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)-ß, 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.

Soybean ascorbate peroxidase suppresses Bax-induced apoptosis in yeast by inhibiting oxygen radical generation.

Bax, a mammalian proapoptotic member of the Bcl-2 family, can induce cell death when expressed in yeast or plant cells. To identify plant Bax inhibitors, we cotransformed a soybean cDNA library and the Bax gene into yeast cells and screened for expressed genes that prevented Bax-induced apoptosis. From the Bax-inhibiting genes isolated, ascorbate peroxidase (sAPX) was selected for characterization. The transcription of sAPX in plants was specifically induced by oxidative stress. Moreover, overexpression of sAPX partially suppressed the H(2)O(2)-sensitive phenotype of yeast cytosolic catalase T (Deltactt)- and thermosensitive phenotype of cytochrome c peroxidase (Deltaccp)-deleted mutant cells. Examination of reactive oxygen species (ROS) production using the fluorescence method of dihydrorhodamine 123 oxidation revealed that expression of Bax in yeast cells generated ROS, which was greatly reduced by coexpression with sAPX. Our results collectively suggest that sAPX inhibits the generation of ROS by Bax, which in turn suppresses Bax-induced cell death in yeast.