Effects of high-intensity interval training in more or less active mice on biomechanical, biophysical and biochemical bone parameters.

High-intensity interval training (HIIT) is of scientific interest due its role in improving physical fitness, but the effects of HIIT on bone health need be carefully explored. Further, it is necessary to know whether HIIT effects on bone health are dependent on the physical activity levels. This may be experimentally tested since we have built a large cage (LC) that allows animals to move freely, promoting an increase of spontaneous physical activity (SPA) in comparison to a small cage (SC). Thus, we examined the effects of HIIT on biophysical, biomechanical and biochemical parameters of bone tissue of C57BL/6J mice living in cages of two different sizes: small (SC) or large (LC) cages with 1320 cm2 and 4800 cm2 floor space, respectively. Male mice were subdivided into two groups within each housing type: Control (C) and Trained (T). At the end of the interventions, all mice were euthanized to extract the femur bone for biophysical, biomechanical and biochemical analyses. Based a significant interaction from two-way ANOVA, trained mice kept in large cage (but not for trained mice housed in SC) exhibited a reduction of tenacity and displacement at failure in bone. This suggests that long-term HIIT program, in addition with a more active lifestyle correlates with exerts negative effects on the bone of healthy mice. A caution must also be raised about the excessive adoption of physical training, at least regarding bone tissue. On the other hand, increased calcium was found in femur of mice housed in LC. In line with this, LC-C mice were more active (i.e. SPA) than other groups. This implies that an active lifestyle without long-term high intensity physical training seems to play a role in promoting benefits to bone tissue. Our data provides new insights for treatment of osteo-health related disorders.

Assessment of safety and efficacy of pine bark extract in normal and ovariectomized mice.

We evaluated the influence of pine bark extract (PBE) on organs, the cytochrome-P450 (CYP) activities in liver and estrogenic effects in normal and ovariectomized (OVX) female mice. The PBE did not affect organ weights and liver-function indexes (activities of alkaline phosphatase, aspartate amino transferase, and alanine amino transferase) at doses; 0.04%, 0.4%, and 2.0% PBE in the diet, in normal and OVX female mice. In the OVX mice, CYP1A1 activity was significantly higher in the 0.4% and 2.0% PBE groups than in the OVX control group, and in the 0.4% and 2.0% PBE groups were significantly higher than in the 0.04% PBE group. CYP1A2 and 3A4 activities were significantly higher in the 2.0% PBE group than in all other groups. The PBE did not affect uterine weight and femoral bone mineral density at all PBE doses. These results showed that the dose of PBE at the recommended human intake, had no toxic and estrogenic effects in normal female and OVX mice, however, it may need attention to use the excess intake of PBE with some drugs in postmenopausal women.

Growth factor-mediated augmentation of long bones: evaluation of a BMP-7 loaded thermoresponsive hydrogel in a murine femoral intramedullary injection model.

