Tag Archives: in vivo

Grapefruit Improves Bone Quality in Orchidectomized Rats Again

Abstract

Grapefruit juice modulates bone quality in rats.

Hypogonadism and oxidative stress increase the risk for developing osteoporosis. The objective of this research was to evaluate the efficacy of drinking grapefruit juice on bone quality in orchidectomized (ORX) and non-ORX rats. Fifty-six 90-day-old male Sprague-Dawley rats were equally divided into four groups–non-ORX rats (sham), sham + grapefruit juice, ORX, and ORX + grapefruit juice–and treated for 60 days. Thereafter, all rats were sacrificed to determine the plasma antioxidant status, insulin-like growth factor I (IGF-I), and indices of bone turnover, bone quality, and calcium and magnesium concentrations in the bone, urine, and feces. Orchidectomy decreased (P < .05) antioxidant status, bone quality, and bone mineral contents and increased (P < .05) indices of bone turnover, urinary deoxypridinoline, calcium, and magnesium, and fecal calcium excretions. In contrast to the ORX group, ORX rats that drank grapefruit juice had an increase (P < .05) in antioxidant status, bone density, and bone mineral contents, delayed femoral fracture, and slowed down (P < .05) bone turnover rate and tended to have a decrease (P = .08) in urinary deoxypridinoline. In sham-treated animals, drinking grapefruit juice increased (P < .05) bone density and tended to increase the femoral strength. The concentration of IGF-I in the plasma was not affected across treatments. In conclusion, drinking grapefruit juice positively affected bone quality by enhancing bone mineral deposition in ORX rats and by improving bone density in non-ORX rats via an undefined mechanism.

Deyhim F, Mandadi K, Faraji B, Patil BS
J Med Food Mar 2008
PMID: 18361744

Grapefruit Improves Bone Quality in Orchidectomized Rats

Abstract

Grapefruit pulp increases antioxidant status and improves bone quality in orchidectomized rats.

Orchidectomy causes oxidative stress and increases the incidence of osteoporosis. The objective of this research was to evaluate whether eating grapefruit pulp (GP) modifies antioxidant status and reduces osteoporosis in orchidectomized rats.
Fifty-six 90-d-old male Sprague-Dawley rats were randomized into two groups: sham-control group (n = 14) and orchidectomized (ORX) group (n = 42). The orchidectomized group was equally divided among the following three treatments: orchidectomy, orchidectomy + 5.0% GP, and orchidectomy + 10% GP. At the termination of the study (day 60), all rats were euthanized and the plasma was collected for antioxidant status and indices of bone turnover. Bone quality and mineral contents in the bone, urine, and feces were evaluated.
Orchidectomy lowered (P < 0.05) antioxidant status, bone quality, bone mineral contents and elevated (P < 0.05) indices of bone turnover, urinary deoxypyridinoline, and fecal calcium excretion. In contrast to the ORX group, independent of dosage, antioxidant status, bone density, and delayed time-induced femoral fracture were higher (P < 0.05) in the GP groups, whereas fecal calcium excretion and urinary deoxypyridinoline excretion were lowered (P < 0.05). GP dose-dependently slowed down bone turnover (P < 0.05), elevated bone calcium and magnesium contents (P < 0.05), tended to lower urinary excretion of magnesium, and numerically improved bone strength.
The beneficial effects of eating red grapefruit on bone quality of ORX rats is due to bone mineral deposition and slowed-down bone turnover.

Deyhim F, Mandadi K, Patil BS, Faraji B
Nutrition Oct 2008
PMID: 18595661

Citrus Positively Affects Bone Strength in Rats

Abstract

Citrus juice modulates bone strength in male senescent rat model of osteoporosis.

An experiment evaluated the effect of citrus juice on enhancing serum antioxidant status and on osteoporosis prevention in orchidectomized rats.
Thirty-six 1-y-old male rats were randomized to two groups: a sham-control group (n = 9) and an orchidectomized group (n = 27). The orchidectomized group was divided into three groups of nine and assigned to one of the following treatments: orchidectomy, orchidectomy plus orange juice, and orchidectomy plus grapefruit juice. Sixty days after initiation of the study, all rats were killed, blood was collected, and serum was harvested for total antioxidant status and indices of bone formation and resorption. Femoral density and biomechanical properties were monitored.
Orchidectomy decreased (P < 0.05) total antioxidant capacity, femoral density, and biomechanical properties and increased (P < 0.05) alkaline phosphatase, acid phosphatase, and urinary excretion of hydroxyproline compared with the sham-control group. In contrast to orchidectomy, orchidectomy plus orange juice and orchidectomy plus grapefruit juice reversed (P < 0.05) orchidectomy-induced antioxidant suppression, decreased (P < 0.05) alkaline phosphatase and acid phosphatase activities, moderately restored (P = 0.07) femoral density, increased (P < 0.05) femoral strength, significantly delayed time-induced femoral fracture, and decreased (P < 0.05) urinary excretion of hydroxyproline.
The present study supports the supposition in that drinking citrus juice positively affects serum antioxidant status and bone strength.

