RESUMO
Traça um padrão de relacionamento entre nanociências, saúde e biologia para estabelecer um panorama histórico no campo das nanociências. Utilizou-se o banco de dados Web of Science, com levantamento inicial pelas palavras-chave nanoscience e nanotechnology e também de palavras relacionadas a biologia e saúde. A aplicação do programa Citespace permitiu visualizar o padrão de relacionamento entre os tópicos lançados na base de pesquisa, proporcionando identificação de momentos de explosão e de ruptura do tema. Os dados obtidos mostram que a relação entre essas áreas emerge a partir de 2006, estando a maioria relacionada a nanomedicina. Trabalhos sobre nanotoxicologia também aparecem de forma significativa, uma vez que essas duas áreas necessitam caminhar juntas.
The article traces a pattern of relationships between nanosciences, health, and biology to provide a historical overview of the nanoscience field. Input data came from the Web of Science databank, through a search first based on the keywords ‘nanoscience' and ‘nanotechnology' and also the selection of words related to biology and health. Application of the Citespace program made it possible to visualize the pattern of relationships between topics in the research base, allowing identification of burst and centrality points on the subject. Data findings show that the relationship between these areas emerged in 2006, most of them related to nanomedicine. There are also a significant number of works on nanotoxicology, since these two areas necessarily come hand in hand.
Assuntos
Ciência , Biologia , Saúde , Nanotecnologia/história , SoftwareRESUMO
The article traces a pattern of relationships between nanosciences, health, and biology to provide a historical overview of the nanoscience field. Input data came from the Web of Science databank, through a search first based on the keywords 'nanoscience' and 'nanotechnology' and also the selection of words related to biology and health. Application of the Citespace program made it possible to visualize the pattern of relationships between topics in the research base, allowing identification of burst and centrality points on the subject. Data findings show that the relationship between these areas emerged in 2006, most of them related to nanomedicine. There are also a significant number of works on nanotoxicology, since these two areas necessarily come hand in hand.
RESUMO
The carbon nanomaterial fullerene (C(60)) can act as anti or pro-oxidant. The aim of this study was to evaluate, in cell suspensions of carp brains (Cyprinus carpio, Cyprinidae), the effect of C(60) after a pre-treatment with polyunsaturated fatty acid (PUFAs) such as omega-3 (docosahexaenoic acid, DHA) and omega-6 (linoleic acid, LA). Assays consisted of a pre-treatment with PUFA (48 h) and then exposure to C(60) (2 h). Cell viability and total anti-oxidant capacity did not differ (p > 0.05). A reduction (p < 0.05) was observed in reactive oxygen species (ROS) and thiobarbituric acid reactive substances (TBARS) concentration in fish brain cells pre-exposed with PUFA groups and then exposed or not with C(60). An antioxidant effect of C(60) was evident since in control group (cells not pre-exposed to PUFA), a significant (p < 0.05) reduction of intracellular ROS concentration was observed, although this reduction was not enough to reduce the TBARS levels. Cysteine levels presented a reduction (p < 0.05) in all groups exposed to C(60). For glutathione (GSH), an increase (p < 0.05) was registered in cells exposed to C(60) without PUFAs pre-treatment and in the C(60) group pre-treated with DHA. Overall C(60) appears to play an antioxidant role that is modulated by PUFA, taking into account its effects on intracellular ROS concentration and MDA levels. Results also suggest that C(60) influences GSH synthesis, as showed for the augmented levels of this antioxidant and also for the lowering of the intracellular cysteine concentration.
