A protective mechanism of licorice (Glycyrrhiza uralensis): isoliquiritigenin stimulates detoxification system via Nrf2 activation

Potential mechanisms by which Jiawei Lianpu Yin inhibits Helicobacter pylori colonization and alleviates gastric mucosal inflammation and damage: Integrated transcriptomics, network pharmacology, and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Helicobacter pylori (H. pylori) infection is a primary cause of gastric mucosal damage and inflammation, and its persistent presence is recognized as a major risk factor for the development of gastric cancer. Despite available treatments, eradication of H. pylori remains a significant clinical challenge, highlighting the urgent need for new therapeutic agents that can disrupt bacterial colonization and facilitate its elimination. Jiawei Lianpu Yin (JWLPY), a traditional herbal formula composed of natural medicinal substances, has been used to treat gastric disorders related to H. pylori infection. However, the precise mechanisms underlying its therapeutic effects have not yet been fully elucidated.

AIM OF THE STUDY

The aim of this study was to investigate whether JWLPY can inhibit H. pylori colonization, alleviate gastric mucosal inflammation and damage, and to explore its underlying mechanisms of action.

MATERIALS AND METHODS

The effects of JWLPY on H. pylori and gastric mucosal injury were evaluated both in vitro and in vivo, using a rat model of H. pylori induced gastritis and an in vitro model of H. pylori induced damage in human gastric mucosal epithelial cells. The mechanisms of action of JWLPY were further investigated through transcriptomic analysis, network pharmacology, and bioinformatics approaches.

RESULTS

JWLPY inhibited the aggregation of inflammatory cells and preserved the integrity of the mucosal barrier, while reducing autophagy and apoptosis in gastric mucosal epithelial cells. Network pharmacology and transcriptomic analyses revealed that JWLPY promotes the assembly and synthesis of MUC5AC in the endoplasmic reticulum by activating the IRE1 XBP1 signaling pathway. This activation enhances protein folding and assembly processes within the endoplasmic reticulum, thereby inhibiting H. pylori colonization in the gastric mucosa.

CONCLUSION

This study is the first to demonstrate that JWLPY inhibits H. pylori colonization in the gastric mucosa, alleviates gastric inflammation and tissue damage, and holds potential as a therapeutic agent for the treatment of H. pylori related gastritis.

Glycyrrhiza uralensis Fisch. Attenuates Dioscorea bulbifera L.-induced liver injury by regulating the FXR/Nrf2-BAs-related proteins and intestinal microbiota

ETHNOPHARMACOLOGICAL RELEVANCE

Dioscorea bulbifera L. (DBL) was a traditional Chinese medicine commonly used to treat goitre and cancer. Nevertheless, its clinical application may lead to liver injury. Glycyrrhiza uralensis Fisch. (GRR) was primarily utilized in traditional Chinese medicine for its ability to harmonize various medicines and mitigate the toxic effects of poisonous herbs. However, the role of GRR in mitigating the liver toxicity of DBL has not been established after combination.

AIM OF THE STUDY

This study aimed to clarify the protective effect of GRR against DBL-induced liver injury in mice and investigate its mechanisms of action.

MATERIALS AND METHODS

75% ethanol was employed to extract DBL and GRR. The extracted components were characterized using LC-MS. Mice were orally gavaged with extracts from each group for 30 days. After the experiment, the pathological changes in the liver of mice were evaluated. Additionally, biochemical markers associated with liver injury were assessed. The primary mechanisms through which GRR mitigates DBL-induced liver injury and the modulation of the liver-intestinal axis by GRR were explored utilizing untargeted metabolomics, targeted BAs metabolomics and 16S rDNA analyses. Furthermore, Western blot and qPCR assessed the protein and mRNA transcription of the farnesoid X receptor (FXR) and nuclear factor-erythroid 2-related factor 2 (Nrf2) as well as BA-related transporters.

RESULTS

GRR dose-dependently attenuated DBL-induced liver injury in mice. It mitigated hepatic pathological changes and alleviated hepatic inflammation and oxidative stress. GRR improved metabolic disorders induced by DBL in mice at the metabolite level, focusing on the ABC transporter. Moreover, GRR may be attributed to its activation of FXR/Nrf2 expression, reduction of cholesterol 7-alpha hydroxylase (CYP7A1) expression, promotion of bile salt export pump (BSEP), multi-drug resistance protein 2 (MRP2), P-glycoprotein (P-gp) and sodium taurocholate cotransport polypeptide (NTCP) expression, reduction of bile acid (BA) synthesis, promotion of BA efflux and reabsorption, and improvement of BA metabolic disorders. In addition, GRR ameliorated DBL-induced intestinal barrier injury and improved the structural organization of the intestinal flora, restoring the overall composition of the intestinal microbiota.

CONCLUSION

GRR exhibited significant alleviation of DBL-induced liver injury, potentially by modulating FXR/Nrf2-BA-related proteins, reducing hepatic BA accumulation, mitigating liver inflammation and oxidative stress, and regulating intestinal flora.

An insight into the therapeutic effects of isoliquiritigenin in breast cancer

Breast cancer ranks as the most widespread malignant condition in women, emerging as a primary contributor to mortality. The primary challenges in cancer treatments involve undesirable side effects. Therefore, exploring natural compounds as additional therapy could provide valuable insights. Isoliquiritigenin (ILN), an isoflavonoid featuring a chalcone moiety primarily sourced from Glycyrrhiza species, has garnered increasing interest in breast cancer research. This review aims to provide a comprehensive understanding of ILN's mechanisms of action in breast cancer, drawing from a range of in vitro and in vivo studies. ILN primarily acts by inhibiting angiogenesis, aromatase, inflammation, and cell proliferation, and preventing invasion and metastasis. Mechanistically, it downregulates miR-374a, phosphoinositide-3-kinase-protein kinase B/Akt, maternal embryonic leucine zipper kinase, vascular endothelial growth factor, and estrogen receptor protein levels, and causes enhancement of Wnt inhibitory factor-1, and Unc-51-like kinase 1 expression to treat breast cancer. ILN emerges as a promising natural option, offering therapeutic advantages with minimal side effects. However, it is important to note that current research on ILN is primarily limited to preclinical models, underscoring the need for further investigation to validate its potential efficacy.

The molecular mechanisms and potential drug targets of ferroptosis in myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury (MIRI), caused by the initial interruption and subsequent restoration of coronary artery blood, results in further damage to cardiac function, affecting the prognosis of patients with acute myocardial infarction. Ferroptosis is an iron-dependent, superoxide-driven, non-apoptotic form of regulated cell death that is involved in the pathogenesis of MIRI. Ferroptosis is characterized by the accumulation of lipid peroxides (LOOH) and redox disequilibrium. Free iron ions can induce lipid oxidative stress as a substrate of the Fenton reaction and lipoxygenase (LOX) and participate in the inactivation of a variety of lipid antioxidants including CoQ10 and GPX4, destroying the redox balance and causing cell death. The metabolism of amino acid, iron, and lipids, including associated pathways, is considered as a specific hallmark of ferroptosis. This review systematically summarizes the latest research progress on the mechanisms of ferroptosis and discusses and analyzes the therapeutic approaches targeting ferroptosis to alleviate MIRI.

