Soy extract phytoestrogens with high dose of isoflavones for menopausal symptoms

Efficacy of plant-derived dietary supplements in improving overall menopausal symptoms in women: An updated systematic review and meta-analysis

This updated systematic review and meta-analysis aims to confirm the effectiveness of plant-based supplements in improving overall menopausal symptoms and vasomotor symptoms. A systematic review of the literature was conducted by searching the PubMed/MEDLINE, Web of Science, EMBASE, and CENTRAL databases up to June 2022. Randomized placebo-controlled clinical trials that evaluated the effects of dietary supplements on menopausal symptoms were included. Outcome measures included daily hot flash frequency, Kupperman's index, Menopause Rating Scale, and Greene Climacteric Scale. Pooled data were analyzed using a fixed-effects model and expressed as a weighted mean difference with a 95% confidence interval for continuous outcomes. For qualitative assessment, 67 studies were selected. For quantitative assessment, 54 reports were obtained from 61 studies. The study participants were peri- or postmenopausal women aged 38-85, most of whom experienced hot flashes as a menopausal symptom. The investigational products included 28 soy-derived, 6 red clover-derived, and 28 other plant-derived supplements. Qualitative assessment revealed that approximately 76% of the studies were generally of fair or good quality, whereas 24% were of low quality. Meta-analysis results indicated significant improvements in all questionnaire scores, including hot flash frequency, in the dietary supplement group compared with the placebo group. Comprehensive evaluation using different questionnaire tools showed that the various plant-derived dietary supplements can significantly alleviate menopausal symptoms. However, further rigorous studies are needed to determine the association of plant-derived dietary supplements with menopausal health because of the general suboptimal quality and heterogeneous nature of current evidence.

Long-term effects of a combination of isoflavones, agnus castus and magnolia extracts on climacteric symptoms and cardiometabolic risk profile in postmenopausal women

OBJECTIVE

To evaluate the long-term effects of a combination of isoflavones, agnus castus and magnolia extracts (combined isoflavone compound [CIC]) on climacteric symptoms and cardiometabolic risk in symptomatic postmenopausal women.

METHODS

This interventional, prospective study evaluated climacteric symptoms, mood and sleep disorders using the 21-item Greene Climacteric Scale (GCS) and 7-item Insomnia Severity Index (ISI) questionnaires; and cardiovascular, metabolic and thrombotic risk markers at baseline (T0) and after 12 months of CIC treatment (T1).

RESULTS

In healthy postmenopausal women (N = 71), 12-month CIC treatment significantly reduced patient-reported vasomotor symptoms (100% vs. 17%), mood disorders (67% vs. 25%) and sleep disorders (89% vs. 19%%) (all p < .001) compared with baseline; and significantly improved GCS psychological, somatic, and vasomotor domain scores and ISI sleep disturbance scores (all p < .05). CIC significantly reduced systolic (p = .022) and diastolic blood pressure (p < .001), and heart rate (p < .001); glucose concentrations (p = .018), HOMA index (p = .013), and ALT (p = .035), homocysteine (p = .005) and NT-proBNP (p = .003) levels.

CONCLUSIONS

Long-term CIC therapy improved vasomotor symptoms, mood disorders, sleep disorders, hemodynamic measurements and cardiometabolic risk markers in healthy postmenopausal women.

CLINICALTRIALS.GOV IDENTIFIER

NCT03699150.

Efficacy and Safety of a Standardized Soy and Hop Extract on Menopausal Symptoms: A 12-Week, Multicenter, Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Objectives: Soy and hop extracts have been investigated as alternatives for hormone replacement therapy. However, their combined efficacy is not known. We investigated the efficacy and safety of a combined soy and hop extract on postmenopausal symptoms. Design: Double-blinded, randomized controlled trial. Settings/Location: Gynecological outpatient clinic of tertiary hospital. Subjects: Seventy-eight women with moderate or severe menopausal symptoms assessed as modified Kupperman Menopoausal Index (KMI) scores >20. Interventions: They received either a combined soy and hop extract (n = 38) or placebo (n = 40). Outcome measures: Menopausal symptoms were evaluated through self-reporting of modified Kupperman Menopausal Index (KMI) scores at baseline and after 6 and 12 weeks. We assessed serum levels of bone metabolism biomarkers, ultrasonographic parameters, hormone profiles, compliance, and safety. Results: After 12 weeks of the treatment, treatment group scores decreased by 20.61 points compared with 14.80 points in the placebo group (p < 0.05). Fatigue, paresthesia, arthralgia, and myalgia, palpitation and vaginal dryness significantly improved more in the treatment group compared with the placebo group after 12 weeks (p < 0.05). Urine N-telopeptide in participants ≥50 years in the treatment group showed a reduced increase. Endometrial thickness and hormonal profiles did not show significant changes in either group. No serious adverse events were reported. Conclusion: The results suggest that 190 mg of combined soy and hop extract is safe and effective for improvement of menopausal symptoms. CRIS No.: KCT0006019.

Effects of a Cereal Bar with a Combination of Phytoestrogens on the Climacteric Symptoms: A Placebo-Controlled, Randomized Trial

OBJECTIVE

This study evaluated whether the consumption of a cereal bar combining different phytoestrogens could contribute to the reduction of climacteric symptoms in women.

METHODS

This is a clinical, prospective, randomized, simple-blind trial. Forty-eight women, aged 40-65 years, with climacteric symptoms, from a city in southwestern Paraná, Brazil. Participants were randomly assigned into two groups; Phytoestrogens group (PHY = 24), which received for 90-day period a cereal bar containing 80.73 milligrams of soybean and flaxseed phytoestrogens, and the placebo group (PLA = 24), which consumed rice flakes biscuit. Clinical, sociodemographic and anthropometric data were collected and climacteric symptoms were assessed using the Kupperman Index (KI).

