Monthly Archives: August 2013

Beta Blockers or Exercise Improve Bone in Rats

Abstract

Combined effects of exercise and propranolol on bone tissue in ovariectomized rats.

The bone response to physical exercise may be under control of the SNS. Using a running session in rats, we confirmed that exercise improved trabecular and cortical properties. SNS blockade by propranolol did not affect this response on cortical bone but surprisingly inhibited the trabecular response. This suggests that the SNS is involved in the trabecular response to exercise but not in the cortical response.
Animal studies have suggested that bone remodeling is under beta-adrenergic control through the sympathetic nervous system (SNS). However, the SNS contribution to bone response under mechanical loading remains unclear. The purpose of this study was to examine the preventive effect of exercise coupled with propranolol on cancellous and cortical bone compartments in ovariectomized rats.
Six-month-old female Wistar rats were ovariectomized (OVX, n = 44) or sham-operated (n = 24). OVX rats received subcutaneous injections of propranolol 0.1 mg/kg/day or vehicle and were submitted or not submitted to treadmill exercise (13 m/minute, 60 minutes/day, 5 days/week) for 10 weeks. Tibial and femoral BMD was analyzed longitudinally by DXA. At death, the left tibial metaphysis and L(4) vertebrae were removed, and microCT was performed to study trabecular and cortical bone structure. Histomorphometric analysis was performed on the right proximal tibia.
After 10 weeks, BMD and trabecular strength decreased in OVX rats, whereas bone turnover rate and cortical porosity increased compared with the Sham group (p < 0.001). Either propranolol or exercise allowed preservation of bone architecture by increasing trabecular number (+50.35% versus OVX; p < 0.001) and thickness (+16.8% versus OVX; p < 0.001). An additive effect of propranolol and exercise was observed on cortical porosity but not on trabecular microarchitecture or cortical width. Biomechanical properties indicated a higher ultimate force in the OVX-propranolol-exercise group compared with the OVX group (+9.9%; p < 0.05), whereas propranolol and exercise alone did not have any significant effect on bone strength.
Our data confirm a contribution of the SNS to the determinants of bone mass and quality and show a antagonistic effect of exercise and a beta-antagonist on trabecular bone structure.

Bonnet N, Beaupied H, Vico L, Dolleans E…
J. Bone Miner. Res. Apr 2007
PMID: 17243867

Nervous System Does Not Induce Bone Growth – Only Resorption?

Abstract

Sympathetic nervous system does not mediate the load-induced cortical new bone formation.

The contribution of the SNS to bone’s response to mechanical loading is unclear. Using a noninvasive model of axial loading of the murine tibia, we found that sciatic neurectomy enhances load-induced new cortical bone formation and that pharmacological blockade of the SNS does not affect such responses, indicating that the SNS does not mediate the osteogenic effects of loading in cortical bone.
There is increasing evidence that the sympathetic nervous system (SNS) contributes to the regulation of bone mass and may influence remodeling by modulating bones’ response to mechanical load-bearing. The aim of this study was to examine the effect of sciatic neurectomy (SN) on the changes in cortical bone formation induced in response to mechanical loading and to investigate whether the SNS is directly involved in such load-induced responses.
Accordingly, load-induced responses were compared in tibias of growing and adult control C57Bl/J6 mice and in mice submitted to unilateral SN; noninvasive axial loading that induced 2,000 microstrain on the tibia lateral midshaft cortex was applied cyclically, 5 or 100 days after surgery, for 7 minutes, 3 days/week for 2 weeks, and mice received calcein on the third and last days of loading. Tibias were processed for histomorphometry, and transverse confocal images from diaphyseal sites were analyzed to quantify new cortical bone formation. Chemical SNS inactivation was achieved by prolonged daily treatment with guanethidine sulfate (GS) or by the introduction of propranolol in drinking water.
Our results show that new cortical bone formation is enhanced by loading in all tibial sites examined and that load-induced periosteal and endosteal new bone formation was greater in the SN groups compared with sham-operated controls. This SN-related enhancement in load-induced cortical bone formation in tibias was more pronounced 100 days after neurectomy than after 5 days, suggesting that longer periods of immobilization promote a greater sensitivity to loading. In contrast, the increases in new bone formation induced in response to mechanical loading were similar in mice treated with either GS or propranolol compared with controls, indicating that inactivation of the SNS has no effect on load-induced cortical new bone formation.
This study shows that SN, or the absence of loading function it entails, enhances loading-related new cortical bone formation in the tibia independently of the SNS.

