Molecular mechanism of Tralopyril-induced enteritis in Pacific oyster (Crassostrea gigas) through multi-pathway modulation: Network toxicology and experimental validation

Abstract

Tralopyril (TP), a representative bromopyrrolonitrile, functions as a broad-spectrum insecticide, raising growing concerns about its potential impact on aquatic organisms and human intestinal health. However, the key targets and toxicity mechanisms underlying TP-induced enteritis remain unclear. In this study, we utilized network toxicology combined with molecular docking to comprehensively explore the potential molecular mechanisms underlying TP-induced enteritis. A total of 166 TP-related enteritis targets were identified through screening the GeneCards database, and 83 homologous genes were identified in Crassostrea gigas (C. gigas). Using the STRING database and Cytoscape analysis, six core target genes were identified: CDK2, CDK1, EZH2, IAP, CASP3, and ER.Functional enrichment analysis, IBR analysis, and acute exposure experiments demonstrated that TP activates NF-κB and MAPK signaling via the IL-17 pathway, leading to the upregulation of pro-inflammatory factors, which enhances inflammatory responses and suppresses immune function. Moreover, TP activates the ubiquitin–proteasome system and disrupts the expression of cell cycle regulators, thereby disturbing the balance between cell proliferation and apoptosis in intestinal tissues, impairing tissue repair and barrier function. Additionally, TP inhibits AMPK activity, disrupts the SIRT1–NAD⁺ signaling pathway, and induces oxidative stress.Molecular docking analysis revealed strong binding affinities between TP and multiple core targets, with binding energies below zero. This study elucidates the key molecular mechanisms underlying TP-induced enteritis and provides a theoretical foundation for its environmental and public health risk assessment.