Preventive effect of Vaccinium uliginosum L. extract and its fractions on age-related macular degeneration and its action mechanisms

Age-related macular degeneration (AMD) is the leading cause of vision loss and blindness among the elderly. Although the pathogenesis of this disease remains still obscure, several researchers have report that death of retinal pigmented epithelium (RPE) caused by excessive accumulation of A2E is crucial determinants of AMD. In this study, the preventive effect of Vaccinium uliginosum L. (V.U) extract and its fractions on AMD was investigated in blue light-irradiated human RPE cell (ARPE-19 cells). Blue light-induced RPE cell death was significantly inhibited by the treatment of V.U extract or its fraction. To identify the mechanism, FAB-MS analysis revealed that V.U inhibits the photooxidation of N-retinyl-N-retinylidene ethanolamine (A2E) induced by blue light in cell free system. Moreover, monitoring by quantitative HPLC also revealed that V.U extract and its fractions reduced intracellular accumulation of A2E, suggesting that V.U extract and its fractions inhibit not only blue light-induced photooxidation, but also intracellular accumulation of A2E, resulting in RPE cell survival after blue light exposure. A2E-laden cell exposed to blue light induced apoptosis by increasing the cleaved form of caspase-3, Bax/Bcl-2. Additionally, V.U inhibited by the treatment of V.U extract or quercetin-3-O-arabinofuranoside. These results suggest that V.U extract and its fractions have preventive effect on blue light-induced damage in RPE cells and AMD.