Red clover extract: a source for substances that activate peroxisome proliferator-activated receptor alpha and ameliorate the cytokine secretion profile of lipopolysaccharide-stimulated macrophages. Menopause. 2010;17:379-387. [PMID: 20142789 DOI: 10.1097/gme.0b013e3181c94617]

Gut microbiota and metabolic profiles in chronic intermittent hypoxia-induced rats: disease-associated dysbiosis and metabolic disturbances

Aim

Chronic intermittent hypoxia (CIH) is a key characteristic of obstructive sleep apnea (OSA) syndrome, a chronic respiratory disorder. The mechanisms of CIH-induced metabolic disturbance and histopathological damage remain unclear.

Methods

CIH-induced rats underwent daily 8-h CIH, characterized by oxygen levels decreasing from 21% to 8.5% over 4 min, remaining for 2 min, and quickly returning to 21% for 1 min. The control rats received a continuous 21% oxygen supply. The levels of hypersensitive C reactive protein (h-CRP), tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), interleukin 8 (IL-8), and nuclear factor kappa-B (NF-κB) were measured by ELISA. Histological analysis of the soft palates was conducted using HE staining. The microbial profiling of fecal samples was carried out by Accu16STM assay. Untargeted metabolomics of serum and soft palate tissue samples were analyzed by UPLC-MS. The protein expression of cAMP-related pathways in the soft palate was determined by Western blot.

Results

After 28 h of CIH induction, a significant increase in pro-inflammatory cytokines was observed in the serum, along with mucosal layer thickening and soft palate tissue hypertrophy. CIH induction altered the diversity and composition of fecal microbiota, specifically reducing beneficial bacteria while increasing harmful bacteria/opportunistic pathogens. Notably, CIH induction led to a significant enrichment of genera such as Dorea, Oscillibacter, Enteractinococcus, Paenibacillus, Globicatella, and Flaviflexus genera. Meanwhile, Additionally, CIH induction had a notable impact on 108 serum marker metabolites. These marker metabolites, primarily involving amino acids, organic acids, and a limited number of flavonoids or sterols, were associated with protein transport, digestion and absorption, amino acid synthesis and metabolism, as well as cancer development. Furthermore, these differential serum metabolites significantly affected 175 differential metabolites in soft palate tissue, mainly related to cancer development, signaling pathways, amino acid metabolism, nucleotide precursor or intermediate metabolism, respiratory processes, and disease. Importantly, CIH induction could significantly affect the expression of the cAMP pathway in soft palate tissue.

Conclusions

Our findings suggest that targeting differential metabolites in serum and soft palate tissue may represent a new approach to clinical intervention and treatment of OSA simulated by the CIH.

Do macrophages play a role in the adverse effects of endocrine disrupting chemicals (EDCs) on testicular functions?

During the past decades, several endocrine disrupting chemicals (EDCs) have been confirmed to affect male reproductive function and fertility in animal studies. EDCs are suspected to exert similar effects in humans, based on strong associations between levels of antiandrogenic EDCs in pregnant women and adverse reproductive effects in infants. Testicular macrophages (tMΦ) play a vital role in modulating immunological privilege and maintaining normal testicular homeostasis as well as fetal development. Although tMΦ were not historically studied in the context of endocrine disruption, they have emerged as potential targets to consider due to their critical role in regulating cells such as spermatogonial stem cells (SSCs) and Leydig cells. Few studies have examined the impact of EDCs on the ability of testicular cells to communicate and regulate each other's functions. In this review, we recapitulate what is known about tMΦ functions and interactions with other cell types in the testis that support spermatogenesis and steroidogenesis. We also surveyed the literature for reports on the effects of the EDCs genistein and DEHP on tMΦ, SSCs, Sertoli and Leydig cells. Our goal is to explore the possibility that EDC disruption of tMΦ interactions with other cell types may play a role in their adverse effects on testicular developmental programming and functions. This approach will highlight gaps of knowledge, which, once resolved, should improve the risk assessment of EDC exposure and the development of safeguards to protect male reproductive functions.

Role of Phytoestrogen-Rich Bioactive Substances (Linum usitatissimum L., Glycine max L., Trifolium pratense L.) in Cardiovascular Disease Prevention in Postmenopausal Women: A Systematic Review and Meta-Analysis

The aim of this report was to determine the impact of flaxseed, soy and red clover, and their bioactive substances on the lipid profile in postmenopausal women in cardiovascular diseases prevention. We used the following databases: MEDLINE (PubMed), EMBASE and the Cochrane Library. Meta-analysis indicates that the intake of flaxseed by postmenopausal women is associated with a statistically significant reduction in total cholesterol (TC) levels (weighted-mean difference (WMD) = -0.26; 95% confidence interval (95% CI): -0.38 to -0.13; p = 0.0001), low-density lipoprotein cholesterol (LDL-C) levels (WMD = -0.19; 95% CI: -0.30 to -0.08; p = 0.0006), and high-density lipoprotein cholesterol (HDL-C) levels (WMD = -0.06; 95% CI: -0.11 to -0.01; p = 0.0150). The effect of soy protein on the lipid profile showed a significant decrease in TC levels: WMD = -0.15; 95% CI: -0.25-0.05; p = 0.0048, LDL-C levels: WMD = -0.15; 95% CI: -0.25-0.05; p = 0.0067, as well as a significant increase in HDL-C levels: WMD = 0.05; 95% CI: 0.02-0.08; p = 0.0034. Changes in the lipid profile showed a significant reduction in TC levels after the use of red clover (WMD = -0.11; 95% CI: -0.18--0.04; p = 0.0017) and a significant increase in HDL-C levels (WMD = 0.04; 95% CI: 0.01 to 0.07; p = 0.0165). This meta-analysis provides evidence that consuming flaxseed, soy and red clover can have a beneficial effect on lipids in postmenopausal women and suggest a favorable effect in preventing cardiovascular diseases.

