Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, ROC.
Pharmacology. 2011;88(3-4):201-12. doi: 10.1159/000331864. Epub 2011 Oct 5.
The effect of the natural product thymol on cytosolic Ca(2+) concentrations (Ca(2+)) and viability in MG63 human osteosarcoma cells was examined.
The Ca(2+)-sensitive fluorescent dye fura-2 was applied to measure Ca(2+).
Thymol at concentrations of 200-1,000 μmol/l induced a Ca(2+) rise in a concentration-dependent fashion. The response was decreased partially by removal of extracellular Ca(2+). Thymol-induced Ca(2+) entry was inhibited by nifedipine, econazole, SK&F96365 and protein kinase C modulators. When extracellular Ca(2+) was removed, incubation with the endoplasmic reticulum Ca(2+) pump inhibitor thapsigargin or 2,5-di-tert-butylhydroquinone (BHQ) inhibited the thymol-induced Ca(2+) rise. Incubation with thymol also inhibited the thapsigargin or BHQ-induced Ca(2+) rise. Inhibition of phospholipase C with U73122 abolished the thymol-induced Ca(2+) rise. At concentrations of 100-600 μmol/l, thymol killed cells in a concentration-dependent manner. This cytotoxic effect was not changed by chelating cytosolic Ca(2+) with 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/AM. Annexin V/propidium iodide staining data suggest that thymol (200 and 400 μmol/l) induced apoptosis in a concentration-dependent manner. Thymol (200 and 400 μmol/l) also increased levels of reactive oxygen species.
In MG63 cells, thymol induced a Ca(2+) rise by inducing phospholipase C-dependent Ca(2+) release from the endoplasmic reticulum and Ca(2+) entry via protein kinase C-sensitive store-operated Ca(2+) channels. Thymol induced cell death that may involve apoptosis via mitochondrial pathways.
研究天然产物麝香草酚对 MG63 人骨肉瘤细胞胞浆游离钙离子浓度(Ca(2+))和活力的影响。
应用 Ca(2+)敏感荧光染料 fura-2 测量Ca(2+)。
麝香草酚浓度为 200-1000μmol/L 时呈浓度依赖性诱导Ca(2+)升高。去除细胞外 Ca(2+)可部分降低反应。尼非地平、依康唑、SK&F96365 和蛋白激酶 C 调节剂抑制麝香草酚诱导的 Ca(2+)内流。去除细胞外 Ca(2+)后，内质网 Ca(2+)泵抑制剂 thapsigargin 或 2,5-二叔丁基对苯二酚 (BHQ)孵育抑制麝香草酚诱导的Ca(2+)升高。麝香草酚孵育也抑制 thapsigargin 或 BHQ 诱导的Ca(2+)升高。U73122 抑制磷脂酶 C 可消除麝香草酚诱导的Ca(2+)升高。在 100-600μmol/L 浓度范围内，麝香草酚呈浓度依赖性杀伤细胞。用 1,2-双(2-氨基苯氧基)乙烷-N,N,N',N'-四乙酸/AM 螯合胞浆 Ca(2+)不改变其细胞毒性作用。 Annexin V/碘化丙啶染色数据表明，麝香草酚(200 和 400μmol/L)呈浓度依赖性诱导细胞凋亡。麝香草酚(200 和 400μmol/L)还增加活性氧水平。
在 MG63 细胞中，麝香草酚通过诱导蛋白激酶 C 敏感的储存操纵型 Ca(2+)通道介导的内质网 Ca(2+)释放和 Ca(2+)内流诱导Ca(2+)升高。麝香草酚诱导的细胞死亡可能涉及通过线粒体途径的细胞凋亡。
