Trifolium pratense isoflavones in the treatment of menopausal hot flushes: a systematic review and meta-analysis

Isoflavones obtained from red clover improve both dyslipidemia and menopausal symptoms in menopausal women: a prospective randomized placebo-controlled trial

OBJECTIVE

This study aimed to investigate the effects of red clover isoflavones on menopausal symptoms and the lipid profile in menopausal females.

METHODS

This study included postmenopausal women with dyslipidemia. The red clover group (n = 39) received 40 mg isoflavone red clover capsule twice daily for 6 months, while placebo (n = 36) was 40 mg starch capsule twice daily. Data were collected at baseline, 3 months and 6 months. The Menopause Rating Scale (MRS) was applied to calculate subdimension and total scores.

RESULTS

The two groups were similar in terms of age, MRS and lipid profile at baseline. In the red clover group, MRS scores decreased significantly at both 3 and 6 months. Similarly, total cholesterol, low-density lipoprotein cholesterol (LDL-C) and triglyceride levels decreased at both 3 months and 6 months. High-density lipoprotein cholesterol increased significantly from baseline to 3 months and 6 months. Except for LDL-C and MRS urogenital score at 3 months, the improvements were significantly in favor of red clover isoflavone treatment.

CONCLUSIONS

Red clover treatment for 3-6 months demonstrated significant improvements in lipid profiles and menopausal symptoms. While promising, further research is crucial to ascertain long-term safety and recommend the use of red clover isoflavones during menopause.

Deciphering Trifolium pratense L. holobiont reveals a microbiome resilient to future climate changes

The plant microbiome supports plant growth, fitness, and resistance against climate change. Trifolium pratense (red clover), an important forage legume crop, positively contributes to ecosystem sustainability. However, T. pratense is known to have limited adaptive ability toward climate change. Here, the T. pratense microbiomes (including both bacteria and fungi) of the rhizosphere and the root, shoot, and flower endospheres were comparatively examined using metabarcoding in a field located in Central Germany that mimics the climate conditions projected for the next 50-70 years in comparison with the current climate conditions. Additionally, the ecological functions and metabolic genes of the microbial communities colonizing each plant compartment were predicted using FUNGuild, FAPROTAX, and Tax4Fun annotation tools. Our results showed that the individual plant compartments were colonized by specific microbes. The bacterial and fungal community compositions of the belowground plant compartments did not vary under future climate conditions. However, future climate conditions slightly altered the relative abundances of specific fungal classes of the aboveground compartments. We predicted several microbial functional genes of the T. pratense microbiome involved in plant growth processes, such as biofertilization (nitrogen fixation, phosphorus solubilization, and siderophore biosynthesis) and biostimulation (phytohormone and auxin production). Our findings indicated that T. pratense microbiomes show a degree of resilience to future climate changes. Additionally, microbes inhabiting T. pratense may not only contribute to plant growth promotion but also to ecosystem sustainability.

Evaluation of Clinical Meaningfulness of Red Clover (Trifolium pratense L.) Extract to Relieve Hot Flushes and Menopausal Symptoms in Peri- and Post-Menopausal Women: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The meta-analysis presented in this article covered the efficacy of red clover isoflavones in relieving hot flushes and menopausal symptoms in perimenopausal and postmenopausal women. Studies were identified by MEDLINE (PubMed), Embase, and the Cochrane Library searches. The quality of the studies was evaluated according to Cochrane criteria. A meta-analysis of eight trials (ten comparisons) demonstrated a statistically significant reduction in the daily incidence of hot flushes in women receiving red clover compared to those receiving placebo: weighted mean difference (WMD—weighted mean difference) −1.73 hot flushes per day, 95% CI (confidence interval) −3.28 to −0.18; p = 0.0292. Due to 87.34% homogeneity, the performed analysis showed substantive difference in comparisons of postmenopausal women with ≥5 hot flushes per day, when the follow-up period was 12 weeks, with an isoflavone dose of ≥80 mg/day, and when the formulations contained a higher proportion of biochanin A. The meta-analysis of included studies assessing the effect of red clover isoflavone extract on menopausal symptoms showed a statistically moderate relationship with the reduction in the daily frequency of hot flushes. However, further well-designed studies are required to confirm the present findings and to finally determine the effects of red clover on the relief of flushing episodes.

Integrated Phytochemical Analysis Based on UPLC-MS and Network Pharmacology Approaches to Explore the Quality Control Markers for the Quality Assessment of Trifolium pratense L

Red clover consists of the overground parts and inflorescence of Trifolium pratense L., a leguminous plant belonging to the genus Trifolium. It is widely distributed worldwide and has long been used in traditional medicine. In this study, a combination approach using UPLC-MS and network pharmacology was applied to explore the quality control markers for the quality assessments of red clover. Firstly, UPLC-MS was used to identify the compounds in different parts of red clover. Twenty-eight compounds were totally identified. According to the traditional clinical efficacy of red clover, a compound-target-function network was constructed by network pharmacology to discover the main active compounds based on the identified compounds. Nine compounds of chlorogenic acid, daidzin, calycosin-7-O-β-d-glucoside, genistin, ononin, daidzein, genistein, formononetin, and biochanin A were filtrated and further confirmed in rat plasma in view of the blood-absorbed components taking effects. Finally, a novel method for simultaneously detecting the nine quality control markers was developed by UPLC-QQQ-MS in an effort to assess the quality of red clover. For all samples, the average contents of the nine compounds measured from high to low consist of formononetin, ononin, biochanin A, genistin, daidzin, calycosin-7-O-β-d-glucoside, genistein, daidzein, and chlorogenic acid. The samples from Gansu province showed the best quality in the three producing areas This study provides new strategies to explore the quality control markers and develops a novel method for the quality assessment of red clover.

