马鞭草总黄酮靶向拓扑异构酶Ⅱ诱导肝癌HepG-2细胞凋亡

摘要

Aim To explore whether total flavonoids of Verbena officinalis L(TFV)can induce apoptosis of HepG-2 cells through targeting topoisomerase Ⅱ.Methods HepG-2 cells were cultured with TFV at 200,100,50 mg·L-1.Cell apoptosis was evaluated by TUNEL-DAPI double staining.TopⅡ activity was detected by supercoiled pBR322 DNA relaxation assay.The levels of the mRNA of TOP Ⅱα,TOP Ⅱβ were analyzed by real time PCR.Expression of Bcl-2,Bax,TOP Ⅱα,TOP Ⅱβ and caspase-3 was analyzed by Western blot.%目的 探讨马鞭草总黄酮靶向拓扑异构酶诱导肝癌HepG-2细胞凋亡及机制.方法 采用质量浓度为50、100、200 mg·L-1的马鞭草总黄酮处理HepG-2细胞,TUNEL-DAPI双染色法检测HepG-2细胞凋亡;超螺旋pBR322 DNA松弛实验分析TopⅡ活性;Real time PCR法分析TOP Ⅱα、TOP Ⅱβ mRNA表达水平;Western blot法分析Bcl-2、Bax、TOP Ⅱα、TOP Ⅱβ和caspase-3蛋白表达水平.结果 质量浓度为50、100、200 mg·L-1的马鞭草总黄酮能促进HepG-2细胞凋亡(P<0.05),抑制TopⅡ的活性,降低TOP Ⅱα、TOP Ⅱβ mRNA表达水平(P<0.05);马鞭草总黄酮可通过抑制 Bcl-2、TOP Ⅱα、TOP Ⅱβ蛋白,增加Bax和caspase-3蛋白水平,诱导细胞凋亡(P<0.05).结论 马鞭草总黄酮抑制TopoⅡ活性是诱导HepG-2细胞凋亡的直接因素,并通过Bcl-2/Bax/caspase-3信号通路启动级联反应,是其体外抗肿瘤作用的重要分子机制.