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Although arsenic (As) is a persistent contaminant in the environment, few studies have assessed its effects over generations, as it requires an animal model with a short lifespan and rapid development, such as the nematode Caenorhabditis elegans. Furthermore, few studies have evaluated the effects of As metabolites such as dimethylarsinic acid (DMAV), and several authors have considered DMA as a moderately toxic intermediate of As, although recent studies have shown that this chemical form can be more toxic than inorganic arsenic (iAs) even at low concentrations. In the present study, we compared the toxic effects of arsenate (AsV) and DMAV in C. elegans over 5 subsequent generations. We evaluated biochemical parameters such as reactive oxygen species (ROS) concentration, the activity of antioxidant defense system (ADS) enzymes such as catalase (CAT) and glutathione-S-transferase (GST), and nonenzymatic components of ADS such as reduced glutathione (GSH) and protein-sulfhydryl groups (P-SH). Exposure to 50 μg L−1 of AsV led to an increase in ROS generation and GSH levels together with a decrease in GST activity, while exposure to DMAV led to an increase in ROS levels, with an increase in lipid peroxidation, CAT activity, and a decrease in GSH levels. In addition, both treatments reduced animal growth from the third generation onward and caused disturbances in their reproduction throughout all 5 generations. This study shows that the accumulated effects of DMA need to be considered; it highlights the importance of this type of multigenerational approach for evaluating the effects of organic contaminants considered low or nontoxic.

Probiotics can be defined as non-pathogenic living organisms used to improve the health of the host and act against the development of pathogens. Shrimp farms have used artisanal strategies to multiply the bacteria of commercial probiotics and thus decrease the costs with the commercial product. The study was conducted at the Marine Station of Aquaculture, FURG, Brazil. The three experiments used homemade protocols of different shrimp farms. Water collections were performed at 00 h and 24 h to quantify bacteria. The experiments were (I) 25 g of Pro-W probiotic, 25 g of powdered milk, 50 mL of molasses, and 25 g of calcium carbonate, (II) 25 g of Pro-W probiotic, 50 g of rice bran, 33.33 g of crystal sugar and 12.5 g of sodium bicarbonate and (III) 25 g of Pro-W probiotic, 25 g of Bokashi Bran, 50 mL of molasses and 12.5 g of sodium bicarbonate. The protocols were based on the traditional practice of shrimp farms in Latin America. Each experiment had 6 treatments and 3 repetitions. The treatments were carried out in freshwater and saltwater. T1: Control in freshwater (only probiotic); T2: Control in saltwater (only probiotic); T3: Negative control in freshwater (only fertilizers); T4: Negative control in saltwater (only fertilizers); T5: Protocol in freshwater (probiotic + fertilizers); T6: Protocol in saltwater (probiotic + fertilizers). The three experiments showed growth of Bacillus, coccoid and filamentous bacteria in all treatments, however the results indicate that the protocols used could not contribute significantly to the replication of commercial probiotics.

In vitro assays were used to determine the effects of aqueous fine particulate matter (PM2.5) extracts on different homogenates of rat organs. The PM2.5 collected from two regions (Seropedica and Duque de Caxias) in Rio de Janeiro, Brazil, were used to evaluate different oxidative damages and redox state. Two PM2.5 extract concentrations (concentrate and 10x dilution) were evaluated using rat tissue homogenates (heart, lung, liver, and kidney). Measurements of total antioxidant capacity (ACAP), lipid peroxidation levels (LPO), reduced glutathione concentrations (GSH), activity of glutamate cysteine ligase (GCL), activity of glutathione S-transferase (GST) and catalase (CAT) were performed. Most PM2.5 aqueous extract concentrations contain numerous metals (e.g. Li, Ti, Fe, Cu, Cd, Sr, among others), which reduced ACAP and generated LPO in most tissue homogenates. Besides this, GST activity decreased in liver and lung, increasing in kidney and heart homogenates. GCL activity increased in lung, liver and kidney and undergo decrease in the heart homogenate. All concentrations of PM2.5 evaluated decreased GSH levels. PM2.5 concentrations for both sites (regions) raised catalase activity in most tissue homogenates except in the liver. In vitro toxicity of the PM2.5 in different tissues, presented an ability to interact with cellular antioxidant defense system, causing depletion of the sulfhydryl stocks, resulting in the damage of biological molecules and inducing oxidative imbalance.

Although arsenic (As) is a persistent contaminant in the environment, few studies have assessed its effects over generations, as it requires an animal model with a short lifespan and rapid development, such as the nematode Caenorhabditis elegans. Furthermore, few studies have evaluated the effects of As metabolites such as dimethylarsinic acid (DMA(V)), and several authors have considered DMA as a moderately toxic intermediate of As, although recent studies have shown that this chemical form can be more toxic than inorganic arsenic (iAs) even at low concentrations. In the present study, we compared the toxic effects of arsenate (As(V)) and DMA(V) in C. elegans over 5 subsequent generations. We evaluated biochemical parameters such as reactive oxygen species (ROS) concentration, the activity of antioxidant defense system (ADS) enzymes such as catalase (CAT) and glutathione-S-transferase (GST), and nonenzymatic components of ADS such as reduced glutathione (GSH) and protein-sulfhydryl groups (P-SH). Exposure to 50 μg L(−1) of As(V) led to an increase in ROS generation and GSH levels together with a decrease in GST activity, while exposure to DMA(V) led to an increase in ROS levels, with an increase in lipid peroxidation, CAT activity, and a decrease in GSH levels. In addition, both treatments reduced animal growth from the third generation onward and caused disturbances in their reproduction throughout all 5 generations. This study shows that the accumulated effects of DMA need to be considered; it highlights the importance of this type of multigenerational approach for evaluating the effects of organic contaminants considered low or nontoxic.

Made available in DSpace on 2022-04-29T08:36:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 The animals from bycatch of the shrimp fisheries can be a source of natural products and bioactive compounds. Thus, the present study aimed to evaluate the bioactivity of protein hydrolysates prepared from the two most abundant crabs from the bycatch of shrimp fisheries in Brazil (Callinectes ornatus and Hepatus pudibundus). Samples of C. ornatus and H. pudibundus were collected in the region of Ubatuba, State of São Paulo, Brazil. Muscles with small pieces of exoskeleton of both species were hydrolyzed using two enzymes, Alcalase 2.4 L® or Protamex®. The in vitro antioxidant capacity was analyzed used three methods: DPPH, sulfhydryl groups, and peroxyl radicals. Additionally, the cytotoxicity of the hydrolysates was investigated using pre-osteoblasts cells. The results showed that the degree of hydrolysis (DH) of H. pudibundus was superior to DH of C. ornatus using both enzymes and was higher when using the enzyme Alcalase 2.4 L® (32.0% ± 1.9). The analysis suggested that the hydrolysates have antioxidant activity. Besides that, no cytotoxic effect was observed on cell viability. Thus, protein hydrolysates of C. ornatus and H. pudibundus have bioactivity, which add value to these bycatch species and suggests their potential use as nutraceutical ingredient in the food industry. Graphic Abstract: [Figure not available: see fulltext.] Aquaculture Center São Paulo State University (UNESP), Campus Jaboticabal, Via de Acesso Prof. Paulo Donato Castellane, s/n 14884-900 Marine Station of Aquaculture Oceanography Institute Federal University of Rio Grande (FURG) Rio Grande, Aquaculture postgraduate Institute of Biological Sciences (ICB) Federal University of Rio Grande (FURG) Department of Chemical and Biological Sciences Bioscience Institute São Paulo State University (UNESP), Campus Botucatu Aquaculture Center São Paulo State University (UNESP), Campus Jaboticabal, Via de Acesso Prof. Paulo Donato Castellane, s/n 14884-900 Department of Chemical and Biological Sciences Bioscience Institute São Paulo State University (UNESP), Campus Botucatu

