Measuring the chemical and cytotoxic variability of commercially available kava (Piper methysticum G. Forster)

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.

Kava (Piper methysticum) in the United States: the quiet rise of a substance with often subtle effects

Background: Piper methysticum, commonly called kava, has long been consumed in beverage form in the Pacific Islands. Kava use in the US has slowly increased since the 1990s, but is not assessed in major epidemiological surveys.Objectives: To analyze social-media posts about kava from current, past, and prospective users, for motivations, patterns of co-use, and effects.Methods: Text from Reddit posts, and accompanying metadata, were collected and thematically coded by two independent raters.Results: 423 posts were collected, spanning January 2006 through December 2021. Of the 1,211 thematic codes applied, 1,098 (90. 7%) were concordant. Motivations for use bifurcated into self-treatment (for psychiatric or physical health conditions) and recreation; these were not mutually exclusive. Kava was rarely considered strongly euphoriant, but was valued as an anxiolytic. Kava was frequently used with other substances, most commonly kratom. Kava was used at lower doses for self-treatment than for other purposes (pseudo-R² = 0.11). Undesirable effects (gastrointestinal upset, fatigue) were mentioned, though less often than benefits. Hepatotoxicity, reported elsewhere as a rare, non-dose-related risk, was disputed on the basis of its not having been experienced by those posting.Conclusion: Kava appears to be conceptualized among Reddit posters as an anxiolytic with few risks or adverse effects. As it grows in popularity, especially among people who use other drugs that are more liable to misuse or addiction, it should be assessed in probability samples (i.e. in the major national drug surveys) and clinical practice for its risks, potential benefits, and possible drug-drug interactions.

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.

An Updated Review on the Psychoactive, Toxic and Anticancer Properties of Kava

Kava (Piper methysticum) has been widely consumed for many years in the South Pacific Islands and displays psychoactive properties, especially soothing and calming effects. This plant has been used in Western countries as a natural anxiolytic in recent decades. Kava has also been used to treat symptoms associated with depression, menopause, insomnia, and convulsions, among others. Along with its putative beneficial health effects, kava has been associated with liver injury and other toxic effects, including skin toxicity in heavy consumers, possibly related to its metabolic profile or interference in the metabolism of other xenobiotics. Kava extracts and kavalactones generally displayed negative results in genetic toxicology assays although there is sufficient evidence for carcinogenicity in experimental animals, most likely through a non-genotoxic mode of action. Nevertheless, the chemotherapeutic/chemopreventive potential of kava against cancer has also been suggested. Both in vitro and in vivo studies have evaluated the effects of flavokavains, kavalactones and/or kava extracts in different cancer models, showing the induction of apoptosis, cell cycle arrest and other antiproliferative effects in several types of cancer, including breast, prostate, bladder, and lung. Overall, in this scoping review, several aspects of kava efficacy and safety are discussed and some pertinent issues related to kava consumption are identified.

Modulating effect of DL-kavain on the mutagenicity and carcinogenicity induced by doxorubicin in Drosophila melanogaster

Kavain, kavalactone, present in Piper methysticum exhibits anticonvulsive, analgesic, anxiolytic, antiepileptic, antithrombotic, anti-inflammatory and antioxidant properties. Given its importance, the aim of the present study was to assess (1) the mutagenic and carcinogenicity of kavain administered alone and (2) the antimutagenic and anticarcinogenic potential when administered simultaneously with the chemotherapeutic drug doxorubicin (DXR) using the Somatic Mutation and Recombination Test (SMART) and Epithelial Tumor Test (ETT) using Drosophila melanogaster as a model system. Third-stage larvae from a standard (ST) and high metabolic bioactivation (HB) crosses were treated with different kavain concentrations (32, 64 or 128 μg/ml), alone or in conjunction with DXR (0.125 mg/ml). In ST descendants, kavain produced no significant mutagenic or recombinogenic effects. In the HB cross, mutagenic activity was observed at kavain concentrations of 64 and 128 μg/ml. In the DXR and kavain co-treatment, a modulating effect of the DXR-mediated mutagenic response dependent upon the concentration was detected in both crosses. In ETT, no marked carcinogenic or anticarcinogenic activity was noted for kavain. However, when kavain was combined with DXR synergistic induction of tumors by the chemotherapeutic drug occurred indicating that kavain enhanced the carcinogenic action of DXR.

