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- Letter:
The chance discovery of oestrogenic activity in laboratory rat
cake.
- Drane H, Patterson
DS, Roberts BA, Saba N
- Food Cosmet
Toxicol 1975 Aug 13:4 491-2
-
- Oestrogenic
activity of soya-bean products.
- Drane HM, Patterson
DS, Roberts BA, Saba N
- Food Cosmet
Toxicol 1980 Aug 18:4 425-7
-
- Dietary
genistein exerts estrogenic effects upon the uterus, mammary gland
and the hypothalamic/pituitary axis in rats.
- Santell RC,
Chang YC, Nair MG, Helferich WG
- J Nutr 1997
Feb 127:2 263-9
- Abstract
- These studies
were undertaken to assess the estrogenic and antiestrogenic effects
of dietary genistein. To determine estrogenic effects, genistein
was mixed into a modified AIN-76 or AIN-93G semipurified diet
at 0 (negative control), 150, 375 or 750 microg/g and 17, beta-estradiol
at 1.0 microg/g and fed to ovariectomized 70-d-old Sprague-Dawley
rats. Estrogenic potency was determined by analyzing uterine weight,
mammary gland development, plasma prolactin and expression of
uterine c-fos. Dietary genistein (375 and 750 microg/g) increased
uterine wet and dry weights (P < 0.05). Mammary gland regression
following ovariectomy was significantly inhibited by dietary genistein
at 750 microg/g (P < 0.05). Plasma prolactin was significantly
greater in ovariectomized rats fed genistein (750 microg/g) compared
with comparable rats not receiving genistein. The relative binding
affinity of genistein to the estrogen receptor (ER) was 0.01 that
of estradiol. Genistein (750 microg/g) induced the uterine expression
of c-fos. To evaluate potential antiestrogenic effects, genistein
and estradiol were mixed into the modified AIN diets at the doses
noted above and fed to ovariectomized rats. Dietary genistein
(375 or 750 microg/g) did not inhibit the effects of estradiol
on uterine weight, mammary gland development or plasma prolactin.
Serum concentration of total genistein (conjugated plus free)
in rats fed 750 microg/g was 2.2 micromol/L and free genistein
was 0.4 micromol/L. Administration of dietary genistein at 750
microg/g can exert estrogenic effects in the uterus, mammary gland
and hypothalamic/pituitary axis. Dietary genistein (750 microg/g)
did not antagonize the action of estradiol in estradiol supplemented
ovariectomized rats or in intact rats.
Birds:
- Phytoestrogens:
adverse effects on reproduction in California quail.
- Leopold AS,
Erwin M, Oh J, Browning B
- Science 1976
Jan 9 191:4222 98-100
- Abstract
- Phytoestrogens,
largely formononetin and genistein, are produced in the leaves
of stunted desert annuals in a dry year. When ingested by California
quail, these compounds apparently inhibit reproduction and prevent
the production of young that will not have adequate food. In a
wet year, forbs grow vigorously and phytoestrogenic substances
are largely absent. Quail then breed prolifically and the abundant
seed crop carries the enlarged population through the winter.
-
- Effects
of dietary and parenteral estrogens on bobwhite reproduction.
- Lien RJ, Cain
JR, Beasom SL
- Poult Sci 1987
Jan 66:1 154-61
- Abstract
- Bobwhites were
fed one of several doses (.01 to 1,000 micrograms/day) of estriol
(E3), beta-estradiol-3-benzoate (E2B), diethylstilbestrol (DES),
or biochanin-A (BA) during two 10-week trials. The initial 2 weeks
of each trial were short day length (10L:14D) followed by 8 weeks
of long day length (16L:8D). In addition, female bobwhites were
given daily injections containing dosages (.01 to 10 micrograms/day)
of E2B, E3, and DES while housed on the same light regimen. Reproductive
performance as assessed by onset of lay, egg production, and egg
fertility was depressed in a dose-dependent manner and was inhibited
by dietary dosages of 1,000 micrograms/day of E3, DES, and E2B.
No consistent effects on reproductive performance were observed
in bobwhites fed up to 1,000 micrograms/day of the phytoestrogen
BA. Injected estrogens appeared approximately 100 times more potent
than dietary estrogens. It was concluded that both dietary and
parenteral estrogen can inhibit reproduction, but in order for
phytoestrogen (BA) in natural feedstuffs to impair reproduction
in bobwhites it would have to be consumed in excess of 1 mg/day.
Cattle:
- Investigations
in central Hessia on the occurrence of estrogenic activity content
of cattle feed]
- Khodabandehlou
H, Hoffmann B, Pallauf J
- DTW Dtsch Tierarztl
Wochenschr 1997 Aug 104:8 291-4
- Abstract
- In 21 farms
which requested consultation for reasons of infertility problems
feed samples (grass silage, n = 20; cornsilage, n = 19; hay, n
= 9; cereal mixture, n = 3, brewers grains, n = 5, ensiled sugar
beet tops, n = 1) were drawn for assay of free (aglycon) and glycosidic
(glycosid) bound oestrogen activity. Following sample preparation
and extraction, the oestrogenic activity was determined using
a radioreceptorassay and only those samples leading to a 50% displacement
of the 3H-estradiol-17 beta-tracer were classified as oestrogen-positive;
values were expressed as ng 17 beta-estradiol equivalents per
g dry matter. Selected samples clearly oestrogen-positive in the
aglycone fraction were submitted to separation by HPLC and cytograms
were established with the intention to allow an assignment of
the oestrogenic activity to the following reference compounds,
coumestrol, genistein, daidzein, formononetin, biochanin A, zeeralenon.
With regard to free oestrogenic activity (aglycon) most of the
grass silages were positive while-with one exception -the cornsilages
were negative as were the hay-samples. The brewers grain samples
were likewise positive and negative. Distinctly lower concentrations
were found for the glycosidic bound oestrogenic activity with
highest levels determined in hay. Results obtained after application
of HPLC showed that the oestrogenic activity could particularly
be attributed to daidzein and biochanin A. In the only oestrogen-positive
cornsilage-sample the activity found corresponded with zearalenon.
Types and concentrations of the oestrogenic activity allow the
conclusion that negative effects on reproduction cannot be excluded.
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