Ipriflavone and low doses of estrogens in the prevention of bone mineral loss in climacterium

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.

Isoformononetin, a methoxydaidzein present in medicinal plants, reverses bone loss in osteopenic rats and exerts bone anabolic action by preventing osteoblast apoptosis

PURPOSE

Daidzein (Daid) has been implicated in bone health for its estrogen-'like' effects but low bioavailability, unfavorable metabolism and uterine estrogenicity impede its clinical potential. This study was aimed at assessing isoformononetin (Isoformo), a naturally occurring methoxydaidzein, for bone anabolic effect by overcoming the pitfalls associated with Daid.

METHODS

Sprague-Dawley ovariectomized (OVx) rats with established osteopenia were administered Isoformo, 17β-oestradiol (E2) or human parathyroid hormone. Efficacy was evaluated by bone microarchitecture using microcomputed tomography and determination of new bone formation by fluorescent labeling of bone. Osteoblast apoptosis was measured by co-labeling of bone sections with Runx-2 and TUNEL. Biochemical markers of bone metabolism were measured by ELISA. Plasma and bone marrow levels of Isoformo and Daid were determined by LC-MS-MS. Rat bone marrow stromal cells were harvested to study osteoblastic differentiation by Isoformo and Daid. New born rat pups were injected with Isoformo and Daid to study the effect of the compounds on the expression of osteogenic genes in the calvaria by real time PCR.

RESULTS

In osteopenic rats, Isoformo treatment restored trabecular microarchitecture, increased new bone formation, increased the serum osteogenic marker (procollagen N-terminal propeptide), decreased resorptive marker (urinary C-terminal teleopeptide of type I collagen) and diminished osteoblast apoptosis in bone. At the most effective osteogenic dose of Isoformo, plasma and bone marrow levels were comprised of ~90% Isoformo and the rest, Daid. Isoformo at the concentration reaching the bone marrow achieved out of its most effective oral dosing induced stromal cell mineralization and osteogenic gene expression in the calvaria of neonatal rats. Isoformo exhibited uterine safety.

CONCLUSIONS

Our study demonstrates that Isoformo reverses established osteopenia in adult OVx rats likely via its pro-survival effect on osteoblasts. Given its bone anabolic and anti-catabolic effects accompanied with safety at uterine level we propose its potential in the management of postmenopausal osteoporosis.

Positive skeletal effects of cladrin, a naturally occurring dimethoxydaidzein, in osteopenic rats that were maintained after treatment discontinuation

Effects of cladrin treatment and withdrawal in osteopenic rats were studied. Cladrin improved trabecular microarchitecture, increased lumbar vertebral compressive strength, augmented coupled remodeling, and increased bone osteogenic genes. A significant skeletal gain was maintained 4 weeks after cladrin withdrawal. Findings suggest that cladrin has significant positive skeletal effects.

INTRODUCTION

We showed that a standardized extract of Butea monosperma preserved trabecular bone mass in ovariectomized (OVx) rats. Cladrin, the most abundant bioactive compound of the extract, promoted peak bone mass achievement in growing rats by stimulating osteoblast function. Here, we studied the effects of cladrin treatment and withdrawal on the osteopenic bones.

METHODS

Adult female Sprague-Dawley rats were OVx and left untreated for 12 weeks to allow for significant estrogen deficiency-induced bone loss, at which point cladrin (1 and 10 mg/kg/day) was administered orally for another 12 weeks. Half of the rats were killed at the end of the treatments and the other half at 4 weeks after treatment withdrawal. Sham-operated rats and OVx rats treated with PTH or 17β-estradiol (E2) served as various controls. Efficacy was evaluated by bone microarchitecture using microcomputed tomographic analysis and fluorescent labeling of bone. qPCR and western blotting measured mRNA and protein levels in bone and uterus. Specific ELISA was used for measuring levels of serum PINP and urinary CTx.

RESULTS

In osteopenic rats, cladrin treatment dose dependently improved trabecular microarchitecture, increased lumbar vertebral compression strength, bone formation rate (BFR), cortical thickness (Cs.Th), serum PINP levels, and expression of osteogenic genes in bones; and reduced expression of bone osteoclastogenic genes and urinary CTx levels. Cladrin had no uterine estrogenicity. Cladrin at 10 mg/kg maintained acquired skeletal gains 4 weeks after withdrawal.

