Brazilian Seaweed Research Articles

Antioxidant potential of two Brazilian seaweeds in response to temperature: Pyropia spiralis (red alga) and Sargassum stenophyllum (brown alga)

Natural antioxidants found in macroalgae represent a significant protective role against oxidative damage. The antioxidant capacity responses to abiotic stresses allow understanding the tolerance and sensitivity of the species. Pyropia and Sargassum inhabiting the intertidal zone exhibit several antioxidant mechanisms against oxidative stress stimulated by environmental factors, such as thermal stress. In this study, we evaluated the antioxidant capacity under different temperatures of the red macroalga Pyropia spiralis and the brown macroalga Sargassum stenophyllum, associated with the composition of mycosporine-like amino acids (MAAs) and phenolic compounds. Antioxidant capacity was determined by four antioxidant assays (ABTS: 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid); DPPH: 2,2-diphenyl-1-picryl-hydrazyl; FRAP: ferric reducing antioxidant power, and metal chelating). Phenolic compounds content was assessed using Folin-Ciocalteau reagent and HPLC, and MAAs using HPLC. In both species, the ABTS assay was the most sensitive antioxidant assay. At low temperature (15 °C), P. spiralis exhibited the lowest EC50 (half maximal effective concentration) in the ABTS assay, the highest total antioxidant capacity index, and high content of MAAs (porphyra-334, shinorine, and palythine). For S. stenophyllum, the lowest EC50 value for ABTS assay was registered at 15 °C, and the lowest total antioxidant capacity index at 30 °C with high content of phlorotannins, probably phloroethols. The information provided by this research may be useful for the study of thermal tolerance and sensitivity in marine macroalgae as well as a template for further investigations of designing phytochemicals in marine macroalgae.

Beta-1,3-glucanase inhibitors in Brazilian brown seaweed.

Beta-1,3-glucanases are enzymes that hydrolyze beta-1,3-glucans, and they are essential for the metabolism of seaweed, plants and fungi. These enzymes also participate in the digestion of herbivore and fungivore animals. Because of the importance of these enzymes in insects, beta-1,3-glucanase inhibitors may be used for the development of new control strategies against agricultural pests and disease vectors. Beta-1,3-glucanase inhibitors have been described in the brown seaweed Laminaria cichorioides, but were never recorded in Brazilian seaweed species. We evaluated the presence of beta-1,3-glucanase inhibitors in samples of Padina gymnospora, Dictyota sp., Colpomenia sinuosa, and Lobophora sp., collected in Arraial d'Ajuda (Bahia). Ethanolic or buffer extracts were used in inhibition tests against the beta-1,3-glucanase of Trichoderma sp. Extracts in buffer showed no inhibition, but ethanolic extracts from all species showed different extents of inhibition. Samples from Dictyota sp. and P. gymnospora showed inhibitions above 75% (absolute ethanol) or 50% (ethanol 50%). In summary, extraction with absolute ethanol resulted in better inhibitions, and P. gymnospora showed the higher inhibitions. Brazilian seaweed may be good sources of beta-1,3-glucanase inhibitors for biochemical and physiological studies of these enzymes. Besides that, these molecules show potential for the development of new biotechnological tools for insect control.

Seaweed resources of Brazil: what has changed in 20 years?

Abstract In 1998 Critchley and Ohno published the book Seaweed resources of the world presenting a synthesis of knowledge on the subject from different regions and countries globally. One chapter by E.C. Oliveira was focused on Brazil. In this article, we present an update of the economically relevant species of Brazilian seaweeds, and their distribution along the coastline, and what has changed over 20 years in the status of the exploited resources, the new species with commercial potential, and relevant legislation. The only introduced commercial species, Kappaphycus alvarezii, was economically exploited for a while in Rio de Janeiro State, but nowadays there are no commercial activities on a large scale. Gracilaria farms in the northeast are still on an artisanal scale, but the expansion of activity is compromised by legal and bureaucratic barriers. Regulations related to the exploitation of natural beds and to the introduction of new strains of K. alvarezii were created between 2006 and 2008. At the end of this article, we present a reflection of what lessons have been learned and what are the prospects for seaweed cultivation in Brazil.