The Structure Basis of Phytochemicals as Metabolic Signals for Combating Obesity

The consumption of phytochemicals, bioactive compounds in fruits and vegetables, has been demonstrated to ameliorate obesity and related metabolic symptoms by regulating specific metabolic pathways. This review summarizes the progress made in our understanding of the potential of phytochemicals as metabolic signals: we discuss herein selected molecular mechanisms which are involved in the occurrence of obesity that may be regulated by phytochemicals. The focus of our review highlights the regulation of transcription factors toll like receptor 4 (TLR4), nuclear factor (erythroid-derived 2)-like 2 (Nrf2), the peroxisome proliferator-activated receptors (PPARs), fat mass and obesity-associated protein (FTO) and regulation of microRNAs (miRNA). In this review, the effect of phytochemicals on signaling pathways involved in obesity were discussed on the basis of their chemical structure, suggesting molecular mechanisms for how phytochemicals may impact these signaling pathways. For example, compounds with an isothiocyanate group or an α, β-unsaturated carbonyl group may interact with the TLR4 signaling pathway. Regarding Nrf2, we examine compounds possessing an α, β-unsaturated carbonyl group which binds covalently with the cysteine thiols of Keap1. Additionally, phytochemical activation of PPARs, FTO and miRNAs were summarized. This information may be of value to better understand how specific phytochemicals interact with specific signaling pathways and help guide the development of new drugs to combat obesity and related metabolic diseases.

Biochanin A as a modulator of the inflammatory response: an updated overview and therapeutic potential

Uncontrolled inflammation and failure to resolve the inflammatory response are crucial factors involved in the progress of inflammatory diseases. Current therapeutic strategies aimed at controlling excessive inflammation are effective in some cases, though they may be accompanied by severe side effects, such as immunosuppression. Phytochemicals as a therapeutic alternative can have a fundamental impact on the different stages of inflammation and its resolution. Biochanin A (BCA) is an isoflavone known for its wide range of pharmacological properties, especially its marked anti-inflammatory effects. Recent studies have provided evidence of BCA's abilities to activate events essential for resolving inflammation. In this review, we summarize the most recent findings from pre-clinical studies of the pharmacological effects of BCA on the complex signaling network associated with the onset and resolution of inflammation and BCA's potential protective functionality in several models of inflammatory diseases, such as arthritis, pulmonary disease, neuroinflammation, and metabolic disease.

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

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

Anti-Inflammatory and Antioxidant Effects of Anthocyanins of Trifolium pratense (Red Clover) in Lipopolysaccharide-Stimulated RAW-267.4 Macrophages

Red clover (Trifolium pratense) possesses various dietary compounds that improve human health. However, the functions of anthocyanins in red clover remain unclear. Here we examined anti-inflammatory and antioxidant effects of red clover extract (RC) and red clover anthocyanins fraction (RCA) using lipopolysaccharide (LPS)-treated RAW 264.7 macrophages and identified dietary compounds. RC and RCA suppressed LPS-induced expression of genes such as tumor necrosis factor (TNF)α, interleukin (IL)1β, inducible nitric oxide synthase (iNOS), monocyte chemoattractant protein (MCP)1, and cyclooxygenase (COX)2. LPS-stimulated intracellular reactive oxygen species (ROS) production also was prevented by both RC and RCA. NADPH oxidase 1 (NOX1) gene and phosphorylation of p47^phox of NOX1 that were increased by LPS were inhibited in the cells treated with RCA. LPS-stimulated nuclear factor erythroid 2-related factor 2 (NRF2) gene expression and nuclear translocation of nuclear factor kappa B (NF-kB) subunit p65 were suppressed together with reduced iNOS and COX2 proteins by RCA. Additionally, 27 polyphenols and 7 anthocyanins from RC were identified and quantified. In conclusion, RC, especially RCA, exerted anti-inflammatory and anti-oxidative activities in vitro by regulating NF-κB and NRF2 signaling pathways, suggesting that anthocyanins in red clover are the potential candidates to reduce inflammation and oxidative stress.

Protective effects of 6,7,4'-trihydroxyisoflavone, a major metabolite of daidzein, on 6-hydroxydopamine-induced neuronal cell death in SH-SY5Y human neuroblastoma cells

Daidzein, one of the important isoflavones, is extensively metabolized in the human body following consumption. In particular, 6,7,4'-trihydroxyisoflavone (THIF), a major metabolite of daidzein, has been the focus of recent investigations due to its various health benefits, such as anti-cancer and anti-obesity effects. However, the protective effects of 6,7,4'-THIF have not yet been studied in models of Parkinson's disease (PD). Therefore, the present study aimed to investigate the protective activity of 6,7,4'-THIF on 6-hydroxydopamine (OHDA)-induced neurotoxicity in SH-SY5Y human neuroblastoma cells. Pretreatment of SH-SY5Y cells with 6,7,4'-THIF significantly inhibited 6-OHDA-induced neuronal cell death, lactate dehydrogenase release, and reactive oxygen species production. In addition, 6,7,4'-THIF significantly attenuated reductions in 6-OHDA-induced superoxide dismutase activity and glutathione content. Moreover, 6,7,4'-THIF attenuated alterations in Bax and Bcl-2 expression and caspase-3 activity in 6-OHDA-induced SH-SY5Y cells. Furthermore, 6,7,4'-THIF significantly reduced 6-OHDA-induced phosphorylation of c-Jun N-terminal kinase, p38 mitogen-activated protein kinase, and extracellular signal-regulated kinase 1/2. Additionally, 6,7,4'-THIF effectively prevented 6-OHDA-induced loss of tyrosine hydroxylase. Taken together, these results suggest that 6,7,4'-THIF, a major metabolite of daidzein, may be an attractive option for treating and/or preventing neurodegenerative disorders such as PD.