CONCLUSION

Cladrin had positive skeletal effects in osteopenic rats that were maintained after treatment withdrawal.

Anabolic agents and the bone morphogenetic protein pathway

A major unmet need in the medical field today is the availability of suitable treatments for the ever-increasing incidence of osteoporosis and the treatment of bone deficit conditions. Although therapies exist which prevent bone loss, the options are extremely limited for patients once a substantial loss of skeletal bone mass has occurred. Patients who have reduced bone mass are predisposed to fractures and further morbidity. The FDA recently approved PTH (1-34) (Teriparatide) for the treatment of postmenopausal osteoporosis after both preclinical animal and clinical human studies indicated it induces bone formation. This is the only approved bone anabolic agent available but unfortunately it has limited use, it is relatively expensive and difficult to administer. Consequently, the discovery of low cost orally available bone anabolic agents is critical for the future treatment of bone loss conditions. The intricate process of bone formation is co-ordinated by the action of many different bone growth factors, some stored in bone matrix and others released into the bone microenvironment from surrounding cells. Although all these factors play important roles, the bone morphogenetic proteins (BMPs) clearly play a central role in both bone cartilage formation and repair. Recent research into the regulation of the BMP pathway has led to the discovery of a number of small molecular weight compounds as candidate bone anabolic agents. These agents may usher in a new wave of more innovative and versatile treatments for osteoporosis as well as orthopedic and dental indications.

Establishment ofin vitro test system for the evaluation of the estrogenic activities of natural products

In order to evaluate estrogenic compounds in natural products, an in vitro detection system was established. For this system, the human breast cancer cell line MCF7 was stably transfected using an estrogen responsive chloramphenicol acetyltransferase (CAT) reporter plasmid yielding MCF7/pDsCAT-ERE119-Ad2MLP cells. To test the estrogenic responsiveness of this in vitro assay system, MCF7/pDsCAT-ERE119-Ad2MLP cells were treated with various concentrations of 17beta-estradiol. Treatments of 10(-8) to 10(-12) M 17beta-estradiol revealed significant concentration dependent estrogenic activities compared with ethanol. We used in vitro assay system to detect estrogenic effects in Puerariae radix and Ginseng radix Rubra extracts. Treatment of 500 and 50 microg/ml of Puerariae radix extracts increased the transcriptional activity approximately 4- and 1.5-fold, respectively, compared with the ethanol treatment. Treatment of 500, 50, and 5 microg/ml of Ginseng radix Rubra extracts increased the transcriptional activity approximately 3.2-, 2.7-, and 1.4-fold, respectively, compared with the ethanol treatment. These observations suggest that Puerariae radix and Ginseng radix Rubra extracts have effective estrogenic actions and that they could be developed as estrogenic supplements.

Use of alternative and complementary medicine in menopause

OBJECTIVES

To review the clinical evidence available for the treatment of menopausal symptoms with alternative and complementary medicine.

METHODS

The MEDLINE, PREMEDLINE and COCHRANE electronic databases for the years 1980-2002 were searched for articles concerning soy products, black cohosh, dong quai, acupuncture, ginseng and evening primrose oil. Studies pertaining to menopausal vasomotor symptoms, lipid profiles and bone mineral densities of postmenopausal women were included. The data from clinical trials were reviewed.

RESULTS

Soy isoflavones slightly decrease total cholesterol and LDL levels. The clinical significance of this small change is yet to be determined. The synthetic isoflavone derivative ipriflavone increases bone mineral density in healthy peri- and postmenopausal women with moderate bone mineral densities. Although earlier reports have claimed that soy is beneficial for the improvement of vasomotor symptoms, recent data do not support this claim. There are insufficient data on the other alternative therapies for treating menopausal symptoms at this time.

CONCLUSION

Alternative and complementary medicine may play a role in the management of menopause, however, well-designed large studies are still needed.

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.

