International Journal of Toxicology

HFO-1234ze(E) is being developed as a next-generation propellant (excipient), with near zero global warming potential, for use in pressurized metered dose inhalers. In accordance with regulatory guidance, an assessment of the carcinogenic potential of HFO-1234ze(E) was required to gain regulatory approval as a new excipient. HFO-1234ze(E) was therefore evaluated in two-year carcinogenicity studies in mice and rats by the inhalation route of administration. Study assessments included in-life observations, organ weights, histopathology, and hematology. Group mean (sex combined) inhaled doses were 2132, 6218, and 21,193 mg/kg/day in mice and 379, 120,8 and 3918 mg/kg/day in rats; in both studies, control animals were exposed to air alone under the same conditions as HFO-1234ze(E)-exposed animals. HFO-1234ze(E) was well tolerated at all doses. There were no HFO-1234ze(E)-related in-life effects and no neoplastic or non-neoplastic findings or effects on hematology in either study. In summary, HFO-1234ze(E) was not carcinogenic in mice or rats. These data support the use of HFO-1234ze(E) as a medical propellant.

Per- and polyfluoroalkylated substances (PFAS) are persistent anthropogenic chemicals widely distributed in the environment that are known to have toxic effects in animals and humans following exposure. Some PFAS have been shown to activate peroxisome proliferator-activated receptor α (PPARα), a transcription factor involved in lipid metabolism, leading to dyslipidemia or liver toxicity. PFAS comprise a wide range of compounds, and variations in their structural characteristics could reveal important details regarding the level of PPARα activation. In this work, using a Chemically Activated LUciferase eXpression (CALUX) assay, we experimentally tested the PPARα activation efficiency of several PFAS compounds of varying chain lengths and functional groups. Activation and potency were compared across and within PFAS class based on chemical differences. When compounds with the same number of carbons or perfluorinated carbons were compared across class, the rank from high to low activator class remained the same. Perfluorocarboxylated ether was found to be the strongest class, while polyfluorotelomer was the weakest, suggesting the importance of structural features in PPARa activation. Perfluorocarboxylates were consistently better PPARα activators than perfluorosulfonates. Comparing within these 2 classes, the number of perfluorinated carbon atoms better predicted activation than the number of carbon atoms. In the perfluorocarboxylated ether, perfluorocarboxylate, and perfluorosulfonate classes, a direct correlation existed between potency and the percentage of PPARα activation (R² = 0.702), a novel observation. These findings provide new insights regarding distinct chemical characteristics of PFAS compounds which may be predictive of PPARα activation level.

Bisphenol A (BPA) is a prevalent environmental endocrine disruptor with potential impacts to the neurological system in humans. This study used an integrated method combining network toxicology, molecular docking, and molecular dynamics simulations to explore the molecular mechanisms underlying BPA-induced neurotoxicity. We identified 255 potential neurotoxicity-related targets through the integration and comprehensive analysis of multiple data sources, including the Comparative Toxicogenomics Database (CTD), ChEMBL, STITCH, GeneCards, and the Online Mendelian Inheritance in Man (OMIM) database. Analysis of the protein-protein interaction (PPI) network unveiled 52 core targets, among which TNF, TP53, INS, ESR1, and PTGS2 emerged as pivotal hubs in the toxicity network. Functional enrichment analysis indicated that the core targets of BPA’s influence on neurotoxicity are predominantly enriched in vital signaling cascades, including inflammatory responses, pathways of neurodegeneration, MAPK signaling pathway, serotonergic synapse pathway, and pathways in cancer. Molecular docking results demonstrated that BPA exhibited stable binding interactions with core targets. Furthermore, molecular dynamics simulations provided insights into the interactions between BPA and key targets (ESR1, TNF, and TP53), supporting the potential conformational stability of these complexes. Collectively, these computational findings contribute to understanding the potential molecular mechanisms of BPA-induced neurotoxicity and are informative for generating hypotheses related to its pathogenesis.

Byakangelicol, a furanocoumarin derived from Angelica dahurica, possesses anti-inflammatory and antitumor activities. Since cytochrome P450 2A6 (CYP2A6) is the major enzyme responsible for coumarin metabolism, it is important to evaluate the effect of byakangelicol on CYP enzyme activity. The purpose was to explore the effects of byakangelicol on CYPs and to provide a reference for its drug development and clinical application. The present study investigated the impact of byakangelicol on CYPs in human liver microsomes (HLMs). Byakangelicol demonstrated the capacity to suppress the activities of CYP1A2, 2A6, and 3A4 in HLMs, with IC₅₀ values of 19.42, 10.11, and 12.80 μM, respectively. Byakangelicol exhibited competitive inhibition of CYP1A2 and 2A6 with K _i values of 9.86 μM and 5.23 μM, whereas the inhibitory effect on CYP3A4 was noncompetitive with a K _i value of 6.55 μM. In addition, the inhibitory effect of byakangelicol on CYP3A4 was found to be time-dependent (K _inact = 0.041 min⁻¹ and K _I = 6.67 μM). This study revealed the inhibitory properties of byakangelicol on CYP1A2, 2A6, and 3A4 activity in HLMs. It suggests the potential for drug–drug interactions when byakangelicol is co-administered with drugs metabolized by these CYPs. These findings offer a foundation for investigating the interaction of byakangelicol with other drugs, which may assist in clinical prescription and drug development.

The international cosmeceutical sector has experienced unprecedented expansion, compelling regulatory bodies to enhance and update systems to tackle consumer protection, product effectiveness, and ethical issues. This review critically evaluates and contrasts regulatory settings in key markets, such as the European Union, United States, Canada, Japan, China, India, and Brazil. The examination is concentrated on key features including product definitions, pre-market approval procedures, and ingredient regulation, labeling requirements, post-market surveillance, and integrating ethical and environmental considerations. The outcome shows significant advances in regulatory harmonization, especially in the area of ingredient safety and adverse event reporting; however, there are still considerable challenges. Pioneering among these are the lack of a standard definition for “cosmeceuticals,” highly variable ingredient limitations, and uneven application practice across jurisdictions. The speedy growth of e-commerce and cross-border sales additionally complicates regulatory control, adding to the possibility of non-compliant or counterfeited products reaching consumers. The review also identifies a shortage of empirical evidence to document the actual impact of recent regulatory reforms in the real world, as well as on innovation and market access. The present study recommends the promotion of international harmonization of standards, enhancement of post-market surveillance, convergence of ethical and sustainability dimensions, and targeted support for small- and medium-sized enterprises. Henceforth, while important progress has been achieved, the future of the industry rests on creating nimble, science-informed, and internationally harmonized regulatory systems that can keep pace with changing technologies and consumers’ and public health priorities, ensuring both consumer safety and industry innovation.