Therapeutic Effect of Fucoidan on Metabolic Diseases: Experimental Data and Clinical Evidence.

The rising prevalence of metabolic diseases represents a major challenge to public health worldwide. Therefore, there is a strong need to conduct research on the effectiveness of complementary and alternative therapies for metabolic disorders. Fucoidan is a fucose-enriched and sulfated polysaccharide extracted from ubiquitous brown seaweed. The antihypertensive, antidiabetic, antiobesity, and hypolipidemic effects of fucoidan have been reported in preclinical research and clinical trials. This study aims to review the mechanisms of action and the experimental and clinical use of different types of fucoidan for the treatment of metabolic diseases.

The Prospective Use of Brazilian Marine Macroalgae in Schistosomiasis Control.

Schistosomiasis is a parasitic disease that affects more than 250 million people. The treatment is limited to praziquantel and the control of the intermediate host with the highly toxic molluscicidal niclosamide. Marine algae are a poorly explored and promising alternative that can provide lead compounds, and the use of multivariate analysis could contribute to quicker discovery. As part of our search for new natural compounds with which to control schistosomiasis, we screened 45 crude extracts obtained from 37 Brazilian seaweed species for their molluscicidal activity against Biomphalaria glabrata embryos and schistosomicidal activities against Schistosoma mansoni. Two sets of extracts were taxonomically grouped for metabolomic analysis. The extracts were analyzed by GC-MS, and the data were subjected to Pattern Hunter and Pearson correlation tests. Overall, 22 species (60%) showed activity in at least one of the two models. Multivariate analysis pointed towards 3 hits against B. glabrata veliger embryos in the Laurencia/Laurenciella set, 5 hits against B. glabrata blastula embryos, and 31 against S. mansoni in the Ochrophyta set. Preliminary annotations suggested some compounds such as triquinane alcohols, prenylated guaianes, dichotomanes, and xenianes. Despite the putative identification, this work presents potential candidates and can guide future isolation and identification.

Lithothamnium calcareum (Pallas) Areschoug seaweed adsorbs aflatoxin B1 in vitro and improves broiler chicken's performance.

This study aimed to evaluate the aflatoxin B1 (AFB1) adsorption capacity of the seaweed Lithothamnium calcareum in vitro and to prevent aflatoxicosis in broiler chickens. In vitro adsorption assays were performed at a single AFB1 concentration (1 µg/mL) and four seaweed concentrations (0.50, 1, 1.5 and 2 mg/mL) at pH 3 and pH 6. The maximum adsorption was obtained at the lowest seaweed content (0.62 and 0.78 µg/mg). Male broiler chickens (256) were housed in metallic cages. Experimental diets were T1 (control), 18 µg/kg AFB1; T2, 18 µg/kg AFB1 and 0.2% L. calcareum (2.0 kg/ton); T3, 1018 µg/kg AFB1; and T4, 1018 µg/kg AFB1 and 0.2% L. calcareum. Performance parameters (live weight, weight gain and feed conversion rate) improved when seaweed was applied. The aspartate-aminotransferase and alanine-aminotransferase levels tend to decrease in birds receiving only seaweed, also the uric acid levels reduced significantly (P Ë‚ 0.05), while birds receiving only AFB1 increased the biochemical parameter levels. The livers from animals fed with AFB1 showed histopathological alterations with disorganization of periportal hepatocytes, necrosis with multifocal coagulation and mild fat degeneration; the livers from T4 had normal appearance. Lithothamnium calcareum was able to prevent aflatoxicosis in broiler chickens and also improved their zootechnical performance.

Physiological and metabolic responses to hypersalinity reveal interpopulation tolerance in the green macroalga Ulva compressa with different pollution histories.

