Inhibitory effects of traditional Chinese herbal medicine Tanreqing injection on proliferation of leukemia cells in vitro and the potential mechanisms / 中西医结合学报

ABSTRACT

Objective: The present study investigates the effects of Tanreqing injection, a compound Chinese herbal medicine, on the proliferation of leukemia cells in vitro and discusses the potential mechanisms. Methods: Tanreqing injection was diluted to a series of concentrations (12, 14, 18, 116, 132, 164, 1128, 1256 and 1512) by volume and then independently applied to treat chronic myeloid leukemia K562 cells and T cell acute lymphocytic leukemia Molt4 cells at the proliferative stage. Cell growth was observed at different time intervals under a microscope. Cell proliferation was determined by cell counting kit-8 assay and the survival curve was delineated. The inhibitory rate and the half inhibitory concentration (IC50) were calculated. Molt4 cells were stained with propidium iodide (PI) and PI/Annexin V and then the cell cycle and apoptosis were analyzed by using flow cytometry. In addition, a real-time quantitative polymerase chain reaction was subjected to detect the expressions of apoptosis-related genes (bcl-2 and caspase-3) after Tanreqing treatment. Results: Tanreqing injection had inhibitory effects on the proliferation of K562 cells and Molt4 cells. The most toxic concentrations were observed between 12 and 116 where cells were almost necrotic. The inhibitory effect manifested in a concentration- and time-dependent manner. The IC50 of K562 and Molt4 was 1333 and 1142, respectively. After 132 Tanreqing injection treatment for 72 h, the number of Molt4 cells in the S phase significantly decreased (P<0.05), and the apoptosis rate markedly increased (P<0.05). In addition, increased caspase-3 expression and decreased bcl-2 expression were also observed (P<0.05). Conclusion: Tanreqing injection can both inhibit the proliferation and promote the apoptosis of leukemia cells in vitro, whereby the potential mechanism seems to be mediated in part by decreasing S phase ratio, down-regulating bcl-2 expression and up-regulating caspase-3 expression.