PC12 and SH‐SY5Y cell lines were obtained from JRDUN Biotechnology (Shanghai, China). The PC12 cells were cultured in RPMI1640 supplemented with 15% horse serum, 2.5% fetal bovine serum, and 100 U mL−1 penicillin–streptomycin. The SH‐SY5Y cells were cultured in DMEM/F12 supplemented with 10% fetal bovine serum and 100 U mL−1 penicillin–streptomycin.