Abstract
Purpose::
The purpose of this study was to determine whether different flavonoids could protect human RPE cells containing A2E or all-trans retinal from light-induced reactive oxygen species (ROS) accumulation.
Methods::
Human ARPE19 cells were treated with A2E or all-trans retinal for different periods of time and then exposed to white light in a humidified CO2 incubator maintained at a constant temperature of 37ºC. Using a high throughput assay system in 96 well plates, we pretreated the ARPE19 cells with a variety of different flavonoids (n=20) at a range of different concentrations and compared the accumulation of ROS levels in the untreated cells to those in the treated cells. ROS levels were measured using a standard dichlorodihydrofluorescein diacetate (H2DCF-dA) assay and the plates were read on a Gemini EM fluorometer.
Results::
ARPE19 cells treated with A2E or all-trans retinal and exposed to white light showed a dose dependent accumulation of high levels of ROS. The levels of ROS production was significantly reduced to varying degrees by a subset of specific flavonoids.
Conclusions::
Light exposure induces the production of high levels of ROS in RPE cells containing A2E or all-trans retinal. Specific flavonoids can inhibit the accumulation of ROS levels during light exposure. These results suggest that specific dietary flavonoids may be beneficial for the treatment of patients with macular diseases associated with oxidative stress in vivo.
Keywords: oxidation/oxidative or free radical damage • nutritional factors • radiation damage: light/UV