Evaluation of acute and sublethal effects of chloroquine (C18H26CIN3) on certain enzymological and histopathological biomarker responses of a freshwater fish Cyprinus carpio

Effects of co-treatment with nano/microplastics and hydroxychloroquine on early development stages of Salmo trutta

As a potential remedy for COVID-19 treatment, hydroxychloroquine (HCQ) attracted considerable scholarly attention early in the pandemic. However, the ecological consequences of HCQ are not well understood, especially regarding their interactions with plastic waste such as nano-and microplastics (PS). This study aimed to investigate colloidal stability, bioaccumulation, and acute toxicity of carboxylate-modified polystyrene-based PS and HCQ, both alone and in combination, to Salmo trutta embryos and larvae. Spectroscopic properties of PS were found to change over time and to be affected by the presence of HCQ in the incubation water of organisms. Confocal microscopy showed that PS and HCQ, both alone and in combination, caused damage to the chorion of the exposed fish embryos. Particles of PS were detected in external tissues of larvae. The impact of the tested substances on fish was found to be dependent on the PS particle size, exposure duration, and the life stage of fish.

In-feed oxolinic acid induces oxidative stress and histopathological alterations in Nile tilapia Oreochromis niloticus

The aquaculture industry urgently requires effective bacterial disease management strategies, necessitating better regulation of antibiotic application. This study investigated the effects of oral oxolinic acid (OA) administration on Oreochromis niloticus at the recommended dose of 12 mg (1 ×) and overdose of 36 mg (3 ×)/kg biomass/day for 7 consecutive days in terms of growth, oxidative stress, residue accretion and histopathology relative to the control. The 1 × and 3 × groups experienced dose-dependent mortalities (3.33-8.33 %). The OA residues peaked in the liver and kidney tissues with dosing and declined upon discontinuation. The residues persisted in the kidney even on day 35 post-dosing. Elevated malondialdehyde and total nitric oxide levels signified oxidative stress and correlated with the tissue level changes in various organs. Histologically, glycogen-type vacuolation and cellular hypertrophy were observed in the liver. The kidney had hydropic swelling, renal epithelium degradation, nephrocalcinosis, vacuolation, and necrosis. Splenic alterations were confined to necrosis and a slight increase in sinusoidal space. Intestinal tissues exhibited a depletion of absorptive vacuoles, epithelial layer degradation, mucinous degeneration, and necrosis. Gills displayed epithelial hyperplasia, thickening of secondary lamellae, and erosion. Nevertheless, the cohort administered the recommended dose exhibited recovery with OA discontinuation. However, none of the assessed parameters normalized in the overdosed group even after 35 days of dose suspension. The results indicated that O. niloticus can safely adapt to and tolerate the toxic effects of OA. As the recommended dose of OA elicited reversible bioresponses effectively in tilapia, it can be utilized in aquaculture with due caution following regulations.

Hydroxylamine-based cometabolism of ammonium-oxidizing bacteria: chloroquine biodegradation and associated nitrogen conversions

Despite the well-reported ability of ammonium-oxidizing bacteria (AOB) to cometabolize non-growth substrates, most relevant studies were substantiated with the ammonium oxidation activity as the driving force and didn't further explore/verify/distinguish the contribution of the hydroxylamine oxidation process of AOB. Therefore, using highly enriched AOB-dominated sludge, a series of dedicated batch tests were conducted in this work to investigate the hydroxylamine-based cometabolic degradation of chloroquine (CLQ), a widely applied drug with a significant environmental concern, and its associated impacts on the nitrogen conversions of AOB. The results indicated that the hydroxylamine oxidation process of AOB could trigger the degradation of CLQ which achieved 0.4-1.2 mg/L CLQ removal under the studied conditions, despite the potentially preferred utilization of CLQ degradation products towards mineralization by AOB over CLQ itself. CLQ and its degradation products wouldn't affect the hydroxylamine oxidation process or the associated N2O production through the hydroxylamine oxidation pathway of AOB. We hope this work will not only provide new perspectives for prospective research on the cometabolic capacity and features of AOB but also inspire the revisit of the literature-reported research on such an important topic.

High-dose hydroxychloroquine induces changes in low-frequency brain oscillations in electrocorticographic records not concurrent with alterations in cardiac, hepatic, and renal function in wistar rats

The toxicity of hydroxychloroquine (HCQ) can impact the function of vital organs, leading to ocular and cardiovascular damage. This study aims to evaluate the toxicity of HCQ through electrocorticographic evaluation and blood biochemical parameters in Wistar rats. The animals received a dose of HCQ of 350 mg/kg via gavage every 12 hours for periods of 24, 48, 72 and 96 hours, with each group consisting of n = 9. After treatment, the animals underwent surgery to implant electrodes in the motor cortex region and subsequently underwent bipolar electrocorticography. The electrodes for acquiring electrocardiographic recordings were fixed in the D II position and blood samples were analyzed for liver and kidney function. The results demonstrated that high doses of HCQ altered electrocorticographic features, decreased cardiac activity throughout treatment, and significantly elevated aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. However, assessment of renal function, as indicated by serum creatinine levels, revealed no significant changes. These results suggest that exposure to high doses of HCQ in rats may disrupt the structures and functions of vital organs.

Commercial dexamethasone degradation by heterogeneous sono/photo-Fenton process using iron zeolite catalyst by an electrodeposition method

Dexamethasone (DXM) was the first drug used to treat COVID-19, only a small part is metabolized and has been identified in wastewater and surface water, conventional treatments do not remove these compounds, therefore new technologies must be developed. A commercially injectable solution containing dexamethasone (DXM) was removed by heterogeneous sono/photo-Fenton (SPF) process using clinoptilolite zeolite (CZ) modified with Fe (CZ-Fe) by an electrodeposition method. The effect of initial concentration (1.2, 3, 5.5, 8, 9.7 mg/L), H2O2 dose (9.8, 15, 22.5, 30, 35.1 mg/L) and hydraulic retention time (HRT, 39.5, 60, 90, 120, 140 min) were evaluated through central composite design (CCD). The frequency of the ultrasound was 140 kHz. The optimal conditions were 5.5 mg/L DXM, 22.5 mg/L H2O2 and 140 min obtaining an 85.4% DXM by UV-Vis, 99% by high-performance liquid chromatography (HPLC) and 76% by chemical oxygen demand (COD) removal. The systems generated 12, 25, 40.5 and 45.5 mg/L of total oxidant at 20, 60, 100 and 140 kHz, respectively. In individual effects, UV radiation removed 23.6%, ultrasound 18.1% and H2O2 14% of DXM. In kinetic studies, the best fit was obtained for the Behnajady-Modirshahla-Ghanbery (BMG) model. SPF improved the mass transfer within the reaction media, the oxidation rate and the consumption of H2O2, and no sludge was generated. Finally, another oxidant formed during the process (H•, HO2•, O2-•) contributed to DXM removal.

Sub-chronic level FLX exposure and biomarker response in Labeo rohita

Selective serotonin reuptake inhibitors (SSRIs) are among the most widely prescribed psychotropic medications globally used to treat depression, anxiety disorders, and related mental health conditions. Among these, Fluoxetine (FLX), recognized by its brand name Prozac, is frequently used. SSRIs increase serotonin levels in the brain, inhibiting its reuptake to enhance mood and emotional stability. However, their widespread production, consumption, and eventual environmental release are raising concerns among aquatic toxicologists and environmental biologists due to their potential impact on ecosystems and human health. This study investigated the long-term (35-days) antioxidant responses in Labeo rohita fingerlings exposed to varying concentrations of FLX (1, 10, and 100 μg/L). Compared to control groups, the activity of superoxide dismutase (SOD) in the brain significantly decreased (P < 0.05) in FLX-treated fish, except at the highest (100 μg/L) concentration on the 35th day. Similarly, catalase (CAT) and glutathione S-transferase (GST) activity were significantly reduced (P < 0.05) across all treatments. Lipid peroxidation (LPO) levels were markedly elevated in FLX-treated fishes, signifying oxidative stress. Acetylcholinesterase activity in brain tissue decreased in FLX-treated groups. These findings provide critical baseline data for molecular toxicology, highlighting the potential effects of pharmaceutical pollutants on non-target aquatic organisms.

Effects of Difenoconazole on Tubifex tubifex: Antioxidant Activity, Insights from GUTS Predictions, and Multi-Biomarker Analysis

The increasing demand for agricultural products has led to a rise in pesticide use, resulting in the pollution of aquatic habitats and raising significant health concerns for both aquatic life and humans. Difenoconazole, a triazole fungicide, is becoming increasingly popular in agriculture, yet its effects on non-target organisms, such as annelids, are not well understood. This study aimed to investigate the toxicological effects of difenoconazole and assess its potential impact on toxicity biomarkers, using Tubifex tubifex as a model organism, to better understand the ecotoxicity of difenoconazole on freshwater annelids. The 96-h LC50 value of difenoconazole was determined to be 2.68 mg/L. Sublethal concentrations (10% and 20% of the 96-h LC50 value; 0.268 and 0.536 mg/L, respectively) caused significant changes in the activities of oxidative stress enzymes. A concentration- and time-dependent decrease in the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione transferase (GST) was observed compared to control organisms. Additionally, malondialdehyde (MDA) concentrations increased throughout the exposure period. An Integrated Biomarker Response (IBR) assessment was used to characterize and illustrate the impact of difenoconazole on T. tubifex. In conclusion, exposure to this fungicide appears to reduce the survival rate of T. tubifex at acute levels and disrupt its normal behavioral patterns. Moreover, it alters oxidative stress enzyme levels during sublethal exposure. Long-term exposure to the fungicide could potentially have population-level consequences, including a reduction in the number of individuals within a population.

