Early responses measured in the brachyuran crab Carcinus maenas exposed to carbamazepine and novobiocin: application of a 2-tier approach

Differential effects of oxytetracycline on detoxification and antioxidant defense in the hepatopancreas and intestine of Chinese mitten crab under cadmium stress

This study aims to evaluate the effects of oxytetracycline (OTC) on detoxification and oxidative defense in the hepatopancreas and intestine of Chinese mitten crab (Eriocheir sinensis) under cadmium (Cd) stress. The crab was exposed to 0.6 μM Cd, 0.6 μM OTC, and 0.6 μM Cd plus 0.6 μM OTC for 42 days. Our results showed that in the intestine, OTC alone enhanced protein carboxylation (PC) and malondialdehyde (MDA) contents, which was associated with the increased OTC accumulation. Compared to Cd alone, Cd plus OTC increased Cd and OTC contents, and reduced detoxification (i.e., glutathione (GSH) content, gene expressions of cytochrome P450 (CYP) isoforms, 7-ethoxyresorufin O-deethylase (EROD) activity, mRNA levels and activities of glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST)), and antioxidant defense (i.e., gene expressions and activities of catalase (CAT) and superoxide dismutase (SOD)) in the intestine, leading to the increased in PC and MDA contents, suggesting that OTC had a synergistic effect on Cd-induced oxidative damage. In the hepatopancreas, although OTC alone increased OTC accumulation, it did not affect PC and MDA contents. Compared to Cd alone, Cd plus OTC reduced MDA content, which was closely related to the improvement of detoxification (i.e., GSH content, mRNA levels of CYP isoforms, EROD activity, gene expressions and activities of GPx, GR and GST), and antioxidant defense (gene expressions and activities of CAT and SOD, metallothionein content). Aryl hydrocarbon receptor (AhR) and nuclear factor E2-related factor 2 (Nrf2) transcriptional expressions were positively correlated with most detoxification- and antioxidant-related gene expressions, respectively, indicating that AhR and Nrf2 were involved in the regulation of these gene expressions. Our results unambiguously demonstrated that OTC had tissue-specific effects on Cd-induced toxicological effect in E. sinensis, which contributed to accurately evaluating Cd toxicity modulated by TCs in crab.

Elucidating the performance of UV-based photochemical processes for the removal of trace organic contaminants: Degradation and toxicity evaluation

In this study, the performance of standalone ultraviolet (UV) photolysis and UV-based advanced oxidation processes (AOPs), namely, UV/hydrogen peroxide, UV/chlorine, UV/persulphate, and UV/permonosulphate, were investigated for the degradation of 31 trace organic contaminants (TrOCs). Under the tested conditions, standalone UV photolysis did not achieve effective removal of TrOCs. To improve the degradation efficiency of UV photolysis, four different oxidants were added individually to the test solution. The effect of these oxidants in the absence of UV irradiation was also explored and only chlorine showed promising degradation of some contaminants. During the chlorination of 31 investigated TrOCs, only six demonstrated greater than 50% degradation. The combined UV-based AOPs demonstrated much improved degradation (ranging from 65 to 100%) depending on TrOC-structure and oxidant concentration. The UV/hydrogen peroxide process showed similar degradation of TrOCs, irrespective of the functional groups (i.e., electron withdrawing groups, EWGs and electron donating groups, EDGs) present in their structures. Conversely, the UV/sulphate and UV/chlorine based processes achieved better degradation of the TrOCs with EDGs in their structures. TrOCs degradation improved up to 40% when oxidants concentrations were increased from 0.1 to 1 mM, and further increasing the concentration to 2 mM did not improve degradation. Toxicity evaluation using bioluminescence test (BLT assay) demonstrated that except for UV/hydrogen peroxide, all UV-based AOPs increased the toxicity of the treated effluent, indicating generation of toxic by-products. This study elucidates the performance of four different UV-based AOPs for the removal of commonly detected diverse TrOCs for the first time.

Effects of carbamazepine in aquatic biota

Carbamazepine (CBZ) is one of the most common pharmaceuticals found in the aquatic environment. Here, we reviewed studies in aquatic animals highlighting that CBZ affected ROS homeostasis but also the neuroendocrine system, cell viability, immunity, reproduction, feeding behavior and growth. Notably, the acetylcholinesterase activity was modified by concentrations of the order of ng L^-1 CBZ. At ≥10 μg L^-1, data pointed that CBZ triggered the production of ROS, modifying the activity of antioxidant enzymes and produced a significant cellular stress at concentrations ≥100 μg L^-1. However, the response appeared species-, organ- and time-dependent, and was impacted by different experimental conditions and the origin of animals. In this context, this review discusses the available data and proposes future research priorities.

Proteomic changes in the solitary ascidian Herdmania momus following exposure to the anticonvulsant medication carbamazepine

The increasing use of pharmaceuticals in human and veterinary medicine, along with their poor removal rates at wastewater treatment facilities is resulting in the chronic release of pharmaceutically-active compounds (PhACs) into the marine environment, where they pose a threat to non-target organisms. A useful approach, as applied in the current study for assessing the effects of PhACs on non-target organisms, is the proteomic approach: the large-scale study of an organism's proteins. Using 'shotgun' proteomics, we identified differentially-expressed proteins based on peptide fragments in the solitary ascidian, Herdmania momus, following a 14-day laboratory experimental exposure to the PhAC carbamazepine (CBZ), an anticonvulsant and antidepressant medication, frequently detected in the aquatic environment. Individuals were exposed to environmentally relevant concentrations: 5 or 10 µg/L of CBZ, in addition to a control treatment. Out of 199 identified proteins, 24 were differentially expressed (12%) between the treatment groups, and thus can potentially be developed as biomarkers for CBZ contamination. Ascidians' phylogenetic position within the closest sister group to vertebrates presents an advantage in examining the pathological effects of PhACs on vertebrate-related organs and systems. Together with the world-wide distribution of some model ascidian species, and their ability to flourish in pristine and polluted sites, they provide a promising tool through which to study the extent and effects of PhAC contamination on marine organisms.

