Evaluation of cell death caused by triterpene glycosides and phenolic substances from Cimicifuga racemosa extract in human MCF-7 breast cancer cells

In Vitro and In Vivo Imaging-Based Evaluation of Doxorubicin Anticancer Treatment in Combination with the Herbal Medicine Black Cohosh

As a substitution for hormone replacement therapy, many breast cancer patients use black cohosh (BC) extracts in combination with doxorubicin (DOX)-based chemotherapy. In this study, we evaluated the viability and survival of BC- and DOX-treated MCF-7 cells. A preclinical model of MCF-7 xenografts was used to determine the influence of BC and DOX administration on tumor growth and metabolism. The number of apoptotic cells after incubation with both DOX and BC was significantly increased (~100%) compared to the control. Treatment with DOX altered the potential of MCF-7 cells to form colonies; however, coincubation with BC did not affect this process. In vivo, PET-CT imaging showed that combined treatment of DOX and BC induced a significant reduction in both metabolic activity (29%) and angiogenesis (32%). Both DOX and BC treatments inhibited tumor growth by 20% and 12%, respectively, and combined by 57%, vs. control. We successfully demonstrated that BC increases cytotoxic effects of DOX, resulting in a significant reduction in tumor size. Further studies regarding drug transport and tumor growth biomarkers are necessary to establish the underlying mechanism and potential clinical use of BC in breast cancer patients.

LC-PDA-MS and GC-MS Analysis of Scorzonera hispanica Seeds and Their Effects on Human Breast Cancer Cell Lines

Scorzonera hispanica is an herbaceous perennial cultivated in Central and Southern Europe. This study aimed to qualitatively and quantitatively evaluate the composition of oil, extracts, and fractions (SH1-SH12) obtained from S. hispanica seeds. Furthermore, an evaluation of biological activities in breast cancer cell lines was also performed. GC-MS analysis revealed that the primary components of the seed oil (SH12) were fatty acids and β-sitosterol. In the evaluation of extracts (SH1-SH3, SH8-SH10) and fractions (SH4-SH7, SH11) composition, the presence of apigenin, derivatives of p-coumaric and caffeic acids, was reported. In the biological assays, methanolic extract (SH1), diethyl ether (SH4), and chloroform (SH11) fractions exhibited cytotoxicity toward cells. The highest activity was observed for fatty acids- and 3,4-dimethoxycinnamate-rich SH11 (IC₅₀: 399.18 μg/mL for MCF-7, 781.26 μg/mL for MDA-MB-231). SH11 was also observed to induce apoptosis in MCF-7 cells (52.4%). SH1, SH4, and SH11 attenuate signaling pathways and affect the expression of apoptosis-, autophagy-, and inflammation-related proteins. SH12 was non-toxic toward either cancer or normal cell lines in concentrations up to 1 mg/mL. The results suggest that S. hispanica seeds exhibit a wide range of potential uses as a source of oil and bioactive compounds for complementary therapy of breast cancer.

Treat more than heat-New therapeutic implications of Cimicifuga racemosa through AMPK-dependent metabolic effects

BACKGROUND

Cimicifuga racemosa extracts (CRE) have obtained a "well-established use status" in the treatment of postmenopausal (i.e., climacteric) complaints, which predominantly include vasomotor symptoms such as hot flushes and sweating, as well as nervousness, irritability, and metabolic changes. Although characteristic postmenopausal complaints are known for a very long time and the beneficial effects of CRE on climacteric symptoms are well accepted, both the pathophysiology of postmenopausal symptoms and the mechanism of action of CREs are not yet fully understood. In particular, current hypotheses suggest that changes in the α-adrenergic and serotonergic signaling pathways secondary to estrogen depletion are responsible for the development of hot flushes.

PURPOSE

Some of the symptoms associated with menopause cannot be explained by these hypotheses. Therefore, we attempted to extend our classic understanding of menopause by integrating of partly age-related metabolic impairments.

METHODS

A comprehensive literature survey was performed using the PubMed database for articles published through September 2021. The following search terms were used: (cimicifuga OR AMPK) AND (hot flush* OR hot flash* OR menopaus* OR osteoporos* OR cancer OR antioxida* OR cardiovasc*). No limits were set with respect to language, and the references cited in the articles retrieved were used to identify additional publications.

RESULTS

We found that menopause is a manifestation of the general aging process, with specific metabolic changes that aggravate menopausal symptoms, which are accelerated by estrogen depletion and associated neurotransmitter dysregulation. Cimicifuga extracts with their metabolic effects mitigate climacteric symptoms but may also modulate the aging process itself. Central to these effects are effects of CRE on the metabolic key regulator, the AMP-activated protein kinase (AMPK).

CONCLUSIONS

As an extension of this effect dimension, other off-label indications may appear attractive in the sense of repurposing of this herbal treatment.

