Anti-osteoporotic effect of Terminalia arjuna (Roxb.) Wight & Arn. In bilateral ovariectomized induced post-menopausal osteoporosis in experimental rats

Objectives In ancient times Terminalia arjuna (Roxb.) Wight & Arn. (TA) was used for fast healing of fracture and to strengthen the bone. However, no scientific study has been done to validate its usefulness in the alleviation of osteoporosis. To investigate the efficacy of stem bark TA against post-menopausal osteoporosis using bilateral ovariectomized rat model. Methods Aqueous (TAA) and methanolic (TAM) extracts of TA was evaluated for its anti-osteoporotic activity. Sham control rats were allotted as Group I (Normal control); Group II animals acted as OVX control (Disease control); Group III OVX rats were treated with estrogen (Standard group – 2 mg/kg) Group IV and V OVX rats give treatment to TAA (250 and 500 mg/kg, p.o.), respectively. This treatment is continue for the four weeks and at the end, serum biochemical parameters such as serum calcium and alkaline phosphate were evaluated. Femoral bone parameters (Compression of vertebrae, femoral neck load testing, Three point bending of tibia, Femur length and weight), histology, body weight, and fifth lumbar vertebra breaking strength were also assessed after the sacrificing the animal. Results In OVX rats, atrophy of uterus and descent of BMD were suppressed by treatment with TAA and TAM. In addition, TAM 500 completely corrected the decreased serum concentration of Calcium, Phosphorus, ALP and TRAP observed in OVX rats. TAA and TAM both increased biomechanical strength significantly in comparison to the sham group. Histological results also revealed its protective action through elevation of bone formation. TAM significantly increase the uterine and femoral bone weight The TAM showed maximum anti-osteoporotic activity in in vivo study as compare to TAA. Conclusions The results, evaluated on the basis of biochemical, bone mineral density, biomechanical, and histopathological parameters, presented that TAA and TAM has a definite antiosteoporotic effect, like to estrogen, especially effective for inhibition bone fracture induced by estrogen deficiency.

Expression of circulating Mir-139-5p is associated with Postmenopausal Osteoporosis in Indian women

Background: Osteoporosis in post-menopausal women is known to progress periodically and is highly associated with inflammation. MicroRNAs regulate inflammatory process, which may therefore control bone metabolism. Deregulation of miRNAs associated with inflammation may lead to development and progression of osteoporosis. We selected four miRNAs known to be involved in inflammation to test their association with post-menopausal osteoporosis. Methods: We quantified four circulating miRNAs, hsa-miR-139-5p, hsa-miR-342-3p, hsa-miR-146a and hsa-miR-24-3p in plasma samples of 25 post-menopausal osteoporosis and 25 post-menopausal healthy subjects. Related biochemical tests were done using Cobas e411 and ELISA. Results: Upon quantification of circulating miRNAs, we observed that hsa-miR-139-5p was expressed higher in post-menopausal osteoporotic samples (p=0.01). The expression of hsa-miR-24-3p was seen lower in osteoporotic samples though not highly significant (p=0.2). Conclusion: Differential expression of hsa-miR-139-5p and hsa-miR-24-3p was seen in osteoporosis subjects. These miRNA could be significantly involved in development and progression of osteoporosis. Further studies are required to highlight miRNAs’ involvement in regulating bone metabolism, which could be manipulated to use them as marker or therapeutic strategies to alleviate osteoporosis.

Combined Effects of Exercise and Denosumab Treatment on Local Failure in Post-menopausal Osteoporosis–Insights from Bone Remodelling Simulations Accounting for Mineralisation and Damage

