Toxic effects of 5-hydroxymethylfurfural on intestinal epithelial cell and its impact on the expression of MAPK pathway-related genes

5-Hydroxymethylfurfural (5-HMF), a common by-product of thermal-processed foods, poses a potential risk of intestinal toxicity upon ingestion. However, its underlying toxic mechanisms remain incompletely understood. In this study, we investigated the effects and potential molecular pathways of 5-HMF using normal human intestinal epithelial cells (HIEC-6). The results showed that 5-HMF inhibited the proliferation of HIEC-6 cells in a concentration-dependent manner and induced apoptosis possibly through both the death receptor and mitochondrial pathways, as evidenced by increased activities of caspase-8 and caspase-9. 5-HMF increased intracellular reactive oxygen species (ROS) levels by 1.42 to 2.12 fold, disrupted antioxidant enzymes activities, and increased malondialdehyde content, indicating oxidative damage. Meanwhile, 5-HMF upregulated the mRNA expression of the pro-inflammatory cytokines TNF-α and IL-6 and downregulated the mRNA and protein expression of key tight junction proteins ZO-1, Occludin and Claudin-1, indicating promotion of inflammation and impairment of epithelial barrier. 5-HMF also altered the mRNA expression of MAPK pathway-associated genes and NF-κB , indicating a possible correlation between this signaling cascade and the toxic effects of 5-HMF. Collectively, these findings provide a theoretical foundation for the risk assessment of dietary 5-HMF exposure and for future mechanistic studies on the role of MAPK signaling in 5-HMF-induced intestinal toxicity.