Objective:To study the effects of triptolide on proliferation and apoptosis of human hepatocytes(L-02 cells)

providing experimental basis for the clinical application of triptolide in treatment of liver diseases and the prevention of its liver toxicity. Method: Culture L-02 cells in vitro and treat the L-02 cells with 10

30

50 nmol·L-1 triptolide respectively for 48 h. Detect the cellular growth and proliferation using trypan blue staining and Brdu incorporation

detect cell cycle distribution using PI staining

detect the percentage of cellular apoptosis using AV/PI double staining

detect the expression levels of p21 and p53 using western blot analysis. Result: Compared with the control

after treated with 10

30

50 nmol·L-1 triptolide

the cell number was reduced from (2.72±1.14)×105 cells/mL to (1.95±0.38)×105

(1.44±0.44)×105

(6.97±0.47)×104 cells/mL respectively;the percentage of Brdu positive cells was reduced from (7.67±0.51)% to (5.67±0.29)%

(4.05±0.14)%

(2.51±0.15)% respectively;the percentage of cells arrested in G1 stage was increased from 65.39% to 68.47%

71.19%

83.98% respectively;the percentage of apoptotic cells was increased from (20.54±1.44)% to (28.02±0.93)%

(36.79±0.49)%

(43.35±1.12)% respectively; the expression level of p21 and p53 protein were both up-regulated

and showed a dose-effect relationship. Conclusion: Triptolide could inhibit L-02 cells proliferation through up-regulation of p21 expression thus arresting cells in G1 stage

and induce cellular apoptosis through up-regulation of p53 expression in L-02 cells.