Selective uptake and biological consequences of environmentally relevant antidepressant pharmaceutical exposures on male fathead minnows

Antidepressant pharmaceuticals have been reported in wastewater effluent at the nanogram to low microgram-per-liter range, and include bupropion (BUP), fluoxetine (FLX), sertraline (SER), and venlafaxine (VEN). To assess the effects of antidepressants on reproductive anatomy, physiology, and behavior, adult male fathead minnows (Pimephales promelas) were exposed for 21 days either to a single concentration of the antidepressants FLX, SER, VEN, or BUP, or to an antidepressant mixture. The data demonstrated that exposure to VEN (305 ng/L and 1104 ng/L) and SER (5.2 ng/L) resulted in mortality. Anatomical alterations were noted within the testes of fish exposed to SER and FLX, both modulators of the neurotransmitter serotonin. Additionally, FLX at 28 ng/L induced vitellogenin in male fish--a common endpoint for estrogenic endocrine disruption. Significant alterations in male secondary sex characteristics were noted with single exposures. Effects of single compound exposures neither carried over, nor became additive in the antidepressant mixtures, and reproductive behavior was not affected. Analysis of brain tissues from the exposed fish suggested increased uptake of FLX, SER and BUP and minimal uptake of VEN when compared to exposure water concentrations. Furthermore, the only metabolite detected consistently in the brain tissues was norfluoxetine. Similar trends of uptake by brain tissue were observed when fish were exposed to antidepressant mixtures. The present study demonstrates that anatomy and physiology, but not reproductive behavior, can be disrupted by exposure to environmental concentrations of some antidepressants. The observation that antidepressant uptake into fish tissues is selective may have consequences on assessing the mode-of-action and effects of these compounds in future studies.

Acute and chronic toxicity of five selective serotonin reuptake inhibitors in Ceriodaphnia dubia

Contamination of surface waters by pharmaceutical chemicals has raised concern among environmental scientists because of the potential for negative effects on aquatic organisms. Of particular importance are pharmaceutical compounds that affect the nervous or endocrine systems because effects on aquatic organisms are possible at low environmental concentrations. Selective serotonin reuptake inhibitors (SSRIs) are drugs used to treat clinical depression in humans, and have been detected in low concentrations in surface waters. In this investigation, the acute and chronic toxicity of five SSRIs (fluoxetine, Prozac; fluvoxamine, Luvox; paroxetine, Paxil; citalopram, Celexa; and sertraline, Zoloft) were evaluated in the daphnid Ceriodaphnia dubia. For each SSRI, the 48-h median lethal concentration (LC50) was determined in three static tests with neonate C. dubia, and chronic (8-d) tests were conducted to determine no-observable-effect concentrations (NOEC) and lowest-observable-effect concentrations (LOEC) for reproduction endpoints. The 48-h LC50 for the SSRIs ranged from 0.12 to 3.90 mg/L and the order of toxicity of the compounds was (lowest to highest): Citalopram, fluvoxamine, paroxetine, fluoxetine, sertraline. Mortality data for the 8-d chronic tests were similar to the 48-h acute data. The SSRIs negatively affected C. dubia reproduction by reducing the number of neonates per female, and for some SSRIs, by reducing the number of broods per female. For sertraline, the most toxic SSRI, the LOEC for the number of neonates per female was 0.045 mg/L and the NOEC was 0.009 mg/L. Results indicate that SSRIs can impact survival and reproduction of C. dubia; however, only at concentrations that are considerably higher than those expected in the environment.

Platelet inhibition by sertraline and N-desmethylsertraline: a possible missing link between depression, coronary events, and mortality benefits of selective serotonin reuptake inhibitors

