Analysis of thirteen populations of black cohosh for formononetin

Unraveling the anti-breast cancer activity of Cimicifugae rhizoma using biological network pathways and molecular dynamics simulation

Cimicifugae is a commonly used treatment for breast cancer, but the specific molecular mechanisms underlying its effectiveness remain unclear. In this research, we employ a combination of network pharmacology, molecular docking, and molecular dynamics simulations to uncover the most potent phytochemical within Cimicifugae rhizoma in order to delve into its interaction with the target protein in breast cancer treatment. We identified 18 active compounds and 89 associated targets, primarily associated to various biological processes such as lipid metabolism, the signaling pathway in diabetes, viral infections, and cancer-related pathways. Molecular docking analysis revealed that the two most active compounds, Formononetin and Cimigenol, exhibit strong binding to the target protein AKT1. Through molecular dynamics simulations, we found that the Cimigenol-AKT1 complex exhibits greater structural stability and lower interaction energy compared to the stigmasterol-AKT1 complex. Our study demonstrates that Cimicifugae rhizoma exerts its effects in breast cancer treatment through a multi-component, multi-target synergistic approach. Furthermore, we propose that Cimigenol, targeting AKT-1, represents the most effective compound, offering valuable insights into the molecular mechanisms underpinning its role in breast cancer therapy.

Phytotherapeutic approach for conquering menopausal syndrome and osteoporosis

Women face a significant change in their reproductive health as menopause sets in. It is marred with numerous physiological changes that negatively impact their quality of life. This universal, transition phase is associated with menopausal and postmenopausal syndrome, which may spread over 2-10 years. This creates a depletion of female hormones causing physical, mental, sexual and social problems and may, later on, manifest as postmenopausal osteoporosis leading to weak bones, causing fractures and ultimately morbidity and mortality. Menopausal hormone therapy generally encompasses the correction of hormone balance through various pharmacological agents, but the associated side effects often lead to cessation of therapy with poor clinical outcomes. However, it has been noticed that phytotherapeutics is trusted by women for the amelioration of symptoms related to menopause and for improving bone health. This could primarily be due to their reduced side effects and lesser costs. This review attempts to bring forth the suitability of phytotherapeutics/herbals for the management of menopausal, postmenopausal syndrome, and menopausal osteoporosis through several published research. It tries to enlist the available botanicals with their key constituents and mechanism of action for mitigating symptoms associated with menopause as well as osteoporosis. It also includes a list of a few herbal commercial products available for these complications. The article also intends to collate the findings of various clinical trials and patents available in this field and provide a window for newer research avenues in this highly important yet ignored health segment.

Benefits of Black Cohosh (Cimicifuga racemosa) for Women Health: An Up-Close and In-Depth Review

Women’s health is an imminent concern worldwide, but it remains an ignored segment of research in most developing countries, and is yet to take the center stage in even developed nations. Some exclusive female health concerns revolve around both pathological and physiological aspects. These gender-specific maladies include breast, cervical, and ovarian cancers, and physiological concerns such as menopause and osteoporosis, which are often coexistent. Recently, women’s health issues, including postmenopausal syndrome, have attracted the attention of researchers and practitioners alike, opening newer pharmaceutical research and clinical avenues. Although not counted as a disease, postmenopausal syndrome (PMS) is a female health phenomenon underpinned by hormonal depletion. Enhanced life expectancy in women has added to their suffering, and pharmacological interventions are needed. Amongst the available treatment modalities, the use of numerous botanicals has emerged as an efficient health management tool for women. Cimicifuga racemosa (CR or Black Cohosh) is a plant/herb which has been traditionally exploited and extensively used by women. This review is an attempt to compile and provide a summary of the importance of CR in complementary and alternative therapies for the improvement of various disorders related to women, such as menopausal syndrome, mammary cancer, and osteoporosis. It aims to systematically highlight the bioactive constituents, pharmacology, pharmacokinetics, therapeutic potentials, quality control processes, chromatographic techniques, and possible mechanisms of action of clinically effective phytomedicine for women’s health. Various clinical trials and patents relating to CR and women’s health have been collated. Furthermore, the plant and its related products have been considered from a regulatory perspective to reveal its commercial feasibility. The present review summarizes the existing data on CR focusing on women’s health, which can help to introduce this traditional phytomedicine to the world and provide some reference for future drug development.

