Reversion Of P-glycoprotein-mediated Multidrug Resistance In Human Leukemic Cell Line By Active Compounds Of ALK From Ginseng Herb In Vitro

Objective To investigate the suppression effects of proliferation and its mechanism on anti-leukemia initiated by active compounds of ALK extracted and isolated from Ginseng herb in human myloid leukemic cell lines K562/ADM with stable MDR phenotype resistance to doxorubicin in vitro.Methods Human leukemia cell line K562 and the Adriamycin(ADR)induced a stable MDR phenotype doxorubicin resistant cell lines K562/ADM were used for the study.Verapamil(VRP)was selected as a positive control drug.Inhibition of cell proliferation of K562 and K562/ADM was measured by MTT assay and semi-solid agar.The changes in ICso were analyzed with the non-cytotoxic dose effect of ALK.Intracellular accumulation of doxorubicin was analyzed by flow cytometry.Gene expression of mdr-1 in drug resistance was detected by RT-PCR.P-gp protein was measured by Western blot and immunocytochemistry method.Results ? ALK within the concentration ranged from 20 mg/L to 100mg/L inhibited the cell proliferation of K562,K562/ADM.,and the inhibition rate ranged from 4.59± 0.09%to 60.5±0.05%;IC50 of K562,K562/ADM cells under ADR was decreased by ALK in 20mg/L and 40mg/L compared to control cells(0.28±0.05,0.12±0.04 vs 2.11± 0.04,P<0.05).The time-and concentration-dependent reversal effects of ALK on the K562/ADM cells were observed for 24,48,and 72 h.The higher the concentration of ALK used,the better the inhibitive effect.?The intracellular concentration of doxorubicin increased from 1.47 ±0.21%to 99.2± 0.09%after 48h.? Expression levels of mdr-1 gene and P-g protein were decreased by ALK,the difference was statistically significant(P<0.01).Conclusions The present study has demonstrated that ALK can serve as a novel,non-toxic modulator of MDR and can reverse the MDR of K562/ADM cells in vitro by increasing intracellular adriamycin concentration,downregulating the expression of mdr-land P-gp protein,which produces the chemotherapy sensitivity of K562/ADM cells.ALK could be a highly feasible candidate for the development of a new MDR reversal agent.Our results above provide the very value of experimental evidence for deep exploration and application in the treatment of patients with myloid leukemia in the future.