Fig. 6

UA increases ROS. RKO cells were treated with UA, stained with DCFH-DA, observed under a microscope (× 200) (a), and the fluorescence were detected by plate reader (b). After pre-incubated with NAC for 2 h, RKO cells were treated with UA, and subjected to detection of Caspase-3 (c), − 8 (d) and − 9 (e) activities and apoptosis (f). ^**p < 0.01, versus control group; ^#p < 0.05, ^##p < 0.01, versus UA group