Category Archives: Silicon

Alcohol Reduces Bone Resorption Markers

Abstract

Moderate ingestion of alcohol is associated with acute ethanol-induced suppression of circulating CTX in a PTH-independent fashion.

The “J shape” curve linking the risk of poor bone health to alcohol intake is now well recognized from epidemiological studies. Ethanol and nonethanol components of alcoholic beverages could influence bone remodeling. However, in the absence of a solid underlying mechanism, the positive association between moderate alcoholic intake and BMD remains questionable because of confounding associated social factors. The objective of this work was to characterize the short-term effects of moderate alcohol consumption on circulating bone markers, especially those involved in bone resorption. Two sequential blood-sampling studies were undertaken in fasted healthy volunteers (age, 20-47 yr) over a 6-h period using beer of different alcohol levels (<0.05-4.6%), solutions of ethanol or orthosilicic acid (two major components of beer), and water +/- calcium chloride (positive and negative controls, respectively). Study 1 (24 subjects) assessed the effects of the different solutions, whereas study 2 (26 subjects) focused on ethanol/beer dose. Using all data in a “mixed effect model,” we identified the contributions of the individual components of beer, namely ethanol, energy, low-dose calcium, and high-dose orthosilicic acid, on acute bone resorption. Markers of bone formation were unchanged throughout the study for all solutions investigated. In contrast, the bone resorption marker, serum carboxy terminal telopeptide of type I collagen (CTX), was significantly reduced after ingestion of a 0.6 liters of ethanol solution (>2% ethanol; p <or= 0.01, RM-ANOVA), 0.6 liters of beer (<0.05-4.6% ethanol; p < 0.02), or a solution of calcium (180 mg calcium; p < 0.001), but only after calcium ingestion was the reduction in CTX preceded by a significant fall in serum PTH (p < 0.001). Orthosilicic acid had no acute effect. Similar reductions in CTX, from baseline, were measured in urine after ingestion of the test solutions; however, the biological variability in urine CTX was greater compared with serum CTX. Modeling indicated that the major, acute suppressive effects of moderate beer ingestion (0.6 liters) on CTX were caused by energy intake in the early phase (approximately 0-3 h) and a “nonenergy” ethanol component in the later phase (approximately 3 to >6 h). The early effect on bone resorption is well described after the intake of energy, mediated by glucagon-like peptide-2, but the late effect of moderate alcohol ingestion is novel, seems to be ethanol specific, and is mediated in a non-calcitonin- and a non-PTH-dependent fashion, thus providing a mechanism for the positive association between moderate alcohol ingestion and BMD.

Sripanyakorn S, Jugdaohsingh R, Mander A, Davidson SL…
J. Bone Miner. Res. Aug 2009
PMID: 19257829 | Free Full Text

Silicon as Orthosilicic Acid Decreases Osteoblast Survivability In Vitro

Abstract

Divergent effects of orthosilicic acid and dimethylsilanediol on cell survival and adhesion in human osteoblast-like cells.

Although dietary silicon (Si) is recognized to be an important factor for the growth and development of bone and connective tissue, its biochemical role has yet to be identified. The predominant Si-containing species in blood and other biofluids is orthosilicic acid, Si(OH)(4). Dimethylsilanediol, (CH(3))(2)Si(OH)(2), is an environmental contaminant that results from decomposition of silicone compounds used in personal hygiene, health care and industrial products. We examined the in vitro effects of both Si species on the survival (colony forming efficiency), proliferation (DNA content), differentiation (alkaline phosphatase activity) and adhesion (relative protein content) of the human osteoblast-like cell lines Saos-2 and hFOB 1.19. Orthosilicic acid yielded a small, dose-dependent decrease in Saos-2 cell survivability up to its 1,700 micromol/L solubility limit, by which point survival was 20% less than that of untreated cells. This negative association, although small, correlated with a reduction in the proliferation and adhesion of Saos-2 cells as well as of hFOB 1.19 and osteoclast-like GCT cells. By contrast, dimethylsilanediol treatment had no discernable influence on Saos-2 survivability at concentrations up to 50 micromol/L, and yet significantly enhanced cell survival at higher doses. Moreover, dimethylsilanediol did not affect proliferation or adhesion of any cell line. The findings show that orthosilicic acid and dimethylsilanediol affect osteoblast-like cells very differently, providing insight into the mechanism by which silicon influences bone health, although the specific site of Si activity remains unknown. There was no evidence to suggest that dimethylsilanediol is cytotoxic at environmental/physiological concentrations.

Duivenvoorden WC, Middleton A, Kinrade SD
J Trace Elem Med Biol 2008
PMID: 18755397

Silicon Antagonizes Calcium and Magnesium in Animals

Abstract

Effects of high levels of dietary silicon on bone development of growing rats and turkeys fed semi-purified diets.

