Kava hepatotoxicity: a clinical survey and critical analysis of 26 suspected cases

AB-free kava enhances resilience against the adverse health effects of tobacco smoke in mice

Tobacco smoke remains a serious global issue, resulting in serious health complications, contributing to the onsets of numerous preventive diseases, and imposing significant financial burdens. Despite regulatory policies and cessation measures aimed at curbing its usage, novel interventions are urgently needed for effective damage reduction. Our preclinical and pilot clinical studies showed that AB-free kava has the potential to reduce tobacco smoke-induced lung cancer risk, mitigate tobacco dependence, and reduce tobacco use. To understand the scope of its benefits in damage reduction and potential limitations, this study evaluated the effects of AB-free kava on a panel of health indicators in mice exposed to 2 - 4 weeks of daily tobacco smoke exposure. Our comprehensive assessments included global transcriptional profiling of the lung and liver tissues, analysis of lung inflammation, evaluation of lung function, exploration of tobacco nicotine withdrawal, and characterization of the causal PKA signaling pathway. As expected, Tobacco smoke exposure perturbed a wide range of biological processes and compromised multiple functions in mice. Remarkably, AB-free kava demonstrated the ability to globally mitigate tobacco smoke-induced deficits at the molecular and functional levels with promising safety profiles, offering a unique promise to mitigate tobacco smoke-related health damages. Further pre-clinical evaluation and clinical translation are warranted to fully harness the potential of AB-free kava in combating tobacco smoke-related harms.

Reducing tobacco-associated lung cancer risk: a study protocol for a randomized clinical trial of AB-free kava

BACKGROUND

Tobacco use is the leading cause of many preventable diseases, resulting in premature death or disease. Given that the majority of adult who smoke want to stop, this health burden could be significantly reduced if the success rate of tobacco cessation can be improved. In addition, most adults planning to quit were interested in trying complementary approaches to facilitating tobacco cessation, which is currently lacking. Therefore, there is an unmet and urgent need for novel interventions to improve the success of tobacco cessation. If such an intervention can reduce tobacco-associated lung carcinogenesis, that will be more desirable. The goal of this project is to develop a safe and effective kava-based intervention to enable tobacco cessation and reduce lung cancer risk, which will improve the health of smokers.

METHODS

A randomized controlled trial will enroll 80 adults who currently smoke at least 10 cigarettes daily and randomize 1:1 into the placebo and AB-free kava arms, being exposed for 4 weeks, with a total of six visits (weeks 0, 1, 2, 4, 8, and 12) to evaluate the compliance and potential issues of AB-free kava use among the participants, explore the potential effect of the AB-free kava intervention on tobacco dependence, tobacco use, and lung carcinogenesis biomarkers. Participants will be enrolled during their primary care clinic visit.

DISCUSSION

Primary care settings play a critical role in tobacco-related disease screening, counseling, and early intervention, as the majority of adults who smoke visit their physicians annually. Building upon our promising pilot human trial results in conjunction with ample compelling lab animal results, and consistent with evidence of kava's benefits from epidemiological data, this trial will evaluate the compliance of AB-free kava among adults who currently smoke with no intention to quit. The other exploratory aims include (1) whether AB-free kava intervention can reduce tobacco use and tobacco dependence; (2) whether AB-free kava use suppresses tobacco-induced carcinogenesis; and (3) the potential of the mechanism-based noninvasive biomarkers in precision AB-free kava intervention. The positive results from this study are expected to provide a great opportunity to effectively reduce smoking rates and tobacco-related diseases.

TRIAL REGISTRATION

ClinicalTrials.gov with the identifier: NCT05081882. Registered on October 18, 2021.

Recreational Drugs and the Risk of Hepatocellular Carcinoma

Recreational or aesthetic drug use is a distinctive behavior of humans, principally attested in the last century. It is known that recreational and illegal drugs are major contributors to the universal morbidity rate worldwide. Many of these substances have a well-established hepatotoxic potential, causing acute or chronic liver injury, liver fibrosis and cirrhosis, but their implications for hepatocellular carcinoma or other varieties of liver tumors are little known. In this article, we perform an extensive literature review, aiming to provide updated information about recreational drug use and the risk of developing liver tumors. Khat use and pyrrolizidine alkaloid consumption (present in some natural plants) have been linked to liver cirrhosis. Kava intake is associated with different liver tumors in animal models but not in humans. Cannabis' potential to accelerate liver fibrosis in chronic hepatitis is controversial according to the existing data. Cigarette smoking is an important contributor to hepatocellular carcinoma, and anabolic androgen steroids are well-defined causes of a variety of liver cancers and other hepatic tumors. Long-term follow-up studies of subjects who have developed injuries in association with the use of recreational drugs are warranted so as to better define the risk of developing hepatocellular carcinoma in association with these substances and, thus, to implement health care policies to combat this preventable cause of cancer.

Characterization of Different Forms of Kava (Piper methysticum) Products by UPLC-MS/MS

There are several forms of kava (Piper methysticum) products available for human consumption, and many factors are known to influence their chemical compositions and therefore their pharmacological properties. Because of the increased popularity of kava intake, a rigorous characterization of their content diversity is prerequisite, particularly due to its known potential to cause hepatotoxicity. To understand the composition diversity of kavalactones and flavokavains in commercial kava products, we developed a UPLC-MS/MS-based analytical method for the quantification of six kavalactones (kavain, dihydrokavain, methysticin, dihydromethysticin, yangonin and desmethoxyyangonin) and two flavokavains (flavokavains A and B) and analyzed their contents in 28 different kava products in the form of capsules, tinctures, traditional aqueous suspensions and dried powders. Our results demonstrated a great variation in terms of the total and relative abundance of the analyzed kavalactones and flavokavains among the analyzed kava preparations. More importantly, the kavalactone abundance in the product label could differ up to 90% from our experimental measurements. Therefore, more rigorous and comprehensive quality control of kava products is required with respect to the content of individual kavalactones and flavokavains. Accurate content information is essential to understand the pharmacological properties and safety of different kava products.

In vivo Structure-Activity Relationship of Dihydromethysticin in Reducing Nicotine-Derived Nitrosamine Ketone (NNK)-Induced Lung DNA Damage against Lung Carcinogenesis in A/J Mice

Lung cancer is the leading cause of cancer-related deaths and chemoprevention should be developed. We recently identified dihydromethysticin (DHM) as a promising candidate to prevent NNK-induced lung tumorigenesis. To probe its mechanisms and facilitate its future translation, we investigated the structure-activity relationship of DHM on NNK-induced DNA damage in A/J mice. Twenty DHM analogs were designed and synthesized. Their activity in reducing NNK-induced DNA damage in the target lung tissues was evaluated. The unnatural enantiomer of DHM was identified to be more potent than the natural enantiomer. The methylenedioxy functional moiety did not tolerate modifications while the other functional groups (the lactone ring and the ethyl linker) accommodated various modifications. Importantly, analogs of high structural similarity to DHM with distinct efficacy in reducing NNK-induced DNA damage have been identified. They will serve as chemical probes to elucidate the mechanisms of DHM in blocking NNK-induced lung carcinogenesis.

