Black cohosh and liver toxicity: is there a relationship?

Black Cohosh: An Uncommon Culprit of Bradycardia in Postmenopausal Women

The use of herbal supplements has become increasingly prevalent, with black cohosh (BC) gaining popularity for managing menopausal symptoms. However, reports of adverse effects associated with BC are limited. We present a case of bradycardia linked to prolonged BC ingestion. A 76-year-old postmenopausal woman who has been taking BC for years has had syncopal attacks multiple times during the past years associated with bradycardia with the heart rate dropping to 30 beats/minute with no identifiable cause. Discontinuation of BC resulted in a gradual resolution of bradycardia, highlighting a plausible association. There were no additional pharmacological or invasive interventions required.

Mechanistic Evaluation of Black Cohosh Extract-Induced Genotoxicity in Human Cells

Black cohosh extract (BCE) is marketed to women as an alternative to hormone replacement therapy for alleviating menopausal symptoms. Previous studies by the National Toxicology Program revealed that BCE induced micronuclei (MN) and a nonregenerative macrocytic anemia in rats and mice, likely caused by disruption of the folate metabolism pathway. Additional work using TK6 cells showed that BCE induced aneugenicity by destabilizing microtubules. In the present study, BCE-induced MN were confirmed in TK6 and HepG2 cells. We then evaluated BCE-induced DNA damage using the comet assay at multiple time points (0.5-24 h). Following a 0.5-h exposure, BCE induced significant, concentration-dependent increases in %tail DNA in TK6 cells only. Although DNA damage decreased in TK6 cells over time, likely due to repair, small but statistically significant levels of DNA damage were observed after 2 and 4 h exposures to 250 µg/ml BCE. A G1/S arrest in TK6 cells exposed to 125 µg/ml BCE (24 h) was accompanied by apoptosis and increased expression of γH2A.X, p-Chk1, p-Chk2, p53, and p21. Conditioning TK6 cells to physiological levels of folic acid (120 nM) did not increase the sensitivity of cells to BCE-induced DNA damage. BCE did not alter global DNA methylation in TK6 and HepG2 cells cultured in standard medium. Our results suggest that BCE induces acute DNA strand breaks which are quickly repaired in TK6 cells, whereas DNA damage seen at 4 and 24 h may reflect apoptosis. The present study supports that BCE is genotoxic mainly by inducing MN with an aneugenic mode of action.

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.

Herb-Induced Liver Injury by Cimicifuga racemosa and Thuja occidentalis Herbal Medications for Fertility

Herb-induced liver injury (HILI) is often an underreported sequela for many herbal remedies due to the lack of safety measurements involving these supplements. Cimicifuga racemosa and Thuja occidentalis are two herbal medications commonly used by women for fertility purposes. Many herbal preparations of these two supplements do not specify the risks behind their individual usage. We present a case of a 40-year-old woman who developed acute liver injury after concomitant use of these two products assessed for causality using the updated RUCAM. Upon a detailed investigation, the patient did not have evidence of underlying liver disease or any other risk factors to explain her presentation. After discontinuation of both herbal supplements, the patient had complete resolution of her symptoms and a significant improvement of transaminitis. This report highlights the importance of potential risk of hepatotoxicity induced by concomitant use of Cimicifuga racemosa and Thuja occidentalis.

Analysis of spontaneous adverse drug reactions to echinacea, valerian, black cohosh and ginkgo in Australia from 2000 to 2015

OBJECTIVE

Assessing adverse drug reactions (ADRs) is a proven method to estimate the safety of medicines. The ADRs to herbal medicines in Australia (and by inference, the safety of herbal medicines in Australia) remain unknown. This study examines spontaneous ADR cases to four of the most popular herbs in Australia from 2000 to 2015: echinacea (Echinacea purpurea), valerian (Valeriana officinalis), black cohosh (Actaea racemosa) and ginkgo (Ginkgo biloba).

METHODS

ADRs of echinacea, valerian, black cohosh and ginkgo reported to the Australian Therapeutic Goods Administration (TGA) between 2000 and 2015 were obtained from the TGA database. Data were collated and analysed according to age, sex, severity, type of ADR and body system affected. Statistics were calculated using GraphPad Prism software.

RESULTS

Most ADRs were mild or moderate. However, every herbal medicine was associated with life-threatening ADRs. In each life-threatening case, the herbal medicine was taken concomitantly with prescription medications. Black cohosh was associated with a significant number of severe ADRs (30.3% of the total), with 39.4% of these ADRs being associated with abnormal hepatic function, hepatitis or hepatotoxicity.

