Tan Tzu-Wei, Tsai Hsin-Ru, Lu Hsu-Feng, Lin Hui-Lu, Tsou Mei-Fen, Lin Yuh-Tzy, Tsai Huei-Yann, Chen Yuh-Fung, Chung Jing-Gung
Department of Pharmacology, China Medical University, Taichung 404, ROC.
Anticancer Res. 2006 Nov-Dec;26(6B):4361-71.
Curcumin (diferuloylmethane), is a natural product derived from the root of the plant Curcuma longa. For centuries, it has been used as a spice and as a herbal medicine in Chinese populations. Curcumin has been shown to inhibit cell proliferation, cell cycle arrest, cyclooxygenase (COX)-1 and -2 expression and apoptosis in several human cancer cell lines. The aim of this investigation was to clarify the mechanisms by which curcumin induced cytotoxicity and apoptosis in human leukemia HL-60 cells. The effects of curcumin on the levels of reactive oxygen species (ROS), Ca+2 production, cyclin E, cdc25c, wee1, Bcl-2, Bax, the changes of mitochondrial membrane potential (MMP), cytochrome c release and the activation of caspase-3 were also investigated in the HL-60 cells. Results of flow cytometry and DAPI staining assays indicated that curcumin induced cytotoxicity and apoptosis in the examined cells. The results from flow cytometry assay indicated that curcumin induced ROS and Ca+2 productions, decreased the levels of MMP and increased the activity of caspase-3, leading to cell apoptosis. Western blot assay also revealed that curcumin increased the levels of Bax and the release of cytochrome c, and decreased the levels of Bcl-2 in the examined cells. The inhibition of caspase-3 activation by z-VAD-fmk (broad-spectrum caspase inhibitor) completely blocked curcumin-induced apoptosis in HL-60 cells.
姜黄素（二阿魏酰甲烷）是一种从姜黄属植物姜黄的根中提取的天然产物。几个世纪以来，它在中国人群中一直被用作香料和草药。姜黄素已被证明在多种人类癌细胞系中可抑制细胞增殖、诱导细胞周期停滞、抑制环氧化酶（COX）-1和-2的表达以及诱导细胞凋亡。本研究的目的是阐明姜黄素诱导人白血病HL-60细胞产生细胞毒性和凋亡的机制。同时，还研究了姜黄素对HL-60细胞中活性氧（ROS）水平、Ca+2产生、细胞周期蛋白E、细胞周期蛋白依赖性激酶25C（cdc25c）、wee1、Bcl-2、Bax、线粒体膜电位（MMP）变化、细胞色素c释放以及半胱天冬酶-3激活的影响。流式细胞术和4',6-二脒基-2-苯基吲哚（DAPI）染色分析结果表明，姜黄素在受试细胞中诱导了细胞毒性和凋亡。流式细胞术分析结果表明，姜黄素诱导了ROS和Ca+2的产生，降低了MMP水平并增加了半胱天冬酶-3的活性，从而导致细胞凋亡。蛋白质免疫印迹分析还显示，姜黄素增加了受试细胞中Bax的水平和细胞色素c的释放，并降低了Bcl-2的水平。z-VAD-fmk（广谱半胱天冬酶抑制剂）对半胱天冬酶-3激活的抑制作用完全阻断了姜黄素诱导的HL-60细胞凋亡。