A Preliminary Study on the Effects of Black Cohosh Preparations on Bone Metabolism of Rat Models With GnRH-a-Induced Peri-Menopausal Symptoms

BACKGROUND

Endometriosis (EMS) is a relapsing and estrogen-dependent disease. For endometriosis such as deep endometriosis and ovarian endometrioid cysts, surgery is the most effective treatment. Long-term follow-up showed that the recurrence rate of endometriosis after surgical treatment was high, so postoperative drugs were needed to reduce recurrence, and Gonadotropin-releasing hormone agonists (GnRH-a) were the most commonly used drug for postoperative management.GnRH-a may reduce the post-treatment endometriosis relapses by lowering the hormone levels in the body. However, the use of GnRH-a can give rise to perimenopausal symptoms, especially osteoporosis, bone loss, and bone pain, for which reason GnRH-a use is often limited. The add-back therapy is often used to alleviate the untoward effects caused by GnRH-a. However, long-term use of hormone drugs may lead to EMS recurrence, thrombosis, and breast cancer. Therefore, a safer and more effective drug is urgently needed to alleviate the untoward effects caused by GnRH-a. In recent years, scholars at home and abroad have found that isopropanolic Cimicifuga racemosa extract (ICR), as a plant extract, can better relieve the symptoms of perimenopausal women. At the same time, some studies have initially confirmed that black cohosh preparations can relieve the perimenopausal symptoms caused by GnRH-a treatment in EMS patients.

OBJECTIVE

To investigate the effect of black cohosh preparations on the bone metabolism of rat models with GnRH-a-induced perimenopausal symptoms.

METHODS

The rat models of perimenopausal symptoms were established by GnRH-a injection. and normal saline (NS injection) was used as the control. According to the modeling method and drug intervention, the rats were randomly divided into four groups: GnRH-a injection + saline intervention group (GnRH-a + NS), saline injection control + saline intervention group (NS + NS), GnRH-a injection + estradiol intervention group (GnRH-a + E2), and GnRH-a injection + black cohosh preparation intervention group (GnRH-a + ICR). The rat models were identified with the vaginal smear method, and then the corresponding drug intervention was administrated for 28 days. After the intervention, the rats were sacrificed. The rats' bone mineral density (BMD) of the distal femur was detected by a dual-energy X-ray bone density scanner. Rat tibia bone tissues were decalcified and made into slices. The pathological and morphological changes of rat tibial bones in each group were observed through HE staining. Histomorphometry parameters of rat tibial bones in each group, such as trabecular bone volume (TBV), trabecular thickness (TbTh), trabecular number (TbN), and trabecular spacing (TbSp), were detected and analyzed by using an automatic image analysis system.

RESULTS

(1) The BMD level of the distal femur in the GnRH-a + NS group was significantly lower than the NS + NS, GnRH-a + E2, and GnRH-a + ICR groups (P<0.01), the BMD levels in GnRH-a + E2 and GnRH-a + ICR groups were slightly lower than the NS + NS group, but there was no significant difference among the three groups (P>0.05). (2) The pathological changes of the tibia bones under the microscope in different groups were as follows: The tibia bone trabecular structure was normal in the NS + NS group, without trabecular thinning or fracture, and the arch structure was normal. In the GnRH-a + NS group, some trabecular structures tapered, the arch structure disappeared, but no obvious bone fracture was observed in the trabecula. In the GnRH-a + E2 and GnRH-a + ICR groups, the trabecular structures were normal, without trabecular bone thinning or fracture, and the arch structures were normal. (3) The TBV level of the GnRH-a + INS group was significantly lower than that of the NS + NS, GnRH-a + E2 and GnRH-a + ICR groups (P<0.01, P<0.05, P<0.01), while there was no significant difference among NS + NS, GnRH-a + E2 and GnRH-a + ICR groups (P>0.05). (4) The TbTh levels in the four groups had no significant difference (P>0.05). Compared with the NS + NS group, the TbTh levels in the GnRH-a + NS, GnRH-a + E2, and GnRH-a + ICR groups showed a descending tendency, while the TbTh levels in the GnRH-a + E2 and GnRH-a + ICR groups were slightly higher than that of the GnRH-a + NS group. However, such differences were not significant statistically (P>0.05). (5) Compared with the NS + NS group, the TbN levels in the GnRH-a + NS, GnRH-a + E2, and GnRH-a + ICR groups decreased remarkably (P<0.05). Compared with the GnRH-a + NS group, the TbN levels in the GnRH-a + E2 and GnRH-a + ICR groups showed a mild descending tendency, but such differences were not significant statistically (P>0.05). (6) The TbSp level of the GnRH-a + NS group was significantly higher than that of the NS + NS, GnRH-a + E2, and GnRH-a + ICR groups (P<0.01), while there was no significant difference among NS + NS, GnRH-a + E2 and GnRH-a + ICR groups (P>0.05).

CONCLUSION

The GnRH-a injection could achieve the desired effect. GnRH-a injection may lead to the loss of bone mass in rats. Black cohosh preparations, like estrogen, may have a protective effect on bone mass loss caused by GnRH-a injection.

