Identification and analysis of the reactive metabolites related to the hepatotoxicity of safrole

Potential herb‒drug interactions between anti-COVID-19 drugs and traditional Chinese medicine

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread worldwide. Effective treatments against COVID-19 remain urgently in need although vaccination significantly reduces the incidence, hospitalization, and mortality. At present, antiviral drugs including Nirmatrelvir/Ritonavir (PaxlovidTM), Remdesivir, and Molnupiravir have been authorized to treat COVID-19 and become more globally available. On the other hand, traditional Chinese medicine (TCM) has been used for the treatment of epidemic diseases for a long history. Currently, various TCM formulae against COVID-19 such as Qingfei Paidu decoction, Xuanfei Baidu granule, Huashi Baidu granule, Jinhua Qinggan granule, Lianhua Qingwen capsule, and Xuebijing injection have been widely used in clinical practice in China, which may cause potential herb-drug interactions (HDIs) in patients under treatment with antiviral drugs and affect the efficacy and safety of medicines. However, information on potential HDIs between the above anti-COVID-19 drugs and TCM formulae is lacking, and thus this work seeks to summarize and highlight potential HDIs between antiviral drugs and TCM formulae against COVID-19, and especially pharmacokinetic HDIs mediated by metabolizing enzymes and/or transporters. These well-characterized HDIs could provide useful information on clinical concomitant medicine use to maximize clinical outcomes and minimize adverse and toxic effects.

Prescription system to calculate precise doses of Chinese herbal medicine to avoid toxic effects

Background and objectives

Traditional Chinese Medicine (TCM) is a therapeutic system which has been practiced for thousands of years. Although for much of its history the decoction of medicinal herbs was the most common method of consuming the herbal treatments, TCM prescriptions are now primarily prepared using concentrated Chinese herbal extracts (CCHE) in powder or granular form. However, determining the precise dose of each single Chinese herbal constituent within a prescription creates a challenge in clinical practice due to the potential risk of toxicity. To alleviate this, we invented the Chinese Intelligence Prescription System (CIPS) to calculate the exact dose of each single herb within an individual prescription.

Methods

In this study, we applied CIPS in a real-world setting to analyze clinical prescriptions collected and prepared at the TCM Pharmacy of China Medical University Hospital (CMUH).

Results

Our investigation revealed that 3% of all prescriptions filled in a 1-month period contained inexact dosages, suggesting that more than 170,000 prescriptions filled in Taiwan in a given month may contain potentially toxic components. We further analyzed the data to determine the excess dosages and outline the possible associated side effects.

Conclusions

In conclusion, CIPS offers TCM practitioners the ability to prepare exact Chinese herbal medicine (CHM) prescriptions in order to avoid toxic effects, thereby ensuring patient safety.

A review of herb-induced liver injury in mainland china

Traditional medicines have greatly contributed to people’s health worldwide. However, in recent years, the frequent occurrence of herb-induced liver injury (HILI) has raised public concerns regarding the safety of herbs. HILI not only severely impacts public health, thus increasing its medical burden, but also consumes medical resources. However, the pharmacoepidemiology and risk factors of HILI are still unclear due to the complexity of herbs (medication theory, drug composition, dual properties of drugs and food, etc.). China is the country with the most extensive use of herbs and cases of HILI worldwide. The safety profile of herbs (especially with respect to HILI) has also affected the use of herbs internationally. Therefore, this review focuses on the epidemic situation of HILI in mainland China to compile its characteristics, while focusing on the three main aspects of patients, drugs, and unreasonable prescriptions to explore the potential risk factors. Our objective was to provide a reference for HILI pharmacovigilance and risk prevention and control and contribute to Chinese knowledge of the realisation of the “Medication without Harm” global safe medication strategic goal of the World Health Organization.