Growth and Osteogenic Differentiation of Discarded Gingiva-Derived Mesenchymal Stem Cells on a Commercial Scaffold

BACKGROUND

In periodontal patients with jawbone resorption, the autologous bone graft is considered a "gold standard" procedure for the placing of dental prosthesis; however, this procedure is a costly intervention and poses the risk of clinical complications. Thanks to the use of adult mesenchymal stem cells, smart biomaterials, and active biomolecules, regenerative medicine and bone tissue engineering represent a valid alternative to the traditional procedures.

AIMS

In the past, mesenchymal stem cells isolated from periodontally compromised gingiva were considered a biological waste and discarded during surgical procedures. This study aims to test the osteoconductive activity of FISIOGRAFT Bone Granular® and Matriderm® collagen scaffolds on mesenchymal stem cells isolated from periodontally compromised gingiva as a low-cost and painless strategy of autologous bone tissue regeneration.

MATERIALS AND METHODS

We isolated human mesenchymal stem cells from 22 healthy and 26 periodontally compromised gingival biopsy tissues and confirmed the stem cell phenotype by doubling time assay, colony-forming unit assay, and expression of surface and nuclear mesenchymal stem cell markers, respectively by cytofluorimetry and real-time quantitative PCR. Healthy and periodontally compromised gingival mesenchymal stem cells were seeded on FISIOGRAFT Bone Granular® and Matriderm® scaffolds, and in vitro cell viability and bone differentiation were then evaluated.

RESULTS

Even though preliminary, the results demonstrate that FISIOGRAFT Bone Granular® is not suitable for in vitro growth and osteogenic differentiation of healthy and periodontally compromised mesenchymal stem cells, which, instead, are able to grow, homogeneously distribute, and bone differentiate in the Matriderm® collagen scaffold.

CONCLUSION

Matriderm® represents a biocompatible scaffold able to support the in vitro cell growth and osteodifferentiation ability of gingival mesenchymal stem cells isolated from waste gingiva, and could be employed to develop low-cost and painless strategy of autologous bone tissue regeneration.

Effects of red clover on perimenopausal and postmenopausal women's blood lipid profile: A meta-analysis

The study aimed to perform a systematic review with meta-analysis of randomized controlled trials (RCTs) to access the effects of red clover isoflavones on the blood lipid profile of both perimenopausal and postmenopausal women. PubMed, Web of Science, Scopus, SciELO, and Cochrane Library were searched for the terms 'red clover', 'Trifolium pratense', and 'randomized controlled trial' during November 2017. Summary measures were reported as weighted mean differences (WMD) with 95% confidence interval (CI). Fixed or random effects models were used for meta-analyses, according to heterogeneity. Risk of bias was measured with the Cochrane tool. Twelve RCTs (totalizing 1284 perimenopausal and postmenopausal women receiving red clover isoflavones for 4 weeks-18 months) resulted in a significant decrease in total cholesterol (WMD = -12.34 mg/dl; 95% CI: -18.21, -6.48), low-density lipoprotein cholesterol (WMD = -10.61 mg/dl; 95% CI: -15.51, -5.72), and triglycerides (WMD = -10.18 mg/dl; 95% CI: -16.23, -4.13) together with a significant increase in high-density lipoprotein cholesterol (WMD = 1.60 mg/dl; 95% CI: 0.17, 3.03). In conclusion, the results demonstrate that the ingestion of red clover may have a beneficial effect on the lipid profile of perimenopausal and postmenopausal women.

A Nutraceutical Approach to Menopausal Complaints

The menopausal transition, or perimenopause, is characterized by menstrual irregularities, vasomotor symptoms, sleep disturbances, mood symptoms, and urogenital tract atrophy. These changes can also affect the quality of life and one’s self-esteem. Hormone replacement therapy (HRT) is considered the best option to achieve therapeutic relief of different menopausal symptoms but is usually restricted to moderate or severe symptoms. Moreover, many women refuse HRT for a variety of reasons concerning the fear of cancer and other adverse effects. According to these considerations, new topics are emerging: Dissatisfaction with drug costs and conventional healthcare, desire for personalized medicines, and the public perception that “natural is good”. In this context, nonhormonal therapies are mostly evolving, and it is not unusual that women often request a “natural” approach for their symptoms. The aim of this study is to investigate nonhormonal therapies that have been identified to reduce the menopausal symptoms.

The Therapeutic Potential and Molecular Mechanism of Isoflavone Extract against Psoriasis

Psoriasis is a common inflammatory disease. It affects 1-3% of the population worldwide and is associated with increasing medical costs every year. Typical psoriatic skin lesions are reddish, thick, scaly plaques that can occur on multiple skin sites all over the body. Topical application of imiquimod (IMQ), a toll-like receptor (TLR)7 agonist and potent immune system activator, can induce and exacerbate psoriasis. Previous studies have demonstrated that isoflavone extract has an antioxidant effect which may help decrease inflammation and inflammatory pain. Through in vivo studies in mice, we found that the topical application to the shaved back and right ear of mice of isoflavone extract prior to IMQ treatment significantly decreased trans-epidermal water loss (TEWL), erythema, blood flow speed, and ear thickness, while it increased surface skin hydration, and attenuated epidermal hyperplasia and inflammatory cell infiltration. Through in vitro experiments, we found that isoflavone extract can reduce IL-22, IL-17A, and TNF-α-induced MAPK, NF-κB, and JAK-STAT activation in normal human epidermal keratinocytes. At the mRNA level, we determined that isoflavone extract attenuated the increased response of the TNF-α-, IL-17A-, and IL-22- related pathways. These results indicate that isoflavone extract has great potential as an anti-psoriatic agent and in the treatment of other inflammatory skin diseases.

