Gracilaria Caudata Research Articles

Sulphated Polysaccharide Isolated from the Seaweed Gracilaria caudata Exerts an Antidiarrhoeal Effect in Rodents.

Diarrhoea is a significant health problem for children in developing countries that causes more than 1 million deaths annually. This study aimed to evaluate the antidiarrhoeal effect of sulphated polysaccharide (PLS) from the alga Gracilaria caudata in rodents. For the evaluation, acute diarrhoea was induced in Wistar rats (150-200 g) by administration of castor oil (10 mg/kg). Then, different parameters, including enteropooling and gastrointestinal transit and its pharmacological modulation by opioid and cholinergic pathways, were assessed using activated charcoal in Swiss Mice (25-30 g). Secretory diarrhoea was examined using cholera toxin (CT) (1 mg/loop)-treated, isolated intestinal loops from Swiss mice (25-30 g), which were also used to examine fluid secretion, loss of chloride ions into the intestinal lumen and absorption. In addition, a GM1-dependent ELISA was used to evaluate the interaction between PLS, CT and the GM1 receptor. Pre-treatment with PLS (10, 30 and 90 mg/kg) reduced faecal mass, diarrhoeal faeces and enteropooling. However, 90 mg/kg more effectively reduced these symptoms; therefore, it was used as the standard dose in subsequent experiments. Gastrointestinal transit was also reduced by PLS treatment via a cholinergic mechanism. Regarding the diarrhoea caused by CT, PLS reduced all study parameters, and the ELISA showed that PLS can interact with both the GM1 receptor and CT. These results show that PLS from G. caudata effectively improved the parameters observed in acute and secretory diarrhoea, which affects millions of people, and may lead to the development of a new alternative therapy for this disease.

Physiological assessment of the mariculture potential of a Gracilaria caudata (Gracilariales, Rhodophyta) variant

On the Brazilian coast, the red alga Gracilaria caudata is exploited for agar production. Recently, among the common red wild type (RD), a greenish-brown variant (GB) was collected from a natural population. The aim of this work was to compare the growth (GR), photosynthesis, and pigment content of GB and RD tetrasporophytes cultivated under two irradiances, 70 and 150 μmol photons m−2 s−1, for a period of 28 days. The GB variant is deficient in phycoerythrin, but it produced higher levels of allophycocyanin (APC) and phycocyanin (PC) at 150 μmol photons m−2 s−1. At this irradiance, no difference of phycoerythrin content was observed between strains, suggesting that RD could be using this pigment as a nitrogen source. RD growth rates, irrespective of irradiance, were higher when compared to GB up to 14 days, although no differences were observed in photosynthesis. During the 14-day period, both color strains showed higher GR, maximum electron transport rate, and effective quantum yield at 150 μmol photons m−2 s−1 when compared to 70 μmol photons m−2 s−1. After that, although no differences were observed in the photosynthetic properties, a decrease in GR was seen at both irradiances when RD and GB simultaneously differentiated tetrasporangia. The GB, although fertile, was better able to maintain its growth and even exceed the growth rates of RD in the last week (150 μmol photons m−2 s−1). This characteristic could be advantageous to the species, favoring GB in natural populations, since G. caudata is normally found in the fertile state along the Brazilian coast, and most individuals are tetrasporophytes. This feature could also be important to the selection of this GB strain for future mariculture in Brazil. In addition, their higher concentration of PC and APC could open prospects for a possible use as source of material for pharmaceuticals and fluorescent applications.

Development and characterization of microsatellite markers in two agarophyte species, Gracilaria birdiae and Gracilaria caudata (Gracilariaceae, Rhodophyta), using next-generation sequencing