Isoliquiritigenin, a potential therapeutic agent for treatment of inflammation-associated diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Licorice is a medicinal herb with a 2000-year history of applications in traditional Chinese medicine. Isoliquiritigenin (ISL) is a bioactive chalcone compound isolated from licorice. It has attracted increasing attention in recent years due to its excellent anti-inflammatory activity.

AIM OF THE STUDY

This study is to provide a comprehensive summary of the anti-inflammatory activity of ISL and the underlying molecular mechanisms, and discuss new insights for its potential clinical applications as an anti-inflammation agent.

MATERIALS AND METHODS

We examined literatures published in the past twenty years from PubMed, Research Gate, Web of Science, Google Scholar, and SciFinder, with single or combined key words of "isoliquiritigenin", "inflammation", and "anti-inflammatory".

RESULTS

ISL elicits its anti-inflammatory activity by mediating various cellular processes. It inhibits the upstream of the nuclear factor kappa B (NF-κB) pathway and activates the nuclear factor erythroid related factor 2 (Nrf2) pathway. In addition, it suppresses the NOD-like receptor protein 3 (NLRP3) pathway and restrains the mitogen-activated protein kinase (MAPK) pathway.

CONCLUSIONS

Current studies indicate a great therapeutical potential of ISL as a drug candidate for treatment of inflammation-associated diseases. However, the pharmacokinetics, biosafety, and bioavailability of ISL remain to be further investigated.

Isoliquiritigenin inhibits apoptosis and ameliorates oxidative stress in rheumatoid arthritis chondrocytes through the Nrf2/HO-1-mediated pathway

Rheumatoid arthritis (RA) is a chronic inflammatory condition known for its irreversible destructive impact on the joints. Chondrocytes play a pivotal role in the production and maintenance of the cartilage matrix. However, the presence of inflammatory cytokines can hinder chondrocyte proliferation and promote apoptosis. Isoliquiritigenin (ISL), a flavonoid, potentially exerts protective effects against various inflammatory diseases. However, its specific role in regulating the nuclear factor E2-associated factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway in chondrocytes in RA remains unclear. To investigate this, this study used human chondrocytes and Sprague-Dawley rats to construct in vitro and in vivo RA models, respectively. The study findings reveal that cytokines markedly induced oxidative stress, the activation of matrix metalloproteinases, and apoptosis both in vitro and in vivo. Notably, ISL treatment significantly mitigated these effects. Moreover, Nrf2 or HO-1 inhibitors reversed the protective effects of ISL, attenuated the expression of Nrf2/HO-1 and peroxisome proliferator-activated receptor gamma-coactivator-1α, and promoted chondrocyte apoptosis. This finding indicates that ISL primarily targets the Nrf2/HO-1 pathway in RA chondrocytes. Moreover, ISL treatment led to improved behavior scores, reduced paw thickness, and mitigated joint damage as well as ameliorated oxidative stress in skeletal muscles in an RA rat model. In conclusion, this study highlights the pivotal role of the Nrf2/HO-1 pathway in the protective effects of ISL and demonstrates the potential of ISL as a treatment option for RA.

Glycyrrhetinic acid ameliorates diosbulbin B-induced hepatotoxicity in mice by modulating metabolic activation of diosbulbin B

Exposure to diosbulbin B (DBB), the primary component of the herbal medicine Dioscorea bulbifera L. (DB), can cause liver injury in humans and experimental animals. A previous study found DBB-induced hepatotoxicity was initiated by CYP3A4-mediated metabolic activation and subsequent formation of adducts with cellular proteins. The herbal medicine licorice (Glycyrrhiza glabra L.) is frequently combined with DB used in numerous Chinese medicinal formulas in an effort to protect against DB-elicited hepatotoxicity. Importantly, glycyrrhetinic acid (GA), the major bioactive ingredient in licorice, inhibits CYP3A4 activity. The study aimed to investigate the protection of GA against DBB-induced hepatotoxicity and the underlying mechanism. Biochemical and histopathological analysis showed GA alleviated DBB-induced liver injury in a dose-dependent manner. In vitro metabolism assay with mouse liver microsomes (MLMs) indicated that GA decreased the generation of metabolic activation-derived pyrrole-glutathione (GSH) conjugates from DBB. Toxicokinetic studies demonstrated that GA increased maximal serum concentration (Cmax ) and area under the serum-time curve (AUC) of DBB in mice. In addition, GA attenuated hepatic GSH depletion caused by DBB. Further mechanistic studies showed that GA reduced the production of DBB-derived pyrroline-protein adducts in a dose-dependent manner. In conclusion, our findings demonstrated that GA exerted protective effect against DBB-induced hepatotoxicity, mainly correlated with suppressing the metabolic activation of DBB. Therefore, the development of a standardized combination of DBB with GA may protect patients from DBB-induced hepatotoxicity.

Evidence-based capacity of natural cytochrome enzyme inhibitors to increase the effectivity of antineoplastic drugs

Cytochrome (CYP) enzymes catalyze the metabolism of numerous exogenous and endogenous substrates in cancer therapy leading to significant drug interactions due to their metabolizing effect. CYP enzymes play an important role in the metabolism of essential anticancer medications. They are shown to be overexpressed in tumor cells at numerous locations in the body. This overexpression could be a result of lifestyle factors, presence of hereditary variants of CYP (Bio individuality) and multi-drug resistance. This finding has sparked an interest in using CYP inhibitors to lower their metabolizing activity as a result facilitating anti-cancer medications to have a therapeutic impact. As a result of the cytotoxic nature of synthetic enzyme inhibitors and the increased prevalence of herbal medication, natural CYP inhibitors have been identified as an excellent way to inhibit overexpression sighting their tendency to show less cytotoxicity, lesser adverse drug reactions and enhanced bioavailability. Nonetheless, their effect of lowering the hindrance caused in chemotherapy due to CYP enzymes remains unexploited to its fullest. It has been observed that there is a substantial decrease in first pass metabolism and increase in intestinal absorption of chemotherapeutic drugs like paclitaxel when administered along with flavonoids which help suppress certain specific cytochrome enzymes which play a role in paclitaxel metabolism. This review elaborates on the role and scope of phytochemicals in primary, secondary and tertiary care and how targeted prevention of cancer could be a breakthrough in the field of chemotherapy and oncology. This opens up a whole new area of research for delivery of these natural inhibitors along with anticancer drugs with the help of liposomes, micelles, nanoparticles, the usage of liquid biopsy analysis, artificial intelligence in medicine, risk assessment tools, multi-omics and multi-parametric analysis. Further, the site of action, mechanisms, metabolites involved, experimental models, doses and observations of two natural compounds, quercetin & thymoquinone, and two plant extracts, liquorice & garlic on CYP enzymes have been summarized.

