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Date:
08-29-2014 | HC# 031442-503
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Re: Herbal Medicine for the Treatment of Endometriosis
Stephens L, Whitehouse J, Polley M. Western
herbal medicine, epigenetics, and endometriosis. J Altern Complement Med. 2013;19(11):853-859.
Endometriosis, a poorly-understood,
estrogen-dependent condition affecting over 10% of Western women of
reproductive age, is characterized by growth and presence of endometrial-like
tissue outside the uterine cavity, usually around the pelvic organs and/or
peritoneum. Extra-uterine endometrial tissue can cause severe pain. Several
theories have been advanced for the occurrence of endometriosis but significant
variability of symptom severity makes it likely to be multifactorial.
Conventional management is based on reducing and preventing recurrence of pain with
non-steroidal anti-inflammatory drugs (NSAIDs) and other analgesics, suppressing
ovarian function with hormonal drugs, and surgical removal of endometriotic
tissue. All have significant drawbacks. A new drug, dienogest, a
19-nortestosterone derivative, reports efficacy and tolerability; however,
uncertainty over individual response rates still fuels interest in other
approaches to management.
Herbal medicine has long been used in China
for endometriosis, and its use is growing in the West. The UK's Royal College
of Obstetricians and Gynaecologists reports that some women use complementary
medicine, including herbs, to manage endometriosis either instead of hormone
replacement therapy (HRT) or alongside conventional drugs. Several of the herbs
commonly used have antiproliferative, antioxidant, anti-inflammatory, and/or
analgesic effects in vitro. Difficulties with integrating herbs into a
multidisciplinary approach, the authors say, stem from poor knowledge of herbal
practice outside the herbalist community.
While herbal and conventional practitioners
diagnose endometriosis using a common model of pathology, herbalists generally
prescribe individual, frequently evaluated herbal regimens and lifestyle
counseling. This individualized approach is supported by advances in
understanding endometriosis' pathology. Immunological, hormonal, genetic, and
environmental factors affect its development and progression, along with
deregulation of several biological pathways. Epigenetic changes (in chromatin
structure and gene expression not from DNA mutations) may be common denominators.
Such changes may be reversed through lifestyle and environmental factors.
Some epigenetic changes seen in endometriosis
are described, including aberrant methylation of promoter cell regions with
either increased or reduced gene expression; downregulation of gene expression
by micro-RNAs (miRNAs), found in 48 of 487 miRNAs in endometriotic lesions; and
histone modification. For example, chronic inflammation leads to
hypermethylation of progesterone receptor B (PR-B) and progesterone resistance
in endometriosis. Hypermethylation alters expression of PR-B and estrogen
receptor β (ER-β). Hypomethylation of the ER-β promoter may induce progesterone
deficiency. DNA methyltransferases (DNMTs) are overexpressed in endometriotic
tissue as compared to control tissue. Endometriosis is heritable and
persistent, and DNA methylation may explain how its aberrations are maintained.
MiRNAs regulate up to 30% of human genes. Downregulated
miRNAs in endometriotic tissue include among their targets transforming growth
factor β, estrogen receptor α, ER- β, and PR; changes in all of these are
associated with endometriosis. MiRNAs affect inflammation, tissue repair, cell
growth, proliferation, apoptosis, and angiogenesis. For example, miR-199a and
miR-16 suppress cyclooxygenase-2 (COX-2). They are downregulated in
endometriosis, raising levels of COX-2 and consequent inflammation. Meanwhile,
increased expression of miR-15b/16 and miR-145 and downregulation of miR-20a,
miR-221, and miR-222 are linked to increased survival of endometrial cells.
Herbs most frequently used for endometriosis at
the University of Westminster's polyclinic are dong quai (Angelica sinensis), licorice (Glycyrrhiza
glabra), poke (Phytolacca americana),
gotu kola (Centella asiatica),
calendula (Calendula officinalis),
black haw (Viburnum prunifolium),
celandine (Chelidonium majus), ginger
(Zingiber officinale), yarrow (Achillea millefolium), lady's mantle (Alchemilla xanthochlora syn. A. vulgaris), thuja (Thuja occidentalis), milk thistle (Silybum marianum syn. Carduus marianus), henbane (Hyoscyamus niger), turmeric (Curcuma longa), and schisandra (Schisandra chinensis). All have shown
antioxidant, anti-inflammatory, anti-spasmodic,
antiproliferative/pro-apoptotic, and/or anti-nociceptive/analgesic effects relevant
in endometriosis in vitro and/or in vivo. Some studies report positive effects
on pelvic pain and inflammation with antioxidants. Overall, there is good evidence
that commonly used herbs can positively affect the epigenome, potentially
reversing the changes seen in endometriosis. Although there is a lack of
clinical studies, existing research gives convincing evidence of their
potential in this debilitating condition.
—Mariann Garner-Wizard
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