The two red algal species, Gracilaria birdiae Plastino and E.C. Oliveira and Gracilaria caudata J. Agardh, are the most important natural sources of agar in Brazil. Using the 454 sequencing system, we identified 464 and 487 perfect microsatellite loci in 6908 and 9602 sequences/contigs from G. birdiae and G. caudata, respectively. After a conservative removal of potentially problematic loci, 144 loci were tested (72 from each species). A total of 25 polymorphic microsatellite loci were defined (13 loci for G. birdiae and 17 loci for G. caudata, including 5 loci common to both species). The five microsatellite loci that cross-amplified in both species showed species-specific differences in allele size. Polymorphic microsatellite loci were used to assess the genetic diversity of both species in their main harvest and cultivation areas on the Brazilian coast. Gene diversity was similar in G. birdiae and G. caudata. However, significant heterozygote deficiency was observed in G. birdiae, whereas heterozygote excess occurred in G. caudata, suggesting that these two related species differ in their mating system. These results also raised new questions on their biology in the field and on their patterns of genetic structure across their geographical ranges. In addition, the 20 loci developed in this study proved successful in identifying each individual in the field as a unique multilocus genotype, and will be useful for studying lineage sorting, breeding programs, or conservation issues.

Intraspecific variation in Gracilaria caudata (Gracilariales, Rhodophyta): growth, pigment content, and photosynthesis

In Brazil, one of the probable reasons for failure in attempts at macroalgal mariculture is the lack of previous studies under controlled conditions. Gracilaria caudata is an important marine red alga which is locally exploited for the production of agar. In this study the aim was to compare in vitro growth rates, pigment content, and photosynthesis in gametophytes and tetrasporophytes of G. caudata from two distinct geographical areas located 2,500 km apart on the Brazilian coast, one in a warmer area closer to the equator (northeastern population), and the other in a colder area closer to the Tropic of Capricorn (southeastern population). Additionally, the artificial ultraviolet B (UVB) radiation effects on strains were evaluated. Under UVB, deleterious effects were observed in all strains. Although the strains from the southeastern population had higher growth rates than those from the northeastern under control condition, the opposite was observed under UVB condition. Under controlled conditions and regardless of the population, growth rates, net photosynthesis, Pmax, Ik, and pigment contents were higher in tetrasporophytes than in gametophytes. Consequently, when determining the real potential of a certain phase in cultivation, the tetrasporophyte appears to be the more promising for future experiments along the Brazilian coast. Furthermore, although the growth rate of southeastern strains under control condition was higher, their higher sensitivity to UVB radiation emphasizes the importance of careful selection of the most suitable sites prior to experimental cultivation. The differences in performance between the southeastern and northeastern strains provide support for the hypothesis of their ecotypic differentiation.

Evaluation of Macroalgae Sulfated Polysaccharides on the Leishmania (L.) amazonensis Promastigote

The sulfated polysaccharides from Solieria filiformis (Sf), Botryocladia occidentalis (Bo), Caulerpa racemosa (Cr) and Gracilaria caudata (Gc) were extracted and extensively purified. These compounds were then subjected to in vitro assays to evaluate the inhibition of these polysaccharides on the growth of Leishmania (L.) amazonensis promastigotes. Under the same assay conditions, only three of the four sulfated polysaccharides were active against L. amazonensis, and the polysaccharide purified from Cr was the most potent (EC50 value: 34.5 μg/mL). The polysaccharides derived from Bo and Sf demonstrated moderate anti-leishmanial activity (EC50 values of 63.7 μg/mL and 137.4 μg/mL). In addition, we also performed in vitro cytotoxic assays toward peritoneal macrophages and J774 macrophages. For the in vitro cytotoxicity assay employing J774 cells, all of the sulfated polysaccharides decreased cell survival, with CC50 values of 27.3 μg/mL, 49.3 μg/mL, 73.2 μg/mL, and 99.8 μg/mL for Bo, Cr, Gc, and Sf, respectively. However, none of the sulfated polysaccharides reduced the cell growth rate of the peritoneal macrophages. These results suggest that macroalgae contain compounds with various chemical properties that can control specific pathogens. According to our results, the assayed sulfated polysaccharides were able to modulate the growth rate and cell survival of Leishmania (L.) amazonensis promastigotes in in vitro assays, and these effects involved the interaction of the sulfated polysaccharides on the cell membrane of the parasites.