The mechanisms of aluminum-induced immunotoxicity in chicks

Aluminum (Al) is a ubiquitous environmental pollutant representing a significant global health hazard to human and animal health, including chicks. Al toxicity causes oxidative stress, leading to tissue injury, and consequently causes various diseases. NRF2 signaling is vital for protecting cells against oxidative stress. Nuclear xenobiotic receptors are activated by exogenous toxins, thereby inducing the transcription of cytochrome P450 enzyme systems (CYP450s) isoforms involved in xenobiotic metabolism and transport. However, little is known about Al-induced oxidative stress, nuclear xenobiotic receptors and fibrosis in chicks and the mechanisms involved. In this study, male chicks were treated with 0 mg/kg and 500 mg/kg Al₂(SO₄)₃ to evaluate the mechanisms for Al-induced immunotoxicity. Histopathology revealed pathological injury, fibrin aggregation, disruption of the Nuclear Xenobiotic Receptors, and alteration of CYP450s homeostasis in Al-treated chicks due to oxidative stress. Notably, regulation of the NRF2 pathway and CYP450s and fibrosis-related genes was found to play a vital role in inhibiting immunotoxicity. This study provides new insights regarding the mechanisms of Al-induced immunotoxicity, including activation of the nuclear xenobiotic receptors, triggering oxidative stress, and altering the homeostasis of CYP450s in chicks. Further, it provides a theoretical basis for controlling Al exposure and highlights the importance of further studying its mechanisms to provide additional information for formulating preventive measures.

Application of ARE-reporter systems in drug discovery and safety assessment

The human body is continuously exposed to xenobiotics and internal or external oxidants. The health risk assessment of exogenous chemicals remains a complex and challenging issue. Alternative toxicological test methods have become an essential strategy for health risk assessment. As a core regulator of constitutive and inducible expression of antioxidant response element (ARE)-dependent genes, nuclear factor erythroid 2-related factor 2 (Nrf2) plays a critical role in maintaining cellular redox homeostasis. Consistent with the properties of Nrf2-mediated antioxidant response, Nrf2-ARE activity is a direct indicator of oxidative stress and thus has been used to identify and characterize oxidative stressors and redox modulators. To screen and distinguish chemicals or environmental insults that affect the cellular antioxidant activity and/or induce oxidative stress, various in vitro cell models expressing distinct ARE reporters with high-throughput and high-content properties have been developed. These ARE-reporter systems are currently widely applied in drug discovery and safety assessment. In the present review, we provide an overview of the basic structures and applications of various ARE-reporter systems employed for discovering Nrf2-ARE modulators and characterizing oxidative stressors.

Deciphering the chemical constituents of Shengjiang Xiexin decoction by ultra-high-performance liquid chromatography-quadrupole/orbitrap high-resolution mass spectrometry and the impact of 20 characteristic components on multidrug resistance-associated protein 2 in the vesicular transport assay

Shengjiang Xiexin decoction, a traditional Chinese medical formula, has been utilized to alleviate the delayed-onset diarrhea induced by irinotecan. However, the chemical constituents of this formula and the activities of its constituents remain unclear. In this study, an ultra-high-performance liquid chromatography-quadrupole/orbitrap high-resolution mass spectrometry was employed to comprehensively analyze the chemical constituents of Shengjiang Xiexin decoction. A total of 270 components including flavonoids, coumarins, triterpenoids, alkaloids, diarylheptanoids and others were identified or characterized. The multidrug resistance-associated protein 2 is an efflux transporter responsible for regulating drug absorption. A total of 20 characteristic components from the formula were selected to evaluate their effects on the function of multidrug resistance-associated protein 2 using the vesicular transport assay. Glycyrrhizic acid and glycyrrhetinic acid were identified as potential multidrug resistance-associated protein 2 inhibitors, while 9 flavonoid aglycones increased the uptake of the substrate [³ H]-estradiol 17-β-glucuronide in the vesicles. This was the first systematical investigation on the chemical constituents from Shengjiang Xiexin decoction and the effect of its characteristic components on the transporter. The results offered a basis for further exploring the detoxification mechanisms of this formula and its interactions with other drugs. This article is protected by copyright. All rights reserved.

A pH/Time/Pectinase-Dependent Oral Colon-Targeted System Containing Isoliquiritigenin: Pharmacokinetics and Colon Targeting Evaluation in Mice

BACKGROUND AND OBJECTIVES

Oral colon-targeted gel beads containing isoliquiritigenin (ISL) were successfully designed in our study. In order to further explore the targeting of the colon by the gel beads, a systematic study of their in vivo pharmacokinetics and colon targeting was performed in mice.

METHODS

Eighteen male mice were included in this study. The mice were separated into six groups at random. We collected blood, stomach, duodenum, jejunum, ileum, and colon tissues at 2, 4, 6, 8, 12, and 24 h after oral administration of gel beads containing isoliquiritigenin at a dose of 20 mg/kg. Gel beads in tissues were recorded and taken out to observe their swelling and erosion. The total ISL concentrations in different tissues and gel beads were analyzed by high-performance liquid chromatography.

RESULTS

All gel beads reached the upper part of the stomach at 2 h with no obvious swelling. Most of the gel beads were still in the lower part of stomach, while a small amount had reached the small intestine at 4 h. A few gel beads reached the colon and swelled at 6 h. Furthermore, the gel beads in the colon were swollen and erosive at 8 h. Meanwhile, the plasma ISL concentration could be detected, which indicated that the ISL in the gel beads was absorbed. At 12 h, the gel beads were almost dissolved and the plasma concentration was 8.33 times that at 8 h. At 24 h, the gel beads had completely disappeared, and the plasma concentration was 2.55 times that at 12 h.

CONCLUSION

The gel beads containing ISL are a sustained, controlled, and colon-targeting delivery system that can alter the ISL distribution in the gastrointestinal tract.

