Measuring GSH/GSSG

GSH (reduced glutathione) and GSSG (oxidized glutathione) were measured by use of GSH/GSSG Glo assay (Promega, Fitchburg, WI, US). The cells were seeded in white, 96-well plates at 4,000 cells per well. After adhering overnight, the cells were either left untreated or exposed to 5 mM DHA for 24 and 48 h. At the end of treatment time, cells were counted on a Celigo to normalize for variations in cell density, then assayed according to the manufacturer’s protocol. Following assay incubation, luminescence was recorded on Tecan M1000. Luminescence values were normalized to cell count and then expressed as a percentage of the untreated control. Results presented as the mean ± SEM of three replicates.