Effects of 1-year ipriflavone treatment on lumbar bone mineral density and bone metabolic markers in postmenopausal women with low bone mass

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.

Ipriflavone attenuates the degeneration of cartilage by blocking the Indian hedgehog pathway

BACKGROUND

To determine if ipriflavone, a novel and safe inhibitor of Indian hedgehog (Ihh) signaling, can attenuate cartilage degeneration by blocking the Ihh pathway.

METHODS

Human chondrocytes were used to evaluate Ihh signaling, cell proliferation, apoptosis, gene, and protein expression of chondrocytes by cell proliferation and apoptosis assays, real-time qPCR, and Western blotting at 48 h after ipriflavone treatment. Human cartilage explants were further used to validate the cell culture results. The effects of ipriflavone on cartilage degeneration in vivo were assessed using the rat ACLT OA model. Two-month-old male SD rats were randomized into 3 groups (n = 75): (1) sham, (2) ACLT alone, and (3) ACLT+ ipriflavone. Ipriflavone was administered intragastrically at 24 h after ACLT for 6 weeks. The extent of OA progression was evaluated by the OARSI score and immunohistochemistry at 12 weeks after surgery. The Ihh signaling pathway and OA-related genes were quantified by real-time PCR.

RESULTS

Cell proliferation in the cells treated with ipriflavone was increased to 36.40% ± 1.32% (5 μM) and 28.54% ± 0.74% (10 μM) from 11.99% ± 0.35% (DMSO) (P < 0.001), and apoptosis was decreased to 12.64% ± 3.7% (5 μM) and 15.18% ± 3.13% (10 μM) from 25.76% ± 5.1% (DMSO) (P < 0.05). Ipriflavone blocked Runx-2 mainly through the Smo-Gli2 pathway. A similar result was found in the cartilage explant culture. Ihh signaling in vivo was inhibited in animals treated with ipriflavone. Safranin-O staining revealed a less cartilage damage with lower OARSI scores (P < 0.05) in the ipriflavone-treated animals compared with untreated animals. The gene expression of Smo and Gli2 was inhibited significantly by ipriflavone (P < 0.05). The OA-related gene and protein type X, MMP-13, and type II collagen-C fragment were reduced, while type II collagen and Agg were increased in the ipriflavone-treated animals (P < 0.05).

CONCLUSIONS

Catabolic genes were disrupted by blocking the Ihh pathway. This finding suggests that disruption of Ihh signaling with ipriflavone provides chondral protection in rat posttraumatic OA.

Skeletal effects of nutrients and nutraceuticals, beyond calcium and vitamin D

There is a need to understand the role of nutrition, beyond calcium and vitamin D, in the treatment and prevention of osteoporosis in adults. Results regarding soy compounds on bone density and bone turnover are inconclusive perhaps due to differences in dose and composition or in study population characteristics. The skeletal benefit of black cohosh and red clover are unknown. Dehydroepiandrosterone (DHEA) use may benefit elderly individuals with low serum dehydroepiandrosterone-sulfate levels, but even in this group, there are inconsistent benefits to bone density (BMD). Higher fruit and vegetable intakes may relate to higher BMD. The skeletal benefit of flavonoids, carotenoids, omega-3-fatty acids, and vitamins A, C, E and K are limited to observational data or a few clinical trials, in some cases investigating pharmacologic doses. Given limited data, it would be better to get these nutrients from fruits and vegetables. Potassium bicarbonate may improve calcium homeostasis but with little impact on bone loss. High homocysteine may relate to fracture risk, but the skeletal benefit of each B vitamin is unclear. Magnesium supplementation is likely only required in persons with low magnesium levels. Data are very limited for the role of nutritional levels of boron, strontium, silicon and phosphorus in bone health. A nutrient rich diet with adequate fruits and vegetables will generally meet skeletal needs in healthy individuals. For most healthy adults, supplementation with nutrients other than calcium and vitamin D may not be required, except in those with chronic disease and the frail elderly.