Herb-induced liver injury (HILI) with 12,068 worldwide cases published with causality assessments by Roussel Uclaf Causality Assessment Method (RUCAM): an overview

Herbal products including herbal medicines are worldwide used in large amounts for treating minor ailments and for disease prevention. However, efficacy of most herbal products has rarely been well documented through randomized controlled trials in line with evidence-based medicine concepts, which could be used to estimate the benefit/risk ratio. Instead, much better documented are adverse reactions such as liver injury associated with the consumption of some herbal products, so called herb-induced liver injury (HILI), which represents a clinical challenge. In order to establish HILI as valid diagnosis, the use of a diagnostic algorithms such as Roussel Uclaf Causality Assessment Method (RUCAM) is widely recommended, although physicians in some countries are reluctant to use RUCAM for their HILI cases. This review on worldwide HILI and RUCAM, developed as part of the artificial intelligence ideas, reveals that China is the leading country with 24 publications on HILI cases that were all assessed for causality using RUCAM, followed by Korea with 15 reports, Germany with 9 reports, the US with 7 reports, and Spain with 6 reports, whereas the remaining countries provided less than 4 reports. The total number of assessed HILI cases is 12,068 worldwide derived from 80 publications but in each report HILI case numbers were variable in a range from 1 up to 6,971. This figure compares with 46,266 cases of drug-induced liver injury (DILI) published worldwide from 2014 to early 2019 also assessed for causality by RUCAM. The original version of RUCAM was validated and established in 1993 and updated in 2016 that should be used in future HILI cases. RUCAM is an objective, structured, and validated method, specifically designed for liver injury. It is a scoring system including case data elements to be assessed and scored individually to provide a final score in five causality gradings. Among the 11,404/12,068 HILI (94.5%) cases assessable for evaluation, causality gradings were highly probable in 4.2%, probable in 15.5%, possible in 70.3%, and unlikely or excluded in 10.0%. To improve the future reporting of RUCAM based HILI cases, recommendations include the strict adherence to instructions outlined in the updated RUCAM and, in particular, to follow prospective data collection on the cases to ensure completeness of case data. In conclusion, RUCAM can well be used to assess causality in suspected HILI cases, and additional efforts are now required to increase the quality of the reported cases.

Herb-induced liver injury: Systematic review and meta-analysis

BACKGROUND

The use of herbal supplements and alternative medicines has been increasing in the last decades. Despite popular belief that the consumption of natural products is harmless, herbs might cause injury to various organs, particularly to the liver, which is responsible for their metabolism in the form of herb-induced liver injury (HILI).

AIM

To identify herbal products associated with HILI and describe the type of lesion associated with each product.

METHODS

Studies were retrieved using Medical Subject Headings Descriptors combined with Boolean operators. Searches were run on the electronic databases Scopus, Web of Science, MEDLINE, BIREME, LILACS, Cochrane Library for Systematic Reviews, SciELO, Embase, and Opengray.eu. Languages were restricted to English, Spanish, and Portuguese. There was no date of publication restrictions. The reference lists of the studies retrieved were searched manually. To access causality, the Maria and Victorino System of Causality Assessment in Drug Induced Liver Injury was used. Simple descriptive analysis were used to summarize the results.

RESULTS

The search strategy retrieved 5918 references. In the final analysis, 446 references were included, with a total of 936 cases reported. We found 79 types of herbs or herbal compounds related to HILI. He-Shou-Wu, Green tea extract, Herbalife, kava kava, Greater celandine, multiple herbs, germander, hydroxycut, skullcap, kratom, Gynura segetum, garcinia cambogia, ma huang, chaparral, senna, and aloe vera were the most common supplements with HILI reported. Most of these patients had complete clinical recovery (82.8%). However, liver transplantation was necessary for 6.6% of these cases. Also, chronic liver disease and death were observed in 1.5% and 10.4% of the cases, respectively.

CONCLUSION

HILI is normally associated with a good prognosis, once the implied product is withdrawn. Nevertheless, it is paramount to raise awareness in the medical and non-medical community of the risks of the indiscriminate use of herbal products.

Idiosyncratic Drug Induced Liver Injury, Cytochrome P450, Metabolic Risk Factors and Lipophilicity: Highlights and Controversies

Progress in understanding the mechanisms of the idiosyncratic drug induced liver injury (iDILI) was highlighted in a scientometric investigation on the knowledge mapping of iDILI throughout the world, but uncertainty remained on metabolic risk factors of iDILI, the focus of the present review article. For the first time, a quantitative analysis of 3312 cases of iDILI assessed for causality with RUCAM (Roussel Uclaf Causality Assessment Method) showed that most drugs (61.1%) were metabolized by cytochrome P450 (CYP) isoforms: 49.6% by CYP 3A4/5, 24.6% by CYP 2C9, 13.2% by CYP 2E1, 7.3% by CYP 2C19, 3.5% by CYP 1A2 and 1.8% by CYP 2D6. Other studies showed high OR (odds ratio) for drugs metabolized by unspecified CYPs but the iDILI cases were not assessed for causality with RUCAM, a major shortcoming. In addition to critical comments on methodological flaws, several risk factors of iDILI were identified such as high but yet recommended daily drug doses, actual daily drug doses taken by the patients, hepatic drug metabolism and drug lipophilicity. These risk factors are subject to controversies by many experts seen critically also by others who outlined that none of these medication characteristics is able to predict iDILI with high confidence, leading to the statement of an outstanding caveat. It was also argued that all previous studies lacked comprehensive data because the number of examined drugs was relatively small as compared to the number of approved new molecular entities or currently used oral prescription drugs. In conclusion, trends are evident that some metabolic parameters are likely risk factors of iDILI but strong evidence can only be achieved when methodological issues will be successfully met.

Health policy versus kava (Piper methysticum): Anxiolytic efficacy may be instrumental in restoring the reputation of a major South Pacific crop

ETHNOPHARMACOLOGICAL RELEVANCE

Kava (Piper methysticum G. Forst. f.) is by far the most important plant used in the islands of Melanesia, Polynesia and Micronesia for its relaxing effects. Kava drinking is a pillar of South Pacific societies and is also the foundation of their economies. Preparations of kava extract as herbal medicinal drugs were banned in Germany in 2002 and again in 2019, with dramatic consequences for the South Pacific economies. In 2002, the major regulatory argument for the ban of kava was safety issues. In 2019, the assessment report of the European Medicines Agency's Herbal Medicinal Product Committee (HMPC) justified a negative benefit-to-risk ratio by a supposed lack of efficacy of ethanolic extracts for an indication of which kava extract preparations never had an approval. In this HMPC report the efficacy in the approved indications 'nervous anxiety, tension and restlessness' was attributed to the extract branded as 'WS 1490', which was assumed to have been prepared with acetone as an extraction solvent. In addition to this change of indication and the attribution of efficacy to acetone kava extract alone, the German health authorities and the HMPC still refuse to discuss quality issues as a likely factor impacting drug safety. The first case reports of liver toxicity were observed with an acetone extract in a timely relationship with the introduction of 'two-day kava' instead of 'noble kava' as used in ethanolic kava extracts.

