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Information about Xenoestrogen

Xenoestrogens are novel, man-made compounds, that differ from archiestrogens (ancient, naturally occuring) produced by living organisms. They mimic the effect of estrogens presenting a potential ecological and human health impact.[1]

Xenoestrogens are part of a heterogeneous group of chemicals that are hormone or endocrine disruptors. They differ from phytoestrogens (estrogenic substances from plants), mycoestrogens (estrogenic substances from fungi, which can be considered as one type of mycotoxin), and pharmacological estrogens (estrogenic action is intended) in that they are man-made. The idea that man-made substances are inherently different from other, similar chemicals is an example of the scientifically discredited theory of vitalism. Estrogens from a variety of sources may have a cumulative effect upon living organisms, and xenoestrogens may be part of a larger picture of a process of estrogenization of the environment. Xenoestrogens have only been recently (less than 70 years) introduced into the environment, as produced by industrial, agricultural, and chemical companies, but similar compound have existed in the environment since the beginnings of life itself. (see phytoestrogens)

Effects

Xenoestrogens have been implicated in a variety of medical problems. Foremost is the concern that xenoestrogens as false messengers disrupt the process of reproduction. Studies have implicated observations of disturbances in wildlife with estrogenic exposure. Reproductive issues which are of concerns in humans are fetal exposure (perhaps leading to hypospadias) and decreased reproductive ability in men (i.e. decrease in sperm numbers). Another issue is the potential effect of xenoestrogens on oncogenes, specifically in relation to breast cancer.

Presence

The ubiquitous presence of such estrogenic substances is a significant health concern, both individually and for a population. Life relies on the transmission of biochemical information to the next generation, and the presence of xenoestrogens may interfere with this transgenerational information process through "chemical confusion" (Vidaeff, Sever). Environmental protection laws and regulations are supposed to protect the environment from hormonal disruption. Agencies such as the United States Environmental Protection Agency and the World Health Organization International Program on Chemical Safety are charged to address these issues.

Research

The study of the problem is difficult and complex. Transgenerational effects are difficult to prove, effects may be multifactorial, and the large variety of substances in question with the absence of unexposed controls do not lend themselves to easy interpretation. Believers that environmental estrogen disruption is a major health hazard are opposed by detractors who argue that observed effects are spurious and inconsistent, or that the quantities of the agents are too low to have any effect.

A 2005 study by Belcher and coworkers demonstrated that even very low levels of a xenoestrogen, in this case Bisphenol A, could affect fetal neural development more than higher levels (PMID 16123166), indicating that classical models where dose equals response may not be applicable in susceptible tissue.

Synthetic chemicals shown to have unintended estrogenic effects

See also

References

  • Vidaeff AC, Sever LE. In utero exposure to environmental estrogens and male reproductive health: a systematic review of biological and epidemiological evidence. Reproductive Toxology 20:5-20,2005.

External links

References

1. ^ Korach, Kenneth S. (1998). Reproductive and Developmental Toxicology. Marcel Dekker Ltd, pp 278-279, 294-295. ISBN 978-0824798574. 
Estrogens (alternative spellings: oestrogens or œstrogens) are a group of steroid compounds, named for their importance in the estrous cycle, and functioning as the primary female sex hormone.
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Endocrine disruptors are exogenous substances that act like hormones in the endocrine system and disrupt the physiologic function of endogenous hormones. Studies have linked endocrine disruptors to adverse biological effects in animals, giving rise to concerns that low-level
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Phytoestrogens sometimes called "dietary estrogens" are a diverse group of naturally occuring non steroidal plant compounds that because of their structural similarity with estradiol (17β-estradiol), have the ability to cause estrogenic or/and antiestrogenic effects.
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Eukarya
Whittaker & Margulis, 1978
(unranked) Opisthokonta

Kingdom: Fungi
(L., 1753) R.T. Moore, 1980[1]

Subkingdom/Phyla

Chytridiomycota
Blastocladiomycota

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Mycotoxin (from the Greek μύκης (mykes, mukos) "fungus") is a toxin produced by an organism of the fungus kingdom, which includes mushrooms, molds and yeasts. Most fungi are aerobic (use oxygen).
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Vitalism, as defined by the Merriam-Webster dictionary,[1] is
  1. a doctrine that the functions of a living organism are due to a vital principle distinct from physicochemical forces