Perspectives Regarding the Role of Biochanin A in Humans

Biochanin A (BCA) is an isoflavone mainly found in red clover with poor solubility and oral absorption that is known to have various effects, including anti-inflammatory, estrogen-like, and glucose and lipid metabolism modulatory activity, as well as cancer preventive, neuroprotective, and drug interaction effects. BCA is already commercially available and is among the main ingredients in many types of supplements used to alleviate postmenopausal symptoms in women. The activity of BCA has not been adequately evaluated in humans. However, the results of many in vitro and in vivo studies investigating the potential health benefits of BCA are available, and the complex mechanisms by which BCA modulates transcription, apoptosis, metabolism, and immune responses have been revealed. Many efforts have been exerted to improve the poor bioavailability of BCA, and very promising results have been reported. This review focuses on the major effects of BCA and its possible molecular targets, potential uses, and limitations in health maintenance and treatment.

Effect of the flavonoid baicalin on the proliferative capacity of bovine mammary cells and their ability to regulate oxidative stress

Background

High-yielding dairy cows are prone to oxidative stress due to the high metabolic needs of homeostasis and milk production. Oxidative stress and inflammation are tightly linked; therefore, anti-inflammatory and/or natural antioxidant compounds may help improve mammary cell health. Baicalin, one of the major flavonoids in Scutellaria baicalensis, has natural antioxidant and anti-inflammatory properties in various cell types, but its effects on bovine mammary epithelial cells (BMECs) have not been investigated.

Methods

Explants from bovine mammary glands were collected by biopsy at the peak of lactation (approximately 60 days after the start of lactation) (n = three animals) to isolate BMECs corresponding to mature secretory cells. Cell viability, apoptosis, proliferative capacity and reactive oxygen species (ROS) production by BMECs were measured after increasing doses of baicalin were added to the culture media in the absence or presence of H₂O₂, which was used as an in vitro model of oxidative stress.

Results

Low doses of baicalin (1–10 µg/mL) had no or only slightly positive effects on the proliferation and viability of BMECs, whereas higher doses (100 or 200 µg/mL) markedly decreased BMEC proliferation. Baicalin decreased apoptosis rate at low concentrations (10 µg/mL) but increased apoptosis at higher doses. ROS production was decreased in BMECs treated with increasing doses of baicalin compared with untreated cells, and this decreased production was associated with increased intracellular concentrations of catalase and NRF-2. Irrespective of the dose, baicalin pretreatment attenuated H₂O₂-induced ROS production.

Discussion

These results indicate that baicalin exerts protective antioxidant effects on bovine mammary cells. This finding suggests that baicalin could be used to prevent oxidative metabolic disorders in dairy cows.

Bone health consequence of adjuvant Anastrozole in monotherapy or associated with biochanin-A in ovariectomized rat model

AIMS

We investigate the consequence of adjuvant anastrozole (ANA) in monotherapy or associated with biochanin A (BCA) in ovariectomized (OVX) rat model and the degree of developing bone loss in both conditions.

MATERIALS AND METHODS

Sixty female rats were assigned to six groups. Five groups were bilaterally OVX, and one was sham operated. The five groups were; ANA group (0.5 mg/kg b.wt orally), BCA (5 mg/kg b.wt intraperitoneally (I/P), co-treated group (BCA + ANA), two control groups receiving even distilled water orally or DMSO I/P for twenty weeks. Bone turnover biomarkers BALP, OC, PTH, TRAP and TNFα were determined in serum. Bone mineral content, histological and morphometric measurements on rat femurs were performed. BMD by X-ray technique on tibias of rats and CT analysis of lumbar vertebrae of all treated and sham groups were applied.

KEY FINDINGS

There was marked elevation in bone turnover biomarkers with high serum Ca and P content in the ANA-treated rats. Moreover marked elevation of TNFα, PTH, TC and TG, ANA caused severe changes in the BMD detected by X-ray in tibial bones and CT analysis of lumbar vertebrae of OVX rats. While I/P injection of BCA ameliorated the adverse bone health decrements caused by ANA.

SIGNIFICANCE

The study highlights the importance of the BCA supplementation in accordance with the ANA therapy in case of ovariectomized rat model of osteoporosis which is clinically presented in Postmenopausal women with breast cancer during which considerable risk of developing osteoporosis is predicted during treatment.

