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1.
Fish Physiol Biochem ; 46(1): 405-416, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31784931

RESUMO

Hypoxia is among the most critical environmental stressors for fish in aquatic environments, and several energetic alterations have been associated with it. The aim of the present study was to evaluate the involvement of the phosphoryl transfer network and its effects on adenosine triphosphate (ATP)-dependent enzymes during hypoxia, as well as the role of oxidative stress in the activity of the phosphoryl transfer network in pacamã (Lophiosilurus alexandri) subjected to severe hypoxia. Branchial creatine kinase (CK; cytosolic and mitochondrial fractions), adenylate kinase (AK), and pyruvate kinase (PK) activities were inhibited after 72 h of exposure to hypoxia compared to their respective normoxia groups, and remained low (except for AK) after 24 and 72 h of re-oxygenation. Activities of the branchial sodium-potassium pump (Na+, K+-ATPase) and proton pump (H+-ATPase) were inhibited in fish exposed to 72 h of hypoxia compared to the normoxia group, remained inhibited after 24 h of re-oxygenation, and were restored to physiological levels after 72 h of re-oxygenation. Levels of branchial reactive oxygen species (ROS) were higher in fish exposed to hypoxia for 72 h compared to the normoxia group, and increased during re-oxygenation. Lipid peroxidation (LOOH) levels were higher in fish subjected to 72 h of hypoxia compared to the normoxia group, and remained higher during re-oxygenation. On the other hand, protein sulfhydryl (PSH) levels were lower in fish exposed to hypoxia for 72 h compared to the normoxia group, and remained low during re-oxygenation. Based on this evidence, inhibition of the activities of enzymes belonging to phosphoryl transfer network contributed to impairing energetic homeostasis linked to ATP production and ATP utilization in gills of pacamã subjected to hypoxia, and remained inhibited during re-oxygenation (except AK activity). Moreover, inhibition of the phosphoryl transfer network impaired activity of ATP-dependent enzymes, which can be mediated by ROS overproduction, lipid peroxidation, and oxidation of SH groups.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31493584

RESUMO

Aflatoxin B1 (AFB1) is one of the most important mycotoxins due to its hepatotoxic and carcinogenic effects on animals. The effect of dietary supplementation with vegetable choline (VC) at 400, 800, and 1200 mg/kg against the deleterious effects of AFB1 (2 ppm/kg diet) in the liver of Nile tilapia (Oreochromis niloticus) was studied. The experimental period was 81 days, and the diet with VC was offered to the fish for 60 days prior to challenge with AFB1. Diets with AFB1 were tested in three replications and animals were analyzed at days 14 and 21 of dietary intake. The addition of VC to tilapia diet increased body weight (days 30 and 60 pre-challenge and day 21 post-challenge). The group fed aflatoxin-contaminated diet presented significantly reduced antioxidant enzymes and increased reactive oxygen species (ROS) levels, thiobarbituric acid reactive species (TBARS) levels, and protein carbonyl (PC) content in the liver. Dietary supplementation with VC at 800 and 1200 mg/kg demonstrated a significant protective effect, avoiding the increase of ROS, TBARS, and PC levels in the liver of tilapia from the aflatoxin contaminated groups. Thus, dietary VC supplementation may be used in tilapia to increase antioxidant status and reduce the negative effects caused by AFB1 toxicity. Based on the findings, it is recommended to use VC as a food supplement for Nile tilapia in order to avoid AFB1 toxication. In addition, decreased aflatoxin toxicity can be attributed to the VC antioxidant property.


Assuntos
Aflatoxina B1/toxicidade , Ração Animal/análise , Colina/farmacologia , Ciclídeos , Doenças dos Peixes/induzido quimicamente , Contaminação de Alimentos , Aflatoxina B1/administração & dosagem , Animais , Catalase/genética , Catalase/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Doença Hepática Induzida por Substâncias e Drogas/veterinária , Colina/administração & dosagem , Dieta/veterinária , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Doenças dos Peixes/tratamento farmacológico , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
3.
Microb Pathog ; 135: 103649, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31374321