Involvement of the NO/cGMP/PKG/KATP pathway and endogenous opioids in the antinociceptive effect of a sulphated-polysaccharide fraction extracted from the red algae, Gracilaria caudata

We investigated the antinociceptive activity of a sulphated-polysaccharide (PLS) fraction extracted from the sea algae Gracilaria caudata against carrageenan-induced hypernociception in mice and the mechanism underlying the antinociceptive activity. Mechanical inflammatory hypernociception was measured with an electronic version of the Von Frey® test. Mice were treated with PLS (2.5, 5.0, and 10 mg/kg, 0.5mL, p.o.) 1h before carrageenan treatment. l-Noarg (100ng/paw; 50μL) was administered 1h before carrageenan administration. l-Arg (l-Arginine; 200 mg/kg; 0.5mL, p.o.) was administered 10min before l-Noarg injection. ODQ (8μg/paw), KT 5823 (1.5μg/paw), glibenclamide (160μg/paw), and naloxone (1.0μg/paw) were administered 30min before carrageenan administration. PLS reduced carrageenan-induced hypernociception (300μg/paw, 50μL, intraplantar injection). PLS-induced analgesia was reversed by l-Noarg, and the effect of l-Noarg was prevented by l-Arg. The soluble guanylyl cyclase inhibitor ODQ, the protein kinase G inhibitor KT 5823, the KATP blocker glibenclamide, and the opioid receptor antagonist naloxone, significantly reversed (P<0.05) the antinociceptive effect of PLS. The present study showed an intrinsic peripheral antinociceptive action of PLS administration in mice. This antinociceptive effect seemed to be mediated by activation of the NO/cGMP/PKG pathway followed by the opening of KATP channels, and depended on endogenous opioids.

Structural characterization of polysaccharide obtained from red seaweed Gracilaria caudata (J Agardh)

Seaweeds are considered an important source of bioactive molecules. In this work the marine red alga Gracilaria caudata was submitted to aqueous extraction of their polysaccharides for 2h at 100°C. The polysaccharide fraction (PGC) presented a recovery of 32.8%. The sulfate content of PGC, calculated by S%, is 1±0.2% and the degree of sulfation accounts for 0.13±0.2. High-Performance Size-Exclusion Chromatography demonstrated that PGC consists of a high molecular weight polysaccharide (2.5×105gmol−1). Chemical analysis of PGC was performed by microanalysis, infrared (FT-IR) and nuclear magnetic resonance (NMR, 1 and 2D) spectroscopy. The structure of PGC is mainly constituted by the alternating residues 3-linked-β-d-galactopyranose and 4-linked-3,6-α-l-anhydrogalactose; however some hydroxyl groups were substituted by methyl groups and pyruvic acid acetal. The biological precursor of 3,6-α-l-anhydrogalactose (6-sulfate-α-l-galactose) was also detected.

Antiinflammatory and antinociceptive effects in mice of a sulfated polysaccharide fraction extracted from the marine red algae Gracilaria caudata

Many algal species contain relatively high concentrations of polysaccharide substances, a number of which have been shown to have anti-inflammatory and/or immunomodulatory activity. In this study, we evaluated the anti-inflammatory and antinociceptive effects in mice of a sulfated polysaccharide fraction (PLS) extracted from the algae Gracilaria caudata. The antiinflammatory activity of PLS was evaluated using several inflammatory agents (carrageenan, dextran, bradykinin, and histamine) to induce paw edema and peritonitis in Swiss mice. Samples of the paw tissue and peritoneal fluid were removed to determine myeloperoxidase (MPO) activity or TNF-α and IL-1β levels, respectively. Mechanical hypernociception was induced by subcutaneous injection of carrageenan into the plantar surface of the paw. Pretreatment of mice by intraperitoneal administration of PLS (2.5, 5, and 10 mg/kg) significantly and dose-dependently reduced carrageenan-induced paw edema (p < 0.05) compared to vehicle-treated mice. Similarly, PLS 10 mg/kg effectively inhibited edema induced by dextran and histamine; however, edema induced by bradykinin was unaffected by PLS. PLS 10 mg/kg inhibited total and differential peritoneal leukocyte counts following carrageenan-induced peritonitis. Furthermore, PLS reduced carrageenan-increased MPO activity in paws and reduced cytokine levels in the peritoneal cavity. Finally PLS pretreatment also reduced hypernociception 3–4 h after carrageenan. We conclude that PLS reduces the inflammatory response and hypernociception in mice by reducing neutrophil migration and cytokines concentration.

