Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Mais filtros

Base de dados
Intervalo de ano de publicação
Sci Total Environ ; : 143794, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33272603


Viticulture plays an important role in generating income for small farms globally. Historically, vineyards use large quantities of phytosanitary products, such as Bordeaux mixture [Ca(OH)2 + CuSO4], to control plant diseases. These products result in the accumulation of copper (Cu) in the soil and increases the risk of transfer to water bodies. Thus, it is important to evaluate whether the presence of Cu-bearing particles in water is toxic to aquatic fauna. This study conducted chemical, mineralogical, and particle size evaluations on water samples and sediments collected from a watershed predominantly cultivated with old vineyards. The proportion of Cu-rich nanoparticles (<10 nm) in the sediment was ~27%. We exposed zebrafish to different dilutions of water and sediment samples that collected directly from the study site (downstream river) under laboratory conditions. Then, we evaluated their exploratory behavior and the stress-related endocrine parameter, whole-body cortisol. We also carried out two experiments in which zebrafish were exposed to Cu. First, we determined the median lethal concentration (LC50-96 h) of Cu and then assessed whether Cu exposure results in effects similar to those associated with exposure to the water and sediment samples collected from the study site. The water and sediment samples directly impacted the exploratory behavior of zebrafish, showing clear anxiety-like behavioral phenotype and stress in terms of cortisol increase (during the second rain event). The Cu exposure did not mimic the same behavioral changes triggered by the water and sediment samples, although it had caused similar stress in the fish. Our results highlight that even at low concentrations, the water and sediment samples from vineyard watershed runoff were able to induce behavioral and endocrine changes that may harm the ecological balance of an aquatic environment.

Stress ; : 1-6, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32013653


We report the effects of acute and chronic stress on the expression of selective immune-related genes and markers of neuronal function in the brain of the zebrafish (Danio rerio). Fish were distributed into three groups: the non-stressed control group; the acute stress (AS) group, submitted to a single stressing episode; and the unpredictable chronic stress (UCS) group, submitted to two daily stressing episodes of alternating times and types of stress. The stressing protocols were applied for a period of 14 days. The UCS protocol triggered the expression of the pro-inflammatory cytokine genes IL-1ß and TNF-α, the anti-inflammatory cytokine IL-10 (negative feedback from the immune system), reduction in cFOS gene expression, and caused neuro-inflammation. The AS protocol had no effect on gene expression. Altered expression of cytokine genes, as observed in our study, correlates with several pathologies associated with neuro-inflammation, and the reduction of cFOS gene expression may indicate the occurrence of reduced neuronal plasticity. Our study further extends our knowledge about the interaction of the immune system and the different forms of stress.

Pharmacol Biochem Behav ; 189: 172841, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31893526


Environmental pollution caused by antipsychotic residues is a relevant ecological problem. Studies revealed that residues of these drugs are present in a wide range of different ecosystems and can have adverse effects on non-target organisms even in low environmental concentrations. Among these antipsychotic drugs, aripiprazole (APPZ) is a second-generation atypical antipsychotic that is a partial agonist of dopaminergic and serotoninergic receptors. APPZ is used to treat schizophrenia, bipolar disorder, autism, obsessive-compulsive disorder, and anxiety or panic disorders. Thus, in this study we posed the following question: "What will be the behavioral effects of waterborne APPZ on fish?" To answer this question, we exposed adult zebrafish to different APPZ concentrations (0.556, 5.56, and 556 ng/L) for 15 min and evaluated their exploratory, anxiety-like, social, and anti-predatory behaviors. Our results showed that, despite the apparent beneficial reversal of stress-induced social impairment and anxiety-like behavior, APPZ exposure impaired the anti-predatory reaction of adult zebrafish. Taken altogether, our results show that APPZ-exposed zebrafish may have a decreased perception of predators, even at concentrations lower than those already detected in the environment. A failure to exhibit an antipredatory response may favor the predator, decrease the fitness of the prey species, and, consequently, affect the food chain. Our results highlight the risks and consequences associated with APPZ residues in water, which may affect aquatic life and endanger species that depend on appropriate behavioral responses for survival.

BMC Vet Res ; 15(1): 99, 2019 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-30909906


BACKGROUND: Haemonchosis affects sheep husbandry and its treatment is often compromised due to the development of anthelminthic resistance. Plant-derived bioactive compounds have been studied as alternative to control Haemonchus contortus. The objective of this study was to evaluate the effect of Senecio brasiliensis extracts on H. contortus egg hatching and infective larvae migration. RESULTS: The aqueous extract from dried and fresh plant and alkaloid-enriched fraction of the previously dried leaves of S. brasiliensis inhibited H. contortus egg hatching. The main plant compound in alkaloid fraction was integerrimine, a pyrrolizidine alkaloid (PA). However, the aqueous extract from dried plant displayed higher efficacy when compared to their alkaloid enriched or non-polar fractions, meaning that, although PAs contributed to the ovicidal effect, other compounds in the plant can also contribute to their effect. Furthermore, the aqueous extract from dried plant also had higher efficacy than aqueous extract from fresh plant in larvae migration inhibition. Finally, extract from dried plant presented low in vitro cytotoxic effect. CONCLUSION: Taken together our results suggest a good anthelmintic effect of S. brasiliensis, especially when aqueous extract is prepared from dried plant. Further in vivo studies should be performed focused on forms of administration of this extract in rearing sheep.

Anti-Helmínticos/farmacologia , Haemonchus/efeitos dos fármacos , Extratos Vegetais/farmacologia , Folhas de Planta , Senécio , Animais , Técnicas In Vitro , Larva/efeitos dos fármacos , Óvulo/efeitos dos fármacos , Folhas de Planta/química , Alcaloides de Pirrolizidina/farmacologia , Senécio/química