The role of phytoestrogens in the prevention and treatment of osteoporosis in ovarian hormone deficiency

Detection of isoflavones and phytoestrogen-rich plant extracts binding to estrogen receptor β using a yeast-based fluorescent assay

Alchemilla vulgaris L., Trifolium pratense L. and Glycyrrhiza glabra L. are important remedies in traditional medicine, known for many usages, including treating gynecological diseases. Despite folkloric use of the plant materials, there is a lack of scientific data to support their therapeutic application. The aims of the present study were to evaluate the relative binding affinities (RBAs) of plant-derived phytoestrogens for estrogen receptor β (ERβ) using fluorescent biosensor in yeast and to apply this assay for the assessment of the potential of plant materials towards ERs and treatment of estrogen-related disorders. Ligand-binding domain of ERβ fused with yellow fluorescent protein (ERβ LBD-YFP) was expressed in S. cerevisiae and fluorescence was detected by fluorimetry and fluorescence microscopy. Structural basis for experimental results was explored by molecular docking. Yeast-based fluorescent assay was successfully optimized and applied for identification of natural phenolic compounds and phytoestrogen-rich plant extracts that interact with ERβ-LBD, making this biosensor a valuable tool for screening estrogenic potential of a variety of plant extracts. This assay can be used for preliminary testing of plant-derived or fungal extracts, but also other sources of environmental substances with ER-modulating activity in order to assess their possible effects on the female reproductive system.

A review on therapeutic mechanism of medicinal plants against osteoporosis: effects of phytoconstituents

Osteoporosis is a metabolic bone disorder that over time results in bone loss and raises the risk of fracture. The condition is frequently silent and only becomes apparent when fractures develop. Osteoporosis is treated with pharmacotherapy as well as non-pharmacological therapies such as mineral supplements, lifestyle changes, and exercise routines. Herbal medicine is frequently used in clinical procedures because of its low risk of adverse effects and cost-effective therapeutic results. In the current review, we have used a thorough strategy to identify some known medicinal plants with anti-osteoporosis capabilities, their origin, active ingredients, and pharmacological information. Furthermore, several signaling pathways, such as the apoptotic pathway, transcription factors, the Wnt/-catenin signaling pathway, and others, are regulated by bioactive components and help to improve bone homeostasis. This review will provide a better understanding of the anti-osteoporotic effects of bioactive components and the concomitant modulations of signaling pathways.

Ameliorative effects of Kyung-Ok-Ko and its mixture with Pueraria lobata Ohwi on postmenopausal osteoporosis by promoting phytoestrogenic activity in rats

Introduction

Kyung-Ok-Ko (KOK) is a popular traditional medicine used as a natural alternative to hormone replacement therapy for treating postmenopausal symptoms in Asia. Pueraria lobata Ohwi (P. lobata) is rich in isoflavones and has been traditionally used in combination with other herbs to produce synergistic and pharmaceutical effects via a multi-target approach for disease treatment. We aimed to investigate the phytoestrogenic effects of KOK extract against postmenopausal symptoms in ovariectomized (OVX) rats and confirm its efficacy by mixing KOK and P. lobata extracts.

Methods

OVX rats were daily oral administrated with KOK and KOK + P. lobata mixture extracts (300-400 mg/kg) and their body weight and tail temperature were monitored for 12 weeks. The biochemical parameters, estradiol levels, and bone turnover markers were measured in the serum samples. Moreover, the estrogen receptor, ER-α and ER-β expression in the uterus and the uterus morphology were evaluated. AMPK, ATG1/ULK1, and mTOR protein expression in the liver were assessed.

Results

The 12-week treatment with KOK and KOK + P. lobata mixture extracts did not cause liver damage or hormonal changes in the OVX rats. The treatments reduced the high lipid accumulation-related body weight gain and the tail temperature increase that was induced by ovariectomy. Further, it exhibited protective effects against hyperlipidemia and osteoporosis. No significant difference was observed in uterine weight compared to the OVX-treated group, while endometrial thickness reduction inhibition was observed due to ovariectomy. Bone mineral density (BMD) and serum osteocalcin levels, which decreased in OVX rats, increased with both treatments. Western blotting analysis showed that ER-α and ER-β were not expressed in the treated rats, whereas these proteins were expressed in Sham-operated rats. No significant differences in the phosphorylation of AMPK were observed; however, the ATG1/ULK1 and mTOR protein phosphorylation levels were upregulated and downregulated in the treated rats compared to those of OVX rats, respectively.

Conclusion

This is the first in vivo study observing the efficacy and synergistic effects of the mixture of KOK and P. lobata. Our results suggest the potential of KOK and KOK + P. lobata mixture as an alternative therapy for alleviating menopausal symptoms.

Prunes preserve hip bone mineral density in a 12-month randomized controlled trial in postmenopausal women: the Prune Study

BACKGROUND

Dietary consumption of prunes has favorable impacts on bone health, but more research is necessary to improve upon study designs and refine our understandings.

OBJECTIVES

We evaluated the effects of prunes (50 g or 100 g/d) on bone mineral density (BMD) in postmenopausal women during a 12-mo dietary intervention. Secondary outcomes include effects on bone biomarkers.

METHODS

The single-center, parallel-arm 12-mo randomized controlled trial tested the effects of 50 g and 100 g prunes compared with a control group on BMD (every 6 mo) and bone biomarkers in postmenopausal women.

RESULTS

In total, 235 women (age 62.1 ± 5.0 y) were randomly allocated into control (n = 78), 50-g prune (n = 79), or 100-g prune (n = 78) groups. Compliance was 90.2 ± 1.8% and 87.1 ± 2.1% in the 50-g and 100-g prune groups. Dropout was 22%; however, the dropout rate was 41% for the 100-g prune group (compared with other groups: 10%, control; 15%, 50 g prune; P < 0.001). A group × time interaction for total hip BMD was observed in control compared with 50-g prune groups (P < 0.05) but not in control compared with 100-g prune groups (P > 0.05). Total hip BMD decreased -1.1 ± 0.2% in the control group at 12 mo, whereas the 50-g prune group preserved BMD (-0.3 ± 0.2%) at 12 mo (P < 0.05). Although hip fracture risk (FRAX) worsened in the control group at 6 mo compared with baseline (10.3 ± 0.5% compared with 9.8 ± 0.5%, P < 0.05), FRAX score was maintained in the pooled (50 g + 100 g) prune groups.