Chemical and Biological Evidence of the Efficacy of Shengxian Decoction for Treating Human Lung Adenocarcinoma

Shengxian Decoction (SXT) is a traditional Chinese medicine prescription comprising several anti-cancer medicinal herbs. However, the anti-cancer effect of SXT has rarely been reported. Herein, we explored the therapeutic potential of SXT for the treatment of lung adenocarcinoma (LUAD). High-performance liquid chromatography analysis of crude SXT extract revealed the abundance of mangiferin, an established anti-cancer compound. The serum pharmacological evaluation revealed that serum SXT suppressed A549 lung cancer cell proliferation in vitro. The tumor-inhibitory activity of SXT was confirmed in vivo via tumor formation assays in nude mice. We applied biochemical, histopathological and imaging approaches to investigate the cellular targets of SXT. The results indicated that the treatment with SXT induced tumor necrosis, and downregulated hypoxia-inducible factor 1 alpha in the serum. In vivo biosafety assessment of SXT revealed low levels of toxicity in mouse models. Our study provides the first scientific evidence that SXT effectively represses cancer cell growth and, thus, may serve as a safe anti-cancer agent for LUAD treatment.

Natural Compounds in Sex Hormone-Dependent Cancers: The Role of Triterpenes as Therapeutic Agents

Sex hormone-dependent cancers currently contribute to the high number of cancer-related deaths worldwide. The study and elucidation of the molecular mechanisms underlying the progression of these tumors was a double-edged sword, leading to the expansion and development of new treatment options, with the cost of triggering more aggressive, therapy resistant relapses. The interaction of androgen, estrogen and progesterone hormones with specific receptors (AR, ER, PR) has emerged as a key player in the development and progression of breast, ovarian, prostate and endometrium cancers. Sex hormone-dependent cancers share a common and rather unique carcinogenesis mechanism involving the active role of endogenous and exogenous sex hormones to maintain high mitotic rates and increased cell proliferation thus increasing the probability of aberrant gene occurrence and accumulation highly correlated with abnormal cell division and the occurrence of malignant phenotypes. Cancer related hormone therapy has evolved, currently being associated with the blockade of other signaling pathways often associated with carcinogenesis and tumor progression in cancers, with promising results. However, despite the established developments, there are still several shortcomings to be addressed. Triterpenes are natural occurring secondary metabolites biosynthesized by various pathways starting from squalene cyclization. Due to their versatile therapeutic potential, including the extensively researched antiproliferative effect, these compounds are most definitely a cornerstone in the research and development of new natural/semisynthetic anticancer therapies. The present work thoroughly describes the ongoing research related to the antitumor activity of triterpenes in sex hormone-dependent cancers. Also, the current review highlights both the biological activity of various triterpenoid compounds and their featured mechanisms of action correlated with important chemical structural features.

Cell Cycle Inhibition and Apoptotic Induction of Vernonia amygdalina Del. Leaves Extract on MCF-7 Cell Line

AIM:

The research aimed to determine the cytotoxic activity, cell cycle inhibition, and apoptosis induction of the ethyl acetate extract of the African leaves Vernonia amygdalina Del. on the MCF-7 cancer cells.

METHODS:

The extraction of Vernonia amygdalina Del. leaves was done using the maceration method whereas the cytotoxic was performed using MTT assay. After that, the cell cycle testing and apoptosis induction were conducted using flow cytometry assay.

RESULTS:

The IC₅₀ values of n-hexane, ethyl acetate, and ethanol extract of Vernonia amygdalina Del. on the MCF-7 cancer cells were 206.211 ± 0.99, 50,365 ± 0.07, and 967.033 ± 2.68 µg/mL, respectively. The percentage of the cycle cell results in the G₀-G₁ phase in the cell control with 72.08% decreased in the treatment with ethyl acetate extract 1/2 IC₅₀ with 62.58% and 1/5 IC₅₀ with 44.72%. For the S and G2-M phase, the highest percentage was found in the ethyl acetate extract 1/5 IC₅₀ treatment with 47.27% and 9.50% which were higher than the control cells with 23.26% and 5.90%.

CONCLUSION:

Based on the results, the Vernonia amygdalina Del. extract provides chemopreventive agent as anti-cancer. Our future study will assess the mechanism of ethyl acetate fraction in inhibiting angiogenesis and metastatic in breast cancer.