Xanthotoxin (8-methoxypsoralen): A review of its chemistry, pharmacology, pharmacokinetics, and toxicity

Xanthotoxin (XAT) is a natural furanocoumarins, a bioactive psoralen isolated from the fruit of the Rutaceae plant Pepper, which has received increasing attention in recent years due to its wide source and low cost. By collecting and compiling literature on XAT, the results show that XAT exhibits significant activity in the treatment of various diseases, including neuroprotection, skin repair, osteoprotection, organ protection, anticancer, antiinflammatory, antioxidative stress and antibacterial. In this paper, we review the pharmacological activity and potential molecular mechanisms of XAT for the treatment of related diseases. The data suggest that XAT can mechanistically induce ROS production and promote apoptosis through mitochondrial or endoplasmic reticulum pathways, regulate NF-κB, MAPK, JAK/STAT, Nrf2/HO-1, MAPK, AKT/mTOR, and ERK1/2 signaling pathways to exert pharmacological effects. In addition, the pharmacokinetics properties and toxicity of XAT are discussed in this paper, further elucidating the relationship between structure and efficacy. It is worth noting that data from clinical studies of XAT are still scarce, limiting the use of XAT in the clinic, and in the future, more in-depth studies are needed to determine the clinical efficacy of XAT.

Asari Radix et Rhizoma consumption lacks relevance for hepatocellular carcinoma in patients: A retrospective cohort study

Objective

Although some studies have linked Asari Radix et Rhizoma (Asari Radix) administration to hepatocellular carcinoma (HCC), few studies have examined the association between the development of HCC and use of Asari Radix among patients in mainland China. This study aimed to evaluate the real-world association between Asari Radix and HCC in patients to strengthen the understanding of Asari Radix safety.

Methods

A retrospective cohort study among hepatitis B virus (HBV)-monoinfected patients and non-HBV-monoinfected patients were performed. Patients over 18 years of age were eligible for inclusion. Prescription records of inpatients and outpatients were inquired to distinguish Asari Radix users and nonusers. The risk of developing HCC among Asari Radix users and nonusers in the HBV cohort and the non-HBV cohort was analyzed.

Results

There were 49 500 HBV and 133 148 non-HBV patients involved in the two cohorts. Among HBV patients (2 901 users; 46 599 nonusers), the prevalence of HCC in Asari Radix users was lower than that in nonusers (145.70 vs. 265.43 per 105). Among non-HBV patients (5 042 users; 128 106 nonusers), the prevalence of HCC in Asari Radix users was lower than that in nonusers (81.62 vs. 134.11 per 105). None of the hazard ratios (HRs) of Asari Radix exposure ranging from 1 g to 200 g in the two cohorts showed correlation between Asari Radix exposure and hepatocarcinogenesis.

Conclusion

An obvious irrelevancy was found between the consumption of Asari Radix and HCC development both in patients with and in those without HBV infection. Use of Asari Radix under 200 g appears safe in terms of HCC risk in the Chinese population; further prospective studies are needed to confirm our results.

Dissecting dietary and semisynthetic volatile phenylpropenes: A compile of their distribution, food properties, health effects, metabolism and toxicities

Phenylpropenes represent a major subclass of plant volatiles, including eugenol, and (E)-anethole. They contribute to the flavor and aroma of many chief herbs and spices, to exert distinct notes in food, i.e., spicy anise- and clove-like to fruit. Asides from their culinary use, they appear to exert general health effects, whereas some effects are specific, e.g., eugenol being a natural local anesthetic. This review represents the most comprehensive overview of phenylpropenes with respect to their chemical structures, different health effects, and their food applications as flavor and food preservatives. Side effects and toxicities of these compounds represent the second main part of this review, as some were reported for certain metabolites generated inside the body. Several metabolic reactions mediating for phenylpropenes metabolism in rodents via cytochrome P450 (CYP450) and sulfotransferase (SULT) enzymes are presented being involved in their toxicities. Such effects can be lessened by influencing their pharmacokinetics through a matrix-derived combination effect via administration of herbal extracts containing SULT inhibitors, i.e., nevadensin in sweet basil. Moreover, structural modification of phenylpropanes appears to improve their effects and broaden their applications. Hence, such review capitalizing on phenylpropenes can help optimize their applications in nutraceuticals, cosmeceuticals, and food applications.

The genus Asarum: A review on phytochemistry, ethnopharmacology, toxicology and pharmacokinetics

ETHNOPHARMACOLOGICAL RELEVANCE

In essentially every quadrant of the globe, many species of genus Asarum are used as a common herbal medicine and appear in many formulas or Kampo. Crude drug from several medicinal plants of genus Asarum (MA) known as Asari Radix et Rhizoma (ARR) has been proven to have the functions of dispelling cold, relieving pain, and reducing phlegm according to Traditional Chinese Medicine (TCM) theory for thousands of years.

