Wogonin modulates hydroperoxide-induced apoptosis via PI3K/Akt pathway in retinal pigment epithelium cells

BACKGROUND: Oxidative stress causes the defects of retinal pigment epithelial (RPE) cells that contribute to age-related macular degeneration (AMD). This study was conducted to determine whether wogonin could prevent H(2)O(2)-induced oxidative stress in RPE cells. METHODS: A RPE cell line, ARPE-19, was obtained for the cell model. ARPE-19 cells were pre-treated with various concentrations of wogonin for 24 h before being exposed to H(2)O(2) for 2 h to induce oxidative stress. Cell metabolic activity was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cellular apoptosis was quantified by the flow cytometry. Protein level was assed by western blot. RESULTS: The RPE cells exposed to to 200 mM H(2)O(2) demonstrated a significant depression in the cell viability; whereas pre-treatment with 50 and 100 mmol/l wogonin could significantly improve the cell viability in a dose-dependent manner. The proportion of PI-positive cells was increased significantly in RPE cells treated with H(2)O(2) alone; whereas pretreatment with 100 mM wogonin significantly reduced H(2)O(2) -induced RPE cell death rate. In protein level, the wogonin use could reduce the level of p-Akt significantly and this is the possible mechanism of the antioxidant effect of wogonin. CONCLUSIONS: Our study showed that wogonin pre-treatment can protect RPE cells from H(2)O(2)-induced apoptosis. This suggests potential effect of wogonin in the prevention of retinal diseases associated with H(2)O(2)-induced oxidative stress such as AMD. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_154