RESUMO

Extracellular adenosine triphosphate (ATP) is as key mediator of immune and inflammatory responses. ATP is normally sequestered in the intracellular milieu and released by apoptotic and necrotic cells, where it acts as a pro-inflammatory mediator in the extracellular milieu. A limited number of studies have explored the involvement of purinergic signaling in oomycete infections, including Saprolegnia parasitica; this is a most destructive oomycete pathogen, associated with high mortality and severe economic losses for fish producers. The aim of this study was to determine whether purinergic signaling exerts anti- or pro-inflammatory effects in spleens of grass carp (Ctenopharyngodon idella) naturally infected by S. parasitica. Animals naturally infected with S. parasitica showed typical gross lesions characterized by cotton-wool tufts on the tail and fins, as well as severe histopathological lesions such as necrosis. Spleen ATP and metabolites of nitric oxide (NOx) levels were higher in fish naturally infected by S. parasitica compared to control on day 7 post-infection (PI). Spleen nucleoside triphosphate diphosphohydrolase (NTPDase) activity (ATP as substrate) was greater in fish naturally infected by S. parasitica than in uninfected on day 7 PI, while no significant differences were observed between groups with respect to NTPDase (adenosine diphosphate as substrate) and 5'-nucleotidase activities. Finally, adenosine deaminase (ADA) activity was lower in fish naturally infected by S. parasitica than in uninfected fish on day 7 PI. In summary, spleen tissue necrosis in the context of saprolegniosis provokes an intense release of ATP into the extracellular milieu, where it interacts with the P2X7 purine receptor and leads to a self-sustained pro-inflammatory deleterious cycle, contributing to an intense inflammatory process. In response to excessive ATP levels in the extracellular milieu, ATP and adenosine hydrolysis were modulated in an attempt to restrict the inflammatory process via upregulation of NTPDase and downregulation of ADA activities. We conclude that the purinergic signaling pathway modulates immune and inflammatory responses during natural infection with S. parasitica.


Assuntos
Trifosfato de Adenosina/metabolismo , Anti-Inflamatórios/metabolismo , Carpas/imunologia , Doenças dos Peixes/imunologia , Doenças dos Peixes/parasitologia , Purinérgicos/metabolismo , Transdução de Sinais , Baço/metabolismo , Adenosina Desaminase/metabolismo , Animais , Carpas/metabolismo , Modelos Animais de Doenças , Doenças dos Peixes/patologia , Proteínas de Peixes/imunologia , Micoses , Necrose , Óxido Nítrico/metabolismo , Saprolegnia/patogenicidade , Baço/patologia
4.
Microb Pathog ; 132: 261-265, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31078710

RESUMO

Aeromonosis is a fish disease that leads to haemorrhagic septicaemia and high mortality. The detection of early behavioural changes associated to this disease could be helpful in anticipating the initiation of treatment, increasing the probability of success. The influence of this disease on the hypothalamic-pituitary-interrenal (HPI) axis and on the brain expression of heat shock proteins (HSP) is little known. Therefore, the aim of this study was to evaluate the effect of Aeromonas hydrophila infection on individual behaviour and brain expression of genes related to stress (slc6a2, hsp90, hspa12a, hsd20b, hsd11b2, crh) in silver catfish (Rhamdia quelen). Thirty fish were divided into healthy and infected groups. The fish of the infected group were inoculated intramuscularly with 50 µL of bacterial suspension (6.4 × 108 CFU/mL), while control animals received 50 µL of saline. On day five post-infection, animals were submitted to the novel tank test, euthanized, and the brain was collected for molecular analysis. Infected fish swam more in the unknown aquarium and presented an increase in brain expression of genes related to HSP (hspa12a) and the route of cortisol synthesis (crh) when compared to uninfected fish. Therefore, this disease causes hyperlocomotion related to stress.


