Activation of nitric oxide synthesis in human endothelial cells by red clover extracts

Gestational bisphenol A exposure induces fatty liver development in male offspring mice through the inhibition of HNF1b and upregulation of PPARγ

Bisphenol A (BPA) is an endocrine-disrupting chemical (EDC) associated with non-alcoholic fatty liver disease (NAFLD). The effects of gestational BPA exposure on hepatic lipid accumulation in offspring are not fully understood. Here, we investigate the sex-dependent effects of gestational BPA exposure on hepatic lipid and glucose metabolism in the offspring of mice to reveal the mechanisms underlying gestational BPA exposure-associated NAFLD. Pregnant mice were administered gavage with or without 1 μg kg-1 day-1 BPA at embryonic day 7.5 (E7.5)-E16.5. Hepatic glucose and lipid metabolism were evaluated in these models. Both male and female offspring mice exhibited hepatic fatty liver after BPA treatment. Lipid accumulation and dysfunction of glucose metabolism were observed in male offspring. We revealed abnormal expression of lipid regulators in the liver and that inhibition of peroxisome proliferator-activated receptor γ (PPARγ) repressed hepatic lipid accumulation induced by gestational BPA exposure. We also found a sex-dependent decrease of hepatocyte nuclear factor 1b (HNF1b) expression in male offspring. The transcriptional repression of PPARγ by HNF1b was confirmed in L02 cells. Downregulation of HNF1b, upregulation of PPARγ, and subsequent upregulation of hepatic lipid accumulation were essential for NAFLD development in male offspring gestationally exposed to BPA as well as BPA-exposed adult male mice. Dysregulation of the HNF1b/PPARγ pathway may be involved in gestational BPA exposure-induced NAFLD in male offspring. These data provide new insights into the mechanism of gestational BPA exposure-associated sex-dependent glucose and lipid metabolic dysfunction. Graphical abstract Schematic of the mechanism of gestational BPA exposure-induced glucose and lipid metabolic dysfunction.

Effect of a new herbal composition comprised of red clover and hop extract on human endothelial cell damage and vasorelaxant activity

Hormone replacement therapy may cause various side effects, including enhancing the risk of cardiovascular disease (CVD) in postmenopausal women. Here, we investigated the effect of red clover and hop extract combination (RHEC) on estrogen receptor (ER) binding and endothelial function of human umbilical vein endothelial cells (HUVECs) to develop an herbal agent for reducing the risk of CVDs. In ER competitor assay, RHEC showed binding affinity toward ERα and ERβ with IC50 values of 5.92 µg/ml and 1.66 µg/ml, respectively. In HUVECs, RHEC significantly increased the cell viability and reduced the reactive oxygen species production against oxidative stress-induced damage. We also showed that RHEC increased the NO production through upregulating the endothelial nitric oxide synthase expression via ER activation in estrogen depleted condition. In particular, RHEC showed greater efficacy with increase in NO and decrease in endothelin-1 than red clover or hop treatment alone. Additionally, 0.3-0.5 mg/ml of RHEC-induced vasorelaxation of rat aortic rings precontracted by phenylephrine. PRACTICAL APPLICATIONS: Recently, a large interest has grown in the synergistic effects of phytochemicals for better therapies to treat various diseases. Red clover and hop are well-known edible plants which are widely used to help relieve postmenopausal symptoms including CVD. However, their combination has not been studied so far. For the first time, we demonstrated that RHEC, a new herbal combination comprising the extracts from red clover and hop, appeared to be effective in protection of endothelial function against oxidative stress and estrogen depletion. Therefore, RHEC could be a potent herbal agent for reducing the risk of endothelial damage.

Medicinal Plants and Phytochemicals for the Treatment of Pulmonary Hypertension

Background

Pulmonary hypertension (PH) is a progressive disease that is associated with pulmonary arteries remodeling, right ventricle hypertrophy, right ventricular failure and finally death. The present study aims to review the medicinal plants and phytochemicals used for PH treatment in the period of 1994 – 2019.