Assuntos
Antioxidantes/metabolismo , Encéfalo/citologia , Carpas/metabolismo , Ácidos Docosa-Hexaenoicos/farmacologia , Fulerenos/farmacologia , Ácido Linoleico/farmacologia , Animais , Encéfalo/metabolismo , Células Cultivadas , Cisteína , Ácidos Docosa-Hexaenoicos/administração & dosagem , Fulerenos/administração & dosagem , Glutationa , Ácido Linoleico/administração & dosagem , Neurônios/efeitos dos fármacos , Espécies Reativas de Oxigênio , Substâncias Reativas com Ácido TiobarbitúricoRESUMO
Studies concerning the impact of nanomaterials, especially fullerene (C(60) ), in fresh water environments and their effects on the physiology of aquatic organisms are still scarce and conflicting. We aimed to assess in vitro effects of fullerene in brain and gill homogenates of carp Cyprinus carpio, evaluating redox parameters. A fullerene suspension was prepared by continued stirring under fluorescent light during two months. The suspension concentration was measured by total carbon content and ultraviolet-visible spectroscopy nephelometry. Characterization of C(60) aggregates was performed with an enhanced dark-field microscopy system and transmission electronic microscopy. Organ homogenates were exposed during 1, 2, and 4 h under fluorescent light. Redox parameters evaluated were reduced glutathione and oxidized glutathione, cysteine and cystine, total antioxidant capacity; activity of the antioxidant enzymes glutathione S-transferase and glutathione reductase (GR), and lipid peroxidation (TBARS assay). Fullerene induced a significant increase (p < 0.05) in lipid peroxidation after 2 h in both organs and reduced GR activity after 1 h (gills) and 4 h (brain) and antioxidant capacity after 4 h (brain). Levels of oxidized glutathione increased in the brain at 1 h and decreased at 2 h as well. Given these results, it can be concluded that C(60) can induce redox disruption via thiol/disulfide pathway, leading to oxidative damage (higher TBARS values) and loss of antioxidant competence.
Assuntos
Encéfalo/efeitos dos fármacos , Carpas/metabolismo , Fulerenos/farmacologia , Brânquias/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Encéfalo/enzimologia , Cisteína/metabolismo , Brânquias/enzimologia , Glutationa/metabolismo , Dissulfeto de Glutationa/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Substâncias Reativas com Ácido Tiobarbitúrico/análise , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/farmacologiaRESUMO
We have evaluated the homology of the electrophile-responsive element (EpRE) core sequence, a binding site for the Nrf2 transcription factor, in the proximal promoters of the mouse and zebrafish glutathione-S-transferase (gst), glutamate cysteine ligase catalytic subunit (gclc) and heat shock protein 70 (hsp70) genes. The EpRE sites identified for both species in the three analyzed genes showed a high similarity with the putative EpRE core sequence. We also produced a transgenic zebrafish model carrying a transgene comprised of the luciferase (luc) reporter gene under transcriptional control of a mouse EpRE sequence. This transgenic model was exposed to copper sulfate, and the reporter gene was significantly activated. The endogenous gst, gclc and hsp70 zebrafish genes were analyzed in the EpRE-Luc transgenic zebrafish and showed an expression pattern similar to that of the reporter transgene used. Our results demonstrate that EpRE is conserved between mouse and zebrafish for detoxification-related genes and that the development of genetically modified models using this responsive element to drive the expression of reporter genes can be an important tool in understanding the action mechanism of aquatic pollutants.
Assuntos
Sulfato de Cobre/toxicidade , Regulação da Expressão Gênica/efeitos dos fármacos , Glutamato-Cisteína Ligase/metabolismo , Glutationa Transferase/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Elementos de Resposta/genética , Animais , Animais Geneticamente Modificados , Domínio Catalítico/genética , Sequência Conservada/genética , Primers do DNA/genética , Inativação Metabólica/genética , Inativação Metabólica/fisiologia , Camundongos , Fator 2 Relacionado a NF-E2/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Peixe-ZebraRESUMO
This study investigated the passive avoidance conditioning in zebrafish (Danio rerio). An instrument was developed for measuring escape responses triggered by a conditioned stimulus. This system allowed quantification of latency of crossing from a light to a dark zone. Zebrafish were trained to swim from an illuminated to a dark compartment, where they received a body shock (training session). The proposed methodology was efficient for evaluation of working, short, and long-term memory formation of an aquatic animal model. The possibility of employing memory measurements in toxicity tests, in order to obtain an ecologically meaningful biomarker response, was also analyzed. In this experiment, immediately after the training session, fish were exposed to three arsenic (As(V)) concentrations. After the test session, the brain was removed for biochemical analyses. A control group was kept in tap water. After exposure, animals were submitted to a one-trial inhibitory avoidance test for measurement of long-term memory (LTM). Results from behavioral and biochemical analyses showed that the three As(V) concentrations impaired LTM (p<0.05) and increased protein oxidation, which suggests an amnesic and pro-oxidant effect of As(V). Evaluation of behavior parameters in aquatic models is an important complement in studies concerning the environmental impact of chemical substances.