Assuntos
Aeromonas hydrophila/patogenicidade , Peixes-Gato/microbiologia , Doenças dos Peixes/microbiologia , Doenças dos Peixes/fisiopatologia , Infecções por Bactérias Gram-Negativas/microbiologia , Infecções por Bactérias Gram-Negativas/fisiopatologia , Infecções por Bactérias Gram-Negativas/veterinária , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/genética , Animais , Comportamento Animal , Encéfalo/metabolismo , Peixes-Gato/genética , Modelos Animais de Doenças , Feminino , Expressão Gênica , Proteínas de Choque Térmico HSP90/genética , Proteínas de Choque Térmico/genética , Locomoção , Masculino , Proteínas da Membrana Plasmática de Transporte de Norepinefrina/genética
5.
Microb Pathog ; 131: 164-169, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30978428

RESUMO

Bacterial diseases are one of the major problems in freshwater fish culture and have been linked to significant losses and high mortality rate. In this study, Nile tilapia Oreochromis niloticus was infected by Providencia rettgeri to evaluate the oxidative stress and antioxidant responses in the fish tissues. Juvenile Nile tilapia was divided into two groups, as follow: control (uninfected) and experimentally infected with 100 µL of P. rettgeri suspension containing 2.4 × 107 viable cells/fish, and the liver and kidney tissues were collected on days 7 and 14 post-infection (PI). Liver and kidney ROS and lipid peroxidation levels were high in infected fish on day 14 PI compared to control group, while superoxide dismutase activity was lower in liver (days 7 and 14 PI) and kidney (day 14 PI) compared to their respective control groups. Liver and kidney antioxidant capacity against peroxyl radicals, non-proteic, and proteic thiols levels was lower in infected tilapia on day 14 PI compared to control group. Based on these results, P. rettgeri infection may elicit oxidative damage via increased ROS production, decreased ROS elimination and inhibits enzymatic and non-enzymatic antioxidant defense systems; which may contribute directly to disease pathophysiology of infected animals.


Assuntos
Antioxidantes/metabolismo , Ciclídeos/metabolismo , Doenças dos Peixes/metabolismo , Estresse Oxidativo , Providencia/patogenicidade , Animais , Brasil , Ciclídeos/imunologia , Ciclídeos/microbiologia , Modelos Animais de Doenças , Infecções por Enterobacteriaceae/imunologia , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/veterinária , Doenças dos Peixes/imunologia , Doenças dos Peixes/microbiologia , Interações Hospedeiro-Patógeno/fisiologia , Rim/metabolismo , Peroxidação de Lipídeos , Fígado/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tilápia/microbiologia
6.
Artigo em Inglês | MEDLINE | ID: mdl-30910599

RESUMO

Mycotoxins are secondary metabolites produced by varieties of fungi that contaminate food and feed resources and are capable of inducing a wide range of toxicity. This problem is extensively aggravated due to the increasing replacement of fish meal by plant-derived proteins. Among the mycotoxins, aflatoxins have received a great deal of attention owing to their great prevalence in plant feedstuffs and to the detrimental effects on animals. The objective of this study was to evaluate whether dietary supplementation with tea tree (Melaleuca alternifolia) oil (TTO) would avoid or minimize the negative impacts on silver catfish (Rhamdia quelen) fed with aflatoxins-contaminated diets. Four treatments were tested: control (fish fed with a control diet); AFB (fish fed with a mycotoxin-contaminated diet - 1893 µg kg-1 of AFB1 and 52.2 µg kg-1 AFB2); TTO (fish fed with a control diet + 1 mL kg-1 of TTO), and TTO + AFB (fish fed with a mycotoxin contaminated diet - 2324 µg kg-1 of AFB1 and 43.5 µg kg-1 AFB2 + 1 mL kg-1 of TTO). Diets were tested in three replications and analyzed at days 5 and 10 of dietary intake. Significantly reduced antioxidant enzymes (SOD, GPx, and GST) and increased lipid peroxidation (LOOH) and protein carbonyl (PC) content in plasma and liver, with 16.6% mortality occurrence, were observed in the group fed aflatoxin-contaminated diet. Furthermore, aflatoxins also significantly increased plasmatic and hepatic ROS levels and decreased hepatic antioxidant capacity against peroxyl radical (ACAP) levels. Plasma cortisol levels were not altered by aflatoxicosis, but the intoxication induced hepatose. Notwithstanding, addition of TTO to the groups receiving aflatoxins showed a protective effect, avoiding the increase of ROS, LOOH, and PC levels in plasma and liver. Moreover, TTO treatment ameliorated the aflatoxin-associated liver damage. Thus, TTO supplementation at concentration of 1 mL kg-1 in feed may be used in fish to increase antioxidant status and reduce the negative effects caused by aflatoxins toxicity.


