HOME HELP CONTACT US SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (10) Citing Articles via Google Scholar Google Scholar Articles by Christoffel, J Articles by Wuttke, W Search for Related Content PubMed PubMed Citation Articles by Christoffel, J Articles by Wuttke, W

Division of Clinical and Experimental Endocrinology, Department of Obstetrics and Gynecology, University of Göttingen, Robert-Koch-Str 40, 37099 Göttingen, Germany

(Requests for offprints should be addressed to W Wuttke; Email: ufkendo{at}med.uni-goettingen.de)

Phytoestrogens are increasingly consumed in artificially high doses as herbal preparations and nutritional supplements. The flavanone 8-prenylnaringenin (8PN) is a potent phytoestrogen, but its benefits and risks after long-term application are poorly identified. Therefore, we tested two doses of 8PN and 17ß-estradiol-3-benzoate (E2B) (effective doses: 6.8 and 68.4 mg/kg body weight (BW) of 8PN, and 0.17 and 0.7 mg/kg BW of 17ß-estradiol (E2)) and compared their effects on uterine weight, pituitary hormones (LH, FSH and prolactin) and the expression of estrogen-regulated genes and of estrogen receptor (ER) and ERß in the hypothalamus, pituitary and uterus. Both doses of E2 and the high dose of 8PN suppressed serum LH and FSH, and stimulated serum prolactin levels, uterine weight, and progesterone receptor, insulin-like growth factor I and complement protein C3 mRNA transcripts. In the preoptic and the mediobasal areas of the hypothalamus, all treatments had negligible effects on ER and ERß and gonadotropin-releasing hormone (GnRH) receptor gene expression, while ERß and GnRH receptor transcripts in the anterior pituitary were reduced under both E2 doses and the high 8PN dose. The mRNA concentrations of the LH and -ß subunits in the pituitary were suppressed by E2 and 8PN. In summary, 8PN had very similar though milder effects than E2 on all tested parameters. Inhibition of climacteric complaints by E2 takes place in the hypothalamus, where it inhibits the overactive GnRH pulse generator. Hence, 8PN may be used to inhibit climacteric symptoms effectively. Human pharmacologic studies will show whether the stimulatory effect on the uterus that was found in the present animal model would require the concomitant administration of progestins to prevent endometrial overstimulation.

This article has been cited by other articles:

				M. Bottner, J. Christoffel, and W. Wuttke Effects of long-term treatment with 8-prenylnaringenin and oral estradiol on the GH-IGF-1 axis and lipid metabolism in rats J. Endocrinol., August 1, 2008; 198(2): 395 - 401. [Abstract] [Full Text] [PDF]

				S. Possemiers, S. Rabot, J. C. Espin, A. Bruneau, C. Philippe, A. Gonzalez-Sarrias, A. Heyerick, F. A. Tomas-Barberan, D. De Keukeleire, and W. Verstraete Eubacterium limosum Activates Isoxanthohumol from Hops (Humulus lupulus L.) into the Potent Phytoestrogen 8-Prenylnaringenin In Vitro and in Rat Intestine J. Nutr., July 1, 2008; 138(7): 1310 - 1316. [Abstract] [Full Text] [PDF]

				J. Bowe, X. F. Li, J. Kinsey-Jones, A. Heyerick, S. Brain, S. Milligan, and K. O'Byrne The hop phytoestrogen, 8-prenylnaringenin, reverses the ovariectomy-induced rise in skin temperature in an animal model of menopausal hot flushes. J. Endocrinol., November 1, 2006; 191(2): 399 - 405. [Abstract] [Full Text] [PDF]