Methods

PubMed, Cochrane and Scopus were searched based on pulmonary hypertension, plant and phytochemical keywords from August 23, 2019. All articles that matched the study based on title and abstract were collected, non-English, repetitive and review studies were excluded.

Results

Finally 41 studies remained from a total of 1290. The results show that many chemical treatments considered to this disease are ineffective in the long period because they have a controlling role, not a therapeutic one. On the other hand, plants and phytochemicals could be more effective due to their action on many mechanisms that cause the progression of PH.

Conclusion

Studies have shown that herbs and phytochemicals used to treat PH do their effects from six mechanisms. These mechanisms include antiproliferative, antioxidant, antivascular remodeling, anti-inflammatory, vasodilatory and apoptosis inducing actions. According to the present study, many of these medicinal plants and phytochemicals can have effects that are more therapeutic than chemical drugs if used appropriately.

Nitric oxide and the biology of pregnancy

Nitric oxide (NO) is a key regulator of both maternal and fetal homeostasis during pregnancy, facilitating the maternal cardio-vascular changes, fetal development and growth and adaptation to extrauterine life. Dysfunction of the NO system during pregnancy is associated to placental and vascular-related diseases such as hypertensive disorders of pregnancy (HDP) and intrauterine growth restriction (IUGR). Emerging therapeutic strategies involving NO precursors, NO donors, natural derivatives or pharmacological modulators of the NO system seem hold promise for the treatment of such conditions of pregnancy.

Estrogen receptor β actions in the female cardiovascular system: A systematic review of animal and human studies

Five medical databases were searched for studies that assessed the role of ERβ in the female cardiovascular system and the influence of age and menopause on ERβ functioning. Of 9472 references, 88 studies met our inclusion criteria (71 animal model experimental studies, 15 human model experimental studies and 2 population based studies). ERβ signaling was shown to possess vasodilator and antiangiogenic properties by regulating the activity of nitric oxide, altering membrane ionic permeability in vascular smooth muscle cells, inhibiting vascular smooth muscle cell migration and proliferation and by regulating adrenergic control of the arteries. Also, a possible protective effect of ERβ signaling against left ventricular hypertrophy and ischemia/reperfusion injury via genomic and non-genomic pathways was suggested in 27 studies. Moreover, 5 studies reported that the vascular effects of ERβ may be vessel specific and may differ by age and menopause status. ERβ seems to possess multiple functions in the female cardiovascular system. Further studies are needed to evaluate whether isoform-selective ERβ-ligands might contribute to cardiovascular disease prevention.

The anti-adhesive and anti-aggregatory effects of phenolics from Trifolium species in vitro

The present in vitro study includes a comparative evaluation of anti-platelet (anti-thrombotic) properties of plant phenolics, isolated from nine different clover (Trifolium) species. The analysis covered phenolic fractions isolated from T. alexandrinum L., T. fragiferum L., T. hybridum L., T. incarnatum L., T. pallidum Waldst et Kit., T. resupinatum L. var. majus Boiss, T. resupinatum L. var. resupinatum, T. scabrum L., and T. pratense L. (red clover). The inhibitory effects of plant preparations (1–50 µg/ml) on hemostatic functions of blood platelets were assessed by measurements of thrombin- or ADP-induced platelet adhesion to fibrinogen, platelet aggregation in platelet-rich plasma (activated with ADP or collagen), and by the determination of PF-4 secretion from platelet α-granules. The influence of T. phenolics on arachidonic cascade in blood platelets was also determined. T. resupinatum var. majus, T. resupinatum var. resupinatum, and T. scabrum had the strongest anti-platelet effects. These preparations displayed the most evident anti-adhesive and anti-aggregatory effects in response to all of the used agonists: thrombin (0.2 U/ml), ADP (10 µM), and collagen (2 µg/ml), and their inhibitory properties were also confirmed by an analysis of PF-4 secretion. T. scabrum and some of other examined clover species possess significantly higher concentrations of both isoflavones and other bioactive phenolics, when compared to red clover. The obtained results suggest that these clovers contain substances with potent anti-platelet properties.