Aloin suppresses lipopolysaccharide‑induced inflammation by inhibiting JAK1‑STAT1/3 activation and ROS production in RAW264.7 cells

The anti-inflammatory effects of aloin, a bioactive ingredient extracted from Aloe vera, have been described previously. The present study aimed to assess these effects and explore the underlying molecular mechanisms. RAW264.7 cells were incubated with different doses of aloin (100, 150 and 200 µg/ml) and lipopolysaccharide (LPS; 100 ng/ml) for the indicated times. Then, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 expression levels were detected by western blot analysis and reverse transcription polymerase chain reaction (RT-PCR). The concentrations of inflammatory cytokines in the cell culture supernatant were determined by ELISA. Total nitric oxide (NO) assay and reactive oxygen species (ROS) kits were used to detect NO and ROS levels, respectively. Mitogen-activated protein kinase, nuclear factor κB and Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway activation were verified by western blot analysis. Confocal and nucleocytoplasmic separation experiments were used to detect STAT nuclear translocation. It was identified that aloin decreased the level of LPS-induced iNOS expression, inhibiting the release of interleukin (IL)-1β, IL-6, tumour necrosis factor-α and NO dose-dependently. Mechanistically, aloin suppressed LPS-induced JAK1-STAT1/3 activation and STAT1/3 nuclear translocation. Additionally, LPS-induced ROS production was inhibited by aloin. Collectively, these data suggest that aloin attenuated LPS-induced inflammation by inhibiting ROS-mediated activation of the JAK1-STAT1/3 signalling pathway, thereby inhibiting the nuclear translocation of STAT1/3 in RAW264.7 cells. The present study provides an experimental basis for the clinical application of aloin in inflammatory-associated diseases.

The Signaling Pathways Involved in the Antiatherosclerotic Effects Produced by Chinese Herbal Medicines

Cardiovascular diseases (CVDs) are considered to be the predominant cause of death in the world. Chinese herb medicines (CHMs) have been widely used for the treatment of CVDs in Asian countries for thousands of years. One reason of high efficacy of CHMs in treating CVDs is attributed to their inhibition in atherosclerosis (AS) development, a critical contributor to CVDs occurrence. Cumulative studies have demonstrated that CHMs alleviate atherogenesis via mediating pathophysiologic events involved in AS. However, there is deficiency in the summaries regarding antiatherogenic signal pathways regulated by CHMs. In this review, we focus on the signal cascades by which herb medicines and relevant extractives, derivatives, and patents improve proatherogenic processes including endothelium dysfunction, lipid accumulation, and inflammation. We mainly elaborate the CHMs-mediated signaling pathways in endothelial cells, macrophages, and vascular smooth muscle cells of each pathogenic event. Moreover, we briefly describe the other AS-related factors such as thrombosis, autophagy, immune response, and noncoding RNAs and effects of CHMs on them in the way of cascade regulation, which is helpful to further illustrate the molecular mechanisms of AS initiation and progression and discover newly effective agents for AS management.

The associations between plasma phytoestrogens concentration and metabolic syndrome risks in Chinese population

Metabolic syndrome (MetS) has become an important issue in the healthcare systems of both developed and developing countries. Phytoestrogens have shown estrogenic effects, which may involve in the etiology of MetS. The current study consisted of 293 MetS cases and 264 healthy controls. The concentrations of seven plasma phytoestrogens (daidzein, genistein, glycitein, equol, enterolactone, enterodiol and coumestrol) were detected by UPLC-MS/MS. Adjusted unconditional logistic regression was used to assess the associations between plasma phytoestrogens concentration and risks of MetS, as well as the associations between plasma phytoestrogens concentration and MetS components. Linear regression was used to evaluate the associations between equol concentration in equol-producers and MetS components. Higher concentrations of total isoflavone and equol were associated with decreased risk of MetS. The equol concentration was negatively associated with waist circumference and positively associated with HDL-C level. Increased daidzein was associated with both lower waist circumference and lower fasting blood glucose levels. Our results suggested that higher plasma total isoflavone, equol and daidzein might decrease MetS risk.

Effect of berberine on PPARα-NO signalling pathway in vascular smooth muscle cell proliferation induced by angiotensin IV

CONTEXT

The available treatments for the abnormal proliferation of vascular smooth muscle cells (VSMCs) are still dismal. Berberine has been demonstrated to possess extensive medicine activity, yet relatively little is known about its effect on VSMCs proliferation. Many studies showed that PPARα and NO participated in the process of VSMCs proliferation.

OBJECTIVE

To evaluate the effect of berberine and its possible influence on PPARα-NO pathway in angiotensin IV-stimulated VSMCs.

MATERIALS AND METHODS

The primary VSMCs were cultured with the tissue explants method, and the proliferation was characterized by MTT and protein content. Protein and mRNA expression were measured by Western blot and real-time RT-PCR, respectively. NO synthase (NOS) activity was measured using a spectrophotometric assay, and NO concentration was measured using the Griess assay.

RESULTS

Angiotensin IV (0.1 nmol/L)-induced VSMCs proliferation was evidenced by increasing the optical density at A₄₉₀ and total protein content (p < 0.01), which was inhibited by berberine (10, 30 and 100 μmol/L) in a concentration-dependent manner (p < 0.05). Angiotensin IV decreased the expression of PPARα at mRNA and protein level (p < 0.05), which occurred in parallel with declining eNOS mRNA expression, NOS activity and NO concentration (p < 0.01). Berberine at 30 μmol/L reversed the effects of angiotensin IV in VSMCs (p < 0.05), which were abolished by MK 886 (0.3 μmol/L) (p < 0.05).

DISCUSSION AND CONCLUSION

The results support the therapeutic effects of berberine on angiotensin IV-induced proliferation in cultured VSMCs at least partially through targeting the PPARα-NO signalling pathway.

