Alterations to embryonic development and teratogenic effects induced by a hospital effluent on Cyprinus carpio oocytes

Rhodamine B, an organic environmental pollutant induces reproductive toxicity in parental and teratogenicity in F1 generation in vivo

This study investigated the reproductive toxicity of rhodamine B in zebrafish and its transgenerational effects on the F1 generation. In silico toxicity predictions revealed high toxicity of rhodamine B, mainly targeting pathways associated with the reproductive and endocrine systems. In vivo experiments on zebrafish demonstrated that rhodamine B exposure at a concentration of 1.5 mg/L led to significant impairments in fecundity parameters, particularly affecting females. Histopathological analysis revealed distinct changes in reproductive organs, further confirming the reproductive toxicity of rhodamine B, with females being more susceptible than males. Gene expression studies indicated significant suppression of genes crucial for ovulation in rhodamine B-treated female fish, highlighting hormonal imbalance as a potential mechanism of reproductive toxicity. Furthermore, bioaccumulation studies showed the presence of rhodamine B in both adult fish gonads and F1 generation samples, suggesting transgenerational transfer of the dye. Embryotoxicity studies on F1 generation larvae demonstrated reduced survival rates, lower hatching rates, and increased malformations in groups exposed to rhodamine B. Moreover, rhodamine B induced oxidative stress in F1 generation larvae, as evidenced by elevated levels of reactive oxygen species and altered antioxidant enzyme activity. Neurotoxicity assessments revealed reduced acetylcholinesterase activity, indicating potential neurological impairments in F1 generation larvae. Additionally, locomotory defects and skeletal abnormalities were observed in F1 generation larvae exposed to rhodamine B. This study provides comprehensive evidence of the reproductive toxicity of rhodamine B in adult zebrafish and its transgenerational effects on the F1 generation.

Polluted water from a storage dam (Villa Victoria, méxico) induces oxidative damage, AChE activity, embryotoxicity, and behavioral changes in Cyprinus carpio larvae

The Villa Victoria dam is one of the most important storage reservoirs in Mexico since it distributes water to more than 20 million inhabitants in the Metropolitan Zone of Mexico City. In this dam, the common carp (Cyprinus carpio) is an important food resource for the inhabitants, so the aim of this work was to evaluate the oxidative damage (lipoperoxidation, oxidized proteins, antioxidant enzymes activity and gene expression), AChE, embryotoxicity and behavioral changes in C. carpio embryos and larvae exposed to water from Villa Victoria dam for 24, 48, 72 and 96 h. The embryotoxicity was evaluated trough the General Morphology Score (GMS) and the teratogenic index. Behavioral changes in basal locomotor activity and thigmotaxis were evaluated in a DanioVision, Noldus ™. An increase in lipid and protein oxidation as well as modification of CAT, SOD and GPx enzymatic activity was observed during the exposure times. The GMS indicated a low development in the embryos, the teratogenic index was less than 1, however teratogenic effects as yolk edema, fin malformation, head malformation and scoliosis were observed. In parallel, an increase in AChE activity and gene expression was observed reflecting changes in distance traveled of the basal locomotor activity and thigmotaxis at the sampling points. In conclusion, pollutants in water from Villa Victoria dam caused oxidative damage, changes in SOD, CAT, GPx and AChE activity as well as embryotoxicity and modifications in the behavior of C. carpio larvae. This study demonstrates the need to implement restoration programs for this reservoir since, contamination in the Villa Victoria dam could eventually endanger aquatic life and human health.

Co-exposure to sodium hypochlorite and cadmium induced locomotor behavior disorder by influencing neurotransmitter secretion and cardiac function in larval zebrafish

Sodium hypochlorite (NaClO) and cadmium (Cd) are widely co-occurring in natural aquatic environment; however, no study has been conducted on effects of their combined exposure on aquatic organisms. To assess effects of exposure to NaClO and Cd in zebrafish larvae, we designed six treatment groups, as follows: control group, NaClO group (300 μg/L), 1/100 Cd group (48 μg/L), 1/30 Cd group (160 μg/L), NaClO+1/100 Cd group, and NaClO+1/30 Cd group analyzed behavior, neurological function and cardiac function. Results revealed that exposure to 1/30 Cd and NaClO+1/30 Cd caused abnormal embryonic development in larvae by altering body morphology and physiological indicators. Combined exposure to NaClO and 1/30 Cd affected the free-swimming activity and behavior of larvae in response to light-dark transition stimuli. Moreover, exposure to 1/30 Cd or NaClO+1/30 Cd resulted in a significant increase in tyrosine hydroxylase and acetylcholinesterase activities, as well as significant changes of various neurotransmitters. Lastly, exposure to 1/30 Cd or NaClO+1/30 Cd influenced the transcription of cardiac myosin-related genes and disturbed the myocardial contractile function. Altogether, our results suggested that combined exposure to NaClO and Cd induced oxidative damage in larvae, resulting in detrimental effects on nervous system and cardiac function, thus altering their swimming behavior.

