title: Tectoridin from Maackia amurensis modulates both estrogen and thyroid receptors.
abstract: OBJECTIVE
  The stem bark of Maackia amurensis has been used as folk medicine for the treatment of cancer, cholecystitis, arthritis, and hyperthyroidism in females. In this study we examined the effects of the ethyl acetate fraction obtained from the 70% ethanol extract of M. amurensis and tectoridin, an active constituent isolated from the ethyl acetate fraction on thyroid and estrogen hormone activity.
  
  
  METHODS
  The effect of the ethanolic extract of M. amurensis stem bark on thyroid hormone activity was evaluated using thyroid hormone responsive-luciferase assay. We isolated tectoridin from the ethyl acetate fraction using a recrystallization method. T-screen assays were used to confirm thyroid hormone activity. The estrogenic activity of the ethyl acetate fraction of M. amurensis and tectoridin was evaluated by estrogen responsive-luciferase assay and estrogen receptor alpha regulation as compared to 17β-estradiol.
  
  
  RESULTS
  Both the ethyl acetate fraction and tectoridin activated thyroid-responsive reporters and increased thyroid hormone-dependent proliferation of rat pituitary GH3 cells, indicating modulation of thyroid hormone receptors. In parallel, the estrogenic activity of the fraction and tectoridin were characterized in a transient transfection system using estrogen-responsive luciferase plasmids in MCF-7 cells. The ethyl acetate fraction and tectoridin activated reporter gene expression and decreased the estrogen receptor protein level.
  
  
  CONCLUSIONS
  These data indicate that tectoridin acts as a weak phytoestrogen as well as a thyroid hormone-like agent by activating both estrogen and thyroid hormone receptors.
authors.affiliation: College of Life Science, Institute of Biotechnology, Department of Bioscience and Biotechnology, Sejong University, Seoul 143-747, Republic of Korea.
authors.forename: Myeongkuk
authors.initials: M
authors.lastname: Shim
authors.affiliation: College of Pharmacy and Research Institute of Pharmaceutical Sciences, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors.forename: Ji-Yeong
authors.initials: JY
authors.lastname: Bae
authors.affiliation: College of Life Science, Institute of Biotechnology, Department of Bioscience and Biotechnology, Sejong University, Seoul 143-747, Republic of Korea. Electronic address: yjlee@sejong.ac.kr.
authors.forename: Young Joo
authors.initials: YJ
authors.lastname: Lee
authors.affiliation: College of Pharmacy and Research Institute of Pharmaceutical Sciences, Gyeongsang National University, Jinju 660-701, Republic of Korea. Electronic address: amj5812@gnu.ac.kr.
authors.forename: Mi-Jeong
authors.initials: MJ
authors.lastname: Ahn
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D004353:Drug Evaluation, Preclinical; D020847:Estrogen Receptor Modulators / Q000302:isolation & purification*; D047628:Estrogen Receptor alpha / Q000378:metabolism; D006801:Humans; D007529:Isoflavones / Q000302:isolation & purification / Q000494:pharmacology*; D061986:MCF-7 Cells; D029901:Maackia / Q000737:chemistry*; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D010946:Plants, Medicinal; D051381:Rats; D011988:Receptors, Thyroid Hormone / Q000819:agonists*; D015533:Transcriptional Activation / Q000187:drug effects
chemical_list: D020847:Estrogen Receptor Modulators; D047628:Estrogen Receptor alpha; D007529:Isoflavones; D010936:Plant Extracts; D011988:Receptors, Thyroid Hormone; C120040:tectoridin
keywords: Estrogen receptor; Maackia amurensis; Tectoridin; Thyroid receptor