The potential of natural products for targeting PPARα

Peroxisome proliferator activated receptors (PPARs) α, -γ and -β/δ are ligand-activated transcription factors and members of the superfamily of nuclear hormone receptor. These receptors play key roles in maintaining glucose and lipid homeostasis by modulating gene expression. PPARs constitute a recognized druggable target and indeed several classes of drugs used in the treatment of metabolic disease symptoms, such as dyslipidemia (fibrates, e.g. fenofibrate and gemfibrozil) and diabetes (thiazolidinediones, e.g. rosiglitazone and pioglitazone) are ligands for the various PPAR isoforms. More precisely, antidiabetic thiazolidinediones act on PPARγ, while PPARα is the main molecular target of antidyslipidemic fibrates. Over the past few years, our understanding of the mechanism underlying the PPAR modulation of gene expression has greatly increased. This review presents a survey on terrestrial and marine natural products modulating the PPARα system with the objective of highlighting how the incredible chemodiversity of natural products can provide innovative leads for this "hot" target.

Botanicals and Their Bioactive Phytochemicals for Women's Health

Botanical dietary supplements are increasingly popular for women's health, particularly for older women. The specific botanicals women take vary as a function of age. Younger women will use botanicals for urinary tract infections, especially Vaccinium macrocarpon (cranberry), where there is evidence for efficacy. Botanical dietary supplements for premenstrual syndrome (PMS) are less commonly used, and rigorous clinical trials have not been done. Some examples include Vitex agnus-castus (chasteberry), Angelica sinensis (dong quai), Viburnum opulus/prunifolium (cramp bark and black haw), and Zingiber officinale (ginger). Pregnant women have also used ginger for relief from nausea. Natural galactagogues for lactating women include Trigonella foenum-graecum (fenugreek) and Silybum marianum (milk thistle); however, rigorous safety and efficacy studies are lacking. Older women suffering menopausal symptoms are increasingly likely to use botanicals, especially since the Women's Health Initiative showed an increased risk for breast cancer associated with traditional hormone therapy. Serotonergic mechanisms similar to antidepressants have been proposed for Actaea/Cimicifuga racemosa (black cohosh) and Valeriana officinalis (valerian). Plant extracts with estrogenic activities for menopausal symptom relief include Glycine max (soy), Trifolium pratense (red clover), Pueraria lobata (kudzu), Humulus lupulus (hops), Glycyrrhiza species (licorice), Rheum rhaponticum (rhubarb), Vitex agnus-castus (chasteberry), Linum usitatissimum (flaxseed), Epimedium species (herba Epimedii, horny goat weed), and Medicago sativa (alfalfa). Some of the estrogenic botanicals have also been shown to have protective effects against osteoporosis. Several of these botanicals could have additional breast cancer preventive effects linked to hormonal, chemical, inflammatory, and/or epigenetic pathways. Finally, although botanicals are perceived as natural safe remedies, it is important for women and their healthcare providers to realize that they have not been rigorously tested for potential toxic effects and/or drug/botanical interactions. Understanding the mechanism of action of these supplements used for women's health will ultimately lead to standardized botanical products with higher efficacy, safety, and chemopreventive properties.

Synthesis and cytotoxicity evaluation of 3-amino-2-hydroxypropoxyisoflavone derivatives

Soy isoflavones exert a wide variety of biological activities, such as antioxidant, anti-inflammatory and anti-cancer properties. Nuclear factor erythroid 2-related factor 2 (Nrf2), a bZip transcription factor, plays a key role in soy isoflavones induced protection against oxidative stress and cancer. To obtain more effective isofavones, a series of 7,4'-bis-(3-amino-2-hydroxypropoxy), 7 or 4'-(3-amino-2-hydroxypropoxy) isoflavone derivatives have been synthesized as potential antitumor agents and Nrf2/ARE (antioxidant response element) activators. The cytotoxicity of these compounds in human cancer cell lines MDA-MB-231, HT-29, HCT116, HepG2 and 7402 was tested by MTT assay. In this study, the cytotoxicity of compound 3b exhibited highest cytotoxic activity and at the safety dose range, it also strongly up-regulated antioxidant response element (ARE)-luciferase reporter activity. In addition, compound 3b induced Nrf2 nuclear translocation and upregulated its downstream target genes NQO-1 and HO-1 at protein level. Taken together, our results suggest that compound 3b could be a potential agent for cancer themotherapy or cancer chemoprevention.

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.

Novel insights into the mechanisms whereby isoflavones protect against fatty liver disease

Fatty liver disease (FLD) is a growing public health problem worldwide. There is an urgent requirement for alternative and natural medicine to treat this disease. As phytochemicals, isoflavones have attracted considerable attention for the prevention of FLD. Numerous studies have revealed that isoflavones protect against FLD through various pathways which modulate fatty acid β-oxidation, lipid synthesis, and oxidative stress. Recently, the aldose reductase (AR)/polyol pathway has been reported to be involved in the development of FLD by modulating hepatic fructose production, peroxisome proliferator-activated receptor (PPAR)α activity, cytochrome P450 (CYP)2E1 expression, and gut bacterial endotoxin-induced cytokine release. It has been reported that some isoflavones are potent AR inhibitors. Here, we review the anti-FLD actions of isoflavones and the proposed mechanism whereby isoflavones protect against FLD, with regard to the AR/polyol pathway. We propose that isoflavones block the AR/polyol pathway and in turn reduce fructose production and subsequent fat accumulation in the liver in diabetic or high-glucose-diet mice. In addition, in rodents with alcoholic liver disease or nonalcoholic fatty liver disease/nonalcoholic steatohepatitis, inhibition of AR by isoflavones may improve PPARα-mediated fatty acid oxidation, reduce hepatic steatosis, and attenuate CYP2E1-mediated oxidative stress or AR/gut bacterial endotoxin-mediated cytokine overproduction, to alleviate progression of FLD.