Trifolium pratense isoflavones improve pulmonary vascular remodelling in broiler chickens

Pulmonary arterial remodelling is a pathological characteristic of pulmonary arterial hypertension (PAH), which contributes to the development of sustained pulmonary hypertension. The aim of this study was to investigate the effects of dietary Trifolium pratense isoflavones on pulmonary vascular remodelling in experimental broiler pulmonary hypertension syndrome. Exposure to sub-thermoneutral environmental temperatures increased broiler's pulmonary hypertension syndrome incidence and raised expression levels of nitric oxide, endothelin and endothelial nitric oxide synthase. Dietary supplementation (20 mg/kg basal diet) with Trifolium pratense isoflavones reduced pulmonary hypertension syndrome incidence and improved pulmonary vascular remodelling without affecting growth performance. The beneficial effect likely came from isoflavone improved pulmonary vascular remodelling. Isoflavone induced inducible nitric oxide synthase expression, which led to increased nitric oxide level. The nitric oxide could mediate vasorelaxation in the lungs. At the same time, the expression of endothelin was downregulated by isoflavone. Dietary supplementation of Trifolium pratense isoflavone might be a potential therapeutic strategy for the treatment of pulmonary hypertension.

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.

Estrogen and phenol red free medium for osteoblast culture: study of the mineralization ability

To design an estrogen and phenol red free medium for cell culture and check its effectiveness and safety on osteoblast growth it is necessary to maintain the estrogen receptors free for tests. For this purpose, we tested some modifications of the traditional culture media: estrogen depleted fetal bovine serum; estrogen charcoal stripped fetal bovine serum and phenol red free α-MEM. The aim of this work is to examine the effects of its depletion in the proliferation, differentiation, and toxicity of mesenchymal stromal cells differentiated into osteoblasts to obtain an effective interference free culture medium for in vitro studies, focused on non-previously studied estrogen receptors. We performed viability tests using the following techniques: MTT, alkaline phosphatase specific activity, formation of mineralized matrix by Alizarin technique and analysis of SEM/EDX of mineralized nodules. The results showed that the culture media with estrogen free α-MEM + phenol red free α-MEM did not impact viability, alkaline phosphatase activity and mineralization of the osteoblasts culture compared to control. In addition, its nodules possess Ca/P ratio similar to hydroxyapatite nodules on the 14th and 21st day. In conclusion, the modified culture medium with phenol red free α-MEM with estrogen depleted fetal bovine serum can be safely used in experiments where the estrogen receptors need to be free.

Estetrol Modulates Endothelial Nitric Oxide Synthesis in Human Endothelial Cells

Estetrol (E4) is a natural human estrogen that is present at high concentrations during pregnancy. E4 has been reported to act as an endogenous estrogen receptor modulator, exerting estrogenic actions on the endometrium or the central nervous system but presenting antagonistic effects on the breast. Due to these characteristics, E4 is currently being developed for a number of clinical applications, including contraception and menopausal hormone therapy. Endothelial nitric oxide (NO) is a key player for vascular function and disease during pregnancy and throughout aging in women. Endothelial NO is an established target of estrogens that enhance its formation in human endothelial cells. We here addressed the effects of E4 on the activity and expression of the endothelial nitric oxide synthase (eNOS) in cultured human umbilical vein endothelial cells (HUVEC). E4 stimulated the activation of eNOS and NO secretion in HUVEC. E4 was significantly less effective compared to E2, and a peculiar concentration-dependent effect was found, with higher amounts of E4 being less effective than lower concentrations. When E2 was combined with E4, an interesting pattern was noted. E4 antagonized NO synthesis induced by pregnancy-like E2 concentrations. However, E4 did not impede the modest induction of NO synthesis associated with postmenopausal-like E2 levels. These results support the hypothesis that E4 may be a regulator of NO synthesis in endothelial cells and raise questions on its peculiar signaling in this context. Our results may be useful to interpret the role of E4 during human pregnancy and possibly to help develop this interesting steroid for clinical use.

