Developmental toxicity and biological responses of zebrafish (Danio rerio) exposed to anti-inflammatory drug ketoprofen

Acute exposure to environmentally relevant concentrations of pharmaceutical pollutants induces neurobehavioral toxicity in zebrafish (Danio rerio)

Pharmaceutical waste from point and non-point sources enters, persists, or disseminates in the environment and is known as environmentally persistent pharmaceutical pollutants. Understanding the impacts of pharmaceutical pollutants on the environment and health is essential. This study investigates the behavioral impacts of pharmaceutical pollutants on aquatic organisms and delineates the possible nexus of oxidative stress. The male zebrafish were exposed to four major representative pharmaceutical pollutants, viz., acetaminophen, carbamazepine, metformin, and trimethoprim at environmentally relevant concentrations individually as well as in a mixture for seven days. Substantial alterations in social interaction, aggressive nature, novel tank exploration, and light and dark zone preferences were recorded and the degree varied to different pharmaceutical pollutants. The activity of oxidative stress markers, superoxide dismutase, glutathione-S-transferase, and catalase, was found to be suppressed to 66-20%, 42-25%, and 59-20% respectively with the elevated malondialdehyde generation (180-260%) compared to control. The activity level of acetylcholine esterase was found to be increased to 200-500% across all treatment groups. Despite the synergistic impacts of pharmaceutical pollutants on the whole system that could not be ascertained, this comprehensive study highlights their toxicity nature to induce neurobehavioral toxicity in zebrafish through oxidative stress mechanisms and altered cholinergic systems.

Recent progress in adverse events of carboxylic acid non-steroidal anti-inflammatory drugs (CBA-NSAIDs) and their association with the metabolism: the consequences on mitochondrial dysfunction and oxidative stress, and prevention with natural plant extracts

INTRODUCTION

Carboxylic acid non-steroidal anti-inflammatory drugs (CBA-NSAIDs) are extensively used worldwide due to their antipyretic, analgesic, and anti-inflammatory effects. CBA-NSAIDs have reasonable margin of safety at therapeutic doses, and in the current climate, do not possess addiction potential like opioid drugs. Studies have revealed that various adverse events of CBA-NSAIDs are related mitochondrial dysfunction and oxidative stress.

AREAS COVERED

This review article summarizes adverse events induced by CBA-NSAIDs, mechanisms of mitochondrial damage, oxidative stress, and metabolic interactions. Meanwhile, this review discusses the treatment and prevention of CBA-NSAIDs damage by natural plant extracts based on antioxidant effects.

EXPERT OPINION

CBA-NSAIDs can induce reactive oxygen species (ROS) production, mediate DNA, protein and lipid damage, lead to imbalance of cell antioxidant status, change of mitochondrial membrane potential, activate oxidative stress signal pathway, thus leading to oxidative stress and cell damage. Adverse events caused by CBA-NSAIDs often exhibit dose and time dependence. In order to avoid adverse events caused by CBA-NSAIDs, it is necessary to provide detailed patient consultation and eliminate influencing factors. Moreover, constructive research studies on the organ-specific toxicity and mechanism of natural plant extracts in preventing and treating metabolic abnormalities of CBA-NSAIDs, will provide important value for warning and guidance for use of CBA-NSAIDs.

Toxicological effect of acetaminophen, metamizole, and nimesulide cocktail on early development of zebrafish

BACKGROUND

Several countries' most incorrectly discarded medicines are acetaminophen (ACM), metamizole (MTZ), and nimesulide (NMS). These xenobiotics easily reach the aquatic environment; such contamination is very important for the health of humans and other species, yet little explored.

OBJECTIVES

To evaluate the cocktail effect of ACM, MTZ, and NMS during zebrafish's initial development.

METHODS

Zebrafish embryos 6-8 h post-fertilization (hpf) were exposed to different concentrations of ACM, MTZ, and NMS, separately, to obtain the 50% lethal concentrations (LC50). Next, the embryos were exposed to distinct concentrations of the cocktail (LC50/2, LC50/5, LC50/10, and LC50/20) in a semi-static system. Samples were analyzed 0, 24, 48, and 96 h after exposure, and the drugs' concentrations in E3 medium were assessed by high-performance liquid chromatography. For embryotoxicity evaluation, the mortality, hatching, and heart rates; total length; and pericardial and yolk sac areas were determined. In addition, body malformations, edemas, presence of pigmentation, and histopathological assessments were also recorded.

RESULTS

The LC50 values obtained for MTZ, ACM, and NMS were 4.69 mgmL-1, 799.98 μgmL-1, and 0.92 μgmL-1, respectively. No difference was observed between the drugs' nominal and observed concentrations at each time point. The cocktail significantly induced mortality and decreased hatching in the LC50/10, LC50/5, and LC50/2 groups. Additionally, body malformations, pigmentation loss, and yolk sac and pericardial edemas were observed in the cocktail groups. The cocktail groups' larvae had decreased total length and slower heart rates compared to the controls (p < 0.05). The histopathological assessment showed that yolk sac edema promoted severe histological changes in the esophageal-intestine junction and intestine in larvae treated with cocktails. Moreover, PAS-positive structures decreased in the esophageal-intestine junction, intestine, and liver in larvae exposed to pharmaceutical cocktails.

CONCLUSION

This study's findings suggest the cocktail of ACM, MTZ, and NMS may be hazardous to aquatic organisms in case of environmental contamination.

Cadmium and ketoprofen accumulation influences aquatic ecosystem demonstrated using in-vivo zebrafish model

The growing concern about pollution and toxicity in aquatic as well as terrestrial organisms is predominantly caused due to waterborne exposure and poses a risk to environmental systems and human health. This study addresses the co-toxic effects of cadmium (Cd) and ketoprofen (KPF), representing heavy metal and pharmaceutical discharge pollutants, respectively, in aquatic ecosystems. A 96-h acute toxicity assessment was conducted using zebrafish embryos. The results indicated that high dosages of KPF (10, 15, and 100 µg/mL) and Cd (10 and 15 µg/mL) reduced survivability and caused concentration-dependent deformities such as scoliosis and yolk sac edema. These findings highlight the potential defects in development and metabolism, as evidenced by hemolysis tests demonstrating dose-dependent effects on blood cell integrity. Furthermore, this study employs adult zebrafish for a 42-day chronic exposure to Cd and KPF (10 and 100 µg/L) alone or combined (10 + 10 and 100 + 100 µg/L) to assess organ-specific Cd and KPF accumulation in tissue samples. Organ-specific accumulation patterns underscore complex interactions impacting respiratory, metabolic, and detoxification functions. Prolonged exposure induces reactive oxygen species formation, compromising antioxidant defense systems. Histological examinations reveal structural changes in gills, gastrointestinal, kidney, and liver tissues, suggesting impairments in respiratory, osmoregulatory, nutritional, and immune functions. This study emphasizes the importance of conducting extensive research on co-toxic effects to assist with environmental risk assessments and safeguard human health and aquatic ecosystems.

Evaluation of the citalopram toxicity on early development of zebrafish: Morphological, physiological and biochemical responses

Citalopram, an antidepressant drug have been detected in different environmental matrices due to its high consumption. Previous study has proved that citalopram may alter the behaviour of aquatic organisms at environmentally relevant concentrations. However, scientific knowledge is still lacking on the ecotoxicological effects of citalopram on aquatic organisms. For this reason, the present study is aimed to investigate the potential toxicity of citalopram in terms of development, antioxidant, neurotoxicity, apoptosis, lipogenesis, and bone mineralization in embryonic and larval zebrafish (Danio rerio) at environmentally relevant concentrations. We noticed that citalopram exposure at 1 and 10 μg/L concentration delays hatching and heartbeat at 24, 48, 72 and 96 hpf. Exposure to citalopram also significantly increased mortality at 10 μg/L. Abnormal development with yolk sac edema, pericardial edema and scoliosis were also observed after citalopram treatment. In addition, citalopram significantly (P < 0.001) induced superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST) and lipid peroxidation (LPO) levels. A significant decrease in acetylcholine esterase (AChE) activity was also observed in citalopram exposed groups. We found significant dose-and time-dependent increases in apoptosis, lipogenesis, and bone mineralization. In conclusion, the findings of the present study can provide new insights on the ecotoxicity of citalopram in the aquatic environment.

