Network Toxicology and In Vivo Studies Reveal the Toxicity and Mechanisms of Tributyl Citrate Carried by Microplastics in Promoting Colitis-to-Tumorigenesis Transformation

Tributyl citrate (TBC), a widely used substitute for phthalate plasticizers, has shown increasing environmental accumulation, raising concerns about its potential human health risks. However, its toxicological effects, particularly regarding gastrointestinal disease progression, remain largely unexplored. In this study, animal experiments first demonstrated that TBC aggravates colonic inflammation in a mouse model of microplastic-induced colitis. Computational toxicology analysis further predicted TBC to possess potential carcinogenic properties, suggesting its role in promoting colitis-associated carcinogenesis. Using integrated bioinformatics approaches, we combined network toxicology, molecular docking, and molecular dynamics simulations to identify the putative toxicological targets and molecular pathways involved in TBC-induced inflammation-to-cancer transition. A total of 299 TBC-related targets were identified from multilevel databases, and 13 core targets were highlighted through STRING and Cytoscape analyses, including AKT2, MAPK1, MAPK3, HSP90AA1, PIK3CD, BCL2, PIK3R1, PIK3CB, ESR1, CASP3, KRAS, and ERBB2. GO and KEGG enrichment analyses indicated that TBC may drive carcinogenic progression via pathways associated with oxidative stress and inflammatory responses. Molecular docking and dynamics simulations validated the stable interactions between TBC and key targets. To further confirm TBC's role in colitis-associated tumorigenesis, we employed an AOM/DSS-induced colorectal cancer mouse model and found that TBC significantly exacerbated both intestinal inflammation and tumor formation. Transcriptomic analysis further validated the enrichment of ROS-mediated chemical carcinogenesis pathways and revealed that intestinal barrier disruption may also be a critical contributor to TBC-mediated cancer progression. Collectively, this study provides a theoretical basis for understanding the molecular mechanisms by which TBC aggravates inflammation-associated colorectal cancer, and offers a framework for risk assessment and regulatory strategies addressing plasticizer exposure in digestive health.