AIM: To investigate the effects of herbal compound 861 (Cpd 861) on cell proliferation in human hepatic stellate cells (LX-2) and human hepatocellular liver carcinoma cells (HepG2), and expression of a-smooth muscle actin (alpha-SMA) in LX-2 cells. METHODS: LX-2 and HepG2 cells were incubated with various concentrations of Cpd 861 (0.1-0.003 mg/mL) for 1, 2, 3, 5 and 7 d. Cell proliferation was analyzed by 3-(4, 5-dimethylthiazol- 2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)- 2H-tetrazolium (MTS) assay. Effects of Cpd861 on the expression of alpha-SMA mRNA in LX-2 cells were measured by real-time quantitative PCR method using SYBR Green I technology. RESULTS: Cpd 861, at 0.1 mg/mL, significantly inhibited LX-2 cell proliferation (15% decrease relative to control, P<0.05) after 3 d of incubation. The inhibitory effects seemed to increase with the treatment time (25% decrease after 5 d of incubation and 35% decrease after 7 d of incubation, P<0.01). However, Cpd 861 did not affect HepG2 cell proliferation at the same concentration used for LX-2 cells. The expression levels of alpha-SMA mRNA decreased significantly when LX-2 cells were exposed to Cpd 861 for 48 h (59% decrease relative to control, P<0.05) or 72 h (60% decrease relative to control, P<0.01). CONCLUSION: Cpd 861 can significantly inhibit LX-2 cell proliferation in a dose-dependant manner, and reduce the expression levels of alpha-SMA mRNA in LX-2 cells. Since hepatic cell proliferation and high level of alpha-SMA are associated with liver fibrosis, the results suggest that Cpd 861 may be useful in the treatment of this disease.