RESULTS

Forty-three women were analyzed (PHY = 21 and PLA = 22). There were significant reductions in the overall KI score in both groups at the end of the intervention period (p < 0.05). However, the comparison between the groups using linear regression models presented expressively better symptom improvement in the PHY group -6.43 over time (95% CI: -11.6; -1.26; p < 0.05) KI points, with perimenopausal -15.15 (95% CI: -28.95; -1.35) and postmenopausal women -19.34 (95% CI: -33.68; -4.99) showed considerably greater reductions in symptoms at the end of the intervention period compared to premenopausal women. There was also significant reduction in symptoms of hot flushes, paresthesia, sexual complaints, insomnia and melancholy.

CONCLUSION

The consumption of a cereal bar containing phytoestrogens was able to improve the symptoms of climacteric syndrome.

The effects of phytoestrogens on postmenopausal health

Phytoestrogens are a group of non-steroidal polyphenolic plant-based substances, commonly used for the treatment of menopause-related conditions. They have both genomic and non-genomic effects, displaying weak affinity for estrogen receptors (ER) and preferentially binding to ER-B over ER-A. However, evidence for the benefits of phytoestrogen consumption has been limited. We conducted a review of recent literature, focusing on systematic reviews and meta-analyses reporting on postreproductive health effects of phytoestrogens. While many trials concerning dietary and supplementary phytoestrogens have been conducted, evidence of clinical efficacy is heterogeneous and inconclusive. There appears to be reduction in the vasomotor symptoms of menopause with phytoestrogen intake; however, it is likely small and slow in onset. Phytoestrogens also appear to improve bone mineral density and markers of cardiovascular risk; however, there is inadequate research regarding long-term outcomes. There appear to be no harmful effects of phytoestrogens on breast, endometrial cancer or colorectal cancer and phytoestrogens intake may in fact be protective. Research regarding the effect of phytoestrogens on cognition is mixed, with most studies reporting no significant association. Overall, individual variations in the metabolism of phytoestrogens and age-related genomic effects may account for the considerable variability in the measured effects of phytoestrogens.

Variation in menopausal vasomotor symptoms outcomes in clinical trials: a systematic review

BACKGROUND

There is substantial variation in how menopausal vasomotor symptoms are reported and measured among intervention studies. This has prevented meaningful comparisons between treatments and limited data synthesis.

OBJECTIVES

To review systematically the outcome reporting and measures used to assess menopausal vasomotor symptoms from randomised controlled trials of treatments.

SEARCH STRATEGY

We searched MEDLINE, Embase, and Cochrane Central Register of Controlled Trials from inception to May 2018.

SELECTION CRITERIA

Randomised controlled trials with a primary outcome of menopausal vasomotor symptoms in women and a sample size of at least 20 women per study arm.

DATA COLLECTION AND ANALYSIS

Data about study characteristics, primary vasomotor-related outcomes and methods of measuring them.

MAIN RESULTS

The search identified 5591 studies, 214 of which were included. Forty-nine different primary reported outcomes were identified for vasomotor symptoms and 16 different tools had been used to measure these outcomes. The most commonly reported outcomes were frequency (97/214), severity (116/214), and intensity (28/114) of vasomotor symptoms or a composite of these outcomes (68/214). There was little consistency in how the frequency and severity/intensity of vasomotor symptoms were defined.

CONCLUSIONS

There is substantial variation in how menopausal vasomotor symptoms have been reported and measured in treatment trials. Future studies should include standardised outcome measures which reflect the priorities of patients, clinicians, and researchers. This is most effectively achieved through the development of a Core Outcome Set. This systematic review is the first step towards development of a Core Outcome Set for menopausal vasomotor symptoms.

TWEETABLE SUMMARY

Menopausal hot flushes and night sweats have been reported in 49 different ways in clinical research. A core outcome set is urgently required.

Complementary and Alternative Medicine for Menopause

Menopause is associated with problematic symptoms, including hot flashes, sleep problems, mood disorders, sexual dysfunction, weight gain, and declines in cognitive functioning. Many women seek complementary and alternative medicine (CAM) for symptom management. This article critically reviews the existing literature on CAM treatments most commonly used for menopausal symptoms. Electronic searches were conducted to identify relevant, English-language literature published through March 2017. Results indicate that mind and body practices may be of benefit in reducing stress and bothersomeness of some menopausal symptoms. In particular, hypnosis is a mind-body intervention that has consistently shown to have a clinically significant effect on reducing hot flashes. Evidence is mixed in regard to the efficacy of natural products and there are some safety concerns. Health care providers should consider the evidence on CAM in providing an integrative health approach to menopausal symptom management.

Effect of soy isoflavones supplement on climacteric symptoms, bone biomarkers, and quality of life in Korean postmenopausal women: a randomized clinical trial

BACKGROUND/OBJECTIVES

Soy isoflavones are expected to improve menopausal symptoms and osteoporosis in women. However, their efficacy is still inconclusive, and there was limited data for postmenopausal women in South Korea. We examined the effects of soy isoflavones on climacteric symptoms, bone biomarkers, and quality of life in Korean postmenopausal women.

SUBJECTS/METHODS

A randomized, double-blind study design was used. Eighty-seven participants who had undergone natural menopause were randomly administered either 70 mg/day isoflavones (n = 43) or placebo (n = 41) for 12 weeks. We assessed the Kupperman index for climacteric symptoms and the menopause-specific quality of life (MENQOL) questionnaire for quality of the life. Biomarkers of bone metabolism were also measured in serum bone-specific alkaline phosphatase (BALP), osteocalcin (OC), N- and C-terminal cross-linking telopeptides of type I collagen (NTx, CTx), and urine-deoxypyridinolin (u-DPD).

