Jianpi Jiedu decoction reverses 5-fluorouracil resistance in colorectal cancer by suppressing the xCT/GSH/GPX4 axis to induce ferroptosis.

Introduction: Innate and acquired chemoresistance in colorectal cancer (CRC) often results in 5-fluorouracil (5-FU) treatment failure. This study aimed to investigate the potential of Jianpi Jiedu (JPJD) decoction to reverse 5-FU resistance in CRC and clarify its potential mechanism of action. Methods: The CCK-8 assay was employed to assess cell activity. Flow cytometry was employed to assess various parameters including cell apoptosis, cell cycle distribution, P-glycoprotein (P-gp) activity, reactive oxygen species levels, and lipid peroxidation. Metabolomics analysis was conducted to identify differentially expressed metabolites. Western blotting was utilized for protein expression analysis. Results: In this study, we demonstrated that the combined JPJD and 5-FU treatment reversed 5-FU resistance in HCT8/5-FU cells, inducing cell apoptosis, causing G2/M-phase cell cycle arrest, and reducing P-gp protein expression and activity. Metabolomics analysis revealed ferroptosis as a key pathway in the development of 5-FU resistance. Furthermore, the combination treatment reversed drug resistance primarily by impacting ferroptosis and triggering critical ferroptosis events through the suppression of the cystine/glutamate transporter (xCT)/glutathione (GSH)/glutathione peroxidase (GPX4) axis. Conclusion: JPJD decoction primarily suppressed the xCT/GSH/GPX4 axis to trigger ferroptosis, thereby effectively reversing 5-FU resistance in colorectal cancer (CRC).