Light Induced Retinal Degeneration is Prevented by Zinc, a Component in the AREDS Formulation(†).
Photochem Photobiol. 2012 Mar 3. Epub 2012 Mar 3. PMID: 22385127
Petticrew Research Laboratory, Department of Biochemistry and Molecular Biology, Boonshoft Schoolof Medicine, Wright State University, Dayton, OH. Department of Ophthalmology, Emory University, Atlanta, GA. Alcon Research Ltd. Fort Worth, TX.
Mineral supplements are often included in multivitamin preparations because of their beneficial effects on metabolism. In this study we used an animal model of light-induced retinal degeneration to test for photoreceptor cell protection by the essential trace element zinc. Rats were treated with various doses of zinc oxide and then exposed to intense visible light for as long as 8h. Zinc treatment effectively prevented retinal light damage as determined by rhodopsin and retinal DNA recovery, histology and electrophoretic analysis of DNA damage and oxidized retinal proteins. Zinc oxide was particularly effective when given before light exposure and at doses 2-4 fold higher than recommended by the age-related eye disease study (AREDS) group. Treated rats exhibited higher serum and retinal pigment epithelial zinc levels and an altered retinal gene expression profile. Using an Ingenuity database, 512 genes with known functional annotations were found to be responsive to zinc supplementation, with 45% of these falling into a network related to cellular growth, proliferation, cell cycle and cell death. While these data suggest an integrated and extensive regulatory response, zinc induced changes in gene expression also appear to enhance antioxidative capacity in retina and reduce oxidative damage arising from intense light exposure.© 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2012 The American Society of Photobiology.