Exposure to low levels of antidiabetic glibenclamide had no evident adverse effects on intestinal microbial composition and metabolic profiles in amphibian larvae

Unmetabolized human pharmaceuticals may enter aquatic environments, and potentially exert adverse effects on the survival of non-target organisms. Here, Pelophylax nigromaculatus tadpoles were exposed to different concentrations of antidiabetic glibenclamide (GLB) for 30 days to evaluate its potential ecotoxicological effect in amphibians using intestinal microbiomic and metabolomic profiles. The mortality rate of GLB-exposed groups appeared to be lower than that of the control group. Despite not being statistically significant, there was a tendency for a decrease in intestinal microbial diversity after exposure. The relative abundance of bacteria phylum Firmicutes was shown to decrease, but those of other phyla did not in GLB-exposed tadpoles. Some potentially pathogenic bacteria (e.g., Clostridium, Bilophila, Hafnia) decrease unexpectedly, while some beneficial bacteria (e.g., Akkermansia, Faecalibacterium) increased in GLB-exposed tadpoles. Accordingly, GLB-induced changes in intestinal microbial compositions did not seem harmful to animal health. Moreover, minor changes in a few intestinal metabolites were observed after GLB exposure. Overall, our results suggested that exposure to low levels of GLB did not necessarily exert an adverse impact on amphibian larvae.

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.

Spirulina (Arthrospira maxima) mitigates the toxicity induced by a mixture of metal and NSAID in Xenopus laevis

Cadmium (Cd) is often detected in the environment due to its wide use in industry; also, NSAIDs are one of the most consumed pharmaceuticals, particularly diclofenac (DCF). Several studies have reported the presence of both contaminants in water bodies at concentrations ranging from ng L-1 to μg L-1; in addition, they have shown that they can induce oxidative stress in aquatic species and disturb signal transduction, cell proliferation, and intercellular communication, which could lead to teratogenesis. Spirulina has been consumed as a dietary supplement; its antioxidant, anti-inflammatory, neuroprotective, and nutritional properties are well documented. This work aimed to evaluate if Spirulina reduces the damage induced by Cd and DCF mixture in Xenopus laevis at early life stages. FETAX assay was carried out: 20 fertilized oocytes were exposed to seven different treatments on triplicate, control, Cd (24.5 μg L-1), DCF (149 μg L-1), Cd + DCF, Cd+DCF+Spirulina (2 mg L-1), Cd+DCF+Spirulina (4 mg L-1), Cd+DCF+Spirulina (10 mg L-1), malformations, mortality, and growth were evaluated after 96 h, also lipid peroxidation, superoxide dismutase and catalase activity were determined after 192 h. Cd increased DCF mortality, Cd and DCF mixture increased the incidence of malformations as well as oxidative damage; on the other hand, the results obtained show that Spirulina can be used to reduce the damage caused by the mixture of Cd and DCF since it promotes growth, reduce mortality, malformations, and oxidative stress in X. laevis.

Syringol, a wildfire residual methoxyphenol causes cytotoxicity and teratogenicity in zebrafish model