Simultaneous determination of both kavalactone and flavokawain constituents by different single-marker methods in kava

Kava, the rhizomes and roots of Piper methysticum Forst, is a popular edible medicinal herb traditionally used to prepare beverages for anxiety reduction. Since the German kava ban has been lifted by the court, the quality evaluation is particularly important for its application, especially the flavokawains which were believed to be responsible for hepatotoxicity. Now, by employing two different standard references and four different methods to calculate the relative correction factors, eight different quantitative analyses of multicomponents by single-marker methods have been developed for the simultaneous determination of eight major kavalactones and flavokawains in kava. The low standard method difference on quantitative measurement of the compounds among the external standard method and ours confirmed the reliability of the mentioned methods. A radar plot clearly illustrated that the contents of dihydrokavain and kavain were higher, whereas flavokawains A and B were lower in different kava samples. Only one of eight samples did not detect flavokawains that may be related to hepatotoxicity. In summary, by using different agents as an internal standard reference, the developed methods were believed as a powerful analytical tool not only for the qualitative and quantitative of kava constituents but also for the other multicomponents when authentic standard substances were unavailable.

Overview of the major classes of new psychoactive substances, psychoactive effects, analytical determination and conformational analysis of selected illegal drugs

The misuse of psychoactive substances is attracting a great deal of attention from the general public. An increase use of psychoactive substances is observed among young people who do not have enough awareness of the harmful effects of these substances. Easy access to illicit drugs at low cost and lack of effective means of routine screening for new psychoactive substances (NPS) have contributed to the rapid increase in their use. New research and evidence suggest that drug use can cause a variety of adverse psychological and physiological effects on human health (anxiety, panic, paranoia, psychosis, and seizures). We describe different classes of these NPS drugs with emphasis on the methods used to identify them and the identification of their metabolites in biological specimens. This is the first review that thoroughly gives the literature on both natural and synthetic illegal drugs with old known data and very hot new topics and investigations, which enables the researcher to use it as a starting point in the literature exploration and planning of the own research. For the first time, the conformational analysis was done for selected illegal drugs, giving rise to the search of the biologically active conformations both theoretically and using lab experiments.

Anticancer activity of Momordica cochinchinensis (red gac) aril and the impact of varietal diversity

Background

Momordica cochinchinensis (Cucurbitaceae) is a nutritionally and medicinally important fruit restricted to South East Asia with diverse morphological and genetic variations but there is limited information on its medicinal potential.

Methods

M. cochinchinensis aril from 44 different samples in Australia, Thailand and Vietnam were extracted using different solvents and tested for its anticancer potential. Anticancer activity of M. cochinchinensis aril on breast cancer (MCF7 and BT474) and melanoma (MM418C1 and D24) cells were compared to control fibroblasts (NHDF). The cytotoxicity of the cells following treatment with the aril extract was determined using CCK-8 assay. Biochemical and morphological changes were analysed using flow cytometry, confocal and transmission electron microscopy to determine the mechanism of cell death.

Results

The water extract from the aril of M. cochinchinensis elicited significantly higher cytotoxicity towards breast cancer and melanoma cells than the HAE extract. The IC₅₀ concentration for the crude water extract ranged from 0.49 to 0.73 mg/mL and induced both apoptotic and necrotic cell death in a dose- and time-dependant manner with typical biochemical and morphological characteristics. The greatest cytotoxicity was observed from Northern Vietnam samples which caused 70 and 50% melanoma and breast cancer cell death, respectively.

Conclusions

The water extract of M. cochinchinensis aril caused significant apoptosis and necrosis of breast cancer and melanoma cells, with varieties from Northern Vietnam possessing superior activity. This highlights the potential of this fruit in the development of novel anticancer agents against such tumours, with specific regions on where to collect the best variety and extraction solvent for optimum activity.

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.

Rapid detection and validated quantification of psychoactive compounds in complex plant matrices by direct analysis in real time-high resolution mass spectrometry - Application to "Kava" psychoactive pepper products

RATIONALE

Classified by the UNODC as a top 20 plant of concern, Piper methysticum (also known as Kava) is being increasingly abused recreationally for its mind-altering effects. It is of significant forensic relevance to establish methods to rapidly identifyand quantify psychoactive compounds, especially those yet to be scheduled ascontrolled substances and which have exhibited various noteworthy health concerns.

