Understanding the impact of environmentally relevant alkyl C12-16 dimethylbenzyl ammonium chloride concentrations on zebrafish health.

Alkyldimethylbenzylammonium chlorides (ADBACs), classified as second-generation quaternary ammonium compounds, are extensively employed across various sectors, encompassing veterinary medicine, food production, pharmaceuticals, cosmetics, ophthalmology, and agriculture. Consequently, significant volumes of ADBAC C12-C16 are discharged into the environment, posing a threat to aquatic organisms. Regrettably, comprehensive data regarding the toxicological characteristics of these compounds remain scarce. This research aimed to determine whether or not ADBAC C12-C16, at environmentally relevant concentrations (0.4, 0.8, and 1.6 µg/L), may instigate oxidative stress and alter the expression of apoptosis-related genes in the liver, brain, gut, and gills of Danio rerio adults (5-6 months). The findings revealed that ADBAC C12-C16 elicited an oxidative stress response across all examined organs following 96 h of exposure. Nonetheless, the magnitude of this response varied among organs, with the gills exhibiting the highest degree of susceptibility, followed by the gut, liver, and brain, in descending order. Only the gut and gills of the examined organs displayed a concentration-dependent reduction in the activity of superoxide dismutase (SOD) and catalase (CAT). Akin to the oxidative stress response, all organs exhibited a marked increase in bax, blc2, casp3, and p53 expression levels. However, the gills and gut manifested a distinctive suppression in the expression of nrf1 and nrf2. Our Principal Component Analysis (PCA) confirmed that SOD, CAT, nrf1, and nrf2 were negatively correlated to oxidative damage biomarkers and apoptosis-related genes in the gills and gut; meanwhile, in the remaining organs, all biomarkers were extensively correlated. From the above, it can be concluded that ADBAC C12-C16 in low and environmental concentrations may threaten the health of freshwater fish.

Prolonged exposure to the synthetic glucocorticoid dexamethasone induces brain damage via oxidative stress and apoptotic response in adult Daniorerio.

Due to its extensive use as a painkiller, anti-inflammatory, and immune modulatory agent, as well as its effectiveness in treating severe COVID-19, dexamethasone, a synthetic glucocorticoid, has gained attention not only for its impact on public health but also for its environmental implications. Various studies have reported its presence in aquatic environments, including urban waters, surface samples, sediments, drinking water, and wastewater effluents. However, limited information is available regarding its toxic effects on nontarget aquatic organisms. Therefore, this study aimed to investigate the mechanism of toxicity underlying dexamethasone-induced brain damage in the bioindicator Danio rerio following long-term exposure. Adult zebrafish were treated with environmentally relevant concentrations of dexamethasone (20, 40, and 60 ng L-1) for 28 days. To elucidate the possible mechanisms involved in the toxicity of the pharmaceutical compound, we conducted a behavioral test battery (Novel Tank and Light and Dark tests), oxidative stress biomarkers, acetylcholinesterase enzyme activity quantification, histopathological analysis, and gene expression analysis using qRT-PCR (p53, bcl-2, bax, caspase-3, nrf1, and nrf2).The results revealed that the pharmaceutical compound could produce anxiety-like symptoms, increase the oxidative-induced stress response, decrease the activity of acetylcholinesterase enzyme, and cause histopathological alterations, including perineuronal vacuolization, granular and molecular layers deterioration, cell swallowing and intracellular spaces. The expression of genes involved in the apoptotic process (p53, bax, and casp-3) and antioxidant defense (nrf1 and nrf2) was upregulated in response to oxidative damage, while the expression of the anti-apoptotic gene bcl-2 was down-regulated indicating that the environmental presence of dexamethasone may pose a threat to wildlife and human health.

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.

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.

Captopril's influence on Danio rerio embryonic development: Unveiling significant toxic outcomes at environmentally relevant concentrations.

