1HNMR-based metabonomic study of sub-chronic hepatotoxicity induced by realgar

Integrated network analysis and metabolomics reveal the molecular mechanism of Yinchen Sini decoction in CCl4-induced acute liver injury

Objective: Yinchen Sini decoction (YCSND), a traditional Chinese medicine (TCM) formula, plays a crucial role in the treatment of liver disease. However, the bioactive constituents and pharmacological mechanisms of action remain unclear. The present study aimed to reveal the molecular mechanism of YCSND in the treatment of acute liver injury (ALI) using integrated network analysis and metabolomics. Methods: Ultra-high-performance liquid chromatography coupled with Q-Exactive focus mass spectrum (UHPLC-QE-MS) was utilized to identify metabolites in YCSND, and high-performance liquid chromatography (HPLC) was applied to evaluate the quality of four botanical drugs in YCSND. Cell damage and ALI models in mice were established using CCl4. 1H-NMR metabolomics approach, along with histopathological observation using hematoxylin and eosin (H&E), biochemical measurements, and reverse transcription quantitative real-time PCR (RT-qPCR), was applied to evaluate the effect of YCSND on CCl4- induced ALI. Network analysis was conducted to predict the potential targets of YCSND in ALI. Result: Our results showed that 89 metabolites in YCSND were identified using UHPLC-QE-MS. YCSND protected against ALI by reducing the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and malondialdehyde (MDA) contents and increasing those of superoxide dismutase (SOD), and glutathione (GSH) both in vivo and in vitro. The 1H-NMRmetabolic pattern revealed that YCSND reversed CCl4-induced metabolic abnormalities in the liver. Additionally, the Kyoto Encyclopedia of Genes and Genome (KEGG) pathway enrichment analysis identified five pathways related to liver injury, including the PI3K-AKT, MAPK, HIF-1, apoptosis, and TNF signaling pathways. Moreover, RT-qPCR showed YCSND regulated the inflammatory response (Tlr4, Il6, Tnfα, Nfκb1, Ptgs2, and Mmp9) and apoptosis (Bcl2, Caspase3, Bax, and Mapk3), and inhibited PI3K-AKT signaling pathway (Pi3k and Akt1). Combined network analysis and metabolomics showed a link between the key targets (Tlr4, Ptgs2, and Mmp9) and vital metabolites (choline, xanthine, lactate, and 3-hydroxybutyric acid) of YCSND in ALI. Conclusion: Overall, the results contribute to the understanding of the therapeutic effects of YCSND on ALI, and indicate that the integrated network analysis and metabolomics could be a powerful strategy to reveal the pharmacological effects of TCM.

Sub-chronic toxicity of an aqueous extract of Epimedium sagittatum (Sieb. Et Zucc.) Maxim. in rats

Epimedium sagittatum (Sieb. et Zucc.) Maxim., a traditional medicinal plant in Asia, is widely used in clinical settings but its safety in vivo is unclear. This study investigated the sub-chronic toxicity of E. sagittatum aqueous extract to rats with a 13-week daily intragastric administration of 7.5, 15, or 30 g/kg. Nine constituents of the aqueous extract were identified by ultra-performance liquid chromatography (UPLC). Organ weights, organ coefficients, serum biochemistry parameters, histopathology, and metabolomic analysis were performed. In female rats, treatment increased the liver, thymus, and adrenal gland coefficients (p < 0.05). Liver, pancreas, and adrenal gland injury were observed. The levels of six metabolites were altered by the treatment (p < 0.05). In male rats, treatment altered liver, heart, and thymus coefficients (p < 0.05) and liver, adrenal gland, and heart injury were observed. The levels of 11 metabolites were altered (p < 0.05). The no-observed-adverse-effect level was not determined but would be below 7.5 g/kg in rats treated for 13 weeks. In female rats, E. sagittatum may injure the liver and pancreas and dysregulate the biosynthesis of phenylalanine, tyrosine, tryptophan, valine, leucine, and isoleucine and the metabolism of phenylalanine. In male rats, the extract may injure the liver and adrenal gland and dysregulate the biosynthesis of valine, leucine, and isoleucine and the metabolism of pyruvate.

Current Trends in Toxicity Assessment of Herbal Medicines: A Narrative Review

Even in modern times, the popularity level of medicinal plants and herbal medicines in therapy is still high. The World Health Organization estimates that 80% of the population in developing countries uses these types of remedies. Even though herbal medicine products are usually perceived as low risk, their potential health risks should be carefully assessed. Several factors can cause the toxicity of herbal medicine products: plant components or metabolites with a toxic potential, adulteration, environmental pollutants (heavy metals, pesticides), or contamination of microorganisms (toxigenic fungi). Their correct evaluation is essential for the patient’s safety. The toxicity assessment of herbal medicine combines in vitro and in vivo methods, but in the past decades, several new techniques emerged besides conventional methods. The use of omics has become a valuable research tool for prediction and toxicity evaluation, while DNA sequencing can be used successfully to detect contaminants and adulteration. The use of invertebrate models (Danio renio or Galleria mellonella) became popular due to the ethical issues associated with vertebrate models. The aim of the present article is to provide an overview of the current trends and methods used to investigate the toxic potential of herbal medicinal products and the challenges in this research field.