Recent Advances in Glycyrrhiza glabra (Licorice)-Containing Herbs Alleviating Radiotherapy- and Chemotherapy-Induced Adverse Reactions in Cancer Treatment

Cancers represent a significant cause of morbidity and mortality worldwide. They also impose a large economic burden on patients, their families, and health insurance systems. Notably, cancers and the adverse reactions to their therapeutic options, chemotherapy and radiotherapy, dramatically affect the quality of life of afflicted patients. Therefore, developing approaches to manage chemotherapy- and radiotherapy-induced adverse reactions gained greater attention in recent years. Glycyrrhiza glabra (licorice), a perennial plant that is one of the most frequently used herbs in traditional Chinese medicine, has been heavily investigated in relation to cancer therapy. Licorice/licorice-related regimes, used in combination with chemotherapy, may improve the adverse effects of chemotherapy. However, there is little awareness of licorice-containing herbs alleviating reactions to radiotherapy and chemotherapy, or to other induced adverse reactions in cancer treatment. We aimed to provide a descriptive review, and to emphasize the possibility that licorice-related medicines could be used as an adjuvant regimen with chemotherapy to improve quality of life (QoL) and to reduce side effects, thus, improving compliance with chemotherapy. The experimental method involved searching different databases, including PubMed, the Cochrane Library, and Wang Fang database, as of May 2022, to identify any relevant studies. Despite a lack of high-quality and large-scale randomized controlled trials, we still discovered the potential benefits of licorice-containing herbs from published clinical studies. These studies find that licorice-containing herbs, and their active ingredients, reduce the adverse reactions caused by chemotherapy and radiotherapy, and improve the QoL of patients. This comprehensive review will serve as a cornerstone to encourage more scientists to evaluate and develop effective Traditional Chinese medicine prescriptions to improve the side effects of chemotherapy and radiation therapy.

Dietary phenolic-type Nrf2-activators: implications in the control of toxin-induced hepatic disorders

Numerous studies have exemplified the importance of nuclear factor erythroid 2-related factor 2 (Nrf2) activation in the alleviation of toxin-induced hepatic disorders primarily through eliminating oxidative stress. Whereafter, increasingly more efforts have been contributed to finding Nrf2-activators, especially from dietary polyphenols. The present review summarized the phenolic-type Nrf2-activators published in the past few decades, analyzed their effectiveness based on their structural characteristics and outlined their related mechanisms. It turns out that flavonoids are the largest group of phenolic-type Nrf2-activators, followed by nonflavonoids and phenolic acids. When counting on subgroups, the top three types are flavonols, flavones, and hydroxycinnamic acids, with curcuminoids having the highest effective doses. Moreover, most polyphenols work through the phosphorylation of Nrf2. Besides, mitogen-activated protein kinases (MAPKs) and protein kinase B (Akt) are the frequent targets of these Nrf2-activators, which indirectly mediate the behavior of Nrf2. However, current data are not sufficient to conclude any structure-activity relationship.

Isolation, Characterization, Pharmacology and Biopolymer Applications of Licorice Polysaccharides: Review

Licorice is known as "Gan-Cao" in traditional Chinese Medicine (TCM), belonging to the genus Glycyrrhiza (Family: Fabaceae/Leguminosae). It has a long medicinal history and wide applications in China. Polysaccharides of licorice (LPs) are one of the key bioactive components. As herbal polysaccharides attracted increasing interest in the past several decades, their extraction, isolation, structural characterization, pharmacological activities, and medicinal application have been explored extensively. It is worth heeding that the method of extraction and purification effects LPs, apart from specie and origin specificity. This review evaluates the method of extraction and purification and demonstrates its performance in gaining specific composition and its structure-activity relationship, which might lead the readers to a fresh horizon for developing advanced treatment strategies. It is recently reported that the conformation of LPs plays a vital role as biopolymers, such as selenized modification, microencapsulation, nanocomposite, liposome formulation, drug/hydrogel combinations, biosensor device, and synergistic effect with a vaccine. In addition, LPs showed a good thermodynamics profile, as these properties enable them to interact with additional supramolecular interaction by chemical modifications or copolymerization. Functional polymers that are responsive to various external stimuli, such as physical, chemical, and biological signals, are a promising study topic. Thus, LPs are emerging as a new biomaterial that can enhance intended formulation along exerting its inherent medicinal effects. It is hoped that this review will provide a basis for the utilization and further developments of licorice polysaccharides in the vast medium.

Population Evolution, Genetic Diversity and Structure of the Medicinal Legume, Glycyrrhiza uralensis and the Effects of Geographical Distribution on Leaves Nutrient Elements and Photosynthesis

Glycyrrhiza uralensis is a valuable medicinal legume, which occurs widely in arid and semi-arid regions. G. uralensis demand has risen steeply due to its high medical and commercial value. Interpret genome-wide information can stimulate the G. uralensis development as far as its increased bioactive compound levels, and plant yield are concerned. In this study, leaf nutrient concentration and photosynthetic chlorophyll index of G. uralensis were evaluated to determine the G. uralensis growth physiology in three habitats. We observed that G. uralensis nutrient levels and photosynthesis differed significantly in three regions (p < 0.05). Whole-genome re-sequencing of the sixty G. uralensis populations samples from different habitats was performed using an Illumina HiSeq sequencing platform to elucidate the distribution patterns, population evolution, and genetic diversity of G. uralensis. 150.06 Gb high-quality clean data was obtained after strict filtering. The 895237686 reads were mapped against the reference genome, with an average 89.7% mapping rate and 87.02% average sample coverage rate. A total of 6985987 SNPs were identified, and 117970 high-quality SNPs were obtained after filtering, which were subjected to subsequent analysis. Principal component analysis (PCA) based on interindividual SNPs and phylogenetic analysis based on interindividual SNPs showed that the G. uralensis samples could be categorized into central, southern, and eastern populations, which reflected strong genetic differentiation due to long periods of geographic isolation. In this study, a total of 131 candidate regions were screened, and 145 candidate genes (such as Glyur001802s00036258, Glyur003702s00044485, Glyur001802s00036257, Glyur007364s00047495, Glyur000028s00003476, and Glyur000398s00034457) were identified by selective clearance analysis based on Fst and θπ values. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed significant enrichment of 110 GO terms including carbohydrate metabolic process, carbohydrate biosynthetic process, carbohydrate derivative biosynthetic process, and glucose catabolic process (p < 0.05). Alpha-linolenic acid metabolism, biosynthesis of unsaturated fatty acids, and fatty acid degradation pathways were significantly enriched (p < 0.05). This study provides information on the genetic diversity, genetic structure, and population adaptability of the medicinal legumes, G. uralensis. The data obtained in this study provide valuable information for plant development and future optimization of breeding programs for functional genes.

Isoliquiritigenin, a potent human monoamine oxidase inhibitor, modulates dopamine D1, D3, and vasopressin V1A receptors

Isoliquiritigenin (= 4,2′,4′-Trihydroxychalcone) (ILG) is a major constituent of the Glycyrrhizae Rhizoma that has significant neuroprotective functions. In the present study, we re-examined the potential of ILG to inhibit human monoamine oxidase (hMAO) in vitro and established its mechanism of inhibition through a kinetics study and molecular docking examination. ILG showed competitive inhibition of hMAO-A and mixed inhibition of hMAO-B with IC₅₀ values of 0.68 and 0.33 µM, respectively, which varied slightly from the reported IC₅₀ values. Since ILG has been reported to reduce dopaminergic neurodegeneration and psychostimulant-induced toxicity (both of which are related to dopamine and vasopressin receptors), we investigated the binding affinity and modulatory functions of ILG on dopamine and vasopressin receptors. ILG was explored as an antagonist of the D₁ receptor and an agonist of the D₃ and V_1A receptors with good potency. An in silico docking investigation revealed that ILG can interact with active site residues at target receptors with low binding energies. These activities of ILG on hMAO and brain receptors suggest the potential role of the compound to ameliorate dopaminergic deficits, depression, anxiety, and associated symptoms in Parkinson’s disease and other neuronal disorders.

