2.8. Determination of Glutathione (GSH) Contents

Glutathione contents were determined using GSH/GSSG-Glo™ Assay Kit (Promega), according to manufacturer’s instructions. Briefly, C2C12 cells were pretreated with either 3–30 μg/mL of CM-SD or 30 μM of IsoR for 1 h, and then exposed to 100 μM of H₂O₂ for 6 h. Cells were lysed with glutathione lysis reagent and then incubated with luciferin generating reagent for 30 min and luciferin detection reagent for 15 min. Luminescence intensities were measured using an automated microplate reader (Infinite 200 PRO; Tecan Group Ltd., Männedorf, Switzerland), and the concentration of GSH was determined from a standard curve.