Identification of Hair Growth Promoting Components in the Kernels of Prunus mira Koehne and Their Mechanism of Action

The application of the seed oil of Prunus mira Koehne (Tibetan name ཁམབུ།), a plant belonging to the Rosaceae family, for the treatment of alopecia has been recorded in Jingzhu Materia Medica (ཤེལ་གོང་ཤེལ་ཕྲེང་།) (the classic of Tibetan medicine) and Dictionary of Chinese Ethnic Medicine. This study aims to reveal the effective components and mechanism of hair growth promotion in the kernel of Prunus mira Koehne. Network pharmacology was used to predict the mechanism of action and effective components in the treatment of the kernel of Prunus mira Koehne. The contents of amygdalin in 12 batches of the kernel of Prunus mira Koehne were determined by HPLC. An animal model of the depilation of KM mice induced by sodium sulfide was created, and five effective components that promoted hair growth were initially screened. In the study of the effectiveness and mechanism of action, KM and C57BL/6 mice are selected as experimental objects, three screening tests for active components of the kernel of P. mira are performed, and three effective components are screened out from the eight components. HE staining was used to detect the number of hair follicles and the thickness of the dermis. RT-PCR and immunohistochemistry were used to evaluate the influence of the expression of indicators in the Wnt/β-catenin signaling pathway in skin, including β-catenin, GSK-3β, and mRNA and protein expression levels of Cyclin D 1 and LEF 1. The network pharmacology study showed 12 signaling pathways involving 25 targets in the treatment of alopecia by the kernel of Prunus mira Koehne. vitamin E (3.125 mg/cm2/d), β-sitosterol (0.061 mg/cm2/d), and linoleic acid (0.156 mg/cm2/d) in the kernel of Prunus mira Koehne can promote hair growth in mice, and the mechanism of action may be related to the Wnt/β-catenin pathway.

Compatibility of Niuhuang Jiedu Tablets Results in Attenuated Arsenic Bioaccumulation and Consequent Protection against Realgar-Induced Toxicity in Mice

Niuhuang Jiedu Tablets (NJT) is a popular over-the-counter traditional Chinese medicine (TCM) preparation. It is composed of realgar (As₂S₂) and seven other TCMs. The safety of NJT is of growing concern because arsenic (As) is carcinogenic to humans. The toxicity of realgar in vivo can mainly be attributed to the absorbed and accumulated As. This study investigated the correlation between the detoxification effects of the other TCMs in NJT on realgar and their influences on arsenic accumulation of realgar in mice. Histopathological examination, clinical biochemical test, and metabolic profiling analysis were used to evaluate the toxicity of realgar. The concentration of arsenic in mice whole blood as the hazard indicator was determined by inductively coupled plasma mass spectrometry (ICP-MS). The compatibility of NJT could decrease arsenic bioaccumulation of realgar in mice whole blood and consequently reduce the toxicity of realgar, which could be considered as one detoxification mechanism to realgar in NJT. The combination of Rhei Radix et Rhizoma, Scutellariae Radix, Platycodonis Radix, and Glycyrrhizae Radix et Rhizoma exhibited almost the same effects as NJT in regulating the serum biochemical parameters and metabolic profiles disturbed by realgar and in reducing arsenic accumulation of realgar in mice whole blood.

Progress in ICP-MS Analysis of Minerals and Heavy Metals in Traditional Medicine

Aim: This study systematically reviewed the application of ICP-MS and its combined technology in the determination of mineral and heavy metal elements in medicinal materials derived from plants, animals, minerals and their preparations (Chinese patent medicine), and biological products. It provides a reference for improving the quality standard of traditional medicine and exploring the effective components, toxic components, and action mechanism of traditional medicine.

Materials and Methods: A total of 234 articles related to the determination of mineral and heavy metal elements in medicinal materials derived from plants, animals, and minerals and their preparations (Chinese patent medicine) were collected from PubMed, CNKI, Web of Science, VIP, and other databases. They were classified and sorted by the inductively coupled plasma-mass-spectrometry (ICP-MS) method.

