Tag Archives: animal

Silicon Increases Osteoblasts and Decreases Osteoclasts in Ovariectomized Rats

Abstract

Short-term effects of organic silicon on trabecular bone in mature ovariectomized rats.

Silicon is known to ensure an essential role in the formation of cross-links between collagen and proteoglycans during bone growth. In this study, we have evaluated the short-term effects of a preventive treatment with silanol, a soluble organic silicon (Si), on trabecular bone in mature ovariectomized rats. Three-month-old rats were sham-operated (sham) or were ovariectomized (OVX) and treated with 10 micrograms/kg/day of 17 beta estradiol (E2), or with 0.1 mg Si/kg/day or 1.0 mg Si/kg/day of silanol for 1 month. Plasma alkaline phosphatase and osteocalcin levels were increased by 50% in OVX rats compared with sham rats and were corrected by E2 but not by silanol treatment. The trabecular bone volume measured at the tibial metaphysis was decreased by 48%, and histomorphometric indices of bone resorption and formation were increased in OVX rats compared with sham, and these parameters were corrected by E2 treatment. Treatment of OVX rats with silanol decreased the osteoclast surface by 31% and the number of osteoclasts by 20%. The mineral apposition rate, the bone formation rate, and the osteoblast surface at the tibia metaphyseal area were increased by 30% at the higher dose of silanol compared with OVX rats. In contrast, silanol treatment had no effect on the periosteal apposition rate. The reduction of the metaphyseal bone resorption and the increased bone formation induced by silanol resulted in a slight improvement of the trabecular bone volume (+14%) compared with controls.

Hott M, de Pollak C, Modrowski D, Marie PJ
Calcif. Tissue Int. Sep 1993
PMID: 8242469

Silicon is Required for Bone Formation in Chicks

Abstract

Silicon: a requirement in bone formation independent of vitamin D1.

Silicon has been reported to be involved in an early stage of bone formation as a result of earlier in vitro and in vivo studies in this laboratory. It is now possible to demonstrate that silicon exerts an effect on bone formation independent of the action of vitamin D. Day-old cockerels were fed Si-deficient and Si-supplemented diets with adequate and no dietary vitamin D under trace element controlled conditions. At the end of 4 weeks chicks receiving dietary vitamin D3 (600 IU) exhibited optimal rates of growth whereas the growth rates of chicks receiving D2 (6000 IU) and no vitamin D were markedly depressed. There were no significant differences between growth of Si-deficient and Si-supplemented chicks on the same level of vitamin D. Skull and bone size was proportional to overall chick growth. However, all chicks on Si-deficient diets irrespective of the level of dietary vitamin D had gross abnormalities of skull architecture, the overall skull appearance being narrower and shorter. The frontal area was narrower and the dorsal median line at the front parietal junction was depressed with a narrowing both posterior and laterally, stunting parietal and occipital areas. These abnormal areas showed fewer trabeculae and less calcification. Analyses of skull frontal bones for hexosamine, collagen, noncollagenous protein, and bone mineral demonstrated that the major difference was in collagen content, the Si-deficient skulls showing considerably less collagen at each level of vitamin D. These findings demonstrate that silicon has a significant effect on the bone matrix independent of vitamin D, and support the earlier postulate that silicon is involved in an early stage of bone formation.

Carlisle EM
Calcif. Tissue Int. 1981
PMID: 6257332

Orthosilicic Acid Increases Bone Density in Ovariectomized Rats

Abstract

Partial prevention of long-term femoral bone loss in aged ovariectomized rats supplemented with choline-stabilized orthosilicic acid.

Silicon (Si) deficiency in animals results in bone defects. Choline-stabilized orthosilicic acid (ch-OSA) was found to have a high bioavailability compared to other Si supplements. The effect of ch-OSA supplementation was investigated on bone loss in aged ovariectomized (OVX) rats. Female Wistar rats (n = 58, age 9 months) were randomized in three groups. One group was sham-operated (sham, n = 21), and bilateral OVX was performed in the other two groups. OVX rats were supplemented orally with ch-OSA over 30 weeks (OVX1, n = 20; 1 mg Si/kg body weight daily) or used as controls (OVX0, n = 17). The serum Si concentration and the 24-hour urinary Si excretion of supplemented OVX rats was significantly higher compared to sham and OVX controls. Supplementation with ch-OSA significantly but partially reversed the decrease in Ca excretion, which was observed after OVX. The increase in bone turnover in OVX rats tended to be reduced by ch-OSA supplementation. ch-OSA supplementation increased significantly the femoral bone mineral content (BMC) in the distal region and total femoral BMC in OVX rats, whereas lumbar BMC was marginally increased. Femoral BMD was significantly increased at two sites in the distal region in OVX rats supplemented with ch-OSA compared to OVX controls. Total lumbar bone mineral density was marginally increased by ch-OSA supplementation. In conclusion, ch-OSA supplementation partially prevents femoral bone loss in the aged OVX rat model.

