Marine macroalgae as a dietary source of genoprotection in gilthead seabream (Sparus aurata) against endogenous and exogenous challenges.

DNA integrity and stability are essential to organisms' health and survival. However, it has been neglected in what concerns to fish farming, disregarding the potential impact of endogenous/ exogenous factors. As marine macroalgae constitute a source of natural compounds with a large spectrum of biological activities, this study, situated in the interface of nutritional-genetic research and development of algae practical applications, aimed to evaluate the genoprotective properties of a macroalgae-enriched diet (total percentage of 5%, incorporating equal percentages of Ulva rigida, Gracilaria gracilis and Fucus vesiculosus) in gilthead seabream (Sparus aurata).

Metals(loids) targeting fish eyes and brain in a contaminated estuary - Uncovering neurosensory (un)susceptibility through bioaccumulation, antioxidant and morphometric profiles.

This study examined the susceptibility of fish (Liza aurata) eyes and brain to metals(loids) contamination under realistic exposure conditions. A multidimensional approach was applied to fish caught at a chronically contaminated site (BAR) and at a reference site of the Tagus estuary (Portugal), which comprised metals(loids) accumulation in eyes and brain together with a battery of enzymatic and non-enzymatic antioxidants, as well as brain morphometry (i.e.

The role of contamination history and gender on the genotoxic responses of the crayfish Procambarus clarkii to a penoxsulam-based herbicide.

The responses of non-target organisms to pesticide exposure are still poorly explored in what concerns the development of adjustments favouring population success. Owing to the vital role of DNA integrity, it is important to identify genome-maintenance skills and their determinant factors. Thus, the major aims of the present study were: (i) to assess the genotoxicity of the penoxsulam-based herbicide (Viper) to the crayfish Procambarus clarkii; (ii) to understand the influence of gender and contamination history in the genotoxic responses following exposure to this herbicide; (iii) to investigate the damage mechanisms involved in putative adjustments shown by P.

Oxidative stress profiles in brain point out a higher susceptibility of fish to waterborne divalent mercury compared to dietary organic mercury.

This study examines, for the first time, the neurotoxicity of Hg(II) and MeHg in fish (Diplodus sargus) in a time-course comparative perspective and considering realistic exposure levels and routes. Both forms followed an identical time-variation pattern of accumulation in the brain, but dietary MeHg was more efficiently transported to the brain. MeHg was substantially eliminated from the brain in 28days of depuration, which did not occur for Hg(II).

Evidences of DNA and chromosomal damage induced by the mancozeb-based fungicide Mancozan in fish (Anguilla anguilla L.).

The formulation Mancozan, containing mancozeb as active ingredient, is among the most widely used fungicides. Although mancozeb has been detected in surface waters, studies addressing the genotoxic risk to fish arising from the use of this formulation, testing environmentally realistic concentrations, are absent from the literature. Hence, this work aimed to investigate the DNA and chromosome damaging potential of Mancozan (0.

Propensity to metal accumulation and oxidative stress responses of two benthic species (Cerastoderma edule and Nephtys hombergii): are tolerance processes limiting their responsiveness?

The chronic exposure of benthic organisms to metals in sediments can lead to the development of tolerance mechanisms, thus diminishing their responsiveness. This study aims to evaluate the accumulation profiles of V, Cr, Co, Ni, As, Cd, Pb and Hg and antioxidant system responses of two benthic organisms (Cerastoderma edule, Bivalvia; Nephtys hombergii, Polychaeta). This approach will provide clarifications about the ability of each species to signalise metal contamination.

Insights into the mechanisms underlying mercury-induced oxidative stress in gills of wild fish (Liza aurata) combining (1)H NMR metabolomics and conventional biochemical assays.

Oxidative stress has been described as a key pathway to initiate mercury (Hg) toxicity in fish. However, the mechanisms underlying Hg-induced oxidative stress in fish still need to be clarified. To this aim, environmental metabolomics in combination with a battery of conventional oxidative stress biomarkers were applied to the gills of golden grey mullet (Liza aurata) collected from Largo do Laranjo (LAR), a confined Hg contaminated area, and São Jacinto (SJ), selected as reference site (Aveiro Lagoon, Portugal).

Insights into neurosensory toxicity of mercury in fish eyes stemming from tissue burdens, oxidative stress and synaptic transmission profiles.

This study aims to contribute to fill a knowledge gap related with Hg effects in fish eyes. As a pioneering strategy, Hg bioaccumulation in eye wall of the wild grey mullet (Liza aurata) was assessed, together with oxidative stress and synaptic transmission profiles. This approach was complemented by the characterisation of environmental contamination (both in water and sediment).

Unravelling the mechanisms of mercury hepatotoxicity in wild fish (Liza aurata) through a triad approach: bioaccumulation, metabolomic profiles and oxidative stress.