Denosumab has been shown to increase bone mineral density (BMD) and reduce the fracture risk in patients with post-menopausal osteoporosis (PMO). Increase in BMD is linked with an increase in bone matrix mineralisation due to suppression of bone remodelling. However, denosumab anti-resorptive action also leads to an increase in fatigue microdamage, which may ultimately lead to an increased fracture risk. A novel mechanobiological model of bone remodelling was developed to investigate how these counter-acting mechanisms are affected both by exercise and long-term denosumab treatment. This model incorporates Frost's mechanostat feedback, a bone mineralisation algorithm and an evolution law for microdamage accumulation. Mechanical disuse and microdamage were assumed to stimulate RANKL production, which modulates activation frequency of basic multicellular units in bone remodelling. This mechanical feedback mechanism controls removal of excess bone mass and microdamage. Furthermore, a novel measure of bone local failure due to instantaneous overloading was developed. Numerical simulations indicate that trabecular bone volume fraction and bone matrix damage are determined by the respective bone turnover and homeostatic loading conditions. PMO patients treated with the currently WHO-approved dose of denosumab (60 mg administrated every 6 months) exhibit increased BMD, increased bone ash fraction and damage. In untreated patients, BMD will significantly decrease, as will ash fraction; while damage will increase. The model predicted that, depending on the time elapsed between the onset of PMO and the beginning of treatment, BMD slowly converges to the same steady-state value, while damage is low in patients treated soon after the onset of the disease and high in patients having PMO for a longer period. The simulations show that late treatment PMO patients have a significantly higher risk of local failure compared to patients that are treated soon after the onset of the disease. Furthermore, overloading resulted in an increase of BMD, but also in a faster increase of damage, which may consequently promote the risk of fracture, specially in late treatment scenarios. In case of mechanical disuse, the model predicted reduced BMD gains due to denosumab, while no significant change in damage occurred, thus leading to an increased risk of local failure compared to habitual loading.

Estrogen withdrawal alters cytoskeletal and primary ciliary dynamics resulting in increased Hedgehog and osteoclastogenic paracrine signalling in osteocytes

Estrogen deficiency during post-menopausal osteoporosis leads to osteoclastogenesis and bone loss. Increased pro-osteoclastogenic signalling (RANKL/OPG) by osteocytes occurs following estrogen withdrawal (EW) and is associated with impaired focal adhesions (FAs) and a disrupted actin cytoskeleton. RANKL production is mediated by Hedgehog signalling in osteocytes, a signalling pathway associated with the primary cilium, and the ciliary structure is tightly coupled to the cytoskeleton. Therefore, the objective of this study was to investigate the role of the cilium and associated signalling in EW-mediated osteoclastogenic signalling in osteocytes. We report that EW leads to an elongation of the cilium and increase in Hedgehog and osteoclastogenic signalling. Significant trends were identified linking cilia elongation with reductions in cell area and % FA area/cell area, indicating that cilia elongation is associated with disruption of FAs and actin contractility. To verify this, we inhibited FA assembly via αvβ3 antagonism and inhibited actin contractility and demonstrated an elongated cilia and increased expression of Hh markers and Rankl expression. Therefore, our results suggest that the EW conditions associated with osteoporosis lead to a disorganisation of αvβ3 integrins and reduced actin contractility, which were associated with an elongation of the cilium, activation of the Hh pathway and osteoclastogenic paracrine signalling.

Review of Current Real-World Experience with Teriparatide as Treatment of Osteoporosis in Different Patient Groups

Teriparatide has proven effective in reducing both vertebral and non-vertebral fractures in clinical trials of post-menopausal and glucocorticoid-induced osteoporosis. Widespread adoption of Teriparatide over the last two decades means that there is now substantial experience of its use in routine clinical practice, which is summarized in this paper. Extensive real-world experience of Teriparatide in post-menopausal osteoporosis confirms the fracture and bone density benefits seen in clinical trials, with similar outcomes identified also in male and glucocorticoid-induced osteoporosis. Conversely, very limited experience has been reported in pre-menopausal osteoporosis or in the use of Teriparatide in combination with other therapies. Surveillance studies have identified no safety signals relating to the possible association of Teriparatide with osteosarcoma. We also review the evidence for predicting response to Teriparatide in order to inform the debate on where best to use Teriparatide in an increasingly crowded therapeutic landscape.

Ethanol Extract of Amomum tsao-ko Ameliorates Ovariectomy-Induced Trabecular Loss and Fat Accumulation

In Asia, Amomum tsao-ko has long been used as a spice or seasoning in food to stimulate digestion. In the present study, we evaluated the effects of ethanol extract of Amomum tsao-ko (EEAT) on menopausal osteoporosis and obesity. After the administration of EEAT in ovariectomy (OVX) mice models for five weeks, microcomputed tomography and a histological analysis were performed to assess, respectively, the trabecular structure and the fat accumulation in adipose, liver, and bone tissues. We also examined the effects of EEAT on a bone marrow macrophage model of osteoclastogenesis by in vitro stimulation from the receptor activator of nuclear factor-kappa Β ligand (RANKL) through real-time PCR and Western blot analysis. In addition, ultrahigh performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) with authentic standards was applied to characterize the phytochemical profiling of EEAT. We found that EEAT significantly decreased OVX-induced body weight gain and fat accumulation, significantly prevented OVX-induced deterioration of bone mineral density and microstructure of trabecular tissues, and significantly inhibited osteoclast differentiation by downregulating NF-κB/Fos/NFATc1 signaling in osteoclasts. Furthermore, UHPLC–MS/MS identified eight beneficial phytochemicals in EEAT. Collectively, these results suggest that EEAT might be an effective nutraceutical candidate to attenuate menopausal osteoporosis by inhibiting osteoclastogenesis and to prevent obesity by suppressing fat accumulation.

