Abstract: Sargassummuticum is a brown seaweed with strong potential to be used as a functional food ingredient, mainly due to its antioxidant properties. It is widely used in traditional oriental medicine for the treatment of numerous diseases. Nevertheless, few studies have been conducted to add scientific evidence on its effects as well as on the mechanisms of action involved. In this work, the human cell line MCF-7 was used as an in vitro cellular model to evaluate the capability of Sargassummuticum enriched fractions to protect cells on an oxidative stress condition. The concentration of the bioactive compounds was obtained by vacuum liquid chromatography applied on methanol (M) and 1:1 methanol:dichloromethane (MD) crude extracts, resulting in seven enriched fractions from the M extraction (MF2–MF8), and eight fractions from the MD extraction (MDF1–MDF8). All fractions were tested for cytotoxic properties on MCF-7 cells and the nontoxic ones were tested for their capacity to blunt the damaging effects of hydrogen peroxide-induced oxidative stress. The nontoxic effects were also confirmed in 3T3 fibroblast cells as a nontumor cell line. The antioxidant potential of each fraction, as well as changes in the cell’s real-time hydrogen peroxide production, in the mitochondrial membrane potential, and in Caspase-9 activity were evaluated. The results suggest that the protective effects evidenced by S. muticum can be related with the inhibition of hydrogen peroxide production and the inhibition of Caspase-9 activity.
Interspecific competition among macroalgae is most often for light (through shading), major nutrients (often nitrogen or phosphate), or space (through domination of the substratum). Sargassummuticum is likely to be a strong competitor for light because it has a tall, positively buoyant thallus, extending as high as 4 m into the water column in subtidal habitats, although it tends to be much shorter in the intertidal zone (up to 2 m). Indeed, many authors have speculated that shading by S. muticum was the mechanism underlying effects on native algae (e.g., Ambrose & Nelson 1982, Sánchez et al. 2005). However, few studies have quantified resource availability in experiments to evaluate which resources are involved in interactions between S. muticum and native algae. Critchley et al. (1990) and Strong et al. (2006) found that surface photosynthetically active radiation (PAR) was reduced by 97% in the uppermost 0.1 m within a dense S. muticum meadow where the fronds extended to the water surface. Manipulative field experiments on the western coast of Vancouver Island, Canada, demonstrated density-dependent effects of S. muticum on macroalgal richness through light competition by shading smaller, understory macroalgae (White & Shurin 2011). Likewise, Britton-Simmons (2004) showed that removal of S. muticum increased light transmission to the substratum by 30–75%. The shading effect varies seasonally, depending on the development of S. muticum fronds, with the most intense shading in late spring (southern Europe) to midsummer (northern Europe) according to the period in which the species reaches the annual largest size (Fernández 1999, Stæhr et al. 2000). If this period coincides with the period of growth of native macroalgae, such as Gelidium spinosum in northern Spain (Sánchez et al. 2005), the effect may be severe. Because the holdfast of Sargassummuticum is relatively small (approximately 2 cm in diameter in large specimens), it seems unlikely that S. muticum would be a strong competitor for primary substratum, except where it occurs at very high densities. Britton-Simmons (2004) found no evidence that S. muticum altered nutrient availability, sedimentation, or water flow. Strong et al. (2006) obtained similar results, finding no difference in sedimentation or reduction in water flow due to S. muticum compared with a native species (Saccharina latissima). Although the measurements of these variables were limited in space and time, they are the only data currently available for these factors. Thus, existing evidence suggests that any negative effects of Sargassummuticum on native algae are mainly due to competition for light, but with a possible role for allelopathy.
The aim of the present study was to assess the underlying demographic traits that determined the population growth of the brown invasive seaweed Sargassummuticum (Yendo) Fensholt (Fucaceae) in two conditions of dominance over the native competitor, Cystoseira humilis in intertidal pools dominated by the native and the invader species, respectively. A detailed demographic analysis of the species was performed at its southern distribution limit in the east Atlantic, on the south-west coast of Portugal, where the expansion of the species range has been recorded. In order to speculate about the demographic mechanisms that determine the invasiveness of S. muticum , we assumed that C. humilis pools were a proxy for an early phase of invasion (only a few S. muticum individuals present), whereas S. muticum pools were a proxy for a late phase of invasion (dominated by an almost monospecific stand of the invader). Specifically, we asked: (i) does the popu- lation growth rate of S. muticum vary with dominance level? (ii) what are the demographic traits that contribute most to the invader’s population growth rate? and (iii) does the relative importance of those traits shift between C. humilis- and S. muticum -dominated pools? To address the first question, both the invader’s population growth rate and its reproductive value, that is, the contribution of each life cycle stage to the next generation, were compared between pool types. The second and third questions were addressed through elasticity analysis of the demographic traits in both pool types.