Effects of an aglycone-rich biotransformed soybean extract in human endothelial cells

Estrogen replacement therapy is not thought to be a safe treatment for prevention of cardiovascular disease in menopausal women; isoflavones are a possible alternative. Estrogen produces beneficial effects on the cardiovascular system by enhancing production of nitric oxide, a vasoprotective and antiatherosclerotic agent. Estrogen-like compounds such as isoflavones are also suggested for increasing nitric oxide production. Isoflavones are present mainly in soy foods as glucosides, but soy isoflavone aglycones, the biologically active estrogen-like compounds, are absorbed faster and in higher amounts than their glucoside derivatives and show higher biological activity, implying that they may be more effective in preventing chronic diseases such as coronary heart disease. We evaluated an extract of soybeans fermented by Aspergillus awamori on which polyphenol glucosides were biotransformed to aglycone forms on production of nitric oxide, prostaglandin E2 and endothelin-1 in vitro in human endothelial cells, comparing it with a non-fermented extract. Bioconverted soybean extracts enhanced endothelin-1, nitric oxide and prostaglandin E2 production, while the unfermented extract only enhanced endothelin-1 production. Thus, only the aglycone-rich forms of soybean extracts were able to increase nitric oxide and prostaglandin E2 production, demonstrating that, in endothelial cells in vitro, they may be usable as therapeutic agents against the development of atherosclerosis.

Phytoestrogens and the metabolic syndrome

Phytoestrogens are a diverse class of non-steroidal compounds that have an affinity for estrogen receptors α and β, for the peroxisome proliferator-activated receptor (PPAR) family and for the aryl hydrocarbon receptor. Examples of phytoestrogens include prenylated flavonoids, isoflavones, coumestans and lignans. Many phytoestrogens counteract the cellular derailments that are responsible for the development of metabolic syndrome. Here we propose a mechanism of action which is based on five pillars/principles. First, phytoestrogens are involved in the downregulation of pro-inflammatory cytokines, such as COX-2 and iNOS, by activating PPAR and by inhibiting IκB activation. Second, they increase reverse cholesterol transport, which is mediated by PPARγ. Third, phytoestrogens increase insulin sensitivity, which is mediated via PPARα. Fourth, they exert antioxidant effects by activating antioxidant genes through KEAP. Fifth, phytoestrogens increase energy expenditure by affecting AMP-activated kinase signaling cascades, which are responsible for the inhibition of adipogenesis. In addition to these effects, which have been demonstrated in vivo and in clinical trials, other effects, such as eNOS activation, may also be important. Some plant extracts from soy, red clover or licorice can be described as panPPAR activators. Fetal programming for metabolic syndrome has been hypothesized; thus, the consumption of dietary phytoestrogens during pregnancy may be relevant. Extracts from soy, red clover or licorice oil have potential as plant-derived medicines that could be used to treat polycystic ovary syndrome, a disease linked to hyperandrogenism and obesity, although clinical trials have not yet been conducted. Phytoestrogens may help prevent metabolic syndrome, although intervention studies will be always be ambiguous, because physical activity and reduced calorie consumption also have a significant impact. Nevertheless, extracts rich in phytoestrogens may be an alternative treatment or may complement conventional treatment for diseases linked with metabolic syndrome. This article is part of a Special Issue entitled 'Phytoestrogens'.