Calomme M, Geusens P, Demeester N, Behets GJ…
Calcif. Tissue Int. Apr 2006
PMID: 16604283

Orthosilicic Acid Stimulates Collagen and Osteoblasts In Vitro

Abstract

Orthosilicic acid stimulates collagen type 1 synthesis and osteoblastic differentiation in human osteoblast-like cells in vitro.

Silicon deficiency in animals leads to bone defects. This element may therefore play an important role in bone metabolism. Silicon is absorbed from the diet as orthosilicic acid and concentrations in plasma are 5-20 microM. The in vitro effects of orthosilicic acid (0-50 microM) on collagen type 1 synthesis was investigated using the human osteosarcoma cell line (MG-63), primary osteoblast-like cells derived from human bone marrow stromal cells, and an immortalized human early osteoblastic cell line (HCC1). Collagen type 1 mRNA expression and prolyl hydroxylase activity were also determined in the MG-63 cells. Alkaline phosphatase and osteocalcin (osteoblastic differentiation) were assessed both at the protein and the mRNA level in MG-63 cells treated with orthosilicic acid. Collagen type 1 synthesis increased in all treated cells at orthosilicic acid concentrations of 10 and 20 microM, although the effects were more marked in the clonal cell lines (MG-63, HCCl 1.75- and 1.8-fold, respectively, P < 0.001, compared to 1.45-fold in the primary cell lines). Treatment at 50 microM resulted in a smaller increase in collagen type 1 synthesis (MG-63 1.45-fold, P = 0.004). The effect of orthosilicic acid was abolished in the presence of prolyl hydroxylase inhibitors. No change in collagen type 1 mRNA level was seen in treated MG-63 cells. Alkaline phosphatase activity and osteocalcin were significantly increased (1.5, 1.2-fold at concentrations of 10 and 20 microM, respectively, P < 0.05). Gene expression of alkaline phosphatase and osteocalcin also increased significantly following treatment. In conclusion, orthosilicic acid at physiological concentrations stimulates collagen type 1 synthesis in human osteoblast-like cells and enhances osteoblastic differentiation.

Reffitt DM, Ogston N, Jugdaohsingh R, Cheung HF…
Bone Feb 2003
PMID: 12633784

Nicotine Not Responsible for Negative Effects of Smoking on Bone Density in Rats

Abstract

The effect of long-term nicotine exposure on bone mineral density and oxidative stress in female Swiss Albino rats.

To evaluate the effect of long-term low or high-dose nicotine exposure on bone mass via measuring bone mineral density (BMD) and oxidant-antioxidant status markers.
Thirty-five female Swiss Albino rats weighing 70 ± 10 g were divided as the control group (n = 12), low-dose nicotine group (n = 12) and high-dose nicotine group (n = 11). While the control group was given only normal drinking water, the low-dose nicotine group had 0.4 mg/kg per day and the high-dose nicotine group, 6.0 mg/kg per day of nicotine added to their water for the period of 1 year. BMD was determined with X-ray absorptiometry of lumbar vertebra, corpus femoris, proximal and distal femur. To evaluate oxidant-antioxidant status malondialdehyde (MDA) levels, superoxide dismutase (SOD) and catalase (CAT) activities were determined.
When comparing the nicotine groups and controls, neither BMD nor oxidant-antioxidant status markers showed any statistically significant difference. In comparison to the controls, 12 months of high-dose oral nicotine exposure did not have a significant effect on BMD and low-dose nicotine exposure led to a statistically insignificant increase in BMD.
Contrary to common belief, the results of this study show that nicotine is not responsible for the decrease in BMD leading to osteoporosis frequently seen in smokers. However, there is a need to explore the other harmful materials in tobacco which may be responsible for the alterations seen in BMD of smokers.

Turan V, Mizrak S, Yurekli B, Yilmaz C…
Arch. Gynecol. Obstet. Feb 2013
PMID: 22955292

Jewel Orchid Prebiotic Extract Prevents Bone Loss in Rats

Abstract

The prebiotic effect of Anoectochilus formosanus and its consequences on bone health.