RESULTS

Scores of the Kupperman index were decreased in both the isoflavones group (-7.0 ± 15.8, P = 0.0074) and placebo group (-6.3 ± 14.6, P = 0.0064) during the intervention, but no significant difference was noted between the groups. Regarding the bone formation markers, the level of serum BALP increased by 6.3 ± 4.1% (P = 0.004) and OC increased by 9.3 ± 6.2% (P < 0.001), meanwhile those of the placebo were not changed. For the bone resorption markers, NTx, CTx, and u-DPD were not significantly different in either group. MENQOL was significant decreased in the isoflavone group (-0.6 ± 0.5) and placebo group (-0.6 ± 0.4), with a significant difference between groups (P = 0.0228).

CONCLUSIONS

Our study suggests that 70 mg isoflavones supplement has beneficial effects on bone formation markers; however, it showed no benefit compared to the placebo on climacteric symptoms or quality of life.

Effect of aerobic exercise and nutrition educationon quality of life and early menopause symptoms:A randomized controlled trial

The aim of the authors in this randomized controlled study was to assess the effect of exercise and nutrition education on quality of life and early menopausal symptoms. This trial was conducted in east Azerbaijan Province, Iran, during the period from 2013 to 2014 with 108 women allocated into one of four groups (n = 27 in each group) by block randomization. The interventions received by the three intervention groups were: nutrition education, aerobic exercise, or exercise plus nutrition education. The control group did not receive any intervention. The Greene and MENQOL menopause symptom scales were completed before and at 8 and 12 weeks after the intervention. The mean Greene score was significantly lower than the control group in the exercise (adjusted mean difference: -5.1) and exercise plus nutrition groups (-8.0) at the end of week 8 and in the nutrition (-4.8), exercise (-8.7), and exercise plus nutrition (-13.2) groups at the end of week 12. Also, the mean MENQOL score was significantly lower than the control group in the exercise (-8.3) and exercise plus nutrition groups (-13.8) at the end of week 8 and in the nutrition (-6.6), exercise (-13.5), and exercise plus nutrition (-22.1) groups at the end of week 12. Nutrition education with aerobic exercise can improve quality of life.

Effects of soy phytoestrogens on pituitary-ovarian function in middle-aged female rats

The aim of this study was to assess the effects of genistein (G) and daidzein (D) on the histological, hormonal, and functional parameters of the pituitary-ovarian axis in middle-aged female rats, and to compare these effects with the effects of estradiol (E), commonly used in the prevention and treatment of menopausal symptoms. Middle-aged (12 month old) Wistar female rats subcutaneously received 35 mg/kg of G, or 35 mg/kg of D, or 0.625 mg/kg of E every day for 4 weeks. Each of the treated groups had a corresponding control group. An intact control group was also established. G and D did not change the intracellular protein content within gonadotropic and lactotropic cells, but vacuolization was observed in all the cell types. In contrast, E caused an inhibition of gonadotropic and stimulation of lactotropic cells. Also, ovaries of middle-aged female rats exposed to G or D have more healthy primordial and primary follicles and less atretic follicles. E treatment in the ovaries had a mostly negative effect, which is reflected by the increased number of atretic follicles in all tested classes. G and D provoked decrease in CuZnSOD and CAT activity, while E treatment increased MnSOD and decreased CuZnSOD and GSHPx activity. All the treatments increased serum estradiol and decreased testosterone levels, while D and E increased the serum progesterone level. In conclusion, soy phytoestrogens exhibited beneficial effects on pituitary-ovarian function in middle-aged female rats, as compared to estradiol.

The isoflavone content of two new alfalfa-derived products for instant beverage preparation

The frequent use of plant-based products to promote health leads to the search for scientific information related to efficacy and safety of those products for human consumption. Two alfalfa-derived products (ADP), freeze-dried juice (FDJ) and dehydrated powder (DP), from alfalfa harvested in Mexico, are being developed as new possible nutraceuticals. To the best of our knowledge, any study reports the real composition of such products used to prepare instant beverages in what concerns isoflavone contents. Seven isoflavones (glycitein, formononetin, biochanin A, daidzein, genistein, daidzin and genistin) were assessed by HPLC-DAD analysis as well as its variation in five different batches of these products. Different solvents were tested in order to choose the best one to extract isoflavones. The results showed the presence of daidzein, genistein, genistin and daidzin in most samples while glycitein, formononetin and biochanin A were not detected. Significant differences between isoflavone contents were found with different solvent systems. Water was the best option to extract daidzein (0.40-1.08 mg per unit and 1.30-4.90 mg per unit for DP and FDJ, respectively) whereas the water-methanol-formic acid mixture was efficient to extract genistein (0.19-0.43 mg per unit and 0.15-0.72 mg per unit for DP and FDJ, respectively). In all cases, the total isoflavone content was higher in freeze-dried juices than in dehydrated powders. Genistein and daidzein were the more abundant isoflavones quantified. Further physiological and nutritional studies are needed to complete the validation of effectiveness and safety of these products.

Quantitative efficacy of soy isoflavones on menopausal hot flashes

AIM

This study aimed to quantitate the efficacy of soy isoflavones in the treatment of menopausal hot flashes.

METHODS

Model based meta-analysis (MBMA) was used to quantitate the efficacy of soy isoflavones. We conducted a systemic literature search to build a time-effect model for placebo and soy isoflavones in treating menopausal hot flashes. Studies were identified, subjected to inclusion and exclusion criteria, and reviewed.