CONCLUSIONS

A 50-g daily dose of prunes can prevent loss of total hip BMD in postmenopausal women after 6 mo, which persisted for 12 mo. Given that there was high compliance and retention at the 50-g dosage over 12 mo, we propose that the 50-g dose represents a valuable nonpharmacologic treatment strategy that can be used to preserve hip BMD in postmenopausal women and possibly reduce hip fracture risk. This trial was registered at clinicaltrials.gov as NCT02822378.

Rational and study design of Randomized Controlled Trial of Dietary Supplementation with prune (dried plums) on bone density, geometry, and estimated bone strength in postmenopausal women: The Prune study

The use of non-pharmacological alternatives to pharmacological interventions, e.g., nutritional therapy, to improve or maintain bone mineral density (BMD) in postmenopausal women has gained traction over the past decade, but limited data exist regarding its efficacy. This paper describes the design of the Prune Study, a randomized controlled trial (RCT) that explored the effectiveness of a 12-month intervention of daily prune consumption on bone density, bone structure and strength estimates, bone turnover, various biomarkers of immune function, inflammation, and cardiovascular health, as well as phenolic and gut microbiota analyses. Postmenopausal women between the ages of 55–75 years were randomized into either control group (no prune consumption; n = 78), 50g prune (50g prune/day; n = 79), or 100g prune (100g prune/day; n = 78). All participants received 1200 mg calcium +800 IU vitamin D₃ daily as standard of care. The Prune Study is the largest and most comprehensive investigation of a dose response of prune consumption on bone health, biomarkers of immune function, inflammation, and cardiovascular health, as well as detailed phenolic and gut microbiota analyses in postmenopausal women. 235 women were randomized and 183 women completed the entire study. The findings of this study will help expand our current understanding of clinical implications and mechanisms underlying the resultant health effects of prune as a functional food therapy.

A comprehensive review on recent novel food and industrial applications of flaxseed: 2014 onwards

Flaxseed or linseed is an oilseed obtained from a plant, known as the flax (Linum usitatissimum). It is a valuable source of various bioactive components such as omega-3 polyunsaturated fatty acids, proteins, lignans, dietary fibres and phytochemicals. The in-vivo, in-vitro studies and research on human subjects and in animal models, conducted throughout the globe, on health benefits associated with the consumption of various forms of flaxseed are discussed in this review. It provides an insight into recent developments and potential applications of flaxseeds in the form of whole seeds, meals, flour or oil in an array of food and feed products and non-food industrial applications. The details about novel health benefits associated with flaxseeds and information related to commercially available flaxseed-based i.e. enriched products are also the salient feature of the review. Here, we have provided the state of the art of most recent comprehensive information post the first detailed review on flaxseed as a modern food released in 2014.

A comprehensive review on recent novel food and industrial applications of flaxseed: 2014 onwards

Flaxseed or linseed is an oilseed obtained from a plant, known as the flax (Linum usitatissimum). It is a valuable source of various bioactive components such as omega-3 polyunsaturated fatty acids, proteins, lignans, dietary fibres and phytochemicals. The in-vivo, in-vitro studies and research on human subjects and in animal models, conducted throughout the globe, on health benefits associated with the consumption of various forms of flaxseed are discussed in this review. It provides an insight into recent developments and potential applications of flaxseeds in the form of whole seeds, meals, flour or oil in an array of food and feed products and non-food industrial applications. The details about novel health benefits associated with flaxseeds and information related to commercially available flaxseed-based i.e. enriched products are also the salient feature of the review. Here, we have provided the state of the art of most recent comprehensive information post the first detailed review on flaxseed as a modern food released in 2014.

Dried plum consumption improves bone mineral density in osteopenic postmenopausal woman: A case report

The use of non-pharmacological alternatives to pharmacological interventions, e.g., nutritional therapy, to improve or maintain bone mineral density (BMD) in postmenopausal women has gained traction over the past decade, but limited data exist regarding its efficacy. The purpose of this case report was to compare changes in BMD of an osteopenic postmenopausal woman over the course of 28 months, including an abrupt change in diet. For the first 12 months, a participant assigned to the control arm of a randomized controlled trial (RCT) only took calcium and vitamin D₃ supplements, but in the following 16 months after completing the RCT, she introduced and maintained daily consumption of 50 g of dried plums in addition to calcium and vitamin D₃ supplements. This case report provides a unique opportunity to follow the trajectory of distinct changes in bone in response to one dietary modification.

The effect of deer antler from East Kalimantan to increase trabecular bone density and calcium levels in serum on osteoporotic mice

OBJECTIVES

Glucocorticoid-induced osteoporosis (dexamethasone) is a primary cause of secondary osteoporosis by the decreasing formation and increasing resorption activities. Previously, the in vitro study showed that 70% ethanol and aqueous extract of deer antler have increased alkaline phosphatase in osteoblast cell that known as marker of bone formation. The mind of this study is to analyze the effect of deer antlers in increasing the bone trabecular density of osteoporosis-induced male mice.

METHODS

This study used a post-test control group design. A total of 54 healthy male mice were randomly divided to nine groups, i.e., healthy control, osteoporotic, positive control, 70% ethanol (4, 8, and 12 mg/kg BW), and aqueous extracts (4, 8, and 12 mg/kg BW) of deer antler groups. All of the interventions were given 1 mL of test sample for 4 weeks orally. The bone densities were determined using histomorphometry by Image J and Adobe Photoshop. The statistical data were performed using SPSS 23 and statistical significance was set at p<0.05.

RESULTS

The results showed that alendronate group, 70% ethanol, and aqueous extract groups increased bone density and calcium levels in serum (p<0.05) compared to osteoporotic group in dose dependent manner. It indicated that 70% ethanol and aqueous extract of deer antler stimulating bone turnover and aqueous extract showed the highest.

CONCLUSIONS

Dexamethasone induction for 4 weeks caused osteoporotic mice and the administration of 70% ethanol and aqueous extracts of deer antler from East Kalimantan increased trabecular bone density and calcium levels in dose dependent manner.

