Insights into the toxicities of UV-328, UV-329, UV-P in HepG2 cells and their roles in AHR-mediated pathway

Accumulation of benzotriazole UV-stabilizers in relation to ingested plastics and associated health metrics in Larus gulls feeding at a landfill in Atlantic Canada

Benzotriazole UV-Stabilizers (BZT-UVs), compounds added to plastics to reduce ultraviolet degradation, are considered contaminants of emerging concern given their environmental persistence and documented toxicity in humans and animals. UV328 is a BZT-UV that has been recently listed to Annex A of the Stockholm Convention; therefore, understanding species exposure is critical information to fulfill international and domestic regulatory obligations. We evaluated hepatic accumulation of 12 plastic additives (including nine BZT-UVs) in Larus gulls in Atlantic Canada. BZT-UV accumulation was assessed in relation to ingested plastics, hepatic heavy metal accumulation, and body condition. Ninety-six percent of gulls had at least one BZT-UV at detectable hepatic concentrations. The most frequently detected BZT-UVs were UVP (91.4 %) and UV328 (76 %), suggesting ubiquitous exposure across individuals. We demonstrated interspecific differences in the relationship between ingested plastics and accumulated contaminants, with a positive relationship detected between ingested plastics and both UVP and UV328 in American herring gulls (Larus argentatus smithsonianus), and a positive relationship between hepatic UV328 and Pb concentrations detected in great black-backed gulls (Larus marinus). We provide evidence that Larus gulls feeding at a coastal landfill are highly exposed to BZT-UVs, and that the relationship between ingested plastics and plastic-associated contaminants varies across sympatric species.

Toxicokinetics of benzotriazole UV stabilizer UV-P in humans after single oral administration

UV-P (2-(2H-Benzotriazol-2-yl)-p-cresol) is used as an ultraviolet (UV) light absorber in coating products, paints, adhesives, and sealants. Due to its widespread industrial and consumer uses, human exposure to UV-P is conceivable. In the study presented herein, initial data on its human in vivo metabolism were obtained for three study participants after single oral administration of 0.3 mg of UV-P/kg body weight. Urine and blood samples of two volunteers were collected up to 48 h after exposure. The third study participant donated urine and blood samples up to 72 h. Maximum levels of UV-P in blood of 184 ± 36 µg/l (85 ± 3% as conjugates) were reached 2.4 ± 1.2 h post-exposure. Maximum excretion rates of UV-P in urine of 2896 ± 884 µg/h (completely conjugated) were reached 3.5 ± 1.1 h post-exposure. 37.2 ± 5.4% of the orally administered dose of UV-P was recovered in urine within 48 h post-exposure. The present study provides insight into the complex absorption, distribution, metabolism, and elimination (ADME) processes of benzotriazole UV stabilizers (BUVS). The study also demonstrates differences in the ADME between sterically hindered BUVS, such as UV-327 and UV-328, and sterically unhindered BUVS, such as UV-P, in which the phenolic hydroxyl group is readily accessible for conjugation with glucuronic acid or sulfate.

Effects of benzotriazoles UV-328, UV-329, and UV-P on the self-renewal and adipo-osteogenic differentiation of human mesenchymal stem cells

Benzotriazole ultraviolet stabilizers (BUVSs) are pervasive environmental contaminants that pose significant risks to human health. This study evaluated the effects of three typical BUVSs (UV-328, UV-329, and UV-P) on human mesenchymal stem cells (hMSCs), which play crucial roles in tissue maintenance and repair. hMSCs were exposed to BUVSs across a range of concentrations, and their maintenance and differentiation capacities were assessed. At concentrations below 50 μM, no significant cytotoxicity was observed. However, at non-cytotoxic doses, UV-P exhibited stronger effects on the differentiation of hMSCs compared to UV-328 and UV-329, significantly inhibiting adipogenesis and enhancing osteogenesis. Mechanistically, UV-P was found to significantly enrich the PPAR signaling pathway during both differentiation processes. Dual-luciferase reporter assays confirmed UV-P's interaction with PPARγ_LBD at an alternate binding site outside the canonical pocket. These findings raise concerns about the health impacts of BUVSs, particularly UV-P, and underscore the need for further investigation into their toxicological profiles.

