Antiosteoclastic Activity of Milk Thistle Extract after Ovariectomy to Suppress Estrogen Deficiency-Induced Osteoporosis

Bone integrity abnormality and imbalance between bone formation by osteoblasts and bone resorption by osteoclasts are known to result in metabolic bone diseases such as osteoporosis. Silymarin-rich milk thistle extract (MTE) and its component silibinin enhanced alkaline phosphatase activity of osteoblasts but reduced tartrate-resistant acid phosphatase (TRAP) activity of osteoclasts. The osteoprotective effects of MTE were comparable to those of estrogenic isoflavone. Low-dose combination of MTE and isoflavone had a pharmacological synergy that may be useful for osteogenic activity. This study attempted to reveal the suppressive effects of MTE on bone loss. C57BL/6 female mice were ovariectomized (OVX) as a model for postmenopausal osteopenia and orally administered 10 mg/kg MTE or silibinin for 8 weeks. The sham-operated mice served as estrogen controls. The treatment of ovariectomized mice with nontoxic MTE and silibinin improved femoral bone mineral density and serum receptor activator of nuclear factor-κB ligand/osteoprotegerin ratio, an index of osteoclastogenic stimulus. In addition, the administration of MTE or silibinin inhibited femoral bone loss induced by ovariectomy and suppressed femoral TRAP activity and cathepsin K induction responsible for osteoclastogenesis and bone resorption. Collectively, oral dosage of MTE containing silibinin in the preclinical setting is effective in preventing estrogen deficiency-induced bone loss.

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Alpinetin Inhibits RANKL-Induced Osteoclastogenesis and Ovariectomy-Induced Bone Loss by Modulating NFATc1 Transcription and Lysosomal Function

10.21203/rs.3.rs-132706/v1 ◽

2020 ◽

Author(s):

Rongxin He ◽

Jinwei Lu ◽

Yazhou Chen ◽

Yong Li ◽

Chenyi Ye ◽

...

Keyword(s):

Bone Resorption ◽

Bone Loss ◽

Bone Matrix ◽

Osteoclast Differentiation ◽

Estrogen Deficiency ◽

Bone Diseases ◽

Dependent Manner ◽

Metabolic Bone Diseases ◽

Lysosomal Function ◽

Metabolic Bone

Abstract BackgroundPostmenopausal osteoporosis is a chronic metabolic bone disease caused by excessive osteoclast activation, and osteoclasts are considered to be the sole participants in the degeneration and resorption of bone matrix for controlling bone integrity and continuity. The biological functions of osteoclasts depend critically on the number and activity of fused polykaryon. Hence, targeting osteoclast differentiation and activity can modulate bone resorption and alleviate osteoporosis. Alpinetin is widely used for excellent anti-inflammatory activities and little side-effect, but its role in osteoporosis remains unknown.ResultsIn this study, we investigated for the first time the ability of alpinetin to inhibit estrogen deficiency-induced bone loss. Alpinetin significantly reduced the expression levels of NFATc1 and its downstream genes, thereby inhibiting osteoclast differentiation in a concentration- and time-dependent manner. Additionally, alpinetin inhibited F-actin ring formation and bone resorption, as well as reduced the activation levels of NF-κB, ERK, and AKT signaling cascades. In mature osteoclasts, alpinetin remarkably inhibited integrin-mediated migration and lysosomal biogenesis and trafficking by modulating the PKCβ/TFEB and ATG5/LC3 axes. Importantly, alpinetin treatment in mice alleviated ovariectomy-induced bone volume loss. ConclusionOur findings strongly suggest that alpinetin plays a significant role in the regulation of NFATc1 production for the differentiation of osteoclasts and inhibits integrin-mediated cell migration and lysosomal function in mature osteoclasts, thus weaken the increased osteolytic ability due to estrogen deficiency. Alpinetin may represent a promising agent for the treatment of osteoporosis and other metabolic bone diseases.