Phytoestrogens and healthy aging: gaps in knowledge. A workshop report

There is an increasing public interest in foods and dietary supplements containing phytoestrogens for the maintenance of health. A workshop was convened to assess evidence for the potential benefits of phytoestrogen-containing foods or supplements on diseases or conditions affecting older populations. Preclinical, clinical, and epidemiologic data on the cardiovascular system, various cancers, bone diseases, and menopausal symptoms were the focus of the discussions. Research on the basis of consumer food choices as well as a presentation from the FDA regarding approval of the use of soy foods to reduce the risk of cardiovascular disease were also presented. Based on the information presented, isoflavone-containing soy foods may have favorable effects on the cardiovascular system, but major knowledge gaps still exist regarding effects ofphytoestrogen supplements on bone diseases, various cancers, menopausal symptoms, and cognitive function.

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.

Phytoestrogens as hormone replacement therapy: an evidence-based approach

Postmenopausal women have sought nonestrogen alternatives to hormone replacement in order to avoid possible risks and side effects of the therapy. Selective estrogen receptor modulators have been developed to tailor therapy to a specific risk/benefit profile that will best fit the patient. More women have looked to phytoestrogens, such as the isoflavones found in the soy plant, to tailor their menopausal therapy in a "natural" way. This review examines the evidence regarding the risks and benefits of isoflavones as hormone replacement therapy. Controlled trials have shown a reduction in postmenopausal hot flashes when subjects' diets were supplemented with soy. There is less evidence for a benefit in vaginal dryness symptoms. Furthermore, dietary supplementation also appears to lower total and low-density lipoprotein cholesterol in hypercholesterolemic subjects. A synthetic isoflavone, ipriflavone, has been shown in controlled trials to prevent postmenopausal bone loss, though there is much less evidence that soy isoflavones will accomplish this goal. Finally, although unopposed estrogen replacement may promote breast and endometrial cancer, there is no evidence that phytoestrogens will do the same. In contrast, great interest has been taken in the potential cancer-protective effects of phytoestrogens, though prospective evidence in postmenopausal women is not available. Although data regarding the use of isoflavone extracts are incomplete, dietary supplementation with soy foods appears to be a safe and possibly beneficial option for postmenopausal women.

Selective estrogen receptor modulators in reproductive medicine and biology

Estrogen replacement therapy has significant potential benefits for postmenopausal women, such as improvement of menopausal symptoms and protection from osteoporosis, but it may also increase a woman's risk of breast cancer. Also, some women do not take hormone replacement therapy because of such undesirable side effects as breast tenderness and uterine bleeding. Therefore, there is much interest in the development of compounds that provide the benefits of estrogen replacement therapy without the risks and side effects. The selective estrogen receptor modulators make up one class of compounds with both estrogen agonist and antagonist activity. This review discusses the clinical indications, risks, benefits, and mechanisms of action of selective estrogen receptor modulators and related compounds.

How significant are environmental estrogens to women?

Women are exposed to xenobiotic estrogens at least to the same extent as men. These estrogenic chemicals are either from plant material in the diet (phytoestrogens) or from industrial sources. Mainly industrially derived environmental estrogens may accumulate within the food chain and persist in human adipose tissue. In contrast, phytoestrogens do not bioaccumulate and are rapidly excreted in urine. The phytoestrogens probably represent the source of most extensive exposure for humans. Epidemiological evidence suggests that diets rich in phytoestrogens are associated with reduced incidences of cardiovascular disease, breast cancer, prostate cancer and osteoporosis. The numerous bioactivities (other than just estrogenicity) of phytoestrogens and related dietary compounds make it difficult to single out the mechanisms mediating such protective effects. The possibility that the newly discovered estrogen receptor beta may be an important modulator of phytoestrogen action is opening up new lines of research. While the evidence suggests that phytoestrogens may be of positive relevance to postmenopausal women, indications that exposure of women to industrially derived xenobiotic estrogens provides risks to health remain unproven. Further work is necessary to clarify the relative importance of 'xenobiotic' estrogens to human health, but it must be emphasized that the estrogenic potency of all the xenobiotic estrogens is very low compared with that of endogenous estrogens.

A systematic review of the skeletal effects of estrogen therapy in postmenopausal women. I. An assessment of the quality of randomized trials published between 1977 and 1995

PURPOSE

To examine the quality of published randomized controlled trials of the effects of estrogen treatment on fracture risk and measures of bone mass.

DATA SOURCES

Articles on estrogen treatment for osteoporosis published between 1977 and 1995 were identified by searching Medline and Excerpta Medica databases and bibliographies of original papers and published reviews.

