Exploring potential targets and mechanisms of 4-Methylbenzylidene camphor-induced developmental neurotoxicity: Integration of network toxicology and zebrafish experimental validation.

As a widely used organic UV filter and emerging environmental pollutant, 4-methylbenzylidene camphor (4-MBC) accumulates in aquatic ecosystems and human tissues, but its developmental neurotoxicity mechanisms remain unclear. This study integrated network toxicology, molecular docking and dynamics simulations, zebrafish experiments, dose-dependent transcriptomics and the adverse outcome pathway (AOP) framework to elucidate the neurotoxic mechanisms of 4-MBC. Network toxicology identified 150 potential targets and 10 core targets (BDNF, DLG4, EGF, etc.), with enrichment analyses highlighting glutamatergic synaptic signaling, MAPK pathway, and DNA replication as candidate key pathways. Molecular docking and dynamics predicted stable binding of 4-MBC to core targets (e.g., DLG4, GRIN2B). Zebrafish exposed to 4-MBC (1, 10, 100 and 1000 μg/L) showed concentration-dependent developmental malformations, lowered hatching rates and suppressed larval locomotion. Transcriptomic analysis identified 311 dose-responsive genes and enriched key pathways, suggesting disrupted glutamatergic transmission, dysregulated MAPK activity and defective DNA replication as potential core drivers. RT-qPCR further verified dose-dependent transcriptional alterations of representative genes at 100 and 1000 μg/L: the synaptic genes bdnf and dlg4 were downregulated, whereas the neurodevelopmental markers ngn1 and shha were upregulated. AOP-based bioinformatic analysis further indicated impaired DNA repair as a potential converged node that may trigger neural progenitor apoptosis and subsequent growth-inhibition phenotypes. Collectively, these findings propose a working model in which 4-MBC disrupts glutamatergic synapses, activates MAPK signaling, and impairs DNA replication to induce developmental neurotoxicity, though direct functional validation of this cascade is warranted, providing insights for environmental and human health risk assessment.