Soy protein with or without isoflavones failed to preserve bone density in gonadal hormone-deficient male rat model of osteoporosis

Soy with its isoflavones has been shown to positively influence bone mineral density in female ovariectomized rats; hence, we hypothesized a similar effect in orchidectomized (ORX) male rats. Forty male Sprague-Dawley rats, aged 95 days, were divided into 4 groups and were either sham operated (Sham) or ORX. The ORX groups were fed a soy protein-based diet (SOY), an isoflavone-depleted soy protein diet (SOY-), or a casein based diet for 65 days after surgery. Orchidectomy increased the rate of bone turnover, resulting in reduced bone mineral density and bone mineral content by 3.5% and 14%, respectively, and compromised biomechanical properties. The mean femoral length of ORX animals was also significantly shorter than Sham animals, but ORX rats that were fed SOY diet did not experience this reduction in bone length, implicating a role for soy protein in bone growth (4.02 ± 0.02, 3.93 ± 0.01, 3.99 ± 0.02, 3.91 ± 0.01 for Sham, ORX, SOY, SOY-, respectively). The SOY and SOY- positively influenced the biomechanical properties of bone such as yield and ultimate force, the measures of bone elasticity, and plasticity. In terms of bone histomorphometry, the data indicate that SOY- tends to reduce ORX-induced increase in bone turnover as evidenced by suppressed bone formation rate/mineralized surface by about 9%. Overall, our results indicated that soy protein, regardless of its isoflavone content, was unable to prevent the ORX-induced femoral decrease in bone density and mineral content. However, soy may enhance the quality of bone as indicated by increased yield force.

Women's health: selected topics

Complementary and alternative medicine (CAM) therapies have become increasingly popular for the treatment of a variety of conditions. The World Health Organization has recognized the value of traditional healing techniques, which are classified as CAM, for 30 years. In the United States nearly 50% of women use CAM for common medical conditions, significantly more than men. This pattern is frequently seen in the treatment of women's health conditions such as infertility, premenstrual syndrome, and menopause. This article provides an integrative approach for conditions commonly encountered in the primary care setting among women, discusses alternative therapies used to treat these health conditions, and provides an evidence-based summary of recommendations based on a review of the literature.

The significance of soy protein and soy bioactive compounds in the prophylaxis and treatment of osteoporosis

Osteoporosis is defined as a progressive systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture. Although bone mass and quality is mainly determined genetically, many other factors, including lifestyle and nutrition also have an impact on bone health. It has been suggested that dietary protein intake may be a risk factor for osteoporosis, and high-protein diets are associated with increased bone loss. Many scientists have examined the relationship between types of protein and urinary calcium excretion, and found that although animal protein was associated with increased urinary calcium excretion, soy protein was not. There is sufficient evidence suggesting soy isoflavones may have potential benefits for bone. Soy protein with naturally occurring phytoestrogens, mainly isoflavones protect against bone loss and synthetic soy ipriflavone in some studies has been shown to favorably affect, but a cause and effect relationship has not been established between the consumption of ipriflavone and maintenance of bone mineral density in post-menopausal women. Therefore it is too early to recommend it as a supplement for this group of women.

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.

Effects of ipriflavone on augmented bone using a guided bone regeneration procedure

: This study investigated the effects of ipriflavone (IP) on augmented bone using a guided bone regeneration (GBR) procedure. In 15 rabbits, two titanium caps were placed into calvarial bone for GBR. The animals were divided into three groups: the No-IP (no intake of IP), Post-IP (IP orally, 10 mg/kg/day after GBR), and Pre-IP (IP intake beginning before GBR) groups. One cap was removed from each rabbit after 3 months, and the remaining site was a control. One month after one cap removal, all the animals were euthanized, and histologic and histomorphometric analyses were performed. In all of the groups, the newly generated tissue was of varying size, and it consisted of thin pieces of mineralized bone and large marrow spaces with fat cells and some hematopoietic cells. In all of the control sites, the newly generated tissue was noted and almost filled the space under the cap. There was a significant difference between groups No-IP and Pre-IP (93.8+/-4.6% vs. 98.5+/-0.8%, P<0.05). The tissue generated at the test sites in all of the groups was resorbed, and its original shape and volume were not maintained 1 month after one cap removal. In particular, the greatest percentage, approximately 20% of the newly generated tissue, was resorbed in the No-IP group (93.8+/-4.6% vs. 73.9+/-3.7%, P<0.05), and approximately 11% and 15% in groups Post-IP and Pre-IP, respectively. The relative amount of mineralized bone generated at the control and test sites was significantly larger in groups Post-IP and Pre-IP when compared with group No-IP, except for the test site between groups No-IP and Post-IP (P<0.05). Therefore, the amount of mineralized tissue generated appeared to increase with an increase in the total IP dose. Within the limitations of this rabbit experimental model, we conclude that the daily intake of IP before or after GBR inhibits the resorption of augmented tissue and would be useful for improving the quality of newly generated bone beyond the skeletal envelope.

