Proximate composition of several macroalgae from the coast of Salinas Bay, Ecuador / Composición proximal de varias macroalgas de la costa de Bahía Salinas, Ecuador

Abstract Seaweeds are accessible and important marine organisms found in coastal zones, which have shown their nutritive potential as food or additive. These organisms are relatively abundant in the coastline of Ecuador, but their biochemical composition has not been adequately studied. Therefore, the aim of this research was to evaluate the proximate composition of seven seaweeds (four red, two brown, and one green) collected from Salinas Bay, Ecuador, as a contribution to the knowledge of the nutritional potential of these organisms that belong to this region. Moisture, ash, fat, fiber and protein contents were determined by standard protocols, while carbohydrates were obtained by difference. Energetic content (or caloric profile) was calculated according to the contributions of macromolecules (fats, proteins and carbohydrates). The parameters in highest proportion found in all species were carbohydrates (32.2-45.5 %) and minerals (or ash, 25.8-36.7 %), which play a significant role in human nutrition and the food industry. Furthermore, protein, fiber, and fat contents were relatively low, with values around 4.7-8.0 %, 0.9-5.0 %, and 0.3-3.0 %, respectively, indicating these organisms are a good option as healthy food. According to statistical analysis (ANOVA), each nutritive parameter was significantly different among the species (P < 0.05). Results indicate edible seaweeds from Ecuador have potential as nutritious food that could offer between 1 500-2 000 kcal kg-1, which is higher than many common vegetables.(AU)

Resumen Las macroalgas marinas son organismos accesibles e importantes de las zonas costeras, los cuales han mostrado su potencial como alimentos o aditivos nutritivos. En la línea costera de Ecuador estos organismos son relativamente abundantes, pero su composición bioquímica no ha sido estudiada adecuadamente. En consecuencia, el objetivo de esta investigación fue evaluar la composición proximal de siete especies de macroalgas (cuatro rojas, dos pardas y una verde) que fueron recolectadas en la Bahía de Salinas, Ecuador, como una contribución al conocimiento del potencial nutricional de estos organismos pertenecientes a esta región. Los contenidos de humedad, cenizas, grasa, fibra y proteínas fueron determinadas mediante protocolos estándares, mientras que el contenido de carbohidrato fue obtenido por diferencia. El contenido energético (o perfil calórico) de las macroalgas fue calculado de acuerdo con las contribuciones de las macromoléculas (grasas, proteínas y carbohidratos). Los parámetros encontrados en mayor proporción en todas las especies fueron: carbohidratos (32.2-45.5 %) y minerales (o cenizas, 25.8-36.7 %), los cuales tienen importancia en la nutrición humana y la industria alimentaria. Además, los contenidos de proteína, fibra y grasa fueron relativamente bajos, encontrando valores alrededor de 4.7-8.0, 0.9-5.0, y 0.3-3.0 %, respectivamente, indicando que estos organismos son una buena y saludable opción como alimento. De acuerdo con el análisis estadístico (ANOVA), cada parámetro nutritivo fue significativamente diferente entre especies (P < 0.05). Los resultados indican que las algas comestibles de Ecuador tienen potencial como alimento nutritivo que pueden ofrecer entre 1 500-2 000 kcal kg-1, un aporte energético un poco mayor que muchos vegetales comunes.(AU)

Extraction, physical-chemical characterization and in vitro inhibitorypotential of thrombin generation of crude sulfated polysaccharides from Brazilian tropical seaweeds / Extração, caracterização físico-química e potencial inibitório in vitro da geração detrombina de polissacarídeos sulfatados brutos de algas marinhas tropicais brasileiras

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) wereanalyzed 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. Withrespect to TG assay, crude SPs modified concentration-dependent and independently from molecular mass TGby both intrinsic/extrinsic pathways in 60-fold diluted human plasma, with total intrinsic inactivation using crudeSPs from A. muscoides in parallel to heparin (p < 0.05). Thrombosis in vitro is differentially modulated by distinctcrude SPs from Brazilian seaweeds.