Hepatotoxicity Comparison of Crude and Licorice-Processed Euodiae Fructus in Rats With Stomach Excess-Cold Syndrome

In recent years, drug-induced liver injury (DILI) has become an important issue of public health. Euodiae Fructus (EF) is a commonly used herb with mild toxicity in clinic, and large doses of EF can cause significant liver damage. Licorice processing might reduce the hepatotoxicity of CEF (crude EF), but up to now, studies on the hepatotoxicity of EF have been hardly reported, let alone its material basis and mechanism of detoxification by licorice processing. This work firstly established a stomach excess-cold syndrome animal model induced by intragastric administration of cold Zhimu (Anemarrhena asphodeloides Bge). Secondly, multiple approaches and indexes were used to evaluate the hepatotoxicity of the drugs in the rats including general behavior, biochemical analysis, protein expressions, and histopathological examination. Thirdly, the hepatotoxicity of three doses of three CEF and LPEF (licorice-processed EF) extracts was systematically investigated, and the hepatotoxicity differences were analyzed and compared comprehensively among the three extracts, three doses, and CEF and LPEF. Finally, the connotation of detoxification of EF by licorice processing was preliminarily discussed according to the changes in toxic components after processing, toxicological characteristics, and TCM (traditional Chinese medicine) theory. All extracts of EF were found to have dose-dependent hepatotoxicity, and the toxicity was in the descending order of water extract, ethanol extract, and volatile oil. The hepatotoxic mechanism of EF may be related to peroxidation damage, inflammatory factor, and mitochondrial injury. The CEF hepatotoxicity can be significantly reduced by licorice processing. EF should be safe for short-term use at pharmacopeial dose under the guidance of the TCM theory. The detoxification mechanism is probably related to the reduction of toxic components and antagonistic action of licorice.

Application of Linear Gradient Solvent System in Centrifugal Partition Chromatography Facilitating Bioassay-Guided Fractionation of Yongdamsagan-Tang, Traditional Oriental Decoction

As important pharmaceutical resources, traditional herbal medicines retain continuous attention. To do that, isolation and identification of bioactive molecules from traditional herbal decoction are important. However, conventional fractionation through octadecyl silica column faces irreversible sample adsorption that causes a bias in bioactivity assessment. However, liquid-liquid chromatographic system suffers tedious K value calculation as well as insufficient capacity in separation power when crude extract composed of widely ranging polarities. Here, we developed a comprehensive linear gradient solvent system for centrifugal partition chromatography (CPC) to aid bioassay-guided isolation. The lower aqueous phase of the n-hexane-acetonitrile-water (10:2:8, v/v) was used as the stationary, whereas its upper organic phase followed by the upper phase of ethyl acetate-acetonitrile-water and water-saturated n-butanol-acetonitrile-water in the same ratio were eluted in a linear gradient mode, thereby increasing polarity in the mobile phase. The HPLC profiling of CPC fraction showed that proposed gradient CPC was suitable to separate metabolites from Yongdamsagan-Tang, a traditional medicinal decoction made of ten herbal plants. Exhibiting a high recovery yield of 98.3%, antioxidant response element (ARE) luciferase-inducing assay in HepG2 cells indicated that the fractions composed of baicalein and wogonin, the marker natural products of Scutellaria baicalensis, were to be the most effective molecules from Yongdamsagan-Tang. The presented results demonstrated that bioassay-guided separation that assisted with a linear gradient CPC is an incomparable alternative to HPLC and biphasic CPC in terms of higher yield rate and redundant K value calculation, respectively, which led to an unbiased/time-saving separation and identification of bioactive molecules from the complex crude extract of natural products.

The genus Glycyrrhiza (Fabaceae family) and its active constituents as protective agents against natural or chemical toxicities

Licorice is the dried roots and rhizomes of various species of the genus Glycyrrhiza (Fabaceae) that have been used in folk medicine from ancient times. Many important research projects have established several beneficial effects for this medicinal herb, including antiinflammatory, antimicrobial, antiviral, antiprotozoal, antioxidant, antihyperglycemic, antihyperlipidemic, hepatoprotective, and neuroprotective. Licorice contains important bioactive components, such as glycyrrhizin (glycyrrhizic, glycyrrhizinic acid), liquiritigenin, liquiritin, and glycyrrhetinic acid. The protective effects of licorice and its main chemical components against toxins and toxicants in several organs including the brain, heart, liver, kidney, and lung have been shown. In this comprehensive review article, the protective effects of these constituents against natural, industrial, environmental, and chemical toxicities with attention on the cellular and molecular mechanism are introduced. Also, it has been revealed that this plant and its main compounds can inhibit the toxicity of different toxins by the antioxidant, antiinflammatory, and anti-apoptotic properties as well as the modulation of Inhibitor of kappaB kinase (IKK), Extracellular signal-regulated protein kinase1/2 (ERK1/2), p38, inducible nitric oxide synthase, and nuclear factor-κB (NF-κB) signaling pathways. More high-quality investigations in both experimental and clinical studies need to firmly establish the efficacy of licorice and its main constituents against toxic agents.

The fate of flavonoids after oral administration: a comprehensive overview of its bioavailability

Despite advancements in synthetic chemistry, nature remains the primary source of drug discovery, and this never-ending task of finding novel and active drug molecules will continue. Flavonoids have been shown to possess highly significant therapeutic activities such as anti-inflammatory, anti-oxidant, anti-viral, anti-diabetic, anti-cancer, anti-aging, neuroprotective, and cardioprotective, etc., However, it has been found that orally administered flavonoids have a critical absorption disorder and, therefore, have low bioavailability and show fluctuating pharmacokinetic and pharmacodynamic responses. A detailed investigation is required to assess and analyze the variation in the bioavailability of flavonoids due to interactions with the intestinal barrier. This review will emphasize on the bioavailability and the pharmacological applications of flavonoids, key factors affecting their bioavailability, and strategies for enhancing bioavailability, which may lead to deeper understanding of the extent of flavonoids as a treatment and/or prevention for different diseases in clinics.

Active ingredients targeting Nrf2 in the Mongolian medicine Qiwei Putao powder: Systematic pharmacological prediction and validation for chronic obstructive pulmonary disease treatment

ETHNOPHARMACOLOGY RELEVANCE

Qiwei Putao powder (Uzhumu-7 in Mongolian) is a traditional Mongolian medicine, which has been widely used for alleviating cough and dyspnea, especially in aged individuals in both Inner Mongolia Autonomous Region and Xinjiang Uygur Autonomous Region of China. However, the active ingredients and exact pharmacological mechanism remain unclear.