Natural toxicants, particularly methoxy phenols (MPs) generated by wildfire lignin, can accumulate in the environment, and cause serious health hazards in living organisms. Although the toxicity of MPs such as guaiacol and catechol has recently been described, there is minimal evidence of ecotoxicological effects of syringol. As a result, this study focuses on determining the toxicity by evaluating the cytotoxic and teratogenic effects of syringol in vitro and in vivo in human embryonic kidney (HEK-293) cells and zebrafish embryos, respectively. The ecotoxicity of syringol was predicted to be 63.8 mg/L using the ECOSAR (ECOlogical Structure Activity Relationship) prediction tool, and molecular docking analysis was used to determine the interaction and binding affinities of syringol with human apoptotic proteins in silico. In HEK-293 cells, exposure of syringol (0.5-2 mg/L) has induced cytotoxicity in a concentration-dependent manner. In zebrafish larvae, exposure of syringol (0.5-2 mg/L) has induced dose-dependent embryo toxic effects (or growth abnormalities such as yolk sac edema, pericardial edema, skeletal abnormality, and hyperemia), and changes in growth morphometrics (head height, eye, yolk sac, and pericardial area, heart rate) in particular, the heart rate of larvae was found to be significantly decreased (p<0.001). After a 4-day experimental trial, the accumulated concentration of syringol in zebrafish larvae was confirmed both qualitatively (HPLC-MS - High Performance Liquid Chromatography-Mass spectrometry) and quantitatively (LC-QTOF-HRMS - Liquid Chromatography-Quadrupolar Time of Flight-High Resolution Mass spectrometry). The craniofacial abnormalities induced by syringol exposure (0.5-2 mg/L) were detected as anomalies in cartilaginous development and locomotor deficits using alcian blue staining and locomotor analyses, respectively. Significant increase in oxidative stress parameters (including reactive oxygen species generation, lipid peroxidation, superoxide dismutase, catalase, lactate dehydrogenase and nitric oxide production) (p<0.001) and substantial decrease in glutathione levels were observed (p<0.05) in syringol exposed zebrafish larvae through enzymatic analysis. Additionally, through acridine orange staining and gene expression analyses, syringol (2 mg/L) was found to activate apoptosis in zebrafish larvae. Considering the cytotoxic, embryotoxic (teratogenicity), and oxidative stress-related apoptotic effects of syringol in the zebrafish model, syringol has the potential to emerge as a potent environmental toxicant posing serious health hazards in many living systems; however, further research on its toxicological effects on the actual ecosystem and in higher animal models is required to confirm its consequences.

Use of computed tomography and magnetic resonance imaging to assess a case of spinal injury in a Showa koi Cyprinus carpio

OBJECTIVE

A privately owned, 4-year-old female Showa koi (ornamental variant of Common Carp Cyprinus carpio) was presented for erratic swimming, air gasping, water spitting, and abnormal orientation in the water column. Initial physical examination revealed an obese patient with no external abnormalities except a small plaque localized to filaments on a right gill hemibranch.

METHODS

The fish was anesthetized using AQUI-S 20E (10% eugenol solution) at 50 mg/L to facilitate diagnostic evaluation. Biopsy of the gill lesion yielded no significant findings. Whole-body computed tomography confirmed an excess of adipose tissue and mild scoliosis, with narrowing of the 10th-11th intervertebral space. A weight loss plan and need for repeat assessment were recommended.

RESULT

The patient's original abnormal behaviors resolved over the following weeks, but it subsequently became hyporexic and depressed. Full-body magnetic resonance imaging (MRI) showed extensive alteration of vertebral centra, with multifocal compression of the spinal cord. Due to the patient's declining clinical condition and the grave prognosis based on MRI findings, the patient was humanely euthanized.

CONCLUSION

Postmortem examination showed severe transmural myelomalacia associated with a vertebral subluxation. This case demonstrates the practical application of advanced cross-sectional imaging that has not been commonly afforded to fish or other lower vertebrates.

Occurrence of emerging organic contaminants and endocrine disruptors in different water compartments in Mexico - A review

This review compiles the studies (2007-2021) regarding the occurrence of emerging organic contaminants (EOCs) and endocrine disruptors (EDs) in wastewater, surface water and groundwater in Mexico. A total of 174 compounds were detected, including pharmaceuticals, hormones, plasticizers, personal care products, sweeteners, drugs, and pesticides considered as EDs. The levels of EOCs and EDs varied from ng/L to 140 mg/L, depending on the compound, location, and compartment. Raw wastewater was the most studied matrix, showing a greater abundance and number of detected compounds. Nevertheless, surface waters showed high concentrations of bisphenol-A, butylbenzil-phthalate, triclosan, pentachlorophenol, and the hormones estrone, 17 α-ethinylestradiol, and 17 β-estradiol, which exceeded the thresholds set by international guidelines. Concentrations of 17 α-ethinylestradiol and triclosan exceeding the above-mentioned limits were reported in groundwater. Cropland irrigation with raw wastewater was the principal activity introducing EOCs and EDs into groundwater. The groundwater abundance of EOCs was considerably lesser than that of wastewater, highlighting the attenuation capacity of soils/aquifers during wastewater infiltration. However, carbamazepine and N,N-diethyl-meta-toluamide showed higher concentrations in groundwater than those in wastewater, suggesting their accumulation/concentration in soils/pore-waters. Although the contamination of water resources represents one of the most environmental concerns in Mexico, this review brings to light the lack of studies on the occurrence of EOCs in Mexican waters, which is important for public health policies and for developing legislations that incorporates EOCs as priority contaminants in national water quality guidelines. Consequently, the development of legislations will support regulatory compliance for wastewater and drinking water, reducing the human exposure.