The effects of Cordyceps sinensis phytoestrogen on estrogen deficiency-induced osteoporosis in ovariectomized rats

BACKGROUND

Isoflavones are naturally occurring plant chemicals belonging to the "phytoestrogen" class. The aim of the present study was to examine the effects of isoflavones obtained from Cordyceps sinensis (CSIF) on development of estrogen deficiency-induced osteoporosis in ovariectomized rats.

METHODS

After the rats were treated orally with CSIF, serum alkaline phosphatase (ALP), tartarate resistant acid phosphatase (TRAP), serum osteocalcin (OC), homocysteine (HCY), C-terminal crosslinked telopeptides of collagen type I (CTX), estradiol and interferonγ (IFN-γ) level were examined. At the same time, the urine calcium, plasma calcium, plasma phosphorus and the mass of uterus, thymus and body were also examined.

RESULTS

The beneficial effects of CSIF on improvement of osteoporosis in rats were attributable mainly to decrease ALP activity, TRAP activity, CTX level and IFN-γ level. At the same time, CSIF also increase the OC and estradiol level in ovariectomized osteopenic rats. The histological examination clearly showed that dietary CSIF can prevent bone loss caused by estrogen deficiency.

CONCLUSION

The significant estrogenic activity of CSIF demonstrated that CSIF has significant estrogenic effects in OVX rats.

Effect of Trifolium pratense extract on methionine-choline-deficient diet-induced steatohepatitis in C57BL/6 mice

AIM

The potential of Trifolium pratense (red clover) extract in the prevention of lipid disorder has attracted increasing attention in recent years. In this study, the aim was to determine whether and how red clover extract affected the development of murine diet-induced non-alcoholic steatohepatitis.

METHODS

Non-alcoholic steatohepatitis was induced in C57BL/6 mice by feeding mice with a methionine-choline-deficient (MCD) diet. Hematoxylin and eosin staining was used for histological analyses. Real-time PCR was used to analyze the mRNA expression levels.

RESULTS

Hepatic steatosis and necroinflammation was observed in MCD diet-fed mice, and this diet-induced steatosis was significantly attenuated, whereas liver inflammation was not significantly attenuated, by red clover extract treatment. Consistent with the results of H&E staining, the MCD diet-induced increase of liver triglycerides and cholesterol levels were significantly reduced by red clover extract treatment. However, with the improvement in hepatic steatosis, mRNA levels of acetyl CoA oxidase, carnitine palmitoyl transferase-1, and liver fatty acid-binding protein, three genes regulated by peroxisome proliferator-activated receptor (PPAR) α, were unaffected.

CONCLUSION

Red clover extract alleviated MCD diet-induced hepatic steatosis, but did not ameliorate liver inflammation in C57BL/6 mice, and the improvement in hepatic steatosis was not through activating PPARα.

Natural product agonists of peroxisome proliferator-activated receptor gamma (PPARγ): a review

Agonists of the nuclear receptor PPARγ are therapeutically used to combat hyperglycaemia associated with the metabolic syndrome and type 2 diabetes. In spite of being effective in normalization of blood glucose levels, the currently used PPARγ agonists from the thiazolidinedione type have serious side effects, making the discovery of novel ligands highly relevant.

Natural products have proven historically to be a promising pool of structures for drug discovery, and a significant research effort has recently been undertaken to explore the PPARγ-activating potential of a wide range of natural products originating from traditionally used medicinal plants or dietary sources. The majority of identified compounds are selective PPARγ modulators (SPPARMs), transactivating the expression of PPARγ-dependent reporter genes as partial agonists. Those natural PPARγ ligands have different binding modes to the receptor in comparison to the full thiazolidinedione agonists, and on some occasions activate in addition PPARα (e.g. genistein, biochanin A, sargaquinoic acid, sargahydroquinoic acid, resveratrol, amorphastilbol) or the PPARγ-dimer partner retinoid X receptor (RXR; e.g. the neolignans magnolol and honokiol). A number of in vivo studies suggest that some of the natural product activators of PPARγ (e.g. honokiol, amorfrutin 1, amorfrutin B, amorphastilbol) improve metabolic parameters in diabetic animal models, partly with reduced side effects in comparison to full thiazolidinedione agonists. The bioactivity pattern as well as the dietary use of several of the identified active compounds and plant extracts warrants future research regarding their therapeutic potential and the possibility to modulate PPARγ activation by dietary interventions or food supplements.

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'.

