Parabens and estrogenic activity

Science Other Studies
#1

Parabens inhibit human skin estrogen sulfotransferase activity: Possible link to paraben estrogenic effects

Jeffery J. Prusakiewicz, a, , Heather M. Harvillea, Yanhua Zhanga, Chrisita Ackermanna and Richard L. Voormana
aDepartment of Pharmacokinetics, Dynamics, and Metabolism, Pfizer Global Research and Development, 2800 Plymouth Rd., 20/342S-D, Ann Arbor, MI 48105, USA
Received 29 November 2006; revised 5 January 2007; accepted 12 January 2007. Available online 19 January 2007.

Abstract
Parabens (p-hydroxybenzoate esters) are a group of widely used preservatives in topically applied cosmetic and pharmaceutical products. Parabens display weak associations with the estrogen receptors in vitro or in cell based models, but do exhibit estrogenic effects in animal models. It is our hypothesis that parabens exert their estrogenic effects, in part, by elevating levels of estrogens through inhibition of estrogen sulfotransferases (SULTs) in skin. We report here the results of a structure-activity-relationship of parabens as inhibitors of estrogen sulfation in human skin cytosolic fractions and normal human epidermal keratinocytes. Similar to reports of paraben estrogenicity and estrogen receptor affinity, the potency of SULT inhibition increased as the paraben ester chain length increased. Butylparaben was found to be the most potent of the parabens in skin cytosol, yielding an IC50 value of 37 ± 5 μM. Butylparaben blocked the skin cytosol sulfation of estradiol and estrone, but not the androgen dehydroepiandrosterone. The parabens were also tested as inhibitors of SULT activity in a cellular system, with normal human epidermal keratinocytes. The potency of butylparaben increased three-fold in these cells relative to the IC50 value from skin cytosol. Overall, these results suggest chronic topical application of parabens may lead to prolonged estrogenic effects in skin as a result of inhibition of estrogen sulfotransferase activity. Accordingly, the skin anti-aging benefits of many topical cosmetics and pharmaceuticals could be derived, in part, from the estrogenicity of parabens.
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TCN-4MVN14R-2&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=fb89d5d23d512f0b13c78be06498c48b

#2

interesting links

http://www.terressentials.com/endocrine.html
http://www.naturalskincaresecrets.com/parabens-and-cancer.html
http://en.wikipedia.org/wiki/Parabens
http://www.naturalphysiques.com/cms/index.php?itemid=210
http://greenfertility.blogspot.com/2007/02/is-your-shampoo-making-you-fat-while.html

#3

Effects of propyl paraben on the male reproductive system

S. Oishi,
Department of Toxicology, Tokyo Metropolitan Research Laboratory of Public Health, 3-24-1, Hyakunin-cho, Shinjuku-ku, Tokyo 169-0073, Japan
Accepted 7 July 2002. Available online 11 October 2002.

Abstract
Parabens are p-hydroxybenzoic acid ester compounds widely used as preservatives in foods, cosmetics, toiletries and pharmaceuticals. These compounds exert a weak estrogenic activity as determined by in vitro estrogen receptor assay and in vivo uterotrophic assay. In a previous study, it was demonstrated by the present author that exposure of post-weaning mammals to butyl paraben adversely affects the secretion of testosterone and the function of the male reproductive system. In the present study, it is shown that propyl paraben also adversely affects the hormonal secretion and the male reproductive functions. Propyl paraben was administered to 3-week-old rats which were divided into four groups of eight animals each, at doses of 0.00, 0.01, 0.10 and 1.00% with the AIN93G modified diet. At the end of 4 weeks, the rats were sacrificed by decapitation and the weights of testes, epididymides, prostates, seminal vesicles and preputial glands were determined. There were no treatment-related effects of propyl paraben on the organ weights in any of the study groups. The cauda epididymal sperm reserves and concentrations decreased in a dose-dependent manner and the difference was significant at dose of 0.10% and above. Daily sperm production and its efficiency in the testis of all groups receiving propyl paraben significantly decreased. The serum testosterone concentration decreased in a dose-dependent manner and the decrease was significant in the group that received the highest dose. The exposure level at which this effect was observed is the same as the upper-limit acceptable daily intake (10 mg/kg body weight/day) of parabens in the European Community and Japan.

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T6P-46YXHCB-1&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=d9db5441ee679ae877ff8e375495b299

It’s funny how many of the products i have been using in my bathroom are all containing parabens.I’m sure most of yours are too.
This with our delicate endocrine condition is certainly not helping us,this is all adding up guys,I’m pretty sure.It’s funny too how i do bloat after washing my hair or having a shave.
I’m going to be avoiding them from now on,even washing less often lol, and see if there are any significative changes.

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