AIM OF THE STUDY

This article reviews the ethnopharmacology, phytochemistry, pharmacology, toxicology and metabolic kinetics related research of genus Asarum to evaluate its ethnopharmacology use and future opportunities for research.

MATERIALS AND METHODS

Information on relevant studies of the genus Asarum was gathered via the Internet using Baidu Scholar, Web of Science, Elsevier, ResearchGate, ACS, Pudmed and Chinese National Knowledge Infrastructure (CNKI). Additionally, information was also obtained from some local books, PhD, MS's dissertations and Pharmacopeias.

RESULTS

The genus Asarum has played an important role in herbal treatment. At present, more than 277 compounds have been isolated or identified from genus Asarum. Among them, volatile oil and lignans are the major active constituents and important chemotaxonomic markers. Modern pharmacological studies indicated that genus Asarum and its active compounds possess a wide range of pharmacological effects, especially analgesic, anti-inflammatory, neuroprotective, cardiovascular protection, antitussive, immunosuppressive, anti-tumor, and microbicidal activities.

CONCLUSIONS

Based on this review, therapeutic potential of genus Asarum has been demonstrated with the pharmacological effects on inflammation, CNS, respiratory regulation, cardiovascular diseases, cancer and microbial infection. The available literature showed that the major activities of the genus Asarum can be attributed to the active lignans and essential oils. Further in-depth studies on the aspects of the genus for mechanism of actions, metabolism, pharmacokinetics, toxicology, drug interactions, and clinical trials are still limited, thereby intensive research and assessments should be performed.

Method Validation and Evaluation of Safrole Persistence in Cowpea Beans Using Headspace Solid-Phase Microextraction and Gas Chromatography

Bioinsecticides are regarded as important alternatives for controlling agricultural pests. However, few studies have determined the persistence of these compounds in stored grains. This study aimed at optimizing and validating a fast and effective method for extraction and quantification of residues of safrole (the main component of Piper hispidinervum essential oil) in cowpea beans. It also sought to assess the persistence of this substance in the grains treated by contact and fumigation. The proposed method used headspace solid-phase microextraction (HS-SPME) and gas chromatography with a flame ionization detector (GC/FID). Factors such as temperature, extraction time and type of fiber were assessed to maximize the performance of the extraction technique. The performance of the method was appraised via the parameters selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy. The LOD and LOQ of safrole were 0.0057 and 0.019 μg kg⁻¹, respectively and the determination coefficient (R²) was >0.99. The relative recovery ranged from 99.26 to 104.85, with a coefficient of variation <15%. The validated method was applied to assess the persistence of safrole residue in grains, where concentrations ranged from 1.095 to 0.052 µg kg⁻¹ (contact) and from 2.16 to 0.12 µg kg ⁻¹ (fumigation). The levels measured up from the fifth day represented less than 1% of the initial concentration, proving that safrole have low persistence in cowpea beans, thus being safe for bioinsecticide use. Thus, this work is relevant not only for the extraction method developed, but also for the possible use of a natural insecticide in pest management in stored grains.

Refined CYP2E1∗ Template∗∗ system to decipher the ligand-interactions

A Template system for a prediction of human CYP2E1-mediated reactions (Drug Metab Rev 2011) has been refined with the introduction of ideas of Trigger-residue and the residue-initiated movement of ligands in the active site. The refined system also includes ideas of bi-molecule binding and angled-placement, which allow to sit diverse types of ligands on Template. With the use of these ideas in common with other Template systems for human CYP1A1, CYP1A2 and CYP3A4 (Drug Metab Pharmacokinet 2016, 2017, 2019, and 2020), 349 reactions of 192 distinct chemicals published as CYP2E1 ligands were examined in the refined system. Verifications of good and poor substrates, regioselectivity and also inhibitory interaction were available faithfully for these ligands from their placements on the refined Template and rules for interaction modes, accompanied with their deciphering information to lead to the judgements. The refined CYP2E1 Template system will thus offer more reliable estimations of human CYP2E1 catalysis toward ligands of diverse structures.