Assessment of triclosan induced histopathological and biochemical alterations, and molecular docking simulation analysis of acetylcholinesterase enzyme in the gills of fish, Cyprinus carpio

Triclosan (TCS), an antimicrobial additive in various personal and health care products, has been widely detected in aquatic environment around the world. The present study investigated the impacts of TCS in the gills of the fish, Cyprinus carpio employing histopathological, biochemical, molecular docking and simulation analysis. The 96 h LC50 value of TCS in C. carpio was found to be 0.968 mg/L. Fish were exposed to 1/1000th (1 µg/L), 1/100th (10 µg/L), and 1/10th (100 µg/L) of 96 h LC50 value for a period of 28 days. The histopathological alterations observed in the gills were hypertrophy, hyperplasia, edematous swellings, and fusion of secondary lamellae in TCS exposed groups. The severity of these alterations increased with both the concentration as well as the duration of exposure. The present study revealed that the activity of antioxidant enzymes such as superoxide dismutase, catalase, glutathione-S-transferase, glutathione reductase, glutathione peroxidase, and reduced glutathione content decreased significantly (p < 0.05) in both concentration and duration dependent manner. However, a significant (p < 0.05) increase in the activity of the metabolic enzymes such as acid phosphatase and alkaline phosphatase was observed in all three exposure concentrations of TCS from 7 to 28 days. The activity of acetylcholinesterase declined significantly (p < 0.05) from 7 to 28 days whereas the content of acetylcholine increased significantly at the end of 28 day. The experimental results were further confirmed by molecular docking and simulation analysis that showed strong binding of TCS with acetylcholinesterase enzyme. The study revealed that long-term exposure to sublethal concentrations of TCS can lead to severe physiological and histopathological alterations in the fish.

Uptake and toxicity of micro-/nanoplastics derived from naturally weathered disposable face masks in developing zebrafish: Impact of COVID-19 pandemic on aquatic life

The unprecedented proliferation of disposable face masks during the COVID-19 pandemic, coupled with their improper disposal, threatens to exacerbate the already concerning issue of plastic pollution. This study evaluates the role of environmentally weathered masks as potential sources of microplastics (MPs) and nanoplastics (NPs) and assesses their adverse impact on the early life stages of zebrafish. Experimental findings revealed that a single disposable mask could release approximately 1.79 × 109 particles, with nearly 70% measuring less than 1 μm, following 60 days of sunlight exposure and subsequent sand-induced physical abrasion. Remarkably, the MPs/NPs (MNPs) emanating from face masks have the potential to permeate the outer layer (chorion) of zebrafish embryos. Furthermore, due to their minute size, these particles can be consumed by the larvae's digestive system and subsequently circulated to other tissues, including the brain. Exposure to mask-derived MNPs at concentrations of 1 and 10 μg/L led to significant cases of developmental toxicity, incited oxidative stress, and prompted cell apoptosis. A subsequent metabolomics analysis indicated that the accumulation of these plastic particles perturbed metabolic functions in zebrafish larvae, primarily disrupting amino acid and lipid metabolism. The outcomes of this research underscore the accelerating possibility of environmental aging processes and physical abrasion in the release of MNPs from disposable face masks. Most importantly, these results shed light on the possible ecotoxicological risk posed by improperly disposed of face masks.

Growth inhibition, oxidative stress and characterisation of mortality in green algae under the influence of beta-blockers and non-steroidal anti-inflammatory drugs

Bisoprolol and ketoprofen are widely used pharmaceuticals in medical treatment hence these substances are occurring in wastewaters and in water environment. This research investigated the toxic effects of bisoprolol and ketoprofen on two microalgae taxa, Chlorella vulgaris and Desmodesmus armatus. The results showed that both drugs inhibited the growth of the species tested and induced a decrease in chlorophyll a content compared to controls. Ketoprofen turned out to be harmful to algae as the half maximal effective concentration (EC50) values (14 days) were 37.69 mg L-1 for C. vulgaris and 40.93 mg L-1 for D. armatus. On the other hand, for bisoprolol, the EC50 values were greater than the established NOEC, 100 mg L-1. Bisoprolol and ketoprofen induced oxidative stress in the tested microorganisms, as indicated by changes in the activities of antioxidant enzymes. Exposure to 100 mg L-1 of drugs significantly increased the activity of catalase, peroxidase and superoxide dismutase. Fluorescence microscopy showed that both medicaments changed the cells' morphology. There was atrophy of chlorophyll in the cells, moreover, dying multinuclear cells and cells without nuclei were observed. In addition, there were atrophic cells, namely cells that lacked nuclei and chlorophyll. Profile area analyses showed that bisoprolol and ketoprofen treated C. vulgaris cells were approximately 4 and 2 times greater compared to control ones. Our experimental findings highlight the ecotoxicological threats for aquatic primary producers from bisoprolol and ketoprofen and provide insight into the characteristics of their death.

Loss of zebrafish pkd1l1 causes biliary defects that have implications for biliary atresia splenic malformation

Biliary atresia is a fibroinflammatory neonatal disease with no effective therapies. A subset of cases (10-20%) is associated with laterality defects - labeled biliary atresia splenic malformation (BASM) syndrome. Recently, whole-exome sequencing of patients with BASM identified deleterious variants in PKD1L1. PKD1L1 is involved in left-right axis determination; however, its role in cholangiocytes is unknown. We generated the pkd1l1hsc117 allele using CRISPR/Cas9 mutagenesis in zebrafish to determine the role of Pkd1l1 in biliary development and function. Wild-type and mutant larvae were assessed for laterality defects, biliary function and biliary tree architecture at 5 days post fertilization. pkd1l1hsc117 mutant larvae exhibited early left-right patterning defects. The gallbladder was positioned on the left in 47% of mutants compared to 4% of wild-type larvae. Accumulation of PED6 in the gallbladder, an indicator of hepatobiliary function, was significantly reduced in pkd1l1hsc117 mutants (46%) compared to wild-type larvae (4%). pkd1l1hsc117 larvae exhibited fewer biliary epithelial cells and reduced density of the intrahepatic biliary network compared to those in wild-type larvae. These data highlight the essential role of pkd1l1 in normal development and function of the zebrafish biliary system, supporting a role for this gene as a cause of BASM.

Developmental toxicity of the emerging contaminant cyclophosphamide and the integrated biomarker response (IBRv2) in zebrafish

The safety of cyclophosphamide (CP) in the early developmental stages is not studied yet; it is important to study the responses at these stages because they might have relevance to CP-administered humans. We studied the developmental toxicity of CP by analysing physiological, morphological, and oxidative stress, neurotransmission enzymes, gene expression and histological endpoints in zebrafish embryos/larvae. The study lasted for 120 hpf at environmentally relevant concentrations of CP. No visible alterations were noticed in the control group. Delayed hatching, slow heart rate, yolk sac oedema, pericardial oedema, morphological deformities, the incompetence of oxidative stress biomarkers, excessive generation of ROS, apoptosis, inhibition of neurotransmitters and histopathological anomalies were observed in CP-treated groups. These alterations were found to be concentration- and duration-dependent effects for physiological and morphological endpoints, whereas concentration-dependent effects were antioxidants, ROS, apoptosis and histological endpoints. Biomarkers and gene expression were standardised using the integrated biomarker response-IBRv2 index. The IBRv2 index showed a concentration-dependent behaviour. A non-lethal developmental and teratogenic effect was observed in CP-treated zebrafish embryos/larvae at the studied concentrations. The studied biomarkers are sensitive, and the responses are interrelated; thus, their responses are useful to assess veiled and unseen hazards of pharmaceuticals.

Ketoprofen as an emerging contaminant: occurrence, ecotoxicity and (bio)removal

Ketoprofen, a bicyclic non-steroidal anti-inflammatory drug commonly used in human and veterinary medicine, has recently been cited as an environmental contaminant that raises concerns for ecological well-being. It poses a growing threat due to its racemic mixture, enantiomers, and transformation products, which have ecotoxicological effects on various organisms, including invertebrates, vertebrates, plants, and microorganisms. Furthermore, ketoprofen is bioaccumulated and biomagnified throughout the food chain, threatening the ecosystem function. Surprisingly, despite these concerns, ketoprofen is not currently considered a priority substance. While targeted eco-pharmacovigilance for ketoprofen has been proposed, data on ketoprofen as a pharmaceutical contaminant are limited and incomplete. This review aims to provide a comprehensive summary of the most recent findings (from 2017 to March 2023) regarding the global distribution of ketoprofen in the environment, its ecotoxicity towards aquatic animals and plants, and available removal methods. Special emphasis is placed on understanding how ketoprofen affects microorganisms that play a pivotal role in Earth's ecosystems. The review broadly covers various approaches to ketoprofen biodegradation, including whole-cell fungal and bacterial systems as well as enzyme biocatalysts. Additionally, it explores the potential of adsorption by algae and phytoremediation for removing ketoprofen. This review will be of interest to a wide range of readers, including ecologists, microbiologists, policymakers, and those concerned about pharmaceutical pollution.

