Oxidative and genetic responses induced by Δ-9-tetrahydrocannabinol (Δ-9-THC) to Dreissena polymorpha

Δ9-tetrahydrocannabinol induces blood-brain barrier disruption: Involving the activation of CB1R and oxidative stress

Cannabis abuse has increased with the continuous relaxation of cannabis policies. However, the mechanism by which Δ9-tetrahydrocannabinol (THC) negatively affects the central nervous system, especially the blood-brain barrier (BBB), remains unclear. THC exposure models were established in vivo and in vitro. The BBB properties were examined using Western blotting (WB), immunofluorescence staining (IF), transendothelial electrical resistance (TEER), and flux of sodium fluorescein (SF). The oxidative stress regulators were examined using IF and assay kits. The activation of cannabinoid receptor 1 (CB1R) was examined using WB and IF. The THC exposure caused barrier integrity damage and endothelial dysfunction in murine and hCMEC/D3 cells, conclude albumin leakage, increased SF permeability and reduced TEER value. The expression of tight junction proteins, including claudin 5, occludin, and junctional adhesion molecules, was decreased. Additionally, key oxidative stress regulators, including reactive oxygen species, hydrogen peroxide, malonaldehyde levels, and antioxidant enzyme activities, including catalase, glutathione peroxidase, glutathione S-transferase, and superoxide dismutase, and heme oxygenase 1, were increased. Activation of CB1R has been detected in brain microvascular endothelial cells in vivo and in vitro. Furthermore, inhibition of oxidative stress and CB1R could mitigate the aforementioned conditions and BBB damage after THC exposure. The effect of THC on murine and human brain microvascular endothelial cells revealed that THC-induced BBB damage was partly mediated by CB1R activation, triggering the oxidative stress response. This study provides new theoretical insights into the mechanisms of THC-induced BBB damage and offers novel scientific evidence for the potential neurotoxicity and adverse reactions induced by THC.

Neuroprotective Actions of Cannabinoids in the Bovine Isolated Retina: Role of Hydrogen Sulfide

Both hydrogen sulfide and endocannabinoids can protect the neural retina from toxic insults under in vitro and in vivo conditions. Purpose: The aim of the present study was two-fold: (a) to examine the neuroprotective action of cannabinoids [methanandamide and 2-arachidonyl glycerol (2-AG)] against hydrogen peroxide (H2O2)-induced oxidative damage in the isolated bovine retina and (b) to evaluate the role of endogenously biosynthesized hydrogen sulfide (H2S) in the inhibitory actions of cannabinoids on the oxidative stress in the bovine retina. Methods: Isolated neural retinas from cows were exposed to oxidative damage using H2O2 (100 µM) for 10 min. When used, tissues were pretreated with methanandamide (1 nM-100 nM) and 2-AG (1-10 µM) for 30 min before a 10 min treatment with H2O2 (100 µM). In some experiments, retinas were pretreated with inhibitors of the biosynthesis of H2S [cystathionine β-synthase/cystathionine γ-lyase (CBS/CSE), aminooxyacetic acid, AOAA 30 µM, or 3-mercaptopyruvate sulfurtransferase (3MST), α-keto-butyric acid, KBA 1 mM] and the CB1-receptor antagonist, AM251 (100 nM) for 30 min before treatment with methanandamide (1 nM-100 µM). Enzyme immunoassay measurement of 8-epi PGF2α (8-isoprostane) levels was performed to assess lipid peroxidation in retinal tissues. Results: In the presence of H2O2 (100 µM), methanandamide (1 nM-100 µM) and 2-AG (1-10 µM) significantly (p < 0.001) blocked the H2O2-induced elevation in 8-isoprostane levels in the isolated bovine retina. In the presence of the CB1 antagonist AM251 (100 nM), the effect of methanandamide (1 nM) on the H2O2-induced 8-isoprostane production was significantly (p < 0.001) attenuated. While AOAA (30 µM) had no significant (p > 0.05) effect on the inhibition of H2O2-induced oxidative stress elicited by methanandamide, KBA (1 mM) reversed the neuroprotective action of methanandamide. Conclusions: The cannabinoids, methanandamide and 2-AG can prevent H2O2-induced oxidative stress in the isolated bovine retina. The neuroprotective actions of cannabinoids are partially dependent upon the activation of the CB1 receptors and endogenous production of H2S via the 3-MST/CAT pathway.

Occurrence, ecotoxicity and ecological risks of psychoactive substances in surface waters

Psychoactive substances (PSs) represent a subset of emerging contaminants. Their widespread production and utilization contribute to a growing ecological burden and risk on a global scale. Conventional wastewater treatment methods have proven insufficient in adequately removing psychoactive substances, leading to their occurrence in surface water ecosystems worldwide. As of present, however, a thorough understanding of their geographical prevalence and distribution patterns remains elusive. Further, in the existing literature, there is a scarcity of comprehensive overviews that systematically summarize the toxicity of various psychoactive substances towards aquatic organisms. Through summarizing almost 140 articles, the present study provides an overview of the sources, pollution status, and biotoxicity of psychoactive substances in surface waters, as well as an assessment of their ecological risks. Concentrations of several psychoactive substances in surface waters were found to be as high as hundreds or even thousands of ng·L-1. In parallel, accumulation of psychoactive substances in the tissues or organs of aquatic organisms was found to potentially cause certain adverse effects, including behavioral disorders, organ damage, and DNA changes. Oxidative stress was found to be a significant factor in the toxic effects of psychoactive substances on organisms. The application of the risk quotient approach indicated that psychoactive substances posed a medium to high risk in certain surface water bodies, as well as the need for sustained long-term attention and management strategies.

Exposure to Synthetic Psychoactive Substances: A Potential Cause for Increased Human Hepatotoxicity Markers

BACKGROUND

Approximately 30 million people worldwide consume new psychoactive substances (NPS), creating a serious public health issue due to their toxicity and potency. Drug-induced liver injury is the leading cause of liver disease, responsible for 4% of global deaths each year.

CONTENT

A systematic literature search revealed 64 case reports, in vitro and in vivo studies on NPS hepatotoxicity. Maximum elevated concentrations of aspartate aminotransferase (136 to 15 632 U/L), alanine transaminase (121.5 to 9162 U/L), total bilirubin (0.7 to 702 mg/dL; 0.04 to 39.03 mmol/L), direct (0.2-15.1 mg/dL; 0.01-0.84 mmol/L) and indirect (5.3 mg/dL; 0.29 mmol/L) bilirubin, alkaline phosphatase (79-260 U/L), and gamma-glutamyltransferase (260 U/L) were observed as biochemical markers of liver damage, with acute and fulminant liver failure the major toxic effects described in the NPS case reports. In vitro laboratory studies and subsequent in vivo NPS exposure studies on rats and mice provide data on potential mechanisms of toxicity. Oxidative stress, plasma membrane stability, and cellular energy changes led to apoptosis and cell death. Experimental studies of human liver microsome incubation with synthetic NPS, with and without specific cytochrome P450 inhibitors, highlighted specific enzyme inhibitions and potential drug-drug interactions leading to hepatotoxicity.

SUMMARY

Mild to severe hepatotoxic effects following synthetic NPS exposure were described in case reports. In diagnosing the etiology of liver damage, synthetic NPS exposure should be considered as part of the differential diagnosis. Identification of NPS toxicity is important for educating patients on the dangers of NPS consumption and to suggest promising treatments for observed hepatotoxicity.

