METHODS: Eighteen post-weaning female Sprague Dawley rats were divided into the following groups: (i) a control group that received vehicle (distilled water and Tween 80); (ii) a group treated with 10 mg/kg body weight (BW) of Genistein (Gen 10); and (iii) a group treated with a higher dose of Genistein (Gen 100). The rats were treated daily for three weeks from postnatal day 22 (P22) to P42. After the animals were sacrificed, blood samples were collected, and the uteri and ovaries were harvested and subjected to light microscopy and immunohistochemical study.
RESULTS: A reduction of the mean weekly BW gain and organ weights (uteri and ovaries) were observed in the Gen 10 group compared to the control group; these findings were reversed in the Gen 100 group. Follicle stimulating hormone and estrogen levels were increased in the Gen 10 group and reduced in the Gen 100 group. Luteinizing hormone was reduced in both groups of Genistein-treated animals, and there was a significant difference between the Gen 10 and control groups (p<0.05). These findings were consistent with increased atretic follicular count, a decreased number of corpus luteum and down-regulation of estrogen receptors-a in the uterine tissues of the Genistein-treated animals compared to the control animals.
CONCLUSION: Post-weaning exposure to Genistein could affect the development of the reproductive system of ovarian-intact experimental rats because of its action on the hypothalamic-pituitary-gonadal axis by regulating hormones and estrogen receptors.
METHODS: Uteri from ovariectomized, female Sprague-Dawley rats receiving seven days estradiol, progesterone or genistein (25, 50 and 100mg/kg/day) were harvested and levels of AQP-1, 2, 5 and 7 proteins and mRNAs were determined by Western blotting and Real-time PCR (qPCR) respectively. Distribution of these proteins in uterus was observed by immunohistochemistry.
RESULTS: Genistein caused a dose-dependent increase in uterine AQP-1, 2, 5 and 7 protein and mRNA expression, however at the levels lower than following estradiol or progesterone stimulations. Effects of genistein were antagonized by estradiol receptor blocker, ICI 182780. Estradiol caused the highest AQP-2 protein and mRNA expression while progesterone caused the highest AQP-1, 5 and 7 protein and mRNA expression in uterus. AQP-1, 2, 5 and 7 protein were found to be distributed in the myometrium as well as in uterine luminal and glandular epithelia and endometrial blood vessels. In conclusion, the observed effects of estradiol, progesterone and genistein on uterine AQP-1, 2, 5 and 7 expression could help to explain the differences in the amount of fluid accumulated in the uterus under these different conditions.
Materials and Methods: All groups of hFOB 1.19 cells were induced with 12.5 μg/ml of BPA except the control (Ctrl) group. Meanwhile, treated groups received phytoestrogens; Daidzein (Dz), Genistein (Gt), Equol (Eq) and 17β-oestradiol (Est) in different concentrations for 24 hr duration.
Results: We found that the protein expression of non-classical oestrogen-related receptor (ERRG) was highly expressed in BPA group, whereas classical oestrogen receptor alpha (ERα) and oestrogen receptor beta (ERβ) were relatively increased with phytoestrogens treatment under BPA exposure. The dense actin cytoskeletal filaments were also observed. qRT-PCR showed up-regulation of mitogen-activated protein kinase 3 (MAPK3) and G protein-coupled receptor 30 (GPR30) expressions; significant down-regulation of ERRG and up-regulation of ERα and ERβ were observed in phytoestrogens-treated cells, which was supported by the increased expressions of oestrogen receptor 1 (ESR1) and oestrogen receptor 2 (ESR2).
Conclusion: Phytoestrogens improved the deteriorative effect of BPA via down-regulation of ERRG in hFOB 1.19 cells. This study showed that the efficacy of consumption of phytoestrogens in rendering them as potential therapeutic strategy in combating the adverse bone effects of BPA.