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1.
Xenobiotica ; 53(4): 309-319, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37476967

RESUMO

Personal care products, such as UV filters, are frequently present in aquatic ecosystems, but studies on their impact on marine organisms are still scarce. Here we addressed the effects of benzophenone-3 (BP-3) on the antioxidant status of Perna perna mussels exposed to concentrations of 0.1 and 3 µg.L-1 for 72 h and 7 days. Glutathione peroxidase (GPx), glutathione reductase (GR), glutathione S-transferase (GST), glucose-6-phosphate dehydrogenase (G6PDH) activity and lipoperoxidation (MDA) were evaluated in the gills. A significant reduction (p < 0.05) in the activity of G6PDH and GPx was observed after exposure for 7 days to 0.1 µg.L-1. However, no significant differences were observed in GST activity and MDA levels, independently of the exposure time. Principal component analysis (PCA) showed an association of BP-3 highest concentration with GR and MDA at 72 h and only with GR at 7 days of exposure. Similarly, the integrated biomarker response (IBR) demonstrated GR and MDA alterations. In conclusion, environmentally relevant concentrations of BP-3 altered antioxidant and auxiliary enzymes, which could cause long-term damage to P.perna mussels. The need to implement more efficient techniques in wastewater treatment systems is pointed out, especially in summer, when UV filters are used more frequently and abundantly.


Assuntos
Perna (Organismo) , Poluentes Químicos da Água , Animais , Antioxidantes , Perna (Organismo)/fisiologia , Ecossistema , Catalase , Glutationa Transferase , Glutationa Redutase/farmacologia , Glutationa Peroxidase/farmacologia , Poluentes Químicos da Água/toxicidade , Biomarcadores
2.
Acta sci., Health sci ; 44: e55845, Jan. 14, 2022.
Artigo em Inglês | LILACS | ID: biblio-1366721

RESUMO

The effects of the aqueous extract of Ilex paraguariensis (Ip)and the flavonoid quercetin were tested during the induction of in vivomyocardial ischemia/ reperfusion in Rattus norvegicus. The antioxidant power of the extract and quercetin were chemically determined. The experimental groups were: control, ischemia/reperfusion induction, Iporal treatment, Iporal treatment and ischemia /reperfusion, quercetin oral treatment, and quercetin oral treatment and ischemia/reperfusion. Rats were anesthetized with sodium thiopental and xylazine via intraperitoneal injection and subsequently underwent 15 minutes of ischemia followed by 15 minutes of reperfusion. Ischemia was promoted by tying the left anterior descending coronary artery. Areas of risk and infarction were stained by intravenous Evans blue and triphenyl tetrazolium chloride. Reactive oxygen species (ROS), antioxidant capacity against peroxylradicals, and lipid peroxidation of the myocardium were quantified. A significant reduction in areas of risk and infarction was detected in the ischemic myocardium treated with Ipand quercetin; ROS generation and lipid peroxidation were significantly reduced, and the antioxidant capacity was elevated. Oral administration of Ippromoted antioxidant benefits in the myocardium during ischemia and reperfusion, which reduced infarction. We suggest that Mate (a hot drink made from steeped dried leaves of Ip) consumption is a potential cardioprotective habit of indigenous people from southern South American countries, which must be better understood scientifically and ethnographically.


Assuntos
Animais , Ratos , Flavonoides , Ilex paraguariensis/efeitos adversos , Isquemia/tratamento farmacológico , Antioxidantes , Quercetina/análise , Ratos , Reperfusão , Administração Oral , Estresse Oxidativo/efeitos dos fármacos , Chás Medicinais/efeitos adversos , Infarto do Miocárdio/tratamento farmacológico
3.
Mar Pollut Bull ; 158: 111401, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32753186

RESUMO

This work aimed to investigate effects of the ocean contamination by the sunscreen Benzophenone-3 (BP3) and acidification, caused by CO2 enrichment, to the yellow clam, Amarilladesma mactroides. Biochemical biomarkers were analyzed in tissues (gills, digestive gland, and mantle) of clams exposed to the environmental concentration of 1 µg/L BP3, at seawater natural pH (pH 8.1) and at lower pH (pH 7.6). The tissues responded in different ways considering their physiological roles. In general, BP3 altered activity of the enzymes, glutathione-S-transferase (GST) and glutathione cysteine ligase (GCL); but mostly increased the level of glutathione (GSH). These effects were enhanced by acidification, without augmenting lipid peroxidation (LPO). Carbonic anhydrase activity (CA) increased after BP3 exposure in the digestive gland and decreased in the gills at pH 7.6, while Ca2+-ATPase activity was affected by acidification only. Changing levels of these enzymes can alter shell formation and affect the bivalve maintenance in impacted environments.