Pharmacokinetic Study of Safrole and Methyl Eugenol after Oral Administration of the Essential Oil Extracts of Asarum in Rats by GC-MS

Asarum is a traditional medicine and has been widely used as remedies for inflammatory diseases, toothache, headache, local anesthesia, and aphthous stomatitis in China, Japan, and Korea. Our previous research found that safrole and methyl eugenol were vital compounds that contribute to distinguish the different species and raw Asarum and its processed products apart. The pharmacokinetics of safrole and methyl eugenol after oral administration of Asarum extract has not been reported yet. In this study, a rapid and simple gas chromatography-mass spectroscopy (GC-MS) method that has a complete run time of only 4.5 min was developed and validated for the simultaneous determination and pharmacokinetic study of safrole and methyl eugenol in rat plasma after administration of Asarum extracts. The chromatographic separation was realized on a DB-17 column (30 m × 0.25 mm × 0.25 μm). And detection was carried out under selected ion monitoring (SIM) mode. Plasma samples were pretreated by n-hexane. The pharmacokinetic parameters provided by this study will be beneficial for further developments and clinical applications of Asarum.

Human Family 1-4 cytochrome P450 enzymes involved in the metabolic activation of xenobiotic and physiological chemicals: an update

This is an overview of the metabolic activation of drugs, natural products, physiological compounds, and general chemicals by the catalytic activity of cytochrome P450 enzymes belonging to Families 1-4. The data were collected from > 5152 references. The total number of data entries of reactions catalyzed by P450s Families 1-4 was 7696 of which 1121 (~ 15%) were defined as bioactivation reactions of different degrees. The data were divided into groups of General Chemicals, Drugs, Natural Products, and Physiological Compounds, presented in tabular form. The metabolism and bioactivation of selected examples of each group are discussed. In most of the cases, the metabolites are directly toxic chemicals reacting with cell macromolecules, but in some cases the metabolites formed are not direct toxicants but participate as substrates in succeeding metabolic reactions (e.g., conjugation reactions), the products of which are final toxicants. We identified a high level of activation for three groups of compounds (General Chemicals, Drugs, and Natural Products) yielding activated metabolites and the generally low participation of Physiological Compounds in bioactivation reactions. In the group of General Chemicals, P450 enzymes 1A1, 1A2, and 1B1 dominate in the formation of activated metabolites. Drugs are mostly activated by the enzyme P450 3A4, and Natural Products by P450s 1A2, 2E1, and 3A4. Physiological Compounds showed no clearly dominant enzyme, but the highest numbers of activations are attributed to P450 1A, 1B1, and 3A enzymes. The results thus show, perhaps not surprisingly, that Physiological Compounds are infrequent substrates in bioactivation reactions catalyzed by P450 enzyme Families 1-4, with the exception of estrogens and arachidonic acid. The results thus provide information on the enzymes that activate specific groups of chemicals to toxic metabolites.

Mechanism-based inactivation of cytochrome P450 enzymes by natural products based on metabolic activation

Cytochrome P450 enzymes (P450 enzymes) are the most common and important phase I metabolic enzymes and are responsible for the majority of the metabolism of clinical drugs and other xenobiotics. Drug-drug interactions (DDIs) can occur when the activities of P450 enzymes are inhibited. In particular, irreversible inhibition of P450 enzymes may lead to severe adverse interactions, compared to reversible inhibition. Many natural products have been shown to be irreversible inhibitors of P450 enzymes. The risks for intake of naturally occurring irreversible P450 enzyme inhibitors have been rising due to the rapid growth of the global consumption of natural products. Irreversible inhibition is usually called mechanism-based inactivation, which is time-, concentration- and NADPH- dependent. Generally, the formation of electrophilic intermediates is fundamental for the inactivation of P450 enzymes. This review comprehensively classifies natural P450 enzyme inactivators, including terpenoids, phenylpropanoids, flavonoids, alkaloids, and quinones obtained from herbs or foods. Moreover, the structure - activity correlations according to the IC₅₀ (or K_i) values reported in the literature as well as the underlying mechanisms based on metabolic activation are highlighted in depth.

Reactive Metabolites: Generation and Estimation with Electrochemistry Based Analytical Strategy as an Emerging Screening Tool

Background:

Analytical scientists have constantly been in search for more efficient and economical methods for drug simulation studies. Owing to great progress in this field, there are various techniques available nowadays that mimic drug metabolism in the hepatic microenvironment. The conventional in vitro and in vivo studies pose inherent methodological drawbacks due to which alternative analytical approaches are devised for different drug metabolism experiments.

