Sodium aescinate induces hepatocyte ferroptosis through the Nrf2/PRDX6/GPX4 axis

Sodium aescinate (SA), a triterpenoid saponin derived from Aesculus hippocastanum seeds, is widely used clinically but has been linked to hepatotoxicity, nephrotoxicity, and phlebitis. We previously reported that SA triggers hepatocyte ferroptosis, and enhancing GSH synthesis via the CTH/cysteine axis activation only partially mitigates liver injury. In this study, we showed that SA disrupted redox homeostasis, promoted lipid peroxidation (LPO), and induced ferroptosis in hepatocytes, concomitant with suppressed Nrf2/PRDX6/GPX4 pathway activity. Mechanistically, SA downregulated the expression and transcriptional activity of Nrf2, reducing its binding to antioxidant response elements (AREs) in the promoters of PRDX6 and GPX4, thereby decreasing their expression. Nrf2 overexpression restored PRDX6 and GPX4 levels, enhanced antioxidant capacity, and attenuated SA-induced ferroptosis. Notably, PRDX6 regulated GPX4 expression and activity by modulating selenium utilization and selenoprotein biosynthesis during SA-induced hepatotoxicity. Both PRDX6 overexpression and selenium supplementation rescued GPX4 and protected against SA-induced ferroptotic damage. The protection conferred by Nrf2/PRDX6 overexpression or selenium supplementation was fully abrogated upon GPX4 knockdown or inhibition with RSL3. Collectively, SA induced ferroptotic liver injury by disrupting the Nrf2/PRDX6/GPX4 axis, culminating in GPX4 deficiency and redox collapse. This study suggests that this cascade represents a promising therapeutic target for SA-induced hepatotoxicity.