Anticipating a global increase in cardiovascular diseases, there is an expected surge in the use of angiotensin-converting enzyme inhibitors, notably captopril (CAP). This heightened usage raises significant environmental apprehensions, mainly due to limited knowledge regarding CAP's toxic effects on aquatic species. In response to these concerns, the current study aimed to tackle this knowledge gap by evaluating the potential influence of nominal concentrations of CAP (0.2-2000 µg/L) on the embryonic development of Danio rerio. The findings revealed that CAP at all concentrations, even at concentrations considered environmentally significant (0.2 and 2 µg/L), induced various malformations in the embryos, ultimately leading to their mortality. Main malformations included pericardial edema, craniofacial malformation, scoliosis, tail deformation, and yolk sac deformation. In addition, CAP significantly altered the antioxidant activity of superoxide dismutase and catalase across all concentrations. Simultaneously, it elevated lipid peroxidation levels, hydroperoxides, and carbonylic proteins in the embryos, eliciting a substantial oxidative stress response. Likewise, CAP, at all concentrations, exerted significant modulatory effects on the expression of genes associated with apoptosis (bax, bcl2, p53, and casp3), organogenesis (tbx2a, tbx2b, and irx3b), and ion exchange (slc12a1 and kcnj1) in Danio rerio embryos. Both augmentation and reduction in the expression levels of these genes characterized this modulation. The Pearson correlation analysis indicated a close association between oxidative damage biomarkers and the expression patterns of all examined genes with the elevated incidence of malformations and mortality in the embryos. In summary, it can be deduced that CAP poses a threat to aquatic species. Nevertheless, further research is imperative to enhance our understanding of the environmental implications of this pharmaceutical compound.

Ecotoxicological evaluation of chitosan biopolymer films particles in adult zebrafish (Danio rerio): A comparative study with polystyrene microplastics.

To mitigate the environmental impact of microplastics (MPs), the scientific community has innovated sustainable and biodegradable polymers as viable alternatives to traditional plastics. Chitosan, the deacetylated form of chitin, stands as one of the most thoroughly investigated biopolymers and has garnered significant interest due to its versatile applications in both medical and cosmetic fields. Nevertheless, there is still a knowledge gap regarding the impact that chitosan biopolymer films (CBPF) may generate in aquatic organisms. In light of the foregoing, this study aimed to assess and compare the potential effects of CBPF on the gastrointestinal tract, gills, brain, and liver of Danio rerio against those induced by MPs. The findings revealed that both CBPF and MPs induced changes in the levels of oxidative stress biomarkers across all organs. However, it is essential to note that our star plots illustrate a tendency for CBPF to activate antioxidant enzymes and for MPs to produce oxidative damage. Regarding gene expression, our findings indicate that MPs led to an up-regulation in the expression of genes associated with apoptotic response (p53, casp3, cas9, bax, and bcl2) in all fish organs. Meanwhile, CBPF produced the same effect in genes related to antioxidant response (nrf1 and nrf2). Overall, our histological observations substantiated these effects, revealing the presence of plastic particles and tissue alterations in the gills and gastrointestinal tract of fish subjected to MPs. From these results, it can be concluded that CBPF does not represent a risk to fish after long exposure.

Assessing the impact of COVID-19 era drug combinations on hepatic functionality: A thorough investigation in adult Danio rerio.

Current and thorough information on the ecotoxicological consequences of pharmaceuticals is accessible globally. However, there remains a substantial gap in knowledge concerning the potentially toxic effects of COVID-19 used drugs, individually and combined, on aquatic organisms. Given the factors above, our investigation assumes pivotal importance in elucidating whether or not paracetamol, dexamethasone, metformin, and their tertiary mixtures might prompt histological impairment, oxidative stress, and apoptosis in the liver of zebrafish. The findings indicated that all treatments, except paracetamol, augmented the antioxidant activity of superoxide dismutase (SOD) and catalase (CAD), along with elevating the levels of oxidative biomarkers such as lipid peroxidation (LPX), hydroperoxides (HPC), and protein carbonyl content (PCC). Paracetamol prompted a reduction in the activities SOD and CAT and exhibited the most pronounced toxic response when compared to the other treatments. The gene expression patterns paralleled those of oxidative stress, with all treatments demonstrating overexpression of bax, bcl2, and p53. The above suggested a probable apoptotic response in the liver of the fish. Nevertheless, our histological examinations revealed that none of the treatments induced an apoptotic or inflammatory response in the hepatocytes. Instead, the observed tissue alterations encompassed leukocyte infiltration, sinusoidal dilatation, pyknosis, fatty degeneration, diffuse congestion, and vacuolization. In summary, the hepatic toxicity elicited by COVID-19 drugs in zebrafish was less pronounced than anticipated. This attenuation could be attributed to metformin's antioxidant and hormetic effects.

