Treatment of bone loss in oophorectomized women with a combination of ipriflavone and conjugated equine estrogen

Isoflavone intervention and its impact on bone mineral density in postmenopausal women: a systematic review and meta-analysis of randomized controlled trials

Due to estrogen deficiency, postmenopausal women may suffer from an imbalance in bone metabolism that leads to bone fractures. Isoflavones, a type of phytoestrogen, have been suggested to improve bone metabolism and increase bone mass. Therefore, isoflavones are increasingly recognized as a promising natural alternative to hormone replacement therapy for postmenopausal women who face a heightened risk of osteoporosis and are susceptible to bone fractures.

PURPOSE

This study aimed to evaluate the efficacy of isoflavone interventions on bone mineral density (BMD) in postmenopausal women by means of systematic review and meta-analysis.

METHODS

The electronic database searches were performed on PubMed, Embase, Scopus, and Cochrane Library databases, covering literature up to April 20, 2023. A random-effects model was used to obtain the main effect estimates, with a mean difference (MD) and its 95% confidence interval (CI) as the effect size summary. The risk of bias assessment was conducted using the Risk of Bias 2 (RoB2) tool.

RESULTS

A total of 63 randomized controlled trials comparing isoflavone interventions (n = 4,754) and placebo (n = 4,272) were included. The results indicated that isoflavone interventions significantly improved BMD at the lumbar spine (MD = 0.0175 g/cm2; 95% CI, 0.0088 to 0.0263, P < 0.0001), femoral neck (MD = 0.0172 g/cm2; 95% CI, 0.0046 to 0.0298, P = 0.0073), and distal radius (MD = 0.0138 g/cm2; 95% CI, 0.0077 to 0.0198, P < 0.0001) in postmenopausal women. Subgroup analysis showed that the isoflavone intervention was effective for improving BMD when the duration was ≥ 12 months and when the intervention contained genistein of at least 50 mg/day.

CONCLUSION

This systematic review and meta-analysis suggests that isoflavone interventions, especially those containing genistein of at least 50 mg/day, can effectively enhance BMD in postmenopausal women.

Dietary l-carnitine supplementation improves bone mineral density by suppressing bone turnover in aged ovariectomized rats

Postmenopausal bone loss is a major public health concern. Although drug therapies are available, women are interested in alternative/adjunct therapies to slow down the bone loss associated with ovarian hormone deficiency. The purpose of this study was to determine whether dietary supplementation of l-carnitine can influence bone density and slow the rate of bone turnover in an aging ovariectomized rat model. Eighteen-month-old Fisher-344 female rats were ovariectomized and assigned to two groups: (1) a control group in which rats were fed ad libitum a carnitine-free (-CN) diet (AIN-93M) and (2) another fed the same diet but supplemented with l-carnitine (+CN). At the end of 8 weeks of feeding, animals were sacrificed and bone specimens were collected for measuring bone mineral content (BMC) and density (BMD) using dual energy X-ray absorptiometry. Femoral microarchitectural properties were assessed by microcomputed tomography. Femoral mRNA levels of selected bone matrix proteins were determined by northern blot analysis. Data showed that tibial BMD was significantly higher in the rat fed the +CN diet than those fed the -CN (control) diet. Dietary carnitine significantly decreased the mRNA level of tartrate-resistant acid phosphatase (TRAP), an indicator of bone resorption by 72.8%, and decreased the mRNA abundance of alkaline phosphatase (ALP) and collagen type-1 (COL), measures of bone formation by 63.6% and 61.2%, respectively. The findings suggest that carnitine supplementation slows bone loss and improves bone microstructural properties by decreasing bone turnover.

The effect of bilateral oophorectomy on bone mineral density

The objective of this study is to investigate the effect of bilateral oophorectomy with total abdominal hysterectomy on bone loss, comparing the cases having surgery before and after the menopause. Bone mineral density (BMD) measurements were obtained from the lumbar spine and femoral neck of totally 127 cases. Out of 127, 105 had surgery before menopause and 22 cases were operated on postmenopausally. The results were compared with the USA normal values. The average age of surgical menopause (SM) cases was 48.45 years with a mean duration of menopause of 5.77 years. The average height and weight were 157.67 cm and 68.19 kg, respectively. The average age of cases having surgery after menopause (SAM) was 62.45 years with a mean duration of 5.59 years after the surgery (duration after menopause is 13.23 years). The average height and weight were 157.45 cm and 73.55 kg, respectively. The average of BMD measurements of lumbar spines L2-L4 was 1.04 gr/cm(2) (BMD = 85.65% and T score = -0.96) in the cases with SM. On the contrary, the average of the BMD measurements of lumbar spines L2-L4 was 1.05 gr/cm(2) (BMD = 101.14% and T score = 0.24) in the cases with SAM. The average of the BMD measurements of femoral neck was 0.85 gr/cm(2) (BMD = 91.39% and T score = -0.64) in the cases with SM. On the contrary, the average of the BMD measurements of femoral neck was 0.82 gr/cm(2) (BMD = 96.69% and T score = -0.31) in the cases with SAM. The bilateral oophorectomy as a surgical procedure is not a statistically significant factor for the acceleration of the bone loss. The main points are the age and the duration of menopause of the patient affecting the bone loss if the surgery is performed before menopause.

