Monthly Archives: March 2014

Curcumin Helps Suppress TNF-alpha and MMP-13 In Vitro

Abstract

Induction of matrix metalloproteinase-13 gene expression by TNF-alpha is mediated by MAP kinases, AP-1, and NF-kappaB transcription factors in articular chondrocytes.

Tumor necrosis factor alpha (TNF-alpha), a major proinflammatory cytokine, induces arthritic joint inflammation and resorption of cartilage by matrix metalloproteinase-13 (MMP-13). RNA for MMP-13 is increased in human arthritic femoral cartilage. Mechanisms of this induction were investigated by pretreating primary human osteoarthritic (OA) femoral head chondrocytes or chondrosarcoma cells with the potential inhibitors of TNF-alpha signal transduction and downstream target transcription factors followed by stimulation with TNF-alpha and analysis of MMP-13 RNA/protein. TNF-alpha rapidly activated phosphorylation of extracellular signal-regulated kinases (ERKs), p38, and c-jun N-terminal kinase (JNK) mitogen-activated protein (MAP) kinases in human chondrocytes. Inhibitors of ERK (U0126, PD98059, and ERK1/2 antisense phosphorothioate oligonucleotide), JNK (SB203580, SP600125, and curcumin), and p38 (SB203580 and SB202190) pathways down-regulated the TNF-stimulated expression of MMP-13. Inhibitors of the transcription factors AP-1 (nordihydroguaiaretic acid, NDGA) and NF-kappaB (curcumin, proteasome inhibitors, and Bay-11-7085) suppressed TNF-alpha-induced MMP-13 expression in primary chondrocytes and SW1353 cells. These results suggest that induction of the MMP-13 gene by TNF-alpha is mediated by ERK, p38, and JNK MAP kinases as well as AP-1 and NF-kappaB transcription factors. Blockade of TNF-alpha signaling and its target transcription factors by the approaches tested here may be beneficial for reducing cartilage breakdown by MMP-13 in arthritis.

Liacini A, Sylvester J, Li WQ, Huang W…
Exp. Cell Res. Aug 2003
PMID: 12878172

Eldecalcitol Stronger than Vitamin D

Abstract

Osteoporosis treatment by a new active vitamin D3 compound, eldecalcitol, in Japan.

Although vitamin D is used mainly as a nutritional supplement in osteoporosis treatment, its active form, 1,25-dihydroxyvitamin D [1,25(OH)(2)D], has an effect to maintain bone remodeling balance as well. Eldecalcitol is an analog of 1,25(OH) (2)D(3) with stronger effects than its native form in improving bone remodeling balance and increasing bone mineral density in osteoporotic patients. Daily 0.75 μg eldecalcitol is superior to 1.0 μg alfacalcidol in preventing new vertebral fractures under vitamin D supplementation, and is approved for osteoporosis treatment in Japan. Eldecalcitol also decreases wrist fractures. Further studies are warranted to examine the effect of eldecalcitol on other nonvertebral fractures, extraskeletal systems including falls, and combined treatment with other drugs in osteoporotic patients, as well as the mechanism of action of eldecalcitol.

Matsumoto T
Curr Osteoporos Rep Dec 2012
PMID: 22918710

Bisphosphonates Help Bone Mass But Not Strength, Elastic Modulus, or Toughness in Rats

Abstract

Higher doses of bisphosphonates further improve bone mass, architecture, and strength but not the tissue material properties in aged rats.