Nanoparticles synergy: Enhancing wheat (Triticum aestivum L.) cadmium tolerance with iron oxide and selenium.

Nanotechnology is capturing great interest worldwide due to their stirring applications in various fields and also individual application of iron oxide nanoparticle (FeO - NPs) and selenium nanoparticles (Se - NPs) have been studied in many literatures. However, the combined application of FeO and Se - NPs is a novel approach and studied in only few studies. For this purpose, a pot experiment was conducted to examine various growth and biochemical parameters in wheat (Triticum aestivum L.) under the toxic concentration of cadmium (Cd) i.e., 50 mg kg-1 which were primed with combined application of two levels of FeO and Se - NPs i.e., 15 and 30 mg L-1 respectively. The results showed that the Cd toxicity in the soil showed a significantly (P < 0.05) declined in the growth, gas exchange attributes, sugars, AsA-GSH cycle, cellular fractionation, proline metabolism in T. aestivum. However, Cd toxicity significantly (P < 0.05) increased oxidative stress biomarkers, enzymatic and non-enzymatic antioxidants including their gene expression in T. aestivum. Although, the application of FeO and Se - NPs showed a significant (P < 0.05) increase in the plant growth and biomass, gas exchange characteristics, enzymatic and non-enzymatic compounds and their gene expression and also decreased the oxidative stress, and Cd uptake. In addition, individual or combined application of FeO and Se - NPs enhanced the cellular fractionation and decreases the proline metabolism and AsA - GSH cycle in T. aestivum. These results open new insights for sustainable agriculture practices and hold immense promise in addressing the pressing challenges of heavy metal contamination in agricultural soils.

Unlocking the phytoremediation potential of organic acids: A study on alleviating lead toxicity in canola (Brassica napus L.).

Soil contamination with toxic heavy metals [such as lead (Pb)] is becoming a serious global problem due to the rapid development of the social economy. Organic chelating agents such as maleic acid (MA) and tartaric acid (TA) are more efficient, environmentally friendly, and biodegradable compared to inorganic chelating agents and they enhance the solubility, absorption, and stability of metals. To investigate this, we conducted a hydroponic experiment to assess the impact of MA (0.25 mM) and TA (1 mM) on enhancing the phytoremediation of Pb under its toxic concentration of 100 µM, using the oil seed crop canola (Brassica napus L.). Results from the present study showed that the Pb toxicity significantly (P < 0.05) decreased plant growth and biomass, photosynthetic pigments, gas exchange attributes and nutritional contents from the roots and shoots of the plants. In contrast, toxic concentration of Pb significantly (P < 0.05) increased oxidative stress indicators in term of malondialdehyde, hydrogen peroxide, and electrolyte leakage, increased enzymatic and non-enzymatic antixoidants and their specific gene expression and also increased organic acid exudation patter in the roots of B. napus. In addition, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that Pb toxicity significantly affected double membranous organelles while Fourier-transform infrared (FTIR) spectroscopy showed an nveiled distinct peak variations in Pb-treated plants, when compared to control. Additionally, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that Pb toxicity significantly affected double-membrane organelles, while Fourier-transform infrared (FTIR) spectroscopy unveiled distinct peak variations in Pb-treated plants compared to the control. The negative impact of Pb toxicity can overcome the application of MA and TA, which ultimately increased plant growth and biomass by capturing the reactive oxygen species, and decreased oxidative stress in B. napus. With the application of MA and TA, the values of the bioaccumulation factor (BAF) and translocation factor (TF) exceeded 1, indicating that the use of MA and TA enhances the phytoremediation potential of B. napus under Pb stress conditions. This finding could be beneficial for field environment studies, especially when explored through in-depth genetic and molecular analysis.