O valor biotecnológico das macroalgas para ensaios de varredura de geração de trombina-GT pouco tem sido explorado usando polissacarídeos sulfatados-PSs como substitutos à heparina. Foramanalisadas e comparadas cinco espécies brasileiras de macroalgas (Gracilaria birdiae, Acanthophora muscoides, Halymenia sp., Caulerpa cupressoides e C. racemosa) quanto à abundância, às característicasfísico-químicas e os ensaios anticoagulantes in vitro de tempo de tromboplastina parcial ativada-TTPA, aotempo de protrombina-TP e a GT. A extração com papaína rendeu (p 100 kDa. Esses procedimentos,combinados ao uso de azul de toluidina/Stains-All, indicaram também polissacarídeos-não sulfatados. OsTTPAs foram dependentes da sulfatação dos PSs brutos e variaram de 2,81 (A. muscoides) a 21,30 UI (Halymenia sp.) vs. heparina (193 UI). O TP não foi alterado. Com respeito ao ensaio de GT, os PSs brutos modificaram, dependente de concentração e independentemente de massa molecular, GT pelas viasintrínseca/extrínseca no plasma humano diluído 60 vezes, com inativação intrínseca total usando PSs brutosde A. muscoides em paralelo à heparina (p < 0,05). A trombose in vitro é modulada diferencialmente porPSs brutos distintos de algas marinhas brasileiras.

Characterization and bioactivities of a novel polysaccharide obtained from Gracilariopsis lemaneiformis

ABSTRACT Gracilariopsis lemaneiformis is a type of red alga that contains seaweed polysaccharide agar. In this study, a novel non-agar seaweed polysaccharide fraction named GCP (short of crude polysaccharide obtained from Gracilariopsis lemaneiformis) was isolated from Gracilariopsis lemaneiformis. Structural analysis showed that GCP shows triple helical chain conformation when dissolved in water and has many branches and long side chains. Also, 1→3 linkage is the major linkage and the sugar structures are galactopyranose configurations linked by β-type glycosidic linkages. Two macromolecular substance fractions (GCP-1 and GCP-2) were purified by DEAE Sepharose Fast Flow column chromatography. Moreover, a splenocyte damage assay and splenocyte proliferation assay were used to analyse the bioactivities of GCP, GCP-1 and GCP-2. It was demonstrated that polysaccharides could protect splenocyte damaged by H2O2; GCP-2 shows a greatest protection rate, that is, 92.8%, which significantly enhanced the splenocyte proliferation, and GCP showed the highest proliferation rate, 9.30%. The results suggested that this type of novel non-agar polysaccharide displayed remarkable antioxidant and immunomodulatory activities and early alkali treatment could decrease the activities. It may represent a potential material for health food and clinical medicines.

Potential role of marine algae extract on 3T3-L1 cell proliferation and differentiation: an in vitro approach

BACKGROUND: From ancient times, marine algae have emerged as alternative medicine and foods, contains the rich source of natural products like proteins, vitamins, and secondary metabolites, especially Chlorella vulgaris (C. vulgaris) contains numerous anti-inflammatory, antioxidants and wound healing substances. Type 2 diabetes mellitus is closely associated with adipogenesis and their factors. Hence, we aimed to investigate the chemical constituents and adipo-genic modulatory properties of C. vulgaris in 3T3-L1 pre-adipocytes. RESULTS: We analysed chemical constituents in ethanolic extract of C. vulgaris (EECV) by LC-MS. Results revealed that the EECV contains few triterpenoids and saponin compounds. Further, the effect of EECV on lipid accumulation along with genes and proteins expressions which are associated with adipogenesis and lipogenesis were evaluated using oil red O staining, qPCR and western blot techniques. The data indicated that that EECV treatment increased differentiation and lipid accumulation in 3T3-L1 cells, which indicates positive regulation of adipogenic and lipogenic activity. These increases were associated with up-regulation of PPAR-γ2, C/EBP-α, adiponectin, FAS, and leptin mRNA and protein expressions. Also, EECV treatments increased the concentration of glycerol releases as compared with control cells. Troglitazone is a PPAR-γ agonist that stimulates the PPAR-y2, adiponectin, and GLUT-4 expressions. Similarly, EECV treatments significantly upregulated PPAR-γ, adiponectin, GLUT-4 expressions and glucose utilization. Further, EECV treatment decreased AMPK-α expression as compared with control and metformin treated cells. CONCLUSION: The present research findings confirmed that the EECV effectively modulates the lipid accumulation and differentiation in 3T3-L1 cells through AMPK-α mediated signalling pathway.

