Monthly Archives: April 2014

p-Hydroxycinnamic Acid Anabolic and Antiresorptive in Rats

Abstract

Phytocomponent p-hydroxycinnamic acid stimulates bone formation and inhibits bone resorption in rat femoral tissues in vitro.

The effect of cinnamic acid or its related compounds, which is present in many plants, on bone metabolism has not been clarified yet. The effect of cinnamic acid, p-hydroxycinnamic acid (HCA), ferulic acid, caffeic acid, or 3,4-dimethoxycinnamic acid (DCA) on bone calcium content in vitro was investigated. Rat femoral-diaphyseal (cortical bone) and -metaphyseal (trabecular bone) tissues were cultured for 48,h in Dulbecco’s modified Eagle’s medium (high glucose, 4.5%) supplemented with antibiotics and bovine serum albumin. The presence of HCA (10(-5) or 10(-4),M) caused a significant increase in calcium content in the diaphyseal or metaphyseal tissues. Such an effect was not observed in the presence of cinnamic acid or other compounds at the concentration of 10(-5) or 10(-4),M. Alkaline phosphatase activity and deoxyribonucleic acid (DNA) content in the diaphyseal or metaphyseal tissues was significantly increased in the presence of HCA (10(-5) or 10(-4),M). The effect of HCA (10(-4),M) in increasing calcium content, alkaline phosphatase activity, and DNA content in the diaphyseal or metaphyseal tissues was completely prevented in the presence of cycloheximide (10(-6),M), an inhibitor of protein synthesis. Thus HCA had anabolic effects on bone components. The presence of parathyroid hormone (PTH; 10(-7),M), a bone-resorbing factor, caused a significant decrease in calcium content and a corresponding elevation in medium glucose consumption, lactic acid production or tartrate-resistant acid phosphatase (TRACP) activity in the diaphyseal or metaphyseal tissues. These alterations were completely prevented in the presence of HCA (10(-5) or 10(-4),M). This study demonstrates that p-hydroxycinnamic acid (HCA) has stimulatory effects on bone formation and inhibitory effects on bone resorption in tissue culture in vitro.

Lai YL, Yamaguchi M
Mol. Cell. Biochem. Nov 2006
PMID: 17036165

p-Hydroxycinnamic Promotes Osteoblasts by Blocking NF-κB in Mouse Cells

Abstract

The bone anabolic carotenoid p-hydroxycinnamic acid promotes osteoblast mineralization and suppresses osteoclast differentiation by antagonizing NF-κB activation.

Numerous plant derived nutritional factors including p-hydroxycinnamic acid (HCA), a member of the carotenoid family, have long been held to possess bone protective properties. Studies in animals have provided a mechanistic basis for these observations by demonstrating the capacity of HCA to promote bone formation and suppress bone resorption in vivo. However, the molecular mechanism by which HCA achieves these effects remains unclear. We have demonstrated that a centralized mechanism by which several other nutritional factors achieve similar effects is through modulation of the nuclear factor-κB (NF-κB) signal transduction pathway. NF-κB activation is essential for osteoclast formation and resorption but potently antagonizes osteoblast differentiation and mineralization. In this study we demonstrate that HCA does indeed antagonize the activation of NF-κB by the key osteoclastogenic cytokine receptor activator of NF-κB (RANKL) in RAW264.7 osteoclast precursors, suppressing their differentiation into osteoclasts. Furthermore, HCA augmented the in vitro differentiation of MC3T3 preosteoblastic cells into mineralizing osteoblasts and relieved the inhibitory action of tumor necrosis factor-α (TNF-α)-induced NF-κB signaling on transforming growth factor-β (TGF-β)- or bone morphogenetic protein-2 (BMP-2)-induced Smad activation, an important pathway in osteoblast commitment and differentiation. Our data provide a mechanism to explain the dual pro-anabolic and anti-catabolic activities of HCA.

Yamaguchi M, Weitzmann MN
Int. J. Mol. Med. Sep 2012
PMID: 22751682

p-Hydroxycinnamic Acid Prevents Bone Loss in Ovariectomized Rats

Abstract

Oral administration of phytocomponent p-hydroxycinnamic acid prevents bone loss in ovariectomized rats.

