ARPE-19 cells (CRL-2302™) were cultured in Dulbecco’s Modified Eagle’s Medium/F-12 medium containing 10% fetal bovine serum as previously described (Park et al., 2022 (link)). Mangiferin and H2O2 (Sigma-Aldrich, St. Louis, MO, USA) were dissolved in dimethyl sulfoxide (Thermo Fisher Scientific, Waltham, MA, USA) to prepare stock solutions, diluted to appropriate concentrations in culture medium, and then treated with cells. To trigger oxidative stress, cells were cultured in medium containing H2O2, and Mangiferin and/or zinc protoporphyrin IX (ZnPP, Sigma-Aldrich) were added 1 h before H2O2 exposure.