BACKGROUND: Due to our aging population, an increase in proximal femur fractures can be expected, which is associated with impaired activities of daily living and a high risk of mortality. These patients are also at a high risk to suffer a secondary osteoporosis-related fracture on the contralateral hip. In this context, growth factors could open the field for regenerative approaches, as it is known that, i.e., the growth factor BMP-7 (bone morphogenetic protein 7) is a potent stimulator of osteogenesis. Local prophylactic augmentation of the proximal femur with a BMP-7 loaded thermoresponsive hydrogel during index surgery of an osteoporotic fracture could be suitable to reduce the risk of further osteoporosis-associated secondary fractures. The present study therefore aims to test the hypothesis if a BMP-7 augmented hydrogel is an applicable carrier for the augmentation of non-fractured proximal femurs. Furthermore, it needs to be shown that the minimally invasive injection of a hydrogel into the mouse femur is technically feasible. METHODS: In this study, male C57BL/6 mice (n = 36) received a unilateral femoral intramedullary injection of either 100 µl saline, 100 µl 1,4 Butan-Diisocyanat (BDI)-hydrogel, or 100 µl hydrogel loaded with 1 µg of bone morphogenetic protein 7. Mice were sacrificed 4 and 12 weeks later. The femora were submitted to high-resolution X-ray tomography and subsequent histological examination. RESULTS: Analysis of normalized CtBMD (Cortical bone mineral density) as obtained by X-ray micro-computed tomography analysis revealed significant differences depending on the duration of treatment (4 vs 12 weeks; p < 0.05). Furthermore, within different anatomically defined regions of interest, significant associations between normalized TbN (trabecular number) and BV/TV (percent bone volume) were noted. Histology indicated no signs of inflammation and no signs of necrosis and there were no cartilage damages, no new bone formations, or new cartilage tissues, while BMP-7 was readily detectable in all of the samples. CONCLUSIONS: In conclusion, the murine femoral intramedullary injection model appears to be feasible and worth to be used in subsequent studies that are directed to examine the therapeutic potential of BMP-7 loaded BDI-hydrogel. Although we were unable to detect any significant osseous effects arising from the mode or duration of treatment in the present trial, the effect of different concentrations and duration of treatment in an osteoporotic model appears of interest for further experiments to reach translation into clinic and open new strategies of growth factor-mediated augmentation.

Charged particle spectrometry to measure 10B concentration in bone.

Osteosarcoma is the most common primary malignant tumour of bone in young patients. The survival of these patients has largely been improved due to adjuvant and neo-adjuvant chemotherapy in addition to surgery. Boron neutron capture therapy (BNCT) is proposed as a complementary therapy, due to its ability to inactivate tumour cells that may survive the standard treatment and that may be responsible for recurrences and/or metastases. BNCT is based on neutron irradiation of a tumour enriched in 10B with a boron-loaded drug. Low-energy neutron capture in 10B creates charged particles that impart a high dose to tumour cells, which can be calculated only knowing the boron concentration. Charged particle spectrometry is a method that can be used to quantify boron concentration. This method requires acquisition of the energy spectra of charged particles such as alpha particles produced by neutron capture reactions in thin tissue sections irradiated with low-energy neutrons. Boron concentration is then determined knowing the stopping power of the alpha particles in the sample material. This paper describes the adaptation of this method for bone, with emphasis on sample preparation, experimental set-up and stopping power assessment of the involved alpha particles. The knowledge of boron concentration in healthy bones is important, because it allows for any dose limitation that might be necessary to avoid adverse effects such as bone fragility. The measurement process was studied through Monte Carlo simulations and analytical calculations. Finally, the boron content of bone samples was measured by alpha spectrometry at the TRIGA reactor in Pavia, Italy, and compared to that obtained by neutron autoradiography. The agreement between the results obtained with these techniques confirms the suitability of alpha spectrometry to measure boron in bone.

A reassessment of the vitamin D requirements of modern broiler genotypes.

We hypothesized that performance and bone mineralization of 2 broiler lines will benefit from increasing vitamin D (vitD) supplementation above current commercial levels and by partial substitution of D3 by 25-OH-D3. Male Ross 308 and 708 chicks (n = 576), were offered diets with low (LD; 1,000), medium (MD; 4,000) or high levels of D3 (HD; 7,000 IU/kg), and medium levels of vitD where the majority of D3 was substituted by 25-OH-D3 (25MD; 1,000 D3+3,000 25-OH-D3 IU/kg). Performance was measured at the end of starter (day 10), grower (day 24), and finisher periods (day 38). Three birds per pen were dissected at the end of each period to assess tibia and femur ash percentage (%), ash weight, bone breaking strength (BBS), and serum levels of 25-OH-D3. Remaining birds were gait scored (GS) at day 37 of age. Genotype and diet did not interact for any trait, whilst performance was not affected by diet. Ross 708 had lower body weight (P < 0.005), higher feed conversion ratio over the grower period (P < 0.05), similar levels of 25-OH-D3, but higher GS (P < 0.05) than Ross 308. Serum 25-OH-D3 levels were affected by diet at the end of the starter and grower periods (P < 0.05), being lowest for LD and highest for 25MD. Diet affected GS (P < 0.01), being higher in LD than 25MD. Femur ash % was higher at the end of the starter and grower periods for 25MD than LD and for both HD and 25MD than LD (P < 0.05). Femur and tibia ash weight were higher for 25MD in comparison to LD birds (P < 0.05) at the end of the grower period. Femur and tibia BBS were higher (P < 0.05) for 25MD in comparison to LD at the end of the grower and finisher periods, respectively. Overall, effects of vitD supply were more pronounced for femur than for tibia mineralization. Results do not suggest supplementation of vitD above current maximum levels and support partial substitution by 25-OH-D3.