Herbal Products Used in Menopause and for Gynecological Disorders

Herbal products are often used as an alternative to pharmacological therapy. Menopausal symptoms and gynecological disorders (such as premenstrual syndrome and dysmenorrhea) are the indications where pharmacological therapy may have serious adverse events, hence many women prefer to use herbal products to help with these symptoms. Here, we reviewed plants and derived products, which are commonly used for the abovementioned indications, focusing on clinical data, safely profile and whether or not their use is justified. We noted that limited data are available on the use of some plants for alleviating the symptoms of menopause and gynecological disorders. While black cohosh (Cimicifuga racemose) and red clover (Trifolium pretense) were consistently shown to help reduce menopausal symptoms in clinical studies, currently available data do not fully support the use of fenugreek (Trigonella foenum-graecum), hops (Humulus lupulus), valerian (Valeriana officinalis), and soybean (Glycine max and Glycine soja) for this indication. For premenstrual syndrome and premenstrual dysphoric disorder, chaste tree (Vitex agnus-castus) shows effectiveness, but more clinical studies are needed to confirm such effect upon the use of evening primrose (Oenothera biennis).

The Phytochemistry of Cherokee Aromatic Medicinal Plants

Background: Native Americans have had a rich ethnobotanical heritage for treating diseases, ailments, and injuries. Cherokee traditional medicine has provided numerous aromatic and medicinal plants that not only were used by the Cherokee people, but were also adopted for use by European settlers in North America. Methods: The aim of this review was to examine the Cherokee ethnobotanical literature and the published phytochemical investigations on Cherokee medicinal plants and to correlate phytochemical constituents with traditional uses and biological activities. Results: Several Cherokee medicinal plants are still in use today as herbal medicines, including, for example, yarrow (Achillea millefolium), black cohosh (Cimicifuga racemosa), American ginseng (Panax quinquefolius), and blue skullcap (Scutellaria lateriflora). This review presents a summary of the traditional uses, phytochemical constituents, and biological activities of Cherokee aromatic and medicinal plants. Conclusions: The list is not complete, however, as there is still much work needed in phytochemical investigation and pharmacological evaluation of many traditional herbal medicines.

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.

Differentiated Evaluation of Extract-Specific Evidence on Cimicifuga racemosa's Efficacy and Safety for Climacteric Complaints

Past reviews on Cimicifuga racemosa (CR) without differentiation between extracts, quality, and indication altogether led to inconsistent data. Therefore, for the first time, we meet the requirements of the system's logic of evidence-based phytotherapy by taking into consideration extracts, pharmaceutical quality (reflected in a regulatory status as medicinal product), and indication. A literature search for clinical studies examining CR's efficacy and safety for menopausal complaints was conducted. The results were sorted by type of extract, regulatory status, and indication. Accordingly, Oxford Levels of Evidence (LOE) and Grades of Recommendation (GR) were determined. CR extracts demonstrated a good to very good safety in general, on estrogen-sensitive organs and the liver. However, only registered CR medicinal products were able to prove their efficacy. Best evidence was provided by the isopropanolic CR extract (iCR): the multitude of studies including more than 11,000 patients demonstrated consistent confirmatory evidence of LOE 1b (LOE 1a for safety) leading to GR A. The studies on the ethanolic extract BNO 1055 including more than 500 patients showed exploratory evidence of LOE 2b resulting in GR B. A positive benefit-risk profile is stated and limited to Cimicifuga racemosa products holding a marketing authorisation for treating climacteric complaints.

Anti-proliferative effect of Klimaktoplan® on human breast cancer cells

OBJECTIVE

With the health concerns of menopausal hormone replacement therapy, alternatives have been sought. Klimaktoplan® is a homeopathic formulation consisting of four main components and has been used for relief of menopausal symptoms for a long time. The study investigated the safety of Klimaktoplan® through its effect on the proliferation of breast cancer (MCF-7) and non-malignant mammary epithelial cells (MCF-10A).

METHODS

MCF-7 and MCF-10A cells were cultured in 312.5, 625, and 1,250 μg/ml Klimaktoplan®. 17-Beta estradiol (E2) and medroxyprogesterone 17-acetate (MPA) were used for comparison with Klimaktoplan®. E2 only (0.001, 0.01, and 0.1 μM), and the combination of E2 (0.001, 0.01, and 0.1 μM) and MPA (0.01, 0.1, and 1 μM) were tested. Control cells for Klimaktoplan® and E2 groups were treated with dimethylsulfoxide (DMSO), and DMSO + ethanol was used for the combination group. Cellular proliferation was evaluated by the formation of insoluble formazan after incubation of 4 days.

RESULTS

Klimaktoplan® had a concentration-dependent anti-proliferative effect on breast cancer cells at 625 and 1,250 μg/ml, while not affecting proliferation of non-malignant mammary cells at any tested concentration. The effect of lactose was evaluated as lactose (the adjuvant of Klimaktoplan®) affect cell growth. E2 and lactose increased the proliferation of both malignant and non-malignant cells. The effect of E2 + MPA on the proliferation of malignant and non-malignant mammary cells was lower than estradiol only, but was higher than control.

CONCLUSIONS

Klimaktoplan® has an anti-proliferative effect on breast cancer cells, but not for non-malignant mammary epithelial cells, unlike E2 and E2 + P. With further research, KP would be a good alternative or additive in women with menopausal symptoms who wish to avoid conventional E or E + P hormone therapy.