Occurrence and risk assessment of pharmaceuticals and cocaine around the coastal submarine sewage outfall in Guarujá, São Paulo State, Brazil

The aim of this study was to screen and quantify 23 pharmaceutical compounds (including illicit drugs), at two sampling points near the diffusers of the Guarujá submarine outfall, State of São Paulo, Brazil. Samples were collected in triplicate during the high (January 2018) and low (April 2018) seasons at two different water column depths (surface and bottom). A total of 10 compounds were detected using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Caffeine (42.3-141.0 ng/L), diclofenac (3.6-85.7 ng/L), valsartan (4.7-14.3 ng/L), benzoylecgonine (0.3-1.7 ng/L), and cocaine (0.3-0.6 ng/L) were frequently detected (75% occurrence). Orphenadrine (0.6-3.0 ng/L) and atenolol (0.1-0.3 ng/L), and acetaminophen (1.2-1.4 ng/L) and losartan (0.7-3.4 ng/L), were detected in 50% and 25% of the samples, respectively. Only one sample (12.5%) detected the presence of carbamazepine (< 0.001-0.1 ng/L). Unexpectedly a lower frequency of occurrence and concentration of these compounds occurred during the summer season, suggesting that other factors, such as the oceanographic and hydrodynamic regimes of the study area, besides the population rise, should be taken into account. Caffeine presented concentrations above the surface water safety limits (0.01 μg/L). For almost all compounds, the observed concentrations indicate nonenvironmental risk for the aquatic biota, except for caffeine, diclofenac, and acetaminophen that showed low to moderate ecological risk for the three trophic levels tested.

Occurrence of Antibiotics in Influent and Effluent from 3 Major Wastewater-Treatment Plants in Finland

Wastewater-treatment plants (WWTPs) are regarded as one of the main sources of antibiotics in the environment. In the present study, the concentrations of multiple antibiotics and their metabolites belonging to 5 antibiotic classes were determined in 3 major Finnish WWTPs. An online solid phase extraction-liquid chromatography-tandem mass spectrometry method was used for the extraction and analysis of the compounds. The method was fully validated using real and synthetic wastewaters. Seven antibiotics and 3 metabolites were found in the analyzed samples. Sulfonamides were removed most efficiently, whereas macrolides usually showed negative removal efficiency during the treatment, which means that the concentrations for individual antibiotics determined in the effluent samples were higher than in the influent samples. Sulfadiazine was found at concentrations up to 1018 ng/L, which was the highest concentration of any of the detected antibiotics in influent. In the effluent samples, the highest mean concentration was found for trimethoprim (532 ng/L). The measured mass loads of the antibiotics and metabolites to the receiving waters ranged from 2 to 157 mg/d per 1000 population equivalent. The evaluated environmental risk assessment showed that clarithromycin and erythromycin might pose a risk to the environment. The present study further underlines the importance of implementing technology for efficient removal of xenobiotics during wastewater treatment. Environ Toxicol Chem 2020;39:1774-1789. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

The glutathione S-transferase genes in marine rotifers and copepods: Identification of GSTs and applications for ecotoxicological studies

Various xenobiotics are constantly being released and accumulated into the aquatic environments and consequently, the aquatic organisms are continuously being exposed to exogenous stressors. Among various xenobiotic detoxifying enzymes, Glutathione S-transferase (GST) is one of the major xenobiotic detoxifying enzyme which is widely distributed among living organisms and thus, understanding of the nature of GSTs is crucial. Previous studies have shown GST activity in response to various xenobiotics yet, full identification of GSTs in marine invertebrates is still limited. This review covers information on the importance of GSTs as a biomarker for emerging chemicals and their response to wide ranges of environmental pollutants as well as in-depth phylogenetic analysis of marine invertebrates, including recently identified GSTs belonging to rotifers (Brachionus spp.) and copepods (Tigriopus japonicus and Paracyclopina nana), with unique class-specific features of GSTs, as well as a new suggestion of GST evolutionary pathway.

Assessing the effect of human pharmaceuticals (carbamazepine, diclofenac and ibuprofen) on the marine clam Ruditapes philippinarum: An integrative and multibiomarker approach

The presence of pharmaceuticals in the aquatic ecosystem has become a topic of growing interest in recent years. In this study, the marine clam Ruditapes philippinarum was exposed during 14 days to concentrations close to those found in the environment: (15 μg L^-1) of carbamazepine (CBZ), diclofenac (DCF) and ibuprofen (IBU), three pharmaceuticals widely used worldwide and commonly found within the aquatic environment. Additionally, exposure was followed by a depuration phase (7 days). A battery of biomarkers (superoxide dismutase SOD, catalase CAT, glutathione reductase GR, total glutathione peroxidase T-GPx, glutathione transferase GST, lipid peroxidation LPO, acetylcholinesterase AChE and metallothionein MT) was evaluated throughout the exposure and depuration. The Integrated Biomarker Response index was calculated with all selected biomarkers and used as a complementary tool in the evaluation of the organisms' health status. Exposure induced changes in the clams' biochemical responses that led to the hypothesis of the harmful role of the pharmaceuticals resulting in negative effects (changes in enzyme activities, LPO and MT levels, related to ROS production) particularly after short-term exposure. However, the clams showed the ability to cope with these imbalances by recovering their general oxidative status by the end of exposure.

Carbamazepine disrupts molting hormone signaling and inhibits molting and growth of Eriocheir sinensis at environmentally relevant concentrations

