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United States Department of Agriculture

Agricultural Research Service

Title: Identification of the Potent Phytoestrogen Glycinol in Elicited Soybean (Glycine max)

Authors
item Boue, Stephen
item Tilghman, Syreeta -
item Elliott, Steven -
item Zimmerman, M. Carla -
item Williams, K. -
item Payton-Stewart, Florastina -
item Miraflor, Allen -
item Howell, Melanie -
item Shih, Betty
item Carter-Wientjes, Carol
item Segar, Chris -
item Beckman, Barbara -
item Wiese, Thomas -
item Cleveland, Thomas
item Mclachlan, John -
item Burow, Matthew -

Submitted to: Endocrinology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 19, 2008
Publication Date: December 30, 2008
Citation: Boue, S.M., Tilghman, S.L., Elliott, S., Zimmerman, M., Williams, K.Y., Payton-Stewart, F., Miraflor, A.P., Howell, M.H., Shih, B.Y., Carter Wientjes, C.H., Segar, C., Beckman, B.S., Wiese, T.E., Cleveland, T.E., Mclachlan, J.A., Burow, M.E. 2009. Identification of the Potent Phytoestrogen Glycinol in Elicited Soybean (Glycine max). Endocrinology. 150(5):2446-2453.

Interpretive Summary: The primary induced isoflavones in soybean, the glyceollins, have been shown to be potent estrogen antagonists in vitro and in vivo. The discovery of the glyceollins’ ability to inhibit cancer cell proliferation has led to the analysis of estrogenic activities of other induced isoflavones. In this study, we investigated a novel isoflavone, glycinol, a precursor to glyceollin that is produced in elicited soy. Sensitive and specific in vitro bioassays were used to determine that glycinol exhibits potent estrogenic activity. Glycinol also induced the expression of estrogen responsive genes. Binding assays revealed a high affinity of glycinol for both estrogen receptors. In addition,computer modeling studies were performed and glycinol was shown to bind similarly to both estrogen receptors. Taken together, these results suggest for the first time that glycinol is estrogenic and may represent an important component of the health effects of soybased foods.

Technical Abstract: The primary induced isoflavones in soybean, the glyceollins, have been shown to be potent estrogen antagonists in vitro and in vivo. The discovery of the glyceollins’ ability to inhibit cancer cell proliferation has led to the analysis of estrogenic activities of other induced isoflavones. In this study, we investigated a novel isoflavone, glycinol, a precursor to glyceollin that is produced in elicited soy. Sensitive and specific in vitro bioassays were used to determine that glycinol exhibits potent estrogenic activity. Estrogen-based reporter assays were performed and glycinol displayed a marked estrogenic effect on ER signaling between 1-10 µM, which correlated with comparable colony formation of MCF-7 cells at 10 µM. Glycinol also induced the expression of estrogen responsive genes (PgR and SDF-1). Competitive binding assays revealed a high affinity of glycinol for both ERa ('C50=13.8 nM) and ERß ('C50=9.1 nM). In addition,ligand receptor modeling (docking) studies were performed and glycinol was shown to bind similarly to both ERa and ERß. Taken together, these results suggest for the first time that glycinol is estrogenic and may represent an important component of the health effects of soybased foods.

Last Modified: 12/18/2014