Olive Polyphenol Protects Retina

SHANGHAI—Hydroxytyrosol may fight age-related macular degeneration by protecting the retina from oxidative stress and serving as a phase II enzyme inducer, according to research from the Chinese Academy of Sciences (J Nutr Biochem. ePub Feb. 8, 2010). Previous investigations by the team found hydroxytyrosol, the major antioxidant polyphenol in olives, could protect human retinal pigment epithelial (RPE) cells from toxin- or peroxidation-induced oxidative stress. In the new study, cultured RPE cells were pretreated with hydroxytyrosol and challenged with acrolein. Pre-treatment protected the cells against acrolein-induced inhibition of nuclear factor-E2-related factor 2 (Nrf2); instead, activating Nrf2 activated detoxifying Phase II enzymes and other antioxidant enzymes. Hydroxytyrosol treatment also activated peroxisome proliferator-activated receptor coactivator 1 alpha (PPARGC1alpha), which enhanced mitochondrial biogenesis.