Therapeutic Potential of Temperate Forage Legumes: A Review

The discovery of bioactive molecules from botanical sources is an expanding field, preferentially oriented to plants having a tradition of use in medicine and providing high yields and availability. Temperate forage legumes are Fabaceae species that include worldwide-important crops. These plants possess therapeutic virtues that have not only been used in veterinary and folk medicine, but have also attracted the interest of official medicine. We have examined here Medicago sativa (alfalfa), Trifolium pratense and T. repens (clovers), Melilotus albus and M. officinalis (sweet clovers), Lotus corniculatus (birdsfoot trefoil), Onobrychis viciifolia (sainfoin), Lespedeza capitata (roundhead lespedeza), and Galega officinalis (goat's rue). The phytochemical complexes of these species contain secondary metabolites whose pharmacological potentials deserve investigation. Major classes of compounds include alkaloids and amines, cyanogenic glycosides, flavonoids, coumarins, condensed tannins, and saponins. Some of these phytochemicals have been related to antihypercholesterolemia, antidiabetic, antimenopause, anti-inflammatory, antiedema, anthelmintic, and kidney protective effects. Two widely prescribed drugs have been developed starting from temperate forage legumes, namely, the antithrombotic warfarin, inspired from sweet clover's coumarin, and the antidiabetic metformin, a derivative of sainfoin's guanidine. Available evidence suggests that temperate forage legumes are a potentially important resource for the extraction of active principles to be used as nutraceuticals and pharmaceuticals.

Effects of a standardised extract of Trifolium pratense (Promensil) at a dosage of 80mg in the treatment of menopausal hot flushes: A systematic review and meta-analysis

OBJECTIVE

To critically assess the evidence for a specific standardised extract of Trifolium pratense isoflavones (Promensil) at a dosage of 80mg/day in the treatment of menopausal hot flushes.

DATA SOURCES

Systematic literature searches were performed in Medline, Scopus, CINAHL Plus, Cochrane, AMED and InforRMIT and citations obtained from 1996 to March 2016. Reference lists were checked; corresponding authors contacted and the grey literature searched for additional publications.

REVIEW METHODS

Studies were selected according to predefined inclusion and exclusion criteria. All randomised clinical trials of a specific standardised extract of Trifolium pratense isoflavones (Promensil) used as a mono-component at 80mg/day and measuring vasomotor symptoms were included. The data extraction and quality assessment were performed independently by one reviewer and validated by a second with any disagreements being settled by discussion. Weighted mean differences and 95% confidence intervals were calculated for continuous data using the fixed-effects model.

RESULTS

Twenty potentially relevant papers were identified, with only five studies meeting the inclusion criteria. The meta-analysis demonstrated a statistical and clinically relevant reduction in hot flush frequency in the active treatment group compared to placebo. Weighted mean difference 3.63 hot flushes per day: [95% CI 2.70-4.56]; p˂0.00001). Due to a lack of homogeneity a priori defined sub-group analyses were performed demonstrating a substantive difference between cross-over and parallel-arm clinical trial designs.

CONCLUSION

There is evidence for a statistical and clinically significant benefit for using a specific standardised extract of red clover isoflavones (Promensil) at 80mg/day for treating hot flushes in menopausal women across the 3 studies included in the meta-analysis. The preparation was safe over the short-term duration of the studies (3 months).

Novel combination of sorafenib and biochanin-A synergistically enhances the anti-proliferative and pro-apoptotic effects on hepatocellular carcinoma cells

Sorafenib (SOR) is the first-line treatment for hepatocellular carcinoma (HCC). However, its use is hindered by the recently expressed safety concerns. One approach for reducing SOR toxicity is to use lower doses in combination with other less toxic agents. Biochanin-A (Bio-A), a promising isoflavone, showed selective toxicity to liver cancer cells. We postulated that combining SOR and Bio-A could be synergistically toxic towards HCC cells. We further evaluated the underlying mechanism. Cytotoxicity assay was performed to determine the IC₅₀ of Bio-A and SOR in HepG2, SNU-449 and Huh-7 cells. Then, combination index in HepG2 was evaluated using Calcusyn showing that the concurrent treatment with lower concentrations of SOR and Bio-A synergistically inhibited cell growth. Our combination induced significant arrest in pre-G and G0/G1 cell cycle phases and decrease in cyclin D1 protein level. Concomitantly, SOR/Bio-A reduced Bcl-2/Bax ratio. Furthermore, this co-treatment significantly increased caspase-3 & -9 apoptotic markers, while decreased anti-apoptotic and proliferative markers; survivin and Ki-67, respectively. Active caspase-3 in HepG2, SNU-449 and Huh-7 confirmed our synergism hypothesis. This study introduces a novel combination, where Bio-A synergistically enhanced the anti-proliferative and apoptotic effects of SOR in HCC cells, which could serve as a potential effective regimen for treatment.

Trifolium species - the latest findings on chemical profile, ethnomedicinal use and pharmacological properties

OBJECTIVES

Clovers (Trifolium, Fabaceae) have a long history of use in folk medicine. Furthermore, during last 3 years, a considerable growth in scientific interest in these plants has been observed. This article summarizes and critically reviews an over 3-year progress of knowledge of ethnomedicinal use, phytochemical profile, physiological effects and possible therapeutic action of various clover species. It contains the latest literature (over 80 papers), originated from international databases (MEDLINE/PubMed, Science Direct/Elsevier, Springer Link, Wiley Online Library) and reports from other international and local scientific periodicals.

