Brown Algae Potential as a Functional Food against Hypercholesterolemia: Review

Therapeutic potential of fucoidan in central nervous system disorders: A systematic review

Central nervous system (CNS) disorders have a complicated pathogenesis, and to date, no single mechanism can fully explain them. Most drugs used for CNS disorders primarily aim to manage symptoms and delay disease progression, and none have demonstrated any pathological reversal. Fucoidan is a safe, sulfated polysaccharide from seaweed that exhibits multiple pharmacological effects, and it is anticipated to be a novel treatment for CNS disorders. To assess the possible clinical uses of fucoidan, this review aims to provide an overview of its neuroprotective mechanism in both in vivo and in vitro CNS disease models, as well as its pharmacokinetics and safety. We included 39 articles on the pharmacology of fucoidan in CNS disorders. In vitro and in vivo experiments demonstrate that fucoidan has important roles in regulating lipid metabolism, enhancing the cholinergic system, maintaining the functional integrity of the blood-brain barrier and mitochondria, inhibiting inflammation, and attenuating oxidative stress and apoptosis, highlighting its potential for CNS disease treatment. Fucoidan has a protective effect against CNS disorders. With ongoing research on fucoidan, it is expected that a natural, highly effective, less toxic, and highly potent fucoidan-based drug or nutritional supplement targeting CNS diseases will be developed.

Brown algae biomass for fucoxanthin, fucoidan and alginate; update review on structure, biosynthesis, biological activities and extraction valorisation

Natural compounds promoting human health are the main focus of research nowadays. Fucoxanthin, fucoidan and alginate are such bioactive compounds that are extracted from marine brown algae. Extracting these 3 compounds through successive extraction enhances the commercial value of the brown algae biomass. There are studies on successive extraction of fucoidan and alginate but not with fucoxanthin which displays various biological bioactivities. Alginate, a polysaccharide presents 45 % in the cell wall of brown algae. Fucoidan, a sulphated polysaccharide proved showing various bioactivities. These bioproducts yield are vary depending on the species. Dictyota species recorded high fucoxanthin content of 7 %. Ascophyllum nodosum was found with high fucoidan of 16.08 % by direct extraction. Maximum alginate of 45.79 % was recorded from the brown alga Sargassum cymosum and by successive extraction 44 % was recorded from Ecklonia radiata. Fucoxanthin exits in two isomers as trans and cis forms. Based on linkage, fucoidan structure is found in 3 forms as 1,3- or 1,4- or alternating 1,3- and 1,4-linked fucose in the polysaccharide residues. Fucoidan composition vary depending on the degree of sulphation, the composition of monosaccharides and location of collection. In alginate, its property relies on the mannuronic acid and guluronic acid composition. Biosynthesis of these 3 compounds is not much explored. Keeping this view which signify sequential extraction towards biomass valorisation, fucoxanthin, fucoidan and alginate extracted from the brown algae species focusing yield, extraction, characterization, biosynthesis and biological activities were compiled and critically analysed and discussed in this review.

The Effect of Sargassum fusiforme and Fucus vesiculosus on Continuous Glucose Levels in Overweight Patients with Type 2 Diabetes Mellitus: A Feasibility Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Brown seaweed is promising for the treatment of type 2 diabetes mellitus (T2DM). Its bioactive constituents can positively affect plasma glucose homeostasis in healthy humans. We investigated the effect of the brown seaweeds Sargassum (S.) fusiforme and Fucus (F.) vesiculosus in their natural form on glucose regulation in patients with T2DM.

METHODS

We conducted a randomized, double-blind, placebo-controlled pilot trial. Thirty-six participants with T2DM received, on a daily basis, either 5 g of dried S. fusiforme, 5 g of dried F. vesiculosus, or 0.5 g of dried Porphyra (control) for 5 weeks, alongside regular treatment. The primary outcome was the between-group difference in the change in weekly average blood glucose levels (continuous glucose monitoring). The secondary outcomes were the changes in anthropometrics, plasma lipid levels, and dietary intake. The data were analyzed using a linear mixed-effects model.

RESULTS

The change in weekly average glucose levels was 8.2 ± 2.1 to 9.0 ± 0.7 mmol/L (p = 0.2) in the S. fusiforme group (n = 12) and 10.1 ± 3.3 to 9.2 ± 0.7 mmol/L (p = 0.9) in the F. vesiculosus group (n = 10). The between-group difference was non-significant. Similarly, no between-group differences were observed for the changes in the secondary outcomes.

