Effects of total flavonoids of Epimedium sagittatum on the mRNA expression of the estrogen receptor α and β in hypothalamus and hippocampus in ovariectomized rats.

OBJECTIVE

To explore the effect of total flavonoids of Epimedium sagittatum (TFE) on the mRNA expressions of the estrogen receptor alpha (ERα) and estrogen receptor beta(ERβ) in hippocampus and hypothalamus in ovariectomized (OVX) Sprague-Dawley(SD) rats, and the mechanism of TFE against postmenopausal osteoporosis.

METHODS

Forty-eight female SD rats,aged 10-11 months old, were randomly divided into 4 groups: a sham group, an ovariectomy group (rats were bilaterally ovariectomized), a TFE group, and a 17β-estradiol group (rats were fed with TFE and 17β-estradiol for 4 months, respectively). The RT-PCR was performed to determine the mRNA expression of ERα and ERβ in hypothalamus and hippocampus.

RESULTS

Serum estradiol level, bone mineral density (BMD) of vertebra,wet weight of uterus, and the mRNA expressions of ERα and ERβ in hypothalamus and hippocampus were markedly decreased in OVX rats, all of which were reversed by 17β-estradiol treatment except the mRNA expression of ERβ. Similar results were achieved by TFE treatment except the wet weight of uterus.

CONCLUSION

TFE can improve BMD of vertebra in the OVX rats without side effects on the uterus. The mechanism may be related to increasing the mRNA expressions of ERα and ERβ in hypothalamus and hippocampus.