Results: Of the 234 articles, 154 were about medicinal materials derived from plants, 15 about medicinal materials derived from animals, 9 about medicinal materials derived from minerals, 46 about Chinese patent medicine, 10 about combined technology application, and 3 about drugs being tested after entering the body. From the 154 articles on medicinal materials derived from plants, 76 elements, including Cu, Cd, Pb, As, Cr, Mn, and Hg, were determined, of which the determination of Cu was the most, with 129 articles. Medicinal materials derived from the roots, stems, leaves, flowers, and fruits and seeds of plants accounted for 25.97%, 18.18%, 7.14%, 7.79%, and 14.94%, respectively. Moreover, medicinal materials derived from the whole plants accounted for 14.94%, and other medicinal materials derived from plants and soil accounted for 11.04%. A total of 137 of the tested medicinal materials were from traditional Chinese medicine, accounting for 88.96%, 12 were from Arabic medicine (including Unani), accounting for 7.79%, 2 were from Tibetan medicine of China, and 1 was from Mongolian medicine of China, 1 was from Miao medicine of China, and 1 was from Zhuang medicine of China. In the 15 articles on medicinal materials derived from animals, 49 elements such as Cu, As, Cd, Hg, Se, Pb, and Mn were determined, of which Cu was the most. All the tested medicinal materials belong to traditional Chinese medicine. From the nine articles on medicinal materials derived from minerals, 70 elements such as Fe, Cu, Zn, Al, As, Se, and Na were determined, of which Fe, Cu, and Zn were the most. The tested medicinal materials all belong to traditional Chinese medicine. From the 46 articles on Chinese patent medicine, 62 elements such as Cu, As, Pb, Cd, Hg, Ni, and Cr were determined, of which Cu was the most. Regarding the tested Chinese patent medicine, 38 articles belong to traditional Chinese medicine, 6 to Tibetan medicine, and 2 to Mongolian medicine of China. Three articles determine the content of metal elements in biological samples such as animal hepatic venous blood, abdominal aortic blood, brain, liver, kidney, urine, and feces, and one article determines the content of metal elements in human lung and serum. From the 10 articles combined with liquid chromatography and gas chromatography, 16 elements such as MMA, DMA, AsIII, AsV, AsB, AsC, and AsI₃ were determined, of which MMA and DMA were the most. It can realize elemental morphology and isotope analysis. The tested medicinal materials and Chinese patent medicine belong to traditional Chinese medicine.

Conclusion: ICP-MS was applied the most in traditional Chinese medicine, followed by Arabic medicine. ICP-MS was used to determine more medicinal materials derived from plants, and Cu was determined the most. The characteristic inorganic element spectrum of medicinal materials can also be established. ICP-MS and its combined technology are widely used in Chinese patent medicine, but the test of biological samples is the least. The information provided in this article can provide a reference for improving the quality standard of traditional medicines and exploring the active ingredients and toxic ingredients and their mechanism of action.

An Experimental Study Reveals the Protective Effect of Autophagy against Realgar-Induced Liver Injury via Suppressing ROS-Mediated NLRP3 Inflammasome Pathway

Realgar, a poisonous traditional Chinese medicine, has been shown to cause liver injury when used for long periods or overdoses. However, the underlying molecular mechanisms and therapeutic targets have not been fully elucidated. The aim of this study is to explore the role of autophagy in sub-chronic realgar exposure-induced liver injury. Here, the liver injury model was established by continuously administrating mice with 1.35 g/kg realgar for 8 weeks. 3-methyladenine (3-MA) and rapamycin (RAPA) were used to regulate autophagy. The results showed that realgar induced abnormal changes in liver function, pathological morphology, expression of inflammatory cytokines, and upregulated NLRP3 inflammasome pathway in mouse livers. RAPA treatment (an inducer of autophagy) significantly improved realgar-induced liver injury and NLRP3 inflammasome activation, while 3-MA (an inhibitor of autophagy) aggravated the realgar-induced liver injury and NLRP3 inflammasome activation. Furthermore, we found that realgar-induced NLRP3 inflammasome activation in mouse livers is mediated by ROS. RAPA eliminates excessive ROS, inhibits NF-κB nuclear translocation and down-regulates the TXNIP/NLRP3 axis, consequently suppressing ROS-mediated NLRP3 inflammasome activation, which may be the underlying mechanism of the protective effect of autophagy on realgar-induced liver injury. In conclusion, the results of this study suggest that autophagy alleviates realgar-induced liver injury by inhibiting ROS-mediated NLRP3 inflammasome activation. Autophagy may represent a therapeutic target in modulating realgar-induced liver injury.

Study on the Mechanism of Reducing Hepatotoxicity of Water-Grinding Realgar by Metabolomics, Morphology, and Chemical Analysis

BACKGROUND

Realgar was usually selected as a substitute for arsenic trioxide to treat acute promyelocytic leukemia due to its higher effect without high cardiotoxicity. In traditional Chinese medicine (TCM), realgar is usually processed by the water-grinding method clinically, but the mechanism of realgar processing detoxification is still unclear. However, it is necessary to take safety and efficacy into account while evaluating a drug.

METHODS

Sixty male Wistar rats were divided into control group, realgar products-treated groups, and corresponding subgroups. Biochemistry analysis and histopathological examination were performed in the study, and plasma samples were collected from all the rats for metabolomics analysis.

