Sublethal effects of the beta-blocker sotalol at environmentally relevant concentrations on the New Zealand mudsnail Potamopyrgus antipodarum

Unraveling the Pollution and Discharge of Aminophenyl Sulfone Compounds, Sulfonamide Antibiotics, and Their Acetylation Products in Municipal Wastewater Treatment Plants

Aminophenyl sulfone compounds (ASCs) are widely used in various fields, such as the pharmaceutical and textile industries. ASCs and their primary acetylation products are inevitably discharged into the environment. However, the high toxicity of ASCs could be released from the deacetylation of acetylation products. Still, the occurrence and ecological risks of ASCs and their acetylation products remain largely unknown. Here, we integrated all of the existing ASCs based on the core structure, together with their potential acetylation products, to establish a database covering 1105 compounds. By combining the database with R programming, 45 ASCs, sulfonamides, and their acetylation products were identified in the influent and effluent of 19 municipal wastewater treatment plants in 4 cities of China. 13 of them were detected for the first time in the aquatic environment, and 12 acetylation products were newly identified. The cumulative concentrations of 45 compounds in the influent and effluent were in the range of 231-9.96 × 103 and 26-2.70 × 103 ng/L, respectively. The proportion of the unrecognized compounds accounted for 60.6% of the influent and 62.8% of the effluent. Furthermore, nearly half of the ASCs (46.7%), other sulfonamides (49.9%), and their acetylation products (46.2%) were discharged from the effluent, posing a low-to-medium risk to aquatic organisms. The results provide a guideline for future monitoring programs, particularly for sulfadiazine and dronedarone, and emphasize that the ecological risk of ASCs, sulfonamides, and their acetylation products needs to be considered in the aquatic environment.

Molecular interactions of polyvinyl chloride microplastics and beta-blockers (Diltiazem and Bisoprolol) and their effects on marine meiofauna: Combined in vivo and modeling study

The ecotoxicological effects of beta-blockers (i.e. Diltiazem and Bisoprolol) and their interactions with the microplastic polyvinyl chloride on marine meiofauna were tested in laboratory microcosms. An experimental factorial design was applied, using meiobenthic fauna collected from the Old Harbor of Bizerte (NE Tunisia), but with a main focus on the nematode communities. The meiobenthic invertebrates were exposed to two concentrations of Diltiazem and Bisoprolol, of 1.8 µg.L^-1 and 1.8 mg.L^-1, respectively, and one concentration of polyvinyl chloride (i.e. 20 mg.kg^-1), separately and mixed. The overall meiofauna abundance was significantly reduced in all treatments, mainly that of polychaetes and amphipods. Moreover, the juveniles-gravid female ratios of the nematode communities were the lowest in the 1.8 µg.L^-1 Bisoprolol treatment and for the 1.8 mg.L^-1 mixture of Diltiazem and microplastics, suggesting that different dosages influence the maturity status of the examined species. The demographic results were also supported by in silico approach. The simulation of molecular interactions revealed acceptable binding affinities (up to -8.1 kcal/mol) and interactions with key residues in the germ line development protein 3 and sex-determining protein from Coenorhabditis elegans. Overall, the experimental outcome strongly indicates synergistic interactions among the beta-blockers Diltiazem and Bisoprolol and the microplastic polyvinyl chloride on marine nematode communities.

A spectrofluorimetric method for the determination of pindolol in natural waters using various organic and cyclodextrin media

A simple, sensitive, and rapid spectrofluorimetric method was developed for the determination of the β-blocker pindolol. The native fluorescence of pindolol was measured in different organic solvents and in cyclodextrin aqueous media. The highest fluorescence signal was obtained in 2-propanol at λ_em = 303 nm with λ_ex = 260 nm. Analytical figures of merit for the spectrofluorimetric determination of pindolol were satisfactory, with wide linear dynamic range (LDR) values of two orders of magnitude, and rather low limit of detection (LOD) values between 0.2 and 8.7 ng/mL. Moreover, the addition of cyclodextrins (HP-β-CD and β-CD) in aqueous media enhanced the fluorescence of pindolol. In addition, the inclusion complexes of pindolol with cyclodextrins were investigated and the stability constants of complexes were calculated by means of the method of nonlinear regression (NLR). The method was successfully applied to the analysis of tap water and natural water samples, spiked with pindolol.

