Ecotoxicological properties of ketoprofen and the S(+)-enantiomer (dexketoprofen): Bioassays in freshwater model species and biomarkers in fish PLHC-1 cell line

Simultaneous enantiomeric separation of linagliptin and clopidogrel by capillary electrophoresis for the individual, combined, and enantiomeric ecotoxicity evaluation on Pseudokirchneriella subcapitata

An analytical methodology was developed in this work enabling the simultaneous enantioseparation of linagliptin and clopidogrel by Capillary Electrophoresis (CE). The use of 10.4 mg/mL carboxymethyl-β-CD (CM-β-CD) as chiral selector in 25 mM phosphate buffer (pH 7.0), at 25 °C and a separation voltage of 30 kV, made possible the chiral separation in 7.4 min, with resolution values of 3.9 and 2.7 for linagliptin and clopidogrel enantiomers, respectively. The analytical characteristics of the developed methodology were evaluated in terms of linearity, precision, trueness, LODs and LOQs, and found adequate for the enantiomeric determination of both drugs. The method was applied to study the stability under abiotic and biotic conditions and the ecotoxicity of both drugs on Pseudokirchneriella subcapitata at individual, combined, and enantiomeric level. Both studies were carried out for each enantiomer of linagliptin, racemic linagliptin, S-clopidogrel, racemic clopidogrel, a mixture of the active enantiomers (R-linagliptin and S-clopidogrel), and a mixture of both racemates. Results obtained showed that individual solutions of S-linagliptin, R-linagliptin, S-clopidogrel, RS-linagliptin, and a mixture of the active enantiomers of both compounds, were stable under abiotic and biotic conditions, regardless of the incubation time; however, the concentration of racemic clopidogrel after 96 h of incubation showed a decay which ranged from 18 to 24 % under abiotic and biotic conditions, respectively. Experimental determination of ecotoxicological parameters demonstrated that all compounds studied (individual enantiomers, racemates, the combination of active enantiomers, and racemic mixtures) are highly toxic to algae. In mixtures, different degrees of antagonisms and synergism were observed.

Ecotoxicological study of seven pharmaceutically active compounds: Mixture effects and environmental risk assessment

Pharmaceutically active compounds (PhACs) have been detected in several aquatic compartments, which has been of environmental concern since PhACs can cause adverse effects on the aquatic ecosystem at low concentrations. Despite the variety of PhACs detected in surface water, ecotoxicological studies are non-existent for many of them, mainly regarding their mixture. In addition, water bodies can continuously receive the discharge of raw or treated wastewater with micropollutants. Thus, PhACs are subject to mixture and interactions, potentiating or reducing their toxicity. Therefore, the present study evaluated the toxicity on Aliivibrio fischeri of seven PhACs, which still needs to be explored in the literature. The effects were evaluated for the PhACs individually and for their binary and tertiary mixture. Also, the experimental effects were compared with the concentration addition (CA) and independent action (IA) models. Finally, an environmental risk assessment was carried out. Fenofibrate (FEN), loratadine (LOR), and ketoprofen (KET) were the most toxic, with EC50 of 0.32 mg L-1, 6.15 mg L-1 and 36.8 mg L-1, respectively. Synergistic effects were observed for FEN + LOR, KET + LOR, and KET + FEN + LOR, showing that the CA and IA may underestimate the toxicity. Environmental risks for KET concerning algae, and LOR e 17α-ethynylestradiol (EE2) for crustaceans and fish were high for several locations. Besides, high removals by wastewater treatment technologies are required to achieve the concentrations necessary for reducing KET and LOR risk quotients. Thus, this study contributed to a better understanding of the toxic interactions and environmental risks of PhACs.

Ecotoxicological effects of ketoprofen and fluoxetine and their mixture in an aquatic microcosm

The effects of fluoxetine (antidepressant) and ketoprofen (analgesic) on aquatic ecosystems are largely unknown, particularly as a mixture. This work aimed at determining the effect of sublethal concentrations of both compounds individually (0.050 mg/L) and their mixture (0.025 mg/L each) on aquatic communities at a microcosm scale for a period of 14 d. Several physicochemical parameters were monitored to estimate functional alterations in the ecosystem, while model organisms (Daphnia magna, Lemna sp., Raphidocelis subcapitata) and the sequencing of 16S/18S rRNA genes permitted to determine effects on specific populations and changes in community composition, respectively. Disturbances were more clearly observed after 14 d, and overall, the microcosms containing fluoxetine (alone or in combination with ketoprofen) produced larger alterations on most physicochemical and biological variables, compared to the microcosm containing only ketoprofen, which suffered less severe changes. Differences in nitrogen species suggest alterations in the N-cycle due to the presence of fluoxetine; similarly, all pharmaceutical-containing systems decreased the brood rate of D. magna, while individual compounds inhibited the growth of Lemna sp. No clear trends were observed regarding R. subcapitata, as indirectly determined by chlorophyll quantification. The structure of micro-eukaryotic communities was altered in the fluoxetine-containing systems, whereas the structure of bacterial communities was affected to a greater extent by the mixture. The disruptions to the equilibrium of the microcosm demonstrate the ecological risk these compounds pose to aquatic ecosystems.