Identification of extracellular polymeric substances layer barrier in chloroquine phosphate-disturbed anammox consortia and mechanism dissection on cytotoxic behavior by computational chemistry

The over-dosing use of chloroquine phosphate (CQ) poses severe threats to human beings and ecosystem due to the high persistence and biotoxicity. The discharge of CQ into wastewater would affect the biomass activity and process stability during the biological processes, e.g., anammox. However, the response mechanism of anammox consortia to CQ remain unknown. In this study, the accurate role of extracellular polymeric substances barrier in attenuating the negative effects of CQ, and the mechanism on cytotoxic behavior were dissected by molecular spectroscopy and computational chemistry. Low concentrations (≤6.0 mg/L) of CQ hardly affected the nitrogen removal performance due to the adaptive evolution of EPS barrier and anammox bacteria. Compact protein of EPS barrier can bind more CQ (0.24 mg) by hydrogen bond and van der Waals force, among which O-H and amide II region respond CQ binding preferentially. Importantly, EPS contributes to the microbiota reshape with selectively enriching Candidatus_Kuenenia for self-protection. Furthermore, the macroscopical cytotoxic behavior was dissected at a molecular level by CQ fate/distribution and computational chemistry, suggesting that the toxicity was ascribed to attack of CQ on functional proteins of anammox bacteria with atom N17 (f-=0.1209) and C2 (f+=0.1034) as the most active electrophilic and nucleophilic sites. This work would shed the light on the fate and risk of non-antibiotics in anammox process.

Prolonged exposure to mercuric chloride induces oxidative stress-mediated nephrotoxicity in freshwater food fish Channa punctatus

Mercury (Hg) is regarded as a serious hazard to aquatic life and is particularly prevalent in aquatic ecosystems. However, there is little evidence available regarding the toxicity of mercury chloride (HgCl2) in vital organs of fish. This study was conducted to assess the effects of HgCl2 (0.039 mg/L and 0.078 mg/L) on oxidative stress-mediated genotoxicity, poikilocytosis, apoptosis, and renal fibrosis after 15, 30, and 45 days of the exposure period. According to the findings, HgCl2 intoxication in fish resulted in a significantly (P < 0.05) elevated lipid peroxidation (LPO), protein carbonyls (PC), lactate dehydrogenase (LDH) activity levels in kidney tissues and significantly (P < 0.05) increased reactive oxygen species (ROS), poikilocytosis, DNA tail length, and the frequency of apoptotic cells (AC%) in blood cells. Kidney's ultra-structure and histopathology revealed its fibrosis, which was evident by mRNA expression of targeted genes KIM1, NOX4, TGFβ, and NFϏβ. Different indicators of oxidative stress, apoptosis, and genotoxicity were altered in a dose and time-dependent manner, according to a two-way ANOVA analysis. There was a considerable positive link between oxidative stress and kidney fibrosis in the fish Channa punctatus, and it is evident from regression correlation and PCA data analysis. The kidney's ultra-structure evaluation and histopathology both revealed a noticeable fibrosis state. Additionally, a significant (P < 0.05) downregulation in PPARδ reveals that fish body was unable to combat diseases such as kidney fibrosis induced by HgCl2. This study shed fresh light on the mechanisms underlying nephrotoxicity caused by HgCl2 exposure.

Blighia sapida Waste Biochar in Batch and Fixed-Bed Adsorption of Chloroquine Phosphate: Efficacy Validation Using Artificial Neural Networks

The present study investigated the potency of biochar prepared from Blighia sapida seedpods (BSSPs) in the uptake of chloroquine phosphate (CQP) from single-component batch and multicomponent fixed-bed adsorption systems. BSSPs presented a highly porous structure with a BET surface area of 1122.05 m2/g, to which adsorption efficiency correlated. The Dubinin-Radushkevich isotherm energy was obtained as 129.09 kJ/mol, confirming the chemisorption nature of the BSSP-CQP adsorption system. The efficiency of the artificial neural network (ANN) was evaluated using the lowest mean square error (MSE = 7.27) and highest correlation coefficient (R2 = 0.9910). A good agreement between the experimental results and the ANN-predicted data indicated the efficiency of the model. The percentage removal of 95.78% obtained for the column adsorption studies indicated the effectiveness of BSSPs in a multicomponent system. The mechanism of the interaction proceeded via hydrogen bonding and electrostatic attraction. This was confirmed by the high desorption efficiency (69.11%) with a HCl eluent. The degree of reversibility was found to be 2.95, indicating the reusability potential of BSSPs. BSSPs are therefore considered multilayered adsorbents with potential applications in pharmaceutical wastewater treatment.

Degradation of Chloroquine by Ammonia-Oxidizing Bacteria: Performance, Mechanisms, and Associated Impact on N2O Production

Since the mass production and extensive use of chloroquine (CLQ) would lead to its inevitable discharge, wastewater treatment plants (WWTPs) might play a key role in the management of CLQ. Despite the reported functional versatility of ammonia-oxidizing bacteria (AOB) that mediate the first step for biological nitrogen removal at WWTP (i.e., partial nitrification), their potential capability to degrade CLQ remains to be discovered. Therefore, with the enriched partial nitrification sludge, a series of dedicated batch tests were performed in this study to verify the performance and mechanisms of CLQ biodegradation under the ammonium conditions of mainstream wastewater. The results showed that AOB could degrade CLQ in the presence of ammonium oxidation activity, but the capability was limited by the amount of partial nitrification sludge (∼1.1 mg/L at a mixed liquor volatile suspended solids concentration of 200 mg/L). CLQ and its biodegradation products were found to have no significant effect on the ammonium oxidation activity of AOB while the latter would promote N2O production through the AOB denitrification pathway, especially at relatively low DO levels (≤0.5 mg-O2/L). This study provided valuable insights into a more comprehensive assessment of the fate of CLQ in the context of wastewater treatment.

A Box-Behnken design-based chemometric approach to optimize the sono-photodegradation of hydroxychloroquine in water media using the Fe(0)/S2O82-/UV system

The huge utilization of hydroxychloroquine in autoimmune infections led to an abnormal increment in its concentration in wastewater, which can pose a real risk to the environment, necessitating the development of a pretreatment technique. To do this, we are interested in researching how hydroxychloroquine degrades in contaminated water. The main goal of this investigation is to optimize the operating conditions for the sono-photodegradation of hydroxychloroquine in water using an ultrasound-assisted Fe(0)/S 2 O 8 2 - /UV system. To get adequate removal of HCQ, a chemometric method based on the Box-Behnken design was applied to optimize the influence of the empirical parameters selected, including Fe(0) dose,S 2 O 8 2 - concentration, pH, and initial HCQ concentration. The quadratic regression model representing the HCQ removal rate (η(%)) was evolved and validated by ANOVA. The optimal conditions as a result of the above-mentioned trade-off between the four input variables, with η(%) as the dependent output variable, were captured using RSM methodology and the composite desirability function approach. For HCQ full decomposition, the optimal values of the operating factors are as follows:S 2 O 8 2 - dose, 194.309 mg/L; Fe(0) quantity, 198.83 mg/L; pH = 2.017, and HCQ initial dose of 296.406 mg/L. Under these conditions, the HCQ removal rate, achieved after 60 min of reaction, attained 98.95%.

Toxicity assessment of perovskite nanocomposites: In vivo study

Perovskite solar cells display potential as a renewable energy source because of their high-power conversion efficiency. However, there is limited understanding regarding the potential impact of perovskite on human health and the ecosystem. In this study, two sets of male Wistar albino rats received 35 injections of perovskite composite at a dosage of 0.372 mg/kg body weight. The animals underwent thorough examinations, encompassing morphometric, hematological, biochemical, histological, and behavioral analyses. Liver, kidney, and testis biopsies were processed and examined histologically. Additionally, two groups of mice (perovskite-treated and control mice, each with n = 10) underwent three behavioral tests: the Elevated Zero Maze test, Marble Burying test, and Light-Dark Box test. Perovskite-treated rats displayed a significant increase in levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, triglycerides, cholesterol, creatinine, blood urea nitrogen, white blood cells, and platelets. However, total bilirubin levels decreased, with no significant alteration in albumin values. Furthermore, exposure to perovskite composite resulted in a slight decrease in lactate dehydrogenase and red blood cell count. Histopathological examination revealed hepatic hydropic degeneration, Kupffer cells hypertrophy and hyperplasia, and renal hydropic degeneration, while testicular tissues remained unaffected. Moreover, behavioral changes were observed in perovskite-treated mice, including depression, anxiety, and compulsive burying activity. These findings suggest that exposure to perovskite can lead to significant hematological and biochemical changes, as well as hepatorenal histopathological alterations and behavioral changes. Additionally, chronic exposure to perovskite materials may induce structural and functional alterations in vital organs.