High-throughput 16S rRNA gene sequencing reveals alterations of intestinal microbiota in myalgic encephalomyelitis/chronic fatigue syndrome patients

Human intestinal microbiota plays an important role in the maintenance of host health by providing energy, nutrients, and immunological protection. Intestinal dysfunction is a frequent complaint in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) patients, and previous reports suggest that dysbiosis, i.e. the overgrowth of abnormal populations of bacteria in the gut, is linked to the pathogenesis of the disease. We used high-throughput 16S rRNA gene sequencing to investigate the presence of specific alterations in the gut microbiota of ME/CFS patients from Belgium and Norway. 43 ME/CFS patients and 36 healthy controls were included in the study. Bacterial DNA was extracted from stool samples, PCR amplification was performed on 16S rRNA gene regions, and PCR amplicons were sequenced using Roche FLX 454 sequencer. The composition of the gut microbiota was found to differ between Belgian controls and Norwegian controls: Norwegians showed higher percentages of specific Firmicutes populations (Roseburia, Holdemania) and lower proportions of most Bacteroidetes genera. A highly significant separation could be achieved between Norwegian controls and Norwegian patients: patients presented increased proportions of Lactonifactor and Alistipes, as well as a decrease in several Firmicutes populations. In Belgian subjects the patient/control separation was less pronounced, however some abnormalities observed in Norwegian patients were also found in Belgian patients. These results show that intestinal microbiota is altered in ME/CFS. High-throughput sequencing is a useful tool to diagnose dysbiosis in patients and could help designing treatments based on gut microbiota modulation (antibiotics, pre and probiotics supplementation).

The expression and role of peroxisome proliferator-activated receptor α in atherosclerosis

Peroxisome proliferator-activated receptor α (PPAR-α) has been detected in the liver, kidney, heart and skeletal muscle. The expression and mechanism of PPAR-α in atherosclerosis remains unclear. The present study was undertaken in order to examine the expression and role of PPAR-α in programmed atherosclerosis induced by a high‑fat diet and balloon-injury in rabbits. Rabbits were randomly divided into 3 groups: control, high-fat diet and high-fat diet+balloon‑injury groups. The high-fat diet and high-fat diet+balloon-injury groups were further divided into 6-, 8- and 10-week groups. Real-time quantitative PCR analysis was used to detect PPAR-α mRNA and immunohistochemistry (IHC) and western blot analysis were used to examine PPAR-α protein expression. Tumor necrosis factor (TNF)-α, interleukin (IL)-10 and P-selectin levels in the rabbits were measured by enzyme-linked immunosorbent assay (ELISA). In the high-fat or high-fat diet+balloon-injury groups, the vascular thickness was markedly higher than in the control group (P<0.01). PPAR-α protein and mRNA were significantly increased in the high-fat diet group as compared with the control group (P<0.01). Furthermore, there were marked changes from 6 to 10 weeks in the high-fat diet group (P<0.01). Compared with the control group, PPAR-α protein and mRNA were increased in the high-fat diet+balloon-injury group (P<0.01). There were significant differences of PPAR-α protein and mRNA at various time points in the high-fat diet+balloon‑injury group, as shown by real-time quantitative PCR and IHC (P<0.01). As shown by western blotting, there were no differences between the high-fat diet + balloon-injury 8- and 10-week groups (P>0.05). In those arteries that were occluded by ≥60%, PPAR-α expression was lower than that in the arteries which were occluded <60% in the high‑fat diet+balloon-injury 10-week group. In the high-fat diet and high-fat diet+balloon-injury groups, the levels of IL-10, TNF-α and P-selectin were upregulated compared with the control group. However, from weeks 8 to 10, TNF-α and P-selectin were decreased and IL-10 was still increased in the high-fat diet+balloon-injury group. The results of this study demonstrate that PPAR-α has preventive effects on atherosclerosis, which may be related to the regulation of inflammation.

The role of cytokines in cardiovascular disease in menopause

Various studies suggest that increased levels of pro-inflammatory cytokines play a key role in the declining ovarian function and the resulting complications associated with menopause. In this review article, the authors outline the role of pro- and anti-inflammatory cytokines in cardiovascular disease during menopause.

Red clover extract exerts antidiabetic and hypolipidemic effects in db/db mice

To investigate the effects of red clover extract on the blood glucose and lipid levels of type 2 diabetic db/db mice, male db/db mice were treated with this extract for a period of 5 weeks. The red clover extract had a significant effect on lowering the blood glucose levels of db/db mice. The serum triglyceride, serum total cholesterol, liver triglyceride and liver cholesterol levels for diabetic mice receiving red clover extract were significantly lower compared to those of the untreated diabetic mice. The mRNA expression of two target genes transcriptionally regulated by peroxisome proliferator-activated receptor (PPAR)γ was determined by quantitative real-time RT-PCR, and red clover extract was observed to significantly upregulate hepatic glucokinase and CD36 expression. Four target genes transcriptionally regulated by PPARα were also assayed, and red clover extract was observed to significantly downregulate hepatic apolipoprotein C3 expression whereas it had no significant effect on apolipoprotein A5, acetyl CoA oxidase and carnitine palmitoyl transferase-1 expression. In addition, hepatic mRNA expression of fatty acid synthase was also observed to be downregulated by red clover extract treatment. Thus, we conclude that red clover extract significantly improves the glucose and lipid homeostasis in db/db diabetic mice and that these effects are achieved at least in part by activating hepatic PPARα/γ and by inhibiting hepatic fatty acid synthase.

New synthetic pyridine derivate as potential elicitor in production of isoflavonoids and flavonoids in Trifolium pratense L. suspension culture

The production of secondary metabolites in Trifolium pratense L. suspension culture of the family of legume plants (Fabaceae) is low, and therefore there was an attempt to increase it by elicitation. New synthetic substance, 2-(2-fluoro-6-nitrobenzylsulfanyl)pyridine-4-carbothioamide, was tested as elicitor--a substance that showed the best elicitation effect after 48-hour application of 1 μmol L⁻¹ concentration. Maximum contents of genistin (11.60 mg g⁻¹ DW), daidzein (8.31 mg g⁻¹ DW), and genistein (1.50 mg g⁻¹ DW) were recorded, and the production of these isoflavonoids thus significantly increased, when compared with the control, by 152%, 151%, and 400%. The maximum content of flavonoids (5.78 mg g⁻¹ DW) and the increase in the production by 142%, when compared with the control, were induced by 6-hour application of 100 μmol L⁻¹ concentration. The tested substance showed to be an effective elicitor of phenylpropane metabolism.

