Hsu S L, Hsieh Y C, Hsieh W C, Chou C J
Department of Education and Research, Taichung Veterans General Hospital, No. 160, Section 3, Chung-Gang Road, 407, Taichung, Taiwan.
Eur J Pharmacol. 2001 Aug 17;425(3):165-71. doi: 10.1016/s0014-2999(01)01144-x.
Baicalein, a flavonoid present in the root of Scutellaria baicalensis Georgi, has been reported to inhibit cell proliferation in several types of cells. In this study, the effect of baicalein on cell growth and the mechanism of growth modulation were examined in primary cultured rat heart endothelial cells. Here, we report that treatment with 100-microM baicalein caused an almost complete inhibition of cell proliferation after 5 days of incubation. Baicalein mediated G1 and G2 growth arrest accompanied by the down-regulation of cyclin D2, cyclin A, cyclin-dependent kinase 1 (Cdk1) and cyclin-dependent kinase 2 (Cdk2), and up-regulation of p15(Ink4B), p21(CIP1/Waf1), p53 and cyclin E. Evaluation of the kinase activity of cyclin-Cdk complexes showed that baicalein decreased Cdk1, Cdk2, cyclin D2 and cyclin A expression in endothelial cells, leading to markedly reduced Cdk/cyclin-associated kinase activities. These results suggest that baicalein inhibits the proliferation of rat heart endothelial cells via G1 and G2 arrest in association with the down-regulation of the expression and function of Cdk1, Cdk2, cyclin D2 and cyclin A proteins, and up-regulation of cyclin E, p15(Ink4B), p53 and p21(CIP1/Waf1).
黄芩素是一种存在于黄芩根中的黄酮类化合物，据报道它能抑制多种类型细胞的增殖。在本研究中，我们检测了黄芩素对原代培养的大鼠心脏内皮细胞生长的影响及其生长调节机制。在此，我们报告，用100微摩尔的黄芩素处理5天后，细胞增殖几乎完全受到抑制。黄芩素介导G1期和G2期生长停滞，同时伴随着细胞周期蛋白D2、细胞周期蛋白A、细胞周期蛋白依赖性激酶1（Cdk1）和细胞周期蛋白依赖性激酶2（Cdk2）的下调，以及p15（Ink4B）、p21（CIP1/Waf1）、p53和细胞周期蛋白E的上调。对细胞周期蛋白-Cdk复合物激酶活性的评估表明，黄芩素降低了内皮细胞中Cdk1、Cdk2、细胞周期蛋白D2和细胞周期蛋白A的表达，导致Cdk/细胞周期蛋白相关激酶活性显著降低。这些结果表明，黄芩素通过G1期和G2期停滞抑制大鼠心脏内皮细胞的增殖，这与Cdk1、Cdk2、细胞周期蛋白D2和细胞周期蛋白A蛋白的表达和功能下调以及细胞周期蛋白E、p15（Ink4B）、p53和p21（CIP1/Waf1）的上调有关。
