Effects of Aqueous Extracts of Cynanchum wilfordii in Rat Models for Postmenopausal Hot Flush

Menopausal hot flushes (HFs), which manifest as a transient increase in skin temperature, occur most frequently in postmenopausal women, and sometimes negatively influence daily life. We investigated the effect of an aqueous extract of Cynanchum wilfordii (CWW) in a rat model of menopausal HFs, where tail skin temperature (TST) is increased after the rapid estrogen decline induced by ovariectomy. Ten-week-old female rats were ovariectomized and treated with CWW for 1 week. We measured TST and rectal temperatures (RT) and investigated serum estradiol. The TST in ovariectomized (OVX) rats was significantly elevated after ovariectomy compared with control rats, whereas the RT in OVX rats was not elevated. Administration of CWW (200 mg/kg/d for 7 days, p.o.) significantly improved the skin temperature increase in OVX rats. The lower level of serum estradiol in OVX rats was significantly increased by supplying E2, but it was not affected by CWW. The present study indicates a need for future research involving treatment with high concentrations of C. wilfordii and measurement over 24 h.