The present study evaluated the prebiotic effect of a standardised aqueous extract of Anoectochilus formosanus (SAEAF) and its effects on osteoporosis in ovariectomised (OVX) rats. The OVX rats were randomly divided into five groups and orally treated with water, SAEAF (200 and 400 mg/kg daily) and inulin (400 mg/kg daily) for 12 weeks. The sham group was orally treated with water. The SAEAF treatment enhanced the number of faecal bifidobacteria in OVX rats. The results of a Ca-balance experiment showed that SAEAF increased apparent Ca absorption and retention. The OVX rats were killed after SAEAF treatment lasting 12 weeks. The SAEAF decreased the caecal pH values and increased the caecal wall weight, caecal mucosa calbindin-D9k mRNA expression, free-Ca concentration and levels of SCFA in the caecum. The mineral content, density and biomechanical strength of bones were lower in OVX rats than the sham group, but these bone losses were prevented by SAEAF administration. Microtomography scanning showed that the SAEAF-treated rats had higher trabecular bone volume than the OVX rats. These results suggest that SAEAF prevented bone loss associated with ovarian hormone deficiency in the rats.

Yang LC, Wu JB, Lu TJ, Lin WC
Br. J. Nutr. May 2013
PMID: 22950799

Boron Increases Strength and Bone Minerals in Rabbits

Abstract

Boron enhances strength and alters mineral composition of bone in rabbits fed a high energy diet.

An experiment was performed to determine whether boron had a beneficial effect on bone strength and composition in rabbits with apparent adiposity induced by a high energy diet. Sixty female New Zealand rabbits, aged 8 months, were randomly divided into five groups with the following treatments for seven months: control 1, fed alfalfa hay only (5.91 MJ/kg); control 2, high energy diet (11.76 MJ and 3.88 mg boron/kg); B10, high energy diet+10 mg/kg body weight boron gavage/96 h; B30, high energy diet+30 mg/kg body weight boron gavage/96 h; B50, high energy diet+50mg/kg body weight boron gavage/96 h. Bone boron concentrations were lowest in rabbits fed the high energy diet without boron supplementation, which suggested an inferior boron status. Femur maximum breaking force was highest in the B50 rabbits. Tibia compression strength was highest in B30 and B50 rabbits. All boron treatments significantly increased calcium and magnesium concentrations, and the B30 and B50 treatments increased the phosphorus concentration in tibia of rabbits fed the high energy diet. The B30 treatment significantly increased calcium, phosphorus and magnesium concentrations in femur of rabbits fed the high energy diet. Principal component analysis of the tibia minerals showed that the three boron treatments formed a separate cluster from controls. Discriminant analysis suggested that the concentrations of the minerals in femur could predict boron treatment. The findings indicate boron has beneficial effects on bone strength and mineral composition in rabbits fed a high energy diet.

Hakki SS, Dundar N, Kayis SA, Hakki EE…
J Trace Elem Med Biol Apr 2013
PMID: 22944583

Cladrin Increases Osteoblast Prolifertion in Rats

Abstract

Differential effects of formononetin and cladrin on osteoblast function, peak bone mass achievement and bioavailability in rats.

Dietary soy isoflavones including genistein and daidzein have been shown to have favorable effects during estrogen deficiency in experimental animals and humans. We have evaluated osteogenic effect of cladrin and formononetin, two structurally related methoxydaidzeins found in soy food and other natural sources. Cladrin, at as low as 10 nM, maximally stimulated both osteoblast proliferation and differentiation by activating MEK-Erk pathway. On the other hand, formononetin maximally stimulated osteoblast differentiation at 100 nM that involved p38 MAPK pathway but had no effect on osteoblast proliferation. Unlike daidzein, these two compounds neither activated estrogen receptor in osteoblast nor had any effect on osteoclast differentiation. Daily oral administration of each of these compounds at 10.0 mg kg(-1) day(-1) dose to recently weaned female Sprague-Dawley rats for 30 consecutive days, increased bone mineral density at various anatomic positions studied. By dynamic histomorphometry of bone, we observed that rats treated with cladrin exhibited increased mineral apposition and bone formation rates compared with control, while formononetin had no effect. Cladrin had much better plasma bioavailability compared with formononetin. None of these compounds exhibited estrogen agonistic effect in uteri. Our data suggest that cladrin is more potent among the two in promoting parameters of peak bone mass achievement, which could be attributed to its stimulatory effect on osteoblast proliferation and better bioavailability. To the best of our knowledge, this is the first attempt to elucidate structure-activity relationship between the methoxylated forms of daidzein and their osteogenic effects.

