Genotoxic effects of carotenoid breakdown products in human retinal pigment epithelial cells.
OBJECTIVE
To investigate the genotoxic effects of lutein (LBP) and beta -carotene breakdown products (beta -apo-8-carotenal, BA8C) and the preventive role of GSH in human retinal pigment epithelial cells (ARPE-19).


METHODS
LBP- and BA8C-induced DNA damage in human retinal pigment epithelial cells (ARPE-19) was determined by comet assay. The DNA damage was quantified by the image analysis system using Comet Score software. ARPE-19 cell viability was determined by CellTiter 96 AQ(ueous) one-solution cell proliferation assay kit. Intracellular GSH levels were measured by Ellman's reagent.


RESULTS
Incubation of serum-starved ARPE-19 cells with LBP and BA8C caused significant DNA damage in a dose- and time-dependent manner. The DNA damage and cell death incurred by LBP and BA8C were significantly prevented by N-acetylcysteine (NAC) but not by alpha -tocopherol + ascorbic acid (T + AA). Furthermore, BSO-induced GSH depletion in ARPE-19 cells caused a significant elevation in LBP- and BA8C-induced DNA damage, whereas increased GSH levels in ARPE-19 cells prevented it.


CONCLUSIONS
Our results suggest that breakdown products of dietary carotenoids could be genotoxic in ARPE-19 cells. LBP-induced genotoxic effects could worsen oxidative stress. The intracellular GSH pool in ARPE-19 cells might play a critical role in carotenoid breakdown products-induced genotoxicity.
AMD Center, Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas 77555-1106, USA.
Nilesh M
NM
Kalariya
Kota V
KV
Ramana
Satish K
SK
Srivastava
Frederik J G M
FJ
van Kuijk
D000111:Acetylcysteine / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001205:Ascorbic Acid / Q000494:pharmacology; D002338:Carotenoids / Q000633:toxicity*; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D020552:Comet Assay; D004247:DNA / Q000187:drug effects*; D004249:DNA Damage; D004305:Dose-Response Relationship, Drug; D005978:Glutathione / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D014975:Lutein / Q000633:toxicity*; D008856:Microscopy, Fluorescence; D055213:Retinal Pigment Epithelium / Q000187:drug effects*; D013997:Time Factors; D024502:alpha-Tocopherol / Q000494:pharmacology
C110652:beta-apo-8'-carotenal; D002338:Carotenoids; D004247:DNA; D005978:Glutathione; D024502:alpha-Tocopherol; D001205:Ascorbic Acid; D000111:Acetylcysteine; D014975:Lutein