(a) Immunohistochemical staining for superoxide dismutase (SOD) expression in rat kidney tissues (n¼6/group) obtained on days 7, 14, and 21 following EG treatment was performed and the average number of positive stained cells per high power field was counted from three independent experiments. Data represent means±s.d. ***P<0.001 versus untreated control; #P<0.05 and ###P<0.001 versus EG; and !!!P<0.001 versus EG+P4, two-way analysis of variance followed by a post hoc analysis. (b–c) Western blot analysis in EG-treated rat kidneys on day 21 following EG treatment for Cu/Zn SOD (b), catalase (c), glutathione peroxidase (c), and b-actin. Data of protein expression represent means±s.d. *P<0.05 versus untreated control and ##P<0.01 versus EG, one-way analysis of variance followed by a post hoc analysis. C, untreated control (distilled water); EG, EG-treated group (0.8% EG/1% ammonium chloride (AC; NH4Cl) in drinking water); and EG+P4 and EG+P20, two PGG-treated groups (0.8% EG/1% AC+4 or 20 mg/kg of PGG in 2% methylcellulose).