1. Academic Validation
  2. Estrogenic activities of Fatty acids and a sterol isolated from royal jelly

Estrogenic activities of Fatty acids and a sterol isolated from royal jelly

  • Evid Based Complement Alternat Med. 2008 Sep;5(3):295-302. doi: 10.1093/ecam/nem036.
Kazu-Michi Suzuki 1 Yoichiro Isohama Hiroe Maruyama Yayoi Yamada Yukio Narita Shozo Ohta Yoko Araki Takeshi Miyata Satoshi Mishima
Affiliations

Affiliation

  • 1 Nagaragawa Research Center, API Co., Ltd, 692-3 Nagara, Gifu 502-0071 and Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-Honmachi, Kumamoto 862-0973, Japan.
Abstract

We have previously reported that royal jelly (RJ) from honeybees (Apis mellifera) has weak estrogenic activity mediated by interaction with estrogen receptors that leads to changes in gene expression and cell proliferation. In this study, we isolated four compounds from RJ that exhibit estrogenic activity as evaluated by a ligand-binding assay for the Estrogen Receptor (ER) beta. These compounds were identified as 10-hydroxy-trans-2-decenoic acid, 10-hydroxydecanoic acid, trans-2-decenoic acid and 24-methylenecholesterol. All these compounds inhibited binding of 17beta-estradiol to ERbeta, although more weakly than diethylstilbestrol or phytoestrogens. However, these compounds had little or no effect on the binding of 17beta-estradiol to ERalpha. Expression assays suggested that these compounds activated ER, as evidenced by enhanced transcription of a reporter gene containing an estrogen-responsive element. Treatment of MCF-7 cells with these compounds enhanced their proliferation, but concomitant treatment with tamoxifen blocked this effect. Exposure of immature rats to these compounds by subcutaneous injection induced mild hypertrophy of the luminal epithelium of the uterus, but was not associated with an increase in uterine weight. These findings provide evidence that these compounds contribute to the estrogenic effect of RJ.

Keywords

10-Hydroxy-2-decenoic acid; 10-Hydroxydecanoic acid; 2-Decenoic acid; 24-Methylenecholesterol; Apis mellifera.

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