METHODS

Direct analysis in real time high-resolution mass spectrometry (DART-HRMS) demonstrated the ability to detect a range of kavalactones in Pipermethysticum derived products and plant material with no sample preparation. Inaddition, a validated method using calibration curves developed with a deuteratedinternal standard was used for the quantification of the psychoactive moleculeyangonin in various products.

RESULTS

DART-HRMS detected the protonated masses of six major kavalactonesand three flavokavains in 18 commercial Kava products. A method consistent withFDA validation guidelines was established for the quantification of yangonin in thevarious complex matrices. Implementation of this method, with an LLOQ of 5 mg/mL, enabled successful quantification of yangonin in 16 Kava products.Concentrations for solid products ranged from 2.71 to 8.99 mg/g, while that forliquid products ranged from 1.03 to 4.59 mg/mL.

CONCLUSIONS

Rapid identification and quantification of psychoactive smallmolecules in plant material can be accomplished using a validated DART-HRMSprotocol. This work illustrates an approach to qualitative and quantitative analysesof a wide variety of complex matrices derived from plants, and demonstrates thatthe commercially available products analyzed are P. methysticum derived and docontain psychoactive yangonin at quantifiable levels.

Biomedical analysis of New Psychoactive Substances (NPS) of natural origin

New psychoactive substances (NPS) can be divided into two main groups: synthetic molecules and active principles of natural origin. With respect to this latter group, a wide range of alkaloids contained in plants, mainly from Asia and South America, can be included in the class of NPS of natural origin. The majority NPS of natural origin presents stimulant and/or hallucinogenic effects (e.g. Catha edulis and Ayahuasca, respectively) while few of them show sedative and relaxing properties (e.g. kratom). Few information is available in relation to the analytical identification of psychoactive principles contained in the plant material. Moreover, to our knowledge, scarce data are present in literature, about the characterization and quantification of the parent drug in biological matrices from intoxication and fatality cases. In addition, the metabolism of natural active principles has not been yet fully investigated for most of the psychoactive substances from plant material. Consequently, their identification is not frequently performed and produced metabolites are often unknown. To fill this gap, we reviewed the currently available analytical methodologies for the identification and quantification of NPS of natural origin in plant material and, whenever possible, in conventional and non-conventional biological matrices of intoxicated and dead subjects. The psychoactive principles contained in the following plants were investigated: Areca catechu, Argyreia nervosa, Ayahuasca, Catha edulis, Ipomoea violacea, Mandragora officinarum, Mitragyna speciosa, Pausinystalia yohimbe, Piper methisticum, Psilocybe, Rivea corymbosa, Salvia divinorum, Sceletium tortuosum, Lactuca virosa. From the results obtained, it can be evidenced that although several analytical methods for the simultaneous quantification of different molecules from the same plants have been developed and validated, a comprehensive method to detect active compounds from different natural specimens both in biological and non-biological matrices is still lacking.

Chemical and in vitro toxicity analysis of a supercritical fluid extract of Kava kava (Piper methysticum)

ETHNOPHARMACOLOGICAL RELEVANCE

Kava and kava extracts have shown great potential as a way to minimize anxiety-associated symptoms and to help alleviate pain. Hepatoxicity has been associated with the consumption of kava products. The chemical compounds, kavalactones (KL) and flavokavains (FK) have been implicated in kava's psychotropic and possible hepatotoxic properties.

AIM OF THE STUDY

To investigate the kavalactone and flavokavain content and in vitro toxicity of KAVOA™, a supercritical carbon dioxide extraction (SFE) of kava.

MATERIALS AND METHODS

Kavalactone and flavokavain content of SFE kava and noble kava root were determined following extraction in acetone, cell culture media, and water using ultra high-performance liquid chromatography (UHPLC). Using water extractions of the kava products, the cell viability and toxicity on the human hepatocellular carcinoma cell line (HepG2) were determined using luminescent and fluorescent assays, respectively. The half maximal inhibitory concentration (IC₅₀) of the SFE kava and noble kava root, extracted in cell culture media, were determined utilizing a luminescent cell viability assay.