Bone remodeling during alveolar repair is impaired by RANKL antagonist

Post-menopausal osteoporosis is detrimental to bone metabolism as well as alveolar repair. This osteometabolic disorder is an obstacle to the success of maxillofacial rehabilitations, since a large number of patients are carriers of the disease. Denosumab is widely used as a treatment for post menopausal osteoporosis. This drug exerts an antiabsorptive action by inhibiting RANKL, helping to reduce the bone loss caused by osteoporosis. This study aimed to evaluate the repair bone formed after the extraction of the upper incisor of estrogen-deficient rats treated with anti-RANKL monoclonal antibody. The rats (Rattus novergicus albinus, Wistar) were ovariectomized or SHAM operated (n=36). Half of the ovariectomized rats were treated with osteoprotegerin with an Fc fragment (OPG-Fc; 10mg/kg, twice a week), the other half received saline solution as control. After 30 days the rats had their right upper incisor extracted. After 60 days of extraction, the alveoli were evaluated by immunohistochemical, computerized microtomography and confocal microscopy. The OPG-Fc decreased the percentage of bone volume (BV/TV), thickness (Tb.Th) and number of alveolar trabecules (Tb.N) when compared to groups that received saline solution (p<0.005). The OPG-Fc increased the separation between the trabecules (Tb.Sp) and the porosity (Po.tot) of the reparative alveolar bone (p<0.005). The OPG-Fc decreased immunolabelling for RANKL and TRAP when compared to groups that received saline solution. Treatment with OPG-Fc decreased bone neoformation but preserved preexisting bone tissue. This data is supported by the mineral apposition rate, which showed higher values for OVX/OPG-Fc when compared to the OVX group.

A fraction of Pueraria tuberosa extract, rich in antioxidant compounds, alleviates ovariectomized-induced osteoporosis in rats and inhibits growth of breast and ovarian cancer cells

Pueraria tuberosa (Roxb. ex Willd.) DC., known as Indian Kudzu belongs to family Fabaceae and it is solicited as “Rasayana” drugs in Ayurveda. In the present study, we analyzed the efficacy of an ethyl acetate fraction from the tuber extract of Pueraria tuberosa (fraction rich in antioxidant compounds, FRAC) against menopausal osteoporosis, and breast and ovarian cancer cells. The FRAC from Pueraria tuberosa was characterized for its phenolic composition (total phenolic and flavonoid amount). Antioxidant property (in vitro assays) of the FRAC was also carried out followed by the analysis of the FRAC for its antiosteoporotic and anticancer potentials. The antiosteoporotic activity of FRAC was investigated in ovariectomy-induced osteoporosis in rats. The cytotoxicity effect was determined in breast and ovarian cancer cells. Gas chromatography/mass spectrometry (GC/MS) analysis of the FRAC was performed to determine its various phytoconstituents. Docking analysis was performed to verify the interaction of bioactive molecules with estrogen receptors (ERs). The FRAC significantly improved various biomechanical and biochemical parameters in a dose-dependent manner in the ovariectomized rats. FRAC also controlled the increased body weight and decreased uterus weight following ovariectomy in rats. Histopathology of the femur demonstrated the restoration of typical bone structure and trabecular width in ovariectomized animals after treatment with FRAC and raloxifene. The FRAC also exhibited in vitro cytotoxicity in the breast (MCF-7 and MDA-MB-231) and ovarian (SKOV-3) cancer cells. Furthermore, genistein and daidzein exhibited a high affinity towards both estrogen receptors (α and β) in the docking study revealing the probable mechanism of the antiosteoporotic activity. GC/MS analysis confirmed the presence of other bioactive molecules such as stigmasterol, β-sitosterol, and stigmasta-3,5-dien-7-one. The FRAC from Pueraria tuberosa has potential for treatment of menopausal osteoporosis. Also, the FRAC possesses anticancer activity.