4.3. Quantification of Intracellular Glutathione

Intracellular glutathione (GSH) was measured using the GSH-Glo^TM Glutathione assay kit (Promega, Madison, WI, USA) according to the manufacturer’s instructions. Briefly, 5000 cells per well were seeded in 96-well optical bottom plates (Thermo scientific, Waltham, MA, USA). After incubating for 24 h, cells were treated with each reagent for 24 h. After removing medium from each well, cells were incubated in 100 μL of GSH-Glo^TM reagent for 30 min, and then 100 μL of reconstituted Luciferin Detection Reagent for 15 min. Luminescent signals were measured using a microplate luminometer Centro LB 960 (Berthold Technologies GmbH & Co.KG, Germany).