RESULTS

No significant toxicity was observed in rats treated with 0.64 g/kg/day grinding realgar (G-r) and water-grinding realgar (WG-r). When the dose increased to 1.92 g/kg/day, the liver weight coefficients of the rats treated with G-r (HG-r: 3.65 ± 0.26%) and WG-r (HWG-r: 3.67 ± 0.14%) increased significantly and severe hepatic injury occurred in comparison to the control group (Group C: 3.00 ± 0.21%). After one week's withdrawal, the liver injury caused by the high dose of WG-r significantly recovered, while the liver damage caused by G-r was more difficult to recover. In metabolomics analysis, 14 metabolites were identified as the potential biomarkers in realgar-treated rats. These metabolites indicated that there were perturbations of the primary bile acid biosynthesis, arachidonic acid metabolism, linoleic acid metabolism, and glycerophospholipid metabolism in the realgar-treated groups.

CONCLUSIONS

These results illustrate that, as a TCM processing method, water grinding had the effect of reducing toxicity, and the metabolomics method may be a valuable tool for studying the toxicity induced by TCM and the mechanism of TCM processing.

Sub-chronic exposure to realgar induces liver injury via upregulating the TXNIP/NLRP3 pathway and disturbing bile acid homeostasis in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Realgar is a traditional Chinese medicine used in China for a long history. Long-time or excessive use of realgar causes liver injury. However, its underlying mechanism is not fully clarified.

AIM OF THE STUDY

In this study, we investigated the toxic effect of sub-chronic exposure to realgar on mice liver, and further revealed its underlying mechanism focused on the TXNIP/NLRP3 pathway and bile acid homeostasis.

MATERIAL AND METHODS

Mice were divided into control and different doses of sub-chronic realgar exposed groups. Total arsenic levels in the blood and liver were determined by atomic fluorescence spectrometry. The effect of realgar on liver function was evaluated by biochemical analysis and histopathological examination. Assay kits were applied for the measurement of oxidative stress indexes, MPO and plasma inflammatory cytokines. The mRNA and proteins involved in the TXNIP/NLRP3 and NF-κB pathways were determined by RT-qPCR, western blot, Immunofluorescence and Immunohistochemistry. UHPLC/MS/MS was used for the quantitative analysis of bile acids (BAs) in mice plasma, liver and urine. The genes related to BAs metabolism were measured by RT-qPCR.

RESULTS

Sub-chronic exposure to realgar led to arsenic accumulation and caused oxidative damage and inflammatory infiltration in mouse liver, finally resulting in liver injury. Realgar treatment activated the NF-κB pathway and significantly upregulated the TXNIP/NLRP3 pathway in mouse liver. Realgar altered the metabolic balance of BAs, which is related to the abnormal expression of BAs transporters and enzymes.

CONCLUSION

Sub-chronic exposure to realgar caused liver injury in mouse, and the mechanism may involve the upregulation of the TXNIP/NLRP3 pathway and disordered BAs homeostasis.

A Metabolic Profiling Study of Realgar-Induced Acute Kidney Injury in Mice

Realgar has been used as a type of mineral drug that contains arsenic for thousands of years. Previous studies have shown that Realgar-induced acute kidney injury is associated with abnormal metabolism, but the underlying mechanism is poorly understood. The aim of this study is to investigate the metabolic changes in serum and kidney tissues of mice exposed to Realgar by using a metabolomic approach and explore the molecular mechanisms of acute kidney injury induced by Realgar. Forty mice were randomly divided into four groups: Control group, 0.5-, 1.0, and 2.0 g/kg Realgar group. After 1 week, the body weight and kidney weight of the mice were measured. The serum and kidney samples were used for LC-MS spectroscopic metabolic profiling. Principal component analysis (PCA), correlation analysis, and pathway analysis were used to detect the nephrotoxic effects of Realgar. Body weight decreased significantly in the 2.0 g/kg group, and the kidney weight index also showed a dose-dependent increase in Realgar. The PCA score plot showed the serum and kidney tissue metabolic profile of mice exposed to 2.0 g/kg Realgar separated from the control group, while the lower-doses of 0.5 g/kg and 1.0 g/kg Realgar shown a similar view to the Control group. Thirty-three metabolites and seventeen metabolites were screened and identified in the serum and kidney of mice in a dose-dependent manner. respectively. Correlation analysis showed a strong correlation among these metabolites. Amino acid metabolism, lipid metabolism, glutathione metabolism, and purine metabolism pathways were found to be mainly associated with Realgar nephrotoxicity. This work illustrated the metabolic alterations in Realgar-induced nephrotoxic mice through a metabolomic approach.

Metabolic Changes in Hyperlipidemic Rats After The Administration of Xuezhikang

Background:

Xuezhikang capsule, which contains cholesterol synthase inhibitors and a large number of natural statins, is put in the clinical application of lipid-lowering and so on. However, the specific use of dose, lipid-lowering effect and the relationship between metabolites are to be further studied.

Introduction:

Metabonomics is the study of the relationship between the change of quantity and physiological changes from metabolites. At present metabolomics has been widely used in drug development and testing. In this study, we developed a metabolomic method based on gas chromatography-mass spectrometry (GC-MS) to find out hyperlipemia-related substances, and study the lipid-lowering mechanism of Xuezhikang.