Safety, tolerability and biological responses of Oreochromis niloticus juveniles upon oral oxolinic acid administration

In aquaculture, oxolinic acid (OA) is used as a second-line treatment at 12 mg/kg biomass/day for seven consecutive days. The present study evaluated the biosafety of 21 days of dietary administration of OA at 0, 12, 36, 60 and 120 mg by assessing the growth, biochemical, erythrocytic morphological and histopathological alterations and residue levels in Oreochromis niloticus. A significant dose-dependent reduction in feed intake and biomass and an increase in mortalities and erythrocytic cellular and nuclear changes were recorded. Significant elevations in plasma glucose, creatinine, alkaline phosphatase, alanine transaminase and aspartate transaminase and a decline in calcium and chloride levels were documented. The kidney, liver and intestine histoarchitecture showed mild to marked alterations. The edible tissue OA residues peaked on day 21 and decreased upon cessation of administration in all the dosing groups. The residue levels in the muscle of the recommended dose group were well within the maximum residue limit set by the European Medicines Evaluation Agency. Although the current study hinted at the safety and tolerability of OA even during long-term usage in O. niloticus in Indian conditions, care must be exercised for its aquacultural application because of its listing as a critically important medicine for humans.

The physiological response of the clam Ruditapes philippinarum and scallop Chlamys farreri to varied concentrations of microplastics exposure

Microplastics (MPs) pollution's impact on the marine ecosystem is widely recognized. This study compared the effects of polyethylene (PE) and polyethylene terephthalate (PET) on two bivalve species, Ruditapes philippinarum (clam) and Chlamys farreri (scallop), at two particle concentrations (10 and 1000 μg/L). MPs were found in the digestive glands and gills of both species. Although clearance rates showed no significant changes, exposure to different MPs caused oxidative stress, energy disruption, and lipid metabolism disorders in both clam and scallop. Histopathological damage was observed in gills and digestive glands. IBR values indicated increasing toxicity with concentration, with PET being more toxic than PE. WOE model suggested increasing hazard with concentration, highlighting higher PET toxicity on clam digestive glands. In contrast, PE hazard increased in gills, showing different species responses. R. philippinarum exhibited higher sensitivity to MPs than C. farreri, providing insights for assessing ecological risk under realistic conditions and stress conditions.

Chronic exposure to tris (2-chloroethyl) phosphate (TCEP) induces brain structural and functional changes in zebrafish (Danio rerio): A comparative study on the environmental and LC50 concentrations of TCEP

Tris (2-chloroethyl) phosphate (TCEP) is a crucial organophosphorus flame retardant widely used in many industrial and commercial products. Available reports reported that TCEP could cause various toxicological effects on organisms, including humans. Unfortunately, toxicity data for TCEP (particularly on neurotoxicity) on aquatic organisms are lacking. In the present study, Danio rerio were exposed to different concentrations of TCEP for 42 days (chronic exposure), and oxidative stress, neurotoxicity, sodium, potassium-adenosine triphosphatase (Na+, K+-ATPase) activity, and histopathological changes were evaluated in the brain. The results showed that TCEP (100 and 1500 µg L-1) induced oxidative stress and significantly decreased the activities of antioxidant enzymes (SOD, CAT and GR) in the brain tissue of zebrafish. In contrast, the lipid peroxidation (LPO) level was increased compared to the control group. Exposure to TCEP inhibited the acetylcholinesterase (AChE) and Na+,K+-ATPase activities in the brain tissue. Brain histopathology after 42 days of exposure to TCEP showed cytoplasmic vacuolation, inflammatory cell infiltration, degenerated neurons, degenerated purkinje cells and binucleate. Furthermore, TCEP exposure leads to significant changes in dopamine and 5-HT levels in the brain of zebrafish. The data in the present study suggest that high concentrations of TCEP might affect the fish by altering oxidative balance and inducing marked pathological changes in the brain of zebrafish. These findings indicate that chronic exposure to TCEP may cause a neurotoxic effect in zebrafish.

Modulatory role ulexit against thiamethoxam-induced hematotoxicity/hepatotoxicity oxidative stress and immunotoxicity in Oncorhynchusmykiss

Contamination of the aquatic environment with different insecticides is a major concern in the aquatic ecosystem today. For this reason, in the designed study, Thiamethoxam (TMX) for which there is limited information on its negative effects on Oncorhynchus mykiss was investigated, its effects on hematotoxicity, oxidative status, cytotoxicity, DNA damage and apoptotic status indicators in blood/liver tissue. However, the antitoxic potential of ulexite (UX) supplementation in the elimination of TMX-mediated toxicity has been determined. LC50-96h value determined for TMX 0.73 mg/L has been determined. As a result of hematology profile, TMX application, RBC, Hgb and Hct values showed a temporal decrease compared to the control group, while increases were determined in MCV, MCH and MCHC values. It was determined that the inhibition/induction of hematological parameters was slowed down by adding UX to the medium. During the trial (48th and 96th hours), it was noted that TMX induced cortisol level, while UX supplementation slowed this induction at 48th hour. Antioxidant enzyme activities were significantly inhibited by TMX application, and MDA and MPO values increased as a result of the stimulation of ROS. It was determined that UX added to the medium showed activity in favor of antioxidants and tried to inhibit MDA and MPO levels. When Nrf-2, one of the inflammation parameters, was compared with the administration and control groups, it was determined that it inhibited depending on time, TNF-α, IL-6, DNA damage and apoptosis were induced, and UX suppressed this situation. The results obtained were evaluated as statistically meaningful. Briefly, it was determined that TMX induced oxidative damage in all tissues at 48th - 96th hours, whereas UX mitigated this situation. The results provide possible in vivo evidence that UX supplements can reduce TMX-mediated oxidative stress and tissues damage in O. mykiss blood and liver tissues.

Ecotoxicity of commonly used oilfield-based emulsifiers on Guinean Tilapia (Tilapia guineensis) using histopathology and behavioral alterations as protocol

This study examined the histological aberrations in the gill and liver tissues and behavioural changes of Tilapia guineensis fingerlings exposed to lethal concentrations of used Oilfield-based emulsifiers for 96 h. Various concentrations of the surfactants were tested, ranging from 0.0 to 15.0 ml/L. The behaviour of the fish was observed throughout the experiment, and the results showed that increasing concentrations of the surfactants led to progressively abnormal behaviour, including hyperventilation and altered opercular beat frequency. These behavioural changes indicated respiratory distress and neurotoxic effects. Histological analysis revealed structural aberrations in the gill and liver tissues, with higher concentrations causing more severe damage, such as lesions, necrosis, inflammation, and cellular degeneration. This implies that surfactants released even at low concentrations are capable of inducing changes in the tissues of aquatic organisms. These findings highlight the toxic effects of the surfactants on fish health and provide biomarkers of toxicity. Future research should focus on understanding the specific mechanisms and long-term consequences of surfactant toxicity on fish genetic composition, populations, and ecosystems to implement effective conservation measures.

Prevalence of pharmaceuticals and personal care products, microplastics and co-infecting microbes in the post-COVID-19 era and its implications on antimicrobial resistance and potential endocrine disruptive effects

The COVID-19 (coronavirus disease 2019) pandemic's steady condition coupled with predominance of emerging contaminants in the environment and its synergistic implications in recent times has stoked interest in combating medical emergencies in this dynamic environment. In this context, high concentrations of pharmaceutical and personal care products (PPCPs), microplastics (MPs), antimicrobial resistance (AMR), and soaring coinfecting microbes, tied with potential endocrine disruptive (ED) are critical environmental concerns that requires a detailed documentation and analysis. During the pandemic, the identification, enumeration, and assessment of potential hazards of PPCPs and MPs and (used as anti-COVID-19 agents/applications) in aquatic habitats have been attempted globally. Albeit receding threats in the magnitude of COVID-19 infections, both these pollutants have still posed serious consequences to aquatic ecosystems and the very health and hygiene of the population in the vicinity. The surge in the contaminants post-COVID also renders them to be potent vectors to harbor and amplify AMR. Pertinently, the present work attempts to critically review such instances to understand the underlying mechanism, interactions swaying the current health of our environment during this post-COVID-19 era. During this juncture, although prevention of diseases, patient care, and self-hygiene have taken precedence, nevertheless antimicrobial stewardship (AMS) efforts have been overlooked. Unnecessary usage of PPCPs and plastics during the pandemic has resulted in increased emerging contaminants (i.e., active pharmaceutical ingredients and MPs) in various environmental matrices. It was also noticed that among COVID-19 patients, while the bacterial co-infection prevalence was 0.2-51%, the fungi, viral, protozoan and helminth were 0.3-49, 1-22, 2-15, 0.4-15% respectively, rendering them resistant to residual PPCPs. There are inevitable chances of ED effects from PPCPs and MPs applied previously, that could pose far-reaching health concerns. Furthermore, clinical and other experimental evidence for many newer compounds is very scarce and demands further research. Pro-active measures targeting effective waste management, evolved environmental policies aiding strict regulatory measures, and scientific research would be crucial in minimizing the impact and creating better preparedness towards such events among the masses fostering sustainability.

