RESUMO
Stress is an energy-demanding process, as well as the responses of the innate immune system, that impose a metabolic overload on cellular energy production, which can affect the cellular redox balance, causing oxidative damage. We evaluated the role of stress in the modulation of innate immune and oxidative/antioxidant mechanisms in juvenile pacu exposed to acute and chronic stressors. The experimental period lasted 30 days, and fish (113.7 ± 35.1 g) were fed commercial feed. During this period, half of the fish were not manipulated (Condition A), and the other half were chased with a dip net for 5 min twice a day (Condition C). After the 30-day period, fish from both groups were sampled (baseline sampling), and the remainders (not sampled) were air exposed for 3 min (acute stressor), returned to the tanks, and were sampled again 30 min, 3 h, 6 h, and 24 h after air exposure. We evaluated biomarkers of stress (circulating cortisol and glucose), the innate immune system (respiratory burst activity/RBA, hemolytic activity of the complement system (HA-AP) and serum concentration of lysozyme), oxidative damage (lipid peroxidation/LPO), and antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; and glutathione peroxidase, GSH-Px). Our results showed that stress, acutely or chronically, caused a transient reduction of RAL and activated the HA-AP. Acutely, stress increased the lysozyme concentration. Furthermore, both conditions caused oxidative stress in the liver, and differently they modulated the antioxidant system, enhancing SOD activity and impairing CAT and GSH-Px activity.
Assuntos
Caraciformes , Estresse Fisiológico , Animais , Glicemia/análise , Catalase/metabolismo , Caraciformes/sangue , Caraciformes/imunologia , Caraciformes/metabolismo , Proteínas do Sistema Complemento , Proteínas de Peixes/metabolismo , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Hemólise , Hidrocortisona/sangue , Imunidade Inata , Leucócitos/metabolismo , Fígado/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Explosão Respiratória , Superóxido Dismutase/metabolismoRESUMO
Wound infections are feared complications due to their potential to increase healthcare costs and cause mortality since multidrug-resistant bacteria reduce treatment options. This study reports the development of a carbomer hydrogel containing biogenic silver nanoparticles (bioAgNPs) and its effectiveness in wound treatment. This hydrogel showed in vitro bactericidal activity after 2 h, according to the time-kill assay. It also reduced bacterial contamination in rat wounds without impairing their healing since the hydrogel hydrophilic groups provided hydration for the injured skin. The high number of inflammatory cells in the first days of the skin lesion and the greater degree of neovascularization one week after wound onset showed that the healing process occurred normally. Furthermore, the hydrogel-containing bioAgNPs did not cause toxic silver accumulation in the organs and blood of the rats. This study developed a bioAgNP hydrogel for the treatment of wounds; it has a potent antimicrobial action without interfering with cicatrization or causing silver bioaccumulation. This formulation is effective against bacteria that commonly cause wound infections, such as Pseudomonas aeruginosa and Staphylococcus aureus, and for which new antimicrobials are urgently needed, according to the World Health Organization's warning.
RESUMO
Response of biomarkers to chemical contamination was evaluated in crabs of the Callinectes genus (Callinectes ornatus and C. bocourti) from two tropical estuaries (São José and São Marcos bays) of the Maranhão State (northeastern Brazil). Biomarkers evaluated included hepatopancreatic metallothionein-like proteins (MTLP) and lipid peroxidation (LPO), as well as muscle acetylcholinesterase (AChE). Tissue concentrations of metals (pereiopod muscle and hepatopancreas), hydrocarbons (hepatopancreas) and organochlorine pesticides (hepatopancreas) were also evaluated. Crab samples were collected in three sites of each estuary (São Marcos Bay and São José Bay). Sampling was performed in August/2012 (dry season), January/2013 (rainy season), August/2013 (dry season), and January/2014 (rainy season). Concentrations of chemical contaminants and responses of biomarkers showed significant spatial (São Marcos Bay and São José Bay) and/or seasonal (dry and rainy seasons) and annual (2012-2014) variability. However, a general higher Zn concentration was observed in hepatopancreas of crabs from São José Bay. In turn, a general higher Cd concentration paralleled by oxidative damage (LPO) was observed in hepatopancreas of crabs from São Marcos Bay. As expected, these findings support the idea that this bay is more intensively or chronically impacted by industrial activities while the São José Bay is likely more affected by domestic activities. Interestingly, LPO level in crab hepatopancreas showed to be the most reliable and adequate biomarker to distinguish the two bays.