The introduction of non-indigenous macroalgae causes many serious ecological impacts affecting native marine com- munities, eroding biodiversity and modifying and/or disrupting the normal functioning of ecosystems (Schaffelke and Hewitt 2007; Bedini et al. 2015; Smith 2016). However, in some cases, the effects are not detectable or even positive (Thomsen 2010; Guerra-García et al. 2012; Thomsen et al. 2013). For example, some invasive habitat formers may be considered as sources of valuable ecosystem functions where native foundation species have been lost (Ramus et al. 2017). Sargassummuticum (Yendo) Fensholt is a habitat-forming brown alga native from south-east Asia and recorded in Morocco since 2011 (Sabour et al. 2013). However, it has re- ceived very little attention despite being common in rocky in- tertidal habitats in the region of El Jadida (Belattmania et al. 2018a, b). S. muticum thalli can grow to lengths of up to 5 m (Sabour et al. 2013), and they are composed of two distinct parts: a perennial part, which contains the holdfast and one or more short main axes; and an annual part, consisting of variably sized secondary axes. S. muticum has a pseudo-perennial life cycle comprising a winter phase with a moderate growth rate and a faster growth phase during spring (Wernberg et al. 2004). This algal species has been introduced in Europe in the early 1970s and is currently widespread in numerous regions worldwide (Engelen et al. 2015). S. muticum has many char- acteristics that make it a successful invader, including high growth rates; rapid colonization of space; tolerance to temper- atures between − 1 °C and 30 °C and survival in salinities below 10‰; high photosynthetic rates; copious reproduction, including asexual and self-fertilization strategies and efficient multiple dispersal mechanisms due to floating and drifting fertile thalli; and high habitat complexity (Norton 1976, 1977a, b; Critchley 1983; Hales and Fletcher 1989; Viejo 1997). The low tolerance of S. muticum to desiccation pre- cludes colonization of regularly emerged littoral areas (Norton 1977a). The optimal tidal zone for S. muticum establishment is the extreme lower shore and shallow sublittoral fringe (Harries
The present study addresses the disentanglement of spatial and temporal shifts in seaweed associated bacterial communities among different seaweed structures using the pseudo-peren- nial invasive brown seaweed Sargassummuticum as a case study. This brown alga is one of the most invasive macroalgae in the northern hemisphere, but its invasive success is not yet entirely understood . Microbiota might play a key role in the acclimatization of this non- native seaweed, but it has been so far poorly examined. As detailed before, several studies indeed showed that bacterial seasonal variations are driven by environmental factors, notably seawater temperature. Seawater temperature data from southern to northern Portugal clearly demonstrate that there is a much larger variation in temperature between seasons in the North as compared to the South . We thus hypothesized that microbial communities associated to S. muticum would show combined effects of spatio-temporal differences, but that these dif- ferences also depend on the seaweed structure/part examined. Next-generation sequencing of the variable regions V5-V7 of bacterial 16S rDNA genes was applied to characterize the diver- sity of associated microbiota and describe differences in microbial community structure.
In this study, we examined whether one of the most success- ful invasive seaweeds, Sargassummuticum (Yendo) Fensholt 1955, also displays the typical high genetic diversity reported in other successfully introduced marine taxa. So far, most marine species studied are animals (e.g., 86% of the studies examined in Rius et al. (2015)), and yet hundreds of introduced seaweeds have been reported (346 species reported as invasive; Thomsen, Wernberg, South, & Schiel, 2016). Among them, S. muticum is an emblematic species for circumglobal invasions and its native distribution and his- tory of introduction are well documented (reviewed in Engelen et al., 2015). This seaweed, native to Asia, was first reported outside its native range in the 1940s in the North East Pacific in the Strait of Georgia, British Columbia. A second wave of introduction started in the 1970s in the North East Atlantic, with a first report on the Isle of Wight, United Kingdom. S. muticum subsequently spread rapidly along the NE Pacific and NE Atlantic coasts, in both southward and northward directions. Its present-day introduced range spans an ex- tremely large latitudinal gradient: from Alaska to Mexico in the NE Pacific and from Norway to Morocco in the NE Atlantic (Figure 1). In the NE Atlantic, the species is particularly well established, form- ing abundant populations, and the expansion is still in progress with
Seaweeds are subject to numerous biological interactions and sometimes to extreme abiotic conditions, so they have developed among other defense mechanisms, the ability to produce biologically active substances. Thus, these organisms produce mainly terpenes and phenols. Among others, the antifungal activity, due to its importance in human and animal health and the production of agricultural products, has been the subject of several studies. In the present work, this activity was investigated in ten seaweeds extracts, by direct bioautography assays, compared to Colletotrichum lagenarium and disk diffusion assay, compared to Aspergillus flavus. The organisms studied were: Stypopodium zonale, Laurencia dendroidea, Ascophyllum nodosum, Sargassummuticum, Pelvetia canaliculata, Fucus spiralis, Sargassum filipendula, Sargassum stenophyllum, Laminaria hyperborea and Gracilaria edulis. S. zonale, L. dendroidea, P. canaliculata, S. muticum, A. nodosum and F. spiralis extracts significantly inhibited the C. lagenarium growth, but not inhibited significantly the A. flavus growth. The presence of terpenes in all of these extracts was confirmed by thin layer chromatography whereas the presence of phenolic compounds was confirmed only in extracts of P. canaliculata, A. nodosum and S. muticum. In chemical study by column chromatography, followed by gas chromatography/mass spectrometry analysis, the terpenes neophytadiene, cartilagineol, obtusol elatol; and the ester ethyl hexadecanoate were identified in the L. dendroidea extract. This is the first report on the activity of seaweed extracts against C. lagenarium, a fungus bearing agricultural importance.
