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Triclocarban (TCC), a common antimicrobial agent widely used in many household and personal care products, has been widely detected in aquatic ecosystems worldwide. Due to its high lipophilicity and persistence in the aquatic ecosystems, TCC is of emerging environmental concern. Despite the frequently reported detection of TCC in the environment and significant uncertainties about its long term effects on aquatic ecosystems, few studies have addressed the chronic effects of TCC in aquatic organisms at ecologically relevant concentrations. Therefore, we aimed at testing a broad range of biological responses in the amphipod Gammarus locusta following a chronic (60 days) exposure to environmentally relevant concentrations of TCC (100, 500 and 2500ng/L). This work integrated biochemical markers of oxidative stress (catalase (CAT), glutathione-s-transferase (GST) and lipid peroxidation (LPO)) and neurotransmission (acetylcholinesterase (AChE)) with several key ecological endpoints, i.e. behaviour, survival, individual growth and reproduction. Significant alterations were observed in all biochemical markers. While AChE showed a dose-response curve (with a significant increased activity at a TCC concentration of 2500ng/L), oxidative stress markers did not follow a dose-response curve, with significant increase at 100 and/or 500ng/L and a decreased activity in the highest concentration (2500ng/L). The same effect was observed in the females' behavioural response, whereas males' behaviour was not affected by TCC exposure. The present study represents a first approach to characterize the hazard of TCC to crustaceans., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Glyphosate based herbicides, including Roundup, are widely employed in agriculture and urban spaces. The objective of this study was to evaluate the toxicological effects of Roundup on the estuarine polychaeta Laeonereis acuta. Biomarkers of oxidative stress as well as acetylcholinesterase and propionilcholinesterase activities were analyzed. Firstly, the LC 50 96h for L. acuta was established (8.19mg/L). After, the animals were exposed to two Roundup concentrations: 3.25mg/L (non-observed effect concentration - NOEC) and 5.35mg/L (LC 10 ) for 24h and 96h. Oxygen consumption was determined and the animals were divided into three body regions (anterior, middle and posterior) for biochemical analysis. An inhibition of both cholinesterase isoforms were observed in animals exposed to both Roundup concentrations after 96h. A significant reactive oxygen species (ROS) reduction was observed in the posterior region of animals in both periods, while antioxidant capacity against peroxyl radicals (ACAP) was reduced in the posterior region of animals exposed for 24h. Considering the antioxidant defense system, both GSH levels and enzyme activities (catalase, superoxide dismutase, glutathione s-transferase, glutathione peroxidase and glutamate cysteine ligase) were not altered after exposure. Lipid peroxidation was reduced in all analyzed body regions in both Roundup concentrations after 24h. Animals exposed to the highest concentration presented a reduction in lipid peroxidation in the anterior region after 96h, while animals exposed to the lowest concentration presented a reduction in the middle region. Overall results indicate that Roundup exposure presents toxicity to L. acuta, causing a disruption in ROS and ACAP levels as well as affects the cholinergic system of this invertebrate species., (Copyright © 2016 Elsevier Inc. All rights reserved.)

We evaluate antioxidant responses of Jenynsia multidentata experimentally exposed to sublethal concentrations of endosulfan (EDS). The main goal was to determine differences in the response between different organs to assess which one was more severely affected. Thus, we exposed females of J. multidentata to EDS during 24h, measuring the activity of GST, GR, GPx, CAT and LPO in brain, gills, liver, intestine and muscle of both exposed fish and controls. GST activity was inhibited in gills, liver, intestine and muscle of exposed fish but was induced in brain. GR and GPx activities were increased in brain and gills at 0.014 and 0.288 microg L(-1), respectively. GPx activity was inhibited in liver and muscle at all studied concentrations whereas inhibition was observed in the intestine above 0.288 microg L(-1). Exposure to 1.4 microg L(-1) EDS caused CAT inhibition and increase of LPO levels in liver. LPO was also increased in brain at almost all concentrations tested. We find that the brain was the most sensitive organ to oxidative damage. Thus, J. multidentata could be used as a suitable bioindicator of exposure to EDS measuring activities of antioxidant enzymes in brain and liver as biomarkers.

