Tag Archives: animal

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.

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

AGE Consumption Increases Resorption in Rats

Abstract

Effects of model Maillard compounds on bone characteristics and functionality.

BACKGROUND: Physical and biomechanical properties of bone can be affected by non-enzymatic crosslinks, which are implicated in bone pathologies such as osteoporosis. The purpose of this study was to analyse the effects of the consumption of model Maillard reaction product (MRP) from glucose-lysine heated for 90 min at 150 °C (GL90) on bone composition and features. Rats were fed either a control diet or a diet containing 30 g kg(-1) GL90 for 88 days. Food consumption and the animals’ body weights were monitored. After sacrifice, the femur, pelvic bone and tibia were removed for analysis of their composition and physical and biomechanical properties. RESULTS: The organic matrix of the femur and the density of the pelvic bone decreased after MRP intake, whereas pentosidine content increased greatly with respect to the control group (41.7 ± 9.9 vs 171.4 ± 3.3 mmol mol(-1) collagen). The rising level of C-telopeptide degradation products from type I collagen (β-CTX) suggested a possible situation of increased bone resorption and/or higher turnover. CONCLUSION: In conjunction, the detrimental effect on the organic matrix, the situation of higher resorption and/or bone turnover indicated by the β-CTX values and the high pentosidine content in bone provoked negative consequences on certain mechanical properties such as the ability to withstand force and absorb energy without failure.

Roncero-Ramos I, Delgado-Andrade C, Rufián-Henares JA, Carballo J…
J. Sci. Food Agric. Feb 2013
PMID: 23420603

Orange Improves Bone in Orchidectomized Rats

Abstract

Feeding orange pulp improved bone quality in a rat model of male osteoporosis.

Oxidative stress and inflammation have been linked to bone loss. We evaluated the effects of feeding orange pulp (OP), a source of vitamin C and flavonoids, on bone quality in a rat model of male osteoporosis. One-year-old retired breeder rats (n = 43) were orchidectomized (ORX) or sham-operated (SHAM). Three days postsurgery, ORX rats were randomly assigned to treatments: ORX or ORX with 2.5% OP, 5% OP, or 10% OP. Diets were isonitrogenous, isocaloric, modified AIN-93M diets with equal fiber content. All ORX rats were fed for 4 months to the mean food intake of the SHAM group. At the end of the study blood, urine and bone samples were collected. Plasma antioxidant capacity and urinary deoxypyridinoline (DPD) were determined. Bone density, structure, and strength were assessed using dual energy X-ray absorptiometry, microcomputed tomography, and finite element analyses. ORX decreased (P < .05) antioxidant status, while OP as low as 2.5% maintained the antioxidant capacity of ORX rats comparable to that of the SHAM group. Cortical thickness at the tibial midshaft was significantly decreased by ORX and increased by OP, and urinary DPD was significantly increased by ORX and decreased by OP. In fourth lumbar trabecular cores, ORX rats had significantly reduced bone volume fraction, connectivity density, and trabecular number and increased trabecular separation. OP significantly increased bone volume fraction and trabecular number and decreased trabecular separation in ORX rats. Improvements due to OP in microarchitectural properties of vertebral bones and in cortical thickness of long bones were subtle but significant. The consistently negative impacts of ORX on bone density, structure, and strength parameters confirm the previously reported importance of testosterone for bone.

Morrow R, Deyhim F, Patil BS, Stoecker BJ
J Med Food Apr 2009
PMID: 19459729