Improvement in Menopause-Associated Hepatic Lipid Metabolic Disorders by Herbal Formula HPC03 on Ovariectomized Rats

Postmenopausal women have an increased risk of developing nonalcoholic fatty liver disease (NAFLD). We formulated a combination of three herb mixtures (HPC03) and observed lipid-lowering efficacy. HepG2 cells were treated with oleic acid to induce an NAFLD model (in vitro). Also, we investigated potential of HPC03 in an ovariectomize- (OVX-) induced NAFLD model (in vivo). We separated the mice into six groups, as follows: SHAM, OVX, OVX + β-estradiol, and OVX + HPC03 (50, 100, and 200 mg/kg). Rats were administered with/without HPC03 for 12 weeks. HPC03 dose dependently inhibited the lipid accumulation involved in lipogenesis in HepG2 cells. The body weight, fat mass, and weights of the liver were decreased in the OVX group than that in the other groups. HPC03 had decreased adiposity that was induced by OVX. HPC03 treatment reduced liver lipid deposition and prevented the increase in serum and liver triglyceride export when there was a deficiency in estradiol. HPC03 improves OVX-induced fatty liver and lipid metabolism. These findings suggest that HPC03 from postmenopausal women has a protective effect during NAFLD conditions.

Effect of echinalkamide identified from Echinacea purpurea (L.) Moench on the inhibition of osteoclastogenesis and bone resorption

Plant cell cultures have been exploited to provide stable production and new secondary metabolites for better pharmacological activity. Fractionation of adventitious root cultures of Echinacea purpurea resulted in the isolation of eleven constituents, including three new compounds. The structures of the three new compounds were determined to be an alkylamide (1), a polyacetylene (2) and a lignan (3) on the basis of combined spectroscopic analysis. To discover new types of antiresorptive agents, we screened for new compounds that regulate osteoclast differentiation, and survival. Among three new compounds, echinalkamide (compound 1) had considerably inhibitory effects on RANKL-induced osteoclast differentiation, and on proliferation of osteoclasts and efficiently attenuated osteoclastic bone resorption without toxicity. In addition, echinalamide treatment inhibited the osteoclast—specific gene expression level. Echinalkamide achieved this inhibitory effect by disturbing phosphorylation of MAPK and activation of osteoclast transcription factors c-Fos and NFATc1. Conclusionally, our study investigated that echinalkamide remarkably inhibited osteoclast differentiation and osteoclast specific gene expression through repression of the MAPK–c-Fos–NFATC1 cascade.

Effect of isopsoralen on Smad7 in osteoblastic MC3T3-E1 cells

The primary pathological change in postmenopausal osteoporosis (PM-OP) is bone collagen loss caused by estrogen depletion. Osteoblasts synthesize type I collagen, which composes the organic matrix of bone. Although isopsoralen stimulates osteoblastic cell proliferation and differentiation, transforming growth factor (TGF)-β1 is an important cell signaling factor for stimulating collagen synthesis. To explore the association between isopsoralen and the synthesis of collagen in vitro, the molecular and biological association between isopsoralen and TGF-β signaling was examined. (CAGA) 12-luciferase-reporter gene was used to measure TGF-β1 signaling activity. Type I collagen was detected by semiquantitative reverse transcription polymerase chain reaction, and mothers against decapentaplegic homolog 7 (Smad7) protein expression levels were analyzed by western blotting. The expression of collagen in MC3T3-E1 cells stimulated with isopsoralen was significantly upregulated compared with the control groups (P<0.05). Conversely, isopsoralen significantly decreased Smad7 protein expression compared with the control groups (P<0.05). Moreover, it was observed that isopsoralen activates the TGF-β1 signaling pathway and ultimately promotes collagen synthesis through inhibition of Smad7 protein expression. Therefore, isopsoralen is a potential target for the treatment of PM-OP.

Dietary Soy Isoflavone: A Mechanistic Insight

Soy, a major component of the diet for centuries contains the largest concentration of isoflavones, a class of phytoestrogens. A variety of health benefits are associated with the consumption of soy primarily because of the isoflavones genistein, daidzein, and glycitein with a potential protective effect against a number of chronic diseases. Owing to the pharmaceutical and nutraceutical properties allied with isoflavonoids and their use in functional foods, there is a growing interest in these compounds. This review throws light on the chemistry, and significant pharmacological and biopharmaceutical aspects of soy isoflavones. This article critically describes the mechanisms of action, infers conclusions and shows opportunity for future research.

Transdermal delivery of estradiol-loaded PLGA nanoparticles using iontophoresis for treatment of osteoporosis

BACKGROUND

Estradiol is one of the therapeutic agents for osteoporosis. We have reported transdermal permeability of estradiol-loaded nanoparticles, and permeability effect of estradiol was enhanced by using nanoparticle system and iontophoresis [Colloids and Surfaces B: Biointerfaces97 (2012), 84-89].

OBJECTIVE

This study was conducted in vivo to evaluate therapeutic efficacy of the estradiol-loaded PLGA nanoparticles for osteoporosis.

METHODS

Prior to the in vivo study, we have determined the surface charge density of the particles and found they have negatively charged polyelectrolyte layers on the surfaces. Ovariectomized female Sprague-Dawley rats were used as an animal model of osteoporosis. They were separated into three groups by administration route of estradiol-loaded PLGA nanoparticles, passive diffusion group, iontophoresis group and control. After treatment, we have measured bone mineral density of spine using an X-ray computed tomography system.

RESULTS

Bone mineral density after iontophoresis was significantly higher than that of passive diffusion and control group. By usage of iontophoresis, the nanoparticles were permeated through follicles and migrated into capillary vessel around follicles, and the loaded drug reached effective blood concentration in plasma of rat.

CONCLUSIONS

From this study, we found that the combination with charged nanoparticle system and iontophoresis is useful to osteoporosis treatment.

Metabolomics and Its Application in the Development of Discovering Biomarkers for Osteoporosis Research

Osteoporosis is a progressive skeletal disorder characterized by low bone mass and increased risk of fracture in later life. The incidence and costs associated with treating osteoporosis cause heavy socio-economic burden. Currently, the diagnosis of osteoporosis mainly depends on bone mineral density and bone turnover markers. However, these indexes are not sensitive and accurate enough to reflect the osteoporosis progression. Metabolomics offers the potential for a holistic approach for clinical diagnoses and treatment, as well as understanding of the pathological mechanism of osteoporosis. In this review, we firstly describe the study subjects of osteoporosis and bio-sample preparation procedures for different analytic purposes, followed by illustrating the biomarkers with potentially predictive, diagnosis and pharmaceutical values when applied in osteoporosis research. Then, we summarize the published metabolic pathways related to osteoporosis. Furthermore, we discuss the importance of chronological data and combination of multi-omics in fully understanding osteoporosis. The application of metabolomics in osteoporosis could provide researchers the opportunity to gain new insight into the metabolic profiling and pathophysiological mechanisms. However, there is still much to be done to validate the potential biomarkers responsible for the progression of osteoporosis and there are still many details needed to be further elucidated.