There is scarce investigation addressing interpopulation tolerance responses to address the influence of a history of chronic stress exposure, as that occurring in polluted environments, in photoautotrophs. We evaluated ecophysiological (photosynthetic activity) and metabolic (oxidative stress and damage) responses of two populations of green macroalga Ulva compressa from polluted (Ventanas) and non-polluted (Cachagua) localions of central Chile, and exposed to controlled hypersalinity conditions of 32 (control), 42, 62 and 82 psu (practical salinity units) for 6 h, 48 h and 6 d. Both primary production (ETRmax) and photosynthetic efficiency (αETR) were generally higher in the population from Cachagua compared to Ventanas at all times and salinities. Moreover, at most experimental times and salinities the population from Ventanas had greater levels of H2O2 and lipid peroxidation that individuals from Cachagua. Total ascorbate was higher in the population of Cachagua than Ventanas at 42 and 82 psu after 6 and 48 h, respectively, while at 6 d concentrations were similar between both populations at all salinities. Total glutathione was greater in both populations after 6 h at all salinities, but at 48 h its concentrations were higher only in the population from Cachagua, a trend that was maintained at 6 d under 82 psu only. Reduced and oxidized ascorbate (ASC and DHA, respectively) and glutathione (GSH and GSSG, respectively) demonstrated similar patterns between U. compressa populations, with an increase oxidation with greater salinities but efficient recycling to maintain sufficient batch of ASC and GSH. When assessing the expression of antioxidant enzymes catalase (CAT), superoxide dismutase (SOD) and dehydroascorbate reductase (DHAR), while the population of Ventanas displayed a general trend of upregulation with increasing salinities along the experiments, U. compressa from Cachagua revealed patterns of downregulation. Results demonstrated that although both populations were still viable after the applied hypersalinities during all experimental times, biological performance was usually more affected in the population from the Ventanas than Cachagua, likely due to a depressed baseline metabolism after a long history of exposition to environmental pollution.

Seasonal Variation of Mycosporine-Like Amino Acids in Three Subantarctic Red Seaweeds.

UV-absorbing compounds, such as mycosporine-like amino acids (MAAs), are a group of secondary metabolites present in many marine species, including red seaweeds. In these organisms, the content and proportion of the composition of MAAs vary, depending on the species and several environmental factors. Its high cosmetic interest calls for research on the content and composition of MAAs, as well as the dynamics of MAAs accumulation in seaweeds from different latitudes. Therefore, this study aimed to survey the content of UV-absorbing MAAs in three Subantarctic red seaweeds during a seasonal cycle. Using spectrophotometric and HPLC techniques, the content and composition of MAAs of intertidal Iridaea tuberculosa, Nothogenia fastigiate, and Corallina officinalis were assessed. Some samples were also analyzed using high-resolution mass spectrometry coupled with HPLC-ESI-MS in order to identify more precisely the MAA composition. I. tuberculosa exhibited the highest MAA values (above 1 mg g-1 of dried mass weight), while C. officinalis showed values not exceeding 0.4 mg g-1. Porphyra-334 was the main component in N. fastigiata, whereas I. tuberculosa and C. officinalis exhibited a high content of palythine. Both content and composition of MAAs varied seasonally, with high concentration recorded in different seasons, depending on the species, i.e., winter (I. tuberculosa), spring (N. fastigiata), and summer (C. officinalis). HPLC-ESI-MS allowed us to identify seven different MAAs. Two were recorded for the first time in seaweeds from Subantarctic areas (mycosporine-glutamic acid and palythine-serine), and we also recorded an eighth UV-absorbing compound which remains unidentified.

Rheology of partially and totally oxidized red seaweed galactans.

Agarose and κ-carrageenan were oxidized using (2,2,6,6-tetramethylpiperidinyl)oxy (TEMPO) in the presence of NaOCl and NaBr. Products with several degrees of oxidation were structurally characterized. The mechanical spectra were determined: derivatives with a medium to high degree of oxidation give rise to polysaccharides that behave like dilute solutions in water, whereas those with a degree of oxidation close to 20 % keep the gelling properties with a different thermo-rheological response towards pH (6.5 or 4.0) and counterions (K+ or Ca2+) in comparison with the native polysaccharides. For instance, they showed a marked dependence on the presence of calcium ions, observed in the increase of thermal stability and dynamic elastic component (G') value, due to the known interaction of this divalent cation with the carboxylate groups. In this sense, these derivatives with low oxidation degrees have proven to be not only thermosensitive, like the native polysaccharide, but also pH- and calcium-sensitive.

Competitive biosorption of Cu2+ and Ag+ ions on brown macro-algae waste: kinetic and ion-exchange studies.