Estrogenic Activity of Coffee Constituents

Here, the constituents of coffee with estrogenic activity are summarized by a comprehensive literature search, and their mechanisms of action for their physiological effects are discussed at the molecular and cellular levels. The estrogenic activity of coffee constituents, such as acids, caramelized products, carbohydrates, lignin, minerals, nitrogenous compounds, oil (lipids), and others, such as volatile compounds, was first evaluated by activity assays, such as animal tests, cell assay, ligand-binding assay, protein assay, reporter-gene assay, transcription assay, and yeast two-hybrid assay. Second, the health benefits associated with the estrogenic coffee constituents, such as bone protection, cancer treatment/prevention, cardioprotection, neuroprotection, and the improvement of menopausal syndromes, were summarized, including their potential therapeutic/clinical applications. Inconsistent results regarding mixed estrogenic/anti-estrogenic/non-estrogenic or biphasic activity, and unbeneficial effects associated with the constituents, such as endocrine disruption, increase the complexity of the effects of estrogenic coffee constituents. However, as the increase of the knowledge about estrogenic cell signaling, such as the types of specific signaling pathways, selective modulations of cell signaling, signal crosstalk, and intercellular/intracellular networks, pathway-based assessment will become a more realistic means in the future to more reliably evaluate the beneficial applications of estrogenic coffee constituents.

Influence of hormone therapy or C. foetida extract on breast tenderness in postmenopausal women

OBJECTIVE

To evaluate the prevalence of breast tenderness in a population treated with menopausal hormone therapy (MHT) or Cimicifuga foetida extract.

METHODS

A prospective, randomized, controlled trial was conducted. Ninety-six postmenopausal women were randomly assigned to three groups: group A, 1 mg estradiol valerate daily plus 4 mg medroxyprogesterone acetate (MPA), days 19-30; group B, 1 mg estradiol valerate daily plus 100 mg micronized progesterone (MP), days 19-30; group C, 100 mg C. foetida extract daily. Breast tenderness was evaluated daily for 12 months.

RESULTS

Seventy-three patients completed the study. Group A had the highest prevalence of breast tenderness, while group C had the lowest. More than 50% of all participants reported no symptoms throughout the period. The participants in group A experienced a sharp increase in breast tenderness after treatment, but decreased after 1 month. No significant decline was found in the duration of pain in group B. The patients in group C reported no remarkable changes after 1 month. Compared to estrogen only, estrogen plus MPA/MP led to a higher incidence of prolonged breast symptoms.

CONCLUSIONS

Compared to MHT groups, C. foetida extract had the lowest prevalence of breast tenderness. Most participants experienced mild or no symptoms.

Traditional uses, phytochemistry, pharmacology and toxicology of the genus Cimicifuga: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Plants of the genus Cimicifuga have long been used as an ethnomedicine in China, Europe, and North America for its high medicinal value and health benefits. Their dried rhizomes are widely used for treating wind-heat headache, toothache, aphtha, sore throat, measles, spot poison, archoptosis, and uterine prolapse. In addition, it is used as a dietary supplement for preventing women menopausal symptoms and osteoporosis.

AIM OF THE REVIEW

This paper aims to provide up-to-date information on the genus Cimicifuga, including botanical characterization, medicinal resources, traditional medicinal uses, phytochemistry, quality control, pharmacological research as well as the toxicology. The possible structural-activity relationships and molecular mechanisms of the bioactive constituents are discussed in ways that contribute to the structural optimization and preclinical safety assessment for further drug design.

MATERIALS AND METHODS

The relevant information on Cimicifuga was collected from scientific databases (such as Google Scholar, PubMed, SciFinder Scholar, Science Direct, CNKI, Baidu Scholar, Web of Science, China Knowledge Resource Integrated Database), Chinese herbal classics, ethnobotanical books, PhD and MSc dissertations, Chinese Pharmacopoeia, published articles in peer-reviewed journals, local magazines, and unpublished materials. In addition, the Plant List (TPL, www.theplantlist.org) was also used to validate the scientific names and synonyms of this plant. The literature cited in this review dated from 1953 to 2017.

RESULTS

The majority of chemical constituents of this plant include triterpenoid glycosides, phenylpropanoids, nitrogenous compounds, chromones, flavonoids and 4α-methyl steroid. Among them, the primary bioactive constituents are believed to be present in the triterpene glycoside fraction. To date, investigation of seven Cimicifuga spp. plants led to the identification of more than 457 compounds. Years of pharmacological research proved that the crude extracts and certain pure compounds obtained from Cimicifuga exhibited menopausal syndrome-treatment, anti-osteoporosis, antiviral, antitumor, antioxidant and antiangiogenic activities. On the other hand, Cimicifuga plant-induced toxicities of liver, cardiovascular, central and peripheral nervous systems have also been reported. Therefore, safety consideration should be placed into a high priority for herbal medicine Cimicifuga therapy in the early stages of development and clinical trials.

CONCLUSIONS

This review presents information on botany, medicinal resources, and traditional medicinal history of some Cimicifuga plants. Modern pharmacology researchers have validated many traditional uses of Cimicifuga species. As the quality control and safety assessment of Cimicifuga plants is still incomplete, only a small part of the plant is permitted to be used as medicines. Expansion of medicinal resources in Cimicifuga is urgently needed to enable its full use. Currently research primarily focuses on the triterpenoid glycosides but there are many other types of compounds which may possess new biological activities however the systematic studies of these compounds are lacking. Extensive study is required on Cimicifuga plant before it can be fully used in clinics as a potent drug candidate.

