title: Protective effects of tomato extract with elevated beta-carotene levels on oxidative stress in ARPE-19 cells.
abstract: Epidemiological studies show that dietary products rich in carotenoids delay the progression of age-related macular degeneration. Experimental evidence from cellular studies on the antioxidant actions of carotenoids in the retinal pigment epithelium is still, however, fragmentary. The present study examined the uptake and protective potential of dietary carotenoids from tomato on the human retinal pigment epithelial cell line ARPE-19. ARPE-19 cells were incubated in medium supplemented with tomato extract containing high levels of beta-carotene, lycopene and traces of lutein. The cellular uptake of carotenoids was analysed by reverse-phase HPLC. Oxidative stress was induced by treatment with 1 mm-H2O2. Nitrotyrosine was detected by immunocytochemistry, and oxidised proteins (protein carbonyls) were measured by a quantitative ELISA method. Lipid peroxidation was assessed by quantifying thiobarbituric acid reactive substances. ARPE-19 cells preferentially accumulated lutein and beta-carotene rather than lycopene. Nitrotyrosine formation was considerably reduced in cells incubated with tomato extract compared with controls after H2O2 treatment. Protein carbonyls were reduced by 30 % (P = 0.015), and the formation of thiobarbituric acid-reactive substances was reduced by 140 % (P = 0.003) in cells incubated with tomato extract. The present study provides the experimental evidence for protective effects of dietary tomatoes rich in carotenoids on oxidative stress in the retinal pigment epithelium.
authors.affiliation: Institute of Biological Chemistry and Nutrition, University of Hohenheim, Garbenstrasse 30, University of Hohenheim, D-70599 Stuttgart, Germany.
authors.forename: Gurunadh R
authors.initials: GR
authors.lastname: Chichili
authors.forename: Donatus
authors.initials: D
authors.lastname: Nohr
authors.forename: Jürgen
authors.initials: J
authors.lastname: Frank
authors.forename: Andrea
authors.initials: A
authors.lastname: Flaccus
authors.forename: Paul D
authors.initials: PD
authors.lastname: Fraser
authors.forename: Eugenia M A
authors.initials: EM
authors.lastname: Enfissi
authors.forename: Hans K
authors.initials: HK
authors.lastname: Biesalski
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D002338:Carotenoids / Q000378:metabolism; D002460:Cell Line; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D015227:Lipid Peroxidation / Q000187:drug effects; D014975:Lutein / Q000378:metabolism; D000077276:Lycopene; D018551:Solanum lycopersicum / Q000737:chemistry*; D018384:Oxidative Stress / Q000187:drug effects*; D010857:Pigment Epithelium of Eye / Q000187:drug effects* / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology; D019207:beta Carotene / Q000378:metabolism
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D019207:beta Carotene; D002338:Carotenoids; D006861:Hydrogen Peroxide; D000077276:Lycopene; D014975:Lutein