Tag Archives: in vivo

PGE2 Increases Bone Formation and Mass in Aging Rats

Abstract

Systemic prostaglandin E2 increases cancellous bone formation and mass in aging rats and stimulates their bone marrow osteogenic capacity in vivo and in vitro.

Prostaglandin E(2) (PGE(2)) has been shown to exert a bone anabolic effect in young and adult rats. In this study we tested whether it possesses a similar effect on bone formation and bone mass in aging rats. Fifteen-month-old rats were injected daily with either PGE(2) at 5 mg/kg or vehicle for 14 days. PGE(2) treatment stimulated the rate of cancellous bone formation (a approximately 5.5-fold increase in bone formation rate), measured by the incorporation of calcein into bone-forming surfaces at the tibial proximal metaphysis. This effect resulted in increased cancellous bone area (+54%) at the same site. Since PGE(2) treatment resulted in a much higher proportion of bone surface undergoing bone formation and thus lined with osteoblasts, we tested the hypothesis that PGE(2) stimulates osteoblast differentiation from bone marrow precursor cells both in vivo and in vitro. We found that ex vivo cultures of bone marrow stromal cells from rats injected for 2 weeks with PGE(2) at 5 mg/kg per day yielded more ( approximately 4-fold) mineralized nodules and exhibited a greater (by 30-40%) alkaline phosphatase activity compared with cultures from vehicle-injected rats, attesting to a stimulation of osteoblastic differentiation by PGE(2). We also compared the osteogenic capacity of bone marrow from aging (15-month-old) versus young (5-week-old) rats and its regulation by PGE(2) in vitro. Bone marrow stromal cell cultures from aging rats exhibited a greatly diminished osteogenic capacity, reflected in reduced nodule formation ( approximately 6% of young animals) and lower alkaline phosphatase activity ( approximately 60% of young animals). However, these parameters could be stimulated in both groups of animals by incubation with 10-100 nM PGE(2). The magnitude of this stimulation was greater in cultures from aging rats (+550% vs +70% in nodule formation of aging compared with young rats). In conclusion, we demonstrate here that PGE(2) exerts a bone anabolic effect in aging rats, similar to the effect we and others have reported in young, growing rats. The PGE(2)-stimulated bone formation, which augments bone mass, most likely results from recruitment of osteoblasts from their bone marrow stromal precursors.

Keila S, Kelner A, Weinreb M
J. Endocrinol. Jan 2001
PMID: 11139777 | Free Full Text

Inhibition of osteoclast differentiation and bone resorption by sauchinone.

Abstract

Inhibition of osteoclast differentiation and bone resorption by sauchinone.

Osteoclasts are bone-specific multinucleated cells generated by differentiation of monocyte/macrophage lineage precursors. Regulation of osteoclast differentiation is considered an effective therapeutic approach to the treatment of bone-lytic diseases. In this study, we investigated effects of sauchinone, a lignan from Saururus chinensis, on osteoclastogenesis induced by the differentiation factor RANKL (receptor activator of nuclear factor kappa B ligand). Sauchinone strongly inhibited the osteoclastogenesis from primary bone marrow-derived macrophages (BMMs). This effect was accompanied by a significant decrease in the level of carbonic anhydrase II, calcitonin receptor, MMP9, and TRAP, which are normally upregulated during osteoclast differentiation. For the induction of osteoclastogenesis-associated genes, RANKL activates multiple transcription factors through mechanisms involving mitogen-activated protein kinases (MAPK) and reactive oxygen species (ROS). Sauchinone greatly attenuated the activation of ERK and, less prominently, that of p38 MAPKs by RANKL. The RANKL-stimulated induction of c-Fos and NFATc1 transcription factors was also abrogated by sauchinone. In addition, the activation of AP-1, NFAT, and NF-kappaB transcription factors was alleviated in sauchinone-treated cells. Sauchinone also diminished the RANKL-stimulated increase of ROS production in BMMs. Consistent with the in vitro anti-osteoclastogenic effect, sauchinone inhibited bone destruction and osteoclast formation caused by lipopolysaccharide in an animal model. Taken together, our data demonstrate that sauchinone inhibits RANKL-induced osteoclastogenesis by reducing ROS generation, which attenuates MAPK and NF-kappaB activation, ultimately leading to the suppression of c-Fos and NFATc1 induction. Also the in vivo effect of sauchinone on bone erosion strengthens the potential usefulness of this compound for diseases involving bone resorption.

