Cellular Oxidative Stress Assays

H9C2 cardiomyocytes were washed twice with ice-cold PBS and then lysed. The glutathione (GSH) content was measured using a GSH and GSSG assay kit (S0053, Beyotime), and the optical density was measured at 405 nm. A lipid oxidation detection kit (S0131S, Beyotime) was used to detect the level of malondialdehyde (MDA), and the optical density value was measured at 535 nm. SOD enzyme activity was detected by a total SOD activity detection kit (WST-8 method) (S0101S, Beyotime), and the optical density value was measured at 450 nm. The Fe²⁺ concentrations of cardiac tissue and cell samples were determined using a Ferrous Iron Colorimetric Assay Kit (E-BC-K773-M, Elabscience, Wuhan, China), measuring absorbance at 590 nm using a microplate reader.