OBJECTIVEThis study aimed to elucidate the protective effects of Da Cheng Qi Decoction (DCQD) on severe acute pancreatitis (SAP) by targeting ferroptosis in pancreatic acinar cells and to establish a predictive signature and nomogram for acute pancreatitis (AP) risk assessment.METHODSWe utilized microarray analysis to delineate gene expression patterns among 32 healthy controls and 87 AP patients stratified by severity. Employing SAP models and NOX2-deficient cells, we investigated the molecular underpinnings of ferroptosis. The impact of DCQD and the ferroptosis inhibitor Fer-1 on gene expression, oxidative stress, and inflammation was assessed. Machine learning algorithms identified differentially expressed genes (DEGs) sensitive to DCQD, SAP, and ferroptosis (DSNFGs), which were validated across multiple datasets. A predictive nomogram integrating DSNFGs was developed, and single-cell analysis provided a comprehensive view of the cellular dynamics.RESULTSThe microarray analysis revealed upregulation of NOX2 and downregulation of GPX4 in AP, with expression patterns correlating with disease severity. DCQD ameliorated SAP-induced pancreatic acinar cell damage and ferroptosis by reducing inflammatory markers and enhancing GPX4 expression. NOX2 knockout mitigated ferroptosis in SAP models, suggesting a key role in the disease process. DCQD and Fer-1 differentially regulated the expression of ferroptosis-related genes, reduced reactive oxygen species (ROS) and high-mobility group box 1 (HMGB1) levels, and suppressed the inflammatory response in a SAP mouse model. The HPLC analysis of DCQD constituents indicated eight components (aloe-emodin, rhein, emodin, chrysophanol, naringin, hesperidin, magnolol, and honokiol) with the capacity to modulate ferroptosis. Venn analysis identified 48 DSNFGs, with a subset of five genes demonstrating significant predictive value. The developed nomogram, based on LASSO regression, showed high accuracy in validation cohorts. Single-cell RNA sequencing (scRNA-seq) and CellChat analysis uncovered heterogeneity and cell-cell communication networks in the pancreas during recovery from pancreatitis, implicating several signaling pathways.CONCLUSIONDCQD and its eight ingredients exert its protective effect in SAP by inhibiting ferroptosis through the NOX2/GPX4 pathway. The DCQD-SAP-ferroptosis-related signature and nomogram offer a novel tool for AP risk assessment, prognosis prediction, and personalized therapeutic strategies in SAP management.