AIM OF THE STUDY

The correlation between clinical benefits and the type of extract preparation was examined.

METHODS

In order to identify the types of kava material and extracts used in clinical trials, the respective publications were compared with regulatory databases and protocols of a German regulatory advisory board.

RESULTS AND CONCLUSIONS

The comparison reveals inconsistencies in the regulatory decisions. In all studies with WS 1490, the evidence points to the use of an ethanolic extract. The efficacy of kava extract for the approved indication was clearly demonstrated. The HMPC report and the recent renewed German regulatory ban of kava therefore require major revision, which should include the impact of the use of "two-day kava" on drug safety. Such a revision could contribute to restoring the reputation of "noble kava" on the international markets.

Highs, Lows, and Health Hazards of Herbology: A Review of Herbal Medications with Psychotropic Effects

Mental health disorders, including depression, anxiety, and insomnia, are leading causes of hospitalization and disability for young and middle-aged adults. Approximately one-half of Americans will be diagnosed with a mental illness during their lifetime. Plants and roots have been used as medicinal agents since the beginning of recorded time. Complementary and alternative medicine or complementary integrative medicine use has been increasing throughout most socioeconomic classes, cultures, and age categories. This article reviews herbal and alternative therapies used to treat anxiety, depression, and insomnia. Indications for use, patient education, and possible interactions with conventional prescribed psychotropic medications are analyzed.

Kava (Piper methysticum) Extract for the Treatment of Nervous Anxiety, Tension and Restlessness

AIM

Prior to the kava ban of 2002, the indication for kava (Piper methysticum) extracts defined by the German Commission E was "nervous anxiety, tension and restlessness". In 2000, an observational trial was started in Germany with the aim of defining symptoms of these indications best treated with kava extract. The trial was interrupted and archived "unevaluated" in 2001 due to the upcoming safety debate on kava. The data from this study has now been analyzed in order to identify symptoms best treated with kava.

METHODS

Documentation was available from 156 patients. Twelve typical symptoms of nervous anxiety, tension and restlessness were assessed on a five-item rating scale, together with the therapeutic context, the perceived time of onset of effects and the safety of application.

RESULTS

The median duration of treatment was 28 days. All individual symptoms showed significant and clinically relevant improvements. The most effective results were seen for nervous tension and restlessness, with better effects in patients with acute versus chronic complaints. The safety of the treatment was found to be excellent, which included the assessment of laboratory data.

CONCLUSIONS

Overall, the study confirms the effective and safe short-term use of kava in the Commission E-defined indication of "nervous anxiety, tension and restlessness", especially in other than chronic cases. The clinical use of kava might be translated into context-related phobias according to ICD-10 F40, or to nervous tension (ICD10 R45.0) or restlessness and excitation (ICD-10 R45.1).

Kava as a Clinical Nutrient: Promises and Challenges

Kava beverages are typically prepared from the root of Piper methysticum. They have been consumed among Pacific Islanders for centuries. Kava extract preparations were once used as herbal drugs to treat anxiety in Europe. Kava is also marketed as a dietary supplement in the U.S. and is gaining popularity as a recreational drink in Western countries. Recent studies suggest that kava and its key phytochemicals have anti-inflammatory and anticancer effects, in addition to the well-documented neurological benefits. While its beneficial effects are widely recognized, rare hepatotoxicity had been associated with use of certain kava preparations, but there are no validations nor consistent mechanisms. Major challenges lie in the diversity of kava products and the lack of standardization, which has produced an unmet need for quality initiatives. This review aims to provide the scientific community and consumers, as well as regulatory agencies, with a broad overview on kava use and its related research. We first provide a historical background for its different uses and then discuss the current state of the research, including its chemical composition, possible mechanisms of action, and its therapeutic potential in treating inflammatory and neurological conditions, as well as cancer. We then discuss the challenges associated with kava use and research, focusing on the need for the detailed characterization of kava components and associated risks such as its reported hepatotoxicity. Lastly, given its growing popularity in clinical and recreational use, we emphasize the urgent need for quality control and quality assurance of kava products, pharmacokinetics, absorption, distribution, metabolism, excretion, and foundational pharmacology. These are essential in order to inform research into the molecular targets, cellular mechanisms, and creative use of early stage human clinical trials for designer kava modalities to inform and guide the design and execution of future randomized placebo controlled trials to maximize kava's clinical efficacy and to minimize its risks.

Evaluation of Anti-Convulsive Properties of Aqueous Kava Extract on Zebrafish Using the PTZ-Induced Seizure Model

Kava roots have been extensively studied in clinical trials as potential candidate anti-anxiety drugs. However, anti-convulsive properties of various tissues of stems of Kava have not been reported to date. The objective of the study was to evaluate the anti-convulsive potential of aqueous extracts prepared from specific tissues of Kava (Piper methysticum) stems in zebrafish, using the PTZ-induced seizure model. The potency of each extract was compared in terms of the intensity of seizure scores and onset time after pre-treating the zebrafish before the PTZ challenge. The results indicate that aqueous extract of Kava stems without peel after 45 min of pre-treatment exhibited anti-convulsive potential at the dose of 50 mg/L. This study provides evidence to the anti-convulsive properties of peeled Kava stems and its potential for investigation and design of candidate anti-convulsive drugs.

Role of liver biopsy in the era of clinical prediction scores for "drug-induced liver injury" (DILI): experience of a tertiary referral hospital

The clinical implications of the biopsy findings in cases of drug-induced liver injury (DILI) are not fully elucidated. The aim of this study was to evaluate the histopathological findings of cases diagnosed as DILI and to correlate them with clinical and biochemical findings (such as causality assessment algorithms). We searched our department database for all cases of liver biopsy with findings consistent with toxic liver disease and selected those with a clinical diagnosis of DILI. The causative relationships were established according to Roussel Uclaf Causality Assessment Method (RUCAM). A total of 53 cases of DILI were reviewed, most of them diagnosed in hospitalized patients (83%). The analytical toxicity profile was hepatocellular (R > 5) in 60% of the cases and cholestatic (R < 2) in 26.4% of cases. The group of drugs most implicated was the anti-microbials (18, 34%). The predominant histological patterns were "necroinflammation" (67.9%) and "cholestasis" (28.3%). The hepatocellular biochemical pattern was not associated with the presence of predominantly necroinflammatory findings in the biopsy (p = 0.44), and the biochemical cholestatic pattern was not associated with the presence of predominantly cholestatic findings in the biopsy (p = 0.51). This study supports that a better insight into the pathologic mechanisms associated with DILI should be based on liver biopsy due to the lack of a uniform correlation between clinical and biochemical patterns. Also, a liver biopsy may be used in those cases where clinical suspicion of DILI persists despite a low score on current causality assessment algorithms.