Recently, clinical depression has been identified as an independent risk factor for increased mortality in patients following acute coronary events. Although the underlying mechanisms of this link remain uncertain, increased platelet activity has been suggested but never proven as the mechanism responsible for this association. Sertraline hydrochloride is a selective serotonin reuptake inhibitor (SSRI), and is an effective antidepressant agent. Its major liver metabolite, N-desmethylsertraline (NDMS), is known to be neurologically inactive. We assessed the in vitro effects of escalating concentrations of sertraline and NDMS on human platelets by aggregometry in plasma and whole blood, by expression of major surface receptors with flow cytometry in washed cells and in the whole blood, and quantitatively by various platelet function analysers in healthy volunteers and patients with coronary artery disease. Pretreatment of blood samples with sertraline and NDMS resulted in a dose-dependent inhibition of platelet-rich plasma aggregation induced by 5 microM ADP (P =, 0.002), by 10 microM ADP (P = 0.0017), by collagen (P = 0.008), and by thrombin (P = 0.026). Whole blood platelet aggregability was also significantly reduced when induced by 20 microM ADP (P = 0.006), and by collagen (P = 0.01). Surface expression of CD9 (P = 0.004), GP Ib (P = 0.0001), GP IIb/IIIa (P = 0.007), VLA-2 (P = 0.01), P-selectin (P = 0.02), and PECAM-1 (P = 0.01), but not the vitronectin receptor, was also reduced in sertraline and NDMS pretreated washed platelets. Whole blood flow cytometry revealed significant inhibition of GP IIb/IIIa (P = 0.008), and P-selectin expression (P = 0.0001) in NDMS treated samples. Closure time was delayed for the collagen-ADP cartridge (P = 0.009), and for the collagen-epinephrin cartridge (P = 0.01), indicating platelet inhibition in whole blood under high shear conditions. Rapid platelet-function assay revealed a decreased (P = 0.002) ability of platelets to agglutinate fibrinogen-coated beads, suggesting GP IIb/IIIa inhibition. Both sertraline, and its neurologically inactive metabolite NDMS, exhibited significant dose-dependent inhibition of human platelets. The documented anti-platelet effects of sertraline and NDMS may be directly related to the mortality benefits of SSRIs after ischemic events including myocardial infarction and stroke.

Aquatic toxicity of sertraline to Pimephales promelas at environmentally relevant surface water pH

Researchers recognize that ionization state may influence the biological activity of weak acids and bases. Dissociation in aqueous solutions is controlled by the pKa of a compound and the pH of the matrix. Because many pharmaceuticals are implicitly designed as ionizable compounds, site-specific variability in pH of receiving waters may introduce uncertainty to ecological risk assessments. The present study employed 48-h and 7-d toxicity tests with Pimephales promelas exposed to the model weak base pharmaceutical sertraline over a gradient of environmentally relevant surface water pHs. The 48-h experiments were completed in triplicate, and the average lethal concentration values were 647, 205, and 72 microL sertraline at pH 6.5, 7.5, and 8.5, respectively. Survivorship, growth, and feeding rate (a nontraditional endpoint linked by other researchers to sertraline's specific mode of action) were monitored during the 7-d experiment. Adverse effects were more pronounced when individuals were exposed to sertraline at pH 8.5 compared to pH 7.5 and 6.5. The pH-dependent toxicological relationships from these studies were related to in-stream pH data for two streams in the Brazos River basin of central Texas, USA. This predictive approach was taken because of the scarcity of environmental analytical data for sertraline. The results of this study emphasized temporal variability associated with in-stream pH linked to seasonal differences within and between these spatially related systems. Relating site-specific pH variability of surface waters to ionization state may allow researchers to reduce uncertainty during ecological risk assessment of pharmaceuticals by improving estimates of biological effects associated with exposure.

Immunotoxicities of microplastics and sertraline, alone and in combination, to a bivalve species: size-dependent interaction and potential toxication mechanism

Although coexposure to pharmaceuticals and microplastics (MPs) may frequently occur, the synergistic impact of MPs and antidepressants on marine species still remains poorly understood. In this study, the immunotoxicities of polystyrene MPs (diameters 500 nm and 30 μm) and sertraline (Ser), alone and in combination, were investigated in a bivalve mollusk Tegillarca granosa. Results showed that both MPs and Ser significantly suppressed the immune responses of T. granosa. In addition, though the toxic effect of Ser was not affected by microscale MPs, an evident synergistic immuno-toxic effect was observed between Ser and nanoscale MPs, which indicates a size-dependent interaction between the two. To further ascertain the underlying toxication mechanisms, the intracellular content of reactive oxygen species, apoptosis status, ATP content, pyruvate kinase activity, plasma cortisol level, and in vivo concentrations of neurotransmitters and cytochrome P450 1A1 were analysed. A transcriptomic analysis was also performed to reveal global molecular alterations following Ser and/or MPs exposure. The obtained results indicated that the presence of nanoscale MPs may enhance the immunotoxicity of Ser by (i) inducing apoptosis of haemocytes and, hence, reducing the THC; (ii) constraining the energy availability for phagocytosis; and (iii) hampering the detoxification of Ser.

