Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
Molecules. 2012 Sep 11;17(9):10916-27. doi: 10.3390/molecules170910916.
The water extract of Gracilaria tenuistipitata have been found to be protective against oxidative stress-induced cellular DNA damage, but the biological function of the ethanolic extracts of G. tenuistipitata (EEGT) is still unknown. In this study, the effect of EEGT on oral squamous cell cancer (OSCC) Ca9-22 cell line was examined in terms of the cell proliferation and oxidative stress responses. The cell viability of EEGT-treated OSCC cells was significantly reduced in a dose-response manner (p < 0.0001). The annexin V intensity and pan-caspase activity of EEGT-treated OSCC cells were significantly increased in a dose-response manner (p < 0.05 to 0.0001). EEGT significantly increased the reactive oxygen species (ROS) level (p < 0.0001) and decreased the glutathione (GSH) level (p < 0.01) in a dose-response manner. The mitochondrial membrane potential (MMP) of EEGT-treated OSCC cells was significantly decreased in a dose-response manner (p < 0.005). In conclusion, we have demonstrated that EEGT induced the growth inhibition and apoptosis of OSCC cells, which was accompanied by ROS increase, GSH depletion, caspase activation, and mitochondrial depolarization. Therefore, EEGT may have potent antitumor effect against oral cancer cells.
石莼水提物已被发现具有对抗氧化应激诱导的细胞 DNA 损伤的保护作用，但石莼（Gracilaria tenuistipitata）的乙醇提取物（EEGT）的生物学功能仍不清楚。在这项研究中，考察了 EEGT 对口腔鳞状细胞癌（OSCC）Ca9-22 细胞系在细胞增殖和氧化应激反应方面的影响。EEGT 处理的 OSCC 细胞的细胞活力呈剂量依赖性显著降低（p<0.0001）。EEGT 处理的 OSCC 细胞的 Annexin V 强度和全半胱天冬酶活性呈剂量依赖性显著增加（p<0.05 至 0.0001）。EEGT 以剂量依赖性方式显著增加活性氧（ROS）水平（p<0.0001）并降低谷胱甘肽（GSH）水平（p<0.01）。EEGT 处理的 OSCC 细胞的线粒体膜电位（MMP）呈剂量依赖性显著降低（p<0.005）。总之，我们已经证明 EEGT 诱导 OSCC 细胞的生长抑制和凋亡，伴随着 ROS 增加、GSH 耗竭、半胱天冬酶激活和线粒体去极化。因此，EEGT 可能对口腔癌细胞具有有效的抗肿瘤作用。