Gautam AK, Bhargavan B, Tyagi AM, Srivastava K…
J. Nutr. Biochem. Apr 2011
PMID: 20579866

Cladrin Increases Bone Formation and Strength in Rats

Abstract

Positive skeletal effects of cladrin, a naturally occurring dimethoxydaidzein, in osteopenic rats that were maintained after treatment discontinuation.

Effects of cladrin treatment and withdrawal in osteopenic rats were studied. Cladrin improved trabecular microarchitecture, increased lumbar vertebral compressive strength, augmented coupled remodeling, and increased bone osteogenic genes. A significant skeletal gain was maintained 4 weeks after cladrin withdrawal. Findings suggest that cladrin has significant positive skeletal effects.
We showed that a standardized extract of Butea monosperma preserved trabecular bone mass in ovariectomized (OVx) rats. Cladrin, the most abundant bioactive compound of the extract, promoted peak bone mass achievement in growing rats by stimulating osteoblast function. Here, we studied the effects of cladrin treatment and withdrawal on the osteopenic bones.
Adult female Sprague-Dawley rats were OVx and left untreated for 12 weeks to allow for significant estrogen deficiency-induced bone loss, at which point cladrin (1 and 10 mg/kg/day) was administered orally for another 12 weeks. Half of the rats were killed at the end of the treatments and the other half at 4 weeks after treatment withdrawal. Sham-operated rats and OVx rats treated with PTH or 17β-estradiol (E2) served as various controls. Efficacy was evaluated by bone microarchitecture using microcomputed tomographic analysis and fluorescent labeling of bone. qPCR and western blotting measured mRNA and protein levels in bone and uterus. Specific ELISA was used for measuring levels of serum PINP and urinary CTx.
In osteopenic rats, cladrin treatment dose dependently improved trabecular microarchitecture, increased lumbar vertebral compression strength, bone formation rate (BFR), cortical thickness (Cs.Th), serum PINP levels, and expression of osteogenic genes in bones; and reduced expression of bone osteoclastogenic genes and urinary CTx levels. Cladrin had no uterine estrogenicity. Cladrin at 10 mg/kg maintained acquired skeletal gains 4 weeks after withdrawal. Cladrin had positive skeletal effects in osteopenic rats that were maintained after treatment withdrawal.

Khan K, Sharan K, Swarnkar G, Chakravarti B…
Osteoporos Int Apr 2013
PMID: 22932734

Soy Isoflavones + Vitamin D3 Improve Bone Density, Stimulate Osteoblasts, and Inhibit Osteoclasts in Ovariectomized Rats

Abstract

Combined effect of soy isoflavones and vitamin D3 on bone loss in ovariectomized rats.

Several studies have shown that soy isoflavones have estrogen-like activities and might constitute an alternative to hormone replacement treatment. The present study investigated the effects of soy isoflavones alone and combined with vitamin D3 on prevention of bone loss.
Sprague-Dawley rats were sham-operated (n = 8) or ovariectomized (OVX; n = 40), and then the OVX rats were randomly assigned to five groups that were untreated or treated for 14 wk with vitamin D3, 17β-estradiol, soy isoflavone extract (SIE), or vitamin D3 plus SIE. The effects of the isoflavones and 1α,25(OH)(2)D(3) on cultured osteoblasts and osteoclasts also were investigated.
In OVX rats, the bone mineral density and trabecular bone volume loss were improved by 17β-estradiol, SIE, or SIE plus vitamin D3 treatment. SIE treatment was more effective than vitamin D3 or 17β-estradiol in inhibiting increases in serum tumor necrosis factor-α levels and osteoblast osteoprotegerin expression. SIE plus vitamin D3 was more effective in increasing osterix expression than each alone. Bone cell cultures showed that the isoflavones induced preosteoblasts to differentiate into osteoblasts and increased osteoblast mineralization. Isoflavones inhibited preosteoclasts and osteoclast proliferation and decreased osteoclast resorption. The combination of isoflavones plus 1α,25(OH)(2)D(3) showed additive effects on the increase in cell proliferation of cultured preosteoblasts.
Treatment with soy isoflavones might be an alternative to hormone replacement therapy in decreasing bone loss from postmenopausal estrogen deficiency. In addition, there are further effects on increasing transcription factor osterix expression and preosteoblast proliferation when these were combined with vitamin D3.

Chang KL, Hu YC, Hsieh BS, Cheng HL…
Nutrition Jan 2013
PMID: 22858193