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Brown Seaweed (brown + seaweed)
Selected AbstractsIn Vitro,Potential of,Ascophyllum nodosum,Phenolic Antioxidant-Mediated ,-Glucosidase and ,-Amylase InhibitionJOURNAL OF FOOD SCIENCE, Issue 3 2010E. Apostolidis ABSTRACT:,Ascophyllum nodosum,is a brown seaweed that grows abundantly in the Northeast coastal region. In this study, the potential of,A. nodosum,for type 2 diabetes management through antioxidant-mediated ,-glucosidase and ,-amylase inhibition was investigated. After the initial screening of 4 locally harvested seaweeds,,A. nodosum,was chosen for its highest phenolic content and was subjected to water extraction. Among extraction ratios of 50 g to 100 to 1000 mL at room temperature, 50 g/400 mL yielded the highest phenolic content of 4.5 mg/g wet weight. For evaluation of extraction temperature ranging from 20 to 80 °C, 50 g/400 mL was chosen as a minimum amount of extractant. Among temperatures studied, extraction at 80 °C resulted in the highest total phenolic contents (4.2 mg/g wet weight). All extracts had similar levels of antioxidant activity in the range of 60% to 70% in terms of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. The 80 °C extract had the highest ,-glucosidase and ,-amylase inhibitory activity with IC50 of 0.24 and 1.34 ,g phenolics, respectively, compared to the IC50 of acarbose, reference inhibitor, being 0.37 and 0.68 ,g. The results show that fresh,A. nodosum,has strong ,-glucosidase and mild ,-amylase inhibitory activities that correlated with phenolic contents. This study suggests a nutraceutical potential of,A. nodosum,based on phytochemical antioxidant and antihyperglycemia activities. [source] Induction of hepatocyte growth factor by fucoidan and fucoidan-derived oligosaccharidesJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 4 2008Kazuhiro Fukuta Fucoidan, which is extracted from brown seaweed, is a complex sulphated polysaccharide that is mostly composed of l -fucose and sulphated ester groups. The structural and anionic characteristics of fucoidan are similar to those of heparin. Heparin stimulates production of hepatocyte growth factor (HGF), which has key roles in tissue regeneration. We have shown that fucoidan and fucoidan-derived oligosaccharides have similar ability to stimulate production of HGF as heparin and heparin-derived oligosaccharides. This induction of HGF by heparin or fucoidan and their oligosaccharide derivates occurs primarily at the level of translation, probably via the same mechanism. Fucoidan may thus be useful to protect tissues and organs from various injuries and diseases, via mechanisms involving HGF. [source] In vitro effects of phlorotannins from Ascophyllum nodosum (brown seaweed) on rumen bacterial populations and fermentationJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2009Yuxi Wang Abstract BACKGROUND: Use of brown algae (seaweed) in ruminant diets is increasing, but the effects of its phlorotannins (PT) on rumen microbial ecology have not been determined. Mixed forage (50:25:25 ground barley silage,alfalfa hay,grass hay) was used as substrate in a batch culture ruminal incubation that included PT extracted from Ascophyllum nodosum, with and without polyethylene glycol. Principal ruminal bacteria were quantified using real-time polymerase chain reaction. RESULTS: At 500 µg mL,1, PT reduced growth of Fibrobacter succinogenes by 78%, 83% and 65% at 6, 12 and 24 h (P < 0.001), Ruminococcus albus at 24 h only (P < 0.01) and did not affect R. flavefaciens. Non-cellulolytic bacteria Selenomonas ruminantium, Ruminobacter amylophilus and Prevotella bryantii were increased (P < 0.001) by PT at 12 and 24 h. Effects of PT on fermentation products (gas production, volatile fatty acid profiles and ammonia accumulation) were consistent with alterations in rumen microbial populations. CONCLUSION: The effects of PT on ruminal bacteria were species-dependent, which suggests that diet may mediate PT effects on animal performance. The variation in sensitivity of ruminal bacteria to PT reflects previously reported effects of condensed tannins from terrestrial plants on microbial populations. Copyright © 2009 Crown in the right of Canada. Published by John Wiley & Sons, Ltd [source] Biosorption of heavy metal using brown seaweed in a regenerable continuous columnASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2008N. Rajamohan Abstract This paper deals with the experimental investigation on removal of cadmium [Cd(II)] ions from an aqueous solution using a marine alga, Sargassum tenerrimum, in a fixed-bed column. The effects of the inlet flow rate and the sorbent bed height on the biosorption of Cd(II) ions were studied. The dynamics of column biosorption was modeled by the bed depth service time (BDST) model and the Thomas model. The BDST model was used to study the dynamic sorption behavior at different bed heights, whereas the Thomas model was used to fit the column biosorption data at different flow rates. The uptake capacity and the breakthrough time increase with an increase in the bed height. The sorption capacities of the bed per unit volume and the rate constant Ka were found to be 3819.42 mg/l and 0.0353 mg/h respectively. In flow rate experiments, the results confirmed that the metal uptake capacity and the metal removal efficiency of S. tenerrimum decreased with increasing flow rate. The Thomas model was used to fit the column biosorption data at different flow rates and model constants were evaluated. After five sorption,desorption cycles, the selected marine alga exhibited a high cadmium uptake of 63.43 mg/g. