(a)
(b)
(c)
Figure 3: STM induces oxidative stress in A549 cells. (a) A549 cells were treated with STM in a dose- and time-dependent manner as indicated and intracellular ROS generation was measured by staining the cells with DCFH-DA. (b) A549 cells were treated with STM for 24 h in the presence or absence of NAC and intracellular GSH/GSSG ratio was measured according to the kit instructions. (c) A549 cells were treated with STM for 24 h in the presence or absence of NAC and TrxR activity was measured according to the kit instructions. Data (from (a), (b), and (c)) are expressed as mean ± SEM of three different experiments. Columns not sharing the same superscript letters within the same group differ significantly ().