Assuntos
Bivalves , Poluentes Químicos da Água , Animais , Benzofenonas , Biomarcadores , Brânquias , Concentração de Íons de Hidrogênio , Peroxidação de Lipídeos
4.
Artigo em Inglês | MEDLINE | ID: mdl-32169415

RESUMO

The present study evaluated the effect of fullerene (C60) under in vitro conditions, in hippocampus homogenates from rats and on the induction of behavioral disabilities. Exposure to in vitro C60 led to an increase in the concentration of reactive oxygen species (ROS) and lipid peroxidation (LPO) of hippocampus treated with of fullerene and suspension. These results indicate that the oxidative stress caused by the exposure to C60 was in part related to an absence of an antioxidant response. In this sense, one-trial inhibitory avoidance task were performed and results showed that fullerene at 0.2 and 0.45 µm impaired the acquisition and consolidation of short and long-term memory. Further, enzymatic analysis in rat hippocampus were not significantly different, however, there was an increase in the content of LPO and ROS produced by fullerene. Overall, the results indicates that fullerene possess neurotoxic properties that impairs behavior and promotes oxidative stress.


Assuntos
Aprendizagem da Esquiva/efeitos dos fármacos , Encéfalo/fisiopatologia , Fulerenos/toxicidade , Peroxidação de Lipídeos , Rememoração Mental/efeitos dos fármacos , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Ratos , Ratos Wistar
5.
Chemosphere ; 248: 125959, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32035379

RESUMO

The emergent demand for food production has increased the widespread use of pesticides, especially glyphosate-based herbicides as they can protect different types of crops, especially transgenic ones. Molecules of glyphosate have been found in water bodies around the world, and its presence can cause negative effects on non-target organisms, such as fish. Glyphosate toxicity appears to be systemic in fish but does not affect their organs equally. Also, its formulations can be more toxic than pure glyphosate. In this sense, we investigated if these variations in toxicity could be related to ATP binding cassette subfamily C (ABCC) transporters and the cellular detoxification capacity, following exposure to herbicides. Thus, adults of Danio rerio were exposed (24 and 96 h) to glyphosate and Roundup Transorb® (RT) at an environmental concentration of 0.1 mg/L, and the activity of ABCC proteins and gene expression of five isoforms of ABCC were analyzed. Glyphosate and RT exposure increased ABCC protein activity and gene expression up to 3-fold when compared to controls, indicating the activation of detoxification mechanisms. Only in the brain of D. rerio, the exposure to RT did not stimulate the activity of ABCC proteins, neither the expression of genes abcc1 and abcc4 that responded to the exposure to pure glyphosate. These results may suggest that the brain is more sensitive to RT than the other target-tissues since the mechanism of detoxification via ABCC transporters were not activated in this tissue as it was in the other.


Assuntos
Glicina/análogos & derivados , Herbicidas/toxicidade , Peixe-Zebra/fisiologia , Transportadores de Cassetes de Ligação de ATP , Animais , Glicina/toxicidade
6.
Biomed Pharmacother ; 109: 1532-1540, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30551405

RESUMO

Nifedipine is a calcium channel blocker dihydropyridine that has been used in the treatment of hypertension. The production of reactive species and calcium overload are the main contributors to myocardial ischemia-reperfusion (I / R) injury. We investigated the ability of novel dihydropyridines (DHPs) to improve the effect of protecting against the injury induced by ischemia and reperfusion in cardioblasts when compared to nifedipine. Forty three DHPs were created varying the fatty chains derived from palmitic acid, stearic acid and oleic acids and aromatic moiety in addition to the addition of chemical elements such as chlorine, nitrogen dioxide, furfural, hydroxyl and methoxy. Cytotoxicity and inhibition of linoleic oxidation were evaluated for all new DHPs and also for nifedipine. The alpha-tocopherol and butylated hydroxytoluene (BHT) were used as antioxidants controls. The compounds with the best antioxidant potential were used in the ischemia and reperfusion (I / R) induction test in cardioblasts (H9c2). Cardioblasts were treated 24 h after assembly of plates and submitted to the ischemia simulation (30 min), after which, normoxia and cellular nutrition conditions were reestablished, simulating reperfusion (additional 30 min). Right after, cell viability, apoptosis, necrosis, and the generation of reactive oxygen species (ROS) were evaluated. Cell viability during I / R was not altered in cells treated with nifedipine, BHT and the new DHP composed of palmitic acid with hydroxyl group in the aromatic substituent. The other new DHPs increased cell viability during I / R simulation and reduced levels of reactive species compared to the I / R group, demonstrating the antioxidant capacity of the new DHPs. Therefore, DHPS with palmitic and oleic acids in the C3 and C5 position with NO2 or Cl in aromatic moiety, presented the highest antioxidant potential (linoleic oxidant test). The new DHPs increased cell viability during I / R simulation and reduced levels of reactive species compared to the ischemia and reperfusion group, demonstrating the antioxidant capacity of the new DHPs. Taken together, these results indicate that those new DHPs have a greater cardioprotective antioxidant capacity to face the damages of ischemia and reperfusion.


