Efekti subhroničnog izlaganja zebrice, danio rerio sintetičkom mošusu

Policiklična jedinjenja sintetičkog mošusa su veoma rasprostranjena i koriste se u velikim količinama kao miris u proizvodima široke potrošnje. Zbog njihove česte upotrebe i otpuštanja mirisa, ova jedinjenja su postala prisutna svuda u životnoj sredini. Toksikološka istraživanja su potvrdila da jedinjenje mošusa predstavlja opasnost za vodene ekosisteme. Cilj ovog istraživanja bio je da se ocene efekti subhroničnog izlaganja sintetičkom mošusu tonalidu na rast riba i odgovore na oksidativni stress kod zebrice (Danio rerio). Test rasta kod mlađi zebrice izvršen je prema OECD metodu broj 215. U toku 28 dana, riba stara 30 dana je bila izložena koncentraciji tonalida (50; 500; 5.000 and 50.000 ng/l). Na kraju eksperimenta, sve ribe su žrtvovane, izmerene, određena je njihova specifična prosečna stopa rasta po tanku, a selektivni oksidativni stress markeri su analizirani u homogenatu celog tela (glutation S-transferaze, glutation reduktaze, glutation peroksidaze, katalaze i lipidne peroksidaze). U našem ekperimentu, nismo pronašli značajne razlike između kontrolne i eksperimentalne grupe u specifičnom prirastu, telesnoj težini i dužini. Međutim, primetili smo značajne promene kod većine oksidativnih stres markera naročito kod eksperimentalne grupe koja je bila izložena najvećoj koncentraciji mošusa (tonalida). U poređenju sa kontrolnom grupom, značajna povećanje je konstatovano u aktivnostima glutation S-transferaze (za koncentracije – 5.000 i 50.000 ng/l) i kataze (za koncentracije – 500, 5.000 i 50.000 ng/l). Sa druge strane, primećeno je značajno smanjenje aktivnosti glutation peroksidaze (za koncentraciju – 500 ng/l) u poređenju sa kontrolnom grupom. Nisu konstatovane promene u aktivnosti glutation reduktaze i nivou lipidne peroksidaze u poređenju sa kontrolnom grupom. Naši rezultati pokazuju da izlaganje zebrice tonalidinu ima značajan uticaj na oksidativne stres markere i enzime za detoksifikaciju. Promene u aktivnostima antioksidantnih enzima se mogu tumačiti kao adaptivni odgovor koji bi zaštitio organizam ribe od toksičnosti prouzrokovane tonalidinom

The Effects of Subchronic Exposure to Metribuzin on Danio rerio

The aim of this study was to assess the impact of metribuzin in surface waters on fish under experimental conditions. The effects of subchronic exposure to metribuzin on fish growth and the development of histopathological changes in selected organs (gill, kidney, liver) and on activity of some biochemical markers (CYP450, EROD) in Danio rerio were investigated during a 28-day toxicity test. Juvenile growth tests were performed on D. rerio according to OECD method number 215. Fish at an initial age of 30 days were exposed to a range of metribuzin concentrations (1.5, 5, 16, 33, and 53 mg L−1). Exposure to metribuzin at 53 mg L−1 was associated with increased mortality. Negative effects with regard to total body weight, length, and the inhibition of specific growth rate were induced at concentrations of 33 and 53 mg L−1. Histopathological examination revealed pathological lesions in the liver in pesticide-exposed fish only at the highest concentration of 53 mg L−1 of metribuzin. Based on the results of growth rate, biochemical markers (CYP450, EROD), and histopathological examination, the lowest observed effect concentration (LOEC) value was 33 mg L−1 and the no observed effect concentration (NOEC) value was 16 mg L−1

Norfloxacin—Toxicity for Zebrafish (Danio rerio) Focused on Oxidative Stress Parameters

The aim of the study was to investigate the effects of subchronic exposure of zebrafish (Danio rerio) to a fluoroquinolone norfloxacin, using selected oxidative stress parameters as a target. Toxicity tests were performed on zebrafish according to the OECD Guidelines number 203 and number 215. In the Subchronic Toxicity Test, a significant (P<0.01) increase in the activity of glutathione peroxidase, glutathione S-transferase, and catalase was found. In the test, norfloxacin did not affect lipid peroxidation and catalytic activity of glutathione reductase. From the results, we can conclude that norfloxacin has a negative impact on specific biochemical processes connected with the production of reactive oxygen species in fish tested

Effects of Subchronic Exposure of Diclofenac on Growth, Histopathological Changes, and Oxidative Stress in Zebrafish (Danio rerio)

The aim of this study was to investigate effects of subchronic exposure to sublethal levels of diclofenac on growth, oxidative stress, and histopathological changes in Danio rerio. The juvenile growth tests were performed on Danio rerio according to OECD method number 215. Fish at the age of 20 days were exposed to the diclofenac environmental concentration commonly detected in the Czech rivers (0.02 mg L−1) and the range of sublethal concentrations of diclofenac (5, 15, 30, and 60 mg L−1) for 28 days. A significant decrease (P<0.01) in the fish growth caused by diclofenac was observed in the concentrations of 30 and 60 mg L−1. The identified value of LOEC (lowest observed effect concentration) was 15 mg L−1 of diclofenac and NOEC (no observed effect concentration) value was 5 mg L−1 of diclofenac. We did not find histopathological changes and changes of selected parameters of oxidative stress (glutathione S-transferase, glutathione reductase) in tested fish. The environmental concentration of diclofenac in Czech rivers did not have any effect on growth, selected oxidative stress parameters (glutathione S-transferase, glutathione reductase), or histopathological changes in Danio rerio but it could have an influence on lipid peroxidation

Effects of Mixture of Pharmaceuticals on Early Life Stages of Tench (Tinca tinca)

Ubiquitous occurrence of pharmaceuticals in aquatic environment results in concern about potential adverse the effects on nontarget organisms. In water, drugs are present in complex mixtures, in which complicated interactions affect toxicity of single components. The purpose of this study was to examine effect of 35-day-long exposure to mixture of ibuprofen, diclofenac, and carbamazepine on the mortality, growth, early ontogeny, and histopathological changes in tench (Tinca tinca). Early life stage toxicity test was carried out using a modified protocol according to OECD guideline 210. Exposure to mixture of pharmaceuticals at concentration of 60 μg·L−1 for each substance was associated with significant increase in mortality, as well as significant increase in growth and elevated incidence of malformations. Any of the tested concentrations resulted in histopathological changes of liver, kidney, skin, or gill. After fourteen days of exposure there was short-term delay of development related to increased concentrations of pharmaceuticals in the mixture (2, 20, and 60 μg·L−1). Environmentally relevant concentrations (0.02; and 0.2 μg·L−1) used in this experiment did not result in toxic impairment of tench