Temporal stability in lipid classes and fatty acid profiles of three seaweed species from the north-eastern coast of Brazil

Lipid and fatty acid profiles provide nutritional information of marine algae, but the analysis of algal fatty acid composition has also been proposed as a chemotaxonomic tool. Although the total lipid (TL) content of macroalgae is usually only 1–6% dry weight (DW), much lower than in microalgae, some species can accumulate interesting long-chain polyunsaturated fatty acids (LC-PUFA) which are essential fatty acids, not produced by humans or animals, that show beneficial health effects. This study aimed to evaluate the lipid and fatty acid profiles of three Brazilian seaweeds, Sargassum vulgare (Ochrophyta), Palisada flagellifera (Rhodophyta), and Ulva fasciata (Chlorophyta) collected from the north-east of Brazil at two seasons (dry and rainy). Lipid and fatty acid profiles in the three macroalgae were stable across seasons. The total fatty acid (TFA) contents of S. vulgare and U. fasciata ranged from 1.3 to 1.5% DW, with the main fatty acids represented by palmitic and oleic acids; however, there was no large accumulation of LC-PUFA. By contrast, P. flagellifera exhibited a lower TFA content (0.8–0.9% DW), but eicosapentaenoic and arachidonic acids accounted for 15–16% and 16–20% of TFA, up to 1.5 and 1.9 mg g-1 DW, respectively. In all species, glycolipids were the most abundant lipid class (60–70%), followed by phospholipids (10–25%), and neutral lipids (10–15%). The composition of each lipid fractions demonstrated that fatty acid profiles of each lipid class were highly species-specific, and lipid profiles were indicative of tropical species. Based on these algae lipid profiles, P. flagellifera could be considered a good source of omega-3 (LC-PUFA). The seasonal stability in the lipid content and fatty acid profiles confers a strong advantage for potential exploitation of those species in the north-eastern regions of Brazil, representing a source of algal biomass with constant biochemical composition all year-round.

Seasonal effects on antioxidant and anti-HIV activities of Brazilian seaweeds

In recent years phytotherapy has been encouraged by Brazilian government agencies and has gained more and more credibility as a way of alternative therapy to complement allopathy. Although little explored in Brazil, seaweeds are promising marine bioresources as herbal medicine. In this context, the aim of the present study was to evaluate the antioxidant activities and reverse transcriptase inhibition (RT-HIV) of crude extracts (methanolic, aqueous, and hot aqueous) from three abundant species in Brazilian rocky shores, Sargassum vulgare (Ochrophyta), Palisada flagellifera (Rhodophyta), and Ulva fasciata (Chlorophyta), under two seasons (dry and rainy). Methanolic extracts from S. vulgare (EC50 = 18.22 ± 2.91 μg mg−1, dry), P. flagellifera (EC50 = 24.85 ± 3.13 μg mg−1, rainy), and U. fasciata (EC50 = 33.41 ± 1.53 μg mg−1, dry) showed the highest β-carotene bleaching activities, while hot aqueous extracts from S. vulgare showed the highest RT-HIV inhibition and antioxidant activities in ABTS, FRAP, and Folin-Ciocalteu assays. In general, the three macroalgae showed considerable antioxidant effects; however, only S. vulgare showed an anti-HIV potential (IC50 10.15 ± 1.77 mg mL−1 for the dry season and IC50 = 22.41 ± 5.74 μg mL−1 for rainy season). Regarding both extract yields and bioactivities, S. vulgare in the rainy season was the most promising alga. In conclusion, the studied seaweeds may be an effective alternative for Brazilian herbal medicine; additionally, seasonal studies are essential, since there were significant differences mainly for extract yields.

<b>Extraction, physical-chemical characterization and <i>in vitro</i> inhibitory potential of thrombin generation of crude sulfated polysaccharides from Brazilian tropical seaweeds

The biotechnological value of macroalgae for screening assays of thrombin generation-TG using sulfated polysaccharides-SPs as substitutes to heparin has been poorly explored. Five Brazilian species of macroalgae ( Gracilaria birdiae , Acanthophora muscoides , Halymenia sp., Caulerpa cupressoides and C. racemosa ) were analyzed and compared for their abundance, physical-chemical characteristics and in vitro anticoagulant assays of activated partial thromboplastin time-APTT, prothrombin time-PT and TG. Papain extraction yielded (p 100 kDa. These procedures, combined with the use of Stains-All, also indicated nonSPs. APTTs ranged from 2.81 ( A. muscoides ) to 21.30 IU ( Halymenia sp.) vs. heparin (193 IU), and were dependent on sulfation of the crude SPs. PT was not altered. With respect to TG assay, crude SPs modified concentration-dependent and independently from molecular mass TG by both intrinsic/extrinsic pathways in 60-fold diluted human plasma, with total intrinsic inactivation using crude SPs from A. muscoides in parallel to heparin (p < 0.05). Thrombosis in vitro is differentially modulated by distinct crude SPs from Brazilian seaweeds.