Critical review of technologies for the on-site treatment of hospital wastewater: From conventional to combined advanced processes

This review aims to assess different technologies for the on-site treatment of hospital wastewater (HWW) to remove pharmaceutical compounds (PhCs) as sustances of emerging concern at a bench, pilot, and full scales from 2014 to 2020. Moreover, a rough characterisation of hospital effluents is presented. The main detected PhCs are antibiotics and psychiatric drugs, with concentrations up to 1.1 mg/L. On the one hand, regarding the presented technologies, membrane bioreactors (MBRs) are a good alternative for treating HWW with PhCs removal values higher than 80% in removing analgesics, anti-inflammatories, cardiovascular drugs, and some antibiotics. Moreover, this system has been scaled up to the pilot plant scale. However, some target compounds are still present in the treated effluent, such as psychiatric and contrast media drugs and recalcitrant antibiotics (erythromycin and sulfamethoxazole). On the other hand, ozonation effectively removes antibiotics found in the HWW (>93%), and some studies are carried out at the pilot plant scale. Even though, some families, such as the X-ray contrast media, are recalcitrant to ozone. Other advanced oxidation processes (AOPs), such as Fenton-like or UV treatments, seem very effective for removing pharmaceuticals, Antibiotic Resistance Bacteria (ARBs) and Antibiotic Resistance Genes (ARGs). However, they are not implanted at pilot plant or full scale as they usually consider extra reactants such as ozone, iron, or UV-light, making the scale-up of the processes a challenging task to treat high-loading wastewater. Thus, several examples of biological wastewater treatment methods combined with AOPs have been proposed as the better strategy to treat HWW with high removal of PhCs (generally over 98%) and ARGs/ARBs (below the detection limit) and lower spending on reactants. However, it still requires further development and optimisation of the integrated processes.

Brain damage induced by contaminants released in a hospital from Mexico: Evaluation of swimming behavior, oxidative stress, and acetylcholinesterase in zebrafish (Danio rerio)

Several studies have indicated that hospital effluents can produce genotoxic and mutagenic effects, cytotoxicity, hematological and histological alterations, embryotoxicity, and oxidative stress in diverse water organisms, but research on the neurotoxic effects hospital wastewater materials can generate in fish is still scarce. To fill the above-described knowledge gap, this study aimed to determine whether the exposure of adult zebrafish (Danio rerio) to several proportions (0.1%, 2.5%, 3.5%) of a hospital effluent can disrupt behavior or impair redox status and acetylcholinesterase content in the brain. After 96 h of exposure to the effluent, we observed a decrease in total distance traveled and an increase in frozen time compared to the control group. Moreover, we also observed a significant increase in the levels of reactive oxygen species in the brains of the fish, especially in hydroperoxide and protein carbonyl content, relative to the control group. Our results also demonstrated that hospital effluents significantly inhibited the activity of the AChE enzyme in the brains of the fish. Our Pearson correlation demonstrated that the response to acetylcholinesterase at the lowest proportions (0.1% and 2.5%) is positively related to the oxidative stress response and the behavioral changes observed. The cohort of our studies demonstrated that the exposure of adult zebrafish to a hospital effluent induced oxidative stress and decreased acetylcholinesterase activity in the brain of these freshwater organisms, which can lead to alterations in their behavior.

Developmental alterations, teratogenic effects, and oxidative disruption induced by ibuprofen, aluminum, and their binary mixture on Danio rerio

Several studies highlighted the ubiquitous presence of ibuprofen and aluminum in the aquatic environment around the world and demonstrated their potential to induce embryotoxic and teratogenic defects on aquatic species individually. Although studies that evaluate developmental alterations induced by mixtures of these pollutants are scarce; and, since environmental contamination presented in the form of a mixture of toxicants with different chemical properties and toxicity mechanisms capable of generating interactions; the objective of this study was to evaluate the developmental defects, teratogenic alterations, and oxidative stress induced by individual forms and the mixture of ibuprofen (IBU) and aluminum (Al) on zebrafish embryos. Oocytes exposed to environmentally relevant concentrations of IBU (0.1-20 μg L-1) and Al (0.01-8 mg L-1) and one binary mixture. The LC50 and EC50 were obtained to calculate the teratogenic index (TI). The IBU LC50, EC50, and TI were 8.06 μg L-1, 2.85 μg L-1 and 2.82. In contrast, Al LC50 was 5.0 mg L-1with an EC50 of 3.58 mg L-1 and TI of 1.39. The main alterations observed for individual compounds were hatching alterations, head malformation, skeletal deformities, hypopigmentation, pericardial edema, and heart rate impairment. The mixture also showed significant delays to embryonic development. Moreover, oxidative stress biomarkers of cellular oxidation and antioxidant defenses at 72 and 96 hpf significantly increased. Results show that environmentally relevant concentrations of ibuprofen (IBU), aluminum (Al), and their mixture promote a series of developmental defects, teratogenic effects, and oxidative disruption on D. rerio embryos, and the interaction of both substances altered the response. In conclusion, morphological and biochemical tests are suitable tools for assessing the health risk of aquatic wildlife by exposure to individual and mixed pollutants in freshwater bodies.