Han KY, Yang D, Chang EJ, Lee Y…
Biochem. Pharmacol. Sep 2007
PMID: 17662251

Glucosamine Accelerates Fracture Repair in Rats

Abstract

Glucosamine-sulfate on fracture healing.

The aim of this study is to determine whether glucosamine-sulfate has any effects on bone-healing.
A unilateral fracture was created in the tibia of sixty-one female rats. Rats were given no drug or 230 mg/kg glucosamine-sulfate daily. Fractures were analyzed during the first, second and fourth weeks after creation of fracture. Quantitative measurement for new bone formation and osteoblast lining were determined histologically. Semiquantitative score for fracture healing was used for histomorphometric analyses. Bridging bone formation was assessed radiographically.
New bone formation and osteoblast lining were significantly higher in glucosamine-treated group at week 1. Surrounding connective tissue was more cellular and vascular, and the newly formed bone trabecules were present in greater amounts in glucosamine-treated group, compared to control group at week 1 and 4. But radiologically, the control group had better scores than that of the glucosamine-treated group at week 4.
These data demonstrate that daily glucosamine-sulfate administration accelerates early phase of fracture repair in the rat tibia, with increased new bone formation and osteoblast lining histologically, but radiologic bone union is not favored on radiographs.

Uğraş A, Güzel E, Korkusuz P, Kaya I…
Ulus Travma Acil Cerrahi Derg Jan 2013
PMID: 23588972 | Free Full Text

Glucosamine No Effect on Three Bone Markers in Horses

Abstract

Serum concentrations of keratan sulfate, osteocalcin, and pyridinoline crosslinks after oral administration of glucosamine to standardbred horses during race training.

To determine the effects of orally administered glucosamine on concentrations of markers of bone and cartilage metabolism in Standardbred horses during race training.
Twenty 16- to 20-month-old Standardbreds beginning race training.
Horses were randomly assigned to 2 groups. One group received glucosamine hydrochloride (4 g, PO, q 12 h), and the second (control) group received glucose (4 g, PO, q 12 h). Serum samples were obtained prior to onset of the study (baseline) and at regular intervals for 48 weeks for determination of concentrations of keratan sulfate (KS), osteocalcin (OC), and pyridinoline crosslinks (PYD).
Osteocalcin concentrations changed significantly with time; mean serum concentrations were significantly higher than baseline values for samples obtained at 24 to 48 weeks after onset of the study. Although a significant effect of time was observed for mean concentration of KS, concentrations did not differ significantly from baseline values at any time during the study when groups were analyzed separately. However, pooled analysis revealed significant increases of mean serum KS concentration at weeks 24 and 30. Significant changes in serum PYD concentrations were not detected. Oral administration of glucosamine did not significantly affect serum concentrations of any of the markers.
Increased serum OC in clinically normal Standardbreds during race training may reflect bone formation that accompanies adaptive remodeling of the appendicular skeleton. For these experimental conditions, glucosamine did not appear to exert a detectable influence on serum concentrations of these 3 markers of connective tissue metabolism.

Caron JP, Peters TL, Hauptman JG, Eberhart SW…
Am. J. Vet. Res. Aug 2002
PMID: 12171162

Tualang Honey Improves Bone Structure in Ovariectomized Rats

Abstract

Protective effects of Tualang honey on bone structure in experimental postmenopausal rats.