MATERIALS AND METHODS

The protective effect of Qiwei Putao powder (QPP) on mice with cigarette smoke (CS)- and lipopolysaccharide (LPS)-induced chronic obstructive pulmonary disease (COPD) was assessed by histopathological hematoxylin and eosin staining, lung coefficient determination and measurement of cytokine levels. The bioactive ingredients and potential targets of the QPP were screened and detected with network pharmacology method and ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS). The mechanism and efficacy of active ingredients were further validated in COPD mice with immunohistochemistry tests, cytokine level measurement and RT-PCR. The expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) in the nucleus, interleukin (IL)-1β, superoxide dismutase (SOD), malondialdehyde (MDA) and tumor necrosis factor-alpha (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA) kits to evaluate oxidative stress and inflammatory conditions in vivo after treatment. The expression of Nrf2 and downstream genes was detected by RT-PCR.

RESULTS

QPP can alleviate pathological changes in the lung during COPD progression. Sixty-one bioactive molecules were identified in QPP, 42 candidate compounds present in UPLC-Q/TOF-MS and 30 predicted COPD-related targets were generated by in silico analysis. A therapeutic network was constructed with all potential targets to predict the preventive effects of the targets on respiratory disease as well as cardiovascular diseases, nervous system diseases, musculoskeletal diseases and bacterial infections. Targets related to inflammation, immunity and oxidative stress (prostaglandin-endoperoxide synthase 2, PTGS2; Nrf2; heat shock protein 90 alpha class A1, HSP90AA1; nitric oxide synthase, NOS2A; etc.) influenced COPD progression the most. We found that Nrf2 promotes a cell antioxidant response and is a key common target in the response to treatment with isoliquiritigenin (ISL), pterostilbene (PTE) and quercetin (QUE), the highly absorbed active ingredients in the formula. The data showed a strong synergistic protective role of these three molecules against the death of human type II alveolar adenocarcinoma (A549) cells through Nrf2 activation following H₂O₂ exposure and provide pharmacological mechanism of QPP in COPD treatment.

Cardiac efficacy and toxicity of aconitine: A new frontier for the ancient poison

Aconitine (AC) is well-known as the main toxic ingredient and active compound of Aconitum species, of which several aconites are essential herbal medicines of Traditional Chinese Medicine (TCM) and widely applied to treat diverse diseases for their excellent anti-inflammatory, analgesic, and cardiotonic effects. However, the cardiotoxicity and neurotoxicity of AC attracted a lot of attention and made it a favorite botanic poison in history. Nowadays, the narrow therapeutic window of AC limits the clinical application of AC-containing herbal medicines; overdosing on AC always induces ventricular tachyarrhythmia and heart arrest, both of which are potentially lethal. But the underlying cardiotoxic mechanisms remained chaos. Recently, beyond its cardiotoxic effects, emerging evidence shows that low doses of AC or its metabolites could generate cardioprotective effects and are necessary to aconite's clinical efficacy. Consistent with TCM's theory that even toxic substances are powerful medicines, AC thus could not be simply identified as a toxicant or a drug. To prevent cardiotoxicity while digging the unique value of AC in cardiac pharmacology, there exists a huge urge to better know the characteristic of AC being a cardiotoxic agent or a potential heart drug. Here, this article reviews the advances of AC metabolism and focuses on the latest mechanistic findings of cardiac efficacy and toxicity of this aconite alkaloid or its metabolites. We also discuss how to prevent AC-related cardiotoxicity, as well as the issues before the development of AC-based medicines that should be solved, to provide new insight into the paradoxical nature of this ancient poison.

Tripterygium wilfordii: An inspiring resource for rheumatoid arthritis treatment

Tripterygium wilfordii Hook F (TwHF)-based therapy is among the most efficient and crucial therapeutics for the treatment of rheumatoid arthritis (RA), which indicates that TwHF is a potential source of novel anti-RA drugs. However, accumulating studies have observed that TwHF-based therapy induces multi-organ toxicity, which prevents the wide use of this herb in clinical practice, although several recent studies have attempted to reduce the toxicity of TwHF. Notably, our research group developed a "Clinical Practice Guideline for Tripterygium Glycosides/Tripterygium wilfordii Tablets in the Treatment of Rheumatoid Arthritis" (No. T/CACM 1337-2020) approved by the China Association of Chinese Medicine to standardize the clinical application of TwHF-based therapy and thus avoid adverse effects. Although great strides have been made toward the characterization of TwHF-based therapy and revealing its underlying pharmacological and toxicological mechanisms, several crucial gaps in knowledge remain as potential barriers to enhance its therapeutic effects on the premise of safety assurance. This review offers a global view of TwHF, ranging from its chemical constituents, quality control, clinical observations, and underlying pharmacological mechanisms to toxic manifestations and mechanisms. We focus on the important and emerging aspects of this field and highlight the major challenges and strategies for using novel techniques and approaches to gain new insights into unresolved questions. We hope that this review will improve the understanding of TwHF application and draw increasing interdisciplinary attention from clinicians that practice both Chinese and Western medicine, basic researchers, and computer scientists.

Herb-Drug Interaction Potential of Licorice Extract and Paclitaxel: A Pharmacokinetic Study in Rats

BACKGROUND AND OBJECTIVES

Licorice is the dried roots and rhizomes of Glycyrrhiza uralensis Fisch (Leguminosae), which is often used with paclitaxel to alleviate paclitaxel-induced pain in clinics. However, the herb-drug interaction between licorice and paclitaxel is still unknown. Our study evaluates the effects of oral licorice on the paclitaxel in rats via pharmacokinetic studies.

METHODS

A simple and rapid ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed to determine paclitaxel in rat. SD rats were randomly divided into 3 groups of 6 animals each as follows: two groups of rats that were pretreated with a daily gavage of licorice (3 g/kg) for 1 or 14 successive days; Control group that was administered distilled water. All rats were then intravenously administered with paclitaxel (3 mg/kg).

RESULTS

The results showed that 14 days pretreatment of licorice could decrease the area under the curve (AUC_0-t) (from 7483.08 ± 528.78 to 6679.12 ± 266.56 mg/L × h) (P < 0.01), and increase the total clearance (CL) (from 0.36 ± 0.02 to 0.39 ± 0.02 L/h/kg) of paclitaxel (P < 0.01). However, a single co-administration of licorice did not significantly alter the pharmacokinetic parameters of paclitaxel, such as AUC_0-t (from 7483.08 ± 528.78 to 7201.24 ± 292.76 mg/L × h) (P > 0.05) and CL (from 0.36 ± 0.02 to 0.36 ± 0.01 L/h/kg) (P > 0.05).