Assessment of the ecotoxicity of the pharmaceuticals bisoprolol, sotalol, and ranitidine using standard and behavioral endpoints

The pharmaceuticals bisoprolol (BIS), sotalol (SOT), and ranitidine (RAN) are among the most consumed pharmaceuticals worldwide and are frequently detected in different aquatic ecosystems. However, very few ecotoxicity data are available in the literature for them. To help fill these data gaps, toxicity tests with the algae Raphidocelis subcapitata, the macrophyte Lemna minor, the cnidarian Hydra attenuata, the crustacean Daphnia similis, and the fish Danio rerio were performed for assessing the ecotoxicity of these pharmaceuticals. Standard, as well as non-standard endpoint, was evaluated, including the locomotor behavior of D. rerio larvae. Results obtained for SOT and RAN showed that acute adverse effects are not expected to occur on aquatic organisms at the concentrations at which these pharmaceuticals are usually found in fresh surface waters. On the other hand, BIS was classified as hazardous to the environment in the acute III category. Locomotor behavior of D. rerio larvae was not affected by BIS and RAN. A disturbance on the total swimming distance at the dark cycle was observed only for larvae exposed to the highest test concentration of 500 mg L^-1 of SOT. D. similis reproduction was affected by BIS with an EC₁₀ of 3.6 (0.1-34.0) mg L^-1. A risk quotient (RQ) of 0.04 was calculated for BIS in fresh surface water, considering a worst-case scenario. To the best of our knowledge, this study presents the first chronic toxicity data with BIS on non-target organisms.

Single and mixture toxicity of four pharmaceuticals of environmental concern to aquatic organisms, including a behavioral assessment

Pharmaceuticals are frequently detected in aquatic environments as mixtures and can cause toxic effects to non-target organisms. We aimed to evaluate the single and mixture effects of the pharmaceuticals metformin, bisoprolol, ranitidine and sotalol using Daphnia similis and Danio rerio. In addition, we aimed to test the predictive accuracy of the mathematical models concentration addition and independent action and to evaluate the nature of the possible toxicological interactions among these pharmaceuticals using the combination index-isobologram model. The acute toxicity of these four pharmaceuticals individually and of their binary mixtures were evaluated using the D. similis tests. Developmental and behavioral effects induced by the pharmaceuticals in quaternary mixtures were evaluated using D. rerio embryos. We observed that most of the binary mixture effects were in the zone between the effects predicted by the concentration addition and the independent action model. The combination index-isobologram model showed to be adequate to describe the nature of possible interactions occurring between the combined pharmaceuticals. Developmental and behavioral acute adverse effects seem not to be induced by the joint action of the quaternary mixture of the evaluated pharmaceuticals on D. rerio embryos, at the concentrations at which they are usually found in surface fresh waters. However, from the results obtained with D. similis, we can conclude that assessing the ecological risk based on the effects of individual pharmaceuticals can underestimate the risk level posed by these environmental contaminants.

A rapid zebrafish embryo behavioral biosensor that is capable of detecting environmental β-blockers