Assuntos
Braquiúros , Praguicidas , Poluentes Químicos da Água , Acetilcolinesterase , Animais , Baías , Biomarcadores , Brasil , Monitoramento Ambiental , Estuários , Hidrocarbonetos , Poluentes Químicos da Água/análiseRESUMO
Glyphosate (GLY) is an herbicide widely used in agriculture. First considered as non-toxic or slightly toxic to bees, GLY and its different formulations have shown, more recently, to affect negatively the survival, development and behavior of these insects, even when used in doses and concentrations recommended by the manufacturer. Thus, the results of research on the toxicity of GLY to bees are often conflicting, which makes a meta-analysis interesting for data integration, generating a statistically reliable result. Therefore, this study aimed to evaluate the GLY effects on mortality of bees through a meta-analysis. For this, a search was carried out in the databases Web of Science, CAPES (Coordination for the Improvement of Higher Education Personnel - Brazil), Scopus, and PubMed. Papers that evaluated the effect of GLY on bee mortality published between 1945 and October 2020, were considered. After obtaining the data, R software was used to perform the meta-analytical tests. Sixteen papers on mortality were selected with 34 data sets. Most of the sets demonstrated differences between the control and experimental groups, showing that the treatments with GLY caused higher mortality of bees. The results considering the methodology used (ingestion or contact), the phase of the biological cycle (adults or larvae), and the dose (ecologically relevant dose and recommended by the manufacturer) were different when compared with their respective control groups. Therefore, GLY can be considered toxic to bees. It is important to emphasize that this meta-analysis identified that papers assessing the toxicity of GLY to bees are still scarce, for both lethal and sublethal effects, mainly for stingless and solitary bee species.
Assuntos
Glicina , Herbicidas , Animais , Abelhas , Brasil , Glicina/análogos & derivados , Glicina/toxicidade , Herbicidas/toxicidade , Larva , GlifosatoRESUMO
Aquatic contamination in agricultural areas is a global problem, characterized by a complex mixture of organic and inorganic pollutants whose effects on biota are unpredictable and poorly investigated. In this context, in the present study, the Neotropical fish Prochilodus lineatus was confined in situ for 120â¯days in two sites with different levels of anthropic impact: 1) a fish hatchery station, within the State University of Londrina (reference site - REF) and 2) an agro-ecosystem area in one of the most productive regions of southern Brazil (experimental site - EXP). We evaluated multiple biomarkers at different levels of biological organization, such as biotransformation and antioxidant enzymes, oxidative damages, DNA damages and liver histopathology. We also evaluated the occurrence of 22 organochlorine pesticides (OCPs) and 6 trace metals in water and sediment; and 33 current-use pesticides (CUPs) in the water; besides the presence of OCPs in the liver and metals in different tissues of the confined fish. The chemical analysis confirmed that the two environments presented different levels of contamination. We verified a distribution gradient of data in the principal component analysis (PCA), separating the REF fish to one side and the fish at the agricultural area (EXP) to the other side. In general, the biomarker responses were more altered in fish from the EXP than fish from the hatchery station; and this fish presented a greater accumulation of endosulfan (an increase of 18× compared to basal value) and showed oxidative, genetic, and histological damage. Through the Biomarkers Response Index (BRI), we found that the EXP fish demonstrated a decrease in health status compared with the REF fish during the confinement time, due to their exposure to a higher concentration of contaminants. In conclusion, the use of multiple biomarkers at different response levels is an important tool for environmental monitoring.
Assuntos
Biomarcadores/metabolismo , Caraciformes/metabolismo , Monitoramento Ambiental , Metais/metabolismo , Praguicidas/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Brasil , Fígado/metabolismo , Distribuição TecidualRESUMO
The λ-cyhalothrin (CL) is a globally used pyrethroid insecticide that has been detected in different water bodies worldwide. However, studies on the effects of CL on freshwater fishes are still incipient. In this context, we evaluated the acute effects of a commercial formulation containing CL (Karate Zeon® CS 50) in juveniles of the teleost Prochilodus lineatus exposed for 96â¯h to four concentrations of the active ingredient (5, 50, 250 and 500â¯ng.L-1). Biochemical, physiological, and genotoxic biomarkers were evaluated in different organs of the fish. Exposure to CL induced significant changes in the enzymatic profiles of P. lineatus, with specific alterations in biotransformation enzymes and antioxidant defence in different tissues. Lipid peroxidation was observed in fish gills and kidney. Increases in esterases were observed in the liver of fish exposed to all CL concentrations evaluated, whereas acetylcholinesterase activity decreased in the muscles of fish at all concentrations. CL also promoted osmoregulatory disorders, with decreases in calcium and magnesium gill ATPases, with consequent hypocalcaemia, in addition an increase in sodium-potassium ATPase activity was observed in the gills of fish exposed to the highest CL concentration, probably in order to compensate a reduction in plasma sodium. Besides, increases in DNA damage were observed in the erythrocytes of fish exposed to all CL concentrations. Thus, despite the low CL concentrations and the short exposure time, this pyrethroid caused hematological adjustments, oxidative stress, osmoregulatory disorders, and DNA damage in P. lineatus, showing that the species is highly sensitive to the deleterious effects of CL.
