Osteoprotective effect of genistein 7-O-phosphate, a derivative of genistein with high bioavailability, in ovariectomized rats

Abstract

Genistein 7-O-phosphate (G7P), generated by a bioconversion process of Bacillus subtilis var. natto with soy isoflavone genistein, is practically water-soluble and more bioavailable than aglyconic genistein. In this study, we assessed the ability of G7P to prevent bone loss in rats with ovariectomy. Twelve-week-old female rats underwent ovariectomy, and genistein or G7P was administered to rats 2 weeks after the surgery by daily oral gavage for another 12 weeks. After sacrifice at the 12th week, the femurs were analyzed by micro computed tomography, histology and biomechanical study. G7P administration prevented the loss of bone mineral density and the reduced Young’s modulus caused by ovariectomy and improved bone architecture observed in histology and tomography. Additionally, G7P treatment resulted in a higher plasma level and inhibition of post-ovariectomy bone loss than did genistein at the same dosage. Therefore, G7P may be potent functional food agent for dealing with postmenopausal osteoporosis.