Oil mixes omega 9, 6 and 3, enriched with seaweed, promoted reduction of thermal burned modulating NF-kB and Ki-67

PURPOSE: To examine the effects of the oil mixes (ω-9, ω-6 and ω-3) in rats subjected to thermal burn. It was also aimed to assess whether the sources of ω3 would interfere with the effect of such mixes on the thermal injury. METHODS: Thirty-six rats distributed into five groups: burned + water, burned + isolipid mix, burned + oil mix 1 (ALA), burned + oil mix 2 (ALA + EPA + DHA of fish) and burned + oil mix 3 (ALA + DHA from seaweed). The thermal injury was involving total thickness of skin. After the burns animals received the oil mixes for seven days. The lesions were evaluated by immunohistochemistry. RESULTS: Animals receiving mix 3 showed a smaller extension of the thermal injury as compared to those that were supplemented with other oils mixes. Expression of Ki-67 in the receiving Mix 3 increased as compared to all the other groups. Animals supplemented with mix 3 were able to inhibit NF-κB in injured tissue. CONCLUSION: Rats received oil mix in which the source of ω3 (ALA+DHA of seaweed) showed inhibition of NF-κB, increase in cell proliferation, and reduction the extension of thermal lesion. .

Anti-inflammatory and analgesic activities of red seaweed Dichotomaria obtusata / Atividades anti-inflamatória e analgésica da alga marinha vermelha Dichotomaria obtusata

The aim of the present work was to investigate the anti-inflammatory and analgesic effects of red seaweed Dichotomaria obtusata, using classic tests in mice (ear edema induced by TPA and writhing induced by acetic acid). The qualitative chemical composition of the aqueous extract (lactones, phenols, triterpenes, steroids and reduced carbohydrates) obtained from this alga was also determined. The results showed that Dichotomaria obtusata (12.5, 25 and 50 mg/kg, ip) inhibited mouse ear edema in a dose-dependent manner. In the writhing test, aqueous extract (12.5, 25, 50 and 100 mg/kg, ip and 100, 200, 400, 800 mg/kg, po) significantly reduced abdominal writhes. In conclusion, this study demonstrated the anti-inflammatory and antinociceptive activities of aqueous extract of D. Obtusata in experimental models. These results suggest that D. obtusata aqueous extract possesses therapeutic potential in the treatment of peripheral painful or/and inflammatory conditions.

O objetivo do presente trabalho é centrado nos efeitos antiinflamatórios e analgésicos da alga vermelha Dichotomaria obtusata por meio de clássicos testes em camundongos (edema de orelha induzido por TPA e contorção induzida por ácido acético). Também foi determinada a composição química qualitativa do extrato (lactonas, fenóis, triterpenos, esteróides e carboidratos reduzidos). Os resultados mostraram que de Dichotomaria obtusata (12,5, 25 e 50 mg/kg, ip) inibiu o edema de orelha do camundongo de forma dose-dependente. No teste de contorção, extrato aquoso (12,5, 25, 50 e 100 mg/kg, ip e 100, 200, 400, 800 mg/kg, po) reduziu o contorções abdominais de forma significativa. Em conclusão, o estudo demonstrou a atividades antiinflamatória e antinociceptiva do extrato aquoso em modelos experimentais. Estes resultados sugerem que o extrato aquoso D.obtusata possuem potencial terapêutico no tratamento de dor periférica e/ou de doenças inflamatórias.