Assuntos
Cardiotônicos/farmacologia , Di-Hidropiridinas/farmacologia , Mioblastos/efeitos dos fármacos , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Antioxidantes/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Mioblastos/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Necrose/tratamento farmacológico , Necrose/metabolismo , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Traumatismo por Reperfusão/metabolismo
7.
Biomed Pharmacother ; 92: 356-364, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28554131

RESUMO

This work investigated the acute effects of the calcium channel blocker nifedipine and its new fatty hybrid derived from palmitic acid, 3,5-dipalmitoyl-nifedipine, compared to endocannabinoid anandamide during the process of inducing ischemia and reperfusion in cardiomyoblast H9c2 heart cells. The cardiomyoblasts were treated in 24 or 96-well plates (according to the test being performed) and maintaining the treatment until the end of hypoxia induction. The molecules were tested at concentrations of 10 and 100µM, cells were treated 24h after assembling the experimental plates and immediately before the I/R. Cell viability, apoptosis and necrosis, and generation of reactive oxygen species were evaluated. Nifedipine and 3,5-dipalmitoyl-nifedipine were used to assess radical scavenging potential and metal chelation. All tested molecules managed to reduce the levels of reactive oxygen species compared to the starvation+vehicle group. In in vitro assays, 3,5-dipalmitoyl-nifedipine showed more antioxidant activity than nifedipine. These results indicate the ability of this molecule to act as a powerful ROS scavenger. Cell viability was highest when cells were induced to I/R by both concentrations of anandamide and the higher concentration of DPN. These treatments also reduced cell death. Therefore, it was demonstrated that the process of hybridization of nifedipine with two palmitic acid chains assigns a greater cardioprotective effect to this molecule, thereby reducing the damage caused by hypoxia and reoxygenation in cardiomyoblast cultures.


Assuntos
Cardiotônicos/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Nifedipino/farmacologia , Ácido Palmítico/farmacologia , Traumatismo por Reperfusão/prevenção & controle , Animais , Bloqueadores dos Canais de Cálcio/química , Bloqueadores dos Canais de Cálcio/farmacologia , Bloqueadores dos Canais de Cálcio/uso terapêutico , Cardiotônicos/química , Cardiotônicos/uso terapêutico , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células Cultivadas , Relação Dose-Resposta a Droga , Miócitos Cardíacos/patologia , Nifedipino/química , Nifedipino/uso terapêutico , Ácido Palmítico/química , Ácido Palmítico/uso terapêutico , Ratos , Ratos Wistar , Traumatismo por Reperfusão/patologia
8.
Neurosci Lett ; 651: 182-187, 2017 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-28432028

RESUMO

This study investigates Se-phenyl-thiazolidine-4-carboselenoate (Se-PTC) protective activity against oxidative and behavioral stress in the model of mania induced by ouabain (OUA) in male rats. The compound used was Se-PTC (50mg/kg) and the positive control LiCl (45mg/kg) was administered for intragastric route (i.g.) 30min prior to administration of OUA (10-5M). OUA was dissolved in artificial cerebrospinal fluid (aCSF) and administered at the 5µl through an intracerebroventricular (i.c.v) cannula. The pretreatment with Se-PTC was effective in preventing the increase in locomotor activity induced by OUA, however the positive control LiCl is capable to block crossing augmentation induced by OUA. Na+/K+-ATPase activity was significantly reduced in OUA group and the Se-PTC to normalize Na+/K+-ATPase activity. Pretreatment with Se-PTC protect against the increase in catalase activity and thiobarbituric acid reactive species (TBARS) content in the brain caused by OUA. Therefore, Se-PTC is effective against OUA-induced hyperactivity and alterations in brain oxidative status of rats.


