RESUMO
In this work we report the occurrence of powerful mutagenic 3-nitrobenzanthrone (3-NBA), in addition to 18 polycyclic aromatic hydrocarbons (PAHs), 6 oxygenated PAHs and 27 nitrated PAHs in polychaete worms. Benzanthrone (BA), another important mutagenic polycyclic aromatic compound (PAC) also was detected in the samples. Polychaete annelids have great ecological relevance, being widely distributed in different environmental conditions, from intertidal zones up to seven thousand feet deep areas. They are abundantly found in both contaminated and uncontaminated areas and, therefore, used as indicators of the pollution status of a given area. As we know, so far, most of these PACs has not been previously reported in living organisms before. The 3-NBA concentrations determined in this study were within 0.11-5.18 µg g-1. Other relevant PACs such as PAHs, quinones and nitro-PAHs were found in maximum concentrations at 0.013 µg g-1 (coronene) to 11.1 µg g-1 (benzo[k]fluoranthene), 0.823 µg g-1 (9,10-phenenthrenequinone) to 12.1 µg g-1 (1,4-benzoquinone) and 0.434 (1-nitronaphthalene) µg g-1 to 19.2 µg g-1 (6-nitrobenzo[a]pyrene), respectively. Principal component analysis (PCA), ternary correlations and diagnostic ratios were employed in order to propose probable sources for PACs. Although statistical analysis preliminarily has indicated both pyrogenic and petrogenic contributions, petrogenic sources were predominant reflecting the impacts of petroleum exploration and intensive traffic of boats in the study area.
Assuntos
Benzo(a)Antracenos/análise , Mutagênicos/análise , Poliquetos/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Animais , Benzo(a)Antracenos/isolamento & purificação , Benzo(a)Antracenos/metabolismo , Monitoramento Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Mutagênicos/metabolismo , Poliquetos/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/isolamento & purificação , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Análise de Componente Principal , Extração em Fase Sólida/métodos , Sonicação , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/metabolismoRESUMO
Chaetopterus variopedatus has been studied for over a century in terms of its physiology, ecology and life history. One focus of research is on its intrinsic bioluminescent emissions, which can be observed as a blue light emitted from the extremities of individual body segments, or as a secreted mucus. Even though research shows that C. variopedatus is a species complex miscategorized as a single species, all of the variants of this polychaete produce light, which has been investigated in terms of both physiology and biochemistry. Despite decades of study, there are still many questions about the luminescence reaction, and, as of yet, no clear function for light emission exists. This review summarizes the current knowledge on C. variopedatus luminescence in addition to briefly describing its morphology, life cycle and ecology. Possible functions for luminescence were discussed using observations of specimens found in Brazil, along with a comparison of previous studies of other luminescent organisms. Further study will provide a better understanding of how and why C. variopedatus produces luminescence, and purifying the protein and luciferin involved could lead to new bioanalytical applications, as this reaction is unique among all known luminescent systems.
Assuntos
Luz , Medições Luminescentes , Poliquetos/metabolismo , Animais , Ecossistema , Poliquetos/fisiologiaRESUMO
The fireworms Odontosyllis spp. are globally distributed and well-known for their characteristic and fascinating mating behavior, with secreted mucus emitting bluish-green light. However, knowledge about the molecules involved in the light emission are still scarce. The fireworms are believed to emit light with a luciferin-luciferase reaction, but biochemical evidence of the luciferase is established for only one species living in Japan and no information is available for its luciferin structure. In this study, we identified a luciferase gene from a related Puerto Rican fireworm. We identified eight luciferase-like genes in this Puerto Rican fireworm, finding amino acid identities between Japanese and Puerto Rican luciferase-like genes to be less than 60%. We confirmed cross reactivity of extracts of the Japanese fireworm luciferin with a recombinant Puerto Rican luciferase (PR1). The emission spectrum of recombinant PR1 was similar to the crude extract of the native luciferase, suggesting that PR1 is a functional luciferase of this Puerto Rican fireworm. Our results indicate that the molecular mechanism of luminescence is widely conserved among fireworms.
