1,721,171 research outputs found
Adverse effects induced by ecgonine methyl ester to the zebra mussel: A comparison with the benzoylecgonine
No full textCocaine and its metabolites are the prevalent psychotropic substances in aquatic environment. However, to date the knowledge on their adverse effects to non-target organisms is inadequate. The aims of this study were to investigate sub-lethal effects induced by the ecgonine methyl ester (EME) to the freshwater bivalve Dreissena polymorpha and to compare its toxicity to that by benzoylecgonine (BE), the other main cocaine metabolite. EME sub-lethal effects were investigated by 14 days in-vivo exposures and a multi-biomarker approach. Slight variations in biomarker responses were found at 0.15 μg/L treatment. 0.5 μg/L EME treatment induced destabilization of lysosome membranes, an overall inactivation of defense enzymes, increases in lipid peroxidation, protein carbonylation and DNA fragmentation, but no variations in fixed genetic damage. The use of a biomarker response index (BRI) showed that at 0.5 μg/L both cocaine metabolites had the same toxicity to zebra mussels specimens
Temporal trends of polycyclic aromatic hydrocarbons (PAHs) in Dreissena polymorpha specimens from Lake Maggiore (Northern Italy)
No full textThe Lake Maggiore (Northern Italy) has been recognized as an aquatic environment heavily contaminated by persistent organic pollutants, mainly organochlorine compounds, but to date limited information is available regarding another class of widespread and hazardous pollutants, such as the polycyclic aromatic hydrocarbons (PAHs). The aim of this study was to investigate seasonal and temporal trends of 18 PAHs accumulated in native Dreissena polymorpha specimens during a 5-year biomonitoring program, as well as to identify the possible PAH emission sources by using isomeric diagnostic ratios. Zebra mussels were sampled both in their pre- (May) and post-reproductive (September) stage over the 2008-2012 period in eight sampling stations covering the whole lake shoreline. PAH concentrations were measured through gas chromatography coupled to mass spectrometry. A notable PAH contamination following an increasing temporal trend was noticed in bivalves from all the sampling stations, with the benzo(alpha)anthracene as the predominant compound. An overall increase in PAH levels was found in the post-reproductive surveys, indicating a marked seasonality of this contamination probably due to the increase in touristic activity during spring-summer months
Oxidative and genetic responses induced by Δ-9-tetrahydrocannabinol (Δ-9-THC) to Dreissena polymorpha
No full textCannabis is the most used illicit substance worldwide and its main psychoactive compound, the Δ-9-tetrahydrocannabinol (Δ-9-THC), is detected in aquatic environments at measurable concentrations. Even though its occurrence is well documented, no information is available on its hazard to aquatic organisms. The aim of this study was to assess the adverse effects induced to zebra mussel (Dreissena polymorpha) specimens by 14 day exposures to environmentally relevant Δ-9-THC concentrations (0.05 μg/L and 0.5 μg/L) by means of the application of a biomarker suite. Catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione S-transferase (GST) activities, as well as the lipid peroxidation (LPO) and protein carbonyl content (PCC), were measured as oxidative stress indices. The single cell gel electrophoresis (SCGE) assay, the DNA diffusion assay and the micronucleus test (MN test) were applied to investigate DNA injuries, while the neutral red retention assay (NRRA) was used to assess Δ-9-THC cytotoxicity. The lowest treatment induced negligible adverse effects to bivalves, while 0.5 μg/L Δ-9-THC exposure caused remarkable alterations in D. polymorpha oxidative status, which lead to significant increase of lipid peroxidation, protein carbonylation and DNA damage
Cyto-genotoxic effects induced by three brominated diphenyl ether congeners on the freshwater mussel Dreissena polymorpha
No full textPolybrominated diphenyl ethers (PBDEs) are a group of highly hydrophobic and persistent chemicals that has been used as flame retardants in several industrial applications. They have been detected in various environmental matrices worldwide and an increasing number of studies have recently been carried out to investigate their potential toxicity on ecosystem communities. Although a variety of biological damage has been documented in vertebrates, the effects on invertebrates are largely unknown. The objective of the present study was to determine the cyto-genotoxic effects induced by single exposure to three concentrations of 2,4,2',4'-tetra BDE (BDE 47), 2,2,4,4,6-penta BDE (BDE-100) and 2,2',4,4',5,6-hexa BDE (BDE-154) on the freshwater mussel Dreissena polymorpha by a