Ferroptosis Mechanism and GPX4-Mediated Lipid Peroxidation in Renal Tubular Cells of Patients with Aristolochic Acid Nephropathy in North West Nigeria

Aristolochic acid nephropathy, caused by consumption of herbal preparations containing plants of the Aristolochia genus, is an increasingly recognised but underdiagnosed cause of progressive renal failure in Nigeria. This study investigates the ferroptosis mechanism, specifically GPX4 downregulation, RSL3-sensitive lipid peroxidation, and iron-dependent cell death in renal tubular cells, in patients with aristolochic acid nephropathy in Sokoto and Zamfara States, North West Nigeria. A translational case-control design was employed, with 50 patients with suspected aristolochic acid nephropathy confirmed by clinical criteria and renal biopsy, 50 patients with chronic kidney disease of other aetiologies, and 40 healthy controls. Renal biopsy sections were analysed by immunohistochemistry for GPX4, ACSL4, and 4-HNE adducts as ferroptosis markers. Urinary aristolochic acid-DNA adducts were detected by HPLC-MS/MS as exposure confirmation. Plasma and urinary lipidomic analysis by UHPLC-MS characterised ferroptotic lipid peroxide accumulation. In vitro validation used human proximal tubular cells treated with aristolochic acid I, with ferroptosis inhibitor (ferrostatin-1) rescue experiments. This study constitutes the first mechanistic investigation of ferroptosis in herbal medicine-induced nephrotoxicity in Africa and proposes GPX4 as a therapeutic target. Keywords: ferroptosis, GPX4, aristolochic acid nephropathy, lipid peroxidation, North West Nigeria.