Behavioural and transcriptional changes in the amphipod Echinogammarus marinus exposed to two antidepressants, fluoxetine and sertraline

In the past decade, there have been increasing concerns over the effects of pharmaceutical compounds in the aquatic environment, however very little is known about the effects of antidepressants such as the selective serotonin re-uptake inhibitors (SSRIs). Many biological functions within invertebrates are under the control of serotonin, such as reproduction, metabolism, moulting and behaviour. The effects of serotonin and fluoxetine have recently been shown to alter the behaviour of the marine amphipod, Echinogammarus marinus (Leach, 1815). The purpose of this study was to observe behavioural and transcriptional modifications in this crustacean exposed to the two most prescribed SSRIs (fluoxetine and sertraline) and to develop biomarkers of neurological endocrine disruption. The animals were exposed to both drugs at environmentally relevant concentrations from 0.001 to 1μg/L during short-term (1h and 1day) and medium-term (8 days) experiments. The movement of the amphipods was tracked using the behavioural analysis software during 12min alternating dark/light conditions. The behavioural analysis revealed a significant effect on velocity which was observed after 1h exposure to sertraline at 0.01μg/L and after 1 day exposure to fluoxetine as low as 0.001μg/L. The most predominant effect of drugs on velocity was recorded after 1 day exposure for the 0.1 and 0.01μg/L concentrations of fluoxetine and sertraline, respectively. Subsequently, the expression (in this article gene expression is taken to represent only transcription, although it is acknowledged that gene expression can also be regulated at translation, mRNA and protein stability levels) of several E. marinus neurological genes, potentially involved in the serotonin metabolic pathway or behaviour regulation, were analysed in animals exposed to various SSRIs concentrations using RT-qPCR. The expression of a tryptophan hydroxylase (Ph), a neurocan core protein (Neuc), a Rhodopsin (Rhod1) and an Arrestin (Arr) were measured following exposure to fluoxetine or sertraline for 8 days. The levels of Neuc, Rhod1 and Arr were significantly down-regulated to approximately 0.5-, 0.29- and 0.46-fold, respectively, for the lower concentrations of fluoxetine suggesting potential changes in the phototransduction pathway. The expression of Rhod1 tended to be up-regulated for the lower concentration of sertraline but not significantly. In summary, fluoxetine and sertraline have a significant impact on the behaviour and neurophysiology of this amphipod at environmentally relevant concentrations with effects observed after relatively short periods of time.

Toxicity screening of diclofenac, propranolol, sertraline and simvastatin using Danio rerio and Paracentrotus lividus embryo bioassays

Early life-stage bioassays have been used as an alternative to short-term adult toxicity tests since they are cost-effective. A single couple can produce hundreds or thousands of embryos and hence can be used as a simple high-throughput approach in toxicity studies. In the present study, zebrafish and sea urchin embryo bioassays were used to test the toxicity of four pharmaceuticals belonging to different therapeutic classes: diclofenac, propranolol, simvastatin and sertraline. Simvastatin was the most toxic tested compound for zebrafish embryo, followed by diclofenac. Sertraline was the most toxic drug to sea urchin embryos, inducing development abnormalities at the ng/L range. Overall, our results highlight the potential of sea urchin embryo bioassay as a promising and sensitive approach for the high-throughput methods to test the toxicity of new chemicals, including pharmaceuticals, and identify several drugs that should go through more detailed toxicity assays.

Microcosm evaluation of the effects of an eight pharmaceutical mixture to the aquatic macrophytes Lemna gibba and Myriophyllum sibiricum

