Zinc enhancement of genistein's anabolic effect on bone components in elderly female rats.
1. The effect of genistein on the bone components in the femoral-metaphyseal and diaphyseal tissues of elderly female rats was investigated. 2. The oral administration of genistein (100 and 200 microg/kg body weight) for 3 days to rats caused a significant increase in alkaline phosphatase activity, deoxyribonucleic acid (DNA) and calcium contents in the femoral-metaphyseal and diaphyseal tissues. A dose of 50 microg genistein/kg appreciably increased alkaline phosphatase activity and DNA content in the metaphyseal but not the diaphyseal tissues. 3. Alkaline phosphatase activity, DNA and calcium contents in the femoral-metaphyseal and diaphyseal tissues were significantly elevated by the oral administration of zinc sulfate (5.5 mg Zn/kg) for 3 days. The effect of zinc on increasing bone DNA and calcium contents was synergistically enhanced by the simultaneous administration of genistein (100 microg/kg). 4. The stimulatory effect of zinc sulfate (10(-5) M) or genistein (10(-5) M) on bone calcium content was also seen in a culture system using the femoral-metaphyseal and diaphyseal tissues in vitro. This effect was completely prevented by the presence of cycloheximide (10(-6) M). 5. The present findings suggest that genistein has an anabolic effect on bone components and that the effect is enhanced by zinc, owing to its stimulating effect on bone protein synthesis.
Laboratory of Endocrinology and Molecular Metabolism, Graduate School of Nutritional Sciences, University of Shizuoka, Shizuoka City, Japan.
Y H
YH
Gao
M
M
Yamaguchi
D000375:Aging; D000818:Animals; D001862:Bone Resorption / Q000139:chemically induced*; D002118:Calcium / Q000378:metabolism; D003513:Cycloheximide / Q000494:pharmacology; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005260:Female; D019833:Genistein / Q000494:pharmacology*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D015032:Zinc / Q000494:pharmacology*
D004791:Enzyme Inhibitors; D011500:Protein Synthesis Inhibitors; D003513:Cycloheximide; D019833:Genistein; D015032:Zinc; D002118:Calcium