Analysis and characterization of methyl esters of fatty acids of some Gracilaria species

The analysis of the total methyl esters of fatty acids from the extracts of Gracilaria birdiae, Gracilaria caudata, Gracilaria cerviconis, Gracilaria domingensis collected in the coast of Paraiba, Northeast Brazil, as well as their chemotaxonomic significance are herein reported for the first time. They can be recognized as a group that represents analogous chemotaxonomic basis since they show common constituents in their composition, such as hexadecanoic acid and cholesterol. Differences found in the fatty acid composition between the studied species reinforce the proposal to transfer G. caudata for the genus Hydropuntia (H. caudata).

Sulfated-Polysaccharide Fraction from Red Algae Gracilaria caudata Protects Mice Gut Against Ethanol-Induced Damage

The aim of the present study was to investigate the gastroprotective activity of a sulfated-polysaccharide (PLS) fraction extracted from the marine red algae Gracilaria caudata and the mechanism underlying the gastroprotective activity. Male Swiss mice were treated with PLS (3, 10, 30 and 90 mg·kg−1, p.o.), and after 30 min, they were administered 50% ethanol (0.5 mL/25 g−1, p.o.). One hour later, gastric damage was measured using a planimeter. Samples of the stomach tissue were also obtained for histopathological assessment and for assays of glutathione (GSH) and malondialdehyde (MDA). Other groups were pretreated with l-NAME (10 mg·kg−1, i.p.), dl-propargylglycine (PAG, 50 mg·kg−1, p.o.) or glibenclamide (5 mg·kg−1, i.p.). After 1 h, PLS (30 mg·kg−1, p.o.) was administered. After 30 min, ethanol 50% was administered (0.5 mL/25g−1, p.o.), followed by sacrifice after 60 min. PLS prevented-ethanol-induced macroscopic and microscopic gastric injury in a dose-dependent manner. However, treatment with l-NAME or glibenclamide reversed this gastroprotective effect. Administration of propargylglycine did not influence the effect of PLS. Our results suggest that PLS has a protective effect against ethanol-induced gastric damage in mice via activation of the NO/KATP pathway.

Bioremediation of aquaculture wastewater using macroalgae and Artemia

Aquaculture produces a significant amount of wastes, consisting of metabolic by-products, leading to general deterioration of water quality. An alternative for reducing nutrient excess is the use of biofilters that can effectively remove nutrients from the water. A laboratory study was conducted to test the efficacy of the macroalgae Gracilaria caudata and the microcrustacean Artemia franciscana to remove nutrients from aquaculture effluents. The experiment consisted of three treatments: macroalgae (1) macroalgae and Artemia (2), and only Artemia (3). The results indicated that the treatment 2 was the most efficient in removing the nitrogenated forms. The maximum reduction values were: NH4=29.8%; NO2=100%; NO3=72.4% and DIN=44.5%. In contrast, the nutrients concentration was significantly higher at the end of the experiment in the treatment 3 than in the other treatments (ANOVA: p<0,001). PO4 showed a significant increase during the experiment, especially in treatments 2 and 3 (ANOVA: p<0.001). The results showed that G. caudata and A. franciscana performed well in absorbing nitrogenated forms. This indicates that the use of these organisms as biofilters has the potential for being an ecologically correct practice and may contribute to improving the water quality of coastal regions.

POTENCIAL DE CRESCIMENTO DE MACROALGAS CULTIVÁVEIS PRESENTES NA ENSEADA DE ARMAÇÃO DO ITAPOCOROY (PENHA, SC): AVALIAÇÃO PRELIMINAR

This work aims to test growth methodology and to evaluate cultivation potential of the red algae Hypnea musciformis (carragenophyte), Gracilaria cervicornis (cf.) and Gracilaria caudata, (agarophytes). In vitro growth was tested for the three algae, and in situ growth was tested for Gracilaria cervicornis (cf.). Preliminary results indicate high growth rates to in situ and in vitro tests, when compared to literature results. Gracilaria cervicornis (cf.) in vitro growth rates ranged from 1,8 to 5,7 % day-1, and in situ growth rates ranged from 2,3 to 8,7 % day-1. Gracilaria caudata presented lower growth rates, which ranged from 0,8 and 4,9 % day-1. Hypnea musciformis presented highest growth rates, which ranged from 5,6 and 15,2 % day-1. This results are preliminary. For a good evaluation of productive and cultivation potencial of this algae, complementary tests are needed. However, observed growth rates suggest this algae deserves more research aiming to implement its cultivation on Enseada de Armacao do Itapocoroy (Penha, SC).

