Improvement effects of a mixed extract of flowers of Pueraria thomsonii Benth. and peels of Citrus unshiu Markovich on postmenopausal symptoms of ovariectomized mice.

BACKGROUND: Menopausal hot flushes occur frequently in postmenopausal women. In the present study, we investigated a regulatory effect of a mixed extract of flowers of Pueraria thomsonii Benth. and peels of Citrus unshiu Markovich (PCE17), an extract of flowers of Pueraria thomsonii Benth. (PE), an extract of peels of Citrus unshiu Markovich (CE), a mixture of tectorigenin 7-O-xylosylglucoside, tectoridin, and tectorigenin (Tec, the active compounds of PE), and hesperidin (Hes, an active compound of CE) on menopausal hot flushes.

METHODS: We examined the anti-hot flushes properties of PCE17, PE, CE, Tec, or Hes using a mouse model of ovariectomy-induced hot flushes.

RESULTS: The ovariectomy-induced rise in the tail skin temperature was significantly prevented by PCE17, PE, CE, Tec, or Hes. PCE17, PE, CE, Tec, or Hes significantly enhanced 5-HT levels and attenuated RANKL levels in the hypothalamus of ovariectomized (OVX) mice. Treatment with PCE17, PE, CE, Tec, or Hes significantly enhanced the levels of estrogen receptor (ER)-β, 5-HT1A, 5-HT2A, and tryptophan hydroxylase mRNA expression in the hypothalamus of OVX mice. PCE17, PE, or CE decreased follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels, but did not increase estrogen levels in the serum of OVX mice. Tec or Hes decreased FSH or LH levels and increased estrogen levels. Treatment with PCE17, PE, CE, or Tec ameliorated vaginal atrophy in OVX mice. Finally, PCE17, PE, CE, Tec, or Hes significantly increased norepinephrine and dopamine levels in the hypothalamus of OVX mice.

CONCLUSION: Thus, these results imply that PCE17 has protective effects against hot flushes.