The objective of the present study was to evaluate the use of fermented and non-fermented whole rice bran for rotifer feeding, based on the effects on growth parameters, antioxidant and oxidative damage responses, and water quality. The study was based on three experiments, which compared the effect of different concentrations of non-fermented whole rice bran, the effect of different concentrations of fermented whole rice bran and the effect of the best concentrations of fermented and non-fermented whole rice bran, as well as the replacement of part of the baking yeast by rice bran. The results showed the best growth performances in treatments with 0.7 g yeast with 1.5 g fermented rice bran, 0.35 g yeast with 0.75 g whole rice bran, and 0.35 g yeast with 0.75 g fermented rice bran. Fermentation of rice bran for 6 hours did not induce oxidative stress in rotifers. This work revealed that the use of 1.5 g of fermented bran and replacement of 50% of yeast with fermented or non-fermented rice bran may be used for rotifer feeding, with the additional benefit of improving the environmental quality due to the lower amount of ammonia released in the water.

In recent times, however, due to the emergence of bacterial strains with resistance to conventional antibiotics, silver has again gained attention as an alternative for developing new efficient bactericides, including the use of silver nanoparticles (AgNPs). However, the improper disposal of these items after use may cause toxicological effects on organisms in the environment. To evaluate the potential environmental hazard of nanosilver-coated dressings, the nematode Caenorhabditis elegans was chosen as a test organism. The assays were conducted in 24-well plates that contain four different sizes of coated dressing to obtain different concentrations. L1 and L4 C. elegans larval stages were exposed to these nanosilver concentrations. Dressing cutouts were arranged between two layers of agar for 3 days and Escherichia coli (OP 50 strain) was added as food source for the worms. After the exposure period, growth, reproduction, fertility, silver concentration in the medium and the concentration of reactive oxygen species (ROS) in the worms were evaluated. Scanning and transmission electron microscopy analyses were performed on the coated dressings, as well as analyses of zeta potential, ionic release and antibacterial power in two bacterial strains (Pseudomonas aeruginosa and Staphylococcus aureus). It was verified the antibacterial power of the coated dressing, in both bacteria strains tested. Characterization of the coated dressing indicated heterogeneous nanoparticles, as well as distinct zeta potentials for the medium in water and saline medium (0.9% NaCl). L1 larval worms exposed to nanosilver-coated dressing showed a high ROS concentration and reductions in growth, fertility and reproduction. Worms exposed to the coated dressing during the L4 stage showed almost no response. Overall, the obtained results indicate the potential environmental hazard of nanosilver-coated dressings. Fil: Ayech, Alinne. Universidade Federal do Rio Grande; Brasil Fil: Josende, M. E.. Universidade Federal do Rio Grande; Brasil Fil: Ventura Lima, J.. Universidade Federal do Rio Grande; Brasil Fil: Ruas, Caroline Pires. Universidade Federal do Rio Grande; Brasil Fil: Gelesky, M. A.. Universidade Federal do Rio Grande; Brasil Fil: Ale, Analía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Cazenave, Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Galdopórpora, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquimica. Instituto de Química y Metabolismo del Fármaco; Argentina Fil: Desimone, Martín Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquimica. Instituto de Química y Metabolismo del Fármaco; Argentina Fil: Duarte, Miriam. Universidade Federal do Rio Grande; Brasil Fil: Halicki, Priscila Cristina Bartolomeu. Universidade Federal do Rio Grande; Brasil Fil: Ramos, Daniela Fernandes. Universidade Federal do Rio Grande; Brasil Fil: Carvalho, L. M.. Universidade Federal de Santa Maria; Brasil Fil: Leal, Gabriela Camera. Universidade Federal de Santa Maria; Brasil Fil: Monserrat, José María. Universidade Federal do Rio Grande; Brasil

Although some studies have showed the effects of different crystalline structures of nTiO2 (anatase and rutile) and their applicability in several fields, few studies has analyzed the effect of coexposure with other environmental contaminants such as copper. Thus, the objective of this study was to evaluate if the coexposure to nTiO2 (nominal concentration of 1 mg/L; anatase or rutile) can increase the incorporation and toxic effect induced by Cu (nominal concentration of 56 μg/L) in different tissues of Linmoperna fortunei after 120 h of exposure. Our results showed that the coexposure increased the accumulation of Cu in the gills and adductor muscle independently of the crystalline form and can positively or negatively modulate the antioxidant system, depending on the tissue analyzed. However, exposure only to rutile nTiO2 induced damage in the adductor muscle evidenced by the infiltration of hemocytes in this tissue. Additionally, histomorphometric changes based on fractal dimension analysis showed that coexposure to both forms of nTiO2 induced damage in the same tissue. These results suggest that both crystalline forms exhibited toxicity depending on the analyzed tissue and that coexposure of nTiO2 with Cu may be harmful in L. fortunei, indicating that increased attention to the use and release of nTiO2 in the environment is needed to avoid deleterious effects in aquatic biota.

Phytoremediation is a low cost technology based on the use of plants to remove a wide range of pollutants from the environment, including the insecticide DDT. However, some pollutants are known to enhance generation of reactive oxygen species (ROS), which can generate toxic effects on plants affecting the phytoremediation efficiency. This study aims to analyze the potential use of antioxidant responses as a measure of tolerance to select plants for phytoremediation purposes. Tomato and zucchini plants were grown for 15 days in soils contaminated with DDTs (DDT + DDE + DDD). Protein content, glutathione-S-transferase (GST), glutathione reductase (GR), glutathione peroxidase (GPx) and catalase (CAT) activities were measured in plant tissues. Exposure to DDTs did not affect protein content or CAT activity in any of the species. GST, GR and GPx activity showed different responses in exposed and control tomato plants. After DDTs exposure, tomato showed increased GR and GPX activity in stems and leaves, respectively, and a decrease in the GST activity in roots. As no effects were observed in zucchini, results suggest different susceptibility and/or defense mechanisms involved after pesticide exposure. Finally, both species differed also in terms of DDTs uptake and translocation. The knowledge about antioxidant responses induced by pesticides exposure could be helpful for planning phytoremediation strategies and for the selection of tolerant species according to particular scenarios. Fil: Mitton, Francesca María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Gonzalez, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Monserrat, José María. Universidad Do Rio Grande Do Sul; Brasil. Universidade Federal do Rio Grande do Sul; Brasil Fil: Miglioranza, Karina Silvia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina

Nanomaterials (NM) exhibit unique properties due their size and relative area, but the mechanisms and effects in the living organisms are yet to be unfold in their totality. Potential toxicity mechanisms concerning NM as carbon nanotubes include oxidative stress generation. Several fluorimetric and colorimetric methods have been systematically used to measure NM toxicity, and controversial results have been reported. One of the problems can be related to the interference effects induced by NM, leading to artifacts that can lead to misleading conclusions. In present study, it was performed in vitro assays with two aquatic species: the zebrafish Danio rerio and the polychaete Laeonereis acuta to evaluate the potential interference capacity of single-wall carbon nanotubes (SWCNT) in a fluorometric method (TBARS assay) to measure lipid peroxidation. Obtained results indicated that gills and brain of zebrafish presented a lowered fluorescence only at extremely high concentrations (50 and 500 mg/L). Determinations in anterior, middle, and posterior body regions of L. acuta showed a quite different pattern: high fluorescence at low SWCNT concentrations (0.5 mg/L) and lowering at the highest (500 mg/L). To eliminate matrix effect of biological samples, tests employing the standard for TBARS assay, 1,3,3-tetramethoxipropane, were run and the results showed again higher fluorescence values at low concentrations (0.5–5 mg SWCNT/L), a technique artifact that could lead to misleading conclusions since higher fluorescence values implicate higher TBARS concentration, implying oxidative stress. Using the colorimetric FOX assay with cumene hydroperoxide as standard presented remarkable better results since no artifacts were observed in the same SWCNT concentration range that employed with the TBARS technique.