Immunomodulatory effects of black cohosh (Actaea racemosa) extract in female B6C3F1/N mice

Black cohosh extracts (BCE; Actaea racemosa) are being used worldwide as an alternative to hormone replacement therapy for the management of menstrual and menopausal symptoms, yet the effects of BCE on the immune system are largely unknown. Female B6C3F1/N mice were treated daily with BCE (0, 62.5, 125, 250, 500, or 1000mg/kg) for 28 days by oral gavage. Liver weights were significantly increased (26-32%) at the 1000mg/kg dose. Dose-related increases in mean corpuscular volume and mean corpuscular hemoglobin were observed. Decreasing trends were observed in all thymic T cell populations, with the most notable dose-responsive effects on immature thymocytes. In the spleen, dose-related decreases were observed in all cell phenotypes evaluated, reaching the level of statistical significance at the 1000mg/kg BCE dose. Splenic natural killer (NK) cell numbers were significantly decreased at all BCE doses, with the exception of absolute NK numbers at the 125mg/kg dose. No effects were observed on T-dependent antibody responses of the humoral immune system, including the antibody-forming cell response to sheep erythrocytes (sRBC) and IgM antibody levels to both sRBC and keyhole limpet hemocyanin. Cytotoxic T cell (TCTL) activity was increased, as was the mixed leukocyte response in one of two studies. Anti-CD3 mediated proliferation and the delayed-type hypersensitivity response were unaffected. No effects were observed on innate immunity or on bone marrow cellularity and colony-forming units. Overall, BCE exposure in B6C3F1/N mice for 28 days at doses up to 1000mg/kg had minimal immune effects, with the exception of an increased TCTL response.

Menopause: a standardized isopropanolic black cohosh extract (remifemin) is found to be safe and effective for menopausal symptoms

This randomized, double-blind, placebo-controlled, multicenter clinical study investigated the efficacy and various safety aspects of a standardized proprietary isopropanolic extract of black cohosh (Remifemin) in a population of 304 postmenopausal women who met strict parameter guidelines that determined the inclusion criteria. This clinical study confirmed previous results, which clearly indicate the efficacy and tolerability of this proprietary black cohosh extract (Remifemin) in addressing menopausal symptoms, particularly hot flashes.

Non-estrogen conventional and phytochemical treatments for vasomotor symptoms: what needs to be known for practice

OBJECTIVE

Non-hormonal treatment for menopausal vasomotor symptoms (VMS) is needed in women in whom there are medical or personal concerns on the use of hormone therapy. This paper reviews conventional and phytochemical therapies available for the relief of VMS, on their mechanisms of action, their efficacy and safety concerns.

METHODS

Medline was searched through Pubmed on the names of the diverse therapies analyzed, up to June 2011. The Cochrane Controlled Clinical Trials Register Database was searched for relevant trials that provided data on treatment of menopausal hot flushes.

RESULTS

All non-estrogen treatments for VMS are less efficacious than estrogen treatment. Randomized trials with neuroendocrine agents show globally modest to moderate reduction of VMS and frequent bothersome adverse events. The variability of effects makes it possible to undergo treatment in search for individual response where estrogen treatment is contraindicated. The antidepressants that interact with cytochrome P450, inhibiting tamoxifen metabolism to endoxifen, interfere with tamoxifen therapy in breast cancer patients. Otherwise, botanical products containing isoflavones from soy bean or red clover have great variability in bioavailability, have a broader spectrum of action than estradiol, and have predominant estrogen receptor-b activity. The efficacy of phytoestrogens on VMS is similar to placebo. They should be avoided in women with breast cancer and, in particular, in women being treated with tamoxifen or aromatase inhibitors due to possible antagonism. Cimicifuga racemosa is not a phytoestrogen, has partial serotonin agonist action and has a modest effect on VMS.

CONCLUSIONS

There are safe non-hormonal conventional treatments for menopausal VMS, although they are less efficacious than estrogens. The indication of phytochemicals is for women who make this choice on personal beliefs; long-term studies of larger groups of patients are needed to assess safety.

Black cohosh (Cimicifuga racemosa) relaxes the isolated rat thoracic aorta through endothelium-dependent and -independent mechanisms

AIM OF THE STUDY

The rhizome of the Cimicifuga racemosa (commonly known as black cohosh) has been used in treatment of climacteric complaints for decades in North America and Europe. A number of studies investigated the estrogenic potential of black cohosh, but its effectiveness is still controversial. Recently, it was reported that the extract of black cohosh acted as an agonist at the serotonin (5-HT) receptor and 5-HT derivative was isolated out of the black cohosh extract. Because it is well known that the 5-HT elicited the various cardiovascular effects including vasorelaxation, we investigated the vasorelaxant effects of the extract of black cohosh and its possible mechanisms of action.