Liver transplantation and the use of KAVA: Case report

BACKGROUND

Self-medication and the belief that herbal products are free of health risks are common in Brazil. The kava (Piper methysticum), known for its anxiolytic action, has a widespread popular use. Hepatotoxicity of kava is reported, including cases of liver transplantation and death. The kava had its use prohibited or restricted in countries like Germany, France, among others. Toxicity may be related to overdosage; however, factors such as botanical characteristics of the plant, the harvesting, storage, and production process may be associated with the development of hepatotoxic substances, such as triggering idiosyncratic reactions.

HYPOTHESIS

In this case, there is a suspicion that the toxicide is intrinsic to the drug; however, the possibility of adulterants and contaminants must be ruled out.

STUDY DESIGN

This study reports the case of a patient who, after using the herbal kava for 52 days, evolved into acute liver failure and liver transplantation.

METHODS

The data were collected directly with the patient and compared with their clinical records. Causality was determined through the RUCAM algorithm. In addition, a phytochemical analysis of the drug used was performed.

RESULTS

According to the patient's report, there is no evidence of overdosage. Results from RUCAM algorithm infer causality between liver damage and the use of kava. The analysis chemical constituents did not find any possible contaminants and major changes in the active compounds. Seven months after transplantation, the patient is well and continues to be followed up by a medical team.

CONCLUSION

Our investigation indicates that there was kava-induced hepatotoxicity at standard dosages. In Brazil, self-medication by herbal medicines is frequent and many patients and health professionals do not know the risks associated with their use. Diagnosing and notifying cases in which plants and herbal medicine induce liver damage is of paramount importance to increase the knowledge about DILI and to prevent or treat similar cases quickly.

Selected α-pyrones from the plants Cryptocarya novoguineensis (Lauraceae) and Piper methysticum (Piperaceae) with activity against Haemonchus contortus in vitro

Due to the widespread occurrence and spread of anthelmintic resistance, there is a need to develop new drugs against resistant parasitic nematodes of livestock animals. The Nobel Prize-winning discovery and development of the anti-parasitic drugs avermectin and artemisinin has renewed the interest in exploring natural products as anthelmintics. In the present study, we screened 7500 plant extracts for in vitro-activity against the barber's pole worm, Haemonchus contortus, a highly significant pathogen of ruminants. The anthelmintic extracts from two plants, Cryptocarya novoguineensis and Piper methysticum, were fractionated by high-performance liquid chromatography (HPLC). Subsequently, compounds were purified from fractions with significant biological activity. Four α-pyrones, namely goniothalamin (GNT), dihydrokavain (DHK), desmethoxyyangonin (DMY) and yangonin (YGN), were purified from fractions from the two plants, GNT from C. novoguineensis, and DHK, DMY and YGN (= kavalactones) from P. methysticum. The three kavalactones induced a lethal, eviscerated (Evi) phenotype in treated exsheathed third-stage larvae (xL3s), and DMY and YGN had moderate potencies (IC₅₀ values of 31.7 ± 0.23 μM and 23.7 ± 2.05 μM, respectively) at inhibiting the development of xL3s to fourth-stage larvae (L4s). Although GNT had limited potency (IC₅₀ of 200–300 μM) at inhibiting L4 development, it was the only compound that reduced L4 motility (IC₅₀ of 6.25–12.50 μM). The compounds purified from each plant affected H. contortus in an irreversible manner. These findings suggest that structure-activity relationship studies of α-pyrones should be pursued to assess their potential as anthelmintics.

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7500 plant extracts were screened against Haemonchus for anthelmintic activity.

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Three of these extracts were potent inhibitors of larval motility and/or development.

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Pure α-pyrones isolated from active fractions exhibited significant nematocidal activity.

Molecular Mechanisms Involved in Oxidative Stress-Associated Liver Injury Induced by Chinese Herbal Medicine: An Experimental Evidence-Based Literature Review and Network Pharmacology Study

Oxidative stress, defined as a disequilibrium between pro-oxidants and antioxidants, can result in histopathological lesions with a broad spectrum, ranging from asymptomatic hepatitis to hepatocellular carcinoma in an orchestrated manner. Although cells are equipped with sophisticated strategies to maintain the redox biology under normal conditions, the abundance of redox-sensitive xenobiotics, such as medicinal ingredients originated from herbs or animals, can dramatically invoke oxidative stress. Growing evidence has documented that the hepatotoxicity can be triggered by traditional Chinese medicine (TCM) during treating various diseases. Meanwhile, TCM-dependent hepatic disorder represents a strong correlation with oxidative stress, especially the persistent accumulation of intracellular reactive oxygen species. Of note, since TCM-derived compounds with their modulated targets are greatly diversified among themselves, it is complicated to elaborate the potential pathological mechanism. In this regard, data mining approaches, including network pharmacology and bioinformatics enrichment analysis have been utilized to scientifically disclose the underlying pathogenesis. Herein, top 10 principal TCM-modulated targets for oxidative hepatotoxicity including superoxide dismutases (SOD), malondialdehyde (MDA), glutathione (GSH), reactive oxygen species (ROS), glutathione peroxidase (GPx), Bax, caspase-3, Bcl-2, nuclear factor (erythroid-derived 2)-like 2 (Nrf2), and nitric oxide (NO) have been identified. Furthermore, hepatic metabolic dysregulation may be the predominant pathological mechanism involved in TCM-induced hepatotoxic impairment.

The Pharmacology, Pharmacokinetics, Efficacy, and Adverse Events Associated With Kava

Kava is a plant with numerous kavapyrones that can induce pharmacologic effects and drug interactions through the cytochrome P450 and P-glycoprotein systems. Kava is used recreationally and for the treatment of anxiety. Clinical trials verify anxiolytic effects in excess of placebo, but the effects are not seen immediately and the optimal dose and dosing schedule needs to be determined. Clinical trials usually lasting for 4 weeks found generally good tolerability and safety; however, dermatologic, hepatologic, and cognitive adverse effects may occur. Some of these adverse effects are known to occur from the kavapyrones themselves, while others can be caused or exacerbated by use of substandard kava products. There is tremendous variability in the constitution of a kava product based on the parts of the plant that are being extracted and the extraction method. The most commonly studied extract for the treatment of anxiety is the acetone extract.

