Change in SOD activity after 3 μM 17-AAG treatment for 16 h, 24 h and 48 h. The ARPE-19 cells were treated with 3 μM 17-AAG for 16, 24 or 48 h, and then SOD activity was determined by an SOD Assay Kit-WST. The SOD activity in RPE cells is upregulated in 16 h and downregulated in 24 h, as determine by comparison with control. However, the SOD activity in RPE cells is almost fully recovered in 48 h. Values are expressed as mean ± SD. *, p < 0.05, indicates a significant difference from control. NS, no significant difference from control.