Toxicological effects of hydroxychloroquine sulfate and chloroquine diphosphate substances on the early-life stages of fish in the COVID-19 pandemic context

Hydroxychloroquine sulfate (HCQ) and chloroquine diphosphate (CQ) have been used at increased rates to treat COVID-19 but can constitute a potential environmental risk. The objective was to evaluate the toxicity of sublethal concentrations of HCQ and CQ in zebrafish embryos/larvae. The 50% lethal concentrations (LC50) of HCQ and CQ at 96 h post-fertilization (hpf) were calculated by testing various concentrations on 2,160 embryos. The LC50 obtained were 560 and 800 µM for HCQ and CQ, respectively. Next, the embryotoxicity assay was performed, where 1,200 embryos were subjected to sublethal concentrations of HCQ and CQ. The hatching and heart rates were recorded. After euthanasia, photomicrographs of all larvae were taken to measure the total length, pericardial and yolk sac areas. The embryos exposed to sublethal concentrations of HCQ and CQ showed delayed hatching at 72 hpf, as well as an increase in the heart rate, larger pericardial and yolk sac areas, and body malformations at 96 hpf. The findings show that HCQ and CQ are toxic to fish in the early development phases. Understanding the mechanisms of toxicity will help extrapolate the effects of 4-aminoquinoline derivatives when they reach the aquatic environment in the context of the COVID-19 pandemic.

Tris(2-chloroethyl) Phosphate Exerts Hepatotoxic Impacts on Zebrafish by Disrupting Hypothalamic-Pituitary-Thyroid and Gut-Liver Axes

The ubiquitous environmental presence of tris(2-chloroethyl) phosphate (TCEP) poses a potential threat to animals; however, little is known about its hepatotoxicity. In this study, the effects of TCEP exposure (0.5 and 5.0 μg/L for 28 days) on liver health and the potential underlying toxification mechanisms were investigated in zebrafish. Our results demonstrated that TCEP exposure led to hepatic tissue lesions and resulted in significant alterations in liver-injury-specific markers. Moreover, TCEP-exposed fish had significantly lower levels of thyrotropin-releasing hormone and thyroid-stimulating hormone in the brain, evidently less triiodothyronine whereas more thyroxine in plasma, and markedly altered expressions of genes from the hypothalamic-pituitary-thyroid (HPT) axis in the brain or liver. In addition, a significantly higher proportion of Bacteroidetes in the gut microbiota, an elevated bacterial source endotoxin lipopolysaccharide (LPS) in the plasma, upregulated expression of LPS-binding protein and Toll-like receptor 4 in the liver, and higher levels of proinflammatory cytokines in the liver were detected in TCEP-exposed zebrafish. Furthermore, TCEP-exposed fish also suffered severe oxidative damage, possibly due to disruption of the antioxidant system. These findings suggest that TCEP may exert hepatotoxic effects on zebrafish by disrupting the HPT and gut-liver axes and thereafter inducing hepatic inflammation and oxidative stress.

Exposure to polypropylene microplastics via diet and water induces oxidative stress in Cyprinus carpio

The occurrence of accumulation of microplastics in humans and wildlife has become a serious concern on a global scale, especially in the last decade. Although there are many studies on microplastics, their biological effects and toxicity on freshwater fish have not been fully revealed. In order to evaluate the potential toxic effects of PP (polypropylene) microplastics in freshwater fish, we performed 1-day, 2-day, 3-day, 4-day, 5-day, 6-day, and 7-day microplastic exposure to different concentrations of the microplastics through water and diet on Cyprinus carpio. Fish samples were divided into 3 groups; Group-A with different PP microplastic concentrations in their water (A_Low:1.0 g/L and A_High:2.5 g/L), Group-B with different PP microplastic concentrations in their diet (B_Low:100 mg/g and B_High:250 mg/g), and Group-C (Control group) free of PP microplastics in their diet and water. The results showed that although microplastics did not cause death in C. carpio, they caused oxidative stress in comparing the MP exposed groups to the control groups. When indices of oxidative stress of fish individuals in all treatment groups were compared with the control group, it was determined that MDA (malondialdehyde) and GSH (glutathione) levels increased, while TPC (total protein content) and CAT (catalase) levels decreased depending on the concentrations and exposure times. Significant differences were observed between the control and treatment groups in the indices of oxidative stress (P<0.05). This study provided basic toxicological data to elucidate and quantify the effects of PP microplastics on freshwater fish. In addition, this study is the first study to indicate that microplastic exposure of carp via diet and water causes oxidative stress in gill tissues and causes changes in CAT, MDA, GSH, and TPC levels. The findings also provide useful reference data for improving knowledge of the effects of microplastics on organisms in freshwater systems.

Ecotoxicological impacts of environmentally relevant concentrations of aspirin in the liver of Labeo rohita: Biochemical and histopathological investigation

Aspirin is one of the emerging pharmaceutical contaminants in the aquatic environment and thus it could impart toxicity to non-target organisms including fish. The present study aims to investigate the biochemical and histopathological alterations in the liver of the fish, Labeo rohita exposed to environmentally relevant concentrations of aspirin (1, 10, and 100 μg/L) for 7, 14, 21, and 28 days. The biochemical investigation revealed a significant (p < 0.05) decrease in the activity of antioxidant enzymes such as catalase, glutathione peroxidase, glutathione reductase; and reduced glutathione content in a concentration and duration dependent manner. Further, the decrease in the activity of superoxide dismutase was in a dose dependent manner. The activity of glutathione-s-transferase, however, increased significantly (p < 0.05) in a dose dependent manner. The lipid peroxidation and total nitrate content showed a significant (p < 0.05) increase in a dose and duration dependent manner. The metabolic enzymes such as acid phosphatase, alkaline phosphatase, and lactate dehydrogenase showed a significant (p < 0.05) increase in all three exposure concentrations and durations. The histopathological alterations in the liver such as vacuolization, hypertrophy of the hepatocytes, nuclear degenerative changes, and bile stagnosis increased in a dose and duration dependent manner. Hence, the present study concludes aspirin has a toxic impact on fish, which is evidenced by its profound effect on biochemical parameters and histopathological analysis. These can be employed as potential indicators of pharmaceutical toxicity in the field of environmental biomonitoring.

A study to assess the health effects of an anticancer drug (cyclophosphamide) in zebrafish (Danio rerio): eco-toxicity of emerging contaminants

Cyclophosphamide (CP) is widely used for treating various kinds of cancer. Because of its high intake, metabolism and excretion, these anticancer medications have been detected in the aquatic environment. There is very limited data on the toxicity and effects of CP on aquatic organisms. The present study aims to assess the toxic effect of CP on certain oxidative stress biomarkers (superoxide dismutase-SOD, catalase-CAT, glutathione peroxidase-GPx, glutathione-GSH, glutathione S-transferases-GST and lipid peroxidation-LPO), protein, glucose, metabolising enzymes (aspartate aminotransferase-AST, alanine aminotransferase-ALT), and ion-regulatory markers (sodium ions-Na⁺, potassium ions-K⁺, and chloride ions-Cl^-), and histology in the gills and liver of Danio rerio at environmentally relevant concentrations (10, 100 and 1000 ng L^-1). Exposure to CP for 42 days led to a significant decrease in SOD, CAT, GST, GPx and GSH levels in the gills and liver tissues of zebrafish. The level of lipid peroxidation in the gills and liver tissues of zebrafish was significantly increased compared to the control group. Chronic exposure significantly changes protein, glucose, AST, ALT, Na⁺, K⁺ and Cl^- biomarkers. Fish exposed to different levels of CP showed necrosis, inflammation, degeneration and hemorrhage in the gills and hepatic tissues. The observed changes in the studied tissue biomarkers were proportional to both dose and time. In conclusion, CP at environmentally relevant concentrations causes oxidative stress, energy demand, homeostasis disturbances, and enzyme and histological alterations in the vital tissues of zebrafish. These alterations were similar to the toxic effects reported in mammalian models.

