Figure 4: Effect of SPE supplementation on oxidative stress in mammary gland hyperplasia of rats induced by estradiol benzoate and progestin administration. (a–f) Representative images of 8-oxo-dG immunostaining in the mammary glands (200x). No apparent 8-oxo-dG-positive cells were observed in the control group (a) and the FPE-treatment-alone group (b). A high percentage of 8-oxo-dG-positive cells were observed in the estradiol benzoate and progestin treatment group (c). Scale bar, 100 μm. However, the percentage of 8-oxo-dG-positive cells decreased upon treatment with FPEs at 30 ml/kg (d), 15 ml/kg (e) and 5 ml/kg (f). (g) Quantification of 8-oxo-dG-positive cells in the mammary glands by ELISA. Data are presented as mean ± SEM. A compared with the control group; B compared with the EB + PR group.