Detection of Isoflavones in Mouse Tibia After Feeding Daidzein

다국어 초록 (Multilingual Abstract)

Many studies suggest that diets rich in isoflavones protect against bone loss or slow the loss of bone mass thatoccurs because of estrogen withdrawal. Although in vitrostudies have reported effects of isoflavones on bone cells, the pres-ence of daidzein and/or equol in bone tissue in vivo has not been reported. The objective of this study was to determine ifdaidzein and equol were present in bone tissue (tibias) after feeding mice a diet containing purified daidzein. Sham mice (n .9) received control diet, and ovariectomized mice were randomized to control diet (Ovx) (n . 9) or control diet containing200 mg of daidzein/kg of diet (n . 8) for 12 weeks. At necropsy, tibias and serum were collected. Mice in the Daidzein grouphad significantly higher (P. .05) levels of both daidzein and equol in tibias than Sham and Ovx mice. Tibia levels of daidzeinand equol were approximately five and four times higher, respectively, than the Sham and Ovx groups. Similarly, mice feddaidzein also had significantly higher (P. .05) serum daidzein and equol than the Sham and Ovx mice. In conclusion, feed-ing a level of daidzein that is attainable by dietary intervention alone results in a high level of both daidzein and equol in tib-ias. These findings suggest that daidzein and its metabolite, equol, have the potential to act directly on bone cells in vivo.

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