Acute exposure to 17-α-ethinylestradiol disrupt the embryonic development and oxidative status of Danio rerio.

17-Alpha-ethinylestradiol (EE2) is an estrogen derived from estradiol (E2). This compound and is one of the most widely used drugs both in humans and animals. Numerous studies have reported the ability of EE2 to alter sex determination and delay sexual maturity, but there are toxic effects that need to be explored. In this work, we analyzed the effect of EE2 on embryonic development and oxidative stress biomarkers in Danio rerio. For this effect, zebrafish embryos in the blastula period (2.5 h post fecundation) were exposed to different concentrations of EE2 (36-106 ng L-1) until 96 hpf. Survival, alterations to embryonic development, and teratogenic effects were evaluated using a stereomicroscope. Furthermore, oxidative stress biomarkers: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) activities, lipid peroxidation (LPX), hydroperoxide content (HPX), and protein carbonyl content (POX) were evaluated at 72 and 96 hpf using spectrophotometric methods. LC50 and EC50 of malformations got values of 82 ng L-1 and 57.7 ng L-1, respectively. The main teratogenic effects found were: chorda malformation, body malformation, and developmental delay. These alterations occurred at 86, 96, and 106 ng L-1. Integrated biomarker index showed that the oxidative stress biomarkers that had the most influence on embryos were SOD, CAT, GPX, and LPX. Overall, our results allow us to conclude that low concentrations of EE2 may potentially alter the development and oxidative status in the early life stages of zebrafish. Therefore, this bio-active estrogen can be considered a hazardous substance for fish.

Survival and malformations rates, oxidative status in early life stages of Cyprinus carpio due to exposure to environmentally realistic concentrations of paracetamol.

Paracetamol (PCM) is among the most consumed analgesic and antipyretic drugs worldwide. Due to its high consumption, this drug has been reported ubiquitously on different water bodies, posing a real threat to aquatic organisms. Until now, several studies have pointed out that PCM may induce oxidative stress, histological damage and developmental disorders on different aquatic species. Nonetheless, there is still a huge knowledge gap about the toxic effects that PCM may induce in species of commercial interest such as the common carp Cyprinus carpio. The aim of this study was to evaluate survival and malformation rates induced by PCM (0.5 µg/L - 3.5 µg/L) in early life stages of common carp. Furthermore, oxidative stress biomarkers were evaluated at 72 and 96 h post fecundation. PCM reduced the survival rate of the embryos of up to 90%, as concentration increased. LC50 and EC50m were 1.29 µg/L and 2.84 µg/L, respectively. Biomarkers of cellular oxidation and antioxidant enzymes were modified in a concentration-dependent way with respect to the control group (p < 0.05). The main developmental alterations observed were lordosis, scoliosis, craniofacial malformations, hypopigmentation, growth retardation, pericardial edema and rachyschisis. These data indicate that environmentally realistic concentrations of PCM could be hazardous and affects the development in early stages of C. carpio. Moreover, our findings also indicate that C. carpio embryos may be a useful in vivo model to evaluate embryonic and teratogenic effects of drugs such as PCM.

Ibuprofen at environmentally relevant concentrations alters embryonic development, induces teratogenesis and oxidative stress in Cyprinus carpio.

Ibuprofen (IBU) is a non-steroidal anti-inflammatory (NSAIDs) that is used in various conditions. The prescriptions and the global consumption of this drug are very high and its annual production oscillates in millions of tons, this generates that the IBU is present in many waterbodies because it is discharged through the municipal, hospital and industrial effluents. For the above, the purpose of this work was to determine if IBU at environmentally relevant concentrations was capable of inducing alterations to embryonic development, teratogenic effects and oxidative stress in oocytes and embryos of Cyprinus carpio. Oocytes of common carp were exposed to IBU concentrations between 1.5 and 11.5 µg L-1 (environmentally relevant). LC50 and EC50 of malformations were determined to calculate the teratogenic index (TI). Also, main alterations to embryonic development and teratogenic effects were evaluated. Oxidative stress was evaluated by determining biomarkers of cellular oxidation and antioxidation using the same concentrations at 72 and 96 hpf in embryos of Cyprinus carpio. The results showed a LC50 of 4.17 µg L-1, EC50 of 1.39 µg L-1 and TI of 3.0. The main embryonic development disorders and teratogenic effects were delayed hatching, hypopigmentation, pericardial edema, yolk deformation, and developmental delay. Biomarkers of cellular oxidation and antioxidants were increased with respect to the control in a concentration-dependent manner. The results of the study allow us to conclude that IBU at environmentally relevant concentrations is capable of inducing embryotoxicity and teratogenicity in a fish of commercial interest like Cyprinus carpio.