KEY FINDINGS

Traditional uses of T. pratense and T. repens have been confirmed, while the folk medicine recommendations for administration of other clovers such as T. burchellianum, T. fragiferum, T. hybridum, T. minus and T. purpureum were reported for the first time. Furthermore, several other clover species were also investigated in terms of their antioxidant, antimicrobial and phytoestrogenic effects for the first time. Only T. alexandrinum, T. pratense and T. medium were examined in animal studies.

SUMMARY

Besides T. pratense, other clovers may be a rich source of bioactive phytochemicals. However, in contradiction to red clover, the therapeutic use of other clovers is still limited by the lack of in-vivo evidence.

A phytochemical and computational study on flavonoids isolated from Trifolium resupinatum L. and their novel hepatoprotective activity

Plants from the genus Trifolium have been utilized in the treatment of chronic diseases by many cultures.

Red clover for treatment of hot flashes and menopausal symptoms: A systematic review and meta-analysis

This study evaluated the efficacy of red clover to relieve hot flashes and menopausal symptoms in peri/postmenopausal women. Electronic databases (MEDLINE, Scopus and the Cochrane Library) were searched. The mean frequency of hot flashes in red clover groups was lower compared with that in the control groups (close to statistical significance). Difference in means (MD) of hot flashes frequency was - 1.99 (- 4.12-0.139; p = 0.067; heterogeneity P > 0.01; I(2) = 94.93%; Random effect model). Subjective (vaginal dryness) and objective (maturation value) symptoms of vaginal atrophy showed a significant improvement with 80-mg dose of red clover. Red clover showed less therapeutic effect on psychology status, sexual problems and sleeping disorders. Red clover consumption may decrease frequency of hot flashes, especially in women with severe hot flashes (≥ 5 per day). Red clover may reduce other menopausal symptoms. Further trials are needed to confirm the current systematic review findings.

Free radical scavenging actions of three Trifolium species in the protection of blood plasma antioxidant capacity in vitro

CONTEXT

Three clover [Trifolium L. (Leguminosae)] species were selected on the basis of data from traditional medicine, phytochemical profiles, and agricultural significance.

OBJECTIVE

The in vitro evaluations of free radical scavenging properties, ferric reducing abilities, and antioxidant effects of extracts from T. pratense L. (crude extract and phenolic fraction), T. pallidum L., and T. scabrum L. (phenolic fractions) were performed.

MATERIALS AND METHODS

Activities of the Trifolium extracts were determined at their final concentrations of 1.5-50 µg/ml. Free radical scavenging properties of methanol extract solutions were estimated by the reduction of DPPH(•) and ABTS(•) radicals. Measurements of the total antioxidant capacity (TAC) were carried out to assess the antioxidant activities of the extracts in human blood plasma under conditions of oxidative stress, induced by 200 μM peroxynitrite.

RESULTS

The phenolic fraction of T. pratense displayed the strongest ABTS(•) and DPPH(•) radical scavenging effects (EC50 value of 21.69 and 12.27 µg/ml, respectively). The EC50 value for T. pallidum extract attained 29.77 and 30.06 µg/ml. The two remaining extracts were less potent scavengers (EC50 value higher than 50 µg/ml). Similar differences were obtained during evaluation of the ferric reducing abilities. Analysis of antioxidant properties of the extracts in blood plasma did not provide such evident differences in their actions, however, it indicated that the T. pratense phenolic fraction displayed the strongest effect.

CONCLUSIONS

The examined Trifolium extracts partly protected blood plasma and enhanced its non-enzymatic antioxidant defense against harmful action of peroxynitrite in vitro.

A molecular docking study of phytochemical estrogen mimics from dietary herbal supplements

PURPOSE

The purpose of this study is to use a molecular docking approach to identify potential estrogen mimics or anti-estrogens in phytochemicals found in popular dietary herbal supplements.

METHODS

In this study, 568 phytochemicals found in 17 of the most popular herbal supplements sold in the United States were built and docked with two isoforms of the estrogen receptor, ERα and ERβ (a total of 27 different protein crystal structures).

RESULTS

The docking results revealed six strongly docking compounds in Echinacea, three from milk thistle (Silybum marianum), three from Gingko biloba, one from Sambucus nigra, none from maca (Lepidium meyenii), five from chaste tree (Vitex agnus-castus), two from fenugreek (Trigonella foenum-graecum), and two from Rhodiola rosea. Notably, of the most popular herbal supplements for women, there were numerous compounds that docked strongly with the estrogen receptor: Licorice (Glycyrrhiza glabra) had a total of 26 compounds strongly docking to the estrogen receptor, 15 with wild yam (Dioscorea villosa), 11 from black cohosh (Actaea racemosa), eight from muira puama (Ptychopetalum olacoides or P. uncinatum), eight from red clover (Trifolium pratense), three from damiana (Turnera aphrodisiaca or T. diffusa), and three from dong quai (Angelica sinensis). Of possible concern were the compounds from men's herbal supplements that exhibited strong docking to the estrogen receptor: Gingko biloba had three compounds, gotu kola (Centella asiatica) had two, muira puama (Ptychopetalum olacoides or P. uncinatum) had eight, and Tribulus terrestris had six compounds.

CONCLUSIONS

This molecular docking study has revealed that almost all popular herbal supplements contain phytochemical components that may bind to the human estrogen receptor and exhibit selective estrogen receptor modulation. As such, these herbal supplements may cause unwanted side effects related to estrogenic activity.

Biological activity of clovers - free radical scavenging ability and antioxidant action of six Trifolium species

CONTEXT

Clovers were chosen on the basis of traditional medicine recommendations, agricultural value, or available information on their promising chemical profiles.