Effects of methoxyisoflavone, ecdysterone, and sulfo-polysaccharide supplementation on training adaptations in resistance-trained males

PURPOSE

Methoxyisoflavone (M), 20-hydroxyecdysone (E), and sulfo-polysaccharide (CSP3) have been marketed to athletes as dietary supplements that can increase strength and muscle mass during resistance-training. However, little is known about their potential ergogenic value. The purpose of this study was to determine whether these supplements affect training adaptations and/or markers of muscle anabolism/catabolism in resistance-trained athletes.

METHODS

Forty-five resistance-trained males (20.5 +/- 3 yrs; 179 +/- 7 cm, 84 +/- 16 kg, 17.3 +/- 9% body fat) were matched according to FFM and randomly assigned to ingest in a double blind manner supplements containing either a placebo (P); 800 mg/day of M; 200 mg of E; or, 1,000 mg/day of CSP3 for 8-weeks during training. At 0, 4, and 8-weeks, subjects donated fasting blood samples and completed comprehensive muscular strength, muscular endurance, anaerobic capacity, and body composition analysis. Data were analyzed by repeated measures ANOVA.

RESULTS

No significant differences (p > 0.05) were observed in training adaptations among groups in the variables FFM, percent body fat, bench press 1 RM, leg press 1 RM or sprint peak power. Anabolic/catabolic analysis revealed no significant differences among groups in active testosterone (AT), free testosterone (FT), cortisol, the AT to cortisol ratio, urea nitrogen, creatinine, the blood urea nitrogen to creatinine ratio. In addition, no significant differences were seen from pre to post supplementation and/or training in AT, FT, or cortisol.

CONCLUSION

Results indicate that M, E, and CSP3 supplementation do not affect body composition or training adaptations nor do they influence the anabolic/catabolic hormone status or general markers of catabolism in resistance-trained males.

The effect of oestrogen and dietary phyto-oestrogens on transepithelial calcium transport in human intestinal-like Caco-2 cells

Recently, dietary phyto-oestrogens (PO) have been suggested as possible alternatives to oestrogen therapy (hormone replacement therapy) as a means of preventing bone loss associated with ovarian hormone deficiency. While PO, which exhibit oestrogen-like activity, act directly on bone cells, their protective effect on bone may be partly due to their ability to enhance Ca absorption. Therefore, the aim of the present study was to investigate the effect of 17beta-oestradiol and two commonly consumed soyabean PO (genistein and daidzein) on Ca absorption in the human Caco-2 intestinal-like cell model. Caco-2 cells were seeded onto permeable filter supports and allowed to differentiate into monolayers. On day 21, the Caco-2 monolayers (n 8-18 per treatment), grown in oestrogen-replete or -deplete media, were then exposed to 10 nm-17beta-oestradiol, 1 nm-1,25-dihydroxycholecalciferol, or 50 micro m-genistein or -daidzein for 24 h. After exposure, transepithelial and transcellular transport of 45Ca and fluorescein transport (a marker of paracellular diffusion) were measured. As expected, 1,25-dihydroxycholecalciferol stimulated Ca absorption in Caco-2 cells, by up-regulating transcellular transport, whereas 17beta-oestradiol had no effect on Ca absorption. Unexpectedly, both PO decreased Ca absorption (by about 17-19 % compared with control, P<0.05), by reducing transcellular Ca transport in Caco-2 cells grown in oestrogen-replete media. This inhibitory effect disappeared when monolayers were grown in oestrogen-deplete media. In conclusion, PO at high luminal concentrations either had no effect or reduced Ca absorption in Caco-2 cells, dependent on oestrogen status. The effect of lower concentrations of these compounds needs to be investigated.