Sargassum filipendula alginate from Brazil: Seasonal influence and characteristics

The aim of this work is focused on the extraction and characterization of the Brazilian seaweed Sargassum filipendula alginate. Alginates obtained at different seasons were characterized by liquid state nuclear magnetic resonance spectroscopy and scanning electron microscopy. The alginate extraction efficiency was about 20%. Different seasons of the year and different stages in the life cycle of Sargassum sp. in southeastern Brazil influenced the M/G and, consequently, the technological properties of extracted alginates.

Seaweed biotechnology in Brazil: six decades of studies on natural products and their antibiotic and other biological activities

The Brazilian seaweed assemblage currently comprises 770 taxa, distributed along 7,367 km of coastline with highly diverse ecological conditions, suggesting a high biotechnological potential for these species. Studies on seaweed biotechnology in Brazil began in 1948 and have produced extensive published information that is presently scattered in many sources. This manuscript presents an overview of biotechnology studies on seaweeds that were carried out in Brazil, from the earliest through 2012, with the purpose of directing new studies in this field. The studies analyzed were retrieved from the curricula of Brazilian seaweed researchers, centralized in the public database Curriculo Lattes, supported by the Brazilian National Council of Technological and Scientific Development (CNPq). Scientific papers dealing with biological activities of natural extracts from native and some non-native seaweeds were selected. The survey was complemented by a search for older references cited in the first group. Together, the studies extend over 64 years, totaling 364 scientific papers investigating the potential of 160 seaweed taxa, including tests for 6 antibiotic activities, 11 categories of other biological activities, and a wide range of natural products. In general, the studies focused on antiinflammatory, antinociceptive, and antiviral activities, and some characterized the effects of molecules, including sulfated polysaccharides, lectins, and terpenes.

Chemical analysis and toxicity of seaweed extracts with inhibitory activity against tropical fruit anthracnose fungi

Banana and papaya are among the most important crops in the tropics, with a value amounting to millions of dollars per year. However, these fruits suffer significant losses due to anthracnose, a fungal disease. It is well known that certain seaweed extracts possess antifungal activity, but no published data appear to exist on the practical application of this property. In the present study, five organic Brazilian seaweed extracts were screened for their activity against banana and papaya anthracnose fungi. Furthermore, cytotoxic and mutagenic effects of the extracts were evaluated by the brine shrimp lethality assay and the Allium cepa root-tip mutagenicity test respectively, while their major components were identified by gas chromatography/mass spectrometry. Strong fungus-inhibitory effects of Ochtodes secundiramea and Laurencia dendroidea extracts were observed on both papaya (100 and 98% respectively) and banana (89 and 78% respectively). This impressive activity could be associated with halogenated terpenes, the major components of both extracts. Only Hypnea musciformis extract showed cytotoxic and mutagenic effects. The results of this study suggest the potential use of seaweed extracts as a source of antifungal agents with low toxicity to control anthracnose in papaya and banana during storage.

Antiviral activity of extracts from Brazilian seaweeds against herpes simplex virus

Organic extracts of 36 species of marine algae (sixteen species of Rhodophyta, eight species of Ochrophyta and twelve species of Chlorophyta) from seven locations on the Brazilian coast were evaluated for their anti-HSV-1 and anti-HSV-2 activity resistant to Acyclovir (ACV). Activity tests in crude extracts, followed by the identification of the major compounds present, were performed for all species. The chemical profiles of all crude extracts were obtained by ¹H-NMR and 13C-NMR spectroscopy. The percentage of extracts with antiviral activity was higher for HSV-1 (86.1%) than for HSV-2 (55.5%). The green algae Ulva fasciata and Codium decorticatum both showed the highest activity (99.9%) against HSV-1, with triacylglycerols and fatty acids as the major components. The red alga Laurencia dendroidea showed good activity against HSV-1 (97.5%) and the halogenated sesquiterpenes obtusol and (-)-elatol were identified as the major components in the extract. Against HSV-2, the green alga Penicillus capitatus (Chlorophyta) and Stypopodium zonale (Ochrophyta) were the most active (96.0 and 95.8%). Atomaric acid, a meroditerpene, was identified as the major secondary metabolite in the S. zonale extract. These results reinforce the role of seaweeds as important sources of compounds with the potential to enter into the pipeline for development of new drugs against herpes simplex.

