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Isoflavones derived from Glycine max (L.) Merr. in the treatment of vaginal atrophy: A new frontier
Rev Assoc Med B ras 2017; 63(9):727-728 727
EDITORIAL
Isoflavones derived from Glycine max (L.) Merr. in the treatment
of vaginal atrophy: A new frontier
Isoflavonas derivadas do G lycine max (L.) M err. no tratamento da atrofia vaginal:
nova fronteira
Sônia Maria Rolim R osa Lima1*, Adriana Bittencourt Campaner1, Antonio Pedro Flores Auge 1
1Department of Obstetrics and Gynecology, Faculdade de Ciências Médicas da Santa Casa de São Paulo, São Paulo, SP, Brazil
*Correspondence:
During the climacteric, many changes take place, caused
both by the decrease of estrogens and other hormones
and by the effects of aging itself.1 Complaints of vasomo-
tor alterations, sleep disturbance, mood changes, and
genitourinary symptoms (GUS) are common. GUS affect
up to 50% of women in this period. They may be chronic
and progressive and their lifelong improvement is unlike-
ly. They can range from mild to severe and are not exclu-
sive to sexually active women. Despite this, many are
unaware that such symptoms result directly from the
decline in estrogen associated with menopause, and that
there are treatments available.2
Due to a common embryological origin, the bladder,
the urethra and the genitals have similar responses to hor-
monal changes, especially to estrogens. The atrophic process
that accompanies the hypoestrogenism can be verified in
the epitheliumand in the pelvic support tissues. The mucous
membranes become thinner, also causing genital prolapse,
vaginal and urinary symptoms become frequent and intense,
the vaginal microbiota changes, and vaginal pH becomes
more alkaline influencing women’s lives globally.3
Despite the many safe and effective options for treat-
ing the changes caused by vulvovaginal atrophy (VVA),
only a minority of women (about 25% in the Western
world and probably much less in other areas) seek medi-
cal help.4 One of the possible reasons for this behavior is
the adverse publicity (not currently justified) disclosed in
recent years for the use of hormone replacement therapy
(HRT) in menopause.
It is worth mentioning that local treatment of VVA is
not associated with the possible risks of systemic HRT.
Among the reasons for not seeking treatment for VVA com-
plaints are cultural ones and an understandable reluctance
to discuss such issues, particularly with a male doctor. On
the other hand, doctors also fail to inform about the pos-
sibilities of treatment for atrophic vaginal symptoms.5
Phytoestrogens are plant-derived chemical substanc-
es structurally or functionally similar to estradiol. The
main phytoestrogen used as a treatment for women in
the climacteric are isoflavones, polyphenolic flavonoids
found naturally in plants such as Glycine max (L.) Merr
and Trifolium pratense L.6 Isoflavones contain a phenolic
ring in a position analogous to estradiol, which allows
them to occupy their receptors in different tissues, and
may present actions similar to endogenous estrogen.7
Isoflavones have been used topically to prevent and
delay skin aging in postmenopausal women. They act on
the skin inhibiting tyrosine kinase, preventing the expression
of mRNA encoding collagenases and elastases (metallopro-
teinases), and thus hindering the degradation of extracel-
lular matrix fibers. Topical use of isoflavones in the skin
can lead to epidermal proliferation, increased synthesis, and
decreased enzymatic degradation of dermal collagen.8,9
To date, studies analyzing the effects of isoflavones
derived from dry extract of Glycine max (L.) Merr, admin-
istered vaginally on vaginal epithelium, on morphometric
features, the behavior of estrogen receptors, the vaginal
flora, and endometrium are scarce. Research was conduct-
ed with postmenopausal women comparing the effects of
isoflavones derived from dry extract of Glycine max (L.) Merr,
conjugated equine estrogens and placebo administered
vaginally on the vaginal epithelium and endometrium. As
a result, there was improvement in the symptoms of vagi-
nal atrophy with a significant increase in the values of cell
maturation, similar to those obtained with conjugated
estrogens, both superior to the placebo group. After treat-
ment, in serum FSH and estradiol concentrations, none of
the groups had an increase in endometrial thickness.10
Another study of the same product administered
vaginally in another group of postmenopausal women
evaluating the symptoms of vaginal dryness and dyspa-
reunia, vaginal epithelial morphology, and estrogen re-