Assuntos
Arsênio/toxicidade , Aprendizagem da Esquiva/efeitos dos fármacos , Condicionamento Clássico/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Mecamilamina/farmacologia , Memória/efeitos dos fármacos , Nicotina/farmacologia , Estresse Oxidativo , Peixe-ZebraRESUMO
In fishes, arsenic (As) is absorbed via the gills and is capable of causing disturbance to the antioxidant system. The objective of present study was to evaluate antioxidant responses after As exposure in gills of zebrafish (Danio rerio, Cyprinidae). Fish were exposed for 48 h to three concentration of As, including the highest As concentration allowed by current Brazilian legislation (10 microg As/L). A control group was exposed to tap water (pH 8.0; 26 degrees C; 7.20 mg O(2)/L). As exposure resulted in (1) an increase (p<0.05) of glutathione (GSH) levels after exposure to 10 and 100 microg As/L, (2) an increase of the glutamate cysteine ligase (GCL) activity in the same concentrations (p<0.05), (3) no significant differences in terms of glutathione reductase, glutathione-S-transferase and catalase activities; (4) a significantly lower (p<0.05) oxygen consumption after exposure to 100 microg As/L; (4) no differences in terms of oxygen reactive species generation and lipid peroxidation content (p>0,05). In the gills, only inorganic As was detected. Overall, it can be concluded that As affected the antioxidant responses increasing GCL activity and GSH levels, even at concentration considered safe by Brazilian legislation.
Assuntos
Antioxidantes/metabolismo , Arsênio/toxicidade , Brânquias/metabolismo , Peixe-Zebra/metabolismo , Animais , Arsênio/metabolismo , Brânquias/efeitos dos fármacos , Glutationa/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos , Consumo de Oxigênio/efeitos dos fármacosRESUMO
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 microg/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.
Assuntos
Antioxidantes , Cobre/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Poliquetos/efeitos dos fármacos , Espécies Reativas de Oxigênio , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/análise , Antioxidantes/metabolismo , Catalase/análise , Catalase/metabolismo , Ensaio Cometa , Dano ao DNA , Glutationa Transferase/análise , Glutationa Transferase/metabolismo , Estresse Oxidativo/fisiologia , Poliquetos/anatomia & histologia , Poliquetos/metabolismo , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismoRESUMO
Induction of many genes encoding detoxifying enzymes and antioxidant proteins is mediated through a common mechanism, which is controlled by electrophile-responsive elements (EpRE) within the regulatory region of those genes. Copper and methyl parathion are environmental pollutants known to induce the expression of EpRE-mediated genes. In order to evaluate the molecular response triggered by these pollutants, a stable cell line was produced, which carries a transgene comprised of the green fluorescent protein (GFP) reporter gene under transcriptional control of the mouse glutathione-S-transferase (gst1) electrophile-responsive element fused to the mouse metallothionein (mt1) minimal promoter. The rat HTC hepatoma cells were transfected with the EpREmt-GFP construct and successfully selected with G418 antibiotic. EpREmt-GFP HTC cells were treated with 0.002 mg L(-1), 0.02 mg L(-1), 0.2 mg L(-1) and 2 mg L(-1) copper sulfate and 0.001 mg L(-1), 0.01 mg L(-1), 0.1 mg L(-1) and 1 mg L(-1) methyl parathion for 48 h. GFP expression was directly quantified in living cells using a microplate fluorimeter. GFP expression was significantly increased in higher concentrations of both pollutants, showing a 1.80- and 2.58-fold induction of GFP at 2mg copper L(-1) and 1mg methyl parathion L(-1), respectively (p<0.01). The results obtained in the present study demonstrate that the EpREmt-GFP HTC cell line can be an interesting model for further development for the study of the cellular response to aquatic pollutants as well as a new tool for environmental monitoring at the molecular level.
