The Effects Of Scutellaria Barbata Extract On The Proliferation And Apoptosis Of Leukemia K562 Cell And The Research Of Relative Mechanism

Objective To investigate the effects of Scutellaria Barbata Extract(SBE) in the proliferation of K562 cells and its apoptosis. And to investigate the effects of VEGF and VEGFR-1 of K562 cell.Methods The K562 cell was cultured in RPMI1640 at different concentration of SBE (0mg/ml,0.1mg/ml,0.2mg/ml,0.5mg/ml,1.0mg/ml) and harvested in 24h,48h,72h. The K562 cell morphology was assayed by inverted microscope; The K562 cell proliferating activity was assessed by MTT assay; The cell apoptosis was examined by flow cytometer (FCM); The expression of VEGFmRNA and VEGFR-1mRNA of K562 was examined by reverse translation-polymerase chain reaction(RT-PCR); The concentration of VEGF was measured by enzyme-linked immunosorbent(ELISA).Results 1. Inverted microscope displayed that with the concentration of SBE increased, the number of K562 cells reduced, but the number of K562 cell debris increased, and K562 cells showed morphological changes of apoptosis such as nuclear fragmentation.2. SBE can inhibit the proliferation of K562 in a dose and time-dependent. After treatment with 0.1mg/ml of SBE for 24h, the inhibition of proliferation of K562 cells was not obviously, Compared with the blank-control group has no statistical significance (p>0.05), But then at the concentration of SBE 0.5mg/ml, interfered K562 cells 24h, the inhibition of proliferation of K562 cells became obviously. Compared with the blank-control group has statistical significance (p<0.05).3. FCM showed that SBE can make the cycle distribution of K562 cell change, with the SBE concentration increased, the counts of K562 cells in the G0/G1 phase of cells increased, while the counts in the S and G2/M phase of cells decreased, compared with the blank-control group and each experiment group, there are significant differences(p<0.05); And FCM also displayed that the apoptosis rate of K562 cells increased in a dose and time-dependent.4. After treatment with SBE for 48h, the expression of VEGFmRNA and VEGFR-1mRNA of K562 cells decreased, the grayscale ratio of Target gene/β-actin declined gradually with dose-dependent, compared between different groups have significant differences(p<0.05).5. ELISA displayed that the concentration of VEGF in K562 cells at blank-control group is 996.78±14.76pg/ml, then after intervention 48h by SBE0.1mg/ml,0.2mg/ml, 0.5mg/ml, 1.0mg/ml, the concentration of VEGF decreased to 760.30±9.47pg/ml, 709.69±11.23pg/ml,549.46±8.63pg/ml,452.78±13.59pg/ml respectively. compared between different groups have significant differences(p<0.05).Conclution Scutellaria Barbata Extract can inhibit the proliferation of the K562 cell, and block the G1/G0 phase of the cell, induce its apoptosis in a dose-dependent(0.1-1.0mg/ml) and time-dependent(24h-72h). And the mechanism of its action may have relation with reduced the concentration of VEGF of K562 cells and decreased the expression of VEGFmRNA and VEGFR-1mRNA.