title: Protective actions of soy isoflavones and n-3 PUFAs on bone mass in ovariectomized rats.
abstract: Ovariectomy (OVX) in female rats precipitates a marked reduction in endogenous estrogen concentrations and induces bone remodeling abnormalities that augment bone loss and increase the risk of developing osteopenia. This research examined the combined effects of two levels of soy isoflavones (IFs), trace (-IF) and high (+IF) (0.03 and 3.43 mg/g protein, respectively), and two levels of n-3 polyunsaturated fatty acids (PUFAs) on bone conservation in 2-month-old sexually mature OVX Sprague-Dawley rats. All dietary treatments provided 110.4 g/kg of fat from either safflower oil (N6) or a blend of safflower oil and menhaden oil (N3). OVX rats were randomly assigned to the N6-IF, N6+IF, N3-IF and N3+IF groups. The OVX and sham rats were euthanized after 12 weeks of feeding. Data for sequential femoral and tibial in vivo bone mineral density and bone mineral content (BMC) measurements were determined every 4 weeks. The hindlimb mineral data indicated a trend toward a positive bone mineral-sparing effect related to +IF. Among the OVX rats, those fed the N3+IF diet had a significantly higher value for tibial BMC. The concentration of serum pyridinoline cross-links was significantly lower in the N3+IF group. These findings indicate a complementary action of soy IFs and n-3 PUFAs for attenuating bone mineral reduction in OVX rats.
authors.affiliation: Center for Enhancing Foods to Protect Health, Lipid Chemistry and Molecular Biology Laboratory, Purdue University, West Lafayette, IN 47907-2009, USA. baw@purdue.edu
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Watkins
authors.forename: Susan
authors.initials: S
authors.lastname: Reinwald
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
authors.forename: Mark F
authors.initials: MF
authors.lastname: Seifert
mesh_terms: D015502:Absorptiometry, Photon; D000818:Animals; D015519:Bone Density / Q000187:drug effects*; D016723:Bone Remodeling / Q000187:drug effects / Q000502:physiology; D004042:Dietary Fats, Unsaturated / Q000494:pharmacology*; D005227:Fatty Acids / Q000032:analysis; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D005260:Female; D005269:Femur / Q000737:chemistry; D007529:Isoflavones / Q000494:pharmacology*; D010052:Ovariectomy; D010053:Ovary / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013025:Glycine max / Q000737:chemistry*
chemical_list: D004042:Dietary Fats, Unsaturated; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D007529:Isoflavones