Photochemistry and pharmacology of 9, 19-cyclolanostane glycosides isolated from genus Cimicifuga

The constituents of Cimicifuga plants have been extensively investigated, and the principal metabolites are 9, 19-cyclolanostane triterpenoid glycosides, which often exhibit extensive pharmacological activities. 9, 19-Cyclolanostane triterpenoid glycosides are distributed widely in genus Cimicifuga rather than in other members of the Ranunculaceae family. So far, more than 140 cycloartane triterpene glycosides have been isolated from Cimicifuga spp.. The aim of this review was to summarize all 9, 19-cyclolanostane triterpenoid glycosides based on the available relevant scientific literatures from 2000 to 2014. Biological studies of cycloartane triterpene glycosides from Cimicifuga spp. are also discussed.

New potential beneficial effects of actein, a triterpene glycoside isolated from Cimicifuga species, in breast cancer treatment

Actein is a triterpene glycoside isolated from the rhizomes of Cimicifuga foetida (Chinese herb “shengma”) which could inhibit the growth of breast cancer cells. Nevertheless, the effect of actein on angiogenesis, which is an essential step for tumor growth and metastasis, has never been reported. Hence, this study aimed to investigate the in vitro and in vivo effects of actein on angiogenesis using human microvascular endothelial cells (HMEC-1), matrigel plug and tumor-bearing mouse models. Our results showed that actein significantly inhibited the proliferation, reduced the migration and motility of endothelial cells, and it could suppress the protein expressions of VEGFR1, pJNK and pERK, suggesting that JNK/ERK pathways were involved. In vivo results showed that oral administration of actein at 10 mg/kg for 7 days inhibited blood vessel formation in the growth factor-containing matrigel plugs. Oral actein treatments (10–15 mg/kg) for 28 days resulted in decreasing mouse 4T1 breast tumor sizes and metastasis to lungs and livers. The apparent reduced angiogenic proteins (CD34 and Factor VIII) expressions and down-regulated metastasis-related VEGFR1 and CXCR4 gene expressions were observed in breast tumors. Our novel findings provide insights into the use of actein for development of anti-angiogenic agents for 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.

Rice hull extracts inhibit proliferation of MCF-7 cells with G₁ cell cycle arrest in parallel with their antioxidant activity

Rice (Oryza sativa L.) has been a major dietary staple worldwide for centuries. Growing interest in the beneficial effects of antioxidants has inspired investigation of rice hulls as an attractive source of chemopreventive compounds for breast cancer intervention. We prepared methanol extracts from rice hulls of three Korean bred cultivars (japonica), Ilpum, Heugjinju, and Jeogjinju, and one japonica weedy rice, WD-3. We examined the antiproliferative potential of the hull extracts on MCF-7 human breast cancer cells and the related mechanisms thereof. Hull extracts inhibited proliferation of the cells and mediated G0/G1 phase arrest by suppressing cyclins and cyclin-dependent kinases, where WD-3 extract showed the most potent. Blockage of p21 expression by small interfering RNA transfection attenuated G1 phase arrest induced by WD-3 extract. The WD-3 extract exhibited greater antioxidant potential and total phenolic compounds, compared with other rice hulls. Gas chromatography-mass spectrometry analysis for the F4 fractioned from WD-3 extract revealed that cinnamic acid derivatives were the major active constituents. The F4 fraction most potently inhibited proliferation of MCF-7 cells than WD-3 extract through the suppression of cell cycle regulatory factors. Collectively, our results suggest that the pigmented rice hulls possess greater antioxidant and chemopreventive activity against breast cancer than the other rice cultivars tested, demonstrating that WD-3 rice hulls are an attractive source of chemopreventive bioactive compounds.

Alteration of anti-inflammatory activity of Harpagophytum procumbens (devil's claw) extract after external metabolic activation with S9 mix

OBJECTIVES

Extracts of the tubers of Harpagophytum procumbens (devil's claw, DC) inhibit different proinflammatory mediators important in the pathophysiology of osteoarthritis. Many plant-derived preparations interfere with cytochrome P450 liver enzymes, which influence their different biological activities. Therefore, the present study was designed to investigate the influence of an external metabolic activation of a DC extract on the cytotoxicity and the release of proinflammatory cytokines.

METHODS

A screening experiment with a panel of 12 inflammatory cytokines identified three as suitable for the study: tumour necrosis factor-α (TNF-α), interleukin (IL) IL-6 and IL-8. They were determined using enzyme-linked immunosorbent assays in lipopolysaccharide (LPS)-stimulated monocytic THP-1 cells, which were treated with rat liver S9 mix metabolically activated DC extract (DCm). For the cytotoxity experiments, a WST-1 assay was used.

