构树叶总黄酮对人肝癌HepG-2细胞增殖及其细胞周期的影响

目的： 研究构树叶总黄酮（total flavonoids of Broussonetia papyrifera，TFBP）对人肝癌细胞HepG-2的生长抑制和诱导凋亡的作用及其机制。 方法： 取对数生长期人肝癌HepG-2细胞，随机分为药物组和对照组，药物组用3，6，9，12 g·L^-1不同质量浓度TFBP作用人肝癌HepG-2细胞24，48，72 h后，采用MTT法检测细胞生长抑制率；Hoechst 33342荧光染色法荧光显微镜观察细胞的形态变化并用流式细胞仪检测细胞的周期及细胞凋亡率。 结果： MTT结果显示，各质量浓度3，6，9，12 g·L^-1的TFBP对HepG-2有增殖抑制作用，并存在浓度和时间依赖关系，3，6，9，12 g·L^-1不同质量浓度TFBP作用人肝癌HepG-2细48 h后，细胞增殖抑制率分别为20.2%，29.44%，39.21%，43.96%；9 g·L^-1的TFBP作用HepG-2细胞72 h后，细胞增殖抑制率可达52.46%，与对照组具有显著性差异（P<0.05）；Hoechst 33342荧光染色可观察到核浓缩及核碎裂等典型细胞凋亡特征及凋亡小体；流式细胞仪结果显示，随着TFBP作用浓度的增加，加药组细胞凋亡率加药组凋亡率与对照组相，有显著差异（P < 0.01），G₀/G₁期细胞逐渐减少，G₂/M期细胞数逐渐增多，与对照组比较差异有显著性（P < 0.05），细胞周期被阻滞在G₂/M期。 结论： TFBP在体外对肝癌细胞HepG-2有明显的增殖抑制和诱导细胞凋亡的作用，其抑制机制可能和诱导细胞凋亡与阻滞细胞周期有关。

Effect of Total Flavonoids of Broussonetia papyrifera on Proliferation and Cell Cycle of Human Hepatocellular Carcinoma Cell Line HepG-2

Objective: The total flavonoids of Broussonetia papyrifera(L.) Vent(TFBP) was investigated for its antitumor activity and induction of apoptosis in human hepatocellular carcinoma cell line HepG-2 in vitro. Method: The HepG-2 cells in logarithmic phase of growth were randomly divided into drug group and control group, with the concentration of 3,6,9,12 g·L^-1 TFBP in hepatocellular carcinoma HepG-2 cells. The intervention durations was 24,48,72 h accordingly, the viability of HepG-2 cells was measured by MTT. Morphology of cell apoptosis was observed by Hoechst 33342 fluorescence staining. The cell cycle and cell apoptosis rate were detected by flow cytometry. Result: TFBP could inhibit the growth of cells and cause apoptosis significantly.The suppression was in a time-and dose-dependent manner,HepG-2 cells were treated with TFBP of 3,6,9,12 g·L^-1 concentrations, the inhibition rates were 20.2%,29.44%,39.21%,43.96% at 48 h. When HepG-2 cells were treated with the concentration of 9 g·L^-1 TFBP, the inhibition rate could be achieved 52.46% at 72 h, there was a significant difference compared with control group (P < 0.05) The typical apoptosis characteristics such as nuclear fragmentation and apoptotic body could be observed under the fluorescence microscope.In the same time, with the increase of drug concentration, cell apoptosis rate increased significantly(P<0.01).TFBP could reduce the cell population in G₁/G₀ phase and increase the cell population in G₂/M phase significantly (P < 0.05).TFBP could induce a G₂/M cell cycle arrest. Conclusion: TFBP has apparent inhibition and apoptosis-inducing effect on HepG-2 cells. TFBP may induce apoptosis and induce a G₂/M cell cycle arrest.