Enantioselectivity in ecotoxicity of pharmaceuticals, illicit drugs, and industrial persistent pollutants in aquatic and terrestrial environments: A review

At present, there is a serious concern about the alarming number of recalcitrant contaminants that can negatively affect biodiversity threatening the ecological status of marine, estuarine, freshwater, and terrestrial ecosystems (e.g., agricultural soils and forests). Contaminants of emerging concern (CEC) such as pharmaceuticals (PHAR), illicit drugs (ID), industrial persistent pollutants, such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) and chiral ionic solvents are globally spread and potentially toxic to non-target organisms. More than half of these contaminants are chiral and have been measured at different enantiomeric proportions in diverse ecosystems. Enantiomers can exhibit different toxicodynamics and toxicokinetics, and thus, can cause different toxic effects. Therefore, the enantiomeric distribution in occurrence cannot be neglected as the toxicity and other adverse biological effects are expected to be enantioselective. Hence, this review aims to reinforce the recognition of the stereochemistry in environmental risk assessment (ERA) of chiral CEC and gather up-to-date information about the current knowledge regarding the enantioselectivity in ecotoxicity of PHAR, ID, persistent pollutants (PCBs and PBDEs) and chiral ionic solvents present in freshwater and agricultural soil ecosystems. We performed an online literature search to obtain state-of-the-art research about enantioselective studies available for assessing the impact of these classes of CEC. Ecotoxicity assays have been carried out using organisms belonging to different trophic levels such as microorganisms, plants, invertebrates, and vertebrates, and considering ecologically relevant aquatic and terrestrial species or models organisms recommended by regulatory entities. A battery of ecotoxicity assays was also reported encompassing standard acute toxicity to sub-chronic and chronic assays and different endpoints as biomarkers of toxicity (e.g., biochemical, morphological alterations, reproduction, behavior, etc.). Nevertheless, we call attention to the lack of knowledge about the potential enantioselective toxicity of many PHAR, ID, and several classes of industrial compounds. Additionally, several questions regarding key species, selection of most appropriate toxicological assays and ERA of chiral CEC are addressed and critically discussed.

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

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

The occurrence of emerging compounds in real urban wastewater before and after the COVID-19 pandemic in Cali, Colombia

The COVID-19 pandemic is considered one of the most significant global disasters in the last years. The rapid increase in infections, deaths, treatment, and the vaccination process has resulted in the excessive use of pharmaceuticals that have entered the environment as micropollutants. Considering the prior information about the presence of pharmaceuticals found in the wastewater of Cali, Colombia, which was collected from 2015 to 2022. The data monitored after the COVID-19 pandemic showed an increase in the concentration of analgesics and anti-inflammatory drugs of up to 91%. This increase was associated with the consumption of pharmaceuticals for mild symptoms, such as fever and pain. Moreover, the increase in concentration of pharmaceuticals poses a highly ecological threat, which was up to 14 times higher than that reported before of COVID-19 pandemic. These results showed that the COVID-19 had not only impacted human health but also had an effect on environmental health.

Integrated Approach for Synthetic Cathinone Drug Prioritization and Risk Assessment: In Silico Approach and Sub-Chronic Studies in Daphnia magna and Tetrahymena thermophila

