%0 Journal Article %T Evaluation of the Estrogenic Activity of Pueraria (Kudzu) Flower Extract and Its Major Isoflavones Using ER-Binding and Uterotrophic Bioassays %A Tomoyasu Kamiya %A Akira Takano %A Yayoi Kido %A Yuki Matsuzuka %A Mayu Sameshima-Kamiya %A Masahito Tsubata %A Motoya Ikeguchi %A Kinya Takagaki %A Junei Kinjo %J Pharmacology & Pharmacy %P 255-260 %@ 2157-9431 %D 2013 %I Scientific Research Publishing %R 10.4236/pp.2013.42036 %X Pueraria flower extract (PFE) is a hot water extract of the Kudzu flower (Pueraria thomsonii). Tea made from dried Kudzu flower is widely used inChina, and PFE is utilized as a nutritional supplement inJapan. PFE contains unique isoflavones such as 6-hydroxygenistein 6,7-di-O-glucoside (6HGDG), tectorigenin 7-O-xylosylglucoside (TGXG), and tectoridin. 6HGDG is known to be metabolized into 6-hydroxygenistein, and TGXG and tectoridin are known to be metabolized into tectorigenin in the digestive tract. Isoflavones typically mimic the effects ¦Ā-estradiol has on estrogen receptors (ERs) and may influence the female genital system in the case of excessive intake. As a result, the upper limit of safe daily consumption of soy isoflavones has been enforced inJapan. In the present study, ER-binding assays were performed using the EnBio estrogen receptor/cofactor assay system to compare the estrogenic activity of 6-hydroxygenistein and tectorigenin to that of the soy isoflavone genistein. In addition, uterotrophic bioassays were performed to investigate the estrogenic effects of PFE in vivo. The ER-binding assays revealed that the ER-binding affinities of 6-hydroxygenistein and tectorigenin were approximately 0.01 - 0.04 that of genistein. Soy isoflavone products also induced an increase %K Estrogenic Activity %K 6-Hydroxygenistein %K Kudzu Flower Extract %K Safety Evaluation %K Tectorigenin %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=30396