Anti-atherogenic properties associated with the antioxidant activity from the hydrophilic extracts of Halimeda incrassata (Chlorophyta, Bryopsidales)

Seaweeds are a source of natural antioxidants having potential application in oxidative stress and associated diseases. In this work, anti-atherogenic properties associated with the antioxidant activity from the hydrophilic extracts of Halimeda incrassata were studied. The phenolic content assessed inthe aqueous extract and fraction phenolic acids (FPA) was 0.13 ± 0.05 and 0.47 ± 0.09 mg of gallic acid equivalents (GAE)/g dry seaweed, respectively. In DPPH?, radical scavenging assay fractions exhibited a dependent concentration. The seaweeds extract inhibited the desoxirribose oxidation in the presenceor absence of EDTA (IC50 = 1.91± 0.09 mg/mL) (IC50 = 2.95 ± 0.01 mg/mL). In vivo antioxidant properties of FPA-H.incrassata were investigated in rats with a CCl4-induced liver injury. Pre-treatment with H.incrassata led to approximately 50% reductions in liver TBARS levels. The treatment with H. incrassataFPA also increased the activity of the CAT enzyme, which in turn resulted in an enhanced antioxidantdefense. The expression of Catalase by PCR-RT technique demonstrated a higher gene expression when compared with that which was observed in the CCl 4-treated group. Antiatherogenic properties were studied in the inhibition of lipoprotein oxidation mediated by Cu2+ or HRP/H2O2, free radicalscavenging, and metal ion chelation, and it was dose dependent with a higher concentration needed for the aqueous extract than for the FPA fraction. Antioxidant activity was also improved in macrophages as evaluated in the cell supernatant (by TBARS formation); and by luminol enhanced chemiluminescence after cell activation with zymosan; and a degree of cell lipoperoxidation wasdecreased by the Halimeda incrassata extract. The results of this work add to the antioxidant potential of the seaweed for its application in oxidative stress associated conditions.Fil: Vidal-Novoa, Alexis. Universidad de la Habana. Facultad de Biología; CubaFil: Costa-Mugica, Ariadna. Universidad de la Habana. Facultad de Biología; CubaFil: Zulueta Díaz, Yenisleidy de Las Mercedes. Universidad de la Habana. Facultad de Biología; Cuba. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Diaz-Gutierrez, Daylín. Universidad de la Habana. Facultad de Biología; CubaFil: de Oliveira e Silva, Ana, Mara. Universidade de Sao Paulo; BrasilFil: Vazquez, Ana María. Center For Molecular Inmunology; CubaFil: Claudina, Zaldívar-Munoz. Universidad de la Habana. Facultad de Biología; CubaFil: Dalva, Assuncao Portari de Mancini. Institute Butantan Sao Paulo; BrasilFil: Mancini-Filho, Jorge. Universidade de Sao Paulo; Brasi

Clionasterol, a triterpenoid from the Kenyan marine green macroalga halimeda macroloba

Peer reviewedPublisher PD

Seagrass can mitigate negative ocean acidification effects on calcifying algae

The ultimate effect that ocean acidification (OA) and warming will have on the physiology of calcifying algae is still largely uncertain. Responses depend on the complex interactions between seawater chemistry, global/local stressors and species-specific physiologies. There is a significant gap regarding the effect that metabolic interactions between coexisting species may have on local seawater chemistry and the concurrent effect of OA. Here, we manipulated CO2 and temperature to evaluate the physiological responses of two common photoautotrophs from shallow tropical marine coastal ecosystems in Brazil: the calcifying alga Halimeda cuneata, and the seagrass Halodule wrightii. We tested whether or not seagrass presence can influence the calcification rate of a widespread and abundant species of Halimeda under OA and warming. Our results demonstrate that under elevated CO2, the high photosynthetic rates of H. wrightii contribute to raise H. cuneata calcification more than two-fold and thus we suggest that H. cuneata populations coexisting with H. wrightii may have a higher resilience to OA conditions. This conclusion supports the more general hypothesis that, in coastal and shallow reef environments, the metabolic interactions between calcifying and non-calcifying organisms are instrumental in providing refuge against OA effects and increasing the resilience of the more OA-susceptible species.E.B. would like to thank the Coordenação de Aperfeiçoamento de Pessoas de Nível Superior (CAPES) for Masters funding. Funding for this project came from the Synergism grant (CNPq 407365/2013-3). We extend our thanks to the Brazil-based Projeto Coral Vivo and its sponsor PetroBras Ambiental for providing the Marine Mesocosm structure and experimental assistance.info:eu-repo/semantics/publishedVersio