RESULTS

From 55 articles, 16 studies of soy isoflavones met the inclusion criteria, and contained 65 and 66 mean effect values in placebo and soy isoflavone groups, respectively, from about 1710 subjects. Interestingly, the developed model was found to describe adequately the time course of hot flashes reduction after administration of placebo and soy isoflavones. Using this model, we found that the maximal percentage change of hot flashes reduction by soy isoflavones was 25.2% after elimination of the placebo effect, accounting for 57% of the maximum effects of estradiol (Emax-estradiol  = 44.9%). However, a time interval of 13.4 weeks was needed for soy isoflavones to achieve half of its maximal effects, much longer than estradiol, which only required 3.09 weeks. These results suggest that treatment intervals of 12 weeks are too short for soy isoflavones, which require at least 48 weeks to achieve 80% of their maximum effects.

CONCLUSIONS

Soy isoflavones show slight and slow effects in attenuating menopausal hot flashes compared with estradiol.

Efficacy of phytoestrogens for menopausal symptoms: a meta-analysis and systematic review

OBJECTIVE

To perform a meta-analysis examining the efficacy of phytoestrogens for the relief of menopausal symptoms.

METHODS

Medline, Cochrane, EMBASE, and Google Scholar databases were searched until September 30, 2013 using the following key words: vasomotor symptoms, menopausal symptoms, phytoestrogens, isoflavones, coumestrol, soy, red clover. Inclusion criteria were (1) randomized controlled trial (RCT), (2) perimenopausal or postmenopausal women experiencing menopausal symptoms, (3) intervention with an oral phytoestrogen. Outcome measures included Kupperman index (KI) changes, daily hot flush frequency, and the likelihood of side-effects.

RESULTS

Of 543 potentially relevant studies identified, 15 RCTs meeting the inclusion criteria were included. The mean age of the subjects ranged from 49 to 58.3 and 48 to 60.1 years, respectively, in the placebo and phytoestrogen groups. The number of participants ranged from 30 to 252, and the intervention periods ranged from 3 to 12 months. Meta-analysis of the seven studies that reported KI data indicated no significant treatment effect of phytoestrogen as compared to placebo (pooled mean difference = 6.44, p = 0.110). Meta-analysis of the ten studies that reported hot flush data indicated that phytoestrogens result in a significantly greater reduction in hot flush frequency compared to placebo (pooled mean difference = 0.89, p < 0.005). Meta-analysis of the five studies that reported side-effect data showed no significant difference between the two groups (p = 0.175).

CONCLUSION

Phytoestrogens appear to reduce the frequency of hot flushes in menopausal women, without serious side-effects.

A systematic review of non-hormonal treatments of vasomotor symptoms in climacteric and cancer patients

The cardinal climacteric symptoms of hot flushes and night sweats affect 24-93% of all women during the physiological transition from reproductive to post-reproductive life. Though efficacious, hormonal therapy and partial oestrogenic compounds are linked to a significant increase in breast cancer. Non-hormonal treatments are thus greatly appreciated.

This systematic review of published hormonal and non-hormonal treatments for climacteric, and breast and prostate cancer-associated hot flushes, examines clinical efficacy and therapy-related cancer risk modulation.

A PubMed search included literature up to June 19, 2014 without limits for initial dates or language, with the search terms, (hot flush* OR hot flash*) AND (clinical trial* OR clinical stud*) AND (randomi* OR observational) NOT review). Retrieved references identified further papers. The focus was on hot flushes; other symptoms (night sweats, irritability, etc.) were not specifically screened. Included were some 610 clinical studies where a measured effect of the intervention, intensity and severity were documented, and where patients received treatment of pharmaceutical quality. Only 147 of these references described studies with alternative non-hormonal treatments in post-menopausal women and in breast and prostate cancer survivors; these results are presented in Additional file 1.

The most effective hot flush treatment is oestrogenic hormones, or a combination of oestrogen and progestins, though benefits are partially outweighed by a significantly increased risk for breast cancer development.

This review illustrates that certain non-hormonal treatments, including selective serotonin reuptake inhibitors, gabapentin/pregabalin, and Cimicifuga racemosa extracts, show a positive risk-benefit ratio.

Key points

Several non-hormonal alternatives to hormonal therapy have been established and registered for the treatment of vasomotor climacteric symptoms in peri- and post-menopausal women.

There are indications that non-hormonal treatments are useful alternatives in patients with a history of breast and prostate cancer. However, confirmation by larger clinical trials is required.

The methanol-soluble fraction of Millettia macrophylla (Fabaceae) stem bark endowed with estrogenic properties has adverse effects on the male reproductive system of Wistar rats

BACKGROUND

The use of traditional medicinal plants to treat various diseases is common in Sub-Saharan African countries, including Cameroon. Millettia macrophylla, one of such plants, was previously found to exhibit estrogenic properties in female Wistar rats. However, its effects on the male reproductive system are unknown. Based on literature evidence that phytoestrogens impair male sexual behavior, we aimed at assessing the effect of the extracts of M. macrophylla stem bark on the male reproductive system of Wistar rats.

MATERIALS AND METHODS

We evaluated the effects of the dichloromethane (DCM) and methanol (MeOH) soluble fractions of M. macrophylla stem bark on male rat sexual behavior, as well as androgen-dependent parameters for 60 days.