The application of biosorption operation has gained attention in the removal and retrieval of toxic metal ions from water bodies. Wastewater from industrial activity generally presents great complexity due to the coadsorption of cations to the inactive biomass binding sites. In this work, the competitive biosorption of Cu(II) and Ag(I) ions was studied in batch systems. A kinetic study applying a non-acidified and acidified waste of Sargassum filipendula in equimolar and non-equimolar metal samples was carried out and the acidified biosorbent was selected due to higher removal rates and selectivity of silver ions. The assays were performed with 2 g L-1 of biosorbent concentration at 25 °C for 12 h and pH was controlled at around 5.0. Copper presented higher affinity for the biosorbent and a fast biosorption kinetic profile, while silver equilibrium times exhibited dependence on the copper concentration. External diffusion is the rate-limiting step in Cu(II) ion removal and it might also limit the kinetic rates of Ag(I) ions with intraparticle diffusion, depending on the initial concentration of metal cations. The ion-exchange mechanism is evidenced and complexation and electrostatic attraction mechanisms might be suggested, explained by simultaneous chemisorption and physisorption processes during the operation. Calcium and sodium were released in considerable amounts by the ion-exchange mechanism. Characterization analyses confirmed the role of several functional groups in the competitive biosorption accompanied by a homogenous covering of both metal ions on the surface of the particles. Particle porosity analyses revealed that the material is macroporous and an appreciable amount of macropores are filled with metal cations after biosorption.

Phytoremediation potential of Ulva ohnoi (Chlorophyta): Influence of temperature and salinity on the uptake efficiency and toxicity of cadmium.

Ulva ohnoi is a green macroalga with fast growth and high rates of nitrogen and phosphorus absorption. Recently, this species has been recorded in several places with record green tide formation in some of them. Using molecular tools, we herein report the first occurrence of this species in Brazil and demonstrate its potential for phytoremediation in typical environmental concentrations of Cd (0.625-15 µg L-1). Similarly, the effects of physicochemical parameters (salinity and temperature) on the toxicity and uptake efficiency of this species were evaluated. Molecular analysis of two sequences (1141 bp) obtained corroborates another 34 sequences for U. ohnoi obtained from GenBank. The addition of Cd in the medium affected photosynthetic parameters and reduced growth rate. U. ohnoi showed resistance to Cd when cultivated at 18 °C, S15 and 18-25 °C, S35, at concentrations between 0.625 and 2.5 µg. L-1 of Cd; yet, positive growth rate was maintained. Dose-dependent accumulation was observed in all combinations of factors used with a maximum value of 4.20 µg Cd per gram of dry seaweed at 15 µg. L-1 of Cd at 18 °C and S35. Maximum value of the concentration factor was 81.3 ±â€¯1.1% of Cd added at the concentration of 0.625 µg. L-1 to S15 and 18 °C. Our results demonstrate the potential of using U. ohnoi in the phytoremediation of Cd in saltwater or brackish water.

Marine prebiotics: Polysaccharides and oligosaccharides obtained by using microbial enzymes.

Utilization of marine algae has increased considerably over the past decades, since biodiversity within brown, red and green marine algae offers possibilities of finding a variety of bioactive compounds. Marine algae are rich sources of dietary fibre. The remarkable positive effects of seaweed dietary fibre on human body are related to their prebiotic activity over the gastrointestinal tract (GIT) microbiota. However, dietary modulation of microorganisms present in GIT can be influenced by different factors such as type and source of the dietary fibre, their molecular weight, type of extraction and purification methods employed, composition and modification of polysaccharide and oligosaccharide. This review will demonstrate evidence that polysaccharides and oligosaccharides from marine algae can be used as prebiotics, emphasizing their use in human health, their application as food and other possible applications. Furthermore, an important approach of microbial enzymes employment during extraction, modification or production of those prebiotics is highlighted.

Environmentally Friendly Valorization of Solieria filiformis (Gigartinales, Rhodophyta) from IMTA Using a Biorefinery Concept.

Marine macroalgae (seaweed) are an excellent source of novel bioactive metabolites. The biorefinery concept applied to seaweed facilitates the extraction of many chemical constituents from the same biomass ensuring that the resource is used fully, generating few residues through a succession of extraction steps. In the present study, the biomass of the carragenophyte Solieria filiformis (Rhodophyta, Gigartinales) cultured in an integrated multi-trophic aquaculture (IMTA) system was evaluated to obtain valuable products by a biorefinery approach. Enzymatic-assisted extraction (EAE) and microwave-assisted extraction (MAE) were the eco-friendly technologies used to ensure an environmentally friendly valorization of the biomass. Three valuable products were successfully recovered: a water-soluble extract rich in proteins and sulfated polysaccharides suitable as a food supplement; a lipid fraction rich in polyunsaturated fatty acids (PUFAs) with potential to be used in the nutraceutical industry; and a pure ι-carrageenan with a powerful antiviral activity against Herpes simplex virus (EC50 = 6.3 µg mL-1) comparable to the commercial antiviral acyclovir (EC50 = 3.2⁻5.4 µg mL-1).