MATERIALS AND METHODS

The extract of black cohosh (BcEx) was examined for its vasorelaxant effects in isolated rat aorta. The aortic rings were equilibrated under resting tension and induced reproducible contraction in organ bath. The control contraction was produced by 300 nM NE, and then BcEx were added. In experiments where specific inhibitors were used, they were added 20 min before NE contraction.

RESULTS

BcEx elicited two phases of relaxation in rat aorta pre-contracted with norepinephrine. The first, a rapid relaxation, which occurred within seconds of BcEx administration, was eliminated by pretreatment with N(G)-nitro-l-arginine (l-NNA) or methylene blue. The endogenous NO synthase substrate l-Arg markedly reversed the action of l-NNA, indicating that BcEx elicited the vasorelaxant effect via the NO/cGMP pathway. The second, slowly developing relaxation was not affected by the endothelium denudation. BcEx-induced endothelium-independent vasorelaxation appears to involve the inhibition of calcium influx mediated by the opening of inward rectifier potassium channels.

CONCLUSIONS

BcEx elicits the vasorelaxant effect via endothelium-dependent and -independent mechanisms and may contribute to a better understanding of a potential link between the use of black cohosh and its beneficial effects on vascular health.

A randomized placebo-controlled trial on the effectiveness of an herbal formula to alleviate menopausal vasomotor symptoms

OBJECTIVE

To evaluate the effectiveness of a formula containing Chinese herbs and Cimicifuga racemosa in alleviating vasomotor symptoms and improving quality of life.

METHODS

Between September 2004 and October 2005, 93 healthy women aged 45 to 65 years who reported six or more vasomotor symptoms per 24 hours were recruited into a 20-week randomized, double-blind, placebo-controlled trial. Women were consulted in clinics conducted within the Sydney metropolitan area. After a 4-week baseline period, women were randomly allocated to receive herbal (equivalent to 3,150 mg dry herb) or identical placebo tablets for 16 weeks. Women recorded the number and severity (1 = mild to 4 = very severe) of vasomotor symptoms in a daily hot flash diary and completed the Greene Climacteric and Hot Flash Related Daily Interference scales at each monthly consultation.

RESULTS

Intention-to-treat and per-protocol analyses found no statistically significant differences in mean hot flash scores (product of frequency and intensity), Greene Climacteric Scale scores, and Hot Flash Related Daily Interference Scale scores between the placebo and herbal treatment groups after 16 weeks of intervention.

CONCLUSIONS

This herbal formula containing Chinese herbs and Cimicifuga cannot be recommended to alleviate menopausal vasomotor symptoms or improve quality of life.

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.

Black cohosh increases metastatic mammary cancer in transgenic mice expressing c-erbB2

Black cohosh is an herbal extract that is often used as an alternative to estrogen-based replacement therapies to treat hot flushes that frequently accompany the transition to menopause. Although cancer-free women as well as breast cancer patients and survivors use black cohosh to relieve vasomotor symptoms, there is limited information on its potential to influence breast cancer development or progression. Therefore, in this study, the effects of black cohosh on mammary tumorigenesis were investigated in the MMTV-neu mouse model due to its similarities to HER2(+) breast cancer, including stochastic development of mammary tumors, which frequently progress to metastatic disease. Using an adjusted dose for the mice to correlate to the recommended dose in women (40 mg/d), no differences were detected in the incidence or onset of mammary tumors in black cohosh-treated versus control females. The lack of effect on mammary tumor development suggests that black cohosh would not influence breast cancer risk if given to women before tumor formation. In contrast, black cohosh significantly increased the incidence of lung metastases in tumor-bearing animals compared with mice fed the isoflavone-free control diet. Additional studies will be needed to correlate these findings to women taking different black cohosh products at various times during breast cancer development; however, these results suggest caution for women using black cohosh, especially for extended periods of time. As metastatic progression is linked to patient survival, these data stress the importance of investigating how women's therapies influence all stages of mammary tumorigenesis, particularly for assessing their safety.

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.

Estrogen-like effect of a Cimicifuga racemosa extract sub-fraction as assessed by in vivo, ex vivo and in vitro assays

Black cohosh (Cimicifuga racemosa) is used in the treatment of painful menstruation and menopausal symptoms. Data about the nature of the active compounds and mechanism(s) of action are still controversial, chiefly with respect to its estrogenic activity. This work aimed to assess the possible estrogenic activity of a commercial dry hydro-alcoholic extract of C. racemosa and its hydrophilic and lipophilic sub-fractions on in vivo, ex vivo, and in vitro assays. In a yeast estrogen screen, only the lipophilic sub-fraction was able to activate the human estrogen receptor alpha, with a lower potency but comparable efficacy to that of 17 beta-estradiol. Neither the total extract nor the lipophilic sub-fraction showed an in vivo uterotrophic effect in 21-day-old rats. Uterine tissues obtained ex vivo from C. racemosa treated animals were generally much less sensitive to oxytocin, prostaglandin F(2alpha,) and bradykinin than tissues obtained from estradiol valerate treated rats. The lipophilic sub-fraction, instead, induced a dose-dependent inhibitory activity on the in vitro response to oxytocin, prostaglandin F(2alpha,) and bradykinin of uterine horns from naïve 28-day-old rats, with a potency rate close to 1:30 of that of 17 beta-estradiol. Reported results confirm the effectiveness of C. racemosa in menstrual distress and further emphasize the possibility that lipophilic constituents bind to an as yet not identified estrogen receptor, likely inversely involved in inflammation.

