Effects of 4-NP (mg/k b. wt) on oxidative stress-related genes expression of experimental rat livers ((A) SOD1, (B) GPx, (C) HSP70). Apoptotic-related genes ((D) Bax, (E) Bcl-2, (F) Casp-9). Hepatotoxicity-related genes ((G) Fas, (H) FasL, (I) TNF-α). The housekeeping gene β-actin is used as an internal positive control. The relative expression of target genes is calculated using 2−ΔΔCt. Error bars represent the standard deviation. Significant difference:*p < 0.05, **p < 0.01 versus control group. n = 6.