Environmentally relevant concentrations of butyl benzyl phthalate triggered oxidative stress and apoptosis in adult zebrafish (Danio rerio) liver: Combined analysis at physiological and molecular levels

Butyl benzyl phthalate (BBP), a typical phthalate plasticizer, is frequently detected in aquatic environments, but its possible effects on fish liver are unknown. In this study, adult zebrafish were exposed to 5-500 μg/L BBP and cultured for 28 days. The toxicity mechanism of environmentally relevant concentrations of BBP in the liver was explored using integrated biomarker response (IBR), molecular docking, and histopathological analysis, based on the tests of oxidative stress, apoptosis, and tissue damage, respectively. The results revealed that exposure to 500 μg/L BBP caused lipid peroxidation and DNA damage and induced inflammatory responses in the liver and intestinal tissues. The accumulation of reactive oxygen species (ROS) is the primary manifestation of BBP toxicity and is accompanied by changes in the activities of antioxidant and detoxification enzymes. Notably, the pro-apoptotic genes (p53 and caspase-3) were still significantly upregulated in the 50 μg/L and 500 μg/L treatment groups on day 28. Moreover, BBP interfered with apoptosis by forming a stable complex with apoptosis proteins (P53 and Caspase-3). Our findings are helpful for understanding the toxicity mechanisms of BBP, which could further promote the assessment of the potential environmental risks of BBP.

Metabolomic analysis reveals the impact of ketoprofen on carbon and nitrogen metabolism in rice (Oryza sativa L.) seedling leaves

Pharmacologically active compounds (PACs) are becoming common pollutants in the natural environment, posing potential risks to crop quality; however, the toxic effects and metabolic changes that they cause in agricultural plants remain unclear. Here, we investigated the effects of ketoprofen on respiration rate, ATP synthesis, carbon and nitrogen metabolism, and metabolomics in rice seedling leaves. The results showed that ketoprofen treatment adversely affected the respiration rate, ATP content, H⁺-ATPase activity and induced changes in the contents of carbon assimilation products (soluble sugar, reducing sugar, sucrose, and starch) and the activities of key enzymes in carbon metabolism (sucrose synthase (SS), sucrose phosphate synthase (SPS), and sucrose invertase (InV)). The contents of nitrate, ammonium, and free amino acids, and the activities of key enzymes involved in nitrogen metabolism (nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), glutamate synthase (GOGAT), and glutamate dehydrogenase (GDH)) were also affected in a concentration-dependent manner. Metabolomics analysis showed that ketoprofen disturbed the type and content of metabolites (amino acids, carbohydrates, and secondary metabolites) to varying degrees and perturbed key metabolic pathways (substance synthesis and energy metabolism), ultimately resulting in the reduction of rice seedling biomass. This study provides important information and a useful reference for the accurate assessment of the environmental risks of PACs.

A mechanistic investigation about hepatoxic effects of borneol using zebrafish

Except for clinical value, borneol is routinely used in food and cosmetics with seldom safety evaluation. To investigate its hepatoxicity, we exposed 3 dpf (days post fertilization) larval zebrafish to borneol at a gradient of concentrations (200-500 μM) for 3 days. Herein, our results revealed that high doses of borneol (300-500 μM) caused liver size decrease or lateral lobe absence. Borneol also seriously disturbed the hepatic protein metabolism presented with the increased activity of alanine aminotransferase (ALT) and lipid metabolism shown with the increased level of triglycerides (TG) and total cholesterol (TC). The lipid accumulation (oil red staining) was detected as well. Additionally, significant upregulation of genes was detected that related to oxidative stress, lipid anabolism, endoplasmic reticulum stress (ERS), and autophagy. Conversely, the lipid metabolism-related genes were markedly downregulated. Moreover, the changes in the superoxide dismutase activity and the level of glutathione and malondialdehyde raised the likelihood of lipid peroxidation. The outcomes indicated the involvement of oxidative stress, ERS, lipid metabolism, and autophagy in borneol-induced lipid metabolic disorder and hepatic injury. This study will provide a more comprehensive understanding of borneol hepatoxicity and the theoretical basis for the safe use of this compound.

Metabolomics analysis of the potential toxicological mechanisms of diquat dibromide herbicide in adult zebrafish (Danio rerio) liver

Although diquat is a widely used water-soluble herbicide in the world, its sublethal adverse effects to fish have not been well characterised. In this study, histopathological examination and biochemical assays were applied to assess hepatotoxicity and combined with gas chromatography-mass spectrometry (GC-MS)-based metabolomics analysis to reveal overall metabolic mechanisms in the liver of zebrafish (Danio rerio) after diquat exposure at concentrations of 0.34 and 1.69 mg·L^-1 for 21 days. Results indicated that 1.69 mg·L^-1 diquat exposure caused cellular vacuolisation and degeneration with nuclear abnormality and led to the disturbance of antioxidative system and dysfunction in the liver. No evident pathological injury was detected, and changes in liver biochemistry were not obvious in the fish exposed to 0.34 mg·L^-1 diquat. Multivariate statistical analysis revealed differences between profiles obtained by GC-MS spectrometry from control and two treatment groups. A total of 17 and 22 metabolites belonging to different classes were identified following exposure to 0.34 and 1.69 mg·L^-1 diquat, respectively. The metabolic changes in the liver of zebrafish are mainly manifested as inhibition of energy metabolism, disorders of amino acid metabolism and reduction of antioxidant capacity caused by 1.69 mg·L^-1 diquat exposure. The energy metabolism of zebrafish exposed to 0.34 mg·L^-1 diquat was more inclined to rely on anaerobic glycolysis than that of normal zebrafish, and interference effects on lipid metabolism were observed. The metabolomics approach provided an innovative perspective to explore possible hepatic damages on fish induced by diquat as a basis for further research.

Isolation and Characterization of Efficient Active Compounds Using High-Performance Centrifugal Partition Chromatography (CPC) from Anti-Inflammatory Activity Fraction of Ecklonia maxima in South Africa

Ecklonia maxima is a brown seaweed, which is abundantly distributed in South Africa. This study investigated an efficient approach using high-performance centrifugal partition chromatography (HPCPC), which has been successfully developed for the isolation and purification of phlorotannins, eckmaxol, and dieckol from the ethyl acetate fraction of E. maxima (EEM). We evaluated EEM for its inhibitory effect against lipopolysaccharide (LPS)-induced inflammatory responses in zebrafish embryos. The separation of eckmaxol and dieckol from samples of EEM using HPCPC was found to be of high purity and yield under an optimal solvent system composed of n-hexane:ethyl acetate:methanol:water (2:7:3:7, v/v/v/v). To evaluate the anti-inflammatory efficacy of EEM containing active compounds, zebrafish embryos exposed to LPS were compared with and without EEM treatment for nitric oxide (NO) production, reactive oxygen species (ROS) generation, and cell death two days after fertilization. These evaluations indicate that EEM alleviated inflammation by inhibiting cell death, ROS, and NO generation induced by LPS treatment. According to these results, eckmaxol and dieckol isolated from brown seaweed E. maxima could be considered effective anti-inflammatory agents as pharmaceutical and functional food ingredients.

Effect of benzotriazole on oxidative stress response and transcriptional gene expression in Oryzias latipes and Danio rerio embryo

Emerging contaminants (EC) such as benzotriazole are being released into the environment in various ways, therefore it is necessary to understand how organisms are affected by EC. In this study, we exposed medaka (Oryzias latipes) and zebrafish (Danio rerio) during their embryonic period (1 day after hatching) to benzotriazole to investigate its effects on oxidative stress (ROS, GSH, GST, SOD, CAT and MDA) and changes in gene expression patterns. In both medaka and zebrafish, the influence of oxidative stress was confirmed through an increased MDA level and changes in the ROS and GSH levels. Antioxidant enzymes such as GST, CAT, and SOD were affected by benzotriazole; however, medaka and zebrafish showed different patterns in the effects by benzotriazole. Results of oxidative stress genes expression showed that medaka had either no influence or had a decrease in the gene expression profile, whereas zebrafish had a statistically significant increase in the expression of some genes. The cyp1a gene expression was increased in both species. However, vtg gene expression was increased only in zebrafish but decreased in medaka, indicating no estrogenic effects in medaka. Apoptosis genes showed changes in expression in both the species but was these changes were not dose-dependent. However, zebrafish caspase-9 gene expression was increased in all of the exposed groups, suggesting the effects on the intrinsic pathway associated with caspase-9. In conclusion, the results indicate that the toxic effects of benzotriazole differ at various levels in the two small fish medaka and zebrafish embryos.

Human Drug Pollution in the Aquatic System: The Biochemical Responses of Danio rerio Adults

Simple Summary

The release of medicinal products for human use in the aquatic environment is now a serious problem, and can be fatal for the organisms that live there. Danio rerio is a freshwater fish that provides the possibility to study the effects of these pollutants on the health of aquatic organisms. The results of the various existing scientific studies are scarce and conflicting. Here, we review the scientific studies that have analyzed these effects, highlighting that the impacts of drugs are evident in the biochemical responses of these animals.