Tahiti sea level : the last deglacial sea level rise in the South Pacific

Integrated Ocean Drilling Program (IODP) Expedition 310 to the reef terraces around Tahiti, French Polynesia, was the second expedition to utilize a mission-specific platform (MSP) and was conducted by the European Consortium for Ocean Research Drilling (ECORD) Science Operator (ESO). The objectives of Expedition 310 are to establish the course of postglacial sea level rise at Tahiti, to define sea-surface temperature (SST) variations for the region over the period 20–10 ka, and to analyze the impact of sea level changes on reef growth and geometry. To meet these objectives, the postglacial reef sequence, which consists of successive reef terraces seaward of the living barrier reef, was cored from a dynamically positioned vessel during October and November 2005. A total of 37 boreholes across 22 sites were cored in water depths ranging from 41.65 to 117.54 m. Borehole logging operations in 10 boreholes provided continuous geophysical information about the drilled strata. The cores were described during the Onshore Science Party at the IODP Bremen Core Repository during February and March 2006, where minimum and some standard measurements were made. Further postcruise research on samples taken during the Onshore Science Party are expected to fulfill the objectives of the expedition

Marine benthic flora and fauna of Gourdon Bay and the Dampier Peninsula in the Kimberley region of North-Western Australia

Surveys undertaken to characterise the marine benthic habitats along the Dampier Peninsula and further south at Gourdon Bay in the Kimberley region of Western Australia were augmented with epibenthic sled sampling of soft and hard bottom habitats. This paper describes the species collected, their biomass and relative abundance for the main groups of marine macrophytes and invertebrates. Five localities were surveyed; Gourdon Bay, Quondong Point to Coulomb Point, Carnot Bay to Beagle Bay, Perpendicular Head and Packer Island. Sampling was limited to fifteen epibenthic dredge operations from a range of habitat types and was designed to target the most common habitat types and to obtain species identifications of the most important species and those which typified different habitat types. Surveys covered a total of 1,350 m 2 of seabed in depths between 11 and 23m. We identified 415 taxa comprising: 1 seagrass, 43 algae, 52 sponges, 30 ascidians, 10 hydroids, 14 scleractinian corals, 52 other cnidarians, 69 crustaceans, 73 molluscs and 71 echinoderms. Despite the limited nature of the sampling, a significant number of new species, range extensions and new records for Western Australia and Australia were recorded. Within the algae, one range extension (Halimeda cf. cuneata f. digitata not previously recorded in Western Australia) and one possible new species of Areschougia were recorded. Two range extensions were present in the ascidians; the solitary ascidian Polycarpa cf. intonata has previously only been recorded in Queensland and Cnemidocarpa cf. radicosa only in temperate Australian waters. There were several range extensions for the crustacea, for example, the sponge crab, Tumidodromia dormia, has only been recorded in Queensland. One species of holothurian of the genus Phyllophorus could not be identified from the literature available and may represent a new species. Similarly, a small species of the echinoid Gymnechinus could possibly be a new species. The collections of hydroids, hard corals, crinoids and molluscs contained no new species or range extensions. There was difficulty in identification of some groups to species level due to the status of the current taxonomic literature (e.g. Cnidaria, Porifera and ascidians) and there may be a number of new species among the material collected. Among the anthozoa, there is at least one new species of Chromonephthea and potentially 10 range extensions to Western Australia. Sinularia cf. acuta and Chromonephthea curvata are both new records for Australia with both previously recorded in Indonesia only. Among the better known taxa (e.g. molluscs, echinoderms, corals), most of the taxa identified to species level have been recorded to occur throughout north-western Australia, however the diversity recorded in this study is less than other parts of the Kimberley and this is almost certainly a result of the small overall area sampled and the single method of collection utilised. The most important species on soft bottom habitats in terms of biomass was the heart urchin Breynia desorii (up to 326 g.m -2). Sponges were the dominant fauna by biomass (up to 620 g.m -2) on hard bottom habitats and biomass was dominated a by a few large cup and massive sponge species (e.g. Pione velans and two unidentified Spheciospongia). The biomass of other filter feeders, especially ascidians (e.g. Aplidium cf. crateriferum), soft corals (e.g. Chromonephthea spp.), gorgonians (e.g. Junceella fragilis and Dichotella gemmacea) was also high, indicating the importance of these groups in characterising hard bottom habitats. Although low in biomass, crinoids such as Comaster multifidus and Comatula pectinata were abundant in samples that included a high biomass of other filter feeders

