Reprint of The nature and utility of the phytoestrogens: a review of the evidence

Acute Effects of Dairy or Soy Milk on Sex Hormones Following Resistance Exercise in Males: A Randomized, Crossover Pilot Trial

INTRODUCTION

Resistance exercise training (RET) can increase muscle mass and strength, and this adaptation is optimized when dietary protein is consumed to enhance muscle protein synthesis. Dairy milk has been endorsed for this purpose; however, allergy and lactose intolerance affect two-thirds of the global population making dairy milk unsuitable for many. Plant-based alternatives such as soy milk have gained popularity and exhibit comparable protein content. However, concerns regarding soy phytoestrogens potentially influencing circulating sex hormones and diminishing the anabolic response to RET have been raised. This study therefore aimed to assess the acute effects of dairy and soy milk consumption on circulating sex hormones (total, free testosterone, free testosterone percentage, total estrogen, progesterone, and sex hormone binding globulin) after RET.

MATERIALS AND METHODS

Six male participants were recruited for a double-blinded, randomized crossover study with either dairy or soy milk provided post RET. Venous samples were collected before and after milk consumption across seven timepoints (0-120 minutes) where circulating sex hormones were analyzed. Two-way ANOVA analyses were applied for repeated measures for each hormone. The area under the curve (AUC) was also calculated between dairy and soy milk. Significance was set at p<0.05.

RESULTS

No significant differences were observed in acute circulating serum for free (p=0.95), % free (p=0.56), and total testosterone (p=0.88), progesterone (p=0.67), or estrogen (p=0.21) between milk conditions. Likewise, no significant differences in AUC were observed between any hormones.

CONCLUSION

These findings suggest that consumption of dairy milk and soy milk have comparable acute effects on circulating sex hormones following RET. Further investigations with expanded sample sizes are needed to strengthen and broaden these initial findings.

In silico guided in vitro study of traditionally used medicinal plants reveal the alleviation of post-menopausal symptoms through ERβ binding and MAO-A inhibition

The slumping level of estrogen and serotonin in menopausal women is directly associated with the occurrence of menopausal symptoms where, estrogen receptor-β (ERβ) and monoamine oxidase-A (MAO-A) are directly involved. The present investigation aimed for validation of promising plants traditionally used to alleviate menopausal symptoms with ERβ mediated MAO-A inhibition potential through in silico disease-target network construction using Cytoscape plugins followed by molecular docking of phytomolecules through AutoDock vina. ADMET parameters of identified bioactive phytomolecules were analysed through swissADME and ProTox II. The efficacy of promising plant leads was further established through in vitro ERβ competitive binding, MAO-A inhibition, enzyme kinetics and free radical quenching assays. In silico analysis suggested glabrene (ΔG = -9.7 Kcal/mol) as most promising against ERβ in comparison to 17β-estradiol (ΔG = -11.4 Kcal/mol) whereas liquiritigenin (ΔG = -9.4 Kcal/mol) showed potential binding with MAO-A in comparison to standard harmine (ΔG = -8.8 Kcal/mol). In vitro analysis of promising plants segregated Glycyrrhiza glabra (IC50 = 0.052 ± 0.007 μg/ml) as most promising, followed by Hypericum perforatum (IC50 = 0.084 ± 0.01 μg/ml), Trifolium pratense (IC50 = 0.514 ± 0.01 μg/ml) and Rumex nepalensis (IC50 = 2.568 ± 0.11 μg/ml). The enzyme kinetics of promising plant leads showed reversible and competitive nature of inhibition against MAO-A. The potency of plant extracts in quenching free radicals was at par with ascorbic acid. The identified four potent medicinal plants with ERβ selective, MAO-A inhibitory and free radical quenching abilities could be used against menopausal symptoms however, finding needs to be validated further for menopausal symptoms in in vivo conditions for drug development.Communicated by Ramaswamy H. Sarma.