Method:

Fifty SD rats (220 ± 20 g) were given high-fat diet. After four-weeks modeling, they were randomly divided into semi-control group, high fat group, simvastatin intervention group and Xuezhikang intervention group (0.23, 0.69, 1.15 mg/kg, low, medium, high), each dosage in eight rats. The control group (rest eight rats) were given normal diet, and no specific treatment. The rats were sacrificed at the end of the experiment.

Result:

The biochemical and body weight indexes of the normal control group and the high fat group were significantly different (P <0.05), which indicated that the model of hyperlipidemia was established success. There was significant difference (P <0.05) between Xuezhikang intervention group and high fat control group (P <0.05), and hyperlipemia metabolomics related markers, oxalic acid, butyric acid, mannitol, glucose, glucuronic acid were found. Glucuronic acid and non-binding bilirubin combined with bilirubin, combined with some of the liver harmful substances, play a detoxification effect.

Conclusion:

The results of metabonomics showed that the high-fat group and the control group have significant differences. Mannose, glucose content is relatively stable, lipid metabolism in high-fat group stearic acid, palmitic acid levels decreased, suggesting that high-fat diet disorders rat body lipid metabolism. It is worth mentioning that the experimental evaluation of rats, such as biochemical indicators and pathological results are prompted to model success, Xuezhikang intervention effect is more significant, consistent with the expected.

Conclusion:

The results of metabonomics showed that the high fat group and the control group were significant difference. Mannose, glucose content is relatively stable, lipid metabolism in high-fat group stearic acid, palmitic acid levels decreased, suggesting that high-fat diet disorders rat body lipid metabolism. It is worth mentioning that the experimental evaluation of rats such as biochemical indicators and pathological results are prompted to model success, Xuezhikang intervention effect is more significant, consistent with the expected.

Liver metabonomics study on the protective effect of glycyrrhetinic acid against realgar-induced liver injury

Glycyrrhetinic acid (GA) is the bioactive ingredient in Glycyrrhizae Radix et Rhizoma. Our previous study has reported that GA has protective effect on realgar-induced hepatotoxicity. However, the details of the hepatoprotective mechanisms of GA on realgar-induced liver injury remain to be elucidated. In the study, mice were divided into control, GA-control, realgar, and co-treated groups. Their liver tissues were used for metabonomics study by ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) method. The results illustrate that GA significantly ameliorate the liver injury and metabolic perturbations caused by realgar. Some metabolites, such as phenylalanine, pyroglutamic acid (PGA), proline, carnitine, nicotinamide, choline, lysophosphatidylcholine (LPC) 16 : 0 and LPC 18 : 2 were found responsible for the hepatoprotective effect of GA. These metabolites are associated with the methylation metabolism of arsenic, cell membrane structure, energy metabolism and oxidative stress. From the results of this study, we infer that the potential hepatoprotective mechanism of GA on realgar-induced liver injury may be associated with reducing arsenic accumulation and its methylation metabolism in the liver, promoting the conjugation of arsenic and GSH to play detoxification effect, and ameliorating the liver metabolic perturbations caused by realgar.

A Systematic Review of the Various Effect of Arsenic on Glutathione Synthesis In Vitro and In Vivo

Background

Arsenic is a toxic metalloid widely present in nature, and arsenic poisoning in drinking water is a serious global public problem. Glutathione is an important reducing agent that inhibits arsenic-induced oxidative stress and participates in arsenic methylation metabolism. Therefore, glutathione plays an important role in regulating arsenic toxicity. In recent years, a large number of studies have shown that arsenic can regulate glutathione synthesis in many ways, but there are many contradictions in the research results. At present, the mechanism of the effect of arsenic on glutathione synthesis has not been elucidated.

Objective

We will conduct a meta-analysis to illustrate the effects of arsenic on GSH synthesis precursors Glu, Cys, Gly, and rate-limiting enzyme γ-GCS in mammalian models, as well as the regulation of p38/Nrf2 of γ-GCS subunit GCLC, and further explore the molecular mechanism of arsenic affecting glutathione synthesis.

