Growth inhibition of human breast cancer cells by herbs and phytoestrogens

Beyond Metabolism: The Complex Interplay Between Dietary Phytoestrogens, Gut Bacteria, and Cells of Nervous and Immune Systems

The human body has a large, diverse community of microorganisms which not only coexist with us, but also perform many important physiological functions, including metabolism of dietary compounds that we are unable to process ourselves. Furthermore, these bacterial derived/induced metabolites have the potential to interact and influence not only the local gut environment, but the periphery via interaction with and modulation of cells of the immune and nervous system. This relationship is being further appreciated every day as the gut microbiome is researched as a potential target for immunomodulation. A common feature among inflammatory diseases including relapsing-remitting multiple sclerosis (RRMS) is the presence of gut microbiota dysbiosis when compared to healthy controls. However, the specifics of these microbiota-neuro-immune system interactions remain unclear. Among all factors, diet has emerged as a strongest factor regulating structure and function of gut microbial community. Phytoestrogens are one class of dietary compounds emerging as potentially being of interest in this interaction as numerous studies have identified depletion of phytoestrogen-metabolizing bacteria such as Adlercreutzia, Parabacteroides and Prevotella in RRMS patients. Additionally, phytoestrogens or their metabolites have been reported to show protective effects when compounds are administered in the animal model of MS, Experimental Autoimmune Encephalomyelitis (EAE). In this review, we will illustrate the link between MS and phytoestrogen metabolizing bacteria, characterize the importance of gut bacteria and their mechanisms of action in the production of phytoestrogen metabolites, and discuss what is known about the interactions of specific compounds with cells immune and nervous system. A better understanding of gut bacteria-mediated phytoestrogen metabolism and mechanisms through which these metabolites facilitate their biological actions will help in development of novel therapeutic options for MS as well as other inflammatory diseases.

Analyzing bioactive effects of the minor hop compound xanthohumol C on human breast cancer cells using quantitative proteomics

Minor prenylated hop compounds have been attracting increasing attention due to their promising anticarcinogenic properties. Even after intensive purification from natural raw extracts, allocating certain activities to single compounds or complex interactions of the main compound with remaining impurities in very low concentration is difficult. In this study, dose-dependent antiproliferative and cytotoxic effects of the promising xanthohumol (XN) analogue xanthohumol C (XNC) were evaluated and compared to XN and a XN-enriched hop extract (XF). It was demonstrated that the cell growth inhibition of human breast cancer cell line (MCF-7) significantly increases after being treated with XNC compared to XN and XF. Based on label-free data-dependent acquisition proteomics, physiological influences on the proteome of MCF-7 cells were analyzed. Different modes of action between XNC and XN treated MCF-7 cells could be postulated. XNC causes ER stress and seems to be involved in cell-cell adhesion, whereas XN influences cell cycles and DNA replication as well as type I interferon signaling pathway. The results demonstrate the utility of using quantitative proteomics for bioactivity screenings of minor hop compounds and underscore the importance of isolating highly pure compounds into their distinct forms to analyze their different and possibly synergistic activities and modes of action.

Prescription of Chinese herbal products is associated with a decreased risk of invasive breast cancer

The finding of a decrease in endometrial cancer incidence among breast cancer survivors following the use of Chinese herbal products (CHPs) has led to speculation that CHPs might play a role in breast cancer prevention.This study provides an overview of breast cancer incidence, comparing CHP users with those who do not use traditional Chinese medicine (TCM), referred to as non-TCM users. The results can provide information to clinicians for counseling women about the preventive use of TCM.A total of 184,386 women (20-79 years of age) were recruited from a nationwide 1-million-person representative sample of those covered by National Health Insurance in Taiwan and were followed from 1999 to 2012. A total of 1853 incidents of invasive breast cancer were diagnosed. The person-year approach with the Poisson assumption was used to estimate the incidence density rate. The age-specific hazard ratios of breast cancer in relation to either CHP or siwutang (SWT) use were calculated with multivariate Cox proportional hazard regression.More than 78% of patients had used a CHP at some point previously. The overall incidence density rate of breast cancer for non-TCM users was estimated at 1.73 per 10,000 patient-years. The corresponding values for CHP and SWT users were lower than those of the non-TCM group (CHP group = 0.85; SWT group = 0.63 per 10,000 patient-years). The covariate adjusted HRs for breast cancer were 0.57 (95% confidence interval [CI] 0.50-0.65) and 0.36 (95% CI 0.28-0.46) in women using CHPs and SWT, respectively. The findings were confirmed using propensity score matching.Consumption of CHPs reduces the incidence of invasive breast cancer. Although the mechanism of action of these products is unclear, their use as a preventive agent for breast cancer is appropriate for many women at an increased risk of breast cancer.

