Purchase this article with an account.
A.M. Hanneken, F.–F. Lin, P. Maher; Flavonoids Protect Human Retinal Pigment Epithelial Cells From Oxidative Stress–Induced Death . Invest. Ophthalmol. Vis. Sci. 2005;46(13):1634.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To determine whether specific dietary and synthetic flavonoids can protect and rescue human retinal pigment epithelial (RPE) cells from oxidative stress–induced death. Methods: We measured the efficacy and potency of a variety of dietary and synthetic flavonoids on the survival of both human ARPE19 cells and primary human RPE cells treated with either hydrogen peroxide or t–butyl hydroperoxide. We determined the effective concentrations (EC50s) and the toxicities (LD50s) of the flavonoids after twenty–four hours using the MTT assay. We compared the efficacy of Vitamins E and C on RPE cell survival under identical conditions. Additionally, we tested the ability of specific flavonoids to rescue RPE cells from cell death at various time intervals after the cells were exposed to oxidative stress. Finally, we examined the ability of the flavonoids to induce phase 2 detoxifying enzymes by immunoblotting for the transcription factor, Nrf2, and the phase 2 gene product, heme–oxygenase 1. Results: We show that specific dietary flavonoids can protect human RPE cells from oxidative stress–induced death with efficacies between 80 – 100% and potencies in the high nM and low uM range. The toxicites of most of the effective flavonoids are low. Several flavonoids are capable of rescuing RPE cells from cell death after the insult has occurred. We also found that many of these flavonoids induce the expression of Nrf2 and the phase 2 gene product, heme–oxygenase 1, in human RPE cells. Conclusions: We have identified a select group of flavonoids which both protect and rescue injured RPE cells from oxidative stress–induced death with a high degree of potency and efficacy and low toxicity. Many of these flavonoids also induce the expression of phase 2 detoxification genes which function to provide additional protection against oxidative stress. This select group of flavonoids and the foods which contain high levels of these compounds may be of clinical benefit to patients with macular degeneration.
This PDF is available to Subscribers Only