Quercetin-loaded solid lipid nanoparticles improve osteoprotective activity in an ovariectomized rat model: a preventive strategy for post-menopausal osteoporosis

A formulation of quercetin-based solid lipid nanoparticles (QSLNs) was developed to increase the bioavailability of quercetin, with an aim to evaluate its effects on bone health in comparison to free quercetin (Q).

Soybean isoflavone treatment induces osteoblast differentiation and proliferation by regulating analysis of Wnt/β-catenin pathway

It has been reported that soybean isoflavones (SI) have anti-bone resorptive activity in vivo. However, little is known about the cellular and molecular mechanisms of this effect. In this study, we investigated the effects of SI on osteoblast differentiation and proliferation. Results showed that SI promoted osteoblast proliferation and differentiation which could be marked as the formation of hydroxyapatite crystals or extracellular matrix and increased ALP level. SI treatment markedly decreased RANKL levels and increased OPG levels in osteoblast cells. SI resulted in activation of the Wnt/β-catenin pathway. These results demonstrate that SI may be a useful remedy for the treatment of osteoporosis.

Time and dose-dependent effects of Labisia pumila on the bone strength of postmenopausal osteoporosis rat model

BACKGROUND

Post-menopausal osteoporosis has long been treated and prevented by estrogen replacement therapy (ERT). Despite its effectiveness, ERT is associated with serious adverse effects. Labisia pumila var. alata (LP) is a herb with potential as an alternative agent to ERT due to its phytoestrogenic, antioxidative and anti-inflammatory effects on bone. This study aimed to determine the effects of LP supplementation on bone biomechanical strength of postmenopausal osteoporosis rat model.

METHODS

Ninety-six female Sprague-Dawley rats aged 4 to 5 months old were randomly divided into six groups; six rats in the baseline group (BL) and eighteen rats in each group of; Sham- operated (Sham), ovariectomised control (OVXC) and ovariectomised with daily oral gavages of Premarin at 64.5 μg/kg (ERT), LP at 20 mg/kg (LP20) and LP at 100 mg/kg (LP100) respectively. These groups were subdivided into three, six and nine weeks of treatment periods. Rats in BL group were euthanized before the start of the study, while other rats were euthanized after completion of their treatments. Femora were dissected out for biomechanical strength analysis using Instron Universal Model 5848 Micro Tester.

RESULTS

OVXC group showed deterioration in the bone biomechanical strength with time. Both ERT and LP supplemented rats showed improvements in bone strength parameters such as maximum load, displacement, stiffness, stress, and Young Modulus. The most improved bone strength was seen in rats given LP at the dose of 100 mg/kg for nine weeks.

CONCLUSION

LP supplementation at 100 mg/kg was more effective than ERT in reversing ovariectomy-induced bone biomechanical changes.

Efficacy and safety of a phyto-SERM as an alternative to hormone therapy

In this review, we analyze the efficacy and safety of DT56a in the treatment of postmenopausal symptoms. Similar to all selective estrogen receptor modulators (SERMs), DT56a demonstrates dual agonistic and antagonistic effects due to the synergy between its components. DT56a is referred to as a plant-origin SERM (phyto-SERM) and, for this reason, its therapeutic capacity in postmenopausal women differs from other phytoestrogens used independently. Although interesting data on relief of vasomotor symptoms have been reported for DT56a, further clinical studies with a greater number of cases and a longer period of study are required to correctly identify its indications for use as an alternative to hormone therapy, especially in preventing osteoporosis.

Phytoestrogens in postmenopause: the state of the art from a chemical, pharmacological and regulatory perspective

Phytoestrogens represent a diverse group of non-steroidal natural products, which seem to have some oestrogenic effects and are often marketed as food supplements. Population exposed to phytoestrogens is potentially increasing, in part because an unfavourable risk-benefit profile of Hormone Replacement Therapy (HRT) for prolonged treatments (e.g., osteoporosis prevention) highlighted by the publication of the Women Health Initiative (WHI) trial in 2002, but also because many post-menopausal women often perceived phytoestrogens in food supplements as a safer alternative than HRT. Despite of increasing preclinical and clinical studies in the past decade, appealing evidence is still lacking to support the overall positive risk-benefit profile of phytoestrogens. Their status as food supplements seems to discourage studies to obtain new evidence, and the chance to buy them by user's initiative make it difficult to survey their prevalence and pattern of use. The aim of the present review is to: (a) outline the clinical scenario underlying the increased interest on phytoestrogens, by overviewing the evolution of the evidence on HRT and its main therapeutic goals (e.g., menopausal symptoms relief, chemoprevention, osteoporosis prevention); (b) address the chemical and pharmacological features (e.g. chemical structure, botanical sources, mechanism of action) of the main compounds (e.g., isoflavones, lignans, coumestans); (c) describe the clinical evidence on potential therapeutic applications; (d) put available evidence on their riskbenefit profile in a regulatory perspective, in light of the recent regulation on health claims of food supplements.

The pros and cons of plant estrogens for menopause

Concerns pertaining to the risk of estrogen exposure through HT have prompted an increase in the use of natural alternatives. Phytoestrogens may provide postmenopausal women with a practical alternative and many women have already begun to utilize phytoestrogen supplements. However, research regarding the efficacy of phytoestrogens as a hormone therapy alternative has been previously pessimistic or questionable at best. This review scrutinizes the most current research regarding the efficacy of three types of phytoestrogens, isoflavones, lignans and coumestans, and their specific effect on the reduction of climacteric symptoms, specifically vasomotor symptoms, vaginal atrophy, insomnia and osteoporosis. A discussion of the research pertaining to the relative safety of each phytoestrogen in terms of breast and endometrial health is also included. Overall, current research demonstrates that phytoestrogens are effective in reducing the intensity of hot flushes, and some phytoestrogen combinations result in a decreased frequency. Certain phytoestrogens have also been shown to decrease vaginal atrophy, improve sleep and cognition, and positively affect bone health. Even though initial research was generally unconvincing, the more recent evidence reviewed here is rather positive. In terms of safety and reports of adverse reactions, trials have not shown an increase in breast cancer risk or increase in endometrial hyperplasia following phytoestrogen use, but trials explicitly designed to find neoplasia have not been reported. Moreover, unlike hormone therapy, lignans may not increase clotting risk in postmenopausal women, thus supplements may serve as a treatment option for patients who have contraindications to hormone therapy. Phytoestrogens may provide a safe and partially effective alternative to HT. However, because research regarding phytoestrogens is relatively new, pharmaco-vigilence is still required, as these products are not yet FDA-approved. This article is part of a Special Issue entitled 'Phytoestrogens'.