When good times go bad: managing 'legal high' complications in the emergency department

Patients can use numerous drugs that exist outside of existing regulatory statutes in order to get "legal highs." Legal psychoactive substances represent a challenge to the emergency medicine physician due to the sheer number of available agents, their multiple toxidromes and presentations, their escaping traditional methods of analysis, and the reluctance of patients to divulge their use of these agents. This paper endeavors to cover a wide variety of "legal highs," or uncontrolled psychoactive substances that may have abuse potential and may result in serious toxicity. These agents include not only some novel psychoactive substances aka "designer drugs," but also a wide variety of over-the-counter medications, herbal supplements, and even a household culinary spice. The care of patients in the emergency department who have used "legal high" substances is challenging. Patients may misunderstand the substance they have been exposed to, there are rarely any readily available laboratory confirmatory tests for these substances, and the exact substances being abused may change on a near-daily basis. This review will attempt to group legal agents into expected toxidromes and discuss associated common clinical manifestations and management. A focus on aggressive symptom-based supportive care as well as management of end-organ dysfunction is the mainstay of treatment for these patients in the emergency department.

Pilot in Vivo Structure-Activity Relationship of Dihydromethysticin in Blocking 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone-Induced O6-Methylguanine and Lung Tumor in A/J Mice

(+)-Dihydromethysticin was recently identified as a promising lung cancer chemopreventive agent, while (+)-dihydrokavain was completely ineffective. A pilot in vivo structure-activity relationship (SAR) was explored, evaluating the efficacy of its analogs in blocking 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced short-term O⁶-methylguanine and long-term adenoma formation in the lung tissues in A/J mice. Both results revealed cohesive SARs, demonstrating that the methylenedioxy functional group in DHM is essential while the lactone functional group tolerates modifications.

Traditional Chinese Medicine (TCM) and Herbal Hepatotoxicity: RUCAM and the Role of Novel Diagnostic Biomarkers Such as MicroRNAs

Background: Traditional Chinese Medicine (TCM) with its focus on herbal use is popular and appreciated worldwide with increased tendency, although its therapeutic efficacy is poorly established for most herbal TCM products. Treatment was perceived as fairly safe but discussions emerged more recently as to whether herb induced liver injury (HILI) from herbal TCM is a major issue; Methods: To analyze clinical and case characteristics of HILI caused by herbal TCM, we undertook a selective literature search in the PubMed database with the search items Traditional Chinese Medicine, TCM, alone and combined with the terms herbal hepatotoxicity or herb induced liver injury; Results: HILI caused by herbal TCM is rare and similarly to drugs can be caused by an unpredictable idiosyncratic or a predictable intrinsic reaction. Clinical features of liver injury from herbal TCM products are variable, and specific diagnostic biomarkers such as microsomal epoxide hydrolase, pyrrole-protein adducts, metabolomics, and microRNAs are available for only a few TCM herbs. The diagnosis is ascertained if alternative causes are validly excluded and causality levels of probable or highly probable are achieved applying the liver specific RUCAM (Roussel Uclaf Causality Assessment Method) as the most commonly used diagnostic tool worldwide. Case evaluation may be confounded by inappropriate or lacking causality assessment, poor herbal product quality, insufficiently documented cases, and failing to exclude alternative causes such as infections by hepatotropic viruses including hepatitis E virus infections; Conclusion: Suspected cases of liver injury from herbal TCM represent major challenges that deserve special clinical and regulatory attention to improve the quality of case evaluations and ascertain patients' safety and benefit.

Herbal Hepatotoxicity: Clinical Characteristics and Listing Compilation

Herb induced liver injury (HILI) and drug induced liver injury (DILI) share the common characteristic of chemical compounds as their causative agents, which were either produced by the plant or synthetic processes. Both, natural and synthetic chemicals are foreign products to the body and need metabolic degradation to be eliminated. During this process, hepatotoxic metabolites may be generated causing liver injury in susceptible patients. There is uncertainty, whether risk factors such as high lipophilicity or high daily and cumulative doses play a pathogenetic role for HILI, as these are under discussion for DILI. It is also often unclear, whether a HILI case has an idiosyncratic or an intrinsic background. Treatment with herbs of Western medicine or traditional Chinese medicine (TCM) rarely causes elevated liver tests (LT). However, HILI can develop to acute liver failure requiring liver transplantation in single cases. HILI is a diagnosis of exclusion, because clinical features of HILI are not specific as they are also found in many other liver diseases unrelated to herbal use. In strikingly increased liver tests signifying severe liver injury, herbal use has to be stopped. To establish HILI as the cause of liver damage, RUCAM (Roussel Uclaf Causality Assessment Method) is a useful tool. Diagnostic problems may emerge when alternative causes were not carefully excluded and the correct therapy is withheld. Future strategies should focus on RUCAM based causality assessment in suspected HILI cases and more regulatory efforts to provide all herbal medicines and herbal dietary supplements used as medicine with strict regulatory surveillance, considering them as herbal drugs and ascertaining an appropriate risk benefit balance.

The Honolulu Liver Disease Cluster at the Medical Center: Its Mysteries and Challenges

In 2013, physicians at the Honolulu Queen’s Medical Center (QMC) noticed that seven liver disease patients reported the use of OxyELITE Pro (OEP), a widely consumed dietary supplement (DS). Assuming a temporal association between OEP use and disease, they argued that OEP was the cause of this mysterious cluster. Subsequent reexamination, however, has revealed that this QMC cohort is heterogeneous and not a cluster with a single agent causing a single disease. It is heterogeneous because patients used multiple DS’s and drugs and because patients appeared to have suffered from multiple liver diseases: liver cirrhosis, liver failure by acetaminophen, hepatotoxicity by non-steroidal antiinflammatory drugs (NSAIDs), resolving acute viral hepatitis by hepatitis B virus (HBV), herpes simplex virus (HSV), and varicella zoster virus (VZV), and suspected hepatitis E virus (HEV). Failing to exclude these confounders and to consider more viable diagnoses, the QMC physicians may have missed specific treatment options in some of their patients. The QMC physicians unjustifiably upgraded their Roussel Uclaf Causality Assessment Method (RUCAM) causality scores so that all patients would appear to be “probable” for OEP. However, subsequent RUCAM reassessments by our group demonstrated a lack of causality for OEP in the evaluated QMC cases. The QMC’s questionable approaches explain the extraordinary accumulation of suspected OEP cases at the QMC in Hawaii as single place, whereas similar cohorts were not published by any larger US liver center, substantiating that the problem is with the QMC. In this review article, we present and discuss new case data and critically evaluate upcoming developments of problematic regulatory assessments by the US Centers for Disease Control and Prevention (CDC), the Hawaii Department of Health (HDOH), and the Food and Drug Administration (FDA), as based on invalid QMC conclusions, clarifying now also basic facts and facilitating constructive discussions.

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.