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Melatonin inhibits osteoclastogenesis and bone loss in ovariectomized mice by regulating PRMT1-mediated signaling

Endocrinology ◽

10.1210/endocr/bqab057 ◽

2021 ◽

Author(s):

Joo-Hee Choi ◽

Ah-Ra Jang ◽

Min-Jung Park ◽

Dong-il Kim ◽

Jong-Hwan Park

Keyword(s):

Bone Loss ◽

Osteoclast Differentiation ◽

Tumor Necrosis Factor Receptor ◽

Estrogen Deficiency ◽

Melatonin Receptors ◽

Mineral Density ◽

Melatonin Treatment ◽

Ovariectomized Mice

Abstract Melatonin, a pineal gland hormone, has been suggested to treat postmenopausal osteoporosis due to its inhibitory effect on osteoclast differentiation. We previously reported that protein arginine methyltransferase 1 (PRMT1) was an important mediator of receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis. However, the relationship between melatonin and PRMT1 in osteoclast differentiation and estrogen deficiency-induced osteoporosis is unclear. In this study, we investigated the inhibitory mechanisms of melatonin in vitro and in vivo by focusing on PRMT1. Melatonin treatment effectively blocked RANKL-induced osteoclastogenesis by inhibiting PRMT1 and asymmetric dimethylarginine (ADMA) expression. RANKL-induced tumor necrosis factor receptor-associated factor 6 (TRAF6) and the phosphorylation of JNK were also suppressed by melatonin, and TRAF6 siRNA attenuated RANKL-induced p-JNK and PRMT1 production. Melatonin inhibited the transcriptional activity of NF-κB by interfering with the binding of PRMT1 and NF-κB subunit p65 in RANKL-treated BMDMs. Our results also revealed that melatonin inhibits RANKL-induced PRMT1 expression through receptors-independent pathway. Thus, the anti-osteoclastogenic effect of melatonin was mediated by a cascade of inhibition of RANKL-induced TRAF6, JNK, PRMT1, and NF-κB signaling in melatonin receptors-independent pathway. In vivo, ovariectomy caused significant decreases in bone mineral density, but melatonin treatment alleviated the ovariectomized (OVX)-induced bone loss by inhibiting bone resorption. Furthermore, the expression PRMT1 and TRAP mRNA was upregulated in OVX-femurs, but effectively suppressed by melatonin injection. These findings suggest that melatonin inhibited osteoclast differentiation and estrogen deficiency-induced osteoporosis by suppressing RANKL-induced TRAF6, JNK, PRMT1, and NF-κB signaling cascades in melatonin receptors-independent pathway.

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Increased PTHrP and Decreased Estrogens Alter Bone Turnover but Do Not Reproduce the Full Effects of Lactation on the Skeleton

Endocrinology ◽

10.1210/en.2010-0566 ◽

2010 ◽

Vol 151 (12) ◽

pp. 5591-5601 ◽

Cited By ~ 38

Author(s):

Laleh Ardeshirpour ◽

Susan Brian ◽

Pamela Dann ◽

Joshua VanHouten ◽

John Wysolmerski

Keyword(s):