Combined effects of dietary carbohydrate levels and ammonia stress on growth, antioxidant capacity and glucose metabolism in juvenile oriental river prawn (Macrobrachium nipponense)

Ammonia is a common environmental stress factor that constrains aquaculture industry development. This study evaluated the effect of carbohydrate levels and ammonia stress in oriental river prawn (Macrobrachium nipponense). The experiment had six treatments containing two water ammonia levels (0 and 5 mg/L) and three dietary carbohydrate levels (low carbohydrate diet (LCD, 10%), medium carbohydrate diet [MCD, 20%], and high carbohydrate diet [HCD, 30%]), and lasted six weeks. The results showed that the prawns fed on MCD had higher weight gain than those fed on LCD and HCD during ammonia stress. Moreover, the prawns fed on MCD had significantly lower acid phosphatase and alkaline phosphatase activities during ammonia stress. Feeding the prawns on the MCD increased B cells in the hepatopancreas during ammonia stress. Interestingly, the prawns fed on MCD had significantly lower superoxide dismutase activity compared to LCD and HCD during ammonia stress. Moreover, the prawns fed on MCD had significantly lower pyruvate kinase activity and pyruvate and lactic acid contents, while those fed on LCD had significantly higher succinic dehydrogenase, 6-phosphogluconic dehydrogenase, and phosphoenol pyruvate carboxykinase activities during ammonia stress. The prawns fed on the MCD increased significantly glutaminase activity and decreased the ammonia content in the serum during ammonia exposure. In addition, feeding the prawns on MCD decreased significantly the expression of apoptosis and inflammation-related genes. Taken together, the MCD supplied energy required to counteract ammonia stress, which increased growth, improved antioxidant capacity, facilitated ammonia excretion, and alleviated inflammation and apoptosis of the oriental river prawn.

Environmentally relevant concentrations of tris (2-chloroethyl) phosphate (TCEP) induce hepatotoxicity in zebrafish (Danio rerio): a whole life-cycle assessment

Tris (2-chloroethyl) phosphate (TCEP), a typical organophosphate flame retardant, is of increasingly great concern considering their ubiquitous presence in aquatic environments and potential ecotoxicity. The present work was aimed to investigate the potential growth inhibition and hepatic stress induced by whole life-cycle exposure to TCEP (0.8, 4, 20 and 100 μg/L) in zebrafish. The results revealed that the body length, body mass and hepatic-somatic index (HSI) of zebrafish were significantly declined after exposure to TCEP for 120 days. GPx activity and GSH content were increased in the liver of zebrafish treated with low concentrations (0.8 and 4 μg/L) of TCEP, while exposure to high concentrations (20 and 100 μg/L) of TCEP reduced antioxidative capacity and elevated lipid peroxidation (LPO) levels. Gene transcription analysis demonstrated that the mRNA levels of nrf2 were altered in a similar manner to the transcription of the downstream genes nqo1 and hmox1, suggesting that Nrf2-Keap1 pathway mediated TCEP-induced oxidative stress in zebrafish liver. In addition, TCEP exposure might alleviate inflammatory response through down-regulating transcription of inflammatory cytokines (il-1β, il-6 and inos), and induce apoptosis via activating the p53-Bax pathway. Moreover, whole life-cycle exposure to TCEP caused a series of histopathological anomalies in zebrafish liver. Overall, our results revealed that lifetime exposure to environmentally relevant concentrations of TCEP could result in growth retardation and induce significant hepatotoxicity in zebrafish.

Life-cycle exposure to tris (2-chloroethyl) phosphate (TCEP) causes alterations in antioxidative status, ion regulation and histology of zebrafish gills

Tris (2-chloroethyl) phosphate (TCEP) has been receiving great concerns owing to its ubiquitous occurrence in various environmental compartments and potential risks to wildlife and humans. Gill is structural basis for ion regulation and homeostasis in fish and susceptible to xenobiotics. However, current knowledge on the impacts of long-term exposure to TCEP on the structure and physiological function of fish gills are insufficient. In this work, zebrafish were exposed to environmental realistic concentrations (0.8, 4, 20 and 100 μg/L) of TCEP from 3 h post ferterlization (hpf) till 120 days post ferterlization (dpf). Our results demonstrated that life-cycle exposure to TCEP significantly decreased the activity of glutathione S-transferase (GST), but elevated the activities of antioxidative enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and increased malondialdehyde (MDA) content in zebrafish gills. Gene transcription analysis implied that the mRNA expressions of antioxidant-related genes (nrf2, cat and nqo1) were induced, while the transcription of gstα1, hmox1, keap1 were down-regulated, indicating that Nrf2-Keap1 pathway might be activated to defend the oxidative stress induced by TCEP. Additionally, the ion homeostasis was disrupted by TCEP exposure, evidenced by reduced activities of Na+/K+-ATPase (NKA), Ca2+-ATPase and Mg2+-ATPase and downregulated transcription levels of ncc, nkcc, cftr and clc-3. Besides, whole-life exposure to TCEP resulted in a series of structural damages to gills, including epithelial lifting, epithelial rupture, telangiectasis, vacuolation, edema and shortened gill lamellae. Overall, our results demonstrated that long-term TCEP exposure could induce oxidative stress, affect ion regulation and cause histological changes in zebrafish gills.

In Situ Generated Dye@MOF/COF Heterostructure for Fluorescence Detection of Chloroquine Phosphate and Folic Acid via Different Luminescent Channels

Metal-organic framework (MOF) and covalent-organic framework (COF) hybrid materials can combine the unique properties of MOF and COF components, and their applications in fluorescence sensing have attracted more and more attention. Herein, ZIF-90 is grown on 3D-COF by a simple in situ growing method in which the 7-amino-4-methylcoumarin (AMC) is encapsulated in ZIF-90 to construct a fluorescent sensor. Chloroquine phosphate (CQP) can coordinate with Zn2+ to decompose the ZIF-90 and release AMC. At 365 nm excitation, the ratiometric fluorescence signal AMC/3D-COF (I430/I598) increases linearly with CQP in a linear range of 4 × 10-5 to 4 × 10-4 M in urine. Under 340 nm excitation, quantitative analysis of CQP in the serum (3 × 10-6 to 4 × 10-5 M) is based on the fluorescence intensity of Zn-CQP/3D-COF (I384/I598). In addition, AMC@ZIF-90/3D-COF (1) exhibits high anti-interference and selectivity in sensing of FA with a "turn off" mode, with a correlation range of 1 × 10-5 to 1 × 10-3 M. The fluorescence color changes triggered by CQP under different excitation conditions, and the different fluorescence responses caused by CQP make it a highly secure anticounterfeiting platform. The synthesized dye@MOF/COF hybrids not only provide a new way to integrate multiple emission to design fluorescent probes for differentiation detection but also offer ideas for the design of anticounterfeiting platforms.

The Effects of Acute Exposure to Ammonia on Oxidative Stress, Hematological Parameters, Flesh Quality, and Gill Morphological Changes of the Large Yellow Croaker (Larimichthys crocea)

Ammonia is considered to be the major chemical pollutant causing fish poisoning in aquaculture. This research aimed to evaluate the impact of acute ammonia exposure on the large yellow croaker's meat quality, gill morphology, liver oxidative stress, and hematological parameters. The fish were exposed to total ammonia nitrogen concentrations of 0, 2.96, 5.92, and 8.87 mg/L for 48 h, respectively. The findings demonstrated that all ammonia-exposed fish had higher liver lactate dehydrogenase and glutamic oxalate transaminase activities. The glucose, blood urea nitrogen, and creatinine levels in 8.87 mg/L total ammonia nitrogen (TAN) were higher than other samples. The total protein, albumin, and triglyceride levels in serum decreased significantly in ammonia-exposed samples. After 48 h of ammonia exposure, superoxide dismutase activities showed a 76.1%, 118.0%, and 156.8% increase when fish were exposed to 2.96, 5.92, and 8.87 mg/L TAN, respectively. Catalase activities and glutathione contents were considerably higher (p < 0.05) in all ammonia-treated samples compared to 0 mg/L TAN. The ammonia-treated gill lamellae become thicker, shorter, and curved. Additionally, the ammonia exposure resulted in the accumulation of free amino acids and the loss of nucleotides. The inosine monophosphate and adenosine monophosphate contents in the flesh were decreased after 12 h of exposure to 2.96, 5.92, and 8.87 mg/L ammonia compared to the control group. Overall, large yellow croakers exposed to ammonia for 6 h presented not only changes in serum composition but also oxidative stress, liver and gill tissue damage and flesh quality deterioration.