Clarification of the mechanisms of mercury (Hg) toxicity in fish remains challenging. An innovative approach to this clarification is the combined assessment of metabolomic shifts, alterations in the antioxidant system and the risk of oxidative damage, and Hg bioaccumulation. This strategy was applied to the livers of golden grey mullet (Liza aurata) inhabiting an Hg-contaminated system in Aveiro Lagoon, Portugal.

Assessment of chromosomal damage induced by a deltamethrin-based insecticide in fish (Anguilla anguilla L.) - a follow-up study upon exposure and post-exposure periods.

The pyrethroid insecticide Decis®, containing deltamethrin as active ingredient, is among the most popular broad-spectrum biocides, with wide application in agriculture and home pest control. The occurrence of deltamethrin in the aquatic environment is well-established, but the possible genotoxic effects of Decis® in non-target organisms, namely fish, remain unknown. Hence, this work aimed to evaluate the cytogenetic damaging potential of Decis® in European eel (Anguilla anguilla L.

Metal accumulation and oxidative stress responses in Ulva spp. in the presence of nocturnal pulses of metals from sediment: a field transplantation experiment under eutrophic conditions.

In aquatic systems under eutrophic conditions, remobilization of metals from sediment to the overlying water may occur. Consequently, adaptive responses of local organisms could result from the accumulation of metals intermittently released from the sediment. In summer 2007, a field transplantation experiment was performed in the Óbidos lagoon (Portugal) with Ulva spp.

Effects of chronic cortisol administration on global expression of GR and the liver transcriptome in Sparus aurata.

The present work was designed to assess the effects of artificially increased high plasma cortisol levels induced by slow-release cortisol implants on the mRNA abundance of the glucocorticoid receptor (GR) in different organs of Sparus aurata (Gilthead sea bream), as well as to evaluate global transcriptional changes in the liver, using the Aquagenomics S. aurata oligo-nucleotide microarray technology. For that purpose, groups of fish were intraperitoneally injected with implants containing two different concentrations of cortisol (50 or 200 μg/g body weight).

Hydroxybenzoate paralytic shellfish toxins induce transient GST activity depletion and chromosomal damage in white seabream (Diplodus sargus).

Fish are routinely exposed to harmful algal blooms that produce noxious compounds and impact the marine food web. This study investigates the role of phase I and II detoxification enzymes on metabolism of the novel paralytic shellfish toxins (PSTs), the hydroxybenzoate analogues recently discovered in Gymnodinium catenatum strains, in the liver of white seabream, assessing ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST) activities. Additionally, the genotoxic potential of hydroxybenzoate PSTs was examined through the erythrocytic nuclear abnormality (ENA) assay.

Juvenile sea bass (Dicentrarchus labrax L.) enzymatic and non-enzymatic antioxidant responses following 17beta-estradiol exposure.

In the context of 17beta-estradiol (E2) as an environmental contaminant, this study was designed to test the hypothesis whether it can modulate antioxidant defenses in Dicentrarchus labrax, taking gills as the target organ. Enzymatic (GPX--glutathione peroxidase; CAT--catalase; GR--glutathione reductase; GST--glutathione S-transferase) and non-enzymatic antioxidants (NP-SH--non protein thiols; GSHt--total glutathione) were measured following 10-day exposure to E2 in two different ways: water diluted (WD, 200 or 2,000 ng/L) and intraperitoneally injected (i.p.

Anguilla anguilla L. oxidative stress biomarkers: an in situ study of freshwater wetland ecosystem (Pateira de Fermentelos, Portugal).

Pateira de Fermentelos (PF) is a natural freshwater wetland in the central region of Portugal. In the last decade, the introduction of agricultural chemicals, heavy metals, domestic wastes, as well as eutrophication and incorrect utility of resources resulted in an increased water pollution. The present research work was carried out to check the various oxidative stress biomarker responses in European eel (Anguilla anguilla L.

Anguilla anguilla L. oxidative stress biomarkers responses to copper exposure with or without beta-naphthoflavone pre-exposure.

The redox cycling of heavy metals as well as their interactions with organic pollutants is a major contributor to the oxidative stress resulting from aquatic pollution. Therefore, in order to evaluate beta-naphthoflavone (BNF), Cu and BNF/Cu-induced oxidative stress with single and subsequent exposures, research was carried out in European eel (Anguilla anguilla L.).

Biotransformation, genotoxic, and histopathological effects of environmental contaminants in European eel (Anguilla anguilla L.).

A prolonged toxicity study was carried out in young European eel (Anguilla anguilla L.) to evaluate the effects of environmental contaminants, namely, two individual standard compounds, benzo[a]pyrene (BaP) and dehydroabietic acid (DHAA), and a complex mixture, bleached kraft pulp mill effluent (BKPME). Fish were exposed to BaP (0.