Flavonoids protect U-937 macrophages against tert-butylhydroperoxide induced oxidative injury.

The study was carried out to determine the relative efficacies of polyphenolic flavonoids, quercetin, catechin and epicatechin against tert-BOOH induced oxidative stress in human macrophage, U-937 cell line. Exposure of the cells to tert-BOOH oxidative stress resulted in a significant increase in cytotoxicity and reactive oxygen species (ROS) generation. Further, a significant decrease in mitochondrial membrane potential and increase in lipid peroxidation and DNA damage was observed in cells exposed to tert-BOOH. Pretreatment of cells with quercetin, catechin and epicatechin significantly inhibited tert-BOOH induced cytotoxicity by inhibiting ROS generation. The flavonoids inhibited DNA damage induced by tert-BOOH and preserved the mitochondrial transmembrane potential significantly. Epicatechin and catechin were found to be more efficient than quercetin in inhibiting tert-BOOH induced cellular damage.