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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.

Recent studies indicate that plant polyphenols could be pointed as potential prebiotic candidates since they may interact with the gut microbiota, stimulating its growth and the production of metabolites. However, little is known about the fate of brown seaweeds’ phlorotannins during their passage throughout the gastrointestinal tract. This work aimed to evaluate the stability and bioaccessibility of Fucus vesiculosus phlorotannins after being submitted to a simulated digestive process, as well as their possible modulatory effects on gut microbiota and short-chain fatty acids production following a fermentation procedure using fecal inoculates to mimic the conditions of the large intestine. The stability of phlorotannins throughout the gastrointestinal tract was reduced, with a bioaccessibility index between 2 and 14%. Moreover, slight alterations in the growth of certain commensal bacteria were noticed, with Enterococcus spp. being the most enhanced group. Likewise, F. vesiculosus phlorotannins displayed striking capacity to enhance the levels of propionate and butyrate, which are two important short-chain fatty acids known for their role in intestinal homeostasis. In summary, this work provides valuable information regarding the behavior of F. vesiculosus phlorotannins along the gastrointestinal tract, presenting clear evidence that these compounds can positively contribute to the maintenance of a healthy gastrointestinal condition.

According to the WHO, cancer was responsible for an estimated 9.6 million deaths in 2018, making it the second global leading cause of death. The main risk factors that lead to the development of this disease include poor behavioral and dietary habits, such as tobacco use, alcohol use and lack of fruit and vegetable intake, or physical inactivity. In turn, it is well known that polyphenols are deeply implicated with the lower rates of cancer in populations that consume high levels of plant derived foods. In this field, phlorotannins have been under the spotlight in recent years since they have shown exceptional bioactive properties, with great interest for application in food and pharmaceutical industries. Among their multiple bioactive properties, phlorotannins have revealed the capacity to interfere with several biochemical mechanisms that regulate oxidative stress, inflammation and tumorigenesis, which are central aspects in the pathogenesis of cancer. This versatility and ability to act either directly or indirectly at different stages and mechanisms of cancer growth make these compounds highly appealing for the development of new therapeutical strategies to address this world scourge. The present manuscript revises relevant studies focusing the effects of phlorotannins to counteract the oxidative stress–inflammation network, emphasizing their potential for application in cancer prevention and/or treatment.

Microwave-assisted extraction (MAE) was carried out to maximize the extraction of phlorotannins from Fucus vesiculosus using a hydroethanolic mixture as a solvent, as an alternative to the conventional method with a hydroacetonic mixture. Optimal MAE conditions were set as ethanol concentration of 57% (v/v), temperature of 75 &deg, C, and time of 5 min, which allowed a similar recovery of phlorotannins from the macroalgae compared to the conventional extraction. While the phlorotannins richness of the conventional extract was slightly superior to that of MAE (11.1 &plusmn, 1.3 vs. 9.8 &plusmn, 1.8 mg PGE/g DWextract), both extracts presented identical phlorotannins constituents, which included, among others, tetrafucol, pentafucol, hexafucol, and heptafucol structures. In addition, MAE showed a moderate capacity to scavenge ABTS&bull, + (IC50 of 96.0 &plusmn, 3.4 &micro, g/mL) and to inhibit the activity of xanthine oxidase (IC50 of 23.1 &plusmn, g/mL) and a superior ability to control the activity of the key metabolic enzyme &alpha, glucosidase compared to the pharmaceutical drug acarbose.