CONCLUSIONS

The results will contribute to better use of licorice in the adjunctive therapy and provide information to study the interaction between herbs and chemotherapy.

Licochalcone A, a licorice flavonoid: antioxidant, cytotoxic, genotoxic, and chemopreventive potential

Licochalcone A (LicoA) is a flavonoid derived from Glycyrrhiza spp. plants. The present study aimed to investigate the antioxidant, cytotoxic, genotoxic, and chemopreventive effects of LicoA in in vitro and in vivo systems. The results showed that LicoA (197.1 μM) scavenged 77.92% of free radicals. Concentrations of 147.75 µM or higher LicoA produced cytotoxicity in Chinese hamster ovary (CHO) fibroblasts. LicoA treatments of 4.43 to 10.34 µM did not exert genotoxic activity, but at 11.8 µM significantly lowered nuclear division indexes, compared to negative control, revealing cytotoxicity. Lower concentrations (1.85 to 7.39 µM) exhibited protective activity against chromosomal damage induced by doxorubicin (DXR) or methyl methanesulfonate (MMS) in CHO cells. LicoA exerted no marked influence on DXR-induced genotoxicity in mouse erythrocytes, but reduced pre-neoplastic lesions induced by 1,2-dimethylhydrazine (DMH) in rat colon at 3.12 to 50 mg/kg b.w. Biochemical markers and body weight indicated no apparent toxicity. These findings contribute to better understanding the mechanisms underlying LicoA-initiated activity as a promising chemopreventive compound.

ABBREVIATIONS

AC, aberrant crypts; ACF, aberrant crypt foci; ALT, alanine aminotransferase; AST, aspartate aminotransferase; BOD, biochemical oxygen demand; CHO, Chinese hamster ovary fibroblast; DMH, 1,2-dimethylhydrazine; DMSO, dimethyl sulfoxide; DPPH, 2,2-diphenyl-1-picrylhydrazyl; DXR, doxorubicin hydrochloride; EDTA, ethylenediaminetetraacetic acid; GA, gallic acid; LicoA, licochalcone A; MMS, methyl methanesulfonate; MNBC, micronucleated binucleated cells; MNPCE, micronucleated polychromatic erythrocyte; NCE, normochromatic erythrocyte; NDI, nuclear division index; PBS, phosphate-buffered saline; PCE, polychromatic erythrocyte; XTT, 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide.

A Study of the Ionic Liquid-Based Ultrasonic-Assisted Extraction of Isoliquiritigenin from Glycyrrhiza uralensis

We successfully extracted isoliquiritigenin from Glycyrrhiza uralensis through the utilization of an ionic liquid-based ultrasonic-assisted extraction (ILUAE) approach. Briefly, we utilized the solution of 1-butyl-3-methylimidazolium bromide ([BMIM]Br) as solvent and optimized key ILUAE parameters such as solid-liquid ratios, concentrations of ionic liquids, and the times of ultrasonication. Based on a single-factor experiment, we utilized the response surface method (RSM) approach to optimize the extraction procedure. The approach revealed that the optimal energy consumption time was 120 min, with the ultrasonic extraction temperature of 60°C. Using these optimized parameters together with the solid-liquid ratio (dried G. uralensis powder: [BMIM]Br of 0.3 mol/L) of 1 : 16.163 and the [BMIM]Br of 0.3 mol/L, we achieved a 0.665 mg/g extraction yield. Overall, these findings thus indicate that we were able to effectively use ILUAE as an efficient approach to reliably extract isoliquiritigenin in a reproducible and environmentally friendly manner.

Key metabolites associated with the onset of flowering of guar genotypes (Cyamopsis tetragonoloba (L.) Taub)

BACKGROUND

Guar (Cyamopsis tetragonoloba (L.) Taub.), a short-day plant, is an economically valuable legume crop. Seeds of guar serve as a source of galactomannan polysaccharide, known as guar gum, which is in demand in the gas and oil industries. The rapid and complete maturation of guar seeds depends on the flowering time of a particular genotype. It is known that flowering in guar is controlled by several gene systems. However, no information about the process and mechanisms that trigger flowering in guar on the molecular and biochemical levels was previously reported. The aim of the study was to investigate the metabolic landscape underlying transition to the flowering in guar using GC-MS-metabolomic analysis.

RESULTS

82 diverse guar genotypes (each in 8 replicates) from the VIR collection were grown under experimental conditions of high humidity and long photoperiod. In the stress environment some guar genotypes turned to flowering early (41 ± 1,8 days from the first true leaf appearance) while for others the serious delay of flowering (up to 95 ± 1,7 days) was observed. A total of 244 metabolites were detected by GC-MS analysis on the third true leaves stage of 82 guar genotypes. Among them some molecules were associated with the transition of the guar plants to flowering. Clear discrimination was observed in metabolomic profiles of two groups of «early flowering» and «delayed flowering» plants, with 65 metabolites having a significantly higher abundance in early flowering genotypes. Among them 7 key molecules were identified by S-plot, as potential biomarkers discriminating of «early flowering» and «delayed flowering» guar genotypes.

CONCLUSIONS

The metabolomic landscape accompanying transition to flowering in guar was firstly described. The results obtained can be used in subsequent genomic research for identifying metabolite-gene associations and revealing genes responsible for the onset of flowering and photoperiod sensitivity of guar. In addition, the detected key metabolites associated with flowering of guar can be employed as biomarkers allowing rapid screening of breeding material for the potentially early flowering genotypes.

Protective effect of isoliquiritigenin on experimental diabetic nephropathy in rats: Impact on Sirt-1/NFκB balance and NLRP3 expression

The prevalence of diabetes mellitus (DM) drastically increases worldwide. Persistent hyperglycemia affects body microvasculature causing injuries to kidney producing diabetic nephropathy (DNE). Manifestation of these microvascular complications is associated with disturbed redox homeostasis. The current study evaluated the effect of isoliquiritigenin (ISLQ), a bioactive chalcone found in licorice which is known for its antioxidant effect, on diabetes-induced renal injury. DM was prompted in male rats by streptozotocin (STZ, 50 mg/kg, intraperitoneally). ISLQ was administrated by oral gavage for 8 weeks at a dose (20 mg/kg/day). Features of renal injury were observed in kidneys of diabetic rats including, albuminuria and deteriorated renal function. Renal dysfunction was associated with reduced sirtuin-1 (Sirt-1) expression, increased renal oxidative stress, nucleotide-binding domain and leucine-rich repeat containing protein-3 (NLRP3), nuclear factor-κB (NFκB) and inflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Moreover, there was significant downregulation of anti-inflammatory cytokine interleukin-10 (IL-10), glomerular and tubular injury and collagen accumulation. ISLQ administration preserved renal function and architecture, restored Sirt1 and renal oxidant-antioxidant balance, dampened inflammation and attenuated collagen accumulation. It can be inferred that ISLQ possess a protective effect and could have a potential as a food supplement to halt development and progression of DNE.

