Tamoxifen is a long acting anti-oestrogen with both oestrogenic and anti-oestrogenic
(14) When endogenous oestrogens are high, the weak oestrogenic nature of soy isoflavones results in anti-oestrogenic
Some patients (20%-28%) do not respond to clomiphene citrate in spite of high dose as the anti-oestrogenic
effect is dose-dependent; a daily dose of clomiphene citrategreater than 150mg is not recommended.16
The alkaloids exhibited more anti-oestrogenic
activity (71.43%) than oestrogenic (28.57%).
Most of the phytooestrogens-based preparations freely available on the market are proposed as legal and non-toxic anti-oestrogenic
compounds (to counterbalance the side effects of anabolic steroids, mainly based on methoxyflafones (Usui, 2006)), as fat lowering products or sexual enhancing compounds based mainly on plant extracts from Commiphora Mukul (Guggulsterone), Eurycoma Longifolia (methoxyflavone), Vitex Agnus Castus and Astragalus Root (isoflavones).
Tamoxifen exerts tissue-dependent oestrogenic and anti-oestrogenic
actions after binding to the ER .
Where concentrations of endogenous oestrogens are relatively high, as in premenopausal women, they can exclude the more potent oestrogen from binding to the receptor and, therefore, the overall effect is anti-oestrogenic
. The presence of two types of oestrogen receptors, the classic ER[alpha] and the more recently discovered ER[beta], is of special relevance to the mechanism of action of phytoestrogens.
A recent Oxford University study found smokers take, on average, around two months longer to conceive because ciggies produce anti-oestrogenic
chemicals which can affect egg quality and even suppress ovulation.
Phyto-oestrogens have both oestrogenic and anti-oestrogenic
effects and they're a drop in the ocean compared to the oestrogens your own body is making.
The centre, which is based at the Welsh School of Pharmacy at Cardiff University, is trying to identify the complex mechanisms that the cancer cells use to become resistant to these anti-oestrogenic
It exhibits anti-oestrogenic
activity in the breast and oestrogen-like actions on the endometrium.2 The drug is associated with an increased risk of endometrial cancer.