Combined effects of soy isoflavone and fish oil on ovariectomy-induced bone loss in mice.
ABSTRACT Both soy isoflavone and n-3 polyunsaturated fatty acids are known to reduce the levels of bone-resorbing cytokines; however, the synergistic effects of these food ingredients have not been examined yet. This study was performed to elucidate the effect of concomitant intake of soy isoflavone and fish oil on bone mass in ovariectomized mice. Eight-week-old ddY female mice were subjected to ovariectomy (OVX) or sham surgery, and then fed an AIN-93G with safflower oil (So) as a control lipid source, isoflavone-supplemented safflower oil (So + I), fish oil instead of safflower oil (Fo) or isoflavone-supplemented fish oil (Fo + I) for 4 weeks. Femoral bone mineral density was significantly decreased by OVX; however, this decrease was inhibited by the intake of isoflavone and/or fish oil. Histomorphometric analyses showed that bone volume and trabecular thickness in the distal femoral trabecular bone were significantly lower in the So group than in the sham group, but those were restored in the Fo + I groups. The number of osteoclasts was significantly decreased by isoflavone intake. The increased rate of bone resorption after OVX was inhibited by isoflavone and/or fish oil. The serum concentration of tumor necrosis factor alpha was increased after OVX, but was significantly lower with the combination of isoflavone with fish oil than isoflavone or fish oil alone. The results of this study indicated that the intakes of soy isoflavone and/or fish oil might have ameliorating effects on bone loss due to OVX. Further, the concomitant intake of soy isoflavone and fish oil at a low dose showed better effects on cytokines related with bone resorption.
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ABSTRACT: Previous studies have identified a positive correlation between the intake of n‑3 fatty acids and bone mineral density in postmenopausal women. The aim of the present study was to determine the effects of fish oil on bone metabolism and to investigate the underlying mechanism using ovariectomized rats. Ovariectomized or sham‑operated (sham) female rats were fed AIN‑76A‑based diets containing 5% corn or fish oil for 2 weeks. Fish oil was found to decrease the plasma levels of arachidonic and linoleic acids, but increased the levels of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Fish oil reversed the increased activity and number of osteoclasts, and decreased calcium (Ca) and hydroxyproline (Hyp) content of the proximal tibia to sham values without affecting the activity or number of osteoblasts. In addition, fish oil suppressed increases in the mRNA and protein levels of macrophage colony‑stimulating factor (M‑CSF), PU.1, microphthalmia-associated transcription factor (MITF), receptor for activation of NFκB (RANK) and RANK ligand (RANKL) and serum levels of tumor necrosis factor α (TNFα), interleukin‑6 (IL-6) and prostaglandin E2 (PGE2). Fish oil was also found to suppress NFκB activation induced by ovariectomy. These results indicate that increases in plasma n‑3 fatty acid levels by fish oil led to the suppression of NFκB activation and subsequent downregulation of TNFα, followed by suppression of M‑CSF and RANKL. Dietary fish oil suppressed ovariectomy‑stimulated osteoclastogenesis by inhibiting the expression of M‑CSF, PU.1, MITF and RANK in the early stages of osteoclastogenesis, upstream of RANKL signaling.Molecular Medicine Reports 04/2013; · 1.48 Impact Factor
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ABSTRACT: Mycoepoxydiene (MED) is a compound isolated from the marine fungal Diaporthe sp. HLY-1 associated with mangroves. MED has various biological effects such as anti-microbial, anti-cancer, and anti-inflammatory activities. However, the effect of MED on the differentiation of osteoclasts, the multinucleated bone-resorbing cells which play a crucial role in bone remodeling, is still unknown. In this study, we showed that MED could inhibit receptor activator of NF-κB ligand (RANKL)-induced osteoclast differentiation and the expression of three well-known osteoclast markers such as tartrate-resistant acid phosphatase, calcitonin receptor, and cathepsin K in bone marrow-derived macrophages. Furthermore, we found that MED inhibited the expression of nuclear factor of activated T cells c1, a key transcriptional factor in osteoclast differentiation, via inhibiting the phosphorylation of TAK1 and then blocking the activation of NF-κB and ERK1/2 pathways. Moreover, MED could prevent bone loss in ovariectomized mice. Taken together, we demonstrate for the first time that MED can suppress RANKL-induced osteoclast differentiation in vitro and ovariectomy-induced osteoporosis in vivo, suggesting that MED is a potential lead compound for the development of novel drugs for osteoporosis treatment.Applied Microbiology and Biotechnology 06/2012; 97(2). · 3.81 Impact Factor
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ABSTRACT: Cancer chemotherapy has been shown to induce long-term skeletal side effects such as osteoporosis and fractures; however, there are no preventative treatments. This study investigated the damaging effects of anti-metabolite methotrexate (MTX) subcutaneous injections (0.75 mg/kg BW) for five days and the potential protective benefits of daily oral gavage of fish oil at 0.5 mL/100 g BW (containing 375 mg of n-3 PUFA/100 g BW), genistein (2 mg/100 g BW), or their combination in young adult rats. MTX treatment alone significantly reduced primary spongiosa height and secondary spongiosa trabecular bone volume. Bone marrow stromal cells from the treated rats showed a significant reduction in osteogenic differentiation but an increase in adipogenesis ex vivo. Consistently, stromal cells had significantly higher mRNA levels of adipogenesis-related proliferator activator activated receptor-γ (PPAR-γ) and fatty acid binding protein (FABP4). MTX significantly increased the numbers of bone-resorbing osteoclasts and marrow osteoclast precursor cell pool while significantly enhancing the mRNA expression of receptor activator for nuclear factor kappa B ligand (RANKL), the RANKL/osteoprotegerin (OPG) ratio, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in the bone. Supplementary treatment with fish oil and/or genistein significantly preserved trabecular bone volume and osteogenesis but suppressed MTX-induced adipogenesis and increases in osteoclast numbers and pro-osteoclastogenic cytokine expression. Thus, Fish oil and/or genistein supplementation during MTX treatment enabled not only preservation of osteogenic differentiation, osteoblast number and bone volume, but also prevention of MTX treatment-induced increases in bone marrow adiposity, osteoclastogenic cytokine expression and osteoclast formation, and thus bone loss.PLoS ONE 08/2013; 8(8):e71592. · 3.53 Impact Factor