OBJECTIVE

This study evaluates and compares free radical scavenging and antioxidant properties of six clover species: Trifolium alexandrinum L. (Leguminosae), Trifolium fragiferum L., Trifolium hybridum L., Trifolium incarnatum L., Trifolium resupinatum var. majus Boiss., and Trifolium resupinatum var. resupinatum L.

MATERIALS AND METHODS

Free radical scavenging activity of the extracts (1.5-50 µg/ml) was estimated by reduction of 1,1-diphenyl-2-picrylhydrazyl (DPPH(•)) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic) acid (ABTS(•)) radicals. The Trifolium extract effects on total antioxidant capacity of blood plasma were determined by the reduction of ABTS(•+) and DPPH(•) radicals, as well as with the use of the ferric reducing ability of plasma (FRAP) assay.

RESULTS

The UPLC analysis of chemical profiles of the examined extracts showed the presence of three or four groups of phenolic substances, including phenolic acids, clovamides, isoflavones, and other flavonoids. The measurements of free radical scavenging and ferric reducing ability of the examined clover extracts revealed the strongest effect for T. alexandrinum. Furthermore, antioxidant activity assays in human plasma have shown protective effects of all extracts against peroxynitrite-induced reduction of total antioxidant capacity.

CONCLUSIONS

Trifolium plants may be a rich source of bioactive substances with antioxidant properties. The examined extracts displayed free radical scavenging action and partly protected blood plasma against peroxynitrite-induced oxidative stress; however, the beneficial effects of T. alexandrinum and T. incarnatum seem to be slightly higher.

Red clover extract for alleviating hot flushes in postmenopausal women: a meta-analysis

The safety and efficacy of red clover for alleviating menopausal hot flushes are yet to be established. The aim of this meta-analysis was to generate evidence from published literature regarding red clover as a treatment option for menopausal hot flushes. The results showed that red clover when compared to placebo was effective in reducing menopausal hot flushes when administered for 3-4 months (MD=-1.34, 95% CI=-1.90 to -0.77, p<0.00001), but their effect did not persist at 12 months (MD=0.89, 95% CI=-0.07 to 1.85, p=0.07).

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.

Biochanin a promotes osteogenic but inhibits adipogenic differentiation: evidence with primary adipose-derived stem cells

Biochanin A has promising effects on bone formation in vivo, although the underlying mechanism remains unclear yet. This study therefore aimed to investigate whether biochanin A regulates osteogenic and adipogenic differentiation using primary adipose-derived stem cells. The effects of biochanin A (at a physiologically relevant concentration of 0.1-1 μM) were assessed in vitro using various approaches, including Oil red O staining, Nile red staining, alizarin red S staining, alkaline phosphatase (ALP) activity, flow cytometry, RT-PCR, and western blotting. The results showed that biochanin A significantly suppressed adipocyte differentiation, as demonstrated by the inhibition of cytoplasmic lipid droplet accumulation, along with the inhibition of peroxisome proliferator-activated receptor gamma (PPAR γ ), lipoprotein lipase (LPL), and leptin and osteopontin (OPN) mRNA expression, in a dose-dependent manner. On the other hand, treatment of cells with 0.3 μM biochanin A increased the mineralization and ALP activity, and stimulated the expression of the osteogenic marker genes ALP and osteocalcin (OCN). Furthermore, biochanin A induced the expression of runt-related transcription factor 2 (Runx2), osteoprotegerin (OPG), and Ras homolog gene family, member A (RhoA) proteins. These observations suggest that biochanin A prevents adipogenesis, enhances osteoblast differentiation in mesenchymal stem cells, and has beneficial regulatory effects in bone formation.

Antioxidative effects of extracts from Trifolium species on blood platelets exposed to oxidative stress

Clovers (Trifolium) may possess a significant therapeutic potential, but the effects of compounds from these plants on blood platelets and haemostasis have been poorly recognized. The present study was designed to evaluate the antioxidative action of extracts from three species of clovers: Trifolium pratense, Trifolium pallidum and Trifolium scabrum in the protection of human blood platelets in vitro. Platelet suspensions were pre-incubated with crude extract and phenolic fraction of T. pratense or phenolic fractions of T. scabrum and T. pallidum, at the final concentrations of 0.5-50 μg/ml. Then, for the induction of oxidative stress, 100 μM peroxynitrite was added. The antioxidative activity of plant extracts was assessed by measurements of the level of 3-nitrotyrosine, thiol groups and lipid peroxidation products (hydroperoxides and thiobarbituric acid-reactive substances). Despite the significant differences in the composition of the investigated extracts, we observed antioxidative effects of all used mixtures. The presence of Trifolium extracts considerably reduced the peroxynitrite-mediated modifications of proteins and diminished peroxidation of lipids in platelets. Our results indicate on a strong antioxidative activity of the tested extracts-statistically significant effects were found even for the lowest concentrations (0.5 μg/ml) of all extracts. This action may be useful in the protection of blood components, very susceptible to oxidative modifications. The obtained results suggest that the examined clovers are a promising source of compounds, valuable for the protection against oxidative stress-induced damage to blood platelets.

Effects of Extracts from Trifolium medium L. and Trifolium pratense L. on Development of Estrogen Deficiency-Induced Osteoporosis in Rats

Some plant species belonging to Trifolium L. genus are a source of isoflavones considered to exert phytoestrogenic activities. The aim of the present study was to examine the effects of standardized extract obtained from aerial parts of Trifolium medium L., in comparison with the extract of Trifolium pratense L., on the development of estrogen deficiency-induced osteoporosis in rats. Both Trifolium extracts, at doses corresponding to 10 and 20 mg/kg of isoflavone aglycones daily, or estradiol (0.2 mg/kg daily), were administered orally to ovariectomized (OVX) rats for 4 weeks. Serum bone turnover markers, bone mass, mineralization, and mechanical properties were studied. In OVX control rats, mechanical properties of the tibial metaphysis and femoral neck were strongly worsened in comparison with sham-operated control rats, and those of femoral diaphysis were unaffected. Estradiol counteracted the worsening of the tibial strength and increases in bone turnover markers. Both extracts significantly increased the strength of the femoral diaphysis and calcium and phosphorus content in the bone mineral, but only T. pratense extract increased the strength of the tibial metaphysis. In conclusion, effects of both Trifolium extracts differed from those of estradiol. It is possible that other than isoflavone extract constituents contributed to their skeletal effects.