Results

This meta-analysis included 30 studies in vivo and 58 studies in vitro, among which in vivo studies showed that arsenic exposure could reduce the contents of GSH (SMD = -2.86, 95% CI (-4.45, -1.27)), Glu (SMD = -1.11, 95% CI (-2.20,-0.02)), and Cys (SMD = -1.48, 95% CI (-2.63, -0.33)), with no statistically significant difference in p38/Nrf2, GCLC, and GCLM. In vitro studies showed that arsenic exposure increased intracellular GSH content (SMD = 1.87, 95% CI (0.18, 3.56)) and promoted the expression of p-p38 (SMD = 4.19, 95% CI (2.34, 6.05)), Nrf2 (SMD = 4.60, 95% CI (2.34, 6.86)), and GCLC (SMD = 1.32, 95% CI (0.23, 2.41)); the p38 inhibitor inhibited the expression of Nrf2 (SMD = -1.27, 95% CI (-2.46, -0.09)) and GCLC (SMD = -5.37, 95% CI (-5.37, -2.20)); siNrf2 inhibited the expression of GCLC, and BSO inhibited the synthesis of GSH. There is a dose-dependent relationship between the effects of exposure on GSH in vitro. Conclusions. These indicate the difference between in vivo and in vitro studies of the effect of arsenic on glutathione synthesis. In vivo studies have shown that arsenic exposure can reduce glutamate and cysteine levels and inhibit glutathione synthesis, while in vitro studies have shown that chronic low-dose arsenic exposure can activate the p38/Nrf2 pathway, upregulate GCLC expression, and promote glutathione synthesis.

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.

Study of the accumulation and distribution of arsenic species and association with arsenic toxicity in rats after 30 days of oral realgar administration

AIM OF THE STUDY

Because the toxicity and efficacy of arsenic is closely related to its chemical species, we conducted examinations of arsenic species accumulation and distribution in the rat body after one-time and 30-day realgar administration and then elucidated the probable roles of different arsenic species in the short-term toxicity of realgar.

MATERIALS AND METHODS

According to ICH M3 guidelines for non-clinical repeated dose toxicity studies and OECD Test guideline TG407 "Repeated Dose 28-Day oral Toxicity Study in Rodents, the doses of realgar set were 10.6 mg/kg, 40.5 mg/kg and 170 mg/kg. Rats were orally administered with realgar for one-tme and 30 days, respectively. Thereafter, biological samples (plasma, urine, liver, kidney, and brain) were obtained from rats and analyzed using high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) to determine realgar metabolism, arsenic species accumulation and distribution. Additionally, the toxicity of realgar in rats was evaluated.

RESULTS

The absorption, distribution and elimination half-life of total arsenic species in realgar were 3.33 hs, 16.08 hs and 24.65 hs, respectively. After 30 days of oral administration of realgar in rats, no significant drug-related toxicity occurred in the rats. Dimethylarsenic acid (DMA) is the most abundant arsenic species. The DMA contents of the liver and kidney of the high-dose realgar group were approximately 40-fold and 50-fold higher than those in the corresponding tissues of the control group, respectively. The arsenic species (III) was mainly detected in the liver and its content was about 40-fold higher than that of the control group. MMA was mainly detected in rat kidney, and the MMA content of the realgar treatment group was more than 2000 times higher than that of the control group.

CONCLUSIONS

Arsenic is rapidly absorbed and distributed over the liver, kidneys and brain, and the distribution and elimination of arsenic in the blood is slow. The realgar doses corresponded to human equivalent doses (HED) of 1.7, 6.4 and 27.2 mg/kg, respectively. Considering that humans are 10 times more sensitive than animals, the realgar dose is equivalent to 0.17, 0.64 and 2.7 mg/kg HED. It can be considered that if patients take no more than 2.7 mg/kg realgar for 2 weeks, there will be no adverse reactions.

Arsenic Bioaccessibility of Realgar Influenced by the Other Traditional Chinese Medicines in Niuhuang Jiedu Tablet and the Roles of Gut Microbiota

Niuhuang Jiedu tablet (NJT), a realgar (As2S2) containing Traditional Chinese Medicine (TCM), is a well-known formula. The safety of NJT is of growing concern since arsenic (As) is considered as one of the most toxic elements. NJT was demonstrated to be safer than realgar by our previous experiments and some other studies. The toxicity of realgar has been shown to be related to the amount of soluble or bioaccessible arsenic. In this study, the influences of the other TCMs in NJT on the bioaccessibility of arsenic from realgar, and the roles of gut microbiota during this process were investigated in vitro. Results showed that Dahuang (Rhei Radix et Rhizoma), Huangqin (Scutellariae Radix), Jiegeng (Platycodonis Radix), and Gancao (Glycyrrhizae Radix et Rhizoma) could significantly reduce the bioaccessibility of arsenic from realgar in artificial gastrointestinal fluids. Gut microbiota played an important role in decreasing the bioaccessibility of realgar because it was demonstrated to be able to absorb the soluble arsenic from realgar in the incubation medium. Dahuang, Huangqin, and Jiegeng could modulate the gut microbiota to enhance its arsenic absorption activity.