Abstract

To date, drug pollution in aquatic systems is an urgent issue, and Danio rerio is a model organism to study the toxicological effects of environmental pollutants. The scientific literature has analyzed the effect of human drug pollution on the biochemical responses in the tissues of D. rerio adults. However, the information is still scarce and conflicting, making it difficult to understand its real impact. The scientific studies are not consistent with each other and, until now, no one has grouped their results to create a baseline of knowledge of the possible impacts. In this review, the analysis of literature data highlights that the effects of drugs on adult zebrafishes depend on various factors, such as the tissue analyzed, the drug concentration and the sex of the individuals. Furthermore, the most influenced biochemical responses concern enzymes (e.g., antioxidants and hydrolase enzymes) and total protein and hormonal levels. Pinpointing the situation to date would improve the understanding of the chronic effects of human drug pollution, helping both to reduce it in the aquatic systems and then to draw up regulations to control this type of pollution.

Exposure to polystyrene microplastics induced gene modulated biological responses in zebrafish (Danio rerio)

The substantial increase in the occurrence of microplastics (MPs) in the aquatic ecosystem has been recognized as an emerging concern today. Studies have revealed the toxicity of microplastics on behavior, physiology, and reproduction of fishes. Despite several reports, there are inadequate literature reports on the impact of microplastics on aquatic forms at the molecular level. The present study was aimed to investigate the adverse effects of polystyrene microplastics (PS-MPs) in adult zebrafish model system. Healthy fishes were exposed to different concentrations (10 and 100 μg L^-1) of PS-MPs for 35 d. The results revealed that PS-MPs exposure induced ROS (Reactive oxygen species) generation disrupting the antioxidant defense system, hepatic enzymology, and neurotransmission. Correspondingly, the histological studies showed PS-MPs induced histopathological lesions, including inflammation, degeneration, necrosis, and hemorrhage, in the brain and liver tissues of zebrafish. Furthermore, PS-MPs exposure significantly upregulated the expressions of gstp1, hsp70l, and ptgs2a gene along with the downregulation of cat, sod1, gpx1a, and ache genes. Therefore, the present study illustrates the potential of PS-MPs to induce different grades of toxic impacts in fishes by altering its metabolic mechanism, histological architecture, and gene regulation pattern through ROS induced oxidative stress.

Occurrence and ecotoxicological risk assessment of non-steroidal anti-inflammatory drugs in South African aquatic environment: What is known and the missing information?

Non-steroidal anti-inflammatory drugs (NSAIDs) are medications used individually or as mixtures with other pharmaceuticals for the treatment of various illnesses. Their easy accessibility and high human consumption have resulted to their detection at high concentrations in South African water resources. In the present work, an extensive review of the occurrence and ecotoxicological risk assessment of NSAIDs in South African aquatic environment is provided. Reviewed literature suggested ibuprofen, naproxen, diclofenac, ketoprofen and fenoprofen as the most prominent NSAIDs in the South African aquatic environment. Among these NSAIDs, higher concentrations of ibuprofen are common in South African waters. As a result, this drug was found to pose high ecotoxicological risks towards the aquatic organisms with the highest risk quotients of 14.9 and 11.9 found for algae in surface water and wastewater, respectively. Like in other parts of the world, NSAIDs are not completely removed in wastewater treatment plants. Removal efficiencies below 0% due to higher concentrations of NSAIDs in wastewater effluents rather than influents were observed in certain instances. The detection of NSAIDs in sediments and aquatic plants could serve as the important starting step to investigate other means of NSAIDs removal from water. In conclusion, recommendations regarding future studies that could paint a clearer picture regarding the occurrence and ecotoxicological risks posed by NSAIDs in South African aquatic environment are provided.

Synthesis and characterization of palladium nanoparticles by chemical and green methods: A comparative study on hepatic toxicity using zebrafish as an animal model

Nanoparticles synthesized by chemical methods are of a matter of concern, whereas, the green methods are said to be eco-friendly and environmentally safe. In this study, the toxicity of palladium nanoparticles (Pd NPs) synthesized through chemical co-precipitation and green route method using Annona squamosa seed kernels (As-Pd NPs) were evaluated using zebrafish as an animal model. The synthesized nanoparticles (NPs) were characterized using UV-Visible spectroscopy, Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray (EDX), Fourier Transform Infrared Spectroscopy (FTIR), Dynamic Light Scattering (DLS) and Zeta potential. Zebrafish (Danio rerio) were exposed to 0.4 ng/L of Pd NPs and As-Pd NPs for 96-h, further oxidative stress parameters and histological changes were evaluated. The superoxide dismutase (SOD), catalase (CAT) activity and the lipid peroxidation (LPO) levels were elevated in the Pd NPs groups. But in the As-Pd NPs group, the SOD activity showed a biphasic nature while the CAT activity gradually declined till the 96-h compared to the control and Pd NPs groups. The LPO levels in the As-Pd NPs groups showed a measurable increase till 72-h and sudden decline at the end of 96-h. Anomalies in the histological changes such as ruptured hepatocytes, sinusoidal congestion, vacuolation and accumulation of erythrocytes were observed in both the NPs treated groups but As-Pd NPs exhibited lesser lesions than the control and Pd NPs groups. However, our present study reveals the possible reliability of the nanoparticles and the mechanism of scavenging activity suggesting that the As-Pd NPs synthesized by green route are less toxic comparing to the chemically synthesized Pd NPs.

In vivo evaluation of Nano-palladium toxicity on larval stages and adult of zebrafish (Danio rerio)

The existence and usage of nano-sized palladium (nano-Pd) as catalytic promoters among industries and researchers have been laid a way to explore the release of nano-Pd particles into the aquatic environment, bio-accumulating in living organisms. However, the data on fate and toxicity in response to nano-Pd on aquatic organisms are very limited. Herein, we report the concentration-specific toxicity of nano-Pd in zebrafish (Danio rerio). Nano-Pd was synthesized and characterized by Field Emission Scanning Electron Microscopy (FE-SEM), Dynamic Light Scattering (DLS) and Zeta potential. To determine the in vivo toxicity of nano-Pd, the 96 hpf larvae and the adult zebrafish were treated with two (22 and 0.4 ng/L) environmental relevant concentrations. High doses of nano-Pd influenced the hatching rate, embryo survival, heartbeat and teratological anomalies in the 96 hpf larvae. Reactive oxygen species (ROS) and apoptosis were also influenced by nano-Pd exposure while the acetylcholinesterase (AChE) activity was declined in a dose dependent manner. In long-term exposure (42 days), the adult fish showed erratic movements in swimming pattern inhibiting the AChE activity in both the concentrations of brain and liver. The antioxidant enzyme activity such as superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), glutathione reductase (GR) and lipid peroxidation (LPO), showed a significant change (P < 0.05) indicating that oxidative stress was induced by nano-Pd. Similarly, nano-Pd also induced histopathological lesions in gill, liver and brain providing an insight of fate and toxicity of nano-Pd in the aquatic environment. Our study contributes a significant mechanism to understand the toxicity concern of nano-Pd in the aquatic environment.

Evaluation of the potential environmental risk from the destination of medicines: an epidemiological and toxicological study

BACKGROUND

The high consumption of medicines by the population and their storage at home might cause an increase in the number of pharmaceutical substances that may be inappropriately discarded in the sanitary sewage, reaching an environmental aquatic. Thus, the effects of these emerging contaminants need more studies.

OBJECTIVES

To identify the profile of most medicines that are discarded by users of community pharmacy and evaluate the toxicity of the most disposed drugs.

METHODS

This was a translational study. A descriptive observational study was carried out for convenience of community pharmacy users using a standardized questionnaire. Subsequently, the lethal concentration 50 (LC₅₀) for medicine that is most frequently discarded was determined. After LC_50, the embryos (n = 144) were exposed to sublethal concentrations for most discarded drug at 24, 48, and 72 h. Mortality, heartbeat, and embryo deformities were used as parameters of toxicity.

RESULTS

Most respondents (96%) had a "home pharmacy." The primary forms of disposal were in the common household waste, kitchen sink, and/or bathroom. The medicines that were most incorrectly discarded by the interviewees were nimesulide (17.1%), dipyrone (10.7%), and paracetamol (5.2%). LC₅₀ of nimesulide was calculated (0.92 μgmL^-1). The toxicological test revealed that embryos exposed to nimesulide showed several abnormalities, such as defects in the spinal cord, tail, yolk sac, as well as pericardial edema. Furthermore, the heartbeat decreased by 30% at a concentration of 0.4 μgmL^-1 as compared with control group. The yolk sac and pericardial areas increased to >100% in all treatment groups when compared with the control group.

CONCLUSION

Respondents disposed medicines in an inappropriate manner primarily in household waste and in the toilet. Nimesulide was the most discarded drug according to study population. Moreover, teratogenic effects such as spinal cord defects, decreasing heartbeats, and increasing pericardial and yolk sac area in embryos were observed after exposure to nimesulide. These results show that nimesulide may promote risk to aquatic organisms and to human health if it is discarded in an unsafe manner.