Removal of residues of psychoactive substances during wastewater treatment, their occurrence in receiving river waters and environmental risk assessment

Continuous consumption combined with incomplete removal during wastewater treatment means residues of psychoactive substances (licit drugs, medications of abuse and illicit drugs) are constantly introduced into the aquatic environment, where they have the potential to affect non-target organisms. In this study, 17 drug residues of psychoactive substances were determined in wastewater influent, effluent and in receiving rivers of six Slovene municipal wastewater treatment plants employing different treatment technologies. Variations in removal efficiencies (REs) during spring, summer and winter were explored, and ecotoxic effects were evaluated using in silico (Ecological Structure-Activity Relationships software-ECOSAR) and in vivo (algal growth inhibition test) methods. Drug residues were detected in influent and effluent in the ng/L to μg/L range. In receiving rivers, biomarkers were in the ng/L range, and there was good agreement between measured and predicted concentrations. On average, REs were highest for nicotine, 11-nor-9-carboxy-∆9-tetrahydrocannabinol (THC-COOH), cocaine residues, and amphetamine (>90 %) and lowest for methadone residues (<30 %). REs were comparable between treatments involving activated sludge and membrane bioreactors, while the moving biofilm bed reactor (MBBR) removed cotinine, cocaine, and benzoylecgonine to a lesser extent. Accordingly, higher levels of nicotine and cocaine residues were detected in river water receiving MBBR discharge. Although there were seasonal variations in REs and levels of drug residues in receiving rivers, no general pattern could be observed. No significant inhibition of algal growth (Chlamydomonas reinhardtii) was observed for the tested compounds (1 mg/L) during 72 h and 240 h of exposure, although effects on aquatic plants were predicted in silico. In addition, environmental risk assessment revealed that levels of nicotine, methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), morphine, and 3,4-methylenedioxymethamphetamine (MDMA) pose a risk to aquatic organisms. Since nicotine and EDDP can have acute and chronic effects, the authors support regular monitoring of receiving surface waters, followed up by regulatory actions.

Patterns of Cannabis- and Substance-Related Congenital General Anomalies in Europe: A Geospatiotemporal and Causal Inferential Study

INTRODUCTION

Recent series of congenital anomaly (CA) rates (CARs) have showed the close and epidemiologically causal relationship of cannabis exposure to many CARs. We investigated these trends in Europe where similar trends have occurred.

METHODS

CARs from EUROCAT. Drug use from European Monitoring Centre for Drugs and Drug Addiction. Income data from World Bank.

RESULTS

CARs were higher in countries with increasing daily use overall (p = 9.99 × 10-14, minimum E-value (mEV) = 2.09) and especially for maternal infections, situs inversus, teratogenic syndromes and VACTERL syndrome (p = 1.49 × 10-15, mEV = 3.04). In inverse probability weighted panel regression models the series of anomalies: all anomalies, VACTERL, foetal alcohol syndrome, situs inversus (SI), lateralization (L), and teratogenic syndromes (TS; AAVFASSILTS) had cannabis metric p-values from: p < 2.2 × 10-16, 1.52 × 10-12, 1.44 × 10-13, 1.88 × 10-7, 7.39 × 10-6 and <2.2 × 10-16. In a series of spatiotemporal models this anomaly series had cannabis metric p-values from: 8.96 × 10-6, 6.56 × 10-6, 0.0004, 0.0019, 0.0006, 5.65 × 10-5. Considering E-values, the cannabis effect size order was VACTERL > situs inversus > teratogenic syndromes > FAS > lateralization syndromes > all anomalies. 50/64 (78.1%) E-value estimates and 42/64 (65.6%) mEVs > 9. Daily cannabis use was the strongest predictor for all anomalies.

CONCLUSION

Data confirmed laboratory, preclinical and recent epidemiological studies from Canada, Australia, Hawaii, Colorado and USA for teratological links between cannabis exposure and AAVFASSILTS anomalies, fulfilled epidemiological criteria for causality and underscored importance of cannabis teratogenicity. VACTERL data are consistent with causation via cannabis-induced Sonic Hedgehog inhibition. TS data suggest cannabinoid contribution. SI&L data are consistent with results for cardiovascular CAs. Overall, these data show that cannabis is linked across space and time and in a manner which fulfills epidemiological criteria for causality not only with many CAs, but with several multiorgan teratologic syndromes. The major clinical implication of these results is that access to cannabinoids should be tightly restricted in the interests of safeguarding the community's genetic heritage to protect and preserve coming generations, as is done for all other major genotoxins.

Acute Hepatic Injury Associated with Acute Administration of Synthetic Cannabinoid XLR-11 in Mouse Animal Model

The widespread recreational use of synthetic cannabinoids (SCs) has become a serious health issue. Reports of life-threatening intoxications related to SC consumption have markedly increased in recent years, including neurotoxicity, cardiotoxicity, nephrotoxicity, and hepatotoxicity. We investigated the impact of acute administration of the synthetic cannabinoid XLR-11 (3 mg/kg, i.p. for 5 consecutive days) on the liver in BALB/c mouse animal model. Using real-time quantitative RT-PCR, MDA assay, and TUNEL assay, we found consistent up-regulation of a variety of genes involved in oxidative stress (NOX2, NOX4, and iNOS), inflammation (TNF-α, IL-1β, IL-6), and apoptosis (Bax) in the liver of XLR-11 treated mice compared to control mice. These finding were supported with an elevation of MDA levels and TUNEL positive cells in the liver of XLR-11 treated mice which further confirm increased oxidative stress and apoptosis, respectively. Histopathological analysis of the liver of XLR-11 treated mice confirmed pronounced hepatic necrosis associated with inflammatory cell infiltration. Furthermore, elevated ALT and AST serum levels were also identified in XLR-11 treated mice indicating possible liver damage. Overall, SC-induced hepatotoxicity seems to be mainly mediated by activated oxidative stress and inflammatory processes in the liver, but the specific mechanisms involved require further investigations. However, the present study shed light on the potential deleterious role of acute administration of SCs in the progression to acute hepatic injury which enhances our understanding of the adverse effect of SC consumption.

Geotemporospatial and causal inferential epidemiological overview and survey of USA cannabis, cannabidiol and cannabinoid genotoxicity expressed in cancer incidence 2003-2017: part 3 - spatiotemporal, multivariable and causal inferential pathfinding and exploratory analyses of prostate and ovarian cancers

BACKGROUND

The epidemiology of cannabinoid-related cancerogenesis has not been studied with cutting edge epidemiological techniques. Building on earlier bivariate papers in this series we aimed to conduct pathfinding studies to address this gap in two tumours of the reproductive tract, prostate and ovarian cancer.

METHODS

Age-standardized cancer incidence data for 28 tumour types (including "All (non-skin) Cancer") was sourced from Centres for Disease Control and National Cancer Institute using SEER*Stat software across US states 2001-2017. Drug exposure was sourced from the nationally representative household survey National Survey of Drug Use and Health conducted annually by the Substance Abuse and Mental Health Services Administration 2003-2017 with response rate 74.1%. Federal seizure data provided cannabinoid concentration data. US Census Bureau provided income and ethnicity data. Inverse probability weighted mixed effects, robust and panel regression together with geospatiotemporal regression analyses were conducted in R. E-Values were also calculated.

