Monthly Archives: August 2013

Chromium Could Have Bone Benefits

Abstract

Anabolic effects of insulin on bone suggest a role for chromium picolinate in preservation of bone density.

Activation of osteoclasts by parathyroid hormone (PTH) is mediated by PTH stimulation of osteoblasts, and is dependent on a PTH-induced rise in protein kinase C activity. Physiological levels of insulin reduce the ability of PTH to activate protein kinase C in osteoblasts, suggesting that insulin may be a physiological antagonist of bone resorption. In addition, insulin is known to promote collagen production by osteoblasts. These findings imply that efficient insulin activity may exert an anabolic effect on bone, and rationalize the many clinical studies demonstrating reduced bone density in Type I diabetes. Recently, the insulin-sensitizing nutrient chromium picolinate has been found to reduce urinary excretion of hydroxyproline and calcium in postmenopausal women, presumably indicative of a reduced rate of bone resorption. This nutrient also raised serum levels of dehydroepiandrosterone-sulfate, which may play a physiological role in the preservation of postmenopausal bone density. The impact of chromium picolinate (alone or in conjunction with calcium and other micronutrients) on bone metabolism and bone density, merits further evaluation in controlled studies.

McCarty MF
Med. Hypotheses Sep 1995
PMID: 8569546

Blueberry Prevents Bone Loss in Ovariectomized Rats

Abstract

Blueberry prevents bone loss in ovariectomized rat model of postmenopausal osteoporosis.

The objective of the present study was to explore the bone protective role of blueberry in an ovariectomized rat model. Thirty 6-month-old female Sprague-Dawley rats were either sham-operated (Sham) or ovariectomized (Ovx) and divided into three groups: Sham, Ovx (control), Ovx+blueberry (5% blueberry w/w). After 100 days of treatment, rats were euthanized, and blood and tissues were collected. Bone mineral density (BMD) and content of whole body, right tibia, right femur and fourth lumbar vertebra were assessed via dual-energy X-ray absorptiometry. As expected, Ovx resulted in loss of whole-body, tibial, femoral, and 4th lumbar BMD by approximately 6%. Blueberry treatment was able to prevent the loss of whole-body BMD and had an intermediary effect on prevention of tibial and femoral BMD when compared to either Sham or Ovx controls. The bone-protective effects of blueberry may be due to suppression of Ovx-induced increase in bone turnover, as evident by lowered femoral mRNA levels of alkaline phosphatase, collagen type I and tartrate-resistant acid phosphatase to the Sham levels. Similarly, serum osteocalcein levels were also lower in the blueberry group when compared to the Ovx control group, albeit not significantly. In summary, our findings indicate that blueberry can prevent bone loss as seen by the increases in BMD and favorable changes in biomarkers of bone metabolism.

Devareddy L, Hooshmand S, Collins JK, Lucas EA…
J. Nutr. Biochem. Oct 2008
PMID: 18328688

Hydrolyzed Collagen Increases Bone Mass in Exercising Rats

Abstract

Hydrolyzed collagen intake increases bone mass of growing rats trained with running exercise.

Some studies have shown that dietary hydrolyzed collagen peptides (HC) effectively prevent age-related bone loss. However, it is not known whether the intake of HC also has positive effect on bone mass or strength when combined with exercise during growth phase.
We examined the effects of 11 weeks of HC intake and running exercise on bone mass and strength in growing rats. Rats were randomized into four groups, the 20% casein group (Casein20), the 40% casein group (Casein40), the 20% HC group (HC20), and the 40% HC group (HC40). Each group was further divided into exercise groups (Casein20 + Ex, Casein40 + Ex, HC20 + Ex, HC40 + Ex) and non-exercise group (Casein20, Casein40, HC20, HC40). In the HC intake groups, 30% of casein protein was replaced with HC. Exercise group rats were trained 6 days per week on a treadmill (25-30 m/min, 60 min) for 60 days. After being sacrificed, their bone mineral content (BMC) and bone strength were evaluated.
Exercise and dietary HC effects were observed in the adjusted BMC of lumbar spine and tibia among the 20% protein groups (p < 0.001 for exercise; p < 0.05 for dietary HC, respectively). These effects were also noted in the adjusted wet weight and dry weight of femur among the 20% protein groups (p < 0.001, p < 0.01 for exercise; p < 0.01, p < 0.001 for dietary HC, respectively). On the other hand, in adjusted bone breaking force and energy, dietary HC effect was not significant. Among the 40% protein groups, similar results were obtained in the adjusted BMC, femoral weight, bone breaking force, and energy. There were no differences between the 20% protein groups and the 40% protein groups.
The present study demonstrated that moderate HC intake (where the diet contains 20% protein, of which 30% is HC) increased bone mass during growth period and further promoted the effect of running exercise. On the other hand, a higher HC intake (where the diet contains 40% protein, of which 30% is HC) had no more beneficial effect on bone mass than the moderate HC intake.

