Integrative network toxicology, molecular dynamics simulation, and experimental validation implicate the...

Aflatoxin B1 (AFB1) is a widespread food contaminant and environmental health concern, but the intestinal signaling events that may precede systemic toxicity remain insufficiently characterized. We hypothesized that AFB1 disrupts intestinal barrier organization through a PDGFRA-associated PI3K-Akt-mTOR signaling response, and we tested this hypothesis by integrating network toxicology, RNA sequencing, molecular docking, molecular dynamics simulations, and experimental models. Integration of 13,365 AFB1-associated genes, 982 intestinal-injury-associated genes, and 1613 differentially expressed genes prioritized PDGFRA, ICAM1, EDN1, and SERPINE1. In silico docking and molecular dynamics predicted AFB1 complexes with PDGFRA, SERPINE1, and ICAM1, with the most favorable predicted binding energy for PDGFRA (-111.9 kJ/mol by MM-PBSA). In Caco-2 cells, AFB1 reduced PDGFRA mRNA expression and the phosphorylation of PDGFRA, PI3K, Akt, and mTOR, increased ICAM1, EDN1, and SERPINE1 expression, disrupted the junctional organization of ZO-1 and Occludin, and reduced cell viability. In mice, a single oral AFB1 exposure produced dose-related histological alterations in the duodenum, jejunum, and ileum. These convergent findings identify suppression of the PDGFRA-PI3K-Akt-mTOR axis as a candidate mechanism associated with AFB1-induced intestinal barrier injury. Because the acute high-dose design exceeds typical environmental exposure scenarios, the identified barrier and signaling endpoints should be viewed as mechanism-based, testable markers that support hazard characterization of dietary AFB1 rather than as proof of causality.