Black Cohosh and Climacteric Symptoms: Growing Knowledge about the Efficacy and Safety

Hormone therapy of perimenopausal and postmenopausal disorders includes, in many cases, treatment with estrogens but many recent studies have raised the question as to whether it brings more dangers than benefits for patients. This has led to an increased use of alternatives, mainly plant derived extracts. Among the botanical supplements and herbal medicinal products, extracts of the rhizome and roots of black cohosh are used worldwide for these purposes. This plant has a long-standing history of being used to treat climateric complaints and its clinical efficacy has been proven in several double-blind placebo controlled studies. In terms of safety, minor and transient adverse effects such as nausea, vomiting, headaches and dizzness have been observed in clinical trials. A few cases of hepatotoxicity have been reported, but a direct association with the use of black cohosh has not been demonstrated. Black cohosh was first thought to be estrogenic in nature, but recent studies have proposed it as selective estrogen receptor modulator (SERM) and serotoninergic, dopaminergic and cholinergic mechanisms have been described. Black cohosh shows great promise for relief of menopausal symptoms, primarly of vasomotor and possibly mood symptoms, with an overall positive safety profile of at least 6 months and likely longer. However, data from longer and in some cases more rigorous clinical trials are necessary to assess high efficacy and to substantiate safety.

Black cohosh (Actaea racemosa, Cimicifuga racemosa) behaves as a mixed competitive ligand and partial agonist at the human mu opiate receptor

Black cohosh is a commonly used botanical dietary supplement for the treatment of climacteric complaints. Because the opiate system in the brain is intimately associated with mood, temperature, and sex hormonal levels, the activity of black cohosh extracts at the human mu opiate receptor (hMOR) expressed in Chinese hamster ovary cells was investigated. The 100% methanol, 75% ethanol, and 40% 2-propanol extracts of black cohosh effectively displaced the specific binding of [3H]DAMGO to hMOR. Further studies of the clinically used ethanol extract indicated that black cohosh acted as a mixed competitive ligand, displacing 77 +/- 4% [3H]DAMGO to hMOR (Ki = 62.9 microg/mL). Using the [35S]GTPgammaS assay, the action of black cohosh was found to be consistent with an agonist, with an EC50 of 68.8 +/- 7.7 microg/mL. These results demonstrate for the first time that black cohosh contains active principle(s) that activate hMOR, supporting its beneficial role in alleviating menopausal symptoms.

Analysis of formononetin from black cohosh (Actaea racemosa)

Black cohosh has been widely used as an herbal medicine for the treatment of symptoms related to menopause in America and Europe during the past several decades, but the bioactive constituents are still unknown. Formononetin is an isoflavone with known estrogen-like activity. This compound was first reported to be isolated from black cohosh in 1985, but subsequent research in 2002 using HPLC-PDA and LC-MS revealed no evidence to show the presence of formononetin in 13 populations of American black cohosh. A more recent report published in 2004 claimed to detect formononetin in an extract of black cohosh rhizomes using a TLC-fluorescent densitometry method. To further resolve these conflicting reports, we analyzed black cohosh roots and rhizomes for the presence of formononetin, using a combined TLC, HPLC-PDA and LC-MS method. We examined both methanolic and aqueous methanolic black cohosh extracts by HPLC-PDA and LC-MS methods, and did not detect formononetin in any extracts. We further determined the limits of detection of formononetin by HPLC-PDA and LC-MS. Our experimental results indicated that the sensitivity and accuracy of the HPLC-PDA and LC-MS methods for the analysis of formononetin were slightly higher than those of the reported fluorescent method, suggesting that the HPLC-PDA and LC-MS methods were reliable for the analysis of formononetin from black cohosh. We also repeated the reported TLC method to concentrate two fractions from a modern black cohosh sample and an 86-year-old black cohosh sample, respectively, and then analyzed these two fractions for formononetin using the HPLC-PDA and LC-MS method instead of the fluorescent method. Formononetin was not detected by HPLC-PDA or LC-MS. From the results of the present study it is not reasonable to attribute the estrogen-like activity of black cohosh extracts to formononetin.

Fulminant hepatic failure associated with the use of black cohosh: a case report

With data from the Women's Health Initiative indicating that estrogen plus progesterone are associated with an increased risk of cardiovascular events, many patients and practitioners are looking for alternative therapies to manage menopausal symptoms. One alternative is black cohosh, an herbal product used primarily to treat these symptoms. In recent years there have been several case reports associating this substance with hepatitis and fulminant hepatic failure. We present a case of a woman who developed hepatic failure requiring liver transplantation from the use of this herb.