Takeda S, Park JH, Kawashima E, Ezawa I…
J Int Soc Sports Nutr 2013
PMID: 23914839 | Free Full Text

Hydrolyzed Collagen as Effective as Raloxifene in Mice

Abstract

Hydrolyzed collagen improves bone status and prevents bone loss in ovariectomized C3H/HeN mice.

This study evaluates the effect of hydrolyzed collagen (HC) on bone health of ovariectomized mice (OVX) at different ages. Twenty-six weeks after the OVX procedure, HC ingestion was still able to improve significantly bone mineral density (BMD) and some femur biomechanical parameters. Moreover, HC ingestion for 1 month before surgery prevented BMD decrease.
HC can play an important role in preserving BMD before osteoporosis appears. The aim of this study was to evaluate the effect of HC on bone health of ovariectomized mice at different ages.
Female C3H mice were either OVX at 3 or 6 months and fed for 6 months (first experiment) or 3 months (second experiment) with diet including 0, 10, or 25 g/kg of HC. In the second experiment, one group received HC 1 month before surgery, and two groups received the supplementation immediately after surgery, one fed ad libitum and the other by gavage. Mice treated with raloxifene were used as a positive control. BMD, femur intrinsic and extrinsic biomechanical properties, and type I collagen C-terminal telopeptide were measured after 12 and 26 weeks. Food intake and spontaneous physical activity were also recorded.
The OVX procedure increased body weight, while food intake decreased, thus suggesting that resting metabolism was decreased. Ingestion of 25 g/kg of HC for 3 or 6 months reduced bone loss significantly in, respectively, 3- and 6-month-old OVX mice. The lowest HC concentration was less efficient. HC ingestion for 3 months is as efficient as raloxifene to protect 3-month-old OVX mice from bone loss. Our results also demonstrated that HC ingestion before surgery prevented the BMD decreases.
This study confirms that dietary collagen reduces bone loss in OVX mice by increasing the diameter of the cortical areas of femurs and can have a preventive effect.

Guillerminet F, Fabien-Soulé V, Even PC, Tomé D…
Osteoporos Int Jul 2012
PMID: 21927918

Hydrolyzed Collagen Improves Bone in Mice

Abstract

Hydrolyzed collagen improves bone metabolism and biomechanical parameters in ovariectomized mice: an in vitro and in vivo study.

Collagen has an important structural function in several organs of the body, especially in bone and cartilage. The aim of this study was to investigate the effect of hydrolyzed collagen on bone metabolism, especially in the perspective of osteoporosis treatment and understanding of its mechanism of action. An in vivo study was carried out in 12-week-old female C3H/HeN mice. These were either ovariectomized (OVX) or sham-operated (SHAM) and fed for 12 weeks with a diet containing 10 or 25 g/kg of hydrolyzed collagen. We measured bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA). C-terminal telopeptide of type I collagen (CTX), marker of bone resorption, and alkaline phosphatase (ALP), marker of bone formation, were assayed after 4 and 12 weeks. Femur biomechanical properties were studied by a 3-point bending test and bone architecture by microtomography. The BMD for OVX mice fed the diet including 25 g/kg of hydrolyzed collagen was significantly higher as compared to OVX mice. The blood CTX level significantly decreased when mice were fed with either of the diets containing hydrolyzed collagen. Finally, we have shown a significant increase in bone strength correlated to geometrical changes for the OVX mice fed the 25 g/kg hydrolyzed collagen diet. Primary cultures of murine bone cells were established from the tibia and femur marrow of BALB/c mice. The growth and differentiation of osteoclasts and osteoblasts cultured with different concentrations (from 0.2 to 1.0 mg/mL) of bovine, porcine or fish hydrolyzed collagens (2 or 5 kDa) were measured. Hydrolyzed collagens (2 or 5 kDa) in the tissue culture medium did not have any significant effects on cell growth as compared to controls. However, there was a significant and dose-dependent increase in ALP activity, a well-known marker of osteogenesis, and a decrease in octeoclast activity in primary culture of bone cells cultured with hydrolyzed collagens (2 kDa only) as compared to the control. It is concluded that dietary hydrolyzed collagen increases osteoblast activity (as measured in primary tissue culture), which acts on bone remodeling and increases the external diameter of cortical areas of the femurs.