Effects of dietary omega-3 fatty acids on bones of healthy mice.

BACKGROUND & AIMS: Altering the lipid component in diets may affect the incidence of metabolic bone disease in patients dependent on parenteral nutrition. Consumption of polyunsaturated fatty acids (PUFA) can impact bone health by modulating calcium metabolism, prostaglandin synthesis, lipid oxidation, osteoblast formation, and osteoclastogenesis. The aim of this study was to evaluate the dietary effects of PUFA on murine bone health. METHODS: Three-weeks-old male (n = 30) and female (n = 30) C57BL/6J mice were randomized into one of three dietary groups. The diets differed only in fat composition: soybean oil (SOY), rich in ω-6 PUFA; docosahexaenoic acid alone (DHA), an ω-3 PUFA; and DHA with arachidonic acid, an ω-6 PUFA, at a 20:1 ratio (DHA/ARA). After 9 weeks of dietary treatment, femurs were harvested for micro-computed tomographic analysis and mechanical testing via 3-point bending. Separate mice from each group were used solely for serial blood draws for measurement of biomarkers of bone formation and resorption. RESULTS: At the microstructural level, although some parameters in cortical bone reached differences that were statistically significant in female mice, these were too small to be considered biologically relevant. Similarly, trabecular bone parameters in male mice were statistically different in some dietary groups, although the biological interpretation of such subtle changes translate into a lack of effect in favor of any of the experimental diets. No differences were noted at the mechanical level and in blood-based biomarkers of bone metabolism across dietary groups within gender. CONCLUSIONS: Subtle differences were noted at the bones' microstructural level, however these are likely the result of random effects that do not translate into changes that are biologically relevant. Similarly, differences were not seen at the mechanical level, nor were they reflected in blood-based biomarkers of bone metabolism. Altogether, dietary consumption of PUFA do not seem to affect bone structure or metabolism in a healthy model of growing mice.

Effects of Long-Term Calcium Supplementation on Rats Bone Mineral Density and Cardiovascular Based on Metabonomics.

Calcium supplements were necessary for those people with low calcium intake and high risk of osteoporosis. Recent cohort studies have shown that long-term calcium supplements may raise the risk of cardiovascular disease, but its mechanism is still unclear. In this study, metabonomics were employed to evaluate the changes of metabolism in rats with long-term calcium supplementation and further seek the potential markers of cardiovascular risk. SD rats were divided into two groups including normal control group (calcium intake, 0.50 g/kg bw) and high calcium supplement group (calcium intake, 2.50 g/kg bw). After 6 mo, the cardiovascular system and bone mineral density were observed. UPLC-MS was used to analyze serum metabonomics in rats. The results showed that the contents of total cholesterol and low-density lipoprotein cholesterol in the high calcium group were significantly higher than those in normal control group (p<0.05). The interventricular septum thickness (IVS), left ventricular mass (LVM), left ventricular posterior wall thickness (LVPW) in the high calcium group were higher than those in normal control group (p<0.05). Serum metabonomics analysis showed that there were persistent changes in many metabolites such as sphingosine and its derivatives (p<0.01) in the comparison between the high calcium group and the normal group. These results indicated that long term calcium supplementation can lead to dyslipidemia in rats, such as the rise of cholesterol and low-density lipoprotein, which might induce myocardial hypertrophy. Long-term calcium supplementation can cause the changes of the amount of sphingosine and its derivatives in the body, which many have potential risk to cardiovascular diseases such as myocardial hypertrophy and atherosclerosis.

