrosis. The UHPLC-MS analysis of this fraction revealed, among others, the presence of a compound tentatively identified as eckstolonol and another as fucofurodiphlorethol, which could be mainly responsible for the promising cytotoxic effects observed in this sample. Overall, the results herein reported contribute to a better understanding of the mechanisms behind the antitumor properties of F. vesiculosus phlorotannin-rich extracts.

Comparison of edible brown algae extracts for the inhibition of intestinal carbohydrate digestive enzymes involved in glucose release from the diet.

Type II diabetes is considered the most common metabolic disorder in the developed world and currently affects about one in ten globally. A therapeutic target for the management of type II diabetes is the inhibition of α- glucosidase, an essential enzyme located at the brush border of the small intestinal epithelium. The inhibition of α-glucosidase results in reduced digestion of carbohydrates and a decrease in postprandial blood glucose. Although pharmaceutical synthetic inhibitors are available, these are usually associated with significant gastrointestinal side effects. In the present study, the impact of inhibitors derived from edible brown algae is being investigated and compared for their effect on glycaemic control. Carbohydrate- and polyphenolic-enriched extracts derived from Ascophyllum nodosum, Fucus vesiculosus and Undaria pinnatifida were characterised and screened for their inhibitory effects on maltase and sucrase enzymes. Furthermore, enzyme kinetics and the mechanism of inhibition of maltase and sucrase were determined using linear and nonlinear regression methods. All tested extracts showed a dose-dependent inhibitory effect of α-glucosidase with IC50 values ranging from 0⋅26 to 0⋅47 mg/ml for maltase; however, the only extract that was able to inhibit sucrase activity was A. nodosum, with an IC50 value of 0⋅83 mg/ml. The present study demonstrates the mechanisms in which different brown seaweed extracts with varying composition and molecular weight distribution differentially inhibit α-glucosidase activities. The data highlight that all brown seaweed extracts are not equal in the inhibition of carbohydrate digestive enzymes involved in postprandial glycaemia.

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

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

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.

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

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

Safety evidence on the administration of Fucus vesiculosus L. (bladderwrack) extract and lamotrigine: data from pharmacokinetic studies in the rat.

Fucus vesiculosus is often incorporated in weight loss dietary supplements to improve weight loss in overweight adults. Obesity is a common condition in epilepsy patients and is indeed increasing in refractory epilepsy and in patients under polytherapy. Since lamotrigine (LTG) is a first-line antiepileptic drug, used in monotherapy or adjunctive therapy, the main objective of this work was to investigate the potential pharmacokinetic-based interactions between F. vesiculosus and LTG in rats. In a first pharmacokinetic study, a single oral dose of F. vesiculosus extract (575 mg/kg, p.o.) was co-administered with a single-dose of LTG (10 mg/kg, p.o.). In a second study, rats were orally pretreated with F. vesiculosus extract (575 mg/kg/day, p.o.) for 14 days and received LTG (10 mg/kg, p.o.) on the 15th day. In the control groups, rats received water instead of the extract. After LTG administration, blood samples were taken until 96 h post-dose, and LTG concentrations measured in plasma were submitted to a non-compartmental pharmacokinetic analysis. The co-administration of F. vesiculosus extract and LTG caused no significant changes in the drug kinetics. However, the repeated pretreatment with F. vesiculosus extract significantly reduced the peak concentrations of LTG and caused a slightly decrease in the extent of systemic drug exposure. Overall, based on these results, no significant clinical impact is expected from the administration of F. vesiculosus dietary supplements and LTG.

Tolerance of Fucus vesiculosus exposed to diesel water-accommodated fraction (WAF) and degradation of hydrocarbons by the associated bacteria.

The viability and physiological state of brown macroalgae Fucus vesiculosus and its associated epiphytic bacteria exposed to diesel water-accommodated fraction (WAF), as well as the capacity of this association to deplete petroleum hydrocarbons (HCs) were experimentally tested. After a 6-day exposure treatment, the algal-surface associated bacteria were identified as primarily hydrocarbon-oxidising bacteria (HOB), and the algal-HOB association was able to deplete petroleum hydrocarbons from the diesel WAF by 80%. The HOB density on the algal surface exposed to diesel WAF was 350% higher compared to the control (i.e. HOB density on the algal surface exposed to ambient seawater), which suggest that they actively proliferated in the presence of hydrocarbons and most likely consumed hydrocarbons as their primary organic substrate. Exposure to diesel WAF did not affect the metabolic activity of F. vesiculosus. Higher lipid peroxidation was observed in F. vesiculosus exposed to diesel WAF while catalase concentration decreased only during the first day of exposure. Results suggest F. vesiculosus is tolerant to oil pollution and the algal-HOB association can efficiently deplete petroleum hydrocarbons in oil-contaminated seas.

Optimization of Phlorotannins Extraction from Fucus vesiculosus and Evaluation of Their Potential to Prevent Metabolic Disorders.

Phlorotannins are phloroglucinol-based phenolic compounds, occurring particularly in brown macroalgae, that have been recognized for their promising bioactive properties. In this study, the extraction of phlorotannins from Fucus vesiculosus was evaluated with particular emphasis on the influential parameters, including the solvent concentration, solvent-solid ratio, extraction temperature and extraction time, using a single-factor design followed by a Box-Behnken design. The maximum total phlorotannin content, determined using the 2,4-dimethoxybenzaldehyde (DMBA) method, corresponded to 2.92 ± 0.05 mg of phloroglucinol equivalents/g dry seaweed (mg PGE/g DS), and was achieved for extracts carried out with acetone 67% (v/v), a solvent-solid ratio of 70 mL/g and temperature at 25 °C. This crude extract, together with a semi-purified phlorotannin fraction, were further evaluated for their anti-enzymatic capacity against α-glucosidase, α-amylase and pancreatic lipase, both showing promising inhibitory effects, particularly against α-glucosidase for which a greater inhibitory effect was observed compared to the pharmaceutical drug acarbose (IC50 = 4.5 ± 0.8 and 0.82 ± 0.3 µg/mL, respectively, against 206.6 ± 25.1 µg/mL). Additionally, the ultra-high-pressure liquid chromatography coupled to mass spectrometry (UHPLC-MS) analysis carried out on the ethyl acetate fraction revealed the presence of fucols, fucophlorethols, fuhalols and several other phlorotannin derivatives. Moreover, possible new phlorotannin compounds, including fucofurodiphlorethol, fucofurotriphlorethol and fucofuropentaphlorethol, have been tentatively identified in this extract. Overall, this study provides evidence that F. vesiculosus phlorotannin-rich extracts hold potential for the management of the activity of α-glucosidase, α-amylase and pancreatic lipase, which are well known to be linked to metabolic disorders such as diabetes and obesity.