Enhanced Light Response Performance of Ceria-Based Composites with Rich Oxygen Vacancy

Increasing the concentration of oxygen vacancies in ceria-based materials to solve the bottleneck of their applications in various fields has always been a research hotspot. In this paper, ceria-based cerium-oxygen-sulfur (Ce-O-S) composites that were composed of CeO2, Ce4O4S3, and Ce2(SO4)3 were synthesized by a precipitation method. The compositional, structural, morphological, and light response characteristics of prepared Ce-O-S composites were investigated by various characterization techniques. The molar ratio of oxygen vacancies to lattice oxygen can reach a maximum of 1.83 with Ce-O-S composites. The band gap values of the Ce-O-S composites were less than 3.00 eV, and the minimum value was 2.89 eV (at pH 12), which successfully extended the light response range from the ultraviolet light region to the short-wave blue light region. The remarkable light response performance of Ce-O-S composites can be mainly attributed to the high proportion of oxygen vacancy. Moreover, the higher proportion of oxygen vacancies can be attributed to the doping of Ce (+3) and S (-2) in the lattice of CeO2, and the synergistic effect of CeO2, Ce4O4S3, and Ce2(SO4)3. Moreover, the ceria-based Ce-O-S composites with rich oxygen vacancy in this research can be applied in light blocking, photocatalysis, and other related fields.

Presence of benzotriazole ultraviolet stabilizers in human urine

Health exposure to benzotriazole ultraviolet stabilizers (BUVSs) may pose diverse toxic impacts on health. Presently, the occurrence of BUVSs in human urine remains inadequately understood. This study analyzed 13 kinds of BUVSs in human urine (n = 182) from the general Chinese adult participants. Totally, nine BUVSs were measurable in these human urine samples. Among the detected BUVSs, 2-(2H-benzotriazol-2-yl)-p-cresol (UV-P) was the most predominant BUVS in the human urine, with the mean concentration of 1.6 μg/g creatinine ( Collapse

Key Words

• Benzotriazole ultraviolet stabilizers
• Human exposure
• Human urine
• UV-326
• UV-328

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MESH Headings

• Humans
• Male
• Female
• Triazoles/urine
• Adult
• Middle Aged
• Young Adult
• Aged
• Ultraviolet Rays
• China
• Environmental Pollutants/urine
• Biological Monitoring/methods

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Affiliation(s)

Weili Mao Department of Pharmacy, Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, Zhejiang, 324000, PR China
Hangbiao Jin Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang, 310032, PR China; Innovation Research Center of Advanced Environmental Technology, Eco-Industrial Innovation Institute ZJUT, Quzhou, Zhejiang, 324400, PR China
Ruyue Guo Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang, 310032, PR China
Kaili Mao Department of Pharmacy, Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, Zhejiang, 324000, PR China.

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A new strategy for the preparation of polylactic acid composites with UV resistance, light conversion, and antibacterial properties

A novel rare earth complex, Eu(IAA)2(phen)2 (EuIP), was synthesized by solution-based synthesis method. Then, EuIP and polylactic acid (PLA) were melt-blended at 190 °C to obtain a multifunctional PLA/EuIP composite. The incorporation of EuIP provided PLA/EuIP composites with good light conversion ability. Under UV irradiation, PLA/EuIP composites converted the absorbed UV light into red light. Moreover, the PLA/1.0EuIP composite exhibited excellent light transmittance of 88 % in the visible region and showed strong red emission under UV light. After UV irradiation for 96 h, the molecular weights and mechanical properties of neat PLA decreased dramatically. Interestingly, the molecular weights and mechanical properties of PLA/EuIP composites did not deteriorate after 96 h of UV irradiation. The reason was that EuIP could absorb UV light and utilize the absorbed energy to emit red fluorescence. Furthermore, PLA/EuIP composites showed good antibacterial activities against E. coli and S. aureus. In addition, in vitro cell experiments showed that PLA/EuIP composites was suitable for the growth of murine breast cancer (4 T1) cells. Besides, enzymatic degradation testing also proved that PLA/EuIP composites had good biodegradability. This work provides an ingenious design strategy for the preparation of PLA/EuIP composites possessing light conversion ability, UV resistance, and antibacterial properties.