Acute exposure to fluoxetine leads to oxidative stress and hematological disorder in Danio rerio adults.

Fluoxetine (FLX), a selective serotonin reuptake inhibitor (SSRI), is consistently introduced into the environment due to its ongoing consumption and inadequate removal by wastewater treatment plants. As a result, the scientific community has displayed a keen interest in investigating the potential toxicological effects associated with this medication. Nevertheless, there is a scarcity of available data regarding the impact of FLX on blood parameters. With this in mind, this study aimed to evaluate the potential toxicological consequences of FLX at environmentally significant concentrations (5, 16, and 40 ng/L) following a 96-hour acute exposure blood parameters in Danio rerio fish. Moreover, the investigation encompassed an assessment of oxidative stress parameters to determine whether the drug could induce disruptions in the REDOX status of the fish. The findings unveiled that FLX prompted the induction of oxidative stress in various organs of the fish, encompassing the liver, gut, brain, and gills. Notably, the gills and brain exhibited heightened susceptibility to the drug's effects compared to other organs. Furthermore, following acute exposure to FLX, there was an upregulation of antioxidant-related genes (sod, cat, gpx, nrf1, and nrf2), thereby providing additional evidence supporting the induction of oxidative stress in the organs of the fish. Lastly, FLX significantly impacted the customary values of various blood parameters, including glucose, blood urea nitrogen, alanine aminotransferase, alkaline phosphatase, red blood cell count, hemoglobin, and hematocrit. Thus, it can be inferred that FLX harmed the overall health status of the fish, resulting in the development of liver disease, anemia, and other associated illnesses.

Health impact assessment after Danio rerio long-term exposure to environmentally relevant concentrations of metformin and guanylurea.

The antidiabetic drug metformin (MET) and its metabolite guanylurea (GUA) have been frequently and ubiquitously detected in surface water. Consequently, there has been a consistent rise in studying the toxicity of MET and GUA in fish over the past decade. Nonetheless, it is noteworthy that no study has assessed the harmful effects both compounds might trigger on fish blood and organs after chronic exposure. Taking into consideration the data above, our research strived to accomplish two primary objectives: Firstly, to assess the effect of comparable concentrations of MET and GUA (1, 40, 100 µg/L) on the liver, gills, gut, and brain of Danio rerio after six months of flow-through exposure. Secondly, to compare the outcomes to identify which compound prompts more significant oxidative stress and apoptosis in organs and blood parameter alterations. Herein, findings indicate that both compounds induced oxidative damage and increased the expression of genes associated with apoptosis (bax, bcl2, p53, and casp3). Chronic exposure to MET and GUA also generated fluctuations in glucose, creatinine, phosphorus, liver enzymes, red and white blood count, hemoglobin, and hematocrit levels. The observed biochemical changes indicate that MET and GUA are responsible for inducing hepatic damage in fish, whereas hematological alterations suggest that both compounds cause anemia. Considering GUA altered to a more considerable extent the values of all endpoints compared to the control group, it is suggested transformation product GUA is more toxic than MET. Moreover, based on the above evidence, it can be inferred that a six-month exposure to MET and GUA can impair REDOX status and generate apoptosis in fish, adversely affecting their essential organs' functioning.

Influence of sucralose, acesulfame-k, and their mixture on brain's fish: A study of behavior, oxidative damage, and acetylcholinesterase activity in Daniorerio.

Sucralose (SUC) and acesulfame-k (ACE-K) are widely used artificial sweeteners worldwide; however, they are frequently detected in aquatic environments due to their low metabolism and inadequate removal during wastewater treatment. The harmful effects of these compounds on hydrobionts have yet to be fully understood, as data on their toxicity is limited and inconclusive. This research aimed to determine the impact of SUC (50, 75, 125 µg/L) and ACE-K (50, 75, 125 µg/L), individually and in combination, on fish's swimming behavior, acetylcholinesterase activity, and oxidative stress response after four months of exposure. Following exposure, adult Danio rerio displayed anxiety-like behavior, as evidenced by increased freezing time and decreased swimming activity. Additionally, analysis of fish brain tissue revealed a disruption of REDOX homeostasis, leading to oxidative stress, which may be responsible for the observed inhibition of AChE activity. The results indicated that ACE-K was more toxic than SUC, and the mixture of both compounds produced a more detrimental effect than when each compound was administered alone. These findings highlight the hazardous impacts of SUC and ACE-K on fish in environmentally relevant concentrations, suggesting that these compounds should be added to the priority pollutant list.

