Rhein Alleviates Cisplatin-Induced Acute Kidney Injury via Downregulation of NOX4-COX2/PGFS Signaling Pathway.

Purpose: Cisplatin (cis-diamminedichloroplatinum II, CDDP), a widely used chemotherapeutic agent, is clinically limited by nephrotoxicity. Rhein, an anthraquinone from Radix Rhein Et Rhizome, shows nephroprotective potential. This study investigated Rhein's protective effects and mechanisms in CDDP-induced acute kidney injury (AKI).

Methods: Network pharmacology identified active components and target genes of Radix Rhein Et Rhizome. Bioinformatics analysis screened differentially expressed genes and conducted functional enrichment (GO/HALLMARK). Molecular docking and molecular dynamic (MD) simulations confirmed Rhein's binding to target proteins. CDDP-induced AKI mouse models and human proximal tubular epithelial cells (HK2) injury models were established to reveal Rhein's nephroprotective mechanisms. Lewis lung carcinoma (LLC) tumor-bearing mice and human A549 lung cancer cells further validated Rhein's compatibility with CDDP antitumor efficacy.

Results: Network pharmacology revealed 12 bioactive components and 420 potential targets of Radix Rhein Et Rhizome, with Rhein as the core component interacting with 50 cross-validated targets. Protein-protein interaction (PPI) network analysis prioritized 16 hub genes functionally enriched in oxidative stress (GO) and inflammatory/apoptotic pathways (HALLMARK). Molecular docking and MD simulations demonstrated Rhein's robust binding stability with NOX4, COX2, and PGFS, indicating multi-target modulation. In vivo, Rhein attenuated CDDP-induced AKI by reducing plasma creatinine, renal KIM-1/NGAL expression, and suppressing tubular apoptosis and inflammation. In vitro, Rhein mitigated CDDP-triggered HK2 cell injury through reducing ROS levels and inhibiting the NOX4-NFκB-COX2/PGFS axis. Notably, Rhein preserved CDDP's tumor-suppressive effects in both LLC-bearing mice and A549 cells.

Conclusion: Rhein protects against CDDP-induced AKI by inhibiting oxidative stress and inflammation through targeting the NOX4-NFκB-COX2/PGFS pathway, without compromising CDDP's antitumor activity. These findings highlight Rhein as a promising adjunctive therapy for CDDP-associated nephrotoxicity.