multi-biomarker approach. We performed on bivalve hemocytes the Single Cell Gel Electrophoresis (SCGE) assay, the DNA Diffusion assay and the Micronucleus test (MN test) to assess genotoxicity, while the Neutral Red Retention Assay (NRRA) was used to evaluate cytotoxic effects. Results showed that BDE-47 did not produce any genetic damage at the tested concentrations (0.1 mu g/L, 0.5 mu g/L and 1 mu g/L), while BDE-100 and BDE-154 can be considered moderately genotoxic, since both primary and fixed DNA injuries were induced. The NRRA indicated a moderate increase in cellular stress in BDEs-treated bivalves. Thus, our data seems to suggest that investigated BDEs may pose a low risk to freshwater mussels at environmental concentrations
CYTO-GENOTOXIC EFFECTS OF SOME PHARMACEUTICAL AND PERSONAL CARE PRODUCTS (PPCPS) ON THE FRESHWATER BIVALVE ZEBRA MUSSEL (DREISSENA POLYMORPHA)
Full text linkPharmaceutical and personal care products (PPCPs) are an emerging class of environmental pollutants that are extensively and increasingly being used in human and veterinary medicine. Due to their continuous production, consumption and often abuse, many studies have shown worldwide measurable concentrations of about 100 of these drugs in the aquatic environment in the high ng L-1 to low μg L-1 range. Among these, antimicrobial, antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs) are three of the most used and frequently detected PPCP classes in aquatic environments. Since these chemicals have physico-chemical characteristics similar to those of harmful xenobiotics, they could be potentially dangerous to aquatic non-target organisms, as they are exposed to contaminants over their whole life span. At present, few studies were carried out in order to evaluate the PPCPs potential toxicity on aquatic organisms. The major part of these researches was aimed to acute toxicity evaluation of few drugs on organisms belonging to different trophic levels. Nonetheless, considering the current low environmental levels, these data are not suitable for an accurate risk assessment since chronic effects are much more probable. In order to enlarge this topic, we decided to evaluate the potential cyto-genotoxicity of a common antimicrobial agent (triclosan; TCS), a widespread antibiotic (trimethoprim; TMP) and three largely used NSAIDs (paracetamol; PCM – diclofenac; DCF – ibuprofen; IBU) on the freshwater bivalve zebra mussel (Dreissena polymorpha). This mussel was chosen as biological model because the invertebrates constitute more the 90% of living species, they play an important role in freshwater ecosystems and are particularly susceptible to environmental stressors. Additionally, previous studies have revealed that D. polymorpha is useful and sensible organism capable of highlighting sub-lethal effects when exposed to synthetic chemicals. In detail, a stepwise in vitro-in vivo multi-biomarker approach was planned to study the potential environmental risk due to these PPCPs. The first screening evaluation was carried out by using an in vitro approach on the mussel hemocytes. Genotoxicity was evaluated by SCGE (single cell gel electrophoresis) and DNA diffusion assay, while cytotoxicity was checked by Neutral Red Retention Assay (NRRA). By analyzing the obtained results we drawn the first toxicity scale for zebra mussel hemocytes (TCS<PCM< DCF<IBU<TMP).
These data lay the groundwork for in vivo exposures, which will allow for a better definition of the observed cyto-genotoxicity of these molecules in a setting miming real environmental exposure. Starting from the most toxic PPCP, an in vivo multi-biomarker battery was applied on D. polymorpha to evaluate their real potential sub-lethal effect. In order to give a marked ecological relevance to our research, mussels were exposed for 96 h to increasing environmentally relevant drug concentrations. Cyto-genotoxicity was determined in mussel hemocytes by the lysosome membrane stability (NRRA), the single cell gel electrophoresis (SCGE) assay, the micronucleus test (MN test) and the assessment of the apoptotic frequency (DNA diffusion assay). Moreover, the probable unbalance of mussels’ oxidative status was evaluated by analyzing the activity of three antioxidant phase I enzymes, namely superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), as well as the detoxifying phase II enzyme glutathione S-transferase (GST) in the cytosolic fraction extracted from a pool of entire mussels. By analyzing the final biomarker data, the PPCP in vitro toxicity scale was partially confirmed. In fact, according to in vitro screening results, TCS was the most toxic drug, followed by PCM, IBU and TMP. On opposite, nonetheless its remarkable in vitro cyto-genotoxicity, in vivo results noticed that current DCF levels do not induce significant adverse effects on D. polymorpha.