DISCUSSION

A daily intake of 5 g of fresh, dried S. fusiforme or F. vesiculosus alongside regular treatment had no differential effect on weekly average blood glucose levels in T2DM.

Macroalgae Bioplastics: A Sustainable Shift to Mitigate the Ecological Impact of Petroleum-Based Plastics

The surge in global utilization of petroleum-based plastics, which notably heightened during the COVID-19 pandemic, has substantially increased its harm to ecosystems. Considering the escalating environmental impact, a pivotal shift towards bioplastics usage is imperative. Exploring and implementing bioplastics as a viable alternative could mitigate the ecological burden posed by traditional plastics. Macroalgae is a potential feedstock for the production of bioplastics due to its abundance, fast growth, and high cellulose and sugar content. Researchers have recently explored various methods for extracting and converting macroalgae into bioplastic. Some of the key challenges in the production of macroalgae bioplastics are the high costs of large-scale production and the need to optimize the extraction and conversion processes to obtain high-quality bioplastics. However, the potential benefits of using macroalgae for bioplastic production include reducing plastic waste and greenhouse gas emissions, using healthier materials in various life practices, and developing a promising area for future research and development. Also, bioplastic provides job opportunities in free enterprise and contributes to various applications such as packaging, medical devices, electronics, textiles, and cosmetics. The presented review aims to discuss the problem of petroleum-based plastic, bioplastic extraction from macroalgae, bioplastic properties, biodegradability, its various applications, and its production challenges.

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.

Nutritional and Antioxidative Benefits of Dietary Macroalgae Supplementation in Weaned Piglets

This study explores the effects of dietary brown macroalgae (Ascophyllum nodosum) inclusion on digestibility and blood biochemical indices and redox markers in piglets fed diets with varying levels (0%, 0.6% and 1%) of macroalgae from 18 to 64 days of age. Macroalgae significantly influenced lipid profiles, reducing total cholesterol levels (quadratic contrast p = 0.001) and demonstrating an increase in high-density lipoprotein cholesterol levels, particularly with 1% macroalgae inclusion (linear contrast p < 0.001), with a decrease in low-density lipoprotein cholesterol in both macroalgae-supplemented groups (linear contrast p = 0.001). Additionally, macroalgae had a positive impact on the activities of antioxidative enzymes (ferric-reducing ability of plasma, superoxide dismutase, reduced glutathione) and reduced lipid peroxidation products (lipid hydroperoxide, malondialdehyde) in the blood, liver tissue, and intestinal epithelium of the ileum, suggesting enhanced antioxidative defense mechanisms. These changes were dose-dependent; in blood plasma, they exhibited both a linear and quadratic response, while in the tissues, the response was primarily linear. Additionally, an increase in the digestibility of crude fat in macroalgae-supplemented groups was observed (linear contrast p < 0.001), highlighting their potential role in improving nutrient absorption and digestion. The study findings emphasize the health benefits of natural, seaweed-based additives in diets, particularly in managing oxidative stress and improving lipid profiles, and highlight the potential of macroalgae as a natural dietary supplement to improve antioxidant systems and lipid metabolism in piglets.

Process optimization and characterization of hydrolysate from underutilized brown macroalgae (Padina tetrastromatica) after fucoidan extraction through subcritical water hydrolysis

The growing demand for macroalgal biomass as a source of proteins, peptides, and amino acids is garnering attention for their biological and functional properties. This study depicts the use of emerging green techniques, i.e. subcritical water, to hydrolyze protein from Padina tetrastromatica. The biomass was treated with subcritical water at varying temperatures between 100 and 220 °C for 10-40 min at a biomass to water proportion of 1:50 (w/v) and pressure of 4.0 MPa. The optimum conditions for recovering the maximum protein (127.2 ± 1.1 mg g-1), free amino acids (58.4 ± 1.0 mg g-1), highest degree of hydrolysis (58.8 ± 1.2 %) and low molecular weight peptides (<650 Da) were found to be 220 °C for 10 min. The amino acid profiling of the hydrolysate revealed that it contains 45 % essential amino acids, with the highest concentration of methionine (0.18 %), isoleucine (0.12 %) and leucine (0.10 %). It was found that the hydrolysate contains phenolics (23.9 ± 1.4 mg GAE g-1) and flavonoids (1.23 ± 0.1 mg QE g-1), which are largely responsible for antioxidant activity. The hydrolysate effectively inhibits acetylcholinesterase and α-amylase in vitro, with IC50 values of 17.9 ± 0.1 mg mL-1 and 16.0 ± 0.5 %, respectively, which can help prevent Alzheimer's disease and diabetes mellitus. Consequently, this study reveals that utilizing eco-friendly subcritical water hydrolysis method, 79 % of the protein was recovered from P. tetrastromatica, which might be an effective source of bioactive peptides in various nutraceutical, pharmaceutical and cosmeceutical applications.

