Noise pollution is recognized as an environmental stressor that affects various biological processes beyond auditory functions, mainly through stress hormones release. This work explored the biological processes, diseases attributable to noise-regulated targets, and the main targets involved in each disease, employing a network toxicology approach. Through various databases and bioinformatics analysis, a total of 577 targets were identified as potential candidates implicated in diseases related to noise exposure, 10 from the GEO database and the rest from other databases. Noise pollution was found to regulate processes such as hormone response, cellular response to cytokines, and circulatory system functions, contributing to the development of the pathological manifestations related to the diseases like hypertension, ischemia, atherosclerosis, and cirrhosis. Hub targets for ischemia included IL-6, CASP3, AKT1, and TNF-α, while NOS3 was related to hypertension, and NOS3, TNF-α, AGT, and IL-1B to atherosclerosis. The targets were found to be linked to vascular regulation and inflammation in cardio- and cerebrovascular diseases. Molecular docking studies indicated stress hormones released by noise exposure regulates these diseases through signaling pathways, without implicating its direct binding to hub targets. The results indicate that individuals with vascular diseases are more vulnerable to the effects of prolonged noise exposure.

Heavy metal and metalloid (HM) exposure poses significant health risks, including cardiovascular disease, cancer, and renal damage. This contamination, prevalent in the Western U.S., involves Arsenic (As), Cadmium (Cd), Uranium (U), and Vanadium (V). Interstitial fluid (ISF) is a source of biomarkers, which can be minimally invasively collected using microneedle array (MA) technology. Our study hypothesized that MA-extracted ISF would facilitate non-invasive HM quantification. We established analytical parameters for HM detection in ISF using inductively coupled plasma-mass spectrometry (ICP-MS), defined baseline ISF HM concentrations in unexposed animal populations, and monitored HM levels in ISF under mixed exposure in animal models. Additionally, we assessed HM levels in ISF and biological fluids from three human subjects. Thirty-six Sprague Dawley rats were divided into cohorts: low-level mixed HMs exposure (5X maximum contaminant level (MCL)); high-level single HM with low-level others (50X MCL for one HM with 5X for others); and unexposed controls. ISF and plasma were collected weekly for eight weeks and analyzed via ICP-MS. Our findings reveal a correlation between ISF and plasma HM levels, underscoring ISF's potential for real-time monitoring of HM exposure. This study also establishes baseline ISF HM levels, illustrating the feasibility of HM quantification using small ISF volumes.

Tetrahydroxy-1,4-benzoquinone (THQ) is a highly redox-active substance that generates reactive oxygen species (ROS), which can induce apoptosis in cell culture experiments. The underlying mechanism for ROS production has previously been postulated to be the autoxidation of THQ to rhodizonic acid (RhA). However, our results suggest that the cells detoxify THQ by reducing it to hexahydroxybenzene (HHB), catalyzed by the NADPH-quinone-oxidoreductase (NQO1). Then, HHB undergoes autoxidation back to THQ, closing a redox cycle that continuously generates ROS. Only this continuous mechanism produces enough ROS to trigger apoptosis. The cell's protective measures can effectively eliminate the ROS generated by a single autoxidation of THQ to RhA because RhA is not reduced back to THQ and thus does not close a redox cycle. This also explains why only fresh THQ solutions are cytotoxic, whereas older THQ solutions, which are readily autoxidized to RhA, are not.

Mitochondria are affected by chemical substances and play a critical role in drug-induced liver injury (DILI). Chemical substances can have a significant impact on various cellular processes, such as the disruption of oxidative phosphorylation, oxidative stress, and alteration of glucose metabolism. Given the consequences of these effects, it is crucial to understand the molecular pathways of chemical substances in the context of hepatotoxicity to prevent and treat DILI. In this regard, the Seahorse XFe24 Analyzer is a valuable tool for assessing mitochondrial bioenergetics and glucose metabolism. The Mito Stress Test and Glycolytic Rate Assay allow real-time assessment of the metabolic state after chemical exposure. Additionally, HepG2 spheroids have emerged as an important alternative tool for assessing hepatotoxicity, as they provide results that are more comparable to those found in humans than monolayer cultures or animal tests (such as rodent tests). By integrating these two powerful tools, it is possible to bridge the gap between animal and human tests, resulting in more reliable results in the assessment of human hepatotoxicity and DILI. However, because of the high variability in characteristics between 3D cultures (such as spheroids and organoids), XF analyzer assays are not well optimized for use with HepG2 spheroids. Here, we describe a streamlined and optimized protocol for performing the Mito Stress Test and Glycolytic Rate Assay using HepG2 spheroids cultured in alginate microcapsules in the Seahorse XFe24 Analyzer.