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

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Combined effect of soy isoflavones and vitamin D3 on bone loss in ovariectomized rats

OBJECTIVE

Several studies have shown that soy isoflavones have estrogen-like activities and might constitute an alternative to hormone replacement treatment. The present study investigated the effects of soy isoflavones alone and combined with vitamin D3 on prevention of bone loss.

METHODS

Sprague-Dawley rats were sham-operated (n = 8) or ovariectomized (OVX; n = 40), and then the OVX rats were randomly assigned to five groups that were untreated or treated for 14 wk with vitamin D3, 17β-estradiol, soy isoflavone extract (SIE), or vitamin D3 plus SIE. The effects of the isoflavones and 1α,25(OH)(2)D(3) on cultured osteoblasts and osteoclasts also were investigated.

RESULTS

In OVX rats, the bone mineral density and trabecular bone volume loss were improved by 17β-estradiol, SIE, or SIE plus vitamin D3 treatment. SIE treatment was more effective than vitamin D3 or 17β-estradiol in inhibiting increases in serum tumor necrosis factor-α levels and osteoblast osteoprotegerin expression. SIE plus vitamin D3 was more effective in increasing osterix expression than each alone. Bone cell cultures showed that the isoflavones induced preosteoblasts to differentiate into osteoblasts and increased osteoblast mineralization. Isoflavones inhibited preosteoclasts and osteoclast proliferation and decreased osteoclast resorption. The combination of isoflavones plus 1α,25(OH)(2)D(3) showed additive effects on the increase in cell proliferation of cultured preosteoblasts.

CONCLUSION

Treatment with soy isoflavones might be an alternative to hormone replacement therapy in decreasing bone loss from postmenopausal estrogen deficiency. In addition, there are further effects on increasing transcription factor osterix expression and preosteoblast proliferation when these were combined with vitamin D3.

Potential antiosteoporotic agents from plants: a comprehensive review

Osteoporosis is a major health hazard and is a disease of old age; it is a silent epidemic affecting more than 200 million people worldwide in recent years. Based on a large number of chemical and pharmacological research many plants and their compounds have been shown to possess antiosteoporosis activity. This paper reviews the medicinal plants displaying antiosteoporosis properties including their origin, active constituents, and pharmacological data. The plants reported here are the ones which are commonly used in traditional medical systems and have demonstrated clinical effectiveness against osteoporosis. Although many plants have the potential to prevent and treat osteoporosis, so far, only a fraction of these plants have been thoroughly investigated for their physiological and pharmacological properties including their mechanism of action. An attempt should be made to highlight plant species with possible antiosteoporosis properties and they should be investigated further to help with future drug development for treating this disease.

Novel anti-angiogenic effects of formononetin in human colon cancer cells and tumor xenograft

Formononetin is a novel herbal isoflavonoid isolated from Astragalus membranaceus, a medicinal plant that possesses antitumorigenic properties. Our previous findings demonstrated that formononetin initiates growth-inhibitory and pro-apoptotic activities in human colon cancer cells. In the present study, we aimed to further examine the potential of formononetin in controlling angiogenesis and tumor cell invasiveness in human colon cancer cells and tumor xenografts. The results showed that formononetin downregulated the expression of the key pro-angiogenic factors, including vascular endothelial growth factor (VEGF) and matrix metalloproteinases. We also discovered that the invasiveness of metastatic colon cancer cells was alleviated following drug treatment. The potential anti-angiogenic effect of formononetin was examined in nude mouse xenografts. The tumor size and the number of proliferating cells were reduced in the tumor tissues obtained from the formononetin-treated group. The serum VEGF level was also reduced in the drug-treated animals when compared to the controls. These findings suggest that formononetin inhibits angiogenesis and tumor cell invasion, and thus support its use in the treatment of advanced and metastatic colon cancers.

A naturally occurring naringenin derivative exerts potent bone anabolic effects by mimicking oestrogen action on osteoblasts

BACKGROUND AND PURPOSE

Naringenin and its derivatives have been assessed in bone health for their oestrogen-'like' effects but low bioavailability impedes clinical potential. This study was aimed at finding a potent form of naringenin with osteogenic action.

EXPERIMENTAL APPROACH

Osteoblast cultures were harvested from mouse calvaria to study differentiation by naringenin, isosakuranetin, poncirin, phloretin and naringenin-6-C-glucoside (NCG). Balb/cByJ ovariectomized (OVx) mice without or with osteopenia were given naringenin, NCG, 17β-oestradiol (E2) or parathyroid hormone (PTH). Efficacy was evaluated by bone microarchitecture using microcomputed tomography and determination of new bone formation by fluorescent labelling of bone. Plasma levels of NCG and naringenin were determined by HPLC.

KEY RESULTS

NCG stimulated osteoblast differentiation more potently than naringenin, while isosakuranetin, poncirin or phloretin had no effect. NCG had better oral bioavailability than naringenin. NCG increased the mRNA levels of oestrogen receptors (ERs) and bone morphogenetic protein (an ER responsive gene) in vivo, more than naringenin. In OVx mice, NCG treatment in a preventive protocol increased bone formation rate (BFR) and improved trabecular microarchitecture more than naringenin or E2. In osteopenic mice, NCG but not naringenin, in a therapeutic protocol, increased BFR and improved trabecular microarchitecture, comparable with effects of PTH treatment. Stimulatory effects of NCG on osteoblasts were abolished by an ER antagonist. NCG transactivated ERβ but not ERα. NCG exhibited no uterine oestrogenicity unlike naringenin.

CONCLUSIONS AND IMPLICATIONS

NCG is a potent derivative of naringenin that has bone anabolic action through the activation of osteoblast ERs and exhibited substantial oral bioavailability.

