Black Cohosh: Considerations of Safety and Benefit

The effect of black cohosh extract and risedronate coadministration on bone health in an ovariectomized rat model

Preparations of black cohosh extract are sold as dietary supplements marketed to relieve the vasomotor symptoms of menopause, and some studies suggest it may protect against postmenopausal bone loss. Postmenopausal women are also frequently prescribed bisphosphonates, such as risedronate, to prevent osteoporotic bone loss. However, the pharmacodynamic interactions between these compounds when taken together is not known. To investigate possible interactions, 6-month-old, female Sprague-Dawley rats underwent bilateral ovariectomy or sham surgery and were treated for 24 weeks with either vehicle, ethinyl estradiol, risedronate, black cohosh extract or coadministration of risedronate and black cohosh extract, at low or high doses. Bone mineral density (BMD) of the femur, tibia, and lumbar vertebrae was then measured by dual-energy X-ray absorptiometry (DEXA) at weeks 0, 8, 16, and 24. A high dose of risedronate significantly increased BMD of the femur and vertebrae, while black cohosh extract had no significant effect on BMD individually and minimal effects upon coadministration with risedronate. Under these experimental conditions, black cohosh extract alone had no effect on BMD, nor did it negatively impact the BMD-enhancing properties of risedronate.

Actein contributes to black cohosh extract-induced genotoxicity in human TK6 cells

Black cohosh extract (BCE) is one of the most popular botanical products for relieving menopausal symptoms. However, recent studies indicate that BCE is not only ineffective for menopausal therapy, but also induces genotoxicity through an aneugenic mode of action (MoA). In this study, the cytotoxicity of five constituents of BCE was evaluated in human lymphoblastoid TK6 cells. Among the five constituents, actein (up to 50 μM) showed the highest cytotoxicity and was thus selected for further genotoxicity evaluations. Actein caused DNA damage proportionally to concentration as evidenced by the phosphorylation of the histone protein H2A.X (γH2A.X) and resulted in chromosomal damage as measured by the increased percentage of micronuclei (MN) in cells. In addition, actein activated DNA damage response (DDR) pathway through induction of p-ATM, p-Chk1, and p-Chk2, which subsequently induced cell cycle changes and apoptosis. Moreover, both BCE and actein increased intracellular reactive oxygen species (ROS) production, decreased glutathione levels, and activated the mitogen-activated protein kinases (MAPK) signaling pathway. N-acetylcysteine, a ROS scavenger, attenuated BCE- and actein-induced ROS production, apoptosis, and DNA damage. These findings indicate that BCE- and actein-induced genotoxicity is mediated through oxidative stress. Taken together, our data show that actein is likely one of the major contributors to BCE-induced genotoxicity.

Modulation of steroidogenesis by Actaea racemosa and vitamin C combination, in letrozole induced polycystic ovarian syndrome rat model: promising activity without the risk of hepatic adverse effect

Background

Complementary remedies such as the Chinese herb ‘Sheng Ma’ (Black cohosh; Actaea racemosa ‘AR’) are being sought to overcome the shortcomings of conventional hormonal and surgical therapies developed for the treatment of polycystic ovary syndrome (PCOS). However, AR-induced hepatotoxicity necessitates a cautionary warning to be labeled on its products as recommended by the United States Pharmacopeia, where four out of seven hepatotoxic cases in Sweden were possibly associated with black cohosh products.

Methods

We investigated the effects, safety, and molecular targets of black cohosh ethanolic extract and/or vitamin C on ovarian functionality and oxidative response in hyperandrogenism-induced PCOS rats. A well-established rat model using oral letrozole, daily, for 21 days was employed. The rats then received the AR extract with and without vitamin C for 28 days. The hormonal evaluation, antioxidant status, histopathological examination, immunohistochemical analysis, cell proliferation, and the expression ratio of the aromatase (Cyp19α1) gene were evaluated. Additionally, holistic profiling of the AR arsenal of secondary metabolites was performed using ultra-high-performance liquid chromatography (UHPLC) coupled with quadrupole high-resolution time of flight mass spectrometry (QTOF-MS).

Results

Beneficial effects were exerted by AR in PCOS rats as antioxidant status, hormonal profile, lipid profile, glucose level, liver functions, and the induced Ki-67 expression in the granulosa, theca cell layers and interstitial stromal cells were all improved. Notably, the combination of AR with vitamin C was not only more effective in reversing the dysregulated levels of testosterone, luteinizing hormone, and mRNA level of Cyp19α1 gene in the PCOS rat, but also safer. The combination regulated both ovarian and hepatic malondialdehyde (MDA) and glutathione (GSH) levels with histological improvement observed in the liver and ovaries. In addition, the untargeted metabolomic profiling enabled the identification of 61 metabolites allocated in five major chemical classes.

