Chemical Research in Toxicology最新文献

We identified and quantified bisphenol A (BPA), a known estrogen-like endocrine disruptor, in disposable face mask samples collected in Hong Kong. Results revealed that BPA is a common contaminant in face masks, with concentrations reaching up to 2 μg/mask. Although polypropylene, the primary material used in mask production, is generally considered to be BPA-free, the contaminant likely originates from additives, such as flame retardants, added during manufacturing. With a dermal absorption coefficient of 0.59 for BPA, the data indicate that mask-borne BPA is readily absorbed by the skin. Notably, 8 of 85 samples could cause the user to exceed the tolerable daily BPA intake set by the European Food Safety Agency (0.0002 μg/kg body weight per day). Additionally, BPA dissolves completely in landfill leachate in less than 70 days, which poses previously unrecognized health and environmental hazards. Given the extensive use of face masks during the pandemic, their role as personal protective equipment for medical practitioners, and the fact that there are currently no regulations regarding BPA contents in masks, it is imperative to investigate the need for regulations in order to safeguard face mask users and the environment.

Apatinib, a commonly used tyrosine kinase inhibitor in cancer treatment, can cause adverse reactions such as hypertension. Hypertension, in turn, can increase the risk of certain cancers. The coexistence of these diseases makes the use of combination drugs more common in clinical practice, but the potential interactions and regulatory mechanisms in these drug combinations are poorly understood. We used the humanized CYP2D6 mouse model to predict the effect of apatinib on the pharmacokinetics and pharmacodynamics of metoprolol and investigated the interactional mechanism. The inhibitory effects and mechanisms of apatinib on metoprolol were investigated in vitro by using wild-type mouse liver microsomes (WT MLMs), humanized CYP2D6 mouse liver microsomes (hCYP2D6 MLMs), and human liver microsomes (HLMs). Molecular docking was utilized to explore the structural basis of the observed inhibitory mode. And in vivo interaction between apatinib and metoprolol was assessed by pharmacokinetics study using the humanized CYP2D6 mice. In vitro studies and molecular docking experiments indicated that apatinib competitively inhibited the metabolism of metoprolol. In vivo findings revealed that the administration of apatinib combined with metoprolol resulted in a significant increase in the AUC_(0-t), AUC_(0-∞) and C_max of metoprolol; additionally, there was a reduction in the CL_z/F and heart rate, indicating that apatinib strongly inhibited metoprolol metabolism. And the homologous CYP2D6 protein in WT mice was more sensitive to apatinib compared to the hCYP2D6 mice. Gender analysis revealed that metoprolol accumulation was more pronounced in male mice when combined with apatinib, indicating a higher susceptibility to cardiotoxicity in males.

4-Aminobiphenyl (4-ABP) is a known human carcinogen that is implicated in the development of bladder cancers in smokers. The amine substituent undergoes bioactivation to generate nitrenium ions capable of covalently modifying DNA nucleobases. The primary adduct of 4-ABP, N-(deoxyguanosin-8-yl)-4-aminobiphenyl (dG-C8-ABP), is a bulky N-linked C8-dG adduct that serves as a biomarker for assessing the cancer risk associated with aromatic amine exposure. In this study, the capture-SELEX method was utilized to isolate DNA aptamers for dG-C8-ABP with high affinity and specificity. Using thioflavin T fluorescence spectroscopy and isothermal titration calorimetry, the parent aptamer PdG-1 has a K_d value below 100 nM and over 50-fold selectivity for dG-C8-ABP against competing analytes. A turn-on fluorescent sensor for dG-C8-ABP diagnostics, developed using a strand displacement assay, is also presented with a limit of detection of 68 nM. Our work represents the first selection of a DNA aptamer for a bulky DNA adduct produced by a known human carcinogen and sets the stage for the creation of ultrasensitive aptasensor platforms to meet the challenge of dG-C8-ABP detection in clinical settings.

Oxidative byproducts of cannabidiol (CBD) are known to be cytotoxic. However, CBD susceptibility to oxidation and resulting toxicity dissolved in two common solvents, ethanol (EtOH) and dimethyl sulfoxide (DMSO), is seldom discussed. Furthermore, CBD products contain a wide range of concentrations, making it challenging to link general health risks associated with CBD cytotoxicity. Here, we report on the effect of CBD and CBD analogues dissolved in EtOH or DMSO at various concentrations. The cells used in these studies were human umbilical vascular endothelial cells (HUVECs). Our findings show significant CBD oxidation to cannabidiol-quinone (CBD-Q) and subsequent cytotoxicity, occurring at 10 μM concentration, regardless of the solution delivery vehicle. Moreover, a new analogue of CBD, cannabidiol-diacetate (CBD-DA), exhibits significantly more stability and reduced toxicity compared with CBD or CBD-Q, respectively. This knowledge is important for determining concentration-dependent health risks of complex cannabinoid mixtures and establishing legal limits.

