Hy 13653

GSCs were treated with or without 50 μM EGCG (MedChemExpress, HY-13653) for 24 h before collection. The determination activity of catalase was performed according to the manufacturer’s instructions (Beyotime Biotechnology, S0051). Briefly, cells were lysed in lysis buffer (Tris–HCl 20 mM PH 7.4, 0.5% NP-40, 250 mM NaCl, 3 mM EGTA, 3 mM EDTA) supplemented with protease inhibitors (Roche) and incubated on ice for 30 min. Cell lysis samples were mixed with the corresponding test solution. After 20 min, catalase activity was detected by a microplate analyzer at an absorbance of 240 nm.

Epigallocatechin gallate (EGCG, 99.91% purity, HY-13653, Medchemexpress, Monmouth, NJ, USA), epicatechin (EC, 99.00% purity, HY-N0001, Medchemexpress) and heparin (99.00% purity, H3393, Sigma-Aldrich, St. Louis, MO, USA) were dissolved into ddH2O at a concentration of 50 mM for storage. The monoclonal antibody (mAb) 5E11 against PCV2 capsid was generated in our laboratory [34 (link)]. The fluorescein isothiocyanate (FITC) conjugated goat anti-mouse IgG (ab6785, Abcam, Cambridge, MA, USA), horse radish peroxidase (HRP) conjugated goat anti-mouse IgG (074-1802, KPL, Milford, MA, USA) and Mouse IgG1 Isotype Control (564416, BD Horizon™, San Jose, CA, USA) were purchased from Abcam, Kirkegaard & Perry Laboratories and BD Biosciences, respectively.