Guillerminet F, Beaupied H, Fabien-Soulé V, Tomé D…
Bone Mar 2010
PMID: 19895915

Low Dose Aspirin May Increase Bone Resorption in Diabetic Mice

Abstract

Low dose aspirin therapy decreases blood glucose levels but does not prevent type i diabetes-induced bone loss.

Diabetes is strongly associated with increased fracture risk. During T1-diabetes onset, levels of blood glucose and pro-inflammatory cytokines (including TNFα) are increased. At the same time, levels of osteoblast markers are rapidly decreased and stay decreased 40 days later at which point bone loss is clearly evident. Inflammation is known to suppress bone formation and induce bone loss. Previous co-culture studies indicate that diabetic bone is inflamed and diabetic bone marrow is capable of enhancing osteoblast death in vitro. Here we investigate a commonly used non-steroidal anti-inflammatory drug, aspirin, to prevent T1-diabetic bone loss in vivo.
We induced diabetes in 16-week-old male C57BL/6 mice and administered aspirin in the drinking water.
Our results demonstrate that aspirin therapy reduced diabetic mouse non-fasting blood glucose levels to less than 400 mg/dl, but did not prevent trabecular and cortical bone loss. In control mice, aspirin treatment increased bone formation markers but did not affect markers of bone resorption or bone density/volume. In diabetic mice, bone formation markers and bone density/volume are decreased and unaltered by aspirin treatment. Bone resorption markers, however, are increased and 2-way ANOVA analysis demonstrates an interaction between aspirin treatment and diabetes (p<0.007). Aspirin treatment did not prevent the previously reported diabetes-induced marrow adiposity.
Taken together, our results suggest that low dose aspirin therapy does not negatively impact bone density in control and diabetic mice, but could potentially increase bone resorption in T1-diabetic mice.

Coe LM, Denison JD, McCabe LR
Cell. Physiol. Biochem. 2011
PMID: 22178944 | Free Full Text

Review: NSAIDs May Inhibit Bone Healing

Abstract

Do nonsteroidal anti-inflammatory drugs affect bone healing? A critical analysis.

Nonsteroidal anti-inflammatory drugs (NSAIDs) play an essential part in our approach to control pain in the posttraumatic setting. Over the last decades, several studies suggested that NSAIDs interfere with bone healing while others contradict these findings. Although their analgesic potency is well proven, clinicians remain puzzled over the potential safety issues. We have systematically reviewed the available literature, analyzing and presenting the available in vitro animal and clinical studies on this field. Our comprehensive review reveals the great diversity of the presented data in all groups of studies. Animal and in vitro studies present so conflicting data that even studies with identical parameters have opposing results. Basic science research defining the exact mechanism with which NSAIDs could interfere with bone cells and also the conduction of well-randomized prospective clinical trials are warranted. In the absence of robust clinical or scientific evidence, clinicians should treat NSAIDs as a risk factor for bone healing impairment, and their administration should be avoided in high-risk patients.

Pountos I, Georgouli T, Calori GM, Giannoudis PV
ScientificWorldJournal 2012
PMID: 22272177 | Free Full Text

Review: NSAIDs on Fracture Healing

Abstract

The effect of nonsteroidal anti-inflammatory drug administration on acute phase fracture-healing: a review.

The analgesic efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs) is well established, and these agents often form an integral part of posttraumatic pain management. However, potentially deleterious effects of resulting prostaglandin suppression on fracture-healing have been suggested.
A systematic literature review involving searches of electronic databases and online sources was performed to identify articles exploring the influence of NSAIDs on fracture-healing.
A structured search approach identified 316 papers as potentially relevant to the topic, and these were manually reviewed. The majority described small-scale studies that were retrospective or observational in nature, with limited control of potentially confounding variables, or presented little key information that was not also present in other studies.
Although increasing evidence from animal studies suggests that cyclooxygenase-2 (COX-2) inhibition suppresses early fracture-healing, in vivo studies involving human subjects have not provided convincing evidence to substantiate this concern. We found no robust evidence to attest to a significant and appreciable patient detriment resulting from the short-term use of NSAIDs following a fracture. The balance of evidence in the available literature appears to suggest that a short-duration NSAID regimen is a safe and effective supplement to other modes of post-fracture pain control, without a significantly increased risk of sequelae related to disrupted healing.