The preventive effect of phytocomponent p-hydroxycinnamic acid (HCA) on ovariectomy (OVX)-induced bone loss was investigated. HCA (250 or 500 microg/100 g body weight) was orally administered once daily for 30 days to OVX rats. The analysis using a peripheral quantitative computed tomography (pQCT) showed that OVX caused bone loss in the femoral-metaphyseal tissues. This change was significantly restored after the administration of HCA (250 or 500 microg/100 g body weight) to OVX rats. Mineral content, mineral density, and polar strength strain index in the femoral-metaphyseal tissues were significantly decreased in OVX rats. These decreases were significantly restored after the administration of HCA (500 microg/100 g) to OVX rats. Moreover, OVX caused a significant decrease in calcium content or alkaline phosphatase activity in the femoral-diaphyseal and -metaphyseal tissues. These decreases were significantly restored after the administration of HCA (250 or 500 microg/100 g) to OVX rats. Deoxyribonucleic acid (DNA) content in the diaphyseal or metaphyseal tissues was significantly increased in OVX rats. These increases were significantly restored after oral administration of HCA (500 microg/100 g). This study demonstrates that HCA has preventive effects on OVX-induced bone loss of rats in vivo.

Yamaguchi M, Lai YL, Uchiyama S, Nakagawa T
Mol. Cell. Biochem. Apr 2008
PMID: 18165927

Mountain Tea Protects Bone in Ovariectomized Rats

Abstract

Protective effect of Sideritis euboea extract on bone mineral density and strength of ovariectomized rats.

The aim of this study was to investigate the potential protective effect of Sideritis euboea extract (SID), commonly consumed as “mountain tea,” on bone mineral density (BMD) and the strength of the ovariectomized (OVX) rat model of osteoporosis.
Thirty-two 10-month-old Wistar rats were separated into controls (sham operated), OVX, and OVX plus SID in their drinking water (dose, 330 mg/kg body weight per day), starting immediately after OVX for 6 months. Tibial BMD at baseline and at 3 and 6 months post-OVX, three-point-bending of the femur, and body and uterine weight at the study end were examined.
BMD percentage change from baseline of the whole tibia was similar in control and OVX + SID rats at 3 months (-3.02% vs -4.67%, P = not significant), revealing a strong osteoprotective effect. At 6 months, the corresponding changes were -6.02% versus -14.37%, P < 0.05, indicating a greater bone loss in treated rats, albeit significantly less than the OVX change (-20.46%; OVX vs OVX + SID, P < 0.05). The proximal (metaphyseal) tibial BMD percentage change from baseline to 3 and 6 months between the OVX and OVX + SID groups (-26.47% vs -15.57% and -31.22% vs -16.57%, respectively) was statistically significant, demonstrating that SID preserved the proximal tibial BMD of the OVX + SID group significantly. Three-point-bending showed a significant increase in the treated compared with the OVX groups. Body and uterine weights were similar in the OVX and treated groups.
SID significantly protected tibial bone loss and improved femoral biomechanical strength in OVX + SID rats compared with OVX rats.

Dontas IA, Lelovas PP, Kourkoulis SK, Aligiannis N…
Menopause Aug 2011
PMID: 21505372

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

Palash Prevents Bone Loss and Stimulates Formation in Ovariectomized Rats

Abstract

Total extract and standardized fraction from the stem bark of Butea monosperma have osteoprotective action: evidence for the nonestrogenic osteogenic effect of the standardized fraction.