Bone Mineral Density ◽

Bone Resorption ◽

Bone Loss ◽

Bone Turnover ◽

Bone Mineral ◽

Gnrh Agonist ◽

Estrogen Deficiency ◽

Trabecular Architecture ◽

Mineral Density ◽

Long Acting

During lactation, calcium is mobilized from the maternal skeleton to supply the breast for milk production. This results in rapid but fully reversible bone loss. Prior studies have suggested that PTHrP, secreted from the breast, and estrogen deficiency, due to suckling-induced central hypogonadism, combine to trigger bone resorption. To determine whether this combination was sufficient to explain bone loss during lactation, we raised PTHrP levels and decreased levels of estrogens in nulliparous mice. PTHrP was infused via osmotic minipumps and estrogens were decreased either by using leuprolide, a long-acting GnRH agonist, or by surgical ovariectomy (OVX). Bone mineral density declined by 23.2 ± 1.3% in the spine and 16.8 ± 1.9% in the femur over 10 d of lactation. This was accompanied by changes in trabecular architecture and an increase in both osteoblast and osteoclast numbers. OVX and PTHrP infusion both induced a modest decline in bone mineral density over 10 d, but leuprolide treatment did not. The combination of OVX and PTHrP was more effective than either treatment alone, but there was no interaction between PTHrP and leuprolide. None of the treatments reproduced the same degree of bone loss caused by lactation. However, both forms of estrogen deficiency led to an increase in osteoclasts, whereas infusion of PTHrP increased both osteoblasts and osteoclasts. Therefore, although the combination of PTHrP and estrogen deficiency contributes to bone loss, it is insufficient to reproduce the full response of the skeleton to lactation, suggesting that other factors also regulate bone metabolism during this period.

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Nobiletin, a Polymethoxy Flavonoid, Suppresses Bone Resorption by Inhibiting NFκB-Dependent Prostaglandin E Synthesis in Osteoblasts and Prevents Bone Loss Due to Estrogen Deficiency

Journal of Pharmacological Sciences ◽

10.1254/jphs.10193sc ◽

2011 ◽

Vol 115 (1) ◽

pp. 89-93 ◽

Cited By ~ 30

Author(s):

Suguru Harada ◽

Tsukasa Tominari ◽

Chiho Matsumoto ◽

Michiko Hirata ◽

Morichika Takita ◽

...

Keyword(s):

Bone Resorption ◽

Bone Loss ◽

Estrogen Deficiency ◽

Prostaglandin E

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A novel inhibitor of NF-κB-inducing kinase prevents bone loss by inhibiting osteoclastic bone resorption in ovariectomized mice

Bone ◽

10.1016/j.bone.2020.115316 ◽

2020 ◽

Vol 135 ◽

pp. 115316 ◽

Cited By ~ 6

Author(s):

Nana Takakura ◽

Miho Matsuda ◽

Masud Khan ◽

Fumitaka Hiura ◽

Kazuhiro Aoki ◽

...

Keyword(s):

Bone Resorption ◽

Bone Loss ◽

Osteoclastic Bone Resorption ◽

Ovariectomized Mice

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Porcupine inhibitors impair trabecular and cortical bone mass and strength in mice

Journal of Endocrinology ◽

10.1530/joe-18-0153 ◽

2018 ◽

Vol 238 (1) ◽

pp. 13-23 ◽

Cited By ~ 12

Author(s):

Thomas Funck-Brentano ◽

Karin H Nilsson ◽

Robert Brommage ◽

Petra Henning ◽

Ulf H Lerner ◽

...

Keyword(s):

Bone Resorption ◽

Bone Loss ◽

Bone Formation ◽

Bone Mass ◽

Trabecular Bone ◽

Cortical Bone ◽

Bone Strength ◽

Bending Test ◽

Bone Homeostasis ◽

Mineral Density

WNT signaling is involved in the tumorigenesis of various cancers and regulates bone homeostasis. Palmitoleoylation of WNTs by Porcupine is required for WNT activity. Porcupine inhibitors are under development for cancer therapy. As the possible side effects of Porcupine inhibitors on bone health are unknown, we determined their effects on bone mass and strength. Twelve-week-old C57BL/6N female mice were treated by the Porcupine inhibitors LGK974 (low dose = 3 mg/kg/day; high dose = 6 mg/kg/day) or Wnt-C59 (10 mg/kg/day) or vehicle for 3 weeks. Bone parameters were assessed by serum biomarkers, dual-energy X-ray absorptiometry, µCT and histomorphometry. Bone strength was measured by the 3-point bending test. The Porcupine inhibitors were well tolerated demonstrated by normal body weight. Both doses of LGK974 and Wnt-C59 reduced total body bone mineral density compared with vehicle treatment (P < 0.001). Cortical thickness of the femur shaft (P < 0.001) and trabecular bone volume fraction in the vertebral body (P < 0.001) were reduced by treatment with LGK974 or Wnt-C59. Porcupine inhibition reduced bone strength in the tibia (P < 0.05). The cortical bone loss was the result of impaired periosteal bone formation and increased endocortical bone resorption and the trabecular bone loss was caused by reduced trabecular bone formation and increased bone resorption. Porcupine inhibitors exert deleterious effects on bone mass and strength caused by a combination of reduced bone formation and increased bone resorption. We suggest that cancer targeted therapies using Porcupine inhibitors may increase the risk of fractures.