Complementary therapies for reducing the risk of osteoporosis in patients receiving luteinizing hormone-releasing hormone treatment/orchiectomy for prostate cancer: a review and assessment of the need for more research

Osteoporosis in women has received a substantial amount of attention, but its impact in men is also significant and noteworthy. Those men who benefit from treatment for prostate cancer with androgen deprivation therapy (ADT) may also be at a higher risk for osteoporosis. Pharmacologic approaches to reduce this risk have received some attention. For example, agents such as bisphosphonates, estrogen receptor-binding drugs (diethylstilbestrol, tamoxifen, and raloxifene), calcitonin, and fluoride are some of the more promising interventions that have been previously outlined. In addition, statin drugs, or hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, have recently been hypothesized to lower osteoporosis risk. However, complementary therapies, which may also have an impact on reducing osteoporosis risk, have not received attention. Dietary and supplemental calcium and vitamin D have been shown, in some preliminary investigations, to maintain bone density in women and men. Numerous healthy and affordable dietary sources of this mineral and vitamin exist, and large intakes can be realistically achieved through proper education. Similarly, the supplemental dosages required to impact risk have been moderate, appear to be safe, are of low cost, and thus may provide an additional route for reducing risk, especially if these interventions are initiated at the start of medical treatment. More studies in men receiving ADT are needed because the existing work has mostly focused on men without castrate levels of male hormone. Additionally, many studies with conventional and nonconventional agents have only focused on individuals with baseline osteoporosis, rather than normal bone mineral densities or osteopenia. Other promising complementary therapies, such as weight-bearing exercise and abstaining from smoking, may also be of benefit. Newer estrogenic-type supplements (eg, ipriflavone) appear interesting and have some preliminary data, but more research is desperately required to determine their actual impact and potential for adverse effects (such as lymphocytopenia from a recent trial). Simple, inexpensive, and potentially effective dietary and supplemental approaches to reduce the risk of osteoporosis in men exist, and they should be discussed with patients. Whether these approaches effectively reduce the risk of osteoporosis in men receiving androgen ablation remains to be determined. The possibility is intriguing, and future research is needed. In the meantime, it is important to keep in mind that these complementary approaches are, at the very least, an integral part of the conventional options used today to the reduce the risk of osteoporosis in men and women.

Usual dietary isoflavone intake, bone mineral density, and bone metabolism in postmenopausal women

Clinical trials of isoflavone supplementation and bone density have been of relatively short duration and yielded inconsistent results. Few studies examined the effects of usual dietary isoflavone intake on bone density, and none examined the effects on markers of bone turnover. This cross-sectional study examines the association of usual, unsupplemented dietary soy intake with bone density at the lumbar spine and hip and markers of bone turnover in postmenopausal women. Participants were 208 postmenopausal Southern California women aged 45-74 years. Information on behavioral and lifestyle factors was obtained, and dietary intake of isoflavones over the past year was assessed with a standardized questionnaire. Bone density was measured at the spine and hip with dual energy x-ray absorptiometry (DEXA). Urinary type I collagen cross-linked N-telopeptides (N-Tx) and pyridinium cross-links (PYR), both markers of bone resorption, and bone alkaline phosphatase (BAP), a marker of bone formation, were assayed. After adjustment for age and obesity, women with the highest daily intake of dietary genistein had N-Tx concentrations 18% lower than those of women who reported no daily genistein consumption (mean 37.29 vs. 45.44, respectively, p = 0.01). After adjustment for all covariates, there were trends toward significant differences in N-Tx (p = 0.09) and spine bone density (p = 0.07), whereby women with the highest level of isoflavone consumption had greater bone density at the spine. These results suggest that usual, unsupplemented dietary isoflavone consumption may be protective against bone loss in postmenopausal women through a reduction in bone resorption.

The effect of an ipriflavone-containing supplement on urinary N-linked telopeptide levels in postmenopausal women

Osteoporosis is a significant health concern to our aging population. We report here the results of a pilot placebo-controlled trial of a dietary supplement containing ipriflavone, calcium, and vitamin D on a urinary marker of bone breakdown in postmenopausal women. Seven postmenopausal women not currently receiving hormone replacement therapy received either an ipriflavone-containing supplement or placebo for 3 months. Urinary N-linked telopeptides, a marker of bone breakdown, declined by 29% in those receiving the supplement, whereas an increase in this marker was observed in the group receiving the placebo. No changes were observed in salivary hormone measurements. Although our sample size was small, to the best of our knowledge, this is the first report that demonstrates changes in N-linked telopeptide levels as a result of consuming an ipriflavone-containing product. Our findings confirm those of other researchers that demonstrate the usefulness of ipriflavone at slowing the progression of bone loss and suggest that measuring N-linked telopeptides may be a useful tool to assess therapeutic efficacy.