Cycloartenol triterpenoid saponins from Cimicifuga simplex (Ranunculaceae) and their biological effects

The constituents of Cimicifuga plants have been extensively investigated, and the principal metabolites are 9,19-cyclolanostane triterpenoid glycosides, which are distributed widely in Cimicifuga plants, but not in other members of the Ranunculaceae family, and are considered to be characteristics of the Cimicifuga genus. This type of triterpenoid glycoside possesses several important biological activities. More than 120 cycloartane triterpene glycosides have been isolated from Cimicifuga simplex Wormsk. The aim of this review article is to summarize all the major findings based on the available scientific literatures on C. simplex, with a focus on the identified 9,19-cyclolanostane triterpenoid glycosides. Biological studies of cycloartane triterpene glycosides from Cimicifuga spp. are also discussed.

A systematic review of non-hormonal treatments of vasomotor symptoms in climacteric and cancer patients

The cardinal climacteric symptoms of hot flushes and night sweats affect 24-93% of all women during the physiological transition from reproductive to post-reproductive life. Though efficacious, hormonal therapy and partial oestrogenic compounds are linked to a significant increase in breast cancer. Non-hormonal treatments are thus greatly appreciated.

This systematic review of published hormonal and non-hormonal treatments for climacteric, and breast and prostate cancer-associated hot flushes, examines clinical efficacy and therapy-related cancer risk modulation.

A PubMed search included literature up to June 19, 2014 without limits for initial dates or language, with the search terms, (hot flush* OR hot flash*) AND (clinical trial* OR clinical stud*) AND (randomi* OR observational) NOT review). Retrieved references identified further papers. The focus was on hot flushes; other symptoms (night sweats, irritability, etc.) were not specifically screened. Included were some 610 clinical studies where a measured effect of the intervention, intensity and severity were documented, and where patients received treatment of pharmaceutical quality. Only 147 of these references described studies with alternative non-hormonal treatments in post-menopausal women and in breast and prostate cancer survivors; these results are presented in Additional file 1.

The most effective hot flush treatment is oestrogenic hormones, or a combination of oestrogen and progestins, though benefits are partially outweighed by a significantly increased risk for breast cancer development.

This review illustrates that certain non-hormonal treatments, including selective serotonin reuptake inhibitors, gabapentin/pregabalin, and Cimicifuga racemosa extracts, show a positive risk-benefit ratio.

Key points

Several non-hormonal alternatives to hormonal therapy have been established and registered for the treatment of vasomotor climacteric symptoms in peri- and post-menopausal women.

There are indications that non-hormonal treatments are useful alternatives in patients with a history of breast and prostate cancer. However, confirmation by larger clinical trials is required.

Synergistic Action of Flavonoids, Baicalein, and Daidzein in Estrogenic and Neuroprotective Effects: A Development of Potential Health Products and Therapeutic Drugs against Alzheimer's Disease

Despite the classical hormonal effect, estrogen has been reported to mediate neuroprotection in the brain, which leads to the searching of estrogen-like substances for treating neurodegenerative diseases. Flavonoids, a group of natural compounds, are well known to possess estrogenic effects and used to substitute estrogen, that is, phytoestrogen. Flavonoid serves as one of the potential targets for the development of natural supplements and therapeutic drugs against different diseases. The neuroprotection activity of flavonoids was chosen for a possible development of anti-Alzheimer's drugs or food supplements. The estrogenic activity of two flavonoids, baicalein and daidzein, were demonstrated by their strong abilities in stimulating estrogen receptor phosphorylation and transcriptional activation of estrogen responsive element in MCF-7 breast cells. The neuroprotection effects of flavonoids against β-amyloid (Aβ) were revealed by their inhibition effects on in vitro Aβ aggregation and Aβ-induced cytotoxicity in PC12 neuronal cells. More importantly, the estrogenic and neuroprotective activities of individual flavonoid could be further enhanced by the cotreatment in the cultures. Taken together, this synergistic effect of baicalein and daidzein might serve as a method to improve the therapeutic efficacy of different flavonoids against Aβ, which might be crucial in developing those flavonoidsin treating Alzheimer's disease in the future.