RESULTS

Quantification of the KAVOA™, a SFE extract of kava and kava root showed similar profiles of kavalactone and flavokavain content. Water extracted SFE and root kava did not show a negative impact on cell viability and toxicity when compared to the vehicle control treated cells. IC₅₀ values were determined for the SFE kava and kava root extracted in cell culture media in respect to cell viability, 78.63 and 47.65 µg/mL, respectively.

CONCLUSIONS

KAVOA™, a supercritical carbon dioxide extract of kava displays a similar kavalactone profile to a noble variety of kava. In relation to total kavalactone content, KAVOA™ also has a lower content of the cytotoxic compound FKB. Aqueous extractions of KAVOA™ and noble kava root had no significant negative impact on cell viability and toxicity on HepG2 cells when compared to vehicle controlled treated cells. Results indicate KAVOA™ demonstrates a similar in vitro safety profile to that of noble kava root when experiments are normalized to kavalactone content.

Kavalactones and Flavokavins Profiles Contribute to Quality Assessment of Kava (Piper methysticum G. Forst.), the Traditional Beverage of the Pacific

Kava (Piper methysticum) is increasingly traded internationally and there is need for a rapid method to analyze kava raw material before export. The objectives of the present study were: (i) to develop a simple and robust protocol for high throughput simultaneous quantification of kavalactones (KLs) and flavokavins (FKs) in kava and (ii) to assess its potential for quality control. Methysticin; dihydromethysticin; kavain; desmethoxyyangonin; dihydrokavain; yangonin; and flavokavin A, B and C were quantified using HPTLC in acetonic extracts of 174 kava varieties. UHPLC analysis was conducted on a subset of six varieties representing the genetic variation of the species. The genetically distinct groups of nobles, two-day and wichmannii varieties were clearly differentiated and multivariate analyses of UHPLC and HPTLC data were congruent. Noble varieties have significantly low FKs/KLs (0.13) and high kavain/flavokavin B (K/FKB = 7.31). Two-day and wichmannii varieties are characterized by high FKs/KLs (0.36, 0.21) and low K/FKB (1.5, 1.7). A high-throughput HPTLC protocol was developed with a total analytical time of 50 min for 20 samples and only 10 mL of mobile phase. The use of acetone, sonication and two different detection wavelengths improves the accuracy compared to previous HPLC studies and confirms that kava varieties exhibit distinct chemotypes clearly differentiated by their FKs/KLs profiles. These results will strengthen the use of Codex Alimentarius regional standards.

The effectiveness and safety of Kava Kava for treating anxiety symptoms: A systematic review and analysis of randomized clinical trials

BACKGROUND

To determine if Kava Kava is an effective treatment for combating symptoms of anxiety despite warnings of hepatotoxicity from the Centers for Disease Control and Prevention (CDC).

METHODS

Databases PubMed, CINAHL, and PsycINFO were utilized to obtain clinical trials on Kava Kava and its effects on anxiety. A total of 11 articles met inclusion/exclusion criteria: 2 for Kava Kava vs. another anti-anxiety medication, 2 detailing additional adverse events, and 7 for Kava Kava vs. placebo. Mantel-Haenszel fixed-effects model was used to analyze the data, with responder rates being pooled to compute weighted risk ratios.

RESULTS

Kava Kava was shown to be more effective than placebo in 3 of the 7 trials. A final risk ratio of 1.50 (95% CI: 1.12, 2.01) from responder rates was calculated in favor of the intervention from 5 clinical trials (n = 330). Adverse events were shown to be the same as placebo (P = 0.574), and laboratory values analyzing hepatotoxicity were no different when compared to baseline except in two studies.

CONCLUSIONS

Kava Kava appears to be a short-term treatment for anxiety, but not a replacement for prolonged anti-anxiety use. Although not witnessed in this review, liver toxicity is especially possible if taken longer than 8 weeks.

A stable isotope dilution tandem mass spectrometry method of major kavalactones and its applications

Kava is regaining its popularity with detailed characterizations warranted. We developed an ultraperformance liquid chromatography high-resolution tandem mass spectrometry (UPLC-MS/MS) method for major kavalactones (kavain, dihydrokavain, methysticin, dihydromethysticin and desmethoxyyangonin) with excellent selectivity and specificity. The method has been validated for different matrices following the Food and Drug Administration guidance of analytical procedures and methods validation. The scope of this method has been demonstrated by quantifying these kavalactones in two kava products, characterizing their tissue distribution and pharmacokinetics in mice, and detecting their presence in human urines and plasmas upon kava intake. As expected, the abundances of these kavalactones differed significantly in kava products. All of them exhibited a large volume of distribution with extensive tissue affinity and adequate mean residence time (MRT) in mice. This method also successfully quantified these kavalactones in human body fluids upon kava consumption at the recommended human dose. This UPLC-MS/MS method therefore can be used to characterize kava products and its pharmacokinetics in animals and in humans.

