Effects of pueraria mirifica, phytoestrogens and 17β-estradiol on growth and expression of ERα in primary culture of porcine endometrial epithelial cells

Abstract

Pueraria mirifica (PM) and its contents of phytoestrogens have estrogenic effects in animal model studies and cell-specific system. However, no evidence of their effects on normal endometrial epithelial cells has been established. This study was to examine the effect of PM, genistein (Ge), diadzein (Di) and estrogen (E2) on the growth of estrogen receptor (ER) and on expression of porcine endometrial epithelial cell (PE cells) for 24, 48 and 72 h. The PE cell number as determined by MTT colorimetric assay was significantly decreased when treated with 10-4 M of Ge, Di and E2, but not PM. However, only at 10-7 M of PM was it found to decrease the cell number following 24 h treatment. The protein analysis of PE cells by Western blot revealed the expression of ERα, but not ERβ. E2 or PM treatment at 10-4 M for 72 h decreased the ratio of ERα/β-actin whereas Ge at the same concentration increased this ratio. The down-regulation of ERα by E2 and PM suggests the same regulatory effect and may be a relevant mechanism of the anti-proliferative effect at high concentration. On the other hand, the over-expression of ERα with anti-proliferative effect by Ge suggests a different mechanism on regulation of endometrial proliferation.