木犀草素对人肝癌细胞HepG2的促凋亡作用

目的：研究木犀草素（Luteolin）对人肝癌细胞HepG2的生长抑制与促凋亡作用机制。 方法：用梯度浓度木犀草素作用于多种肿瘤细胞，以MTT法检测药物对细胞的生长抑制作用，以流式细胞术检测HepG2细胞内活性氧水平，以Annexin V-FITC/PI双染法利用流式细胞术检测HepG2细胞凋亡情况，以Western-blot检测HepG2细胞凋亡相关通路蛋白表达水平。 结果：木犀草素对多种肿瘤细胞的生长具有浓度和时间依赖的抑制作用（72 h最高抑制率超过60%），并能有效降低HepG2细胞内活性氧水平（约降低41.11%）。木犀草素作用下HepG2细胞凋亡率可达14.43%左右。木犀草素能够降低HepG2细胞内iASPP蛋白表达水平并上调p53与ASPP2蛋白表达。 结论：木犀草素能够抑制肿瘤细胞生长，降低HepG2细胞内活性氧水平，并调节细胞内相关凋亡通路蛋白水平，从而诱导HepG2细胞凋亡。

Pro-apoptotic effects of luteolin on hepatoma HepG2 cells

Objective： To investigate the effect of luteolin on cell growth and apoptosis of HepG2 cells in vitro. Methods： Cultured HepG2，HL60，A549 and LO2 cells were treated with luteolin for different doses (0 μg/ml，2.5 μg/ml，10 μg/ml and 20 μg/ml) and varied times (0 h，24 h，48 h and 72 h).Cell viability was measured with MTT assay and IC50 was calculated.The reactive oxygen species (ROS) levels in HepG2 cells treated with luteolin for 6 h and 12 h were measured with flow cytometry.Cell apoptosis of HepG2 cells treated with luteolin for 24h was examined with flow cytometry and Annexin V-FITC/PI.Expression levels of apoptosis pathway proteins (p53，ASPP2 and iASPP) in HepG2 cells were detected with western blot and the dose and time-effect was analyzed. Results： Luteolin effectively inhibited tumor cell proliferation in a dose- and time-dependent manner，and the inhibition rates of 20μg/ml Luteolin for 72h were 39.34%，62.90%，57.57% and 62.90% to LO2，HepG2，HL60 and A549 cells，respectively.The intracellular ROS level was decreased in HepG2 cells by 13.88% and 41.11% after being treated with luteolin for 6 h and 12 h，respectively.The apoptosis rate of HepG2 cells treated with luteolin for 24 h was 14.43%，and western blot showed that luteolin reduced the expression level of iASPP by 77.07% and up-regulated the expression of p53 by 179.37% and ASPP2 by 725.02% in HepG2 cells treated with luteolin for 12 h. Conclusion： Luteolin has anti-proliferative and pro-apoptotic activity on hepatoma HepG2 cells，which is associated with the altered expression of pro-apoptotic factors and decreased ROS level in HepG2 cells.