Functions of Danggui Buxue Tang, a Chinese Herbal Decoction Containing Astragali Radix and Angelicae Sinensis Radix, in Uterus and Liver are Both Estrogen Receptor-Dependent and -Independent

Danggui Buxue Tang (DBT), a herbal decoction containing Astragali Radix (AR) and Angelicae Sinensis Radix (ASR), has been used in treating menopausal irregularity in women for more than 800 years in China. Pharmacological results showed that DBT exhibited significant estrogenic properties in vitro, which therefore suggested that DBT could activate the nuclear estrogen receptors. Here, we assessed the estrogenic properties of DBT in an ovariectomized in vivo rat model: DBT was applied to the ovariectomized rats for 3 days. The application of DBT did not alter the weight of uterus and liver, as well as the transcript expression of the proliferation markers including the estrogen receptors α and β. However, DBT stimulated the transcript expression of the estrogen responsive genes. In addition, the inductive role of DBT on the expression of members of the aryl hydrocarbon receptor family in uterus and liver of ovariectomized rats was confirmed. These responses of DBT however were clearly distinct from the response pattern detectable here for 17β-estradiol. Therefore, DBT exhibited weak, but significant, estrogenic properties in vivo; however, some of its activities were independent of the estrogen receptor. Thus, DBT could be an exciting Chinese herbal decoction for an alternative treatment of hormone replacement therapy for women in menopause without subsequent estrogenic side effects.