To determine the hepatoprotective effect of silymarin with Chang cell cultures. Specifically, to investigate the antioxidant properties of silymarin and its protective function in reducing pro-apoptotic markers.Intracellular free radical levels were assessed with dichlorofluorescein (DCF) fluorescence after exposing cells to an oxidative stress of 400 μmol/L H2O2 for 20 min. Levels of cellular ATP and bax expression were examined to evaluate the protective effects of silymarin.Silymarin significantly reduced the DCF fluorescence signal. Cell viability, assessed by the MTT assay, showed that silymarin enhanced the cell growth. Drug treatment was also associated with enhanced ATP levels, and reduced Bax and protein mRNA levels.Silymarin can function as a hepatoprotectant against free radical damage due to oxidative stress. The protective nature extends to reducing levels of pro-apoptotic Bax protein. Silymarin may be a useful adjuvant for the treatment of specific liver diseases.