title: Time dependency of uterine effects of naringenin type phytoestrogens in vivo.
abstract: Phytoestrogens exhibit significant estrogen agonistic/antagonistic properties in animals and humans. Naturally occurring flavonoids with a naringenin backbone like 8-prenylnaringenin (8-PN) and 6-(1,1-dimethylallyl)naringenin (6-DMAN) are considered to be some of the most potent phytochemicals activating nuclear receptors. 8-PN is a more potent estrogenic substance while 6-DMAN appears to have a higher antiandrogenic potency, however these are less well characterized compared to other phytoestrogens such as genistein. The aim of this study was to assess the estrogenic properties of 8-PN and 6-DMAN in an ovariectomized in vivo rat model. 8-PN and 6-DMAN were applied at concentrations of 15mg/kgBW. We assessed the uterotrophic response after 7h, 24h and 72h of treatment. In contrast to 8-PN, 6-DMAN did not alter uterine wet weight or the level of expression of proliferation markers at any time point. In contrast to the uterotrophic response, 6-DMAN stimulated uterine mRNA expression of estrogen responsive genes carrying an estrogen response element (ERE) in the ovariectomized rats, but to a lesser extent than E2 and 8-PN. In all treatment regimens, the mRNA expression of estrogen receptors alpha and beta mRNA was measured. In summary, we assessed the time dependent uterine responses and estrogenic activities of 6-DMAN and 8-PN. In contrast to 8-PN which mimicked the E2 induced responses on uterine wet weight and gene expression, 6-DMAN has no uterotrophic effect and only regulated the mRNA expression of genes carrying an ERE. Therefore, 6-DMAN is an exciting candidate molecule for future investigations and potentially a natural occurring selective estrogen receptor modulator.
authors.affiliation: Molecular Cell Physiology and Endocrinology, Institute for Zoology, Technische Universität Dresden, Germany. Oliver.Zierau@tu-dresden.de
authors.forename: Oliver
authors.initials: O
authors.lastname: Zierau
authors.forename: Georg
authors.initials: G
authors.lastname: Kretzschmar
authors.forename: Frank
authors.initials: F
authors.lastname: Möller
authors.forename: Carmen
authors.initials: C
authors.lastname: Weigt
authors.forename: Günter
authors.initials: G
authors.lastname: Vollmer
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism; D047629:Estrogen Receptor beta / Q000235:genetics / Q000378:metabolism; D005260:Female; D044950:Flavanones / Q000008:administration & dosage / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D009929:Organ Size / Q000187:drug effects; D010052:Ovariectomy; D048789:Phytoestrogens / Q000008:administration & dosage / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014599:Uterus / Q000033:anatomy & histology / Q000187:drug effects* / Q000378:metabolism*
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D044950:Flavanones; D048789:Phytoestrogens; D012333:RNA, Messenger; C005273:naringenin