Category Archives: Drugs

Nitroglycerin Not Effective in Postmenopausal Bone Loss

Abstract

Transdermal nitroglycerin therapy may not prevent early postmenopausal bone loss.

Osteoporosis is common among postmenopausal women; animal studies and human pilot studies support the concept of nitric oxide (NO) donors reducing bone mineral density loss. The objective of the study was to evaluate whether NO donor, nitroglycerin, prevents postmenopausal bone loss.
 This was a 3-yr randomized, double blinded, single-center, placebo-controlled clinical trial.
The single-center study was conducted at the University of Medicine and Dentistry-Robert Wood Johnson Medical School (New Brunswick, NJ).
Participants included 186 postmenopausal women aged 40-65 yr, with lumbar bone mineral density (BMD) T-scores of 0 to -2.5.
Women, stratified by lumbar T-score (<-1.50 and >or=-1.50) and years since menopause (<or=5 and >5 yr), were randomized to receive nitroglycerin ointment (22.5 mg as Nitro-Bid) or placebo ointment received daily for 3 yr. Both groups took 630 mg daily calcium plus 400 IU vitamin D supplements.
BMD was measured at 6 months and annually by dual-energy x-ray absorptiometry. Percent change in lumbar vertebrae BMD was the primary outcome. Hip BMD, total body bone mineral content, and height were secondary outcomes.
After 36 months of therapy, changes of -2.1% in the active group (n = 88) and -2.5% in the placebo group (n = 82) in lumbar spine BMD were seen (P = 0.59; 95% confidence interval -1.001, 1.975). Secondary outcomes also did not differ by intervention arm. The active group reported more headaches compared with the placebo group (57 vs. 14%, P < 0.001). Other adverse and serious adverse events were not different.
BMD changes did not substantially differ between postmenopausal women who received the dose of nitroglycerin tested, in comparison with a placebo. Once-daily dosing with 22.5 mg of transdermal-administered nitroglycerin was not effective (compliance adjusted dose was only approximately 16 mg/d); a sub-therapeutic dose.

Wimalawansa SJ, Grimes JP, Wilson AC, Hoover DR
J. Clin. Endocrinol. Metab. Sep 2009
PMID: 19549739 | Free Full Text

Minocycline Increases Bone Formation and Decreases Resorption in Ovariectomized Rats

Abstract

Minocycline prevents the decrease in bone mineral density and trabecular bone in ovariectomized aged rats.

In the current study, we examined the effects of minocycline, on the osteopenia of ovariectomized aged rats. Old female rats were randomly divided into five groups: sham, ovariectomized control and ovariectomized treated with minocycline, 17beta-estradiol, or both agents. Bone samples were collected 8 wk after the treatment. Ovariectomy reduced bone mineral density of the whole femur and at the condylar, distal metaphyseal and head-neck-trochanter regions 10%-19% and the loss of bone density was prevented by treatment with minocycline or 17beta-estradiol. Histomorphometric analysis of distal femur showed ovariectomy reduced the trabecular bone area, the trabecular bone number, trabecular bone thickness and increased the trabecular bone separation. The microanatomic structure of trabecular bone also showed that the number of nodes, node to node, cortical to node, node to free end was reduced by ovariectomy. Treatment with minocycline attenuated the effect of ovariectomy on trabecular bone in aged animals. In contrast, cortical bone was not affected by ovariectomy or minocycline treatment. The effect of minocycline on bone turnover was also examined. Minocycline increased osteoid surface, mineralizing surface, mineral apposition rate, bone formation rate and reduced eroded surface. We have therefore concluded that the modest increase in bone mineral density and the improvement in the trabecular bone status noted in minocycline treated ovariectomized aged rats is likely due to an increase in bone formation coupled with a decrease in bone resorption.

Williams S, Wakisaka A, Zeng QQ, Barnes J…
Bone Dec 1996
PMID: 8968031

Tetracyclines Prevent Bone Loss Induced by Inflammation

Abstract

Tetracyclines convert the osteoclastic-differentiation pathway of progenitor cells to produce dendritic cell-like cells.