KEY FINDINGS

DC dose-dependently suppressed the release of TNF-α, IL-6 and IL-8 in LPS-stimulated monocytic THP-1 cells at non-cytotoxic concentrations (50-250 μg/ml). The metabolic activation of the DC extract by S9 mix did not alternate its cytotoxicity and did not diminish its inhibitory effect. This effect was improved in the case of TNF-α inhibition as reflected by their EC50 values of 116 ± 8.2 μg/ml and 49 ± 3.5 μg/ml for DC and DCm (P < 0.01).

CONCLUSIONS

Cytokines inhibitory activity of DC was not affected after its external metabolic activation. However, the amount of harpagoside and caffeic acid derivates was decreased. Other components of the extract might have contributed to its anti-inflammatory effect.

An Evidence-Based Systematic Review of Black cohosh (Cimicifuga racemosa, Actaea racemosa) by the Natural Standard Research Collaboration

An evidence-based systematic review of black cohosh (Cimicifuga racemosa, Actaea racemosa) by the Natural Standard Research Collaboration consolidates the safety and efficacy data available in the scientific literature using a validated, reproducible grading rationale. This article includes written and statistical analysis of clinical trials, plus a compilation of expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing.

Phytochemistry of cimicifugic acids and associated bases in Cimicifuga racemosa root extracts

INTRODUCTION

Earlier studies reported serotonergic activity for cimicifugic acids (CA) isolated from Cimicifuga racemosa. The discovery of strongly basic alkaloids, cimipronidines, from the active extract partition and evaluation of previously employed work-up procedures has led to the hypothesis of strong acid/base association in the extract.

OBJECTIVE

Re-isolation of the CAs was desired to permit further detailed studies. Based on the acid/base association hypothesis, a new separation scheme of the active partition was required, which separates acids from associated bases.

METHODOLOGY

A new 5-HT(7) bioassay guided work-up procedure was developed that concentrates activity into one partition. The latter was subjected to a new two-step centrifugal partitioning chromatography (CPC) method, which applies pH zone refinement gradient (pHZR CPC) to dissociate the acid/base complexes. The resulting CA fraction was subjected to a second CPC step. Fractions and compounds were monitored by (1)H NMR using a structure-based spin-pattern analysis facilitating dereplication of the known acids. Bioassay results were obtained for the pHZR CPC fractions and for purified CAs.

RESULTS

A new CA was characterised. While none of the pure CAs was active, the serotonergic activity was concentrated in a single pHZR CPC fraction, which was subsequently shown to contain low levels of the potent 5-HT(7) ligand, N(omega)-methylserotonin.

CONCLUSION

This study shows that CAs are not responsible for serotonergic activity in black cohosh. New phytochemical methodology (pHZR CPC) and a sensitive dereplication method (LC-MS) led to the identification of N(omega)-methylserotonin as serotonergic active principle.

Black cohosh (Cimicifuga racemosa): a systematic review of adverse events

Black cohosh (Cimicifuga racemosa) is used most often to treat symptoms that can occur during menopause. However, in the last years, several concerns regarding its safety have been voiced. The aim of this systematic review was to evaluate the clinical evidence for or against the safety of black cohosh. Systematic literature searches were conducted in 5 computerized databases (Medline, Embase, Amed, Phytobase, and Cochrane Library). The references of all located articles were scanned for further relevant publications. Any type of clinical data that included case reports and observational studies was considered. No language restrictions were imposed. Thirteen clinical trials (all of which indicated relative safety), 3 postmarketing surveillance studies, 4 case series, and 8 single case reports were identified. Clinical studies suggest black cohosh to be safe. In most case reports, causal attribution is problematic. In conclusion, black cohosh has been associated with serious safety concerns that urgently require further investigation.

Ethanolic extract of Actaea racemosa (black cohosh) potentiates bone nodule formation in MC3T3-E1 preosteoblast cells

Aceaea racemosa (formerly Cimicifuga racemosa, black cohosh, AR) extracts have been widely used as an alternative to hormonal replacement therapy for menopausal symptoms. Recent evidences suggest AR extracts are also effective in protecting against postmenopausal bone loss. To determine whether AR has any direct anabolic effect on osteoblasts, we investigated the ethanolic extract of AR on bone nodule formation in mouse MC3T3-E1 preosteoblast cells. AR did not stimulate osteoblast proliferation. Rather, at high doses of 1000 ng/mL for 48 h, AR suppressed (7.2+/-0.9% vs. control) osteoblast proliferation. At 500 ng/mL, a significant increase in bone nodule formation was seen with Von Kossa staining. Using quantitative PCR analysis, AR was shown to enhance the gene expression of runx2 and osteocalcin. Co-treatment with ICI 182,780, the selective estrogen receptor antagonist, abolished the stimulatory effect of AR on runx2 and osteocalcin gene induction, as well as on bone nodule formation in MC3T3-E1 cells. This is a first report of the direct effect of AR on enhancement of bone nodule formation in osteoblasts, and this action was mediated via an estrogen receptor-dependent mechanism. The results provide a scientific rationale at the molecular level for the claim that AR can offer effective prevention of postmenopausal bone loss.