RESULTS

Data showed a significant decrease (p<0.05) in the wiring-touch frequency, mount frequency, intromission frequency, ejaculatory frequency, penile-licking frequency, and computed indices of sexual behavior, throughout the experimental period, as well as a significant increase (p<0.001) in mount, intromission, and ejaculatory latencies as well as post-ejaculatory interval. Moreover, we observed a significant decrease (p<0.05) in the androgen-dependent sexual parameters evaluated. The DCM extract did not induce significant effects on the assessed parameters.

CONCLUSIONS

These results suggest that long-term exposure to the estrogenic MeOH fraction of M. macrophylla stem bark negatively alters sexual behavior and spermatogenesis.

Exogenous hormonal regulation in breast cancer cells by phytoestrogens and endocrine disruptors

Observations on the role of ovarian hormones in breast cancer growth, as well as interest in contraception, stimulated research into the biology of estrogens. The identification of the classical receptors ERα and ERβ and the transmembrane receptor GPER and the resolution of the structure of the ligand bound to its receptor established the principal molecular mechanisms of estrogen action. The presence of estrogen-like compounds in many plants used in traditional medicine or ingested as food ingredients, phytoestrogens, as well as the estrogenic activities of many industrial pollutants and pesticides, xenoestrogens, have prompted investigations into their role in human health. Phyto- and xenoestrogens bind to the estrogen receptors with a lower affinity than the endogenous estrogens and can compete or substitute the hormone. Xenoestrogens, which accumulate in the body throughout life, are believed to increase breast cancer risk, especially in cases of prenatal and prepuberal exposure whereas the role of phytoestrogens is still a matter of debate. At present, the application of phytoestrogens appears to be limited to the treatment of post-menopausal symptoms in women where the production of endogenous estrogens has ceased. In this review we discuss chemistry, structure and classification, estrogen signaling and the consequences of the interactions of estrogens, phytoestrogens and xenoestrogens with their receptors, the complex interactions of endogenous and exogenous ligands, the evaluation of the health risks related to xenoestrogens, and the perspectives toward the synthesis of potent third generation selective estrogen receptor modulators (SERMs).

Effects of different doses of soy isoflavones on bone tissue of ovariectomized rats

AIM

Studies report that hormone replacement prevents osteoporosis, but there are doubts whether isoflavones are really efficient in this process. The aim of this study was to evaluate the effects of different doses of soy isoflavones on bone tissue of ovariectomized rats.

METHODS

Forty female rats at the age of 6 months were ovariectomized and, after 3 months, the animals were divided into four groups: GI - Control (treated with drug vehicle); GII - treated with isoflavones (80 mg/kg per day); GIII - treated with isoflavones (200 mg/kg per day) and GIV - treated with isoflavones (350 mg/kg per day). Soy isoflavones were administered by gavage for 90 consecutive days. After treatment, the rats were euthanized and their distal femurs were removed for histological routine, histochemistry and biochemical study. Histological sections were stained with hematoxylin-eosin or subjected to picrosirius red and alcian blue methods. Shafts of femurs were submitted to biochemical assay and tibias were subjected to biophysical and biomechanical tests.

RESULTS

In distal femurs, the trabecular bone volume was higher in the groups treated with isoflavones, being higher in GIV, while the cortical bone width and the presence of mature type I collagen fibers were higher in GII. At the trabecular bone region, the percentage of total glycosaminoglycans (GAGs) was higher in GII and the percentage of only sulfated GAGs was higher in GIII, while the higher content of chondroitin sulfate in shafts of femurs was seen in GIV. Biophysical and biomechanical tests in tibias did not differ among the groups.

CONCLUSION

Our data indicate that soy isoflavones improve bone quality in femurs of rats by increasing histomorphometric parameters, the content of GAGs and mature type I collagen fibers. These positive effects are dose-dependent and it was different in cortical and trabecular bone.

Phytoestrogens for menopausal vasomotor symptoms

BACKGROUND

Vasomotor symptoms, such as hot flushes and night sweats, are very common during the menopausal transition. Hormone therapy has traditionally been used as a highly effective treatment, but concerns about increased risk of some chronic diseases have markedly increased the interest of women in alternative treatments. Some of the most popular of these treatments are foods or supplements enriched with phytoestrogens-plant-derived chemicals that have estrogenic action.

OBJECTIVES

To assess the efficacy, safety and acceptability of food products, extracts and dietary supplements containing high levels of phytoestrogens when compared with no treatment, placebo or hormone therapy for the amelioration of vasomotor menopausal symptoms (such as hot flushes and night sweats) in perimenopausal and postmenopausal women.

SEARCH METHODS

Searches targeted the following electronic databases: the Cochrane Menstrual Disorders and Subfertility Group Specialised Register of randomised trials (29 July 2013), the Cochrane Register of Controlled Trials (CENTRAL; 29 July 2013), MEDLINE (inception to 29 July 2013), EMBASE (inception to 29 July 2013), AMED (1985 to 29 July 2013), PsycINFO (inception to 29 July 2013) and CINAHL (inception to 29 July 2013). Attempts were made to access grey literature by sending letters to pharmaceutical companies and performing searches of ongoing trial registers. Reference lists of included trials were also searched.

SELECTION CRITERIA

Studies were included if they were randomised, included perimenopausal or postmenopausal participants with vasomotor symptoms (hot flushes or night sweats), lasted at least 12 weeks and provided interventions such as foods or supplements with high levels of phytoestrogens (not combined with other herbal treatments). Trials that included women who had breast cancer or a history of breast cancer were excluded.

DATA COLLECTION AND ANALYSIS

Selection of trials, extraction of data and assessment of quality were undertaken by at least two review authors. Most trials were too dissimilar for their results to be combined in a meta-analysis, so these findings are provided in narrative 'Summary of results' tables. Studies were grouped into broad categories: dietary soy, soy extracts, red clover extracts, genistein extracts and other types of phytoestrogens. Five trials used Promensil, a red clover extract; results of these trials were combined in a meta-analysis, and summary effect measures were calculated.

