AIM: To investigate the antif ibrotic effects of peginterferon- alpha 2b and taurine on oxidative stress markers and hepatocellular apoptosis. METHODS: Sixty rats with CCl4-induced liver fibrosis were divided into 4 groups (n = 15). Group 1 was left for spontaneous recovery (SR). Groups 2-4 received peginterferon-alpha 2b, taurine, and their combination, respectively, for four weeks. Histological f ibrosis scores, histomorphometric analysis, tissue hydroxyproline, tissue MDA, GPx and SOD activities were determined. Activated stellate cells and hepatocellular apoptosis were also evaluated. RESULTS: The degree of f ibrosis decreased in all treatment groups compared to spontaneous recovery group. Taurine alone and in combination with peginterferon-alpha 2b reduced oxidative stress markers, but peginterferon-alpha 2b alone did not. Apoptotic hepatocytes and activated stellate cells were higher in groups 2-4 than in group 1. Combined taurine and peginterferon-alpha 2b further reduced fibrosis and increased activated stellate cell apoptosis, but could not improve oxidative stress more than taurine alone.CONCLUSION: Peginterferon-alpha 2b exerts anti- f ibrotic effects on rat liver fibrosis. It seems ineffective against oxidative stress in vivo. Peginterferon-alpha 2b in combination with taurine seems to be an antif ibrotic strategy. AIM: To investigate the antif ibrotic effects of peginterferon-alpha 2b and taurine on oxidative stress markers and hepatocellular apoptosis. METHODS: Sixty rats with CCl4-induced liver fibrosis were divided into 4 groups (n = 15). Group 1 was left for spontaneous Groups 2-4 received peginterferon-alpha 2b, taurine, and their combination, respectively, for four weeks. Histological f ibrosis scores, histomorphometric analysis, tissue hydroxyproline, tissue MDA, GPx and SOD activities were determined. Activated stellate cells and hepatocellular apoptosis were also evaluated. RESULTS: The degree of f ibrosis decreased in all treatment groups compared to spontaneous recovery group. Taurine alone and in combination with peginterferon-alpha 2b reduced oxidative stress markers, but peginterferon-alpha 2b alone did not. Apoptotic hepatocytes and activated stellate cells were higher in groups 2-4 than in group 1. Combined taurine and peginterferon-alpha 2b further reduced fibros is and increased activated stellate cell apoptosis, but could not improve oxidative stress more than taurine alone. CONCLUSION: Peginterferon-alpha 2b exerts anti- f ibrotic effects on rat liver fibrosis. It seems ineffective against oxidative stress in vivo. combination with taurine seems to be an antif ibrotic strategy.