Laminarin Reduces Cholesterol Uptake and NPC1L1 Protein Expression in High-Fat Diet (HFD)-Fed Mice

Aberrantly high dietary cholesterol intake and intestinal cholesterol uptake lead to dyslipidemia, one of the risk factors for cardiovascular diseases (CVDs). Based on previous studies, laminarin, a polysaccharide found in brown algae, has hypolipidemic activity, but its underlying mechanism has not been elucidated. In this study, we investigated the effect of laminarin on intestinal cholesterol uptake in vitro, as well as the lipid and morphological parameters in an in vivo model of high-fat diet (HFD)-fed mice, and addressed the question of whether Niemann-Pick C1-like 1 protein (NPC1L1), a key transporter mediating dietary cholesterol uptake, is involved in the mechanistic action of laminarin. In in vitro studies, BODIPY-cholesterol-labeled Caco-2 cells were examined using confocal microscopy and a fluorescence reader. The results demonstrated that laminarin inhibited cholesterol uptake into Caco-2 cells in a concentration-dependent manner (EC50 = 20.69 μM). In HFD-fed C57BL/6J mice, laminarin significantly reduced the serum levels of total cholesterol (TC), total triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C). It also decreased hepatic levels of TC, TG, and total bile acids (TBA) while promoting the excretion of fecal cholesterol. Furthermore, laminarin significantly reduced local villous damage in the jejunum of HFD mice. Mechanistic studies revealed that laminarin significantly downregulated NPC1L1 protein expression in the jejunum of HFD-fed mice. The siRNA-mediated knockdown of NPC1L1 attenuated the laminarin-mediated inhibition of cholesterol uptake in Caco-2 cells. This study suggests that laminarin significantly improves dyslipidemia in HFD-fed mice, likely by reducing cholesterol uptake through a mechanism that involves the downregulation of NPC1L1 expression.

The Hypocholesterolemic Potential of the Edible Algae Fucus vesiculosus: Proteomic and Quantitative PCR Analysis

A brown seaweed consumed worldwide, Fucus vesiculosus, has been used to prevent atherosclerosis and hypercholesterolemia, among other uses. However, the mechanisms of action that lead to these effects are not yet fully understood. This work aims to study the in vitro effect of an aqueous extract of F. vesiculosus, previously characterized as rich in phlorotannins and peptides, on the expression of different proteins involved in the synthesis and transport of cholesterol. A proteomic analysis, Western blot, and qRT-PCR analysis were performed to identify protein changes in HepG2 cells exposed to 0.25 mg/mL of the F. vesiculosus extract for 24 h. The proteomic results demonstrated that, in liver cells, the extract decreases the expression of four proteins involved in the cholesterol biosynthesis process (CYP51A1, DHCR24, HMGCS1 and HSD17B7). Additionally, a 12.76% and 18.40% decrease in the expression of two important transporters proteins of cholesterol, NPC1L1 and ABCG5, respectively, was also observed, as well as a 30% decrease in NPC1L1 mRNA levels in the cells exposed to the extract compared to control cells. Our study reveals some of the mechanisms underlying the actions of bioactive compounds from F. vesiculosus that may explain its previously reported hypocholesterolemic effect, future prospecting its use as a functional food.

