Department of Biochemistry, Institute for Medical Sciences, Chonbuk National University Medical School, Jeonju, Korea.
J Breast Cancer. 2011 Mar;14(1):8-13. doi: 10.4048/jbc.2011.14.1.8. Epub 2011 Mar 31.
Chemotherapies for breast cancer generally have strong cellular cytotoxicity and severe side effects. Thus, significant emphasis has been placed on combinations of naturally occurring chemopreventive agents. Silibinin is a major bioactive flavonolignan extracted from milk thistle with chemopreventive activity in various organs including the skin, prostate, and breast. However, the mechanism underlying the inhibitory action of silibinin in breast cancer has not been completely elucidated. Therefore, we investigated the effect of silibinin in MCF-7 human breast cancer cells and determined whether silibinin enhances ultraviolet (UV) B-induced apoptosis.
The effects of silibinin on MCF-7 cell viability were determined using the MTT assay. The effect of silibinin on PARP cleavage, as the hallmark of apoptotic cell death, and p53 protein expression in MCF-7 cells was analyzed using Western blot. The effect of silibinin on UVB-induced apoptosis in MCF-7 cells was analyzed by flow cytometry.
A dose- and time-dependent reduction in viability was observed in MCF-7 cells treated with silibinin. Silibinin strongly induced apoptotic cell death in MCF-7 cells, and induction of apoptosis was associated with increased p53 expression. Moreover, silibinin enhanced UVB-induced apoptosis in MCF-7 cells.
Silibinin induced a loss of cell viability and apoptotic cell death in MCF-7 cells. Furthermore, the combination of silibinin and UVB resulted in an additive effect on apoptosis in MCF-7 cells. These results suggest that silibinin might be an important supplemental agent for treating patients with breast cancer.
乳腺癌的化疗药物通常具有较强的细胞细胞毒性和严重的副作用。因此，人们非常重视天然化学预防剂的组合。水飞蓟素是一种从奶蓟中提取的主要生物活性黄酮醇，具有预防各种器官（包括皮肤、前列腺和乳房）癌症的作用。然而，水飞蓟素在乳腺癌中的抑制作用的机制尚未完全阐明。因此，我们研究了水飞蓟素对 MCF-7 人乳腺癌细胞的影响，并确定水飞蓟素是否增强了紫外线（UV）B 诱导的细胞凋亡。
用 MTT 法测定水飞蓟素对 MCF-7 细胞活力的影响。用 Western blot 分析水飞蓟素对 MCF-7 细胞 PARP 切割（凋亡细胞死亡的标志）和 p53 蛋白表达的影响。用流式细胞术分析水飞蓟素对 MCF-7 细胞中 UVB 诱导的细胞凋亡的影响。
水飞蓟素处理 MCF-7 细胞后，细胞活力呈剂量和时间依赖性降低。水飞蓟素强烈诱导 MCF-7 细胞发生凋亡性细胞死亡，诱导的细胞凋亡与 p53 表达增加有关。此外，水飞蓟素增强了 MCF-7 细胞中 UVB 诱导的细胞凋亡。
水飞蓟素诱导 MCF-7 细胞丧失细胞活力和凋亡性细胞死亡。此外，水飞蓟素与 UVB 的联合作用对 MCF-7 细胞的凋亡具有相加作用。这些结果表明，水飞蓟素可能是治疗乳腺癌患者的重要辅助药物。
