From:
Sukie Crandall
Date: 2009-01-04 00:09:04 UTC
Subject: Re: Need recommendation on an ear wash
To: fhl <ferrethealth@yahoogroups.com>
Since it has been a while since i looked up the
worrisome effects of tea tree oil and lavender
oil I decided to look in PubMed. Abstracts
are like press releases. They are meant to be
shared.
http://www.ncbi.nlm.nih.gov/pubmed/17267908
with full text here:
http://content.nejm.org/cgi/content/full/356/5/479
BEGIN QUOTED ABSTRACT
N Engl J Med. 2007 Feb 1;356(5):479-85.
Comment in:N Engl J Med. 2007 Jun 14;356(24):2541-2; author reply=20
2543-4.N Engl J Med. 2007 Jun 14;356(24):2542-3; author reply 2543-4.N=20
Engl J Med. 2007 Jun 14;356(24):2542; author reply 2543-4.N Engl J=20
Med. 2007 Jun 14;356(24):2543; author reply 2543-4.Prepubertal=20
gynecomastia linked to lavender and tea tree oils.
Henley DV, Lipson N, Korach KS, Bloch CA.
Receptor Biology Section, Laboratory of Reproductive and Developmental=20
Toxicology, National Institute of Environmental Health Sciences,=20
Research Triangle Park, NC 27709, USA.
Most cases of male prepubertal gynecomastia are classified as=20
idiopathic. We investigated possible causes of gynecomastia in three=20
prepubertal boys who were otherwise healthy and had normal serum=20
concentrations of endogenous steroids. In all three boys, gynecomastia=20
coincided with the topical application of products that contained=20
lavender and tea tree oils. Gynecomastia resolved in each patient=20
shortly after the use of products containing these oils was=20
discontinued. Furthermore, studies in human cell lines indicated that=20
the two oils had estrogenic and antiandrogenic activities. We conclude=20
that repeated topical exposure to lavender and tea tree oils probably=20
caused prepubertal gynecomastia in these boys. 2007 Massachusetts=20
Medical Society
PMID: 17267908
END QUOTE
A later independent study confirmed estrogenic potential but not which=20
components are to blame:
http://www.ncbi.nlm.nih.gov/pubmed/18255254
BEGIN QUOTE
Toxicol In Vitro. 2008 Jun;22(4):1038-42. Epub 2007 Dec 31.
What you see may not always be what you get--bioavailability and=20
extrapolation from in vitro tests.
Nielsen JB.
Environmental Medicine, Institute of Public Health, University of=20
Southern Denmark, Winsl=F8wparken 17, DK-5000 Odense C, Denmark.
In human risk assessment, bioavailability needs to be considered when=20
relying on in vitro toxicity results. For single chemicals, this=20
quantitative challenge is often handled through a bioavailability=20
factor. For mixtures, however, things are more complicated. Thus,=20
individual constituents may not only interact toxicodynamically and=20
toxicokinetically, but the composition of constituents reaching the=20
target site may also differ from what was present at the site of=20
exposure due to the differences in their bioavailabilities. A recent=20
study concluded on the in vivo potential of Australian tea-tree oil=20
(TTO) to act as an endocrine disruptor based on an in vitro protocol=20
measuring the growth of MCF-7 cells following chemical exposure to=20
TTO. TTO is primarily used topically in humans, and is not a single=20
chemical but is a mixture with some constituents penetrating the skin=20
which others do not. The present study evaluated in an identical in=20
vitro model to what extent TTO and its skin penetrating constituents=20
affected the growth of MCF-7 cells. The estrogenic potency of TTO was=20
confirmed, but none of the bioavailable TTO constituents demonstrated=20
estrogenicity. The present study, therefore, cautions in vitro to in=20
vivo extrapolations from the mixtures of constituents with potentially=20
varying bioavailabilities.
END QUOTE
So, for this ferret get to the vet to find a safer option for the=20
ferret, please.
There does not yet appear to be any independent study which either=20
confirms or denies lavender being estrogenic.
Hey, a person doesn't need a ferret who might develop symptoms similar=20
to adrenal disease just because the ferret is getting estrogenic=20
substances that are actually causing the problem...
Sukie (not a vet)
Recommended ferret health links:
http://pets.groups.yahoo.com/group/ferrethealth/
http://ferrethealth.org/archive/
http://www.afip.org/ferrets/index.html
http://www.miamiferret.org/fhc/
http://www.ferretcongress.org/
http://www.trifl.org/index.shtml
http://homepage.mac.com/sukie/sukiesferretlinks.html
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