In the present study, different in vitro and electrochemical protocols were employed to determine the mitoprotective properties of carbon nanotubes family (pristine-CNT, oxidized-CNT) based on free radical scavenging ability against the most aggressive reactive oxygen species (ROS) as hydroxyl radical (·OH) formed by Fenton-Haber-Weiss reaction, which was experimentally induced on isolated rat-liver mitochondria through Fe 2+ ions overload. The results suggest that the mitochondrial Fenton-inhibition response involves a significant reduction of (·OH) concentration linked to iron-complexing ability of CNT-family, following the order: carboxylated-CNT > pristine-CNT ∼ hydroxylated-CNT, without affecting the electrochemical mitochondrial membrane potential in Fe 2+ -overloaded mitochondria. Besides, a new in silico dose-response QSPR-model was applied suggesting reliability for the CNT-dose-effect series predictions towards the mitochondrial Fenton ROS-inhibition with excellent linear behavior on the training set ( R 2 = 0.901; R 2 ( adj .) = 0.901; Q 2 ( LOO-CV ) = 0.901) and test set ( Q 2 F1 = 0.9008; Q 2 F2 = 0.9008; Q 2 F3 = 0.9009; MAE = 21.213) for internal and external validation respectively, with p 70,000 data points. Lastly, these experimental and theoretical evidences open a gate to the rational design of novel carbon nanomaterials toward mitochondrial nanomedicine based redox-targeting as an alternative of treatment of several chronic diseases where pathological Fenton-reaction mechanisms have been directly involved.

This study examined the effects of waterborne silver nanoparticles (AgNPs) on juvenile fish Piaractus mesopotamicus (“pacú”), and analyzed toxicological endpoints such as metal burdens, oxidative stress and genotoxicity in a short-term assay. Fish were individually exposed to 0 (control), 2.5, 10, and 25 μg AgNPs/L. After 24 h, silver accumulation was greater in the brain than the liver and gills at all silver concentrations. Fish exposed to higher AgNPs concentrations showed major alterations in oxidative stress markers. An increase in lipid peroxidation (LPO) levels was observed in the liver of fish exposed to 10 μg AgNPs/L with no changes in the antioxidant enzymes activities. In the case of the 25 μg AgNPs/L treatment, a hepatic activation of the enzymatic antioxidant defense occurred, and LPO levels resulted unaltered. On the other hand, the brain presented the highest LPO levels at both 10 and 25 μg AgNPs/L exposures. The AgNPs toxicity was also evidenced by the DNA damage in fish erythrocytes at higher concentrations. Summarizing, a short exposure to sublethal concentrations of AgNPs is enough to generate deleterious effects on fish, including DNA damage. Fil: Bacchetta, Carla. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Ale, Analía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Simoniello, Maria Fernanda. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina Fil: Gervasio, Susana Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentina Fil: Davico, Carla. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias; Argentina Fil: Rossi, Andrea Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias; Argentina Fil: Desimone, Martín Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; Argentina Fil: Poletta, Gisela Laura. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina Fil: Lopez, Gerardo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; Argentina. NanoteK S.A,; Argentina Fil: Monserrat, José María. Universidade Federal do Rio Grande do Norte; Brasil. Instituto Nacional de Ciência e Tecnologia Nanomateriais de Carbono; Brasil Fil: Cazenave, Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias; Argentina

As a consequence of their unique characteristics, the use of Engineered Nanomaterials (ENMs) is rapidly increasing in industrial, agricultural products, as well as in environmental technology. However, this fast expansion and use make likely their release into the environment with particular concerns for the aquatic ecosystems, which tend to be the ultimate sink for this type of contaminants. Considering the settling behaviour of particulates, benthic organisms are more likely to be exposed to these compounds. In this way, the present review aims to summarise the most recent data available from the literature on ENMs behaviour and fate in aquatic ecosystems, focusing on their ecotoxicological impacts towards marine and estuarine bivalves. The selection of ENMs presented here was based on the OECD's Working Party on Manufactured Nanomaterials (WPMN), which involves the safety testing and risk assessment of ENMs. Physical-chemical characteristics and properties, applications, environmental relevant concentrations and behaviour in aquatic environment, as well as their toxic impacts towards marine bivalves are discussed. Moreover, it is also identified the impacts derived from the simultaneous exposure of marine organisms to ENMs and climate changes as an ecologically relevant scenario. published

Carbon nanomaterials (CNM), such as graphene oxide (GO), have been the focus of study in several areas of science mostly due to their physical-chemical properties. However, data concerning the potential toxic effects of these CNM in bivalves are still scarce. When present in the aquatic systems, the combination with other contaminants, as well as pH environmental variations, can influence the behavior of these nanomaterials and, consequently, their toxicity. Thus, the main goal of this study was to evaluate the effect of exposure of clam Ruditapes philippinarum to GO when acting alone and in the combination with copper (Cu), under two pH levels (control 7.8 and 7.3). A 28-day exposure was performed and metabolism and oxidative stress-related parameters were evaluated. The effects caused by GO and Cu exposures, either isolated or co-exposed, showed a direct and dependent relationship with the pH in which the organisms were exposed. In clams maintained at control pH (7.8), Cu and GO + Cu treatments showed lower lipid peroxidation (LPO) and lower electron transport system (ETS) activity, respectively. In clams maintained at low pH, glutathione-S-transferases (GSTs) activities were increased in Cu and Cu + GO treatments, whereas reduced glutathione (GSH) levels were increased in Cu treatment and ETS activity was higher in GO + Cu. Thus, it can be observed that clams responses to Cu and GO were strongly modulated by pH in terms of their defense system and energy production, although this does not result into higher LPO levels.

