Prevention of postmenopausal osteoporosis and associated fractures: Clinical evaluation of the choice between estrogen and bisphosphonates

lncRNA WT1-AS is upregulated in osteoporosis and regulates the apoptosis of osteoblasts by interacting with p53

In cervical cancer, cellular tumor antigen p53 (p53) interacts with long non-coding WT1 antisense RNA (WT1-AS) and this protein serves an important role in osteoporosis. The present study aimed to investigate the role of WT1-AS in osteoporosis. WT1-AS was upregulated in the plasma of patients with osteoporosis and was positively correlated with p53 expression. Altered expression of WT1-AS and p53 separated patients with osteoporosis from healthy controls. Expression levels of WT1-AS and p53 decreased with prolonged treatment. In osteoblasts, WT1-AS overexpression resulted in increased p53 expression, while WT1-AS small interfering RNA (siRNA) silencing resulted in decreased p53 expression. In addition, WT1-AS overexpression resulted in increased apoptosis rate, while WT1-AS siRNA silencing resulted in decreased apoptosis rate in osteoblasts. p53 overexpression attenuated the effects of WT1-AS siRNA silencing on cell apoptosis. Therefore, WT1-AS was upregulated during osteoporosis and regulated the apoptosis of osteoblasts by interacting with p53.

Time and dose-dependent effects of Labisia pumila on the bone strength of postmenopausal osteoporosis rat model

BACKGROUND

Post-menopausal osteoporosis has long been treated and prevented by estrogen replacement therapy (ERT). Despite its effectiveness, ERT is associated with serious adverse effects. Labisia pumila var. alata (LP) is a herb with potential as an alternative agent to ERT due to its phytoestrogenic, antioxidative and anti-inflammatory effects on bone. This study aimed to determine the effects of LP supplementation on bone biomechanical strength of postmenopausal osteoporosis rat model.

METHODS

Ninety-six female Sprague-Dawley rats aged 4 to 5 months old were randomly divided into six groups; six rats in the baseline group (BL) and eighteen rats in each group of; Sham- operated (Sham), ovariectomised control (OVXC) and ovariectomised with daily oral gavages of Premarin at 64.5 μg/kg (ERT), LP at 20 mg/kg (LP20) and LP at 100 mg/kg (LP100) respectively. These groups were subdivided into three, six and nine weeks of treatment periods. Rats in BL group were euthanized before the start of the study, while other rats were euthanized after completion of their treatments. Femora were dissected out for biomechanical strength analysis using Instron Universal Model 5848 Micro Tester.

RESULTS

OVXC group showed deterioration in the bone biomechanical strength with time. Both ERT and LP supplemented rats showed improvements in bone strength parameters such as maximum load, displacement, stiffness, stress, and Young Modulus. The most improved bone strength was seen in rats given LP at the dose of 100 mg/kg for nine weeks.

CONCLUSION

LP supplementation at 100 mg/kg was more effective than ERT in reversing ovariectomy-induced bone biomechanical changes.

Preventive effects of the methanol soluble fraction of Millettia macrophylla Benth (Fabaceae) on an osteoporosis-like model of ovariectomized Wistar rats

BACKGROUND

Millettia macrophylla Benth is a Cameroonian medicinal plant traditionally used to alleviate menopause-related problems. The methanol soluble fraction of this plant was shown to exhibit estrogenic effects in vitro in Human Embryonic kidney cells, and in vivo on ovariectomized rat following the classical uterotrophic assay. Since estrogens have been involved in bone remodeling process, the present study then aimed at evaluating bone loss preventive effects of the methanol soluble fraction of Millettia macrophylla (MM-met) in ovariectomized rat model.

METHODS

Twenty-five healthy Wistar female rats (3-month-old) were randomly assigned to a sham-operated group and to four treated ovariectomized (OVX) groups. Treatments lasted 8 weeks and animals were sacrificed. The uterus, the femoral and the tibia bones of each animal were collected, weighed and fixed in 10% formalin for histological analysis.

RESULTS

Results showed that ovariectomy decreased uterine wet weight (p<0.01), induced body weight gain (p<0.01), decreased both femoral and tibia bone density and mineral content and increased alkaline phosphatase activity (p<0.05). E2V and MM-met treatments in general prevented bone mass loss and/or bone density loss. At all tested doses, MM-met induced a significant decrease of alkaline phosphatase activity (p<0.05). As observed with E2V, MM-met also induced a significant protective effect on bone, and this was indicated by an abundance of bone marrow in an almost intact trabecular network.

CONCLUSIONS

The overall results show that the methanol soluble fraction of Millettia macrophylla may prevent ovariectomy-induced bone mass loss and deterioration of the trabecular microarchitecture.