The objective of this study was to evaluate the effects of Tualang honey on trabecular structure and compare these effects with those of calcium supplementation in ovariectomized rats.
Forty female, Sprague-Dawley rats were randomly divided into five groups (n =8): four controls and one test arm. The control arm comprised a baseline control, sham-operated control, ovariectomized control, and ovariectomized calcium-treated rats (receiving 1% calcium in drinking water ad libitum). The test arm was composed of ovariectomized, Tualang honey-treated rats (received 0.2 g/kg body weight of Tualang honey). Both the sham-operated control and ovariectomized control groups received vehicle treatment (deionized water), and the baseline control group was sacrificed without treatment.
All rats were orally gavaged daily for six weeks after day one post-surgery. The bone structural analysis of rats in the test arm group showed a significant increase in the bone volume per tissue volume (BV/TV), trabecular thickness (Tb.Th) and trabecular number (Tb.N) and a significant decrease in inter-trabecular space (Tb.Sp) compared with the ovariectomized control group. The trabecular thickness (Tb.Th) in the test arm group was significantly higher compared with the ovariectomized-calcium treated group, and the inter-trabecular space (Tb.Sp) in the test arm group was significantly narrower compared with the ovariectomized-calcium treated group.
In conclusion, ovariectomized rats that received Tualang honey showed more improvements in trabecular bone structure than the rats that received calcium.

Zaid SS, Sulaiman SA, Othman NH, Soelaiman IN…
Clinics (Sao Paulo) Jul 2012
PMID: 22892923 | Free Full Text

From “Review of the Medicinal Effects of Tualang Honey and a Comparison with Manuka Honey”

Tualang honey (TH) is a Malaysian multifloral jungle honey. In recent years, there has been a marked increase in the number of studies published in medical databases regarding its potential health benefits. The honey is produced by the rock bee (Apis dorsata), which builds hives on branches of tall Tualang trees located mainly in the north-western region of Peninsular Malaysia. This review collates the results of the various studies of TH that range from research on tissue culture to randomised control clinical trials. Findings thus far show that, TH has antimicrobial, anti-inflammatory, antioxidant, antimutagenic, antitumor, and antidiabetic properties, in addition to wound-healing attributes. Some of its properties are similar to the well-researched Manuka honey (New Zealand and/or Australian monofloral honey). Distinct differences include higher phenolics, flavonoids, and 5-(hydroxymethyl) furfural (HMF). Compared with Manuka honey, TH is also more effective against some gram-negative bacterial strains in burn wounds.

 

CR Suppresses Bone Formation and Increases Resorption in Obese Rats

Abstract

Energy-restricted diet benefits body composition but degrades bone integrity in middle-aged obese female rats.

This study investigates the effects of a restricted diet (RD) on body composition and musculoskeletal health along with endocrines and molecular mechanism in established mature obese rats. Twenty female rats were fed with a high-fat diet (HFD) ad libitum for 4 months and then assigned to either HFD or RD group for another 4 months. Another 10 rats were on a low-fat diet for 8 months. Outcome measures included body composition, bone mineral density, microarchitecrure, and strength; serum leptin, adiponectin, insulin-like growth factor I, and liver glutathione peroxidase activity; and protein expression and spleen tumor necrosis factor α messenger RNA expression. We hypothesized that mature obese rats on a 35% energy restriction diet for 4 months would improve body composition but degrade microstructural and mechanical properties of long bones, and such changes in musculoskeletal integrity are related to the modulation of obesity-related endocrines and proinflammation. Relative to HFD, RD benefited body composition (decreased body weight and %fat mass and increased %fat-free mass); decreased insulin-like growth factor I and leptin; elevated adiponectin, glutathione peroxidase activity and protein expression and tumor necrosis factor α messenger RNA expression; and suppressed bone formation and increased bone resorption, resulting in decreased trabecular and cortical bone volume, bone mineral density, and bone strength. Relative to low-fat diet, RD had a similar effect on body composition and serum markers but increased bone turnover rate and decreased bone mineral density and strength. Our data suggest that long-term RD has a negative impact on bone remodeling in obese female rats, probably through modification of endocrines and elevation of proinflammation.

