Fig. 2

The uptake of 5-FU and 5-FU-mediated ROS production after the application of ultrasound. a Relative cumulative amounts of 5-FU in the 5-FU alone and US + 5-FU groups in BEL-7402 cells (^★ p < 0.05 vs. 5-FU group). b Representative intracellular ROS (green fluorescence) after the treatment. c The relative level of intracellular ROS by the fluorescent intensity quantified with IOD values. Data was presented as the mean ± SD (n = 6, ^★ p < 0.05 vs. other three groups; ^★★ p < 0.05 NAC-treated vs. NAC-untreated US + 5-FU group)