text: AIM: To investigate the anti-hepatofibrotic effects of Gardenia jasminoides in liver fibrosis. METHODS: Male Sprague-Dawley rats underwent common bile duct ligation (BDL) for 14 d and were treated with Gardenia jasminoides by gavage. The effects of Gardenia jasminoides on liver fibrosis and the detailed molecular mechanisms were also assessed in human hepatic stellate cells (LX-2) in vitro. RESULTS: Treatment with Gardenia jasminoides decreased serum alanine aminotransferase (BDL vs BDL + 100 mg/kg Gardenia jasminoides, 146.6    15 U/L vs 77    6.5 U/L, P = 0.0007) and aspartate aminotransferase (BDL vs BDL + 100 mg/kg Gardenia jasminoides, 188    35.2 U/L vs 128    19 U/L, P = 0.005) as well as hydroxyproline (BDL vs BDL + 100 mg/kg Gardenia jasminoides, 438    40.2  g/g vs 228    10.3  g/g liver tissue, P = 0.004) after BDL. Furthermore, Gardenia jasminoides significantly reduced liver mRNA and/or protein expression of transforming growth factor b1 (TGF-b1), collagen type   I   (Col   I) and a-smooth muscle actin (a-SMA). Gardenia jasminoides significantly suppressed the upregulation of TGF-b1, Col   I   and a-SMA in LX-2 exposed to recombinant TGF-b1. Moreover, Gardenia jasminoides inhibited TGF-b1-induced Smad2 phosphorylation in LX-2 cells. CONCLUSION: Gardenia jasminoides exerts antifibrotic effects in the liver fibrosis and may represent a novel antifibrotic agent.