Qingyu formula inhibits ferroptosis in HK-2 cells and in a diabetic nephropathy mouse model via the Nrf2/SLC7A11/GPX4 pathway

Background Diabetic kidney disease (DKD) is a severe microvascular complication, and ferroptosis is a major contributor to its pathogenesis. This study investigated the protective effects of Qingyu formula (QYF), a traditional Chinese medicine prescription, against ferroptosis in high glucose-induced renal injury. Methods In vitro, human renal tubular cells (human kidney 2 [HK-2]) under high glucose conditions were treated with QYF. In vivo, the induced diabetic mice received QYF interventions. Biochemical and molecular assays assessed cell viability, oxidative stress, ferroptosis markers (Fe²⁺, glutathione [GSH], malondialdehyde) and nuclear factor erythroid 2-related factor 2/solute carrier family 7 member 11/glutathione peroxidase 4 (Nrf2/SLC7A11/GPX4) pathway activity. Results Qingyu formula enhanced cell viability and reduced reactive oxygen species in high glucose-treated HK-2 cells. It mitigated ferroptosis by decreasing Fe²⁺ accumulation and increasing GSH levels both in vivo and in vitro. Mechanistically, QYF upregulated GPX4, Nrf2 and SLC7A11. In diabetic mice, it improved metabolic parameters and reduced proteinuria in a dose-dependent manner, with high doses showing efficacy similar to that of clinically used irbesartan. Conclusions Qingyu formula protects against high glucose-induced renal injury by suppressing ferroptosis via the activation of the Nrf2/SLC7A11/GPX4 pathway. These findings support QYF as a promising candidate for targeting ferroptosis in DKD. Future studies should identify its active constituents and evaluate its efficacy in clinical trials.