Made available in DSpace on 2019-10-04T11:57:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-04-01 Instituto Nacional de Ciencia e Tecnologia Nanomaterial de Carbono Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Given the increasing use of carbon nanotubes (CNT) in several industries and technological applications, it is essential to perform in vivo toxicological studies with these nanomaterials to evaluate their potential ecotoxicity. Dopamine (DA) and serotonin (5HT) are key neurotransmitters for brain functions and behavioral responses. Determination of DA and 5HT were performed in brain samples from zebrafish Danio rerio exposed i.p. to single-walled CNT (SWCNT), besides analyzing acetylcholinesterase (AChE) and ectonucleotidases activity, lipid peroxidation and total antioxidant capacity. Results showed that treatment with SWCNT increased between 3 and 6-fold the concentration of DA and 5HT (p < 0.05). Similarly, a significant reduction (p < 0.05) in AChE activity was observed in the brains of SWCNT exposed zebrafish when compared to the control groups. Cholinergic, serotonergic, and dopaminergic systems, through AChE activity and serotonin and dopamine levels, respectively were affected by SWCNT in the zebrafish brain. Alterations in these neurotransmitters can potentially affect several physiological and behavioral that they control. Univ Fed Rio Grande FURG, ICB, Av Italia Km 8 S-N,Cx P 474, BR-96200970 Rio Grande, RS, Brazil Univ Fed Rio Grande FURG, ICB, Progmma Posgrad Ciencias Fisiol FAC, Rio Grande, RS, Brazil Rede Nanotoxicol MCTI CNPq, Brasilia, DF, Brazil Inst Nacl Ciencia & Tecnol Nanomat Carbono CNPq, Belo Horizonte, MG, Brazil Fac Biociencias PUCRS INCT TM CNPq, Porto Alegre, RS, Brazil Univ Estadual Paulista, Sao Jose Do Rio Preto, SP, Brazil Univ Fed Rio Grande do Sul, Porto Alegre, RS, Brazil Univ Fed Minas Gerais, Belo Horizonte, MG, Brazil Univ Estadual Paulista, Sao Jose Do Rio Preto, SP, Brazil CNPq: 421701/2017-0

Made available in DSpace on 2021-06-25T10:36:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-04-16 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Shrimp trawling is an important socio-economic activity; however, the bycatch can be problematic to the environment. Thus, the present study investigated potential uses of the bycatch to generate value-added products. The biological activity of the protein hydrolysates obtained from the two most abundant fish species (Micropogonias furnieri and Paralonchurus brasiliensis) was evaluated. Muscle and skin samples of both species were hydrolyzed using two enzymes, Alcalase 2.4 L® or Protamex®. The in vitro antioxidant capacity against peroxyl radicals, DPPH, and sulfhydryl groups were analyzed. Cell viability, Western Blotting, Zymogram, and Real-time PCR analyses were performed. The results showed that the hydrolysates have antioxidant activity and no effect on cell viability at doses lower than 16 mg/mL. In addition, they can modulate extracellular remodelling and intracellular pathways related to cell adhesion. Thus, the hydrolysis of the fish bycatch allows the release of bioactive peptides with potential use in the food industry. Aquaculture Center São Paulo State University (UNESP), Campus Jaboticabal Marine Station of Aquaculture Aquaculture postgraduate Oceanography Institute Federal University of Rio Grande (FURG) Rio Grande Institute of Biological Sciences (ICB) Federal University of Rio Grande (FURG) Department of Chemistry and Biochemistry Bioscience Institute São Paulo State University (UNESP), Campus Botucatu Aquaculture Center São Paulo State University (UNESP), Campus Jaboticabal Department of Chemistry and Biochemistry Bioscience Institute São Paulo State University (UNESP), Campus Botucatu

The production and use of graphene-based nanomaterials is rapidly increasing. However, few data are available regarding the toxicity of these nanomaterials in aquatic organisms. In the present study, the toxicity of few-layer graphene (FLG) (obtained by chemical exfoliation) was evaluated in different tissues of the shrimp Litopenaeus vannamei following exposure to FLG through a diet for four weeks. Transmission electron microscopy and dynamic light scattering measurements showed a distribution of lateral sheet sizes between 100 and 2000 nm with the average length and width of 800 and 400 nm, respectively. Oxidative stress parameters were analyzed, indicating that FLG exposure led to an increase in the concentration of reactive oxygen species, modulated the activity of antioxidant enzymes such as glutamate cysteine ligase and glutathione-S-transferase, and reduced glutathione levels and total antioxidant capacity. However, the observed modulations were not sufficient to avoid lipid and DNA damage in both gill and hepatopancreas tissues. Furthermore, graphene exposure resulted in morphological changes in hepatopancreas tissues. These results demonstrate that exposure to FLG through the diet induces alterations in the redox state of cells, leading to a subsequent oxidative stress situation. It is therefore clear that nanomaterials presenting these physico-chemical characteristics may be harmful to aquatic biota.

The intensity of exercise determines the metabolic pathway and the energetic substrate that is spent. Our study sought to identify the effects of different intensities of swimming on myocardial oxidative status and the blood lipid profile. Eighty Wistar rats (male and female) submitted to different intensities of a swimming regimen (low, LS; moderate, MS; or high, HS) for 16 weeks. Samples of blood and myocardium from the left ventricle were collected to determine lipid profiles and oxidative status. Reactive oxygen species (ROS) and antioxidant capacity against peroxyl radicals (ACAP), lipid profiles and lipid peroxidation was analyzed. ROS levels and ACAP were higher in male rats than in female rats overall (p

Two microcosm types -sediment-biota and biota-biota- were constructed to simulate different pathways of BDE-47 uptake, metabolism and oxidative stress effects in two key estuarine invertebrates (polychaete Laeonereis acuta and crab Cyrtograpsus angulatus). In the sediment-biota experiment, both species were exposed to spiked sediments; an environmentally reported and a high concentration of BDE-47 for 2 weeks. In the biota-biota experiment, crabs were fed with polychaetes pre-exposed to BDE-47 in the sediment-biota experiment. The sediment-biota experiment first revealed that polychaetes significantly accumulated BDE-47 (biota-sediment accumulation factor >2; p < 0.05) to a much greater extent than the crab organs (muscle, hepatopancreas, gills) at both sediment concentrations. For oxidative stress responses, polychaete and crab tissues exposed to spiked sediment showed a significant increase (p < 0.05) of only glutathione S-transferase (GST) activity with respect to controls in both BDE-47 concentrations. No lipid peroxidation (TBARS) or total antioxidant capacity (ACAP) changes were evident in the species or organs exposed to either BDE-47 sediment concentration. The biota-biota experiment showed that feeding crabs with pre-exposed polychaetes caused BDE-47 accumulation in organs as well as significant amounts of BDE-47 eliminated through feces (p < 0.05). Unlike the sediment-biota exposure, crabs fed with pre-exposed BDE-47 polychaetes showed the most conspicuous oxidative stress responses. Significant changes in GST and ACAP in both hepatopancreas and gills, in addition to enhanced TBARS levels in the hepatopancreas with respect to controls (p < 0.05), revealed that BDE-47 assimilated by invertebrates represents a potential source of toxicity to their predators. No methoxylated metabolites (MeO-PBDEs) were detected during BDE-47 metabolism in the invertebrates in either of the two different exposure types. In contrast, hydroxylated metabolites (OH-PBDEs) were detected in polychaetes and crab organs/feces in both experiments. Our results demonstrate that PBDE hydroxylation is one of the main biotransformation routes of BDE-47 in estuarine animals, which could be associated with the oxidative stress responses found. Fil: Diaz Jaramillo, Mauricio Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Miglioranza, Karina Silvia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Gonzalez, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Barón, E.. Instituto de Diagnóstico Ambiental y Estudios del Agua; España. Consejo Superior de Investigaciones Científicas; España Fil: Monserrat, José María. Universidade Federal do Rio Grande; Brasil Fil: Eljarrat, E.. Instituto de Diagnóstico Ambiental y Estudios del Agua; España. Consejo Superior de Investigaciones Científicas; España Fil: Barceló, D.. Instituto de Diagnóstico Ambiental y Estudios del Agua; España. Consejo Superior de Investigaciones Científicas; España

Background Nematodes are used in many different fields of science, including environmental and biomedical research. Counting and/or estimating nematode numbers is required during research. Although being one of the most common procedures, this apparently simple task is a time-consuming process, prone to errors and concerns regarding procedure, reliability, and accuracy. When an estimate is necessary, there is a traditional manual counting procedure that in this study it will be called as “drop method” (DM). This popular method that extrapolates an animal count from a small drop of fluid shows a high coefficient of variation. To solve this problem, the present study used the free-living nematode Caenorhabditis elegans to develop a new estimation procedure that was based on a relationship between area and volume of a larger sample. Results The new method showed a low coefficient of variation and a close relationship between estimated and real counts of the total number of nematodes in large C. elegans suspensions. Reactive oxygen concentration was measured as an example of method application and to allow comparison between methods. Conclusion The proposed method is accurate, facile and reproducible, requiring simple, inexpensive materials that make it an excellent alternative to the DM manual counting procedure. Although the DM is faster, its estimates are not as accurate or as precise as those of the new proposed method. Electronic supplementary material The online version of this article (10.1186/s12575-018-0089-2) contains supplementary material, which is available to authorized users.