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Phytoestrogens sometimes called "dietary estrogens" are a diverse group of naturally occuring non steroidal plant compounds that because of their structural similarity with estradiol (17β-estradiol), have the ability to cause estrogenic or/and antiestrogenic effects.
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Hypospadias is a birth defect of the urethra in the male that involves an abnormally placed urinary meatus (opening). Instead of opening at the tip of the glans of the penis, a hypospadic urethra opens anywhere along a line (the urethral groove
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A spermatozoon or spermatozoan (pl. spermatozoa), from the ancient Greek σπέρμα (seed) and ζῷον (living being) and more commonly known as a sperm cell
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An oncogene is a modified gene, or a set of nucleotides that codes for a protein and is believed to cause cancer. Genetic mutations resulting in the activation of oncogenes increase the chance that a normal cell will develop into a tumor cell.
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Breast cancer
Classification & external resources

Histopathologic image from ductal cell carcinoma in situ (DCIS) of breast. Hematoxylin-eosin stain.
ICD-10 C 50.
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Environmental law is a body of law, which is a system of complex and interlocking statutes, common law, treaties, conventions, regulations and policies which seek to protect the natural environment which may be affected, impacted or endangered by human activities.
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Environmental Protection Agency
EPA

Environmental Protection Agency logo

Agency overview
Formed December 2, 1970

Employees 17,964 (2005) [1]
Annual Budget $7.
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Bisphenol A is a chemical compound containing two phenol functional groups. It belongs to the phenol class of aromatic organic compounds. It is widely prepared and sold and various important polymers/plastics are made from it.
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4-Methylbenzylidene camphor, short 4-MBC, also 3-(4-Methylbenzylidene)bornan-2-one, or 3-(4-Methylbenzylidene)-dl-camphor is an organic camphor derivative that is used in the cosmetic industry for its ability to protect the skin against UV, specifically
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Butylated hydroxyanisole (BHA) is a mixture of two isomeric organic compounds, 2-tert-butyl-4-hydroxyanisole and 3-tert-butyl-4-hydroxyanisole. It is prepared from 4-methoxyphenol and isobutylene. It is a waxy solid that exhibits antioxidant properties.
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Atrazine, 2-chloro-4-(ethylamine)-6-(isopropylamine)-s-triazine, is an s-triazine-ring herbicide that is used globally to stop pre- and post-emergence broadleaf and grassy weeds in major crops.
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Bisphenol A is a chemical compound containing two phenol functional groups. It belongs to the phenol class of aromatic organic compounds. It is widely prepared and sold and various important polymers/plastics are made from it.
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Dieldrin is a chlorinated hydrocarbon originally produced in 1948 by J. Hyman & Co, Denver, as an insecticide. The molecule has a ring structure based on naphthalene.

Dieldrin is closely related to aldrin which itself breaks down to form dieldrin.
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''For other uses: see DDT (disambiguation).

DDT (from its trivial name, Dichloro-Diphenyl-Trichloroethane) is one of the best known synthetic pesticides. It was originally synthesized in 1874 but its insecticidal properties were not discovered until 1939.
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Endosulfan is a neurotoxic organochlorine insecticide of the cyclodiene family of pesticides. It is highly toxic and an endocrine disruptor, and it is banned in the European Union, the Philippines, Cambodia, and several countries.
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Erythrosine (Tetraiodofluorescein) is a cherry-pink coal based fluorone food dye. Its maximum absorbance is at 530 nm[1] in an aqueous solution, and it is subject to photodegradation.
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Heptachlor is an insecticide that usually comes in the form of a white or tan powder, the tan powder being of lower purity. It is similar to insecticide chlordane. Heptachlor was widely used in the past to kill insects.
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Lindane is a synthetic chemical that was initially developed as an agricultural insecticide and then formulated for medical use due to its antiparasitic efficacy against scabies and lice.
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Methoxychlor is a synthetic organochlorine used as an insecticide. It is applied to protect crops, ornamentals, livestock, and pets against fleas, mosquitoes, cockroaches, and other insects.
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Nonylphenol is an organic compound of the wider family of alkylphenols. It is a product of industrial synthesis formed during the alkylation process of phenols, particularly in the synthesis of polyethoxylate detergents.
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Polychlorinated biphenyls (PCBs) are a class of organic compounds with 1 to 10 chlorine atoms attached to biphenyl and a general chemical formula of C12H10-xClx.
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Parabens are a group of chemicals widely used as preservatives in the cosmetic and pharmaceutical industries. Parabens are effective preservatives in many types of formulas.
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Phthalates, or phthalate esters, are a group of chemical compounds that are mainly used as plasticizers (substances added to plastics to increase their flexibility). They are chiefly used to turn polyvinyl chloride from a hard plastic into a flexible plastic.
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