Synthetic cathinones (SC) are drugs of abuse that have been reported in wastewaters and rivers raising concern about potential hazards to non-target organisms. In this work, 44 SC were selected for in silico studies, and a group of five emerging SC was prioritized for further in vivo ecotoxicity studies: buphedrone (BPD), 3,4-dimethylmethcathinone (3,4-DMMC), butylone (BTL), 3-methylmethcathinone (3-MMC), and 3,4-methylenedioxypyrovalerone (MDPV). In vivo short-term exposures were performed with the protozoan Tetrahymena thermophila (28 h growth inhibition assay) and the microcrustacean Daphnia magna by checking different indicators of toxicity across life stage (8 days sublethal assay at 10.00 µg L-1). The in silico approaches predicted a higher toxic potential of MDPV and lower toxicity of BTL to the model organisms (green algae, protozoan, daphnia, and fish), regarding the selected SC for the in vivo experiments. The in vivo assays showed protozoan growth inhibition with MDPV > BPD > 3,4-DMMC, whereas no effects were observed for BTL and stimulation of growth was observed for 3-MMC. For daphnia, the responses were dependent on the substance and life stage. Briefly, all five SC interfered with the morphophysiological parameters of juveniles and/or adults. Changes in swimming behavior were observed for BPD and 3,4-DMMC, and reproductive parameters were affected by MDPV. Oxidative stress and changes in enzymatic activities were noted except for 3-MMC. Overall, the in silico data agreed with the in vivo protozoan experiments except for 3-MMC, whereas daphnia in vivo experiments showed that at sublethal concentrations, all selected SC interfered with different endpoints. This study shows the importance to assess SC ecotoxicity as it can distress aquatic species and interfere with food web ecology and ecosystem balance.

Determination and risk assessment of pharmaceutical residues in the urban water cycle in Selangor Darul Ehsan, Malaysia

The environmental fate of non-steroidal anti-inflammatory drugs (NSAIDs) in the urban water cycle is still uncertain and their status is mainly assessed based on specific water components and information on human risk assessments. This study (a) explores the environmental fate of NSAIDs (ibuprofen, IBU; naproxen, NAP; ketoprofen, KET; diazepam, DIA; and diclofenac, DIC) in the urban water cycle, including wastewater, river, and treated water via gas chromatography-mass spectrophotometry (GCMS), (b) assesses the efficiency of reducing the targeted NSAIDs in sewage treatment plant (STP) using analysis of variance (ANOVA), and (c) evaluates the ecological risk assessment of these drugs in the urban water cycle via teratogenic index (TI) and risk quotient (RQ). The primary receptor of contaminants comes from urban areas, as a high concentration of NSAIDs is detected (ranging from 5.87 × 103 to 7.18 × 104 ng/L). The percentage of NSAIDs removal in STP ranged from 25.6% to 92.3%. The NAP and KET were still detected at trace levels in treated water, indicating the persistent presence in the water cycle. The TI values for NAP and DIA (influent and effluent) were more than 1, showing a risk of a teratogenic effect. The IBU, KET, and DIC had values of less than 1, indicating the risk of lethal embryo effects. The NAP and DIA can be classified as Human Pregnancy Category C (2.1 > TI ≥ 0.76). This work proved that these drugs exist in the current urban water cycle, which could induce adverse effects on humans and the environment (RQ in high and low-risk categories). Therefore, they should be minimized, if not eliminated, from the primary sources of the pollutant (i.e., STPs). These pollutants should be considered a priority to be monitored, given focus to, and listed in the guideline due to their persistent presence in the urban water cycle.

Pharmaceuticals in the Aquatic Environment: A Review on Eco-Toxicology and the Remediation Potential of Algae

The pollution of the aquatic environment has become a worldwide problem. The widespread use of pesticides, heavy metals and pharmaceuticals through anthropogenic activities has increased the emission of such contaminants into wastewater. Pharmaceuticals constitute a significant class of aquatic contaminants and can seriously threaten the health of non-target organisms. No strict legal regulations on the consumption and release of pharmaceuticals into water bodies have been implemented on a global scale. Different conventional wastewater treatments are not well-designed to remove emerging contaminants from wastewater with high efficiency. Therefore, particular attention has been paid to the phycoremediation technique, which seems to be a promising choice as a low-cost and environment-friendly wastewater treatment. This technique uses macro- or micro-algae for the removal or biotransformation of pollutants and is constantly being developed to cope with the issue of wastewater contamination. The aims of this review are: (i) to examine the occurrence of pharmaceuticals in water, and their toxicity on non-target organisms and to describe the inefficient conventional wastewater treatments; (ii) present cost-efficient algal-based techniques of contamination removal; (iii) to characterize types of algae cultivation systems; and (iv) to describe the challenges and advantages of phycoremediation.

Aquatic concentration and risk assessment of pharmaceutically active compounds in the environment

Pharmaceutically active compounds are increasingly detected in raw and treated wastewater, surface water, and drinking water worldwide. These compounds can cause adverse effects to the ecosystem even at low concentrations and, to assess these impacts, toxicity tests are essential. However, the toxicity data are scarce for many PhACs, and when available, they are dispersed in the literature. The values of pharmaceuticals concentration in the environment and toxicity data are essential for measuring their environmental and human health risks. Thus this review verified the concentrations of pharmaceuticals in the aquatic environment and the toxicity related to them. The risk assessment was also carried out. Diclofenac, naproxen, erythromycin, roxithromycin, and 17β-estradiol presented a high environment risk and 17α-ethinylestradiol presented a high human health risk. This shows the potential of these pharmaceuticals to cause adverse effects to the ecosystem and humans and establishes the necessity of their removal through advanced technologies.