Pulp and paper mill effluent compounds pollute the aquatic environment and are responsible for increased biochemical alterations and genotoxicity in aquatic organisms such as fish. Adult eels (Anguilla anguilla L) were exposed during 8, 16, 24, and 72 h to the following conditions: (1) aerated, filtered, and dechlorinated tap water (C); (2) 2.5% (v/v) sewage water previously treated with activated sludge (T); (3) bleached kraft pulp and paper mill effluent collected at the river Vouga, close to an ancient sewage outlet (Portucel), diluted in tap water [25% (E25) and 50% (E50)]; and (4) bleached kraft pulp and paper mill effluent sediment [water-soluble fraction (S)]. Liver biotransformation induced by the above conditions was measured as ethoxyresorufin-O-deethylase (EROD), cytochrome P450 (P450) (Phase I), and glutathione-S-transferase (GST) (Phase II). Genotoxicity was also determined as blood/liver DNA strand breaks and erythrocytic nuclear abnormalities (ENA) induced on European eel (A. anguilla L). Liver EROD activity was significantly increased in eels at 8 and 16 h exposure to E25, as well as at 16, 24, and 72 h exposure to E50. S exposure induced liver EROD activity only at 24h. A significant decrease in liver P450 was observed at 72 h exposure to T, whereas a significant P450 increase at 16 h was followed by a significant decrease at 24h exposure to E25. Another P450 significant increase was noticed at 72 h exposure to S. Liver GST activity (Phase II) demonstrated a significant increase at 72 h exposure to E50 and to S. A significant decrease in blood DNA integrity was observed at 72 h exposure to T and at 24 and 72 h to S. Blood DNA integrity significantly decreased at 16 and 24 h exposure to E25, as well as at 8, 16, and 24 h exposure to E50. Liver DNA integrity significantly decreased at 72 h exposure to T and at 16 h exposure to S. Moreover, liver DNA integrity was significantly decreased at 24h exposure to E25 and E50, and 72 h to E50. A. anguilla L. increased ENA frequency was detected in T at 16, 24, and 72 h, whereas in E25 and S it was observed at 8, 16, and 24 h. Furthermore, E50 ENA frequency increased at 24 h exposure.

The effects of naphthalene (NAP) and beta-naphthoflavone (BNF) on phase I biotransformation and genotoxicity in Anguilla anguilla L. were evaluated. Phase II biotransformation and cortisol levels were also assessed in NAP-treated fish. Two groups of eels were exposed to either a NAP or a BNF concentration range (0.1-2.7 microM) for different exposure periods (2-72 h). An early significant ethoxyresorufin O-deethylation (EROD) activity inhibition was observed, especially for the highest NAP concentrations at 2-6 h exposure and for BNF at 2h exposure. However, a significant EROD activity increase was detected from 16 to 72 h exposure for NAP and from 4 to 72 h exposure for BNF. The cytochrome P450 (P450) content was not dose related. However, with regard to BNF exposure, P450 was the first biomarker to respond. Liver alanine transaminase (ALT) activity was measured as an indicator of hepatic health condition. ALT results demonstrated that the EROD activity decrease, previously described for NAP, was not related to tissue damage. Nevertheless, the highest BNF concentrations were demonstrated to induce liver damage and to impair the EROD activity response. An increased genotoxic response, measured as erythrocytic nuclear abnormalities (ENA), was observed during the first 8h NAP exposure. However, for exposures longer than 8 h, ENA frequency returned to the control levels. This response profile may reflect a considerable DNA repair capacity and/or a metabolic adaptation providing an efficient NAP biotransformation and consequent detoxification. BNF revealed no ENA alterations for all concentrations and exposure lengths. In the NAP experiment a causal relationship between immature erythrocytes (IE) and ENA frequency disappearance was not found. BNF results with regard to IE frequency revealed an ability to alter the balance between erythropoiesis and removal of erythrocytes. Liver glutathione S-transferase activity was significantly induced after 2 and 48 h NAP exposure. A cortisol-impaired response seems to occur from 4 to 24 h NAP exposure, demonstrating an endocrine disruption. However, an adaptation process seems to occur after 48 h, since the plasma cortisol had a tendency to increase. The present findings confirm the usefulness of the adopted biomarkers. The ecological risk associated with aquatic contamination by NAP was also confirmed by the present data.