Carbamazepine (CBZ), one of the most frequently detected pharmaceutical compounds in aquatic environments, has recently been shown to cause chronic toxicity and endocrine disruption in a variety of non-target aquatic organisms. However, neither the effects nor the specific mechanism of CBZ action on the molting of crustaceans is well understood. The aim of this study was to investigate the effects of CBZ on the molting and growth of the Chinese mitten crab Eriocheir sinensis, a native and economically important species in China, and to elucidate the specific mechanisms through which molt inhibition occurs. Juvenile E. sinensis were treated with four nominal environmentally relevant concentrations (0.01, 0.1, 1, or 10 μg/L) of CBZ for acute (4 days) and chronic (40 days) exposures. After acute exposure, chitinase activity in the epidermis and 20-hydroxyecdysone (20-HE) concentration in the hemolymph were significantly decreased (p < 0.05) following treatment with 10 μg/L CBZ, whereas epidermal chitobiase activity significantly decreased (p < 0.05) in response to both 1 and 10 μg/L CBZ treatments. Transcript levels of the genes encoding crustacean hyperglycemic hormone (chh) and molt-inhibiting hormone (mih) in the eyestalks were also markedly induced after 1 or 10 μg/L CBZ treatment (p <  0.05), whereas the expression of genes encoding ecdysone receptor (ecr) and crustacean retinoid X receptor (rxr) in the hepatopancreas were significantly suppressed (p < 0.05) after acute exposure. Moreover, under chronic exposure, CBZ inhibited the molting and growth of E. sinensis, resulting in a longer time before molting was completed (TBM), as well as a lower molting increment (MI) with 1 or 10 μg/L treatment (p < 0.05). Collectively, these data indicate that CBZ can inhibit the molting process of E. sinensis by interfering with the activity of chitinolytic enzymes and molting hormone signaling, suggestive that carbamazepine may have long-term effects on crab development. We also confirmed that CBZ may function as an endocrine disruptor in decapod crustaceans, a phenomenon that has previously been reported in vertebrates.

Acute and Chronic Toxicity of Carbamazepine on the Release of Chitobiase, Molting, and Reproduction in Daphnia similis

As one of the most frequently detected pharmaceutical compounds in aquatic environments, carbamazepine (CBZ) has recently been shown to cause acute and chronic toxicity in a variety of non-target aquatic organisms. However, little is known about the ecotoxicological effects it has on the molting and reproduction of crustaceans. The aim of the present work was to evaluate the acute and chronic toxic responses to CBZ in the crustacean Daphnia similis. After acute exposure (4 days), CBZ did not cause lethal toxicity at the tested concentrations. However, CBZ did inhibit the molting and release of chitobiase at concentrations higher than 6.25 μg/L, with 96 h EC₅₀ (median effective concentration) values of 864.38 and 306.17 μg/L, respectively. The results of chronic exposure showed that the mean number of molts, size of the first brood, mean number of offspring per brood, mean number of broods per female, and total offspring per female decreased significantly with increasing CBZ concentrations. Significant effects of CBZ on the molting or fecundity in D. similis were observed even at concentrations as low as 0.03 μg/L. In conclusion, CBZ can cause inhibition of molting, delayed reproduction, and reduced fecundity in D. similis. CBZ toxicity to D. similis depends on the timing and duration of the exposure. Moreover, our results indicated that CBZ would act as an endocrine disrupter in D. similis, as with vertebrates (e.g., fish).

Ecotoxicological effects of losartan on the brown mussel Perna perna and its occurrence in seawater from Santos Bay (Brazil)

The antihypertensive losartan (LOS) has been detected in wastewater and environmental matrices, however further studies focused on assessing the ecotoxicological effects on aquatic ecosystems are necessary. Considering the intensive use of this pharmaceutical and its discharges into coastal zones, our study aimed to determine the environmental concentrations of LOS in seawater, as well as to assess the biological effects of LOS on the marine bivalve Perna perna. For this purpose, fertilization rate and embryolarval development were evaluated through standardized assays. Phase I (ethoxyresorufin O‑deethylase EROD and dibenzylfluorescein dealkylase DBF) and II (glutathione S-transferase GST) enzymes, glutathione peroxidase (GPx), Cholinesterase (ChE), lipoperoxidation (LPO) and DNA damage were used to analyze sublethal responses in gills and digestive gland of adult individuals. Lysosomal membrane stability was also assessed in hemocytes. Our results showed the occurrence of LOS in 100% of the analyzed water samples located in Santos Bay, Sao Paulo, Brazil, in a range of 0.2 ng/L-8.7 ng/L. Effects on reproductive endpoints were observed after short-term exposure to concentrations up to 75 mg/L. Biomarker responses demonstrated the induction of CYP450 like activity and GST in mussel gills exposed to 300 and 3000 ng/L of LOS, respectively. GPx activity was also increased in concentration of exposure to 3000 ng/L of LOS. Cyto-genotoxic effects were found in gills and hemocytes exposed in concentrations up to 300 ng/L. These results highlighted the concern of introducing this class of contaminants into marine environments, and pointed out the need to include antihypertensive compounds in environmental monitoring programs.

Health status alterations in Ruditapes philippinarum after continuous secondary effluent exposure before and after additional tertiary treatment application

A mobile pilot plant was set up in a wastewater treatment plant (WWTP) in southwest Spain to address potential adverse effects of effluents as a whole contaminant, which are discharging into marine environments. Ruditapes philippinarum specimens were exposed to different effluent concentrations (50%, 25%, 12.5%, 6.25%, and 3.15%) during seven days. After effluent exposure, lysosomal membrane stability alterations (LMS), changes in the energy status storage (total lipids content (TLP) and in the mitochondrial electron transport (MET), inhibition of inflammatory mechanisms (cyclooxygenase activity (COX)), and neurotoxic effects (acetylcholinesterase (AChE) were determined in exposed organisms. Furthermore, potential toxic reduction in the effluent was analysed by the application of an additional microalgae tertiary treatment called photobiotreatment (PhtBio). Results after PhtBio confirmed the toxic effect reduction in exposed organisms. Neuroendocrine effects, alterations in energy budget and in lipid storage revealed alterations in clam's health status causing stress conditions after effluent exposure.

Physiological and biochemical alterations induced in the mussel Mytilus galloprovincialis after short and long-term exposure to carbamazepine

The bivalve Mytilus galloprovincialis collected in the Ria de Aveiro, was selected to evaluate the acute and chronic effects of carbamazepine (CBZ) at environmentally relevant concentrations. CBZ is an antiepileptic drug widely found in the aquatic environment with toxic effects to inhabiting organisms. However, few studies evaluated the acute and chronic toxicity of this drug. The experiment was performed by exposing mussels to 0.0, 0.3, 3.0, 6.0 and 9.0 CBZ μg/L, for 96 h and 28 days. To assess the toxicity of the drug, a battery of biomarkers related to mussels general physiological health status and oxidative stress was applied. CBZ was quantified in mussel tissues by an Enzyme-Linked Immunosorbent Assay (ELISA). The results obtained show that CBZ did not induce oxidative stress. However, our findings demonstrated that the drug was taken up by mussels even though presenting low bioconcentration factor (BCF) values (up to 2.2). Furthermore, our results demonstrated that after a chronic exposure the physiological parameters, namely the condition and gonadosomatic indices, were negatively affected which may impair organisms' reproductive capacity with consequences to population sustainability.