Methods:

Electrochemistry has gained attention due to its benefits over conventional metabolism studies. Because of the protein binding nature of reactive metabolites, it is difficult to identify them directly after formation, although the use of trapping agents aids in their successful identification. Furthermore, various scientific reports confirmed the successful simulation of drug metabolism studies by electrochemical cells. Electrochemical cells coupled with chromatography and mass spectrometry made it easy for direct detection of reactive metabolites. In this review, an insight into the application of electrochemical techniques for metabolism simulation studies has been provided. The sole use of electrochemical cells, as well as their setups on coupling to liquid chromatography and mass spectrometry has been discussed. The importance of metabolism prediction in early drug discovery and development stages along with a brief overview of other conventional methods has also been highlighted.

Conclusion:

To the best of our knowledge, this is the first article to review the electrochemistry based strategy for the analysis of reactive metabolites. The outcome of this ‘first of its kind’ review will significantly help the researchers in the application of electrochemistry based bioanalysis for metabolite detection.

Differences in xanthotoxin metabolites in seven mammalian liver microsomes

Xanthotoxin, abundantly occurring in fruits, vegetables, grapefruit juice and oils, is widely used in medicine for the treatment of psoriasis and vitiligo. Xanthotoxin possesses the ability to inhibit mechanism-based cytochrome P450 (CYP450)-mediated activities in rats and mice. Furthermore, it time-dependently obstructs a number of CYP450-mediated functions in humans. CYP450 enzymes are most abundant in the liver and induce metabolic activation of numerous xenobiotic compounds. The present study aimed to identify the similarities and differences in xanthotoxin metabolism in liver microsomes of 7 mammalian species, including human liver microsomes (HLM), Rhesus monkey liver microsomes (RMLM), Cynomolgus monkey liver microsomes (CMLM), Sprague Dawley rat liver microsomes (RLM), mouse liver microsomes (MLM), Dunkin Hartley guinea pig liver microsomes (PLM) and Beagle dog liver microsomes (DLM). Ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometric analysis was used to determine the metabolites. A total of 3 metabolites were detected in RMLM, CMLM and RLM. Furthermore, two metabolites were observed in MLM, HLM, PLM and DLM. By analyzing the type and quantity of metabolites, the metabolism of xanthotoxin in MLM was indicated to be most similar to that in HLM. The metabolic transformations of xanthotoxin in the liver microsomes of the 7 species were analyzed in further detail. On the whole, the results of the present study provide a deeper understanding of the metabolic patterns of xanthotoxin in liver microsomes of different species, which may prove to be advantageous regarding the metabolic mechanisms of action of xanthotoxin. Further insight into drug metabolism with respect to different species will also aid in the selection of appropriate animal models for further research.

The Relative Content and Distribution of Absorbed Volatile Organic Compounds in Rats Administered Asari Radix et Rhizoma Are Different between Powder- and Decoction-Treated Groups

Asari Radix et Rhizoma (ARR) is an important traditional Chinese medicine. Volatile organic compounds (VOCs) are the main active constituents of ARR. Research on the metabolite profile of VOCs and the difference of absorbed constituents in vivo after an administration of ARR decoction and powder will be helpful to understand the pharmacological activity and safety of ARR. In this study, headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS) was applied to profile the VOCs from ARR in rats in vivo. A total of 153 VOCs were tentatively identified; 101 were original constituents of ARR (98 in the powder-treated group and 43 in the decoction-treated group) and 15 were metabolites, and their metabolic reactions were mainly oxidation and reduction, with only two cases of methylation and esterification, and 37 unclassified compounds were identified only in the ARR-treated group. Of the 153 VOCs identified, 131 were reported in rats after oral administration of ARR for the first time, containing 79 original constituents, 15 metabolites, and 37 unclassified compounds. In the powder-treated group, methyleugenol, safrole, 3,5-dimethoxytoluene (3,5-DMT), 2,3,5-trimethoxytoluene (2,3,5-TMT), and 3,4,5-trimethoxytoluene (3,4,5-TMT) were the main absorbed constituents, the relative contents of which were significantly higher compared to the decoction-treated group, especially methyleugenol, safrole, and 3,5-DMT. In the decoction-treated group, 3,4,5-TMT, 2,3,5-TMT, kakuol, and eugenol were the main constituents with a higher content and wider distribution. The results of this study provide a reference for evaluating the efficacy and safety of ARR.

