title: Up-regulation of BSEP and MRP2 by Calculus Bovis administration in 17α-ethynylestradiol-induced cholestasis: Involvement of PI3K/Akt signaling pathway.
abstract: BACKGROUND
  Calculus Bovis, also known as Niuhuang, is a rare traditional Chinese medicine that has been widely used in China for 2000 years in pharmacology for sedation, anti-spasm, relieving fever, diminishing inflammation and recovering gallbladder functions.
  
  
  OBJECTIVE
  This study aimed to investigate the choleretic potential and molecular responses in rats to Calculus Bovis (CB) administration after 17α-ethynylestradiol (EE)-induced cholestasis.
  
  
  METHODS
  CB (50 and 100mg/kg per day) was intragastrically (i. g.) given to experimental rats for five consecutive days in coadministration with EE (5mg/kg daily for five days, s.c.). The levels of serum biomarkers were determined biochemically. The histopathology of the liver tissue was evaluated. Expression of bile salt export pump (BSEP) and multidrug resistance-associated protein 2 (MRP2) were studied by western blot and immunohistochemical assay. The expression of Akt and phospho-Akt (pAkt) were also measured by western blot.
  
  
  RESULTS
  In response to EE, CB treatment significantly prevented an increase in serum levels of alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma glutamyltransferase (GGT) and total bilirubin (TBIL). CB treatment also repaired tissue lesions caused by EE. Western blots showed that EE significantly decreased the protein expression of BSEP and MRP2. EE also dramatically increased levels of pAkt and decreased levels of Akt. Compared to the EE group, CB treatment increased levels of hepatic BSEP and MRP2 while pAkt levels decreased and Akt levels increased. Immunohistochemistry also indicated that EE decreased the expression of BSEP and MRP2. LY294002 is a selective PI3K inhibitor and showed similar beneficial effects as CB. Decreased expression of BSEP and MRP2 caused by EE were also prevented by LY294002 treatment.
  
  
  CONCLUSIONS
  Calculus Bovis administration can alleviate liver injury and up-regulate the expression of BSEP and MRP2 in 17α-ethynylestradiol-induced cholestasis by a mechanism that may involve inhibiting the activated PI3K/Akt signaling pathway.
authors.affiliation: Department of Pharmacy, Puai Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Wu
authors.affiliation: Department of Pharmacy, General Hospital of the Yangtze River Shipping, Wuha 430022, China.
authors.forename: Qianrui
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Pharmacy, Puai Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Gastroenterology, The Fifth Hospital of Huangshi City, Huangshi 435005, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Medicine, City College, Wuhan University of Science and Technology, Wuhan 430083, China.
authors.forename: Ji
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Pharmacy, Puai Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China. Electronic address: 546751430@qq.com.
authors.forename: Hongping
authors.initials: H
authors.lastname: Song
mesh_terms: D000074020:ATP Binding Cassette Transporter, Subfamily B, Member 11; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D000818:Animals; D001663:Bilirubin / Q000097:blood; D001688:Biological Products; D015415:Biomarkers / Q000097:blood; D002756:Cholagogues and Choleretics / Q000494:pharmacology*; D002779:Cholestasis / Q000139:chemically induced / Q000201:enzymology / Q000473:pathology / Q000517:prevention & control*; D004195:Disease Models, Animal; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D004958:Estradiol / Q000031:analogs & derivatives*; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D008099:Liver / Q000000981:diagnostic imaging* / Q000201:enzymology / Q000473:pathology; D008297:Male; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000378:metabolism; D058539:Phosphatidylinositol 3-Kinase / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects; D015854:Up-Regulation
chemical_list: D000074020:ATP Binding Cassette Transporter, Subfamily B, Member 11; D018528:ATP-Binding Cassette Transporters; D001663:Bilirubin; D001688:Biological Products; D015415:Biomarkers; D002756:Cholagogues and Choleretics; D004365:Drugs, Chinese Herbal; D004958:Estradiol; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D058539:Phosphatidylinositol 3-Kinase; D000081082:Phosphoinositide-3 Kinase Inhibitors; D047428:Protein Kinase Inhibitors; D051057:Proto-Oncogene Proteins c-akt; C490548:Abcb11 protein, rat; C423013:Abcc2 protein, rat; C489542:Abcc4 protein, rat; C121824:ethylenestradiol; C570000:niuhuang
keywords: 17α-ethynylestradiol; Akt; Bile salt export pump; Calculus Bovis; Multidrug resistance-associated protein 2; PAkt