title: Dietary quercetin inhibits bone loss without effect on the uterus in ovariectomized mice.
abstract: Quercetin is a major dietary flavonoid found in onions and other vegetables, and potentially has beneficial effects on disease prevention. In the present study, we demonstrate for the first time the effects of dietary quercetin on bone loss and uterine weight loss by ovariectomy in vivo. Female mice were ovariectomized (OVX) and were randomly allocated to 3 groups: a control diet or a diet with 0.25% (LQ) or 2.5% quercetin (HQ). After 4 weeks, dietary quercetin had no effects on uterine weight in OVX mice, but bone mineral density of the lumbar spine L4 and femur measured by peripheral quantitative computed tomography (pQCT) was higher in both the sham and the HQ groups than in the OVX group. Histomorphometric analysis showed that the HQ group restored bone volume (BV/TV) completely in distal femoral cancellous bone, but did not reduce the osteoclast surface area and osteoclast number when compared with the OVX group. In in-vitro experiments using mouse monocyte/macrophage cell line RAW264.7 cells, however, quercetin and its conjugate, quercetin-3-O-beta-D: -glucuronide dose-dependently inhibited the receptor activator of nuclear factor-kappa B ligand (RANKL)-induced osteoclast differentiation, and the RANKL-stimulated expression of osteoclast related genes was also inhibited by quercetin. The luciferase reporter assay showed that quercetin did not appear to have estrogenic activity through estrogen receptors. These results suggest that dietary quercetin inhibits bone loss without effect on the uterus in OVX mice and does not act as a potent inhibitor of osteoclastogenesis or as a selective estrogen receptor modulator in vivo.
authors.affiliation: Department of Clinical Nutrition, Institute of Health Biosciences, The University of Tokushima, Tokushima 770-8503, Japan.
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Tsuji
authors.forename: Hironori
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Tadatoshi
authors.initials: T
authors.lastname: Sato
authors.forename: Yoko
authors.initials: Y
authors.lastname: Mizuha
authors.forename: Yoshichika
authors.initials: Y
authors.lastname: Kawai
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Taketani
authors.forename: Shigeaki
authors.initials: S
authors.lastname: Kato
authors.forename: Junji
authors.initials: J
authors.lastname: Terao
authors.forename: Takahiro
authors.initials: T
authors.lastname: Inakuma
authors.forename: Eiji
authors.initials: E
authors.lastname: Takeda
mesh_terms: D000818:Animals; D001835:Body Weight; D015519:Bone Density; D001842:Bone and Bones / Q000378:metabolism; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D005260:Female; D005419:Flavonoids / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008159:Lumbar Vertebrae / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D041681:NIH 3T3 Cells; D010052:Ovariectomy / Q000379:methods*; D011794:Quercetin / Q000031:analogs & derivatives / Q000494:pharmacology*; D053245:RANK Ligand / Q000378:metabolism; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods; D014599:Uterus / Q000187:drug effects*
chemical_list: D005419:Flavonoids; D053245:RANK Ligand; C443401:quercetin 3-O-glucuronide; D011794:Quercetin