The synergetic effects of 4-nonylphenol and polyethylene microplastics in Cyprinus carpio juveniles using blood biomarkers

Microplastics are widely distributed in aquatic ecosystems along with other chemical pollutants. Therefore, it is vital to study the health-hazardous effects of MPs in combination with 4-nonylphenol (4-NP), which is a highly abundant industrial waste and a critical alkylphenol endocrine disruptor. We investigated the effects of the exposure to polyethylene microplastics (PE-MPs), 4-NP, and their combination on blood biomarkers in Cyprinus carpio juveniles. Four study groups were treated for 15 consecutive days: (1) control group, (2) 10 mg/L PE-MP group, (3) 10 mg/L PE-MPs + 200 µg/L 4-NP group, and (4) 200 µg/L 4-NP group, followed by 15 days of recovery. Biochemical analyses showed that creatine kinase, lactate dehydrogenase, glucose, liver enzymes, total protein, and A/G ratios were significantly increased after exposure to PE-MPs, 4-NP, and the combination. Hematological parameters (RBC's, Hb, Ht, neutrophil percentage, and WBC's) were significantly decreased in the three exposure groups, whereas mean corpuscular volume and lymphocyte percentages were significantly increased. The 15-day recovery period improved most hematobiochemical parameters and PE-MP accumulation indices. Taken together, we demonstrated the hazardous effects of PE-MP and 4-NP combinations on C. carpio blood parameters and highlighted their potential risk to human health.

Efficiency of hematological, enzymological and oxidative stress biomarkers of Cyprinus carpio to an emerging organic compound (alphamethrin) toxicity

Alphamethrin is one of the extensively used pyrethroids. Its non-specific mode-of-action might affect the non-target-organisms. Its toxicity data on aquatic organisms are lacking. We determined the toxicity (35 days) of alphamethrin (0.6µg/L and 1.2µg/L) on non-target-organisms by evaluating the efficiency of hematological, enzymological and antioxidants biomarkers of Cyprinus carpio. Compared with the control group, the efficiency of the biomarkers studied was significantly (p<0.05) impaired in the alphamethrin groups. Alphamethrin-toxicity altered hematology, transaminases and the potency of LDH of fish. ACP and ALP activity and biomarkers of oxidative stress in the gills, liver and muscle tissues were affected. IBRv2 index reveals that the biomarkers were inhibited. The observed impairments were the toxicity effects of alphamethrin with respect to concentration and time. The effectiveness of biomarkers for alphamethrin toxicity was like the toxicity data available on other banned insecticides. Alphamethrin could cause multiorgan toxicity on aquatic organisms at µg/L level.

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.

Toxic Effect of Silver Nanoparticles on Liver, Gill and Muscle Tissues of Zebrafish <i>Danio rerio</i>

The present study was aimed to evaluate the toxic effect of Silver nanoparticle on the liver, gill and muscle tissues of the Zebrafish, Danio rerio.  The experiment was designed to understand the chronic toxicity of silver nanoparticles (AgNPs) in adult fish, Danio rerio.  In the chronic toxicity study adult fish, Danio rerio were divided in to two groups.  First group was experimental group in which fish were successively treated with a graded series of 0.3, 0.6, 0.9 mg/l an average 60 nm. PVP. coated AgNPs treatment were given for 21 days, at the end of experimental period, Reduced glutathione activity (GSH), Lipid peroxidation activity (LPO), Lactate dehydrogenase (LDH) and Total protein  in liver, gill and muscle tissues were assayed. Second group were kept as a control which was free from AgNPs exposure.  The levels of Reduced glutathione activity (GSH) and Total protein were found to be decreased were as Lipid peroxidation activity (LPO) and Lactate dehydrogenase activity (LDH) were found to be elevated in liver, gill and muscle tissue of AgNPs treated Zebrafish Danio rerio. 

Real-time determination of water status upon simultaneous zebrafish exposure to sublethal concentrations of CuSO4

Water pollution from commonly occurring contaminants (metals, xenobiotics, etc.) is a serious global problem. Copper is a commonly occurring water contaminant. A variety of physiological and biological methods have been developed to monitor water quality. The assessment of biological responses is an effective method for identifying the harmful effects of contaminants on ecosystems. Fish is a highly recommended animal model in water quality monitoring. Swimming consistency (firmness) and respiratory metabolism (oxygen consumption rate, carbon dioxide excretion rate and respiratory quotient) are essential for fish to maintain body homeostasis toward coping with environmental stress. We exposed zebrafish to different concentrations (Treatment I-0.1 mg/L and Treatment II-1.58 mg/L) of CuSO₄. We have continuously quantified the strength of behavior (swimming consistency) and physiological (respiratory rates) biomarkers for ten days using an online monitoring system of swimming behavior and external respiration. Swimming consistency and respiratory rates of zebrafish (p<0.05) decreased in the CuSO₄-treated groups compared to the control group. Avoidance behavior has led to an endpoint behavior at copperiedus. The time-delayed toxic effect has resulted in CuSO₄ treatment groups. We checked for swimming consistency aberration on the artificial neural array, Self-organizing map (SOM). Circadian rhythms were influenced by prolonged exposure to CuSO₄ toxicity. A concentration- and duration-dependent behavior anomaly was noted in this study. Swimming behavior and respiratory metabolism patterns are sensitive non-invasive stress biomarkers for water quality monitoring studies.

Biotin alleviates hepatic and intestinal inflammation and apoptosis induced by high dietary carbohydrate in juvenile turbot (Scophthalmus maximus L.)

Excessive dietary carbohydrate commonly impairs the functions of liver and intestine in carnivorous fish. In the present study, a 10-week feeding trial was carried out to explore the regulation of biotin on the hepatic and intestinal inflammation and apoptosis in turbot (Scophthalmus maximus L.) fed with high carbohydrate diets. Three isonitrogenous and isolipidic experimental diets were designed as follows: the CC diet with 18.6% of carbohydrate and 0.04 mg/kg of biotin, the HC diet with 26.9% of carbohydrate and 0.05 mg/kg of biotin, and the HCB diet with 26.9% of carbohydrate and 1.62 mg/kg of biotin. Results showed that high dietary carbohydrate (HC diet) impaired the morphology of liver and intestine, however, inclusion of dietary biotin (HCB diet) normalized their morphology. Inflammation-related gene expression of nuclear factor κB p65 (nf-κb p65), tumor necrosis factor α (tnf-α), interleukin-1β (il-1β), il-6 and il-8, and the protein expression of NF-κB p65 in the liver and intestine were significantly up-regulated in the HC group compared to those in the CC group (P < 0.05), the HCB diet decreased their expression compared to the HC group (P < 0.05). The gene expression of il-10 and transforming growth factor-β (tgf-β) in the liver and intestine were significantly decreased in the HC group compared to the CC group (P < 0.05), and inclusion of dietary biotin increased the il-10 and tgf-β expression in the liver and intestine (P < 0.05). Moreover, compared to the CC group, the HC group had a stronger degree of DNA fragmentation and more TUNEL-positive cells in the liver and intestine, and the HCB group had a slighter degree of DNA fragmentation and fewer TUNEL-positive cells compared to the HC group. Meanwhile, the gene expression of B-cell lymphoma protein-2-associated X protein (bax) and executor apoptosis-related cysteine peptidase 3 (caspase-3) were significantly up-regulated and the gene expression of B-cell lymphoma-2 (bcl-2) was significantly down-regulated both in the liver and intestine in the HC group compared with those in the CC group (P < 0.05). Inclusion of dietary biotin significantly decreased the bax and caspase-3 mRNA levels and increased bcl-2 mRNA level in the liver and intestine (P < 0.05). In conclusion, high dietary carbohydrate (26.9% vs 18.6%) induced inflammation and apoptosis in liver and intestine. Supplementation of biotin (1.62 mg/kg vs 0.05 mg/kg) in diet can alleviate the high-dietary-carbohydrate-induced hepatic and intestinal inflammation as well as inhibit apoptosis in turbot. The present study provides basic data for the application of biotin into feed, especially the high-carbohydrate feed for turbot.