MAIN RESULTS

A total of 43 randomised controlled trials (4,364 participants) were included in this review. Very few trials provided data suitable for inclusion in a meta-analysis. Among the five trials that yielded data assessing the daily frequency of hot flushes suitable for pooling, no significant difference overall was noted in the incidence of hot flushes between participants taking Promensil (a red clover extract) and those given placebo (mean difference (MD) -0.93, 95% confidence interval (CI) -1.95 to 0.10, I(2) = 31%). No evidence indicated a difference in percentage reduction in hot flushes in two trials between Promensil and placebo (MD 20.15, 95% CI -12.08 to 52.38, I(2) = 82%). Four trials that were not combined in meta-analyses suggested that extracts with high (> 30 mg/d) levels of genistein consistently reduced the frequency of hot flushes. Individual results from the remaining trials were compared in broad subgroups such as dietary soy, soy extracts and other types of phytoestrogens that could not be combined. Some of these trials found that phytoestrogen treatments alleviated the frequency and severity of hot flushes and night sweats when compared with placebo, but many trials were small and were determined to be at high risk of bias. A strong placebo effect was noted in most trials, with a reduction in frequency ranging from 1% to 59% with placebo. No indication suggested that discrepant results were due to the amount of isoflavone in the active treatment arm, the severity of vasomotor symptoms or trial quality factors. Also, no evidence indicated that these treatments caused oestrogenic stimulation of the endometrium or the vagina or other adverse effects when used for up to two years.

AUTHORS' CONCLUSIONS

No conclusive evidence shows that phytoestrogen supplements effectively reduce the frequency or severity of hot flushes and night sweats in perimenopausal or postmenopausal women, although benefits derived from concentrates of genistein should be further investigated.

Expression of flavonoid 6-hydroxylase candidate genes in normal and mutant soybean genotypes for glycitein content

Soybean seeds accumulate large amounts of isoflavones (genistein, daidzein and glycitein), secondary metabolites known for their phytoestrogenic activities. Isoflavone composition depends on the seed part and glycitein is almost found exclusively in hypocotyls. Moreover, two major phenotypes are encountered in soybean cultivars, with either low (35 %) or high (55 %) levels of glycitein in their hypocotyls. This trait was under a quasi-mendelian heredity, implicating at most one or two genes. A CYP71D9 cDNA displaying a flavonoid 6-hydroxylase (F6H) activity had previously been isolated from elicitor-induced soybean (Glycine max L.) cells. This enzyme allows the synthesis of the glycitein flavanone intermediate (6,7,4'- trihydroxyflavanone) by catalyzing the A-ring hydroxylation of liquiritigenin. In this study, the CYP71D9 gene (F6H1) and two other candidates (F6H2 and F6H3) were studied using contrasted soybean cultivars for glycitein content (0, 35, 55 and 80 %). Their expression was observed in chitosan elicited leaves. They encode P450 proteins of 496, 469 and 481 amino acids respectively and were expressed in leaves with or without elicitation. The expression patterns of these three genes were performed in cotyledons and hypocotyls at different developmental stages. F6H1 and F6H2 were not expressed in the developing seed. F6H3 was only expressed in hypocotyls. Its expression levels did not correlate with hypocotyls glycitein content, but it was not expressed in the null mutant for glycitein. Thus, this F6H3 gene is a good potential candidate for glycitein biosynthesis in soybean seed.

The short-term effects of soybean intake on oxidative and carbonyl stress in men and women

Beyond other beneficial effects, a soy-rich diet has been shown to reduce the risk of cardiovascular diseases and diabetic complications. Reduction of oxidative and carbonyl stress has been proposed as the underlying mechanism, but the evidence for this is lacking. The aim of our study was to evaluate the effects of short-term increased soy intake on oxidative and carbonyl stress parameters in young volunteers. Young healthy probands (omnivores) of both genders (55 women, 33 men) were given soybeans (2 g/kg bodyweight daily) for one week. Markers of oxidative and carbonyl stress were measured in plasma at the beginning and at the end of one week soybean intake and after another week of a wash-out period. Total antioxidant capacity was increased by soybean intake in both genders. This led to decreased levels of advanced oxidation protein products in women, but not in men. On the contrary, in men, soybean intake increased lipoperoxidation. No effects on carbonyl stress markers (advanced glycation end products-specific fluorescence and fructosamine) were found. Soybean intake has gender-specific effects on oxidative stress in young healthy probands potentially due to divergent action and metabolism of phytoestrogens in men and women. Effects of soybean intake on carbonyl stress should be evaluated in longer studies.

Extracted or synthesized soybean isoflavones reduce menopausal hot flash frequency and severity: systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

This analysis was conducted to determine the efficacy of extracted or synthesized soybean isoflavones in the alleviation of hot flashes in perimenopausal and postmenopausal women.

METHODS

PubMed and The Cochrane Controlled Clinical Trials Register Database were searched for relevant articles reporting double-blinded randomized controlled trials through December 14, 2010. References within identified articles, as well as peer-reviewed articles that had come to the attention of the authors through other means, were also examined for suitability. This systematic review and meta-analysis, which evaluated the effects of isoflavones on the frequency, severity, or composite score (frequency × severity) of hot flashes compared with placebo was conducted according to Cochrane Handbook guidelines.