RESULTS

19,877 age-standardized cancer rates were returned. Based on these rates and state populations this equated to 51,623,922 cancer cases over an aggregated population 2003-2017 of 124,896,418,350. Inverse probability weighted regressions for prostate and ovarian cancers confirmed causal associations robust to adjustment. Cannabidiol alone was significantly associated with prostate cancer (β-estimate = 1.61, (95%C.I. 0.99, 2.23), P = 3.75 × 10- 7). In a fully adjusted geospatiotemporal model at one spatial and two temporal years lags cannabidiol was significantly independently associated with prostate cancer (β-estimate = 2.08, (1.19, 2.98), P = 5.20 × 10- 6). Cannabidiol alone was positively associated with ovarian cancer incidence in a geospatiotemporal model (β-estimate = 0.36, (0.30, 0.42), P <  2.20 × 10- 16). The cigarette: THC: cannabidiol interaction was significant in a fully adjusted geospatiotemporal model at six years of temporal lag (β-estimate = 1.93, (1.07, 2.78), P = 9.96 × 10- 6). Minimal modelled polynomial E-Values for prostate and ovarian cancer ranged up to 5.59 × 1059 and 1.92 × 10125. Geotemporospatial modelling of these tumours showed that the cannabidiol-carcinogenesis relationship was supra-linear and highly sigmoidal (P = 1.25 × 10- 45 and 12.82 × 10- 52 for linear v. polynomial models).

CONCLUSION

Cannabinoids including THC and cannabidiol are therefore important community carcinogens additive to the effects of tobacco and greatly exceeding those of alcohol. Reproductive tract carcinogenesis necessarily implies genotoxicity and epigenotoxicity of the germ line with transgenerational potential. Pseudoexponential and causal dose-response power functions are demonstrated.

Algal-based system for removal of emerging pollutants from wastewater: A review

The bioremediation of emerging pollutants in wastewater via algal biotechnology has been emerging as a cost-effective and low-energy input technological solution. However, the algal bioremediation technology is still not fully developed at a commercial level. The development of different technologies and new strategies to cater specific needs have been studied. The existence of multiple emerging pollutants and the selection of microalgal species is a major concern. The rate of algal bioremediation is influenced by various factors, including accidental contaminations and operational conditions in the pilot-scale studies. Algal-bioremediation can be combined with existing treatment technologies for efficient removal of emerging pollutants from wastewater. This review mainly focuses on algal-bioremediation systems for wastewater treatment and pollutant removal, the impact of emerging pollutants in the environment, selection of potential microalgal species, mechanisms involved, and challenges in removing emerging pollutants using algal-bioremediation systems.

Occurrence, bioaccumulation and toxicological effect of drugs of abuse in aquatic ecosystem: A review

Drugs of abuse are a group of emerging contaminants. As the prevalence of manufacture and consumption, there is a growing global environmental burden and ecological risk from the continuous release of these contaminants into environment. The widespread occurrence of drugs of abuse in waste wasters and surface waters is due to the incomplete removal through traditional wastewater treatment plants in different regions around the world. Although their environmental concentrations are not very high, they can potentially influence the aquatic organisms and ecosystem function. This paper reviews the occurrence of drugs of abuse and their metabolites in waste waters and surface waters, their bioaccumulation in aquatic plants, fishes and benthic organisms and even top predators, and the toxicological effects such as genotoxic effect, cytotoxic effect and even behavioral effect on aquatic organisms. In summary, drugs of abuse occur widely in aquatic environment, and may exert adverse impact on aquatic organisms at molecular, cellular or individual level, and even on aquatic ecosystem. It necessitates the monitoring and risk assessment of these compounds on diverse aquatic organisms in the further study.

Canadian Cannabis Consumption and Patterns of Congenital Anomalies: An Ecological Geospatial Analysis

OBJECTIVES

Cannabis is a known teratogen. Data availability addressing both major congenital anomalies and cannabis use allowed us to explore their geospatial relationships.

METHODS

Data for the years 1998 to 2009 from Canada Health and Statistics Canada was analyzed in R. Maps have been drawn and odds ratios, principal component analysis, correlation matrices, least squares regression and geospatial regression analyses have been conducted using the R packages base, dplyr, epiR, psych, ggplot2, colorplaner and the spml and spreml functions from package splm.

RESULTS

Mapping showed cannabis use was more common in the northern Territories of Canada in the Second National Survey of Cannabis Use 2018. Total congenital anomalies, all cardiovascular defects, orofacial clefts, Downs syndrome and gastroschisis were all found to be more common in these same regions and rose as a function of cannabis exposure. When Canada was dichotomized into high and low cannabis use zones by Provinces v Territories the Territories had a higher rate of total congenital anomalies 450.026 v 390.413 (O.R. = 1.16 95%C.I. 1.08-1.25, P = 0.000058; attributable fraction in exposed 13.25%, 95%C.I. 7.04-19.04%). In geospatial analysis in a spreml spatial error model cannabis was significant both alone as a main effect (P < 2.0 × 10) and in all its first and second order interactions with both tobacco and opioids from P < 2.0 × 10.

CONCLUSION

These results show that the northern Territories of Canada share a higher rate of cannabis use together with elevated rates of total congenital anomalies, all cardiovascular defects, Down's syndrome and gastroschisis. This is the second report of a significant association between cannabis use and both total defects and all cardiovascular anomalies and the fourth published report of a link with Downs syndrome and thereby direct major genotoxicity. The correlative relationships described in this paper are confounded by many features of social disadvantage in Canada's northern territories. However, in the context of a similar broad spectrum of defects described both in animals and in epidemiological reports from Hawaii, Colorado, USA and Australia they are cause for particular concern and indicate further research.

The Endocannabinoid System and Invertebrate Neurodevelopment and Regeneration

Cannabis has long been used for its medicinal and psychoactive properties. With the relatively new adoption of formal medicinal cannabis regulations worldwide, the study of cannabinoids, both endogenous and exogenous, has similarly flourished in more recent decades. In particular, research investigating the role of cannabinoids in regeneration and neurodevelopment has yielded promising results in vertebrate models. However, regeneration-competent vertebrates are few, whereas a myriad of invertebrate species have been established as superb models for regeneration. As such, this review aims to provide a comprehensive summary of the endocannabinoid system, with a focus on current advances in the area of endocannabinoid system contributions to invertebrate neurodevelopment and regeneration.

Autopsy, thanatopraxy, cemeteries and crematoria as hotspots of toxic organic contaminants in the funeral industry continuum

The occurrence and health risks of toxic organic contaminants (TOCs) in the funeral industry are relatively under-studied compared to other industries. An increasing body of literature reports TOCs including emerging contaminants in the funeral industry, but comprehensive reviews of the evidence are still lacking. Hence, evidence was analysed to address the proposition that, the funeral industry constitutes several hotspot reservoirs of a wide spectrum of TOCs posing ecological and human health risks. TOCs detected include embalming products, persistent organic pollutants, synthetic pesticides, pharmaceuticals, personal care products and illicit drugs. Human cadavers, solid wastes, wastewaters and air-borne particulates from autopsy, thanatopraxy care facilities (mortuaries, funeral homes), cemeteries and crematoria are hotspots of TOCs. Ingestion of contaminated water, and aquatic and marine foods constitutes non-occupational human exposure, while occupational exposure occurs via inhalation and dermal intake. Risk factors promoting exposure to TOCs include unhygienic burial practices, poor solid waste and wastewater disposal, and weak and poorly enforced regulations. The generic health risks of TOCs are quite diverse, and include; (1) genotoxicity, endocrine disruption, teratogenicity and neurodevelopmental disorders, (2) development of antimicrobial resistance, (3) info-disruption via biomimicry, and (4) disruption of ecosystem functions and trophic interactions. Barring formaldehyde and inferential evidence, the epidemiological studies linking TOCs in the funeral industry to specific health outcomes are scarce. The reasons for the lack of evidence, and limitations of current health risk assessment protocols are discussed. A comprehensive framework for hazard identification, risk assessment and mitigation (HIRAM) in the funeral industry is proposed. The HIRAM includes regulatory, surveillance and control systems such as prevention and removal of TOCs. Future directions on the ecotoxicology of mixtures, behaviour, and health risks of TOCs are highlighted. The opportunities presented by emerging tools, including isotopic labelling, genomics, big data analytics (e.g., machine learning), and in silico techniques in toxicokinetic modelling are highlighted.