Kava-241 reduced periodontal destruction in a collagen antibody primed Porphyromonas gingivalis model of periodontitis

AIM

The aim of this study was to evaluate the effect of Kava-241, an optimized Piper methysticum Kava compound, on periodontal destruction in a collagen antibody primed oral gavage model of periodontitis.

METHODS

Experimental periodontitis was induced by oral gavage of Porphyromonas gingivalis (P. gingivalis) + type II collagen antibody (AB) in mice during 15 days. Mice were treated with Kava-241 concomitantly or prior to P. gingivalis gavage and compared to untreated mice. Comprehensive histomorphometric analyses were performed.

RESULTS

Oral gavage with P. gingivalis induced mild epithelial down-growth and alveolar bone loss, while oral gavage with additional AB priming had greater tissular destruction in comparison with gavage alone (p < .05). Kava-241 treatment significantly (p < .05) reduced epithelial down-growth (72%) and alveolar bone loss (36%) in P. gingivalis+AB group. This Kava-241 effect was associated to a reduction in inflammatory cell counts within soft tissues and an increase in fibroblasts (p < .05).

CONCLUSION

Priming with type II collagen antibody with oral gavage is a fast and reproducible model of periodontal destruction adequate for the evaluation of novel therapeutics. The effect of Kava-241 shows promise in the prevention and treatment of inflammation and alveolar bone loss associated with periodontitis. Further experiments are required to determine molecular pathways targeted by this therapeutic agent.

Traditional preparations of kava (Piper methysticum) inhibit the growth of human colon cancer cells in vitro

BACKGROUND

Epidemiological studies indicate there is low incidence of colon cancer in the South Pacific islands, including Fiji, West Samoa, and Vanuatu. Cancer incidence has been shown to be inversely associated with kava (Piper methysticum G. Forst.) ingestion. Hypothesis/Purpose: Kava prepared traditionally will inhibit the growth of human cancer cells. This investigation entails preparation and analysis of kava extracts and study of the growth inhibitory activity of the extracts, alone and combined with hibiscus.

STUDY DESIGN

We will prepare kava as in Micronesia - as a water extract, high in particulate content, alone or combined with sea hibiscus (Hibiscus tiliaceus L.) - and examine the components and growth inhibitory activity.

METHODS

We obtained ground kava prepared in the traditional way from lateral roots and sea hibiscus mucilage and sap from different sources in Micronesia, and prepared water extracts (unfiltered, as well as filtered, since in traditional use the kava beverage contains a high particulate content) and partitions. We used the MTT assay to determine the growth inhibitory activity of the preparations on colon and breast cancer cells and nonmalignant intestinal epithelial cells. LC-MS analysis was used to examine the components of the kava and sea hibiscus extracts and partitions.

RESULTS

Traditional preparations of kava inhibit the growth of breast and colon cancer cells. Among the kava preparations, the order of decreasing activity was Fiji(2), Fiji(1), Hawaii; the unfiltered preparations from Fiji were more active than the filtered. Phytochemical analysis indicated that filtering reduced most kavalactone and chalcone content. For example, for Fiji(2), the ratio of dihydromethysticin in filtered/unfiltered kava was 0.01. Thus, for the extracts from Fiji, growth inhibitory activity correlates with the content of these compounds. Unfiltered and filtered kava from Fiji(1) were more active on malignant than nonmalignant intestinal epithelial cells. Since kava is prepared in Micronesia by squeezing the extract through sea hibiscus bark, we assayed the growth inhibitory activity of combinations of kava and sea hibiscus sap and found that sea hibiscus enhanced the growth inhibitory effect of kava.

CONCLUSION

Our results show that traditional kava, alone or combined with sea hibiscus, displays activity against human cancer cells and indicate it will be worthwhile to develop and further analyze these preparations to prevent and treat colon and other cancers. Our findings suggest it is important to examine the activity of plants in the form that people consume them.

