Hormones 2016

Oestrogens, conjugated
Toxicity
Side effects include loss of bone mineral density, BMD changes in adult
women, bleeding irregularities, cancer risks, and thromboembolic disorders
(drugbank, 2013g).
Oestrogens, conjugated
This is deprecated because it is in the form of an extract from the urine
of pregnant mares containing the effective substances, i.e. oestrogen
metabolites. This was one of the earliest commercial preparations available
for hormone replacement treatment, which have now been superseded
by the use of monosubstances with clearly defined pharmacokinetic and
pharmacodynamic features. It is known that the preparation contains
oestradiol metabolites as well as equilin metabolites which are specific
to horses. However, there is still a lack of knowledge about the exact
components of the urine extract. Hitherto unidentified components have
been recognised recently in the extract (Bhavnani, 1998). These are delta-
8-oestrone and its metabolites; furthermore 16α-hydroxy metabolites and
catechol metabolites of equilin are also allegedly present. It is now
known that these oestrogen metabolites possess effects other than their
oestrogenicity (Lippert, A. O. Mueck, and H. Seeger, 1999). Thus, some have
opposing effects: for instance, D-ring metabolites may exert proliferationstimulating
effects on cells, but A-ring metabolites proliferation-inhibiting
effects. In general, D-ring metabolites still have an oestrogenic effect,
while A-ring metabolites may even show antioestrogenic effects. There
has been recent interest in these oestrogen metabolites because there are
indications that they can be involved in the development of hormonedependent
tumours, e.g. breast cancer (Lippert, A. O. Mueck, and H. Seeger,
1999). It has been shown that these equilin metabolites have toxic properties
with carcinogenic potential through the formation of quinones (Zhang
et al., 1999). A special carcinogenic risk factor may be the formation of
semiquinone-adducts with DNA (Shen et al., 1998). Equilin metabolites
appear to have stronger carcinogenic effects than comparable oestradiol
metabolites (Bhavnani, 1998), (Lippert, A. O. Mueck, and H. Seeger, 2000).
As this information was established in 1999, to use it in later years is
unforgivable.
Conjugated estrogens, a mixture of the water-soluble salts of sulfate esters
from estrone, equilin, 17 α-dihydroequilin, and other related steroids, may
be derived from pregnant equine urine or yam and soy plants (drugbank,
2015a).
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Version 2016.3576– – Document LATEXed – 1st May 2016
[git] • Branch: 1.5 @ 26b5e6d • Release: 1.5 (2016-05-01)