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.

Acute exposure to realistic concentrations of Bisphenol-A trigger health damage in fish: Blood parameters, gene expression, oxidative stress.

Despite much information regarding BPA toxicity in fish and other aquatic organisms, data is still misleading as most studies have utilized concentrations several orders of magnitude higher than those typically found in the environment. As an illustration, eight of the ten studies investigating the impact of BPA on the biochemical and hematological parameters of fish have employed concentrations on the order of mg/L. Therefore, the results may not accurately represent the effects observed in the natural environment. Considering the information above, our study aimed to 1) determine whether or not realistic concentrations of BPA might alter the biochemical and blood parameters of Danio rerio and trigger an inflammatory response in the fish liver, brain, gills, and gut and 2) determine which organ could be more affected after exposure to this chemical. Findings pinpoint that realistic concentrations of BPA prompted a substantial increase in antioxidant and oxidant biomarkers in fish, triggering an oxidative stress response in all organs. Likewise, the expression of different genes related to inflammation and apoptosis response was significantly augmented in all organs. Our Pearson correlation shows gene expression was closely associated with the oxidative stress response. Regarding blood parameters, acute exposure to BPA generated biochemical and hematological parameters increased concentration-dependent. Thus, it can be concluded that BPA, at environmentally relevant concentrations, threatens aquatic species, as it prompts polychromasia and liver dysfunction in fish after acute exposure.

Oxidative stress as regulator of neuronal impairment after exposure to hospital effluents in Danio rerio.

The variety of activities carried out within hospitals results in their final discharges being considered hotspots for the emission of emerging pollutants. Hospital effluents contain different substances capable of altering the health of ecosystems and biota, furthermore, little research has been done to elucidate the adverse effects of these anthropogenic matrices. Taking this into account, herein we aimed to establish whether exposure to different proportions (2 %, 2.5 %, 3 %, and 3.5 %) of hospital effluent treated by hospital wastewater treatment plant (HWWTP) can induce oxidative stress, behavioral alterations, neurotoxicity, and disruption of gene expression in Danio rerio brain. Our results demonstrate that the hospital effluent under-study induces an anxiety-like state and alters swimming behavior, as fish exhibited increased freezing episodes, erratic movements and traveled less distance than the control group. In addition, after exposure we observed a meaningful rise in biomarkers related to oxidative damage, such as protein carbonyl content (PCC), lipoperoxidation level (LPX), hydroperoxide content (HPC), as well as an increase in enzyme antioxidant activities of catalase (CAT), and superoxide dismutase (SOD) upon short-term exposure. Moreover, we discovered an inhibition of acetylcholinesterase (AChE) activity in a hospital effluent proportion-dependent manner. Regarding gene expression, a significant disruption of genes related to antioxidant response (cat, sod, nrf2), apoptosis (casp6, bax, casp9), and detoxification (cyp1a1) was observed. In conclusion, our outcomes suggest that hospital effluents enhance the emergence of oxidative molecules, and promote a highly oxidative environment at the neuronal level that favors the inhibition of AChE activity, which consequently explains the anxiety-like behavior observed in D. rerio adults. Lastly, our research sheds light on possible toxicodynamic mechanism by which these anthropogenic matrices may trigger damage in D. rerio brain.

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.

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.

A comprehensive approach to how hospital effluents lead to oxidative stress and shift the gene expression in target organs of Danio rerio.