A probable case of doping in an Olympic athlete coming back from ancient Greece (V cent. B.C.).

We present here the hypothesis of doping in an athlete coming back from the ancient Greece, dating back to V century B.C. There are some bone alterations due to the sports that he probably practiced, and that are represented on the amphorae (prices of his victories) found near his sepulchre. The skeleton shows a considerable mass and bone density. The chemical analyses performed on the bone emphasized the presence of arsenic, while the X-ray and CAT scan examinations revealed a quite big sella turcica. These two aspects might have influenced the performances of this athlete, and in the same time might have provoked his death at the age of about 30 years.

Dietary Natural N-Acetyl-d-Glucosamine Prevents Bone Loss in Ovariectomized Rat Model of Postmenopausal Osteoporosis.

Postmenopausal osteoporosis has seriously affected the life quality of elderly women. A natural polymer, chitin, obtained from shells of crab and shrimp, has been widely used in the biomedical field owing to its nontoxicity, biocompatibility, and biodegradability. In this study, natural N-acetyl-d-glucosamine (NAG) was prepared from liquefied chitin. The protective activities of NAG in postmenopausal osteoporosis were evaluated on Sprague Dawley rats and osteoblast-based models. Results showed that oral administration of NAG boosted trabecular bone volume and trabecular numbers. Additionally, the calcium content in the femur and tibia increased, and femoral biomechanical properties improved. Furthermore, NAG supplementation significantly lowered alkaline phosphatase levels and increased calcium content in the serum of ovariectomized rats. In vitro studies showed that NAG markedly promoted cell proliferation and stimulated osteoblast differentiation of mouse calvaria origin MC3T3-E1 cells with increased alkaline phosphatase activity in a concentration-dependent manner. Moreover, NAG effectively protected osteoblasts from oxidative damage induced by hydrogen peroxide. In conclusion, our data provide an additional foundation for dietary supplementation of NAG, which could protect and reverse osteopenia in postmenopausal women.

The Content of Structural and Trace Elements in the Knee Joint Tissues.

Many elements are responsible for the balance in bone tissue, including those which constitute a substantial proportion of bone mass, i.e., calcium, phosphorus and magnesium, as well as minor elements such as strontium. In addition, toxic elements acquired via occupational and environmental exposure, e.g., Pb, are included in the basic bone tissue composition. The study objective was to determine the content of strontium, lead, calcium, phosphorus, sodium and magnesium in chosen components of the knee joint, i.e., tibia, femur and meniscus. The levels of Sr, Pb, Ca, P, Na and Mg were the highest in the tibia in both men and women, whereas the lowest in the meniscus. It should be noted that the levels of these elements were by far higher in the tibia and femur as compared to the meniscus. In the components of the knee joint, the level of strontium showed the greatest variation. Significant statistical differences were found between men and women only in the content of lead.

The effect of dietary magnesium and caseinphosphopeptides on bone metabolism in rats.