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Boldine Ameliorates Estrogen Deficiency-Induced Bone Loss via Inhibiting Bone Resorption

Frontiers in Pharmacology ◽

10.3389/fphar.2018.01046 ◽

2018 ◽

Vol 9 ◽

Cited By ~ 4

Author(s):

Kun Chen ◽

Zheng-tao Lv ◽

Peng Cheng ◽

Wen-tao Zhu ◽

Shuang Liang ◽

...

Keyword(s):

Bone Resorption ◽

Bone Loss ◽

Estrogen Deficiency

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Tumor Necrosis Factor-α Mediates Osteopenia Caused by Depletion of Antioxidants

Endocrinology ◽

10.1210/en.2004-1058 ◽

2005 ◽

Vol 146 (1) ◽

pp. 113-118 ◽

Cited By ~ 69

Author(s):

C. J. Jagger ◽

J. M. Lean ◽

J. T. Davies ◽

T. J. Chambers

Keyword(s):

Bone Loss ◽

Bone Cells ◽

Buthionine Sulfoximine ◽

Estrogen Deficiency ◽

Antioxidant Defenses ◽

Ovariectomized Mice ◽

Thiol Antioxidant ◽

Factor Α ◽

Tnfα Receptors ◽

Necrosis Factor

We recently found that estrogen deficiency leads to a lowering of thiol antioxidant defenses in rodent bone. Moreover, administration of agents that increase the concentration in bone of glutathione, the main intracellular antioxidant, prevented estrogen-deficiency bone loss, whereas depletion of glutathione by buthionine sulfoximine (BSO) administration provoked substantial bone loss. It has been shown that the estrogen-deficiency bone loss is dependent on TNFα signaling. Therefore, a model in which estrogen deficiency causes bone loss by lowering antioxidant defenses predicts that the osteopenia caused by lowering antioxidant defenses should similarly depend on TNFα signaling. We found that the loss of bone caused by either BSO administration or ovariectomy was inhibited by administration of soluble TNFα receptors and abrogated in mice deleted for TNFα gene expression. In both circumstances, lack of TNFα signaling prevented the increase in bone resorption and the deficit in bone formation that otherwise occurred. Thus, depletion of thiol antioxidants by BSO, like ovariectomy, causes bone loss through TNFα signaling. Furthermore, in ovariectomized mice treated with soluble TNFα receptors, thiol antioxidant defenses in bone remained low, despite inhibition of bone loss. This suggests that the low levels of antioxidants in bone seen after ovariectomy are the cause, rather than the effect, of the increased resorption. These experiments are consistent with a model for estrogen-deficiency bone loss in which estrogen deficiency lowers thiol antioxidant defenses in bone cells, thereby increasing reactive oxygen species levels, which in turn induce expression of TNFα, which causes loss of bone.

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Identification and Functional Characterization of Metabolites for Bone Mass in Peri-/Post-menopausal Chinese Women

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/clinem/dgab146 ◽

2021 ◽

Author(s):

Rui Gong ◽

Hong-Mei Xiao ◽

Yin-Hua Zhang ◽

Qi Zhao ◽

Kuan-Jui Su ◽

...