Tetracyclines, such as doxycycline and minocycline, are used to suppress the growth of bacteria in patients with inflammatory diseases. Tetracyclines have been shown to prevent bone loss, but the mechanism involved is unknown. Osteoclasts and dendritic cells (DCs) are derived from common progenitors, such as bone marrow-derived macrophages (BMMs). In this article, we show that tetracyclines convert the differentiation pathway, resulting in DC-like cells not osteoclasts. Doxycycline and minocycline inhibited the receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis of BMMs, but they had no effects on cell growth and phagocytic activity. They influenced neither the proliferation nor the differentiation of bone-forming osteoblasts. Surprisingly, doxycycline and minocycline induced the expression of DC markers, CD11c and CD86, in BMMs in the presence of RANKL. STAT5 is involved in DC differentiation induced by GM-CSF. Midostaurin, a STAT5-signaling inhibitor, and an anti-GM-CSF-neutralizing Ab suppressed the differentiation induced by GM-CSF but not by tetracyclines. In vivo, the injection of tetracyclines into RANKL-injected mice and RANKL-transgenic mice suppressed RANKL-induced osteoclastogenesis and promoted the concomitant appearance of CD11c(+) cells. These results suggested that tetracyclines prevent bone loss induced by local inflammation, including rheumatoid arthritis and periodontitis, through osteoclast-DC-like cell conversion.

Kinugawa S, Koide M, Kobayashi Y, Mizoguchi T…
J. Immunol. Feb 2012
PMID: 22250082 | Free Full Text

Minocycline Inhhibits Osteoclastogenesis in Mouse Cells

Abstract

Inhibitory effect of minocycline on osteoclastogenesis in mouse bone marrow cells.

To study the effects of minocycline hydrochloride (MINO) on the formation of tartrate-resistant acid phosphatase (TRAP) staining-positive multinucleated osteoclast-like cells in mouse bone marrow cells (BMCs) treated with 1α,25(OH)(2)D(3) or soluble receptor activator of nuclear factor-κB ligand (s-RANKL).
Mouse BMCs were cultured in alpha-modified minimum essential medium containing foetal calf serum (10%) and tetracyclines (2.5, 5 and 10μM), such as MINO, tetracycline hydrochloride (TC), oxytetracycline hydrochloride (OXT) or doxycycline (DOXY) in the presence of 1α,25(OH)(2)D(3) (10nM) or s-RANKL (20ng/ml) for 7 days, and the number of TRAP staining-positive osteoclast-like cells was counted. In RNA isolated from BMCs treated with 1α,25(OH)(2)D(3) or s-RANKL in the presence or absence of MINO, the expressions of osteoclast differentiation relating to mRNA were analysed by reverse transcription-polymerase chain reaction. Cell viability was examined in mouse BMCs and rabbit osteoclasts treated with MINO (0.25-20μM and 2-50μM, respectively) for 24h.
MINO, TC, OXT or DOXY inhibited 1α,25(OH)(2)D(3)-induced osteoclast-like cell formation in mouse BMCs dose dependently. MINO suppressed 1α,25(OH)(2)D(3)-induced up-regulation of mRNA expressions of TRAP, cathepsin K, carbonic anhydrase II, and calcitonin receptor, but not RANKL. MINO inhibited s-RANKL-induced osteoclast-like cell formation and up-regulation of mRNA expressions for nuclear factor of activated T-cells c1 (NFATc1), a key regulator of osteoclast differentiation; however, MINO had no effects on the viability of mouse BMCs and rabbit osteoclasts.
MINO inhibits RANKL-induced osteoclastogenesis via down-regulation of NFATc1 mRNA expression in osteoclast precursor cells.

Nagasawa T, Arai M, Togari A
Arch. Oral Biol. Sep 2011
PMID: 21377143

Minocycline Stimulates Bone Formation in Ovariectomized Rats

Abstract

Effect of minocycline on osteoporosis.

The effect of oral minocycline on osteopenia in ovariectomized (OVX) old rats was examined in this study. Rats were divided into 4 groups: sham-operated, OVX followed by treatment with vehicle, minocycline, or 17 beta-estradiol. The treatment was initiated one day after OVX and proceeded for 8 wks. OVX reduced bone mineral density (BMD) in the whole femur and in the femoral regions that are enriched in trabecular bone. Treatment with minocycline or estrogen prevented a decrease in BMD. Femoral trabecular bone area, trabecular number, and trabecular thickness were reduced, and trabecular separation was increased by OVX. Treatment with minocycline or estrogen abolished the detrimental effects induced by OVX. OVX also reduced indices that reflect the interconnectivity of trabecular bone, and the loss of trabecular connectivity was prevented by treatment with minocycline or estrogen. Based on the levels of urinary pyridinoline, we showed that the effect of estrogen, but not minocycline, was primarily through its inhibitory effect on bone resorption. Analysis of bone turnover activity suggests that OVX increased parameters associated with bone resorption (eroded surface) and formation (osteoid surface, mineralizing surface, mineral apposition rate, and bone formation rate). Treatment with minocycline reduced bone resorption modestly and stimulated bone formation substantially. In contrast, treatment with estrogen drastically reduced parameters associated with both bone resorption and formation. We have concluded that oral minocycline can effectively prevent the decrease in BMD and trabecular bone through its dual effects on bone resorption and formation.

