Glutathione (gsh)

The intracellular MDA production was determined using a thiobarbituric acid reactive species (TBARS) assay kit (Cayman, USA). A total of 1 × 10⁷ cells were homogenized in PBS, and the lysates were incubated with TBA color reagents at 50°C for 60 min. The MDA-TBA adducts were then measured colorimetrically at 540 nm. The total protein concentration was determined through the Bradford assay (Tiangen, China), and the results are expressed as [MDA] in nmol per mg of protein. GSH was determined according to the recycling system through the reaction of 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB) and GSH (Dojindo, Japan). The concentration of GSH in the sample solutions was determined using a calibration curve and is expressed as nmol of GSH per mg of protein. The SOD activity was measured using an assay kit (Dojindo, Japan) according to the manufacturer's protocol. The CAT activity was assayed according to the method developed by Góth and is expressed as mU per mg of protein based on the rate of decrease of the hydrogen peroxide [21 (link)].