Tag Archives: positive

Phenytoin Increases Bone Growth via TGF-Beta In Vitro

Abstract

Osteogenic actions of phenytoin in human bone cells are mediated in part by TGF-beta 1.

We have recently demonstrated that phenytoin, a widely used therapeutic agent for seizure disorders, has osteogenic effects in rats and in humans in vivo, and in human bone cells in vitro. The goal of the present study was to determine the mechanism of the osteogenic action of phenytoin in normal human mandible-derived bone cells. Because many osteogenic agents increased bone cell proliferation through mediation by growth factors, we tested the hypothesis that the osteogenic effects of phenytoin involved the release of a growth factor by measuring the mRNA level of several bone cell growth factors and insulin-like growth factor (IGF) binding proteins with Northern blots using specific cDNA probes. Treatment with 5-50 microM phenytoin reproducibly and markedly increased (up to 6-fold, p < 0.001) the mRNA of transforming growth factor (TGF)-beta 1, but not that of other growth factors (i.e., IGF-II, platelet-derived growth factor-A [PDGF-A], PDGF-B, and TGF-beta 2) and IGF binding proteins (i.e., IGFBP-3, -4, and -5). The stimulation was dose dependent, with an optimal dose of 10-50 microM. Maximal increase was seen after 1 h of phenytoin treatment. The release of biologically active TGF-beta activity in conditioned media was measured with the mink lung cell proliferation inhibition assay. Twenty-four hours of phenytoin treatment significantly increased the production of biologically active TGF-beta (2-fold, p < 0.05) with the optimal dose between 5-50 microM. Comparisons between the in vitro osteogenic effects of phenytoin and those of TGF-beta 1 reveal that these two agents at their respective optimal doses had similar maximal stimulatory effects on [3H]thymidine incorporation, alkaline phosphatase (ALP)-specific activity, and type I alpha-2 collagen mRNA expression in human bone cells. The stimulatory effects of phenytoin on [3H]thymidine incorporation and ALP-specific activity were completely blocked by a neutralizing anti-TGF-beta antibody. In conclusion, these findings demonstrate for the first time that at least some of the osteogenic actions of phenytoin in human bone cells could be in part mediated by TGF-beta 1.

Nakade O, Baylink DJ, Lau KH
J. Bone Miner. Res. Dec 1996
PMID: 8970889

D-Pinitol Inhibits Osteoclasts in Rats

Abstract

D-pinitol inhibits RANKL-induced osteoclastogenesis.

Numerous studies have indicated that inflammatory cytokines play a major role in osteoclastogenesis, leading to the bone resorption that is frequently associated with osteoporosis. D-pinitol, a 3-methoxy analogue of D-chiroinositol, was identified as an active principle in soy foods and legumes. Here we found that D-pinitol markedly inhibited the receptor activator of nuclear factor kappa B ligand (RANKL)-induced osteoclastic differentiation from bone marrow stromal cells and RAW264.7 macrophage cells. In addition, D-pinitol also reduced RANKL-induced p38 and JNK phosphorylation. Furthermore, RANKL-mediated increase of IKK, IκBα, and p65 phosphorylation and NF-κB-luciferase activity was inhibited by D-pinitol. However, D-pinitol did not affect the proliferation and differentiation of osteoblasts. In addition, D-pinitol also prevented the bone loss induced by ovariectomy in vivo. Our data suggest that D-pinitol inhibits osteoclastogenesis from bone marrow stromal cells and macrophage cells via attenuated RANKL-induced p38, JNK, and NF-κB activation, which in turn protect bone loss from ovariectomy.

Liu SC, Chuang SM, Tang CH
Int. Immunopharmacol. Mar 2012
PMID: 22269833

D-Chiro-Inositol Inhibits Osteoclasts In Vitro

Abstract

D-chiro-inositol negatively regulates the formation of multinucleated osteoclasts by down-regulating NFATc1.