Safrole-induced expression of proinflammatory responses is associated with phosphorylation of mitogen-activated protein kinase family and the nuclear factor-κB/inhibitor of κB pathway in macrophages

Objective:

Safrole, also called shikimol and Sassafras, is the carcinogenic and phenylpropanoid compound extracted from Sassafras tree and anise, betel, and camphor. Moreover, a high concentration of safrole can be occur in the saliva because of betel nut or areca quid chewing which a common habit observed in Southern and Southeastern Asia. Notably, macrophages are crucial phagocytic cells of the immune system. Nonetheless, to date, no evidence has been reported regarding safrole-induced proinflammatory response and the corresponding mechanism in macrophages.

Materials and Methods:

In the present study, the cytokines expression, NO generation, protein phosphorylation, and expression were assessed by enzyme-linked immunosorbent assay, Griess reagent, and Western blot assay, respectively.

Results:

In this study, we determined that safrole induces the generation of nitric oxide and proinflammatory cytokines, including tumor necrosis factor-α, interleukin-1β, and IL-6 in RAW264.7 macrophages in a concentration-dependent manner. Furthermore, inhibitor of κB (IκB) degradation was caused by safrole in a concentration-dependent manner. In addition, the phosphorylation of nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) family, including p38 MAPK, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase, was induced by safrole began to increase at 10 μM and attained a plateau at 100 μM.

Conclusion:

These results indicated that safrole induces the expression of proinflammatory responses in macrophages through the NF-κB/IκB pathway and its upstream factor, MAPK family phosphorylation.

Integrative transcriptomics and metabolomics analyses provide hepatotoxicity mechanisms of asarum

Asarum is frequently applied in combination with other agents for prescriptions in practices of Traditional Chinese Medicine. A number of studies have previously indicated that asarum treatment induces lung toxicity by triggering inflammation. However, the potential effects of asarum in the liver and the underlying mechanisms have remained largely elusive. Therefore, transcriptomics and metabolomics approaches were used in the present study to examine the mechanisms of the hepatotoxicity of asarum. Specifically, mRNA and metabolites were obtained from rat liver samples following intragastric administration of asarum powder. RNA sequencing analysis was subsequently performed to screen for differentially expressed genes (DEGs), and a total of 434 DEGs were identified in liver tissue samples, 214 of which were upregulated and 220 were downregulated. Pathway enrichment analysis found that these genes were particularly enriched in processes including the regulation of p53 signaling, metabolic pathways and bile secretion. To investigate potential changes to the metabolic profile as a result of asarum treatment, a metabolomics analysis was performed, which detected 14 significantly altered metabolites in rat liver samples by gas chromatography-mass spectrometry. These metabolites were predominantly members of the taurine, hypotaurine and amino acid metabolic pathways. Metscape network analyses were subsequently performed to integrate the transcriptomics and metabolomics data. Integrative analyis revealed that the DEGs and metabolites were primarily associated with bile acid biosynthesis, amino acid metabolism and the p53 signaling pathway. Taken together, these results provide novel insight into the mechanism of asarum-mediated hepatotoxicity, which may potentially aid the clinical diagnosis and future therapeutic intervention of asarum poisoning.

Classification, hepatotoxic mechanisms, and targets of the risk ingredients in traditional Chinese medicine-induced liver injury

Traditional Chinese medicine (TCM) has become a crucial cause of drug-induced liver injury (DILI). Differ from chemical medicines, TCM feature more complex and mostly indefinite components. This review aimed to clarify the classification, underlying mechanisms and targets of the risk components in TCM-induced liver injury to further guide the secure application of TCM. Relevant studies or articles published on the PubMed database from January 2008 to December 2019 were searched. Based on the different chemical structures of the risk ingredients in TCM, they are divided into alkaloids, glycosides, toxic proteins, terpenoids and lactones, anthraquinones, and heavy metals. According to whether drug metabolism is activated or hepatocytes are directly attacked during TCM-induced liver injury, the high-risk substances can be classified into metabolic activation, non-metabolic activation, and mixed types. Mechanisms of the hepatotoxic ingredients in TCM-induced hepatotoxicity, including cytochrome P450 (CYP450) induction, mitochondrial dysfunction, oxidative damage, apoptosis, and idiosyncratic reaction, were also summarized. The targets involved in the risk ingredient-induced hepatocellular injury mainly include metabolic enzymes, nuclear receptors, transporters, and signaling pathways. Our periodic review and summary on the risk signals of TCM-induced liver injury must be beneficial to the integrated analysis on the multi-component, multi-target, and multi-effect characteristics of TCM-induced hepatotoxicity.