β-Blockers (BB) are one of the most commonly prescribed pharmaceuticals used for treating cardiovascular and acute anxiety-related disorders. This class of drugs inhibit β-adrenoceptor signalling and given their growing, widespread use, BB are routinely detected in surface waters at nM concentrations. This is concerning as trace levels of BB impart developmental and reproductive dysfunction in non-target aquatic organisms, with potential for ecological risks. To date, environmental pharmaceutical risks to non-target animals are not part of the monitoring framework due to the lack of bioassays for assessing their biological effects. Behavioral endpoints have the advantage of a systems-level integration of multiple sensory signals and motor responses for toxicity screening; however, they are not currently used for risk assessment of environmental contaminants. The zebrafish (Danio rerio) embryo photomotor response (zfPMR) has been used in high-throughput behavioral screenings for neuroactive drug effects at high, therapeutic concentrations. Our objective here was to examine if we could utilize the zfPMR for screening environmental levels of BB. Embryos were placed into 96-well plates, exposed to chemicals and/or municipal wastewater effluent (MWWE), and their zfPMRs were measured with video-analysis. To specifically target BB, embryos were co-treated with isoproterenol, a β-adrenergic agonist that stimulates the zfPMR, and the inhibition of isoproterenol-induced response was used as a biomarker of BB exposure. Our results reveal that the inhibition of isoproterenol-stimulated zfPMRs can be used as a biosensor capable of detecting BB in the parts-per-billion to parts-per-trillion in water samples, including diluted MWWE. The method developed detects BB in spite of the presence of other neuroactive compounds in water samples. This systems level approach of rapid screening for BB effects provides the most promising evidence to date that behavioral neuromodulation can be potentially applied for environmental effects monitoring of pharmaceuticals.

The fate of sotalol in aqueous chlorination: Kinetics, mechanisms and ecotoxicity assessment

Unmetabolized pharmaceuticals often enter the water treatment plants and exposed to various treatment processes. Among these water treatment processes, disinfection is a process which involves the application of chemical oxidation to remove pathogen. Untreated pharmaceuticals from primary and secondary treatment have the potential to be exposed to the chemical oxidation process during disinfection. This study investigated the kinetics and mechanism of the degradation of sotalol during chlorination process. Chlorination with hypochlorous acid (HOCl) as main reactive oxidant has been known as one of the most commonly used disinfection methods. The second order rate constant for the reaction between sotalol and free available chlorine (FAC) was found to decrease from 60.1 to 39.1M^-1min^-1 when the pH was increased from 6 to 8. This result was mainly attributed by the decreased of HOCl concentration with increasing pH. In the real water samples, the presence of the higher amount of organic content was found to reduce the efficiency of chlorination in the removal of sotalol. This result showed that sotalol competes with natural organic matter to react with HOCl during chlorination. After 24h of FAC exposure, sotalol was found to produce three stable transformation by-products. These by-products are mainly chlorinated compounds. According to the acute and chronic toxicity calculated using ECOSAR computer program, the transformation by-products are more harmful than sotalol.

Occurrence, ecotoxicological effects and risk assessment of antihypertensive pharmaceutical residues in the aquatic environment--A review

This study presents a review of the investigated antihypertensives in different aquatic compartments. It aims to compare these data with those regarding ecotoxicity effects in order to find out ecotoxicological data gaps for these pharmaceuticals and to point out the need for future studies. In addition, part of this article is dedicated to the risk assessment of the parent compounds atenolol, metoprolol, propranolol and verapamil, which are of great environmental concern in terms of contamination levels and for which there are sufficient ecotoxicological data available. 79 articles were retrieved presenting quantization data for 34 different antihypertensives and/or their metabolites. Only 43 articles were found regarding acute and chronic ecotoxicological effects of antihypertensive drugs. The results indicated that the beta-blockers atenolol, metoprolol and propranolol are the antihypertensives most frequently detected in the aquatic environment. They are also the drugs which reached the highest maximum concentrations in surface waters in the data reported in the literature. The highest percentages of ecotoxicity data regarding antihypertensives were also related to these beta-blockers. On the other hand, there is clearly a lack of ecotoxicity data, especially the chronic ones, regarding other antihypertensives. The environmental risk assessment (ERA) showed that all three of the evaluated beta-blockers can pose a potential long-term risk for non-target organisms of both fresh and marine water species. However, more meaningful ecotoxicity data for antihypertensives, including saltwater species, are required to refine and enlarge these results. Additional studies focusing on potential interactions between pharmaceutical mixtures, including antihypertensives, are also an urgent need.