de Souza RL, Pitsillides AA, Lanyon LE, Skerry TM…
J. Bone Miner. Res. Dec 2005
PMID: 16294269

Berberine, Icariin, and Curculigoside from Er-Xian Inhibit Resorption

Abstract

Effects and interaction of icariin, curculigoside, and berberine in er-xian decoction, a traditional chinese medicinal formula, on osteoclastic bone resorption.

Er-Xian decoction (EXD), a traditional Chinese medicine, has been reported to have a protective effect against bone loss in ovariectomized osteoporotic rats, and the inclusion of icariin (I), curculigoside (C), and berberine (B) in EXD displays inhibitory effects on osteoclastic bone resorption. In the present paper, we investigated the interaction and effects of I, C, B, and their combination on bone resorption activity in vitro on osteoclasts derived from rat bone marrow cells. ICB synergistically decreased the formation of bone resorption pits, the number of multinucleated osteoclasts, and the activity of tartrate-resistant acid phosphatase (TRAP) and showed antagonistic or additive effects on cathepsin K activity in the coculture system of osteoblasts and bone marrow cells in the presence of 1, 25-dihydroxyvitamin D(3) and dexamethasone. The combination of ICB also enhanced the inhibitory effects on the formation of F-actin ring, a cytoskeleton structure of osteoclasts induced from bone marrow cells with macrophage colony stimulation factor (M-CSF) and receptor activator of NF-κB ligand (RANKL). In addition, ICB synergistically improved the ratio of protein expression of osteoprotegerin (OPG) and RANKL in osteoblasts and interfered with the mitogen-activated protein kinases (MAPKs) pathway in osteoclast. These results clearly show that I, C, B, and their combination in EXD exert effects of mutual reinforcement. However, IBC does not show an intensified adverse effect in the ovariectomized murine model, as revealed by change in body and uterine weight, confirming the safety of EXD. These observations are in agreement with the rationality of the formula used in this paper.

Xue L, Jiao L, Wang Y, Nie Y…
Evid Based Complement Alternat Med 2012
PMID: 23243450 | Free Full Text

Guduchi Increases Osteoblasts and Mineralization In Vitro

Abstract

Effects of Tinospora cordifolia (Menispermaceae) on the proliferation, osteogenic differentiation and mineralization of osteoblast model systems in vitro.

Ancient Indian ayurvedic literature prescribes Tinospora cordifolia as a remedy to rheumatoid arthritis, inflammatory and allied diseases of musculo skeletal system. To investigate the effects of the alcoholic extract of Tinospora cordifolia (TC) on the proliferation, differentiation and mineralization of bone like matrix on osteoblast model systems in vitro and hence its possible use as a potential anti-osteoporotic agent.
Two in vitro osteoblast model systems were used in the study viz., human osteoblast-like cells MG-63 and primary osteoblast cells isolated from femur of rats. Cell growth and viability was assessed by standard colorimetric assays like MTT assay. The cell differentiation into osteoblastic lineage was evaluated by the activities of bone marker alkaline phosphatase. The effect of the extract on matrix mineralization was assessed by alizarin red-s staining and Von kossa staining. Cell morphology was studied by phase contrast microscopy and light microscopy (Giemsa/crystal violet staining).
Results indicate that the alcoholic extract of TC at a dosage of 25μg/ml stimulated the growth of osteoblasts, increased the differentiation of cells into osteoblastic lineage and increased the mineralization of bone like matrix on both the osteoblast model systems used in the study. Cell morphology studies clearly indicated the increase in cell numbers and absence of adverse change in the cell morphology on treatment with the extract.
TC extract has a potential influence on osteogenesis and hence its use could be explored as a potential anti-osteoporotic agent.

