Effects of ME on oxidative stress and apoptosis <i>in</i><i>vitro</i>.

<p>(<b>A</b>, <b>B</b>) Intracellular levels of ROS in SK-N-SH cells treated with H₂O₂ (<b>A</b>) or PCB-52 (<b>B</b>) for 24 h with or without prior ME incubation. ROS levels were determined using DCFH-DA assay. The fluorescence was measured and expressed as percentage compared to untreated cells (n=3 independent experiments for each bar). (<b>C</b>, <b>D</b>) Caspase-3 activity in SK-N-SH cells treated with H₂O₂ (<b>C</b>) or PCB-52 (<b>D</b>) with or without ME preincubation. Caspase-3 activity was measured using colorimetric assay. Data were expressed as percentage of the activity compared to untreated cells (n=5 independent experiments for each bar). *<i>P</i> < 0.05, ** <i>P</i> < 0.01, *** <i>P</i> < 0.001 compared to untreated control; ^#<i>P</i> < 0.05, ^##<i>P</i> < 0.01 compared to cells treated with corresponding chemicals concentration with no ME preincubation.