Cryptotanshinone and wogonin up-regulate eNOS in vascular endothelial cells via ERα and down-regulate iNOS in LPS stimulated vascular smooth muscle cells via ERβ

Phytoestrogens were widely used as natural alternatives to estrogen for treating cardiovascular diseases. They have been reported to have cardioprotective and anti-inflammatory response, but the mechanisms remain unclear. In this study, we found cryptotanshinone and wogonin exhibited phytoestrogenic property in an estrogen-responsive reporter assay. In EA.hy926 cells, treatment of cryptotanshinone and wogonin led to significant increase in NO production levels, which were inhibited by co-incubation of estrogen receptor (ER)α antagonist methyl-piperidino-pyrazole (MPP). The expression of endothelial NO synthase (eNOS) and ERα were up-regulated with the same treatment, indicating they stimulate NO and eNOS expression via ERα-dependent pathway in endothelial cells. While in lipopolysaccharide activated vascular smooth muscle cell line A7r5, cryptotanshinone and wogonin exerted anti-inflammatory effects by inhibiting NO and inducible NO synthase expression via ERβ-dependent pathway. The reduction of NO synthesis was not affected by MPP, and was abrogated by ERβ antagonist R,R-tetrahydrochrysene. Our findings provide the potential molecular mechanism of cryptotanshinone and wogonin as phytoestrogens for their cardioprotective effects, which exerted regulatory effects on NO synthesis through differential regulation of estrogen receptors. It can be employed as a basis for evaluating the beneficial effects of phytoestrogens in the treatment of patients at risk of cardiovascular disease.

An 8-O-4' norlignan exerts oestrogen-like actions in osteoblastic cells via rapid nongenomic ER signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Sambucus williamsii Hance (SWH), which belongs to the Caprifoliaceae family distributed in various regions of China, Korea and Japan, has been used as a folk medicine for treatment of bone and joint diseases in China for thousands of years. In previous studies, SWH was shown to possess anti-osteoporosis, healing fracture, anti-inflammatory and analgesic activities. Our previous studies showed that SWH extract effectively suppressed ovariectomy-induced increase in bone turnover and improved bone mineral density and bone biomechanical strength in rats as well as in mice. An 8-O-4' norlignan, (7R,8S)-1-(4-hydroxy-3-methoxyphenyl)-2-[4-(3-hydroxypropyl)-2-methoxyphenoxy]-1,3-propanediol (PPD) was previously isolated and identified as the bioactive ingredient in SWH. The present study aimed to characterize the bone protective effects as well as its mechanism of actions in osteoblasts.

MATERIALS AND METHODS

Bone protective actions of PPD on different cells were determined by proliferation assay, alkaline phosphatase (ALP) activity assay, calcium deposition as well as real-time reverse transcriptase-polymerase chain reaction (RT-PCR). In addition, estrogen receptor (ER) antagonist ICI182,780 and mitogen-activated protein kinase kinase (MEK) inhibitor U0126 blocking assays, competitive ER radioligand binding assay, ERE-dependent luciferase reporter assay and immunoblotting were used to determine if PPD activated ER and if the effects of PPD on osteoblastic functions were ER dependent.

RESULTS

PPD exerted anabolic effects in osteoblasts and its effects were abolished by co-incubation with ICI182,780 or U0126. PPD induced mRNA expressions of Runx2, ALP, osteocalcin, and increased the ratio of osteoprotegerin/receptor activator of nuclear factor κB (OPG/RANKL). PPD failed to bind to either ERα or ERβ and did not activate ERE-luciferase activity via ER. PPD induced the phosphorylation of extracellular regulated kinases (ERK) and its effect was completely abolished by U0126. It also induced the phosphorylation of ERα at serine 118.

CONCLUSION

These data show that PPD is a bioactive compound in SWH that exerts oestrogen-like actions in osteoblast-like cells via ligand-independent, estrogen response element (ERE)-independent and mitogen-activated protein (MAP) Kinase-mediated rapid nongenomic ER signaling pathway.

Wrinkle reduction in post-menopausal women consuming a novel oral supplement: a double-blind placebo-controlled randomized study

Objective

The maintenance of youthful skin appearance is strongly desired by a large proportion of the world's population. The aim of the present study was therefore to evaluate the effect on skin wrinkling, of a combination of ingredients reported to influence key factors involved in skin ageing, namely inflammation, collagen synthesis and oxidative/UV stress. A supplemented drink was developed containing soy isoflavones, lycopene, vitamin C and vitamin E and given to post-menopausal women with a capsule containing fish oil.

Method

We have performed a double-blind randomized controlled human clinical study to assess whether this cocktail of dietary ingredients can significantly improve the appearance of facial wrinkles.

Results

We have shown that this unique combination of micronutrients can significantly reduce the depth of facial wrinkles and that this improvement is associated with increased deposition of new collagen fibres in the dermis.