Brain-Derived Neurotrophic Factor and Oxidative Stress in Cannabis Dependence

INTRODUCTION

Neurotrophin levels and oxidative stress markers such as ceruloplasmin and free thiols have been shown to contribute to pathophysiology in several psychiatric disorders.

OBJECTIVE

Our aim is to evaluate whether those markers are altered in cannabis dependence.

METHODS

Forty-five cannabis-dependent patients diagnosed according to the DSM-IV criteria and 45 healthy controls matched according to sex, age, BMI, and smoking status were enrolled. Brain-derived neurotrophic factor (BDNF), ceruloplasmin, lipid hydroperoxide, and total free thiols were measured in both groups. Those who had psychiatric comorbidities were excluded before sampling.

RESULTS

We found significantly increased BDNF, ceruloplasmin, and lipid hydroperoxide, and decreased free thiol levels in patients with cannabis dependence. There is also a positive correlation between BDNF and lipid hydroperoxide (n = r = 0.472, p < 0.001) and a negative correlation between BDNF and total thiols (n = r = -0.412, p = 0.001).

CONCLUSIONS

Increased BDNF might be a sign of impaired neuronal plasticity that is crucial for memory formation and adaptive response to drug addiction. Neuronal plasticity in the ventral tegmental area dopaminergic neurons was implied to play a role in substance addiction disorders, and these adaptations can be secondary to oxidative stress. Our findings, including increased lipid hydroperoxide, ceruloplasmin, and decreased free thiols, might support this hypothesis. In conclusion, cannabis dependency alters BDNF levels and increases oxidative stress.

The effect of cannabis toxicity on a model microbiome bacterium epitomized by a panel of bioluminescent E. coli

The world acceptance of medical cannabis slowly widens. Cannabinoids are known as the main therapeutic active compounds in the cannabis plant, yet their bioactive physiological effects are still unknown. In this study, the mode of action of nine selected cannabinoids was examined using a bioluminescent bacterial panel, as well as the extracts of six different cannabis varieties and cannabinoids standards artificial mixtures. The bacterial panel was composed of genetically modified E. coli bacteria that is commonly found in the gut microbiome, to which a lux operon was added to various stress promoters. The panel was exposed to the cannabinoids in order to identify bacterial defense mechanism, via the aforementioned specific stress types response. This enables the understanding of the toxicity mode of action of cannabinoids. From all the tested cannabinoids, only delta-9-tetrahydrocannabinol (THC) and delta-9-tetrahydrocannabinolic acid A (THCA) produced a genotoxic effect, while the other tested cannabinoids, demonstrated cytotoxic or oxidative damages. Unlike pure cannabinoids, cannabis plant extracts exhibited mostly genotoxicity, with minor cytotoxicity or oxidative stress responses. Moreover, cannabinoids standards artificial mixtures produced a different response patterns compared to their individual effects, which may be due to additional synergistic or antagonistic reactions between the mixed chemicals on the bacterial panel. The results showed that despite the lack of cannabigerol (CBG), cannabidivarin (CBDV), cannabinol (CBN), and cannabichromene (CBC) in the artificial solution mimicking the CN6 cannabis variety, a similar response pattern to the cannabinoids standards mixture was obtained. This work contributes to the understanding of such correlations and may provide a realistic view of cannabinoid effects on the human microbiome.

A critical review on the detection, occurrence, fate, toxicity, and removal of cannabinoids in the water system and the environment

Cannabinoids are a group of organic compounds found in cannabis. Δ⁹-tetrahydrocannabinol (THC) and cannabidiol (CBD), the two major constituents of cannabinoids, and their metabolites are contaminants of emerging concern due to the limited information on their environmental impacts. As well, their releases to the water systems and environment are expected to increase due to recent legalization. Solid-phase extraction is the most common technique for the extraction and pre-concentration of cannabinoids in water samples as well as a clean-up step after the extraction of cannabinoids from solid samples. Liquid chromatography coupled with mass spectrometry is the most common technique used for the analysis of cannabinoids. THC and its metabolites have been detected in wastewater, surface water, and drinking water. In particular, 11-nor-9-carboxy-Δ⁹-tetrahydrocannabinol (THC-COOH) has been detected at concentrations up to 2590 and 169 ng L^-1 in untreated and treated wastewater, respectively, 79.9 ng L^-1 in surface water, and 1 ng L^-1 in drinking water. High removal of cannabinoids has been observed in wastewater treatment plants; this is likely a result of adsorption due to the low aqueous solubility of cannabinoids. Based on the estrogenicity and cytotoxicity studies and modelling, it has been predicted that THC and THC-COOH pose moderate risk for adverse impact on the environment. While chlorination and photo-oxidation have been shown to be effective in the removal of THC-COOH, they also produce by-products that are potentially more toxic than regulated disinfection by-products. The potential of indirect exposure to cannabinoids and their metabolites through recreational water is of great interest. As cannabinoids and especially their by-products may have adverse impacts on the environment and public health, more studies on their occurrence in various types of water and environmental systems, as well as on their environmental toxicity, would be required to accurately assess their impact on the environment and public health.

Interactive effects between sinking polyethylene terephthalate (PET) microplastics deriving from water bottles and a benthic grazer

The information concerning the toxicity of sinking microplastics (MPs) on benthic marine animals, particularly benthic grazers, is still scant. No study focused on biological weathering of sinked MPs operated by benthic organisms. This study aims at investigating the ingestion and the effects induced by 7-days dietary exposure to environmentally relevant amount (8, 80 and 800 particles/g of food) of irregular shaped and sized (diameter 12.6-1,065 μm; mean diameter 316 ± 12 μm) polyethylene terephthalate microplastics (PET-MPs) on a common marine benthic grazer, the sea urchin Paracentrotus lividus. Adverse effects were investigated on digestive tract at biochemical (oxidative stress biomarkers) and tissue level (histopathological analyses). Potential alteration of MP structure/surface and PET macromolecules due to the ingestion of PET-MPs within the sea urchin digestive tract were investigated. Results showed that PET-MPs were efficiently egested by sea urchins without producing histological alterations on digestive tract tissues, only inducing a slight modulation of oxidative status. Sea urchin grazing activity and the related transit of PET-MPs within animal digestive tract slightly affected MP structure and PET composition. These findings suggest that PET-MPs might represent an hazard for benthic grazer organisms, which can partially contribute to the degradation of PET in marine ecosystems.

Review on the occurrence and biological effects of illicit drugs in aquatic ecosystems

Illicit drugs (IDs) and their metabolites are recognized as contaminants of emerging concern. After consumption, illicit drugs are partially metabolized and excreted unchanged in urine and feces or as active metabolites reaching wastewater treatment plants (WWTPs). Furthermore, most WWTPs are insufficient in the treatment of effluents containing IDs, which may be released into aquatic ecosystems. Once in the water or sediment, these substances may interact and affect non-target organisms and some evidences suggest that illicit drugs may exhibit pseudo-persistence because of a continuous environmental input, resulting in long-term exposure to aquatic organisms that may be negatively affected by these biologically active compounds. We reviewed the literature on origin and consumption, human metabolism after consumption, aquatic occurrences, and toxicity of the major groups of illicit drugs (opioids, cannabis, synthetic drugs, and cocaine). As a result, it could be concluded that illicit drugs and their metabolites are widespread in diverse aquatic ecosystems in levels able to trigger sublethal effects to non-target organisms, besides to concentrate in seafood. This class of emerging contaminants represents a new environmental concern to academics, managers, and policymakers, whose would be able to assess risks and identify proper responses to reduce environmental impacts.