Shen CL, Zhu W, Gao W, Wang S…
Nutr Res Aug 2013
PMID: 23890357

Vitamin K2 (menatetrenone) effectively prevents fractures and sustains lumbar bone mineral density in osteoporosis.

Abstract

Vitamin K2 (menatetrenone) effectively prevents fractures and sustains lumbar bone mineral density in osteoporosis.

We attempted to investigate whether vitamin K2 (menatetrenone) treatment effectively prevents the incidence of new fractures in osteoporosis. A total of 241 osteoporotic patients were enrolled in a 24-month randomized open label study. The control group (without treatment; n = 121) and the vitamin K2-treated group (n = 120), which received 45 mg/day orally vitamin K2, were followed for lumbar bone mineral density (LBMD; measured by dual-energy X-ray absorptiometry [DXA]) and occurrence of new clinical fractures. Serum level of Glu-osteocalcin (Glu-OC) and menaquinone-4 levels were measured at the end of the follow-up period. Serum level of OC and urinary excretion of deoxypyridinoline (DPD) were measured before and after the treatment. The background data of these two groups were identical. The incidence of clinical fractures during the 2 years of treatment in the control was higher than the vitamin K2-treated group (chi2 = 10.935; p = 0.0273). The percentages of change from the initial value of LBMD at 6, 12, and 24 months after the initiation of the study were -1.8 +/- 0.6%, -2.4 +/- 0.7%, and -3.3 +/- 0.8% for the control group, and 1.4 +/- 0.7%, -0.1 +/- 0.6%, and -0.5 +/- 1.0% for the vitamin K2-treated group, respectively. The changes in LBMD at each time point were significantly different between the control and the treated group (p = 0.0010 for 6 months, p = 0.0153 for 12 months, and p = 0.0339 for 24 months). The serum levels of Glu-OC at the end of the observation period in the control and the treated group were 3.0 +/- 0.3 ng/ml and 1.6 +/- 0.1 ng/ml, respectively (p < 0.0001), while the serum level of OC measured by the conventional radioimmunoassay (RIA) showed a significant rise (42.4 +/-6.9% from the basal value) in the treated group at 24 months (18.2 +/- 6.1% for the controls;p = 0.0081). There was no significant change in urinary DPD excretion in the treated group. These findings suggest that vitamin K2 treatment effectively prevents the occurrence of new fractures, although the vitamin K2-treated group failed to increase in LBMD. Furthermore, vitamin K2 treatment enhances gamma-carboxylation of the OC molecule.

Shiraki M, Shiraki Y, Aoki C, Miura M
J. Bone Miner. Res. Mar 2000
PMID: 10750566

 

I don’t know why they had to say “the vitamin K2-treated group failed to increase in LBMD”, when they could have said the vitamin K2-treated group prevented the decrease in LBMD seen in the control group, or that LBMD was increased compared to controls.

Vitamin K2 (MK-4) Prevents Glucocorticoid Bone Loss

Abstract

Vitamin K2 inhibits glucocorticoid-induced bone loss partly by preventing the reduction of osteoprotegerin (OPG).

We have recently demonstrated that glucocorticoid (GC) suppresses bone formation and enhances bone resorption, with resultant bone loss. This altered bone turnover is not due to the action of parathyroid hormone (PTH), but appears to be related to the suppression of osteoprotegerin (OPG). As vitamin K2 (menatetrenone) has been used for the treatment of osteoporosis, the present study was carried out to evaluate the effect of vitamin K2 on GC-induced bone loss. Twenty patients with chronic glomerulonephritis treated with GC for the first time were chosen for this study. Ten patients received GC alone (group A) and the other 10 patients each received 15 mg of vitamin K2 per day in addition to GC (group B). Markers of bone metabolism, including serum OPG, osteocalcin (OC), bone-specific alkaline phosphatase activity (BAP), PTH, tartrate-resistant acid phosphatase (TRAP), and bone mineral density (BMD), were measured before and during the treatment. OPG was significantly decreased in group A (P < 0.001), while no significant change was seen in group B. TRAP was markedly increased in both groups, more particularly in group A (P < 0.01). PTH was decreased in group A, but was increased in group B. OC was decreased at month 1 but subsequently increased until month 12 in both groups. BAP had decreased at month 3 in group A (P < 0.05), but not in group B. BMD of the lumbar spine was significantly reduced after 6 months (P < 0.01), and 12 months (P < 0.001) of treatment in group A, whereas there was no remarkable change in group B. The present study demonstrated that the inhibition exerted by vitamin K2 of the reduction in OPG induced by GC may, at least in part, play a role in the prevention and treatment of GC-induced bone loss.

