morin and Osteoporosis

Strontium ranelate (SrR) has been used as the ultimate choice for osteoporosis treatment. However, the development of more tolerable and bioactive Sr

Topics: Bone Density Conservation Agents; Calcification, Physiologic; Cell Differentiation; Cells, Cultured; Flavonoids; Humans; Osteoblasts; Osteoclasts; Osteoporosis; Strontium

Our aim is to investigate the potential therapeutic value of morin against osteoporosis and elucidate the mechanism of action. Osteoporosis was induced in rats by a subcutaneous injection of dexamethasone (DEX) for 5 weeks. Body weight was regularly monitored. Body mineral density (BMD) was determined at proximal femurs using dual energy X-ray absorptiometry. Pathological examination was performed by hematoxylin and eosin staining. The relative expression of osteogenic and bone resorption markers was determined by real-time polymerase chain reaction and Western blotting, respectively. Activation of the MAPK signaling pathway was analyzed by Western blotting. Body weight and BMD were both significantly decreased in osteoporotic rats, although BMD was partially restored by intraperitoneal morin administration. Morin treatment also increased the number of trabecular bones in DEX-induced rats. Mechanistically, morin reversed the decrease of osteogenic markers and increase of bone resorption markers, which might eventually be mediated by modulation of MAPK signaling cascades. Here, we uncovered the therapeutic effect of morin against osteoporosis and demonstrated its suppressive action on the MAPK pathway in this disease.

Topics: Animals; Dexamethasone; Female; Flavonoids; Glucocorticoids; Mitogen-Activated Protein Kinases; Osteoporosis; Rats; Rats, Sprague-Dawley; Signal Transduction

The purpose of this study was to gain insights into the variations seen in the electron paramagnetic resonance (EPR) spectroscopy of the native signals of teeth and bones used for retrospective dosimetry measurements. We determined that changes occur in the long-lived free radicals responsible for the native signal of cortical bone in aging or diseased human females and aged ovariectomized rats. This was done by measuring the magnitude of the broad (BC) and narrow (NC) components of the native EPR signal of bone following chemical extraction, aging, crushing and thermal annealing. Bone from the upper midshaft of femora of young (17-34 years old, n=5) and elderly (70-92 years old, n=18) females was examined. The results showed that the elderly women had significantly higher BC than the younger women (P<0.01). A similar interpretation was made of the data from an aging female rat osteoporosis model. The results for the NC signals were similar. Finally, dramatic decreases in both NC and BC signals were seen in HIV positive and uncontrolled diabetic (one each) patients indicating the need for studying this signal for a broad spectrum of metabolic disorders. Experiments were performed which strongly indicate that iron liganded with organic molecules is the source of the BC signal. Finally, the accuracy achieved in this study indicates that resolving the dosimetric signal (g=2.0018) should be improved by subtraction of the deconvoluted NC and BC signals from the original spectrum.

Topics: Adolescent; Adult; Aged; Aging; Animals; Antioxidants; Bone and Bones; Electron Spin Resonance Spectroscopy; Female; Femur; Flavonoids; Free Radicals; Humans; Iron; Ligands; Middle Aged; Osteoporosis; Ovariectomy; Radiometry; Rats; Rats, Sprague-Dawley; Women