Behavioral endpoints are of increasing interest in toxicology because of their sensitivity, but require clear guidance for experimental design. This study describes the design of a hypoxia chamber for use with pond snails, . Studies assessing the switch from water- to air-breathing in hypoxic conditions have previously utilized methods that neglect intricacies of animal behavior such as handling stress and acclimation. The chamber provides a linear decline in dissolved oxygen, against which surfacing behavior for air-breathing can be precisely measured. The maximum biomass of snails suitable for use in the hypoxia chamber, such that the nitrogen-driven deoxygenation curve is not altered by the snails' own metabolism, was established to be greater than 10 adult snails. The capacity of most analysis softwares is below accurately tracking 10 individuals at once, indicating this is likely not a limitation. The size of snails determined the amount of time each episode of aerial respiration was, with smaller snails spending more time air-breathing. A proof-of-principle experiment using acute copper exposure (0 - 60 µg/L) yielded a concentration-response curve, with greater copper concentrations inhibiting air-breathing. The chamber described in the present study provides an improved framework for assessing hypoxic response and is presented in a manner allowing for further modification to meet unique research needs.

Endocrine-disrupting chemicals (EDCs) significantly contribute to health issues by interfering with hormonal functions. Bisphenol A (BPA), a prominent EDC, is extensively utilized as a monomer and plasticizer in producing polycarbonate plastic and epoxy resins, making it one of the highest-demanded chemicals in commercial use. This is the major component used in plastic products, including bottles, containers, storage items, and food serving ware. Exposure of BPA happens through oral, respiratory, transdermal routes and eye contact. As an EDC, BPA disrupts hormonal binding, leading to various health problems, such as cancers, reproductive abnormalities, metabolic syndrome, immune dysfunction, neurological effects, cardiovascular problems, respiratory issues, and obesity. BPA mimics the hormone estrogen but exhibits a weak affinity for estrogen receptors. This weak binding affinity triggers multiple cell death pathways, including necroptosis, pyroptosis, apoptosis, ferroptosis, and autophagy, across different cell types. Numerous clinical, , and experiments have demonstrated that BPA exposure results in unfavorable health effects. This review highlights the mechanisms of cell death pathways initiated through BPA exposure and the associated negative health consequences. The extensive use of BPA and its frequent detection in environmental and biological models underscore the urgent need for further investigation into its effects and the development of safe alternatives. Addressing the health risks posed by BPA involves a comprehensive approach that includes reducing exposure and finding novel substitutes to lessen its detrimental impact on humans.

During out-of-area military operations, the presence of carcinogenic and/or genotoxic agents has been reported, posing potential health risks to deployed soldiers. Military working dogs (MWDs), trained to detect explosives in the same environments as soldiers, could also serve as sentinel animals, providing valuable information on exposure to hazardous agents. These dogs can help identify environmental and potential adverse effects on their health and that of their handlers, possibly before relevant pathologies manifest. This study aims to evaluate the effectiveness of 33 Italian Army MWDs, deployed to the Lebanese theater for six consecutive months from October 2013 to January 2015, as sentinel animals for detecting exposure to genotoxic agents. The Cytokinesis-Block MicroNucleus (CBMN) assay was used to assess DNA damage, cytostasis, and cytotoxicity in the lymphocytes of these dogs. DNA damage events were specifically scored in once-divided binucleated cells (BCs) and included: a) micronuclei (MNi), indicative of chromosome breakage and/or whole chromosome loss; b) nucleoplasmic bridges (NPBs), a marker of DNA misrepair and/or telomere end-fusions; and c) nuclear buds (NBUDs), which signal the elimination of amplified DNA and/or DNA repair complexes. Our findings revealed an increase in chromosomal damage, assessed before and after deployment, with a statistically significant rise in MNi frequency, thus supporting the use of MWDs as sentinels for human exposure to hazardous agents.