Labisia pumila regulates bone-related genes expressions in postmenopausal osteoporosis model

BACKGROUND

Labisia Pumila var. alata (LPva) has shown potential as an alternative to estrogen replacement therapy (ERT) in prevention of estrogen-deficient osteoporosis. In earlier studies using postmenopausal model, LPva was able to reverse the ovariectomy-induced changes in biochemical markers, bone calcium, bone histomorphometric parameters and biomechanical strength. The mechanism behind these protective effects is unclear but LPva may have regulated factors that regulate bone remodeling. The aim of this study is to determine the bone-protective mechanism of LPva by measuring the expressions of several factors involved in bone formative and resorptive activities namely Osteoprotegerin (OPG), Receptor Activator of Nuclear Factor kappa-B Ligand (RANKL), Macrophage-Colony Stimulating Factor (MCSF) and Bone Morphogenetic Protein-2 (BMP-2).

METHODS

Thirty-two female Wistar rats were randomly divided into four groups: Sham-operated (Sham), ovariectomized control (OVXC), ovariectomized with Labisia pumila var. alata (LPva) and ovariectomized with ERT (Premarin) (ERT). The LPva and ERT were administered via daily oral gavages at doses of 17.5 mg/kg and 64.5 μg/kg, respectively. Following two months of treatment, the rats were euthanized and the gene expressions of BMP-2, OPG, RANKL and MCSF in the femoral bones were measured using a branch - DNA technique.

RESULTS

The RANKL gene expression was increased while the OPG and BMP-2 gene expressions were reduced in the OVXC group compared to the SHAM group. There were no significant changes in the MCSF gene expressions among the groups. Treatment with either LPva or ERT was able to prevent these ovariectomy-induced changes in the gene expressions in ovariectomized rats with similar efficacy.

CONCLUSION

LPva may protect bone against estrogen deficiency-induced changes by regulating the RANKL, OPG and BMP-2 gene expressions.

Effects of a low-dose oral estrogen only treatment on bone mineral density and quantitative ultrasonometry in postmenopausal women

INTRODUCTION

The aim of this study was to evaluate an oral low-dose estrogen therapy on bone mineral density (BMD) and quantitative ultrasonometry (QUS) in osteopenic postmenopausal women.

MATERIAL AND METHODS

This prospective, open-label cohort study investigated 120 postmenopausal hysterectomized women. Forty-seven women had been treated with 0.3 mg conjugated equine estrogen daily (ET). Primary end point was the change in BMD at the spine after 24 months. Secondary end points were among other changes in QUS at the os calcis and phalanges.

RESULTS

After matching 42 participants in the ET group, 42 controls were analyzed. The change in BMD differed significantly after 24 months (p = 0.019). Women on ET showed significant increase of spine and hip Z-score, whereas controls showed significant decreases in spine and total hip BMD. In QUS of the os calcis and the phalanges, a number of variables showed a significant improvements with ET.

CONCLUSION

Our results comprised a positive effect of an oral low-dose estrogen therapy on BMD. Limitations of the study are the small sample size and the open-label, non-randomized cohort study design. The findings are in accordance to the common literature and support the use of ET in the primary prevention of postmenopausal bone loss.

Labisia pumila Prevents Complications of Osteoporosis by Increasing Bone Strength in a Rat Model of Postmenopausal Osteoporosis

Estrogen replacement therapy (ERT) is the main treatment postmenopausal osteoporosis. However, ERT causes serious side effects, such as cancers and thromboembolic problems. Labisia pumila var. alata (LPva) is a herb with potential as an alternative to ERT to prevent complications of osteoporosis, especially fragility fractures. This study was conducted to determine the effects of LPva on the biomechanical strength of femora exposed to osteoporosis due to estrogen deficiency, using the postmenopausal rat model. Thirty-two female rats were randomly divided into four groups: Sham-operated (Sham), ovariectomized control (OVXC), ovariectomized with Labisia pumila var. alata (LP), and ovariectomized with ERT (Premarin) (ERT). The LPva and ERT were administered via oral gavage daily at doses of 17.5 mg/kg and 64.5 μg/kg, respectively. Following two months of treatment, the rats were euthanized, and their right femora were prepared for bone biomechanical testing. The results showed that ovariectomy compromised the femoral strength, while LPva supplementation to the ovariectomized rats improved the femoral strength. Therefore, LPva may be as effective as ERT in preventing fractures due to estrogen-deficient osteoporosis.

Labisia pumila protects the bone of estrogen-deficient rat model: a histomorphometric study

ETHNOPHARMACOLOGICAL RELEVANCE

Labisia pumila var. alata (LP) is a phytoestrogenic herb with potential as an alternative to Estrogen Replacement Therapy (ERT) in the treatment of postmenopausal osteoporosis. LP has been reported to produce similar effects to ERT on the bone markers, but could not match ERT in terms of maintaining the bone calcium in postmenopausal osteoporosis rat model. This study aimed to examine in detail the effects of LP on the bone of postmenopausal osteoporosis rat model using bone histomorphometry.