Due to their large spectrum of bioactive properties, much attention has recently been drawn to phlorotannins&mdash, i.e., phenolic compounds characteristic from brown macroalgae. This study aimed to evaluate the antioxidant and anti-inflammatory properties of F. vesiculosus phlorotannin extracts and purified fractions. Overall, the crude extract and its ethyl acetate fraction (EtOAc) showed good radical scavenging activity, particularly towards nitric oxide (NO&bull, ). Subsequent subfractions of EtOAc (F1 to F9) with different molecular weights were then shown to inhibit lipopolysaccharide-induced NO&bull, production in macrophages, with stronger effects being observed for fractions of lower MWs. Of the three intracellular markers analyzed, inducible NO&bull, synthase showed the highest sensitivity to almost all the phlorotannin-rich samples, followed by interleukin 1&beta, and cyclooxygenase 2, which was only inhibited by F2. Furthermore, this subfraction inhibited the phosphorylation and degradation of inhibitory protein &kappa, B&alpha, thus preventing the activation of NF-&kappa, B and blocking the inflammatory cascade at the transcriptional level. This sample was characterized by the presence of a major compound with a deprotonated molecular ion at m/z 507 with a fragmentation pattern coherent with that of a phlorotannin derivative. Overall, this work unveiled some of the mechanistic aspects behind the anti-inflammatory capacity of phlorotannins from F. vesiculosus, endorsing its use as a possible natural source of anti-inflammatory compounds.

Active coating development for prevention and control of microbial contamination is an extremely challenging technology. In this field, the potential of plant-based compounds to be used as a complement or an alternative to the synthetic preservatives have drawn increasing attention from the food industry. In this study, an active coating containing Origanum virens essential oil (EO-WPC) was applied on the surface of two traditional Portuguese sausages (painhos and alheiras) during industrial production. For 4 months, both products were regularly monitored for their physicochemical properties and total microbial load. Sensory evaluation was also carried out for each sausage type. The application of the EO-WPC caused little variations on the moisture content and texture profile. Higher acidity and protection against color fading was observed particularly in painhos, while coated alheiras had a significant reduction of the lipid peroxidation. Inhibition of the total microbial load was observed for both coated sausages, resulting in an extension of the shelf life of approximately 20 and 15 days for painhos and alheiras, respectively. Sensory analysis revealed an overall positive acceptance. These results support the great potential of O. virens EO to be used as food preservative in processed meat products.

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 &plusmn, 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 &deg, C. This crude extract, together with a semi-purified phlorotannin fraction, were further evaluated for their anti-enzymatic capacity against &alpha, glucosidase, &alpha, amylase and pancreatic lipase, both showing promising inhibitory effects, particularly against &alpha, glucosidase for which a greater inhibitory effect was observed compared to the pharmaceutical drug acarbose (IC50 = 4.5 &plusmn, 0.8 and 0.82 &plusmn, 0.3 &mu, g/mL, respectively, against 206.6 &plusmn, 25.1 &mu, g/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 &alpha, amylase and pancreatic lipase, which are well known to be linked to metabolic disorders such as diabetes and obesity.

Salvia elegans Vahl., Salvia greggii A. Gray, and Salvia officinalis L. decoctions were investigated for their health-benefit properties, in particular with respect to antioxidant activity and inhibitory ability towards key enzymes with impact in diabetes and obesity (&alpha, glucosidase, &alpha, amylase and pancreatic lipase). Additionally, the phenolic profiles of the three decoctions were determined and correlated with the beneficial properties. The S. elegans decoction was the most promising in regard to the antioxidant effects, namely in the scavenging capacity of the free radicals DPPH&bull, NO&bull, and O2&bull, &ndash, and the ability to reduce Fe3+, as well as the most effective inhibitor of &alpha, glucosidase (EC50 = 36.0 &plusmn, 2.7 &mu, g/mL vs. EC50 = 345.3 &plusmn, 6.4 &mu, g/mL and 71.2 &plusmn, 5.0 &mu, g/mL for S. greggii and S. officinalis, respectively). This superior activity of the S. elegans decoction over those of S. greggii and S. officinalis was, overall, highly correlated with its richness in caffeic acid and derivatives. In turn, the S. officinalis decoction exhibited good inhibitory capacity against xanthine oxidase activity, a fact that could be associated with its high content of flavones, in particular the glycosidic forms of apigenin, scutellarein and luteolin.

