Protective effects of tomato extract with elevated β-carotene levels on oxidative stress in ARPE-19 cells

• Published in: British journal of nutrition 2006-10, Vol.96 (4), p.643-649
• Main Authors: Chichili, Gurunadh R., Nohr, Donatus, Frank, Jürgen, Flaccus, Andrea, Fraser, Paul D., Enfissi, Eugenia M. A., Biesalski, Hans K.
• Format: Article
• Language: English
• Subjects: AMD; antioxidant activity; Antioxidants - pharmacology; beta Carotene - metabolism; beta-carotene; Biological and medical sciences; carbonyl compounds; Carotenoids; Carotenoids - metabolism; Cell Line; cell lines; cultured cells; epithelium; Feeding. Feeding behavior; Fundamental and applied biological sciences. Psychology; high performance liquid chromatography; Humans; Hydrogen Peroxide - pharmacology; immunocytochemistry; lipid peroxidation; Lipid Peroxidation - drug effects; lutein; Lutein - metabolism; lycopene; Lycopersicon esculentum - chemistry; Oxidative stress; Oxidative Stress - drug effects; Pigment Epithelium of Eye - drug effects; Pigment Epithelium of Eye - metabolism; plant extracts; Plant Extracts - pharmacology; Retina; Retinal pigment epithelium; Tomato; tomatoes; uptake mechanisms; Vertebrates: anatomy and physiology, studies on body, several organs or systems; ß-carotene
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1079/BJN20061843

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 ß-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 ß-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.