Assuntos
Cobre/toxicidade , Ecotoxicologia/métodos , Regulação da Expressão Gênica/efeitos dos fármacos , Metil Paration/toxicidade , Testes de Toxicidade/métodos , Poluentes Químicos da Água/toxicidade , Animais , Linhagem Celular Tumoral , Perfilação da Expressão Gênica , Genes Reporter/genética , Proteínas de Fluorescência Verde/genética , Camundongos , Ratos , Reprodutibilidade dos Testes , Transgenes/genéticaRESUMO
Benzo[a]pyrene (BaP) is ubiquitously distributed in the environment, being considered the most phototoxic element among polycyclic aromatic hydrocarbon (PAHs). In presence of oxygen, PAHs can act as a photosensitizer by means of promoting photo-oxidation of biological molecules (photodynamic action, PDA). Thus, the present study analyzed the photodynamic action of BaP under UVA irradiation (BaP + UVA) and its oxidative effects on K562 cells. The evaluation of BaP kinetics showed that the highest intracellular concentration occurred after 18 h of incubation. Cell viability, reactive oxygen species (ROS) generation, lipid peroxidation, DNA damage (breaks and DNA-protein cross-link [DNAPC]) were assessed after exposure to BaP, UVA and BaP plus UVA irradiation (BaP + UVA). Cell viability was decreased just after exposure to BaP + UVA. Lipid peroxidation and DNA breaks increased after BaP + UVA exposure, while the DNAPC increased after BaP, UVA and BaP + UVA exposure, suggesting that BaP + UVA effects were a consequence of both type II (producing mainly singlet oxygen) and type I (producing others ROS) mechanisms of PDA.
Assuntos
Benzo(a)pireno/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , DNA/metabolismo , Dano ao DNA , Humanos , Células K562 , Cinética , Oxirredução/efeitos dos fármacos , Oxirredução/efeitos da radiação , Estresse Oxidativo , Fotoquímica , Ligação Proteica , Proteínas/metabolismoRESUMO
Multidrug resistance (MDR) is an obstacle in cancer treatment. An understanding of how tumoral cells react to oxidants can help us elucidate the cellular mechanism involved in resistance. Microcystins are cyanobacteria hepatotoxins known to generate oxidative stress. The aim of this study was to compare the sensitivity to microcystins of human tumoral cell lines with (Lucena) and without (K562) MDR phenotype. Endpoints analyzed were effective microcystins concentration to 50% of exposed cells (EC50), antioxidant enzyme activity, lipid peroxidation, DNA damage, reactive oxygen species (ROS) concentration, and tubulin content. Lucena were more resistant and showed lower DNA damage than K562 cells (P<0.05). Although microcystins did not alter catalase activity, a higher mean value was observed in Lucena than in K562 cells. Lucena cells also showed lower ROS concentration and higher tubulin content. The higher metabolism associated with the MDR phenotype should increase ROS concentration and make for an improved antioxidant defense against the toxic effects of microcystins.
Assuntos
Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Microcistinas/farmacologia , Oxidantes/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Linhagem Celular Tumoral , Humanos , Células K562 , Redes e Vias Metabólicas , Tubulina (Proteína)/metabolismoRESUMO
The aim of this study was to analyze the total antioxidant capacity (TOSC), generation of reactive oxygen species (ROS) and lipid peroxidation (LPO) in the different body regions of the estuarine polychaeta Laeonereis acuta (Nereididae) sampled at non-polluted (NOPOL) and polluted (POL) sites from Lagoa dos Patos (Southern Brazil). Organisms collected at POL during summer showed similar (p>0.05) TOSC values along the body, but worms collected at NOPOL presented higher (p<0.05) TOSC values in the posterior (P) region in respect of anterior (A) region and middle (M) region. TOSC in the P region at NOPOL was higher (p<0.05) compared with the same body region of worms at POL. In summer, ROS concentration was higher in A and M regions of worms at POL in respect of the organisms at NOPOL. During winter all the regions showed higher ROS in worms sampled at POL. It was registered absence of season influence on LPO content, but in the P region at NOPOL in summer there were lower LPO levels compared with the others regions (p<0.05). In vitro assays showed that P region, despite a higher basal ROS, presented a higher competence to cope with pro-oxidants compared with A and M regions (p<0.05), corroborating the field results. A lower proteic sulfhydril content was observed in P in respect of the other regions (p<0.05) supporting the idea of a highest oxidant condition in this region. The results indicate that worms collected at the POL site are confronted to higher ROS concentrations, affecting its antioxidant capacity, a result that depends of body regions.
