洋葱提取物诱导人肝癌HepG2细胞凋亡及其分子机制研究

Apoptosis of HepG2 Cells Induced by Allium ascalonicum L. Extract and Its Mechanism

目的研究洋葱提取物对人肝癌HepG2细胞增殖和凋亡的影响及其机制。方法采用Alamar blue法检测洋葱提取物对HepG2细胞增殖的抑制作用;光学显微镜和Hoechst 33258荧光染色观察细胞的形态变化;流式细胞术分析其对HepG2细胞凋亡的影响;Western blot和Caspase 3活性检测试剂盒分析洋葱提取物诱导HepG2细胞凋亡的作用机制;Caspase 9抑制剂(Z-LEHD-FMK)验证相关的调控信号转导通路。结果洋葱提取物明显抑制HepG2细胞的增殖并且诱导其凋亡;下调HepG2细胞中Bcl-2和survivin的表达,上调Bax,Bad,Apaf-1,p53,Caspase 9的蛋白表达水平,同时Caspase 3酶活性显著提高;Z-LEHD-FMK能够逆转洋葱提取物对HepG2细胞增殖的抑制活性。结论洋葱提取物能够通过激活Caspase 9内源性凋亡信号通路而促进HepG2细胞凋亡。

OBJECTIVE To investigate the promotion of Allium ascalonicum L. extract （OE） on the apoptosis of human hepatic carcinoma cell line HepG2 and its mechanism. METHODS Alamar blue assay was used for detecting the influence of OE on the proliferation of HepG2. The morphological changes of cells were observed under inverted microscope and Hoechst 33258 stainning. The cell apoptosis were detected by flow cytometry. Western blot and Caspase 3 activity kit were used to detect the protein expression in HepG2 cells treated with OE. Z-LEHD-FMK was used to validate the signal transduction pathway. RESULTS OE inhibited the proliferation and induced the apoptosis of HepG2 cells in a dose-dependent manner. The expression of Bcl-2 and survivin was downreagulated in HepG2 cells treated with OE, and Bax, Bad, Apaf-1, p53 and Caspase 9 were upregulated. Besides, the Caspase 3 activity was significantly increased. Z-LEHD- FMK significantly inversed the cell viability of HepG2 cell inhibited by OE. CONCLUSION These results confirm that onion extract induces the apoptosis of HepG2 through mitochondria-mediated pathway.