Toxic effects of the antihistamine cetirizine in mussel Mytilus galloprovincialis

Recent studies have become increasingly focused on the assessment of pharmaceuticals occurrence in aquatic ecosystems, however the potential toxicity to non-target organisms is still largely unknown. The antihistamine cetirizine is a commonly used pharmaceutical, already detected in surface waters of marine aquatic systems worldwide. In the present study Mytilus galloprovincialis mussels were exposed to a range of cetirizine concentrations (0.3, 3.0, 6.0 and 12.0 μg/L), resembling moderate to highly contaminated areas, over 28 days. The responses of different biochemical markers were evaluated in mussels whole soft tissue, and included energy-related parameters (glycogen content, GLY; protein content, PROT; electron transport system activity, ETS), and oxidative stress markers (superoxide dismutase activity, SOD; catalase activity, CAT; glutathione S-transferases activity, GSTs; lipid peroxidation levels, LPO; reduced (GSH) and oxidized (GSSG) glutathione content). The results obtained demonstrated that with the increase of exposure concentrations mussels tended to increase their energy reserves and maintain their metabolic potential, which was significantly higher only at the highest concentration. Our findings clearly revealed that cetirizine inhibited the activity of GSTs and although induced the activity of antioxidant enzymes (SOD and CAT) mussels were not able to prevent cellular damages observed through the increase of LPO associated to the increase of exposure concentrations. Thus, this study confirmed that cetirizine induces toxic effects in Mytilus galloprovincialis, which, considering their trophic relevance, wide use as bioindicator and wide spatial distribution of this species, can result in ecological and economic negative impacts at a large scale.

Effects of novobiocin and methotrexate on the benthic amphipod Ampelisca brevicornis exposed to spiked sediments

The marine amphipod Ampelisca brevicornis was used as model organism of benthic macrofauna to assess the possible adverse effects of pharmaceuticals bound to sediments. Organisms were exposed to sediment spiked with novobiocin (NOV) and methotrexate (MTX) for 10 days in order to estimate the acute toxicity (lethal effects) produced by the two compounds. The surviving organisms were pooled and analyzed to determine their sublethal responses associated with different phases of metabolism (enzyme activities in phases I and II), oxidative stress (antioxidant enzyme activities and lipid peroxidation), and genotoxicity (DNA damage in the form of strand breaks). No lethal or sublethal effects were observed in the amphipods exposed to NOV. For organisms exposed to sediments spiked with MTX the results were found to calculate the concentration that was lethal to 50% of the organisms exposed in the toxicity tests (LC₅₀ of 30.36 ng/g). MTX also induced the metabolism of enzyme detoxification activities in phases I and II. Oxidative stress and DNA damage in particular were also observed, indicating responses associated with MTX's mechanism of action. Both mortality and the set of applied biomarkers allowed for the assessment of bioavailability, oxidative stress, and genotoxicity of NOV and MTX. The information obtained in this investigation can assist in ecological risk assessment of marine sediments contaminated by pharmaceuticals.

Effects of pharmaceuticals and personal care products on marine organisms: from single-species studies to an ecosystem-based approach

Pharmaceuticals and personal care products (PPCPs) are contaminants of emerging concern that are increasing in use and have demonstrated negative effects on aquatic organisms. There is a growing body of literature reporting the effects of PPCPs on freshwater organisms, but studies on the effects of PPCPs to marine and estuarine organisms are limited. Among effect studies, the vast majority examines subcellular or cellular effects, with far fewer studies examining organismal- and community-level effects. We reviewed the current published literature on marine and estuarine algae, invertebrates, fish, and mammals exposed to PPCPs, in order to expand upon current reviews. This paper builds on previous reviews of PPCP contamination in marine environments, filling prior literature gaps and adding consideration of ecosystem function and level of knowledge across marine habitat types. Finally, we reviewed and compiled data gaps suggested by current researchers and reviewers and propose a multi-level model to expand the focus of current PPCP research beyond laboratory studies. This model includes examination of direct ecological effects including food web and disease dynamics, biodiversity, community composition, and other ecosystem-level indicators of contaminant-driven change.

Hediste diversicolor as bioindicator of pharmaceutical pollution: Results from single and combined exposure to carbamazepine and caffeine

Several environmental stressors have been identified as key and/or emerging drivers of habitat change that could significantly influence marine near-shore ecosystems. These include increasing discharges of pharmaceutical contaminants into the aquatic coastal systems. Pharmaceutical drugs are often detected in aquatic environments but still information on their toxicity impacts on inhabiting species is scarce, especially when acting in combination. Furthermore, almost no information is available on the impacts of pharmaceuticals in polychaetes, often the most abundant taxon in benthic communities and commonly used as indicator species of environmental conditions. Therefore, the present study aimed to evaluate the biochemical alterations induced in the polychaete Hediste diversicolor, from a low contaminated area at the Ria de Aveiro lagoon (Portugal), by the antiepileptic drug carbamazepine (0.0 - control, 0.3, 3.0, 6.0 and 9.0μg/L) and the stimulant caffeine (0.0 - control, 0.5, 3.0, and 18.0μg/L), acting alone and in combination (0.3 CBZ+0.5 CAF and 6.0 CBZ+3.0 CAF). Glutathione S-transferases (GSTs), superoxide dismutase (SOD) and catalase (CAT) activities was determined in Hediste diversicolor from each condition. Lipid peroxidation (LPO), glutathione reduced and oxidized (GSH and GSSG), glycogen and electron transport system (ETS) were also measured. The results obtained clearly revealed that both drugs induced oxidative stress in H. diversicolor, shown by the increase on LPO levels and decrease on total glutathione and GSH/GSSG ratio with the increase of exposure concentrations. Furthermore, the present findings demonstrated that polychaetes biotransformation capacity as well as antioxidant defense mechanisms were not sufficiently efficient to fight against the excess of reactive oxygen species (ROS) leading to LPO when organisms were exposed to both drugs. Our results also demonstrated that polychaetes tended to decrease the activity of ETS when exposed to drugs, avoiding energy expenditure which may prevent them from greater damages. The present study further revealed that the impacts induced by the combination of both drugs were similar to those obtained at the highest drugs concentrations acting alone.

