Abstract
Oestrogen deficiency leads to a considerable bone loss, thus, osteopenia and osteoporosis
are serious complications after menopause.
Objectives
To evaluate the effects of a daidzein metabolite equol on bone mass density (BMD)
and markers of bone remodelling in an ovariectomized (ovx) rat model of postmenopausal
bone loss and compare them with the effects of 17β-estradiol.
Methods
Twenty-eight female Sprague–Dawley rats were ovx and fed soy-free chow only (control
group, n = 8), or with the addition of oestradiol-3 benzoate (E2B) (10 mg/kg, n = 10) or equol (400 mg/kg, n = 10). At baseline and after 6-week treatment period, proximal tibia and lumbar spine
BMD were measured using computer tomography. Animals were then sacrificed, blood was
collected and uteri were removed.
Results
Similarly to E2B, dietary equol decreased weight gain and showed mild uterotropic
activity. E2B attenuated ovx induced BMD loss at proximal tibia whereas equol had
no effect. At lumbar spine, however, equol not only attenuated trabecular bone loss
but also increased its density. This effect was also apparent in animals treated with
E2B. Cortical BMD at proximal tibia and lumbar spine were not very much influenced
by ovx and treatment with E2B or equol did not induce significant changes at these
sites. Plasma osteocalcin and type I collagen fragments (cross-laps) in equol treated
animals did not differ from the controls whereas in E2B treated animals they were
both significantly decreased.
Conclusions
In spite of its mild uterotropic potential, dietary equol shows limited bone sparing
effects in ovx rats.
Keywords
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Article info
Publication history
Published online: October 10, 2007
Accepted:
September 9,
2007
Received in revised form:
August 27,
2007
Received:
February 13,
2007
Identification
Copyright
© 2007 Elsevier Ireland Ltd. Published by Elsevier Inc. All rights reserved.