Sasaki N, Kusano E, Takahashi H, Ando Y…
J. Bone Miner. Metab. 2005
PMID: 15616893 | Free Full Text

The dose in the abstract is wrong. They used 15mg three times per day. That is 45mg per day and the same as the prescription dose used in Japan.

The patients were randomly divided into two groups before treatment. Informed consent was obtained from all subjects. Ten patients (6 men, and 2 premenopausal and 2 postmenopausal women ) received GC alone (group A) and the other 10 patients (6 men and 2 premenopausal and 2 postmenopausal women) each received 15 mg of vitamin K2 (menatetrenone; Glakay; Eisai, Tokyo, Japan) three times per day in addition to GC (group B) during the study period. The profiles of the patients are shown in Table 1. Renal function was normal in all subjects (serum Cr level 1.2mg/dl). There were no significant differences between the two groups in age, body mass index, or dose of GC (Table 1), or in various serum and urinary biochemical parameters at baseline (Table 2).

 

Protodioscin Inhibits Bone Loss in Ovariectomized Rats

Abstract

In vivo antiosteoporotic activity of a fraction of Dioscorea spongiosa and its constituent, 22-O-methylprotodioscin.

The antiosteoporotic activity of the 90 % EtOH fraction of the water extract of rhizomes of Dioscorea spongiosa and methylprotodioscin, its major constituent, were examined in the model of postmenopausal bone loss using ovariectomized (OVX) rats or mice. After 6 weeks treatment, the proximal tibia of rats or mice and the distal femora of mice were scanned by peripheral quantitative computed tomography (pQCT). Both the 90 % EtOH fraction (100 mg/kg/d) and methylprotodioscin (50 mg/kg/d) significantly inhibited bone loss in bone mineral content (BMC) and bone mineral density (BMD) in total, cancellous and cortical bones, and the decrease in bone strength indexes induced by OVX, without side effect on the uterus.

Yin J, Tezuka Y, Kouda K, Le Tran Q…
Planta Med. Mar 2004
PMID: 15114498

Diosgenin and Lovastatin Prevent Bone Loss in Ovariectomized Rat

Abstract

Osteoprotective effect of Monascus-fermented dioscorea in ovariectomized rat model of postmenopausal osteoporosis.

This experiment established the ovariectomized (OVX) rat model of postmenopausal osteoporosis and examined the effect of the oral administration of different dosages of dioscorea, red mold dioscorea (RMD), and soy isoflavones on bone mineral density (BMD). Three months after osteoporosis had been induced and 4 weeks after feeding had begun, the tibia and femur BMD of OVX rats administered RMD showed significant increases compared with that of all other groups of OVX rats. Closer examination using microcomputed tomography also revealed that the RMD-administered rats had denser trabecular bone volume and a higher trabecular number compared to all other rat groups. Reconstructed 3D imaging indicated increases in cancellous bone mineral content, cancellous bone mineral density, and cortical bone mineral content of the proximal tibia in OVX rats. These findings indicate that administration of monacolin K and phytoestrogen diosgenin could prevent bone loss induced by estrogen deficiency.

Chiang SS, Chang SP, Pan TM
J. Agric. Food Chem. Sep 2011
PMID: 21800902