title: Estrogenic activity of the chlorinated derivatives of estrogens and flavonoids using a GFP expression system.
abstract: Estrogenic chemicals are widely reported to be present in the environment. Their chlorinated derivatives are considered to be produced through the chlorination process in water purification and sewage treatment plants. In this study, several chlorinated derivatives of estrogens and flavonoids, including phytoestrogens, were synthesized by the reaction with hypochlorous acid, and their estrogenic activities were investigated using a devised GFP expression system in human breast carcinoma MCF7 cells. The chlorinated derivatives were less estrogenic than the parent compounds. The EC(50) ranking of estrogen-related compounds was 17β-estradiol (E2)>4-ClE2>estrone (E1)>4-ClE1>10-Cl-1,4-estradiene-3,17-dione (10-Cl-3,17-dione)>2-ClE2>2-ClE1. 2,4-diClE2, 2,4-diClE1, and 2,4,16,16-tetraClE1 showed lower or no estrogenic activity. Genistein and daidzein are well known as phytoestrogens. 6,8-diCl-genistein, 3',8-diCl-daidzein, (+)-6,8-diCl-naringenin, and 6,8-diCl-apigenin showed lower estrogenic activity than their parent compounds. 3',5',8-triCl-daidzein exhibited no estrogenic activity. No activity was detected in chrysin, (+)-catechin, and their chlorinated derivatives. Similar results were obtained in a cell proliferation assay using MCF7 cells.
authors.affiliation: Laboratory of Microbiology and Host Defenses, School of Food and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
authors.forename: Ryoko
authors.initials: R
authors.lastname: Kuruto-Niwa
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ito
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Goto
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Nakamura
authors.forename: Ryushi
authors.initials: R
authors.lastname: Nozawa
authors.forename: Yoshiyasu
authors.initials: Y
authors.lastname: Terao