The aim of this study was to determine the skeletal effects of Butea total extract (BTE) and its acetone soluble fraction (ASF) from Butea monosperma, which is rich in methoxyisoflavones, in ovariectomized (OVx) rats, a model for postmenopausal bone loss.
BTE (1.0 g kg d) and ASF (100 mg kg d) were given orally for 12 weeks to adult OVx rats. The sham-operated and ovariectomy + vehicle groups served as controls. Bone mineral density, osteoid formation (mineral apposition rate and bone formation rate), bone microarchitecture, and bone turnover/resorption markers were studied. Phytoestrogens in rats given BTE and ASF were analyzed by high-performance liquid chromatography. One-way analysis of variance was used to test significance of effects.
OVx rats treated with either BTE or ASF exhibited increased bone mineral density in trabecular bones and improved trabecular microarchitecture compared with the ovariectomy + vehicle group. ASF treatment was more efficient than BTE treatment in maintaining trabecular microarchitecture. Serum osteocalcin and urinary type 1 collagen levels in OVx rats treated with either BTE or ASF were significantly lower than those of the ovariectomy + vehicle group. ASF treatment led to increased mineral apposition rate and bone formation rate compared with ovariectomy + vehicle, whereas BTE had no such effect. In the uterotropic assay, BTE was mildly estrogenic in adult OVx rats. In immature rats, BTE exhibited both estrogenicity and antiestrogenicity. ASF had neither uterine estrogenicity nor antiestrogenicity. Analysis of phytoestrogens revealed significant enrichment of cladrin, isoformononetin, and medicarpin in ASF over BTE.
Derived from B monosperma, ASF at a 10-fold lower dose than that of BTE was effective in preventing OVx-induced bone loss and stimulated new-bone formation.

Pandey R, Gautam AK, Bhargavan B, Trivedi R…
Menopause
PMID: 20395887

Palash Reduces Bone Loss in Ovariectomized Rats

Abstract

Greater Skeletal Gains in Ovary Intact Rats at Maturity Are Achieved by Supplementing a Standardized Extract of Butea monosperma Stem Bark that Confers Better Bone Conserving Effect following Ovariectomy and Concurrent Treatment Withdrawal.

With a longitudinally designed study, we tested whether an acetone soluble fraction (ASF) from the stem bark of Butea monosperma resulted in maximizing bone gain in rats during growth and maturation and thus protected against osteopenia following ovariectomy (OVx) with concomitant treatment withdrawal. Female rats at weaning were given ASF (100 mg/kg/d) or vehicle for 12 weeks, and baseline skeletal parameters (micro-CT) and total plasma antioxidant status (TAS) were measured. At this stage, one group was OVx and the other group was sham operated. Vehicle group (untreated) after OVx was given E2 or continued with vehicle (OVx control). ASF group after OVx was given vehicle (ASF withdrawn, ASFW). After another 12 weeks, all groups were killed and various skeletal parameters were determined. ASF resulted in substantially better skeletal parameters and higher plasma TAS over control at maturity. Rats treated with ASF before OVx had reduced rates of bone loss compared to OVx control. Twelve weeks after OVx, the ASFW group exhibited better trabecular microarchitectural preservation, bone turnover profiles, increased cortical deposition, and biomechanical strength over the OVx control, and the effects were comparable to OVx + E2 group. ASF supplementation during skeletal growth could maximize bone accrual and could confer increased resistance to post-OVx osteopenia despite treatment withdrawal.

Srivastava K, Khan K, Tyagi AM, Khan MP…
Evid Based Complement Alternat Med 2013
PMID: 23710224 | Free Full Text

O-methoxy substitutions of free phenolic hydroxyl groups of the most abundant soy isoflavones (genistein and daidzein) enhance the lipophilicity, metabolic stability, and uterine safety, thus improving pharmacokinetic/metabolic stability profiles of genistein and daidzein and, consequently, enhance the pharmacodynamic effect (in vivo potency) [12, 13]. In our phytopharmacological evaluation program, aimed at discovering effective alternative strategy for reducing the risk of developing postmenopausal osteopenia, we showed that a standardized fraction (an acetone soluble fraction, ASF) made from the stem bark of Butea monosperma contained four methoxyisoflavones: cajanin (7-methoxy genistein), medicarpin (a methoxypterocarpan with cyclized genistein ring structure), isoformononetin (7-methoxy daidzein), and cladrin (3′4,-dimethoxy daidzein) at percent concentration of 0.061, 0.019, 0.007, and 0.003, respectively [14]. Each one of these, when administered to female rats for four weeks after weaning resulted in increased BMD, bone strength, and bone formation rate with varying efficacy. In vitro, all four compounds stimulated osteoblast function more potently than genistein and daidzein by different modes of action [15–17]. These observations prompted us to hypothesize that the presence of these methoxyisoflavones in the ASF could synergistically augment peak bone mass accrual in female rats at maturity that will confer a superior bone conserving ability after surgical menopause (due to ovariectomy, OVx) even as the treatment is withdrawn.