Seaweeds are known to be a good supply of key nutrients including carbohydrates, protein, minerals, polyunsaturated lipids, as well as several other health-promoting compounds capable of acting on a wide spectrum of disorders and/or diseases. While these marine macroalgae are deeply rooted in the East Asian culture and dietary habits, their major application in Western countries has been in the phycocolloid industry. This scenario has however been gradually changing, since seaweed consumption is becoming more common worldwide. Among the numerous edible seaweeds, members of the genus Fucus have a high nutritional value and are considered good sources of dietary fibers and minerals, especially iodine. Additionally, their wealth of bioactive compounds such as fucoidan, phlorotannins, fucoxanthin and others make them strong candidates for multiple therapeutic applications (e.g., antioxidant, anti-inflammatory, anti-tumor, anti-obesity, anti-coagulant, anti-diabetes and others). This review presents an overview of the nutritional and phytochemical composition of Fucus spp., and their claimed biological activities, as well as the beneficial effects associated to their consumption. Furthermore, the use of Fucus seaweeds and/or their components as functional ingredients for formulation of novel and enhanced foods is also discussed.

Flavonoids, a group of secondary metabolites widely distributed in the plant kingdom, have been acknowledged for their interesting medicinal properties. Among them, natural flavones, as well as some of their synthetic derivatives, have been shown to exhibit several biological activities, including antioxidant, anti-inflammatory, antitumor, anti-allergic, neuroprotective, cardioprotective and antimicrobial. The antioxidant properties of flavones allow them to demonstrate potential application as preventive and attenuating agents in oxidative stress, i.e., a biological condition that is closely associated to aging process and several diseases. Some flavones interfere in distinct oxidative-stress related events by directly reducing the levels of intracellular free radicals (hydroxyl, superoxide and nitric oxide) and/or of reactive species (e.g. hydrogen peroxide, peroxynitrite and hypochlorous acid) thus preventing their amplification and the consequent damage of other biomolecules such as lipids, proteins and DNA. Flavones can also hinder the activity of central free radical-producing enzymes, such as xanthine oxidase and nicotinamide adenine dinucleotide phosphate oxidase (NADPH-oxidase) or inducible nitric oxide synthase (iNOS) and can even modulate the intracellular levels of pro-oxidant and/or antioxidant enzymes. The evaluation of flavones antioxidant ability has been extensively determined in chemical or biological in vitro models, but in vivo therapy with individual flavones or with flavones-enriched extracts has also been reported. The present manuscript revises relevant studies focusing the preventive effects of flavones on stress-related diseases, namely the neurological and cardiovascular diseases, and diabetes and its associated complications.

Fucaceae is the most dominant algae family along the intertidal areas of the Northern Hemisphere shorelines, being part of human customs for centuries with applications as a food source either for humans or animals, in agriculture and as remedies in folk medicine. These macroalgae are endowed with several phytochemicals of great industrial interest from which phlorotannins, a class of marine-exclusive polyphenols, have gathered much attention during the last few years due to their numerous possible therapeutic properties. These compounds are very abundant in brown seaweeds such as Fucaceae and have been demonstrated to possess numerous health-promoting properties, including antioxidant effects through scavenging of reactive oxygen species (ROS) or enhancement of intracellular antioxidant defenses, antidiabetic properties through their acarbose-like activity, stimulation of adipocytes glucose uptake and protection of β-pancreatic cells against high-glucose oxidative stress; anti-inflammatory effects through inhibition of several pro-inflammatory mediators; antitumor properties by activation of apoptosis on cancerous cells and metastasis inhibition, among others. These multiple health properties render phlorotannins great potential for application in numerous therapeutical approaches. This review addresses the major contribution of phlototannins for the biological effects that have been described for seaweeds from Fucaceae. In addition, the bioavailability of this group of phenolic compounds is discussed.