Induction of apoptosis in cultured rat gastric epithelial cells by ipriflavone: comparison with indomethacin

Based on a previous report illustrating severe gastrointestinal side effects with ipriflavone, we examined the effects of ipriflavone on cell death in cultured rat gastric epithelial cells compared with other chemicals, including indomethacin. Low concentrations of ipriflavone, indomethacin, dexamethasone, and estradiol all induced cell death in gastric epithelial cells. DNA from cultured cells treated with ipriflavone showed fragmentation by electrophoresis. Also, some of the cultured cells treated with ipriflavone were positively stained by TUNEL. In order to confirm induction of apoptosis by ipriflavone, rescue from ipriflavone-induced cell death with Z-DEVD-FMK (0.02-0.1 mM), which is a caspase 3 inhibitor, or PGE(2) (0.01-10 mM), was tested. Only Z-DEVD-FMK was observed to rescue the cells from cell death. Similar results were obtained with indomethacin, dexamethasone and estradiol. These results suggest that ipriflavone, indomethacin, dexamethasone and estradiol induce cell death of cultured rat gastric epithelial cells by apoptosis.

Soy protein isolate with isoflavones does not prevent estradiol-induced endometrial hyperplasia in postmenopausal women: a pilot trial

OBJECTIVE

To test the hypothesis that soy protein isolate (SPI) with isoflavones opposes the proliferative effects of exogenous estradiol (E2) on the endometrium after menopause.

DESIGN

Thirty-nine postmenopausal women were randomized to receive daily for 6 months either 0.5 mg E2 + placebo, 1.0 mg E2 + placebo, 0.5 mg E2 + 25 g SPI with 120 mg isoflavones, or 1.0 mg E2 + 25 g SPI with 120 mg isoflavones. Primary outcome measures were endometrial histology, ultrasound endometrial thickness, and Ki67 staining quantification, a marker of cellular proliferation. Secondary outcome measures were serum lipids and markers of bone resorption.

RESULTS

Endometrial hyperplasia, endometrial stromal and epithelial cellular proliferation, and sonographically measured endometrial thickness were similarly affected in all groups. SPI did not lessen the beneficial effects of E2 on lipids and markers of bone resorption.

CONCLUSION

In this pilot study, SPI with isoflavones did not protect the endometrium from E2-induced hyperplasia in postmenopausal women. If higher, long-term doses of isoflavone supplementation are found to be safe for postmenopausal women, then future studies combining E2 with isoflavones may be feasible as an alternative to traditional hormone replacement therapy.

Efficacy of a soy rich diet in preventing postmenopausal osteoporosis: the Menfis randomized trial

OBJECTIVES

To compare the effect of a soy rich diet and hormone replacement therapy (HRT) on the main biomarkers of bone turnover and bone mineral density (BMD) at postmenopausal age.

METHODS

187 healthy asymptomatic postmenopausal women, aged 39-60, were recruited and randomized into a soy rich diet group, a HRT group, and a control group. Bone biomarkers and BMD were evaluated at baseline and after 6 months at the end of the study.

RESULTS

Diet is not as effective as HRT in reducing the postmenopausal turnover; however diet stimulates bone osteoblastic activity, as evidenced by significant increase in osteocalcin concentrations. BMD decreases significantly only in the control group, but not in the intervention groups.

CONCLUSIONS

Our data suggest that soy products could be effective in reducing the risk of osteoporosis in asymptomatic postmenopausal women, but our findings should be confirmed before recommending the diet as a valid alternative to HRT.

Combination treatment of osteoporosis: a clinical review

OBJECTIVE

Because of the limited efficacy of available agents and to limit toxicity, there is considerable interest in combination pharmacotherapy for osteoporosis.

METHODS

A search was performed for randomized controlled trials in MEDLINE (1966-present) using the keywords osteoporosis treatment and combination.

RESULTS

Twenty-four randomized controlled trials evaluated osteoporosis medications in combination. Study duration ranged from 1 to 4 years. No serious adverse events were definitively attributable to study drugs. Fracture reduction outcome is not shown for any combination regimen. The literature was mixed regarding bone density augmentation. Combinations of nandrolone decanoate plus calcitonin, calcitonin plus growth hormone (GH), or pamidronate plus GH may be contradictory or detrimental to bone mineral density (BMD). For postmenopausal osteoporosis or osteopenia, four combinations appear to increase hip and lumbar BMD: 10 mg alendronate with 0.625 mg conjugated equine estrogens (CEE), cyclic etidronate with 0.625mg CEE, 10 mg alendronate with 2 mg estradiol (E(2)), and tibolone with fluoride. For steroid-related osteoporosis, intermittent etidronate with fluoride increases lumbar BMD.

CONCLUSIONS

The few trials including Food and Drug Administration (FDA)-approved medications suggest that 10 mg/day alendronate with estrogen (equivalent of 0.625 mg CEE daily) can increase BMD moreso than each medication given singly in postmenopausal osteoporotic women. Estrogen dose and type must be controlled in future trials. Long-term safety data are lacking. The utility of these combinations rests on whether bone density changes will translate into decreased fracture rates.