Assuntos
Aflatoxinas/toxicidade , Ração Animal/análise , Peixes-Gato , Doença Hepática Induzida por Substâncias e Drogas/veterinária , Doenças dos Peixes/induzido quimicamente , Óleo de Melaleuca/farmacologia , Animais , Anti-Infecciosos Locais/uso terapêutico , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Contaminação de Alimentos , Hidrocortisona , Distribuição Aleatória , Óleo de Melaleuca/administração & dosagem
7.
Chemosphere ; 223: 124-130, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30772591

RESUMO

The objective of this study was to evaluate whether antiparasitic eprinomectin may be an environmental contaminant in water compartment in low concentrations, negatively affecting neurotransmission and, consequently, the natural behavior of the jundiá (Rhamdia quelen). Fish were randomly allocated in tanks and exposed for 24 and 48 h to eprinomectin concentrations in water [0.0 (Control), 1.124 (T1), 1.809 (T2) and 3.976 (T3) µg L-1], followed by 48 h of recovery in eprinomectin-free water, in order to evaluate the behavioral parameters, levels of reactive oxygen species (ROS) in the brain, as well as cerebral enzymatic activities of acetylcholinesterase (AChE) and of the sodium-potassium ATPase pump (Na+/K+-ATPase). Especially at the two highest concentrations of eprinomectin (T2 and T3), the fish showed alterations in natural behavior, particularly hyperlocomotion and longer time on the surface. Furthermore, at these same concentrations, cerebral ROS levels increased and cerebral AChE activity decreased. At the highest concentration (T3) cerebral Na+/K+-ATPase activity was reduced. Increased ROS and impairment of AChE and Na+/K+-ATPase enzymes in the brain may have contributed directly to behavioral changes, due to neuronal damage and synapse impairment. Even after 48 h in water without eprinomectin, behavioral changes and neurotoxic effects were observed in fish, suggesting residual effects of the antiparasitic. In conclusion, eprinomectin even in low concentrations may be a hazardous environmental contaminant for aquatic organisms, as it causes brain damage and affects the natural behavior of fish.


Assuntos
Acetilcolinesterase/efeitos dos fármacos , Peixes-Gato/fisiologia , Ivermectina/análogos & derivados , ATPase Trocadora de Sódio-Potássio/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Encéfalo/enzimologia , Inibidores da Colinesterase , Ivermectina/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Poluentes Químicos da Água/toxicidade
8.
Fish Physiol Biochem ; 45(1): 155-166, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30120603

RESUMO

In teleost fish, stress initiates a hormone cascade along the hypothalamus-pituitary-interrenal (HPI) axis to provoke several physiological reactions in order to maintain homeostasis. In aquaculture, a number of factors induce stress in fish, such as handling and transport, and in order to reduce the consequences of this, the use of anesthetics has been an interesting alternative. Essential oil (EO) of Lippia alba is considered to be a good anesthetic; however, its distinct chemotypes have different side effects. Therefore, the present study aimed to investigate, in detail, the expression of genes involved with the HPI axis and the effects of anesthesia with the EOs of two chemotypes of L. alba (citral EO-C and linalool EO-L) on this expression in silver catfish, Rhamdia quelen. Anesthesia with the EO-C is stressful for silver catfish because there was an upregulation of the genes directly related to stress: slc6a2, crh, hsd20b, hspa12a, and hsp90. In this study, it was also possible to observe the importance of the hsd11b2 gene in the response to stress by handling. The use of EO-C as anesthetics for fish is not recommended, but, the use of OE-L is indicated for silver catfish as it does not cause major changes in the HPI axis.