Long-term exposure to environmentally relevant concentrations of ibuprofen and aluminum alters oxidative stress status on Danio rerio

Despite the ubiquitous presence of multiple pollutants in aqueous environments have been extensively demonstrated, the ecological impact of chemical cocktails has not been studied in depth. In recent years, environmental studies have mainly focused on the risk assessment of individual chemical substances neglecting the effects of complex mixtures even though it has been demonstrated that combined effects exerted by pollutants might represent a greater hazard to the biocenosis. The current study evaluates the effects on the oxidative stress status induced by individual forms and binary mixtures of ibuprofen (IBU) and aluminum (Al) on brain, gills, liver and gut tissues of Danio rerio after long-term exposure to environmentally relevant concentrations (0.1-11 μg L^-1 and 0.05 mg L^-1- 6 mg L^-1, respectively). Lipid peroxidation (LPO), Protein carbonyl content (PCC) and activity of Superoxide Dismutase (SOD), Catalase (CAT), and Glutathione Peroxidase (GPX) were evaluated. Moreover, concentrations of both toxicants and the metabolite 2-OH-IBU were quantified on test water and tissues. Results show that ibuprofen (IBU) and aluminum (Al) singly promote the production of radical species and alters the oxidative stress status in all evaluated tissues of zebrafish, nevertheless, higher effects were elicited by mixtures as different interactions take place.

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 EC_50m 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.

An overview of homogeneous and heterogeneous photocatalysis applications for the removal of pharmaceutical compounds from real or synthetic hospital wastewaters under lab or pilot scale

The last few decades, Pharmaceutical Active Compounds (PhACs) have been considered as emerging contaminants due to their continuous release and persistence to aquatic environment even at low concentrations. A growing number of research articles have shown the occurrence of numerous PhACs in various wastewater treatment plant influents, hospital effluents, and surface waters all over the world. The rising concern regarding PhACs, which present high recalcitrance towards conventional treatment methods, has provoked extensive research in the field of their effective remediation. This review provides a comprehensive assessment of homogeneous and heterogeneous photocatalytic applications for the removal of PhACs, from real or artificial hospital wastewater effluents. These two representative advanced oxidation processes (AOPs) are assessed in terms of their efficiency to remove PhACs, reduce the COD and toxicity as well as increase the biodegradability of the effluent. Simultaneously with their efficiency the operational costs of the processes are considered. Their potential combination with other processes is critically discussed, as this option seems to enhance the treatment efficiency and simultaneously overcome the limitations of each individual process. Moreover, the type of reactors as well as the main parameters that should be considered for the design and the development of photoreactors for wastewater treatment are reviewed. Finally, based on the literature survey, indications for future work are provided.

Metformin environmental exposure: A systematic review

This review discussed the occurrence, ecological impacts, and effects of metformin, a drug used for type 2 diabetes among other diseases. It is one of the most commonly found medicines in aquatic environments owing to its incomplete metabolism in the human body, and is eventually disposed in wastewater. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses were followed as a guide. After searching various databases, 48 eligible studies were selected for the review. Metformin reportedly occurs in different environmental matrices, as measurable concentrations of metformin are found in sewage (urban and hospital), influent/sludge/effluent from wastewater treatment plants, surface water (rivers, lakes, estuaries, oceans, and non-specific sources), tap/drinking water, and sediment (lake and recipient seawaters). Data on metformin detection in aquatic environments in 14 countries were studied, but a consensus on the risk patterns of pharmaceutical products was not determined. Many studies have been conducted on different test organisms, demonstrating that metformin can drive the expression of diverse genes, particularly those responsible for endocrine hormone pathways. Chronic exposure to metformin can be tested using models and other tools to understand this field, which remains largely unexplored. Our results contribute to the current ecotoxicology knowledge related to typically used drugs and provide a basis for further investigations.