Human pharmaceuticals in the marine environment: Focus on exposure and biological effects in animal species

Marine waters have been poorly investigated for the occurrence of pharmaceutical contamination. Recent data confirm that pharmaceuticals occur widely in marine and coastal environments; therefore, assessment of potential risk to marine species needs further efforts. The present study represents the first extensive review of pharmaceutical contamination in marine environments addressing the effects on the marine biota analyzed at the molecular, cellular, and individual levels. Because pharmaceuticals differ from conventional pollutants, being designed to interact with specific physiological pathways at low doses, the most recent evidence on modes of action and physiological alterations on marine animal species are discussed. Data on spatial distributions of pharmaceuticals in waters and sediments, as well as bioaccumulation rates, are also presented. The present review also seeks to expand knowledge of how the quality of coastal and marine environments could be efficiently monitored to anticipate possible health and environmental risks.

Long-term exposure to caffeine and carbamazepine: Impacts on the regenerative capacity of the polychaete Diopatra neapolitana

The toxicity induced in non-target organisms by pharmaceutical drugs has been the focus of several studies. In the aquatic environment, most of the studies have been devoted to fish and bivalves, while little is known on the impacts induced in polychaetes. The present study evaluated the impacts of carbamazepine and caffeine on the regenerative capacity of Diopatra neapolitana, a polychaete species with high ecological and economic relevance. Under laboratory controlled conditions polychaetes were exposed, during 28 days, to carbamazepine (Ctl-0.0; 0.3; 3.0; 6.0; 9.0 μg/L) and caffeine (Ctl-0.0; 0.5; 3.0; 18.0 μg/L). During the experiment, at days 11, 18, 25, 32, 39 and 46 after amputation, for each specimen, the percentage of the body width regenerated was determined and the number of new segments was counted. The regenerative capacity was assessed considering the number of days needed to achieve full regeneration and the total number of new segments. The obtained results revealed that with the increase of drugs concentrations organisms regenerated less new segments and took longer to completely regenerate.

General stress, detoxification pathways, neurotoxicity and genotoxicity evaluated in Ruditapes philippinarum exposed to human pharmaceuticals

A battery of biomarkers was evaluated on Ruditapes philippinarum exposed during 14 days to caffeine, ibuprofen, carbamazepine and novobiocin (0.1, 1, 5, 10, 15, and 50µgL(-1)). The battery included general stress (lysosomal membrane stability - LMS) analysed in the hemolymph, and biochemical biomarkers analysed in digestive gland tissues including: biomarkers of phase I (etoxyresorufin O-deethylase - EROD, dibenzylfluorescein dealkylase - DBF), phase II (gluthathione-S-transferase - GST), oxidative stress (gluthathione reductase - GR, gluthathione peroxidase - GPX, lipid peroxidation - LPO), neurotoxicity (acetylcholinesterase activity - AChE), and genotoxicity (DNA damage). Pharmaceuticals tested induced the sublethal responses (even at the environmental range 0.1µgL(-1)). At this low concentration; caffeine, ibuprofen and carbamazepine decreased the LMS significantly compared with controls (p<0.05). The four compounds induced significantly the detoxification metabolism and oxidative stress (p<0.05). Neurotoxicity was noticed in clams exposed to caffeine and carbamazepine (p<0.05). Ibuprofen, carbamazepine and novobiocin produced genotoxic effects (p<0.05). Results from this research validate the use of biomarkers when assessing the effects of pharmaceuticals within a marine environmental risk assessment framework, using as a laboratory bioassay model the species R. philippinarum.

The impacts of pharmaceutical drugs under ocean acidification: New data on single and combined long-term effects of carbamazepine on Scrobicularia plana

Ocean acidification and increasing discharges of pharmaceutical contaminants into aquatic systems are among key and/or emerging drivers of environmental change affecting marine ecosystems. A growing body of evidence demonstrates that ocean acidification can have direct and indirect impacts on marine organisms although combined effects with other stressors, namely with pharmaceuticals, have received very little attention to date. The present study aimed to evaluate the impacts of the pharmaceutical drug Carbamazepine and pH 7.1, acting alone and in combination, on the clam Scrobicularia plana. For this, a long-term exposure (28 days)was conducted and a set of oxidative stress markers was investigated. The results obtained showed that S. plana was able to develop mechanisms to prevent oxidative damage when under low pH for a long period, presenting higher survival when exposed to this stressor compared to CBZ or the combination of CBZ with pH 7.1. Furthermore, the toxicity of CBZ on S. plana was synergistically increased under ocean acidification conditions (CBZ + pH 7.1): specimens survival was reduced and oxidative stress was enhanced when compared to single exposures. These findings add to the growing body of evidence that ocean acidification will act to increase the toxicity of CBZ to marine organisms,which has clear implications for coastal benthic ecosystems suffering chronic pollution from pharmaceutical drugs.

Is the step-wise tiered approach for ERA of pharmaceuticals useful for the assessment of cancer therapeutic drugs present in marine environment?