Comparison of extraction and transesterification methods on the determination of the fatty acid contents of three Brazilian seaweed species

Seaweeds are photosynthetic organisms important to their ecosystem and constitute a source of compounds with several different applications in the pharmaceutical, cosmetic and biotechnology industries, such as triacylglycerols, which can be converted to fatty acid methyl esters that make up biodiesel, an alternative source of fuel applied in economic important areas. This study evaluates the fatty acid profiles and concentrations of three Brazilian seaweed species, Hypnea musciformis (Wulfen) J.V. Lamouroux (Rhodophya), Sargassum cymosum C. Agardh (Heterokontophyta), and Ulva lactuca L. (Chlorophyta), comparing three extraction methods (Bligh & Dyer - BD AOAC Official Methods - AOM; and extraction with methanol and ultrasound - EMU) and two transesterification methods (7% BF3 in methanol - BF3; and 5% HCl in methanol - HCl). The fatty acid contents of the three species of seaweeds were significantly different when extracted and transesterified by the different methods. Moreover, the best method for one species was not the same for the other species. The best extraction and transesterification methods for H. musciformis, S. cymosum and U. lactuca were, respectively, AOM-HCl, B&D-BF3 and B&D-BF3/B&D-HCl. These results point to a matrix effect and the method used for the analysis of the fatty acid content of different organisms should be selected carefully.

Screening for antifungal activities of extracts of the brazilian seaweed genus Laurencia (Ceramiales, Rhodophyta)

The resistance of pathogens to commonly used antibiotics has enhanced morbidity and mortality and has triggered the search for new drugs. Several species of the red alga genus Laurencia are very interesting candidates as potential sources of natural products with pharmaceutical activity because they are known to produce a wide range of chemically interesting halogenated secondary metabolites. This is an initial report of the antifungal activities of the secondary metabolites of five species of Laurencia, collected in the state of Espirito Santo, against three strains of pathogenic fungi: Candida albicans (CA), Candida parapsilosis (CP), and Cryptococcus neoformans (CN). Minimum inhibitory concentrations (MIC) of the algal extracts were determined by serial dilution method in RPMI 1640 Medium in 96-well plates according to the NCCLS and microbial growth was determined by absorbance at 492nm. A result showing maintenance or reduction of the inoculum was defined as fungistatic, while fungicidal action was no observed growth in the 10 µL fungistatic samples subcultured in Sabouraud Agar. Our results indicate that apolar extracts of Laurencia species possess antifungal properties and encourage continued research to find new drugs for therapy of infectious diseases in these algae.

Photosynthetic properties of three Brazilian seaweeds

Photosynthetic performance of distinct marine macroalgae, Ulva fasciata Delile (green alga), Lobophora variegata (J. V. Lamouroux) Womersley ex E. C. Oliveira (brown alga), and Plocamium brasiliensis (Greville) M. A. Howe & W. R. Taylor (red alga), were compared using a pulse amplitude-modulated fluorometer. The maximum quantum yield (Fv/Fm) ranged from 0.80 to 0.51, and the lowest value was found in P. brasiliensis. Under 400 µmol photons m-2 s-1 irradiance, the highest value of photochemical quenching (qP = 0.92 ± 0.13) was observed for U. fasciata. The red alga P. brasiliensis dissipated high amounts of excitation energy (qN = 0.56 ± 0.09), resulting in relatively low values for the effective quantum yield of PS-II (0.23 ± 0.04), as well as for the relative electron transport rate (3.3 ± 0.7). The high photosynthetic potential found for U. fasciata partially explains the species ability for rapid growth and high productivity.

Antifouling activity of natural products from Brazilian seaweeds

Abstract Antifouling chemical defense is likely an evolutionary response to the ecological disadvantages of epibiosis, particularly for photosynthetic organisms. Seaweed natural products with antifouling activity can provide effective, environmentally friendly alternatives to currently used antifouling paint booster biocides. The aim of this work was to assess the antifouling potential of natural products from Brazilian littoral seaweeds. Crude organic extracts from 51 populations comprising 42 species of macroalgae from eight locations along the Brazilian coast were tested against a relevant fouling organism in laboratory bioassays, the brown mussel Perna perna. In five cases, antifouling activities of purified compounds were also tested. A total of nine macroalgae were also cultured and tested for the presence of inducible defenses against fouling. Ecologically relevant field tests were performed in 11 cases to confirm laboratory results. Despite the unbalanced number of macroalgae tested among different localities, there seems to be no latitudinal trend of increased antifouling activity towards lower latitudes, where fouling pressure is presumed to be higher. However, there was a clear phylogenetic pattern in antifouling activity, with red macroalgae having the highest proportion (55%) of active species (moderate or strong fouling inhibition), followed by brown macroalgae (14%). Green seaweeds never exhibited strong antifouling activity (≥80% inhibition of byssal attachment relative to controls). Some degree of induced antifouling defense was observed in seven species (78%). These results appear to support known trends of secondary metabolite production among seaweeds and suggest that research efforts should be focused on tropical red macroalgae in the quest for new antifoulants. On the other hand, it seems clear that macroalgal groups, such as green algae, must have mechanisms of defenses against fouling that are not chemical.