The effect of dietary magnesium (Mg) or caseinphosphopeptides (CPPs) on bone metabolism has been reported. However, few studies have investigated the effects of simultaneous supplementation of Mg and CPPs. Sixty-three 3-week-old Sprague-Dawley male rats were divided into seven groups and fed a specified diet for 45 days. Body characteristics, bone physicochemical indicators, and bone metabolism indicators relative to bone metabolism were analyzed. We found that, first, a dietary Mg deficiency resulted in increased bone formation and decreased bone resorption. Second, dietary Mg or CPP supplementation promoted bone formation and prevented bone resorption. Third, dietary Mg supplementation with CPPs also functioned to enhance bone formation and prevent bone resorption. There were synergistic effects on femur length, serum parathyroid hormone level and urinary deoxypyridinoline of the HS-Mg-CPP group (0.2% Mg, 0.1% CPPs). The increase in the femur length of the HS-Mg-CPP group compared with the control group was 6% which was much higher than that of HS-Mg (1%) or CPPs (5%). The induction in serum parathyroid hormone content in the HS-Mg-CPP group was 33% compared with the control group which was higher than that of the induction of the HS-Mg (19%) or CPP (23%) group. The induction in the deoxypyridinoline content of the HS-Mg-CPP (43%) group compared with the control group was remarkably higher than that of HS-Mg (8%) or CPPs (16%). Overall our results demonstrated that high doses of Mg (0.2%) and CPPs (0.1%) in combination produced synergistic effects on femur length, serum parathyroid hormone level and urinary deoxypyridinoline in rats, which is important for a better understanding of the effect of Mg and CPPs on bone metabolism.

Bone natural autofluorescence and confocal laser scanning microscopy: Preliminary results of a novel useful tool to distinguish between forensic and ancient human skeletal remains.

The fast, high-throughput distinction between palaeoanthropological/archaeological remains and recent forensic/clinical bone samples is of vital importance in the field of medico-legal science. In this paper, a novel dating method was developed using the autofluorescence of human bones and the confocal laser scanning microscope as the means to distinguish between archaeological and forensic anthropological skeletal findings. Human bones exhibit fluorescence, typically induced by natural antibiotics that are absorbed by collagen, and provide secondary, exogenous fluorophores. However, primary natural fluorescence (or autofluorescence) caused by enigmatic endogenous fluorophores is also present as a micro-phenomenon, whose nature is still obscure. Here, we show that the endogenous fluorophores are mucopolysaccharides of the Rouget-Neumann sheath and, more relevant, that the intensity of the natural fluorescence in human bone decreases in a relationship to the antiquity of the samples. These results suggest that the autofluorescence of bone is a promising technique for the assessment of skeletal remains that may be potentially of medico-legal interest. A larger study is proposed to confirm these findings and to create a predictive model between the autofluorescence intensity and the time since death.

Inclusion of excess dietary calcium in diets for 100- to 130-kg growing pigs reduces feed intake and daily gain if dietary phosphorus is at or below the requirement.

An experiment was conducted to test the hypothesis that the requirement for standardized total tract digestible (STTD) Ca by pigs from 100 to 130 kg depends on the concentration of STTD P in the diet. Ninety pigs (average initial BW: 99.89 ± 3.34 kg) were randomly allotted to 15 experimental diets. Each diet was fed to 6 replicate pigs using a randomized complete block design. Fifteen corn and soybean meal-based diets were formulated and phytate and Na were constant among treatments. Diets were formulated using a 3 × 5 factorial design with diets containing 0.11%, 0.21%, or 0.31% STTD P and 0.12%, 0.29%, 0.46%, 0.61%, or 0.78% total Ca (0.08%, 0.18%, 0.29%, 0.38%, or 0.49% STTD Ca). The P concentrations ranged from 48 to 152% of the STTD P requirement for 100- to 125-kg pigs and the Ca concentrations ranged from 27 to 173% of the total Ca requirement. Experimental diets were fed for 28 d and pigs were individually housed. Pig and feeder weights were recorded at the beginning and at the conclusion of the experiment to calculate ADFI, ADG, and G:F. On d 28, all pigs were euthanized and the right femur was extracted. Ash, Ca, and P concentrations were determined from the de-fatted, dried femurs. Results indicated that as dietary concentrations of STTD Ca increased, ADFI decreased (main effect of Ca, < 0.05), regardless of the dietary concentration of P. The model to predict ADFI (ADFI = 3.6782 - 1.2722 × STTD Ca [%]; = 0.001) was dependent only on the concentration of dietary STTD Ca, but not on the concentration of dietary STTD P. In contrast, the model to predict ADG depended on both STTD Ca and STTD P (1.4556 - 1.4192 × STTD Ca [%] - 1.0653 × STTD P [%] + 4.2940 STTD Ca [%] × STTD P [%]; = 0.002). There were no effects of STTD Ca or STTD P on G:F. Linear increases were observed for bone ash, bone Ca, and bone P as dietary concentrations of STTD Ca increased for all concentrations of STTD P, but the increase was greater at the greatest concentration of STTD P than at lower concentrations (interaction, < 0.001). In conclusion, results indicate that the estimated requirement for dietary STTD Ca by 100- to 130-kg pigs needed to maximize ADG, bone ash, and bone Ca depends on the concentration of STTD P in the diet. Results also indicate that feeding Ca in excess of the current requirement for total Ca is detrimental to growth performance of pigs from 100 to 130 kg unless P is also included above the requirement.