Physiological and physico-chemical characterization of dietary fibre from the green seaweed Ulva fasciata Delile / Caracterização fisiológica e físico-química da fibra alimentar da macroalga marinha verde Ulva fasciata Delile

This work aims to assess the potential of the green seaweed Ulva fasciata Delile as an alternative source of dietary fibre (DF). Total DF content was determined, some of its physico-chemical properties described and the physiological effects of U. fasciata meal on rats fed a hypercholesterolemic diet were investigated. U. fasciata may be considered a potential alternative source of DF with a total content of about 400 g.kg-1 (dry basis) and interesting physico-chemical properties: water retention capacity of 8.74 g/water.g-1 dry sample (seaweed meal) and 0.90 (seaweed carbohydrate extract), lipid adsorption capacity of 4.52 g/oil.g-1 dry sample (seaweed meal) and 5.70 (seaweed carbohydrate extract), intrinsic viscosity of 2.4 dl.g-1 (seaweed carbohydrate extract) and cation exchange capacity of 3.51 Eq.kg-1 (seaweed carbohydrate extract). The diet containing seaweed meal was able to keep rats' total cholesterol (TC) down without causing any undesirable increase in LDL-C fraction. No evidence of toxic and/or antinutritional components in the seaweed meal was detected. Rats showed a fecal volume much greater (13 g) than that fed on cellulose diet ( 7 g) (p < 0.05). These properties confer on the seaweed the potential to be used in food technology for the acquisition of low-calorie food and might be important in body weight control, reduction of blood TC and LDL-C as well as in prevention of gastrointestinal diseases.

Este trabalho objetivou avaliar o potencial da alga marinha verde Ulva fasciata Delile como fonte alternativa de fibra alimentar. Foram realizadas a determinação do teor de fibra alimentar total e a descrição de algumas propriedades físico-químicas, e os efeitos fisiológicos da farinha da alga seca sobre ratos alimentados com dieta hipercolesterolemizante foram investigados. Esta alga pode ser considerada uma fonte alternativa potencial de fibra com cerca de 400 g.kg-1 (base seca) e propriedades físico-químicas interessantes: uma capacidade de retenção de água de 8,74 g/água.g-1 de amostra seca (farinha de alga) e 0,90 (extrato de carboidratos), uma capacidade de adsorção de lipídeos de 4,52 g/óleo.g-1 de amostra seca (farinha de alga) e 5,70 (extrato de carboidratos), uma viscosidade intrínseca de 2,4 dl.g-1 (extrato de carboidrato da alga) e capacidade de troca iônica de 3,51 Eq.kg-1 (extrato de carboidrato). A dieta contendo farinha de alga foi capaz de manter baixos os níveis de colesterol total de ratos sem causar aumento indesejável na fração LDL-C. Nenhuma evidência de componentes tóxicos e/ou antinutricionais na farinha de alga foi encontrada. Os ratos mostraram um volume fecal maior (13 g) do que aqueles alimentados com dieta contendo celulose como fonte de fibra (7 g) (p < 0,05). Essas propriedades conferem a alga o potencial de ser utilizada na tecnologia de alimentos para a aquisição de alimentos de baixas calorias, podendo ser importante para o controle do peso corporal, redução do colesterol sanguíneo total e da fração LDL-C, como também na prevenção de doenças gastrintestinais.

Anti-inflammatory activities of methanol extracts from various seaweed species.

Thirty-seven species of common seaweeds from the coast of Korea were screened for anti-inflammatory activity Methanol extracts of the seaweeds were tested against mouse ear edema and erythema induced by phorbol myristate acetate. At 40 mg ml(-1) of extract, edema was strongly suppressed by the seaweeds Undaria pinnatifida and Ulva linza, with relative inhibition of 85 and 84%, respectively These two seaweeds also showed the greatest suppression of erythema, with inhibition of 78 and 70%, respectively IC50 values of U. pinnatifida were 10, 15, and 18 mg ml(-1) when inflammation symptoms of edema, erythema, and blood flow, respectively were measured. The IC50 of U. linza was 20, 26, and 31 mg ml(-1) when edema, erythema, and blood flow, respectively, were measured. A linear correlation among inhibition rates of edema, erythema, and blood flow was observed with high confidence.

