Combined exposure effects and potential mechanisms of volatile organic compounds on liver fibrosis in the US population: an integrative epidemiological and computational toxicology analysis

BACKGROUND: Volatile organic compounds (VOCs) are widespread environmental pollutants that can cause oxidative stress and hepatocellular damage. However, epidemiological evidence linking VOC exposure to liver fibrosis and the underlying molecular mechanisms remains limited. METHODS: Data were obtained from the 2017-2020 National Health and Nutrition Examination Survey (NHANES). Liver fibrosis was defined using the NAFLD fibrosis score (NFS > 0.676). Weighted logistic regression, restricted cubic spline (RCS), and weighted quantile sum (WQS) models were applied to evaluate individual and combined associations of nine blood VOCs with liver fibrosis after adjusting for demographic, lifestyle, and biochemical covariates. To explore potential mechanisms, network toxicology and molecular docking were conducted. RESULTS: -trend < 0.05). RCS analysis showed a nonlinear dose-response relationship between 1,4-Dichlorobenzene and liver fibrosis risk. Network toxicology identified 176 overlapping targets enriched in PI3K-AKT and MAPK signaling pathways, with SRC, AKT1, AKT3, PIK3CA, and PIK3CD as hub genes. Molecular docking confirmed stable binding between 1,4-Dichlorobenzene and these proteins, with binding energies ranging from -7.5 to -8.5 kcal/mol. CONCLUSION: Blood 1,4-dichlorobenzene exposure is positively associated with an increased risk of liver fibrosis in the U.S. population, potentially through PI3K-AKT and MAPK pathway activation. This integrative approach provides new insights into VOC-induced hepatic fibrosis.