Conclusion

This study demonstrates that consumption of a mixture of soy isoflavones, lycopene, vitamin C, vitamin E and fish oil is able to induce a clinically measureable improvement in the depth of facial wrinkles following long-term use. We have also shown, for the first time with an oral product, that the improvement is associated with increased deposition of new collagen fibres in the dermis.

Résumé

Assessment of the estrogenicity of the diet of a healthy female Spanish population based on its isoflavone content

Phytoestrogens are natural components of plants consumed by humans. The hormonal activity of these substances has long been known. Various in vitro tests have demonstrated the agonistic or antagonistic estrogenic activity of some phytoestrogens. The objective of this study was to estimate the supply of isoflavones in the diet of a healthy adult female population and to assess its estrogenic effect. The diet was assessed by questionnaire and the estrogenicity of the estimated isoflavone content was tested by E-screen, finding a mean total estrogenic capacity of 0.129 × 10⁻¹⁰ eq.E₂ (12.9 pmol day⁻¹), corresponding to a daily isoflavone intake of 265.8 μg day⁻¹. This study offers a preliminary insight into the phytoestrogen content of the diet of a healthy active population of Spanish women. The effects of this additional hormonal burden are highly controversial, and this approach to estimating dietary phytoestrogen intake of specific populations may help to elucidate its implications for human health.

Pomegranate seed oil in women with menopausal symptoms: a prospective randomized, placebo-controlled, double-blinded trial

OBJECTIVE

The aim of this study was to investigate the potential effects of pomegranate seed oil (PGS) on menopausal symptoms.

METHODS

The prospective randomized, placebo-controlled, double-blinded trial was completed by 81 postmenopausal women, who received two daily doses of either 30 mg PGS containing 127 μg of steroidal phytoestrogens per dose or a placebo for 12 weeks. The participants reported their number of hot flashes and completed the Menopause Rating Scale II at baseline and at weeks 4, 8, 12, and 24. At baseline and after 12 weeks, hormonal status was determined.

RESULTS

After 12 weeks of treatment, PGS reduced the number of hot flashes per day by 4.3 (38.7%), whereas placebo reduced it by 2.5 (25.6%). Both groups were significant compared with baseline, but the treated group was not significant compared with the placebo group (P = 0.17). After 24 weeks, the treated group showed a mean of 7.1 (interquartile range, 4.0) hot flashes per day compared with the placebo group with a mean of 8.8 (interquartile range, 5.0; P = 0.02). Although the overall sum score of the Menopause Rating Scale II parameters at week 12 decreased in the treated group from 16.0 to 9.0 at week 12 and in the placebo group from 18.0 to 14.5 (P = 0.08), the sum score of the vegetative somatic symptoms subgroup decreased strongly versus placebo (P < 0.03), attributable mainly to an improvement in sleeping disorders. PGS did not affect the hormone status, and no adverse effects were reported.

CONCLUSIONS

In postmenopausal women, PGS does not significantly reduce hot flashes within a 12-week observation period, but further studies are needed to investigate the long-term effect.

Metabolomics in serum of ovariectomised rats and those exposed to 17β-oestradiol and genistein

OBJECTIVE

Metabolites profiling provides global insights in characterisations and interactions of metabolites under specific physiological or pathologic states. The aim of this study was to examine serum metabolic changes in bilateral ovariectomised (OVX) rats and those exposed to 17β-oestradiol (E(2), 30 μg/kg bw, sc.) or genistein (50 μg/kg bw, sc.) for 12 weeks.

METHODS

Serum samples were detected by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-q-TOF-MS). Significant variables were found by the orthogonal partial least-squares analysis and identified by matching their tandem MS fragmentation patterns with reference standards.

RESULTS

There were 54 variables changed in OVX group compared with sham group. Genistein might induce more intensive changes of metabolites than E(2) in OVX rats. Among the 54 significant variables of OVX group, 8 and 20 were found to be affected by E(2) and genistein, respectively. Finally, four of them were identified as arachidonic acid (AA), eicosapentaenoic acid (EPA), ergocalciferol and cholecalciferol. Both E(2) and genistein could reverse levels of AA, EPA and ergocalciferol to sham levels. Only genistein treatment could reverse the level of cholecalciferol.

CONCLUSIONS

This study provided a serum profile of ovary dysfunction and showed some similarities and differences between E(2) and genistein treatments of the OVX model.