Partial characterization and anticoagulant activity of a heterofucan from the brown seaweed Padina gymnospora

The brown algae Padina gymnospora contain different fucans. Powdered algae were submitted to proteolysis with the proteolytic enzyme maxataze. The first extract of the algae was constituted of polysaccharides contaminated with lipids, phenols, etc. Fractionation of the fucans with increasing concentrations of acetone produced fractions with different proportions of fucose, xylose, uronic acid, galactose, and sulfate. One of the fractions, precipitated with 50 percent acetone (v/v), contained an 18-kDa heterofucan (PF1), which was further purified by gel-permeation chromatography on Sephadex G-75 using 0.2 M acetic acid as eluent and characterized by agarose gel electrophoresis in 0.05 M 1,3 diaminopropane/acetate buffer at pH 9.0, methylation and nuclear magnetic resonance spectroscopy. Structural analysis indicates that this fucan has a central core consisting mainly of 3-ß-D-glucuronic acid 1-> or 4-ß-D-glucuronic acid 1 ->, substituted at C-2 with alpha-L-fucose or ß-D-xylose. Sulfate groups were only detected at C-3 of 4-alpha-L-fucose 1-> units. The anticoagulant activity of the PF1 (only 2.5-fold lesser than low molecular weight heparin) estimated by activated partial thromboplastin time was completely abolished upon desulfation by solvolysis in dimethyl sulfoxide, indicating that 3-O-sulfation at C-3 of 4-alpha-L-fucose 1-> units is responsible for the anticoagulant activity of the polymer.

The effect of temperature and irradiance on the growth and carotenogenic capacity of seven strains of Dunaliella salina (Chlorophyta) cultivated under laboratory conditions

The carotenogenic microalga Dunaliella salina is cultivated as a natural source of ¾ƒ-carotene. The 9-cis isomer of ¾ƒ-carotene is found only in natural sources having commercial advantages over the all-trans isomer due to its high liposolubility and antioxidant power. High irradiance appears to stimulate specifically all-trans ¾ƒ-carotene accumulationin D. salina, whereas low temperature apparently elicits ¾ƒ-carotene and 9-cis ¾ƒ-carotene production. We studied the effect of temperature and irradiance on the growth and the carotenogenesis of three Chilean (CONC-001, CONC-006 and CONC-007) and four non-Chilean (from Mexico, China, Australia and Israel) strains of D. salina cultivated under two photon flux densities (40 and 110 _ 6mol photons.m-2.s-1) and two temperatures (15 and 26ùª C). The Chilean strain CONC-001 and all of the non-Chilean strains exhibited the highest growth rates and the maximum cell densities, whereas the Chilean strains CONC-006 and CONC-007 showed the lowest values in both parameters. The Australian strain showed the highest accumulation of total carotenoids per unit volume (40.7 mg.L-1), whereas the Chilean strains CONC-006 and CONC-007, the only ones isolated from Andean environments, yielded the highest amounts of carotenoids per cell (61.1 and 92.4 pg.cell_1, respectively). Temperature was found to be more effective than irradiance in changing the qualitative and quantitative carotenoids composition. The Chilean strains accumulated 3.5-fold more ¾ƒ-carotene than the non-Chilean strains when exposed to 15ùª C and, unlike the non-Chilean strains, also accumulated this pigment at 26ùª C. The 9-cis/all-trans ¾ƒ-carotene ratio was > 1.0 in all treatments for all strains, and the values were not greatly influenced by either temperature or photon flux density. Physiological and biotechnological implications of these results are discussed.

