Category Archives: Supplements

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

IP-6 Inhibits Mineralization of Mouse Osteoblasts Cultures

Abstract

Inositol hexakisphosphate inhibits mineralization of MC3T3-E1 osteoblast cultures.

Inositol hexakisphosphate (IP6, phytic acid) is an endogenous compound present in mammalian cells and tissues. Differentially phosphorylated forms of inositol are well-documented to have important roles in signal transduction, cell proliferation and differentiation, and IP6 in particular has been suggested to inhibit soft tissue calcification (specifically renal and vascular calcification) by binding extracellularly to calcium oxalate and calcium phosphate crystals. However, the effects of IP6 on bone mineralization are largely unknown. In this study, we used MC3T3-E1 osteoblast cultures to examine the effects of exogenous IP6 on osteoblast function and matrix mineralization. IP6 at physiologic concentrations caused a dose-dependent inhibition of mineralization without affecting cell viability, proliferation or collagen deposition. Osteoblast differentiation markers, including tissue-nonspecific alkaline phosphatase activity, bone sialoprotein and osteocalcin mRNA levels, were not adversely affected by IP6 treatment. On the other hand, IP6 markedly increased protein and mRNA levels of osteopontin, a potent inhibitor of crystal growth and matrix mineralization. Inositol alone (without phosphate), as well as inositol hexakis-sulphate, a compound with a high negative charge similar to IP6, had no effect on mineralization or osteopontin induction. Binding of IP6 to mineral crystals from the osteoblast cultures, as well as to synthetic hydroxyapatite crystals, was confirmed by a colorimetric assay for IP6. In summary, IP6 inhibits mineralization of osteoblast cultures by binding to growing crystals through negatively charged phosphate groups and by induction of inhibitory osteopontin expression. These data suggest that IP6 may regulate physiologic bone mineralization by directly acting extracellularly, and by serving as a specific signal at the cellular level for the regulation of osteopontin gene expression.

Addison WN, McKee MD
Bone Apr 2010
PMID: 20079473

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 Overload Inhibits Osteoblasts via Oxidative Stress

Abstract

Iron overload inhibits osteoblast biological activity through oxidative stress.

Iron overload has recently been connected with bone mineral density in osteoporosis. However, to date, the effect of iron overload on osteoblasts remains poorly understood. The purpose of this study is to examine osteoblast biological activity under iron overload. The osteoblast cells (hFOB1.19) were cultured in a medium supplemented with different concentrations (50, 100, and 200 μM) of ferric ammonium citrate as a donor of ferric ion. Intracellular iron was measured with a confocal laser scanning microscope. Reactive oxygen species (ROS) were detected by 2,7-dichlorofluorescin diacetate fluorophotometry. Osteoblast biological activities were evaluated by measuring the activity of alkaline phosphatase (ALP) and mineralization function. Results indicated that iron overload could consequently increase intracellular iron concentration and intracellular ROS levels in a concentration-dependent manner. Additionally, ALP activity was suppressed, and a decline in the number of mineralized nodules was observed in in vitro cultured osteoblast cells. According to these results, it seems that iron overload probably inhibits osteoblast function through higher oxidative stress following increased intracellular iron concentrations.

He YF, Ma Y, Gao C, Zhao GY…
Biol Trace Elem Res May 2013
PMID: 23334864

Mild Low Iron Promotes Osteoblasts; Excess or Serious Low Iron Bad In Vitro

Abstract

A comparison of the biological activities of human osteoblast hFOB1.19 between iron excess and iron deficiency.

Bone metabolism has a close relationship with iron homeostasis. To examine the effects of iron excess and iron deficiency on the biological activities of osteoblast in vitro, human osteoblast cells (hFOB1.19) were incubated in a medium supplemented with 0-200 μmol/L ferric ammonium citrate and 0-20 μmol/L deferoxamine. The intracellular iron was measured by a confocal laser scanning microscope. Proliferation of osteoblasts was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay. Apoptotic cells were detected using annexin intervention V/PI staining with a flow cytometry. Alkaline phosphatase (ALP) activity was measured using an ALP assay kit. The number of calcified nodules and mineral area was evaluated by von Kossa staining assay. The expressions of type I collagen and osteocalcin of cultured osteoblasts were detected by reverse transcriptase polymerase chain reaction and Western blot. Intracellular reactive oxygen species (ROS) was measured using the oxidation-sensitive dye 2,7-dichlorofluorescin diacetate by flow cytometry. The results indicated that excessive iron inhibited osteoblast activity in a concentration-dependent manner. Low iron concentrations, in contrast, produced a biphasic manner on osteoblasts: mild low iron promoted osteoblast activity, but serious low iron inhibited osteoblast activity. Osteogenesis was optimal in certain iron concentrations. The mechanism underlying biological activity invoked by excessive iron may be attributed to increased intracellular ROS levels.

Zhao GY, Zhao LP, He YF, Li GF…
Biol Trace Elem Res Dec 2012
PMID: 23054865

Iron Overload Inhibits Osteoblasts in Mouse and Rat Cells

Abstract

Excess iron inhibits osteoblast metabolism.

Hemochromatosis is an iron overload disorder associated with osteopenia and osteoporosis. To learn more about the effects of iron on bone cells, we examined the effects of ferric ion on the proliferation, differentiation, and mineralization of two types of cultured osteoblasts, the cell line MC3T3-E1 and rat calvarial osteoblast-like (ROB) cells. We used ferric ammonium citrate (FAC) as a donor of ferric ion, and FAC inhibited the proliferation of MC3T3-E1 cells in a dose-dependent manner. FAC (0.1-1 microg/ml) inhibited indices of osteoblast differentiation, such as the expression of type I collagen (mRNA and protein), the activity of alkaline phosphatase, and the deposition of calcium by osteoblasts. These results suggest that iron overload might give rise to osteoporosis by inhibiting osteoblast proliferation and differentiation.

Yamasaki K, Hagiwara H
Toxicol. Lett. Dec 2009
PMID: 19735707

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

Iron Increase Associated with Decreased Bone Density During Spaceflight

Abstract

Iron status and its relations with oxidative damage and bone loss during long-duration space flight on the International Space Station.

Increases in stored iron and dietary intake of iron during space flight have raised concern about the risk of excess iron and oxidative damage, particularly in bone.
The objectives of this study were to perform a comprehensive assessment of iron status in men and women before, during, and after long-duration space flight and to quantify the association of iron status with oxidative damage and bone loss.
Fasting blood and 24-h urine samples were collected from 23 crew members before, during, and after missions lasting 50 to 247 d to the International Space Station.
Serum ferritin and body iron increased early in flight, and transferrin and transferrin receptors decreased later, which indicated that early increases in body iron stores occurred through the mobilization of iron to storage tissues. Acute phase proteins indicated no evidence of an inflammatory response during flight. Serum ferritin was positively correlated with the oxidative damage markers 8-hydroxy-2′-deoxyguanosine (r = 0.53, P < 0.001) and prostaglandin F2α (r = 0.26, P < 0.001), and the greater the area under the curve for ferritin during flight, the greater the decrease in bone mineral density in the total hip (P = 0.031), trochanter (P = 0.006), hip neck (P = 0.044), and pelvis (P = 0.049) after flight.
Increased iron stores may be a risk factor for oxidative damage and bone resorption.

Zwart SR, Morgan JL, Smith SM
Am. J. Clin. Nutr. Jul 2013
PMID: 23719548

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