Assuntos
Antioxidantes/metabolismo , Monitoramento Ambiental/métodos , Poliquetos/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Brasil , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Poliquetos/anatomia & histologia , Poliquetos/metabolismo , Estações do AnoRESUMO
Several environmental pollutants, including metals, can induce oxidative stress. So, the objective of this study was to evaluate the effects of arsenic (As(III), as As(2)O(3)) on the antioxidant responses in the polychaete Laeonereis acuta. Worms were exposed to two environmentally relevant concentrations of As, including the highest previously allowed by Brazilian legislation (50 microg As/l). A control group was kept in saline water (10 per thousand) without added metal. It was observed that: (1) a peak concentration of lipid peroxide was registered after 2 days of exposure to 50 microg As/l (61+/-3.2 nmol CHP/g wet weight) compared to the control group (43+/-4.5 nmol CHP/g wet weight), together with a lowering of the activity of the antioxidant enzyme catalase (-47 and -48%, at 50 or 500 microg As/l respectively) and a higher superoxide dismutase activity (+305% at 50 microg As/l with respect to the control group); (2) a lower conjugation capacity through glutathione-S-transferase activity was observed after 7 days of exposure to 50 microg As/l (-48% compared to the control group); (3) a significant increase in As concentration was verified after 1 week of exposure to both As concentrations (50 and 500 microg/l); (4) worms exposed to As showed a limited accumulation of related methylated As species and the levels of non-toxic As species like arsenobetaine (AsB) and arsenocholine (AsC) remained unchanged during the exposure period when compared with the controls. Overall, it can be concluded that As interfered in the antioxidant defense system of L. acuta, even at low concentrations (50 microg/l) that Brazilian legislation previously considered safe. The fact that worms exposed to As showed high levels of methylated As species indicates the methylation capability of L. acuta, although the high levels of inorganic As suggest that not all the administered As(III) (as As(2)O(3)) is completely removed or biotransformed after 7 days of exposure.
Assuntos
Anelídeos/efeitos dos fármacos , Arsênio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Anelídeos/enzimologia , Catalase/metabolismo , Glutationa Transferase/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismoRESUMO
Studies have shown that supplementation with berries rich in anthocyanins are effective in reducing oxidative stress associated with aging, and are beneficial in reversing age-related neuronal and behavioral changes. However, there are few reports on other biological activities of these polyphenols, such as genoprotective effects. The present experiments were performed to study the possible effects of 30-day administration of a lyophilized extract of Vaccinium ashei berries on cognitive performance using step-down inhibitory avoidance, open-field habituation and elevated plus-maze tasks, as well as on DNA damage in the hippocampus and cerebral cortex. The present study showed that the extract significantly enhanced long-term memory in the inhibitory avoidance task, induced an increase in the number of crossings during open-field habituation and had an anxiolytic effect in the elevated plus-maze task. Moreover, the extract reduced oxidative DNA damage in brain tissue in vitro. These results suggest that supplementation with V. ashei berries to mice improves performance on memory tasks and has a protective effect on DNA damage, possibly due to the antioxidant activity of polyphenols, including anthocyanins.
Assuntos
Antocianinas/farmacologia , Comportamento Animal/efeitos dos fármacos , Mirtilos Azuis (Planta) , Dano ao DNA/efeitos dos fármacos , Frutas , Extratos Vegetais/farmacologia , Animais , Ansiolíticos/farmacologia , Aprendizagem da Esquiva/efeitos dos fármacos , Córtex Cerebral/efeitos dos fármacos , Ensaio Cometa , Habituação Psicofisiológica/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , CamundongosRESUMO
Biomarkers of exposure (liver metallothionein-like proteins content and catalase and glutathione S-transferase activities) and effect (liver lipoperoxidation and blood cell DNA damage) of contaminants were analyzed in the Brazilian flounder Paralichthys orbignyanus from the Patos Lagoon estuary (Southern Brazil). Flounders were collected for a year in two sites: "Coroa do Boi" (polluted site) and "Saco do Justino" (non-polluted site). Results indicated that micronucleated cells frequency was the best biomarker to distinguish flounders from the two sites. Taken together, data from DNA damage analyses (micronucleus test and comet assay) indicated that flounders from the non-polluted site efficiently repaired the DNA breaks, contrary to those from the polluted site, which probably had their DNA repair system inhibited or exhausted. Furthermore, data from enzyme activities (catalase and GST) and lipid peroxidation indicated that flounders from the polluted site were under oxidative stress in summer and autumn.