Saccharification of Brown Macroalgae Using an Arsenal of Recombinant Alginate Lyases: Potential Application in the Biorefinery Process.

Alginate lyases (endo and exo-lyases) are required for the degradation of alginate into its constituting monomers. Efficient bioethanol production and extraction of bioactives from brown algae requires intensive use of these enzymes. Nonetheless, there are few commercial alginate lyase preparations, and their costs make them unsuitable for large scale experiments. A recombinant expression protocol has been developed in this study for producing seven endo-lyases and three exo-lyases as soluble and highly active preparations. Saccharification of alginate using 21 different endo/exo-lyase combinations shows that there is complementary enzymatic activity between some of the endo/exo pairs. This is probably due to favorable matching of their substrate biases for the different glycosidic bonds in the alginate molecule. Therefore, selection of enzymes for the best saccharification results for a given biomass should be based on screens comprising both types of lyases. Additionally, different incubation temperatures, enzyme load ratios, and enzyme loading strategies were assessed using the best four enzyme combinations for treating Macrocystis pyrifera biomass. It was shown that 30°C with a 1:3 endo/exo loading ratio was suitable for all four combinations. Moreover, simultaneous loading of endo-and exo-lyases at the beginning of the reaction allowed maximum alginate saccharification in half the time than when the exo-lyases were added sequentially.

The impact of short-term depositions of macroalgal blooms on widgeon-grass meadows in a river-dominated estuary.

Macroalgal blooms can trigger adverse biogeochemical conditions at the sediment-water interface of shallow coastal areas, hence threatening critical habitats such as seagrasses meadows. The direction and magnitude of macroalgal blooms impacts on the aquatic ecosystem can be context-dependent, varying according to the local hydrodynamic conditions. Thus, studies investigating the impacts of stagnant algal depositions on the benthos may fail to address realistic situations and interactions which are common in well-flushed systems. This is especially true for the South America coast, where no study has investigated the effects of macroalgal blooms on seagrasses meadows. To fully understand the impacts of macroalgal blooms on sediment biogeochemistry and seagrass habitats across distinct environmental conditions and biogeographical regions, two independent, complementary field experiments replicated the natural temporal patterns of drift macroalgal mats depositions on unvegetated and vegetated (Ruppia maritima meadows) shoals of the Patos Lagoon estuary (PLE), a subtropical, high hydrodynamic system in southern Brazil. Transitory depositions of algal mats alleviated deleterious biogeochemical conditions in the sediment-water interface of unvegetated bottoms. Nevertheless, these unstable algal depositions promoted significant reductions in R. maritima biomass, by reducing their shoot height and density, and rhizome length. That plant biomass reductions were followed by a decrease in the abundance of the dominant infaunal tanaidacean Monokalliapseudes schubarti, indicating that algal impacts on seagrasses were transferred to higher trophic levels. Our results suggest that, although unstable deposition of drift algal mats can attenuate potential adverse impacts at the sediment-water interface, the physical stress during mats advection can still trigger small seagrass losses. This process may diminish the resilience of R. maritima meadows in the PLE, with impacts on estuarine nutrient cycling and secondary production. We conclude that, although harmful drift macroalgal blooms area global phenomenon, the mechanisms through which macroalgae impair seagrass habitats may vary according to the environmental context. Therefore, further studies are necessary to identify the underlying mechanisms of drift macroalgae-seagrass-macrofauna interactions in high hydrodynamic systems and their generality across distinct biogeographical areas.

The Bisindole Alkaloid Caulerpin, from Seaweeds of the Genus Caulerpa, Attenuated Colon Damage in Murine Colitis Model.