STUDY SELECTION

Studies selected were randomized controlled trials of the efficacy of estrogens in preventing loss of bone mass or fractures in postmenopausal women.

DATA EXTRACTION

Data extraction and quality assessment were performed in duplicate, with assistance of a manual. Raters were blinded as to authors and their affiliations and the publication details.

RESULTS

Of 99 eligible randomized controlled trials published between 1977 and 1995, eight included no extractable data, and 23 contained results that were published in duplicate. Total quality scores increased over time, but this was accounted for by improvements only in the measurement technologies used to estimate bone mineral content or density. There was no improvement in the quality of randomization methods, the extent to which withdrawals were accounted for, or in the baseline comparability of treated and control patients. Neither sample sizes nor durations of follow-up increased over time.

CONCLUSIONS

This body of literature fails to address whether estrogen therapy reduces fracture rates, and does not allow for comparison of the effects of different active therapies on change in bone density. Although there were improvements in the techniques for estimating bone mass and delivering estrogen treatment, the studies published in the 1990s were no more informative for making clinical or policy decisions than those published in the 1970s.

Effects of combined low dose of the isoflavone derivative ipriflavone and estrogen replacement on bone mineral density and metabolism in postmenopausal women

OBJECTIVES

To assess the pattern of biochemical markers of bone metabolism and vertebral bone mineral density in early postmenopausal women treated with combined ipriflavone and low dose conjugated estrogens.

METHODS

Bone biochemical markers and vertebral bone density were evaluated in a longitudinal, comparative, 2 year study conducted in postmenopausal women treated with sole calcium supplementation (500 mg/day), or with either ipriflavone (IP) at the standard dose (600 mg/day) plus the same calcium dose, low dose conjugated estrogens (CE) (0.3 mg/day) plus calcium, or low dose IP (400 mg/day) plus low dose CE (0.3 mg/day) plus calcium. The results were analyzed by repeated measures analysis of variance, as appropriate.

RESULTS

No modifications of both urinary excretion of hydroxyproline and plasma osteocalcin levels were observed in calcium and in CE-treated women, while vertebral bone density significantly decreased (P < 0.0001) in both groups. In IP or IP + CE-treated women, plasma osteocalcin did not show any modification, while urinary hydroxyproline showed a significant (P < 0.05) decrease, that paralleled a significant (P < 0.05) increase in vertebral bone density.

CONCLUSION

Postmenopausal IP administration, at the standard dose of 600 mg/day, can prevent the increase in bone turnover and the decrease in bone density that follow ovarian failure. The same effect can be obtained with the combined administration of low dose (400 mg/day) IP with low dose (0.3 mg/day) CE.

Salmon calcitonin plus intravaginal estriol: an effective treatment for the menopause

OBJECTIVE

Intravaginal estriol (E3) effectively improves postmenopausal genito-urinary disturbances, without stimulating endometrial proliferation. The aim of the present study was to evaluate the effect of intravaginal estriol (E3) plus nasal spray salmon calcitonin (sCT), to improve neurovegetative symptoms and to prevent the decline of bone mineral density (BMD) of postmenopausal women.

METHODS

Two hundred and fourteen (214) healthy postmenopausal women were treated for 12 months with: (1) E3 (0.5 mg every other day) + Ca (0.5 g/day); (2) E3 + Ca + sCT (50 IU x 2/day); (3) sCT + Ca; (4) Ca. Climacteric complaints, such as hot flushes and sweating, BMD at the distal 1/10 of the radius, analyzed by dual photon absorptiometry, urinary excretion of hydroxyproline and serum alkaline phosphatase were evaluated at baseline and every 6 months. At the same time, patient compliance and drug tolerability were evaluated.

RESULTS

E3 but not sCT, improved hot flushes and sweating. E3 blunted but not completely counteracted the BMD decline observed in women treated with only Ca, and reduced urinary hydroxyproline excretion. sCT markedly increased BMD values and reduced both urinary hydroxyproline excretion and serum alkaline phosphatase. These effects were not potentiated by E3 coadministration. All treatments were well tolerated.

CONCLUSIONS

Present data indicate that the combined administration of intravaginal E3 and sCT may represent an alternative therapeutic regimen for those postmenopausal women who do not accept or have contraindications to classical hormone replacement therapy.