Vascular effects of phytoestrogens and alternative menopausal hormone therapy in cardiovascular disease

Phytoestrogens are estrogenic compounds of plant origin classified into different groups including isoflavones, lignans, coumestans and stilbenes. Isoflavones such as genistein and daidzein are the most studied and most potent phytoestrogens, and are found mainly in soy based foods. The effects of phytoestrogens are partly mediated via estrogen receptors (ERs): ERα, ERβ and possibly GPER. The interaction of phytoestrogens with ERs is thought to induce both genomic and non-genomic effects in many tissues including the vasculature. Some phytoestrogens such as genistein have additional non-ER-mediated effects involving signaling pathways such as tyrosine kinase. Experimental studies have shown beneficial effects of phytoestrogens on endothelial cells, vascular smooth muscle, and extracellular matrix. Phytoestrogens may also affect other pathophysiologic vascular processes such as lipid profile, angiogenesis, inflammation, tissue damage by reactive oxygen species, and these effects could delay the progression of atherosclerosis. As recent clinical trials showed no vascular benefits or even increased risk of cardiovascular disease (CVD) and CV events with conventional menopausal hormone therapy (MHT), phytoestrogens are being considered as alternatives to pharmacologic MHT. Epidemiological studies in the Far East population suggest that dietary intake of phytoestrogens may contribute to the decreased incidence of postmenopausal CVD and thromboembolic events. Also, the WHO-CARDIAC study supported that consumption of high soybean diet is associated with lower mortalities from coronary artery disease. However, as with estrogen, there has been some discrepancy between the experimental studies demonstrating the vascular benefits of phytoestrogens and the data from clinical trials. This is likely because the phytoestrogens clinical trials have been limited in many aspects including the number of participants enrolled, the clinical end points investigated, and the lack of long-term follow-up. Further investigation of the cellular mechanisms underlying the vascular effects of phytoestrogens and careful evaluation of the epidemiological evidence and clinical trials of their potential vascular benefits would put forward the use of phytoestrogens as an alternative MHT for the relief of menopausal symptoms and amelioration of postmenopausal CVD.

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.

Effects of phytoestrogens derived from soy bean on expression of adhesion molecules on HUVEC

BACKGROUND

The risks of hormone replacement therapy have led to a search for new alternatives such as phytoestrogens, plant compounds with estrogen-like biological activity. Isoflavones are the phytoestrogens most extensively studied and can be found in soybean, red clover and other plants. Due to this estrogen-like activity, phytoestrogens can have some effect on atherosclerosis. Human umbilical vein endothelial cells (HUVEC) have been extensively used to study the biology and pathobiology of human endothelial cells and most of the knowledge acquired is due to experiments with cultures of these cells.

OBJECTIVE

To evaluate the effects of the phytoestrogen extracts from Glycine max soy bean, genistein, formononetin, biochanin A and daidzein, as well as a mixture of these extracts (Mix), on expression of adhesion molecules, VCAM-1, ICAM-1 and E-selectin, by endothelial cell HUVEC, stimulated with lipopolysaccharide.

METHODS

HUVEC were cultured in medium EBM(2), pretreated with isoflavones for 24 and 48 h and then stimulated with lipopolysaccharide; in addition, isoflavones were added, after stimulation by lipopolysaccharide, to HUVEC. We evaluated the production of VCAM-1, ICAM-1 and E-selectin on cell surface, by cell-based enzyme immunoassay, and of sVCAM-1, sICAM-1 and sE-selectin in culture supernatant, by ELISA.

RESULTS

Genistein, formononetin, biochanin A and daidzein, as well as the Mix were able to reduce VCAM-1, ICAM-1 and E-selectin on cell surface and in culture supernatant. Conclusion Isoflavones extracted from Glycine max soy bean, in vitro, presented antiatherogenic effects, reducing the expression of adhesion molecules and acting as preventive agents as well as therapeutic agents.

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.

