The Protection and Antioxidant Mechanisms of Corticosteroids in LPSTreated Retinal Pigment Epithelial Cells

Dexamethasone (DEX) and triamcinolone acetonide (TA) are two corticosteroids as anti-inflammatory agents that have been used as an anti-inflammation in several diseases to protect against oxidative damage. The present study examined the anti?oxidant effect of DEX and TA on lipopolysaccharide (LPS)-induced intracellular reactive oxygen species (ROS) in human retinol epithelium ARPE-19 cells. DEX and TA markedly inhibited the LPSinduced intracellular ROS level. DEX and TA also inhibited the expression of NADPH oxidase subunit gp91 and p22. Moreover, the expression of two antioxidant enzymes, heme oxygenase-1 (HO-1) expression and gammaglutamylcysteine synthetase (gamma-GCS), were increased by DEX and TA treatment in LPS-treated ARPE-19 cells. These results indicate that DEX and TA inhibits the intracellular ROS response by blocking the NADPH oxidase pathway and may increase some antioxidant enzymes in LPS -induced ARPE-19 cells. Therefore, DEX and TA may be useful as antioxidant agents against oxidative damage in anti-inflammatory diseases.