Fate of Emerging Contaminants in High-Rate Activated Sludge Systems

High-rate activated sludge (HRAS) systems are designed to shift the energy-intensive processes to energy-saving and sustainable technologies for wastewater treatment. The high food-to-microorganism (F/M) ratios and low solid retention times (SRTs) and hydraulic retention times (HRTs) applied in HRAS systems result in the maximization of organic matter diversion to the sludge which can produce large amounts of biogas during anaerobic digestion, thus moving toward energy-neutral (or positive) treatment processes. However, in addition to the energy optimization, the removal of emerging contaminants (ECs) is the new challenge in wastewater treatment. In the context of this study, the removal efficiencies and the fates of selected ECs (three endocrine disruptors (endocrine disrupting chemicals (EDCs))—nonylphenol, bisphenol A and triclosan, and four pharmaceuticals (PhACs)—ibuprofen, naproxen, diclofenac and ketoprofen) in HRAS systems have been studied. According to the results, EDCs occurred in raw wastewater and secondary sludge at higher concentrations compared to PhACs. In HRAS operating schemes, all compounds were poorly (<40%) to moderately (<60%) removed. Regarding removal mechanisms, biotransformation was found to be the dominant process for PhACs, while for EDCs sorption onto sludge is the most significant removal mechanism affecting their fates and their presence in excess sludge.

Novel organ-specific effects of Ketoprofen and its enantiomer, dexketoprofen on toxicological response transcripts and their functional products in salmon

Racemic ketoprofen (RS-KP) and its enantiomer, dexketoprofen (S(+)-KP) are widely used non-steroidal anti-inflammatory drugs (NSAIDs), and commonly detected in the aquatic environment. The present study has evaluated the toxicological effects of RS-KP and S(+)-KP on biotransformation and oxidative stress responses in gills and liver of Atlantic salmon. Fish were exposed for 10 days using different concentrations of RS-KP (1, 10 and 100 μg/L) and S(+)-KP (0.5, 5 and 50 μg/L). Biotransformation and oxidative stress responses were analysed at both transcript and functional levels. In the gills, significant inhibitory effect at transcriptional and enzymatic levels were observed for biotransformation and oxidative stress responses. On the contrary, biotransformation responses were significantly increased at transcriptional and translational levels in the liver, while the associated enzymatic activities did not parallel this trend and were inhibited and further demonstrated by principal component analysis (PCA). Our findings showed that both compounds produced comparable toxicological effects, by producing organ-specific effect differences. RS-KP and S(+)-KP did not bioaccumulate in fish muscle, either due to rapid metabolism or excretion as a result of their hydrophobic properties. Interestingly, the inhibitory effects observed in the gills suggest that these drugs may not undergo first pass metabolism, that might result to downstream differences in toxicological outcomes.

Single and combined effects of carbamazepine and copper on nervous and antioxidant systems of zebrafish (Danio rerio)

Various pollutants co-exist in the aquatic environment such as carbamazepine (CBZ) and copper (Cu), which can cause complex effects on inhabiting organisms. The toxic impacts of the single substance have been studied extensively. However, the studies about their combined adverse impacts are not enough. In the present study, zebrafish were exposed to environmental relevant concentrations of CBZ (1, 10, and 100 μg/L), Cu (0.5, 5, and 10 μg/L) and the mixtures (1 μg/L CBZ + 0.5 μg/L Cu, 10 μg/L CBZ + 5 μg/L Cu, 100 μg/L CBZ + 10 μg/L Cu) for 45 days, the effects on nervous and antioxidant systems of zebrafish were investigated. The results demonstrated that, in comparison with single exposure group, the combined presence of CBZ and Cu exacerbated the effect of antioxidant system (the ability of inhibition of hydroxyl radicals (IHR), superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST)) but not nervous system (Acetylcholinesterase [AChE]). The qPCR results supported the changes of corresponding enzymes activities. Hepatic histopathological analysis verified the results of biomarkers. Our work illustrated that the toxicity of mixed pollutants is very complicated, which cannot simply be inferred from the toxicity of single pollutant, and calls for more co-exposure experiments to better understanding of the co-effects of pollutants on aquatic organisms.

Evaluation of ketoprofen toxicity in two freshwater species: Effects on biochemical, physiological and population endpoints

Among the most used non-steroidal anti-inflammatory drugs (NSAIDs), ketoprofen (KTF) assumes an important position. Nevertheless, its ecotoxicological effects in non-target organisms are poorly characterized, despite its use and frequency of occurrence in aquatic matrices. Thus, the aim of this study was to evaluate the possible toxicological effects of KTF contamination, in two freshwater species, Lemna minor and Daphnia magna, by measuring biochemical, physiological and population parameters. To attain this objective, both species were exposed to KTF at the same concentrations (0, 0.24, 1.2, 6 and 30 μg/L). L. minor plants were exposed during 4 d to these levels of KTF, and the enzymatic activity (catalase (CAT), glutathione S-transferases (GSTs) and carbonic anhydrase (CA)), and pigments content (chlorophylls a, b and total and carotenoids) were analyzed to evaluate the toxicity of this drug. D. magna was acutely and chronically exposed to KTF, and enzymatic activities (CAT, GSTs and cyclooxygenase (COX)), the feeding rates, and reproduction traits were assessed. In L.minor, KTF provoked alterations in all enzyme activities, however, it was not capable of causing any alteration in any pigment levels. On the other hand, KTF also provoked alterations in all enzymatic activities in D. magna, but did not affect feeding rates and life-history parameters. In conclusion, exposure to KTF, provoked biochemical alterations in both species. However, these alterations were not reflected into deleterious effects on physiological and populational traits of L. minor and D. magna.

Effects of ketoprofen on rice seedlings: Insights from photosynthesis, antioxidative stress, gene expression patterns, and integrated biomarker response analysis

Pharmacologically active compounds found in reclaimed wastewater irrigation or animal manure fertilizers pose potential risks for agriculture. The mechanism underlying the effects of ketoprofen on rice (Oryza sativa L.) seedlings was investigated. The results showed that low concentrations (0.5 mg L^-1) of ketoprofen slightly stimulate growth of rice seedlings, while high concentrations can significantly inhibit growth by reducing biomass and causing damage to roots. Ketoprofen affects photosynthetic pigment content (Chla, Chlb, and carotenoids) and chlorophyll synthesis gene (HEMA, HEMG, CHLD, CHLG, CHLM, and CAO) expression. Fluorescence parameters such as minimum fluorescence (F₀), maximum fluorescence (F_m), variable fluorescence (F_v), potential photosynthetic capacity (F_v/F₀), maximum quantum efficiency of PSII photochemistry (F_v/F_m), electron transfer rate (ETR), and Y(II), Y(NPQ), Y(NO) values were affected, showing photosynthetic electron transfer was blocked. Active oxygen radical (O₂^•-and H₂O₂), malondialdehyde and proline content increased. Superoxide dismutase, catalase and ascorbate peroxidase activities, glutathione content and antioxidant-related gene (FSD1, MSD1, CSD1, CSD2, CAT1, CAT2, CAT3, APX1, APX2) expression were induced. Higher integrated biomarker response values of eight oxidative stress response indexes were obtained at higher ketoprofen concentrations. Ultrastructure observation showed that ketoprofen causes cell structure damage, chloroplast swelling, increase in starch granules, and reduction in organelles. This study provides some suggested toxicological mechanisms and biological response indicators in rice due to stress from pharmacologically active compounds.

Ketoprofen affects swimming behavior and impairs physiological endpoints of Daphnia magna

Ketoprofen (KET) is a nonsteroidal anti-inflammatory and analgesic drug commonly used in human and veterinary medicine. This compound is detected in aquatic reservoirs however, little is known about its influence on cladocerans. Therefore, the aim of our study was to determine the influence of KET at concentrations of 0.005 mg/L, 0.05 mg/L, 0.5 mg/L, 5 mg/L and 50 mg/L on behavioral (swimming speed, hopping frequency) and physiological endpoints (heart rate, thoracic limb activity, mandible movements) of Daphnia magna after 24 h and 48 h exposure. The study showed that swimming speed frequency was decreased after 24 h and 48 h at all the concentrations used in the experiment. Hopping frequency was also inhibited, however the lowest amount of the drug induced transient increase of the parameter after 24 h and its subsequent decrease to the control level after 48 h. Although after 24 h of the exposure physiological parameters: heart rate, thoracic limb activity and mandible movements showed slightly lower sensitivity to KET than the behavioral endpoints: were found to be inhibited after 48 h. The results revealed that both behavioral and physiological endpoints of daphnids responded to KET also at the environmental level, therefore in natural conditions this drug should be considered as a hazardous toxicant to crustaceans.

