Oestrogen natural

Ashby J., Lefevre P.A., OdumJ., Harris C.A., Routledge E.J., Sumpter J.P. (1997) Synergy between synthetic oestrogens Nature 385, 494. 

Meat, dairy products and eggs contain low levels of natural hormones, including oestrogens, progesterone and testosterone, possibly enhanced by the use of hormones for veterinary purposes or as growth enhancers. " ... 

Farmed animals tend to be subjected to compounds that can be classified more easily as drugs. In some cases, animals may encounter compounds in nature that have considerable limitations in inclusion in the diets of farmed animals. An example is the inclusion of zearalenone (Figure 1) and its derivatives in animal diets these have anabolic and oestrogenic properties " and are permitted to be used in some areas of the world but are prohibited from use in others, such as European Union countries. Thus this compound and its reduced isomers (zearalenols, zeranols) improve growth rates in animals but can cause reproductive problems, especially in pigs. Ralgro, which is a commercially prepared derivative of zearalenone, is used as an ear implant in beef cattle as a growth promoter in... 

Dodds, E.C., Fitzgerald, M.E.H., and Lawson, W. (1937). Oestrogenic activity of some hydrocarbon derivatives of ethylene. Nature 140, 772-772. 

MAZUR w and adlercreutz h (1998) Natural and anthropogenic environmental oestrogens the scientific basis for risk assessment. Naturally occurring oestrogens in food. Pure Appl Chem. 70 (2) 1759-76. 

Brzozowski AM, Pike AC, Dauter Z (1997) Molecular basis of agonism and antagonism in the oestrogen receptor. Nature 389 753... 

Green S, Walter P, Kumar V, Krust A, BornertJM, Argos P, Chambon P (1986a) Human oestrogen receptor cDNA sequence, expression and homology to v-erb-A. Nature 320 134... 

King WJ, Greene GL (1984) Monoclonal antibodies localize oestrogen receptor in the nuclei of target cells. Nature 307 745... 

Welshons WV, Lieberman ME, Gorski J (1984) Nuclear localization of unoccupied oestrogen receptors. Nature 307 747... 

Sutherland RL, Murphy LC, San Foo M, Green MD, Whybourne AM, Krozowski ZS (1980) High-affinity anti-oestrogen binding site distinct from the oestrogen receptor. Nature 288(5788) 273-275... 

F8. Fotsis, T., Zhang, T., Pepper, M. S., Adlercreutz, H., Montesano, R., Nawroth, P. P., and Schwergerer, L., The endogenous oestrogen metabolite 2-methoxyoestradiol inhibits angiogenesis and suppresses tumour growth. Nature (London) 368, 237-239 (1994). 

T3. Thorpe, S. A., Christensen, I. J., Rasmussen, B. B., and Rose, C.. Short recun-ence-free survival associated with high oestrogen receptor levels in the natural history of postmenopausal, primary breast cancer. Eur. J. Cancer 29A, 971-977 (1993). 

Since the development of the oral contraceptive steroids in the 1960s, various steroids and procedures have been used. Synthetic steroids are now used since their half-hves in the body are longer than the natural steroids. Combined oestrogen-progesterone contraception involves taking one piU each day which contains a synthetic progestogen plus an oestrogen. The pill is taken for 21 dyas, with a break for... 

Thus, the natural oestrogen estrone can be converted into the drug ethinylestradiol by nucleophilic addition. Ethinylestradiol is some 12 times more effective than estradiol when taken orally, and is widely used in oral contraceptive preparations. In drug nomenclature, the systematic name ethynyl- for the HC=C- group is usually presented as ethinyl-. 

Natural oestrogens generally only retain a significant proportion of their activity if administered intravenously. Several synthetic analogues have been developed which can be administered orally. Most of these substances also display more potent activity than native oestrogen. The most important synthetic oestrogen analogues include ethinyloestradiol and diethylstilboestrol (often simply termed stilboestrol). These are orally active and are approximately 10 and 5 times (respectively) more potent than oestrone. 

Oestradiol Natural oestrogen Oestrogen replacement therapy in menopausal, post-menopausal or menstrual disorders. Management of breast cancer in post-menopausal women and prostate cancer in man... 

Oestrone Natural oestrogen Uses similar to oestradiol... 

Ferrando, R., M. M. Guilleux, and A. Guerrillot-Venet. Oestrogen content of plants as a function of conditions of culture. Nature 1961 192 1205. Ahmad, Y. S. A note of the plants of the medicinal value found in Pakistan. Govt of Pakistan Press, Karachi 1957. Walker, B. S., and J. C. Janney. Estrogenic substances. II. An analysis of plant sources. Endocrinology... 

Bronsens JJ, Parker MG. Oestrogen receptor hijacked. Nature 423, 487 88, 2003. 

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