Hospital effluents represent a threat to the environment owing to the content of toxic substances capable of altering the structure and function of ecosystems. Despite the available information about the impact of hospital effluents on aquatic organisms, the molecular mechanism underlying this process has received little or no attention. The present study aimed to evaluate the oxidative stress and gene expression induced by different proportions (2 %, 2.5 %, 3 % and 3.5 %) of hospital effluent treated by hospital wastewater treatment plant (HWWTP) in liver, gut, and gills of Danio rerio at different exposure times. Significant increases in the levels of protein carbonylation content (PCC), hydroperoxides content (HPC), lipoperoxidation level (LPX) and superoxide dismutase (SOD) and catalase (CAT) activity were observed in most of the organs evaluated at the four proportions tested with respect to the control group (p < 0.05). It was found that at longer exposure times there is a lower response in SOD activity, suggesting catalytic depletion due to the oxidative environment at the intracellular level. The lack of complementarity between SOD and mRNA activity patterns indicates that the activity itself is subordinated to post-transcriptional processes. Upregulation of transcripts related to antioxidant processes (sod, cat, nrf2), detoxification (cyp1a1) and apoptosis (bax, casp6, and casp9) was observed in response to oxidative imbalance. On the other hand, the metataxonomic approach allowed the characterization of pathogenic bacterial genera such as Legionella, Pseudomonas, Clostridium XI, Parachlamydia and Mycobacterium present in the hospital effluent. Our findings indicate that although hospital effluent was treated by HWWTP, it caused oxidative stress damage and disrupted gene expression by decreasing the antioxidant response in Danio rerio.

Realistic concentrations of Bisphenol-A trigger a neurotoxic response in the brain of zebrafish: Oxidative stress, behavioral impairment, acetylcholinesterase inhibition, and gene expression disruption.

Bisphenol A (BPA) is a micro-pollutant found in various environmental matrices at concentrations as low as ng/L. Recent studies have shown that this compound can cause oxidative damage and neurotoxic effects in aquatic organisms. However, there is a lack of research investigating the effects of BPA at environmentally relevant concentrations. Therefore, this study aimed to assess the neurotoxic effects of acute BPA exposure (96 h) at environmentally relevant concentrations (220, 1180, and 1500 ng/L) in adult zebrafish (Danio rerio). The Novel Tank trial was used to evaluate fish swimming behavior, and our results indicate that exposure to 1500 ng/L of BPA reduced the total distance traveled and increased freezing time. Furthermore, the evaluation of biomarkers in the zebrafish brain revealed that BPA exposure led to the production of reactive oxygen species and increased acetylcholinesterase activity. Gene expression analysis also indicated the overexpression of mbp, α1-tubulin, and manf in the zebrafish brain. Based on our findings, we concluded that environmentally relevant concentrations of BPA can cause anxiety-like behavior and neurotoxic effects in adult zebrafish.

Methodological - Theoretical approach to phenomenological studies on the experience of medication use: A systematic review.

BACKGROUND: The study of medication use should include pharmacological, family, and social dimensions to explain how the lived experiences, beliefs, and perceptions of everyone, and their social and cultural environment affects consumption, using for this purpose the qualitative approach. OBJECTIVE: To conduct a systematic review of the theoretical-methodological approaches to phenomenology to identify studies that allow an understanding of patients' experiences with the use of medications.a. METHODS: A systematic literature search was conducted following the PRISMA guidelines to identify studies that address phenomenological research on patients' experiences of medications used and to apply them in subsequent studies. A thematic analysis was performed using ATLAS.ti software to facilitate data management. RESULTS: Twenty-six articles were identified, most of them including adult patients diagnosed with chronic degenerative diseases. The semantic network obtained places Phenomenology at the center as the interpretative referential framework, with three theoretical approaches: descriptive, interpretative, and perceptual under the philosophies of Husserl, Heidegger, and Merleau-Ponty respectively; two techniques to collect data which are in-depth interview and focus groups; and to explore the life experiences of patients and understand the meaning in the context of their lives, thematic analysis, content analysis, and interpretative phenomenological analysis were identified. CONCLUSIONS: It was evidenced that Qualitative Research approaches, methodologies, and techniques are applicable to describe people's experiences towards the use of medications. Phenomenology constitutes a useful referential framework in qualitative research to explain the experiences and perceptions about the disease and the use of medicines.