Embryonic Exposure to Benzotriazole Ultraviolet Stabilizer 327 Alters Behavior of Rainbow Trout Alevin

Benzotriazole ultraviolet (UV) stabilizers (BUVSs) are used in great quantities during industrial production of a variety of consumer and industrial goods. As a result of leaching and spill, BUVSs are detectable ubiquitously in the environment. As of May 2023, citing concerns related to bioaccumulation, biomagnification, and environmental persistence, (B)UV(S)-328 was recommended to be listed under Annex A of the Stockholm Convention on Persistent Organic Pollutants. However, a phaseout of UV-328 could result in a regrettable substitution because the replacement chemical(s) could cause similar or unpredicted toxicity in vivo, relative to UV-328. Therefore, the influence of UV-327, a potential replacement of UV-328, was investigated with respect to early life development of newly fertilized rainbow trout embryos (Oncorhynchus mykiss), microinjected with environmentally relevant concentrations of UV-327. Developmental parameters (standard length), energy consumption (yolk area), heart function, blue sac disease, mortality, and behavior were investigated. Alevins at 14 days posthatching, exposed to 107 ng UV-327 g-1 egg, presented significant signs of hyperactivity; they moved on average 1.8-fold the distance and at 1.5-fold the velocity of controls. Although a substantial reduction in body burden of UV-327 was observed at hatching, it is postulated that UV-327, due to its lipophilic properties, interfered with neurological development and signaling from the onset of neurogenesis. If these results hold true across multiple taxa and species, a potential contributor to neurodevelopmental disorders might have been identified. These findings suggest that UV-327 poses an unknown hazard to rainbow trout embryos and alevins, rendering UV-327 a potential regrettable substitution to UV-328. However, a qualified statement on a regrettable substitution requires a comparative investigation on the teratogenic effects between the two BUVSs. Environ Toxicol Chem 2024;00:1-10. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Embryonic Exposure to UV-328 Impairs the Cell Cycle in Zebrafish (Danio rerio) by Inhibiting the p38 MAPK/p53/Gadd45a Signaling Pathway

The benzotriazole UV stabilizer UV-328 is well known for its potent antioxidative properties; however, there are concerns about how it may affect signaling nodes and lead to negative consequences. This study identified the key signaling cascades involved in oxidative stress in zebrafish (Danio rerio) larvae and evaluated the cell cycle arrests and associated developmental alternations. Exposure to UV-328 at 0.25, 0.50, 1.00, 2.00, and 4.00 μg/L downregulated gene expression associated with oxidative stress (cat, gpx, gst, and sod) and apoptosis (caspase-3, caspase-6, caspase-8, and caspase-9) at 3 days postfertilization (dpf). The transcriptome aberration in zebrafish with disrupted p38 mitogen-activated protein kinase (MAPK) cascades was validated based on decreased mRNA expressions of p38 MAPK (0.36-fold), p53 (0.33-fold), and growth arrest and DNA damage-inducible protein 45 α (Gadd45a) (0.52-fold) after a 3- and 14-day exposure alongside a correspondingly decreased protein expression. The percentage of cells in the Gap 1 (G1) phase increased from 69.60% to a maximum of 77.07% (p < 0.05) in the 3 dpf embryos. UV-328 inhibited the p38 MAPK/p53/Gadd45a regulatory circuit but promoted G1 phase cell cycle arrest, abnormally accelerating the embryo hatching and heart rate. This study provided mechanistic insights that enrich the risk profiles of UV-328.

Molecular Docking of Natural Compounds for Potential Inhibition of AhR

The aryl hydrocarbon receptor (AhR) is a highly conserved environmental sensor, historically known for mediating the toxicity of xenobiotics. It is involved in numerous cellular processes such as differentiation, proliferation, immunity, inflammation, homeostasis, and metabolism. It exerts a central role in several conditions such as cancer, inflammation, and aging, acting as a transcription factor belonging to the basic helix-loop-helix/Per-ARNT-Sim (bHLH-PAS) protein family. A key step in the canonical AhR activation is AhR-ARNT heterodimerization followed by the binding to the xenobiotic-responsive elements (XREs). The present work aims to investigate the potential AhR inhibitory activity of selected natural compounds. Due to the absence of a complete structure of human AhRs, a model consisting of the bHLH, the PAS A, and the PAS B domains was constructed. Blind and focused docking simulations revealed the presence of further binding pockets, different from the canonical one presented in the PAS B domain, which could be important for AhR inhibition due to the possibility to impede AhR:ARNT heterodimerization, either preventing conformational changes or masking crucial sites necessary for protein-protein interaction. Two of the compounds retrieved from the docking simulations, i.e., β-carotene and ellagic acid, confirmed their capacity of inhibiting benzo[a]pyrene (BaP)-induced AhR activation in in vitro tests on the human hepatoma cell line HepG2, validating the efficacy of the computational approach.