Investigation of DNA damage, oxidative stress, and inflammation in synthetic cannabinoid users

BACKGROUND

The widespread use of synthetic cannabinoids (SCs) among youth has become an important public health problem. Several life-threatening side effects of SC have been reported, including cardiovascular, gastrointestinal, neurological, renal, metabolic, ophthalmologic, and pulmonary effects, besides skin toxicity and hepatotoxicity.

METHODS

Given that high levels of SC can lead to oxidative stress, DNA damage, and inflammation, it has been aimed in this study to investigate the effects of SC in aspects of primary DNA damage, plasma total oxidant status (TOS)/total antioxidant status (TAS), thiol-disulfide homeostasis, myeloperoxidase (MPO) level, and cytokine levels (interleukin 1 beta (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor-alpha (TNF-α)) of 40 SC users (SCUs) in Turkey.

RESULTS

Mean plasma TOS levels were significantly higher in the SCUs group than in the healthy group (HG). Similarly, mononuclear leukocyte DNA damage, plasma TOS, MPO activity, disulfide, oxidative stress index levels, IL-1β, IL-6, and TNF-α levels were significantly higher in the SCU group than in the HG, whereas plasma TAS, total, and native thiol levels were significantly lower in the SCU group than in the HG.

CONCLUSION

It is concluded that SC can cause increase in oxidative stress and in inflammatory processes in addition to its potential for DNA damage. Additional studies with larger sample sizes and longer durations should be held to understand more specific outcomes of SC use.

Transformation potential of cannabinoids during their passage through engineered water treatment systems: A perspective

Cannabinoids are incipient contaminants with limited literature in the context of water treatment. With increasing positive public opinion toward legalization and their increasing use as a pharmaceutical, cannabinoids are expected to become a critical class of pollutant that requires attention in the water treatment industry. The destructive removal of cannabinoids via chlorination and other oxidation processes used in drinking water and wastewater treatment requires careful investigation, because the oxidation and disinfection byproducts (DBPs) may pose significant risks for public health and the environment. Understanding transformation of cannabinoids is the first step toward the development of management strategies for this emerging class of contaminant in natural and engineered aquatic systems. This perspective reviews the current understanding of cannabinoid occurrence in water and its potential transformation pathways during the passage through drinking water and wastewater treatment systems with chlorination process. The article also aims to identify research gaps on this topic, which demand attention from the environmental science and engineering community.

Biochemical and behavioral effects induced by cocaine exposure to Daphnia magna

Illicit drugs and their metabolites have been identified as emerging aquatic pollutants. Cocaine (COC) is one of the most used illicit drug worldwide. After human consumption, COC enters the aquatic ecosystems, where it is commonly detected in ng L^-1 concentration range. Although a number of studies have shown that the exposure to environmental concentrations of COC can induce diverse biochemical, molecular and histological effects on aquatic organisms, the information of COC-induced behavioral alterations is scant. Thus, the present study aimed at exploring both biochemical and behavioral effects induced by the exposure to two environmental concentrations (50 ng L^-1 and 500 ng L^-1) of COC on the freshwater cladoceran Daphnia magna. Specimens were exposed to selected COC concentrations for 21 days and the effects on the oxidative status, including the amount of reactive oxygen species and the activity of antioxidant (SOD, CAT and GPx) and detoxifying (GST) enzymes, and swimming activity were investigated after 7, 14 and 21 days of treatment, while effects on reproductive success was assessed after 21-days only.. Exposure to COC induced an overproduction of reactive oxygen species and a modulation of the activity of defense enzymes. Moreover, COC affected the swimming behavior and altered the reproductive success of treated specimens. Our results highlighted that environmental concentrations of COC can cause adverse effects at different levels of the biological hierarchy in a zooplanktonic species, confirming the potential threat due to this illicit drug for the aquatic community.

Aquatic Phytotoxicity to Lemna minor of Three Commonly Used Drugs of Addiction in Australia

The manufacturing and consumption of drugs of addiction has increased globally and their widespread occurrence in the environment is an emerging concern. This study evaluated the phytotoxicity of three compounds: methamphetamine, codeine and morphine; commonly reported in Australian urban water, to the aquatic plant Lemna minor under controlled conditions. L. minor was sensitive to lower drug concentrations when administered in multi-compound mixtures (100-500 µg L^-1) than when applied individually (range 600-2500 µg L^-1), while no adverse effects were observed at environmentally-relevant concentrations (1-5 µg L^-1) detected in wastewater effluent. In conclusion, the results show that the concentrations of these compounds discharged into the environment are unlikely to pose adverse phytotoxic effects. These three compounds are known to be the most stable of their group under such conditions indicating that with this respect it is safe to use recycled water for existing regulated reclaimed purposes including agricultural or parklands irrigation or replenishing surface and groundwater. However, more research on the analysis of methamphetamines and opiates in municipal effluents is needed to reassure the likely environmental hazard of these neuroactive drug classes to aquatic organisms. Given the ever-growing production and aquatic disposal of discharge wastewater globally, this study provides timely and valuable insights into the likely drug-related impacts of effluent disposal on aquatic plants in receiving environments.

Distinct inflammatory profiles in HIV-infected individuals under antiretroviral therapy using cannabis, cocaine or cannabis plus cocaine

OBJECTIVES

To evaluate the effects of cannabis and/or cocaine use on inflammatory, oxidative stress status and circulating monocyte subsets in HIV-infected individuals under antiretroviral therapy.

DESIGN

Soluble CD14 (sCD14), intestinal fatty acid-binding protein (IFABP), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, IL-8, IL-10, C-reactive protein (CRP) and oxidative stress markers were examined. The monocyte subsets and their activation and cytokine production by peripheral blood mononuclear cells (PBMCs) of HIV-1 infected individuals upon lipopolysaccharide (LPS)-stimulation were also investigated.

METHODS

sCD14, IFABP, TNF-α, IL-6, IL-8 and IL-10 levels were evaluated using ELISA, CRP by turbidimetry; lipid peroxidation (TBARS) spectrofluometrically and total thiol levels by using 5-5'-dithio-bis (2-nitrobenzoic acid) reagent. Monocyte subsets and activation were assessed by flow cytometry.

RESULTS

All HIV-infected drug user groups showed higher sCD14 levels compared with HIV+ nondrug users. IFABP was increased in HIV+ drug-users in relation to healthy individuals. Cannabis use lowered the percentages of inflammatory, nonclassical, activated-classic and activated-inflammatory monocytes. Cocaine users showed increased plasmatic TNF-α and TBARS levels, decreased thiols content and lower activated-classic and inflammatory-monocyte percentages. Cannabis-plus-cocaine use increased CRP, IL-8 and IL-6/IL-10 ratio, but decreased thiol content, and inflammatory and activated-classic monocyte percentages. PBMCs of cannabis and cannabis-plus-cocaine users showed low-potential cytokine production either spontaneously or under LPS-stimulation.