Deyhim F, Garica K, Lopez E, Gonzalez J…
Nutrition May 2006
PMID: 16472977

Exercise Limits Effects of Excessive Alcohol on Bone in Rats

Abstract

Regular exercise limits alcohol effects on trabecular, cortical thickness and porosity, and osteocyte apoptosis in the rat.

Excessive alcohol consumption is known to be a cause of secondary osteoporosis whereas physical activity is recommended in prevention of osteoporosis. This study was designed to analyze the effects of physical exercise on bone parameters in chronic alcohol-fed rats.
Forty-eight male Wistar rats were divided in four groups: Control (C), Alcohol (A), Exercise (E) and Alcohol+Exercise (AE). A and AE groups drank a solution composed of ethanol and water (35% volume/volume for 17 weeks). E and AE groups were submitted to treadmill training for 14 weeks (60 min/day, 5 times/week). Bone mineral density (BMD) was assessed by DXA, the trabecular and cortical microarchitectural parameters by microCT and serum osteocalcin, NTx and leptin concentrations by ELISA assays. Bone mechanical parameters were evaluated through mechanical testing. Osteocyte apoptosis was analyzed with cleaved caspase-3 immunostaining.
Alcohol-fed rats had significantly lower body weight (-28%), fat (-46%) and lean mass (-25%) compared to controls. BMD (-8%), trabecular (-12%) and cortical thickness (-27%) were significantly lower with alcohol whereas porosity (+38%) and pore number (+42%) were higher. Exercise combined with alcohol prevented lower Tb.Th (+20%), Ct.Th (+30%), stress (+26%) and higher Ct.Po (-24%) and osteocyte apoptosis (-91%) compared to A. However, WB BMD (-4%) and femur BMD were still lower in AE versus C.
Regular physical activity has beneficial effects on some microarchitectural parameters in alcohol-fed rats. However, regular treadmill exercise does not compensate for the effects of heavy chronic alcohol consumption on whole body bone density.

Maurel DB, Boisseau N, Pallu S, Rochefort GY…
Joint Bone Spine Oct 2013
PMID: 23380443

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….

Phenytoin Inhibits Osteoclasts in Mice

Abstract

Diphenylhydantoin inhibits osteoclast differentiation and function through suppression of NFATc1 signaling.

Diphenylhydantoin (DPH) is widely used as an anticonvulsant drug. We examined the effects of DPH on osteoclast differentiation and function using in vivo and in vitro assay systems. Transgenic mice overexpressing a soluble form of RANKL (RANKL Tg) exhibited increased osteoclastic bone resorption. Injection of DPH into the subcutaneous tissue overlying calvaria of RANKL Tg mice suppressed the enhanced resorption in the calvaria. In co-cultures of mouse osteoblasts and bone marrow cells, DPH inhibited lipopolysaccharide (LPS)-induced osteoclast formation. DPH affected neither the mRNA expression of RANKL and osteoprotegerin nor the growth of mouse osteoblasts in culture. On the other hand, DPH inhibited the RANKL-induced formation of osteoclasts in cultures of mouse bone marrow-derived macrophages (BMMphis) and of human peripheral blood-derived CD14(+) cells. DPH concealed LPS-induced bone resorption in mouse calvarial organ cultures and inhibited the pit-forming activity of mouse osteoclasts cultured on dentine slices. DPH suppressed the RANKL-induced calcium oscillation and expression of nuclear factor of activated T cells c1 (NFATc1) and c-fos in BMMphis. Moreover, DPH inhibited the RANKL-induced nuclear localization and auto-amplification of NFATc1 in mature osteoclasts. Both BMMphis and osteoclasts expressed mRNA of a T-type calcium channel, Cav3.2, a target of DPH. Blocking the expression of Cav3.2 by short hairpin RNAs significantly suppressed RANKL-induced osteoclast differentiation. These results suggest that DPH inhibits osteoclast differentiation and function through suppression of NFATc1 signaling. The topical application of DPH may be a therapeutic treatment to prevent bone loss induced by local inflammation such as periodontitis.