We report the results of a series of experiments designed to determine the effects of ibandronate (Ibn) and risedronate (Ris) on a number of bone quality parameters in aged osteopenic rats to explain how bone material and bone mass may be affected by the dose of bisphosphonates (BP) and contribute to their anti-fracture efficacy. Eighteen-month old female rats underwent either ovariectomy or sham surgery. The ovariectomized (OVX) groups were left untreated for 2 months to develop osteopenia. Treatments started at 20 months of age as follows: sham and OVX control (treated with saline), OVX + risedronate 30 and 90 (30 or 90 microg/kg/dose), and OVX + ibandronate 30 and 90 (30 or 90 microg/kg/dose). The treatments were given monthly for 4 months by subcutaneous injection. At sacrifice at 24 months of age the 4th lumbar vertebra was used for microCT scans (bone mass, architecture, and degree of mineralization of bone, DMB) and histomorphometry, and the 6th lumbar vertebra, tibia, and femur were collected for biomechanical testing to determine bone structural and material strength, cortical fracture toughness, and tissue elastic modulus. The compression testing of the vertebral bodies (LVB6) was simulated using finite-element analysis (FEA) to also estimate the bone structural stiffness. Both Ibn and Ris dose-dependently increased bone mass and improved vertebral bone microarchitecture and mechanical properties compared to OVX control. Estimates of vertebral maximum stress from FEA were correlated with vertebral maximum load (r=0.5, p<0.001) and maximum stress (r=0.4, p<0.005) measured experimentally. Tibial bone bending modulus and cortical strength increased compared to OVX with both BP but no dose-dependent effect was observed. DMB and elastic modulus of trabecular bone were improved with Ibn 30 compared to OVX but were not affected in other BP-treated groups. DMB of tibial cortical bone showed no change with BP treatments. The fracture toughness examined in midshaft femurs did not change with BP even with the higher doses. In summary, the anti-fracture efficacy of BP is largely due to their preservation of bone mass and while the higher doses further improve the bone structural properties do not improve the localized bone material characteristics such as tissue strength, elastic modulus, and cortical toughness.

Shahnazari M, Yao W, Dai W, Wang B…
Bone May 2010
PMID: 19931661

Bisphosphonates and Osteonecrosis Laser Treatment

Abstract

Bisphosphonates and osteonecrosis: an open matter.

Osteonecrosis of the Jaw (ONJ) in patients on long-term Bisphosphonate Therapy (BPT) is being reported in the last ten years in the literature with increasing frequency. The therapy for this condition is a real dilemma. Temporary suspension of BPT offers no short term benefits, hyperbaric oxygen has no proven efficiency and therefore is not recommended, intermittent or continuous antibiotic with surgical debridement can be beneficial to palliate the symptoms. Er:YAG laser can be used to eliminate necrotic portions of the bone by partial or total resection of the jaws as an alternative to conventional rotary tools. The high degree of affinity of this wavelength for water and hydroxyapatite means the soft tissue and bone can both be treated. The technique can also be used for conservative interventions by gradually evaporating the part of necrotic bone, getting close to the healthy area. One certain advantage of the Er:YAG laser is its bactericidal and biostimulatory action, inducing the healing of the soft tissues and the bone, quicker than in conventional treatments. In conclusion, from our experience, it is possible to observe that an early conservative surgical approach with Er:YAG laser associated to biostimulation, LLLT (Low Level Laser Therapy), for BRONJ could be considered as more efficacious in comparison to medical therapy or other techniques.

Vescovi P
Clin Cases Miner Bone Metab Sep 2012
PMID: 23289026 | Free Full Text

Lactosucrose Enhances Calcium Absorption in Young Women

Abstract

Long-term administration of 4G-beta-D-galactosylsucrose (lactosucrose) enhances intestinal calcium absorption in young women: a randomized, placebo-controlled 96-wk study.