Anti-Hypercholesterolemia Effects of Edible Seaweed Extracts and Metabolomic Changes in Hep-G2 and Caco-2 Cell Lines

Hypercholesterolemia is a major risk for the development of cardiovascular diseases (CVDs), the main cause of mortality worldwide, and it is characterized by high levels of circulating cholesterol. The drugs currently available for hypercholesterolemia control have several side effects, so it is necessary to develop new effective and safer therapies. Seaweeds serve as sources of several bioactive compounds with claimed beneficial effects. Eisenia bicyclis (Aramé) and Porphyra tenera (Nori) are edible seaweeds that were previously recognized as rich in bioactive compounds. In the present study, we aim to evaluate the anti-hypercholesterolemia effect of these two seaweed extracts and their health potential. Both extracts, but more efficiently Aramé extract, have liver 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) inhibitory activity as well as the capability to reduce approximately 30% of cholesterol permeation through human Caco-2 cells by simulating the intestinal lining, which is a target for hypercholesterolemia treatments. An untargeted metabolomic assay on human intestinal Caco-2 and liver Hep-G2 cell lines exposed to Aramé and Nori extracts revealed changes in the cells' metabolism, indicating the extracts' health beneficial effects. The metabolic pathways affected by exposure to both extracts were associated with lipid metabolism, such as phospholipids, and fatty acid metabolism, amino acid pathways, cofactors, vitamins, and cellular respiration metabolism. The effects were more profound in Aramé-treated cells, but they were also observed in Nori-exposed cells. The metabolite modifications were associated with the protection against CVDs and other diseases and to the improvement of the cells' oxidative stress tolerance. The results obtained for the anti-hypercholesterolemia properties, in addition to the revelation of the positive impact on cell metabolism, offer an important contribution for further evaluation of these seaweed extracts as functional foods or for CVD prevention.

The atheroprotective role of fucoidan involves the reduction of foam cell formation by altering cholesterol flux-associated factors in macrophages

Atherosclerosis is characterized by the accumulation of lipid-laden cells in the arterial walls, resulting from dysregulation of cholesterol homeostasis in the macrophage, triggered by oxidized low-density lipoprotein (oxLDL). Previous studies have shown that fucoidan, a sulfated polysaccharide from brown seaweeds, has several atheroprotective activities, however, the mechanism of fucoidan protection is not fully understood. Thus, we investigated the effect of fucoidan on atherogenesis in apolipoprotein E-deficient (ApoE-/-) mice, on oxLDL uptake by macrophages, and on the expression of the flux-associated scavenger receptors by macrophages. Also, we examined the absorption and biodistribution of orally administered fucoidan. ApoE-/- mice fed on a cholesterol-rich diet supplemented with 1% fucoidan showed reduced dyslipidemia and atherosclerosis. Fucoidan was detected in blood and peripheral tissue after gavage, suggesting that it can exert direct systemic effects. In vitro, fucoidan reduced macrophage oxLDL uptake, which resulted in lower foam cell formation. This effect was associated with downregulation of the cholesterol influx-associated scavenger receptor (SR)-A expression, and upregulation of the cholesterol efflux-associated SR-B1 expression. In conclusion, fucoidan prevented oxLDL-mediated foam cell formation in macrophages by downregulating SR-A1/2 and by up-regulating SR-B1.

How Do Brown Seaweeds Work on Biomarkers of Dyslipidemia? A Systematic Review with Meta-Analysis and Meta-Regression

Dyslipidemia is a common chronic disease that increases the risk of cardiovascular disease. Diet plays an important role in the development of dyslipidemia. As people pay increased attention to healthy eating habits, brown seaweed consumption is increasing, particularly in East Asian countries. The association between dyslipidemia and brown seaweed consumption has been previously demonstrated. We searched for keywords associated with brown seaweed and dyslipidemia in electronic databases such as PubMed, Embase, and Cochrane. Heterogeneity was estimated using the I2 statistic. The 95% confidence interval (CI) of the forest plot and heterogeneity were confirmed using meta-ANOVA and meta-regression. Funnel plots and publication bias statistical tests were used to determine publication bias. Statistical significance was set at p < 0.05. In this meta-analysis, we found that brown seaweed intake significantly decreased the levels of total cholesterol (mean difference (MD): −3.001; 95% CI: −5.770, −0.232) and low-density lipoprotein (LDL) cholesterol (MD: −6.519; 95% CI: −12.884, −0.154); nevertheless, the statistically significant association of brown seaweed intake with high-density lipoprotein (HDL) cholesterol and triglycerides were not observed in our study (MD: 0.889; 95% CI: −0.558, 2.335 and MD: 8.515; 95% CI: −19.354, 36.383). Our study demonstrated that brown seaweed and its extracts decreased total cholesterol and LDL cholesterol levels. The use of brown seaweeds may be a promising strategy to reduce the risk of dyslipidemia. Future studies involving a larger population are warranted to investigate the dose–response association of brown seaweed consumption with dyslipidemia.

