Ferroptosis-IN-21 is an inhibitor of ferroptosis that combats renal ischemia-reperfusion injury by directly scavenging peroxy free radicals to prevent cell death. It demonstrates broad-spectrum, nanomolar-level inhibitory potency against various ferroptosis inducers in renal tubular epithelial cells and effectively suppresses the accumulation of lipid reactive oxygen species (ROS). Additionally, Ferroptosis-IN-21 significantly alleviates renal ischemia-reperfusion injury in mice, as evidenced by improved histological damage and functional impairment, reduced expression of inflammatory cytokines, and decreased levels of lipid peroxidation biomarkers such as 4-hydroxynonenal. Ferroptosis-IN-21 is a potential candidate in research for developing ferroptosis-targeted therapeutics.

Ferroptosis-IN-21 (compound 6) at concentrations of 0.01-10 μM over 24 hours exhibits nanomolar-level cytoprotective activity in HT-1080 cells (EC50 = 61.7 nM) and can completely reverse cell death at a concentration of 200 nM. It also dose-dependently protects human renal cortical epithelial cells (HKC) and human renal proximal tubule epithelial cells (HK-2) from ferroptosis induced by RSL-3 and FIN-56, demonstrating its broad-spectrum anti-ferroptosis efficacy. Additionally, Ferroptosis-IN-21 at 50-500 nM for 24 hours significantly inhibits RSL-3-induced lipid ROS accumulation and MDA elevation without affecting GPX4 protein levels. At 10 μM, it lacks iron chelation capabilities, ruling out mechanisms involving iron chelation. Furthermore, at concentrations of 1-80 μM over 30 minutes, Ferroptosis-IN-21 displays potent direct radical scavenging activity in cell-free DPPH assays.

Ferroptosis-IN-21 (administered at 5 and 10 mg/kg via intraperitoneal injection 24 and 1 hour before modeling) demonstrates significant renal protective effects against ischemic acute kidney injury in a mouse model of renal ischemia-reperfusion.