Geno-cytotoxicity and congenital malformations produced by relevant environmental concentrations of aluminum, diclofenac and their mixture on Cyprinus carpio. An interactions study

Several studies highlight the presence of aluminum and diclofenac in water bodies around the world and their ability to induce oxidative stress and a negative effect on biomolecules in several aquatic species. However, studies evaluating the toxic effect of mixtures of these contaminants are scarce. The objective of this work was to determine the genotoxic, cytotoxic and embryotoxic effect of the mixture of aluminum and diclofenac at environmentally relevant concentrations on Cyprinus carpio. Juveniles of Cyprinus carpio were exposed to 0.31 μg L^-1 of diclofenac, 24.45 mg L^-1 of aluminum, and a mixture of both contaminants at the same concentrations for 12, 24, 48, 72 and 96 h. After the exposure time the liver, gills and blood were extracted and the following biomarkers were evaluated: micronucleus frequency, comet assay, caspase activity and TUNEL test. On the other hand, Cyprinus carpio embryos were exposed to diclofenac (0.31 μg L^-1), aluminum (0.06 mg L^-1) and their mixture at the same concentrations and exposure time. Microscopic observation was performed to evaluate embryonic development at 12, 24, 48, 72 and 96 h. Diclofenac (0.31 μg L^-1) induces significant increases in micronucleus frequency with respect to control (p < 0.05), in all tissues. Aluminum (24.45 mg L^-1) significantly increases DNA damage index in liver and blood cells with respect to control (p < 0.05). All treatments increase caspases activity in all tissues with respect to control (p < 0.05). Diclofenac increases the percentage of TUNEL-positive cells in liver and blood; while aluminum and the mixture increases it significantly in gills and blood with respect to the control (p < 0.05). The mixture significantly delays embryonic development, while aluminum and the mixture significantly increase teratogenic index with respect to control (p < 0.05). In conclusion, exposure to environmental concentrations of aluminium, diclofenac and their mixture induces genotoxic damage, cell death by apoptosis and negative effects on the development of Cyprinus carpio and the toxic response is modified by the interaction of the xenobiotics.

Morphometric analysis of developing zebrafish embryos allows predicting teratogenicity modes of action in higher vertebrates

The early identification of teratogens in humans and animals is mandatory for drug discovery and development. Zebrafish has emerged as an alternative model to traditional preclinical models for predicting teratogenicity and other potential chemical-induced toxicity hazards. To prove its predictivity, we exposed zebrafish embryos from 0 to 96 h post fertilization to a battery of 31 compounds classified as teratogens or non-teratogens in mammals. The teratogenicity score was based on the measurement of 16 phenotypical parameters, namely heart edema, pigmentation, body length, eye size, yolk size, yolk sac edema, otic vesicle defects, otoliths defects, body axis defects, developmental delay, tail bending, scoliosis, lateral fins absence, hatching ratio, lower jaw malformations and tissue necrosis. Among the 31 compounds, 20 were detected as teratogens and 11 as non-teratogens, resulting in 94.44 % sensitivity, 90.91 % specificity and 87.10 % accuracy compared to rodents. These percentages decreased slightly when referred to humans, with 87.50 % sensitivity, 81.82 % specificity and 74.19 % accuracy, but allowed an increase in the prediction levels reported by rodents for the same compounds. Positive compounds showed a high correlation among teratogenic parameters, pointing out at general developmental delay as major cause to explain the physiological/morphological malformations. A more detailed analysis based on deviations from main trends revealed potential specific modes of action for some compounds such as retinoic acid, DEAB, ochratoxin A, haloperidol, warfarin, valproic acid, acetaminophen, dasatinib, imatinib, dexamethasone, 6-aminonicotinamide and bisphenol A. The high degree of predictivity and the possibility of applying mechanistic approaches makes zebrafish a powerful model for screening teratogenicity.

Effects of effluent from a hospital in Mexico on the embryonic development of zebrafish, Danio rerio

Hospitals consume a large amount of water, so they also generate large amounts of wastewater, which contain a wide variety of contaminants. It is important to consider that hospital effluents are a mixture of pollutants that can interact with each other and have a negative impact on aquatic species of water bodies. The aim of this study was to evaluate the effects induced by a hospital effluent using Danio rerio embryos. In this study, Danio rerio embryos were exposed to different concentrations of the hospital effluent and a lethality test was evaluated and the malformations present in zebrafish embryos were evaluated. The lethal concentration of effluent 50% was 6.1% and the effective malformation concentration was of 2.5%. The teratogenic index was 2.45%. The main malformations identified were yolc sac malformation, pericardial edema, hatching abnormalities, hypopigmentation, tail deformation, chorda malformation, without fin, chorion deformation and craniofacial malformation. The risks that this type of water represents for the survival of living organisms, as well as the presence of malformations in them, are reference indicators for a future regulation focused on the adequate treatment of hospital effluents.