MATERIALS AND METHODS

Thirty two female rats were randomly divided into groups of: Sham operated (Sham), ovariectomized control (OVXC), ovariectomized with Labisia pumila var. alata (LP) and ovariectomized with ERT (Premarin®) (ERT). The LP and ERT were administered through the route of oral gavage daily at the dose of 17.5 mg/kg and 64.5 μg/kg respectively. Following 2 months of treatment, rats were euthanized and the left femurs were dissected out and prepared for bone histomorphometry.

RESULTS

Histomorphometric analysis revealed osteoporotic changes for the ovariectomized rats. Supplementation of LP to ovariectomized rats could prevent these osteoporotic changes, as effective as ERT.

CONCLUSION

This confirmed that LP has potential as an alternative to ERT for prevention of postmenopausal osteoporosis.

The effects of Labisia pumila var. alata on bone markers and bone calcium in a rat model of post-menopausal osteoporosis

AIM OF THE STUDY

Postmenopausal osteoporosis is mainly treated with estrogen replacement therapy (ERT). However, ERT causes side effects, mainly breast cancer, uterine cancer and thromboembolic problems. Labisia pumila var. arata (LPva), a herb with phytoestrogenic effects has the potential to be used as an alternative agent to ERT. This study was conducted to determine the effects of LPva on bone biochemical markers and bone calcium content in ovariectomised rats.

MATERIALS AND METHODS

Thirty two Wistar rats were divided into 4 groups, with 8 rats in each group. The first group was sham operated (Sham), the second group was ovariectomised (OVX), the third (LPva) and fourth group (ERT) were also ovariectomised and given LPva 17.5 mg/kg and Premarin(®) 64.5 μg/kg, respectively. Blood samples were taken before and after treatment to measure osteocalcin and C-terminal telopeptide of type 1 collagen levels using ELISA while the fifth lumbar bone samples were taken to measure bone calcium content using the Atomic Absorption Spectrophotometer (AAS).

RESULTS

The osteocalcin levels were significantly higher in both the LPva and ERT groups compared to the OVX group. The CTX levels were significantly lower in both the LPva and ERT groups compared to the OVX group. However, only the ERT group had significantly higher bone calcium level compared to the OVX group.

CONCLUSION

The supplementation of 17.5 mg/kg of LPva to ovariectomised rats for 8 weeks was able to prevent the changes in bone biochemical markers but failed to prevent the bone calcium loss induced by ovariectomy.

Effects of ipriflavone on postmenopausal syndrome and osteoporosis

OBJECTIVE

To investigate the therapeutic effects of ipriflavone on postmenopausal syndrome and osteoporosis in women.

METHODS

A randomized and double-blind study was conducted. Sixty postmenopausal women with osteoporosis were chosen and they were randomly divided into three groups: Treatment group I was given oral compound calcium acid chelate and Vitamin AD guttate; treatment group II was given oral compound calcium acid chelate, Vitamin AD guttate and ipriflavone; Control group was given placebo and compound calcium acid chelate. The postmenopausal syndrome, bone mineral density (BMD), and bone biochemical markers were assessed 6 and 12 months after the treatment.

RESULTS

In treatment group II, hot flush and ostalgia syndromes were dramatically relieved, BMD and serum calcium level increased markedly and alkaline phosphatase, parathyroid hormone and tartrate-resistant acid phosphatase decreased markedly, comparing with treatment group I and control group (p < 0.05).

CONCLUSION

Ipriflavone could inhibit bone resorption and promote bone formation. It is an effective drug for the prevention and treatment to menopausal syndrome and osteoporosis. Ipriflavone could be used as a supplement to estrogen replacement treatment.

Estrogens and the intervertebral disc

Intervertebral discs are an integral part of the vertebral column. It has been shown that menopause has a negative effect on bone and on intervertebral discs. Estrogen has a beneficial effect of preserving the health of collagen-containing tissues, including the intervertebral disc. The intervertebral disc allows for mobility of the spine, and maintains a uniform stress distribution of the area of the vertebral endplates. Also, the disc influences spinal height. The disc tissue is adapted for this biomechanical function. The function of the spine is impaired if there is a loss of disc tissue. Narrowing of the disc space due to degeneration of intervertebral discs is associated with a significantly increased risk of vertebral fractures. Estrogen should be seen as the first-choice therapy for bones and other collagen-rich tissues, such as intervertebral discs, because it maintains homeostasis of the bone-remodelling unit. Unlike bisphosphonates, estrogen is unique in its ability to regenerate bone collagen after its disintegration, apart from suppressing osteoclastic activity. Besides, there is insufficient data on deterioration in bone qualities and micro-cracks in patients on long-term bisphosphonates.