Herbal hepatotoxicity in traditional and modern medicine: actual key issues and new encouraging steps

Plants are natural producers of chemical substances, providing potential treatment of human ailments since ancient times. Some herbal chemicals in medicinal plants of traditional and modern medicine carry the risk of herb induced liver injury (HILI) with a severe or potentially lethal clinical course, and the requirement of a liver transplant. Discontinuation of herbal use is mandatory in time when HILI is first suspected as diagnosis. Although, herbal hepatotoxicity is of utmost clinical and regulatory importance, lack of a stringent causality assessment remains a major issue for patients with suspected HILI, while this problem is best overcome by the use of the hepatotoxicity specific CIOMS (Council for International Organizations of Medical Sciences) scale and the evaluation of unintentional reexposure test results. Sixty five different commonly used herbs, herbal drugs, and herbal supplements and 111 different herbs or herbal mixtures of the traditional Chinese medicine (TCM) are reported causative for liver disease, with levels of causality proof that appear rarely conclusive. Encouraging steps in the field of herbal hepatotoxicity focus on introducing analytical methods that identify cases of intrinsic hepatotoxicity caused by pyrrolizidine alkaloids, and on omics technologies, including genomics, proteomics, metabolomics, and assessing circulating micro-RNA in the serum of some patients with intrinsic hepatotoxicity. It remains to be established whether these new technologies can identify idiosyncratic HILI cases. To enhance its globalization, herbal medicine should universally be marketed as herbal drugs under strict regulatory surveillance in analogy to regulatory approved chemical drugs, proving a positive risk/benefit profile by enforcing evidence based clinical trials and excellent herbal drug quality.

Fatal kavalactone intoxication by suicidal intravenous injection

Kavalactones are a group of compounds found in kava, a beverage or extract prepared from the rhizome of the kava plant (Piper methysticum). Traditionally kava extracts have been used for their anxiolytic and sedative properties. Sales of kava extracts were severely restricted or prohibited in European countries in 2002 following several cases of serious hepatotoxicity. Here we report a case where high concentrations of kavalactones and ethanol were detected in post mortem femoral blood. An injection needle with a 10-mL syringe containing 7.5 mL of slightly yellowish liquid was found next to the victim, and there were numerous needle prints on both lower arms following the venous tracks. No evidence of other cause of death was found in the medico-legal investigation. The case was therefore classified as suicide using an injection of kavalactones intravenously together with alcohol poisoning.

A new animal model for Polygonum multiflorum Thunb-induced liver injury in rats and its potential mechanisms

The model is established successfully with the activation of LPS. Its pathogenesis is associated with the expression of mTLR4 in rats' liver. MicroRNA-122 is certificated to be an ideal potential serum biomarker for this model.

Flavokawains a and B in kava, not dihydromethysticin, potentiate acetaminophen-induced hepatotoxicity in C57BL/6 mice

Anxiolytic kava products have been associated with rare but severe hepatotoxicity in humans. This adverse potential has never been captured in animal models, and the responsible compound(s) remains to be determined. The lack of such knowledge greatly hinders the preparation of a safer kava product and limits its beneficial applications. In this study we evaluated the toxicity of kava as a single entity or in combination with acetaminophen (APAP) in C57BL/6 mice. Kava alone revealed no adverse effects for long-term usage even at a dose of 500 mg/kg bodyweight. On the contrary a three-day kava pretreatment potentiated APAP-induced hepatotoxicity, resulted in an increase in serum ALT and AST, and increased severity of liver lesions. Chalcone-based flavokawains A (FKA) and B (FKB) in kava recapitulated its hepatotoxic synergism with APAP while dihydromethysticin (DHM, a representative kavalactone and a potential lung cancer chemopreventive agent) had no such effect. These results, for the first time, demonstrate the hepatotoxic risk of kava and its chalcone-based FKA and FKB in vivo and suggest that herb–drug interaction may account for the rare hepatotoxicity associated with anxiolytic kava usage in humans.

Review article: Herbal hepatotoxicity--an update on traditional Chinese medicine preparations

BACKGROUND

Although evidence for their therapeutic efficacy is limited, herbal traditional Chinese medicine (TCM) preparations increasingly gain popularity. In contrast to other herbal products, adverse effects by herbal TCM including liver toxicity were rarely reported. In recent years, more cases were published, providing new clinical challenges.

AIM

To summarise comprehensively the literature on herbal TCM hepatotoxicity since 2011.

METHODS

PubMed was searched using key words related to TCM, the results were restricted to full English-language publications and abstracts published since 2011. In addition, the database of the National Institutes of Health (NIH) and LiverTox was accessed under the topic 'Drug record: Chinese and other Asian herbal medicines'.

RESULTS

Since 2011, new case reports and case series provided evidence for herbal hepatotoxicity by TCM, focusing on nine TCM herbal mixtures and four individual TCM herbs with potential health hazards. These were the TCM products Ban Tu Wan, Chai Hu, Du Huo, Huang Qin, Jia Wei Xia Yao San, Jiguja, Kamishoyosan, Long Dan Xie Gan Tang, Lu Cha, Polygonum multiflorum products, Shan Chi, 'White flood' containing the herbal TCM Wu Zhu Yu and Qian Ceng Ta, and Xiao Chai Hu Tang. Other developments include the establishment of a new and early diagnostic serum marker for hepatotoxicity caused by pyrrolizidine alkaloids, assessed using ultra performance liquid chromatography-mass spectrometry analysis, and new regulatory details to improve herbal TCM product quality and safety.

CONCLUSION

Stringent evaluation of the risk/benefit ratio is essential to protect traditional Chinese medicines users from health hazards including liver injury.

Herbs and liver injury: a clinical perspective

Despite a perception that herbal and dietary supplements are safe, devastating liver injury has been reported to result from their use. The difficulty in characterizing liver injury attributable to herbal and dietary supplements stems from the permissive regulatory environment, the complexity of marketed products, and underreporting by the patients who use them. Despite these limitations, researchers, clinicians, and regulators have increasing awareness of the need for study in this area.

Adverse drug reactions in some African herbal medicine: literature review and stakeholders' interview

BACKGROUND

In view of the large consumption of herbal medicine in Africa countries, it is likely that many adverse drugs reactions go unrecorded with either patients failing to present to health services, or no pharmacovigilance analysis being made, or the analysis not being reported centrally. This problem is of interest especially for those who are working in the general area of adverse drug reactions or stakeholders in the domain of herbal medicine for considering safety issues.

METHODS

We are particularly interested in the way that the use of very well-known and highly valued plants is linked to the observation of adverse drug reactions in African countries. We investigated, through a literature review and using the Internet (with a semantic search strategy), some well-known or popular medicinal plants used in African herbal medicine (AHM). Other information on the properties related to use, and characteristics of medicinal plants was complemented by some interviews with stakeholders.