The blackberry fruit: a review on its composition and chemistry, metabolism and bioavailability, and health benefits

Blackberry (Rubus sp.) fruit contains high levels of anthocyanins and other phenolic compounds, mainly flavonols and ellagitannins, which contribute to its high antioxidant capacity and other biological activities. Blackberry phenolic composition and concentrations are known to be influenced by genetics, growing conditions, and maturation. Despite the current knowledge of their chemistry, research specific to blackberry phenolic compounds' health benefits, metabolism, bioavailability, and mechanism by which they confer health benefits is scarce. Blackberry phenolic compounds have protective effects on age-related neurodegenerative diseases and bone loss in vivo and can inhibit low-density lipoprotein and liposomal oxidation in vitro. Blackberry extracts have also exerted antimutagenic effects in vitro and in vivo by modifying cell signaling pathways and suppressing tumor promotion factors. However, the antiobesity, antidiabetic, antimicrobial, and anti-inflammatory properties of blackberry phenolic compounds need investigation. Similarly, studies that elucidate the in vivo physiologically effective concentrations of blackberry phenolic compounds are necessary.

Prepubertal daidzein exposure enhances mammary gland differentiation and regulates the expression of estrogen receptor-alpha and apoptotic proteins

Mechanism of chemoprevention by daidzein (500 μg/g bwt) was examined by injecting it subcutaneously at 16th, 18th, and 20th day postpartum, followed by counting of terminal end buds (TEBs), terminal ducts (TDs), and lobules and immunohistochemistry of ER-α, Bcl2, Bax, and caspase-3. DNA fragmentation was also analysed to measure the apoptosis level. Estradiol benzoate (EB) (500 ng/g bwt) and dimethyl sulphoxide (DMSO) were used as reference and vehicle, respectively. Observations show a significant enhancement of mammary gland differentiation at postnatal day 21 (PND21) as well as PND50. There was a significant decrease of ER-α expression at PND21 and increase in its expression at PND50, in daidzein-treated animals. The ratio of expression of Bcl-2 to Bax proteins increased at PND50 the same whereas, it decreased at PND50 due to daidzein. An increased expression of caspase-3 and DNA fragmentation was also seen due to daidzein at PND50. The mammary gland of EB-treated animals showed response a somewhat similar to that of daidzein-treated animals.

Comparative effects of dried plum and dried apple on bone in postmenopausal women

Aside from existing drug therapies, certain lifestyle and nutritional factors are known to reduce the risk of osteoporosis. Among the nutritional factors, dried plum or prunes (Prunus domestica L.) is the most effective fruit in both preventing and reversing bone loss. The objective of the present study was to examine the extent to which dried plum reverses bone loss in osteopenic postmenopausal women. We recruited 236 women, 1-10 years postmenopausal, not on hormone replacement therapy or any other prescribed medication known to influence bone metabolism. Qualified participants (n 160) were randomly assigned to one of the two treatment groups: dried plum (100 g/d) or dried apple (comparative control). Participants received 500 mg Ca plus 400 IU (10 μg) vitamin D daily. Bone mineral density (BMD) of lumbar spine, forearm, hip and whole body was assessed at baseline and at the end of the study using dual-energy X-ray absorptiometry. Blood samples were collected at baseline, 3, 6 and 12 months to assess bone biomarkers. Physical activity recall and 1-week FFQ were obtained at baseline, 3, 6 and 12 months to examine physical activity and dietary confounders as potential covariates. Dried plum significantly increased BMD of ulna and spine in comparison with dried apple. In comparison with corresponding baseline values, only dried plum significantly decreased serum levels of bone turnover markers including bone-specific alkaline phosphatase and tartrate-resistant acid phosphatase-5b. The findings of the present study confirmed the ability of dried plum in improving BMD in postmenopausal women in part due to suppressing the rate of bone turnover.

Dietary phyto-oestrogens: molecular mechanisms, bioavailability and importance to menopausal health

Following the high-profile studies on hormone replacement therapy which provided little evidence in support of the drug therapy improving future health, there remains a growing demand for dietary solutions for maintaining health and preventing disease as women age. Although interest in the relative importance of phyto-oestrogens to human health has increased dramatically over the last decade, the effective dose for health benefits and hypothetical issues on safety remain to be resolved. Plausible mechanisms and epidemiological data are available to support the concept that phyto-oestrogen-rich diets exert physiological effects, but optimal doses and sources of these compounds have still not been elucidated for specific health benefits. In addition, much of the current mechanistic data are difficult to interpret as the experiments have incorporated levels of phyto-oestrogens that may not be achievable in vivo and have to date only used aglycones and glycosides of the pure compounds rather than examining the biological effects of gut and liver metabolites. The present review will concentrate on the isoflavone subclass of phyto-oestrogens, as, to date, these compounds have received most attention from both a commercial and research perspective.

Effect of beer drinking on ultrasound bone mass in women

OBJECTIVE

To study the effect of beer consumption on bone mass in a group of healthy women, by using phalangeal bone ultrasound to evaluate the amplitude-dependent speed of sound.

METHODS

This was a cross-sectional study of 1697 healthy women (mean age 48.4 y, body mass index (BMI) 19.0-32.0 kg/m(2)), recruited in a clinical convenience sample and screened for the existence of disease and/or medication that would affect calcium metabolism. Of this total, 710 were premenopausal, 176 were perimenopausal, and 811 were postmenopausal. The women recruited completed a questionnaire that contained detailed sections on current cigarette, alcohol, caffeine, and nutrient consumption. In terms of current alcohol intake, the subjects were classified as moderate drinkers, light drinkers, and nondrinkers. Drinkers were also analyzed according to the kind of alcohol consumed: wine or beer.

RESULTS

Quantitative bone ultrasound values were greater in the beer drinkers compared with the no beer and/or wine drinkers. Taking the amplitude-dependent speed of sound as a dependent variable, and age, BMI, gonadal status, intake of beer and wine, and number of cigarettes per day as independent variables, we found age (beta = -1.52), BMI (beta = -3.86), gonadal status (beta = -27.47), and beer intake (beta = 1.06) to be significant.

CONCLUSION

The greater bone density found in women beer drinkers might be a result of the phytoestrogen content of this alcoholic drink; this requires further investigation.

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.