Conclusion

This study demonstrated the benefit of the combinatorial effects of AR and vitamin C in mitigating the reproductive and metabolic disorders associated with PCOS with the elimination of AR hepatotoxic risk.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-021-00444-z.

Feruloyl dopamine-O-hexosides are efficient marker compounds as orthogonal validation for authentication of black cohosh (Actaea racemosa)-an UHPLC-HRAM-MS chemometrics study

Due to the complexity and variation of the chemical constituents in authentic black cohosh (Actaea racemosa) and its potential adulterant species, an accurate and feasible method for black cohosh authentication is not easy. A high-resolution accurate mass (HRAM) LC-MS fingerprinting method combined with chemometric approach was employed to discover new marker compounds. Seven hydroxycinnamic acid amide (HCAA) glycosides are proposed as potential marker compounds for differentiation of black cohosh from related species, including two Asian species (A. foetida, A. dahurica) and two American species (A. pachypoda, A. podocarpa). These markers were putatively identified by comparing their mass spectral fragmentation behavior with those of their authentic aglycone compounds and phytochemistry reports. Two isomers of feruloyl methyldopamine 4-O-hexoside ([M + H]⁺ 506) and one feruloyl tyramine 4-O-hexoside ([M + H]⁺ 476) contributed significantly to the separation of Asian species in principle component analysis (PCA) score plot. The efficacy of the models built on four reasonable combinations of these markers in differentiating black cohosh and its adulterants were evaluated and validated by partial least-square discriminant analysis (PLS-DA). Two models based on these reduced dataset achieved 100% accuracy based on the current sample collection, including the model that used only three feruloyl dopamine-O-hexoside isomers ([M + H]⁺ 492) and one feruloyl dopamine-O-dihexoside ([M + H-hexosyl]⁺ at m/z 492). Graphical abstract Hydroxycinnamic acid amide glycosides are proposed as potential marker compounds for authentication of black cohosh.

Authentication of the botanical origin of Western herbal products using Cimicifuga and Vitex products as examples

Various herbal medicines have been developed and used in various parts of the world for thousands of years. Although locally grown indigenous plants were originally used for traditional herbal preparations, Western herbal products are now becoming popular in Japan with the increasing interest in health. At the same time, there are growing concerns about the substitution of ingredients and adulteration of herbal products, highlighting the need for the authentication of the origin of plants used in herbal products. This review describes studies on Cimicifuga and Vitex products developed in Europe and Japan, focusing on establishing analytical methods to evaluate the origins of material plants and finished products. These methods include a polymerase chain reaction-restriction fragment length polymorphism method and a multiplex amplification refractory mutation system method. A genome-based authentication method and liquid chromatography-mass spectrometry-based authentication for black cohosh products, and the identification of two characteristic diterpenes of agnus castus fruit and a shrub chaste tree fruit-specific triterpene derivative are also described.

Cycloartane Triterpenes from the Aerial Parts of Actaea racemosa

Investigating the phytochemical equivalence of the aerial parts of Actaea racemosa (syn. Cimicifuga racemosa) relative to the widely used roots/rhizomes, this study provides a perspective for the potential use of renewable ("green") plant parts as a source of black cohosh botanical preparations. In addition to the characterization of Nω-methylserotonin as one representative marker of the Actaea alkaloids, nine cycloartane triterpenes were isolated and characterized, including the two new triterpene glycosides (1S,15R)-1,15,25-trihydroxy-3-O-β-d-xylopyranosyl-acta-(16S,23R,24R)-16,23;16,24-binoxoside (1) and 3-O-α-l-arabinopyranosyl-(1S,24R)-1,24,25-trihydroxy-15-oxo-acta-(16R,23R)-16,23-monoxoside (2). Their structures were elucidated by spectroscopic data interpretation. The relative configuration of 1 was deduced by (1)H iterative full-spin analysis (HiFSA), making it the first example of the complete analysis of the complex (1)H NMR spectrum of a triterpene glycoside. In addition to the new compounds 1 and 2, the aerial plant parts were shown to contain the previously known binoxosides 3, 4, 6, and 7, the monoxoside 8, and the binoxols 5 and 9. Overall, the metabolome of the aerial plant parts consists of a variety of Actaea triterpenes, similar to those found in roots/rhizomes, a tendency toward C-1 and C-7 hydroxylation of the cycloartanol skeleton, a greater abundance of aglycones, and the presence of comparable amounts of Nω-methylserotonin.