Nickel biosorption using Gracilaria caudata and Sargassum muticum

Two seaweeds ( Sargassum muticum, S.m. and Gracilaria caudata, G.c.) collected on the coasts of Cuba have been tested and compared for nickel biosorption. The metal was efficiently bound to the biomass at pH 3 for S.m. and pH 5 for G.c. Sorption isotherms, at the optimum pH, showed that S.m. is more efficient than G.c.: maximum sorption capacity reached about 70 mg Ni g −1 and 45 mg Ni g −1 for S.m. and G.c., respectively. The isotherms were modeled using the Langmuir equation (which fits better experimental data than the Freundlich and Temkin equations). Sorption kinetics were also carried out varying metal concentration, sorbent dosage particle size and temperature. The kinetics were modeled using the pseudo-second order rate equation and the intraparticle diffusion equation.

Evaluation of Gracilaria caudata J. Agardh for bioremediation of nutrients from shrimp farming wastewater

The accelerated development of shrimp farming in Brazil in recent decades has caused negative impacts to the environment. The most evident effects resulting from this activity is the increase in organic material, the reduction in oxygen and the excessive rise in water nutrients. Thus, there is a need for finding alternative solutions that can mitigate the negative impacts caused by this activity. A potentially viable solution is the use of macroalgae to remove nutrients from the cultivation systems. This study examined in situ (shrimp pond), the growth and storage of nitrogen and phosphorous from the macroalga Gracilaria caudata. A short-term measurement experiment was also conducted to evaluate the bioremediation potential this species. These results showed positive values for biomass and growth during the study period, except at day 45 for the tubular nets and day 75 for the cages, when they reached lower values than those of the initial weight. The results obtained indicate that G. caudata may reach annual production of 59.16 ton ha −1 of wet weight, which corresponds to 11.83 ton dry weight. Nitrogen and phosphorous content in the algal tissues increased with time. The mean for the period was 2.61 ± 0.26% and 0.20 ± 0.03% for the nitrogen and phosphorous, respectively. An estimate of the data showed that 1 ha of cultivated algae has the potential to remove 0.309 ton ha −1 year −1 of nitrogen and 0.024 ton ha −1 year −1 of phosphorous. The study of the biofiltration capacity of G. caudata showed a significant reduction in nutrients. The removal of NH 4–N was around 59.5%, NO 3–N 49.6% and PO 4–P 12.3% in 4 h. These results suggest that although G. caudata showed relatively modest growth rates, they can be cultivated together with shrimp and can contribute to the removal of nitrogen and phosphorous from the pond. Moreover, the capacity to efficiently remove nutrients demonstrated in laboratory experiments encourages the use of this alga as a bioremediation agent.

α-, β-caroteno e α-tocoferol em algas marinhas in natura

The aim of this work was to evaluate the potential of 32 marine macro algae species, members of Chlorophyta, Rhodophyta and Phaeophyta, as sources of a-carotene, b-carotene and a-tocopherol. Both b-carotene and a-carotene were found in all species of green macroalgae analyzed. The maximum content of a-carotene was detected in algae belonging to Caulerpa genus and the minimum in Codium decorticatum. The amount of b-carotene found was minimum in Caulerpa mexicana and maximum in Ulva fasciata. Among the Rhodophyta species, eleven contain a-carotene, the maximum content was found in Botryocladia occidentalis. b-Carotene was found in all red macroalgae analyzed presenting the lowest and highest values in Gracilaria caudata and Bryothamnion triquetrum, respectively. Species of Phaeophyta contained b-carotene but no a-carotene. The lowest value for b-carotene was found in Dictyopteris delicatula and the highest in Padina gymnospora. In Chlorophyta, the amount of a-tocopherol was maximum in Codium decorticatum and minimum in Caulerpa prolifera. In Rhodophyta, twelve species contained a-tocopherol, the highest value was found in Enantiocladia duperreyi. a-Tocopherol was detected in all Phaeophyta species analyzed. The highest and lowest values were found in Lobophora varigata and Dictyota dichotoma, respectively.