Pharmaceuticals have been detected in surface waters of the US and Europe, originating largely from two sources, sewage effluent and agricultural runoff. These compounds often occur as mixtures leading to potential combined effects. In order to investigate the effects of a realistic pharmaceutical mixture on an ecosystem, a study utilizing 15 of 12,000 L aquatic microcosms treated with eight common pharmaceuticals (atorvastatin, acetaminophen, caffeine, sulfamethoxazole, carbamazepine, levofloxacin, sertraline, and trimethoprim) at total (summed) molar concentrations of 0, 0.044, 0.608, 2.664, and 24.538 micromol/L (n = 3) was conducted. Phytotoxicity was assessed on a variety of somatic and pigment endpoints in rooted (Myriophyllum sibiricum) and floating (Lemna gibba) macrophytes over a 35-day period. EC10, EC25 and EC50 values were calculated for each endpoint exhibiting a concentration-dependent response. Generally, M. sibiricum and L. gibba displayed similar sensitivity to the pharmaceutical mixture, with phytotoxic injury evident in both species, which was concentration dependent. Through single compound 7-day daily static renewal toxicity tests with L. gibba, the sulfonamide antibiotic sulfamethoxazole, the fluoroquinolone antibiotic levofloxacin and the blood lipid regulator atorvastatin were found to be the only compounds to elicit phytotoxic effects in the concentration range utilized (0-1000 microg/L). Atorvastatin concentration was highly correlated to decreased pigment content in L. gibba, likely inhibiting the known target enzyme HMGR, the rate-limiting enzyme in isoprenoid biosynthesis. Hazard quotients were calculated for both microcosm and laboratory studies; the highest HQ values were 0.235 (L. gibba) and 0.051 (L. gibba), which are below the threshold value of 1 for chronic risks. The microcosm data suggest that at an ecological effect size of >20%, biologically significant risks are low for L. gibba and M. sibiricum exposed to similar mixtures of pharmaceutical compounds. For M. sibiricum and L. gibba, respective minimum differences of 5 and 1%, were detectable, however, these effect sizes are not considered ecologically significant.

Toxicity and hazard of selective serotonin reuptake inhibitor antidepressants fluoxetine, fluvoxamine, and sertraline to algae

The toxicity of SSRIs to algae/phytoplankton was investigated using the US EPA ECOSAR, acute single-species growth inhibition assays, species sensitivity distributions (SSDs), and an outdoor microcosm mixture experiment. Worst-case ECOSAR estimates of SSRI toxicity to algae ranged from 0.73 to 13.08 mg/L. Sertraline was the most toxic SSRI tested in single-species growth inhibition assays followed by fluoxetine and fluvoxamine with worst-case 96-h IC10s of 4.6, 31.3, and 1662 microg/L, respectively. HC5s of 2.4, 3.6, and 1100 microg/L were estimated, respectively, for sertraline, fluoxetine, and fluvoxamine toxicity to algae-using SSDs. Microcosm phytoplankton structural endpoints were more sensitive than functional endpoints in the short term. However, in the long term, structural endpoints were resilient and functional endpoints remained impacted even after a period of recovery. The worst-case EC10 determined from the outdoor microcosm mixture toxicity to phytoplankton communities was 15.2 nM. Although SSRIs are toxic to algae, hazard quotients using worst-case PECs represent a margin of safety of 20 to phytoplankton. Although SSRIs do not appear to pose a hazard to primary production, this assessment is not protective of higher aquatic organisms and further research into the chronic toxicity to low levels of SSRIs to higher-level aquatic species is recommended.

Growth and development of tadpoles (Xenopus laevis) exposed to selective serotonin reuptake inhibitors, fluoxetine and sertraline, throughout metamorphosis

Selective serotonin reuptake inhibitors (SSRIs) are widely prescribed drugs that are present in sewage effluents and surface waters. The objective of the present study was to determine whether low environmentally relevant concentrations of the SSRIs fluoxetine and sertraline could impair growth and development in tadpoles of the African clawed frog (Xenopus laevis) and to evaluate if such effects may be caused by a disruption of the neuroendocrine system. Tadpoles were exposed to SSRIs at concentrations of 0.1, 1, and 10 microg/L for 70 d throughout metamorphosis. No effects on deformities were observed. Tadpoles exposed to fluoxetine (10 microg/L) and sertraline (0.1, 1, and 10 microg/L) exhibited reduced growth at metamorphosis. Tadpoles exposed to sertraline (0.1 and 1 microg/L) exhibited an acceleration of development as indicated by an increase in the time to tail resorption. The effects of SSRIs on growth and development in tadpoles were likely driven by reduced food intake. Reduced feeding rates were observed in SSRI-exposed tadpoles, and nutritional status can influence growth and development in amphibians via effects on the neuroendocrine system. Only sertraline was capable of causing developmental toxicity in tadpoles at environmentally relevant concentrations. These data warrant additional research to characterize the risks to human health and wildlife from pharmaceutical exposures.