Honey, propolis, and pollen are three important components of the beehive produced by honeybees mixing different plant parts (nectar, resin and pollen) with their own secretions, for further usage with different purposes in the hive. The fact that these natural products have been associated with numerous health benefits has attracted the attention of researchers resulting in a significant raise of scientific studies attesting their biological properties. Among the various constituents of honey, propolis and pollen, the phenolic compounds are the ones most frequently related to the beneficial properties of these products and hence, one of the main investigated groups. Their characterization is important to understand individual contribution(s) and synergistic effects of each compound for the overall biological effects of the bee product. To pursuit this goal, spectrophotometric techniques including HPLC, GC and TLC, alongside with the respective detection methods such as DAD, FLD and MS, have been developed and improved in order to offer better and more accurate separative performances. The aim of this review is to give an approach on the course that the chromatographic techniques have taken until the most recent trends on this field applied to the separation and characterization of the phenolic constituents of honey, propolis and bee pollen as well as an overall perspective of variability in terms of phenolic composition that can be found in the three bee products mentioned. The authors gratefully acknowledge the financial support provided by the Foundation for Science and Technology (FCT) to CERNAS (Project PEstOE/ AGR/UI0681/2011) and of FCT the European Union, QREN, FEDER, COMPETE, for funding the Organic Chemistry Research Unit (QOPNA) (project PEst-C/QUI/UI0062/2013; FCOMP-01-0124-FEDER- 037296). info:eu-repo/semantics/publishedVersion

Seaweeds are well-known for their exceptional capacity to accumulate essential minerals and trace elements needed for human nutrition, although their levels are commonly very variable depending on their morphological features, environmental conditions, and geographic location. Despite this variability, accumulation of Mg, and especially Fe, seems to be prevalent in Chlorophyta, while Rhodophyta and Phaeophyta accumulate higher concentrations of Mn and I, respectively. Both red and brown seaweeds also tend to accumulate higher concentrations of Na, K, and Zn than green seaweeds. Their valuable mineral content grants them great potential for application in the food industry as new ingredients for the development of numerous functional food products. Indeed, many studies have already shown that seaweeds can be used as NaCl replacers in common foods while increasing their content in elements that are oftentimes deficient in European population. In turn, high concentrations of some elements, such as I, need to be carefully addressed when evaluating seaweed consumption, since excessive intake of this element was proven to have negative impacts on health. In this regard, studies point out that although very bioaccessible, I bioavailability seems to be low, contrarily to other elements, such as Na, K, and Fe. Another weakness of seaweed consumption is their capacity to accumulate several toxic metals, which can pose some health risks. Therefore, considering the current great expansion of seaweed consumption by the Western population, specific regulations on this subject should be laid down. This review presents an overview of the mineral content of prevalent edible European macroalgae, highlighting the main factors interfering in their accumulation. Furthermore, the impact of using these marine vegetables as functional ingredients or NaCl replacers in foods will be discussed. Finally, the relationship between macroalgae’s toxic metals content and the lack of European legislation to regulate them will be addressed.

Eriocephalus africanus , an Asteraceae plant endemic from South Africa and naturalized in the Mediterranean region, is commonly used in culinary and in traditional medicine. Despite the claimed health benefits attributed to this plant by the folk medicine, there is still a lack of scientific data to support this information. The present study describes the main phenolic composition of hydroethanolic extracts from stems and leaves of E. africanus , along with the assessment of their antioxidant properties. The identification of the phenolic constituents on the stems and leaves from E. africanus was carried out by LC-DAD-ESI/MS n , and the structures of the two major HPLC-eluted compounds were further confirmed by NMR analysis. Both extracts were rich in mono- and di-caffeoylquinic acids, which accounted for approximately 90% and 74% of total quantified phenolics, for the stems and leaves extracts, respectively. Besides, eriodictyol-hexuronide was found in considerable amounts in the extract from the leaves. One must highlight that these compounds together with other minor phenolic acids (namely other caffeoyl, ferulic and protocatechuic acid derivatives) and flavonoids (including hesperetin and eriodictyol) were herein identified for the first time. Furthermore, through three in vitro methods, namely 2,2-diphenyl-1-picrylhydrazyl (DPPH ) radical scavenging, ferric reducing antioxidant power and lipid peroxidation inhibition capacity assays, the antioxidant capacity of the extracts was measured, revealing promising properties. Overall, these results are an important contribution for the elucidation of the phenolic composition of E. africanus , as well as for the understanding of the biological properties of this medicinal plant species.