The Effects And Mechanisms Of Glycyrrhetic Acid On The Proliferate Activity In K562 Leukemic Cells

Object To investigate the effects of glycyrrhetic acid (GA) on the proliferate acitivity in K562 leukemic cells in vitro, and explore the possible mechanisms.Methods Cell proliferate activity was detected by MTT assay. Hoechst 33258 staining was used to evaluate the morphological changes in K562 cells induced by GA. The influence on cell cycle was studied by a propidium iodide method. Both flow cytometry (FCM) and RT-PCR technologies were applied to assess the expression of cyclin D1 and cyclin E proteins.Results GA presented the striking proliferation inhibition, as well as apoptosis induction potency on K562 cells in vitro in a time- and dose-dependent manner, with IC50 value for 48 h being (93.1±3.7)μmol/L. Moreover, cells treated with GA showed accumulation in G0/G1 phase, reduction in the percentage of cells in G2/M phase and significant change in S phase in groups with middle and maxium concentration of GA. The contents of cyclin D1 and cyclinE were found to be downregulated at both protein and gene levels in K562 cells in a dose-dependent manner when treated with various concentrations of GA.Conclusions GA presents the potent inhibition on proliferation of K562, induction on apoptosis, and cell-cycle arrest in leukemia cells in G0/G1 phase, which might correspond to the down regulation of the expression of cyclinD1 and cyclin E. GA, as a Chinese materia medica, indicates a potential for acute leukemia.