title: Inhibitory effects of traditional Chinese herbal medicine Tanreqing injection on proliferation of leukemia cells in vitro and the potential mechanisms.
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 (1:2, 1:4, 1:8, 1:16, 1:32, 1:64, 1:128, 1:256 and 1:512) 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 1:2 and 1:16 where cells were almost necrotic. The inhibitory effect manifested in a concentration- and time-dependent manner. The IC50 of K562 and Molt4 was 1:333 and 1:142, respectively. After 1:32 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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Geriatric Hematology, Chinese PLA General Hospital, Beijing 100853, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
authors.forename: Xue-chun
authors.initials: XC
authors.lastname: Lu
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Hong-li
authors.initials: HL
authors.lastname: Zhu
mesh_terms: D053148:Caspase 3 / Q000378:metabolism; D045744:Cell Line, Tumor / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects*; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D006801:Humans; D007938:Leukemia / Q000473:pathology; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000473:pathology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism
chemical_list: D004365:Drugs, Chinese Herbal; D019253:Proto-Oncogene Proteins c-bcl-2; C540817:tanreqing; C505407:CASP3 protein, human; D053148:Caspase 3