CONCLUSION

In HIV infection, the use of cannabis induces predominantly an anti-inflammatory profile. The use of cocaine and cannabis-plus-cocaine showed a mixed pro-inflammatory and anti-inflammatory profile, with predominance of inflammatory status. Further studies are required to better understand the action of these drugs in HIV infection.

Micronucleus Experiments with Bivalve Molluscs

The micronucleus (MN) test, as an index of accumulated DNA damage during the lifespan of cells, is the most applied assay in aquatic animals to assess the exposure to a complex mixture of genotoxic pollutants. An increase in MN frequency was reported on mussels exposed to the most common environmental pollutants under laboratory conditions, such as heavy metals, polycyclic aromatic hydrocarbons, and ionizing radiation. The test was applied in a large number of biomonitoring studies in different geographic areas to identify the exposure to different classes of pollutants with good discrimination power and to evaluate the recovery effects after accidental pollution events. A standardized MN assay protocol in hemocytes and gill cells for use in bivalve species, including scoring of different cell types, necrotic and apoptotic cells and nuclear anomalies, was established following the “cytome approach”. The mussel MNcytome (MUMNcyt) assay, using the proposed detailed criteria for the identification of cell types, is suitable for application in experimental studies under controlled conditions and in biomonitoring programs in aquatic environments.

Occurrence, control and fate of contaminants of emerging concern in environmental compartments in Brazil

This is the first review to present data obtained in Brazil over the years regarding contaminants of emerging concern (CEC) and to contrast it with contamination in other countries. Data gathered indicated that caffeine, paracetamol, atenolol, ibuprofen, cephalexin and bisphenol A occur in the μg L^-1 range in streams near urban areas. While endocrine disruptors are frequently detected in surface waters, highest concentrations account for 17α-ethynylestradiol and 17β-estradiol. Organochlorine pesticides are the most frequently found and persistent in sediments in agricultural regions. Moreover, in tropical agricultural fields, pesticide volatilization and its implications to ecosystem protection must be better investigated. The reality represented here for Brazil may be transposed to other developing countries due to similarities related to primitive basic sanitation infrastructure and economic and social contexts, which contribute to continuous environmental contamination by CEC. Municipal wastewater treatment facilities in Brazil, treat up to the secondary stage and lead to limited CEC removal. This is also true for other nations in Latin America, such as Argentina, Colombia and Mexico. Therefore, it is an urgent priority to improve sanitation infrastructure and, then, the implementation of tertiary treatment shall be imposed.

A laboratory-study on the analytical determination and removal processes of THC-COOH and bezoylecgonine in the activated sludge reactor

The present study focused on 11-nor-9carboxy-Δ9-THC (THC-COOH) and Benzoylecgonine (BE), the most common metabolites of cannabis and cocaine, respectively, present in the domestic sewage entering the wastewater treatment plants. The aims of the study were: (1) to validate the analytical method of detection in wastewater and sludge; (2) to determine contribution of biodegradation and other processes to the removal in the biological reactor of the wastewater treatment plant (WWTP) and the response of biomass to different drug concentrations. The Ultra-Performance Liquid Chromatography coupled to tandem Mass Spectrometry method showed to be repeatable and reliable (recovery>75%; repeatability<10-15%; bias uncertainty<10) for measurements in wastewater; the ultrasound assisted extraction (USE) demonstrated to be reliable as pre-treatment of activated sludge solid phase. Both drugs were fully removed from the liquid phase in the lab-scale biological reactor within 24 h. Biodegradation was the main BE removal mechanism, and the first order kinetic model provided the best fitting of the experimental data. THC-COOH was mainly removed due to a combination of adsorption and biodegradation; adsorption was better described by the pseudo-second order kinetic model and the Freundlich isotherm. Both drugs at the higher concentrations caused inhibition of nitrogen oxidation and carbon removal.

Occurrence of illicit drugs in water and wastewater and their removal during wastewater treatment

This review critically evaluates the types and concentrations of key illicit drugs (cocaine, amphetamines, cannabinoids, opioids and their metabolites) found in wastewater, surface water and drinking water sources worldwide and what is known on the effectiveness of wastewater treatment in removing such compounds. It is also important to amass information on the trends in specific drug use as well as the sources of such compounds that enter the environment and we review current international knowledge on this. There are regional differences in the types and quantities of illicit drug consumption and this is reflected in the quantities detected in water. Generally, the levels of illicit drugs in wastewater effluents are lower than in raw influent, indicating that the majority of compounds can be at least partially removed by conventional treatment processes such as activated sludge or trickling filters. However, the literature also indicates that it is too simplistic to assume non-detection equates to drug removal and/or mitigation of associated risks, as there is evidence that some compounds may avoid detection via inadequate sampling and/or analysis protocols, or through conversion to transformation products. Partitioning of drugs from the water to the solids fraction (sludge/biosolids) may also simply shift the potential risk burden to a different environmental compartment and the review found no information on drug stability and persistence in biosolids. Generally speaking, activated sludge-type processes appear to offer better removal efficacy across a range of substances, but the lack of detail in many studies makes it difficult to comment on the most effective process configurations and operations. There is also a paucity of information on the removal effectiveness of alternative treatment processes. Research is also required on natural removal processes in both water and sediments that may over time facilitate further removal of these compounds in receiving environments.

Evaluation of Oxidant/Antioxidant Status and Cytokine Levels in Patients with Cannabis Use Disorder

Objective

Cannabis is the most commonly used illegal drug in the world and it has several adverse effects such as anxiety, panic reactions and psychotic symptoms. In this study, we aimed to evaluate oxidant, anti-oxidant status and cytokine levels in individuals with cannabis use disorder.

Methods

Thirty-four patients with cannabis use disorder and 34 healthy controls were enrolled to the study. Serum total antioxidant status, total oxidant status and cytokine levels were investigated in patients with cannabis use disorder and healthy controls.

Results

We found increased levels of total oxidant status, oxidative stress index and interleukin (IL) 1β, IL-6, IL-8, and tumor necrosis factor (TNF) α in individuals with cannabis dependency compared to healthy people. When we compared total antioxidant status, IL-12, and interferon (IFN) γ levels, there were no differences in both groups. There was positive correlation between IL-6 and total oxidant status, oxidative stress index levels.

Conclusion

The oxidative balance of individuals with cannabis use disorder was impaired and they had higher levels of IL-1β, IL-6, IL-8, and TNF-α, which is a pro-inflammatory cytokine and indicates increased inflammation compared to healthy controls. Thus, these findings suggest that cannabis increased inflammation and impaired the oxidative balance.

Increase in cannabis use may indirectly affect the health status of a freshwater species

Cannabis is the most used illicit drug worldwide and in some countries a new regulatory policy makes it legal under some restrictions. This situation could lead to a substantial increase in environmental levels of the cannabis active principle (Δ-9-tetrahydrocannabinol [Δ-9-THC]) and its main metabolite, 11-nor-9-carboxy-Δ⁹ -tetrahydrocannabinol (THC-COOH). Although previous studies have highlighted the toxicity of Δ-9-THC, the adverse effects of THC-COOH on aquatic organisms is completely unknown, even though such effects could be more significant because the environmental concentrations of THC-COOH are higher than those of the parent compound. The present study aimed to assess oxidative and genetic damage to the zebra mussel (Dreissena polymorpha) because of 14-d exposures to 3 THC-COOH concentrations, mimicking a current environmental situation (100 ng/L), as well as exposure to 2 possible worst-case scenarios (500 ng/L and 1000 ng/L), because of the potential increase in THC-COOH in surface waters. Variations in the activity of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione S-transferase (GST) were measured, as well as levels of lipid peroxidation and protein carbonyl content. Genetic injuries were investigated by single-cell gel electrophoresis assay, DNA diffusion assay, and the micronucleus test. A significant imbalance in antioxidant defense enzymes was noted in response to the 3 tested concentrations, whereas oxidative damage was noted only at the higher one. Moreover, an increase in DNA fragmentation in zebra mussel hemocytes, but no fixed genetic damage, was found. Although the results showed that THC-COOH toxicity was lower than that of Δ-9-THC, the increase in cannabis use might increase its levels in freshwaters, enhancing its hazard to bivalves and likely to the whole aquatic community. Environ Toxicol Chem 2017;36:472-479. © 2016 SETAC.