Assuntos
Biomarcadores/análise , Exposição Ambiental , Monitoramento Ambiental , Linguados/fisiologia , Animais , Biometria , Brasil , Catalase/efeitos dos fármacos , Catalase/metabolismo , Dano ao DNA/efeitos dos fármacos , Feminino , Linguados/genética , Glutationa Transferase/efeitos dos fármacos , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Metalotioneína/análise , Testes para Micronúcleos/veterinária , Estações do Ano , Água do Mar/química , Poluição da Água/efeitos adversosRESUMO
Biomarkers of exposure and effect of pollutants were analyzed in croakers Micropogonias furnieri (Teleostei: Sciaenidae) captured in winter and summer in a polluted and in a non-polluted site at the Patos Lagoon estuary (Southern Brazil). Catalase and glutathione S-transferase activities (exposure biomarkers) and lipid peroxidation (effect biomarker) were analyzed in liver samples. Other two effect biomarkers were also studied: blood cells DNA damage (through comet assay and micronucleus test) and respiratory burst measurements. In a broad view, results point to an important seasonal variation of the biochemical biomarkers analyzed. However, data obtained clearly indicate that croakers collected in winter at the polluted site were subjected to a level of clastogenic agents sufficient to generate irreversible genetic damages (mutations) and impair the fish immune system.
Assuntos
Biomarcadores/análise , Dano ao DNA/fisiologia , Exposição Ambiental , Perciformes/fisiologia , Poluição da Água/efeitos adversos , Animais , Células Sanguíneas/efeitos dos fármacos , Brasil , Catalase/efeitos dos fármacos , Catalase/metabolismo , Dano ao DNA/efeitos dos fármacos , Monitoramento Ambiental , Doenças dos Peixes/induzido quimicamente , Glutationa Transferase/efeitos dos fármacos , Glutationa Transferase/metabolismo , Doenças do Sistema Imunitário/induzido quimicamente , Doenças do Sistema Imunitário/veterinária , Peroxidação de Lipídeos/efeitos dos fármacos , Metalotioneína/análise , Perciformes/genética , Perciformes/imunologia , Explosão Respiratória/efeitos dos fármacos , Estações do Ano , Água do Mar/químicaRESUMO
Polychaeta species like Laeonereis acuta (Nereididae) usually secrete great amounts of mucus that wrap the animal inside. Taking into account that fungi action in the sediment and UV radiation acting on dissolved organic matter in the water produces reactive oxygen species (ROS) like hydrogen peroxide (H(2)O(2)), it was considered that the mucus secretion could represent an antioxidant defense against environmental ROS. Antioxidant enzymes (catalase-CAT; superoxide dismutase-SOD; glutathione peroxidase-GPx and glutathione-S-transferase-GST) and total antioxidant capacity (TOSC) were determined in worms and mucus secretion. Higher (p<0.05) CAT, GPx and TOSC values were registered in mucus samples respect worms, SOD activity was similar (p>0.05) in both kind of samples, and absence of GST activity was observed in mucus samples, suggesting absence of catalyzed phase II reactions. In assays conducted with hepatoma cell lines exposed to H(2)O(2), it was verified that: (1) mucus co-exposure significantly (p<0.05) lowered DNA damage induced by H(2)O(2); (2) ROS production was significantly (p<0.05) reduced when cells were exposed simultaneously with mucus samples and H(2)O(2) respect H(2)O(2) alone. It can be concluded that the mucus production contributes substantially to the antioxidant defense system of the worm against environmental ROS through the interception or degradation of H(2)O(2), peroxyl and hydroxyl radicals.
Assuntos
Antioxidantes/metabolismo , Muco/metabolismo , Poliquetos/metabolismo , Animais , Catalase/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Contagem de Colônia Microbiana , Dano ao DNA , Poluentes Ambientais/toxicidade , Glutationa Peroxidase/metabolismo , Glutationa Transferase/metabolismo , Peróxido de Hidrogênio/toxicidade , Radical Hidroxila/metabolismo , Muco/enzimologia , Muco/microbiologia , Peróxidos/metabolismo , Poliquetos/enzimologia , Ratos , Espécies Reativas de Oxigênio/toxicidade , Superóxido Dismutase/metabolismoRESUMO
Hydrogen peroxide (H(2)O(2)) is a naturally occurring prooxidant molecule, and its effects in the macroinvertebrate infauna were previously observed. The existence of a gradient of antioxidant enzymes activity (catalase [CAT], glutathione peroxidase [GPx], superoxide dismutase [SOD], and glutathione-S-transferase [GST]) and/or oxidative damage along the body of the estuarine polychaeta Laeonereis acuta (Polychaeta, Nereididae) was analyzed after exposure to H(2)O(2). Because this species secretes conspicuous amounts of mucus, its capability in degrading H(2)O(2) was studied. The results suggest that L. acuta deal with the generation of oxidative stress with different strategies along the body. In the posterior region, higher CAT and SOD activities ensure the degradation of inductors of lipid peroxidation such as H(2)O(2) and superoxide anion (O(2)(.-)). The higher GST activity in anterior region aids to conjugate lipid peroxides products. In the middle region, the lack of high CAT, SOD, or GST activities correlates with the higher lipid hydroperoxide levels found after H(2)O(2) exposure. Ten days of exposure to H(2)O(2) also induced oxidative stress (lipid peroxidation and DNA damage) in the whole animal paralleled by a lack of CAT induction. The mucus production contributes substantially to H(2)O(2) degradation, suggesting that bacteria that grow in this secretion provide this capability.
