Tribulus terrestris Ameliorates Oxidative Stress-Induced ARPE-19 Cell Injury through the PI3K/Akt-Nrf2 Signaling Pathway

Figure 6

Inhibitor of PI3K/Akt signaling pathway blocked the upregulation of mRNA expression levels of Nrf2, HO-1, NQO1, and GCLM by EE-TT treatment in ARPE-19 cells. ARPE-19 cells were pretreated with or without the inhibitors of 10 μM LY294002, 0.25 μM SCH772984, and 0.5 μM of AEB071 for 1 h, followed by a 24 h exposure to 200 μg/mL EE-TT. The mRNA expression levels of Nrf2 (a), HO-1(b), NQO1 (c), and GCLM (d) for each sample were measured by real-time PCR, and the fold changes of each gene are shown in the bar graph compared with the control sample (nontreated cells, value of 1). All data are shown as , , , vs. the control sample (nontreated cells); ^#, ^##, ^### vs. the sample with EE-TT treated only cells.

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