Kurmis AP, Kurmis TP, O’Brien JX, Dalén T
J Bone Joint Surg Am May 2012
PMID: 22552671

Indomethacin Impares Fracture Healing in Mice

Abstract

Anti-inflammatory treatment increases angiogenesis during early fracture healing.

Both inflammation and angiogenesis are crucial for normal fracture healing. The goal of this work was to determine how anti-inflammatory treatment affects angiogenesis during early stages of fracture repair.
Tibia fractures were created in adult mice and animals were treated with indomethacin (2 mg/kg/day), a non-steroidal anti-inflammatory drug, or PBS once a day beginning from 1 day before fracture and continuing to 6 days after fracture. Animals were killed at 7, 14, and 28 days after injury for histomorphometric analysis of fracture healing. A second group of animals were killed at 3 and 7 days after injury to measure tissue levels of VEGF and interleukin-1 beta (IL-1β). A third group of animals were killed at 3 and 7 days after injury for stereology analysis of macrophage and neutrophil infiltration and tissue vascularization.
Indomethacin significantly decreased bone and cartilage formation at 7 days after fracture compared to controls. Indomethacin decreased the tissue levels of IL-1β at 3 days after fracture but did not affect the recruitment of macrophages or neutrophils to injured limbs. Indomethacin-treated fractures had similar length density and surface density of vasculature as the controls at 3 days after injury. At 7 days after fracture, vasculature in indomethacin-treated fractures exhibited higher length density and surface density than that in controls. By 28 days after injury, indomethacin-treated fractures still exhibited defects in fracture repair.
Anti-inflammatory treatments using indomethacin impair bone and cartilage formation and increase tissue vascularization in the callus during early fracture healing.

Lu C, Xing Z, Wang X, Mao J…
Arch Orthop Trauma Surg Aug 2012
PMID: 22622792

Aspirin Prevents Bone Loss in Ovariectomized Rats

Abstract

[Effect of cyclooxygenase-2 on bone loss in ovariectomized rats].

To investigate mechanism of cyclooxygenase-2 (COX-2) in bone loss in a postmenopausal osteoporosis (PMOP) rat mode with ovarietomy (OVX).
Forty female Sprague Dawley adult rats at age of 3 months were randomly divided into 4 groups, 10 in each group, including sham-operated (sham) group, OVX group, OVX treated with nilesteriol (OVX + E) group and OVX treated with aspirin (OVX + P) group. All rats in OVX, OVX + E and OVX + P groups underwent ovarietomy under abdominal anesthesia with 10% chloral hydrate. Rats in sham group were only taken with fat tissue with same weight under bilateral ovary. After surgery, penicillin was administered to prevent infection. At day 7 after surgery, agents were given by intragastric administration for 12 weeks. Nilestriol at 1.0 mg/kg was used in OVX + E group once a week, aspirin at 45 mg×kg⁻¹(×d⁻¹ was used in OVX + P group once a day. Saline with same volume was used in rats in sham and OVX groups. All agents were administered one time per day. Dose of agents were adjusted by weight per week. At end of study, bone mineral density (BMD) of right femurs and lumbar vertebrae 3-5 (L(3-5)) were measured. Morphology of bone was detected by hematoxylineosin, and expression of COX-2 was determined by immunohistochemistry staining.
(1) BMD:BMD of right femur and L(3-5) was (0.209 ± 0.010) g/cm² and (0.230 ± 0.012) g/cm² in sham group and (0.181 ± 0.008) g/cm² and (0.201 ± 0.016) g/cm² in OVX group, which reached statistical difference (P < 0.01). BMD of right femur and L(3-5) was (0.203 ± 0.009) g/cm² and (0.224 ± 0.028) g/cm² in OVX + E group and (0.200 ± 0.011) g/cm² and (0.204 ± 0.003) g/cm² in OVX + P group, which were all higher than those in OVX group (P < 0.01, P < 0.05). However, there was no statistical difference in BMD between OVX + E and OVX + P group (P > 0.05). (2) Morphology of bone:bone trabeculae became fewer and degenerated in OVX group. However, bone trabeculae were regular and dense in OVX + P group and OVX + E group, which were similar to those in sham group. (3) Expression of COX-2:cells with COX-2 positive and expression of COX-2 around bone trabeculae in OVX group were more than those in sham, OVX + E and OVX + P group.
COX-2 plays an important role in PMOP. Aspirin could prevent bone loss by decreasing COX-2 expression in OVX rats.

Guo Y, Zhang CY, Tian Y, DI JM…
Zhonghua Fu Chan Ke Za Zhi Jun 2012
PMID: 22932114