Behavioral and biochemical responses in freshwater fish Carassius auratus exposed to sertraline

Sertraline is one of the most commonly prescribed selective serotonin reuptake inhibitors and is frequently detected in the aquatic environment. However, knowledge regarding relationships among molecular or biochemical endpoints involved in modes of action (MOAs) of sertraline and ecologically important behavioral responses of fish is insufficient. The present study aimed to investigate the bioconcentration and possible adverse outcomes pathways (AOPs) in crucian carp (Carassius auratus) exposed to various concentrations of sertraline (4.36, 21.3 and 116 μg L(-1)) for 7 d. Bioconcentration factor values were in the range of 19.5-626 in liver, 6.94-285 in brain, 4.01-146 in gill and 0.625-43.1 in muscle during the entire period of exposure. Liver superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activities and brain acetylcholinesterase (AChE) activity were selected as biochemical endpoints associated with MOAs. Swimming activity, shoaling, feeding rate and food consumption were determined to assess behavioral responses. Fish plasma levels of sertraline exceeding human therapeutic doses were also predicted from external exposure concentrations. Significant enhancements in CAT, GPx, AChE and swimming activities and decreases in shoaling tendency, feeding rate and food consumption were observed when fish plasma levels exceeded human therapeutic thresholds. Shoaling, feeding rate and food consumption were correlated with the activities of SOD, CAT and GST. A significant positive correlation between swimming activity and AChE activity was also observed. As such, our study provides important AOPs linking biochemical responses with ultimate ecologically relevant behavioral endpoints.

Aquatic ecotoxicity of the selective serotonin reuptake inhibitor sertraline hydrochloride in a battery of freshwater test species

Sertraline hydrochloride is a selective serotonin reuptake inhibitor (SSRI) widely prescribed to patients suffering from psychiatric disorders. Pharmaceutical products such as sertraline have been identified in environmental waters. This study describes the evaluation of sertraline using a battery of freshwater species representing four trophic levels. The species most sensitive to sertraline were Daphnia magna 21 d reproduction test, Pseudokirchneriella subcapitata 72 h growth inhibition, and Oncorhynchus mykiss 96 h mortality, with the Microtox assay being the least sensitive assay. The D. magna 21 d reproduction test was approximately two orders of magnitude more sensitive than the other bioassays. These results show the advantages of having a tiered approach within a test battery. The presented results indicate that sertraline hydrochloride adversely affects aquatic organisms at levels several orders of magnitude higher than that reported in municipal effluent concentrations, however adverse effects may result from lower concentration exposures, further research into chronic toxicity is therefore advocated.

Effect of antidepressants on circadian rhythms in fish: Insights and implications regarding the design of behavioural toxicity tests

Selective Serotonin Reuptake Inhibitors (SSRIs) and Serotonin and Norepinephrine Reuptake Inhibitors (SNRIs) are widely prescribed for the treatment of depression and anxiety disorders. Consequently, these compounds are frequently identified in global waterways where they may pose a hazard to aquatic biota. Evidence demonstrates these compounds to be capable of influencing the behaviour of fish, but the relevance of many reported behavioural endpoints is unclear and the value of some findings has been questioned. Since these compounds act on neuroendocrine-mediated pathways in vertebrates, the present study explored how exposure to two representative SSRIs (fluoxetine and sertraline) and an SNRI (venlafaxine) affect circadian rhythms in fish. Male mosquitofish (Gambusia holbrooki) were exposed to 1, 10 and 100μg/L concentrations of these compounds individually and when present as a full mixture, for a period of one week. Neither fluoxetine nor sertraline had an impact on diurnal activity patterns when fish were exposed to these compounds alone at any concentration, whereas venlafaxine significantly disrupted normal circadian rhythmicity but only at 100μg/L. When fish were exposed to the full mixture, significantly altered diurnal activity patterns were rapidly observed at nominal concentrations of 1 and 100μg/L, but there was no effect at 10μg/L. This sort of non-monotonic dose relationship is not altogether unusual for fish exposed to antidepressants, but it poses a problem when attempting to evaluate potential risks to the aquatic environment. To evaluate the possibility for misinterpretation when collecting behavioural data over short temporal scales, the data for each day of the experiment was analysed separately. The outcomes demonstrate the importance of longer periods of data collection, which may be necessary to capture the full range of natural behavioural variability that exists both amongst and within individual fish. More importantly, these findings may help reveal why discrepancies are commonly being reported in the literature with regards behavioural effects in fish exposed to antidepressants. It is thus suggested that research be aimed at documenting behavioural variability in fish species used in toxicity testing, to establish guidelines for quality control and where possible inform the development of standardised methodologies so that behavioural analysis can be more appropriately applied to the broad field of aquatic toxicology.