Multi-biomarker investigation to assess toxicity induced by two antidepressants on Dreissena polymorpha

Antidepressants are one of the main pharmaceutical classes detected in the aquatic environment. Nevertheless, there is a dearth of information regarding their potential adverse effects on non-target organisms. Thus, the aim of this study was the evaluation of sub-lethal effects on the freshwater mussel Dreissena polymorpha of two antidepressants commonly found in the aquatic environment, namely Fluoxetine (FLX) and Citalopram (CT). D. polymorpha specimens were exposed to FLX and CT alone and to their mixture (MIX) at the environmental concentration of 500ng/L for 14days. We evaluated the sub-lethal effects in the mussel soft tissues by means of a biomarker suite: the activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and the activity of the phase II detoxifying enzyme glutathione-S-transferase (GST). The oxidative damage was evaluated by lipid peroxidation (LPO) and protein carbonylation (PCC), while genetic damage was tested on D. polymorpha hemocytes by Single Cell Gel Electrophoresis (SCGE) assay, DNA diffusion assay and micronucleus test (MN test). Finally, the functionality of the ABC transporter P-glycoprotein (P-gp) was measured in D. polymorpha gills. Our results highlight that CT, MIX and to a lesser extent FLX, caused a significant alteration of the oxidative status of bivalves, accompanied by a significant reduction of P-gp efflux activity. However, only FLX induced a slight, but significant, increase in apoptotic and necrotic cell frequencies. Considering the variability in biomarker response and to perform a toxicity comparison of tested molecules, we integrated each endpoint into the Biomarker Response Index (BRI). The data integration showed that 500ng/L of FLX, CT and their MIX have the same toxicity on bivalves.

Genotoxic properties of XLR-11, a widely consumed synthetic cannabinoid, and of the benzoyl indole RCS-4

Aim of this study was the investigation of the genotoxic properties of XLR-11 [1-(5-fluoropentyl)-1H-indol-3-yl](2,2,3,3-tetramethylcyclopropyl)methanone, a widely consumed synthetic cannabinoid (SC), and of the benzoyl indole RCS-4 (4-methoxyphenyl)(1-pentyl-1H-indol-3-yl)methanone). We characterized the DNA-damaging properties of these drugs in different experimental systems. No evidence for induction of gene mutations was detected in bacterial (Salmonella/microsome) tests, but clear dose-dependent effects were found in in vitro single cell gel electrophoresis (SCGE) assays with human lymphocytes and with buccal- and lung-derived human cell lines (TR-146 and A-549). These experiments are based on the determination of DNA migration in an electric field and enable the detection of single- and double-strand breaks and apurinic sites. Furthermore, we found that both drugs induce micronuclei which are formed as a consequence of chromosomal aberrations. The lack of effects in SCGE experiments with lesion-specific enzymes (FPG, Endo III) shows that the DNA damage is not caused by formation of oxidatively damaged bases; experiments with liver enzyme homogenates and bovine serum albumin indicate that the drugs are not converted enzymatically to DNA-reactive intermediates. Furthermore, results with buccal- and lung-derived human cells show that gaseous treatment of the cells under conditions which reflect the exposure situation in drug users may cause damage of the genetic material in epithelia of the respiratory tract. Since DNA instability is involved in the etiology of cancer, these findings can be taken as an indication that consumption of the SCs may cause tumors in the respiratory tract of consumers.

Amphetamine exposure imbalanced antioxidant activity in the bivalve Dreissena polymorpha causing oxidative and genetic damage

Illicit drugs have been recognized as emerging aquatic pollutants due to their presence in aquatic ecosystems up to µg/L level. Among these, the synthetic psycho-stimulant drug amphetamine (AMPH) is commonly found in both surface and wastewaters worldwide. Even though the environmental occurrence of AMPH is well-known, the information on its toxicity towards non-target freshwater organisms is completely lacking. This study investigated the imbalance of the oxidative status and both oxidative and genetic damage induced by a 14-day exposure to two concentrations (500 ng/L and 5000 ng/L) of AMPH on the freshwater bivalve Dreissena polymorpha by the application of a biomarker suite. We investigated the activity of antioxidant enzymes (SOD, CAT and GPx), the phase II detoxifying enzyme GST, the lipid peroxidation level (LPO) and protein carbonyl content (PCC), as well as primary (Single Cell Gel Electrophoresis assay) and fixed (DNA diffusion assay and Micronucleus test) genetic damage. Our results showed that a current realistic AMPH concentration (500 ng/L) did neither cause notable imbalances in enzymatic activities, nor oxidative and genetic damage to cellular macromolecules. In contrast, the bell-shaped trend of antioxidants showed at the highest tested concentration (5000 ng/L) suggested an overproduction of reactive oxygen species, leading to oxidative damage, as confirmed by the significant increase of protein carbonylation and DNA fragmentation.

Sublethal effects induced by morphine to the freshwater biological model Dreissena polymorpha

Opioids 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.

Effects of Various Illicit Drugs on Immune Capacity of Blue Mussel (Mytilus Edulis)

Not available

Toxicity decrease in urban wastewaters treated by a new biofiltration process

We carried out a project aimed to evaluate the possible role played by the freshwater zebra mussel (Dreissena polymorpha) in the possible decrease of some environmental pollutants recalcitrant to tradition wastewater treatments. By the help of a pilot-plant built in the largest wastewater treatment plant of Milan (Italy), we tested several waste mixtures in order to measure the chemicals' abatement made by mussels' biofiltration. This study represents the last step of the wider project and it aimed to evaluate if the decrease in the concentration of some urban pollutants measured in wastewaters was followed by a corresponding toxicity reduction. Thus, we performed 7-day exposures under laboratory conditions to test the toxicity of the raw wastewaters and those preliminary filtered by zebra mussels, through the measurement of different end-points of acute and chronic toxicity. Results showed a clear positive effect of mussels' biofiltration mainly to decrease the acute toxicity made by the two tested wastewater mixtures, while the biomarkers' suite used to evaluate the chronic toxicity showed contradictory results.