Assuntos
Comportamento Animal/efeitos dos fármacos , Transtorno Bipolar/tratamento farmacológico , Transtorno Bipolar/metabolismo , Encéfalo/efeitos dos fármacos , Fármacos Neuroprotetores/administração & dosagem , Compostos Organosselênicos/administração & dosagem , Estresse Oxidativo/efeitos dos fármacos , Tiazolidinas/administração & dosagem , Animais , Transtorno Bipolar/induzido quimicamente , Encéfalo/metabolismo , Modelos Animais de Doenças , Locomoção/efeitos dos fármacos , Masculino , Ouabaína/administração & dosagem , Ratos Wistar
9.
Pharm Biol ; 53(2): 242-50, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25420516

RESUMO

CONTEXT: Psidium cattleianum Sabine (Myrtacea) is rich in vitamin C and phenolic compounds, including epicatechin and gallic acid as the main components. OBJECTIVE: To evaluate the antifungal and antioxidant capacity in vitro of the essential oil of araçá (EOA). The acute toxicity of the EOA also was evaluated in mice. MATERIALS AND METHODS: The leaves of the P. cattleianum were extracted by steam distillation. The antioxidant capacity was evaluated by in vitro tests [1,1-diphenyl-2-picryl-hydrazyl (DPPH), 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS), ferric ion reducing antioxidant power (FRAP), linoleic acid oxidation, thiobarbituric acid reactive species (TBARS)], and ex vivo analysis [TBARS, δ-aminulevunilate dehydratase (δ-Ala-D) and catalase activity, non-protein thiols (NPSH), and ascorbic acid levels]. The toxicity was studied in mice by a single oral administration of EOA; and the antifungal activity was performed with five strains of fungi. RESULTS: The EOA exhibited antioxidant activity in the FRAP assay and reduced lipid peroxidation in the cortex (Imax = 32.90 ± 2.62%), hippocampus (IC50 = 48.00 ± 3.00 µg/ml and Imax = 32.90 ± 2.62%), and cerebellum (Imax = 45.40 ± 14.04%) of mice. Acute administration of the EOA by the oral route did not cause toxicological effects in mice (LD50 > 500 µg/ml). The EOA also showed antifungal activity through of the determination minimum inhibitory concentration (MIC) values ranging from 41.67 ± 18.04 to 166.70 ± 72.17 µg/ml for tested strains. CONCLUSION: The results of present study indicate that EOA possess antioxidant properties, antifungal and not cause toxicity at tested doses.


Assuntos
Antifúngicos/farmacologia , Antioxidantes/farmacologia , Óleos Voláteis/isolamento & purificação , Psidium/química , Animais , Antifúngicos/química , Antifúngicos/isolamento & purificação , Antifúngicos/toxicidade , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/toxicidade , Compostos de Bifenilo/química , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Candida/efeitos dos fármacos , Relação Dose-Resposta a Droga , Radicais Livres/química , Rim/efeitos dos fármacos , Rim/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Óleos Voláteis/toxicidade , Picratos/química , Folhas de Planta/química , Testes de Toxicidade Aguda , Trichosporon/efeitos dos fármacos
10.
Eur J Pharmacol ; 742: 131-8, 2014 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-25218989

RESUMO

In this study, the antioxidant and antidepressant-like activities of the semi-synthetic compound α-phenylseleno citronellal (PhSeCIT) and the natural terpenoid R-citronellal (CIT) were evaluated. The biological potential of PhSeCIT and CIT was evaluated by antioxidant in vitro assays, such as 1,1-diphenyl-2-picryl-hydrazyl (DPPH), 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS), ferric ion reducing antioxidant power (FRAP) and linoleic acid oxidation. The compounds were also assessed by ex vivo tests to determine the acute toxicity, levels of thiobarbituric acid reactive species (TBARS), δ-aminolevulinate dehydratase (δ-Ala-D) and Na(+)/K(+) ATPase activities. The antidepressant-like activity of compounds in the tail suspension test (TST) and forced swimming test (FST) was also investigated. The results demonstrated that the addition of an organoselenium group to (R)-citronellal increased its antioxidant properties, since PhSeCIT showed better activity than CIT. The treatment of mice with both compounds did not cause death of any animals. The levels of TBARS were significantly reduced by PhSeCIT in liver and cortex of animals, whereas CIT did not alter these parameters. In the TST and FST, PhSeCIT showed promising antidepressant-like activity, while CIT was not active in this test. Taken together, these data demonstrate the role of selenium in the antioxidant and antidepressant-like activities of (R)-citronellal.