Williams S, Wakisaka A, Zeng QQ, Barnes J…
Adv. Dent. Res. Nov 1998
PMID: 9972125

Minocycline Increases Bone Density in Ovariectomized Rats

Abstract

Treatment of osteoporosis with MMP inhibitors.

In the current study, we examined the effects of minocycline on the osteopenia of ovariectomized (OVX) aged rats using the marrow ablation model. This injury induces rapid bone formation followed by bone resorption in the marrow cavity. Old female rats were randomly divided into five groups: sham, OVX, OVX + minocycline (5-15 mg/day, orally), OVX + 17 beta-estradiol (25 micrograms/day, subcutaneously), and OVX + both agents. Rats were OVX, treated with minocycline and/or estrogen, followed by marrow ablation. Bone samples were collected 16 days post-marrow ablation. X-ray radiography of bones operated on showed that treatment of OVX old rats with minocycline increased bone mass in diaphyseal region. Diaphyseal bone mineral density (BMD) was measured by DEXA scan. Diaphyseal BMD of OVX rats was increased 17-25% by treatment with 5-15 mg of minocycline or 17 beta-estradiol. The effects of minocycline and estrogen treatments on the expression of osteoblast and osteoclast markers were also examined. Northern and dot blot analysis of RNA samples showed that treatment of OVX aged rats with minocycline increased the expression of type I collagen (COL I) (49%) and decreased that of interleukin-6 (IL-6) (31%). In contrast, estrogen treatment decreased the expression of interleukin-6 (IL-6) (39%), carbonic anhydrase II (CA II) (36%), and osteopontin (OP) (37%). Neither minocycline nor 17 beta-estradiol had an effect on the expression of osteocalcin (OC) and alkaline phosphatase (AP). To elucidate the mechanism by which minocycline prevented the loss of bone in OVX aged rats, we examined the colony-formation potential of bone marrow stromal cells in ex vivo cultures. Minocycline stimulated the colony-forming efficiency of marrow stromal cells derived from old animals. We have therefore concluded that the modest increase in BMD noted in OVX aged rats, in response to minocycline treatment, may be due to a change in bone remodeling that favors bone formation; and the anabolic effect of minocycline is likely due to its effect on the expression of COL I and/or the metabolism of osteoprogenitor cells.

Williams S, Barnes J, Wakisaka A, Ogasa H…
Ann. N. Y. Acad. Sci. Jun 1999
PMID: 10415730

Teriparatide Increases Bone Strength More Than Density

Abstract

Femoral strength in osteoporotic women treated with teriparatide or alendronate.

To gain insight into the clinical effect of teriparatide and alendronate on the hip, we performed non-linear finite element analysis of quantitative computed tomography (QCT) scans from 48 women who had participated in a randomized, double-blind clinical trial comparing the effects of 18-month treatment of teriparatide 20 μg/d or alendronate 10mg/d. The QCT scans, obtained at baseline, 6, and 18 months, were analyzed for volumetric bone mineral density (BMD) of trabecular bone, the peripheral bone (defined as all the cortical bone plus any endosteal trabecular bone within 3 mm of the periosteal surface), and the integral bone (both trabecular and peripheral), and for overall femoral strength in response to a simulated sideways fall. At 18 months, we found in the women treated with teriparatide that trabecular volumetric BMD increased versus baseline (+4.6%, p<0.001), peripheral volumetric BMD decreased (-1.1%, p<0.05), integral volumetric BMD (+1.0%, p=0.38) and femoral strength (+5.4%, p=0.06) did not change significantly, but the ratio of strength to integral volumetric BMD ratio increased (+4.0%, p=0.04). An increase in the ratio of strength to integral volumetric BMD indicates that overall femoral strength, compared to baseline, increased more than did integral density. For the women treated with alendronate, there were small (<1.0%) but non-significant changes compared to baseline in all these parameters. The only significant between-treatment difference was in the change in trabecular volumetric BMD (p<0.005); related, we also found that, for a given change in peripheral volumetric BMD, femoral strength increased more for teriparatide than for alendronate (p=0.02). We conclude that, despite different compartmental volumetric BMD responses for these two treatments, we could not detect any overall difference in change in femoral strength between the two treatments, although femoral strength increased more than integral volumetric BMD after treatment with teriparatide.