The reproduction-based filter had a major effect on the predicted expansion of the leading edge range, even though the number of studies that we could use were limited (5 out of 36). More data from different regions would have certainly been valuable to ascertain the variance of the reproductive window over a larger range of en- vironments. We however do not believe that this would dramatically change our results, as the reproductive window documented so far by these studies was very large. Sargassummuticum is more uncommon in its native than in the invaded ranges, thus the kernel density plots show a higher number of occurrences at cooler temperatures in the invaded ranges (Figure 2). However, since the lowest SST reached by the species is similar between the native and invaded ranges (Table S3.1 in Supporting Information Appendix S3), it is likely that the spe- cies was already pre-adapted to the thermal ranges of the non-native conditions. The question of shifts in phenology and in physiology requirements following introductions is also to be further addressed (Guisan, Petitpierre, Broennimann, Daehler, & Kueffer, 2014). With the data obtained so far, which mostly rely on local studies, it is uncer- tain to which extent physiological requirements are stable over vari- ous regions in similar environments. In another invasive seaweed, the Pacific kelp Undaria pinnatifida, Murphy et al., (2016), Murphy et al., (2017) showed that using physiological data (e.g., growth or survival as a function of irradiance or SST) obtained in the native range per- fectly predicted data observed in the field in the introduction range. Whether such conservatism also holds in S. muticum requires further studies. Similarly, ENMs rely on the assumption of niche conservatism. Benefitting from the introduction of S. muticum in different regions, comparative analyses of the ecosystems colonized by this seaweed would be particularly interesting to carry out to better examine pu- tative realized niche shifts following the introduction process, as an outcome of acclimatization and adaptive evolution processes (Guisan et al., 2014; Chefaoui & Varela-Álvarez, 2018).
O parâmetro b nos dois ensaios apresentou valores expressivos (505,11 ± 3,96 e 481,80 ± 7,18 L g -1 ), representando grande afinidade da biomassa pelas TR. Esses resultados são mais elevados, em média, que àqueles encontrados para metais pesados em diversas espécies de Sargassum, como as estudadas por Volesky e Zolan (1995), as quais apresentaram valores de b (L g -1 ) iguais a 209 para cádmio e 261 para chumbo em Sargassum natans. Para as algas Sargassum fluitans, Sargassum fluitans imobilizada em glutaraldeído e Sargassum vulgare imobilizada em formaldeído e HCl 214, 1282 e 93 para chumbo, respectivamente . Os valores obtidos nos ensaios nas condições experimentais anteriormente descritas para b mostraram que o lantânio é removido da solução e adsorvido pela biomassa mais rapidamente que o neodímio. Entretanto, tais resultados são muito próximos (cuja diferença pode ser menor quando se consideram os desvios), de maneira que os resultados apresentados não são suficientes para inferir tal informação.