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.

Pharmacological mechanisms of black cohosh in Sprague-Dawley rats

BACKGROUND

Studies indicate that extracts and purified components from black cohosh inhibit the growth of human breast cancer cells, but the molecular targets and signaling pathways have not yet been defined.

PURPOSE

This study examines the pharmacological mechanisms and toxicological effects in the short term of the herb black cohosh on female Sprague-Dawley rats.

MATERIALS AND METHODS

To assess effects on gene activity and lipid content, we treated female Sprague-Dawley rats with an extract of black cohosh enriched in triterpene glycosides (27%) at 35.7 or 0mg/kg. Four animals for each group were sacrificed at 1, 6 and 24h after treatment; liver tissue and serum samples were obtained for gene expression and lipid analysis.

RESULTS

Microarray analysis of rat liver tissue indicated that black cohosh markedly downregulated mitochondrial oxidative phosphorylation genes. Phospholipid biosynthesis and remodeling, PI3-Kinase and sphingosine signaling were upregulated, driven largely by an upregulation of several isoforms of phospholipase C. Hierarchical clustering indicated that black cohosh clustered with antiproliferative compounds, specifically tubulin binding vinca alkaloids and DNA alkylators. In support of this, black cohosh repressed the expression of cyclin D1 and ID3, and inhibited the proliferation of HepG2, p53 positive, liver cancer cells. Black cohosh reduced the level of free fatty acids at 6 and 24h and triglycerides at 6h in the serum, but increased the free fatty acid and triglyceride content of the treated livers at 24h.

CONCLUSION

Our results suggest that black cohosh warrants further study for breast cancer prevention and therapy.

In silico toxicology models and databases as FDA Critical Path Initiative toolkits

In silico toxicology methods are practical, evidence-based and high throughput, with varying accuracy. In silico approaches are of keen interest, not only to scientists in the private sector and to academic researchers worldwide, but also to the public. They are being increasingly evaluated and applied by regulators. Although there are foreseeable beneficial aspects--including maximising use of prior test data and the potential for minimising animal use for future toxicity testing--the primary use of in silico toxicology methods in the pharmaceutical sciences are as decision support information. It is possible for in silico toxicology methods to complement and strengthen the evidence for certain regulatory review processes, and to enhance risk management by supporting a more informed decision regarding priority setting for additional toxicological testing in research and product development. There are also several challenges with these continually evolving methods which clearly must be considered. This mini-review describes in silico methods that have been researched as Critical Path Initiative toolkits for predicting toxicities early in drug development based on prior knowledge derived from preclinical and clinical data at the US Food and Drug Administration, Center for Drug Evaluation and Research.

Phytochemical fingerprinting to thwart black cohosh adulteration: a 15 Actaea species analysis

INTRODUCTION

The popular use of black cohosh products (Actaea racemosa L., syn. Cimicifuga racemosa L.) is growing as the demand for alternatives to estrogen therapy has increased. Critical to safe use is the assurance of unadulterated, high-quality products. Questions have been raised about the safety of black cohosh due to cases of liver toxicity in patients who reported taking it; subsequent evaluation found some products to be adulterated with other related herbal species. Correct plant species identification is a key first step for good manufacturing practices of safe black cohosh products.

OBJECTIVES

To develop analytical methods which distinguish black cohosh from other species (American and Asian) of Actaea increasingly found as adulterants in commercially available black cohosh products.

MATERIAL AND METHODS

Fifteen species of Actaea were collected from North America and Asia, and the phytochemical fingerprints of these samples were established using HPLC-PDA and LC-MS techniques.

RESULTS

The HPLC and LC-MS fingerprints for polyphenols and triterpene glycosides revealed distinct patterns that make black cohosh clearly distinguishable from most other species of Actaea. Two marker compounds, cimifugin and cimiracemoside F, were found to be important to distinguish black cohosh from most Asian species of Actaea. Formononetin was not found from either Asian or American species of Actaea.

CONCLUSIONS

Phytochemical fingerprinting is a practical, reliable method for authenticating black cohosh and distinguishing it from other species of Actaea increasingly found as adulterants in commercially available black cohosh products. This should facilitate the continued development of high-quality, unadulterated black cohosh products.