Neutrophil migration induced in vivo and in vitro by marine algal lectins.

Since some plant and mammalian lectins specific for monosaccharides are able to induce neutrophil migration, we studied the neutrophil migration-inducing activities of marine algal lectins, specific for complex oligosaccharides from glycoproteins, from Amansia multifida (AM), Bryothamnion seaforthii (BS), Bryothamnion triquetrum (BT) and Gracilaria caudata (GC). The neutrophil migration-inducing activity of AM, BS, BT and GC was assayed in vitro and in vivo in the peritoneal cavity or dorsal air pouch of rats or mice, and was inhibited by glycans. AM, BS, BT and GC induced neutrophil migration in vivo and in vitro, determining bell-shaped dose-dependent curves. Maximal neutrophil influx was determined by BT in rats and by AM in mice. Maximal human neutrophil chemotaxis was obtained with GC. These activities were not inhibited by glycoproteins previously identified as being recognized by these lectins. D-mannose was a strong inhibitor, especially of BT activity both in vitro and in vivo. Algal lectins induced neutrophil migration, which was inhibited by a monosaccharide, contrasting with the view that they only recognize complex oligosaccharides. Neutrophil chemotaxis assays are appropriate to study low molecular mass lectins containing a single carbohydrate recognition domain, as is the case of some lectins from algae and mammals.

Male gametogenesis in the red algae Gracilaria and Gracilariopsis (Rhodophyta, Gracilariales)

Male gametogenesis in Gracilaria caudata J. Agardh, G. mammillaris (Montagne) Howe and Gracilariopsis tenuifrons (Bird et Oliveira) Fredericq et Hommersand, with respectively, “ verrucosa”, “ textori” and “ chorda” types of spermatangial arrangement, were compared using light and electron microscopy. Although the development of spermatangia among the three species is clearly distinctive when viewed with light microscopy, there are only minor differences in spermatial subcellular structure. In the three species studied, spermatangial mother cells (SMC) differ from surrounding vegetative cells by having poorly developed chloroplasts and numerous plastoglobuli. Endoplasmic reticulum is concentrated at the cell periphery, contributing to the formation of the spermatangial vesicle (SV). The spermatangial nucleus is pushed to the upper end of the cell due to an expansion of the large SV and chloroplasts and starch grains are lacking. In the process of maturation, small cytoplasmic vesicles fuse with the cell membrane to form a mucilaginous envelope around each spermatium. Before being released, the SV releases its contents to the outside, breaking the pit connection with the SMC. Spermatangia have a cell wall with two layers, but spermatia are naked when released.

Growth Rate Responses of Five Commercial Strains of Gracilaria (Rhodophyta, Gracilariales) to Temperature and Light

Abstract Growth rate responses of five strains of four economically important species of Gracilaria from South America, Africa and Asia were studied under several temperature and light combinations, in experiments lasting from one to four weeks. Gracilaria tenuistipitata var. liui from the People's Republic of China was the most eurythermic of the species studied, growing at temperatures from 13.5 to 33.1 C, and all photon flux densities (15–91 μmol‐photons/m2 per sec). Gracilaria caudata from Brazil did not survive at 13.5 C and G. chilensis did not survive at 30.2 C, while G. gracilis from Namibia and Argentina survived up to 33.1 C. No strain survived at 35.8 C or higher. In general, there was a trend to an increase in growth rate with temperature, but this varied with the irradiance and the duration of the experiments. There was a clear interaction between temperature and photon flux density, and the duration of the experimental period interfered significantly in the growth responses. All strains tested, including G. chilensis from Chile and G. gracilis from Argentina and Namibia, could be cultivated under ambient conditions of temperature and photon flux density on the southern coast of Brazil.