Fatal acute arsenic poisoning by external use of realgar: Case report and 30 years literature retrospective study in China

Realgar (arsenic sulfide) is widely used in combination with other herbs as Chinese patent medicine to treat a variety of diseases in China. As a mineral arsenic, its mild toxicity was also well known. Longtime over-dose usage or wrongly oral intake of realgar can cause chronic arsenic poisoning and/or death, but acute fatal arsenic poisoning resulted from short-term dermal use of realgar-containing medicine was very rare. Here, we present the case of a 35-year-old Chinese man, who was diagnosed with severe psoriasis and died of fatal acute arsenic poisoning after he applied a local folk prescription ointment containing mainly the realgar to the affected skin for about 4 days. The autopsy showed multiple punctate hemorrhages over the limbs, pleural effusion, edematous lungs with consolidation, mild myocardial hypertrophy and normal-looking kidneys. The histopathological examination of renal tissue showed severe degeneration, necrosis and desquamation of renal tubular epithelial cells, presence of protein cast and a widened edematous interstitium with interstitial fibrosis. The presence of arsenic in large amount in the ointment (about 6%), in blood (1.76 μg/mL), and in skin (4.71 μg/g), were confirmed analytically. We also provide the clinical records of the deceased and briefly reviewed 7 similar cases in literature (6 in Chinese and 1 in English) in the past 30 years in China.

Application of metabolomics in toxicity evaluation of traditional Chinese medicines

Traditional Chinese medicines (TCM) have a long history of use because of its potential complementary therapy and fewer adverse effects. However, the toxicity and safety issues of TCM have drawn considerable attention in the past two decades. Metabolomics is an “omics” approach that aims to comprehensively analyze all metabolites in biological samples. In agreement with the holistic concept of TCM, metabolomics has shown great potential in efficacy and toxicity evaluation of TCM. Recently, a large amount of metabolomic researches have been devoted to exploring the mechanism of toxicity induced by TCM, such as hepatotoxicity, nephrotoxicity, and cardiotoxicity. In this paper, the application of metabolomics in toxicity evaluation of bioactive compounds, TCM extracts and TCM prescriptions are reviewed, and the potential problems and further perspectives for application of metabolomics in toxicological studies are also discussed.

Tissue metabolomics study to reveal the toxicity of a traditional Tibetan medicine 'Renqing Changjue' in rats

Renqing Changjue (RQCJ), a precious Traditional Tibetan Medicine (TTM), has been widely used in the management of diseases of the digestive system, toxinosis and pyreticosis. However, in the formula, a significant level of heavy metals, which are potential toxic elements, are present. Therefore, it is important to assess the toxicity of RQCJ dynamically and holistically. In the present study, a ¹H NMR metabolomics approach and inductively coupled plasma mass spectrometry (ICP-MS) were implemented to analyze the samples of liver, kidney and spleen from rats treated with RQCJ. The results revealed that 9 metabolites in the liver, 13 metabolites in the kidney and 16 metabolites in the spleen were significantly altered, which suggest that disturbances in TCA cycle, amino acid metabolism, energy metabolism and oxidative stress are produced by successive administration of RQCJ over 15 days. Complemented by histopathology and biochemical assay, the trends of the metabolite levels indicate that RQCJ caused tissue injury to a certain extent, which was evidenced by the high levels of As and Hg in the tissue. The toxic effects of RQCJ were alleviated in liver and kidney during the recovery period, and RQCJ may cause long-term damage in spleen. These findings provide a significant experimental proof on the estimated safety and valuable information about the metabolism of RQCJ, which will be valuable in determining the health risks of the drug.

Nuclear magnetic resonance-based metabolomic investigation reveals metabolic perturbations in PM2.5-treated A549 cells

Exposure to PM_2.5 is associated with an increased risk of lung diseases, and oxidative damage is the main reason for PM_2.5-mediated lung injuries. However, little is known about the early molecular events in PM_2.5-induced lung toxicity. In the present study, the metabolites in PM_2.5-treated A549 cells were examined via a robust and nondestructive nuclear magnetic resonance (NMR)-based metabolic approach to clarify the molecular mechanism of PM_2.5-induced toxicity. NMR analysis revealed that 12 metabolites were significantly altered in PM_2.5-treated A549 cells, including up-regulation of alanine, valine, lactate, ω-6 fatty acids, and citrate and decreased levels of gamma-aminobutyric acid, acetate, leucine, isoleucine, D-glucose, lysine, and dimethylglycine. Pathway analysis demonstrated that seven metabolic pathways which included alanine, aspartate and glutamate metabolism, aminoacyl-tRNA biosynthesis, taurine and hypotaurine metabolism, arginine and proline metabolism, starch and sucrose metabolism, valine, leucine and isoleucine biosynthesis, and tricarboxylic acid cycle were mostly influenced. Our results indicate that NMR technique turns out to be a simple and reliable method for exploring the toxicity mechanism of air pollutant.