Chronic effects of simultaneous electromyostimulation and vibration on leg blood flow in spinal cord injury.

STUDY DESIGN: Randomized two-group parallel. OBJECTIVES: The objective of this study was to analyze the adaptations on the popliteal artery (mean blood velocity (MBV), peak blood velocity (PBV), arterial resting diameter (RD) and blood flow (BF)) induced by 12 weeks of simultaneous application of whole-body vibration and electromyostimulation (WBV+ES) in patients with spinal cord injury (SCI). Secondarily, the musculoskeletal effects of this therapy on the gastrocnemius muscle thickness (MT) and femoral neck bone mineral density (BMD) were analyzed. SETTING: Valladolid, Spain. METHODS: Seventeen SCI patients (American Spinal Injury Association (ASIA) A or B) were randomly assigned to the experimental group (EG=9) or the control group (CG=8). Each subject was assessed in four different occasions: at baseline, after 6 weeks (Post-6) and 12 weeks of the treatment (Post-12) and 8 weeks after the end of the treatment (Post-20). Subjects in the EG performed 30 10-min sessions of WBV+ES during 12 weeks. RESULTS: In the EG, RD increased compared with the baseline value at Post-6 (9.5%, P<0.01), Post-12 (19.0%, P<0.001) and Post-20 (16.7%, P<0.001). Similarly, in the EG, BF increased compared with the baseline value and with CG only at Post-12 ((33.9%, P<0.01) and (72.5%, P<0.05), respectively). Similarly, WBV+ES increased the MT of the gastrocnemius. BMD of both hips remained invariable during the study. CG showed no change at any point. CONCLUSIONS: WBV+ES improved popliteal artery BF, RD and MT after 12 weeks in SCI patients. This increase in RD remained above baseline after 8 weeks. The combination of WBV and ES could be considered a promising alternative to reverse the musculoskeletal atrophy and improve peripheral vascular properties in SCI patients.

Puerarin prevents bone loss in ovariectomized mice and inhibits osteoclast formation in vitro.