Abiramasundari G, Sumalatha KR, Sreepriya M
J Ethnopharmacol May 2012
PMID: 22449439

Hypothesis: Berberine Potential in Diabetic Osteopathy

Abstract

Possible therapeutic potential of berberine in diabetic osteopathy.

Diabetic osteopathy is a complication that leads to decreased bone mineral density, bone formation and having high risk of fractures that heals slowly. Diabetic osteopathy is a result of increase in osteoclastogenesis and decrease in osteoblastogenesis. Various factors viz., oxidative stress, increased inflammatory markers, PPAR-γ activation in osteoblast, activation of apoptotic pathway, increased glucose levels and inhibitory effect on parathyroid hormone etc. are mainly responsible for decreased bone mineral density. Berberine is an isoquinoline alkaloid widely used in Asian countries as a traditional medicine. Berberine is extensively reported to be an antioxidant, anti-inflammatory, antidiabetic, and having potential to treat diabetic complications and glucocorticoid induced osteoporosis. The osteoclastogenesis decreasing property of berberine can be hypothesized for inhibiting diabetic osteopathy. In addition, chronic treatment of berberine will be helpful for increasing the osteoblastic activity and expression of the modulators that affect osteoblastic differentiation. The apoptotic pathways stimulated due to increased inflammatory markers and nucleic acid damages could be reduced due to berberine. Another important consideration that berberine is having stimulatory effect on glucagon like peptide release and insulin sensitization that will be helpful for decreasing glucose levels and therefore, may exerts osteogenesis. Thiazolidinediones show bone loss due to activation of PPAR-γ in osteoblasts, whereas berberine stimulates PPAR-γ only in adipocytes and not in osteoblasts, and therefore the decreased bone loss due to use of thiazolidinediones may not be observed in berberine treatment conditions. Berberine decreases the advanced glycation end-products (AGE) formation in diabetic condition which will be ultimately helpful to decrease the stiffness of collagen fibers due to AGE-induced cross linking. Lastly, it is also reported that berberine has inhibitory effect on parathyroid hormone and enhances marker genes like osteocalcin, which are responsible for the osteoblastic activity. From these evidences, we hypothesized that berberine may have potential in the treatment of diabetic osteopathy.

Rahigude AB, Kaulaskar SV, Bhutada PS
Med. Hypotheses Oct 2012
PMID: 22840327

Berberine + D3 + K1 + Hop Rho Iso-α-Acids Improves Bone Profile in Postmenopausal Women

Abstract

Nutritional supplementation of hop rho iso-alpha acids, berberine, vitamin D₃, and vitamin K₁ produces a favorable bone biomarker profile supporting healthy bone metabolism in postmenopausal women with metabolic syndrome.

Metabolic syndrome poses additional risk for postmenopausal women who are already at risk for osteoporosis. We hypothesized that a nutritional supplement containing anti-inflammatory phytochemicals and essential bone nutrients would produce a favorable bone biomarker profile in postmenopausal women with metabolic syndrome. In this 14-week, randomized trial, 51 women were instructed to consume a modified Mediterranean-style, low-glycemic-load diet and to engage in aerobic exercise. Those in the intervention arm (n = 25) additionally received 200 mg hop rho iso-alpha acids, 100 mg berberine sulfate trihydrate, 500 IU vitamin D₃, and 500 μg vitamin K₁ twice daily. Forty-five women completed the study. Baseline nutrient intake did not differ between arms. Compared with baseline, the intervention arm exhibited an approximate 25% mean decrease (P < .001) in serum osteocalcin (indicative of bone turnover), whereas the placebo arm exhibited a 21% increase (P = .003). Serum 25-hydroxyvitamin D increased 23% (P = .001) in the intervention arm and decreased 12% (P = .03) in the placebo arm. The between-arm differences for osteocalcin and 25-hydroxyvitamin D were statistically significant. Serum insulin-like growth factor I was statistically increased in both arms, but the between-arm differences were not statistically significant. Subanalysis showed that among those in the highest tertile of baseline insulin-like growth factor I, the intervention arm exhibited a significant increase in amino-terminal propeptide of type I collagen, whereas the placebo arm showed a significant decrease at 14 weeks. Treatment with rho iso-alpha acids, berberine, vitamin D₃, and vitamin K₁ produced a more favorable bone biomarker profile indicative of healthy bone metabolism in postmenopausal women with metabolic syndrome.