Casticin potentiates TRAIL-induced apoptosis of gastric cancer cells through endoplasmic reticulum stress

Background

Casticin is one of the main active components obtained from Fructus Viticis and has been reported to exert anti-carcinogenic activity on a variety of cancer cells but the precise mechanism underlying this activity remains unclear.

Materials and Methods

Apoptotic activities of casticin (1.0 µmol/l) and TRAIL (25, 50 ng/ml) alone or in combination in the gastric cancer cell lines BGC-823, SGC-7901 and MGC-803 were detected by the use of a cell apoptosis ELISA detection kit, flow cytometry (FCM) with propidium iodide (PI) staining and activities of caspase-3, -8 and -9 by ELISA and cleavage of polyADP-ribose polymerase (PARP) protein using western blot analysis. Death receptors (DR) expression levels were evaluated using FCM analysis and western blotting. 2′, 7′-dichlorofluorescein diacetate (DCFH-DA) was used as a probe to measure the increase in reactive oxygen species (ROS) levels in cells. Multiple interventions, such as siRNA transfection and pharmacological inhibitors were used to explore the mechanisms of these actions.

Results

Subtoxic concentrations of casticin significantly potentiated TRAIL-induced cytotoxicity and apoptosis in BGC-823, SGC-7901 and MGC-803 cells. Casticin dramatically upregulated DR5 receptor expression but had no effects on DR4 or decoy receptors. Deletion of DR5 by siRNA significantly reduced the apoptosis induced by the co-application of TRAIL and casticin. Gene silencing of the CCAAT/enhancer binding protein homologous protein (CHOP) and pretreatment with salubrinal, an endoplasmic reticulum (ER) stress inhibitor, attenuated casticin-induced DR5 receptor expression, and apoptosis and ROS production. Casticin downregulated the expression levels of the cell survival proteins cFLIP, Bcl-2, XIAP, and survivin. In addition, casticin also induced the expressions of DR5 protein in other gastric cancer cells (SGC-7901 and MGC-803).

Conclusion/Significance

Casticin enhances TRAIL-induced apoptosis through the downregulation of cell survival proteins and the upregulation of DR5 receptors through actions on the ROS-ER stress-CHOP pathway.

Specialty supplements and breast cancer risk in the VITamins And Lifestyle (VITAL) Cohort

BACKGROUND

Use of nonvitamin, nonmineral "specialty" supplements has increased substantially over recent decades. Several supplements may have anti-inflammatory or anticancer properties. Additionally, supplements taken for symptoms of menopause have been associated with reduced risk of breast cancer in two case-control studies. However, there have been no prospective studies of the association between the long-term use of these supplements and breast cancer risk.

METHODS

Participants were female members of the VITamins And Lifestyle (VITAL) Cohort. Postmenopausal women, ages 50 to 76 years, who were residents of western Washington State, completed a 24-page baseline questionnaire in 2000 to 2002 (n = 35,016). Participants were queried on their recency (current versus past), frequency (days/week), and duration (years) of specialty supplement use. Incident invasive breast cancers (n = 880) from 2000 to 2007 were obtained from the Surveillance, Epidemiology, and End Results registry. Multivariable-adjusted hazards ratios (HR) and 95% confidence intervals (95% CI) were estimated by Cox proportional hazards models.

RESULTS

Current use of fish oil was associated with reduced risk of breast cancer (HR, 0.68; 95% CI, 0.50-0.92). Ten-year average use was suggestive of reduced risk (P trend = 0.09). These results held for ductal but not lobular cancers. The remaining specialty supplements were not associated with breast cancer risk: Specifically, use of supplements sometimes taken for menopausal symptoms (black cohosh, dong quai, soy, or St. John's wort) was not associated with risk.

