Combining Bisphosphonates with Hormone Therapy for Postmenopausal Osteoporosis

Isolation and identification of peptides from Pinctada martensii with osteogenic activity

Marine organisms have attracted considerable attention in recent years. In this study, peptides with osteogenic activity from Pinctada martensii were isolated and identified. Additionally, the effects of the hydrolysates on MC3T3-E1 cell proliferation and differentiation were evaluated using the MTT and alkaline phosphatase (ALP) assays, respectively. First, trypsin, pancreatin, and neutral protease were used to hydrolyse the intact shellfish. The hydrolysates with the greatest effects on osteoblast proliferation and ALP activity were separated and purified. Second, fraction WP2 was isolated and purified using a Sephadex G-25 column. WP2, which had the highest osteogenic activity, increased cell growth by 48.57 ± 0.05% and ALP activity by 6.27 ± 0.07 mU. Finally, four novel peptides were identified in WP2 (FDNEGKGKLPEEY, IVLDSGDGVTH, IVLDSGDGVSH, and SSENSDLQRQ) by Orbitrap Fusion Lumos Tribrid orbital liquid chromatography-mass spectrometry. Our findings revealed that P. martensii contains peptides with potential osteogenic activity.

Promoting Effect of Pinostrobin on the Proliferation, Differentiation, and Mineralization of Murine Pre-osteoblastic MC3T3-E1 Cells

Pinostrobin (PI), a natural flavonoid found in a variety of plants, is well known for its rich pharmacological activities. However, its osteogenic function remains unclear. The aim of this study is to evaluate the effect of PI on the proliferation, differentiation, and mineralization of murine pre-osteoblastic MC3T3-E1 cells in vitro using MTT, alkaline phosphatase (ALP) activity, the synthesis of collagen I (Col I) assay, and Von-Kossa staining, respectively. The expression of osteocalcin (OCN) mRNA in cells was detected by real-time PCR. The effect of PI on the differentiation of dexamethasone (DEX)-suppressed cells was also investigated. The results showed that PI greatly promoted the proliferation of MC3T3-E1 cells at 5–80 μg/mL (p < 0.05 or p < 0.01), and caused a significant elevation of ALP activity, Col I content, and mineralization of osteoblasts at 10–40 μg/mL (p < 0.05 or p < 0.01), and the expression levels of OCN gene were greatly upregulated after PI treatment (p < 0.01). Furthermore, PI could rescue the inhibition effect of cell differentiation induced by DEX. Taken together, these results indicated that PI could directly promote proliferation, differentiation, and mineralization of MC3T3-E1 cells and has potential for use as a natural treatment for osteoporosis.

Effects of Combination Therapy of Alendronate and Hormonal Therapy on Bone Mineral Density in Postmenopausal Korean Women: Multicenter, Randomized Controlled Clinical Trial

This study evaluated the effects of combination treatment with alendronate (ALEN) and hormone therapy (HT) on bone mineral density (BMD) in postmenopausal Korean women. This multicenter, randomized, controlled clinical trial enrolled 344 postmenopausal women with low BMD. The women received HT (0.625 mg/day of conjugated equine estrogen and 2.5 mg/day of medroxyprogesterone acetate) alone or in combination with ALEN (10 mg/day) for 1 year. Changes in BMD and biochemical markers of bone turnover were evaluated. Data from 203 women (HT alone, 99; combination treatment, 104) who completed this study were analyzed. BMD at the lumbar spine and total hip increased significantly in both treatment groups after 1 year. There were no significant differences between HT alone vs. the combination of ALEN and HT in mean BMD increase at the lumbar spine (6.9% vs. 7.9%) and total hip (3.7% vs. 3.8%). Combined therapy suppressed serum osteocalcin and urinary deoxypyridinoline to a greater extent than HT alone. In conclusion, compared to HT alone, combination treatment with ALEN and HT for 1 year did not offer a benefit in BMD in postmenopausal Korean women with low BMD.

Effects of continuous combined hormone replacement therapy and clodronate on bone mineral density in osteoporotic postmenopausal women: a 5-year follow-up

OBJECTIVE

To determine the effects of HRT with or without clodronate on bone mineral density (BMD) change and bone turnover markers.

DESIGN

Prospective, partly randomized trial.

SETTING

Kuopio University Hospital, Finland.

POPULATION

167 osteoporotic women (61+/-2.7 years; T-score<or=-2.5 SD).