The mystery of the Hawaii liver disease cluster in summer 2013: A pragmatic and clinical approach to solve the problem

BACKGROUND AND AIM

In the fall of 2013, the US Centers for Disease Control and Prevention (CDC) published a preliminary report on a cluster of liver disease cases that emerged in Hawaii in the summer 2013. This report claimed a temporal association as sufficient evidence that OxyELITE Pro (OEP), a dietary supplement (DS) mainly for weight loss, was the cause of this mysterious cluster. However, the presented data were inconsistent and required a thorough reanalysis.

MATERIAL AND METHODS

To further investigate the cause(s) of this cluster, we critically evaluated redacted raw clinical data of the cluster patients, as the CDC report received tremendous publicity in local and nationwide newspapers and television. This attention put regulators and physicians from the medical center in Honolulu that reported the cluster, under enormous pressure to succeed, risking biased evaluations and hasty conclusions.

RESULTS

We noted pervasive bias in the documentation, conclusions, and public statements, also poor quality of case management. Among the cases we reviewed, many causes unrelated to any DS were evident, including decompensated liver cirrhosis, acute liver failure by acetaminophen overdose, acute cholecystitis with gallstones, resolving acute hepatitis B, acute HSV and VZV hepatitis, hepatitis E suspected after consumption of wild hog meat, and hepatotoxicity by acetaminophen or ibuprofen. Causality assessments based on the updated CIOMS scale confirmed the lack of evidence for any DS including OEP as culprit for the cluster.

CONCLUSIONS

Thus, the Hawaii liver disease cluster is now best explained by various liver diseases rather than any DS, including OEP.

Flavokawains A and B from kava (Piper methysticum) activate heat shock and antioxidant responses and protect against hydrogen peroxide-induced cell death in HepG2 hepatocytes

Context Flavokawains are secondary metabolites from the kava plant (Piper methysticum Forst. f., Piperaceae) that have anticancer properties and demonstrated oral efficacy in murine cancer models. However, flavokawains also have suspected roles in rare cases of kava-induced hepatotoxicity. Objective To compare the toxicity flavokawains A and B (FKA, FKB) and monitor the resulting transcriptional responses and cellular adaptation in the human hepatocyte cell line, HepG2. Materials and methods HepG2 were treated with 2-100 μM FKA or FKB for 24-48 h. Cellular viability was measured with calcein-AM and changes in signalling and gene expression were monitored by luciferase reporter assay, real-time PCR and Western blot of both total and nuclear protein extracts. To test for subsequent resistance to oxidative stress, cells were pretreated with 50 μM FKA, 10 μM FKB or 10 μM sulphoraphane (SFN) for 24 h, followed by 0.4-2.8 mM H2O2 for 48 h, and then viability was assessed. Results FKA (≤100 μM) was not toxic to HepG2, whereas FKB caused significant cell death (IC50=23.2 ± 0.8 μM). Both flavokawains activated Nrf2, increasing HMOX1 and GCLC expression and enhancing total glutathione levels over 2-fold (p < 0.05). FKA and FKB also activated HSF1, increasing HSPA1A and DNAJA4 expression. Also, flavokawain pretreatment mitigated cell death after a subsequent challenge with H2O2, with FKA being more effective than FKB, and similar to SFN. Conclusions Flavokawains promote an adaptive cellular response that protects hepatocytes against oxidative stress. We propose that FKA has potential as a chemopreventative or chemotherapeutic agent.

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.

Hepatotoxicity Induced by "the 3Ks": Kava, Kratom and Khat

The 3Ks (kava, kratom and khat) are herbals that can potentially induce liver injuries. On the one hand, growing controversial data have been reported about the hepatotoxicity of kratom, while, on the other hand, even though kava and khat hepatotoxicity has been investigated, the hepatotoxic effects are still not clear. Chronic recreational use of kratom has been associated with rare instances of acute liver injury. Several studies and case reports have suggested that khat is hepatotoxic, leading to deranged liver enzymes and also histopathological evidence of acute hepatocellular degeneration. Numerous reports of severe hepatotoxicity potentially induced by kava have also been highlighted, both in the USA and Europe. The aim of this review is to focus on the different patterns and the mechanisms of hepatotoxicity induced by “the 3Ks”, while trying to clarify the numerous aspects that still need to be addressed.

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.

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.