Realistic mixture of illicit drugs impaired the oxidative status of the zebra mussel (Dreissena polymorpha)

Illicit drugs are considered to be emerging aquatic pollutants since they are commonly found in freshwater ecosystems in the high ng L(-1) to low μg L(-1) range concentrations. Although the environmental occurrence of the most common psychoactive compounds is well known, recently some investigations showed their potential toxicity toward non-target aquatic organisms. However, to date, these studies completely neglected that organisms in the real environment are exposed to a complex mixture, which could lead to dissimilar adverse effects. The present study investigated the oxidative alterations of the freshwater bivalve Dreissena polymorpha induced by a 14-d exposure to an environmentally relevant mixture of the most common illicit drugs found in the aquatic environment, namely cocaine (50 ng L(-1)), benzoylecgonine (300 ng L(-1)), amphetamine (300 ng L(-1)), morphine (100 ng L(-1)) and 3,4-methylenedioxymethamphetamine (50 ng L(-1)). The total oxidant status (TOS) was measured to investigate the increase in the reactive oxygen species' levels, while the activity of antioxidant enzymes and glutathione S-transferase were measured to note the eventual imbalances between pro-oxidant and antioxidant molecules. In addition, oxidative damage was assessed by measuring the levels of lipid peroxidation and protein carbonylation. Significant time-dependent increases of all the antioxidant activities were induced by the mixture. Moreover, the illicit drug mixture significantly increased the levels of carbonylated proteins and caused a slight variation in lipid peroxidation. Our results showed that a mixture of illicit drugs at realistic environmental concentrations can impair the oxidative status of the zebra mussel, posing a serious hazard to the health status of this bivalve species.

A review on emerging contaminants in wastewaters and the environment: current knowledge, understudied areas and recommendations for future monitoring

This review identifies understudied areas of emerging contaminant (EC) research in wastewaters and the environment, and recommends direction for future monitoring. Non-regulated trace organic ECs including pharmaceuticals, illicit drugs and personal care products are focused on due to ongoing policy initiatives and the expectant broadening of environmental legislation. These ECs are ubiquitous in the aquatic environment, mainly derived from the discharge of municipal wastewater effluents. Their presence is of concern due to the possible ecological impact (e.g., endocrine disruption) to biota within the environment. To better understand their fate in wastewaters and in the environment, a standardised approach to sampling is needed. This ensures representative data is attained and facilitates a better understanding of spatial and temporal trends of EC occurrence. During wastewater treatment, there is a lack of suspended particulate matter analysis due to further preparation requirements and a lack of good analytical approaches. This results in the under-reporting of several ECs entering wastewater treatment works (WwTWs) and the aquatic environment. Also, sludge can act as a concentrating medium for some chemicals during wastewater treatment. The majority of treated sludge is applied directly to agricultural land without analysis for ECs. As a result there is a paucity of information on the fate of ECs in soils and consequently, there has been no driver to investigate the toxicity to exposed terrestrial organisms. Therefore a more holistic approach to environmental monitoring is required, such that the fate and impact of ECs in all exposed environmental compartments are studied. The traditional analytical approach of applying targeted screening with low resolution mass spectrometry (e.g., triple quadrupoles) results in numerous chemicals such as transformation products going undetected. These can exhibit similar toxicity to the parent EC, demonstrating the necessity of using an integrated analytical approach which compliments targeted and non-targeted screening with biological assays to measure ecological impact. With respect to current toxicity testing protocols, failure to consider the enantiomeric distribution of chiral compounds found in the environment, and the possible toxicological differences between enantiomers is concerning. Such information is essential for the development of more accurate environmental risk assessment.

Environmentally relevant concentrations of galaxolide (HHCB) and tonalide (AHTN) induced oxidative and genetic damage in Dreissena polymorpha

Synthetic musk compounds (SMCs) are extensively used as fragrances in several personal care products and have been recognized as emerging aquatic pollutants. Among SMCs, galaxolide (HHCB) and tonalide (AHTN) are extensively used and have been measured in aquatic ecosystems worldwide. However, their potential risk to organisms remains largely unknown. The aim of this study was to investigate whether 21-day exposures to HHCB and AHTN concentrations frequently measured in aquatic ecosystems can induce oxidative and genetic damage in Dreissena polymorpha. The lipid peroxidation (LPO) and protein carbonyl content (PCC) were measured as oxidative stress indexes, while the DNA precipitation assay and the micronucleus test (MN test) were applied to investigate genetic injuries. HHCB induced significant increases in LPO and PCC levels, while AHTN enhanced only protein carbonylation. Moreover, significant increases in DNA strand breaks were caused by exposure to the highest concentrations of HHCB and AHTN tested in the present study, but no fixed genetic damage was observed.

Uptake and depuration kinetics of lead (Pb) and biomarker responses in the earthworm Eisenia fetida after simultaneous exposure to decabromodiphenyl ether (BDE209)

Lead (Pb) and BDE209 (decabromodiphenyl ether) are the main contaminants at e-waste recycling sites, and their potential toxicological effects on terrestrial organisms have received extensive attention. However, the impact on earthworms of exposure to the two chemicals remains almost unknown. Therefore, indoor incubation tests were performed on control and contaminated soil samples to determine the uptake and toxicity of Pb in the presence of BDE209 to the earthworm Eisenia fetida. The results have demonstrated that the presence of BDE209 facilitated the release of Pb into soil porewater. Compared with exposure to Pb alone, simultaneous exposure to BDE209 significantly enhanced the Pb uptake rate at the level of p<0.05, while decreased the depuration rate, ultimately resulting in a larger bioaccumulation factor (BAF) value. Additionally, BDE209 addition reduced the antioxidant enzymatic activities [superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and glutathione-s-transferase (GST)] and total antioxidant capacity (T-AOC). The decline trend in antioxidant enzymatic activities and T-AOC might explain an increase in lipid peroxidation reflected by the observed augment in malondialdehyde (MDA) level. Moreover, a biomarker of the lysosomal membrane stability, measured by neutral red retention time (NRRT), was also investigated. The NRRT obviously declined in the joint presence of BDE209, indicating a distinct time-response relationship. The results of these observations have provided a basic understanding of the potential eco-toxicological effects of joint heavy metal and BDE209 exposure on terrestrial invertebrates in a multi-contamination context of ecosystems.

A review of ecological effects and environmental fate of illicit drugs in aquatic ecosystems

Although illicit drugs are detected in surface waters throughout the world, their environmental fate and ecological effects are not well understood. Many illicit drugs and their breakdown products have been detected in surface waters and temporal and spatial variability in use translates into "hot spots and hot moments" of occurrence. Illicit drug occurrence in regions of production and use and areas with insufficient wastewater treatment are not well studied and should be targeted for further study. Evidence suggests that illicit drugs may not be persistent, as their half-lives are relatively short, but may exhibit "pseudo-persistence" wherein continual use results in persistent occurrence. We reviewed the literature on the ecological effects of these compounds on aquatic organisms and although research is limited, a wide array of aquatic organisms, including bacteria, algae, invertebrates, and fishes, have receptors that make them potentially sensitive to these compounds. In summary, illicit drugs occur in surface waters and aquatic organisms may be affected by these compounds; research is needed that focuses on concentrations of illicit drugs in areas of production and high use, environmental fate of these compounds, and effects of these compounds on aquatic ecosystems at the concentrations that typically occur in the environment.

Does zebra mussel (Dreissena polymorpha) represent the freshwater counterpart of Mytilus in ecotoxicological studies? A critical review

One of the fundamentals in the ecotoxicological studies is the need of data comparison, which can be easily reached with the help of a standardized biological model. In this context, any biological model has been still proposed for the biomonitoring and risk evaluation of freshwaters until now. The aim of this review is to illustrate the ecotoxicological studies carried out with the zebra mussel Dreissena polymorpha in order to suggest this bivalve species as possible reference organism for inland waters. In detail,we showed its application in biomonitoring, as well as for the evaluation of adverse effects induced by several pollutants, using both in vitro and in vivo experiments. We discussed the advantages by the use of D. polymorpha for ecotoxicological studies, but also the possible limitations due to its invasive nature.

Environmental concentrations of 3,4-methylenedioxymethamphetamine (MDMA)-induced cellular stress and modulated antioxidant enzyme activity in the zebra mussel

Recent 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 μg/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 μg/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.