Black Cohosh: Insights into its Mechanism(s) of Action

The Women's Health Initiative found that combination estrogen and progesterone hormone replacement therapy increases breast cancer and cardiovascular disease risk, which compelled many women to seek herbal alternatives such as black cohosh extract (BCE) to relieve their menopausal symptoms. While several clinical trials document the efficacy of BCE in alleviating menopausal symptoms, preclinical studies to determine how BCE works have yielded conflicting results. Part of this is because there is not a universally accepted method to standardize the dose of black cohosh triterpenes, the presumed active ingredients in the extract. Although the mechanism by which BCE relieves symptoms is unknown, several hypotheses have been proposed: it acts 1) as a selective estrogen receptor modulator, 2) through serotonergic pathways, 3) as an antioxidant, or 4) on inflammatory pathways. We found that while the most prominent triterpene in BCE, 23-epi-26-deoxyactein, suppresses cytokine-induced nitric oxide production in brain microglial cells, the whole BCE extract actually enhanced this pathway. A variety of activities have been reported for black cohosh and its compounds, but the absorption and tissue distribution of these compounds is unknown.

Growth inhibitory activity of extracts and compounds from Cimicifuga species on human breast cancer cells

The purpose of this report is to explore the growth inhibitory effect of extracts and compounds from black cohosh and related Cimicifuga species on human breast cancer cells and to determine the nature of the active components. Black cohosh fractions enriched for triterpene glycosides and purified components from black cohosh and related Asian species were tested for growth inhibition of the ER(-) Her2 overexpressing human breast cancer cell line MDA-MB-453. Growth inhibitory activity was assayed using the Coulter Counter, MTT and colony formation assays. Results suggested that the growth inhibitory activity of black cohosh extracts appears to be related to their triterpene glycoside composition. The most potent Cimicifuga component tested was 25-acetyl-7,8-didehydrocimigenol 3-O-beta-d-xylopyranoside, which has an acetyl group at position C-25. It had an IC(50) of 3.2microg/ml (5microM) compared to 7.2microg/ml (12.1microM) for the parent compound 7,8-didehydrocimigenol 3-O-beta-d-xylopyranoside. Thus, the acetyl group at position C-25 enhances growth inhibitory activity. The purified triterpene glycoside actein (beta-d-xylopyranoside), with an IC(50) equal to 5.7microg/ml (8.4microM), exhibited activity comparable to cimigenol 3-O-beta-d-xyloside. MCF7 (ER(+)Her2 low) cells transfected for Her2 are more sensitive than the parental MCF7 cells to the growth inhibitory effects of actein from black cohosh, indicating that Her2 plays a role in the action of actein. The effect of actein on Her2 overexpressing MDA-MB-453 and MCF7 (ER(+)Her2 low) human breast cancer cells was examined by fluorescent microscopy. Treatment with actein altered the distribution of actin filaments and induced apoptosis in these cells. These findings, coupled with our previous evidence that treatment with the triterpene glycoside actein induced a stress response and apoptosis in human breast cancer cells, suggest that compounds from Cimicifuga species may be useful in the prevention and treatment of human breast cancer.

Gene expression profiling reveals effects of Cimicifuga racemosa (L.) NUTT. (black cohosh) on the estrogen receptor positive human breast cancer cell line MCF-7

BACKGROUND

Extracts from the rhizome of Cimicifuga racemosa (black cohosh) are increasingly popular as herbal alternative to hormone replacement therapy (HRT) for the alleviation of postmenopausal disorders. However, the molecular mode of action and the active principles are presently not clear. Previously published data have been largely contradictory. We, therefore, investigated the effects of a lipophilic black cohosh rhizome extract and cycloartane-type triterpenoids on the estrogen receptor positive human breast cancer cell line MCF-7.

RESULTS

Both extract and purified compounds clearly inhibited cellular proliferation. Gene expression profiling with the extract allowed us to identify 431 regulated genes with high significance. The extract induced expression pattern differed from those of 17beta-estradiol or the estrogen receptor antagonist tamoxifen. We observed a significant enrichment of genes in an anti-proliferative and apoptosis-sensitizing manner, as well as an increase of mRNAs coding for gene products involved in several stress response pathways. These functional groups were highly overrepresented among all regulated genes. Also several transcripts coding for oxidoreductases were induced, as for example the cytochrome P450 family members 1A1 and 1B1. In addition, some transcripts associated with antitumor but also tumor-promoting activity were regulated. Real-Time RT-PCR analysis of 13 selected genes was conducted after treatment with purified compounds - the cycloartane-type triterpene glycoside actein and triterpene aglycons - showing similar expression levels compared to the extract.