Metabolic and bone effects after administration of ipriflavone and salmon calcitonin in postmenopausal osteoporosis

Forty postmenopausal women with bone mineral density (BMD) > 2 standard deviations below the mean value for healthy age matched controls were enrolled into an open controlled study to evaluate the metabolic and bone effects of ipriflavone (IP) versus salmon calcitonin (sCT) over a 12 month period. Both treatments significantly increased BMD after 6 and 12 months. A 4.3% increase of BMD was obtained in the IP treated group and a 1.9% in the sCT treated group after 12 months (p < 0.001 between treatments). Bone metabolism markers (serum osteocalcin, alkaline phosphatase, urinary calcium and hydroxyproline/creatinine ratio) were significantly reduced in both groups (p < 0.001). The reduction of urinary hydroxyproline/creatinine ratio was significantly greater (p < 0.05) in the IP group after 12 months. Both treatments were well tolerated. Four patients in the IP group reported gastralgia while two patients in the sCT group reported pruritus and one patient epistaxis.

Ipriflavone prevents the bone mass reduction in premenopausal women treated with gonadotropin hormone-releasing hormone agonists

In the present study we assessed the effects of ipriflavone in the prevention of increased bone turnover and the rapid bone loss that follows medical induced hypogonadism caused by the administration of a gonadotropin hormone-releasing hormone agonist (GnRH-A). In a double blind, placebo-controlled study, ipriflavone (600 mg/day, tdd (three divided doses)) or identical placebo tablets were given with 500 mg/day of calcium to patients treated with 3.75 mg leuproreline acetate every 30 days, for 6 months. In placebo-treated subjects (n = 39), urinary hydroxyproline excretion and plasma bone GLA protein levels showed a substantial (P < 0.01) increase, while spine bone density and total body bone density significantly (P < 0.01) decreased after 3 and 6 months of GnRH-A administration. Conversely, in ipriflavone treated group (n = 39), no significant difference in bone markers and bone density was evidenced. These data indicate that ipriflavone can restrain the bone remodeling processes and prevent the rapid bone loss that follows medical induced hypogonadism. Thus, ipriflavone administration can be of value in the prevention of osteopenia in women treated with GnRH-A.

Ipriflavone: pharmacological properties and usefulness in postmenopausal osteoporosis

Ipriflavone (IP) is an isoflavone derivative available in several countries for investigational and/or therapeutic use. Inhibition of bone resorption was demonstrated in several models, both in vitro and in vivo for IP and its metabolites. Their mechanisms of action on bone are not yet fully elucidated but some of them are widely accepted. IP does not possess, per se, any estrogenic activity. It appears that IP-related inhibition of bone resorption might be mediated by an indirect effect on osteoclast and related to an inhibition of recruitment and/or differentiation of pre-osteoclast, maybe through a modulation of osteoblast response to PTH. Clinical studies in Paget's disease of bone or primary hyperparathyroidism have confirmed preferential inhibition of bone resorption suggesting a clinical interest in postmenopausal osteoporosis. Preliminary (1 year) results of double blind placebo controlled studies designed in postmenopausal and senile osteoporosis confirm a reduction in bone turnover rate in patients treated with 600 mg/day of IP, resulting in a significant bone-sparing effect both at lumbar and radial levels. All clinical and pharmacological trials confirm a very good tolerance of IP with a frequency of adverse reactions equal to that observed during administration of a placebo. Providing ongoing studies will confirm the actual promising preliminary results, IP seems a very interesting new non hormonal approach for prevention and treatment of postmenopausal and senile osteoporosis.

New treatment strategies: ipriflavone, strontium, vitamin D metabolites and analogs

Drugs used to treat osteoporosis can be grouped in two main categories: those that decrease bone resorption and those that increase bone formation. Antiresorptive drugs are active in preventing bone fractures in patients characterized by a negative calcium balance. However, because antiresorptive agents are often coupled to inhibition of bone formation, inhibitors of bone resorption may not be candidates as potential curative drugs in osteoporosis. Conversely, drugs that act by increasing bone formation produce an increase in bone mass above the fracture threshold; therefore, these agents are good candidates for the treatment of osteoporosis. The ideal curative drug in osteoporosis should have the ability both to decrease bone resorption and to maintain a relatively high rate of bone formation, thus inducing a favorable uncoupling of bone remodeling.