Contenido en algunos nutrientes del alga marina comestible Monostroma undulatum Wittrock de la costa patagónica argentina / Chemical composition and seasonal fluctuations of the edible green seaweed, Monostroma undulatum, Wittrock, from the Southern Argentina coast

The chemical composition of green seaweed, Monostroma undulatum, Wittrock, growing in the Southern Argentina coast, was studied. Samples were collected in Puerto Deseado, province of Santa Cruz (47 degrees 45'L.S., 65 degrees 55'L.W.), from October to December 1999 and 2000. It has been analyzed six sample during this period. Algae were washed with sea water and dried at room temperature for 24 hs. Moisture, nitrogen, lipids and ashes were determined according to AOAC; fiber (total, soluble and insoluble), according to Lahaye. After mineralization with nitric acid, sodium and potassium were determined by flame photometry, calcium by complexometric method, and phosphorus by Gomori's method. The ranges expressed per 100 g dry algae were: protein (Nx6.25): 12.89-21.85; ashes (g): 33.92-40.05; lipid (g): 0.32-1.47; total fiber (g): 14.36-19.6; digestible carbohydrates (calculated by difference) (g): 20.86-32.48; sodium (g): 7.39-13.11; potassium (g): 1.38-3.18; calcium (mg): 149-226; phosphorus (mg): 190-447; Vitamin C (mg): 159-455. These results show that this green seaweed is an important source for protein, fiber, macronutrients minerals and vitamin C, during the macroscopic period. There was an important fluctuation that must be taken into account to consider the commercial collection to use it in human nutrition.

Algas marinas de Baja California Sur, México: valor nutrimental / Marine algae of Baja California Sur, Mexico: nutritional value

The Baja California Peninsula is one of the richest regions of seaweed resources in México. The objective of this study was to determine the chemical composition of some marine algae species of Baja California Sur, with an economical potential due to their abundance and distribution, and to promote their use as food for human consumption and animal feeding. The algae studied were Green (Ulva spp., Enteromorpha intestinalis, Caulerpa sertularoides, Bryopsis hypnoides), Red (Laurencia johnstonii, Spyridia filamentosa, Hypnea valentiae) and Brown (Sargassum herporizum, S. sinicola, Padina durvillaei, Hydroclathrus clathrathus, Colpomenia sinuosa). The algae were dried and ground before analysis. In general, the results showed that algae had a protein level less than 11 per cent, except L. johnstonii with 18 per cent and low energy content. The ether extract content was lower than 1 per cent. However, the algae were a good source of carbohydrates and inorganic matter.

A fucan from the brown seaweed Spatoglossum schröederi inhibits Chinese hamster ovary cell adhesion to several extracellular matrix proteins

Fucans, a family of sulfated polysaccharides present in brown seaweed, have several biological activities. Their use as drugs would offer the advantage of no potential risk of contamination with viruses or particles such as prions. A fucan prepared from Spatoglossum schröederi was tested as a possible inhibitor of cell-matrix interactions using wild-type Chinese hamster ovary cells (CHO-K1) and the mutant type deficient in xylosyltransferase (CHO-745). The effect of this polymer on adhesion properties with specific extracellular matrix components was studied using several matrix proteins as substrates for cell attachment. Treatment with the polymer inhibited the adhesion of fibronectin to both CHO-K1 (2 x 10(5))()and CHO-745 (2 x 10(5) and 5 x 10(5)) cells. No effect was detected with laminin, using the two cell types. On the other hand, adhesion to vitronectin was inhibited in CHO-K1 cells and adhesion to type I collagen was inhibited in CHO-745 cells. In spite of this inhibition, the fucan did not affect either cell proliferation or cell cycle. These results demonstrate that this polymer is a new anti-adhesive compound with potential pharmacological applications

Chemotaxis and chemical defenses in seaweed susceptibility to herbivory

Recent studies have show that small marine herbivores with limited mobility (mesograzers) often feed on macroalgae chemically defended against fishes or sea-urchins. In order to verify the involved mechanisms of chemotaxis or chemical defense into this process in Brazilian littoral, two species of brown alga Dictyota menstrualis and Dictyota mertensii were studied against the limited mobility herbivores, the amphipod Parhyale hawaiensis and the crab Pachygrapsus transversus. These two species were studied in order to verify the action of their crude extracts in the defense and chemotaxis processes related to limited mobility of these herbivores. Feeding preference assays revealed that P. hawaiensis do not eaten these Dictyota species. P. transversus do not eaten D. menstrualis either, but consumed large amounts of D. mertensii. Chemical deterrence assays showed that extracts of these species act as feeding deterrent to both species of herbivores. In addition, chemotaxis assays demonstrated that both herbivores are significantly negative chemotactic probably due to the presence of complementary metabolites into artificial foods. Considering that both Dictyota species exhibit active extracts against these small herbivores, we suppose that the non-occurrence of these herbivore species in close relationship with the seaweeds D. menstrualis and D. mertensii may explain the defense action of both extracts related to these mesograzers