Phytoestrogens and post reproductive health

The use of phytoestrogens for various perceived health benefits is widespread. Despite 20 years of research the evidence for any significant health benefits remains inconclusive. Pre clinical trials have demonstrated both non-genomic and genomic actions of constituents of phytoestrogens including selective, but weak, binding to estrogen receptors, with a preference for ER B over ER A. Evidence of clinically relevant biological effects from observational studies and randomized trials has, in general, been lacking. Despite many trials there remains little evidence that phytoestrogens, whether dietary or supplemented, significantly relieve menopausal vasomotor symptoms or cognition. Several potential mechanisms for a positive effect on bone and cardiovascular health have been demonstrated however no fracture prevention data or cardiovascular end point benefit has yet been demonstrated. In vitro effects of phytoestrogens on breast cells have been both stimulatory and inhibitory however net effects appear neutral with observational studies finding no change in breast cancer risk. No effect has been seen on endometrial or other cancers and side effect profiles have, in general, been mild.

Red clover extract: a source for substances that activate peroxisome proliferator-activated receptor alpha and ameliorate the cytokine secretion profile of lipopolysaccharide-stimulated macrophages

OBJECTIVE

Inflammation and hyperlipidemia or dyslipidemia contribute to an increased risk of atherosclerosis and cardiovascular disease. Cardiovascular disease represents one of the major causes of premature death worldwide. The activation of peroxisome proliferator-activated receptor (PPAR) alpha, a drug target for hyperlipidemia and dyslipidemia, leads to an improved blood lipid profile. In this study, we determined the putative anti-inflammatory and PPARalpha stimulatory activities of red clover, an alternative to the classic hormone therapy used currently to treat menopausal symptoms.

METHODS

Lipopolysaccharide-induced macrophages were used as a model for anti-inflammatory activity, and a chimeric GAL4-PPARalpha system was used as a model for putative hypolipidemic activity.

RESULTS

Red clover extract and the isoflavones genistein and biochanin A were moderate PPARalpha activators. Daidzein only slightly activated PPARalpha, but its metabolite 6-hydroxydaidzein exerted a much higher PPARalpha activity. Similarly, the metabolite 3'-hydroxygenistein achieved higher activation efficiency than its precursor, genistein, did. In lipopolysaccharide-stimulated macrophages, red clover extract and its compounds reduced the secretion of proinflammatory cytokines, interleukin-6 and tumor necrosis factor alpha, increased the secretion of the anti-inflammatory interleukin-10, and/or reduced the expression of nuclear factor-kappaB, inducible nitric oxide synthase, and/or cyclooxygenase 2. Tumor necrosis factor alpha production was most efficiently reduced by biochanin A and genistein. Interleukin-6 levels were most efficiently reduced by genistein and equol.

CONCLUSIONS

Owing to its PPARalpha activation and modulation of the secreted cytokine profile, red clover extract is a putative candidate for preventing atherosclerosis and, thus, cardiovascular disease.

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.

Effect of Trifolium pratense-derived isoflavones on the lipid profile of postmenopausal women with increased body mass index

BACKGROUND

Since current clinical evidence indicates that conventional estrogen hormone therapy (HT) increases cardiovascular risk, alternatives to estrogens are growing in popularity, especially among high-risk populations.

OBJECTIVE

To determine the effect of Trifolium pratense-derived isoflavone supplementation on the lipid profile of postmenopausal women with increased body mass index (BMI).

METHODS

Sixty postmenopausal women aged > 40 years, HT non-users, were randomly assigned to one of two groups: either two capsules of T. pratense (80 mg red clover isoflavones) daily for a 90-day period or placebo of equal design. After a 7-day washout period, medication was crossed-over for another 90 days. Total cholesterol (TC), triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol (LDL-C) and lipoprotein A (LpA) levels were assessed at baseline, 90 and 180 days. Women were divided into two groups: those with increased BMI (>or=25 kg/m(2)) and those with BMI < 25 kg/m(2).