METHODS

Estradiol 2 mg+NETA 1 mg, randomization to additional 800 mg clodronate (n=55, HT+C-group) or placebo (n=55, HT-group); if contraindications to HRT, clodronate (n=57, C-group).

MAIN OUTCOME MEASURES

BMD by DXA after 1, 3 and 5 years, serum osteocalcin (OC) and bone-specific alkaline phosphatase (BAP) at the baseline and after 3 years.

RESULTS

After 5 years, adjusted lumbar BMD increased by 4.2% in the HT-group and 3.7% in the HT+C-group. The C-group showed a decrease of -1.1%, the total difference being 5.3% and 4.8% between HT, HT+C vs. C-group, respectively (p<0.001). In the femoral neck, the adjusted 5-year BMD benefit was 1.3% and 2.4% in the HT- and HT+C-groups, respectively, the net loss of BMD in the C-group was -3.3% (p<0.05 between HT+C vs. C). By 3 years, OC decreased by 55.0%, 70.3% and 53.8% in the HT-, HT+C- and C-groups, respectively (p<0.001 vs. baseline). The significant decreases of BAP were 39.4% in the HT-group, 42.1% in the HT+C-group and 30.2% in the C-group with no significant differences between the groups after adjustments.

CONCLUSIONS

In postmenopausal women with osteoporosis, HRT increased spinal and femoral BMD, but the combination of HRT and clodronate did not offer an extra gain of bone mass.

AA, Acúrcio FDA. Treatment of postmenopausal osteoporosis in women: a systematic review

Osteoporosis, a typical disease of the elderly, has become a frequent and relevant public health problem. Several drugs are available for treatment of osteoporosis, some of which are currently dispensed by the Brazilian Unified National Health System. The objective of this study was to present a systematic review of drugs for treatment of osteoporosis, focusing on the adequacy of clinical protocols based on existing evidence in the scientific literature. We conducted a search for randomized clinical trials in PubMed and LILACS that presented results for bone mineral density, incidence of vertebral fractures, and adverse effects. 32 articles met the review's inclusion criteria. Bisphosphonates were reported to have consistently reduced the risk of vertebral fractures. Hormone replacement therapy showed positive outcomes, but its use has been found to increase the risk of cardiovascular disease and breast cancer. Teriparatide and monofluorophosphate also showed efficacy against osteoporosis. Calcium and vitamin D were given to patients as food supplements.

ENA Actimineral Resource A restores bone loss and bone quality in ovariectomized rats

The purpose of this study was to examine the effects of ENA Actimineral Resource A (ENA-A), seaweed origin alkaline water, on postmenopausal osteoporosis in ovariectomized (OVX) rats. The 12-week old Wistar rats were divided randomly into 4 groups: ovariectomized (OVX), OVX plus 0.5% ENA-A, OVX plus 5% ENA-A and OVX plus 10% ENA-A. A histopathological analysis indicated that ENA-A could prevent OVX-induced bone loss by increasing femur trabecular bone area in a dose-dependent manner. ENA-A significantly (p<0.05) increased serum estradiol levels, decreased serum osteocalcin activity and suppressed serum pyridinoline (PYD) levels. The in vitro effects of ENA-A were also studied using MC3T3-E1 cells. ENA-A significantly stimulated cell proliferation and increased both ALP activity and calcium deposition in a dose-dependent manner. These results suggest that the treatment of ovariectomized rats with ENA-A not only prevents bone resorption but also appears to maintain the cancellous bone structure of postmenopausal osteoporosis.

Combining Bisphosphonates with Raloxifene to Treat Osteoporosis: A Review of the Evidence

Objective:

To evaluate published studies regarding the combination of a bisphosphonate and raloxifene in the treatment of osteoporosis.

Data Sources:

A MEDLINE search (1966–February 2006) was conducted using the search terms osteoporosis, alendronate, risedronate, ibandronate, raloxifene, bisphosphonate, treatment, and selective estrogen-receptor modulators.

Study Selection and Data Extraction:

Clinical trials examining the efficacy of bisphosphonate and raloxifene in the treatment of osteoporosis were reviewed. Two trials evaluated alendronate or clodronate plus raloxifene for the treatment of osteoporosis in postmenopausal women.

Data Synthesis:

The results demonstrated a significant increase in lumbar bone mineral density (BMD) and conflicting results in the femoral BMD. Fracture risk was not assessed in either study.

Conclusions:

Published trials assessed BMD rather than fracture risk and were limited by methodologic flaws. Due to insufficient clinical outcomes data, combining these antiresorptive treatments cannot be recommended.