and washed twice with PBS. The cells were stained
with 20 μMof DCFH-DA for 15 min at room temperature and subjected
to determination of intracellular ROS production using a FACScan flow
cytometer (Becton Dickinson Immunocytometry Systems, San Jose, CA).
Approximately 1 104 counts were made for each sample. The ROS
production (expressed as a percent) was calculated by CELL Quest
software.