Trifolium species-derived substances and extracts--biological activity and prospects for medicinal applications

BACKGROUND

Despite of the fact that clovers (family: Fabaceae; genus: Trifolium) have been known for many centuries as important forage plants and valuable herbs in folk medicine, their phytochemical characteristics and biological activity remain only partly established.

AIM OF THE STUDY

The presentation of the current knowledge of physiological effects, therapeutic action, new trends in the investigation of Trifolium plants and suggestions for the future applications of these herbs in therapy of various disorders.

METHODS

A critical review of literature on the biological activity of Trifolium plants, with the indication on important gaps, was performed. The compilation of existing information on physiological effects and medicinal value of clovers, derived from both traditional medicine recommendations and scientific reports, is presented.

RESULTS

The available data indicate on the abundance of biologically active substances in Trifolium plants, including numerous flavonoids, saponins, clovamides and phenolic acids. The best known clover - Trifolium pratense L. (red clover) - is used for the production of herbal medicines, an alternative to the conventional hormonal replacement therapy. The biological activity and potential therapeutic effects of other Trifolium species have gained a considerable scientific interest; extracts obtained from various clovers have been shown to possess antioxidative and antiinflammatory activities, inhibiting angiogenesis and displaying anti-cancer properties.

CONCLUSIONS

Clovers other than T. pratense also seem to be a promising source of valuable phytochemicals, such as isoflavones and various flavonoids. However, the therapeutic use of these Trifolium species is significantly limited by the lack of clinical evidence; thus further studies are needed.

The effect of red clover isoflavone supplementation over vasomotor and menopausal symptoms in postmenopausal women

OBJECTIVE

To evaluate the effect of red clover isoflavone supplementation over vasomotor and overall menopausal symptoms in postmenopausal women.

METHODS

One hundred and nine postmenopausal women aged 40 or more were assigned to randomly receive either two daily capsules of the active compound (80 mg red clover isoflavones, Group A) or placebo of equal appearance (Group B) for a 90-day period. After a washout period of 7 days, medication was crossed over and taken for 90 days more. Daily hot flush and night sweat frequency and overall menopausal symptom intensity (Kupperman Index) were measured at baseline, 90, 97 and 187 days.

RESULTS

Daily hot flush/night sweat frequency and Kupperman Index values were similar in both studied groups at baseline. All indices significantly decreased after red clover phase in Group A, corresponding, respectively to a 73.5%, 72.2% and 75.4% average decrement. These decrements were significantly higher than those observed for Group B after placebo phase (8.2%, 0.9% and 6.7% respectively). In Group A, after washout and placebo phases all values significantly increased. In Group B, all indices remained similar after placebo and washout phases, however significantly dropping after red clover treatment. These values were also significantly lower than those observed in Group A after placebo phase. No side effects were encountered after treatment with the active compound or placebo.

CONCLUSION

Red clover isoflavone supplementation was more effective than placebo in reducing daily vasomotor frequency and overall menopausal intensity in postmenopausal women.

Taking an integrated approach: managing women with phytoestrogens

An integrated approach can be employed when counselling women about menopausal management options, where lifestyle, complementary therapies and hormone replacement therapy (HRT) are discussed. Women might opt to use an alternative approach to HRT for a variety of reasons, e.g. fear of side-effects and risks or contraindications to HRT. There are many choices of dietary and herbal approaches for menopausal symptoms, which essentially divide into food supplements and herbal medicines. The choice can often be overwhelming and confusing for the woman. Of concern, the evidence for efficacy and safety of some of these complementary therapies can be extremely limited or non-existent. In order to enable women to make a fully informed choice, it is important that, when a recommendation is made regarding a specific complementary therapy, it should focus on preparations for which a significant dataset exists for efficacy and safety and in which there is ongoing research and development. One of the most extensively studied food supplements has been the phytoestrogenic preparation containing red clover isoflavones. There have been six randomized trials thus far studying the impact on vasomotor symptoms, three of which have shown a significant benefit compared to placebo. There are also data from small randomized and observational trials showing positive outcomes for surrogate markers of osteoporosis and cardiovascular disease. A recent study using validated depression scales has shown that women using red clover isoflavones may also derive psychological benefits. Safety data are reassuring for the endometrium and breast, although further studies would be welcome, particularly in women with significant medical risks.

Effect of Red Clover Isoflavones over Skin, Appendages, and Mucosal Status in Postmenopausal Women

Objective. Evaluate in postmenopausal women the effect of red clover extract (RCE) isoflavones over subjective status of skin, appendages, and several mucosal sites. Method. Postmenopausal women (n = 109) were randomly assigned to receive either two daily capsules of the active compound (80 mg RCE, Group A) or placebo of equal appearance (Group B) for a 90-day period. After a washout period of 7 days, medication was crossed over and taken for 90 days more. Subjective improvement of skin, appendages, and several mucosal site status was assessed for each studied group at 90 and 187 days using a visual analogue scale (VAS). In addition, libido, tiredness, and urinary, sleep, and mood complaints were also evaluated. Results. Women after RCE intervention (both groups) reported better subjective improvement of scalp hair and skin status, libido, mood, sleep, and tiredness. Improvement of urinary complaints, nail, body hair, and mucosa (oral, nasal, and ocular) status did not differ between treatment phases (intra- and intergroup). Overall satisfaction with treatment was reported higher after RCE intervention (both groups) as compared to placebo. Conclusion. RCE supplementation exerted a subject improvement of scalp hair and skin status as well as libido, mood, sleep, and tiredness in postmenopausal women.

