Novel 3-hydroxypyridin-4(1H)-One derivatives as ferroptosis inhibitors with iron-chelating and reactive oxygen species scavenging activities and therapeutic effect in cisplatin-induced cytotoxicity.

Recent advances in understanding the role of iron and ROS in cell death suggest new therapeutic avenues to treat organ damage including acute kidney injury (AKI). Inhibiting ferroptosis was expected to have great potential for the treatment of this disease. Ferroptosis is characterized by iron-dependent lipid peroxidation and currently, a majority of reported ferroptosis inhibitors belong to either radical-trapping antioxidants or iron chelators. However, clinically used iron chelators such as deferoxamine and deferiprone have limited efficacy against ferroptosis (generally with EC50 > 100 μM), despite their proven safety. Herein, we present the rational design of novel ferroptosis inhibitors by incorporating the naturally occurring cinnamic acid scaffold and the 3-hydroxypyridin-4(1H)-one iron-chelating pharmacophore. Through ABTS˙+ radical-scavenging assay, oxygen radical absorbance capacity (ORAC) measurement, Fe3+ affinity evaluation, and anti-erastin-induced HT22 cell ferroptosis assays, we identified compound 9c as the most prospective ferroptosis inhibitor (ABTS˙+, IC50 = 4.35 ± 0.05 μM; ORCA = 23.79 ± 0.56 TE; pFe3+ = 18.59; EC50 = 14.89 ± 0.08 μM, respectively). Notably, 9c dose-dependently alleviated cell death in cisplatin-induced AKI model. Our results provide insight into the development of new ferroptosis inhibitors through rational incorporation of pharmacophores from existing ferroptosis inhibitors, and compound 9c could be a promising lead compound worth further investigation.