Este estudo investigou o uso de enzimas exógenas em dietas para juvenis de pampo prateado Trachinotus marginatus. Foram preparadas seis dietas (43% de proteí­­na, 8% de lipí­­dio), contendo 0 (TC), 25 (T25), 50 (T50), 100 (T100), 250 (T250) e 500 (T500) mg kg-1 do complexo enzimático Rovabio ® Max AP. Avaliou-se os efeitos sobre o crescimento, composição de carcaça, ní­­veis de glicogênio e triglicerí­­deo no fí­­gado e possí­­veis alterações na morfologia do intestino e fí­­gado. Os resultados mostraram diferença significativa (p < 0,05) no desempenho de crescimento dos peixes dos tratamentos T100, T250 e T500, com grande concentração de triglicerí­­deos e alteração na morfologia do fí­­gado nos peixes dos tratamentos T250 e T500. A concentração de cálcio nos ossos também teve um aumento significativo (p < 0,05) nos peixes dos tratamentos T50, T100 e T250 em relação ao controle. Entretanto, não houve diferença significativa (p > 0,05) na composição de carcaça, morfologia do intestino e concentração de glicogênio no fí­­gado.Esses resultados indicam que o uso de 100 mg kg-1 de enzimas na dieta mostrou ser o melhor ní­­vel de inclusão para juvenis de pampo prateado, favorecendo o crescimento e a concentração de cálcio nos ossos. Sem efeitos significativos sobre os ní­­veis de triglicerí­­deos no fí­­gado

EMBO Reports (2018) e46008 Science appears to be in a crisis caused by the failure to replicate published results, which is undermining confidence in the scientific literature. This reproducibility crisis is not only evident in large‐scale replication efforts to evaluate studies from various laboratories [1], but also within laboratories themselves [2]. The problem has been extensively discussed among the scientific community, as many scientists have had troubles with replication themselves [3]. A recent survey of 1,576 researchers found that around 90% agreed that the reproducibility crisis is real [3]. There are many factors that influence the reproducibility of published results, including statistical methods, publication bias, lack of transparency, insufficient detail in the description of methods and variability of conditions and protocols between laboratories [1], [2], [4]. Some of these, such as lack of transparency and insufficient detail, directly impair scientists’ ability to properly evaluate a study and to replicate the experiments. Others, such as misuse of statistics and publication bias, lead to systematic biases that undermine the reliability of the entire literature. But there is another, even more insidious factor that has received considerably less attention: random variation. A few years ago, Halsey et al [5] published a commentary on the sample‐to‐sample variability of the P ‐value. They showed that with low statistical power—which is ubiquitous in the literature—the P ‐value can vary widely between samples of the same populations. As part of …

Graphene has been shown to induce toxicity in mammals and marine crustaceans; however, information regarding oxidative stress in fish is scarce. The aim of this study was to evaluate the mechanism of graphene toxicity in different tissues of Danio rerio, considering different parameters of stress. Animals were injected intraperitoneally (i.p.) with 10 μL of suspensions containing different graphene concentrations (5 and 50 mg/L); the gills, intestine, muscle and brain were analysed 48 h later. There was no significant difference in the expression of the gclc (glutamate cysteine ligase catalytic subunit) and nrf2 (nuclear factor (erythroid-derived 2)-like 2) genes after exposure. In contrast, glutamate cysteine ligase (GCL) and glutathione-S-transferase (GST) activities were modulated and the glutathione (GSH) concentration was reduced in different tissues and at different concentrations. Lipid damage was observed in the gills. Histological analyses were performed to observe if the exposure could induce pathological damage in these tissues. The results showed pathological effects in all tissues, excluding the intestine, after exposure to both concentrations. Overall, these results indicate that graphene induces different grades of toxicological effects that are dependent on the analysed organ, with distinct pathological effects on some and oxidative effects on others. However, the brain and gills seem to be the primary target organs for graphene toxicity.

The study of key molecular mechanisms of mitochondrial dysfunctions, which are responsible for neurodegenerative diseases, is a critical step to assist for the diagnosis and therapy success. In this regard, we suggest an alternative of treatment on neurodegenerative disorders-based on Single-Walled Carbon Nanotubes (SWCNT) as potential mito protective -(Phe)-F0-ATPase targeting nanoparticles toward Precision Molecular Nanomedicine against pathological ATP-hydrolysis conditions. Herein, we used ab initio computational simulation to analyze the structural and electronic properties from SWCNT-family with zigzag topologies (n, m - Hamada indices n > 0; m = 0) like: SWCNT-pristine, SWCNT-COOH, SWCNT-OH, SWCNT-monovacancy interacting with the critical (Phe)-residues of the mitochondrial F0-ATPase and using oligomycin A (specific Phe-F0-ATPase inhibitor) as reference control. Then, we show that the SWCNT-family can be potentially used to selectively inhibit the (Phe)-F0-ATPase activity liked to pathological mitochondrial ATP-hydrolysis associated to human neurodegenerative disorders by using DFT-ab initio simulation. The in-silico results suggest the formation of more stable complexes of interaction following the order: SWCNT-COOH/F0-ATPase complex (1.79 eV) > SWCNT-OH/F0-ATPase complex (0.61 eV) > SWCNT/F0-ATPase complex (0.45 eV) > SWCNT-monovacancy/F0-ATPase complex (0.43 eV) based on the strength of the chemisorption interactions. These theoretical evidences open new horizons towards mito-target precision nanomedicine.

Interactions between the single walled carbon nanotube (SWCNT) family and a mitochondrial ADP/ATP carrier (ANT-1) were evaluated using constitutional (functional groups, number of carbon atoms, etc.) and electronic nanodescriptors defined by (n, m)-Hamada indexes (armchair, zig-zag and chiral). The Free Energy of Binding (FEB) was determined by molecular docking simulation and the results showed that FEB was statistically more negative (p SWCNT-OH > SWCNT, suggesting that polar groups favor the anchorage to ANT-1. In this regard, it was showed that key ANT-1 amino acids (Arg 79, Asn 87, Lys 91, Arg 187, Arg 234 and Arg 279) responsible for ADP-transport were conserved in ANT-1 from different species examined to predict SWCNT interactions, including shrimp Litopenaeus vannamei and fish Danio rerio commonly employed in ecotoxicology. The SWCNT-ANT-1 inter-atomic distances for the key ANT-1 amino acids were similar to that with carboxyatractyloside, a classical inhibitor of ANT-1. Significant linear relationships between FEB and n-Hamada index were found for zig-zag SWCNT and SWCNT-COOH (R2 = 0.95 in both cases). A Perturbation Theory-Nano-Quantitative Structure-Binding Relationship (PT-NQSBR) model was fitted that was able to distinguish between strong (FEB < −14.7 kcal mol−1) and weak (FEB ≥ −14.7 kcal mol−1) SWCNT–ANT-1 interactions. A simple ANT-1-inhibition respiratory assay employing mitochondria suspension from L. vannamei, showed good accordance with the predicted model. These results indicate that this methodology can be employed in massive virtual screenings and used for making regulatory decisions in nanotoxicology.