RESULTS

From 277 potentially relevant publications, 19 trials (reported in 20 articles) were included in the systematic review (13 included hot flash frequency; 10, severity; and 3, composite scores), and 17 trials were selected for meta-analyses to clarify the effect of soybean isoflavones on hot flash frequency (13 trials) and severity (9 trials). Meta-analysis revealed that ingestion of soy isoflavones (median, 54 mg; aglycone equivalents) for 6 weeks to 12 months significantly reduced the frequency (combined fixed-effect and random effects model) of hot flashes by 20.6% (95% CI, -28.38 to -12.86; P < 0.00001) compared with placebo (heterogeneity P = 0.0003, I = 67%; random effects model). Meta-analysis also revealed that isoflavones significantly reduced hot flash severity by 26.2% (95% CI: -42.23 to -10.15, P = 0.001) compared with placebo (heterogeneity, P < 0.00001, I = 86%; random effects model). Isoflavone supplements providing more than 18.8 mg of genistein (the median for all studies) were more than twice as potent at reducing hot flash frequency than lower genistein supplements.

CONCLUSIONS

Soy isoflavone supplements, derived by extraction or chemical synthesis, are significantly more effective than placebo in reducing the frequency and severity of hot flashes. Additional studies are needed to further address the complex array of factors that may affect efficacy, such as dose, isoflavone form, baseline hot flash frequency, and treatment duration.

Effective and clinically meaningful non-hormonal hot flash therapies

Although many non-hormonal compounds have shown statistically significant benefit over placebo in hot flash randomized controlled trials (RCTs), these studies have varied considerably in basic methodology making it challenging to deduce which compounds have the greatest potential to provide clinically meaningful benefit. This review used evidence-based methodology closely mirroring the FDA and EMEA guidelines as a template to identify "well-designed" RCTs from which effective and clinically meaningful non-hormonal hot flash therapies could be identified. In addition, pertinent safety information was reviewed. Out of 3548 MEDLINE citations and abstracts, 51 well-designed hot flash RCTs were identified. From these trials, gabapentin, oxybutynin ER, desvenlafaxine, soy-derived isoflavones and black cohosh each showed a clinically meaningful treatment effect in at least 1 RCT. Among these 5 compounds, only gabapentin demonstrated consistent and statistically significant benefit over placebo in all of its well-designed RCTs. Desvenlafaxine, soy-derived isoflavones, and black cohosh demonstrated statistically significant benefit over placebo in 75%, 21%, and 17% of the well-designed RCTs for each compound, respectively. There was only 1 well-designed RCT using oxybutynin ER, which showed it to have a robust and clinically meaningful benefit. In terms of safety, there have been cardiovascular risks associated with desvenlafaxine use in postmenopausal women with hot flashes. The use of anticonvulsants, in general, has been associated with an absolute 0.21% increase in suicidal thoughts and behavior. Further research is needed with several of these nonhormonal compounds to replicate these findings and to also directly compare their efficacy and tolerability with those of hormone replacement therapy.

In utero and postnatal exposure to isoflavones results in a reduced responsivity of the mammary gland towards estradiol

SCOPE

Exposure scenarios during different stages of development of an organism are discussed to trigger adverse and beneficial effects of isoflavones (ISO). The aim of this study was to investigate how in utero and postnatal ISO exposure modulates the estrogen sensitivity of the mammary gland and to identify the underlying molecular mechanisms.

METHODS AND RESULTS

Therefore, rats were exposed to either ISO-free (IDD), ISO-rich (IRD) or genistein-rich diet (GRD), up to young adulthood. Proliferative activity (PCNA expression) in the mammary gland at different ages and the estrogen sensitivity of the mammary gland to estradiol (E₂) or genistein (GEN) in adult ovariectomized animals was determined and compared with different treatments. Treatment with E₂ resulted in a significant lower proliferative and estrogenic response of the mammary gland in IRD and GRD compared with IDD. This correlates to a change in the gene expression pattern and a decrease in the ratio of estrogen receptor alpha (ERα) beta (ERβ

CONCLUSIONS

Our results provide evidence that in utero and postnatal exposure to a diet rich in ISO but also to GEN reduces the sensitivity of the mammary gland toward estrogens and support the hypothesis that in utero and postnatal ISO exposure reduces the risk to develop breast cancer.

In vitro estrogenic activity of two major compounds from the stem bark of Erythrina lysistemon (Fabaceae)

Plant-derived estrogen-like compounds, so called phytoestrogens, are given much attention due to their potential therapeutic use. In our previous work the ethylacetate extract of Erythrina lysistemon stem bark showed estrogenic effects on cell culture systems and ovariectomized Wistar rats. Using classical chromatographic methods, two constituents of Erythrina lysistemon have been isolated, referred to here as compounds 1 (alpinumisoflavone) and 2 (abyssinone V-4'-methyl-ether), and their structures successfully determined using spectroscopic techniques. To test their binding affinity, the ligand binding assay has been used on estrogen α receptor, and estrogen β receptor. Furthermore, transactivation assay in stably or transiently transfected human osteosarcoma (U2OS-estrogen α receptor and estrogen β receptor) cells were used to examine their estrogenic activity. The regulations of some estrogen receptor target genes were also investigated. Both compounds bind to estrogen α and β receptors. They significantly increased luciferase activity in a dose-dependent manner and induced the endogenous estrogen receptor-estrogen response element (ERE) interaction in U2OS-estrogen α receptor and estrogen β receptor cells. In contrast, when co-treated with E2, compound 2 did not antagonize E2 activity in both systems whereas, 1 significantly suppressed E2 activity despite its low binding affinity to estrogen β receptor. This result suggests a non-competitive mechanism. Both compounds also altered the expression of estrogen receptor target genes such as growth regulation by estrogen in breast cancer 1 (GREB1) and Cyclin D1 in breast cells. These results suggest that compounds 1 and 2 endow estrogenic activity and may be the active principles of Erythrina lysistemon.