Osteoclasts (OCs) are multinucleated giant cells that resorb bone matrix. Accelerated bone destruction by OCs might cause several metabolic bone-related diseases, such as osteoporosis and inflammatory bone loss. D-pinitol (3-O-methyl-D-chiro-inositol) is a prominent component of dietary legumes and is actively converted to D-chiro-inositol, which is a putative insulin-like mediator. In this study, we analyzed the effect of D-chiro-inositol on OC differentiation.
To analyze the role of D-chiro-inositol on OC differentiation, we examined OC differentiation by the three types of osteoclastogenesis cultures with tartrate-resistant acid phosphatase (TRAP) staining and solution assay. Then, we carried out cell fusion assay with purified TRAP(+) mononuclear OC precursors. Finally, we analyzed the effect of D-chiro-inositol on OC maker expression in response to the regulation of nuclear factor of activated T cells c1 (NFATc1).
We demonstrated that D-chiro-inositol acts as an inhibitor of receptor activator of NF-κB ligand-induced OC differentiation. The formation of multinucleated OCs by cell-cell fusion is reduced by treatment with D-chiro-inositol in a dose-dependent manner. In addition, we demonstrated that D-chiro-inositol inhibits the expression of several osteoclastogenic genes by down-regulating NFATc1.
We have shown that D-chiro-inositol is negatively involved in osteoclastogenesis through the inhibition of multinucleated OC formation by cell-cell fusion. The expression of NFATc1 was significantly down-regulated by D-chiro-inositol in OCs and consequently, the expression of OC marker genes was significantly reduced. Hence, these results show that D-chiro-inositol might be a good candidate to treat inflammatory bone-related diseases or secondary osteoporosis in diabetes mellitus.

Yu J, Choi S, Park ES, Shin B…
J. Clin. Immunol. Dec 2012
PMID: 22711011

Phytate Associated with Reduced Bone Loss and Fractures in Postmenopausal Women

Abstract

Protective effect of myo-inositol hexaphosphate (phytate) on bone mass loss in postmenopausal women.

The objective of this paper was to evaluate the relationship between urinary concentrations of InsP6, bone mass loss and risk fracture in postmenopausal women.
A total of 157 postmenopausal women were included in the study: 70 had low (≤0.76 μM), 42 intermediate (0.76-1.42 μM) and 45 high (≥1.42 μM) urinary phytate concentrations. Densitometry values for neck were measured at enrollment and after 12 months (lumbar spine and femoral neck), and 10-year risk fracture was calculated using the tool FRAX(®).
Individuals with low InsP6 levels had significantly greater bone mass loss in the lumbar spine (3.08 ± 0.65 % vs. 0.43 ± 0.55 %) than did those with high phytate levels. Moreover, a significantly greater percentage of women with low than with high InsP6 levels showed more than 2 % of bone mass loss in the lumbar spine (55.6 vs. 20.7 %). The 10-year fracture probability was also significantly higher in the low-phytate group compared to the high-phytate group, both in hip (0.37 ± 0.06 % vs 0.18 ± 0.04 %) and major osteoporotic fracture (2.45 ± 0.24 % vs 1.83 ± 0.11 %).
It can be concluded that high urinary phytate concentrations are correlated with reduced bone mass loss in lumbar spine over 12 months and with reduced 10-year probability of hip and major osteoporotic fracture, indicating that increased phytate consumption can prevent development of osteoporosis.

López-González AA, Grases F, Monroy N, Marí B…
Eur J Nutr Mar 2013
PMID: 22614760

IP-6 Inhibits Osteoclastogenesis and Increases Resorption of Mature Osteoclasts In Vitro

Abstract

Inositol hexakisphosphate inhibits osteoclastogenesis on RAW 264.7 cells and human primary osteoclasts.