An Mg-MOFs based multifunctional medicine for the treatment of osteoporotic pain

Bone pain is the primary problem for patients with osteoporosis. Ketoprofen is clinically used to treat osteoporotic pain, while long-term oral administration of ketoprofen can cause some side effects. In addition, osteoporosis is also accompanied by bone mass loss and inflammation. In this study, we designed a multifunctional drug (Ket@Mg-MOF-74) adopted Mg-MOF-74 to load ketoprofen to treat osteoporotic pain, bone loss and inflammation comprehensively. Mg-MOF-74 was prepared, and the physicochemical characterization proved that it had excellent physical and chemical stability. Ket@Mg-MOF-74 was synthesized by post-synthetic modification method and a high loading rate of ketoprofen was confirmed. Drug release and ion release experiments indicated Ket@Mg-MOF-74 had a good controlled release of ketoprofen and Mg in solution. Cell experiments in vitro proved the compound drug could significantly reduce the expression of pain-related genes of cyclooxygenase 2 (COX2), obviously up-regulated the expression of osteogenic cytokines and remarkably down-regulated the secretion of pro-inflammatory factors. Therefore, Ket@Mg-MOF-74 is believed a promising painkiller for osteoporotic bone pain, with the function of anti-inflammatory and promoting bone formation.

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

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

Toxic effects of NSAIDs in non-target species: A review from the perspective of the aquatic environment

The presence of pharmaceuticals in the aquatic environment, both in marine and freshwater reservoirs, is a major concern of global environmental protection. Among the drugs that are most commonly used, NSAIDs tend to dominate. Currently, being aware of the problem caused by drug contamination, it is extremely important to evaluate the scale and the full spectrum of its consequences, from short-term to long-term effects. The influence on non-target aquatic animals can take place at many levels, and the effects can be seen both in behaviour and physiology, but also in genetic alterations or reproduction disorders, affecting the development of entire populations. This review summarises all the advances made to estimate the impact of NSAIDs on aquatic animals. Multicellular animals from all trophic levels, inhabiting both inland waters, seas and oceans, have been considered. Particular attention has been paid to chronic studies, conducted at low, environmentally-relevant concentrations, to estimate the real effects of the present pollution. The number of such studies has indeed increased in recent years, allowing for a better insight into the possible consequences of pharmaceutical pollution. It should be stressed, however, that our knowledge is still limited to a few model species, while there are many groups of organisms completely unexplored regarding the effects of drugs. Therefore, the main aim of this paper was to summarise the current state of knowledge on the toxicity of NSAIDs in aquatic animals, also identifying important gaps and major issues requiring further analysis.

Pharmacokinetics of Ketoprofen in Nile Tilapia (Oreochromis niloticus) and Rainbow Trout (Oncorhynchus mykiss)

The objective of this study was to document the pharmacokinetics of ketoprofen following 3 mg/kg intramuscular (IM) and intravenous (IV) injections in rainbow trout (Oncorhynchus mykiss) and 8 mg/kg intramuscular (IM) injection in Nile tilapia (Oreochromis niloticus). Plasma was collected laterally from the tail vein for drug analysis at various time intervals up to 72 h following the injection of ketoprofen. In trout, area under the curve (AUC) levels were 115.24 μg hr/mL for IM and 135.69 μg hr/mL for IV groups with a half-life of 4.40 and 3.91 h, respectively. In both trout and tilapia, there were detectable ketoprofen concentrations in most fish for 24 h post-injection. In tilapia, there was a large difference between the R- and S-enantiomers, suggesting either chiral inversion from R- to S-enantiomer or more rapid clearance of the R-enantiomer. AUC values of the S- and R-enantiomers were 510 and 194 μg hr/Ml, respectively, corresponding to a faster clearance for the R-enantiomer. This study shows that there were very high plasma concentrations of ketoprofen in trout and tilapia with no adverse effects observed. Future studies on the efficacy, frequency of dosing, analgesia, adverse effects, and route of administration are warranted.