The effects of a phosphorothionate, 2-butenoic acid-3-(diethoxyphosphinothioyl) methyl ester (RPR-II), on the activities of glutathione S-transferase (GST) and UDP-glucuronyltransferase (UDPGT) and the level of glutathione (GSH) were evaluated in rats after administration of RPR-II at 0.014 (low), 0.028 (medium), and 0.042 (high) mgkg(-1)day(-1) for 90 days and also at 28 days (withdrawal) after stopping treatment. Brain GST activity and GSH level decreased significantly at the high dose on the 45th and 90th days of treatment. Dose- and time-dependent decreases in GST activity and GSH was level were observed in lung at medium and high doses and in kidneys at all three doses on both the 45th and 90th days. UDPGT activity increased significantly in kidneys at the medium and high doses at 45 and 90 days. Brain and lung did not display any significant variations in UDPGT activity when compared with the control. Interestingly, the withdrawal study revealed that the effect was reversible within 28 days of cessation of treatment, when enzyme activity reverted to levels close to those of controls. The study revealed that RPR-II affected the GSH- and GST-dependent detoxification system of the treated tissues of rat and its potential to modulate the enzymes is in the order kidneys>lung>>brain. The present subacute study suggests that RPR-II may bring about physiological upsets by altering GSH- and GST-dependent events in different tissues of exposed organisms.

Fourth-instar Chironomus riparius Meigen larvae were exposed to the organophosphate (OP) insecticide pirimiphos methyl (0, 0.1, 1.0, and 10 microg/L) for 48, 72, or 96 h at three temperatures (3, 12, or 22 degrees C). Two biochemical biomarkers, acetylcholinesterase (AChE) and glutathione S-transferase (GST), were measured in individual larvae from each treatment. AChE activity was inhibited by the OP in a dose-responsive fashion. This response remained similar at all three temperatures, demonstrating that AChE is a robust and specific biomarker. Exposure duration had little effect on AChE activity. In contrast, GST activity was induced at the highest OP insecticide concentration, but induction was also evident at 3 degrees C. There was a significant effect of exposure duration, with an overall decline in GST activity over time. This result agrees with previous work suggesting that GSTs are not particularly suitable for use as a biomarker of pesticide exposure or effect in Chironomus., ((c) 2002 Elsevier Science (USA).)

Chironomus riparius Meigen were exposed to sediment spiked with 0, 0.01, 0.05, and 0.10 mg chlorpyrifos/kg dry sediment for 48 h as late third-instar larvae. Acetylcholinesterase activity, glutathione-S-transferase activity, burrowing behavior, emergence time, and adult dry weight were measured to determine which were the most sensitive biomarkers of exposure and effect for short-term sublethal exposures. There was a significant drop in acetylcholinesterase activity at the two highest concentrations, but no effect on glutathione-S-transferase activity. Behavioral and life history biomarkers were sensitive only to the highest concentration of chlorpyrifos. The association of life history changes (female weight and male emergence times) with a significant inhibition of acetylcholinesterase activity suggests that this can be used as a biomarker of exposure and effect., (Copyright 2001 Academic Press.)