Methotrexate (MTX) and tamoxifen (TMX) cancer therapeutic drugs have been detected within the aquatic environment. Nevertheless, MTX and TMX research is essentially bio-medically orientated, with few studies addressing the question of its toxicity in fresh water organisms, and none to its' effect in the marine environment. To the authors' knowledge, Environmental Risk Assessments (ERA) for pharmaceuticals has mainly been designed for freshwater and terrestrial environments (European Medicines Agency-EMEA guideline, 2006). Therefore, the purpose of this research was (1) to assess effect of MTX and TMX in marine organism using the EMEA guideline, (2) to develop an ERA methodology for marine environment, and (3) to evaluate the suitability of including a biomarker approach in Phase III. To reach these aims, a risk assessment of MTX and TMX was performed following EMEA guideline, including a 2-tier approach during Phase III, applying lysosomal membrane stability (LMS) as a screening biomarker in tier-1 and a battery of biochemical biomarkers in tier-2. Results from Phase II indicated that MTX was not toxic for bacteria, microalgae and sea urchin at the concentrations tested, thus no further assessment was required, while TMX indicated a possible risk. Therefore, Phase III was performed for only TMX. Ruditapes philippinarum were exposed during 14 days to TMX (0.1, 1, 10, 50 μg L(-1)). At the end of the experiment, clams exposed to environmental concentration indicated significant changes in LMS compared to the control (p<0.01); thus a second tier was applied. A significant induction of biomarkers (activity of Ethoxyresorufin O-deethylase [EROD], glutathione S-transferase [GST], glutathione peroxidase [GPX], and lipid peroxidation [LPO] levels) was observed in digestive gland tissues of clams compared with control (p<0.01). Finally, this study indicated that MTX was not toxic at an environmental concentration, whilst TMX was potentially toxic for marine biota. This study has shown the necessity to create specific guidelines in order to evaluate effects of pharmaceuticals in marine environment which includes sensitive endpoints. The inadequacy of current EMEA guideline to predict chemotherapy agents toxicity in Phase II was displayed whilst the usefulness of other tests were demonstrated. The 2-tier approach, applied in Phase III, appears to be suitable for an ERA of cancer therapeutic drugs in the marine environment.

The effects of carbamazepine on macroinvertebrate species: Comparing bivalves and polychaetes biochemical responses

In the present study, the bivalve Scrobicularia plana and the polychaete Diopatra neapolitana were exposed to an increasing carbamazepine (CBZ) concentration gradient. Both species are among the most widely used bioindicators, and CBZ is one of the most commonly found drugs in the aquatic environment. After a chronic exposure (28 days), the results obtained revealed that CBZ induced biochemical alterations in both species. Our findings demonstrated that S. plana and D. neapolitana reduced the CBZ accumulation rate at higher CBZ concentrations, probably due to their capacity to decrease their feeding rates at stressful conditions. Nevertheless, this defence mechanism was not enough to prevent both species from oxidative stress. In fact, S. plana and D. neapolitana were not able to efficiently activate their antioxidant defence mechanisms which resulted in the increase of lipid peroxidation, especially at the highest CBZ concentrations. Comparing both species, it seems that S. plana was the most sensitive species since stronger biochemical alterations were observed in this species.

Yes, caffeine, ibuprofen, carbamazepine, novobiocin and tamoxifen have an effect on Corbicula fluminea (Müller, 1774)

Reports indicating the presence of pharmaceutical in fresh water environment in the ngL(-1) to µgL(-1) range are occurring with increasing frequency. It is also a fact that pharmaceuticals may produce adverse effects on aquatic organisms. Nevertheless, there is still a lack of knowledge regarding how these emergent contaminants may affect aquatic biota. The goal of this research was to evaluate the sublethal responses in Corbicula fluminea such as, general stress (lysosomal membrane stability [LMS]), biomarkers of phase I and II (etoxyresorufin O-deethylase [EROD], dibenzylfluorescein dealkylase [DBF], gluthathione-S-transferase [GST]), oxidative stress (gluthathione reductase [GR], gluthathione peroxidase [GPX], lipid peroxidation [LPO]), and biomarkers of effect (DNA damage) after 21 days of exposure to caffeine, ibuprofen, carbamazepine, novobiocin and tamoxifen at 0.1, 1, 5, 10, 15, 50µgL(-1). Environmental concentrations tested in this study caused general stress and produced changes on biomarkers tested. LMS, responses from phase I and II enzymatic activity, oxidative stress, and biomarker of effect represent important ecotoxicological information, and will provide a useful reference for the assessment of selected drugs and the effects which these compounds may have on aquatic invertebrates, using C. fluminea as a bioindicator species.

Toxicological evaluation of sediment samples spiked with human pharmaceutical products: Energy status and neuroendocrine effects in marine polychaetes Hediste diversicolor

There is a lack of studies about the ecotoxicology of pharmaceutical products on marine environment. To predict possible adverse effects of pharmaceutical products on benthic biota, polychaetes Hediste diversicolor were exposed for 14-days to pharmaceutical-spiked sediments under laboratory conditions. Carbamazepine (CBZ), ibuprofen (IBP) and propranolol (PRO) at concentrations of 500ngg(-1), 50ngg(-1), 5ngg(-1), 0.5ngg(-1) and 0.05ngg(-1), fluoxetine (FX) and 17α-ethynylestradiol (EE2) at concentrations of 100ngg(-1), 10ngg(-1), 1ngg(-1), 0.1ngg(-1) and 0.01ngg(-1), including environmental concentrations (underlined), were spiked in marine sediment samples. After the exposure, cellular energy status (total lipids content - TLP; and mitochondrial electron transport activity - MET), metabolism of monoamines (monoamine oxidase activity - MAO) and inflammation properties (cyclooxygenase activity - COX) were observed in polychaetes. CBZ increased TLP content and MET activity, and decreased MAO activity in polychaetes. IBP did not interfere on the TLP level, but on the MET and MAO activities (environmental concentrations). FX did not cause changes in the energy status. Therefore, environmental concentration diminished MAO activity. EE2 did not affect the energy status, however, MAO activity was significantly lower in polychaetes exposed to environmental concentration. PRO increased TLP level in polychaetes, but not MET activity. MAO activity was significantly lower for polychaetes exposed to environmental concentration. Except FX, all pharmaceuticals showed anti-inflammatory properties confirmed by the decrease of COX activity. Pharmaceutical products affected H. diversicolor physiology and health. As a benthic top predator, adverse effects on sea-worms can potentially culminate in ecosystem perturbations.

