Fig. 5

Effect of BBR on hepatic endoplasmic reticulum (ER) stress in Mdr2^−/− mice. a Representative heatmap of the key genes involved in ER stress response in the liver, comparing BBR-treated group with the Control group. The RNA-seq data were normalized using a Z-score for tag counts, with red and blue colors denoting high and low gene expression, respectively. b Relative mRNA expression levels of ER stress-related genes (Chop, Atf4, Xbp-1, and Dusp1), normalized with HPRT1 as an internal control. c Representative immunoblot images of phosphorylated (p)-ERK, total ERK, ATF4, and XBP-1. d Representative immunoblot images of nuclear CHOP. e Relative protein level of p-ERK, normalized using ERK as a loading control. f Relative protein level of CHOP, normalized with Histone H3 as a loading control. g Relative protein levels of ATF4 and XBP-1, normalized against β-actin as a loading control. Data are expressed as mean ± SEM. Statistical significance compared to the control group is indicated as *p < 0.05, **p < 0.01, ***p < 0.001 (n = 9–12)