(A) Measurement of intracellular ROS in NRK49F cells by DCFH-DA dye showed the quantity of ROS increased significantly after treatment with various concentrations of DBP (1, 10, 100 μmol/L). (B) Measurement of intracellular ROS in NRK52E cells by DCFH-DA dye showed the quantity of ROS increased significantly after treatment with various concentrations of DBP (1, 10, 100 μmol/L). (C) Real-time PCR assessed the expression of antioxidant genes (Gpx1, Cat, GR, Gst) of NRK49F cells exposed to various concentrations of DBP (1, 10, 100 μmol/L). (D) Real-time PCR assessed the expression of antioxidant genes (Gpx1, Cat, GR, Gst) of NRK52E cells exposed to various concentrations of DBP (1, 10, 100 μmol/L). (E) Measurement of intracellular ROS by DCFH-DA dye in NRK49F cells in DBP-exposed, vitamin C-exposed group and unexposed controls. (F) Measurement of intracellular ROS by DCFH-DA dye in NRK52E cells in DBP-exposed, vitamin C-exposed group and unexposed controls. (G) Real-time PCR assessed the expression of antioxidant genes (Gpx1, Cat, GR, Gst) of NRK49F cells in DBP-exposed, vitamin C-exposed group and unexposed controls. (H) Real-time PCR assessed the expression of antioxidant genes (Gpx1, Cat, GR, Gst) of NRK52E cells in DBP-exposed, vitamin C-exposed group and unexposed controls. Data represent mean ± SD. n = 6 rats per group, *P < 0.05.