Nonsteroidal anti-inflammatory drugs (NSAIDs) cause male-biased sex differentiation in zebrafish

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used pharmaceuticals to treat pain, fever and inflammation. NSAIDs are also known to have many side effects including adverse effects on reproduction in both humans and animals. As NSAIDs usage is not regulated they are frequently detected at high concentrations in the environment. In order to understand the effect of NSAIDs on zebrafish sex differentiation, we used seven different NSAIDs which were either Cox-1 selective, Cox-1 biased, non-selective or COX-2 selective. We show that at higher concentration, NSAIDs are toxic to zebrafish embryo as they lead to mortality and hatching delay. Gene expression analysis following short term exposure of NSAIDs led to downregulation of female specific genes including zp2, vtg2 foxl2 and wnt4. Long term exposure of larvae to environmentally relevant concentrations of Cox-2 selective and non-selective NSAIDs resulted in male-biased sex ratio which confirmed the qRT-PCR analysis. However, the Cox-1 selective acetylsalicylic acid and the Cox-1 biased ketoprofen did not alter sex ratio. The observed male-biased sex ratio could also be due to induction of apoptosis process as the genes including p21 and casp8 were significantly upregulated following exposure to the Cox-2 selective and the non-selective NSAIDs. The present study indicates that NSAIDs alter sex differentiation in zebrafish, primarily through inhibition of Cox-2. This study clearly demonstrates that the use of NSAIDs and their release into the aquatic environment should be carefully monitored to avoid adverse effects to the aquatic organisms.

Polyvinyl chloride microplastics induce growth inhibition and oxidative stress in Cyprinus carpio var. larvae

The occurrence and accumulation of microplastics in wildlife and humans have become a serious global scale concern over the last decade. To evaluate the potential toxic effects of PVC (polyvinyl chloride) microplastics in freshwater fish larvae, we conducted chronic 30-day and 60-day dietary exposure using Cyprinus carpio var. larvae. We exposed the larvae to four treatments with different microplastic concentrations (10%, 20%, and 30%) using food rationed diets, in conjunction with a non-plastic control. The results indicated that microplastics significantly inhibited weight gain and growth under all PVC treatments, compared to the control group. SOD (superoxide dismutase) and CAT (catalase) activities were analyzed, and an inverse relationship between them was observed. The activities of GPx (glutathione peroxidase) initially ascended and then descended with increased PVC concentrations following 30 days of exposure. A dose dependent downtrend was observed after 60 days of exposure. Malondialdehyde (MDA) levels were significantly reduced upon exposure to different concentrations of microplastics in various tissues. Altered antioxidant-related gene expression was observed in the livers of larvae exposed to the PVC microplastics. The transcription of CYP1A and GSTa initially increased, and then decreased under higher microplastics concentrations following 30 days of exposure. Furthermore, histological studies revealed cytoplasmic vacuolation in the liver under exposure to 20% and 30% microplastics. This investigation provided basic toxicological data toward elucidating and quantifying the impacts of PVC microplastics on freshwater organisms.

Photosynthetic toxicity of non-steroidal anti-inflammatory drugs (NSAIDs) on green algae Scenedesmus obliquus

The widespread use of pharmaceuticals and personal care products (PPCPs) has raised serious concerns regarding their potential ecotoxicological effects. We examined the photosynthetic toxicity of four non-steroidal anti-inflammatory drugs (NSAIDs), i.e. ibuprofen (rac-IBU and S-(+)-IBU), aspirin (ASA) and ketoprofen (KEP) on the green alga Scenedesmus obliquus. Our results showed that NSAIDs exerted inhibitory effects on algal growth; the IC_50-24h of S-(+)-IBU, rac-IBU, ASA, and KEP was 123.29, 107.91, 103.05, and 4.03 mg/L, respectively. KEP was the most toxic, ASA was slightly more toxic than rac-IBU, and S-(+)-IBU was the least toxic. NSAIDs adversely affected the cellular ultrastructure, as evident from plasmolysis, chloroplast deformation and disintegration. NSAID treatments decreased the chlorophyll and carotenoid content, and chlorophyll fluorescence parameters such as minimum fluorescence yield (F₀), maximum fluorescence yield (F_m), maximum photochemical quantum yield (F_v/F_m), PSII (photosystem II) effective quantum yield [Y(II)], photosynthetic electron transfer rate (ETR), and the photochemical quenching (qP), were also adversely affected. Algal photosynthetic and respiratory rates decreased following NSAID treatments, and the expression of genes involved in photosynthetic electron transport (psaA, psaB, psbB, psbD, and rbcL) was down-regulated. Furthermore, the functioning of the photosynthetic electron transport chain from PSI (photosystem I) to PSII, carbon assimilation, and photorespiration were affected. Our results suggest that NSAIDs can exert considerable toxic effects on the photosynthetic system of S. obliquus. These results provide a basis for evaluating the environmental safety of NSAIDs.

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.

Monobutyl phthalate (MBP) can dysregulate the antioxidant system and induce apoptosis of zebrafish liver

In this paper, the acute toxicity of monobutyl phthalate (MBP), the main hydrolysis product of dibutyl phthalate, on adult zebrafish liver antioxidant system was studied. Compared the toxicity effect of MBP and DBP by histopathology and apoptosis experiments, we speculated that the toxic effects of DBP on animals may be caused by its metabolite MBP. The results indicated that the antioxidant Nrf2-Keap1 pathway was insufficient to resist MBP-induced hepatotoxicity and led to an imbalance of membrane ion homeostasis and liver damage. Decreased cell viability, significant tissue lesions and early hepatocyte apoptosis were observed in the zebrafish liver in MBP exposure at high concentration (10 mg/L). The activities of antioxidant enzymes and ATPases in zebrafish liver were inhibited with increased malondialdehyde (MDA) content and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities. Integrated biomarker response (IBR) calculation results indicated that MBP mainly inhibited catalase (CAT) activity. Simultaneously, the expression of antioxidant-related genes (SOD, CAT, GPx, Nrf2, HO-1) was down-regulated, while apoptosis-related genes (p53, bax, cas3) were significantly up-regulated.

Tamoxifen-induced hepatotoxicity via lipid accumulation and inflammation in zebrafish

Tamoxifen is a clinical drug for estrogen receptor (ER)-positive breast cancer. Recently, it has been detected in aquatic environment. The residual drugs will produce certain biological activity and create a risk to aquatic organism when they enter the water environment. Therefore, it has great significance to study the ecotoxicity of tamoxifen. In the study, we used zebrafish as a model of aquatic to investigate the ecotoxic mechanism of tamoxifen to aquatic. We found that tamoxifen induced liver lipid accumulation in zebrafish, which showed a significant hepatotoxicity with smaller liver area and bigger yolk area. Though biochemical and pathologic measurement, tamoxifen treated group showed higher transaminase and lipid content. The elevated liver lipid synthesis might due to the increase of lipid metabolism related gene Srebf1, Srebf2 and Fasn. Moreover, inflammatory cytokine Tnf-α, Il-1β And Il-6 were increased. This result confirmed the toxicity of tamoxifen to aquatic, suggested liver injury was the main characteristic of its ecotoxicity. This study indicated it is important to avoid tamoxifen discharging into the aquatic ecology and provided a theoretical basis of prevention tamoxifen-induced ecotoxicity to aquatic.

Evaluation of single and combined effects of cadmium and micro-plastic particles on biochemical and immunological parameters of common carp (Cyprinus carpio)

The growing accumulation of microplastics (MPs) in aquatic environments is a global concern. MPs are capable to interact with other environmental contaminants, including heavy metals, altering their toxicity. The aim of the study was to investigate the sub-lethal effects of cadmium chloride (Cd) alone and in combination with MPs on common carp (Cyprinus carpio). Multi-biomarkers, including plasma biochemical parameters and intrinsic immunological factors, were measured after 30 days of exposure. Exposure to Cd or NPs reduced the plasma activities of acetylcholinesterase (AChE) and gamma-glutamyl-transferase (GGT) and increased aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) and alkaline phosphatase (ALP). Exposure to both compounds enhanced the observed effects except for AST activity and ALP at the highest concentrations, whereas evidenced an antagonistic interaction in ALT. Plasma total protein, albumin, and globulin levels were decreased, and the levels of glucose, triglyceride, and cholesterol levels increased mainly in the Cd groups with no additional effects derived from the co-exposure to both stressors. Lysozyme and alternative complement (ACH50) activities and the levels of total immunoglobulins, and complement C3 and C4 in fish exposed to Cd and MPs were lower than those in the control group and this decrease was more significant by the mixture of both compounds. These findings showed that the exposure to Cd or MPs alone is toxic to fish altering the biochemical and immunological parameters. Moreover, these alterations are even greater when the Cd and the MPS are combined suggesting synergistic effects in increasing Cd toxicity and vice versa.

