Acute and chronic toxicity of the benzodiazepine diazepam to the tropical crustacean Mysidopsis juniae

Impact of Benzodiazepine Delorazepam on Growth and Behaviour of Artemia salina Nauplii

Benzodiazepines, a significant group of newly recognised water contaminants, are psychotropic medications prescribed for common anxiety symptoms and sleep disorders. They resist efficient degradation during sewage treatment and endure in aquatic environments. Their presence in aquatic matrices is increasing, particularly after the recent pandemic period, which has led many people to systematically use benzodiazepines to manage anxiety. In previous studies, an important interference of this class of drugs on both the larval and adult stages of some aquatic species has been demonstrated, with effects on behaviour and embryonic development. This study examined the influence of delorazepam, a diazepam metabolite, on Artemia salina development to gain insight into responses in naupliar larvae. Results demonstrated that treatments (1, 5, and 10 µg/L) increase the hatching percentage and induce a desynchronisation in growth. Mortality was only slightly increased (close to 10% at six days post-hatching), but lipid reserve consumption was modified, with the persistence of lipid globules at the advanced naupliar stages. Locomotory activity significantly decreased only at 10 µg/L treatment. No teratogenic effects were observed, though modest damages were noticed in the posterior trunk and eyes, two targets of environmental toxicity. The negative impact of delorazepam on Artemia salina adds to those already reported in other species of invertebrates and vertebrates, which are not yet considered targets of these drugs. This study underscores the need for further research and immediate attention to this class of contaminants and the importance of monitoring their presence during environmental risk assessments.

Benzodiazepine Interference with Fertility and Embryo Development: A Preliminary Survey in the Sea Urchin Paracentrotus lividus

Psychotropic drugs and benzodiazepines are nowadays among the primary substances of abuse. This results in a large and constant release into aquatic environments where they have potentially harmful effects on non-target organisms and, eventually, human health. In the last decades, evidence has been collected on the possible interference of benzodiazepines with reproductive processes, but data are few and incomplete. In this study, the possible negative influence of delorazepam on fertilization and embryo development has been tested in Paracentrotus lividus, a key model organism in studies of reproduction and embryonic development. Sperm, eggs, or fertilized eggs have been exposed to delorazepam at three concentrations: 1 μg/L (environmentally realistic), 5 μg/L, and 10 μg/L. Results indicate that delorazepam reduces the fertilizing capacity of male and female gametes and interferes with fertilization and embryo development. Exposure causes anatomical anomalies in plutei, accelerates/delays development, and alters the presence and distribution of glycoconjugates such as N-Acetyl-glucosamine, α-linked fucose, and α-linked mannose in both morulae and plutei. These results should attract attention to the reproductive fitness of aquatic species exposed to benzodiazepines and pave the way for further investigation of the effects they may exert on human fertility. The presence of benzodiazepines in the aquatic environment raises concerns about the reproductive well-being of aquatic species. Additionally, it prompts worries regarding potential impacts on human fertility due to the excessive use of anxiolytics.

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

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

Environmental concentrations of a delorazepam-based drug impact on embryonic development of non-target Xenopus laevis

Benzodiazepines, psychotropics drugs used for treating sleep disorders, anxiety and epilepsy, represent a major class of emerging water pollutants. As occurs for other pharmaceutical residues, they are not efficiently degraded during sewage treatment and persist in effluent waters. Bioaccumulation is already reported in fish and small crustaceans, but the impact and consequences on other "non-target" aquatic species are still unclear and nowadays of great interest. In this study, we investigated the effects of a pharmaceutical preparation containing the benzodiazepine delorazepam on the embryogenesis of Xenopus laevis, amphibian model species, taxa at high risk of exposure to water contaminants. Environmental (1 μg/L) and two higher (5 and 10 μg/L) concentrations were tested on tadpoles up to stage 45/46. Results demonstrate that delorazepam interferes with embryo development and that the effects are prevalently dose-dependent. Delorazepam reduces vitality by decreasing heart rate and motility, induces marked cephalic and abdominal edema, as well as intestinal and retinal defects. At the molecular level, delorazepam increases ROS production, modifies the expression of some master developmental genes and pro-inflammatory cytokines. The resulting stress condition significantly affects embryos' development and threatens their survival. Similar effects should be expected as well in embryos belonging to other aquatic species that have not been yet considered targets for these pharmaceutical residues.

Acute and chronic effects of diazepam on the polychaete Hediste diversicolor: Antioxidant, metabolic, pharmacologic, neurotoxic and behavioural mechanistic traits

Pharmaceutical drugs are widespread environmental contaminants, but data about their adverse effects are still limited to a few compounds. This study analyzed the acute (96 h) and chronic (28 days) impacts of environmentally realistic levels of diazepam (acute exposure: 0.001, 0.01, 0.1, 1, 10 μg/L; chronic exposure: 0.1, 1, 10, 100, 1000 ng/L), in the polychaete Hediste diversicolor, by measuring behavioral and biochemical (catalase [CAT], glutathione-S-transferases [GSTs], cholinesterases [ChEs], glutathione peroxidase [GPx], lipid peroxidation [TBARS]) parameters. Acute exposure to diazepam altered behavioral traits, decreasing burrowing times and causing hyperactivity, whilst burrowing time increased and hypoactivity resulted after chronic exposure. All biomarkers were affected after the chronic exposure, with the exception of lipid peroxidation. Our data demonstrate that realistic levels of diazepam may impair behavioral and biochemical traits in polychaetes, suggesting that diazepam exposure presents a significant challenge to the environment that supports these organisms.

Toxicity of a mixture of monoaromatic hydrocarbons (BTX) to a tropical marine microcrustacean

This study evaluated the toxicity of benzene, toluene, and xylenes (BTX), isolated and in binary mixtures to Mysidopsis juniae. The organisms were exposed to BTX, and combined effect patterns were predicted by applying the theoretical models of Concentration Addition and Independent Action. According to the LC50 of the isolated compounds, xylene (16.1 ± 2.4 mg L^-1) was considered the most toxic, followed by toluene (38.0 ± 5.3 mg L^-1) and, lastly, benzene (78.0 ± 2.9 mg L^-1). The binary combinations showed deviations from additivity, with exposure to the xylene-benzene mixture presenting as antagonistic, while the xylene-toluene and toluene-benzene mixtures were better explained by a dose ratio deviation, with toluene being responsible for the antagonistic pattern. This study provides new insights into toxicity prediction of a BTX mixture, which adds value to the risk assessment procedure over evaluation of chemical hazards on a case-by-case basis.