Assuntos
Aldeídos/farmacologia , Antidepressivos/farmacologia , Antioxidantes/farmacologia , Monoterpenos/farmacologia , Compostos Organosselênicos/farmacologia , Monoterpenos Acíclicos , Aldeídos/química , Aldeídos/toxicidade , Animais , Antidepressivos/química , Antidepressivos/toxicidade , Antioxidantes/química , Antioxidantes/toxicidade , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Ácido Linoleico/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Monoterpenos/química , Monoterpenos/toxicidade , Atividade Motora/efeitos dos fármacos , Compostos Organosselênicos/química , Compostos Organosselênicos/toxicidade , Plantas Medicinais , Sintase do Porfobilinogênio/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
11.
Chem Biol Interact ; 205(2): 100-7, 2013 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-23830813

RESUMO

The antioxidant potential of organoselenium compounds has been extensively investigated because oxidative stress is a hallmark of a variety of human diseases. In this study, we report the influence of substituent groups on the antioxidant activity of (R)-Se-aryl thiazolidine-4-carboselenoate (Se-PTC) in several in vitro assays. The amino group in the thiazolidine ring affects the antioxidant activity of the compound. Our data revealed that Se-PTC a had higher radical scavenging efficiency in the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS(+)) assays compared to other compounds. In the ferric ion reducing antioxidant power (FRAP) assay, Se-PTC a exhibited ferric-reducing ability at concentrations as low as 5µM. However, this effect was diminished when the amino group was protected with carbamate (Se-PTC d). In the nitric oxide scavenging assay, Se-PTC c presented better NO-scavenging than Se-PTC b. However, Se-PTC a and d did not prevent NO formation at any of the tested concentrations. Se-PTC c decreased the sodium nitroprussate-induced lipid peroxidation in the cortex and hippocampus of mice. In summary, we demonstrate that Se-PTC is a promising antioxidant compound and that the compound's activity is influenced by the amino group and by the characteristics of the arylselenium substituents. Thus, these compounds may be used as synthetic antioxidants that provide protection against oxidative diseases.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Compostos Organosselênicos/química , Compostos Organosselênicos/farmacologia , Tiazolidinas/química , Tiazolidinas/farmacologia , Animais , Benzotiazóis/química , Benzotiazóis/farmacologia , Compostos de Bifenilo/química , Compostos de Bifenilo/farmacologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Humanos , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Camundongos , Picratos/química , Picratos/farmacologia , Relação Estrutura-Atividade , Ácidos Sulfônicos/química , Ácidos Sulfônicos/farmacologia
12.
J Med Food ; 13(2): 336-42, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20170358

RESUMO

The aim of this study was to carry out pharmacological screening in order to evaluate the potential effects of lyophilized fruits of different cultivars of Vaccinium ashei Reade (Family Ericaceae) berries, commonly known as rabbiteye blueberries, on nociception. This was achieved using the formalin, hot plate, tail-flick, and writhing tests in mice. During this experiment the mice consumed approximately 3.2-6.4 mg/kg/day (p.o.) of the anthocyanins. The extract was administered for 21 days or 60 minutes before test. Morphine and diclofenac (10 mg/kg, p.o.) as the standard drug (positive control) and water (via oral gavage) as the negative control were administered before all tests. The blueberry extract produced a significant decrease in constrictions induced by acetic acid and caused graded inhibition of the second phase of formalin-induced pain. Moreover, in both the hot plate and tail-flick tests, it significantly increased the threshold. These data suggest that the extract from V. ashei produced antinociceptive effects, as demonstrated in the experimental models of nociception in mice. Additional experiments are necessary in order to clarify the true target for the antinociceptive effects of rabbiteye blueberry extract.


Assuntos
Analgésicos/uso terapêutico , Antocianinas/uso terapêutico , Mirtilos Azuis (Planta)/química , Dor/tratamento farmacológico , Fitoterapia , Extratos Vegetais/uso terapêutico , Ácido Acético , Analgésicos/farmacologia , Animais , Antocianinas/farmacologia , Diclofenaco/farmacologia , Diclofenaco/uso terapêutico , Modelos Animais de Doenças , Formaldeído , Frutas , Temperatura Alta , Masculino , Camundongos , Morfina/farmacologia , Morfina/uso terapêutico , Contração Muscular , Dor/etiologia , Limiar da Dor/efeitos dos fármacos , Extratos Vegetais/farmacologia
13.
Comp Biochem Physiol C Toxicol Pharmacol ; 150(3): 337-42, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19501674

RESUMO

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-Zebra
14.
Comp Biochem Physiol C Toxicol Pharmacol ; 149(4): 538-43, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19138757

RESUMO

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 fármacos
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