Eco-endocrinological dynamics: Unraveling dexamethasone's influence on the interrenal axis in juvenile carp Cyprinus carpio.

This study delves into the eco-endocrinological dynamics concerning the impact of dexamethasone (DXE) on the interrenal axis in juvenile carp, Cyprinus carpio. Through a comprehensive analysis, we investigated the effects of DXE exposure on oxidative stress, biochemical biomarkers, gene expression, and bioaccumulation within the interrenal axis. Results revealed a concentration-dependent escalation of cellular oxidation biomarkers, including 1) hydroperoxides content (HPC), 2) lipid peroxidation level (LPX), and 3) protein carbonyl content (PCC), indicative of heightened oxidative stress. Concurrently, the activity of critical antioxidant enzymes, superoxide dismutase (SOD), and catalase (CAT), significantly increased, underscoring the organism's response to oxidative insult. Notable alterations were observed in biochemical biomarkers, particularly Gamma-glutamyl-transpeptidase (GGT) and alkaline phosphatase (ALP) activity, with GGT displaying a significant decrease with increasing DXE concentrations. Gene expression analysis revealed a significant upregulation of stress and inflammation response genes, as well as those associated with sensitivity to superoxide ion presence and calcium signaling, in response to DXE exposure. Furthermore, DXE demonstrated a concentration-dependent presence in interrenal tissue, with consistent bioconcentration factors observed across all concentrations tested. These findings shed light on the physiological and molecular responses of juvenile carp to DXE exposure, emphasizing the potential ecological implications of DXE contamination in aquatic environments. Understanding these dynamics is crucial for assessing the environmental impact of glucocorticoid pollutants and developing effective management strategies to mitigate their adverse effects on aquatic ecosystems.

Short-term exposure to dexamethasone at environmentally relevant concentrations impairs embryonic development in Cyprinus carpio: Bioconcentration and alteration of oxidative stress-related gene expression patterns.

In recent years and as a result of the Covid-19 pandemic, the consumption of dexamethasone (DXE) has increased. This favors that this corticosteroid is highly released in aquatic environments, generating deleterious effects in aquatic organisms. The information on the toxic effects of DXE in the environment is still limited. Thus, the objective of this work was to determine whether DXE at short-term exposure can cause alterations to embryonic development and alteration of oxidative stress-related gene expression patterns in Cyprinus carpio. For this purpose, common carp embryos (2 hpf) were exposed to realistic concentrations of DXE until 96 hpf. Alterations to embryonic development were evaluated at 12, 24, 48, 72 and 96 hpf. In addition, oxidative stress in carp embryos at 72 and 96 hpf was evaluated by cellular oxidation biomarkers (lipoperoxidation level, hydroperoxide and carbonyl protein content) and antioxidant enzymes activities (superoxide dismutase and catalase). Oxidative stress-related gene expression (sod, cat and gpx1) was also evaluated. Our results showed that DXE concentrations above 35 ng/L are capable of producing alterations to embryonic development in 50 % of the embryo population. Furthermore, DXE was able to induce alterations such as scoliosis, hypopigmentation, craniofacial malformations, pericardial edema and growth retardation, leading to the death of half of the population at 50 ng/L of DXE. Concerning oxidative stress, the results demonstrated that DXE induce oxidative damage on the embryos of C. carpio. In conclusion, DXE is capable of altering embryonic development and generating oxidative stress in common carp C. carpio.

Integrative approach to elucidate the embryological effects of caffeine in Cyprinus carpio: Bioconcentration and alteration of oxidative stress-related gene expression patterns.

Caffeine (CAF) is an alkaloid, which acts as a central nervous system (CNS) stimulant drug. In recent years, CAF has been recurrently detected in water bodies, generating deleterious effects in aquatic organisms. The information on the toxic effects of CAF in the environment is still limited. Thus, the objective of this work was to determine whether CAF at environmentally relevant concentrations (CAF concentrations were selected based on studies on the worldwide occurrence of this compound and on the toxicity of CAF in aquatic species) is capable of inducing alterations to embryonic development and alteration of oxidative stress-related gene expression patterns in Cyprinus carpio. For this purpose, common carp embryos (2 hpf) were exposed to realistic concentrations of CAF until 96 hpf. Alterations to embryonic development and teratogenic effects were evaluated at 12, 24, 48, 72 and 96 hpf. In addition, oxidative stress in carp embryos at 72 and 96 hpf was evaluated by cellular oxidation biomarkers (lipoperoxidation level, hydroperoxide content and carbonyl protein content) and antioxidant enzymes activities (superoxide dismutase and catalase). Oxidative stress-related gene expression (sod, cat and gpx1) was also evaluated. Our results showed that CAF concentrations above 500 ng/L are capable of producing teratogenic effects. Furthermore, CAF was able to induce alterations such cardiac malformations, somite alterations, pericardial edema and chorda malformations. Concerning oxidative stress, the results demonstrated that CAF induce oxidative damage on the embryos of C. carpio. Our outcomes also showed up-regulations in genes related to antioxidant activity sod, cat and gpx by CAF exposure. In conclusion CAF at environmentally relevant concentrations is able to alter the embryonic development of common carp by the oxidative stress pathway. Based on the above evidence, it can be inferred that acute exposure to CAF can lead to a toxic response that significantly harms fish's health, adversely affecting their essential organs' functioning.

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.