Our data point out that the use of a tied in vitro/in vivo approach is a useful method to study in depth the toxicity of new environmental pollutants. In vitro studies, thanks to their simplicity, reliability and speed, provide basic information on the toxicity of xenobiotics and often assist in hypothesizing or testing the probable mechanism of action of pollutants. In addition, they can act as a guide to direct additional research and could be used in first environmental risk assessment (ERA) evaluations. On this basis, in vivo approach, miming the real environmental conditions of exposure (concentrations, uptake pathways, defense mechanisms, metabolism) allow us to evaluate the effective environmental hazard of single PPCPs and/or their mixtures and it furnish more precise and in-depth information of their toxicity on aquatic species for further ERA operations.
Considering the relevance of in vitro tests in ecotoxicological preliminary analyses, in vitro cultures of zebra mussel hemocytes, gill and digestive gland cells were developed in collaboration with the Irish Centre for Environmental Toxicology (ICET - Galway, Ireland). These innovatory techniques were applied to investigate the potential in vitro cytotoxicity of atenolol (ATL), carbamazepine (CBZ), diclofenac (DCF) and gemfibrozil (GEM) and to discriminate the most sensitive cell type for further applications. On overall, DCF was the more cytotoxic compound for zebra mussel cells, followed by GEM, CBZ and ATL, while gill cells and hemocytes seemed to be the most sensitive targets for tested PPCPs
Environmental concentrations of 3,4-methylenedioxymethamphetamine (MDMA)-induced cellular stress and modulated antioxidant enzyme activity in the zebra mussel
No full textRecent monitoring studies showed measurable levels of the 3,4-methylenedioxymethamphetamine (MDMA) in aquatic environments. However, no information is currently available on its potential hazard to aquatic non-target organisms. The aim of this study was to investigate the potential sub-lethal effects induced by 14-day exposures to low MDMA concentrations (0.05 and 0.5 mu g/L) to zebra mussel (Dreissena polymorpha) specimens through the application of a biomarker suite. The trypan blue exclusion method and the neutral red retention assay (NRRA) were used to assess MDMA cytotoxicity. The activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione S-transferase (GST), as well as the lipid peroxidation (LPO) and protein carbonyl content (PCC), were measured as oxidative stress indexes. The single cell gel electrophoresis (SCGE) assay, the DNA diffusion assay, and the micronucleus test (MN test) were applied to investigate DNA damage, while filtration rate was measured as physiological parameter. Despite significant decrease in lysosome membrane stability, hemocyte viability and imbalances in CAT and GST activities pointed out at the end of the exposure to 0.5 mu g/L, no significant variations for the other end points were noticed at both the treatments, suggesting that environmentally relevant MDMA concentrations did not induce deleterious effects to the zebra mussel
Sublethal effects induced by morphine to the freshwater biological model Dreissena polymorpha
Full text linkOpioids are considered as emerging contaminants in aquatic ecosystems, mainly due to their large illicit consume worldwide. Morphine (MOR) is the main opiate and it was commonly found at measurable concentrations in freshwaters. Even though its occurrence is well documented, just limited information is available regarding its hazard to nontarget organisms. The aim of this study was of the evaluation of sublethal effects induced by MOR to the freshwater bivalve Dreissena polymorpha. We exposed mussels to two MOR concentrations (0.05 μg/L and 0.5 μg/L) for 14 days and we investigated the sublethal effects by a suite of biomarkers. The Neutral Red Retention Assay (NRRA) was used as a test of cytotoxicity, while the oxidative stress was evaluated by the activity of antioxidant and detoxifying enzymes, namely catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione-S-transferase (GST), and by measuring the levels of lipid peroxidation (LPO) and protein carbonylation (PCC). The genetic damage was assessed by the Single Cell Gel Electrophoresis (SCGE) assay, the DNA diffusion assay and the micronucleus test (MN test). Finally, the filtration rate of D. polymorpha was evaluated in order to investigate possible physiological effects. Both tested concentrations reduced the lysosome membrane stability of bivalves, but only the highest MOR concentration induced significant changes in the activity of antioxidant enzymes (SOD, CAT, and GPx) and increase in lipid peroxidation levels. Slight increase in primary DNA fragmentation was noticed, while no fixed genetic damage and alterations of the filtering rate were found
Variation of antioxidant activity in Dreissena polymorpha specimens exposed to 2,2',4,4',5,6'-hexa BDE (BDE-154)