Toxicity of traditional Chinese medicine herbal and mineral products

Traditional Chinese medicine (TCM) has been used to treat numerous kinds of diseases for more than 2000 years in eastern Asian countries. A portion of the TCM herbal and mineral products are believed to be toxic according to modern standards, and are still widely prescribed in the clinic. However, some TCM products considered to be non-toxic or low-toxic have been reported to possess significant toxicological effects on different organs in both animal and human models. In this review, we define the term "toxic" in TCM, and then we summarize the advances in pharmacology and toxicology research of Toxic Traditional Chinese Medicine (TTCM), including Chinese aconite (Fu Zi), Arsenic Trioxide, Tripterygium wilfordii Hook f. (Thunder God Vine), herbal drugs derived from plants in the Aristolochiaceae Juss. family (Ma Dou Ling), and other TCM products. Finally, the compatibility art of TCM and modern pharmaceutical approaches to manage undesired toxicity of TTCM is discussed. Promoting pharmacology and toxicology studies of TTCM and non-toxic TCM is critical for the further development and safety of TCM in clinical practice.

Herb-Induced Liver Injury: Phylogenetic Relationship, Structure-Toxicity Relationship, and Herb-Ingredient Network Analysis

Currently, hundreds of herbal products with potential hepatotoxicity were available in the literature. A comprehensive summary and analysis focused on these potential hepatotoxic herbal products may assist in understanding herb-induced liver injury (HILI). In this work, we collected 335 hepatotoxic medicinal plants, 296 hepatotoxic ingredients, and 584 hepatoprotective ingredients through a systematic literature retrieval. Then we analyzed these data from the perspectives of phylogenetic relationship and structure-toxicity relationship. Phylogenetic analysis indicated that hepatotoxic medicinal plants tended to have a closer taxonomic relationship. By investigating the structures of the hepatotoxic ingredients, we found that alkaloids and terpenoids were the two major groups of hepatotoxicity. We also identified eight major skeletons of hepatotoxicity and reviewed their hepatotoxic mechanisms. Additionally, 15 structural alerts (SAs) for hepatotoxicity were identified based on SARpy software. These SAs will help to estimate the hepatotoxic risk of ingredients from herbs. Finally, a herb-ingredient network was constructed by integrating multiple datasets, which will assist to identify the hepatotoxic ingredients of herb/herb-formula quickly. In summary, a systemic analysis focused on HILI was conducted which will not only assist to identify the toxic molecular basis of hepatotoxic herbs but also contribute to decipher the mechanisms of HILI.

Metabolic Activation of Myristicin and Its Role in Cellular Toxicity

Myristicin is widely distributed in spices and medicinal plants. The aim of this study was to explore the role of metabolic activation of myristicin in its potential toxicity through a metabolomic approach. The myristicin- N-acetylcysteine adduct was identified by comparing the metabolic maps of myristicin and 1'-hydroxymyristicin. The supplement of N-acetylcysteine could protect against the cytotoxicity of myristicin and 1'-hydroxymyristicin in primary mouse hepatocytes. When the depletion of intracellular N-acetylcysteine was pretreated with diethyl maleate in hepatocytes, the cytotoxicity induced by myristicin and 1'-hydroxymyristicin was deteriorated. It suggested that the N-acetylcysteine adduct resulting from myristicin bioactivation was closely associated with myristicin toxicity. Screening of human recombinant cytochrome P450s (CYPs) and treatment with CYP inhibitors revealed that CYP1A1 was mainly involved in the formation of 1'-hydroxymyristicin. Collectively, this study provided a global view of myristicin metabolism and identified the N-acetylcysteine adduct resulting from myristicin bioactivation, which could be used for understanding the mechanism of myristicin toxicity.