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

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

Quality screening of the Lagos lagoon sediment by assessing the cytotoxicity and toxicological responses of rat hepatoma H4IIE and fish PLHC-1 cell-lines using different extraction approaches

In this study, sediment samples from Makoko and Ikorodu sites of the Lagos lagoon (Nigeria) were screened for toxicological responses on mammalian and fish cell lines using different extraction methods. Rat hepatoma H4IIE and fish PLHC-1 cell-lines were exposed to serial dilutions of the elutriate, polar and non-polar extracts. We evaluated exposed cells for cytotoxicity and aryl hydrocarbon receptor (AhR)-mediated toxicity. Cells exposed to polar and water extracts from Makoko and Ikorodu showed viability percentage of >80% at 48 h. On the other hand, exposure to the non-polar extracts exhibited cell viability of 50-60% at all tested dilutions. For both cell lines, a significant concentration-dependent induction of cyp1a mRNA was observed after exposure to the different extracts from both sites. Interestingly, the extracts affected functional enzymes differently for both cell lines. For H4IIE cells, while EROD activity paralleled cyp1a mRNA expression patterns, MROD showed significant concentration-specific reduction in cells exposed to polar and water extracts. On the contrary, while the MROD activity paralleled cyp1a mRNA, EROD activity was significantly inhibited in PLHC-1 cells exposed to water-, polar and non-polar extracts from both sites. These observations paralleled sediments PAH contamination burden from the study sites as revealed by co-relation analysis. In conclusion, although the different extracts did not exert high cytotoxic effects (except the non-polar) at the tested concentrations, they significantly modulated phase I biotransformation responses, showing that the studied sediments contain complex chemical mixture in the different extracts, with potential for overt physiological and general health consequences.

Evaluating the enantiospecific differences of non-steroidal anti-inflammatory drugs (NSAIDs) using an ecotoxicity bioassay test battery

Wastewater treatment plants are a major pathway for pharmaceuticals to the aquatic environment. Many pharmaceuticals, including non-steroidal anti-inflammatory drugs (NSAIDs), are chiral chemicals and the biological activity of their enantiomers can differ. Few studies have assessed the effects of different NSAID enantiomers on non-target organisms. However, this information is important for environmental risk assessment to ensure that the effects of more potent enantiomers are not overlooked. In the current study, enantiomers of naproxen, ibuprofen, ketoprofen and flurbiprofen were evaluated in bioassays with bacteria, algae and fish cells. All enantiomers induced bacterial toxicity, with (R)-naproxen more toxic than (S)-naproxen (EC₅₀ 0.75 vs 0.93 mg/L) and (S)-flurbiprofen more toxic than (R)-flurbiprofen (EC₅₀ 1.22 vs 2.13 mg/L). Both (R)-flurbiprofen and (S)-flurbiprofen induced photosystem II inhibition in green algae, with (R)-flurbiprofen having a greater effect in the assay after 24 h (EC₁₀ 5.47 vs 9.07 mg/L). Only the (R)-enantiomers of flurbiprofen and ketoprofen induced ethoxyresorufin-O-deethylase (EROD) activity in fish cells, while (S)-naproxen was 2.5 times more active than (R)-naproxen in the EROD assay. While enantiospecific differences were observed for all assays, the difference was less than an order of magnitude. This indicates that the risk of overlooking the effect of more potent NSAID enantiomers is minor for the studied test systems and supports the use of racemic (or single enantiomer) effect data for environmental risk assessment. However, further investigation of the (R)-enantiomer of commonly used NSAID ketoprofen is recommended as it was at least six times more potent in the EROD assay than the inactive (S)-ketoprofen.

Biotransformation and oxidative stress responses in rat hepatic cell-line (H4IIE) exposed to racemic ketoprofen (RS-KP) and its enantiomer, dexketoprofen (S(+)-KP)

Pharmaceuticals such as racemate ketoprofen (RS-KP) and its enantiomer, dexketoprofen (S(+)-KP) are highly detectable non-steroidal anti-inflammatory drugs (NSAIDs) in the aquatic environment and therefore are designated as one of the most emerging groups of pollutants that can affect environmental and human health. The potential impact of these pharmaceuticals was assessed for the first time in vitro using a rat hepatocellular carcinoma cell line (H4IIE). Cells were exposed to low and high concentrations of these drugs. Cytotoxicity was determined by MTT reduction assay; CYP1A1 transcriptional and enzymatic levels together with canonical oxidative stress responsive markers (GPx, GR, GST and CAT) were also investigated. Cells exposed to RS-KP and S(+)-KP did not show cytotoxicity effect at the concentrations tested. However, this study highlighted differences between RS-KP and S(+)-KP in most of the evaluated markers, showing compound-, concentration- and time-specific effect patterns which suggest a potential stereo-selective toxicity of these drugs.