Comparative Study on Reduction of Bone Loss and Lipid Metabolism Abnormality in Ovariectomized Rats by Soy Isoflavones, Daidzin, Genistin, and Glycitin.

Abstract

The risk of coronary heart disease drastically increases after menopause. 1) Arteriolosclerosis induced by lipid metabolism abnormality after menopause has been recognized as a major risk factor for cardiovascular disease.2) Osteoporosis associated with ovarian hormone deficiency following menopause is the most common cause of age-related bone loss. A sharp decrease in estrogen production causes rapid hormone-related bone loss during the first decade after menopause. 3)Post-menopausal estrogen replacement therapy (ERT) has shown potential for reduction or prevention of coronary heart disease, 4) and is considered to be the most effective method to reduce the rate of osteoporosis in post menopausal women.5) However, ERT may be accompanied by unacceptable side effects such as endometrial and breast cancer in some women. 6) Therefore, ERT is recommended only for women who have no contraindications. Thus, it would be most helpful to discover a natural and safe dietary substance that minimizes bone loss and/or improves lipid metabolism in post menopausal women.It is well known that soybeans contain free isoflavones, daidzein, genistein and glycitein, and their glycoside derivatives. Daidzin, genistin and their acylated derivatives account for the major portion of isoflavones in soybeans, while glycitin and its acylated derivatives are minor components.7) It is not easy to prepare gram amounts of isoflavones, especially glycitein and glycitin, from soybeans or by synthesis for biological testing in vivo. 7,8) Both in vitro and in vivo studies have shown that daidzein, genistein, and their glycosides exert a weak estrogenic effect. 9) Therefore, numerous studies have been performed with daidzein and genistein, but there has been only one biological study on the estrogenic activity of glycitein in vitro and in vivo, 10) to our knowledge. Several investigators have reported that soybean consumption may contribute to lower risk of the postmenopausal diseases, including coronary heart disease 11) and osteoporosis. 12)Recently, the hypocholesterolemic and osteoporosis-ameliorating properties of soy protein isolate, which is a rich source of isoflavones, have received much attention.13) It is not yet clear whether the preventive effect of soy protein on lipid and bone metabolism abnormality is due to its amino acid composition, to nonprotein constituents such as saponins, phytic acids and isoflavones, or to a combination of these factors. However, there has been increasing interest in the soy isoflavones and their biological activities in recent year. 14)Several recent reports indicate that soy isoflavones may have beneficial effects on bone. Recent studies indicate that oral administration of daidzin, genistin and their succinyl derivatives significantly prevents bone loss in an ovx model 15) and genistein is also effective.16) Further, daidzin inhibits atrophy of the uterus, while genistin or genistein does not at the examined dose. The findings of these studies suggest that the action mechanism of daidzin on bone loss is ...

O tratamento com isoflavonas mimetiza a ação do estradiol no acúmulo de gordura em ratas ovariectomizadas

“…Estes resultados indicam que as ISO apresentam efeitos positivos no perfi l lipídico de ratas OVX. Esta observação é consistente com os relatos de vários pesquisadores, que também utilizaram como modelo experimental ratas OVX tratadas com ISO (48,51,52).…”

Anti-obese and anti-diabetic effects of a mixture of daidzin and glycitin on C57BL/6J mice fed with a high-fat diet

“…[17][18][19] It was also reported that glycitin has preventive effect on bone loss and osteonecrosis. 20,21) However, to our knowledge, there are few studies that have been done on the effects of glycoside-form isoflavone supplementation on lipid metabolism associated with diabetes mellitus. In the present study, we have studied the changes caused by both diet and treatment with a mixture of daidzin and glycitin which are the *Corresponding author.…”

Metabolomics Reveals Novel Pathways and Differential Mechanistic and Elicitor-Specific Responses in Phenylpropanoid and Isoflavonoid Biosynthesis in Medicago truncatula Cell Cultures

“…Particularly important are the phenylpropanoid-derived isoflavonoids that serve as key signaling molecules in plant-microbe interactions and as primary defense compounds. Isoflavonoids have also been ascribed a large number of pharmacological and nutraceutical properties, including chemoprevention of osteoporosis (Alekel et al, 2000;Uesugi et al, 2001) and other postmenopausal disorders (MerzDemlow et al, 2000), antioxidants related to improved cardiovascular health (Lichtenstein, 1998;Setchell and Cassidy, 1999;Heim et al, 2002), and reduced risk of breast and prostate cancers in humans (Adlercreutz, 1998;Lamartiniere, 2000). However, a more comprehensive understanding of isoflavonoid biosynthesis is still needed for the efficient engineering and exploitation of these compounds for plant, animal, and human benefit.…”