RESULTS

Fifty-three women (88.3%) completed the trial. T. pratense isoflavone supplementation had a positive effect on the lipid profile of women with increased BMI, evidenced by a significant decrease in TC, LDL-C and LpA levels.

CONCLUSIONS

Isoflavones derived from T. pratense are an attractive alternative therapeutic option for high-risk populations such as postmenopausal women with increased BMI and abnormal lipid profile.

Clinical studies of red clover (Trifolium pratense) dietary supplements in menopause: a literature review

Red clover (Trifolium pratense L., Fabaceae) botanical dietary supplements have received much attention recently for their potential use in the treatment of menopause symptoms, maintenance/improvement of bone and cardiovascular health, and reported benign effects on the breast and endometrium. Literature searches of four computerized databases were run to identify clinical studies of red clover botanical dietary supplements. The manufacturer of the red clover products used in the majority of the studies was contacted for unpublished information and/or clarification regarding the chemical content of their products. Red clover studies were reviewed that pertained to women's health or menopause. Clinical evidence is presently lacking to support the efficacy of semipurified red clover isoflavone extracts for alleviation of climacteric vasomotor symptoms or reduction of low-density lipoprotein levels in the blood. Furthermore, the safety of use of red clover isoflavone supplements in patients with breast or endometrial cancer has not been established. Limited evidence suggests possible efficacy in maintenance of bone health and improvement of arterial compliance, a risk factor for atherosclerosis. This literature review covers red clover botanical dietary supplement clinical studies having a possible impact on the health care of mature and menopausal women, and provides historical perspective regarding the traditional uses of red clover.

Phytoestrogens: perpetrators or protectors?

Phytoestrogens are estrogen-like substances produced by plants that account for some of the constituents present in vegetation that may be responsible for the health benefits of a diet rich in fruit and vegetables. Phytoestrogens have a plethora of different actions that they are capable of exerting on cellular metabolism. This review will focus on some of the major non-estrogen receptor-mediated cellular effects used by phytoestrogens and will draw attention to the fact that while they may have a number of beneficial effects, particularly in offering a protective effect against some hormone-dependent cancers, such as breast and prostate cancer, they may also have possible unfavorable effects by interfering with the functioning of normal cellular activities such as receptor-mediated signal transduction and DNA replication, as well as being genotoxic, mutagenic and promoting the proliferation of some cancer cells.

Rapid Estrogen Actions in the Cardiovascular System

In the last two decades, several studies have unveiled a series of original signaling mechanisms through which so-called "nuclear" receptors can mediate rapid actions of steroid hormones. These rapid signaling actions are independent of the synthesis of mRNA or protein, and are therefore known as "nontranscriptional" or "nongenomic" as opposed to the classical genomic mechanisms. Nongenomic signaling of estrogens plays a prominent role in nonreproductive tissues, and between these is the vascular wall. At this level, estrogen triggers rapid vasodilatation, exerts anti-inflammatory effects, stimulates endothelial growth and migration, and protects the vessels from atherosclerotic degeneration. Nongenomic signaling mechanisms have been involved in many of these actions and are increasingly considered to be of importance for vascular function in physiological and pathophysiological conditions. Rapid actions of steroid hormones have been implicated with vascular as well as with myocardial protection in animal experimental models. Moreover, the nongenomic signaling of estrogens is tightly interconnected with the nuclear pathways, and there are several indications that, through nongenomic modulation of signaling cascades, estrogens are also able to modulate the expression of several relevant genes in endothelial cells. In conclusion, while we are still in an early phase of the investigations of the nontranscriptional actions of steroid hormone receptors, it is clear that this newly recognized category of signaling mechanisms is responsible for critical steroid actions in nonreproductive tissues.

WAY-202196, a selective estrogen receptor-beta agonist, protects against death in experimental septic shock

OBJECTIVE

To determine the effect of an estrogen receptor-beta selective agent in experimental models of systemic infection and sepsis.