Global gene expression in larval zebrafish (Danio rerio) exposed to selective serotonin reuptake inhibitors (fluoxetine and sertraline) reveals unique expression profiles and potential biomarkers of exposure

Larval zebrafish (Danio rerio) were exposed (96 h) to selective serotonin reuptake inhibitors (SSRIs) fluoxetine and sertraline and changes in transcriptomes analyzed by Affymetrix GeneChip Zebrafish Array were evaluated to enhance understanding of biochemical pathways and differences between these SSRIs. The number of genes differentially expressed after fluoxetine exposure was 288 at 25 μg/L and 131 at 250 μg/L; and after sertraline exposure was 33 at 25 μg/L and 52 at 250 μg/L. Same five genes were differentially regulated in both SSRIs indicating shared molecular pathways. Among these, the gene coding for FK506 binding protein 5, annotated to stress response regulation, was highly down-regulated in all treatments (results confirmed by qRT-PCR). Gene ontology analysis indicated at the gene expression level that regulation of stress response and cholinesterase activities were influenced by these SSRIs, and suggested that changes in transcription of these genes could be used as biomarkers of SSRI exposure.

Molecular and behavioral responses of zebrafish embryos/larvae after sertraline exposure

Sertraline (SER) is one of the most frequently detected antidepressant drugs in aquatic environments. However, knowledge regarding SER-induced behavioral alterations in fish is insufficient, as well as the mechanisms underlying SER-induced toxicity. The present study aimed to determine behavioral and molecular responses in larval fish following SER exposure with a focus on its mode of action. Zebrafish embryos (~6 h-post-fertilization, hpf) were exposed to one of three concentrations of SER (1, 10, 100 μg/L) for 6 days, respectively. Evaluated parameters included development, behavior, transcripts related to serotonin signaling, serotonin levels, and acetylcholinesterase activity. Accelerated hatching of zebrafish embryos was observed for those fish exposed to 100 μg/L SER at 54 hpf. Locomotor activity (e.g. distance moved and mobile cumulative duration) was significantly reduced in larval zebrafish following exposure to 10 and 100 μg/L SER. Conversely, larval fish showed increased dark-avoidance after exposure to 1-100 μg/L SER. Of the measured transcripts related to serotonin signaling, only serotonin transporter (serta) and serotonin receptor 2c (5-ht2c) mRNA levels were increased in fish in response to 10 μg/L SER treatment. However, serotonin levels were unaltered in larvae exposed to SER. There were no differences among groups in acetylcholinesterase activity at any concentration tested. Taking together, the results evidenced that exposure to SER alters behavioral responses in early-staged zebrafish, which may be related to the abnormal expression of 5-ht2c. This study elucidates molecular responses to SER and characterizes targets that may be sensitive to antidepressant pharmaceuticals in larval fish.

Two antidepressants fluoxetine and sertraline cause growth retardation and oxidative stress in the marine rotifer Brachionus koreanus

To understand effects of two widely used antidepressant on the antioxidant defense mechanism in the marine rotifer Brachionus koreanus, we assessed acute toxicity and measured population growth, reactive oxygen species (ROS) levels, glutathione (GSH) levels, and antioxidant enzymatic activities (GST, GR, and SOD) in response to fluoxetine hydrochloride (FLX) and sertraline hydrochloride (SER). The no observed effect concentration-24 h of fluoxetine and sertraline were 1000 μg/L and 450 μg/L, respectively, whereas the median lethal concentration (LC50)-24 h of fluoxetine and sertraline were 1560 μg/L and 507 μg/L, respectively. Both fluoxetine and sertraline caused significant reduction (P < 0.05) in the population growth rate indicating that both antidepressants have a potential adverse effect on life cycle parameters of B. koreanus. The intracellular ROS level and GSH level were significantly modulated (P < 0.05) in response to fluoxetine and sertraline. In addition, antioxidant enzymatic activities have shown significant modulation (P < 0.05) in response to FLX and SER in B. koreanus. Furthermore, transcriptional profiles of antioxidant genes (GSTs, SODs, and GR) have shown modulation in response to FLX compared to SER-exposed B. koreanus. Our results indicate that fluoxetine and sertraline induce oxidative stress, leading to reduction in the population density and modulation of antioxidant defense mechanism in the marine rotifer B. koreanus.