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.

Survival and malformation rate in oocytes and larvae of Cyprinus carpio by exposure to an industrial effluent

Pharmaceuticals are used for the prevention or treatment of diseases, and due to their manufacturing process they are continuously released to water bodies. One of the pharmacological groups detected in aquatic environments is non-steroidal anti-inflammatory drugs (NSAIDs) at trace concentrations. This study evaluated the survival and malformation rate in oocytes and larvae of Cyprinus carpio (C. carpio) after exposure to different proportions of an industrial effluent. Initially, the industrial effluent was sampled from an NSAID manufacturing plant located in the city of Toluca, State of Mexico, subsequently the physicochemical characterization and determination of the concentration of chemical compounds present were carried out. On the other hand, the lethal concentration 50 (LC50) and the effective concentration 50 (EC50) were calculated to determine the teratogenic index (TI), as well as the alterations to the embryonic development and the teratogenic effects on oocytes and larvae of C. carpio at the following proportions of the industrial effluent: 0.1, 0.3, 0.5, 0.7, 0.9 and 1.1%, following the Test Guideline 236, which describes a Fish Embryo Acute Toxicity test, the exposure times were 12, 24, 48, 72 and 96 h post-fertilization. The contaminants detected were NaClO (2.6 mg L^-1) and NSAIDs such as diclofenac, ibuprofen, naproxen and paracetamol in the range of 1.09-2.68 mg L^-1. In this study the LC50 was 0.275%, the EC50 0.133% and the TI 2.068. Several malformations were observed in all proportions of the industrial effluent evaluated, however the most severe such as spina bifida and paravertebral hemorrhage were observed at the highest effluent proportion. The industrial effluent evaluated in this study represents a risk for organisms that are in contact with it, since it contains chemical compounds that induce embryotoxic and teratogenic effects as observed in oocytes and larvae of C. carpio.

Embryotoxic and teratogenic profile of tretracycline at environmentally relevant concentrations on Cyprinus carpio

The objective of this work was to evaluate whether tetracycline (TC) in environmentally relevant concentrations was able to induce alterations to embryonic development and teratogenic effects in oocytes and embryos of Cyprinus carpio. For this purpose, an embryolethality study was conducted and the lethal concentration 50 (LC₅₀) and effective concentration 50 of malformations (EC₅₀) were calculated, and with these data the teratogenic index (TI) was determined. The main alterations to embryonic development and the teratogenic effects produced by TC on embryos of C. carpio were determined using the Kimmel and Hersem scale adapted for Cyprinus carpio. LC₅₀ and EC₅₀ were respectively 500.08 and 145.3 μg L^-1.TC was shown to be teratogenic with teratogenic index of 3.44, and the main malformations identified in concentrations of 90-900 μg L^-1 were malformation in tail, modified chorda structure, pericardical edema, scoliosis and malformations of the heart. A significant decrease in concentration-dependent in Kimmel and Hersem score was observed. The results allow us to conclude that TC at environmentally relevant concentrations is capable of inducing embryotoxic and teratogenic effects, generating risk in the integrity of the common carp C. Carpio.

Occurrence, toxic effects and removal of metformin in the aquatic environments in the world: Recent trends and perspectives

Metformin (MET) is the most common drug used to treat type 2 diabetes, but also it is used as an anticancer agent and as a treatment for polycystic ovary syndrome. This drug is not metabolized in the human body, and may enter into the environment through different pathways. In wastewater treatments plants (WWTPs), this contaminant is mainly transformed to guanylurea (GUA). However, three further transformation products (TPs): (a) 2,4- diamino-1,3,5-triazine, 4-DAT; (b) 2-amino-4-methylamino-1,3,5-triazine, 2,4-AMT; and (c) methylbiguanide, MBG; have also been associated with its metabolism. MET, GUA and MBG have been found in WWTPs influents, effluents and surface waters. Furthermore, MET and GUA bioaccumulate in edible plants species, fish and mussels potentially contaminating the human food web. MET is also a potential endocrine disruptor in fish. Phytoremediation, adsorption and biodegradation have shown a high removal efficiency of MET, in laboratory. Nonetheless, these removal methods had less efficiency when tried in WWTPs. Therefore, MET and its TPs are a threat to the human being as well as to our environment. This review comprehensively discuss the (1) pathways of MET to the environment and its life-cycle, (2) occurrence of MET and its transformation products (3) removal, (4) toxic effects and (5) future trends and perspectives of possible methods of elimination in water in order to provide potential options for managing these contaminants.