En Cuba, la materia prima para obtener ácido algínico y sus sales son algas en su mayoría del género Sargassum (Phaeophyta, Fucales), que provenientes del Mar de los Sargazos arriban funda- mentalmente a las siguientes regiones del país: Cayo Coco, Cayo Largo del Sur, Caibarién, Santiago de Cuba, Cabo Cruz y Playa Santa Lucia 9 . En el presente trabajo se estudia la decoloración con
Alginates are natural polysaccharides composed of linear polymers of 1-4 linked β-D- mannuronic and α-L-guluronic acid residues in widely varying composition and sequential arrangements. The purpose of this study was to evaluate the anti cancer potential of two alginates –V (low viscosity) and +V (high viscosity), isolated from the seaweed Sargassum vulgare. Alginates were tested for cytotoxicity using the brine shrimp lethality assay, sea urchin development assay, hemolysis assay and MTT assay using HL- 60, MCF-7, CEM, HCT-8 and B16 tumor cell lines. None of the compounds tested showed in vitro toxicity. On the other hand, alginates showed antitumor activity in vivo against Sarcoma 180 cells transplanted in mice. Both alginates inhibited the growth of solid tumor in mice implanted with 5 x 10 5 tumor cells after
Brazil. Both shores are semi-sheltered and located close to each other. Based on a visual assessment, Lamberto presents turbid waters, whereas Perequê, clear waters. The climate is subtropical, with rainy summers and dry winters, and the air temperature varies from 19.5 to 25.9°C during the year. The sublittoral of both shores is dominated by boulders of several sizes, which are in turn colonized by different species of brown algae Sargassum spp. (Phaeophyceae), which are common to several shores in the region (S ZÉCHY & P AULA , 2000). In the studied
The Sargassum filipendula marine algae was collected in São Paulo seashore (São Sebastião, Brazil) by the Biology Institute of São Paulo University (CebiMar). The samples were washed and rinsed in distilled water and stored at –20 °C. Algae samples were dried at 60 °C overnight and stored in a dry cabinet. The biomass was ground and sieved and fractions measuring from 0.71 to 1.0 mm were collected for further experiments.
Saravia e Tavares (1997) utilizaram Sargassum sp. para verificar a possibilidade de utilização dessa alga no tratamento do efluente de uma indústria de processamento de couro. Os ensaios em batelada indicaram que a melhor relação massa de alga/volume de efluente foi de 1/30, aliando maior capacidade de adsorção com uma menor concentração de cromo residual. Os resultados dos ensaios em sistema contínuo, constituído de 3 colunas em série com cerca de 20 gramas de biomassa, mostraram que houve uma boa retenção de cromo pela biomassa ao longo das três colunas. Os resultados mostraram ainda que o limite de saturação para a primeira coluna se deu após 100 minutos de operação, enquanto que para a segunda e terceira colunas este limite ocorreu em 150 e 270 minutos, respectivamente. A eficiência do processo foi da ordem de 86% e a capacidade de remoção de 169,4 mg cromo/g biomassa. Os testes de regeneração da Sargassum sp com lavagens sucessivas de ácido nítrico e clorídrico (10 %) alteraram negativamente a capacidade de biossorção da biomassa .
The present study examines the chemical composition and their effects on free radicals, inflammation, angiogenesis, coagulation, VEGF effects and cellular proliferation of a polysaccharides from alga Sargassum vulgare. The sulfated polysaccharide was extracted from brown seaweed by proteolysis with enzymes maxataze. The presence of proteins and sugars were observed in crude polysaccharides. Fractionation of this crude extract was made with growing concentration of acetone (0.3-1.5 v) and produced four groups of polysaccharides. Anionic polysaccharides from brown seaweed Sargassum vulgare, SV1and PSV1 were fractionated (SV1) and purified (PSV1), and displayed with high total sugars and sulfate content and very low level of protein. This fucan SV1 contains low levels of protein and high carbohydrate and sulfate content. This polysaccharides prolonged activated partial thromboplastin time (aPTT) at 50 µg (>240 s). SV1 was found to have no effect on prothrombin time (PT), corresponding to the extrinsic pathway of coagulation. SV1 exhibits high antithrombotic action in vivo, with a concentration ten times higher than heparin. Polysaccharides from S. vulgare promoted direct inhibition enzymatic activity of thrombin and stimulated enzymatic activity of FXa. SV1 showed optimal inhibitory activity of thrombin (50.2±0.28%) at a concentration of 25 μg/mL. Its antioxidant action on scavenging radicals by DPPH was (22%), indicating the polymer has no cytotoxic action (hemolytic) on ABO and Rh blood types in different erythrocyte groups and displays strong anti-inflammatory action on all concentrations tested in the carrageenan-induced paw edema model, demonstrated by reduced edema and cellular infiltration. Angiogenesis is a dynamic process of proliferation and differentiation. It requires endothelial proliferation
If we consider the proportion of S. unicornis present in relation to other microhabitats from Ubatuba Bay occupied by the crabs (i.e., fital areas, poriferan, cnidarian and ascidian colonies, sea anemones, among others), the present study revealed that S. unicornis heads provided shelter for a great diversity of species and constituted a resource for brachyuran crabs. In the same period, another study was realized about the composition of Brachyura living in Sargassum cymosum algae on the same beach (Mantelatto & Corrêa, 1996). Although this algae constituted a much more available resource in this area, the diversity of species and the number of individuals were lower than that documented to S. unicornis colonies.