|
|
||||||||
1 From the Departments of Ophthalmology and 2 Biochemistry, Emory University School of Medicine, Atlanta, Georgia.
OBJECTIVE. To determine whether oltipraz (4-methyl-5-pyrazinyl-3H-1,2-dithiole-3-thione) protects against oxidative injury in cultured human retinal pigment epithelial (hRPE) cells.
METHODS. Primary cultured hRPE cells were incubated with various concentrations of oltipraz followed by treatment with the chemical oxidant tert-butylhydroperoxide (tBH). Cell viability was assessed by release of lactate dehydrogenase (LDH) and cleavage of WST-1. Intracellular and mitochondrial levels of glutathione (GSH) were measured by HPLC. Glutathione S-transferase (GST), NADPH-quinone reductase (NQR), and glutathione peroxidase (GPx) were measured by specific enzyme activity assays.
RESULTS. Treatment of hRPE cells with oltipraz inhibited tBH-induced cell death in a concentration-dependent manner with significant inhibition at 50 µM. Olitpraz (50 µM) increased GSH levels in hRPE cells by approximately 18% and in hRPE mitochondrial fractions by approximately 50% after 24 hours of exposure. Treatment with oltipraz increased GST and NQR activities by approximately 21% and 11%, respectively.
CONCLUSIONS. Oltipraz protects hRPE cells against tBH induced injury. The mechanism of protection is likely to include increased cellular and mitochondrial GSH levels and induction of detoxification enzymes, including GST and NQR. Dietary supplementation with oltipraz or other dithiolethiones may help protect the hRPE against oxidant induced injury.
This article has been cited by other articles:
![]() |
K. A. Rezaei, Y. Chen, J. Cai, and P. Sternberg Modulation of Nrf2-Dependent Antioxidant Functions in the RPE by Zip2, a Zinc Transporter Protein Invest. Ophthalmol. Vis. Sci., April 1, 2008; 49(4): 1665 - 1670. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Wang, Y. Chen, P. Sternberg, and J. Cai Essential Roles of the PI3 Kinase/Akt Pathway in Regulating Nrf2-Dependent Antioxidant Functions in the RPE Invest. Ophthalmol. Vis. Sci., April 1, 2008; 49(4): 1671 - 1678. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. S. Ko, S. J. Lee, J. W. Kim, J. W. Lim, and S. G. Kim DIFFERENTIAL EFFECTS OF THE OXIDIZED METABOLITES OF OLTIPRAZ ON THE ACTIVATION OF CCAAT/ENHANCER BINDING PROTEIN-{beta} AND NF-E2-RELATED FACTOR-2 FOR GSTA2 GENE INDUCTION Drug Metab. Dispos., August 1, 2006; 34(8): 1353 - 1360. [Abstract] [Full Text] [PDF] |
||||
![]() |
K.-N. Ha, Y. Chen, J. Cai, and P. Sternberg Jr Increased Glutathione Synthesis through an ARE-Nrf2-Dependent Pathway by Zinc in the RPE: Implication for Protection against Oxidative Stress. Invest. Ophthalmol. Vis. Sci., June 1, 2006; 47(6): 2709 - 2715. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. A. Voloboueva, J. Liu, J. H. Suh, B. N. Ames, and S. S. Miller (R)-{alpha}-Lipoic Acid Protects Retinal Pigment Epithelial Cells from Oxidative Damage Invest. Ophthalmol. Vis. Sci., November 1, 2005; 46(11): 4302 - 4310. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Piton, E. Le Ferrec, S. Langouet, C. Rauch, E. Petit, F. Le Goff, A. Guillouzo, and F. Morel Oltipraz regulates different categories of genes relevant to chemoprevention in human hepatocytes Carcinogenesis, February 1, 2005; 26(2): 343 - 351. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. S. Armstrong, M. Whiteman, H. Yang, D. P. Jones, and P. Sternberg Jr Cysteine Starvation Activates the Redox-Dependent Mitochondrial Permeability Transition in Retinal Pigment Epithelial Cells Invest. Ophthalmol. Vis. Sci., November 1, 2004; 45(11): 4183 - 4189. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Gao and P. Talalay Induction of phase 2 genes by sulforaphane protects retinal pigment epithelial cells against photooxidative damage PNAS, July 13, 2004; 101(28): 10446 - 10451. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |