Active pharmaceutical ingredients and mechanisms underlying phasic myometrial contractions stimulated with the saponin extract from Paris polyphylla Sm. var. yunnanensis used for abnormal uterine bleeding

作者：Lin Guo, J. Su, Baojuan Deng, Zu‐Yin Yu, Liping Kang, Zuohui Zhao, Yajun Shan, J.P. Chen, B. Ma, Y.W. Cong · 发表于：Human Reproduction · 年份：2008 · DOI：10.1093/humrep/den001 · 被引用次数：64 · 研究领域：Phytochemical Studies and Bioactivities、Phytochemistry and Bioactive Compounds、Ion Transport and Channel Regulation

BACKGROUND: Total steroidal saponins of Paris polyphylla Sm. var. yunnanensis (TSSP) have been widely used in China for the treatment of abnormal uterine bleeding (AUB). But until now, the main active constituents and the mechanisms underlying the pharmacological actions on uterine activity have not been described. METHODS: Total steroidal saponins were extracted with EtOH and purified by chromatography. In vitro isometric contraction studies were performed using myometrial strips from estrogen-primed or pregnant rats. Intracellular calcium was monitored under a confocal microscope using Fluo-3 AM-loaded myometrial cells. RESULTS: TSSP dose-dependently induced phasic myometrial contractions in vitro. Experiments with calcium channel blockers or kinase inhibitors demonstrated that the TSSP-stimulated myometrial contraction was mediated by an increase in [Ca(2+)](i) via influx of extracellular calcium and release of intracellular calcium. Through bioassay-guided separation, it was found that total spirostanol saponins exhibited contractile activity in myometrium and Pennogenin-3-O-alpha-L-arabinofuranosyl(1-->4)[alpha-L-rhamnopyranosyl(1-->2)]-beta-D-glucopyranoside (PARG) was identified as the active ingredient of TSSP. Furthermore, the contractile response of rat myometrium to PARG was significantly enhanced with advancing pregnancy. CONCLUSIONS: These data provide evidence that myometrial contractility stimulated by TSSP results from [Ca(2+)](i) increase and supports the pos...