SARS-CoV-2 pharmaceutical drugs: a critical review on the environmental impacts, chemical characteristics, and behavior of advanced oxidation processes in water

This review summarizes research data on the pharmaceutical drugs used to treat the novel SARS-CoV-2 virus, their characteristics, environmental impacts, and the advanced oxidation processes (AOP) applied to remove them. A literature survey was conducted using the electronic databases Science Direct, Scopus, Taylor & Francis, Google Scholar, PubMed, and Springer. This complete research includes and discusses relevant studies that involve the introduction, pharmaceutical drugs used in the SARS-CoV-2 pandemic: chemical characteristics and environmental impact, advanced oxidation process (AOP), future trends and discussion, and conclusions. The results show a full approach in the versatility of AOPs as a promising solution to minimize the environmental impact associated with these compounds by the fact that they offer different ways for hydroxyl radical production. Moreover, this article focuses on introducing the fundamentals of each AOP, the main parameters involved, and the concomitance with other sources and modifications over the years. Photocatalysis, sonochemical technologies, electro-oxidation, photolysis, Fenton reaction, ozone, and sulfate radical AOP have been used to mineralize SARS-CoV-2 pharmaceutical compounds, and the efficiencies are greater than 65%. According to the results, photocatalysis is the main technology currently applied to remove these pharmaceuticals. This process has garnered attention because solar energy can be directly utilized; however, low photocatalytic efficiencies and high costs in large-scale practical applications limit its use. Furthermore, pharmaceuticals in the environment are diverse and complex. Finally, the review also provides ideas for further research needs and major concerns.

Synergistic effect of chloroquine and copper to the euryhaline rotifer Proales similis

Chloroquine (CQ) has been widely used for many years against malaria and various viral diseases. Its important use and high potential to being persistent make it of particular concern for ecotoxicological studies. Here, we evaluated the toxicity of CQ alone and in combination with copper (Cu) to the euryhaline rotifer Proales similis. All experiments were carried out using chronic toxicity reproductive five-day tests and an application factor (AF) of 0.05, 0.1, 0.3, and 0.5 by multiplying the 24-h LC₅₀ values of CQ (4250 µg/L) and Cu (68 µg/L), which were administered in solution. The rate of population increase (r, d^-1) ranged from 0.50 to 52 (controls); 0.20 to 0.40 (CQ); 0.09 to 0.43 (Cu); and -0.03 to 0.30 (CQ-Cu) and showed significant decrease as the concentration of both chemicals in the medium increased. Almost all tested mixtures induced synergistic effects, mainly as the AF increased. We found that the presence of Cu intensifies the vulnerability of organisms to CQ and vice versa. These results stress the potential hazard that these combined chemicals may have on the aquatic systems. This research suggests that P. similis is sensitive to CQ as other standardized zooplankton species and may serve as a potential test species in the risk assessment of emerging pollutants in marine environments.

Hydroxychloroquine Adsorption in Aqueous Medium Using Clinoptilolite Zeolite

The presence of drugs on a large scale in aquatic matrices raises concern and requires the study of efficient technologies to remove these compounds. This study investigated the adsorption capacity of the natural zeolite clinoptilolite (CP) in removing the drug hydroxychloroquine (HCQ). Zeolite was characterized by BET, XRD, FT-IR, SEM, and pH_pzc techniques. The kinetic model that best fits the experimental data was the pseudo-first-order and the SIPS isotherm provided the best fit. The Langmuir isotherm RL separation factor (> 0.01) indicated that the adsorption process was favorable and the Freundlich isotherm (n > 1) suggested that the adsorption mechanism occurred mainly by physisorption, with intraparticle diffusion as the step limiting the process. The process was spontaneous (ΔG°_ads < 0), endothermic (ΔH°_ads > 0), and with increased randomness at the solid-solution interface (ΔS°_ads > 0). The initial pH variation of the effluent was not favorable for the adsorption process and the zeolite was easily regenerated for later use. The ecotoxicological tests with Artemia salina and Lactuca Sativa proved that the final effluent did not show toxicity after the adsorption treatment. Based on the results obtained in this work, clinoptilolite zeolite is a potential adsorbent for reducing HCQ toxicity in aquatic matrices.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11270-022-05787-3.

Pharmaceutical compounds used in the COVID-19 pandemic: A review of their presence in water and treatment techniques for their elimination

During the COVID-19 pandemic, high consumption of antivirals, antibiotics, antiparasitics, antiprotozoals, and glucocorticoids used in the treatment of this virus has been reported. Conventional treatment systems fail to efficiently remove these contaminants from water, becoming an emerging concern from the environmental field. Therefore, the objective of the present work is to address the current state of the literature on the presence and removal processes of these drugs from water bodies. It was found that the concentration of most of the drugs used in the treatment of COVID-19 increased during the pandemic in water bodies. Before the pandemic, Azithromycin concentrations in surface waters were reported to be in the order of 4.3 ng L-1, and during the pandemic, they increased up to 935 ng L-1. Laboratory scale studies conclude that adsorption and advanced oxidation processes (AOPs) can be effective in the removal of these drugs. Up to more than 80% removal of Azithromycin, Chloroquine, Ivermectin, and Dexamethasone in aqueous solutions have been reported using these processes. Pilot-scale tests achieved 100% removal of Azithromycin from hospital wastewater by adsorption with powdered activated carbon. At full scale, treatment plants supplemented with ozonation and artificial wetlands removed all Favipiravir and Azithromycin, respectively. It should be noted that hybrid technologies can improve removal rates, process kinetics, and treatment cost. Consequently, the development of new materials that can act synergistically in technically and economically sustainable treatments is required.

Excessive manganese alters serum biochemical indices, induces histopathological alterations, and activates apoptosis in liver and cerebrum of Jianzhou Da'er goat (Capra hircus)

The present study aimed to explore the toxic effects of excessive dietary Mn in livers and cerebrums of Jianzhou Da'er goat (Capra hircus). Three-month old goats were assigned into three groups: control group, fed on basal diet; Mn I group, fed on the basal diet mixed with MnCl₂ (2.5 g/kg); Mn II group, fed on the basal diet mixed with MnCl₂ (5 g/kg). Compared with the control group, the activities of serum alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and the concentrations of interferon-γ (IFN-γ) in Mn I and Mn II groups were significantly increased, but the concentrations of IgG in Mn I and Mn II groups were significantly decreased (p < 0.05). The activities of superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), and the concentrations of glutathione (GSH) in Mn I and Mn II groups were significantly decreased, whereas the concentrations of malondialdehyde (MDA) in Mn I and Mn II groups were significantly increased in livers and cerebrums (p < 0.05). Moreover, the hepatocytes necrosed, inflammatory cells infiltrated, chromatin concentrated, mitochondrial cristae reduced in Mn I and Mn II groups. The nerve cells necrosed, blood vessels congested, inflammatory cells infiltrated, mitochondrial electron density and mitochondrial cristae decreased, and vacuolization increased in Mn I and Mn II groups. Furthermore, the mRNA expressions of tumor necrosis factor alpha (TNF-α), tumor necrosis factor receptor type 1 (TNFR1), fas-associated protein via a death domain (FADD), Bcl2-associated X (Bax), cysteinyl aspartate specific proteinase 3, 8, 9 (Caspase-3, 8, 9) in Mn I and Mn II groups were significantly increased (p < 0.05), but the mRNA expressions of B-cell lymphoma-2 (Bcl-2) in Mn I and Mn II groups were significantly decreased (p < 0.05) in livers. The mRNA expressions of Bcl-2, Bax, Caspase-3, 9, 7, 12 in Mn I and Mn II groups were significantly increased (p < 0.05), however, the ratio of Bcl-2/Bax in Mn I and Mn II groups was significantly decreased (p < 0.05) in cerebrums. In summary, our results provided new insights for better understanding the mechanisms of Mn toxicity in Capra hircus.

Removal of hydroxychloroquine from an aqueous solution using living microalgae: Effect of operating parameters on removal efficiency and mechanisms

Wastewater contaminated with hydroxychloroquine (HCQ) poses a serious threat to the environment and human life. This study aimed to evaluate the ability of living microalgae to remove HCQ from an aqueous solution. Batch mode experiments were conducted under different conditions to investigate the effect of operating parameters on HCQ removal efficiency and mechanisms. Equilibrium, kinetic and thermodynamic study was also carried out to better describe the interactions between HCQ and microalgae. The maximum HCQ removal was 92.10 ± 1.25% obtained under optimal pH of 9.9 ± 0.1, a contact time of 45 min, a stirring speed of 300 rpm, an initial HCQ concentration of 20 mg/L, and a microalgae dose of 100 mg/L. The Langmuir isotherm and the pseudo-second-order kinetic model were best suited for the biosorption experiments, and the maximum biosorption capacity was 339.02 mg/g. The thermodynamic study showed that the biosorption process was exothermic and spontaneous. Experiments on real wastewater showed that the HCQ removal was not significantly affected by the presence of other contaminants in the water. PRACTITIONER POINTS: The best HCQ removal was 92.10 ± 1.25% obtained under optimal conditions. The Langmuir isotherm and the pseudo-second-order kinetic model were best suited for the biosorption experiments. The maximum biosorption capacity was 339.02 mg/g. The thermodynamic study showed that the biosorption process was exothermic and spontaneous. The microalgae studied can be successfully used in HCQ removal from water.

