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Fermented soybeans by Rhizopus oligosporus reduce femoral bone loss in ovariectomized rats

BACKGROUND/OBJECTIVES: Soy isoflavones are structurally similar to estrogen and bind to estrogen receptors, suggesting that they exhibit estrogenic activities; therefore, they are referred to as phytoestrogens. Fermentation may affect the bioavailability of isoflavones altering soy isoflavone glycos...

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Autores principales: Yoo, Hyun-Wook, Chang, Moon-Jeong, Kim, Sun-Hee
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Korean Nutrition Society and the Korean Society of Community Nutrition 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4198967/
https://www.ncbi.nlm.nih.gov/pubmed/25324934
http://dx.doi.org/10.4162/nrp.2014.8.5.539
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author Yoo, Hyun-Wook
Chang, Moon-Jeong
Kim, Sun-Hee
author_facet Yoo, Hyun-Wook
Chang, Moon-Jeong
Kim, Sun-Hee
author_sort Yoo, Hyun-Wook
collection PubMed
description BACKGROUND/OBJECTIVES: Soy isoflavones are structurally similar to estrogen and bind to estrogen receptors, suggesting that they exhibit estrogenic activities; therefore, they are referred to as phytoestrogens. Fermentation may affect the bioavailability of isoflavones altering soy isoflavone glycosides in the form of aglycones. Thus, this study investigated the effects of fermented soybeans by Rhizopus oligosporus on bone metabolism in both young rats as a pilot test and in ovariectomized (ovx) old rats as a model of menopause. MATERIALS/METHODS: In the pilot test, a total of 24 seven-week-old female Sprague-Dawley (SD) rats were fed one of three diets for a period of four weeks: casein, unfermented soybean product, or fermented soybean product by R. oligosporus. In the ovx rat model, 20-week-old SD rats weighing 260-290 g underwent either sham-operation (n = 10) or bilateral ovariectomy (n = 30) and were then fed the AIN-93M diet for one week. Thereafter, rats were fed sham-casein, ovx-casein, ovx-soybean, or ovx-fermented soybean diet for five weeks. After decapitation, femoral bones were isolated and preserved in 9% formalin for assessment of bone mineral density (BMD), bone mineral content (BMC), and bone-breaking strength (BBS). RESULTS: Ovx rats showed significantly increased weight gain and decreased uterine wet weight. Of particular interest, ovx rats fed fermented soybeans showed increased uterine wet weights compared to control rats. Fermented soybean diet caused a significant increase in plasma 17-β estradiol concentrations in young rats, and 17-β estradiol levels were enhanced in ovx rats to match those of sham-operated ones. Significantly lower femoral BMD and BMC were observed in ovx rats compared to sham-operated controls, whereas bone areas did not differ statistically among the groups. In addition, BBS tended to be increased in ovx rats fed soybeans and fermented soybeans. CONCLUSIONS: Supplementation of fermented soybeans could have preventive and therapeutic effects against osteoporosis in postmenopausal women.
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spelling pubmed-41989672014-10-16 Fermented soybeans by Rhizopus oligosporus reduce femoral bone loss in ovariectomized rats Yoo, Hyun-Wook Chang, Moon-Jeong Kim, Sun-Hee Nutr Res Pract Original Research BACKGROUND/OBJECTIVES: Soy isoflavones are structurally similar to estrogen and bind to estrogen receptors, suggesting that they exhibit estrogenic activities; therefore, they are referred to as phytoestrogens. Fermentation may affect the bioavailability of isoflavones altering soy isoflavone glycosides in the form of aglycones. Thus, this study investigated the effects of fermented soybeans by Rhizopus oligosporus on bone metabolism in both young rats as a pilot test and in ovariectomized (ovx) old rats as a model of menopause. MATERIALS/METHODS: In the pilot test, a total of 24 seven-week-old female Sprague-Dawley (SD) rats were fed one of three diets for a period of four weeks: casein, unfermented soybean product, or fermented soybean product by R. oligosporus. In the ovx rat model, 20-week-old SD rats weighing 260-290 g underwent either sham-operation (n = 10) or bilateral ovariectomy (n = 30) and were then fed the AIN-93M diet for one week. Thereafter, rats were fed sham-casein, ovx-casein, ovx-soybean, or ovx-fermented soybean diet for five weeks. After decapitation, femoral bones were isolated and preserved in 9% formalin for assessment of bone mineral density (BMD), bone mineral content (BMC), and bone-breaking strength (BBS). RESULTS: Ovx rats showed significantly increased weight gain and decreased uterine wet weight. Of particular interest, ovx rats fed fermented soybeans showed increased uterine wet weights compared to control rats. Fermented soybean diet caused a significant increase in plasma 17-β estradiol concentrations in young rats, and 17-β estradiol levels were enhanced in ovx rats to match those of sham-operated ones. Significantly lower femoral BMD and BMC were observed in ovx rats compared to sham-operated controls, whereas bone areas did not differ statistically among the groups. In addition, BBS tended to be increased in ovx rats fed soybeans and fermented soybeans. CONCLUSIONS: Supplementation of fermented soybeans could have preventive and therapeutic effects against osteoporosis in postmenopausal women. The Korean Nutrition Society and the Korean Society of Community Nutrition 2014-10 2014-05-15 /pmc/articles/PMC4198967/ /pubmed/25324934 http://dx.doi.org/10.4162/nrp.2014.8.5.539 Text en ©2014 The Korean Nutrition Society and the Korean Society of Community Nutrition http://creativecommons.org/licenses/by-nc/3.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Original Research
Yoo, Hyun-Wook
Chang, Moon-Jeong
Kim, Sun-Hee
Fermented soybeans by Rhizopus oligosporus reduce femoral bone loss in ovariectomized rats
title Fermented soybeans by Rhizopus oligosporus reduce femoral bone loss in ovariectomized rats
title_full Fermented soybeans by Rhizopus oligosporus reduce femoral bone loss in ovariectomized rats
title_fullStr Fermented soybeans by Rhizopus oligosporus reduce femoral bone loss in ovariectomized rats
title_full_unstemmed Fermented soybeans by Rhizopus oligosporus reduce femoral bone loss in ovariectomized rats
title_short Fermented soybeans by Rhizopus oligosporus reduce femoral bone loss in ovariectomized rats
title_sort fermented soybeans by rhizopus oligosporus reduce femoral bone loss in ovariectomized rats
topic Original Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4198967/
https://www.ncbi.nlm.nih.gov/pubmed/25324934
http://dx.doi.org/10.4162/nrp.2014.8.5.539
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