Aquatic ecotoxicity of an antidepressant, sertraline hydrochloride, on microbial communities

Sertraline hydrochloride (Ser-HCl), a widely used antidepressant, becomes an aquatic contaminant via metabolic excretion and improper disposal; however, it is unknown how Ser-HCl affects aquatic microbial communities. The present study investigated the effects of Ser on the structures of aquatic microbial communities via high-throughput sequencing analyses. Ser-HCl treatment inhibited the growth of two model algae (the green alga, Chlorella vulgaris, and the cyanobacterium, Microcystis aeruginosa) and decreased the chlorophyll a (Chl-a) concentration in the microcosm to reduce the photosynthetic efficiency. High-throughput sequencing analyses showed that exposure to Ser-HCl disturbed the balance of cyanobacteria species by stimulating the growth of specific cyanobacteria. Among eukaryotes, the richness as well as the diversity indices were significantly enhanced after 5 days of Ser-HCl treatment but sharply decreased with exposure time. Nucleariida occupied an absolute majority (97.83%) within the eukaryotes, implicating that Ser-HCl disturbed the ecological equilibrium in microcosms. Ser-HCl will continue to be an environmental contaminant due to its wide usage and production. Our current study clarified the potential ecological risk of Ser-HCl to aquatic microorganisms. These findings suggest that more attention should be given to the negative effects of these bioactive pollutants on aquatic environments.

Adverse effects of the SSRI antidepressant sertraline on early life stages of marine invertebrates

Widespread contamination of coastal environments by emerging compounds includes low concentrations of pharmaceuticals. These pollutants are not currently incorporated in monitoring programs despite their effects on non-target organisms are very little documented. Among the selective serotonin reuptake inhibitor (SSRI) antidepressants, sertraline (SRT) is one of the most prescribed globally. In this work, earlier life stages of Amphibalanus amphitrite, Brachionus plicatilis and Mytilus galloprovincialis were exposed to environmental concentrations of SRT in order to study both sub-lethal and lethal responses in 24/48 h-tests. Low concentrations of SRT altered significantly swimming behavior in A. amphitrite and B. plicatilis giving 48 h-EC₅₀ (μg/L) of 113.88 and 282.23, respectively whereas higher values were observed for mortality and immobilization. EC₅₀ embryotoxicity with M. galloprovincialis was 206.80 μg/L. This work add new data about SRT ecotoxicity on marine invertebrates and confirms the applicability of behavioral endpoints to evaluate the environmental impact of antidepressants in marine organisms.

Preclinical toxicological evaluation of sertraline hydrochloride

The toxicity profile of the antidepressant drug sertraline was determined in a series of preclinical studies in mice, rats, rabbits and dogs. Acute, subchronic, reproductive, chronic and carcinogenicity studies were conducted by the oral route. The highest doses tested in these studies were the maximum tolerated doses based on clinical signs, decreased food consumption, body weight effects, organ weight changes or clinical/anatomical pathology findings. Genetic toxicity studies were also performed. The liver was identified as a target organ in the mouse, rat and dog. The observed liver findings were consistent with hepatic xenobiotic-metabolizing enzyme induction and included hepatomegaly, hepatocellular hypertrophy, slightly increased serum transaminase activity and proliferation of smooth endoplasmic reticulum. Hepatocellular fatty change, a minimal toxic effect, was seen in mice and rats. There was no teratogenicity in studies conducted at maternally toxic doses in rats and rabbits. Decreased neonatal survival and growth observed in these studies have been previously reported in reproduction studies with serotonin reuptake inhibitors. Sertraline was not genotoxic in an extensive battery of tests. Carcinogenicity tests were negative in rats, while benign liver tumors were slightly increased in drug-treated male mice. Liver tumors were considered secondary to the enzyme inducing potential of sertraline and not indicative of human risk.

Joint effects of nine antidepressants on Raphidocelis subcapitata and Skeletonema marinoi: A matter of amine functional groups