The harmful by-product of paracetamol is known as N-Acetyl-p-benzoquinoneimine, (NAPQI). When paracetamol is given at therapeutic dosages or in excess, it undergoes Phase I metabolism in the liver via Cytochrome P-450 2E1 (CYP2E1), and then it produces NAPQI. Previous studies reported that a non-ionic surfactant known as Brij 35 (Polyoxyethylene lauryl ether) has been shown to be an effective inhibitor of CYP2E1 and P-glycoprotein (P-gp). Hence, this and investigation set out to assess Brij 35 impact on paracetamol CYP2E1-mediated metabolism. For the investigation, isolated rat hepatocytes were used. Male Wistar rats were used for studies. There were thirty rats in total, with six individuals each group distributed among the five groups. The first group animals received 0.5% sodium carboxy methyl cellulose (control group); the second group animals treated with 300 mg/kg of paracetamol; the third group animals treated with Brij 35 (5 mg/kg) along with 300 mg/kg of paracetamol; the fourth group animals treated with 10 mg/kg of Brij 35 along with 300 mg/kg of paracetamol and the fifth group animals treated with 20 mg/kg of Brij 35 along with 300 mg/kg of paracetamol for consecutive 21 days. The current study found that paracetamol plasma concentrations were much higher and NAPQI plasma concentrations were much lower when Brij 35 was co-administered may be due to inhibition of CYP2E1-mediated metabolism and P-gp-mediated intestinal transport of paracetamol. Brij 35 also reduced the increased hepatic and renal markers with significant hepatoprotective and nephroprotective changes in the histopathological investigation.

Current studies have clearly shown that aristolochic acid (AA) exposure can induce a variety of diseases, such as kidney disease, liver cancer, and urinary tract cancer (UTC). However, no studies have systematically analyzed and integrated these results. Therefore, we aimed to elucidate the association between AA exposure and the risk of safety outcomes for AA-related overall disease and different types of disease it causes. We conducted an exhaustive search of PubMed, EMBASE, Web of Science, and the Cochrane Library for relevant material up to April 2024. For AA-related overall disease, AA exposure was significantly associated with an increased incidence of AA-related overall disease (OR: 1.289, 95% CI: 1.183 - 1.404). For different types of disease, AA exposure was significantly associated with increased incidence of kidney disease (OR: 1.279, 95% CI: 1.029 - 1.590), UTC (OR: 1.842, 95% CI: 1.376 - 2.465) and liver cancer (OR: 1.146, 95% CI: 1.040 - 1.262). No significant association was found between AA exposure and the incidence of brain disease (OR: 1.161, 95% CI: 0.989 - 1.362). This study systematically analyzed various safety outcomes associated with AA exposure to provide a solid scientific basis for future prevention strategies and clinical management.

Adverse drug reactions (ADR) remain a challenge in modern healthcare, particularly given the increasing complexity of therapeutics. WHO's definition of an adverse drug reaction as a response to a drug that is noxious and unintended and occurs at doses normally used in man for the prophylaxis, diagnosis or therapy of disease, or for modification of physiological function. This definition underscores the importance of monitoring and mitigating unintended drug effects, particularly for widely used medications like valproic acid (VPA). An anticonvulsant medicine which is frequently used in treatment of epilepsy and other neurological conditions is valproic acid (VPA), is frequently associated with hepatotoxicity, a severe ADR that complicates its clinical use, which can take two different forms: Type I, which is defined by dose-dependent and reversible liver damage, and Type II, an idiosyncratic reaction that can result in severe liver failure, frequently complicates its clinical application. Oxidative stress, the creation of reactive metabolites, mitochondrial dysfunction, carnitine shortage, immune-mediated reactions, glutathione depletion, and blockage of the bile salt export pump (BSEP) are some of the numerous underlying mechanisms of Valproic acid-induced hepatic damage. The production of reactive oxygen species and the liver's antioxidant protection are out of balance as a cause of oxidative stress, which is a significant factor in VPA intoxication. Reactive oxygen species (ROS) are defined as "a collective term for a variety of reactive molecules and free radicals derived from molecular oxygen". This includes species such as superoxide anion, hydrogen peroxide, hydroxyl radical, and singlet oxygen, have long been implicated in oxidative damage inflicted on fatty acids, DNA and proteins as well as other cellular components. The integrity of the hepatocyte may be compromised by the over production of ROS, which can create cellular damage such as protein oxidation and lipid peroxidation. Liver damage is further exacerbated by reactive metabolites produced by VPA metabolism, which have the ability to covalently attach to biological macromolecules. As VPA reduces mitochondrial bioenergetics, it causes ATP depletion and consequent cellular death, which is another important component of VPA-induced hepatotoxicity. Increased urea cycle activity leads to hyperammonemia, which aggravates the liver and causes neurotoxicity. VPA can also accelerate the build-up of fatty acids, which increases the risk of steatosis, due to its interaction with the metabolism of carnitine. Immune-mediated processes have been shown to increase liver injury, implying that the immunity system may possibly be involved in VPA hepatotoxicity. Hepatocyte injury and cholestasis are caused by BSEP inhibition, which impairs bile flow. As another point of view, glutathione depletion, a result of oxidative stress, reduces the liver's ability to neutralize toxic compounds. The complex interaction between biochemical and cellular mechanisms that underlie valproic acid's hepatotoxic potential calls for additional research to clarify the precise pathways implicated and create mitigation techniques for this ADR.