Inoxitol hexakisphosphate (IP6) has been found to have an important role in biomineralization and a direct effect inhibiting mineralization of osteoblasts in vitro without impairing extracellular matrix production and expression of alkaline phosphatase. IP6 has been proposed to exhibit similar effects to those of bisphosphonates on bone resorption, however, its direct effect on osteoclasts (OCL) is presently unknown. The aim of the present study was to investigate the effect of IP6 on the RAW 264.7 monocyte/macrophage mouse cell line and on human primary osteoclasts. On one hand, we show that IP6 decreases the osteoclastogenesis in RAW 264.7 cells induced by RANKL, without affecting cell proliferation or cell viability. The number of TRAP positive cells and mRNA levels of osteoclast markers such as TRAP, calcitonin receptor, cathepsin K and MMP-9 was decreased by IP6 on RANKL-treated cells. On the contrary, when giving IP6 to mature osteoclasts after RANKL treatment, a significant increase of bone resorption activity and TRAP mRNA levels was found. On the other hand, we show that 1 µM of IP6 inhibits osteoclastogenesis of human peripheral blood mononuclear cells (PBMNC) and their resorption activity both, when given to undifferentiated and to mature osteoclasts.
Our results demonstrate that IP6 inhibits osteoclastogenesis on human PBMNC and on the RAW264.7 cell line. Thus, IP6 may represent a novel type of selective inhibitor of osteoclasts and prove useful for the treatment of osteoporosis.

Arriero Mdel M, Ramis JM, Perelló J, Monjo M
PLoS ONE 2012
PMID: 22905230 | Free Full Text

Low IP-6 a Risk Factor for Osteoporosis

Abstract

Phytate (myo-inositol hexaphosphate) and risk factors for osteoporosis.

Several risk factors seem to play a role in the development of osteoporosis. Phytate is a naturally occurring compound that is ingested in significant amounts by those with diets rich in whole grains. The aim of this study was to evaluate phytate consumption as a risk factor in osteoporosis. In a first group of 1,473 volunteer subjects, bone mineral density was determined by means of dual radiological absorptiometry in the calcaneus. In a second group of 433 subjects (used for validation of results obtained for the first group), bone mineral density was determined in the lumbar column and the neck of the femur. Subjects were individually interviewed about selected osteoporosis risk factors. Dietary information related to phytate consumption was acquired by questionnaires conducted on two different occasions, the second between 2 and 3 months after performing the first one. One-way analysis of variance or Student’s t test was used to determine statistical differences between groups. Bone mineral density increased with increasing phytate consumption. Multivariate linear regression analysis indicated that body weight and low phytate consumption were the risk factors with greatest influence on bone mineral density. Phytate consumption had a protective effect against osteoporosis, suggesting that low phytate consumption should be considered an osteoporosis risk factor.

López-González AA, Grases F, Roca P, Mari B…
J Med Food Dec 2008
PMID: 19053869

Phytate Associated with Bone Density in Posmenopausal Women of Mallorca

Abstract

[The influence of consumption of phytate on the bone mass in posmenopausal women of Mallorca].

Osteoporosis is a serious health problem in the population, mainly for postmenopausal women. Therefore, it is important to develop programs to decrease prevalence. The main objective of this study is to determine the influence of phytate consumption on bone mineral density.
The bone mineral density was evaluated in postmenopausal women by means of dual X-ray double energy absorptiometry for calcaneous (C), lumbar spine (LS) and femoral neck (FN). The results obtained were related to the consumption of phytate by means of a dietary questionnaire.
In the three different areas (C, LS, FN) we observed significantly higher values of T-score in women that consumed adequate amounts of phytate as opposed to those that did not, (C 0.1 vs. -0.5, LS -1.2 and -2.5 and FN -0.2 and -1.2). There is also an increase in the T-score as more phytate is consumed, up to a maximum of two times a week (C -0.7 in non consumers, -0.2 in those that consume phytate once a week and 0.2 in those that consume phytate twice a week; LS -2.8, -1.7 and 1.1 and finally, CF -1.3, -0.6 and -0.1).
The results obtained seem to indicate that the adequate consumption of phytate may play an important role in the prevention of bone mineral density loss in postmenopausal women.

López-González AA, Grases F, Marí B, Vicente-Herrero MT…
Reumatol Clin
PMID: 21794821 | Free Full Text

Phytate Associate with Bone Density in Postmenopausal Women

Abstract

Phytate levels and bone parameters: a retrospective pilot clinical trial.