Keyword(s):

Fatty Acids ◽

Bone Loss ◽

Osteoclast Differentiation ◽

Dodecanoic Acid ◽

Mineral Density ◽

Ovariectomized Mice ◽

Post Menopausal ◽

Functional Mechanisms

Abstract Context Although metabolic profiles appear to play an important role in menopausal bone loss, the functional mechanisms by which metabolites influence bone mineral density (BMD) during menopause are largely unknown. Objective We aimed to systematically identify metabolites associated with BMD variation and their potential functional mechanisms in peri-/post-menopausal women. Design and Methods We performed serum metabolomic profiling and whole-genome sequencing for 517 perimenopausal (16%) and early postmenopausal (84%) women aged 41 to 64 years in this cross-sectional study. Partial least squares (PLS) regression and general linear regression analysis were applied to identify BMD-associated metabolites, and weighted gene co-expression network analysis was performed to construct co-functional metabolite modules. Furthermore, we performed Mendelian randomization analysis to identify causal relationships between BMD-associated metabolites and BMD variation. Finally, we explored the effects of a novel prominent BMD-associated metabolite on bone metabolism through both in vivo/in vitro experiments. Results Twenty metabolites and a co-functional metabolite module (consisting of fatty acids) were significantly associated with BMD variation. We found dodecanoic acid (DA), within the identified module, causally decreased total hip BMD. Subsequently, the in vivo experiments might support that dietary supplementation with DA could promote bone loss, as well as increase the osteoblast and osteoclast numbers in normal/ovariectomized mice. DA treatment differentially promoted osteoblast and osteoclast differentiation, especially for osteoclast differentiation at higher concentrations in vitro (e.g.,10, 100μM). Conclusions This study sheds light on metabolomic profiles associated with postmenopausal osteoporosis risk, highlighting the potential importance of fatty acids, as exemplified by DA, in regulating BMD.

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Serum Concentrations of Cross-Linked N-Telopeptides of Type I Collagen: New Marker for Bone Resorption in Hemodialysis Patients

Clinical Chemistry ◽

10.1373/clinchem.2005.051524 ◽

2005 ◽

Vol 51 (12) ◽

pp. 2312-2317 ◽

Cited By ~ 42

Author(s):

Yoshifumi Maeno ◽

Masaaki Inaba ◽

Senji Okuno ◽

Tomoyuki Yamakawa ◽

Eiji Ishimura ◽

...

Keyword(s):

Bone Resorption ◽

Bone Loss ◽

Type I Collagen ◽

Bone Alkaline Phosphatase ◽

Bone Resorption Marker ◽

Type I ◽

Serum Concentrations ◽

Mineral Density ◽

Intact Osteocalcin ◽

Bone Formation Markers

Abstract Background: Urinary cross-linked N-telopeptide of type I collagen (NTX) is a reliable bone resorption marker in patients with metabolic bone disease. We assessed a clinically available serum NTX assay suitable for anuric patients on hemodialysis (HD). Methods: Serum concentrations of NTX, C-terminal telopeptide of type I collagen (β-CTX), pyridinoline (PYD), and deoxypyridinoline (DPD) were determined as bone resorption markers, and those of bone alkaline phosphatase (BAP) and intact osteocalcin (OC) as bone formation markers, in 113 male HD patients (mean age, 59.3 years; mean HD duration, 67.7 months). Each patient’s bone mineral density (BMD) in the distal third of the radius was measured twice, with a 2-year interval between measurements, by dual-energy x-ray absorptiometry. Results: Serum NTX correlated significantly with β-CTX, PYD, DPD, BAP, and intact OC. NTX, as well as β-CTX, PYD, DPD, BAP, and intact OC, correlated significantly with BMD at the time of measurement. NTX, β-CTX, and DPD correlated significantly with the annual change in BMD during the 2-year period thereafter, in contrast to PYD, BAP, and intact OC. Patients in the highest quartile of serum NTX concentrations showed the fastest rate of bone loss. The sensitivity and specificity for detecting rapid bone loss were 48% and 83%, respectively, for serum NTX. Conclusion: Serum NTX may provide a clinically relevant serum assay to estimate bone turnover in HD patients.

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