Water-Soluble Saccharina latissima Polysaccharides and Relation of Their Structural Characteristics with In Vitro Immunostimulatory and Hypocholesterolemic Activities

Brown macroalgae are an important source of polysaccharides, mainly fucose-containing sulphated polysaccharides (FCSPs), associated with several biological activities. However, the structural diversity and structure-function relationships for their bioactivities are still undisclosed. Thus, the aim of this work was to characterize the chemical structure of water-soluble Saccharina latissima polysaccharides and evaluate their immunostimulatory and hypocholesterolemic activities, helping to pinpoint a structure-activity relationship. Alginate, laminarans (F1, neutral glucose-rich polysaccharides), and two fractions (F2 and F3) of FCSPs (negatively charged) were studied. Whereas F2 is rich in uronic acids (45 mol%) and fucose (29 mol%), F3 is rich in fucose (59 mol%) and galactose (21 mol%). These two fractions of FCSPs showed immunostimulatory activity on B lymphocytes, which could be associated with the presence of sulphate groups. Only F2 exhibited a significant effect in reductions in in vitro cholesterol's bioaccessibility attributed to the sequestration of bile salts. Therefore, S. latissima FCSPs were shown to have potential as immunostimulatory and hypocholesterolemic functional ingredients, where their content in uronic acids and sulphation seem to be relevant for the bioactive and healthy properties.

Edible Seaweeds Extracts: Characterization and Functional Properties for Health Conditions

Seaweeds are popular foods due to claimed beneficial health effects, but for many there is a lack of scientific evidence. In this study, extracts of the edible seaweeds Aramé, Nori, and Fucus are compared. Our approach intends to clarify similarities and differences in the health properties of these seaweeds, thus contributing to target potential applications for each. Additionally, although Aramé and Fucus seaweeds are highly explored, information on Nori composition and bioactivities is scarce. The aqueous extracts of the seaweeds were obtained by decoction, then fractionated and characterized according to their composition and biological activity. It was recognized that fractioning the extracts led to bioactivity reduction, suggesting a loss of bioactive compounds synergies. The Aramé extract showed the highest antioxidant activity and Nori exhibited the highest potential for acetylcholinesterase inhibition. The identification of the bioactive compounds in the extracts allowed to see that these contained a mixture of phloroglucinol polymers, and it was suggested that Nori’s effect on acetylcholinesterase inhibition may be associated with a smaller sized phlorotannins capable of entering the enzyme active site. Overall, these results suggest a promising potential for the use of these seaweed extracts, mainly Aramé and Nori, in health improvement and management of diseases, namely those associated to oxidative stress and neurodegeneration.

Characterization and Cytotoxic Activity of Microwave-Assisted Extracted Crude Fucoidans from Different Brown Seaweeds

Microwave-assisted extraction (MAE) is recognized as a green method for extraction of natural products. The current research aimed to explore the MAE for fucoidans extraction from different brown seaweeds, including Fucus vesiculosus, F. spiralis, and Laminaria saccharina. Following several solvent-extraction pre-treatment steps and MAE optimization, the algal biomasses were extracted in a ratio of 1:25 in 0.1 M HCl containing 2 M CaCl2 for 1.0 min. The results showed that L. saccharina's extract was different from the others, regarding the highest sugar content reached 0.47 mg glucose equivalent/mg extract being confirmed by monosaccharide composition analysis and the lowest fucoidan content and sulfation degree at 0.09 mg/mg extract and 0.13, respectively. Moreover, these findings were confirmed by tentative structural elucidation based on Fourier-transform infrared spectrometry which also showed a different spectrum. However, the MAE enhanced melanoidins formation in products, which was confirmed by the intense band at 1420 cm-1. Interestingly, the results of monomeric composition showed that fucoidan extract by MAE from F. vesiculosus belonged to sulfated galactofucans which are known for their potential bioactivities. Furthermore, the cytotoxic activity of the four fucoidans in concentrations ranging from 4.9 µg/mL to 2500 µg/mL was investigated and correlated with the chemical characterization showing that F. vesiculosus_MAE fucoidan was the most potent and safest. The current research revealed the chemical heterogeneity of fucoidans regarding taxonomical class and used greener extraction method of fucoidans toward the achievement of the UN sustainability goals.