DESIGN

WAY-202196, a nonsteroidal selective estrogen receptor-beta agonist, was tested in the murine listeriosis model, the neutropenic rat Pseudomonas aeruginosa infection, and the mouse cecal ligation and puncture sepsis models.

SETTING

University-affiliated biomedical research laboratory.

SUBJECTS

BALB/c mice and Sprague-Dawley rats.

INTERVENTIONS

WAY-202196 or control (vehicle) was administered orally in doses ranging from 1.5 to 50 mg/kg at various time points in the three experimental model systems.

MEASUREMENTS AND MAIN RESULTS

Susceptibility of mice treated with a single oral dose of up to 50 mg/kg WAY-202196 did not differ from those treated with vehicle alone after systemic challenge by Listeria monocytogenes, suggesting a lack of generalized immunosuppression. In the neutropenic rat model, daily administration of WAY-202196 (50 mg/kg) significantly increased survival against an otherwise lethal challenge of P. aeruginosa 12.4.4 compared with the control group (83% vs. 25% survival; p < 0.05). Preservation of intestinal mucosal weight and prevention of histopathologic changes were also observed with the administration of WAY-202196. Similar results were obtained in a cecal ligation and puncture model, in which multiple oral doses of WAY-202196 (50 mg/kg) improved survival (83% vs. 0%; p < 0.05), preserved intestinal epithelial integrity, and significantly reduced systemic bacteremia and peritoneal interleukin-6 and tumor necrosis factor levels. The estrogen receptor-beta agonist provided a comparable level of protection in both male and female animals.

CONCLUSION

These results indicate that oral administration of WAY-202196 preserved gastrointestinal barrier function and improved outcome in experimental models of systemic infection and inflammation. WAY-202196 and similar agents may prove useful clinically as a novel treatment strategy for the treatment or prevention of severe sepsis.

The effect of red clover isoflavones on menopausal symptoms, lipids and vaginal cytology in menopausal women: a randomized, double-blind, placebo-controlled study

BACKGROUND

The unexpected results of the Women's Health Initiative study have decreased the use of conventional hormone therapy (HT), changing physicians' and patients' attitudes towards HT and increasing their interest in alternative options.

OBJECTIVE

The present study aimed to evaluate the effect of isoflavones contained in red clover extracts (Trifolium pratense) on menopausal symptoms, lipids and vaginal cytology in menopausal women.

METHODS

Sixty postmenopausal women aged >40 years, non-users of HT, with Kupperman index score 15, were double-blindly randomized to receive either a commercially available red clover isoflavone supplement (80 mg/day) or placebo for 90 days. Subsequently, after a 7-day washout period, subjects switched to receive the opposite treatment for a further 90 days. Kupperman index score was determined and fasting blood and vaginal cytologic sampling performed at baseline, 90 and 180 days.

RESULTS

Fifty-three women (88.3%) completed the trial. Mean age was 51.3 +/- 3.5 years, 69.7% of the women were aged 50 years or more. There was no significant effect on body mass index, weight or blood pressure after either treatment phase. Baseline Kupperman index score decreased significantly after each treatment phase, with the decrease more pronounced after the isoflavone phase (baseline: 27.2 +/- 7.7; after isoflavone: 5.9 +/- 3.9; after placebo: 20.9 +/- 5.3, p < 0.05). Red clover isoflavone supplementation significantly decreased the rate of menopausal symptoms and had a positive effect on vaginal cytology as expressed by improvement in karyopyknotic, cornification and basal cell maturation indices. Mean total cholesterol, low-density lipoprotein-cholesterol and triglyceride levels also decreased; however, only the latter was significantly lower compared with placebo.

CONCLUSIONS

Compared with placebo, red clover isoflavone supplementation in postmenopausal women significantly decreased menopausal symptoms and had a positive effect on vaginal cytology and triglyceride levels.

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.