A critical view of the effects of phytoestrogens on hot flashes and breast cancer risk

The increased risk of breast cancer recently observed with some specific estro-progestin associations has raised concerns about the harmful effects of menopausal hormone replacement therapy (HRT). It has been proposed that phytoestrogens (PEs), which have a similar chemical structure to estrogens, could be used as HRT. The main selling points of these preparations concern the management of hot flashes and their potential beneficial effects on breast tissue. In this review, we will address the effects of PE on hot flashes and breast cancer risk as well as the questions raised on a chemical point of view. We conclude that the efficacy of a PE rich diet or nutritional supplements is not clearly established. The use of PE as an alternative for HRT cannot be advocated for now, due to insufficient and conflicting data on efficacy and safety. Moreover, due to the hormone dependence of breast cancer, PE use must be contraindicated in breast cancer survivors.

Soy extracts versus hormone therapy for reduction of menopausal hot flushes: indirect comparison

OBJECTIVE

The aim of this study was to make an indirect comparison of the results from meta-analyses that evaluated the severity of hot flushes in postmenopausal women exposed to hormone therapy (HT) or soy extracts.

METHODS

A systematic review and meta-analysis of HT and soy extracts related to the reduction of hot flushes in postmenopausal women versus the same control (placebo) were conducted. In addition, the combination of the overall results obtained from these two meta-analyses (indirect comparison) was adjusted to the common control (placebo).

RESULTS

The indirect standardized mean difference (SMD) obtained from the combination of both individual meta-analyses was calculated by using the following equation: SMD(indirect SOY vs HT) = SMD(soy) - SMD(HT), with a total indirect variance (var) equivalent to the following equation: var(total) = var(soy) + var(HT). These calculations yielded a point estimate of -0.84 (95% CI, -1.33 to -0.35) for the indirect SMD favorable to HT.

CONCLUSIONS

HT and soy interventions showed a significant difference in efficacy for the reduction of hot flushes in postmenopausal women when each treatment was compared with placebo. However, using indirect comparison, there is a statistically significant difference between HT and soy extracts in their effects on hot flushes.

The effect of soy-derived isoflavones over hot flushes, menopausal symptoms and mood in climacteric women with increased body mass index

BACKGROUND

Risk-benefit issues raised after the WHI have significantly increased the use of alternative treatments for the menopause. Despite this, data regarding the effect of soy isoflavones over mood and menopausal symptoms in high risk populations is still lacking.

OBJECTIVE

To evaluate the effect of soy derived isoflavones over hot flushes, menopausal symptoms and mood in climacteric women with increased body mass index (BMI).

METHODS

Fifty symptomatic climacteric women aged 40 to 59 with increased BMI (≥ 25) were recruited to receive oral 100 mg/day of soy derived isoflavones (Climasoy) for 3 months. Hot flushes (frequency/intensity), menopausal symptoms (Menopause Rating Scale [MRS]) and mood (Hamilton Depressive Rating Scale [HDRS]) were evaluated at baseline and at 90 days.

RESULTS

A total of 45 women completed the study. After 3 months of soy isoflavone supplementation hot flushes significantly decreased in percentage, number and severity (100% to 31.1%; 3.9 ± 2.3 to 0.4 ± 0.8 and 2.6 ± 0.9 to 0.4 ± 0.8, respectively, p < 0.001). MRS scores (total and for subscales) reflecting general menopausal symptoms also significantly decreased compared to baseline. Regarding mood, after three months total HDRS scores and the rate of women presenting depressed mood (scores ≥ 8) significantly decreased (16.3 ± 5.4 to 6.9 ± 5.2 and 93.3% to 28.9%, respectively, p < 0.05). There was no effect on blood pressure levels or BMI values after treatment.

CONCLUSION

In this high risk climacteric population, soy derived isoflavone treatment improved mood as well as vasomotor and general menopausal symptoms. More research is required to determine if the positive effect over mood is a direct or an indirect one through hot flush alleviation.

The soybean concentrated extract proliferates the vagina of adult rats

OBJECTIVE

The aim of this study was to evaluate changes induced on the vagina of ovariectomized rats after treatment with soybean concentrated extract or conjugated equine estrogens and the association of both drugs.

METHODS

We conducted an experimental study with 50 ovariectomized rats that were randomly divided into five equal groups of 10 animals: GI received vehicle, GII received soybean concentrated extract 46 mg/kg per day, GIII received soybean concentrated extract 120 mg/kg per day, GIV received conjugated equine estrogens 50 μg/kg per day, and GV received conjugated equine estrogens 50 μg/kg and soybean concentrated extract 46 mg/kg per day. The substances were administered by gavage during 21 consecutive days. After that, the animals were killed under anesthesia and the vagina was removed for histological and immunohistochemical analysis. Data were initially submitted to analysis of variance. Whenever a significant difference was detected, the study was complemented with the Tukey-Kramer test for multiple comparisons.

RESULTS

GII did not show any differences on the vaginal epithelium or collagen compared with GI. GIII presented an increase in vaginal epithelium and collagen amount. GIV had the highest amount of collagen and the signals of vaginal proliferation. GV did not show any additional effect compared with GIV.

CONCLUSIONS

Our data suggest that a high dose of isoflavone-rich soy extract may have positive effects on the vaginal structures of ovariectomized rats, but this action is less than that of estrogen treatment on vaginal thickness. In addition, soy extract may not block the estrogen effect on vaginal tissue.