Assuntos
Caraciformes/fisiologia , Dano ao DNA , Eritrócitos/patologia , Fungicidas Industriais/toxicidade , Nitrilas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Piretrinas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Biotransformação , Eritrócitos/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Piretrinas/metabolismoRESUMO
Metal bioaccumulation and oxidative stress biomarkers were determined in Prochilodus lineatus to understand the effects of short-term exposure to a triple-mixture of Zn, Mn, and Fe. Three independent tests were carried out, in which fish were exposed to 3 concentrations of Zn (0.18, 1.0, and 5.0 mg L-1 ), Mn (0.1, 0.5, and 5.0 mg L-1 ), and in the mix test to Fe (5.0 mg L-1 ) and a mixture of Zn (1.0 mg L-1 ) + Mn (0.5 mg L-1 ), with and without Fe. After exposure for 96 h, tissues were removed for metal bioaccumulation analysis and oxidative stress biomarkers were determined in liver, along with DNA damage in blood cells. Our results revealed that Zn and Mn were bioaccumulated in fish tissues after exposure to 5.0 mg L-1 , whereas Fe only bioaccumulated in muscle and gills after mixture exposure. Results indicated that 1 metal interfered with the other's bioaccumulation. In P. lineatus, 5 mg L-1 of both Mn and Fe were toxic, because damage was observed (lipid peroxidation [LPO] in liver and DNA damage in blood cells), whereas Zn induced liver responses (metallothionein [MT] and reduced glutathione [GSH] increases) to prevent damage. In terms of bioaccumulation and alterations of oxidative stress biomarkers, we showed that Zn, Mn, and Fe triple-mixture enhances individual metal toxicity in Neotropical fish P. lineatus. Environ Toxicol Chem 2018;37:1749-1756. © 2018 SETAC.
Assuntos
Caraciformes/metabolismo , Ferro/toxicidade , Manganês/toxicidade , Poluentes Químicos da Água/toxicidade , Zinco/toxicidade , Animais , Biomarcadores/metabolismo , Dano ao DNA , Água Doce , Brânquias/metabolismo , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos , Fígado/metabolismo , Metalotioneína/metabolismo , Estresse OxidativoRESUMO
This study investigated the action of titanium dioxide nanoparticles (TiO2-NPs), on the gills and kidneys of Neotropical freshwater fish, Prochilodus lineatus, with emphasis on reactive oxygen species (ROS) production, antioxidant responses, and morphological changes. Fish were exposed to 1, 5, 10, and 50 mg L-1 nominal TiO2-NPs suspended into water for 2 or 14 days. In gills, ROS decreased and glutathione (GSH) increased after 2 days, while ROS and GSH increased and superoxide dismutase activity decreased after 14 days. In kidneys, GSH and lipoperoxidation increased after 2 days and catalase activity decreased after 14 days. Common histopathologies in gills were epithelium hyperplasia, cellular hypertrophy, proliferation of mitochondria-rich cells (MRC), and lamellar stasis; in kidneys, there were cellular and nuclear hypertrophy, focal tubule degeneration, necrosis, and melanomacrophage (MM) proliferation. Although environmentally unlikely, high-dose exposures clarified biological effects of TiO2-NPs, such as ROS formation and MRC responses in the gills, which may impair ionic balance. It was also found that MM are likely responsible for eliminating NPs in the kidney. These findings will help to regulate TiO2-NP disposal, but longer-term studies are still needed.
Assuntos
Caraciformes/metabolismo , Ecotoxicologia/métodos , Biomarcadores Ambientais , Nanopartículas/toxicidade , Titânio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/análise , Antioxidantes/metabolismo , Água Doce , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Brânquias/patologia , Glutationa/análise , Glutationa/metabolismo , Rim/efeitos dos fármacos , Rim/metabolismo , Rim/patologia , Fígado/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Nanopartículas/química , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Testes de Toxicidade Aguda , Poluentes Químicos da Água/químicaRESUMO
Imidacloprid (IMI), a systemic neonicotinoid insecticide widely used in worldwide scale, is reported in freshwater bodies. Nevertheless, there is a lack of information about IMI sublethal effects on freshwater fish. Thus, the aim of this study was to identify the potential hazard of this insecticide to the South American fish Prochilodus lineatus exposed for 120â¯h to four IMI concentrations (1.25, 12.5, 125, and 1250⯵gâ¯L-1). A set of biochemical, genotoxic and physiological biomarkers were evaluated in different organs of the fish. IMI exposure induced significant changes in the enzymatic profiles of P. lineatus, with alterations in the activity of biotransformation and antioxidant enzymes in different tissues. Redox balance of the tissues was affected, since oxidative damage such as lipoperoxidation (LPO) and protein carbonylation (PCC) were evidenced in the liver, gills, kidney and brain of fish exposed to different IMI concentrations. Fish exposed to all IMI concentrations showed decreased blood glucose indicating an increase of energetic demand. DNA damage was evidenced by the comet test, in the erythrocytes of fish all the concentrations evaluated. We integrated these results in the Integrated Biomarker Response (IBR) index, which evidenced that the organs most affected by IMI exposure were the liver and kidney, followed by the gills. Our results highlight the importance of investigating different target tissues after IMI exposure and show the sublethal effects of IMI in some of them; they also warn to the possible consequences that fish living in freshwater ecosystems can suffer due to IMI exposure.