CONCLUSIONS

Fish oil may be inversely associated with breast cancer risk.

IMPACT

Fish oil is a potential candidate for chemoprevention studies. Until that time, it is not recommended for individual use for breast cancer prevention.

Black cohosh has central opioid activity in postmenopausal women: evidence from naloxone blockade and positron emission tomography neuroimaging

OBJECTIVE

To test whether black cohosh (BC) exhibits an action on the central endogenous opioid system in postmenopausal women.

DESIGN

This was a mechanistic study conducted in the same individuals of luteinizing hormone pulsatility with a saline/naloxone challenge (n = 6) and positron emission tomography with [C]carfentanil, a selective micro-opioid receptor radioligand (n = 5), before and after 12 weeks of unblinded treatment with a popular BC daily supplement.

RESULTS

BC treatment for 12 weeks at a standard dose (Remifemin, 40 mg/day) had no effect on spontaneous luteinizing hormone pulsatility or estrogen concentrations. With naloxone blockade, there was an unexpected suppression of mean luteinizing hormone pulse frequency (saline vs naloxone = 9.0 +/- 0.6 vs 6.0 +/- 0.7 pulses/16 h; P = 0.056), especially during sleep when the mean interpulse interval was prolonged by approximately 90 minutes (saline night interpulse interval = 103 +/- 9 min vs naloxone night interpulse interval = 191 +/- 31 min, P = 0.03). There were significant increases in mu-opioid receptor binding potential in the posterior and subgenual cingulate, temporal and orbitofrontal cortex, thalamus, and nucleus accumbens ranging from 10% to 61% across brain regions involved in emotional and cognitive function. In contrast, binding potential reductions of lesser magnitude were observed in regions known to be involved in the placebo response (anterior cingulate and anterior insular cortex).

CONCLUSIONS

Using two different challenge paradigms for the examination of central opioid function, a neuropharmacologic action of BC treatment was demonstrated in postmenopausal women.

Effects of phytoestrogen on mitochondrial structure and function of hippocampal CA1 region of ovariectomized rats

The present study was undertaken to evaluate whether estrogen deprivation might lead to mitochondrial alteration of hippocampal neurons of ovariectomized (OVX) rats, and to evaluate the protective effect of estrogen and phytoestrogen on the mitochondrial alteration. First, OVX rats were used to mimic the pathologic changes of neurodegeneration of postmenopausal female, and we looked into the alteration of the mitochondrial ultrastructure and ATP content of hippocampal CA1 region after ovariectomy on different phase by transmission electron microscope (TEM) and reversed-phase high-performance liquid chromatography (HPLC), and found the best phase points of the alteration of the mitochondrial ultrastructure and ATP content. Next, estrogen and phytoestrogen were administered to the OVX rats for the protective effects on the mitochondrial ultrastructure and ATP content. Meanwhile, the density, size, shape, and distribution parameters of mitochondrial ultrastructure were analyzed according to the morphometry principle. The experimental results presented that (1) The alteration of mitochondrial ultrastructure elicited by ovariectomy worsened with the days going on, and the changes were the most noteworthy in volume density (Vv), average surface area (S), specific surface area (delta), and particle dispersity (Clambdaz) on 12th day (P < 0.05 or P < 0.01). Moreover, there was no statistical significance of the numerical density (Nv) among the five groups in the first step experiment. (2) The treatment with estrogen, genistein (Gs), and ipriflavone (Ip) significantly reversed the effect elicited by ovariectomy on Vv, S, delta, Clambdaz, Nv, and particle average diameter (D) of mitochondria of hippocampal CA1 region (P < 0.05). (3) Furthermore, ATP content of hippocampal CA1 region after ovariectomy declined significantly on 7th day (P < 0.05), and estrogen and phytoestrogen could reverse the alteration (P < 0.05). Taken together, these results revealed that phytoestrogen may have a protective role against the neurodegeneration after menopause via protecting mitochondrial structure and functions. Phytoestrogen may be a good alternative as a novel therapeutic strategy for menopausal syndrome.