This study determined the effect of long-term administration of 4(G)-beta-D-galactosylsucrose (lactosucrose; LS) on intestinal calcium absorption. In a randomized, single-blind, parallel-group study, LS (n=9, 6.0 g twice daily) or a placebo (maltose; n=8, 6.0 g twice daily) was administered to healthy young women for 92 wk: the study also included a 4-wk post-administration period. All participants completed the study. Dietary nutrient intake; fecal weight, pH, and moisture content; fecal concentrations of short-chain fatty acids (SCFA), putrefactive products, ammonia, and minerals (calcium, magnesium, phosphorus, and iron); and serum calcium and osteocalcin concentrations were measured every 24 wk. Urinary pyridinoline (PYR) and deoxypyridinoline (DPD), and urinary calcium excretion were measured every 12 wk. Significant effects of oligosaccharide treatment, time, and the interaction between oligosaccharide treatment and time were observed for fecal pH, SCFA, ammonia, and putrefactive product values (p<0.05). Fecal pH, ammonia, and putrefactive product values decreased in the LS group, and the fecal SCFA concentration significantly increased during the administration period; these changes were not observed 4 wk post-administration. To examine the mineral balance of calcium, magnesium, and phosphorus in detail, all the participants completed a 6-d mineral balance study, sometime between week 56 and 60 of the longer study. During the mineral balance study, the daily calcium intake was set at 400 mg; all feces and urine were collected each day for 6 d after an 8-d acclimation period. In the balance study, fecal calcium excretion was significantly lower in the LS group than in the placebo group (p<0.05), and apparent calcium absorption and retention, apparent magnesium and phosphorus absorption, and magnesium retention were significantly higher in the LS group than in the placebo group (p<0.05). Our results suggest that the administration of LS produces a long-term enhancement of intestinal calcium absorption in healthy young women with lower than recommended calcium intakes.

Teramoto F, Rokutan K, Sugano Y, Oku K…
J. Nutr. Sci. Vitaminol. Oct 2006
PMID: 17190104 | Free Full Text

BMD did not differ between groups.

The lack of change in BMD might have been influenced by enhanced intestinal phosphorus absorption as a consequence of the enhanced intestinal calcium absorption during LS administration.

The insufficient calcium intake, age of the participants, ratio of calcium to phosphorus in the diet, and changes in LS administration may have influenced BMD.

Onion Inhibits Osteoclasts In Vitro

Abstract

Water solution of onion crude powder inhibits RANKL-induced osteoclastogenesis through ERK, p38 and NF-kappaB pathways.

Onion powder has been reported to decrease the ovariectomy-induced bone resorption of rats. However, the molecular mechanism of onion powder on the bone cells has not been reported. Here, we report that water solution of onion crude powder decreases the osteoclastogenesis from co-cultures of bone marrow stromal cells and macrophage cells. Additionally, water solution of onion crude powder inhibits the RANKL-induced ERK, p38 and NF-kappaB activation in macrophages. In summary, our data showed that onion powder may benefit bone through an anti-resorption effect on the osteoclasts.
A nutritional approach is important for both prevention and treatment of osteoporosis. Onion has been reported to decrease the ovariectomy-induced bone resorption. However, the functional effects of onion on the cultured osteoclasts and osteoblasts remain largely unknown. Here, we found that water solution of onion crude powder markedly inhibited the receptor activator of nuclear factor kappa B ligand (RANKL)-induced osteoclastogenesis through ERK, p38 and NF-kappaB pathways. Other studies were also designed to investigate the potential signaling pathways involved in onion-induced decrease in osteoclastogenesis.
The osteoclastogenesis was examined using the TRAP staining method. The MAPKs and NF-kappaB pathways were measured using Western blot analysis. A transfection protocol was used to examine NF-kappaB activity.
Water solution of onion crude powder inhibited the RANKL plus M-CSF-induced osteoclastic differentiation from either bone marrow stromal cells or from RAW264.7 macrophage cells. Treatment of RAW264.7 macrophages with RANKL could induce the activation of ERK, p38 and NF-kappaB that was inhibited by water solution of onion crude powder. On the other hand, it did not affect the cell proliferation and differentiation of human cultured osteoblasts.
Our data suggest that water solution of onion crude powder inhibits osteoclastogenesis from co-cultures of bone marrow stromal cells and macrophage cells via attenuation of RANKL-induced ERK, p38 and NF-kappaB activation.

Tang CH, Huang TH, Chang CS, Fu WM…
Osteoporos Int Jan 2009
PMID: 18506384

Risedronate, Atorvastatin, Estrogen, Raloxifene, and Clomiphene Compared in Ovariectomized Rats

Abstract

Comparative effects of risedronate, atorvastatin, estrogen and SERMs on bone mass and strength in ovariectomized rats.