This study aimed to evaluate the effects of adding guar gum, a non-starch polysaccharide, to the diet of Mugil liza juveniles. The juveniles (mean weight = 0.38 ± 0.01 g) were fed one of three diets with increasing supplement levels (4%, 8%, and 12%) and a control diet without additional gum for 60 days, in order to evaluate the effects on zootechnical performance, proximate composition, liver parameters, morphological alterations to the intestinal tract, and modulation of gastrointestinal microbiota. The animals fed 8% and 12% gum presented a significantly lower mean final weight, weight gain, specific growth rate, food intake rate, and protein intake rate than the control. Adding gum to the diets also reduced the dry matter, crude protein, and carcass fat levels. All treatments with added gum resulted in increased liver glycogen, and the cholesterol levels were significantly reduced in fish fed 4% and 8% supplement levels. No intestinal morphological alterations were observed in the animals. However, a modulating effect was noted on the microbial community, altering the bacterial quantity and composition throughout the tract segments. The use of guar gum is not recommended in Mugil liza diets, at least above 4%.

Carbon nanotubes (CNT) are promising materials for biomedical applications, especially in the field of neuroscience; therefore, it is essential to evaluate the neurotoxicity of these nanomaterials. The present work assessed the effects of single-walled CNT functionalized with polyethylene glycol (SWCNT-PEG) on the consolidation and retrieval of contextual fear memory in rats and on oxidative stress parameters in the hippocampus. SWCNT-PEG were dispersed in water at concentrations of 0.5, 1.0, and 2.1 mg/mL and infused into the rat hippocampus. The infusion was completed immediately after training and 30 min before testing of a contextual fear conditioning task, resulting in exposure times of 24 h and 30 min, respectively. The results showed that a short exposure to SWCNT-PEG impaired fear memory retrieval and caused lipid peroxidation in the hippocampus. This response was transient and overcome by the mobilization of antioxidant defenses at 24 h. These effects occurred at low and intermediate but not high concentration of SWCNT-PEG, suggesting that the observed biological response may be related to the concentration-dependent increase in particle size in SWCNT-PEG dispersions.

Mitochondrial Permeability Transition Pore (MPTP) is involved in neurodegeneration, hepatotoxicity, cardiac necrosis, nervous and muscular dystrophies. We used different experimental protocols to determine the mitoprotective activity (%P) of different carbon nanotubes (CNT) against mitochondrial swelling in multiple boundary conditions (bj). The experimental boundary conditions explored included different sub-sets of combinations of the following factors b0 = three different mitochondrial swelling assays using the MPT-inductor (Ca2+, Fe3+, H2O2) combined or not with a second MPT-inductor and swelling control assays using MPT-inhibitor (CsA, RR, EGTA), b1 = exposure time (0–600 s), and b2 = CNT concentrations (0–5 μg ml−1). Other boundary conditions (bk) changed were the CNT structural parameters b3 = CNT type (SW, SW + DW, MW), b4 = CNT functionalization type (H, OH, COOH). We also changed different of CNT like b5 = molecular weight/functionalization ratio (minW/maxW) or b6 = maximal and minimal diameter (Dmin/Dmax) as physic-chemical properties (Vk). Next, we employed chemoinformatics ideas to develop a new Perturbation Theory (PT) model able to predict the %P of CNT in multiple experimental conditions. We investigated different output functions of the absorbance ′f(eij) used in PL4/PL5 methods like (eij, 1/eij, 1/eij2, or −log eij) as alternative outputs of the model. The inputs are in the form an additive functions with linear/non-linear terms. The first term is a function 0f(〈eij〉) of the average absorbance 〈eij〉 (expected value) in different assays (bj). The concentration dependent terms are linear functions of concentration, or hill-shaped curves similar to PL4/PL5 functions (used in dose–response analysis). The CNT structure perturbation terms are linear/non-linear functions of Box–Jenkins operators (ΔVkj). The ΔVkj are moving averages (deviations) of the Vk of the CNT with respect to their expected values 〈Vkj〉. The best model found predicted the values of absorbance (measure of mitoprotective activity vs. mitochondrial swelling) with regression coefficient R2 = 0.997 for >6000 experimental data points (q2 = 0.994). Last, we used the model to carry out a simulation of the changes on mitoprotective activity for CNT family after one increase of 1–10% of the minWi and maxDi of CNT.

[Abstract] This study presents the impact of carbon nanotubes (CNTs) on mitochondrial oxygen mass flux (Jm) under three experimental conditions. New experimental results and a new methodology are reported for the first time and they are based on CNT Raman spectra star graph transform (spectral moments) and perturbation theory. The experimental measures of Jm showed that no tested CNT family can inhibit the oxygen consumption profiles of mitochondria. The best model for the prediction of Jm for other CNTs was provided by random forest using eight features, obtaining test R-squared (R2) of 0.863 and test root-mean-square error (RMSE) of 0.0461. The results demonstrate the capability of encoding CNT information into spectral moments of the Raman star graphs (SG) transform with a potential applicability as predictive tools in nanotechnology and material risk assessments Instituto de Salud Carlos III; PI13/02020 Instituto de Salud Carlos III; PI13/00280 Galicia. Consellería de Cultura, Educación e Ordenación Universitaria; R2014/025 Galicia. Consellería de Cultura, Educación e Ordenación Universitaria; GRC2014/049 Galicia. Consellería de Cultura, Educación e Ordenación Universitaria; R2014/039 Ministerio de Economía y Competitividad; UNLC08-1E-002 Ministerio de Economía y Competitividad ; UNLC13-13-3503 Ministerio de Economía y Competitividad; CTQ2016-74881-P País Vasco.Gobierno; IT1045-16 Brasil. Conselho Nacional de Desenvolvimento Científico e Tecnológico; 308539/2016-8 Brasil. Conselho Nacional de Desenvolvimento Científico e Tecnológico; 454332/2014-9

Soil contamination by organic compounds is of great concern worldwide since it could act as a major environmental repository. The success of phytoremediation is conditioned by two main factors: the availability and toxicity of the compound to be remediated, and the plant species ability to incorporate or degrade the contaminants. This study aimed to assess the potential of different plants species for remediation of aged DDTs residues in soil. Tomato, sunflower, soybean and alfalfa plants were grown in contaminated soils (p,p′-DDE 455.3, p,p′-DDT 63.5 ng g−1 dry weight) for 15 and 60 days. Phytoremediation was evaluated by studying the pollutant dynamics in the soil–plant system and lipid peroxidation (LPO) as an effect biomarker. Results showed that soil DDTs levels were diminished after 60 days of plant growth, due to the combined effect of DDTs uptake by roots and rhizospheric degradation. The relative accumulation of each compound was dependent on soil levels (p,p′-DDE > p,p′-DDT > p,p′-DDD) and all species presented root >aerial accumulation pattern, evidencing DDTs translocation. Tomato plants were the most effective in the enhancement of pollutants bioavailability in the rizospheric soil. Plants growth induced physicochemical changes in soil and those are evidenced by increasing dehydrogenase activity and DDTs metabolism, mainly in soybean and tomato soil fractions. Root bioconcentration factors >1 were observed in 15 days tomato and alfalfa plants. Growth dilution effect was observed in roots of all species at 60 days, except soybean. DDTs uptake nor affected tomato and alfalfa plants growth neither caused oxidative stress. Considering the accumulation potential, tolerance (expressed as no evident phytotoxicity effects) and interaction with soil matrix in terms of metabolism and availability, tomato plants seems to be the best phytoremediator candidates for aged soil DDTs residues. Fil: Mitton, Francesca María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Miglioranza, Karina Silvia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Gonzalez, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Shimabukuro, Valeria Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Monserrat, José María. Universidade Federal do Rio Grande do Sul; Brasil