Lamb JJ, Holick MF, Lerman RH, Konda VR…
Nutr Res May 2011
PMID: 21636012

Berberine is Antiosteoporotic in Rats

Abstract

Anti-osteoporotic activity of aqueous-methanol extract of Berberis aristata in ovariectomized rats.

Traditionally Berberis aristata is employed for its supposed properties in treatment of joint pain and also used in alleviating symptoms of menopause. The aim of the present study is to evaluate the antiosteoporotic effect of Berberis aristata in ovariectomized (OVX) rats.

Sprague-Dawley rats were divided into sham and OVX groups. The OVX rats were further divided into four groups, which received standard estrogen (0.0563 mg/kg) and 100, 300, and 500 mg/kg aqueous-methanol extract of Berberis aristata, daily for 42 days. The uterine weight, bone loss, ash content, biomechanical, biochemical and histopathological observation were carried out for antiosteoporotic activity.
The experimental animals treated with Berberis aristata aqueous-methanol extract showed dose dependent activity. The significant increase in uterine weight, femur BMD, ash content and lumbar hardness were observed. In addition, increased levels of calcium and phosphorus in serum and significant decreased in urine were observed as compared to control OVX group. The histopathological results also confirm the protective effect of extract.
The present findings strongly suggest that Berberis aristata possess the potent antiosteoporosis activity in ovariectomized rats and substantiates the ethnic use in treatment of postmenopausal osteoporosis.

Yogesh HS, Chandrashekhar VM, Katti HR, Ganapaty S…
J Ethnopharmacol Mar 2011
PMID: 21182919

Coptisine Inhibits Osteoclasts In Mouse Cells

Abstract

Coptisine inhibits RANKL-induced NF-κB phosphorylation in osteoclast precursors and suppresses function through the regulation of RANKL and OPG gene expression in osteoblastic cells.

Excessive receptor activator of NF-κB ligand (RANKL) signaling causes enhanced osteoclast formation and bone resorption. The downregulation of RANKL expression and its downstream signals may be an effective therapeutic approach to the treatment of bone loss diseases such as osteoporosis. Here, we found that coptisine, one of the isoquinoline alkaloids from Coptidis Rhizoma, exhibited inhibitory effects on osteoclastogenesis in vitro. Although coptisine has been studied for its antipyretic, antiphotooxidative, dampness dispelling, antidote, antinociceptive, and anti-inflammatory activities in vitro and in vivo, its effects on osteoclastogenesis have not been investigated. Therefore, we evaluated the effects of coptisine on osteoblastic cells as well as osteoclast precursors for osteoclastogenesis in vitro. The addition of coptisine to cocultures of mouse bone marrow cells and primary osteoblastic cells with 10(-8) M 1α,25(OH)(2)D(3) caused significant inhibition of osteoclast formation in a dose-dependent manner. Reverse transcriptase polymerase chain reaction (RT-PCR) analyses revealed that coptisine inhibited RANKL gene expression and stimulated the osteoprotegerin gene expression induced by 1α,25(OH)(2)D(3) in osteoblastic cells. Coptisine strongly inhibited RANKL-induced osteoclast formation when added during the early stage of bone marrow macrophage (BMM) cultures, suggesting that it acts on osteoclast precursors to inhibit RANKL/RANK signaling. Among the RANK signaling pathways, coptisine inhibited NF-κB p65 phosphorylations, which are regulated in response to RANKL in BMMs. Coptisine also inhibited the RANKL-induced expression of NFATc1, which is a key transcription factor. In addition, 10 μM coptisine significantly inhibited both the survival of mature osteoclasts and their pit-forming activity in cocultures. Thus, coptisine has potential for the treatment or prevention of several bone diseases characterized by excessive bone destruction.

