The Mechanism of Antioxidant Actions by NSAIDs/ASA in Cultured Human Lens Epithelial Cells

Abstract

Abstract: : Purpose: To study the possible mechanisms for protection against oxidative stress by indomethacin, diclofenac, celecoxib (NSAIDs) or acetylsalicylic acid (ASA) in cultured human lens epithelial cells (HLEC). Methods: Changes in peroxide levels in HLEC was measured after exposure to low concentrations (0, 0.005, 0.05 or 0,5 µM) of indomethacin, diclofenac, celecoxib or acetylsalicylic acid for 24 hours. The cells were assayed at regular intervals during 24 h using 2’,7’–dichlorodihydrofluorescein diacetate (DCFH–DA). Cultured HLEC were incubated with H₂O₂ (200 µM) alone or in the presence of NSAIDs/ASA. The cells were then assayed for changes in GSH levels using monochlorobimane (MCB). Results: NSAIDs/ASA at concentrations previous described to be effective against oxidative stress in HLEC did not affect peroxide levels in cultured HLEC. The reducing capacity as measured as the GSH levels, were not significantly changed in oxidatively stressed HLEC. No toxic effects on GSH or peroxide levels were present. Conclusions: Indomethacin, diclofenac, celecoxib or acetylsalicylic acid does not exert their protective actions against oxidative stress via changed levels of endogenous peroxide or GSH.

Keywords: antioxidants • cataract • oxidation/oxidative or free radical damage