Biochemical and physiological responses of Carcinus maenas to temperature and the fungicide azoxystrobin

Research on the effects of thermal stress is currently pertinent as climate change is expected to cause more severe climate-driven events. Carcinus maenas, a recognised estuarine model organism, was selected to test temperature-dependence of azoxystrobin toxicity, a widely applied fungicide. Crabs' responses were assessed after a 10-d acclimation at different temperatures (5°C, 22°C, and 27°C) of which the last 72h were of exposure to an environmental concentration of azoxystrobin. SOD and GST activities, mitochondrial oxygen consumption rates and protein content, as well as the Coupling Index were determined. The hypothesis proposed that extreme temperatures (5°C and 27°C) and azoxystrobin would affect crabs' responses. Results showed statistically significant different effects of SOD and all oxygen rates measured promoted by temperature, and that neither 30.3μgL(-1) of azoxystrobin nor the combined effect were crab-responsive. Protein content at 5°C was statistically higher when compared with the control temperature (22°C). The Coupling Index revealed both a slight and a drastic decrease of this index promoted by 5°C and 27°C, respectively. Regarding azoxystrobin effects, at 22°C, this index only decreased slightly. However, at extreme temperatures it fell 47% at 5°C and slightly increased at 27°C. Results provided evidence that crabs' responses to cope with low temperatures were more effective than their responses to cope with high temperatures, which are expected in future climate projections. Moreover, crabs are capable of handling environmental concentrations of azoxystrobin. However, the Coupling Index showed that combined stress factors unbalance crabs' natural capability to handle a single stressor.

How life history influences the responses of the clam Scrobicularia plana to the combined impacts of carbamazepine and pH decrease

In the present study, the bivalve Scrobicularia plana, collected from two contrasting areas (pristine location and mercury contaminated area), was selected to assess the biochemical alterations imposed by pH decrease, carbamazepine (an antiepileptic) and the combined effect of both stressors. The effects on oxidative stress related biomarkers after 96 h exposure revealed that pH decrease and carbamazepine induced alterations on clams, with greater impacts on individuals from the contaminated area which presented higher mortality, higher lipid peroxidation and higher glutathione S-transferase activity. These results emphasize the risk of extrapolating results from one area to another, since the same species inhabiting different areas may be affected differently when exposed to the same stressors. Furthermore, the results obtained showed that, when combined, the impact of pH decrease and carbamazepine was lower than each stressor acting alone, which could be related to the defence mechanism of valves closure when bivalves are under higher stressful conditions.

Chronic toxicity of the antiepileptic carbamazepine on the clam Ruditapes philippinarum

The impacts of carbamazepine (CBZ) on aquatic organisms are yet not well investigated. The present study aimed to better understand the chronic effects of environmentally relevant concentrations of CBZ. The experiment was performed by exposing the filter feeding clam Ruditapes philippinarum to 0.00, 0.03, 0.30, 3.00 and 9.00μg/L, during 28days. To assess the chronic toxicity of the drug a battery of biomarkers related with health status and oxidative stress was applied. In order to quantify CBZ in the clam's tissues and in water samples ELISA was used. The present study showed three types of responses on the clams after a chronic exposure to CBZ. For control condition and the lower concentrations (0.03 and 0.30μg/L) a "similar" metabolic state was observed and the most efficient antioxidant status leading to the elimination of reactive oxygen species formed during the metabolism of CBZ. The concentration of 3.00μg/L seemed to be a "threshold" concentration, beyond which the concentration levels of CBZ began to exert a toxic effect, compromising the activity of biotransformation and antioxidant enzymes, with notorious effects at the highest CBZ concentration (9.00μg/L). CBZ also seemed to alter the energy-related responses, especially the glycogen and electron system responses, revealing a slowdown in metabolism at the higher exposure concentrations (3.00 and 9.00μg/L). Overall, the present study demonstrated that the higher CBZ concentrations can lead to the impairment of antioxidant enzymes compromising the neutralization of reactive oxygen species, and thus the ability to cope with oxidative stress.

Are standard tests sensitive enough to evaluate effects of human pharmaceuticals in aquatic biota? Facing changes in research approaches when performing risk assessment of drugs

Nowadays, the presence of pharmaceutical products in aquatic environments is not only common, but is also of significant concern regarding the adverse effect they may produce to aquatic biota. In order to determine the adverse effects of caffeine (CAF), ibuprofen (IBU), carbamazepine (CBZ) and novobiocin (NOV), at environmental occurring concentrations, standardized endpoints applied in current guidelines were evaluated in four organisms including bioluminescence response in Vibrio fischeri, growth inhibition in Isochrysis galbana (marine water) and Pseudokirchneriella subcapitata (fresh water) and fertilization and embryo-larval development in Paracentrotus lividus. To reach this aim bioassays were implemented by exposing organisms to water spiked with drugs dissolved in DMSO (0.001% v/v). Risk characterization was performed, calculating the environmental impact of drugs by calculating environmental concentration and predicted no effect concentration ratio (MEC/PNEC). Results indicate that acute toxicity was found above environmental concentrations in the order of mg L(-1) for bacteria bioluminescence, microalgae growth inhibition and sea urchin fertilization. However, teratogenicity was observed on sea urchin after exposure to environmental concentrations of drugs at 0.00001 mg L(-1); at this concentration CBZ and IBU were found to reduce significantly the embryo-larval development compared to controls (p<0.01). The risk calculated for selected drugs suggested they are harmless for aquatic environment except when applying the embryo-larval development endpoint. Endpoints applied in this study showed the necessity of using more sensitive responses, when assessing risk of pharmaceuticals in aquatic environments, since endpoints applied in current guidelines may not be suitable.

A candidate short-term toxicity test using Ampelisca brevicornis to assess sublethal responses to pharmaceuticals bound to marine sediments

Lethal and sublethal responses related to different phases of metabolism (phases I and II enzymatic activities), neurotoxicity (acetylcholinesterase activity), oxidative stress (lipid peroxidation and antioxidant enzyme activities), and genetic damage (DNA strand breaks) were analysed to assess the possible adverse effects of pharmaceuticals bound to marine sediments. The crustacean amphipod Ampelisca brevicornis was chosen as the bioindicator species. Organisms were exposed for 10 days to sediment spiked with pharmaceutical compounds frequently used and previously detected in the environment: carbamazepine (CBZ), ibuprofen (IBP), fluoxetine (FX), 17α-ethynylestradiol (EE2), propranolol (PRO), and caffeine (CAF). Short-term bioassay to evaluate amphipod mortality was recommended to assess pollution by CBZ, FX, and PRO. IBP and PRO were metabolized by phases I and II detoxification enzymatic activities. Oxidative stress was caused by PRO and CAF. Contrary to expected results, DNA damage (strand breaks) decreased after the exposure of amphipods to sediment spiked with IBP, FX, EE2, PRO, and CAF (including environmental concentrations). FX was neurotoxic to amphipods. The battery of biomarkers tested allowed the assessment of bioavailability, oxidative stress, genotoxicity, and neurotoxicity of the pharmaceuticals analysed. The results of this study suggested that pharmaceutical products at concentrations currently found in the environment might cause a wide variety of adverse effects (based on laboratory studies). The results obtained here are useful for environmental risk assessment of marine sediments contaminated by pharmaceuticals. Nevertheless, more research is needed using field-based marine sediments.