Quantification of illicit drugs and controlled substances, in urine or as surface contamination, is often performed using expensive analytical techniques such as liquid chromatography with tandem mass spectrometry (LC-MS/MS). A time and cost-effective semi-quantitative surface-wipe and urine screening multiplex immunoassay for fentanyl and its analogues was developed in this investigation. We previously created a surface wipe multiplex immunoassay for methamphetamine, caffeine, cocaine, tetrahy-drocannabinol (THC) and oxycodone. This fluorescent covalent microsphere immunosorbent assay (FCMIA) is a competitive assay where drugs compete with protein-drug conjugates attached to microspheres for antibodies. It was assembled using a commercially available fentanyl antibody and protein-conjugate. Surface recovery from ceramic tiles was assessed by FCMIA, with results ranging from 26% for fentanyl to 60% for methamphetamine. Only fentanyl and its structurally similar analogues showed significant response to the fentanyl assay whereas, analogues structurally similar to carfentanil gave no response. Non-fentanyl drug assays did not appreciably detect fentanyl or its analogues. Overall, this method is a useful tool for assessing surface contamination and the effectiveness of decontamination by multiple drugs of abuse, potentially lowering workplace exposures. To broaden applicability, different antibodies or aptamers must be developed to detect structural differences found in classes of analogues such as carfentanil.

The rat S9 microsome fraction is commonly used to assess compound metabolite formation during genotoxicity assessments. However, methods using S9 have not been standardized for genotoxicity studies, and different experimental methods are used at various facilities. Therefore, this study investigated whether the differences between the two experimental conditions (1) S9 inducers, phenobarbital + beta-naphthoflavones vs. Aroclor 1254 and (2) the plate incubation vs. preincubation method) in the micro-Ames test would affect the results. Nitrosamine and in-house genotoxicity-positive compounds were used with benzopyrene and 2-aminofluorene as positive control compounds. No differences were observed in the genotoxicity results in the groups treated with the positive control. However, the S9 fraction induced by Aroclor 1254 showed higher cytochrome P450 activity than the fraction induced by phenobarbital and beta-naphthoflavone. The incubation method also affected the results; the nitrosamine compounds showed different genotoxicity activity between the plate incorporation method and preincubation method. In-house aminomethyl quinoline compounds also showed different results depending on the S9 type. These results suggest that different inducers and methods induce various metabolic enzyme activities, which may lead to differences in genotoxicity through distinct metabolite production.

Pymetrozine (a pyridine azomethine pesticide) is one of the most commonly and frequently used insecticides. Scanty information is available about the deleterious effects of Pymetrozine on fish especially bighead carp. Hence, the current study investigated chronic toxicological effects of pymetrozine in bighead carp. A total of 80 fish were reared and divided into four groups(A-D) each containing 20 fish. Pymetrozine was given to experimental fish of groups B, C, and D mixed in water at doses of 5, 10, and 15 mg/L respectively for 30 days. Group A remained as control group. On days 10, 20, and 30 of the experiment, blood and other visceral tissues were collected for analysis of genotoxic effects, erythrocytic morphological and nuclear changes, antioxidant enzymes, and oxidative stress profile. The results revealed significantly higher values of various nuclear abnormalities (erythrocyte with micronuclei, red blood cells with condensed and lobed nuclei) and morphological changes (pear shaped erythrocyte, spindle shaped erythrocytes and spherocyte) in erythrocytes of bighead carp. The investigations on status of antioxidant enzymes and oxidative stress indicated higher values of oxidative stress biomarkers and lower values of antioxidant enzymes in visceral organs (brain, liver, gills, and kidneys) of treated fish. The findings on genotoxic potential of pymetrozine revealed a considerably increased frequency of DNA damage in isolated cells of multiple tissues (brain, liver, gills, and kidneys) of experimental fish at higher doses. In conclusion, it may be suggested that pymetrozine induces toxic effects via disruption of physiological mechanisms of multiple visceral organs of bighead carp.