CONCLUSION

This study highlights the lack of public awareness with regard to herb-drug interactions, since most of the severe ADRs involved a herb-drug interaction.

Assessment of acute, 14-day, and 13-week repeated oral dose toxicity of Tiglium seed extract in rats

BACKGROUND

Seed of mature Croton tiglium Linne, also known as Tiglium seed (TS), has been widely used as a natural product due to its several health beneficial properties including anti-tumor and antifungal activities. Despite its ethnomedicinal beneficial properties, toxicological information regarding TS extract, especially its long-term toxicity, is currently limited. Therefore, the objective of the present study was to evaluate acute and subchronic toxicity of TS extract in rats after oral administration following test guidelines of the Organization for Economic Cooperation and Development (OECD).

METHODS

Toxicological properties of TS extract were evaluated by toxicity assays to determine its single-dose acute toxicity (125, 250, 500, 1000, or 2000 mg/kg), 14-day repeated-dose toxicity (125, 250, 500, 1000, or 2000 mg/kg) and 13-week repeated-dose toxicity (31.25, 62.5, 125, 250, and 500 mg/kg) in Sprague-Dawley rats and F344 rats. Hematological, serum biochemical, and histopathological parameters were analyzed to determine its median lethal dose (LD50) and no-observed-adverse-effect-level (NOAEL).

RESULTS

Oral single dose up to 2000 mg/kg of TS extract resulted in no mortalities or abnormal clinical signs. In 13-week toxicity study, TS extract exhibited no dose-related changes (mortality, body weight, food/water consumption, hematology, clinical biochemistry, organ weight, or histopathology) at dose up to 500 mg/kg, the highest dosage level suggested based on 14-day repeat-dose oral toxicity study.

CONCLUSION

Acute oral LD50 of TS extract in rats was estimated to be greater than 2000 mg/kg. NOAEL of TS extract administered orally was determined to be 500 mg/kg/day in both male and female rats. Results from these acute and subchronic toxicity assessments of TS extract under Good Laboratory Practice regulations indicate that TS extract appears to be safe for human consumption.

Naturally Occurring Nrf2 Activators: Potential in Treatment of Liver Injury

Oxidative stress plays a major role in acute and chronic liver injury. In hepatocytes, oxidative stress frequently triggers antioxidant response by activating nuclear erythroid 2-related factor 2 (Nrf2), a transcription factor, which upregulates various cytoprotective genes. Thus, Nrf2 is considered a potential therapeutic target to halt liver injury. Several studies indicate that activation of Nrf2 signaling pathway ameliorates liver injury. The hepatoprotective potential of naturally occurring compounds has been investigated in various models of liver injuries. In this review, we comprehensively appraise various phytochemicals that have been assessed for their potential to halt acute and chronic liver injury by enhancing the activation of Nrf2 and have the potential for use in humans.

RUCAM in Drug and Herb Induced Liver Injury: The Update

RUCAM (Roussel Uclaf Causality Assessment Method) or its previous synonym CIOMS (Council for International Organizations of Medical Sciences) is a well established tool in common use to quantitatively assess causality in cases of suspected drug induced liver injury (DILI) and herb induced liver injury (HILI). Historical background and the original work confirm the use of RUCAM as single term for future cases, dismissing now the term CIOMS for reasons of simplicity and clarity. RUCAM represents a structured, standardized, validated, and hepatotoxicity specific diagnostic approach that attributes scores to individual key items, providing final quantitative gradings of causality for each suspect drug/herb in a case report. Experts from Europe and the United States had previously established in consensus meetings the first criteria of RUCAM to meet the requirements of clinicians and practitioners in care for their patients with suspected DILI and HILI. RUCAM was completed by additional criteria and validated, assisting to establish the timely diagnosis with a high degree of certainty. In many countries and for more than two decades, physicians, regulatory agencies, case report authors, and pharmaceutical companies successfully applied RUCAM for suspected DILI and HILI. Their practical experience, emerging new data on DILI and HILI characteristics, and few ambiguous questions in domains such alcohol use and exclusions of non-drug causes led to the present update of RUCAM. The aim was to reduce interobserver and intraobserver variability, to provide accurately defined, objective core elements, and to simplify the handling of the items. We now present the update of the well accepted original RUCAM scale and recommend its use for clinical, regulatory, publication, and expert purposes to validly establish causality in cases of suspected DILI and HILI, facilitating a straightforward application and an internationally harmonized approach of causality assessment as a common basic tool.