Cyp7a1

CP was purchased from Jiangsu Hengrui Medicine Co., Ltd. (Lianyungang, China). The ginseng sample (JSPACM-03-1) was collected from Jilin province and authenticated by Prof. Song-Lin Li via morphological and histological methods according to ginseng monograph in Chinese Pharmacopoeia (Version 2010). The voucher specimen was deposited in Department of Pharmaceutical Analysis and Metabolomics, Jiangsu Province Academy of Traditional Chinese Medicine. Reference compounds, including ginsenoside Re, Rg1, Rf, Ro, Rb1, Rc, Rb2, Rb3, Rd, 20(S)-Rg2, 20(S)-Rh2, 20(R)-Rg2 and 20(S)-Rg3, were purchased from Sichuan Victory Co. Ltd. (Chengdu, China). HPLC grade acetonitrile and methanol were purchased from Merck Company (Darmstadt, Germany). Antibodies for FXR, CYP7A1, CYP8B1, NTCP, OAT 2 and OAT 3, GST, BSEP, MRP 3, GCLM, GCLC, GS, NRF 1, NRF 2 and F4/80 were obtained from Santa Cruz Biotechnology (CA, USA). Brusatol was purchased from Beijing Zhili Biological Technology Co. Ltd. (Beijing, China). Ultra-pure water was prepared using Milli-Q SP system (Millipore, Bedford, MA, USA). All other reagents were of analytical grade and obtained from commercial sources.

Liver samples were homogenized in modified RIPA buffer containing 50 mM Tris, 150 mM NaCl, 1 mM EDTA, 1% Triton X-100, 0.5% sodium deoxycholate and 1% SDS supplemented with protease and phosphatase inhibitors (Roche). CYP7A1 (Catalog #: sc25536, 200 μg ml⁻¹, 1:500 dilution), CYP7B1 (Catalog #: sc26087, 200 μg ml⁻¹, 1:500 dilution) and β-actin (Catalog #: sc47778, 200 μg ml⁻¹, 1:1,000 dilution) antibodies were purchased from Santa Cruz and KLF15 (Catalog #: ab2647, 0.5 mg ml⁻¹, 1:1,000 dilution) antibody was from Abcam (Cambridge, MA, USA) for immunoblot analyses. Immunoblot signals were quantified using ImageJ (ImageJ 1.48v, NIH). Full-length images of immunoblots are shown in Supplementary Figures 7–8.