Assuntos
Luciferases/metabolismo , Luminescência , Poliquetos/enzimologia , Poliquetos/genética , Proteínas Recombinantes/metabolismo , Sequência de Aminoácidos , Animais , Japão , Luciferases/genética , Poliquetos/metabolismo , Porto Rico , Proteínas Recombinantes/genética , Homologia de SequênciaRESUMO
The increasing consumption of anticancer drugs through single and/or combinatory chemotherapy worldwide raised concern regarding their toxicity burden in coastal zones. The toxicity of a mixture of three compounds involving the drugs cisplatin (CisPt), cyclophosphamide (CP) and tamoxifen (TAM) was determined on the marine polychaete Nereis diversicolor exposed to an increasing range of their concentrations, respectively: Mix A: 0.1 + 10 + 0.1 ng L-1; Mix B: 10 + 100 + 10 ng L-1; Mix C: 100 + 500 + 25 ng L-1; Mix D: 100 + 1000 + 100 ng L-1. Different endpoints were assessed, including disturbance in the burrowing behaviour, neurotoxicity (acetylcholinesterase - AChE activity), antioxidant enzymes (superoxide dismutase - SOD; catalase - CAT; selenium-dependent glutathione peroxidase - Se-GPx and total glutathione peroxidases T-GPx activities), biotransformation metabolism (glutathione-S-transferases - GST), lipid peroxidation (LPO) and genotoxicity (DNA damage). Biological effects of the mixtures of anticancer compounds on N. diversicolor were compared with previous studies about effects on the same biological model under single-drug exposure conducted with the same molecules. Regarding SOD activity, TAM showed an antagonist effect over CisPt and CP in mixtures C and D. In Mix D, there was a synergistic effect of TAM and CisPt that inhibited CAT activity and an additive interaction of CisPt and CP on the Phase II biotransformation enzyme. Drugs in Mix A also suppressed polychaetes' GST activity, although different from the respective single-drug responses, besides able to induce T-GPx activity, that was not sufficient to avoid oxidative damage and mid-grade DNA damage. Due to the absence of burrowing impairment in Mix A, mechanisms involved in neurotoxicity were other than the one driven by AChE alterations. At the intermediary concentrations (Mix B and C), only LPO occurred. Data from drugs individually may not predict the risks provided by mixtures.
Assuntos
Antineoplásicos/toxicidade , Poliquetos/fisiologia , Poluentes Químicos da Água/toxicidade , Acetilcolinesterase/metabolismo , Animais , Antineoplásicos/metabolismo , Antioxidantes/metabolismo , Biotransformação , Catalase/metabolismo , Ciclofosfamida/metabolismo , Dano ao DNA , Glutationa Peroxidase/metabolismo , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Poliquetos/metabolismo , Selênio/metabolismo , Superóxido Dismutase/metabolismoRESUMO
A somewhat disparate, yet temporally cohesive, set of phytoplankton abundance, microphytobenthos, including the diatom Pseudo-nitzschia, benthic infauna, and sediment toxin data were used to develop a theory for the transfer of domoic acid (DA) from the toxic diatom to the benthos in the highly productive waters of the northern Gulf of Mexico near the Mississippi River plume. Archived samples and new data were used to test the theory that DA is likely to be incorporated into benthic consumers. High spring abundances of potentially toxic Pseudo-nitzschia diatoms were simultaneously present in the surface waters, bottom waters and on the seafloor. Examination of the gut contents of a typical deposit-feeding and suspension-feeding polychaete, Paraprionospio pinnata, during similar periods of high Pseudo-nitzschia abundance in surface water indicated consumption of the diatoms. Demersal fishes, particularly Atlantic croaker, are known to consume these polychaetes, with a potential for transfer of DA to even higher trophic levels. These findings warrant a theory to be tested with further studies about the trophic linkage of a phytoplankton toxin into the benthic food web.