A Bioactive Substance Derived from Brown Seaweeds: Phlorotannins

Phlorotannins are a type of natural active substance extracted from brown algae, which belong to a type of important plant polyphenol. Phloroglucinol is the basic unit in its structure. Phlorotannins have a wide range of biological activities, such as antioxidant, antibacterial, antiviral, anti-tumor, anti-hypertensive, hypoglycemic, whitening, anti-allergic and anti-inflammatory, etc. Phlorotannins are mainly used in the fields of medicine, food and cosmetics. This paper reviews the research progress of extraction, separation technology and biological activity of phlorotannins, which will help the scientific community investigate the greater biological significance of phlorotannins.

Global seaweed farming and processing in the past 20 years

Seaweed has emerged as one of the most promising resources due to its remarkable adaptability, short development period, and resource sustainability. It is an effective breakthrough to alleviate future resource crises. Algal resources have reached a high stage of growth in the past years due to the increased output and demand for seaweed worldwide. Several aspects global seaweed farming production and processing over the last 20 years are reviewed, such as the latest situation and approaches of seaweed farming. Research progress and production trend of various seaweed application are discussed. Besides, the challenges faced by seaweed farming and processing are also analyzed, and the related countermeasures are proposed, which can provide advice for seaweed farming and processing. The primary products, extraction and application, or waste utilization of seaweed would bring greater benefits with the continuous development and improvement of applications in various fields.

Graphical Abstract

Nanoformulation of Seaweed Eisenia bicyclis in Albumin Nanoparticles Targeting Cardiovascular Diseases: In Vitro and In Vivo Evaluation

Natural products, especially those derived from seaweeds, are starting to be seen as effective against various diseases, such as cardiovascular diseases (CVDs). This study aimed to design a novel oral formulation of bovine albumin serum nanoparticles (BSA NPs) loaded with an extract of Eisenia bicyclis and to validate its beneficial health effects, particularly targeting hypercholesterolemia and CVD prevention. Small and well-defined BSA NPs loaded with Eisenia bicyclis extract were successfully prepared exhibiting high encapsulation efficiency. Antioxidant activity and cholesterol biosynthesis enzyme 3-hydroxy-3 methylutaryl coenzyme A reductase (HMGR) inhibition, as well as reduction of cholesterol permeation in intestinal lining model cells, were assessed for the extract both in free and nanoformulated forms. The nanoformulation was more efficient than the free extract, particularly in terms of HMGR inhibition and cholesterol permeation reduction. In vitro cytotoxicity and in vivo assays in Wistar rats were performed to evaluate its safety and overall effects on metabolism. The results demonstrated that the Eisenia bicyclis extract and BSA NPs were not cytotoxic against human intestinal Caco-2 and liver HepG2 cells and were also safe after oral administration in the rat model. In addition, an innovative approach was adopted to compare the metabolomic profile of the serum from the animals involved in the in vivo assay, which showed the extract and nanoformulation's impact on CVD-associated key metabolites. Altogether, these preliminary results revealed that the seaweed extract and the nanoformulation may constitute an alternative natural dosage form which is safe and simple to produce, capable of reducing cholesterol levels, and consequently helpful in preventing hypercholesterolemia, the main risk factor of CVDs.

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.

Recent advances in biological properties of brown algae-derived compounds for nutraceutical applications

The increasing demand for nutraceuticals in the circular economy era has driven the research toward studying bioactive compounds from renewable underexploited resources. In this regard, the exploration of brown algae has shown significant growth and maintains a great promise for the future. One possible explanation could be that brown algae are rich sources of nutritional compounds (polyunsaturated fatty acids, fiber, proteins, minerals, and vitamins) and unique metabolic compounds (phlorotannins, fucoxanthin, fucoidan) with promising biological activities that make them good candidates for nutraceutical applications with increased value-added. In this review, a deep description of bioactive compounds from brown algae is presented. In addition, recent advances in biological activities ascribed to these compounds through in vitro and in vivo assays are pointed out. Delivery strategies to overcome some drawbacks related to the direct application of algae-derived compounds (low solubility, thermal instability, bioavailability, unpleasant organoleptic properties) are also reviewed. Finally, current commercial and legal statuses of ingredients from brown algae are presented, considering future therapeutical and market perspectives as nutraceuticals.

