Division of Urology, Department of Surgery, Taichung Veterans General Hospital, Taichung 40705, Taiwan.
Department of Life Science, Tunghai University, Taichung 40704, Taiwan.
Eur J Pharmacol. 2018 Dec 5;840:79-88. doi: 10.1016/j.ejphar.2018.09.033. Epub 2018 Oct 1.
Escin (β-escin) is used as traditional folk medicine. The anti-tumour effects of escin have been demonstrated in vitro in certain cell lines, but its effect on bladder cancer has not been well investigated. In this study, the apoptotic activity of escin dissolved in dimethyl sulfoxide (DMSO) in bladder cancer cells and normal peripheral blood mononuclear cells (PBMC) and SV-HUC1 cells (controls) was determined. Cell cytotoxicity was assessed using the MTT assay. Cell cycle, Reactive oxygen species (ROS) generation, annexin V-FITC staining (for detecting early apoptosis), and changes in mitochondrial membrane potential were evaluated using flow cytometry. Expression of apoptosis-related proteins such as Fas (CD95) death receptor/FADD (Fas-associated protein with death domain) and BCL2 family of proteins was assessed using immunoblotting. Escin dose-dependently inhibited the growth of human bladder cancer cells, and showed IC of ~40 μM. The cell population in the sub-G1 phase, annexin-V staining, Fas expression, ratio of BAX/BCL2, cleavage of activated caspase-3/-8/-9, increase in poly (ADP-ribose) polymerase (PARP) levels, and suppression of nuclear factor kappa B (NF-κB) were observed after 24 h of escin treatment. Escin decreased mitochondrial membrane potential and increased cytochrome C release via generation of reactive oxygen species, which led to apoptosis of bladder cancer cells. Furthermore, escin effectively inhibited bladder tumour growth in a xenograft mouse model. Together, these results demonstrate that escin induces apoptosis in human bladder cancer cells through the Fas death receptor and mitochondrial pathways and inhibits bladder tumour growth. Escin is a potential chemotherapeutic agent for bladder cancer.
七叶皂苷（β-七叶皂苷）被用作传统的民间药物。七叶皂苷在某些细胞系中的体外抗肿瘤作用已得到证实，但对膀胱癌的作用尚未得到很好的研究。在这项研究中，确定了溶解在二甲基亚砜（DMSO）中的七叶皂苷在膀胱癌细胞和正常外周血单核细胞（PBMC）和 SV-HUC1 细胞（对照）中的凋亡活性。使用 MTT 测定法评估细胞细胞毒性。通过流式细胞术评估细胞周期、活性氧（ROS）的产生、膜联蛋白 V-FITC 染色（用于检测早期凋亡）以及线粒体膜电位的变化。使用免疫印迹法评估凋亡相关蛋白（如 Fas（CD95）死亡受体/FADD（Fas 相关死亡结构域蛋白）和 BCL2 家族蛋白）的表达。七叶皂苷浓度依赖性地抑制人膀胱癌细胞的生长，IC 约为 40µM。在 escin 处理 24 小时后，观察到细胞群体进入 sub-G1 期、膜联蛋白 V 染色、Fas 表达、BAX/BCL2 比值、激活的 caspase-3/-8/-9 的切割、多聚（ADP-核糖）聚合酶（PARP）水平的增加和核因子 kappa B（NF-κB）的抑制。Escin 通过生成活性氧来降低线粒体膜电位并增加细胞色素 C 释放，从而导致膀胱癌细胞凋亡。此外，Escin 可有效抑制异种移植小鼠模型中的膀胱癌肿瘤生长。总之，这些结果表明，Escin 通过 Fas 死亡受体和线粒体途径诱导人膀胱癌细胞凋亡，并抑制膀胱癌肿瘤生长。Escin 是膀胱癌的一种潜在化疗药物。