Caulerpin (CLP), an alkaloid from algae of the genus Caulerpa, has shown anti-inflammatory activity. Therefore, this study aimed to analyze the effect of CLP in the murine model of peritonitis and ulcerative colitis. Firstly, the mice were submitted to peritonitis to evaluate which dose of CLP (40, 4, or 0.4 mg/kg) could decrease the inflammatory infiltration in the peritoneum. The most effective doses were 40 and 4 mg/kg. Then, C57BL/6 mice were submitted to colitis development with 3% dextran sulfate sodium (DSS) and treated with CLP at doses of 40 and 4 mg/kg. The disease development was analyzed through the disease activity index (DAI); furthermore, colonic tissue samples were submitted to histological analysis, NFκB determination, and in vitro culture for cytokines assay. Therefore, CLP at 4 mg/kg presented the best results, triggering improvement of DAI and attenuating the colon shortening and damage. This dose was able to reduce the TNF-α, IFN-γ, IL-6, IL-17, and NFκB p65 levels, and increased the levels of IL-10 in the colon tissue. Thus, CLP mice treatment at a dose of 4 mg/kg showed promising results in ameliorating the damage observed in the ulcerative colitis.

Influence of dissolved organic matter and oil on the biosorption of BTEX by macroalgae in single and multi-solute systems.

The effect of dissolved organic matter (DOM) and oil on the removal of the water-soluble compounds benzene, toluene, ethylbenzene, and xylene isomers (BTEX) by two low-cost biosorbents Macrocystis pyrifera and Ulva expansa) was evaluated. DOM decreased the adsorption capacity of toluene, ethylbenzene, and xylenes of the two biosorbents. In contrast, the removal of benzene increased under the same conditions in single and multi-solute systems: this effect was dominant in U. expansa biomass treatments. In the presence of DOM and oil in solutions, the removal of BTEX notoriously increased, being oil that contributed the most. Solubility and hydrophobicity of pollutants played a key role in the adsorption process. The attractions between BTEX molecules and biosorbents were governed by π-π and hydrophobic interactions. Affinities of biosorbents for BTEX were mainly in the order of X > E > T > B. The Langmuir and Sips equations adjusted the adsorption isotherms for BTEX biosorption in deionized and natural water samples, but in the case of oily systems, the Freundlich equation seemed to have a better fit. The biosorption processes followed a pseudo-second-order rate in all the cases.

Comparison of dairy desserts produced with a potentially probiotic mixed culture and dispersions obtained from Gracilaria birdiae and Gracilaria domingensis seaweeds used as thickening agents.

Dairy desserts have emerged as interesting options for the incorporation of probiotics, bioactive ingredients and alternative sources of thickeners. This shows an opportunity to investigate the use of Gracilaria seaweeds in the formulation of potentially probiotic dairy desserts. This study aimed to compare the effects of dispersions obtained from Gracilaria domingensis and Gracilaria birdiae used as thickening agents on texture properties of dairy desserts fermented with SAB 440-A, composed of the starter Streptococcus thermophilus and the potential probiotics Bifidobacterium animalis and Lactobacillus acidophilus, and also to study their physicochemical characteristics, microbial viability and sensory acceptability. No significant differences between desserts with G. birdiae or G. domingensis dispersions regarding total solids, ash and fat content, as well as pH, titratable acidity, the viability of the microorganisms of the mixed culture and sensory acceptability were verified (P > 0.05). Nonetheless, the dessert with G. domingensis dispersion showed higher dietary fibre content and significantly increased firmness than the one produced with G. birdiae (P < 0.05). Moreover, B. animalis was able to maintain higher populations, above 7 log cfu g-1 during 21 days of storage of desserts, in the presence of either G. birdiae or G. domingensis dispersions, despite the fact that L. acidophilus has shown low viability in the final products. Therefore, the G. domingensis dispersion is suitable to be used as a thickening agent to produce dairy desserts with enhanced firmness and good sensory acceptability, it being also advisable to use only B. animalis as a probiotic for this product.

Expression profile of desiccation tolerance factors in intertidal seaweed species during the tidal cycle.