Nanoparticles (NPs) possess the ability to penetrate cells and elicit a rapid and targeted immune response, influenced by their distinct physicochemical properties. These particles can engage with both micro and macromolecules, thereby impacting various downstream signaling pathways that may lead to cell death. This review provides a comprehensive overview of the primary mechanisms contributing to the immunotoxicity of both organic and inorganic nanoparticles. The effects of carbon-based nanomaterials (CNMs), including single-walled carbon nanotubes, multi-walled carbon nanotubes, graphene, and metal oxide nanoparticles, on various immune cell types such as macrophages, neutrophils, monocytes, dendritic cells (DCs), antigen-presenting cells (APCs), and RAW 264.7 cells are examined. The immune responses discussed encompass inflammation, oxidative stress, autophagy, and apoptosis. Additionally, the roles of pro-inflammatory cytokines such as IL-1β, IL-6, TNF-α, and IFN-γ, along with JAK/STAT signaling pathways, are highlighted. The interaction of NPs with oxidative stress pathways, including MAPK signaling and Nrf2/ARE signaling, is also explored. Furthermore, the mechanisms by which nanoparticles induce damage to organelles such as lysosomes, the endoplasmic reticulum, exosomes, and Golgi bodies within the immune system are addressed. The review also emphasizes the genotoxic and epigenetic mechanisms associated with the immunotoxicity of NPs. Recent advancements regarding the immunotherapeutic potential of engineered NPs are reported. The roles of autophagy and apoptosis in the immunotoxicity of NPs merit further investigation. In conclusion, understanding how engineered nanoparticles modulate immune responses may facilitate the prevention and treatment of human diseases, including cancer and autoimmune disorders.

The inherent adaptability of human mesenchymal stromal cells (hMSCs) to differentiate into neural lineages provides a valuable resource for investigating potential neurotoxicity in humans. By harnessing the ability of hMSCs to transform into astrocytes, we can evaluate the effects of various agents on these vital cells. Our protocol employs hMSCs sourced from umbilical cord tissue, ensuring a readily available supply of high-quality cells. The hMSC-to-neural workflow encompasses six essential steps: hMSC culture, followed by the generation of embryoid bodies (EBs) from these cells on specialized surfaces. Next, EBs and cells are expanded in a growth-promoting medium, directing them toward neural lineages. Subsequent differentiation into immature astrocytes is achieved through the use of specific factors. The process continues with the maturation of EBs/cells into astrocyte-like cells (hALCs) under optimized conditions, culminating in the final development of hALCs in a specialized medium. This methodology yields cells that display astrocyte morphology and express characteristic markers such as GFAP and S100β. The protocol is efficient, requiring roughly 6 weeks to generate hALCs from primary hMSCs without genetic manipulation. The application of hMSCs in evaluating cell damage triggered by neurotoxicants like MeHg and MGO underscores their potential as a valuable component within a more extensive battery of neurotoxicity tests.

Acetamiprid is a neonicotinoid insecticide used against various insect pests. Serious concerns are emerging regarding their adverse effects on non-target organisms and organs. This study aimed to investigate the mechanistic toxic effect of oral administration of acetamiprid at 21.7 and 43.4 mg/kg body weight on the histological structure and pancreatic function of male Wistar rats and the potential effect of carnosine in mitigating this toxicity for 30 consecutive days. Thirty-six animals were divided into six groups: the control group received distilled water, the second group received 200 mg/kg body weight of carnosine, two groups received 21.7 and 43.4 mg/kg of acetamiprid, and two groups received 21.7 and 43.4 mg/kg + 200 kg/kg body weight of acetamiprid and carnosine, respectively. Acetamiprid caused a significant decrease in body weight ( < 0.001), pancreatic somatic index ( < 0.001), and amylase level ( ≤ 0.0001) and increased lipase level ( ≤ 0.0001), blood glucose level ( ≤ 0.0001), histological scores ( ≤ 0.01), and malondialdehyde level (0.01< < 0.0001). Administration of carnosine led to a slight improvement in the increase of lipase ( ≤ 0.01) and the decrease of amylase ( ≤ 0.001) secretions and prevention of histopathological features induced by acetamiprid. Our results pointed out for the first time the toxic effect of acetamiprid and the preventive effect of carnosine on rat pancreatic structure and function.