The widespread use of perfluorooctanesulfonic acid (PFOS) has raised concerns regarding its potential on pregnant women, particularly in relation to the development of pre-eclampsia (PE). This study investigates the impact of PFOS exposure on the LncRNA/Rnd3 axis in pregnant mice and its association with trophoblast cell functions in PE. Bioinformatics analysis revealed PFOS-related gene alterations in PE, with pathways enriched in apoptotic signaling and cytokine interactions. Experimental findings showed the downregulation of Oip5os1 and Rnd3, along with the upregulation of miR-155, affecting trophoblast behavior. Animal experiments confirmed that PFOS-induced gene expression changes are linked to PE progression. PFOS exposure impairs trophoblast proliferation and migration via the Oip5os1/miR-155/Rnd3 axis, contributing to PE development.

This study employed high-time-resolution systems to examine the transient properties of aerosols and gases emitted from electronic cigarette (EC) puffs. Using a fast aerosol sizer, we measured particle size distributions (PSDs) across various EC brands (JUUL, VUSE, VOOPOO), revealing sizes ranging from 5 to 1000 nm at concentrations of 10⁷ to 10¹⁰ cm^-3. Most aerosols were found to be in the ultrafine range (below 100 nm), with JUUL-, VUSE-, and VOOPOO-producing aerosols with geometric mean sizes of 19.9, 47.3, and 29.4 nm, respectively. Applying the International Commission on Radiological Protection (ICRP) deposition model and assuming no further evolution of aerosols in the respiratory system, we estimated particle deposition in different respiratory regions: 45-60% in the alveolar region, 10-25% in the tracheobronchial region, and 20-35% in the extrathoracic region. The highest single-puff deposition was observed with the VOOPOO device at 60 W, depositing 180.1 ± 7.6 μg in the alveolar region. The gas emissions (CO₂, NO_x, CO, and total hydrocarbons) were measured at different power settings of the VOOPOO EC. Single-puff NO_x and CO levels exceeded the permissible exposure limits of the Occupational Safety and Health Administration, indicating potential acute exposure risks. Higher power settings were correlated with increased gas mixing ratios, suggesting more e-liquid vaporization and possible chemical transformations at higher temperatures. These findings demonstrated significant health risks associated with ultrafine particles from high-power ECs and emphasize the need for advanced measurements to accurately assess their physicochemical properties and potential health implications.

Alkaloids, a class of low-molecular-weight nitrogenous compounds, attract a great deal of interest because of their biological activities and therapeutic potential. Yet, surprisingly little is known about their interactions with drug transporters, especially Organic Anion Transporting Polypeptide 1B1 (OATP1B1), a liver-specific uptake transporter, which is closely associated with drug-induced liver injury (DILI). This study aims to investigate the inhibitory effects of 160 alkaloids on OATP1B1, assess the hepatoprotective effects against bosentan-induced liver injury, and elucidate the structure-activity relationships of alkaloids with OATP1B1. Four alkaloids, including dihydroberberine, deacetyltaxol, dihydrocapsaicin, and tetrahydropalmatine, significantly inhibited OATP1B1 transport activity in OATP1B1-HEK293 cells (>50%), which reduced the OATP1B1-mediated uptake of methotrexate and microcystin-LR, and consequently decreased their cell toxicity. In bosentan-induced liver injury models, 4 alkaloids reduced serum total bile acid (TBA) levels and liver concentration of bosentan to different degrees, especially deacetyltaxol, which exhibited the most potent hepatoprotective effect against bosentan. The pharmacophore model suggested that the critical pharmacophores of alkaloid inhibitors are hydrogen bond acceptors and hydrophobic groups. Our findings pave the way for predicting the potential risks of alkaloids-containing food/herb-drug interactions in humans and optimizing the alkaloid structure for alleviating OATP1B1-related DILI.

Cobalt is a crucial trace element that widely exists in natural environments and is necessary for normal physiological function. However, excessive cobalt exposure leads to various adverse health effects, especially hematological and endocrine dysfunctions. Here, we investigated the toxicity of cobalt on early erythropoiesis by using ex vivo cultured erythroid progenitor cells (EPCs). We exposed EPCs to cobalt chloride (CoCl₂) and observed that their proliferation was significantly reduced after treatment with 50 μM CoCl₂ for 3 days and 10 μM CoCl₂ for 4 days. Furthermore, CoCl₂ exposure reduced the proportion of S phase cells and induced apoptosis of EPCs in a dose-dependent manner (20-100 μM). Notably, further studies revealed that CoCl₂ exposure inhibited the expression and phosphorylation of the erythroid proliferation master gene c-Kit. During EPC differentiation, treatment with CoCl₂ hindered the enucleation of erythrocytes. Consistent with these findings, the RNA-seq results revealed that CoCl₂ treatment inhibited the expression of several genes related to both proliferation and differentiation. The gene responsible for nucleoprotein export during enucleation, Xpo7, was also downregulated. Gene ontology analysis revealed that CoCl₂ treatment inhibited a variety of biological processes, including DNA replication and ribosome synthesis. In summary, we demonstrated that sustained excessive CoCl₂ exposure impaired the function of the EPCs.