OBJECTIVE:To investigate the effect of Banxia Xiexin decoction (BXD) on Helicobacter pylori (Hp)-related peptic ulcers (PUs) and the possible mechanism underlying BXD actions via the transforming growth factor-β/small mothers against decapentaplegic (TGF-β/Smad) signaling pathway.METHODS:PU patients with cold-heat complex syndrome were randomly assigned to groups that received Chinese or West medicines with 20 patients in each group.Serum was collected after 7 d of treatment.The healthy group included 20 individuals.Gastric mucosal epithelial cell line GES-1 was cultured in vitro and randomly divided into the following seven groups:control,model,healthy,West Medicine,prior treatment,low dosage,and high dosage.After 72 h of treatment with the corresponding serum,the mRNA and protein expression levels of TGF-β1,Smad3,and Smad7 were measured by reverse transcription quantitative polymerase chain reaction and west blotting,respectively.RESULTS:The mRNA expression levels of TGF-β1 and Smad3 in GES-1 cells were increased after Hp introduction,and these increased levels were reduced by the BXD-containing serum.The protein levels of p-Smad3,but not TGF-β1 or Smad3,were significantly increased in Hp-treated GES-1 cells,and treatment with the BXD-containing serum markedly decreased the protein levels.Smad7 expression was significantly enhanced following treatment with the BXD-containing serum at transcriptional and protein levels in a dose-dependent manner.CONCLUSION:BXD regulates the TGF-β/Smad signaling pathway by inhibiting the expression of TGF-β1 and Smad3,and increasing the expression of Smad7.