Abstract
Aflatoxin G1 (AFG1), a member of the aflatoxin family with cytotoxic and carcinogenic properties, is one of the most common mycotoxins occurring in various agricultural products, animal feed, and human foods and drinks worldwide. Epithelial cells in the gastrointestinal tract are the first line of defense against ingested mycotoxins. However, the toxicity of AFG1 to gastric epithelial cells (GECs) remains unclear. In this study, we explored whether and how AFG1-induced gastric inflammation regulates cytochrome P450 to contribute to DNA damage in GECs. Oral administration of AFG1 induced gastric inflammation and DNA damage in mouse GECs associated with P450 2E1 (CYP2E1) upregulation. Treatment with the soluble TNF-α receptor sTNFR:Fc inhibited AFG1-induced gastric inflammation, and reversed CYP2E1 upregulation and DNA damage in mouse GECs. TNF-α-mediated inflammation plays an important role in AFG1-induced gastric cell damage. Using the human gastric cell line GES-1, AFG1 upregulated CYP2E1 through NF-κB, causing oxidative DNA damage in vitro. The cells were also treated with TNF-α and AFG1 to mimic AFG1-induced TNF-α-mediated inflammation. TNF-α activated the NF-κB/CYP2E1 pathway to promote AFG1 activation, which enhanced DNA cellular damage in vitro. In conclusion, AFG1 ingestion induces TNF-α-mediated gastric inflammation, which upregulates CYP2E1 to promote AFG1-induced DNA damage in GECs.