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd. [source] A VANADIUM BROMOPEROXIDASE CATALYZES THE FORMATION OF HIGH-MOLECULAR-WEIGHT COMPLEXES BETWEEN BROWN ALGAL PHENOLIC SUBSTANCES AND ALGINATES,JOURNAL OF PHYCOLOGY, Issue 1 2009Leonardo Tavares Salgado The interaction between phenolic substances (PS) and alginates (ALG) has been suggested to play a role in the structure of the cell walls of brown seaweeds. However, no clear evidence for this interaction was reported. Vanadium bromoperoxidase (VBPO) has been proposed as a possible catalyst for the binding of PS to ALG. In this work, we studied the interaction between PS and ALG from brown algae using size exclusion chromatography (SEC) and optical tweezers microscopy. The analysis by SEC revealed that ALG forms a high-molecular-weight complex with PS. To study the formation of this molecular complex, we investigated the in vitro interaction of purified ALG from Fucus vesiculosus L. with purified PS from Padina gymnospora (Kütz.) Sond., in the presence or absence of VBPO. The interaction between PS and ALG only occurred when VBPO was added, indicating that the enzyme is essential for the binding process. The interaction of these molecules led to a reduction in ALG viscosity. We propose that VBPO promotes the binding of PS molecules to the ALG uronic acids residues, and we also suggest that PS are components of the brown algal cell walls. [source] DECREASE IN DYNAMIC VISCOSITY AND AVERAGE MOLECULAR WEIGHT OF ALGINATE FROM LAMINARIA DIGITATA DURING ALKALINE EXTRACTION,JOURNAL OF PHYCOLOGY, Issue 2 2008Peggy Vauchel Alginates are natural polysaccharides that are extracted from brown seaweeds and widely used for their rheological properties. The central step in the extraction protocol used in the alginate industry is the alkaline extraction, which requires several hours. In this study, a significant decrease in alginate dynamic viscosity was observed after 2 h of alkaline treatment. Intrinsic viscosity and average molecular weight of alginates from alkaline extractions 1,4 h in duration were determined, indicating depolymerization of alginates: average molecular weight decreased significantly during the extraction, falling by a factor of 5 between 1 and 4 h of extraction. These results suggested that reducing extraction time could enable preserving the rheological properties of the extracted alginates. [source] In vitro determination of digestible and unavailable protein in edible seaweedsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2002Isabel Goñi Abstract Edible seaweeds are considered a complementary source of food protein for human and animal nutrition. The physiological effects of seaweed protein depend on the degree of enzymatic digestion of protein in the small intestine and bacterial fermentation in the large intestine. The objective of this work was to estimate total, digestible, fermentable and unavailable protein in some red and brown seaweeds. Brown seaweeds Fucus vesiculosus, Laminaria digitata and Undaria pinnatifida and red seaweeds Chondrus crispus and Porphyra tenera were treated with pepsin and pancreatin to separate digestible protein. Residues containing indigestible protein were inoculated for 24,h with rat caecal droppings, and protein contents were evaluated in the non-fermented residue. Protein content in the seaweeds ranged from 8.9 to 25% of dry matter. Digestible protein was the major protein fraction (69%) only in P tenera; in the other seaweeds, this fraction ranged from 15 to 45%. Significant amounts of unavailable protein were found in all samples (2,24%). The distribution of total protein among the three fractions, ie digestible, fermentable and unavailable protein, could yield information about the physiological and metabolic consequences of the intake of seaweed proteins. © 2002 Society of Chemical Industry [source] Reestablishment of the Southern California Rocky Intertidal Brown Alga, Silvetia compressa: An Experimental Investigation of Techniques and Abiotic and Biotic Factors That Affect Restoration SuccessRESTORATION ECOLOGY, Issue 2010Stephen G. Whitaker Previous research has indicated that many rocky intertidal macrophyte communities in southern California, and other locations around the world, have shifted from larger, highly productive, fleshy seaweeds toward a smaller, less productive, disturbance-tolerant flora. In widespread decline are ecologically important, canopy-forming, brown seaweeds, such as the southern California rockweed species Silvetia compressa. Restoration efforts are common for depleted biogenic species in other habitats, but restoration within rocky intertidal zones, particularly on wave-exposed coasts, has been largely unexplored. In two phases, we attempted to restore Silvetia populations on a southern California shore by transplanting live plants and experimentally investigating factors that affect their survival. In Phase I, we implemented a three-way factorial design where juvenile Silvetia thalli were transplanted at four sites with a combination of simulated canopy and herbivore exclusion treatments. Transplant survival was low, although enhanced by the presence of a canopy; site and herbivore presence did not affect survival. In Phase II, we used a two-way factorial design, transplanting two size classes of rockweeds (juveniles and reproductive adults) on horizontal and partially shaded, north-facing vertical surfaces at a target location where this rockweed has been missing since at least the 1970s. Transplant survival was moderate but lower than natural survival rates. Larger thalli exhibited significantly higher survival rates than smaller thalli in both the transplanted and naturally occurring populations, particularly on vertical surfaces. Higher mortality on horizontal surfaces may have been due to differences in desiccation stress and human trampling. Transplanting reproductive adults resulted in the subsequent recruitment of new individuals. [source] | |||||||||||||