OGD/R model and drug treatment

PC12 cells were cultured in DMEM containing 10% FBS at 37℃. For similar cerebral IR injury in vitro, oxygen-glucose deprivation/reperfusion (OGD/R) model was established as previously described.²¹ In brief, PC12 cells were cultured in glucose-free and serum-free DMEM (Thermo Fisher Scientific), and incubated in a hypoxic environment with 94% N₂, 1% O₂, and 5% CO₂ at 37℃ for 6 h. Then, the medium was replaced with complete DMEM (Thermo Fisher Scientific), and the cells were cultured in a normal environment with 95% air and 5% CO₂ at 37℃ for 24 h. PC12 cells were divided into the control group (untreated), OGD/R group (OGD/R treatment), and OGD/R+didymin group (PC12 cells were pretreated with 10–40 µM didymin 24 h before OGD/R treatment).