MAIN CONCLUSION: The transcriptional modulation of desiccation tolerance factors in P. orbicularis explains its successful recuperation after water deficit. Differential responses to air exposure clarify seaweed distribution along intertidal rocky zones. Desiccation-tolerant seaweed species, such as Pyropia orbicularis, can tolerate near 96% water loss during air exposure. To understand the phenotypic plasticity of P. orbicularis to desiccation, several tolerance factors were assessed by RT-qPCR, Western-blot analysis, and enzymatic assays during the natural desiccation-rehydration cycle. Comparative enzymatic analyses were used to evidence differential responses between P. orbicularis and desiccation-sensitive species. The results showed that during desiccation, the relative mRNA levels of genes associated with basal metabolism [trehalose phosphate synthase (tps) and pyruvate dehydrogenase (pdh)] were overexpressed in P. orbicularis. Transcript levels related to antioxidant metabolism [peroxiredoxin (prx); thioredoxin (trx); catalase (cat); lipoxygenase (lox); ferredoxin (fnr); glutathione S-transferase (gst)], cellular detoxification [ABC transporter (abc) and ubiquitin (ubq)], and signal transduction [calmodulin (cam)] increased approximately 15- to 20-fold, with the majority returning to basal levels during the final hours of rehydration. In contrast, actin (act) and transcription factor 1 (tf1) transcripts were down-regulated. ABC transporter protein levels increased in P. orbicularis during desiccation, whereas PRX transcripts decreased. The antioxidant enzymes showed higher specific activity in P. orbicularis under desiccation, and sensitive species exhibited enzymatic inactivation and scarce ABC and PRX protein detection following prolonged desiccation. In conclusion, the reported findings contribute towards understanding the ecological distribution of intertidal seaweeds at the molecular and functional levels.

The brown seaweed Sargassum cymosum: changes in metabolism and cellular organization after long-term exposure to cadmium.

Sargassum cymosum was exposed to cadmium (Cd) to determine any physiological and ultrastructural effects. To accomplish this, S. cymosum samples were cultivated under photosynthetic active radiation (PAR) and Cd (0, 0.1, 0.2, 0.4 and 0.8 mg L-1) during 7 and 14 days in laboratory-controlled conditions (0 mg L-1 Cd at both exposure times as control). Seaweeds had high retention capacity (over 90 %) for both exposure times. Growth rates showed significant increases by 14 days, especially for 0.1 and 0.4 mg L-1 Cd. Photosynthetic parameters were unaffected by Cd treatments. Chlorophyll contents were present in higher concentrations for all Cd treatments compared to respective control. Carotenoid profile showed significant differences in total composition and proportion of fucoxanthin and ß-carotene, and no lutein was detected at 14 days. Phenolic and flavonoid compounds showed major accumulation at 14 days. Transmission electron microscopy (TEM) analyses presented major alterations in Cd-treated samples, when compared with respective control, in particular disorganization of cell wall fibrils. When compared to respective control samples, multivariate analyses showed disparate and complex interactions among metabolites in Cd-exposed seaweeds, giving evidence of physiological defence response. Thus, it can be concluded that Cd is a stressor for S. cymosum, resulting in physiological and structural alterations related to defence mechanisms against oxidative stress and toxicological effects resulting from long-term metal exposure. However, in the present paper, some observed changes also appear to result from acclimation mechanisms under lower concentration of Cd relative to the tolerance of S. cymosum to experimental conditions.

De novo transcriptome analysis of the red seaweed Gracilaria chilensis and identification of linkers associated with phycobilisomes.

This work reports the results of the Illumina RNA-Seq of a wild population of female haploid plants of Gracilaria chilensis (Bird et al., 1986) (Rhodophyta, Gigartinalis). Most transcripts were de novo assembled in 12,331 contigs with an average length of 1756bp, showing that 96.64% of the sequences were annotated with known proteins. In particular, the identification of linker proteins of phycobilisomes (PBS) is reported. Linker proteins have primary been identified in cyanobacteria but the information available about them in eukaryotic red alga is not complete, and this is the first report in G. chilensis. This resource will also provide the basis for the study of metabolic pathways related to polysaccharide production.

Assessment oxidative stress biomarkers and metal bioaccumulation in macroalgae from coastal areas with mining activities in Chile.

The aim of this study was to evaluate the effect on seaweeds Scytosiphon lomentaria and Ulva rigida of coastal waters of sites with mining activity, using oxidative stress biomarkers and heavy metal determination both in water and in tissue. The greatest bioaccumulation factors in S. lomentaria and U. rigida were founded for iron and arsenic in Quintay. Bioaccumulation factor in S. lomentaria in descending order was Fe> Cu> Zn> Cd> Cr> As> Mo and in U. rigida, in descending order, was Fe> Cu> Cd> Zn> Cr> Mo> As. Both species had higher antioxidant activity levels in areas with high mining activities. The concentration of metals in waters such as copper and arsenic in S. lomentaria, and iron, arsenic, and cadmium in U. rigida were related with oxidative stress biomarkers measured in both species. The use of both species is proposed to monitor the bioavailability and oxidative damage in coastal areas with mining activity. This work will generate a significant knowledge about the impact of mining wastes on macroalgal community in the area of north-central Chile.