Evaluation of the botanical authenticity and phytochemical profile of black cohosh products by high-performance liquid chromatography with selected ion monitoring liquid chromatography-mass spectrometry

Black cohosh (Actaea racemosa L., syn. Cimicifuga racemosa L.) has become increasingly popular as a dietary supplement in the United States for the treatment of symptoms related to menopause, but the botanical authenticity of most products containing black cohosh has not been evaluated, nor is manufacturing highly regulated in the United States. In this study, 11 black cohosh products were analyzed for triterpene glycosides, phenolic constituents, and formononetin by high-performance liquid chromatography-photodiode array detection and a new selected ion monitoring liquid chromatography-mass spectrometry method. Three of the 11 products were found to contain the marker compound cimifugin and not cimiracemoside C, thereby indicating that these plants contain Asian Actaea instead of black cohosh. One product contained both black cohosh and an Asian Actaea species. For the products containing only black cohosh, there was significant product-to-product variability in the amounts of the selected triterpene glycosides and phenolic constituents, and as expected, no formononetin was detected.

No estrogen-like effects of an isopropanolic extract of Rhizoma Cimicifugae racemosae on uterus and vena cava of rats after 17 day treatment

The effects of black cohosh extracts (Rhizoma Cimicifugae racemosae) on primary estrogen target organs, like mammary gland and endometrium are better described then those on other estrogen-sensitive systems e.g. the vasculature. We therefore treated ovariectomized DA/Han rats for 17 days with an isopropanolic Cimicifuga racemosa rhizoma extract (iCR) alone and in combination with the pure antiestrogen fulvestrant. As control groups vehicle, estradiol, fulvestrant, and estradiol fulvestrant cotreatment were used. Effects of all substances were investigated by vena cava and uterine gene expression analysis using real-time-PCR. Uterus wet weight was increased after estradiol treatment compared to the negative controls but none of the other treatments including the treatment with iCR had a uterotrophic effect. While estradiol-induced changes in uterine gene expression were mainly analogous to those detectable in shorter term experiments, iCR showed no or slightly antiestrogenic effects on gene expression in the uterus. This is mirrored in the vena cava where iCR had a very minor impact on the expression of the genes analyzed. While C. racemosa is effectively used for treatment of peri- and post-menopausal symptoms for a long time its mechanism of action remains unresolved. Contrary to earlier suggestions C. racemosa does not seem to act as an estrogen agonist, but possibly as a weak antiestrogen.

Antihypertensive and cognitive effects of grape polyphenols in estrogen-depleted, female, spontaneously hypertensive rats

Both endogenous and dietary estrogens reduce hypertension and enhance cognitive abilities in estrogen-depleted female spontaneously hypertensive rats (SHR). Many of the beneficial effects of estrogens/phytoestrogens also appear to be provided by other polyphenols (e.g., proanthocyanidins) in grape seed, which lack appreciable estrogenic receptor binding. The present study tested the hypothesis that similar to phytoestrogens, proanthrocyanidins in grape seed polyphenols reduce salt-sensitive hypertension in young, estrogen-depleted SHR. SHR were ovariectomized at 4 wk of age and placed on phytoestrogen-free diets with or without 0.5% grape seed extract added and with high (8.0%) or basal (0.6%) NaCl. After 10 wk on the diets, grape proanthrocyanidin supplementation significantly reduced arterial pressure in the rats fed the basal (10 mmHg) and high (26 mmHg)-NaCl diet, compared with the nonsupplemented controls. In vitro superoxide production was significantly reduced (23%) by the grape seed polyphenols. Spatial learning (8-arm-radial maze) in the SHR on the basal NaCl diets was improved by dietary grape seed polyphenols. These results indicate that grape seed polyphenols decrease arterial pressure in SHR, probably via an antioxidant mechanism.

Menopause, micronutrients, and hormone therapy

Micronutrient and herbal/phytochemical supplements are of increasing interest as potential alternatives to using estrogen therapy in treating menopausal symptoms. This article provides an overview of the questionnaires that assess menopausal symptoms and research efforts to better standardize symptom assessment. The reported rate of symptoms varies by ethnicity, stage of menopause, hormonal therapy and the measurement method. The use of estrogen therapy has declined sharply after the Women's Health Initiative (WHI) Hormone Trial was stopped early because the potential risks outweighed potential benefits. There is a limited research base that addresses the efficacy of supplements in controlling menopausal symptoms. The generalizability of several studies is limited because the study participants experiences menopause as the results of treatment for breast cancer. The article concludes with a review of guidelines and of issues that need to be addressed in future research studies with emphasis on questions related to clinical practice.