Assuntos
Diatomáceas/metabolismo , Cadeia Alimentar , Sedimentos Geológicos/química , Ácido Caínico/análogos & derivados , Poliquetos/metabolismo , Animais , Diatomáceas/química , Golfo do México , Ácido Caínico/metabolismo , Fitoplâncton/metabolismo , Estações do AnoRESUMO
The feasibility of biomarkers to accurately detect pollution in estuaries and coastal areas appears to be overestimated in the scientific literature, and is likely stemming from a bias towards publishing only positive results. Herein, we test the applicability of antioxidant capacity and lipid peroxidation to detect potential in situ sewage impacts on a subtropical estuary. We experimentally assessed variation in malondialdehyde (MDA, an indicator of lipid peroxidation) and total antioxidant capacity against peroxyl radicals (ACAP) through transplantations of the worm Laeonereis culveri from control to sewage-polluted areas. Variations in biomarkers were more related to natural environmental variability and small-scale heterogeneity among areas than to experimental exposure to sewage. Use of oxidative stress biomarkers is promising but further experimental work under real-life conditions is necessary to further validate and establish their accuracy and feasibility for practical purposes.
Assuntos
Biomarcadores Ambientais , Estuários , Estresse Oxidativo/efeitos dos fármacos , Poliquetos/efeitos dos fármacos , Esgotos , Animais , Antioxidantes/metabolismo , Brasil , Ecotoxicologia/métodos , Monitoramento Ambiental/métodos , Peroxidação de Lipídeos/efeitos dos fármacos , Malondialdeído/análise , Malondialdeído/metabolismo , Peróxidos/análise , Peróxidos/metabolismo , Poliquetos/metabolismo , Esgotos/análise , Esgotos/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidadeRESUMO
Polychaetes that inhabit the sediments of estuaries are important prey to many species all around the world. Laeonereis acuta is a deposit feeder living in estuaries along the Atlantic coast of South America. Ragworms accumulate metals from the sediment, and represent a means of entry of sediment contaminants into the trophic network. The concentrations of Zn, Pb, Cu, Cr and Cd were determined in polychaetes and sediments (total and extractable) from six estuarine beaches of Río de la Plata. The associations between total and extractable concentrations in sediment and accumulated concentrations in L. acuta were analyzed. Sediments extracted by weak acid digestion appear to be a good proxy model of bioavailable metal fractions in the sediment. The association between metals in sediment and polychaetes denotes the role of L. acuta as an important link in metal trophic transfer from sediments to potential fish and bird predators of the worm.
Assuntos
Monitoramento Ambiental/métodos , Estuários , Sedimentos Geológicos/química , Metais Pesados/análise , Poliquetos/metabolismo , Oligoelementos/análise , Poluentes Químicos da Água/análise , Animais , Disponibilidade Biológica , Metais Pesados/metabolismo , Modelos Biológicos , Oligoelementos/metabolismo , Uruguai , Poluentes Químicos da Água/metabolismoRESUMO
Chlorothalonil is an active biocide applied in antifouling paints, and also used as fungicide in agricultural activities with the purpose to protect plants from foliar and seed diseases. Thus, the aim of this study was to evaluate the effects of chlorothalonil exposure on biochemical biomarkers of oxidative metabolism as well as on cholinesterases in the estuarine polychaete Laeonereis acuta. Animals were exposed for 24 and 96â¯h to the following nominal concentrations of chlorothalonil: 0.1, 10.0 and 100.0⯵g/L. The antioxidant capacity against peroxyl radicals (ACAP) and the activity of the enzymes catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), glutamate cysteine ligase (GCL), acetylcholinesterase (AChE) and propionylcholinesterase (PChE) were evaluated in whole-body tissue. In addition, the levels of reduced glutathione (GSH), lipid peroxidation (LPO), glycogen and lactate levels were also analyzed. A reduction in ACAP levels was observed in animals exposed to the higher chlorothalonil concentration, concomitantly with an induction of GST activity as well as diminution in GSH content in these animals. This disturbance in the redox state of animal tissues leads to an oxidative stress situation, resulting in an induction in LPO levels. It was also demonstrated that chlorothalonil exposure causes alteration in AChE activity, possibly related to damage to membrane lipids. These results demonstrated that chlorothalonil possesses harmful effects to estuarine animals and its use as antifouling biocide has to be carefully reconsidered in risk analysis studies.