Evaluation of the estrogenic effects of dietary perinatal Trifolium pratense

This study was designed to investigate the potential estrogenic effects of perinatal dietary phytoestrogens on the rat uterus. Pregnant rats were divided to three groups provided the following diets: (1) rat chow, (2) rat chow with 7.5% Trifolium (T.) pratense, or (3) rat chow supplemented with 17β-estradiol (0.5 mg/kg). The dams in each group were kept on the same diet during pregnancy and lactation. Female offspring were euthanized on day 21 at which time body and organ weights were recorded and tissue samples were taken for histology. Immunohistochemistry was performed to detect estrogen receptor alpha (ERα) and progesterone receptor (PR) levels. Our results revealed estrogen-like biological effects of perinatal T. pratense exposure. Relative uterus and ovary weights in the experimental groups were increased compared to control. The number of uterine glands and luminal epithelium heights were also increased. However, there were no statistically significant changes detected in the immunostaining intensity of ERα and PR between the groups.

Risks and benefits of dietary isoflavones for cancer

A high intake of fruits and vegetables is associated with a lower risk of cancer. In this context, considerable attention is paid to Asian populations who consume high amounts of soy and soy-derived isoflavones, and have a lower risk for several cancer types such as breast and prostate cancers than populations in Western countries. Hence, interest focuses on soyfoods, soy products, and soy ingredients such as isoflavones with regard to their possible beneficial effects that were observed in numerous experiments and studies. The outcomes of the studies are not always conclusive, are often contradictory depending on the experimental conditions, and are, therefore, difficult to interpret. Isoflavone research revealed not only beneficial but also adverse effects, for instance, on the reproductive system. This is also the case with tumor-promoting effects on, for example, breast tissue. Isoflavone extracts and supplements are often used for the treatment of menopausal symptoms and for the prevention of age-associated conditions such as cardiovascular diseases and osteoporosis in postmenopausal women. In relation to this, questions about the effectiveness and safety of isoflavones have to be clarified. Moreover, there are concerns about the maternal consumption of isoflavones due to the development of leukemia in infants. In contrast, men may benefit from the intake of isoflavones with regard to reducing the risk of prostate cancer. Therefore, this review examines the risks but also the benefits of isoflavones with regard to various kinds of cancer, which can be derived from animal and human studies as well as from in vitro experiments.

Clovamide-rich extract from Trifolium pallidum reduces oxidative stress-induced damage to blood platelets and plasma

Numerous plants (including clovers) have been widely used in folk medicine for the treatment of different disorders. This in vitro study was designed to examine the antioxidative effects of the clovamide-rich fraction, obtained from aerial parts of Trifolium pallidum, in the protection of blood platelets and plasma against the nitrative and oxidative damage, caused by peroxynitrite (ONOO(-)). Carbonyl groups and 3-nitrotyrosine in blood platelet and plasma proteins were determined by ELISA tests. Thiol groups level was estimated by using 5,5'-dithio-bis(2-nitro-benzoic acid, DTNB). Plasma lipid peroxidation was measured spectrophotometrically as the production of thiobarbituric acid reactive substances. The results from our work indicate that clovamide-rich T. pallidum extract may reveal the protective properties in the prevention against oxidative stress. The presence of clovamide-rich T. pallidum extract (12.5-100 μg/ml) partly inhibited ONOO(-)-mediated protein carbonylation and nitration. All the used concentrations of T. pallidum extract reduced lipid peroxidation in plasma. The antioxidative action of the tested extract in the protection of blood platelet lipids was less effective; the extract at the lowest final concentration (12.5 μg/ml) had no protective effect against lipid peroxidation. The present results indicate that the extract from T. pallidum is likely to be a source of compounds with the antioxidative properties, useful in the prevention against the oxidative stress-related diseases.

Safety and efficacy of black cohosh and red clover for the management of vasomotor symptoms: a randomized controlled trial

OBJECTIVE

The aim of this study was to evaluate the safety and efficacy of black cohosh and red clover compared with placebo for the relief of menopausal vasomotor symptoms.

METHODS

This study was a randomized, four-arm, double-blind clinical trial of standardized black cohosh, red clover, placebo, and 0.625 mg conjugated equine estrogens plus 2.5 mg medroxyprogesterone acetate (CEE/MPA; n = 89). Primary outcome measures were reduction in vasomotor symptoms (hot flashes and night sweats) by black cohosh and red clover compared with placebo; secondary outcomes included safety evaluation, reduction of somatic symptoms, relief of sexual dysfunction, and overall improvement in quality of life.

RESULTS

Reductions in number of vasomotor symptoms after a 12-month intervention were as follows: black cohosh (34%), red clover (57%), placebo (63%), and CEE/MPA (94%), with only CEE/MPA differing significantly from placebo. Black cohosh and red clover did not significantly reduce the frequency of vasomotor symptoms as compared with placebo. Secondary measures indicated that both botanicals were safe as administered. In general, there were no improvements in other menopausal symptoms.

CONCLUSIONS

Compared with placebo, black cohosh and red clover did not reduce the number of vasomotor symptoms. Safety monitoring indicated that chemically and biologically standardized extracts of black cohosh and red clover were safe during daily administration for 12 months.