This study evaluated the relationship between phytate urinary levels and bone characteristics in a large population of postmenopausal women. The study population consisted of 180 postmenopausal women who participated in a descriptive cross-sectional study. A urine sample was collected from each subject to determine phytate levels and the volunteers were divided into two groups according to phytate urinary concentration (i.e., low and high levels). Bone mineral density was determined in the lumbar spine and femoral neck of groups with low and high phytate urinary levels. Urinary levels of phytate were linked to dietary phytate consumption. Hence, bone mineral density values were significantly higher in the lumbar spines and femoral necks of women who consumed high levels of phytate than in women with low urinary phytate concentrations. Higher urinary levels of phytate correlated with higher bone mineral density in the lumbar spine and femoral necks of postmenopausal women. This finding demonstrates the potential use of phytate in the treatment of bone related diseases, as it uses a mechanism of action similar to some bisphosphonates.

Lopez-Gonzalez AA, Grases F, Perello J, Tur F…
Front Biosci (Elite Ed) 2010
PMID: 20515779

Iron Deficiency Causes Lower Bone Density in Rats

Abstract

Iron deficiency negatively affects vertebrae and femurs of rats independently of energy intake and body weight.

The question of whether iron deficiency has direct adverse effects on vertebral trabecular bone and long bones was answered by this study. Four groups of female weanling rats were fed for 5 wk diets that were 1) control; 2) calcium restricted, 1.0 g Ca/kg diet; 3) iron deficient, <8 mg Fe/kg diet; or 4) control, pair-fed to the iron-deficient group. Whole body and femur DEXA analysis revealed that calcium-restricted and iron-deficient rats had lower bone mineral density (BMD) and content (BMC) than pair-fed and control rats. However, pair-fed rats also had decreased BMD and BMC compared to control rats. The third lumbar trabecular bone microarchitecture in both diet-restricted groups had decreased bone volume fraction (BV/TV) and trabecular number and thickness, a less favorable structural model index, and increased trabecular separation compared with the controls and the pair-fed groups as determined by microcomputer tomography. The control and pair-fed groups did not differ from one another, suggesting that iron deficiency and calcium restriction affected vertebrae independently of food intake and body weight. Finite element analysis revealed lower force to compress the vertebrae and lower stiffness but greater von Mises stress in calcium-restricted and iron-deficient groups compared to the control and pair-fed groups. Urinary deoxypyridinium crosslinks, serum osteocalcin, and cholcalciferol were increased in calcium-restricted rats compared to the other 3 groups. Using micro-CT imaging technology, this study demonstrated microarchitectural pathology due to iron deficiency upon vertebral trabecular bone compared to the control and pair-fed rats, although not to the same extent as severe calcium restriction.

Medeiros DM, Stoecker B, Plattner A, Jennings D…
J. Nutr. Nov 2004
PMID: 15514276 | Free Full Text

Zinc Acexamate Stimulates Fracture Healing in Rats at Different Doses

Abstract

Stimulatory effect of zinc acexamate administration on fracture healing of the femoral-diaphyseal tissues in rats.

The effect of zinc acexamate on fracture healing of the femoral-diaphyseal tissues in rats was investigated in vivo. Zinc acexamate (0.3 and 10.0 mg Zn/100 g body weight per day) was orally administered to rats (4 weeks old) surgically fractured the femoral diaphysis for 14 to 28 days. Calcium content and alkaline phosphatase activity in the femoral-diaphyseal tissues were significantly decreased in rats with fracture healing, while bone acid phosphatase activity and protein content were markedly increased. The administration of zinc acexamate (10.0 mg Zn/100 g) for 28 days caused a significant increase in calcium content, alkaline and acid phosphatases activities, protein and deoxyribonucleic acid (DNA) contents in the femoral-diaphyseal tissues of rats with fracture healing. With the lower dose (3.0 mg Zn/100 g), zinc compound had a partial effect on bone components. Femoral mineral density in rats with fracture healing was significantly increased by the administration of zinc acexamate (10.0 mg Zn/100 g) for 28 days. Femoral-diaphyseal zinc content was significantly decreased in rats with fracture healing. This decrease was completely restored by the administration of zinc acexamate (10.0 mg Zn/100 g) for 28 days. The present study suggests that the supplement of zinc compound stimulates fracture healing of the femoral-diaphyseal tissues in rats.

Igarashi A, Yamaguchi M
Gen. Pharmacol. Apr 1999
PMID: 10323487