An environmental assessment of the John Pennekamp Coral Reef State Park and the Key Largo Coral Reef Marine Sanctuary (Unpublished 1983 Report)

The Pennekamp Coral Reef State Park was established in 1960 and the Key Largo National Marine Sanctuary in 1975. Field studies, funded by NOAA, were conducted in 1980 - 1981 to determine the state of the coral reefs and surrounding areas in relation to changing environmental conditions and resource management that had occurred over the intervening years. Ten reef sites within the Sanctuary and seven shallow grass and hardbottom sites within the Park were chosen for qualitative and quantitative studies. At each site, three parallel transects not less than 400 m long were run perpendicular to the reef or shore, each 300 m apart. Observations, data collecting and sampling were done by two teams of divers. Approximately 75 percent of the bottom within the 18-m isobath was covered by marine grasses, predominantly turtle grass. The general health of the seagrasses appeared good but a few areas showed signs of stress. The inner hardbottom of the Park was studied at the two entrances to Largo Sound. Though at the time of the study the North Channel hardbottom was subjected to only moderate boat traffic, marked changes had taken place over the past years, the most obvious of which was the loss of the extensive beds of Sargassum weed, one of the most extensive beds of this alga in the Keys. Only at this site was the green alga Enteromorpha encountered. This alga, often considered a pollution indicator, may denote the effects of shore run off. The hardbottom at South Channel and the surrounding grass beds showed signs of stress. This area bears the heaviest boat traffic within the Park waters causing continuous turbidity from boat wakes with resulting siltation. The offshore hardbottom and rubble areas in the Sanctuary appeared to be in good health and showed no visible indications of deterioration. Damage by boat groundings and anchors was negligible in the areas surveyed. The outer reefs in general appear to be healthy. Corals have a surprising resiliency to detrimental factors and, when conditions again become favorable, recover quickly from even severe damage. It is, therefore, a cause for concern that Grecian Rocks, which sits somewhat inshore of the outer reef line, has yet to recover from die-off in 1978. The slow recovery, if occurring, may be due to the lower quality of the inshore waters. The patch reefs, more adapted to inshore waters, do not show obvious stress signs, at least those surveyed in this study. It is apparent that water quality was changing in the keys. Water clarity over much of the reef tract was observed to be much reduced from former years and undoubtedly plays an important part in the stresses seen today over the Sanctuary and Park. (PDF contains 119 pages

Increasing Carbon Dioxide Concentration and Temperature on Growth and Histopathology of Tropic Macroalgae Halimeda SP

The increasing CO2 concentration and temperature affected growth, chlorophyll content, calcium content, and histological tissue of tropical macroalgae Halimeda sp. The study was conducted to examine the interaction effect of the increased CO2 concentration and temperature on growth, chlorophyll-a content, calcium content, and histological tissue of tropical macroalgae Halimeda sp in a laboratory. Research was set with a completely randomized factorial design at 3 levels of factors (A) the CO2 concentration: 385 ppm (ambient), 750 ppm (medium), 1000 ppm (high), and 3 levels of factor (B) the temperature: 30oC, 32oC, 34oC. Microcolony of macroalgae Halimeda sp were selected and obtained from the Lae-lae island then growing in the aquarium 30 x 30 x 45 cm3. Biological parameters observed were growth rate (total, specific and relative), chlorophyll-a content, calcium content, and histopathology tissue. The results showed that the increased of CO2 concentration and temperature negatively affected on the growth of Halimeda sp, reduced of the growth rate, the chlorophyll-a content, calcium content and damaged to histopatology tissue of the Halimeda sp at trophical macroalgae