Effect of triclosan (TCS) on the protein content and associated histological changes on tilapia, Oreochromis mossambicus (Peters, 1852)

Triclosan is a chlorinated phenolic antimicrobial agent having a wide application in commercial and healthcare products. The toxic effects of the emerging pollutant, triclosan (TCS), on behavior, protein content, and associated histological alterations in the muscle tissue of the freshwater fish Oreochromis mossambicus were studied. Healthy fishes were exposed to five different acute concentrations of TCS, viz., 0.131, 0.262, 0.523, 1.046, and 2.092 ppm for a period of 96 h. The 96-h LC₅₀ of TCS for O. mossambicus was determined as 0.715 ppm using probit analysis. The fishes were also chronically exposed to the five different concentrations of TCS based on LC₅₀ to study the toxic effects of long-term exposure. The protein content of the fish muscle gradually decreased with an increase in the concentration of TCS. Further, the histological alterations such as splitting of myotomes, vacuolar degeneration, degenerated myotomes, multifocal degeneration of myocytes, degeneration of myoepithelium, myolysis, melanomacrophage in the dermis, vacuolation in the epidermis, atrophy of myotomes, and necrosis were observed during the acute and chronic exposure of fishes to TCS. The study revealed that TCS can affect the aquatic organisms even at a minimum concentration of 0.715 ppm causing changes in the behavior and biochemical constituents of tilapia.

Candidate antiviral drugs for COVID-19 and their environmental implications: a comprehensive analysis

Emerging from Wuhan, China, SARS-CoV-2 is the new global threat that killed millions of people, and many are still suffering. This pandemic has not only affected people but also caused economic crisis throughout the world. Researchers have shown good progress in revealing the molecular insights of SARS-CoV-2 pathogenesis and developing vaccines, but effective treatment against SARS-CoV-2-infected patients are yet to be found. Several vaccines are available and used in many countries, while many others are still in clinical or preclinical studies. However, this involves a long-term process, considering the safety procedures and requirements and their long-term protection capacity and in different age groups are still questionable. Therefore, at present, the drug repurposing of the existing therapeutics previously designed against other viral diseases seems to be the only practical approach to mitigate the current situation. The safety of most of these therapeutic agents has already been tested. Recent clinical reports revealed promising therapeutic efficiency of several drugs such as remdesivir, tenofovir disoproxil fumarate, azithromycin, lopinavir/ritonavir, chloroquine, baricitinib, and cepharanthine. Besides, plasma therapies were used to treat patients and prevent fatal outcomes. Thus, in this article, we have summarized the epidemiological and clinical data from several clinical trials conducted since the beginning of the pandemic, emphasizing the efficiency of the known agents against SARS-CoV-2 and their harmful side effects on the human body as well as their environmental implications. This review shows a clear overview of the current pharmaceutical perspective on COVID-19 treatment.

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.

Environmental impacts of COVID-19 treatment: Toxicological evaluation of azithromycin and hydroxychloroquine in adult zebrafish

One of the most impact issues in recent years refers to the COVID-19 pandemic, the consequences of which thousands of deaths recorded worldwide, are still inferior understood. Its impacts on the environment and aquatic biota constitute a fertile field of investigation. Thus, to predict the impact of the indiscriminate use of azithromycin (AZT) and hydroxychloroquine (HCQ) in this pandemic context, we aim to assess their toxicological risks when isolated or in combination, using zebrafish (Danio rerio) as a model system. In summary, we observed that 72 h of exposure to AZT and HCQ (alone or in binary combination, both at 2.5 μg/L) induced the reduction of total protein levels, accompanied by increased levels of thiobarbituric acid reactive substances, hydrogen peroxide, reactive oxygen species and nitrite, suggesting a REDOX imbalance and possible oxidative stress. Molecular docking analysis further supported this data by demonstrating a strong affinity of AZT and HCQ with their potential antioxidant targets (catalase and superoxide dismutase). In the protein-protein interaction network analysis, AZT showed a putative interaction with different cytochrome P450 molecules, while HCQ demonstrated interaction with caspase-3. The functional enrichment analysis also demonstrated diverse biological processes and molecular mechanisms related to the maintenance of REDOX homeostasis. Moreover, we also demonstrated an increase in the AChE activity followed by a reduction in the neuromasts of the head when zebrafish were exposed to the mixture AZT + HCQ. These data suggest a neurotoxic effect of the drugs. Altogether, our study demonstrated that short exposure to AZT, HCQ or their mixture induced physiological alterations in adult zebrafish. These effects can compromise the health of these animals, suggesting that the increase of AZT and HCQ due to COVID-19 pandemic can negatively impact freshwater ecosystems.

A critical review on environmental presence of pharmaceutical drugs tested for the covid-19 treatment

On March 11, 2020, the World Health Organization (WHO) declared COVID-19 a pandemic. The outbreak caused a worldwide impact, becoming a health threat to the general population and its professionals. To date, there are no specific antiviral treatments or vaccines for the COVID-19 infection, however, some drugs are being clinically tested. The use of these drugs on large scale raises great concern about their imminent environmental risk, since the elimination of these compounds by feces and urine associated with the inefficiency of sewage treatment plants in their removal can result in their persistence in the environment, putting in risk the health of humans and of other species. Thus, the goal of this work was to conduct a review of other studies that evaluated the presence of the drugs chloroquine, hydroxychloroquine, azithromycin, ivermectin, dexamethasone, remdesivir, favipiravir and some HIV antivirals in the environment. The research indicated the presence of these drugs in the environment in different regions, with concentration data that could serve as a basis for further comparative studies following the pandemic.

Hydroxychloroquine in COVID-19: therapeutic promises, current status, and environmental implications

The outbreak of novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected the entire world with its infectious spread and mortality rate. The severe cases of coronavirus disease 2019 (COVID-19) are characterized by hypoxia and acute respiratory distress syndrome. In the absence of any specific treatment, just the preventive and supportive care options are available. Therefore, much focus is given to assess the available therapeutic options not only to avoid acute respiratory failure and hypoxia but also to reduce the viral load to control the severity of the disease. The antimalarial drug hydroxychloroquine (HCQ) is among the much-discussed drugs for the treatment and management of COVID-19 patients. This article reviews the therapeutic potential of HCQ in the treatment of COVID-19 based on the available in vitro and clinical evidence, current status of registered HCQ-based clinical trials investigating therapeutic options for COVID-19, and environmental implications of HCQ.

Can use of hydroxychloroquine and azithromycin as a treatment of COVID-19 affect aquatic wildlife? A study conducted with neotropical tadpole

The impacts on human health and the economic and social disruption caused by the pandemic COVID-19 have been devastating. However, its environmental consequences are poorly understood. Thus, to assess whether COVID-19 therapy based on the use of azithromycin (AZT) and hydroxychloroquine (HCQ) during the pandemic affects wild aquatic life, we exposed (for 72 h) neotropical tadpoles of the species Physalaemus cuvieri to the water containing these drugs to 12.5 μg/L. We observed that the increase in superoxide dismutase and catalase in tadpoles exposed to AZT (alone or in combination with HCQ) was predominant to keep the production of NO, ROS, TBARS and H2O2 equitable between the experimental groups. In addition, the uptake of AZT and the strong interaction of AZT with acetylcholinesterase (AChE), predicted by the molecular docking analysis, were associated with the anticholinesterase effect observed in the groups exposed to the antibiotic. However, the unexpected increase in butyrylcholinesterase (BChE) in these same groups suggests its constitutive role in maintaining cholinergic homeostasis. Therefore, taken together, our data provide a pioneering evidence that the exposure of P. cuvieri tadpoles to AZT (alone or in combination with HCQ) in a predictably increased environmental concentration (12.5 μg/L) elicits a compensatory adaptive response that can have, in the short period of exposure, guaranteed the survival of the animals. However, the high energy cost for maintaining physiological homeostasis, can compromise the growth and development of animals and, therefore, in the medium-long term, have a general negative effect on the health of animals. Thus, it is possible that COVID-19 therapy, based on the use of AZT, affects wild aquatic life, which requires greater attention to the impacts that this drug may represent.

Environmental impact assessment of COVID-19 therapeutic solutions. A prospective analysis

Several medicinal products for human use are currently under consideration as potential treatment for COVID-19 pandemic. As proposals cover also prophylactic use, the treatment could be massive, resulting in unprecedent levels of antiviral emissions to the aquatic environment. We have adapted previous models and used available information for predicting the environmental impact of representative medicinal products, covering the main groups under consideration: multitarget antiparasitic (chloroquines and ivermectin), glucocorticoids, macrolide antibiotics and antiviral drugs including their pharmacokinetic boosters. The retrieved information has been sufficient for conducting a conventional environmental risk assessment for the group of miscellaneous medicines; results suggest low concern for the chloroquines and dexamethasone while very high impact for ivermectin and azithromycin, even at use levels well below the default value of 1% of the population. The information on the ecotoxicity of the antiviral medicines is very scarce, thus we have explored an innovative pharmacodynamic-based approach, combining read-across, quantitative structure-activity relationship (QSAR), US EPA's Toxicity Forecaster (ToxCast) in vitro data, pharmacological modes of action, and the observed adverse effects. The results highlight fish sublethal effects as the most sensitive target and identify possible concerns. These results offer guidance for minimizing the environmental risk of treatment medication for COVID-19.