Prevention of chemically induced mammary tumorigenesis by daidzein in pre-pubertal rats: the role of peroxidative damage and antioxidative enzymes

Isoflavones are biologically active plant derived compounds that have several health promoting effects. In the present study hitherto unknown effects of one of the well known isoflavonoids, daidzein, has been evaluated on its chemo-preventive action against breast cancers in pre-pubertal rats. Either daidzein (500 mug/g bwt) or vehicle, dimethyl sulphoxide (DMSO), was administered at 16th, 18th, and 20th day post-partum and the chemopreventive efficacy was evaluated in dimethylbenz[a]nthracene (DMBA) induced Sprague-Dawley rats, at 50th day. To elucidate the mechanism of action, the antioxidative status was also examined in the liver and mammary gland of prebubertal rats using two different doses of daidzein (0.5 mg/kg bwt and 50 mg/kg bwt, p.o.) for 10 days. The specific activity of antioxidant enzymes as well as reduced glutathione (GSH) level and peroxidative damage were evaluated spectrophotometrically, both in liver as well as in mammary gland. Animals treated with daidzein pre-pubertally, showed a significant reduction in the tumorigenesis of mammary gland up to 37.4% as compared to animals induced for tumors with DMBA. In animals treated with 50 mg/kg of daidzein, a significant increase in the specific activities of the antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione transferase (GST), DT-diaphorase (DTD), and in GSH content were observed in both liver and mammary gland. Expectedly, the specific activity of lactate dehydrogenase (LDH) and level of peroxidative damage was decreased, as compared to that of control group of animals. Our results suggest that, daidzein can be considered as a potent chemopreventive agent against mammary carcinogenesis in pre-pubertal animals, with modulation of antioxidant enzymes being one of its mechanisms of actions.

Coronary vasomotor and blood flow responses to isoflavone-intact soya protein in subjects with coronary heart disease or risk factors for coronary heart disease

Results in animals suggest favourable coronary vasomotor actions of isoflavones; however, the effects of isoflavones on the human coronary circulation have not been determined. In the present study, we therefore investigated the effects of short-term isoflavone-intact soya protein ingestion on basal coronary arterial tone and stimulated vasoreactivity and blood flow in patients with CHD (coronary heart disease) or risk factors for CHD. Seventy-one subjects were randomized, double-blind, to isoflavone-intact soya protein [active; n=33, aged 58+/-8 years (mean+/-S.D.)] or isoflavone-free placebo (n=38, aged 61+/-8 years) for 5 days prior to coronary angiography. In 25 of these subjects, stimulated coronary blood flow was calculated from flow velocity, measured using intracoronary Doppler and coronary luminal diameter before and after intracoronary adenosine, ACh (acetylcholine) and ISDN (isosorbide dinitrate) infusions. Basal and stimulated coronary artery luminal diameters were measured using quantitative coronary angiography. Serum concentrations of the isoflavones genistein, daidzein and equol were increased by active treatment (P<0.001, P<0.001 and P=0.03 respectively). Basal mean luminal diameter was not significantly different between groups (active compared with placebo: 2.9+/-0.7 compared with 2.73+/-0.44 mm, P=0.31). There was no difference in luminal diameter, flow velocity and volume flow responses to adenosine, ACh or ISDN between groups. Active supplement had no effect on basal coronary artery tone or stimulated coronary vasoreactivity or blood flow compared with placebo. Our results suggest that short-term consumption of isoflavone-intact soya protein is neither harmful nor beneficial to the coronary circulation of humans with CHD or risk factors for CHD. These results are consistent with recent cautions placed on the purported health benefits of plant sterols.

Analysis of biologically active compounds in water by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry

A new method based on ultra-performance liquid chromatography (UPLC) quadrupole time-of-flight mass spectrometry ((Q-ToF)-MS) was developed for the analysis of 32 biologically active compounds including anti-inflammatories, analgesics, lipid regulators, psychiatric drugs, anti-ulcer agents, antibiotics, beta-blockers and phytoestrogens. This new method allows chromatographic analysis in 14 min, with instrumental detection limits from 2 to 84 pg, and limits of quantification ranging from 0.1 to 15 ng/L in tap water, and from 2 to 300 ng/L in wastewater. The potential of liquid chromatography with triple quadrupole mass spectrometry (LC/QqQ-MS) was compared with that of UPLC/(Q-ToF)-MS for the analysis of biologically active compounds in water samples. LC/Q-ToF provides accurate mass information and a significantly higher mass resolution than quadrupole analyzers. The available mass resolution of ToF instruments diminishes the problem of isobaric interferences and helps the analysis of trace compounds in complex samples. In this work UPLC/Q-ToF chromatograms were recorded containing full scan spectral data. The m/z values of analytes were extracted from the total ion chromatogram (TIC) and the accurate masses of the compounds were obtained. In addition, to increase the selectivity of ToF measurements a narrow accurate mass interval (20 m m/z units mass window) was used to reconstruct the chromatographic traces. However, regarding quantitative performance in terms of dynamic range and limits of detection (LODs), typical LODs achieved by QqQ instruments operating in multiple-reaction monitoring (MRM) mode ranged from 1 to 50 ng/L in wastewater, and the linear response for QqQ instruments generally covers three orders of magnitude. This is an important advantage over ToF instruments and one of the reasons why QqQ instruments are widely used in quantitative environmental analysis.

Flaxseed and soy protein isolate, alone and in combination, differ in their effect on bone mass, biomechanical strength, and uterus in ovariectomized nude mice with MCF-7 human breast tumor xenografts

In our previous study, flaxseed (FS) reduced while soy protein isolate (SPI) stimulated MCF-7 breast tumor growth in ovariectomized mice. In addition, combining SPI and FS resulted in a negation of SPI-induced tumor growth. In this study, the effects of SPI, FS, and their combination were further examined on mouse bone and uterus to further ensure overall safety of the breast cancer treatments. Ovariectomized mice with established MCF-7 xenografts were fed either a basal diet (control), or a basal diet supplemented with 10% FS, 20% SPI, or SPI + FS for 25 wk. Mouse bones were analyzed for mineral and biomechanical strength properties, and uterus weight was measured. The SPI group had a higher femur bone mineral density and biomechanical strength parameters (yield load, stiffness, and peak load) compared to control, while the FS group significantly increased femur stiffness and peak load. The SPI + FS group did not affect femur mineral, but significantly reduced whole femur area and length and increased femur yield load, stiffness, and peak load. Uterus weight was significantly increased by the SPI + FS group, while SPI alone induced an intermediate effect. In conclusion, all dietary treatments induced beneficial effects on bone in a preclinical mouse model of postmenopausal breast cancer. Although the SPI + FS and SPI groups exerted stimulatory effects on uterus weight, other histological parameters need to be measured to determine the overall safety of these breast cancer treatments on the uterus.