The aim of this study was to investigate bone protective effects of risedronate, atorvastatin, raloxifene and clomiphene citrate in ovariectomized rats.
Our study was conducted on 63 rats at Experimental Research Center of Celal Bayar University. Six-month-old rats were divided into seven groups. There were five drug administered ovariectomized groups, one ovariectomized control group without drug administration and one non-ovariectomized control group without drug administration. Eight weeks postovariectomy, rats were treated with the bisphosphonate risedronate sodium, the statin atorvastatin, the estrogen 17beta-estradiol and the selective estrogen receptor modulators (SERMs) raloxifene hydrochloride and clomiphene citrate by gavage daily for 8 weeks. At the end of the study, rats were killed under anesthesia. For densitometric evaluation, left femurs and tibiae were removed. Left femurs were also used to measure bone volume. Right femurs were used for three-point bending test.
Compared to ovariectomized group, femur cortex volume increased significantly in non-ovariectomized group (p=0.016). Compared to non-ovariectomized group, distal femoral metaphyseal and femur midshaft bone mineral density values were significantly lower in ovariectomized group (p=0.047). In ovariectomy+atorvastatin group, whole femur and femur midshaft bone mineral density and three-point bending test maximal load values were significantly higher than ovariectomized group (p=0.049, 0.05, and 0.018). When compared to the ovariectomized group, no significant difference was found with respect to femoral maximum load values in groups treated with risedronate, estrogen, raloxifene and clomiphene (p=0.602, 0.602, 0.75, and 0.927). In ovariectomy+risedronate group, femur midshaft bone mineral density values were significantly higher than the values in ovariectomized group (p=0.023). When compared to ovariectomized group, no significant difference was found with respect to femur midshaft bone mineral density values in groups treated with estrogen, raloxifene and clomiphene (p=0.306, 0.808, and 0.095).

While risedronate sodium prevented the decrease in bone mineral density in ovariectomized rats, atorvastatin maintained mechanical characteristics of bone and also prevented the decrease in bone mineral density as risedronate sodium.

Uyar Y, Baytur Y, Inceboz U, Demir BC…
Maturitas Jul 2009
PMID: 19386450

Review: Statins and Bone Formation

Abstract

Statins, bone formation and osteoporosis: hope or hype?

Osteoporosis is a major health problem affecting both men and women. Statins, besides their action as lipid-lowering agents, seem to have additional pleiotropic properties, among them a beneficial effect on bone mineral density. The entirety of experimental and the majority of clinical studies as well as the only relevant meta-analysis suggest that statins have an anabolic effect on bone metabolism. Statins, osteoporosis and adipogenesis share the same pathway, RANKL/OPG. It would appear that an imbalance in this pathway could be responsible for the manifestation of some metabolic disorders such as diabetes mellitus, atherogenesis, multiple myeloma, osteoporosis. Possibly in the future, drugs which can intervene in this biochemical and pathophysiological cascade, like statins, in a variety of doses, could be used for the management of ectopic ossification syndromes and other bone disorders, even as an additive treatment. Until then, further large longitudinal randomized controlled studies for each statin separately are required to confirm this hypothesis.

Tsartsalis AN, Dokos C, Kaiafa GD, Tsartsalis DN…
Hormones (Athens)
PMID: 22801558 | Free Full Text

All the available data from the literature, including evidence from experimental studies as well as from the vast majority of observational studies and the results of a single meta-analysis, suggested that there is a positive effect of statins on BMD, although another meta-analysis by Bauer et al72 showed evidence that the beneficial effects on BMD and on fracture risk are observational, while many limitations and the placebo-controlled trials did not demonstrate any clear-cut benefit. However, the in vitro and some clinical studies (Chuengsamarn et al71) suggest that statins inhibit bone resorption and stimulate bone formation, having a dual action on bone metabolism. Therefore, in the future statins might gain a position among drugs used for the prevention and management of osteoporosis, taking into account that clinicians already have a good deal of experience in prescribing statins, for other indications, and feel familiar with this drug family. Their anabolic and anti-resorptive effects on bone make them an ideal candidate for osteoporosis treatment.

Simvastatin Intensifies Bone Formation and Decreases Resorption in Ovariectomized Rats

Abstract

Effects of simvastatin on the development of osteopenia caused by ovariectomy in rats.