Keaveny TM, McClung MR, Wan X, Kopperdahl DL…
Bone Jan 2012
PMID: 22015818

Garlic < Lovastatin < Estrogen Effective in suppressing Bone loss in Ovariectomized Rats

Abstract

Effects of garlic oil on postmenopausal osteoporosis using ovariectomized rats: comparison with the effects of lovastatin and 17beta-estradiol.

The purpose of this study was to examine the antiosteoporosis effects of garlic oil in an ovariectomized (Ovx) rat model of osteoporosis and to compare its efficacy with lovastatin (a synthetic hypocholesterolemic drug) and 17beta-estradiol (a potent antiosteoporotic agent). Animals were divided into five groups: sham-operated control, ovariectomized, ovariectomized supplemented with lovastatin, ovariectomized supplemented with garlic oil and ovariectomized supplemented with 17beta-estradiol. In our study, the development of a high rate of bone turnover and osteoporosis in the ovariectomized animals were confirmed by significant alterations of serum alkaline phosphatase activity, serum tartrate-resistant acid phosphatase activity, urinary excretion of calcium, phosphate, hydroxyproline and urinary calcium to creatinine ratio, when compared with the sham-operated control group. Supplementation of these animals with either garlic oil or lovastatin or 17beta-estradiol, in addition to their hypocholesterolemic effect, could counterbalance all these changes. The results revealed that all three compounds significantly protected the hypogonadal bone loss as reflected by higher bone densities and higher bone mineral contents than the ovariectomized group of animals. The results emphasize that, like 17beta-estradiol, the hypocholesterolemic compounds garlic oil and lovastatin are also effective in suppressing bone loss owing to estrogen deficiency and their efficacy in the order of lower to higher is garlic < lovastatin < 17beta-estradiol.

Mukherjee M, Das AS, Das D, Mukherjee S…
Phytother Res Jan 2006
PMID: 16397916

Phenytoin Inhibits Osteoblasts In Vitro and In Vivo; Low Doses Increase Osteoblasts In Vitro

Abstract

Long-term anticonvulsant therapy leads to low bone mineral density–evidence for direct drug effects of phenytoin and carbamazepine on human osteoblast-like cells.

Anticonvulsant therapy causes changes in calcium and bone metabolism and may lead to decreased bone mass with the risk of osteoporotic fractures. The two widely used antiepileptic drugs phenytoin and carbamazepine are recognized to have direct effects on bone cells. The aim of our study was to measure the influence of long-term treatment with antiepileptic drugs on bone mineral density (BMD) and to look on direct effects of carbamazepine and phenytoin on human osteoblast-like cells. BMD was measured by dual-energy X-ray absorptiometry. Markers of bone formation and bone resorption were determined in serum and urine. Data of 59 patients were compared to 55 age and sex matched controls. Direct effects of phenytoin and carbamazepine on human osteoblast-like cells were investigated in experimental studies. BMD in the lumbar spine region (L2 through L4) was significantly lower in the patient group as compared to controls (p < 0.0004). At femoral sites BMD was lower in patients, but this difference did not reach statistical significance. The decrease in BMD at both sites was dependent on the duration of therapy. Excretion of pyridinoline crosslinks was markedly increased in the patients. 25-hydroxy-vitamin D3 and 1,25-dihydroxy-vitamin D3 were significantly decreased in patients. Proliferation rate of human osteoblast-like cells was increased by phenytoin in low doses. Both, phenytoin and carbamazepine inhibited cell growth at concentrations equivalent to therapeutic doses for the treatment of epileptic diseases. Our clinical and experimental data indicate that long-term treatment with anticonvulsant drugs leads to a lower BMD. The experimentally observed decrease in bone cell proliferation might be clinically associated with impaired new bone formation. Beside alterations in calcium and vitamin D homeostasis leading to osteomalazia, direct effects of anticonvulsant drugs on bone cells may contribute to the damaging effects on the skeletal system.

Feldkamp J, Becker A, Witte OW, Scharff D…
Exp. Clin. Endocrinol. Diabetes 2000
PMID: 10768830

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