Contenido de algunos nutrientes, minerales y variaciones estacionales en Porphyra columbina, alga comestible de la Costa Patagónica argentina / Contents of some nutrients, minerals and seasonal fluctuations in Porphyra columbina, an edible marine algae from the Argentine Patagonic coast

Las algas roja, Porphyra sp., son comestibles, de sabor agradable y abundantes en las costas patagónicas de Argentina. Por la carencia de datos nacionales de composición, y dada su creciente incorporación en la alimentación humana de Occidente, se estudió el contenido de algunos minerales esenciales de Porphyra columbina Montagne (Rodophyta Bangiales). Las algas se recolectaron mensualmente, en forma manual, en el Golfo de San Jorge (30 Km al Sur de la ciudad de Comodoro Rivadavia), desde abril de 1993 hasta febrero de 1994. Se lavaron con agua de mar y se secaron a la temperatura ambiente de las viviendas (20-25 grados Celsius) tal como se comercializan en la región. Se determinaron humedad y cenizas (según AOAC) y, luego de mineralizar con ácido nítrico, sodio y potasio (fotometría de llama), calcio, magnesio y hierro (espectrofotometría de absorción atómica) y fósforo (método de Gomori). Los resultados, expresados por 100g de alga seca, evidenciaron un contenido de humedad entre 7.03 y 11,00g/100g y de cenizas entre 16,18 y 22,70g/100g. Los minerales mayoritarios fueron: sodio (3,18 a 6,41g/100g), potasio (1,24 a 1,96g/100g) y magnesio (600 a 836mg/100g). El fósforo osciló entre 78 y 276mg/100g, el calcio entre 63 y 108mg/100g y el hierro entre 3,9 y 26,4mg/100g. Fueron importantes las variaciones mensuales, encontrando los mayores valores de cenizas, sódio, potasio y magnesio en los meses de invierno (junio y julio).

Presencia de lectinas, taninos e inhibidores de proteasas en algas marinas de las costas Venezolanas / Presence of lectins, tannins and protease inhibitors in Venezuelan marine algae

Se estudió la presencia de lectinas, taninos e inhibidores de proteases, en 27 especies de algas colectadas en barreras coralinas de cuatro regiones de Venezuela. Sólo seis de las especies estudiadas, presentaron actividad hemaglutinante atribuible a lectinas, obteniéndose los mayores títulos de hemaglutinación com eritrocitos tratados con pronasa. En cuatro de las especies, las lectinas fueron inhibidas por más de un azúcar sencillo y por la mucina de glándula submaxilar de bovino: Caulerpa sertularioides, Enteromorpha intestinalis, Codium repens y Codium isthmocladum (Chlorophyta). La lectina de Grateloupia filicina fue inhibida solamente por NAcGal. Ninguno de los compuestos probados inhibió la hemaglutinación causada por Halimeda opuntia. El tratamiento de los extractos con polivinilpolipirrolidona eliminó la actividad hemaglutinante de las algas pardas y rojas, menos en dos especies de rodofitas: Grateloupia filicina e Hypnea cervicornis, lo que hace presumir la presencia de lectinas en ambas. Los taninos presentes en las Phaeophyta y Rhodophyta estudiadas son aparentemente del tipo florotaninos con un mayor contenido en las primeras. Sólo se encontró actividad inhibidora de tripsina en: Padina gymnospora (Phaeophyta) y Acantophora spicifera (Rhodophyta). En ningún caso se encontró actividad inhibidora contra subtilisina.