CONCLUSION

No estrogenic but antiproliferative and proapoptotic gene expression was shown for black cohosh in MCF-7 cells at the transcriptional level. The effects may be results of the activation of different pathways. The cycloartane glycosides and - for the first time - their aglycons could be identified as an active principle in black cohosh.

Effects of black cohosh on estrogen biosynthesis in normal breast tissue in vitro

OBJECTIVES

To investigate the effect of black cohosh on the estrogen biosynthesis in the breast in vitro.

METHODS

Steroid sulfatase (STS) activity was studied in normal breast tissue obtained from pre- and postmenopausal women undergoing reduction mammoplasty. STS protein expression was studied by immunohistochemistry and western blotting. Breast tissue was incubated in vitro without or with black cohosh (iCR) at concentrations ranging from 0.1mg/ml to 1 ng/ml. STS activity was evaluated by incubating homogenized breast tissue with [3H]-estrone sulfate, separating the formed products, estrone (E1) and estradiol (E2), by thin layer chromatography and measuring the amounts of E1 and E2 by scintillation counting.

RESULTS

STS protein expression and enzymatic activity were detected in all specimens investigated. In all groups, significantly more E1 than E2 was produced. Local estrogen formation was decreased in premenopausal breast tissue by treatment with iCR at 0.1mg/ml (p<or=0.05).

CONCLUSIONS

iCR decreases local estrogen formation in normal human breast tissue in vitro. This may contribute to the lack of hormonal effects of black cohosh in breast tissue observed in previous studies.

An isopropanolic extract of black cohosh does not increase mammographic breast density or breast cell proliferation in postmenopausal women

OBJECTIVE

The aim of this study was to determine the effects of the isopropanolic extract of black cohosh (Remifemin) on mammographic breast density and breast epithelial proliferation in healthy, naturally postmenopausal women with climacteric symptoms.

DESIGN

This was a prospective, open, uncontrolled drug safety study in which baseline status was compared with status after 6 months of treatment by blinded observers. A total of 74 women were treated with 40 mg black cohosh daily, and 65 women completed the study. Mammograms were performed, and breast cells were collected by percutaneous fine needle aspiration biopsies at baseline and after 6 months. Mammographic density was quantified according to the Wolfe classification or a percentage scale. Breast cell proliferation was assessed using the Ki-67/MIB-1 monoclonal antibody. Safety was monitored by adverse event reporting, laboratory assessments, and measurement of the endometrium by vaginal ultrasound.

RESULTS

None of the women showed any increase in mammographic breast density. Furthermore, there was no increase in breast cell proliferation. The mean change +/- SD in proportion of Ki-67-positive cells was -0.5% +/- 2.4% (median, 0.0; 95% CI = -1.32 to 0.34) for paired samples. The mean change in endometrial thickness +/- SD was 0.0 +/- 0.9 mm (median, 0.0). A modest number of adverse events were possibly related to treatment, but none of these were serious. Laboratory findings and vital signs were normal.

CONCLUSIONS

The findings suggest that the isopropanolic extract of black cohosh does not cause adverse effects on breast tissue. Furthermore, our data do not indicate to any endometrial or general safety concerns during 6 months of treatment.

Ethanolic extracts of black cohosh (Actaea racemosa) inhibit growth and oestradiol synthesis from oestrone sulphate in breast cancer cells

Extracts of black cohosh (Actaea racemosa) and soy are used as 'natural' alternatives to conventional hormone replacement therapy (HRT) and there is some evidence that soy may protect against breast cancer by inhibiting the production of active oestrogens. This study compares the action of ethanolic extracts of black cohosh (BCE) and genistein on growth and enzyme activity in MCF-7 and MDA-MB-123 breast cancer cells. BCE inhibited growth at the two highest doses tested, i.e. 50 and 100 microg/ml, whilst genistein stimulated growth in the oestrogen receptor positive (ER(+)) MCF-7 cells, but at high doses it inhibited growth in both cell lines. BCE did not affect the conversion of androstenedione to oestradiol and only the highest doses (50 and 100 microg/ml) significantly inhibited the conversion of oestrone to oestradiol in MDA cells. In contrast, BCE induced a dose-dependent inhibition of the conversion of oestrone sulphate to oestradiol in both cell lines, whilst in human granulosa lutein (GL) cells enzyme activity was only inhibited at the highest dose of BCE. Genistein had no significant effect on enzyme activity in breast cancer cells and like BCE only the highest doses (10 and 50 microM) inhibited enzyme activity in human GL cells. In vivo genistein may have growth stimulatory effects on breast tissue but BCE not only inhibits growth but inhibits the conversion of oestrone sulphate to active oestradiol, considered by some, to be the preferred pathway of oestradiol synthesis in breast tissue.