Assuntos
Fungicidas Industriais/toxicidade , Nitrilas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Poliquetos/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Acetilcolinesterase/metabolismo , Animais , Antioxidantes/metabolismo , Catalase/metabolismo , Colinesterases/metabolismo , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Transferase/metabolismo , Glicogênio/análise , Ácido Láctico/análise , Peroxidação de Lipídeos/efeitos dos fármacos , Peróxidos/metabolismo , Poliquetos/metabolismo , Espectrofotometria , Superóxido Dismutase/metabolismoRESUMO
The objective of this study was to analyze the toxicological responses of the estuarine polychaete Laeonereis acuta after acute (96h), subchronic (7 days) and chronic (14 days) exposure to cadmium (Cd). Concentrations of metallothioneins (MT), lipid peroxidation (LPO), total Cd and metal-rich granules (MRG) were evaluated. Seasonal variations of MT and LPO levels in the wild were also measured. Polychaetes were obtained in the Quequén estuary located southeast of Buenos Aires Province, Argentina. For the acute toxicity assay, individuals were exposed to 10; 30, 65; 310; 600; 1300; 2000; 4300; 8100; 16300µgCdL-1, which included levels of environmental relevance and median lethal concentrations (LC50) for related species of polychaete. Based on 96h LC50 values, polychaetes were exposed to sublethal doses of Cd. The concentrations for both subchronic and chronic assays were: 10; 30; 65; 310; 600; 1300; 2000; 4300µgCdL-1. The 96h LC50 value was 8234.9µgL-1, which was within the values reported for other species of polychaete, indicating a high tolerance to Cd. MT induction was not observed for any time exposure. In additoin, LPO levels showed no differences with respect to control levels, which indicated an absence of oxidative damage caused by Cd. However, the total Cd and MRG-Cd concentrations in L. acuta in all tested treatments showed significant differences with respect to control levels. L. acuta were able to accumulate Cd in their tissues in the form of granules which are the main mechanism of Cd detoxification.
Assuntos
Cádmio/toxicidade , Poliquetos/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Argentina , Relação Dose-Resposta a Droga , Estuários , Dose Letal Mediana , Peroxidação de Lipídeos/efeitos dos fármacos , Metalotioneína/metabolismo , Poliquetos/metabolismo , Testes de Toxicidade Aguda , Testes de Toxicidade Crônica , Testes de Toxicidade SubcrônicaRESUMO
The estuaries of the Aconcagua and Maipo Rivers of central Chile are receptors of residues that contain metals from anthropic activities including agriculture, mining and smelters, which have different levels in the two basins. This study postulates that the exposition to metals is different in the two estuaries and that their sediments contain bioavailable chemical agents that produce oxidative stress. The aim of the study was to evaluate the effect of estuarine sediments on the polychaete Perinereis gualpensis using oxidative stress biomarkers and to determine the metal concentrations in sediments and their accumulation in P. gualpensis. Sediments and organisms were collected in December 2015 and January 2016 in the estuaries. The Catapilco estuary was used as control, since its basin has little anthropic activity. The metal concentrations of Fe Cu, Pb, Zn and Cd were determined in tissues of the organisms and in sediments. The granulometry, conductivity, redox potential, pH and organic matter in sediments were determined, as well as catalase activity and lipid peroxidation. The results show that the concentrations of metals in sediments were higher in the estuary of the Aconcagua River: Cu: 48 ± 2µgg-1; Fe: 154 ± 19mgg-1, Pb: 20 ± 3µgg-1 and Zn: 143 ± 20µgg-1. In tissues, Pb and Fe were higher in the estuary of the Maipo River, while Cd was detected only in the Catapilco River mouth. Catalase activity was greater in the estuary of the Aconcagua River and lipid peroxidation in the estuary of the Catapilco River. Significant regressions were found between biomarkers of oxidative stress and metal concentrations in tissues of P. gualpensis. In conclusion, the sediments of the studied estuaries contain bioavailable chemical agents that provoke oxidative stress in P. gualpensis, which may be a risk for the benthic communities of these ecosystems. This species is proposed to monitor metals bioavailability and oxidative stress in estuarine sediments.