Pigment Composition of Nine Brown Algae from the Iberian Northwestern Coastline: Influence of the Extraction Solvent

Brown algae are ubiquitously distributed in the NW coastline of the Iberian Peninsula, where they stand as an underexploited resource. In this study, five solvents were applied to the extraction of pigments from nine brown algae, followed by their determination and quantification by HPLC-DAD. A total of 13 compounds were detected: Six were identified as chlorophylls, six were classified as xanthophylls, and one compound was reported as a carotene. Fucoxanthin was reported in all extracts, which is the most prominent pigment of these algae. Among them, L. saccharina and U. pinnatifida present the highest concentration of fucoxanthin (4.5-4.7 mg∙g-1 dry weight). Ethanol and acetone were revealed as the most efficient solvents for the extraction of pigments, showing a maximal value of 11.9 mg of total pigments per gram of dry alga obtained from the ethanolic extracts of H. elongata, followed by the acetonic extracts of L. ochroleuca. Indeed, ethanol was also revealed as the most efficient solvent according to its high extraction yield along all species evaluated. Our results supply insights into the pigment composition of brown algae, opening new perspectives on their commercial exploitation by food, pharmaceutical, and cosmeceutical industries.

Algal polysaccharides and derivatives as potential therapeutics for obesity and related metabolic diseases

The potential and challenges of algal polysaccharides and their derivatives as potential therapeutic agents for obesity and its related metabolic diseases.

Untargeted metabolomic study of HepG2 cells under the effect of Fucus vesiculosus aqueous extract

RATIONALE

Fucus vesiculosus has been described with potential to develop functional foods containing bioactive compounds against various diseases. However, more studies are needed to better understand its functioning and its previously reported bioactivities, mainly at the molecular level.

METHODS

An untargeted metabolomic study was performed to analyse HepG2 cells exposed to F. vesiculosus aqueous extract, rich in phlorotannins and peptides, during 24 h. This study was carried out using liquid chromatography combined with high-resolution tandem mass spectrometry.

RESULTS

This metabolomic study showed significant changes in HepG2 metabolites in the presence of the extract, standing out being the increased intensity of various fatty acid amides (oleamide, (Z)-eicos-11-enamide, linoleamide, palmitamide, dodecanamide and stearamide). This group of metabolites is reported in the literature with anticancer and hypocholesterolemic activity, bioactivities also described for F. vesiculosus. The extract induced, likewise, the expression of glutathione indicating its antioxidant effect.

CONCLUSIONS

This study demonstrated the potential of the compounds present in the F. vesiculosus aqueous extract for the development of natural drugs, nutraceuticals or dietary supplements, justified at the molecular level by changes in cell metabolites related to anticancer and hypocholesterolemic activity. The results here described, using an untargeted metabolomic approach, may contribute to a better understanding of algal behaviour, when used as food, in health-promoting effects.

Supercritical fluid extraction (SCFE) as green extraction technology for high-value metabolites of algae, its potential trends in food and human health

Application of high-value algal metabolites (HVAMs) in cosmetics, additives, pigments, foods and medicines are very important. These HVAMs can be obtained from the cultivation of micro- and macro-algae. These metabolites can benefit human and animal health in a physiological and nutritional manner. However, because of conventional extraction methods and their energy and the use of pollutant solvents, the availability of HVAMs from algae remains insufficient. Receiving their sustainability and environmental benefits have recently made green extraction technologies for HVAM extractions more desirable. But very little information is available about the technology of green extraction of algae from these HVAM. This review, therefore, highlights the supercritical fluid extraction (SCFE) as principal green extraction technologyand theirideal parameters for extracting HVAMs. In first, general information is provided concerning the HVAMs and their components of macro and micro origin. The review also includes a description of SCFE technology's properties, instrumentation operation, solvents used, and the merits and demerits. Moreover, there are several HVAMs associated with their numerous high-level biological activities which include high-level antioxidant, anti-inflammatory, anticancer and antimicrobial activity and have potential health-beneficial effects in humans since they are all HVAMs, such as foods and nutraceuticals. Finally, it provides future insights, obstacles, and suggestions for selecting the right technologies for extraction.