Evaluation of the ameliorative effects of Phyllanthus niruri on the deleterious insecticide imidacloprid in the vital organs of chicken embryos

Background

Insecticides are widely used in agriculture to curb the loss caused by insects. These insecticides are incorporated into the food chain and accumulate in the human body, as well disturb the various metabolic pathways. Imidacloprid is an insect neurotoxin commonly used in agriculture to control the insect pests. P. niruri is a traditional medicinal shrub widely used as an anti-inflammatory, antipyretic, and anti-lethality agent.

Objective

The present study is designed to evaluate the ameliorative effects of Phyllanthus niruri (Bhumi amla) on the deleterious Insecticide imidacloprid in the vital organs of Chicken embryos.

Materials and methods

The embryonated chicken eggs were divided into the four groups (one control and three treated groups); the chorioallantoic membranes of control received 200 μl phosphate buffer saline, whereas group I and group II received 100 μg imidacloprid and 200 μl aqueous extract of P. niruri (PNE) respectively. Group III received both 100 μg imidacloprid and 200 μl PNE. The serum was collected on the 18th day its development; which was subjected to the biochemical analysis based on colorimetric assay in semi-automated biochemical analyzer using commercial kits.

Results

We observed significant in ovo effects of imidacloprid on chicken embryos; the values of aspartate aminotransferase (AST), alanine aminotransferase (ALT), were increased in imidacloprid treated group I; histopathology also revealed damage to the liver (necrotic areas and dilated blood sinusoids). Alkaline phosphatase (ALP), amylase, cholesterol, triglycerides protein and albumin levels were also altered significantly (p < 0.05).

Conclusion

The serum biochemicals were returned back to the nearly normal levels. PNE has ameliorated and overcome the effects of imidacloprid reasonably with the subsequent treatment among group III. Hence, P. niruri may be used to minimize the effects of an accidental exposure of imidacloprid.

Histological, biochemical and transcriptomic analyses reveal liver damage in zebrafish (Danio rerio) exposed to phenanthrene

Phenanthrene (PHE) is a common polycyclic aromatic hydrocarbon (PAH) in aquatic environments, and this contaminant can cause adverse effects on teleostean performance. In this study, we exposed the model freshwater fish (zebrafish; Danio rerio) to 300 μg/L PHE for 15 days. Histological analysis demonstrated that liver morphology deteriorated in PHE-exposed zebrafish, and cellular damage in the liver increased. Biological analysis revealed that exposure to PHE elicited significant changes in glutathione S-transferases (GST) and superoxide dismutase (SOD) activities. 476 differentially expressed genes (DEGs) were identified in liver between control and PHE treated groups through the transcriptomic analysis. Gene Ontology enrichment analysis (GO) suggested that PHE exposure induced changes in the expression of genes associated with "lipid transporter activity", "catalytic activity", "metal ion binding", "lipid transport" and "transmembrane transport". Furthermore, the "vitamin digestion and absorption" and "fat digestion and absorption" pathways enriched in Kyoto Encyclopedia of Genes and Genomes analysis (KEGG). Additionally, five candidate biomarkers associated with the PHE response in zebrafish were identified. In conclusion, our results elucidate the physiological and molecular responses to PHE exposure in the liver of zebrafish, and provide a framework for further studies of the mechanisms underlying the toxic effects of polycyclic aromatic hydrocarbons (PAHs) on aquatic organisms.

Biological response and developmental toxicity of zebrafish embryo and larvae exposed to multi-walled carbon nanotubes with different dimension

The development and use of nanomaterials are increasing significantly. Among nanomaterials, carbon nanotubes are of particular interest due to its distinctive physicochemical properties. This material composed of sheets of graphite has very high thermal conductivity, metallic-type electrical conductivity, stiffness, toughness and unique ability to bond to itself in an extended network with extraordinary strength. Its application in the industry is continuously growing, which could lead to the accumulation in the environment and a consequent impact on both humans and ecosystems. Considering that environmental systems are dynamic, it is difficult to predict the risks associated with the release of nanomaterials to the environment. Bioindicators are useful tools as primary signals of environmental risk, and their responses reveal the organism and ecosystem health.

In the present study, we evaluated the impact of multi-walled carbon nanotubes with different dimensions and agglomeration pattern on zebrafish embryo and larvae; mainly, studies were focused on physiological and behavioral responses. In embryos, measurements were hatching rate, morphology changes, and viability. In larvae, locomotor activity, heart rate, innate inflammatory response, general and tissue-specific morphology were measured. MWCNT-S (short, wide and mostly dispersed) caused depression of the locomotor activity of larvae, indicating an alteration of the central nervous system, and depression of neutrophil migration activity. MWCNT-L (long, thin and agglomerated) caused malformations during larval development, a decrease of neutrophil migration and alteration of cardiac rhythm. Results obtained for both carbon nanotubes were different, highlighting the importance of dimensions of the same nanomaterial, and also the kind of agglomeration and shape adopted, for the toxic effects on organisms.

Dietary diisononylphthalate contamination induces hepatic stress: a multidisciplinary investigation in gilthead seabream (Sparus aurata) liver

In this study, adult gilthead seabream (Sparus aurata) were exposed for 21 days to Di-iso-nonylphthalte (DiNP at 15 and 1500 μg kg^-1 bw day^-1) via the diet. This plastic additive has been recently introduced to replace the di-(2-ethylhexyl)phthalate, the toxicity of which has been demonstrated conclusively both in vivo and in vitro trials. An analysis of a set of biomarkers involved in stress and immune response provides evidence of hepatic toxicity by DiNP in the present study. Both hsp70 and gr mRNA levels were upregulated significantly by DiNP, while plasma cortisol increased only in fish fed with the lowest DiNP dose. The oxidative stress markers g6pdh, glut red, gpx1 and CAT were upregulated by DiNP; gst mRNA was induced by the high dose and gck mRNA was downregulated significantly by the low dose. The mRNA levels of genes involved in the immune response, such as pla2, 5-lox, tnfa and cox2, were upregulated significantly only by the high dose of DiNP, while il1 mRNA increases in both doses. These molecular evidences were complemented with features obtained by Fourier Transform Infrared Imaging (FTIRI) analysis regarding the hepatic distribution of the main biological macromolecules. The FTIRI analysis showed an alteration of biochemical composition in DiNP samples. In particular, the low dose of DiNP induced an increase of saturated and unsaturated lipids and phosphorylated proteins, and a decrease of glycogen levels. The levels of caspase did not change significantly in the study, suggesting that DiNP does not activate apoptosis. Finally, the results also suggested the onset of hepatic oxidative stress and the activation of immune response, adding new knowledge to the already described hepatic DiNP toxicity.

Sub-lethal toxicity of chlorpyrifos alone and in combination with polyethylene glycol to common carp (Cyprinus carpio)

In the present study, sub-lethal effects of chlorpyrifos, alone (25 and 50 μg L^-1) and in combination with Polyethylene glycol (5 and 10 mg L^-1), on common carp were investigated. Exposure to chlorpyrifos caused significant changes in all blood biochemical parameters compared to control groups. Total protein, triglyceride, glucose levels, as well as lactate dehydrogenase (LDH), gamma-glutamyl transferase (GGT), and creatine phosphokinase (CPK) activities in plasma changed after exposure to 10 mg L^-1 polyethylene glycol (PEG), while fish exposed to PEG did not show any significant difference in aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and acetylcholinesterase (AChE) activities and albumin and globulins levels. Exposure to a combination of chlorpyrifos and PEG caused a significant change in AST, GGT, CPK, LDH and AChE activity, total protein and glucose level. The influence of chlorpyrifos and PEG combination on ALP, cholesterol, triglyceride, albumin, and globulin depends on the concentration of the insecticide and PEG. With a reduction in chlorpyrifos concentration, PEG can maintain ALP activity and albumin at a normal level. Although fish exposure to chlorpyrifos, alone or in combination with polyethylene glycol, significantly increased malondialdehyde (MDA) and catalase (CAT) level, it decreased total antioxidant level (TAN). Exposure to just polyethylene glycol had no impact on CAT activity, TAN and MDA level. According to the results, PEG can have an antagonistic effect on chlorpyrifos toxicity, depending on these two materials concentration. However, chlorpyrifos increased the toxicity of PEG.