RESULTS

Although substantial progress has been made in elucidating the mechanisms of action of many drugs, the pharmacological actions of many medicinal plants are generally not well understood. The results of a literature review suggest that the reported adverse drug reactions of herbal remedies are often due to a lack of understanding of their preparation and appropriate use. The results of stakeholders' interviews suggest that there is a growing need to provide patients with correct information about the herbal medicines they consume.

CONCLUSION

An important aspect of herbal medicine is the correct, timely, and integrated communication of emerging data on risk as an essential part of pharmacovigilance, which could actually improve the health and safety of patients. This calls for improved collaboration between traditional practitioners and modern healthcare professionals, researchers, and drug regulatory authorities. In addition, there is a need for an adverse drug reaction reporting system to facilitate the collection, monitoring, and evaluation of adverse drug events.

Herbal hepatotoxicity: analysis of cases with initially reported positive re-exposure tests

BACKGROUND

Positive re-exposure tests are diagnostic hallmarks for hepatotoxicity.

OBJECTIVE

To test validity of positive re-exposures in herb induced liver injury.

METHODS

We searched Medline database for cases of herb induced liver injury with positive re-exposures and analysed 34 cases for positive re-exposure test criteria of baseline alanine aminotransferase< 5N before re-exposure, and re-exposure alanine aminotransferase ≥ 2× baseline alanine aminotransferase. Re-exposure test was negative, if baseline alanine aminotransferase< 5N combined with re-exposure alanine aminotransferase< 2× baseline alanine aminotransferase, or if baseline alanine aminotransferase≥ 5N regardless of the re-exposure alanine aminotransferase including no available re-exposure alanine aminotransferase result.

RESULTS

In 21/34 cases (61.8%), criteria for a positive re-exposure were fulfilled, with negative tests in 6/34 cases (17.6%) or uninterpretable ones in 7/34 cases (20.6%). Confirmed positive re-exposure tests established potential of herb induced liver injury for Aloe, Chaparral, Chinese herbal mixtures, Chinese Jin Bu Huan, Chinese Syo Saiko To, Germander, Greater Celandine, Green tea, Kava, Mistletoe, Polygonum multiflorum, and Senna, with up to 4 case reports per herb.

CONCLUSIONS

Among 34 cases of herb-induced liver injury with initially reported positive re-exposure tests, 61.8% of the cases actually fulfilled established test criteria and provided firm diagnoses of herb induced liver injury by various herbs.

Drug and herb induced liver injury: Council for International Organizations of Medical Sciences scale for causality assessment

Causality assessment of suspected drug induced liver injury (DILI) and herb induced liver injury (HILI) is hampered by the lack of a standardized approach to be used by attending physicians and at various subsequent evaluating levels. The aim of this review was to analyze the suitability of the liver specific Council for International Organizations of Medical Sciences (CIOMS) scale as a standard tool for causality assessment in DILI and HILI cases. PubMed database was searched for the following terms: drug induced liver injury; herb induced liver injury; DILI causality assessment; and HILI causality assessment. The strength of the CIOMS lies in its potential as a standardized scale for DILI and HILI causality assessment. Other advantages include its liver specificity and its validation for hepatotoxicity with excellent sensitivity, specificity and predictive validity, based on cases with a positive reexposure test. This scale allows prospective collection of all relevant data required for a valid causality assessment. It does not require expert knowledge in hepatotoxicity and its results may subsequently be refined. Weaknesses of the CIOMS scale include the limited exclusion of alternative causes and qualitatively graded risk factors. In conclusion, CIOMS appears to be suitable as a standard scale for attending physicians, regulatory agencies, expert panels and other scientists to provide a standardized, reproducible causality assessment in suspected DILI and HILI cases, applicable primarily at all assessing levels involved.

Herbal hepatotoxicity: suspected cases assessed for alternative causes

BACKGROUND AND OBJECTIVES

Alternative explanations are common in suspected drug-induced liver injury (DILI) and account for up to 47.1% of analyzed cases. This raised the question of whether a similar frequency may prevail in cases of assumed herb-induced liver injury (HILI).

METHODS

We searched the Medline database for the following terms: herbs, herbal drugs, herbal dietary supplements, hepatotoxic herbs, herbal hepatotoxicity, and herb-induced liver injury. Additional terms specifically addressed single herbs and herbal products: black cohosh, Greater Celandine, green tea, Herbalife products, Hydroxycut, kava, and Pelargonium sidoides. We retrieved 23 published case series and regulatory assessments related to hepatotoxicity by herbs and herbal dietary supplements with alternative causes.

RESULTS

The 23 publications comprised 573 cases of initially suspected HILI; alternative causes were evident in 278/573 cases (48.5%). Among them were hepatitis by various viruses (9.7%), autoimmune diseases (10.4%), nonalcoholic and alcoholic liver diseases (5.4%), liver injury by comedication (DILI and other HILI) (43.9%), and liver involvement in infectious diseases (4.7%). Biliary and pancreatic diseases were frequent alternative diagnoses (11.5%), raising therapeutic problems if specific treatment is withheld; pre-existing liver diseases including cirrhosis (9.7%) were additional confounding variables. Other diagnoses were rare, but possibly relevant for the individual patient.

CONCLUSION

In 573 cases of initially assumed HILI, 48.5% showed alternative causes unrelated to the initially incriminated herb, herbal drug, or herbal dietary supplement, calling for thorough clinical evaluations and appropriate causality assessments in future cases of suspected HILI.

Herbal hepatotoxicity: Challenges and pitfalls of causality assessment methods

The diagnosis of herbal hepatotoxicity or herb induced liver injury (HILI) represents a particular clinical and regulatory challenge with major pitfalls for the causality evaluation. At the day HILI is suspected in a patient, physicians should start assessing the quality of the used herbal product, optimizing the clinical data for completeness, and applying the Council for International Organizations of Medical Sciences (CIOMS) scale for initial causality assessment. This scale is structured, quantitative, liver specific, and validated for hepatotoxicity cases. Its items provide individual scores, which together yield causality levels of highly probable, probable, possible, unlikely, and excluded. After completion by additional information including raw data, this scale with all items should be reported to regulatory agencies and manufacturers for further evaluation. The CIOMS scale is preferred as tool for assessing causality in hepatotoxicity cases, compared to numerous other causality assessment methods, which are inferior on various grounds. Among these disputed methods are the Maria and Victorino scale, an insufficiently qualified, shortened version of the CIOMS scale, as well as various liver unspecific methods such as the ad hoc causality approach, the Naranjo scale, the World Health Organization (WHO) method, and the Karch and Lasagna method. An expert panel is required for the Drug Induced Liver Injury Network method, the WHO method, and other approaches based on expert opinion, which provide retrospective analyses with a long delay and thereby prevent a timely assessment of the illness in question by the physician. In conclusion, HILI causality assessment is challenging and is best achieved by the liver specific CIOMS scale, avoiding pitfalls commonly observed with other approaches.