Koide M, Kinugawa S, Ninomiya T, Mizoguchi T…
J. Bone Miner. Res. Aug 2009
PMID: 19292614

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

Zinc Acexamate Can Restore Bone in Diabetic Rats

Abstract

Alteration in serum and bone component findings induced in streptozotocin-diabetic rats is restored by zinc acexamate.

The effect of zinc acexamate in streptozotocin (STZ)-induced diabetic rats was investigated. Rats received a single subcutaneous administration of STZ (6.0 mg/100 g body weight), and the animals were orally administered once daily for 14 days with zinc acexamate (2.5, 5 or 10 mg/100 g body weight). The administration of STZ caused a significant increase in serum glucose, triglyceride and calcium levels and a significant decrease in body weight, serum zinc and inorganic phosphorus levels, indicating diabetic condition. Moreover, calcium content, alkaline phosphatase activity and deoxyribonucleic acid (DNA) content in the femoral-diaphyseal and -metaphyseal tissues were significantly reduced in STZ-diabetic rats. The change in these serum and bone components of STZ-diabetic rats was significantly restored by the oral administration of zinc acexamate (2.5, 5 or 10 mg Zn/100 g body weight). The restoration of bone components was not seen by the oral administration of zinc sulfate (2.5 mg Zn/100 g) for 14 days. Moreover, when the femoral-diaphyseal and -metaphyseal tissues obtained at 14 days after STZ administration were cultured for 48 h in a medium containing either vehicle or zinc acexamate (10(-5) M), the femoral calcium content and alkaline phosphatase activity were significantly increased in vitro. The effect of zinc acexamate was completely abolished in the presence of cycloheximide (10(-6) M), an inhibitor of protein synthesis. The present study demonstrates that the oral administration of zinc acexamate has a preventive effect on STZ-induced diabetic condition in rats, and that it can restorate bone loss of STZ-induced diabetes in vivo.

Uchiyama S, Yamaguchi M
Int. J. Mol. Med. Dec 2003
PMID: 14612972

Yamaguchi M, Uchiyama S
Int. J. Mol. Med. Nov 2003
PMID: 14533005

Melatonin Improves Formation:Resorption Ratio in Women

Abstract

Melatonin osteoporosis prevention study (MOPS): a randomized, double-blind, placebo-controlled study examining the effects of melatonin on bone health and quality of life in perimenopausal women.

The purpose of this double-blind study was to assess the effects of nightly melatonin supplementation on bone health and quality of life in perimenopausal women. A total of 18 women (ages 45-54) were randomized to receive melatonin (3mg, p.o., n=13) or placebo (n=5) nightly for 6 months. Bone density was measured by calcaneal ultrasound. Bone turnover marker (osteocalcin, OC for bone formation and NTX for bone resorption) levels were measured bimonthly in serum. Participants completed Menopause-Specific Quality of Life-Intervention (MENQOL) and Pittsburgh Sleep Quality Index (PSQI) questionnaires before and after treatment. Subjects also kept daily diaries recording menstrual cycling, well-being, and sleep patterns. The results from this study showed no significant change (6-month-baseline) in bone density, NTX, or OC between groups; however, the ratio of NTX:OC trended downward over time toward a ratio of 1:1 in the melatonin group. Melatonin had no effect on vasomotor, psychosocial, or sexual MENQOL domain scores; however, it did improve physical domain scores compared to placebo (mean change melatonin: -0.6 versus placebo: 0.1, P<0.05). Menstrual cycling was reduced in women taking melatonin (mean cycles melatonin: 4.3 versus placebo: 6.5, P<0.05), and days between cycles were longer (mean days melatonin: 51.2 versus placebo: 24.1, P<0.05). No differences in duration of menses occurred between groups. The overall PSQI score and average number of hours slept were similar between groups. These findings show that melatonin supplementation was well tolerated, improved physical symptoms associated with perimenopause, and may restore imbalances in bone remodeling to prevent bone loss. Further investigation is warranted.

Kotlarczyk MP, Lassila HC, O’Neil CK, D’Amico F…
J. Pineal Res. May 2012
PMID: 22220591