title: Anabolic effect of genistein on bone metabolism in the femoral-metaphyseal tissues of elderly rats is inhibited by the anti-estrogen tamoxifen.
abstract: Whether the anabolic effect of genistein on bone metabolism in the femoral-metaphyseal tissues of elderly rats is inhibited by the anti-estrogen tamoxifen was investigated in vitro. Bone tissues were cultured for 24 h in the medium containing either vehicle or genistein. The presence of genistein (10(-6) and 10(-5) M) caused a significant increase in calcium content, alkaline phosphatase activity and DNA content in the bone tissues. The effect of genistein (10(-5) M) in increasing bone alkaline phosphatase activity and DNA content was equal to the stimulatory effect of 17 beta-estradiol (10(-10) and 10(-9) M) on the bone components. The genistein effect was not significantly enhanced by the presence of 17 beta-estradiol (10(-10) and 10(-9) M). The anti-estrogen tamoxifen (10(-7) M) completely blocked the effect of 17 beta-estrogen in increasing bone alkaline phosphatase activity and DNA content. The genistein (10(-5) M)-induced increases in bone alkaline phosphatase activity and DNA content were completely abolished by the presence of tamoxifen (10(-7) and 10(-6) M), although tamoxifen itself had no effect on the bone components. The present study demonstrated that the anabolic effect of genistein on bone components is inhibited by anti-estrogen tamoxifen. The effect of genistein may be mediated through estrogen-like action.
authors.affiliation: Laboratory of Endocrinology and Molecular Metabolism, Graduate School of Nutritional Sciences, University of Shizuoka, Shizuoka City, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Y H
authors.initials: YH
authors.lastname: Gao
mesh_terms: D000375:Aging / Q000187:drug effects / Q000378:metabolism*; D000469:Alkaline Phosphatase / Q000187:drug effects; D000818:Animals; D004965:Estrogen Antagonists / Q000494:pharmacology; D005260:Female; D005269:Femur / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism*; D005270:Femur Head / Q000187:drug effects / Q000378:metabolism; D019833:Genistein / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D009924:Organ Culture Techniques; D051381:Rats; D017208:Rats, Wistar; D013629:Tamoxifen / Q000494:pharmacology*
chemical_list: D004965:Estrogen Antagonists; D013629:Tamoxifen; D019833:Genistein; D000469:Alkaline Phosphatase