The growth inhibitory effect of actein on human breast cancer cells is associated with activation of stress response pathways

Previous studies indicate that the triterpene glycoside actein from the herb black cohosh inhibits growth of human breast cancer cells. This study seeks to identify genes altered in human breast cancer cells by treatment with actein, using gene expression analysis. We treated MDA-MB-453 human breast cancer cells with actein at 2 doses, 20 or 40 microg/mL, for 6 or 24 hr. We identified 5 genes that were activated after each of the treatments that are known to play a role in cellular responses to diverse stresses, including the DNA damage and unfolded protein responses. In addition, four genes that mediate the integrated stress response (ISR), including activating transcription factor 4, were induced under at least one of the 4 treatment conditions. We used hierarchical clustering to define clusters comprising patterns of gene expression. Two ISR genes, activating transcription factor 3 (ATF3) and DNA damage- inducible transcript 3, and lipid biosynthetic genes were activated after exposure to actein at 40 microg/mL for 6 hr, whereas the cell cycle genes cyclin E2 and cell division cycle 25A were repressed. Our results suggest that actein induces 2 phases of the ISR, the survival phase and the apoptotic phase, depending on the dose and duration of treatment. We confirmed the results of gene expression analysis with real-time RT-PCR for 18 selected genes and Western blot analysis for ATF3. Since actein activated transcription factors that enhance apoptosis, and repressed cell cycle genes, it may be useful in the prevention and therapy of breast cancer.

Cytotoxic cycloartane triterpene saponins from Actaea asiatica

Three new 9,19-cycloartane triterpene glycosides, asiaticoside A (1), asiaticoside B (2), and 25-O-ethylcimigenol-3-O-beta-D-xylopyranoside (3), together with cimiacemoside I (4), 25-O-acetylcimigenol-3-beta-O-D-xyloside (5), and 25-anhydrocimigenol-beta-O-D-xyloside (6) were isolated from the roots/rhizomes extract of Actaea asiatica, and their structures were established by spectroscopic methods (IR, HRESIMS, and NMR). Compounds 1-3, 5, and 6 had notable cytotoxicity against HepG2 and MCF-7 cancer cell lines.

Isopropanolic extract of black cohosh stimulates osteoprotegerin production by human osteoblasts

An isopropanolic extract (iCR) from the rhizomes of Cimicifuga racemosa (black cohosh) is used an alternative in the treatment of menopausal symptoms, and animal studies suggest positive skeletal effects. iCR stimulated osteoblastic OPG protein secretion by 3- to 5-fold as early as 12 h without affecting RANKL expression. The iCR effect, abrogated by the pure estrogen receptor antagonist ICI 182,780, also enhanced ALP activity (4-fold) and osteocalcin expression (3-fold), possibly contributing to the skeletal effects of black cohosh.

INTRODUCTION

Despite its positive effects on the skeleton, estrogen replacement therapy is no longer recommended as first-line therapy for the prevention and treatment of postmenopausal osteoporosis because it increases cardiovascular, thromboembolic, and breast cancer risk. Recently, herbal therapeutics such as an isopropanolic extract (iCR) from the rhizomes of Cimicifuga (=Actaea) racemosa (black cohosh) are gaining interest as an alternative in the treatment of menopausal symptoms. Whereas animal studies in rats suggest positive skeletal effects, the mechanism of its actions on bone cells remain unclear. RANKL is essential for osteoclast formation and activation, while osteoprotegerin (OPG) neutralizes RANKL.

MATERIALS AND METHODS

In this study, we assessed the effects of iCR on OPG and RANKL mRNA steady-state levels by semiquantitative RT-PCR and on protein production by an ELISA system in human osteoblasts (hOBs).

RESULTS

Under serum-free conditions, treatment with iCR increased OPG mRNA levels and protein secretion of hOBs by 2- to 3-fold in a dose-dependent manner, with a maximum effect at a 10(6)-fold dilution of iCR (p < 0.001) after 24-48 h. Time-course experiments indicated a stimulatory effect of iCR on osteoblastic OPG protein secretion by 3- to 5-fold (p < 0.001) as early as 12 h, whereas RANKL expression was very low and was not found to be modulated by iCR. Of note, the stimulatory effect of iCR on OPG production was abrogated by the pure estrogen receptor antagonist ICI 182,780. Moreover, iCR enhanced two osteoblastic differentiation markers, bone-specific alkaline phosphatase activity and osteocalcin expression, by up to 4- and 3-fold, respectively (p < 0.001).

CONCLUSIONS

Our data suggest that iCR enhances differentiation and increases the OPG-to-RANKL ratio of normal human osteoblasts. These effects may contribute to the positive skeletal effects of black cohosh.