Assuntos
Peixes-Gato/fisiologia , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Lippia/química , Monoterpenos/farmacologia , Óleos Vegetais/farmacologia , Anestesia/veterinária , Anestésicos/química , Anestésicos/farmacologia , Animais , Sistema Hipotálamo-Hipofisário/fisiologia , Monoterpenos/química , Óleos Voláteis/farmacologia , Óleos Vegetais/química
9.
Fish Physiol Biochem ; 44(4): 1253-1264, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29777417

RESUMO

In aquaculture, nutrition and supplemented diets have been shown to affect broodstock reproductive performance. In this study, we investigated the effects of dietary supplementation with Cymbopogon flexuosus essential oil (CFEO) microcapsules on reproductive-related parameters in silver catfish (Rhamdia quelen) male broodfish. Adult male broodstocks were separated into three groups according to the concentrations of supplemented CFEO (0.0 = control; 1.0 or 3.0 mL per kg of diet). After 20 days under experimental conditions, the animals were euthanized and the gonads were harvested for gonadosomatic index, sperm analysis, oxidative stress, and histopathology; testosterone levels were measured in the plasma; gene expression of prl, smtl, pomca, and pomcb was assessed in the pituitary gland by real-time PCR. The results showed no alterations on reproductive parameters in R. quelen males treated with Cymbopogon flexuosus essential oil compared to the control-diet animals. In conclusion, CFEO microcapsules supplied for 20 days in the concentrations of 1.00 or 3.00 mL per kilogram of diet did not affect the reproduction criteria evaluated in this study in male silver catfish.


Assuntos
Peixes-Gato/fisiologia , Cymbopogon/química , Dieta/veterinária , Suplementos Nutricionais , Óleos Voláteis/farmacologia , Óleos Vegetais/farmacologia , Reprodução , Animais , Proteínas de Peixes/metabolismo , Masculino , Estresse Oxidativo/efeitos dos fármacos
10.
Fish Physiol Biochem ; 44(1): 21-34, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28948452

RESUMO

The viability using Lippia alba essential oil as an anesthetic for fish was studied, particularly with respect to physiological effects during recovery. Anesthesia of silver catfish (Rhamdia quelen) using 100 and 300 µL L-1 of two different chemotypes of L. alba essential oil (citral EO-C and linalool EO-L) prevented the increase of plasma cortisol levels caused by handling, but did not avoid alterations in energetic metabolism. Silver catfish did not have increased the levels of thiobarbituric acid reactive species in the kidney and liver during recovery after anesthesia with either EO, avoiding lipid damage. On the other hand, fish anesthetized with EO-C showed higher protein carbonylation levels, superoxide dismutase, catalase, and glutathione S-transferase activities and non-protein thiol group levels in both tissues compared to controls. Our results suggest that both oils show antioxidant capacity, but anesthesia with EO-L does not cause damage to lipids or proteins, only temporary changes, typical of physiological adjustments during recovery from anesthesia. Therefore, EO-L is an effective anesthetic for silver catfish with fewer side effects than EO-C.


Assuntos
Anestésicos/farmacologia , Peixes-Gato , Lippia/química , Monoterpenos/farmacologia , Óleos Vegetais/farmacologia , Animais , Metabolismo Energético/efeitos dos fármacos , Hidrocortisona/sangue , Monoterpenos/química , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Estresse Oxidativo , Óleos Vegetais/química
11.
J Parasit Dis ; 41(2): 345-351, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28615837

RESUMO

Parasitic diseases have an enormous health and economic impact and are a particular problem in tropical regions of the world. Disease caused by protozoa, such as trypanosomiasis, are the cause of most parasite related morbidity and mortality. Thus, the aim of this study was to verify the trypanocidal effectiveness of Lippia alba and Lippia origanoides against Trypanosoma evansi in vitro and in vivo. L. alba and L. origanoides were used in vitro on trypomastigotes at different concentrations (0.5, 1.0 and 2.0 %) and exposure times (0, 1, 3, 6 and 9 h). The three concentrations tested showed trypanocidal activity in vitro, completely eliminating the parasites in small concentration after 6 h of assay. In vivo tests were performed using mice as the experimental model. T. evansi infected mice were treated with L. alba and L. origanoides with dose of 1.5 mL kg-1 during 5 days. These protocols did not provide curative efficacy, however the mice treated with L. origanoides showed a significant increase in the longevity when compared to control group. Active compounds present in essential oils, such as L. origanoides, may potentiate the treatment of trypanosomosis when associated with other trypanocidal drugs.

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