title: Effects of 18α-glycyrrhizin on TGF-β1/Smad signaling pathway in rats with carbon tetrachloride-induced liver fibrosis.
abstract: BACKGROUND
  Glycyrrhizin has various pharmacological effects including hepato-protection. This study aimed to investigate the potential mechanism underlying the protective effects of 18α-glycyrrhizin (18α-GL) in rats with carbon tetrachloride (CCl4) induced liver fibrosis.
  
  
  METHODS
  Male Sprague-Dawley (SD) rats were randomly divided into control group, fibrosis group, 25 mg/kg 18α-GL group and 12.5 mg/kg 18α-GL group. Rats in experimental groups were subcutaneously injected with 40% CCl4 twice weekly for 8 weeks. Immunohistochemical examination was carried out to detect the protein expressions of collagen I, collagen III, TGF-β1, p-Smad2, p-Smad3, Smad 7 and SP-1, in the liver, and the mRNA and protein expressions of these genes were determined in the liver by real time PCR and Western blot assay, respectively.
  
  
  RESULTS
  18α-GL ameliorated histological changes and significantly suppressed collagen deposition. 18α-GL significantly decreased the mRNA expressions of TGF-β1, Smad2, Smad3 and SP-1 in the liver. Immunohistochemical staining revealed that TGF-β1, p-Smad2, p-Smad3 and SP-1 expressions reduced following 18α-GL therapy. Western blot assay showed p-Smad2, p-Smad3, smad2 and smad3 expressions decreased after 18α-GL treatment. The mRNA and protein expression of Smad7 remained unchanged.
  
  
  CONCLUSIONS
  18α-GL is able to attenuate CCl4 induced liver fibrosis in rat.
authors.affiliation: Department of Gastroenterology, Shanghai First People's Hospital, Shanghai Jiaotong University School of Medicine Shanghai 200080, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Qu
authors.affiliation: Department of Gastroenterology, Shanghai First People's Hospital, Shanghai Jiaotong University School of Medicine Shanghai 200080, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zong
authors.affiliation: Department of Gastroenterology, Shanghai First People's Hospital, Shanghai Jiaotong University School of Medicine Shanghai 200080, China.
authors.forename: Mingyi
authors.initials: M
authors.lastname: Xu
authors.affiliation: Department of Gastroenterology, Shanghai First People's Hospital, Shanghai Jiaotong University School of Medicine Shanghai 200080, China.
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Department of Gastroenterology, Shanghai First People's Hospital, Shanghai Jiaotong University School of Medicine Shanghai 200080, China.
authors.forename: Lungen
authors.initials: L
authors.lastname: Lu
mesh_terms: D000818:Animals; D002251:Carbon Tetrachloride; D006034:Glycyrrhetinic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008103:Liver Cirrhosis / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects*; D051785:Smad Proteins / Q000378:metabolism*; D053773:Transforming Growth Factor beta1 / Q000378:metabolism*
chemical_list: D051785:Smad Proteins; D053773:Transforming Growth Factor beta1; C119129:18alpha-glycyrrhetinic acid; D002251:Carbon Tetrachloride; D006034:Glycyrrhetinic Acid
keywords: 18α-glycyrrhizin; Smad; TGF-β1; collagen; liver fibrosis