Red clover extract ameliorates dyslipidemia in streptozotocin-induced diabetic C57BL/6 mice by activating hepatic PPARα

The effects of red clover extract and its bioactive components, biochanin A and formononetin, on the blood glucose and lipid levels of streptozotocin (STZ) induced-diabetic mice were investigated. Male diabetic C57BL/6 mice were induced by multiple low-dose STZ administration and then treated with red clover extract or isoflavones for a period of 3 weeks. Red clover extract had no significant effect on lowering the blood glucose levels of STZ-diabetic mice. Similarly, biochanin A and formononetin exerted no hypoglycemic effect. However, the serum triglycerides, total cholesterols and low-density lipoprotein-cholesterol levels for STZ-diabetic mice receiving red clover extract were significantly lower than that of untreated STZ-diabetic mice. In addition, treatment with biochanin A or formononetin significantly ameliorated these lipid profiles in diabetic mice. The mRNA expression of two target genes transcriptionally regulated by peroxisome proliferator-activated receptor (PPAR) α were determined by semi-quantitative RT-PCR and biochanin A or formononetin were found to significantly down-regulate hepatic APOC3 expression, whereas they had no significant effect on hepatic APOA5 expression. Thus we conclude that red clover extract and biochanin A or formononetin significantly ameliorate the lipid profiles of STZ-diabetic mice and these effects are achieved at least in part by activating hepatic PPARα.

Anti-inflammatory effects and the underlying mechanisms of action of daidzein in murine macrophages stimulated with Prevotella intermedia lipopolysaccharide

BACKGROUND AND OBJECTIVE

Host modulatory agents directed at inhibiting specific proinflammatory mediators could be beneficial in terms of attenuating periodontal disease progression and potentially enhancing therapeutic responses. The aim of this study was to investigate whether daidzein could modulate the production inflammatory mediators in macrophages stimulated with lipopolysaccharide (LPS) from Prevotella intermedia, a pathogen implicated in periodontal disease, and to delineate underlying mechanisms of action.

MATERIAL AND METHODS

LPS was extracted from P. intermedia ATCC 25611 cells by the standard hot phenol-water method. The amounts of nitric oxide (NO) and interleukin-6 (IL-6) secreted into the culture medium were assayed. A real-time PCR was performed to quantify inducible nitric oxide synthase (iNOS) and IL-6 mRNA expression. We used immunoblot analysis to characterize iNOS protein expression, phosphrylation of c-Jun N-terminal kinase (JNK) and p38, degradation of inhibitory κB-α (IκB-α), nuclear translocation of nuclear factor-κB (NF-κB) subunits and phosphorylation of signal transducer and activator of transcription 1 (STAT1). The DNA-binding activity of NF-κB was assessed by using ELISA-based kits.

RESULTS

Daidzein significantly inhibited the production of NO and IL-6, as well as their mRNA expression, in P. intermedia LPS-treated RAW264.7 cells. The JNK and p38 pathways were not involved in the regulation of LPS-induced NO and IL-6 release by daidzein. Daidzein inhibited the degradation of IκB-α induced by P. intermedia LPS. In addition, daidzein suppressed NF-κB transcriptional activity via regulation of the nuclear translocation and DNA-binding activity of NF-κB p50 subunit and blocked STAT1 phosphorylation.

CONCLUSION

Although additional studies are required to dissect the molecular mechanism of action, our results suggest that daidzein could be a promising agent for treating inflammatory periodontal disease. Further research in animal models of periodontitis is necessary to better evaluate the potential of daidzein as a novel therapeutic agent to treat periodontal disease.

Isoflavones and PPAR Signaling: A Critical Target in Cardiovascular, Metastatic, and Metabolic Disease

Isoflavone intake through foods and dietary supplements has both health advocates and critics. The latter come from a concern about the estrogenic effects of isoflavones in certain species. However, careful removal of isoflavones and other estrogens from the diet of rodents leads to the metabolic syndrome. These results suggest that isoflavones have other mechanisms of action, potentially those involving regulation of fatty acid metabolism via the nuclear receptors PPARα and PPARγ. The goal of this paper was to examine the evidence for isoflavone/PPAR signaling and to identify diseases in which such signaling would have an important impact. It is therefore of note that investigators using a chemical structure approach to discover PPAR ligands identified isoflavones as the best structures in the library of compounds that they tested. Future studies will involve careful identification of the underlying mechanisms whereby isoflavones have their action via PPAR signaling.

Potential health-modulating effects of isoflavones and metabolites via activation of PPAR and AhR

Isoflavones have multiple actions on cell functions. The most prominent one is the activation of estrogen receptors. Other functions are often overlooked, but are equally important and explain the beneficial health effects of isoflavones. Isoflavones are potent dual PPARα/γ agonists and exert anti-inflammatory activity, which may contribute to the prevention of metabolic syndrome, atherosclerosis and various other inflammatory diseases. Some isoflavones are potent aryl hydrocarbon receptor (AhR) agonists and induce cell cycle arrest, chemoprevention and modulate xenobiotic metabolism. This review discusses effects mediated by the activation of AhR and PPARs and casts a light on the concerted action of isoflavones.