The present study aimed to evaluate the effects of benzocaine and tricaine methanesulfonate on oxidative stress parameters of juvenile tambaqui tissues. Fish (n=80) were anesthetized with benzocaine (100 mg L-1) or tricaine (240 mg L-1) and two control groups were used (non-anesthetized fish and fish exposed to ethanol-only). After anesthetic induction 10 fish/anesthetic were euthanized after 3, 12 and 24 hours post-anesthesia and tissue samplings (gills, liver and brain) were performed. Samples were submitted to analyses of enzyme activity glutathione-S-transferase (GST), cellular lipid peroxidation (TBARS) and total antioxidant capacity (ACAP). ACAP increased in gills of benzocaine treatment after 12 hours. The liver showed a reduction in ACAP of tricaine treatment after 12 hours. Both anesthetic treatments showed an increase of ACAP at 24 hours compared to control group. The activity of the GST enzyme increased in the gills for treatments benzocaine and tricaine after 3 and 12 hours. Liver showed increased GST activity (benzocaine after 24 hours and tricaine after 3 and 24 hours). Lipid damage decreased in gills (both anesthetics) and brain (tricaine) after 24 hours. The results demonstrate that benzocaine and tricaine did not cause oxidative damage in juvenile tambaqui under the experimental conditions herein established.

The current molecular docking study provided the Free Energy of Binding (FEB) for the interaction (nanotoxicity) between VDAC mitochondrial channels of three species (VDAC1-Mus musculus, VDAC1-Homo sapiens, VDAC2-Danio rerio) with SWCNT-H, SWCNT-OH, SWCNT-COOH carbon nanotubes. The general results showed that the FEB values were statistically more negative (p : (SWCNT-VDAC2-Danio rerio) > (SWCNT-VDAC1-Mus musculus) > (SWCNT-VDAC1-Homo sapiens) > (ATP-VDAC). More negative FEB values for SWCNT-COOH and OH were found in VDAC2-Danio rerio when compared with VDAC1-Mus musculus and VDAC1-Homo sapiens (p a significant correlation (0.66 > r2 > 0.97) was observed between n-Hamada index and VDAC nanotoxicity (or FEB) for the zigzag topologies of SWCNT-COOH and SWCNT-OH. Predictive Nanoparticles-Quantitative-Structure Binding-Relationship models (nano-QSBR) for strong and weak SWCNT-VDAC docking interactions were performed using Perturbation Theory, regression and classification models. Thus, 405 SWCNT-VDAC interactions were predicted using a nano-PT-QSBR classifications model with high accuracy, specificity, and sensitivity (73–98%) in training and validation series, and a maximum AUROC value of 0.978. In addition, the best regression model was obtained with Random Forest (R2 of 0.833, RMSE of 0.0844), suggesting an excellent potential to predict SWCNT-VDAC channel nanotoxicity. All study data are available at https://doi.org/10.6084/m9.figshare.4802320.v2.

Even though technologies involving nano/microparticles have great potential, it is crucial to determine possible toxicity of these technological products before extensive use. Fullerenes C60are nanomaterials with unique physicochemical and biological properties that are important for the development of many technological applications. The aim of this study was to evaluate the consequences of nonphotoexcited fullerene C60exposure in brain acetylcholinesterase expression and activity, antioxidant responses, and oxidative damage using adult zebrafish as an animal model. None of the doses tested (7.5, 15, and 30 mg/kg) altered AChE activity, antioxidant responses, and oxidative damage when zebrafish were exposed to nonphotoexcited C60nano/microparticles during 6 and 12 hours. However, adult zebrafish exposed to the 30 mg/kg dose for 24 hours have shown enhanced AChE activity and augmented lipid peroxidation (TBARS assays) in brain. In addition, the up-regulation of brain AChE activity was neither related to the transcriptional control (RT-qPCR analysis) nor to the direct action of nonphotoexcited C60nano/microparticles on the protein (in vitroresults) but probably involved a posttranscriptional or posttranslational modulation of this enzymatic activity. Taken together these findings provided further evidence of toxic effects on brain after C60exposure.

South American cyprinodontiform fish are potential candidates to be used as model biomarker species of exposure in environmental toxicology. The aim of this study was to identify molecular and biochemical biomarkers of pollution using Poecilia vivipara (Poecilidae) and Jenynsia multidentata (Anablepidae). Partial nucleotide sequences for cytochrome P-450 1A (CYP1A), a classical biomarker of exposure to organic contaminants in fish, were identified in P. vivipara and J. multidentata (approximately 650 nucleotides) using degenerated primers and polymerase chain reaction (PCR). These sequences shared approximately 90% identity in the predicted amino acid sequence with the corresponding CYP1A region of Fundulus heteroclitus. Real-time quantitative PCR (RT-qPCR) analysis confirmed that CYP1A transcription was markedly induced in the liver and gills of J. multidentata (approximately185-fold and 20-fold, respectively) and P. vivipara (122-fold and 739-fold, respectively) 24 h after exposure to 1 μM synthetic CYP1A inducer β-naphthoflavone (BNF). At 24 h after injection with 1 μg/g environmental carcinogenic contaminant benzo[a]pyrene (BaP), a decreased total antioxidant capacity against peroxyl radicals was observed both in liver of J. multidentata and gills of P. vivipara. BaP injection in both fish did not produce changes in lipid peroxide (thiobarbituric acid-reactive substances, TBARS) levels, suggesting an absence of an oxidative stress condition. The newly identified CYP1A may thus serve as general biomarker of exposure to organic contaminant in future studies using P. vivipara and J. multidentata. Data also indicate the importance of species-specific differences in biomarker responses in these South American cyprinodontiform fish, suggesting distinct resistance/susceptibility properties to polycyclic aromatic hydrocarbons.

