Effects of fluorescent light on growth of bovine retinal pigment epithelial cells in vitro incubated with linoleic acid or linoleic acid hydroperoxide

Light-induced peroxidation of polyunsaturated fatty acids (PUFA) may genera te lipid hydroperoxides, which may have toxic effects on retinal pigment ep ithelial (RPE) cells in vitro. We investigated the effects of cool-white fl uorescent light on the RPE cells incubated with linoleic acids (LA) or lino leic acid hydroperoxides (LHP) and the influence of antioxidative enzymes. We measured the bovine RPE cell number after exposure to fluorescent light (610 and 1,200 lux) in the presence of LA or LHP. Furthermore, the effects of superoxide dismutase (SOD) and catalase on LA- or LHP-treated RPE cells were also examined. Both LA and LHP treatment increased RPE cell number under weak illumination (610 lux), but dose-dependently decreased the number of cells exposed to s trong illumination (1,200 fur), With exposure to strong illumination, LA ca used a greater reduction in RPF cell number than LHP. Multiple linear regre ssion analysis showed that the number of RPE cells was significantly decrea sed in a manner dependent on the interactions of the illuminance of light a nd the concentrations of LA or LHP, The antioxidative enzymes significantly ameliorated the damage to RPE cells from LA or LHP and exposure to light. Therefore, the exposure to fluorescent light augmented the cytotoxic effect s of LA and LHP on RPE cells, and this effect is likely to be mediated by r eactive oxygen species.