Antidepressants are among the most prescribed pharmaceuticals throughout the world. Their presence has already been detected in several aquatic ecosystems worldwide and their effects on non-target organisms justify the growing concern of both the public and regulatory authorities. These emerging pollutants do not occur as isolated compounds but rather as multi-component mixtures, which may lead to increased adverse effects compared to individual compounds. Freshwater and marine algae seem particularly sensitive to pharmaceuticals, including antidepressants. Studies assessing the toxicity of antidepressant mixture to algae focused mainly on binary mixtures of selective serotonin reuptake inhibitors. In the present experiment, the freshwater algae Raphidocelis subcapitata (formerly known as Pseudokirchneriella subcapitata) and the marine diatom Skeletonema marinoi were exposed to equitoxic mixtures of 9 antidepressants (fluvoxamine, fluoxetine, sertraline, duloxetine, venlafaxine, clomipramine, amitriptyline, and citalopram) at different concentrations. The growth inhibition was measured. Results showed that the toxicity of this mixture was higher than the effects of each individual component, highlighting simple additivity or synergistic effects, whereas tested concentrations were below the 10% inhibition concentration (IC₁₀) of each compound. Moreover, the QSAR analysis highlighted that antidepressants would act through narcosis (non-specific mode of action) towards the two species of algae. However, more specific effects can be observed by differentiating compounds with a primary/secondary amine from those with a tertiary amine. These mixture effects on algal species have to be assessed, especially since any impacts on phytoplankton could ultimately impact higher trophic levels (less food, secondary poisoning).

Environmentally relevant concentrations of methamphetamine and sertraline modify the behavior and life history traits of an aquatic invertebrate

Pharmaceutically active compounds are major contaminants of aquatic environments that show direct and indirect effects on aquatic organisms even at low concentrations. The aim of this study was to assess the effects of the illicit drug methamphetamine and the antidepressant sertraline on clonal marbled crayfish Procambarus virginalis. Crayfish exposed to the environmentally relevant concentrations of methamphetamine of ∼1 μg L^-1 did not exhibit significant differences from unexposed controls in distance moved, velocity, and activity level with or without available shelter. Sertraline-exposed (∼1 μg L^-1) crayfish were significantly more active, regardless of available shelter, and moved greater distances when shelter was available, compared to control crayfish. Crayfish exposed to methamphetamine and sertraline spent significantly more time outside the shelters compared to controls. Sertraline-exposed crayfish spawned more frequently and showed higher mortality than controls. The results suggest that the low environmental concentrations of the tested compounds could alter the behavior and life history traits of crayfish, resulting in higher reproductive effort and mortality.

Antidepressants are cytotoxic to rat primary blood brain barrier endothelial cells at high therapeutic concentrations

Antidepressants are commonly employed for the treatment of major depressive disorders and other psychiatric conditions. We investigated the relatively acute cytotoxic effects of three commonly prescribed antidepressants: fluoxetine, sertraline, and clomipramine on rat primary blood brain barrier endothelial cells over a concentration range of 0.1-100μM. At therapeutic concentrations (0.1μM) no significant cytotoxicity was observed after 4, 24, or 48h. At high therapeutic to overdose concentrations (1-100μM), antidepressants reduced cell viability in proportion to their concentration and exposure duration. At 1μM, antidepressants significantly reduced mitochondrial membrane potential. At drug concentrations producing ~50% inhibition of cell viability, all drugs significantly reduced cellular oxygen consumption rates, activities of mitochondrial complexes I and III, and triggered a significant increase of lactate production. Fluoxetine (6.5μM) and clomipramine (5.5μM) also significantly lowered transcellular transport of albumin. The mechanism of cellular cytotoxicity was evaluated and at high concentrations all drugs significantly increased the production of reactive oxygen species, and significantly increased the activity of the pro-apoptotic caspases-3, 8, and 9. Comet assays revealed that all drugs were genotoxic. Pre-incubation of cells with glutathione significantly ameliorated antidepressant-induced cytotoxicity, indicating the potential benefit of treatment of overdosed patients with antioxidants.

Ecological implications of altered fish foraging after exposure to an antidepressant pharmaceutical

Pharmaceutical residues are increasingly detected in environmental and biological samples, some at levels known to adversely affect non-target organisms; however, less is known of how these organism-level effects relate to the ecology of aquatic systems. Foraging processes may be used as behavioral endpoints that link effects on individuals to the population and community levels, enabling risk assessment of environmental contaminants at larger ecological scales. In this study, we performed feeding trials using juvenile Eurasian perch (Perca fluviatilis) exposed to the selective serotonin reuptake inhibitor (SSRI) sertraline to test the hypothesis that sertraline alters foraging ecology of the fish in terms of their functional response. We found an exposure-dependent decrease in feeding with increasing sertraline concentrations. Further experiments revealed that feeding rates decrease at both low and high prey densities, indicating effects on both attack rate and handling time, respectively. Because the functional response can shape consumer-resource dynamics, such effects may alter the stability of predator-prey systems and consequently, community structure.