| Background: Matrine and oxymatrine, the major components in Traditional Chinese medicine kuh-seng, are often used clinically in oncotherapy. However, the exactly underlying mechanism remains elusive. Lines of evidence have indicated that the dysregulated glucose metabolism plays an important role for the vigorous proliferation of tumor cells and has also proved to be the potential target for cancer therapy. Previous studies show that matrine treatment inhibits proliferation and induces cell differentiation and apoptosis in leukemia cells. In this study, the effects of matrine on glucose metabolism in human leukemia K562 cells were investigated.Objectives: 1. To determine the content of matrine in the cell lysate and the cell culture supernate in matrine-treated K562 cells. 2. To investigate the changes of pyruvate kinase (PK) activity in K562 cells incubated alone in the presence of matrine(M), oxymatrine(OM), the combination of M with OM (M&OM), kuh-seng alkaloids and Sophora flavescens extracts, respectively. 3. To investigate the changes of the amount of lactic acid in K562 cells exposed to the combination of M and OM.Methods: High pressure liquid chromatography (HPLC) was estabalished to measure the content of matrine in the cell lysate and the cell culture supernate in K562 cells exposed to matrine. The Pyruvate Kinase Assay Kit was used to detect PK activity in K562 cells incubated with the agents and the lysate of K562 cells treated directly by agents. HPLC was adopted to test the amount of lactic acid in K562 cells incubated with the combination of M with OM.Results: 1.The content of matrine in the culture supernate was found to be decreased to mearly 190μg/mL and 390μg/mL respectively in K562 cells exposed to 200μg/mL and 400μg/mL of matrine for 24 h.On the contrary, the content of matrine in the cell lysate increased slightly.2. The inhibition rate of PK activity in K562 cells in the presence of 200μg/mL or 400μg/mL of M, the same dose of OM, and the combination of M and OM (M& OM) for 6 days or 7 days (medium containg agent was changed after 3 days incubation) are shown below: (1) M 0.56±0.97%, 2.66±2.31%(3d+3d); 2.73±2.74%, 4.06±2.00%(3d+4d); (2) OM 1.35±0.66%, 3.11±1.30%(3d+3d); 1.56±0.73%, 4.31±2.47%(3d+4d); (3) M & OM 10.85±3.76%, 39.96 ±2.28%(3d +3d); 17.00±2.87%, 47.78±2.42%(3d+4) . The statistically significant difference was found in the combination group (P<0.01).3. PK activity was noticed to be down-regulated in a dose-dependent fashion after the lysate of K562 cells treated directly with kuh-seng alkaloids or Sophora flavescens extracts. The rate of inhibition increased from 21.64% and 43.57% to 88.07% and 94.10% in cells incubated with kuh-seng alkaloids and Sophora flavescens extracts at the doses of 0.4 mg/mL and 2.0 mg/mL respectively. No significant change of PK activity was observed in the lysate exposed to the agents including M, OM, and M&OM.4. The amount of lactic acid in K562 cells incubated with the combination of M with OM was maintained at the level of approximately 3.2μg/mL per 104 cells, which had no statistic significant difference compared to the untreated K562 cells.Conclusion: The content of matrine in K562 cells was increased and maintained at a stabe level in cells incubated with matrine for 24h. The treatment with combination of M and OM decreased the activity of PK in K562 cells. Kuh-seng alkaloids and Sophora flavescens extracts alone inhibited the activity of PK in the lysate of K562 cells in a dose-dependent pattern. No significant effect of the combination of M and OM on the production of lactate was observed in K562 cells. |
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