Copper nanoparticles (CuNPs) are increasingly used across various industries due to their catalytic, antimicrobial, and electrical properties. However, their potential toxicity in aquatic environments, particularly to non-target organisms like fish, remains poorly understood. This study investigated the effects of CuNP exposure on rainbow trout () by comprehensively evaluating hematological, biochemical, antioxidant, molecular, and histopathological parameters. Rainbow trout fingerlings were exposed to varying concentrations of CuNPs (0.2 mg/L, 0.6 mg/L, and 1.0 mg/L) for 7, 14, and 21 days. The results revealed significant dose-dependent declines in hemoglobin (Hb) and red blood cell (RBC) counts, alongside increases in white blood cell (WBC) counts, indicating an immune response to CuNPs-induced stress. Serum biochemistry showed disruptions in albumin, globulin, cholesterol, and triglycerides, suggesting impaired liver function and altered lipid metabolism. Antioxidant enzyme activity, including catalase (CAT), increased significantly, reflecting oxidative stress, while lipid peroxidation (LPO) levels unexpectedly decreased, suggesting possible activation of compensatory mechanisms. Histopathological analysis confirmed severe gill and liver damage, including hypertrophy, hyperplasia, lamellar fusion, necrosis, and cellular degeneration. Molecular analysis showed upregulation of oxidative and, inflammatory genes, and signs of apoptosis. These findings underscore the toxic potential of CuNPs in aquatic environments and highlight the need for careful regulation and environmental monitoring to mitigate their impact.

Metallic nanoparticles, with their large surface area to volume ratio, are increasingly important in various life fields, but they can cause varying toxic effects on fish. This study investigates the toxicological effects of silver nanoparticles (AgNPs) on rainbow trout (), focusing on hematological, biochemical, antioxidant, and histopathological changes. Fish were exposed to varying concentrations of AgNPs (0.2, 0.8, and 1.4 mg/L) for 21 days. Hematological analysis revealed significant reductions in red blood cell (RBC) counts, hemoglobin (Hb), and hematocrit (HCT) at higher AgNPs concentrations, while white blood cell (WBC) counts increased, indicating immune system activation. Biochemical assays demonstrated dose-dependent decreases in total protein and albumin, alongside increased cholesterol and triglyceride levels, suggesting impaired liver function and disrupted lipid metabolism. Antioxidant enzyme activity (SOD, CAT, GST) initially increased at lower AgNPs concentrations but declined at higher exposures, indicating oxidative stress. Molecular analysis further supported these findings, with upregulation of oxidative stress-related genes (SOD1, CAT) and inflammatory markers (HSP70, IL-1β). Histopathological examinations revealed necrosis, hyperplasia, and lamellar fusion in the gills, along with significant liver damage, including vacuolation and Kupffer cell proliferation, particularly at the highest exposure. Behavioral assays showed erratic swimming and reduced feeding in fish exposed to higher AgNPs concentrations. This study highlights the dose-dependent toxic effects of AgNPs on rainbow trout and underscores the potential for long-term, possibly irreversible damage at higher exposure levels. These findings emphasize the need for stricter environmental regulations on nanoparticle use to mitigate their ecological impact.

Methaqualone, introduced in the 1960s as a sedative-hypnotic alternative to barbiturates, was withdrawn from the market due to its side effects and growing recreational use. Despite this, interest in methaqualone and its analogs remains high, raising concerns about potential abuse in the future. An ultra-high-performance liquid chromatography method coupled with triple quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS) was developed to determine nine methaqualone-related compounds simultaneously. Biological samples were prepared using liquid-liquid extraction with ethyl acetate at pH9; quantification was performed in blood using multiple reaction monitoring (MRM) mode. Methaqualone- served as an internal standard. The limit of quantification (LOQ) ranged from 0.1 to 0.2 ng/mL, with precision and accuracy within 20%. Recovery ranged from 84.2% to 113.7%. The developed method allowed chromatographic separation of all compounds tested, including two structural isomers: methylmethaqualone and etaqualone. The mass spectra acquired from quadrupole time-of-flight mass spectrometer allowed for the elucidation of comprehensive fragmentation study of methaqualone derivatives. The described situation poses a significant problem from the analytical point of view, as well as interpretation and forensic toxicological expertise. The developed method will contribute to increased analytical capabilities and enhanced detection of compounds from the methaqualone group that may appear on the illicit market.

Despite the rising popularity of disposable e-cigarettes, little is known about their chemical characteristics, or their impact on users' health. This work attempts to summarize current knowledge about chemical composition and known health effects of disposable e-cigarettes.