Assuntos
Caraciformes/metabolismo , Dano ao DNA/efeitos dos fármacos , Brânquias , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/farmacocinética , Animais , Biomarcadores/metabolismo , Biotransformação , Caraciformes/anatomia & histologia , Eritrócitos/efeitos dos fármacos , Água Doce , Brânquias/metabolismo , Inseticidas/toxicidade , Rim/metabolismo , Fígado/metabolismo , Distribuição Tecidual , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidadeRESUMO
Landfills represent a severe environmental problem mainly due to the generation of leachates, and this study aimed to evaluate sublethal effects of a domestic landfill leachate in the freshwater bivalve Corbicula fluminea. Clams were submitted to in situ tests along a stream, at three sites, representing increasing distances from the leachate discharge (Pq1, Pq2, and Pq3), for 1, 5, and 15 days. The following biomarkers were analyzed in the gills and digestive glands: 7-ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST) activities, multixenobiotic resistance mechanism (MXR), total antioxidant capacity (TAC), reactive oxygen species (ROS), and lipid peroxidation (LPO). Metallothionein (MT) content was determined in the gills and DNA damage in hemocytes. The mortality rate of animals during in situ tests was reduced as the distance from the leachate discharge source increased. On the other hand, biomarker results showed sublethal effects on C. fluminea confined at all sites of PqS. GST, TAC, ROS, and DNA damage were the most significant biomarkers for this species and should be considered for future monitoring and assessment of freshwater environments located in landfill areas.
Assuntos
Corbicula/metabolismo , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água/metabolismo , Animais , Biomarcadores/metabolismo , Corbicula/química , Citocromo P-450 CYP1A1/metabolismo , Dano ao DNA , Brânquias/metabolismo , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Metalotioneína/metabolismo , Poluentes Químicos da Água/químicaRESUMO
For decades, the extraction of minerals has intensified in order to meet the demand of industry. Iron ore deposits are important sources of metals, such as iron (Fe) and manganese (Mn). The particulate ores can be dispersed during extraction, transport and storage, with potential to induce biological impacts. Amphibians are very sensitive to environmental stressors. Therefore, the present study aimed to assess the effects of iron ore, Fe and Mn exposure during the metamorphosis of Lithobates catesbeianus. Endpoints analyzed included morphological (biometrical and developmental analyses), whole body Fe and Mn concentration in, plasma ferritin concentration, erythrocyte DNA damage (measured through comet assay and micronucleus test) and liver activity of enzymes involved in oxidative status [glutathione S-transferase (GST) and catalase (CAT)]. Tadpoles were kept under control condition (no contaminant addition) or exposed to iron ore (3.79mg/L as fine particulate matter); Fe (nominal concentration: 0.51mg/L Fe as C10H12FeN2NaO8; Fe-EDTA); and Mn (nominal concentration: 5.23mg/L Mn as 4H2O.MnCl2) for 30 days. Virtually, no mortality was observed, except for one tadpole found dead in the iron ore treatment. However, tadpoles exposed to iron ore had longer tail than those kept under control conditions while tadpoles exposed to manganese chloride showed higher body length than control ones. Exposure to Fe and Mn induced a delay in tadpole metamorphosis, especially when these metals are presented not as a mixture (iron ore). Tadpoles exposed to iron ore had increased whole body Fe and Mn while those exposed to Fe and Mn accumulated each metal individually. Tadpoles exposed to any of the contaminants tested showed a significant increase in erythrocyte DNA damage and frequency of micronuclei. In addition, they showed higher liver GST activity respect with those kept under control conditions. Plasma ferritin concentration and liver CAT activity were higher only in tadpoles exposed to iron ore. These findings indicated that tadpoles accumulated Fe and Mn at the whole body level after exposure to the single metals or to their mixture as iron ore. In addition, they indicate that Fe and Mn accumulation can induce oxidative stress with consequent significant developmental, genotoxic and biochemical effects in L. catesbeianus tadpoles.