The present study aimed at investigating the effects of Puerarin (PR), a major isoflavonoid isolated from the Chinese medicinal herb Puerariae radix, on bone metabolism and the underlying mechanism of action. The in vivo assay, female mice were ovariectomized (OVX), and the OVX mice were fed with a diet containing low, middle, and high doses of PR (2, 4, and 8 mg·d(-1), respectively) or 17ß-estradiol (E2, 0.03 µg·d(-1)) for 4 weeks. In OVX mice, the uterine weight declined, and intake of PR at any dose did not affect uterine weight, compared with the control. The total femoral bone mineral density (BMD) was significantly reduced by OVX, which was reversed by intake of the diet with PR at any dose, especially at the low dose. In the in vitro assay, RAW264.7 cells were used for studying the direct effect of PR on the formation of osteoclasts. PR reduced the formation of tartrate resistant acid phosphatase (TRAP)-positive multi-nucleated cells in the RAW 264.7 cells induced by receptor activator for nuclear factor-κB Ligand (RANKL). MC3T3-E1 cells were used for studying the effects of PR on the expression of osteoprotegerin (OPG) and RANKL mRNA expression in osteoblasts. The expression of OPG mRNA and RANKL mRNA was detected by RT-PCR on Days of 5, 7, 10, and 12 after PR exposure. PR time-dependently enhanced the expression of OPG mRNA and reduced the expression of RANKL mRNA in MC3T3-E1 cells. In conclusion, our results suggest that PR can effectively prevent bone loss in OVX mice without any hyperplastic effect on the uterus, and the antiosteoporosis activity of PR may be related to its effects on the formation of osteoclasts and the expression of RANKL OPG in osteoblasts.

Supplemental levels of iron and calcium interfere with repletion of zinc status in zinc-deficient animals.

Negative interactions between minerals interfering with each other's absorption are of concern when iron and calcium supplements are given to pregnant women and children. We have previously reported that supplemental levels of iron and calcium inhibit the bioaccessibility of zinc, and compromise zinc status in rats fed diets with high levels of these two minerals. The present study examined the effect of supplemental levels of iron and calcium on the recovery of zinc status during a zinc repletion period in rats rendered zinc-deficient. Iron and calcium, both individually and in combination, significantly interfered with the recovery of zinc status in zinc deficient rats during repletion with normal levels of zinc in the diet. Rats maintained on diets containing supplemental levels of these two minerals had significantly lower body weight, and the concentration of zinc in serum and organs was significantly lower than in zinc-deficient rats not receiving the supplements. Iron and calcium supplementation also significantly inhibited the activity of zinc-containing enzymes in the serum as well as liver. Both iron and calcium independently exerted this negative effect on zinc status, while their combination seemed to have a more prominent effect, especially on the activities of zinc containing enzymes. This investigation is probably the first systematic study on the effect of these two minerals on the zinc status of zinc deficient animals and their recovery during repletion with normal amounts of zinc.

Flaxseed flour, compared to flaxseed oil, contributes to femoral structure in male rats subjected to early weaning.

The aim of this study was to analyze whether flaxseed flour or flaxseed oil treatment contributes to femoral structure in male rats subjected to early weaning. Pups were weaned for separation from mothers at 14 days (early weaning, EW) or 21 days (control, C). After 21 days, the control (C60) was fed with the control diet. The EW group was divided based on control (EWC60), flaxseed flour (EWFF60) and flaxseed oil (EWFO60) diets until 60 days. Femoral dimension, bone mineral density (BMD), bone mineral content (BMC), area and biomechanical properties were determined. EWFO60 showed lower (P < 0.05) femur mass. EWC60 and EWFO60 showed lower (P < 0.05) distance between epiphyses, diaphysis width and BMD. BMC was lower (P < 0.05) in EWC60 (vs. C60 and EWFF60). EWC60 and EWFO60 showed lower (P < 0.05) maximum force (vs. C60). Breaking strength was lower (P < 0.05) in EWFO60 (vs. C60). EWFF60 showed higher (P < 0.05) rigidity. Flaxseed flour abbreviated the femoral fragility secondary to early weaning.

Polysaccharides of Trametes versicolor Improve Bone Properties in Diabetic Rats.