Lee JW, Iwahashi A, Hasegawa S, Yonezawa T…
J Nat Med Jan 2012
PMID: 21656335

Berberine Decreases Bone Loss in Rat Cells

Abstract

Effects of berberine on differentiation and bone resorption of osteoclasts derived from rat bone marrow cells.

To observe the effects of berberine on osteoclastic differentiation and bone resorption action in vitro, and to investigate the cellular mechanism of its inhibitory effects on bone resorption.
The multinucleated osteoclasts (MNCs) were derived by 1,25-dihydroxyvitamin D3 and dexamethasone from bone marrow cells in the coculture system with primary osteoblastic cells. The tartrate-resistant acid phosphatase (TRAP) staining and image analysis of bone resorption pit on dental slices were used to identify osteoclast. The activity of TRAP was measured by p-nitrophenyl sodium phosphate assay. The bone resorption pit area on the bone slices formed by osteoclasts was measured by computer image processing.
At the concentrations of 0.1, 1 and 10 micromol/L, berberine dose-dependently suppressed the formation of TRAP-positive multinucleated cells, the TRAP activity and the osteoclastic bone resorption. The strongest inhibitory effect was exhibited at the concentration of 10 micromol/L, with the inhibiting rate of 60.45%, 42.12% and 72.69% respectively.
Berberine can decrease bone loss through inhibition of osteoclast formation, differentiation and bone resorption.

Wei P, Jiao L, Qin LP, Yan F…
Zhong Xi Yi Jie He Xue Bao Apr 2009
PMID: 19361364 | Free Full Text

Palmatine Inhibits Resorption in Mouse Cells

Abstract

Palmatine attenuates osteoclast differentiation and function through inhibition of receptor activator of nuclear factor-κb ligand expression in osteoblast cells.

Osteoclasts are the only cell type capable of resorbing mineralized bone, and they act under the control of numerous cytokines produced by supporting cells such as osteoblasts and stromal cells. Among cytokines, receptor activator of nuclear factor-κB ligand (RANKL) was found to be a key osteoclastogenetic molecule that directly binds to its cognate receptor, RANK, on osteoclast precursor cells. In turn, RANKL, which is an essential factor for differentiation and activation of osteoclasts, is one of the major targets of anti-resorptive agents. In this study, we found that palmatine, an isoquinoline alkaloid originally isolated from Coptis chinensis, had an inhibitory effect on osteoclast differentiation and function in vitro. Palmatine inhibited osteoclast formation in the co-culture system with mouse bone marrow cells (BMC) and osteoblasts in the presence of 10 nM 1α,25-(OH)(2)D(3). Palmatine did not affect osteoclast formation induced by RANKL in the BMC cultures. Reverse-transcription polymerase chain reaction (RT-PCR) analysis showed that palmatine significantly inhibited the expression of 1α,25-(OH)(2)D(3)-induced expression of RANKL mRNAs in stromal cells without loss of cell viability. Moreover, palmatine suppressed resorption pit formation by mature osteoclasts on dentin slices and induced disruption of actin ring formation in mature osteoclasts with an impact on cell viability. Taken together, these results suggest that palmatine attenuates osteoclast differentiation through inhibition of RANKL expression in osteoblast cells, and its inhibitory effect on bone resorption is due to its disruptive effect on actin rings in mature osteoclasts. Therefore, palmatine might be an ideal candidate as an anti-resorptive agent for the prevention and treatment of bone disorders such as osteoporosis.

Lee JW, Mase N, Yonezawa T, Seo HJ…
Biol. Pharm. Bull. 2010
PMID: 20930384 | Free Full Text