The uptake, toxicity, and elimination of atrazine and trifluoroacetate (TFA) were studied in early life stages of the zebrafish (Danio rerio). Furthermore, the effects of these xenobiotics on soluble (s) and microsomal (m) glutathione S-transferases (GST) of zebrafish embryos were investigated using 1-chloro-2,4-dinitrobenzene (CDNB), 1,2-dichloro-4-nitrobenzene (DCNB), and [(14)C]atrazine. [(14)C]Atrazine was taken up by the embryos within seconds, unhindered by the chorions. It accumulated in the embryos by a factor of 19 after 24 h of exposure time. LC(50) (48 h) was determined at 36.8 mg/L. At a level of 5 mg/L atrazine, activities of s and m GSTs were elevated in most stages, especially in prim 6 and long pec stage (24, 48 h after fertilization, respectively). GST activity toward atrazine was detectable only in untreated D. rerio eggs, increasing with developmental time. [(14)C]Atrazine was eliminated from the embryos between 24 and 48 h, indicating a possible metabolism to a more hydrophilic GSH conjugate. [(14)C]TFA was taken up by embryos, reaching at maximum fivefold the concentration of the incubation medium after 10 h. The chorions served no physiological protection. TFA (1 g/L) caused low elevation of the GST activity. No acute toxic effects (48 h) were observed up to 4 g/L TFA., (Copyright 2000 Academic Press.)

This report describes a study of the effects of bacterial endotoxin [lipopolysaccharide (LPS)] on cytochrome P450 levels and ethoxyresorufin O-deethylase (EROD) and glutathione S-transferase (GST) activities in liver and two main immune organs of carp: spleen and head kidney. Also studied was the paucity of the carp drug-metabolizing system in an environment subject to pollution by a polycyclic aromatic hydrocarbon, 3-methylcholanthrene (3MC), when fish respond to an immune activation by lipopolysaccharide (LPS). In the presence of bacterial endotoxin the basal cytochrome P450 levels were decreased in liver and spleen. EROD activity was increased in liver and basal GST activity was increased in spleen. When fish were treated concomitantly with 3MC and LPS, a suppression of cytochrome P450 induction in liver and head kidney was observed. EROD activity induced by 3MC was not modified by administration of LPS. GST activity was suppressed by treatment with LPS and inducing agent in liver and head kidney. In the present study it was found that endotoxin can have profound and differential effects on fish basal biotransformation of drugs in the liver and immune organs. Also, the induction of biotransformation enzymes by 3MC was modified when fish responded to an immune stimulation., (Copyright 1998 Academic Press.)

Several biochemical responses were measured in silver crucian carp (Carassius auratus gibelio) after exposure to sediments obtained from contaminated Ya-Er Lake, No. 1 pond, and an unpolluted reference site, Honglian Lake. After 1 week of exposure, a significant induction of the phase I biotransformation enzyme (ethoxylresorufin-o-deethylase, EROD) was found (83-fold of control), whereas the phase II biotransformation enzyme (glutathione S-transferase, GST) exhibited a slight, but significant induction (1.4-fold of control) after 4 weeks of exposure. The level of cellular glutathione in the liver was also slightly elevated after 4 weeks of exposure. The delayed response of GST to the contaminants indicates that the phase I and phase II biotransformation enzymes are regulated differently in fish. The results suggest that EROD is a sensitive bioindicator to assess the toxicity of dioxin-contamined sediment in the laboratory.

Caging field experiments were conducted on young European eel (Anguilla anguilla) and on rainbow trout (Onchorynchus mykiss) for the determination of a biomonitoring protocol of freshwater streams. Hepatic monooxygenase and conjugation enzyme activities were measured as biomarkers of exposure to some organic pollutants. Laboratory studies were performed to compare the responsiveness of these two species concerning their enzymatic activities. The induction of monooxygenase activity, measured as the deethylation of 7-ethoxyresorufin (EROD activity) was examined by beta-naphtoflavone (beta-NF) treatment. Dose-response study revealed that EROD activity increased significantly from 1 mg beta-NF/kg bw and was on a plateau at 50 mg beta-NF/kg bw for both species. No significant effect on glutathione S-transferase (GST) activity was observed. During a time-course study, EROD activity increased, starting from the second day for both species. In European eel, this enzymatic activity decreased significantly from the seventh day, whereas no significant decrease was observed for rainbow trout after 14 days. During a 2-week field study, EROD and GST activities were measured in fish held in cages upstream and downstream of a polluted area. For both species, the induction of EROD activity was observed in the polluted site after 14 days of caging; GST activity was not significantly affected. Monooxygenase activity appeared to be a sensitive tool for biomonitoring freshwater streams for both species.