Two experiments were conducted using a completely randomized design to study the effects of high levels of silicon (Si) supplementation on bone development, structure, and strength in growing rats and turkeys. Rats were supplemented at two dietary Si levels: 0 and 500 ppm; and the turkeys were supplemented at four dietary Si levels: 0, 135, 270, and 540 ppm in semi-purified diets of dextrose-albumin for rats and dextrose-casein for turkeys. The experiments lasted 8 and 4 weeks for the rats and turkeys, respectively. Physical, mechanical, and chemical parameters of bones were measured. All the physical and mechanical measures of bone size and strength were not different (P > 0.05) between treatments in rats and turkeys except the moment of inertia, which was lower (P < 0.01) in rats on the 500 ppm Si level of supplementation. There were small but consistent reductions in structural and strength parameters with Si supplementation which were not wholly due to differences in bodyweights of the rats and turkeys. Although bone mineral composition was not affected (P > 0.05) by Si supplementation, plasma magnesium (P = 0.08) in rats and plasma calcium (P < 0.05) in turkeys were reduced by high levels of Si supplementation. The antagonistic relations of high Si levels with calcium and magnesium were deemed to be the mechanisms through which high Si imposes its deleterious effects on bone size and strength.

Kayongo-Male H, Julson JL
Biol Trace Elem Res 2008
PMID: 18418557

Arginine May Increase Bone Formation by Increasing Silicon Absorption in Rats

Abstract

Dietary silicon and arginine affect mineral element composition of rat femur and vertebra.

Both arginine and silicon affect collagen formation and bone mineralization. Thus, an experiment was designed to determine if dietary arginine would alter the effect of dietary silicon on bone mineralization and vice versa. Male weanling Sprague-Dawley rats were assigned to groups of 12 in a 2 x 2 factorially arranged experiment. Supplemented to a ground corn/casein basal diet containing 2.3 microg Si/g and adequate arginine were silicon as sodium metasilicate at 0 or 35 microg/g diet and arginine at 0 or 5 mg/g diet. The rats were fed ad libitum deionized water and their respective diets for 8 wk. Body weight, liver weight/body weight ratio, and plasma silicon were decreased, and plasma alkaline phosphatase activity was increased by silicon deprivation. Silicon deprivation also decreased femoral calcium, copper, potassium, and zinc concentrations, but increased the femoral manganese concentration. Arginine supplementation decreased femoral molybdenum concentration but increased the femoral manganese concentration. Vertebral concentrations of phosphorus, sodium, potassium, copper, manganese, and zinc were decreased by silicon deprivation. Arginine supplementation increased vertebral concentrations of sodium, potassium, manganese, zinc, and iron. The arginine effects were more marked in the silicon-deprived animals, especially in the vertebra. Germanium concentrations of the femur and vertebra were affected by an interaction between silicon and arginine; the concentrations were decreased by silicon deprivation in those animals not fed supplemental arginine. The change in germanium is consistent with a previous finding by us suggesting that this element may be physiologically important, especially as related to bone DNA concentrations. The femoral and vertebral mineral findings support the contention that silicon has a physiological role in bone formation and that arginine intake can affect that role.

Seaborn CD, Nielsen FH
Biol Trace Elem Res Dec 2002
PMID: 12462747

Arginine is an essential amino acid for the rat. In animals L-arginine apparently induces growth hormone and insulin-like growth factor-1 responses and stimulates nitric oxide synthase. Growth hormone and insulin-like growth factor-1 are important mediators of bone turnover and osteoblastic bone formation, whereas nitric oxide is a potent inhibitor of osteoclastic bone resorption (1). By affecting these physiological regulators of bone remodeling, L-arginine could potentially increase bone formation over bone resorption and, consequently, increase bone mass.

There is experimental evidence suggesting that arginine supplementation promotes bone formation. A mixture of lactose, L-arginine, and L-lysine improved fracture healing of rabbits subjected to an osteotomy of the left fibula (2). These authors suggested that arginine was involved not only in the increase of intestinal calcium absorption but also in collagen synthesis. Although there is evidence that L-arginine affects bone maintenance minimal attention has been given to the possible interaction between arginine and other macro and/or trace minerals, including silicon associated with mineralized bone formation and remodeling.

Silicon can affect bone formation and remodeling (3). The basic amino acids such as arginine can increase silicon absorption (4). Therefore the effects of silicon on bone mineralization may be modified by the amount of arginine in the diet….

Review: Nutrients Involved in Maintaining Healthy Bone

Abstract

Update on nutrients involved in maintaining healthy bone.

Osteoporosis is a leading cause of morbidity and mortality in the elderly and influences quality of life, as well as life expectancy. Currently, there is a growing interest among the medical scientists in search of specific nutrients and/or bioactive compounds of natural origin for the prevention of disease and maintenance of bone health. Although calcium and vitamin D have been the primary focus of nutritional prevention of osteoporosis, a recent research has clarified the importance of several additional nutrients and food constituents. Based on this review of the literature, supplementation with vitamins B, C, K, and silicon could be recommended for proper maintenance of bone health, although further clinical studies are needed. The results of studies on long-chain polyunsaturated fatty acids, potassium, magnesium, copper, selenium, and strontium are not conclusive, although studies in vitro and in animal models are interesting and promising.

Rondanelli M, Opizzi A, Perna S, Faliva MA
Endocrinol Nutr Apr 2013
PMID: 23273614