Ochratoxin A exposure causes meiotic failure and oocyte deterioration in mice

Ochratoxin A (OTA) is a mycotoxin produced by fungi and occurs naturally in various foodstuffs and some animal-derived products. This mycotoxin can cause deleterious effects on kidney, liver, central nervous, and immune system. However, potential mechanisms regarding how OTA disrupts the mammalian oocyte quality have not been clearly defined. In this study, we proved that OTA weakened oocyte quality by impairing oocyte meiotic maturation. We found that female mice treated with 1 mg/kg body weight OTA by intraperitoneal (IP) injection for 7 days displayed ovarian dysfunction and decreased offspring number. We also found that OTA treatment at 7.5 μM for 16 h decreased the rate of first polar body extrusion by disrupting spindle and chromosome alignment. In addition, OTA caused oxidative stress by inducing the accumulation of reactive oxygen species and consumption of antioxidants during meiosis, consequently resulting in oocytes apoptosis. Mitochondrial damage and insufficient energy supply were also observed in OTA-pretreated oocytes, which led to the meiotic failure of oocyte. Moreover, the epigenetic modifications were also affected, showing with altered 5 mC, 5hmC, H3K9ac, and H3K9me3 levels in mice oocytes. In summary, these results showed that OTA could decrease oocyte maturation and fertility by inducing oxidative stress and epigenetic changes.

Exposure to water-accommodated fractions of two different crude oils alters morphology, cardiac function and swim bladder development in early-life stages of zebrafish

The present study investigated the developmental toxicity of water-accommodated fractions (WAFs) of Oman crude oil (OCO) and Merey crude oil (MCO) on zebrafish (Danio rerio) in early-life stages (ELS). Based on total petroleum hydrocarbons (TPH), LC₅₀ values manifested that OCO WAF was 1.2-fold more lethal to zebrafish embryos than MCO WAF. As for hatching rate, EC₅₀ value for OCO WAF was 5.7-fold lower than that for MCO WAF. To evaluate the sublethal morphological effects, semi-quantitative extended general morphological score (GMS) and general teratogenic score (GTS) systems were adopted. The GMS and GTS scores indicated that the WAFs caused remarkable developmental delay and high frequencies of malformation in a dose-dependent manner. Additionally, OCO and MCO WAFs exposure exhibited severe bradycardia (reduced heart rate) and overt reduction of stroke volume, with a concomitant decrease in the cardiac output. Meanwhile, the WAFs also induced dose-dependent down-regulated expressions of several key functional genes of excitation-contraction coupling in cardiomyocytes, including ryr2, atp2a2a, atp2a2b, ncx1h, and kcnh2. For key gene markers of swim bladder development, results showed that high dose of TPH induced significant down-regulation of hb9 and anxa5 with no obvious change of acta2, suggesting that the WAFs could affect the specification and development of epithelium and outer mesothelium of swim bladder in zebrafish ELS. A strong negative relationship between the failure of swim bladder inflation and cardiac dysfunction via cardiac output was found. All these findings provide novel insights into the complicated mechanisms of the developmental toxicity of crude oil on fish in ELS.

Hospital wastewaters treatment: Fenton reaction vs. BDDE vs. ferrate(VI)

Various types of micropollutants, e.g., pharmaceuticals and their metabolites and resistant strains of pathogenic microorganisms, are usually found in hospital wastewaters. The aim of this paper was to study the presence of 74 frequently used pharmaceuticals, legal and illegal drugs, and antibiotic-resistant bacteria in 5 hospital wastewaters in Slovakia and Czechia and to compare the efficiency of several advanced oxidations processes (AOPs) for sanitation and treatment of such highly polluted wastewaters. The occurrence of micropollutants and antibiotic-resistant bacteria was investigated by in-line SPE-LC-MS/MS technique and cultivation on antibiotic and antibiotic-free selective diagnostic media, respectively. The highest maximum concentrations were found for cotinine (6700 ng/L), bisoprolol (5200 ng/L), metoprolol (2600 ng/L), tramadol (2400 ng/L), sulfamethoxazole (1500 ng/L), and ranitidine (1400 ng/L). In the second part of the study, different advanced oxidation processes, modified Fenton reaction, ferrate(VI), and oxidation by boron-doped diamond electrode were tested in order to eliminate the abovementioned pollutants. Obtained results indicate that the modified Fenton reaction and application of boron-doped diamond electrode were able to eliminate almost the whole spectrum of selected micropollutants with efficiency higher than 90%. All studied methods achieved complete removal of the antibiotic-resistant bacteria present in hospital wastewaters.