The value of plant collections in ethnopharmacology: a case study of an 85-year-old black cohosh (Actaea racemosa L.) sample

Ethnopharmacological collections of plants used in traditional medical systems are a valuable but often underappreciated resource for scientific investigation. These collections contain many samples of plants currently employed in herbal and pharmaceutical medicine, and questions on stability and storage life can be examined using these historic collections as vouchers. A sample of black cohosh (Actaea racemosa L.), collected in 1919 by the physician and plant explorer Henry Hurd Rusby, was recently identified in the collections of The New York Botanical Garden and analyzed for its triterpene glycosidic and phenolic constituents qualitatively and quantitatively by high-performance liquid chromatography-photodiode array detector (HPLC-PDA) and liquid chromatography-mass spectrophotometry (LC-MS). A comparison of the triterpene glycosidic and phenolic constituents of the 85-year-old plant sample with those of a modern collection of Actaea racemosa showed the similarity of the two samples, confirming the stability of the older sample, despite its curation over the years under a variety of conditions. Quantitative analyses indicated that both plant samples have similar amounts of the four major triterpene glycosides, but the total amount of the six major phenolic constituents measured in the 85-year-old plant material is lower than the amount measured in the modern plant material. Methanol extracts of the two plant materials were tested for their antioxidant activity, and both extracts showed similar antioxidant activity.

Phytoestrogens

Collectively, plants contain several different families of natural products among which are compounds with weak estrogenic or antiestrogenic activity toward mammals. These compounds, termed phytoestrogens, include certain isoflavonoids, flavonoids, stilbenes, and lignans. The best-studied dietary phytoestrogens are the soy isoflavones and the flaxseed lignans. Their perceived health beneficial properties extend beyond hormone-dependent breast and prostate cancers and osteoporosis to include cognitive function, cardiovascular disease, immunity and inflammation, and reproduction and fertility. In the future, metabolic engineering of plants could generate novel and exquisitely controlled dietary sources with which to better assess the potential health beneficial effects of phytoestrogens.

Phytoestrogens: a review of the present state of research

Phytoestrogens are a diverse group of plant-derived compounds that structurally or functionally mimic mammalian estrogens and show potential benefits for human health. The number of articles published on phytoestrogens has risen dramatically in the past couple decades. Further research continues to demonstrate the biological complexity of phytoestrogens, which belong to several different chemical classes and act through diverse mechanisms. This paper discusses the classification of phytoestrogens, methods of identification, their proposed mechanisms of action and botanical sources for phytoestrogens. The effects of phytoestrogens on breast and prostate cancers, cardiovascular disease, menopausal symptoms and osteoporosis will also be examined including research on benefits and risks.

Black cohosh acts as a mixed competitive ligand and partial agonist of the serotonin receptor

Extracts of the rhizome of black cohosh [Actaea racemosa L., formerly called Cimicifuga racemosa (L.) Nutt.] were evaluated for potential mechanisms of action in the alleviation of menopausal hot flashes. Ovariectomized Sprague-Dawley rats were administered a 40% 2-propanol extract of black cohosh [4, 40, and 400 mg/(kg.day)] by gavage for 2 weeks with or without estradiol [50 microg/(kg.day)] to determine if black cohosh could act as an estrogen or antiestrogen on the basis of an increase in uterine weight or vaginal cellular cornification. No effects were observed on uterine weight or on vaginal cellular cornification in rats treated with black cohosh alone or in combination with 17beta-estradiol, indicating this black cohosh extract had no estrogenic or antiestrogenic properties in the ovariectomized rat model. To evaluate other potential pathways by which black cohosh might reduce menopausal hot flashes, serotonin activity was first assessed by the inhibition of radioligand binding to cell membrane preparations containing recombinant human serotonin receptor (5-HT) subtypes. A 40% 2-propanol extract of black cohosh was tested against 10 subtypes of the serotonin receptor, revealing the presence of compounds with strong binding to the 5-HT(1A), 5-HT(1D), and 5-HT(7) subtypes. Subsequent binding studies were carried out using 5-HT(1A) and 5-HT(7) receptors because of their association with the hypothalamus, which has been implicated in the generation of hot flashes. The black cohosh 40% 2-propanol extract inhibited [(3)H]lysergic acid diethylamide (LSD) binding to the human 5-HT(7) receptor (IC(50) = 2.4 +/- 0.4 microg/mL) with greater potency than binding of [(3)H]-8-hydroxy-2-(di-N-propylamino)tetralin to the rat 5-HT(1A) receptor (IC(50) = 13.9 +/- 0.6 microg/mL). Analysis of ligand binding data indicated that components of a black cohosh methanol extract functioned as a mixed competitive ligand of the 5-HT(7) receptor. In addition, a black cohosh methanol extract elevated cAMP levels in 293T-5-HT(7)-transfected HEK cells, suggesting the extract acted as a partial agonist at the receptor. The elevation in cAMP mediated by the black cohosh extract could be reversed in the presence of the antagonist methiothepin, indicating a receptor-mediated process. These data suggest that reductions in hot flashes in some women taking black cohosh may not be due to estrogenic properties. This study identifies other possible biological targets of black cohosh that could account for reported biological effects.