Improvement of postmenopausal depressive and anxiety symptoms after treatment with isoflavones derived from red clover extracts

OBJECTIVE

To evaluate the effect of isoflavones derived from red clover extracts (MF11RCE) over anxiety and depressive symptoms among postmenopausal women.

METHODS

One hundred and nine postmenopausal women aged 40 or more were randomly assigned to receive two daily capsules of MF11RCE (80mg red clover isoflavones, Group A) or placebo of equal appearance (Group B) for a 90-day period. After a washout period of 7 days, medication was crossed over and taken for 90 days more. Anxiety and depressive symptoms were measured at baseline, 90 and 187 days with the Hospital Anxiety and Depression Scale (HADS) and Zung's Self Rating Depression Scale (SDS).

RESULTS

After receiving the MF11RCE compound the total HADS (anxiety and depression subscale scores also) and the total SDS scores decreased significantly. This effect was equivalent to a 76.9% reduction in the total HADS score (76% for anxiety and 78.3% for depression) and an 80.6% reduction in the total SDS score. After placebo, total HADS (anxiety and depression subscale also) and total SDS scores also decreased significantly in comparison to baseline but only equivalent to an average 21.7% decline.

CONCLUSION

Red clover derived isoflavones (MF11RCE) were effective in reducing depressive and anxiety symptoms among postmenopausal women.

Efficacy of isoflavones in relieving vasomotor menopausal symptoms - A systematic review

This review assessed the efficacy of isoflavone supplements to reduce vasomotor symptoms in menopausal women by reviewing all published randomized controlled trials. Systematic literature searches were carried out in 70 databases. Randomized and placebo controlled studies were included if they investigated the treatment of isoflavone supplements derived from soy or red clover on vasomotor symptoms in peri- or postmenopausal women for at least 12 wks. Data were analyzed concerning outcome and methodological quality of the study. Twenty-three trials met the inclusion criteria, thereof 17 investigated soy isoflavones and 6 red clover isoflavones. Without exception, selected trials examining the effect of red clover isoflavones were already assessed in several meta-analyses and were therefore excluded from this evaluation. As the soy isoflavone studies were very heterogeneous concerning interventions and outcome measures, meta-analysis could not be performed and trials were systematically assessed in a structured approach. Included soy isoflavone studies had numerous quality deficiencies and did not consistently show a reduction of flushes after treatment with soy isoflavones. Therefore, there is no conclusive evidence, but only some indication of a benefit of soy isoflavones on hot flush frequency or severity.

Research on antioxidant effects and estrogenic effect of formononetin from Trifolium pratense (red clover)

Antioxidant and estrogenic effects of formononetin on ovariectomized mice have been investigated in the present study. The adult female Kunming mice were divided into 5 groups: sham-operated group, ovariectomized group, stilbestrol replacement therapy group (0.20 mg/kg day), low-dose formononetin group (0.05 g/kg day) and high-dose formononetin group (0.5 g/kg day). The mice in the latter 4 groups were ovariectomized. The drug was given by oral administration for 6 months. Estrogenic effect was determined by the change of uterine weight, and oxidant effects were determined by the content of SOD, GSH-Px, CAT and MDA. The intake of formononetin increased the uterine weight of the mice significantly as well as the content of SOD, GSH-Px, CAT, and reduced MDA in body. Formononetin had obvious antioxidant effects and estrogenic effect, and the estrogenic effect was not dosage-related.

Trifolium L.--a review on its phytochemical and pharmacological profile

Plants from the genus Trifolium have been used in traditional medicine by many cultures. In Turkish folk medicine, for example, some Trifolium species are used for their expectorant, analgesic, antiseptic properties and also to treat rheumatic aches. Some species are also grown as pasture crops for animals in the Mediterranean. The high quercetin concentration and soyasaponin occurrence make the seeds of some Trifolium species a potential source of health beneficial phytochemicals for use in human nutrition. However, Trifolium pratense has also gained popularity due to research into its use for the treatment for menopausal symptoms. This paper provides an overview of the phytochemical and pharmacological profile of Trifolium species.

Effects of soy protein and isoflavones on circulating hormone concentrations in pre- and post-menopausal women: a systematic review and meta-analysis

BACKGROUND

Hormonal effects of soy and isoflavones have been investigated in numerous trials with equivocal findings. We aimed to systematically assess the effects of soy and isoflavones on circulating estrogen and other hormones in pre- and post-menopausal women.

METHODS

The Cochrane Library, MEDLINE and EMBASE (plus reviews and experts) were searched to December 2007. Inclusion of randomized or residential crossover trials of soy or isoflavones for 4 or more weeks on estrogens, SHBG, FSH, LH, progesterone and thyroid hormones in women was assessed independently in duplicate. Six percent of papers assessed were included. Data concerning participants, interventions, outcomes, potential effect modifiers and trial quality characteristics were extracted independently in duplicate.

RESULTS

Forty-seven studies (11 of pre-, 35 of post- and 1 of perimenopausal women) were included. In premenopausal women, meta-analysis suggested that soy or isoflavone consumption did not affect primary outcomes estradiol, estrone or SHBG concentrations, but significantly reduced secondary outcomes FSH and LH [by ∼20% using standardized mean difference (SMD), P = 0.01 and 0.05, respectively]. Menstrual cycle length was increased by 1.05 days (95% CI 0.13, 1.97, 10 studies). In post-menopausal women, there were no statistically significant effects on estradiol, estrone, SHBG, FSH or LH, although there was a small statistically non-significant increase in total estradiol with soy or isoflavones (∼14%, SMD, P = 0.07, 21 studies).

CONCLUSIONS

Isoflavone-rich soy products decrease FSH and LH in premenopausal women and may increase estradiol in post-menopausal women. The clinical implications of these modest hormonal changes remain to be determined.