Abstract
<title>Abstract</title> <p> Benzo[ <italic>a</italic> ]pyrene (BaP), a highly toxic polycyclic aromatic hydrocarbon, is classified as a Group 1 carcinogen. Although BaP-induced carcinogenicity, oxidative stress, and developmental toxicity are well established, the mechanisms linking xenobiotic-induced stress responses to endocrine-metabolic dysfunction remain poorly understood. Here, we combined high-resolution magic angle spinning (HR-MAS) NMR-based metabolite profiling with targeted mRNA expression analysis to characterize BaP-induced toxicity in intact zebrafish embryos. BaP exposure caused developmental abnormalities, including reduced hatching success and survival rates, and induced widespread reactive oxygen species (ROS) accumulation in multiple organs, including the liver and brain. HR-MAS NMR revealed metabolic reprogramming involving lipid, amino acid, and energy metabolism, with alterations associated with mitochondrial function. These changes were accompanied by altered expression of genes involved in xenobiotic detoxification, antioxidant defense, mitochondrial homeostasis, and neurodevelopmental regulation. Importantly, coordinated downregulation of <italic>Cyp2r1</italic> , <italic>Cyp27a1</italic> , and <italic>Dhcr7</italic> mRNA expression identified disruption of vitamin D metabolism and cholesterol-derived precursor synthesis as a previously unrecognized target of BaP toxicity. These findings reveal an endocrine-metabolic mechanism linking BaP-induced oxidative stress and transcriptional dysregulation to disruption of the cholesterol synthesis and vitamin D metabolism. This study provides a systems-level understanding of BaP toxicity and highlights vitamin D axis dysfunction as a potential contributor to metabolic reprogramming and developmental toxicity following environmental toxicant exposure. </p>