RESUMEN
The estrogenic and antiestrogenic activities of Epimedii Herba, which is a traditional medicinal herb used in Korea and China were investigated in this study. The in vitro estrogen receptor (ER) mediated estrogenic/antiestrogenic activities of an Epimedii Herba extract (Epi ext) and its major components were determined using an estrogen responsive element driven reporter gene assay in MCF-7/ERE and HEK293T cells. The Epi ext exhibited ERα- and ERß-mediated estrogenic activity with an EC(50) of 5.0 and 17.8 µM in HEK293T cells, respectively. Prenylflavonoid glycosides such as icariin (ICA), epimedin A, B, and C did not show any in vitro estrogenic or antiestrogenic activities. Icaritin (ICT) and quercetin exhibited in vitro ER mediated estrogenic activity with a more potent interaction with ERß. In vivo estrogenic activities of the Epi ext, ICA and ICT were compared using an uterotrophic assay. Although the potency of in vitro estrogenic activity was in the order of ICT>Epi ext>ICA, ICA had the strongest estrogenic activity and next ICT in ovariectomized rats. These results collectively suggest that phytoestrogens possess both estrogenic and antiestrogenic activity, and that the differential expression of these two compounds with opposing activities is dependent on the physiological environment in terms of estrogen level, which may be the case in humans.
Asunto(s)
Epimedium/química , Moduladores de los Receptores de Estrógeno/farmacología , Estrógenos/farmacología , Extractos Vegetales/farmacología , Animales , Línea Celular , Femenino , Humanos , Técnicas In Vitro , Ratas , Ratas Sprague-DawleyRESUMEN
Epimedii Herba is a traditional medicinal herb used in Korea and China and exerts estrogenic activity. In this study, we investigated the effect of peripubertal administration of Epimedii Herba on pubertal development in female rats using a modified protocol of the rodent 20-day pubertal female assay. Female Sprague-Dawley rats (21 days old after weaning, 10 rats per group) were divided into five groups: saline (Con), ethinyl estradiol (E2), Epimedii Herba ext (Ext), icariin (ICI), and icaritin (ICT), which were administered by oral gavage (E2 by subcutaneous injection) from postnatal day (PND) 21 through PND40. The time to vaginal opening (VO) was shorter for the Epimedii groups, particularly for the ICT group (p<0.05). Treatment with ICI and ICT significantly increased the duration of the estrus cycle (ICI, 2.78 days; ICT, 4.0 days; control, 1.78 days). Ovary weight was reduced by E2 treatment and increased by the Ext, ICI, and ICT treatments while the weight of the uterus and pituitary glands increased significantly only in the E2 and ICT groups. Although Epimedii Herba displayed relatively weak estrogenic activity, its repeated administration could affect pubertal development in female rats.