Fig. 4.

Effects of unshiu mikan (A), sweet orange (B), boiled tomato (C), hesperidin (D), rutin (E), and narirutin (F) on tert-butyl hydroperoxide (t-BHP)-induced reactive oxygen species (ROS) generation in HepG2 cells. Cells pretreated with different concentrations (50 to 200 μg/mL) of juice powders and hesperidin, rutin, and narirutin at concentrations of 2.5 to 100 μM or Trolox (10 μM) for 1 h were stimulated with 200 μM t-BHP for 30 min. ROS levels were measured by 2′,7′-dichlorodihydrofluorescein diacetate with fluorescent analysis. The control values were obtained in the absence of t-BHP (200 μM), juice powders, and flavonoids and after the addition of t-BHP (200 μM). Trolox was used as a positive control. Data are expressed as the mean±SD of three independent experiments. Significantly different from the t-BHP-treated group at *P<0.05 and the control group at ^###P<0.001.