Clinical and causality assessment in herbal hepatotoxicity

INTRODUCTION

Herbal hepatotoxicity represents a poorly understood, neglected and multifaceted disease with numerous confounding variables and missing established causality in the majority of cases. This review discusses overt shortcomings in its clinical and causality assessment and suggests improvements.

AREAS COVERED

A selective literature search of PubMed using the terms herbal hepatotoxicity, herb-induced liver injury, drug hepatotoxicity and drug-induced liver injury was performed to identify published case reports, spontaneous case reports, case series and review articles regarding hepatotoxicity due to herbs, herbal drugs and herbal dietary supplements. Covered areas focused on confounding variables related to the documentation of the herbal product and the clinical course, hepatotoxicity and reexposure criteria, temporal association, comedication and alternative causes with special attention to preexisting diseases of the liver, bile ducts and the pancreas. Of particular interest were recent discussions of approaches designed and validated for hepatotoxicity causality, such as the scale of CIOMS (Council for International Organizations of Medical Sciences).

EXPERT OPINION

The authors call for substantial improvements in data quality of herbal products and case characteristics and strongly recommend using the CIOMS scale to assess causality in suspected herbal hepatotoxicity.

Herbal hepatotoxicity: a critical review

This review deals with herbal hepatotoxicity, identical to herb induced liver injury (HILI), and critically summarizes the pitfalls associated with the evaluation of assumed HILI cases. Analysis of the relevant publications reveals that several dozens of different herbs and herbal products have been implicated to cause toxic liver disease, but major quality issues limit the validity of causality attribution. In most of these reports, discussions around quality specifications regarding herbal products, case data presentations and causality assessment methods prevail. Though the production of herbal drugs is under regulatory surveillance and quality aspects are normally not a matter of concern, low quality of the less regulated herbal supplements may be a critical issue considering product batch variability, impurities, adulterants and herb misidentifications. Regarding case data presentation, essential diagnostic information is often lacking, as is the use of valid and liver specific causality assessment methods that also consider alternative diseases. At present, causality is best assessed by using the Council for International Organizations of Medical Sciences scale ( CIOMS) in its original or updated form, which should primarily be applied prospectively by the treating physician when evaluating a patient rather than retrospectively by regulatory agencies. To cope with these problems, a common quality approach by manufacturers, physicians and regulatory agencies should strive for the best quality. We propose steps for improvements with impact on future cases of liver injury by herbs, herbal drugs and herbal supplements.

Herbal hepatotoxicity: a hidden epidemic

Complementary and alternative therapies, including herbal products, have become increasingly popular in the general population and among patients and physicians. Regulations and pharmacovigilance regarding herbal drugs are still incomplete and need to be improved. In fact, herbals are commonly marketed on the Internet, and in many countries they are sold as food supplements, which are beyond the control of drug regulatory agencies. In Europe and the U.S., reports of hepatotoxicity from these products, including those advertised for liver diseases, are accumulating. Many herbal drugs are also commonly used in children, and in women during pregnancy and lactation, because they are believed to be "natural" and, therefore, "harmless." One emerging problem is people preferring herbal-based slimming aids to conventional dietary and physical activity. In Italy, the use of non-conventional therapies has been reported for 13.6 % of the population, and 3.7 % freely use herbal drugs, unaware of the risks associated with a potential interaction with prescription drugs. In our review, we discuss the problem of the lack of standardization of herbal drugs, the lack of randomized clinical trials regarding the majority of these products, the unawareness of risks by the patients who buy and use them, and, further, the problem of underreporting. For the most commonly used herbal products and slimming aids, we describe their potential hepatotoxicity mechanisms, the causality assessment necessary for a correct diagnosis, and the clinical patterns for which these products seem to be responsible.

Review article: herbal and dietary supplement hepatotoxicity

BACKGROUND

Herbal and dietary supplements are commonly used throughout the World. There is a tendency for underreporting their ingestion by patients and the magnitude of their use is underrecognised by Physicians. Herbal hepatotoxicity is not uncommonly encountered, but the precise incidence and manifestations have not been well characterised.

AIMS

To review the epidemiology, presentation and diagnosis of herbal hepatotoxicity. This review will mainly discuss single ingredients and complex mixtures of herbs marketed under a single label.

METHODS

A Medline search was undertaken to identify relevant literature using search terms including 'herbal', 'herbs', 'dietary supplement', 'liver injury', 'hepatitis' and 'hepatotoxicity'. Furthermore, we scanned the reference lists of the primary and review articles to identify publications not retrieved by electronic searches.

RESULTS

The incidence rates of herbal hepatotoxicity are largely unknown. The clinical presentation and severity can be highly variable, ranging from mild hepatitis to acute hepatic failure requiring transplantation. Scoring systems for the causality assessment of drug-induced liver injury may be helpful, but have not been validated for herbal hepatotoxicity. Hepatotoxicity features of commonly used herbal products, such as Ayurvedic and Chinese herbs, black cohosh, chaparral, germander, greater celandine, green tea, Herbalife, Hydroxycut, kava, pennyroyal, pyrrolizidine alkaloids, skullcap, and usnic acid, have been individually reviewed. Furthermore, clinically significant herb-drug interactions are also discussed.

CONCLUSIONS

A number of herbal medicinal products are associated with a spectrum of hepatotoxicity events. Advances in the understanding of the pathogenesis and the risks involved are needed to improve herbal medicine safety.

Herbal hepatotoxicity: a tabular compilation of reported cases

BACKGROUND

Herbal hepatotoxicity is a field that has rapidly grown over the last few years along with increased use of herbal products worldwide.

AIMS

To summarize the various facets of this disease, we undertook a literature search for herbs, herbal drugs and herbal supplements with reported cases of herbal hepatotoxicity.

METHODS

A selective literature search was performed to identify published case reports, spontaneous case reports, case series and review articles regarding herbal hepatotoxicity.

RESULTS

A total of 185 publications were identified and the results compiled. They show 60 different herbs, herbal drugs and herbal supplements with reported potential hepatotoxicity, additional information including synonyms of individual herbs, botanical names and cross references are provided. If known, details are presented for specific ingredients and chemicals in herbal products, and for references with authors that can be matched to each herbal product and to its effect on the liver. Based on stringent causality assessment methods and/or positive re-exposure tests, causality was highly probable or probable for Ayurvedic herbs, Chaparral, Chinese herbal mixture, Germander, Greater Celandine, green tea, few Herbalife products, Jin Bu Huan, Kava, Ma Huang, Mistletoe, Senna, Syo Saiko To and Venencapsan(®). In many other publications, however, causality was not properly evaluated by a liver-specific and for hepatotoxicity-validated causality assessment method such as the scale of CIOMS (Council for International Organizations of Medical Sciences).

CONCLUSIONS

This compilation presents details of herbal hepatotoxicity, assisting thereby clinical assessment of involved physicians in the future.