Spirulina platensis Alleviated the Hemotoxicity, Oxidative Damage and Histopathological Alterations of Hydroxychloroquine in Catfish (Clarias gariepinus)

The current study aims at evaluating the toxicity of hydroxychloroquine (HCQ) as a pharmaceutical residue in catfish (Clarias gariepinus) and the protective role of Spirulina platensis (SP). Four groups were used in this study: (1) a control group, (2) a group exposed to 3.16 mg/l of HCQ, (3) a group exposed to 3.16 mg/l of HCQ + 10 mg/l of SP, and (4) a group exposed to 3.16 mg/l of HCQ + 20 mg/l of SP for 15 days of exposure. The HCQ-treated group showed a significant decline in the hematological indices and glucose, total protein, and antioxidant levels in relation to the control group, whereas the HCQ-treated group showed a significant increase in the levels of creatinine, uric acid, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) as well as the percentage of poikilocytosis and nuclear abnormalities of RBCs in relation to the control group. The histopathological evaluation of the liver indicated dilation of the central vein, vacuolization, degeneration of hepatocytes and pyknotic nuclei, as well as reduction of glomeruli, dilation of Bowman's space, and degeneration of renal tubules in the kidney of the HCQ-treated group. Spirulina platensis (SP) rendered the hematological and biochemical indexes as well as antioxidant levels and the histological architecture to normal status in a dose-dependent manner. Accordingly, the current study recommends the use of SP to remedy the toxic effects of HCQ.

FoxO3 Modulates LPS-Activated Hepatic Inflammation in Turbot (Scophthalmus maximus L.)

In mammals, forkhead box O3 (foxo3) plays important roles in liver immune system. The foxo3 can regulate cell cycle, DNA repair, hypoxia, apoptosis and so on. However, as such an important transcription factor, few studies on foxo3 in fish have been reported. The present study characterized the foxo3 in turbot (Scophthalmus maximus L.). Lipopolysaccharide (LPS) incubated in vitro (hepatocytes) and injected in vivo (turbot liver) were used to construct inflammatory models. The foxo3 was interfered and overexpressed to investigate its functions in liver inflammation. The open reading frame (ORF) of foxo3 was 1998 bp (base pair), encoding 665 amino acids. Sequence analysis showed that foxo3 of turbot was highly homologous to other fishes. Tissue distribution analysis revealed that the highest expression of foxo3 was in muscle. Immunofluorescence result showed that foxo3 was expressed in cytoplasm and nucleus. Knockdown of foxo3 significantly increased mRNA levels of tumor necrosis factor-α (tnf-α), interleukin-1β (il-1β), interleukin-6 (il-6), myeloid-differentiation factor 88 (myd88), cd83, toll-like receptor 2 (tlr-2) and protein level of c-Jun N-terminal kinase (JNK) in sifoxo3 + LPS (siRNA of foxo3+ LPS) group compared with NC + LPS (negative control + LPS) group in turbot hepatocytes. Overexpressed foxo3 significantly decreased mRNA levels of tnf-α, il-6, nuclear transcription factor-kappa B (nf-κb), cd83, tlr-2 and the protein level of JNK in vitro. In vivo analysis, foxo3 knockdown significantly increased levels of GOT in serum after LPS injection compared with NC+LPS group. Overexpressed foxo3 significantly decreased levels of GPT and GOT in pcDNA3.1-foxo3+LPS group compared with pcDNA3.1+LPS group in vivo. Foxo3 knockdown significantly increased mRNA levels of tnf-α, il-1β, il-6, nf-κb, myd88 and protein level of JNK in vivo in sifoxo3+LPS group compared with NC+LPS group in turbot liver. Overexpressed foxo3 significantly decreased mRNA levels of il-1β, il-6, myd88, cd83, jnk and protein level of JNK in pcDNA3.1-foxo3+LPS group compared with pcDNA3.1+LPS group in turbot liver. The results indicated that foxo3 might modulate LPS-activated hepatic inflammation in turbot by decreasing the proinflammatory cytokines, the levels of GOT and GPT as well as activating JNK/caspase-3 and tlr-2/myd88/nf-κb pathways. Taken together, these findings indicated that FoxO3 may play important roles in liver immune responses to LPS in turbot and the research of FoxO3 in liver immunity enriches the studies on immune regulation, and provides theoretical basis and molecular targets for solving liver inflammation and liver injury in fish.

Toxicity of hydroxychloroquine, a potential treatment for COVID-19, on free-living marine nematodes

On March 2020, hydroxychloroquine (HCQ) was recommended as a treatment for COVID-19 high risk patients. Following the massive and widespread use of HCQ worldwide, a discernible high quantity is anticipated to end-up through the sewage systems in marine coastal areas. A closed microcosm study was undertaken herein for 30 days where meiobenthic nematodes were exposed to a range of HCQ concentrations (3.162, 31.62 and 63.24 μg.ml^-1). After one month of exposure in HCQ, the total abundances and Shannon-Wiener index of the assemblages decreased, whereas the individual mass and the Trophic Diversity Index increased at the highest concentrations. Overall, a numerical negative impact was observed for the epistrate feeders and non-selective deposit feeders, however, this benefited to the omnivores-carnivores, and particularly to the Oncholaimids. Such responses of the nematodes 2B and the corresponding taxa are bioindicative of current- or post-COVID-19 crisis risks in relation with the bioaccumulation of HCQ in seafood.

Responses of Cirrhinus mrigala to second-generation fluoroquinolone (ciprofloxacin) toxicity: Assessment of antioxidants, tissue morphology, and inorganic ions

Ciprofloxacin drugs are a second-generation fluoroquinolone highly prescribed medication against various bacterial infections in human and aquaculture practices. These drugs are chemically designed to persist in the body long enough to achieve target objectives. Extensive usage has resulted in ciprofloxacin becoming a ubiquitous contaminant in the environment. Unfortunately, the ecotoxicological profiles for ciprofloxacin are scanty. This study was aimed to assess the ecotoxicity of ciprofloxacin at environmentally relevant concentrations (1 μg/L, and 1.5 μg/L) to a cultivable fish Cirrhinus mrigala. Responses of antioxidant enzymes, histological anomalies, and inorganic ion levels were studied. SOD activity in gill, liver, and kidney tissues was elevated in ciprofloxacin-exposed groups when compared with the control group. CAT activity was predominantly decreased in ciprofloxacin treated groups relative to the control group. GST activity in the ciprofloxacin treated groups was increased (except kidney tissues [Treatment I (1 μg/L)], and gill tissues fifteenth day) significantly (p < .05). The LPO level was elevated in the ciprofloxacin treatment groups throughout the study period (except Treatment II (1.5 μg/L) tenth day in kidney tissues). A series of histological anomalies were noticed in the gill, liver, and kidney tissues of the ciprofloxacin treated groups. Ciprofloxacin exposure caused a significant decrease of sodium, potassium, and chloride levels in the plasma of C. mrigala. A parallel among an imbalanced oxidative defense system, tissue structural changes, and alterations of plasma inorganic ions could be considered as a reliable biomarker for antibiotic toxicity study. This study could be a primary platform for further toxicity studies to understand the potential molecular impacts and adverse effects of ciprofloxacin on aquatic organisms.

Alterations in hematological and biochemical parameters, oxidative stress, and immune response in Takifugu rubripes under acute ammonia exposure

Ammonia is a major pollutant in aquatic environments and poses a considerable threat to the survival of fish. In this study, we investigated the toxic effects of ammonia on the hematological and biochemical parameters, oxidative stress, and immune responses in Takifugu rubripes. Juvenile T. rubripes (average weight 246.17 ± 3.54 g) were exposed to different concentrations of ammonia (0, 5, 50, 100, and 150 mg/L) for 96 h. The results showed that the hematological parameters (hemoglobin, hematocrit, red blood cell, and white blood cell count) were significantly reduced in response to ammonia exposure. Of the plasma components, such as serum total protein, albumin, glucose, glutamic-oxalacetic transaminase, and glutamic-pyruvic transaminase, were significantly altered in response to ammonia exposure. Additionally, the levels of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and glutathione peroxidase (GPx) were increased after exposure to low concentration ammonia exposure. However, when fish were exposed to a high concentration of ammonia, these parameters showed the opposite trend, suggesting that an increase in antioxidant enzymes during the early stages of ammonia exposure may contribute to the removal of the induced reactive oxygen species (ROS) and protect the cells from oxidative damage. However, as the ammonia concentration and exposure time increased, the overproduction of ROS accelerated the depletion of antioxidant enzymes. Ammonia exposure significantly increased the expression of heat shock proteins (HSP70 and HSP90). Ammonia poisoning elevated gene expressions of TLR-3, TNF-α, IL-6, IL-12, and IL-1β in the gills, causing an inflammatory response. Our findings provide new insights into the mechanisms involved in ammonia-induced aquatic toxicology in marine fish, which may aid in their captive management.