No full textWe evaluated the imbalance of the oxidative status in zebra mussel (Dreissena polymorpha) specimens exposed for 96 h to environmentally relevant concentrations (0.1, 0.5, and 1 mu g/L) of the 2,2',4,4',5,6'-hexa BDE (BDE-154). The activities of three antioxidant enzymes, catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and the phase II detoxifying enzyme glutathione S-transferase (GST), were measured in the cytosolic fraction from a pool of zebra mussels. Significant variations in the activity of each single enzyme were noticed at each treatment, indicating that exposure to BDE-154 was able to impair the oxidative status of treated bivalves through the increase of reactive oxygen species. In detail, SOD and GPx were significantly induced, while CAT and GST were depressed with respect to the baseline levels. These data have confirmed that the raise of oxidative stress is the main cause of the BDE-154-induced genetic damage observed in a previous study on the zebra mussel
Chemical and biomarker responses for site-specific quality assessment of the Lake Maggiore (Northern Italy)
No full textSince the 1990s, the Lake Maggiore (Northern Italy) has been recognized as an aquatic environment contaminated by DDTs and other persistent organic pollutants, but to date just few studies were carried out to investigate the effects of pollution to aquatic organisms. The aim of this study was the application of a stepwise approach based on chemical data, a suite of biomarkers and the integration of their responses into a biomarker response index (BRI) to evaluate the site-specific quality assessment in different sampling stations of Lake Maggiore, one of the largest European lakes. We used as biological model the freshwater bivalve Zebra mussel (Dreissena polymorpha). Several hundred bivalve specimens were sampled on May 2011 from eight sampling sites located along the lake shoreline. We measured levels of DDTs, PCBs, HCHs, HCB, and PAHs accumulated in D. polymorpha soft tissues by GC/MSn, while the activities of catalase, superoxide dismutase, glutathione peroxidase, and glutathione S-transferase, as well as the lipid peroxidation and protein carbonyl content were evaluated in homogenates from native bivalves as oxidative stress indices. Moreover, DNA damage was investigated by the alkaline precipitation assay. Significant imbalances of enzymatic activity were found in mussels from most of the sampling sites, as well as notable increases of damage to macromolecules. Health status of mussels from Baveno was greatly affected by lake pollution, probably due to high levels of DDTs measured in this site, while a wide variability in biomarker responses was found in all the other stations. The application of a BRI allowed distinguishing impacts of pollution to bivalves, confirming mussels from Baveno as the most threatened and revealing that also the health status of bivalves from Suna, Brissago, Pallanza, and Laveno is affected. These evidences suggest the usefulness of a specific index to integrate all the biomarker endpoints in order to provide a correct environmental risk assessment
Sub-lethal effects induced by a mixture of three non-steroidal anti-inflammatory drugs (NSAIDs) on the freshwater bivalve Dreissena polymorpha
No full textNon-steroidal anti-inflammatory drugs (NSAIDs) are the sixth top-selling drugs worldwide and are commonly found in freshwater ecosystems in the high ng/l to low mu g/l range. Recent studies have investigated both the acute and the chronic toxicity of single NSAIDs on different biological models, but these studies have completely neglected the fact that, in the environment, non-target organisms are exposed to mixtures of drugs that have unforeseeable toxicological behavior. This work investigated the sub-lethal effects induced by a mixture of three common NSAIDs, namely, diclofenac, ibuprofen and paracetamol, on the freshwater bivalve, the zebra mussel (Dreissena polymorpha). The mussels were exposed to three different environmental concentrations of the mixture (Low, Mid and High). A multi-biomarker approach was used to highlight cyto-genotoxic effects and the imbalance of the oxidative status of the treated specimens. The Neutral Red Retention Assay (NRRA) was used as a biomarker of cytotoxicity, whereas the activities of catalase, superoxide dismutase, glutathione peroxidase and glutathione S-transferase were measured to assess the role played by the oxidative stress enzymes. In addition, the single cell gel electrophoresis assay, the DNA Diffusion assay and the micronucleus test were used to investigate possible genotoxic effects. According to our NRRA results, each treatment was able to induce a significant cellular stress in bivalves, probably due to the raise of oxidative stress, as indicated by the alteration of enzyme activities measured in treated specimens. Moreover, the mixture induced significant enhancements of DNA fragmentation, which preluded fixed genetic damage, as highlighted by the increase of both apoptotic and micronucleated cells
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