This study investigates the effects of Trametes versicolor (L.:Fr.) Pilát (TVP, also known as Yunzhi) on bone properties in diabetic rats. Forty-five male Wistar rats (8 weeks old) were fed either a chow diet (control) or a high-fat diet throughout the study period of 28 days. Animals in the high-fat-diet group were injected with nicotinamide and streptozotocin to induce diabetes mellitus (DM). The DM rats were divided into a group receiving distilled water (vehicle) and another group receiving TVP at 0.1 g/kg weight by gavage. Relative to the vehicle group, TVP gavage lowered postprandial blood sugar (225 ± 18 mg/dL for TVP vs 292 ± 15 mg/dL for vehicle, p < 0.001) on day 26. Compared to the vehicle group, TVP mitigated DM-induced bone deterioration as determined by increasing bone volume of proximal tibia (22.8 ± 1.4% for TVP vs 16.8 ± 1.3% for vehicle, p = 0.003), trabecular number (p = 0.011), and femoral bone strength (11% in maximal load, 22% in stiffness, 14% in modulus, p < 0.001), and by reducing loss of femoral cortical porosity by 25% (p < 0.001). Our study demonstrates the protective effect of TVP on bone properties was mediated through, in part, the improvement of hyperglycemic control in DM animals.

High-Dose α-Tocopherol Supplementation Does Not Induce Bone Loss in Normal Rats.

Oxidative stress affects bone turnover. Preventative effects of antioxidants such as vitamin E on reduced bone mineral density and fractures associated with aging, osteoporosis, and smoking have been examined in animals and humans. The effects of vitamin E (α-tocopherol; αT) on bone health have yielded conflicting and inconclusive results from animal studies. In this study, to determine the bone effects of αT, we investigated the in vivo effects of αT on the bone mineral density, bone mass, bone microstructure, bone resorption, and osteogenesis through peripheral quantitative computed tomography (pQCT) measurements, micro-computed tomography (micro-CT) analyses, and bone histomorphometry of lumbar vertebrae and femurs in normal female Wistar rats fed diets containing αT in different quantities (0, 30, 120, or 600 mg/kg diet) for 8 weeks. To validate our hypotheses regarding bone changes, we examined ovariectomized rats as an osteoporosis model and control sham-operated rats in parallel. As expected, ovariectomized rats had reduced bone mineral density in lumbar vertebrae and the distal metaphyses of their femurs, reduced bone mass and deteriorated microstructure of cancellous bones in the vertebral body and distal femur metaphyses, and reduced bone mass due to resorption-dominant enhanced bone turnover in secondary cancellous bones in these sites. In comparison, αT administered to normal rats, even at the highest dose, did not induce reduced bone mineral density of lumbar vertebrae and femurs or a reduced bone mass or fragile microstructure of cancellous bones of the vertebral body and distal femur metaphyses. Instead, αT-fed rats showed a tendency for an osteogenesis-dominant bone mass increase in secondary cancellous bones in the vertebral body, in which active bone remodeling occurs. Thus, αT consumption may have beneficial effects on bone health.

Micro-distribution of uranium in bone after contamination: new insight into its mechanism of accumulation into bone tissue.

After internal contamination, uranium rapidly distributes in the body; up to 20 % of the initial dose is retained in the skeleton, where it remains for years. Several studies suggest that uranium has a deleterious effect on the bone cell system, but little is known regarding the mechanisms leading to accumulation of uranium in bone tissue. We have performed synchrotron radiation-based micro-X-ray fluorescence (SR µ-XRF) studies to assess the initial distribution of uranium within cortical and trabecular bones in contaminated rats' femurs at the micrometer scale. This sensitive technique with high spatial resolution is the only method available that can be successfully applied, given the small amount of uranium in bone tissue. Uranium was found preferentially located in calcifying zones in exposed rats and rapidly accumulates in the endosteal and periosteal area of femoral metaphyses, in calcifying cartilage and in recently formed bone tissue along trabecular bone. Furthermore, specific localized areas with high accumulation of uranium were observed in regions identified as micro-vessels and on bone trabeculae. These observations are of high importance in the study of the accumulation of uranium in bone tissue, as the generally proposed passive chemical sorption on the surface of the inorganic part (apatite) of bone tissue cannot account for these results. Our study opens original perspectives in the field of exogenous metal bio-mineralization.