Role of Sandhika: A Polyherbal Formulation on MC3T3-E1 Osteoblast-like Cells

Sandhika is a polyherbal formulation, (water soluble fraction of Commiphora mukul, Boswellia serrata, Semecarpus anacardium and Strychnos nux vomica), which has been in clinical use in India for last 20 years. Its modified formulation BHUx has shown specific inhibition of cyclooxygenase (COX)-2 and lipoxygenase (LOX)-15 and has prevented diet-induced atherosclerosis in rabbits. In order to explore the possibility of the use of Sandhika for the management of osteoporosis, we have examined its influence on MC3T3-E1 osteoblast-like cells in presence of lipopolysaccharide (1 microg/ml) in terms of calcium nodule formation and alkaline phosphatase activity. MC3T3-E1 osteoblast-like cells (80% confluence in 6-well plates) were treated with water extract of Sandhika, for 10 days, in the concentration range of 0.5 to 16 mg/ml final concentration, in presence of LPS. Media was changed on every third day and culture supernatant was collected after every change to assess the alkaline phosphatase activity and on the tenth day, cells were washed and stained with "Alizarin S" for visualization of calcium nodules by using Meta Morph software (Universal Imaging, Downingtown, PA). The results showed significant enhancement in calcium nodule formation in the dose dependent manner up to 2 mg/ml, followed by gradual decrease at higher concentrations. This change was accompanied with the increase in the alkaline phosphatase activity in these plates, indicating a potential anabolic effect of this polyherbal formulation on osteoblast-like cells under inflammatory conditions induced by LPS.

The bone-protective effect of the phytoestrogen genistein is mediated via ER alpha-dependent mechanisms and strongly enhanced by physical activity

Reduced estrogen levels occurring during menopause in women are accompanied by a variety of disorders, e.g. hot flushes, depressions, osteoporosis, increase in body weight and reduced movement drive. The phytoestrogen genistein (GEN) has been demonstrated to have a significant bone-protective potency. In order to study the ER subtype-specific effects of this phytoestrogen on bone in an animal model, ovariectomized (OVX) female Wistar rats were either treated with 17beta-estradiol (E(2)) (4 microg/kg/day), the ER alpha-specific agonist (ALPHA) 16 alpha-LE(2) (10 microg/kg/day), the ER beta-specific agonist (BETA) 8 beta-VE(2) (100 microg/kg/day) or GEN (10 mg/kg/day) for 3 weeks. Vehicle-treated OVX animals served as controls. All animals had the opportunity of voluntary wheel running. Movement activity, changes of body weight and trabecular bone mineral density (BMD) in the tibia were analyzed. E(2) and ALPHA treatment, but not treatment with BETA, significantly increased the movement activity of OVX rats. Treatment with GEN resulted in a significant decrease of movement activity as compared to OVX animals. Bone mineral density in the trabecular area of the tibia and the expression of bone morphogenetic protein-2 (BMP-2) were significantly reduced in OVX- and BETA-treated rats as compared to rats substituted with E(2), ALPHA and GEN. The bone-protective effect of ALPHA was antagonized by co-treatment with the pure antiestrogen Faslodex (ICI). In order to distinguish hormone-dependent effects from those of exercise, we performed an additional experiment where the animals had no opportunity of wheel running. The results demonstrate that physically inactive rats have a stronger decrease of bone mineral density than physically active animals. Very surprisingly, our data demonstrate that GEN has no bone-protective activity in the absence of physical activity. In contrast, ALPHA and E(2) are bone-protective in the presence and absence of physical activity. In conclusion, our data provide evidence that the effects of E(2) on body weight, movement drive and protection of bone mineral density are mediated via ER alpha, whereas activation of ER beta has only a limited effect. Our data also indicate that the bone-protective effects of GEN may be mediated via ER alpha-dependent mechanisms and that physical activity has a strong impact on the bone-protective potency of this phytoestrogen.

Genistein alone and in combination with the mammalian lignans enterolactone and enterodiol induce estrogenic effects on bone and uterus in a postmenopausal breast cancer mouse model

The use of phytoestrogens, such as isoflavones and lignans, for treatment of postmenopausal breast cancer is increasing, but their effects on bone and other major organs are not clear. While the isoflavone genistein (GEN) has been shown to prevent or slow the loss of bone mineral density (BMD), the effect of lignans enterodiol (END) and enterolactone (ENL) are unknown. In this study, we determined in ovariectomized mice with human MCF-7 breast tumor xenografts the effects of the lignans, and GEN, alone and in combination, on bone and uterus. Mice with established MCF-7 tumors were fed a basal diet (AIN-93G), divided into 5 groups, and given daily subcutaneous injections (10 mg/kg body weight) of either ENL, END, GEN, a mixture of these compounds (MIX), or vehicle as a negative control for 22 weeks. Results showed that GEN acts estrogenically in both the uterus and bone by increasing the uterus weight, femur BMD, and femur biomechanical strength (yield load), while the lignans do not. However, treatment with MIX induced minimal effects on femur biomechanical strength parameters but significantly increased uterus weight. A significant positive correlation was observed between MCF-7 tumor volume and femur BMD and biomechanical strength parameters (femur peak load and yield load) but not with uterus weight, suggesting that the uterus may respond differently to phytoestrogens compared to MCF-7 tumors and bone. It is concluded that GEN induces beneficial effects on bone but has adverse effects on tumors and uterus in this model of postmenopausal breast cancer. The lignans do not exert adverse effects on any tissue, however, when combined with GEN, they exert an adverse effect on the uterus.

Phytoestrogens derived from red clover: an alternative to estrogen replacement therapy?

The benefits of plant extracts from soy and red clover as alternatives to conventional hormone replacement therapy (HRT) have been debated in the past. Here, an attempt has been made to summarize the biochemical and pharmacological data in the light of clinical aspects. Red clover and soy extracts contain isoflavones, which have a high affinity to estrogen receptor alpha (ERalpha), estrogen receptor beta (ERbeta), progesterone receptor (PR) and androgen receptor (AR). The higher affinity to ERbeta compared to ERalpha has been used as an explanation why red clover extracts function as food additives to treat menopausal disorders and may reduce risk of breast cancer. Biochemical analysis shows that these representatives of phytoestrogens have multiple actions beside selective estrogen receptor modulator (SERM)-activity. They act as selective estrogen enzyme modulators (SEEMs), have antioxidant activity and interact with transcription factors such as NF-kappaB. Furthermore, it is indicated that they have protective effects on osteoporosis and the cardiovascular system. Currently 40-50mg of isoflavones (biochanin A, daidzein, formononetin and genistein) are recommended as daily dose. This recommendation is based on the daily intake of phytoestrogens in a traditional Japanese diet.