Presence of the pharmaceutical drug carbamazepine in coastal systems: effects on bivalves

Carbamazepine (CBZ), an antiepileptic drug, is one of the most commonly detected pharmaceutical drugs in aquatic ecosystems, and is used as a marker of urban pollution. Since CBZ is designed to exert a biological effect, when it reaches aquatic environment high probability exist for toxic effects on non-target organisms. The present study evaluated the acute toxicity of environmentally relevant concentrations of CBZ (0.00, 0.03, 0.30, 3.00, 9.00μg/L) in the edible clams Venerupis decussata (a native species) and Venerupis philippinarum (an invasive species) collected from the Ria de Aveiro. The effects on both species were assessed through the use of a battery of biomarkers mainly related with health status and oxidative stress. Furthermore, in this work an alternative and promising tool, the direct competitive immunoassay ELISA, for the direct CBZ quantification in clam's tissues, was applied. The results of the present work showed that CBZ in clam's tissues increased with the exposure concentration and V. decussata gave slightly higher values than V. philippinarum. Although the clams accumulated lower levels of CBZ than the concentration of exposure, these concentrations were enough to impair the health status and induce oxidative stress. However, a different response to CBZ was observed in the two species. While in V. philippinarum the lipid peroxidation levels increased at the highest CBZ concentration (9.00μg/L), in V. decussata a significant decrease was seen. Moreover, glutathionse S-transferase activity was stimulated in V. decussata and decreased in V. philippinarum. Nevertheless, an induction of glutathione reductase, superoxide dismutase and cytochrome P450 3A4 activities was found in both species as a result of the exposure. The results indicate that, probably, V. philippinarum have a less efficient antioxidant system than V. decussata, and are therefore less capable to neutralize oxidative stress and consequently more sensitive to CBZ. The risk quotient determined for the Ria de Aveiro was higher than 1 indicating that a ecotoxicological risk is suspected. Furthermore, bioaccumulation of CBZ in clams should be taken into consideration since this chemical might be transferred along the food chain and affect non-target organisms.

Bioavailability, oxidative stress, neurotoxicity and genotoxicity of pharmaceuticals bound to marine sediments. The use of the polychaete Hediste diversicolor as bioindicator species

A set of "early warning responses", measured as biomarkers of exposure and effect, was applied in the marine bioindicator Hediste diversicolor, in a way to assess the environmental quality of sediment affected by pharmaceutical contamination. Sublethal responses were determined in the sea-worms after 14-days of exposure to sediment spiked with some of the most representative pharmaceutical products found in the environment: carbamazepine (CBZ), ibuprofen (IBP), fluoxetine (FX), 17α-ethynylestradiol (EE2) and propranolol (PRO), including the environmental concentrations. Phases I (ethoxyresorufin O-deethylase - EROD and dibenzylfluorescein dealkylase - DBF) and II (glutathione S-transferase - GST) of the metabolism, antioxidant system (glutathione peroxidase - GPX and glutathione reductase - GR), neurotoxicity (acetylcholinesterase - AChE) and oxidative effects (lipid peroxidation - LPO and DNA damage strand breaks) were selected to evaluate the sublethal responses in the sea-worms. FX, EE2 and PRO were detoxified by the phase I of the metabolism (EROD activity). On the other hand, phase II (GST-activity) did not respond in sea-worms exposed to pharmaceutical products, except for the environmental concentrations of CBZ (activation) and PRO (deactivation). Neurotoxicity was induced in sea-worms exposed to EE2 (only the environmental concentrations), FX, IBP and CBZ. Oxidative effect determined as LPO increased in sea-worms exposed to environmental concentrations of IBP, EE2 and PRO. Genetic damage increased in sea-worms exposed to IBP and diminished for FX, EE2 and PRO. Our results indicated the toxicity of pharmaceutical products and recommended the battery of biomarkers and the bioindicator specie H. diversicolor for the environmental quality assessment of sediment affected by pharmaceutical contamination.

The crab Carcinus maenas as a suitable experimental model in ecotoxicology

Aquatic ecotoxicology broadly focuses on how aquatic organisms interact with pollutants in their environment in order to determine environmental hazard and potential risks to humans. Research has produced increasing evidence on the pivotal role of aquatic invertebrates in the assessment of the impact of pollutants on the environment. Its potential use to replace fish bioassays, which offers ethical advantages, has already been widely studied. Nevertheless, the selection of adequate invertebrate experimental models, appropriate experimental designs and bioassays, as well as the control of potential confounding factors in toxicity testing are of major importance to obtain scientifically valid results. Therefore, the present study reviews more than four decades of published research papers in which the Green crab Carcinus maenas was used as an experimental test organism. In general, the surveyed literature indicates that C. maenas is sensitive to a wide range of aquatic pollutants and that its biological responses are linked to exposure concentrations or doses. Current scientific knowledge regarding the biology and ecology of C. maenas and the extensive studies on toxicology found for the present review recognise the Green crab as a reliable estuarine/marine model for routine testing in ecotoxicology research and environmental quality assessment, especially in what concerns the application of the biomarker approach. Data gathered provide valuable information for the selection of adequate and trustworthy bioassays to be used in C. maenas toxicity testing. Since the final expression of high quality testing is a reliable outcome, the present review recommends gender, size and morphotype separation in C. maenas experimental designs and data evaluation. Moreover, the organisms' nutritional status should be taken into account, especially in long-term studies. Studies should also consider the crabs' resilience when facing historical and concurrent contamination. Finally, experimental temperature and salinity should be harmonised so as to obtain reliable comparisons between different studies. Concerning future reaserch areas, data gathered in the present review reveals that in vitro assays derived from C. maenas are still lacking. Also, a complete C. maenas genome sequencing programme will be essencial for cutting-edge reseach.