Assuntos
Adaptação Fisiológica/fisiologia , Peróxido de Hidrogênio/metabolismo , Estresse Oxidativo/fisiologia , Poliquetos/enzimologia , Análise de Variância , Animais , Catalase/metabolismo , Ensaio Cometa , Dano ao DNA/fisiologia , Glutationa Peroxidase/metabolismo , Glutationa Transferase/metabolismo , Muco/metabolismo , Poliquetos/fisiologia , Superóxido Dismutase/metabolismo , Fatores de TempoRESUMO
The photoprotector role of pigment dispersion in the melanophores of the crab, Chasmagnathus granulata, against DNA and oxidative damages caused by UV-A and UV-B was investigated. Intact and eyestalkless crabs were used. In eyestalkless crabs, the dorsal epidermis of the cephalothorax (dispersed melanophores) and the epidermis of pereiopods (aggregated melanophores) were analyzed. Intact crabs showed only dispersed melanophores in the two epidermis. Antioxidant enzymes activity and lipoperoxidation content were analyzed after UV-A (2.5 J/cm2) or UV-B (8.6 J/cm2) irradiation. DNA damage was analyzed by single cell electrophoresis (comet) assay, after exposure to UV-B (8.6 J/cm2). UV-A radiation increased the glutatione-S-transferase activity in the pereiopods epidermis of eyestalkless crabs (P<0.05). UV-B radiation induced DNA damage in the dorsal epidermis of eyestalkless crabs (P<0.05). In pereiopod epidermis of eyestalkless crabs, there was no significant difference between control and UV-B-exposed crabs. In the pereiopods epidermis of eyestalkless, the control group showed higher scores of DNA damage and approximately 50% of cellular viability. Because in eyestalkless and irradiated crabs the cellular viability was approximately 5%, it was not possible to observe nuclei for determination of DNA damage. The findings show that melanophores can play a role in the defense against harmful effects of a momentary exposure to UV radiation.
Assuntos
Antioxidantes/efeitos da radiação , Dano ao DNA , Decápodes/enzimologia , Decápodes/efeitos da radiação , Glutationa Transferase/efeitos da radiação , Raios Ultravioleta , Animais , Antioxidantes/metabolismo , Catalase/metabolismo , Catalase/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , DNA/efeitos dos fármacos , DNA/efeitos da radiação , Decápodes/química , Relação Dose-Resposta à Radiação , Epiderme/química , Epiderme/efeitos da radiação , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos/efeitos da radiação , Melanóforos/química , Melanóforos/fisiologia , Pigmentos Biológicos/efeitos da radiaçãoRESUMO
Laeonereis acuta was seasonally collected in an industrially polluted site (P) and in an unpolluted site (UP) at the Patos Lagoon estuary (southern Brazil). Glutathione S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT) activity (U/mg protein) was determined in five groups of worms from each site. Metallothionein (MT - mol GSH/g ww) and lipid peroxides content (LPO - nmoles of cumene hydroperoxide/g ww) were also measured. Annual mean values for CAT (UP=3.7+/-0.3; P=5.7+/-0.6), GST (UP=0.034+/-0.003; P=0.045+/-0.004) and MT (UP=0.15+/-0.02; P=0.23+/-0.03) were higher (p<0.05) in worms from the P site. In autumn, CAT activity was higher (p<0.05) in worms from the P site (7.6 +/- 1.3) than in those from the UP site (3.6 +/- 0.4). In summer, MT concentration was higher in worms from the P site (0.37 +/- 0.03) than in those from the UP site (0.19 +/- 0.01). No significant difference (p>0.05) in the LPO content was observed in worms from the different sites or collected in different seasons. These results indicate that worms from the polluted site showed higher antioxidant responses than those from the unpolluted site, sufficient to prevent oxidative damage in terms of LPO.