Objective:To study the hepato-protective activity of glycyrrhizin

liquiritin and isoliquritigenin on a new HL-7702 cells injury model induced by acetaminophen.Method:HL-7702 cells injury induced by 20 mmol·L-1 acetaminophen for 3 hours were chosen as the liver cells injury model and the effect of glycyrrhizin

liquiritin and isoliquritigenin was assayed.The main index was MTT.Result:The new HL-7702 cells injury model induced by acetaminophen was successful.Glycyrrhizin

liquiritin and isoliquiritigenin had hepato-protective activity on the cell model.The minimum effective concentration of glycyrrhizin was 0.001 6 μmol·L-1.The hepato-protective maximum efficacy of glycyrrhizin was 47.0% at the concentration of 0.2 μmol·L-1.The minimum effective concentration of liquiritin was 0.4 μmol·L-1.The hepato-protective maximum efficacy of liquiritin was 22.9 % at the concentration of 2 μmol·L-1.The minimum effective concentration of isoliquritigenin was 0.4 μmol·L-1.The hepato-protective maximum efficacy of isoliquritigenin was 72.6%at the concentration of 250 μmol·L-1.Conclusion:The new HL-7702 cells injury model induced by acetaminophen could be applied on studying the hepato-protective effect of drugs.The hepato-protective activity of licorice has connection with not only glycyrrhizin

liquiritin but also isoliquritigenin.Therefore

it is not enough to treat glycyrrhizin

liquiritin as the quality evaluation index for licorice.