Chiu Chiz-Hao, Chou Yu-Cheng, Lin Jing-Pin, Kuo Chao-Lin, Lu Hsu-Feng, Huang Yi-Ping, Yu Chien-Chih, Lin Meng-Liang, Chung Jing-Gung
* Departments of Biological Science and Technology, China Medical University, Taichung 404, Taiwan.
** Division of Neurosurgical Oncology, Neurological Institute, Taichung Veterans General Hospital, Taichung 407, Taiwan.
Am J Chin Med. 2015;43(7):1453-69. doi: 10.1142/S0192415X15500822. Epub 2015 Oct 18.
Solanum lyratum (SLEC) Thunberg (Solanaceae) has been used as a traditional herbal medicine in China for centuries. Numerous studies have shown that SLEC Thunberg (Solanaceae) extract inhibited cancer cell growth in vitro. Herein, we investigated cell death-induced by EcoAc, water, chloroform, butanol extract of SLEC in human oral cancer cell lines (HSC-3, SAS, and CAL-27) in vitro. Different SLEC extract induced cytotoxic effects in human oral cancer cells were examined by contrast phase microscopy. We selected the chloroform extract of SLEC to examine the cytotoxic effects by using DAPI staining, comet assays, flow cytometric assay, Western blotting and examination of confocal laser microscopy. SLEC decreased the percentage of viable cells, induced G0/G1 arrest and apoptosis. These effects were concentration- and time-dependent manners. SLEC increased protein levels of p21, p16, CDK2, and cyclin D1 in HSC-3, SAS, and CAL-27 cells. Also, SLEC increased CDK6 in HSC-3 and CAL-27 cells, but inhibited CDK6 in SAS cells. Cyclin E in HSC-3 and SAS cells was increased by SLEC, but it was inhibited in CAL-27 cells. SLEC suppressed the anti-apoptotic proteins Bcl-2 and Bcl-xl, but increased the pro-apoptotic proteins Bax and Bad in HSC-3, SAS, and CAL-27 cells. SLEC promoted the production of reactive oxygen species (ROS) and Ca²⁺, decreased the mitochondrial membrane potential (Δψm) and stimulated NO production in HSC-3, SAS, and CAL-27 cells. Specific caspase inhibitors (caspase-8 inhibitor: Z-IETD-FMK; caspase-9 inhibitor: Z-LEHD-FMK and caspase-3 inhibitor: Z-DEVD-FMK) for caspase-8, -9, and -3 blocked SLE-activated caspase-8, -9, and -3 activities which were associated with an increase in the percentage of viable cells. Taken together, SLE induced G0/G1 arrest and apoptosis via extrinsic- and intrinsic-dependent pathways in HSC-3, SAS, and CAL-27 cells.
白英（Solanum lyratum (SLEC) Thunberg）（茄科）在中国作为传统草药已使用了数百年。大量研究表明，白英（茄科）提取物在体外可抑制癌细胞生长。在此，我们研究了白英的乙酸乙酯、水、氯仿、正丁醇提取物在体外对人口腔癌细胞系（HSC-3、SAS和CAL-27）诱导的细胞死亡。通过相差显微镜检查不同白英提取物对人口腔癌细胞的细胞毒性作用。我们选择白英的氯仿提取物，通过使用DAPI染色、彗星试验、流式细胞术检测、蛋白质免疫印迹法以及共聚焦激光显微镜检查来检测其细胞毒性作用。白英降低了活细胞百分比，诱导G0/G1期阻滞和细胞凋亡。这些作用呈浓度和时间依赖性。白英增加了HSC-3、SAS和CAL-27细胞中p21、p16、CDK2和细胞周期蛋白D1的蛋白水平。此外，白英增加了HSC-3和CAL-27细胞中的CDK6，但抑制了SAS细胞中的CDK6。白英增加了HSC-3和SAS细胞中的细胞周期蛋白E，但在CAL-27细胞中受到抑制。白英抑制了抗凋亡蛋白Bcl-2和Bcl-xl，但增加了HSC-3、SAS和CAL-27细胞中促凋亡蛋白Bax和Bad。白英促进了活性氧（ROS）和Ca²⁺的产生，降低了线粒体膜电位（Δψm），并刺激了HSC-3、SAS和CAL-27细胞中一氧化氮的产生。针对半胱天冬酶-8、-9和-3的特异性半胱天冬酶抑制剂（半胱天冬酶-8抑制剂：Z-IETD-FMK；半胱天冬酶-9抑制剂：Z-LEHD-FMK和半胱天冬酶-3抑制剂：Z-DEVD-FMK）阻断了白英激活的半胱天冬酶-8、-9和-3活性，这与活细胞百分比增加有关。综上所述，白英通过外源性和内源性依赖途径在HSC-3、SAS和CAL-27细胞中诱导G0/G1期阻滞和细胞凋亡。