In consequence of their growing use and demand, the inevitable environmental presence of nanomaterials (NMs) has raised concerns about their potential deleterious effects to aquatic environments. The carbon NM fullerene (C60), which forms colloidal aggregates in water, and its water-soluble derivative fullerol (C60(OH)18–22), which possesses antioxidant properties, are known to be photo-excited by ultraviolet (UV) or visible light. To investigate their potential hazards to aquatic organisms upon exposure to UV sunlight, this study analyzed (a) the in vitro behavior of fullerene and fullerol against peroxyl radicals (ROO ) under UV-A radiation and (b) the effects of these photo-excited NMs on oxidative stress parameters in functional gills extracted from the fish Cyprinus carpio (Cyprinidae). The variables measured were the total antioxidant capacity, lipid peroxidation (TBARS), the activities of the antioxidant enzymes glutathione reductase (GR) and glutamate cysteine ligase (GCL), and the levels of the non-enzymatic antioxidant glutathione (GSH). The obtained results revealed the following: (1) both NMs behaved in vitro as antioxidants against ROO in the dark and as pro-oxidants in presence of UV-A, the latter effect being reversed by the addition of sodium azide, which is a singlet oxygen (1O2) quencher; (2) fullerene induced toxicity with or without UV-A incidence, with a significant (p

Taking into account the concept of the “Trojan Horse”, where contaminants may have its entry into specific organs potentiated by its association with nanomaterials, the aim of this study was to analyze the joint toxic effects induced by an organic nanomaterial, fullerene (C 60 ) with the metalloid arsenic (As III ). Hepatocytes of zebrafish Danio rerio were exposed to As III (2.5 or 100 μM), C 60 or As + C 60 for 4 h, not altering cells viability. Intracellular reactive oxygen species concentration was reduced in cells exposed only to the C 60 (1 mg/L) and in the treatment of 100 μM As III + C 60 . Co-exposure with C 60 abolished the peak of the antioxidant glutathione (GSH) registered in cells exposed to the lowest As III concentration (2.5 μM). A similar result was observed in terms of lipid damage (TBARS). Total antioxidant capacity was significantly higher at both As III concentrations co-exposed to C 60 when compared with the control group. Activity of glutathione-S-transferase omega, a limiting enzyme in the methylation pathway of As III , was reduced in the 100 μM As III + C 60 treatment. Cells co-exposed to C 60 had a significantly higher accumulation of As III , showing a “Trojan Horse” effect which did not result in higher cell toxicity. Instead, co-exposure of As III with C 60 showed to reduce cellular injury.

The objective of this study was to analyse biochemical responses induced by the carbon nanomaterial fullerene (C60) in the polychaete Perinereis gualpensis (Nereididae). The activity of glutathione-S-transferase (GST), glutathione reductase (GR) and glutamate cysteine ligase (GCL), as well as total antioxidant capacity, concentration of glutathione (GSH) and malondialdehyde (TBARS), were analysed. Estuarine worms were maintained in sediments collected at an unpolluted site and spiked with fullerene (3 mg C60·g−1 sediment). A control group was run in parallel. Scanning electron microscope (SEM) images of sediment and fullerene indicated that the size of the carbon nanomaterial should enable it to be ingested by the polychaete. No evidence of oxidative damage (TBARS) was observed in any of the treatments, and the same was true for GSH and GCL measurements (p>0.05). Total antioxidant capacity was higher in the C60 group after 2 and 7 d when compared with the control group (p

Pollution is a world problem with immeasurable consequences. Heavy metal compounds are frequently found as components of anthropogenic pollution. Here we evaluated the effects of the treatment with cadmium acetate, lead acetate, mercury chloride, and zinc chloride in acetylcholinesterase activity and gene expression pattern, as well as the effects of these treatments in antioxidant competence in the brain of an aquatic and well-established organism for toxicological analysis, zebrafish (Danio rerio, Cyprinidae). Mercury chloride and lead acetate promoted a significant decrease in acetylcholinesterase activity whereas they did not alter the gene expression pattern. In addition, the antioxidant competence was decreased after exposure to mercury chloride. The data presented here allowed us to hypothesize a signal transmission impairment, through alterations in cholinergic transmission, and also in the antioxidant competence of zebrafish brain tissue as some of the several effects elicited by these pollutants.

This study aimed to analyze oxidative stress parameters, including levels of the antioxidant glutathione (GSH), activity of glutamate-cysteine ligase (GCL) and glutathione-S-transferase (GST), total antioxidant capacity and protein oxidation, in the polychaete Perinereis gualpensis (Nereididae) collected from the Biobio, Itata, Valdivia and Lingue estuaries in Chile, which present different degrees of anthropogenic pressure. Sampling sites were characterized considering a geographic information system and the physicochemical characteristics of water and sediment. Significant differences (p

Numerous studies have shown that melatonin exerts some influence on the antioxidant defense system (ADS) in vertebrates, but for crustaceans no such effect has been demonstrated till now. However, earlier reports did show a similar profile of daily variations in the ADS of the gills and the melatonin content of the eyestalk in the crab Neohelice granulata and, thus, the aim of this study was to take a closer look at the effects of melatonin in the gill ADS of N. granulata. Gill ADS is to a minor extent modulated by reactive oxygen species (ROS), because only the nonproteic sulfhydryl (NP-SH) content increases (p0.05) in the presence of hydrogen peroxide (H(2)O(2)). No significant differences (p0.05) were observed in the melatonin content of the hemolymph between intact and eyestalkless crabs. Gills from intact and eyestalkless crabs injected with physiological saline showed a daily variation in the total peroxyl radical scavenging capacity (TPRSC) (p0.05) with two peaks, one at the photophase and another at the scotophase. However, in the gills of eyestalkless crabs injected with melatonin (2 x 10(-12)mol crab(-1)), the daily variation in TPRSC values was abolished (p0.05). This molecule did not change the NP-SH content (p0.05) in vitro, but decreased (p0.05) the oxygen consumption in gills when incubated for 120 min. In the in vivo experiments melatonin also decreased (p0.05) the oxygen consumption in eyestalkless crabs after 390 min. The results suggest that melatonin does not act directly on the ADS of the gills of N. granulata, but decreases the aerobic metabolism possibly involved in variations of tissue ADS.

Antioxidant enzymes, total antioxidant capacity (TOSC) and concentration of reactive oxygen species (ROS) were measured in anterior (A), middle (M) and posterior (P) body regions of Laeonereis acuta after copper (Cu; 62.5 μg/l) exposure. A catalase (CAT) activity gradient observed in control group (lowest in A, highest in P) was not observed in Cu exposed group. Glutathione- S -transferase (GST) activity in A region of Cu group was higher than in A region of the control group. DNA damage (comet assay) was augmented in the A region of Cu group. Since copper accumulation was similar in the different body regions, sensitivity to copper in A regions seems to be related to lowest CAT activity. In sum, copper exposure lowered TOSC, a result that at least in part can be related to lowering of antioxidant enzymes like CAT. DNA damage was induced in the anterior region, where a lower CAT activity was observed.

The nutritional quality of biofilm, a microbial community associated to an organic matrix, was evaluated in artificial substrate (polyethylene screen) in net cages during 30 days in the Patos Lagoon estuary, Southern Brazil. During this period, samples of biofilm were collected each 5 days for analysis of chlorophyll a, microorganisms abundance, dry weight, protein and lipid contents. During the study, chlorophyll a varied from 0.38 to 2.75 μg cm−2; dry weight between 7.16 and 17.63 mg cm−2; protein content from 0.43 to 1.76 mg cm−2 and lipid concentration between 1.21 and 4.23 mg cm−2. The variation of lipid in the biofilm was closely related to the abundance of free heterotrophic bacteria (34.25–56.54 × 106 cells cm−2), filamentous cyanobacteria (7.5–15.9 × 106 filaments cm−2), flagellates (6.92–12.89 × 106 cells cm−2) and mainly nematodes (29–1,414 organisms cm−2), while protein content varied similarly to the abundance of unicellular centric diatoms (52.10–179.81 × 103 cells cm−2), and nematodes. This information will allow a better management of food supply to raised aquatic organism with the utilization of natural productivity in the culture systems, with considerable decrease in production costs.