Title:L-Sulforaphane Confers Protection Against Oxidative Stress in an In Vitro Model of Age-Related Macular Degeneration
Volume: 11
Author(s): Nabeela K. Dulull, Daniel A. Dias, Thilini R. Thrimawithana and Faith A.A. Kwa*
Affiliation:
- Discipline of Laboratory Medicine, School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC 3083,Australia
Keywords:
Age-related macular degeneration, glutathione-S-transferase, L-Sulforaphane, metabolomic profiling, oxidative
stress, retinal pigment epithelium.
Abstract: Background: In age-related macular degeneration, oxidative damage and abnormal neovascularization
in the retina are caused by the upregulation of vascular endothelium growth factor and
reduced expression of Glutathione-S-transferase genes. Current treatments are only palliative. Compounds
from cruciferous vegetables (e.g. L-Sulforaphane) have been found to restore normal gene expression
levels in diseases including cancer via the activity of histone deacetylases and DNA methyltransferases,
thus retarding disease progression.
Objective: To examine L-Sulforaphane as a potential treatment to ameliorate aberrant levels of gene
expression and metabolites observed in age-related macular degeneration.
Method: The in vitro oxidative stress model of AMD was based on the exposure of Adult Retinal
Pigment Epithelium-19 cell line to 200μM hydrogen peroxide. The effects of L-Sulforaphane on cell
proliferation were determined by MTS assay. The role of GSTM1, VEGFA, DNMT1 and HDAC6
genes in modulating these effects was investigated using quantitative real-time polymerase chain reaction.
The metabolic profiling of L-Sulforaphane-treated cells via gas-chromatography massspectrometry
was established. Significant differences between control and treatment groups were validated
using one-way ANOVA, student t-test and post-hoc Bonferroni statistical tests (p<0.05).
Results: L-Sulforaphane induced a dose-dependent increase in cell proliferation in the presence of
hydrogen peroxide by upregulating Glutathione-S-Transferase μ1 gene expression. Metabolic profiling
revealed that L-Sulforaphane increased levels of 2-monopalmitoglycerol, 9, 12, 15,-(Z-Z-Z)-
Octadecatrienoic acid, 2-[Bis(trimethylsilyl)amino]ethyl bis(trimethylsilyl)-phosphate and nonanoic
acid but decreased β-alanine levels in the absence or presence of hydrogen peroxide, respectively.
Conclusion: This study supports the use of L-Sulforaphane to promote regeneration of retinal cells
under oxidative stress conditions.