Potential cytotoxic activity of some Brazilian seaweeds on human melanoma cells

In vitro screening of the crude extracts of some Brazilian coastal seaweeds for cytotoxic activity against a cultured human melanoma cancer cell line using the sulphorhodamine B assay was performed. The crude dichloromethane:chloroform extract of Stypopodium zonale showed good cytotoxic activity against the C32 cell line. The crude acetone extract and aqueous phase of Lobophora variegata did not show any activity, but semi-purified fractions XAD LOB I and II could inhibit the growth of melanoma cells. The crude acetone extract of Caulerpa racemosa showed some cytotoxicity, but caulerpin isolated from this extract did not show any such activity. The crude acetone extract of Spatoglossum schroederi was not able to inhibit the growth of C32 melanoma cells.

α-Amylase inhibitors from Brazilian seaweeds and their hypoglycemic potential

The acetone crude extract of Lobophora variegata did not show any α-amylase inhibition activity. On the contrary, acetone crude extract of both Spatoglossum schroederi and Caulerpa racemosa inhibited the enzyme activity, with an ED 50 of 0.58 and 0.09 mg/ml.

Effects of iota-carrageenan on the rheological properties of starches

The phycocolloid iota-carrageenan (ι-CAR) was extracted from the Brazilian seaweed Meristiella gelidium. At a concentration of 5 mg ml −1 it was mixed with solutions of common corn starch (CS), high amylose starch (MS), waxy corn starch (WS) and YS starch (YS), to give systems at a final concentration of 25 g l −1, which were subjected to rheological measurements. Each mixture gave rise to a different behaviour under dynamic rheological conditions showing a distinct degree of interaction between ι-CAR and the starch. The presence of ι-CAR in ι-CAR-WS, ι-CAR-MS and ι-CAR-CS systems resulted in synergy manifested as enhancements in thermal stability (absence of hysteresis), resulting in thermoreversible gels softer and more stable between 45 and 85 °C. In the ι-CAR-YS system, the synergistic effect occurred as an improvement in solid character, increasing the elastic nature of the gel, suggesting that the structural characteristic of YS, more regular structure with amylopectin having a low molar mass, can contribute to enhanced intermolecular binding.

Is the Mussel Test a good Indicator of Antifouling Activity? A Comparison Between Laboratory and Field Assays

Current antifouling technologies rely on metal-based paints, but due to their toxicity, an expected worldwide ban of organotin-containing paints is now prompting the quest for safe and effective alternatives. One of these is antifouling coatings whose active components are naturally occurring compounds in marine organisms. A number of laboratory bioassays has been designed to search for antifouling compounds. However, there is no evidence to date that these assays provide results reproducible through ecologically realistic field experiments. Natural concentrations of the extracts from the Brazilian seaweeds Laurencia obtusa and Stypopodium zonale were tested in the laboratory through the 'mussel test' and in the field through the 'phytagel method' in order to compare the efficiency of these methods in assessing antifouling activity. L. obtusa extract significantly inhibited fouling in both the laboratory and field assays, while S. zonale stimulated fouling in both assays. Major compounds from the extracts were identified. The findings suggest that the 'mussel test' is a reliable time and cost-saving screening method for antifouling substances, although field assays are more sensitive for detection of their activity spectrum.

An annotated list of the Brazilian seaweeds in Dickie's herbarium

The Brazilian seaweeds studied by G. Dickie (1874) have been critically reviewed and several names corrected according to new taxonomic concepts. Some doubtful records have been indicated.

A Study of Agar from Two Brazilian Seaweeds

American Journal of BotanyVolume 35, Issue 5 p. 287-292 Article A STUDY OF AGAR FROM TWO BRAZILIAN SEAWEEDS H. J. Humm, H. J. Humm Duke University, Marine Laboratory, Beaufort, North CarolinaSearch for more papers by this authorL. G. Williams, L. G. Williams Duke University, Marine Laboratory, Beaufort, North CarolinaSearch for more papers by this author H. J. Humm, H. J. Humm Duke University, Marine Laboratory, Beaufort, North CarolinaSearch for more papers by this authorL. G. Williams, L. G. Williams Duke University, Marine Laboratory, Beaufort, North CarolinaSearch for more papers by this author First published: 01 May 1948 https://doi.org/10.1002/j.1537-2197.1948.tb08078.xCitations: 8AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume35, Issue5May 1948Pages 287-292 RelatedInformation