Simvastatin is a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the rate-determining enzyme for cholesterol synthesis which is used in the treatment of hypercholesterolemias, particularly in type IIa and IIb hyperlipoproteinemias, frequently in postmenopausal women. Inhibition of cholesterol synthesis by simvastatin may cause disorders of bone remodelling. The aim of the present study was to investigate the effects of simvastatin (3 mg and 6 mg/kg/day per os) administered for 4 weeks on the development of ovariectomy-induced osteopenia in 3-month-old female Wistar rats. The experiments were carried out on six groups of animals: I (C)–sham operated rats, II (S-3)–sham operated rats + simvastatin 3 mg/kg/day p.o., III (S-6)–sham operated rats + simvastatin 6 mg/kg/day p.o., IV (OVX)–ovariectomized rats, V (OVX + S-3)–ovariectomized rats + simvastatin 3 mg/kg/day p.o., VI (OVX + S-6)–ovariectomized rats + simvastatin 6 mg/kg/day p.o. In all the groups, we examined body weight gain, and macrometrical, histomorphometrical and mechanical parameters. Bilateral ovariectomy induced osteopenic skeletal changes in mature female rats. In cortical bone, ovariectomy intensified resorption processes at the marrow cavity, as indicated by a decrease in endosteal transverse growth and an increase in transverse cross-section surface area of the marrow cavity in the tibia. Intensification of resorption processes was observed in cancellous bone (a statistically significant decrease in the width of trabeculae in the epiphysis and metaphysis of the femur). Structural changes in the long bones resulting from bilateral ovariectomy were manifested by deterioration of mechanical properties of the shaft and neck of the femur. The force needed to fracture the neck and shaft of the femur was significantly smaller than that in sham operated rats. Simvastatin (3 and 6 mg/kg/day p.o.) slightly influenced bone remodelling in sham operated rats. Simvastatin (3 and 6 mg/kg p.o. daily) administered to ovariectomized rats intensified bone formation processes and decreased bone resorption processes induced by bilateral ovariectomy, showing stronger activity at 6 mg/kg.

Pytlik M, Janiec W, Misiarz-Myrta M, Gubała I
Pol J Pharmacol
PMID: 12856828 | Free Full Text

Omega-3 Promotes Bone in Young Rats

Abstract

Consumption of different sources of omega-3 polyunsaturated fatty acids by growing female rats affects long bone mass and microarchitecture.

Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) consumption has been reported to improve bone health. However, sources of ω-3 PUFAs differ in the type of fatty acids and structural form. The study objective was to determine the effect of various ω-3 PUFAs sources on bone during growth. Young (age 28d) female Sprague-Dawley rats were randomly assigned (n=10/group) to a high fat 12% (wt) diet consisting of either corn oil (CO) or ω-3 PUFA rich, flaxseed (FO), krill (KO), menhaden (MO), salmon (SO) or tuna (TO) for 8 weeks. Bone mass was assessed by dual-energy X-ray absorptiometry (DXA) and bone microarchitecture by micro-computed tomography (μCT). Bone turnover markers were measured by enzyme immunoassay. Lipid peroxidation was measured by calorimetric assays. Results showed that rats fed TO, rich in docosahexaenoic acid (DHA, 22:6ω-3) had higher (P<0.009) tibial bone mineral density (BMD) and bone mineral content (BMC) and lower (P=0.05) lipid peroxidation compared to the CO-fed rats. Reduced lipid peroxidation was associated with increased tibial BMD (r2=0.08, P=0.02) and BMC (r2=0.71, P=0.01). On the other hand, rats fed FO or MO, rich in alpha-linolenic acid (ALA, 18:3ω-3), improved bone microarchitecture compared to rats fed CO or SO. Serum osteocalcin was higher (P=0.03) in rats fed FO compared to rats fed SO. Serum osteocalcin was associated with improved trabecular bone microarchitecture. The animal study results suggest consuming a variety of ω-3 PUFA sources to promote bone health during the growth stage.

Lukas R, Gigliotti JC, Smith BJ, Altman S…
Bone Sep 2011
PMID: 21672645