Metabolic alterations in triptolide-induced acute hepatotoxicity

Triptolide, a major active constitute of Tripterygium wilfordii Hook. F, is prescribed for the treatment of autoimmune diseases in China. One of its most severe adverse effects observed in the clinical use is hepatotoxicity, but the mechanism is still unknown. Therefore, the present study applied an LC/MS-based metabolomic analysis to characterize the metabolomic changes in serum and liver induced by triptolide in mice. Mice were administered triptolide by gavage to establish the acute liver injury model, and serum biochemical and liver histological analyses were applied to assess the degree of toxicity. Multivariate data analyses were performed to investigate the metabolic alterations. Potential metabolites were identified using variable importance in the projection values and Student's t-test. A total of 30 metabolites were observed that were significantly changed by triptolide treatment and the abundance of 29 metabolites was correlated with the severity of toxicity. Pathway analysis indicated that the mechanism of triptolide-induced hepatotoxicity was related to alterations in multiple metabolic pathways, including glutathione metabolism, tricarboxylic acid cycle, purine metabolism, glycerophospholipid metabolism, taurine and hypotaurine metabolism, pantothenate and CoA biosynthesis, pyrimidine metabolism and amino acid metabolism. The current study provides new mechanistic insights into the metabolic alterations that lead to triptolide-induced hepatotoxicity.

Metabolic Profiling Analysis of the Alleviation Effect of the Fractions of Niuhuang Jiedu Tablet on Realgar Induced Toxicity in Rats

Niuhuang Jiedu Tablet (NJT) is a classical formula in treating acute tonsillitis, pharyngitis, and so on. In the formula, significant level of Realgar as a potentially toxic element is contained. Our previous experiments revealed that it was less toxic for combined Realgar in NJT. However, the active fraction of this prescription with toxicity alleviation effect on Realgar was still obscure. NJT was divided into five different polar fractions (NJT-PET, NJT-25, NJT-50, NJT-75, and NJT-95), and we explored the toxicity alleviation effect on Realgar. Based on 1H NMR spectra of urine and serum from rats, PCA and PLS-DA were performed to identify different metabolic profiles. Liver and kidney histopathology examinations and serum clinical chemistry analysis were also performed. With pattern recognition analysis of metabolites in urine and serum, Realgar group showed a clear separation from control group, while the metabolic profiles of NJT-PET, NJT-25, NJT-50, and NJT-95 groups were similar to Realgar group, and the metabolic profiles of NJT and NJT-75 groups were very close to control group. Statistics results were confirmed by the histopathological examination and biochemical assay. The present work indicated that 75% EtOH fraction of NJT was the most valid fraction with the toxicity alleviation effect on Realgar.

Plasma metabolomics study of the hepatoprotective effect of glycyrrhetinic acid on realgar-induced sub-chronic hepatotoxicity in mice via 1H NMR analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Realgar, a type of mineral drug that contains arsenic, is concurrently used with Glycyrrhizae Radx et Rhizoma to reduce its toxicity in many Chinese herbal formulations. Glycyrrhetinic acid (GA) is the bioactive ingredient in Glycyrrhizae Radx et Rhizoma. In this study, the protective effects of GA on realgar-induced hepatotoxicity was investigated using ¹H nuclear magnetic resonance (¹H NMR)-based metabolomic approaches.

MATERIALS AND METHODS

Mice were divided into control, GA, realgar, and GA and realgar co-administration groups. Their plasma samples were used for a metabolomics study.

RESULTS

GA can protect the mice against realgar-induced hepatotoxicity to some extent by relieving alterations in the clinical biochemical parameters and the damage to hepatocytes. Metabolic profiling via principal components analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) indicated that the metabolic perturbation caused by realgar was reduced by GA. Six metabolites, including 3-hydroxybutyrate (3-HB), very low density/low density lipoprotein (VLDL/LDL), N-acetylglycoprotein (NAc), lactate, choline and D-glucose, were considered as potential biomarkers that are involved in the toxicity reduction effect of GA on realgar-induced hepatotoxicity. The correlation analysis showed that these potential biomarkers were all positively correlated with ALT and AST activities (correlation coefficient > 0.5). Lipid and energy metabolism pathways were found to be primarily associated with the hepatoprotective effect of GA.

CONCLUSIONS

GA has an effective protection function by regulating the lipid and energy metabolism to liver injuries that are induced by realgar.

Understanding the Molecular Mechanisms of the Interplay Between Herbal Medicines and Gut Microbiota

Herbal medicines (HMs) are much appreciated for their significant contribution to human survival and reproduction by remedial and prophylactic management of diseases. Defining the scientific basis of HMs will substantiate their value and promote their modernization. Ever-increasing evidence suggests that gut microbiota plays a crucial role in HM therapy by complicated interplay with HM components. This interplay includes such activities as: gut microbiota biotransforming HM chemicals into metabolites that harbor different bioavailability and bioactivity/toxicity from their precursors; HM chemicals improving the composition of gut microbiota, consequently ameliorating its dysfunction as well as associated pathological conditions; and gut microbiota mediating the interactions (synergistic and antagonistic) between the multiple chemicals in HMs. More advanced experimental designs are recommended for future study, such as overall chemical characterization of gut microbiota-metabolized HMs, direct microbial analysis of HM-targeted gut microbiota, and precise gut microbiota research model development. The outcomes of such research can further elucidate the interactions between HMs and gut microbiota, thereby opening a new window for defining the scientific basis of HMs and for guiding HM-based drug discovery.