Licochalcone L, an undescribed retrochalcone from Glycyrrhiza inflata roots

Glycyrrhiza inflata Batalin is among the three glycyrrhizin producing Glycyrrhiza species and can be distinguished from other species with regard to its retrochalcone contents. Seven retrochalcones, echinatin and licochalcones A, C, D, E, K, and L were isolated and characterized from the chloroform extract of G. inflata roots. Among the isolates, licochalcone L was found to be previously undescribed. Structure elucidation of these specialised metabolites was achieved through NMR and mass spectroscopic data analyses.

Isoliquiritigenin triggers developmental toxicity and oxidative stress-mediated apoptosis in zebrafish embryos/larvae via Nrf2-HO1/JNK-ERK/mitochondrion pathway

Isoliquiritigenin (ISL) is an emerging natural flavonoid found in the roots of licorice, exhibits antioxidant, anti-cancer, anti-inflammatory, anti-allergic, cardioprotective, hepatoprotective and neuroprotective properties. However, the effect of ISL in embryonic development is yet to be elucidated, and the mechanisms underlying its target-organ toxicity and harmful side effects are still unclear. In the present study, we employed zebrafish embryos to study the developmental toxicity effect of ISL and its underlying mechanisms. Zebrafish embryos upon treatment with either vehicle control (0.1% DMSO) or ISL solutions for 4-96 h post fertilization (hpf) showed that ISL exposure instigated severe developmental toxicity in heart, liver, and nervous system. Mortality and morphological abnormalities were also observed. High concentrations of ISL exposure resulted in abnormal phenotypes and embryonic malformations including pericardial edema, swim bladder defects, yolk retention, curved body shape and shortening of body length. Moreover, ISL exposure led to significant loss of dopaminergic neurons accompanied by reduced locomotor behaviour. Apoptotic cells were predominantly located in the heart area of 96 hpf embryo. Additionally, ISL significantly increased the levels of reactive oxygen species, lipid peroxidation content and decreased antioxidant enzyme activities. The expressions pattern of apoptosis-related genes Bad, Cyto c, Caspase-9, Caspase-3 and Bax/Bcl-2 indicated that the oxidative stress-induced apoptosis triggered by ISL suggest involvement of Nrf2-HO1/JNK-ERK/mitochondrion pathways. In conclusion, here we provide first evidence that demonstrate ISL-induced dose-dependent developmental toxicity in zebrafish embryos. Furthermore, gene expression patterns in the embryos correlate the above and reveal potential genetic mechanisms of developmental toxicity.

TCM treatment of allergy induced by stainless steel implants for tibiofibular fracture: A case report

Background: Metal allergy is frequently seen. Orthopedic metal implants, such as external fixators or other stainless implants, contain chromium, nickel, and molybdenum, which can cause type IV hypersensitivity. Case summary: A patient diagnosed with open comminuted tibiofibular fracture was treated with external fixation surgery, and she showed contact dermatitis and eczema-like symptoms 2 weeks postoperatively. She was then diagnosed as allergic to several metals by patch test and subsequently treated with traditional Chinese medicine (TCM), both orally and externally for 1 month. TCM treatment significantly alleviated the hypersensitive symptoms and made the patient bear the external fixator for 2 months until bone union. Conclusion: TCM therapy may be an effective treatment for external fixation-induced metal allergy and contact dermatitis.

Isoliquiritigenin attenuates lipopolysaccharide-induced cognitive impairment through antioxidant and anti-inflammatory activity

Background

Oxidative stress and neuroinflammation are central pathogenic mechanisms common to many neurological diseases. Isoliquiritigenin (ISL) is a flavonoid in licorice with multiple pharmacological properties, including anti-inflammatory activity, and has demonstrated protective efficacy against acute neural injury. However, potential actions against cognitive impairments have not been examined extensively. We established a rat model of cognitive impairment by intracerebroventricular injection of lipopolysaccharide (LPS), and examined the effects of ISL pretreatment on cognitive function, hippocampal injury, and hippocampal expression of various synaptic proteins, antioxidant enzymes, pro-inflammatory cytokines, and signaling factors controlling anti-oxidant and pro-inflammatory responses.

Results

Rats receiving LPS alone demonstrated spatial learning deficits in the Morris water maze test as evidenced by longer average escape latency, fewer platform crossings, and shorter average time in the target quadrant than untreated controls. ISL pretreatment reversed these deficits as well as LPS-induced decreases in the hippocampal expression levels of synaptophysin, postsynaptic density-95, brain-derived neurotrophic factor, superoxide dismutase, glutathione peroxidase, and BCL-2. ISL pretreatment also reversed LPS-induced increases in TUNEL-positive (apoptotic) cells, BAX/BCL-2 ratio, and expression levels of tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and C-C motif chemokine ligand 3. Pretreatment with ISL increased the expression levels of phosphorylated (p)-GSK-3β, nuclear NRF2, HO-1 mRNA, and NQO1 mRNA, and reversed LPS-induced nuclear translocation of nuclear factor (NF)-κB.

Conclusions

ISL protects against LPS-induced cognitive impairment and neuronal injury by promoting or maintaining antioxidant capacity and suppressing neuroinflammation, likely through phosphorylation-dependent inactivation of GSK-3β, enhanced expression of NRF2-responsive antioxidant genes, and suppression of NF-κB-responsive pro-inflammatory genes.

The Alexipharmic Mechanisms of Five Licorice Ingredients Involved in CYP450 and Nrf2 Pathways in Paraquat-Induced Mice Acute Lung Injury

Oxidative stress is an important mechanism in acute lung injury (ALI) induced by paraquat (PQ), one of the most widely used herbicides in developing countries. In clinical prophylaxis and treatment, licorice is a widely used herbal medicine in China due to its strong alexipharmic characteristics. However, the corresponding biochemical mechanism of antioxidation and detoxification enzymes induced by licorice's ingredients is still not fully demonstrated. In this study, the detoxification effect of licorice was evaluated in vivo and in vitro. The detoxification and antioxidation effect of its active ingredients involved in the treatment was screened systematically according to Absorption, Distribution, Metabolism, and Excretion (ADME): predictions and evidence-based literature mining methods in silico approach. Data shows that licorice alleviate pulmonary edema and fibrosis, decrease Malondialdehyde (MDA) contents and increase Superoxide Dismutase (SOD) activity in PQ-induced ALI mice, protect the morphologic appearance of lung tissues, induce cytochrome 3A4 (CYA3A4) and Nuclear factor erythroid 2-related factor 2 (Nrf2) expression to active detoxification pathways, reduce the accumulation of PQ in vivo, protect or improve the liver and renal function of mice, and increase the survival rate. The 104 genes of PPI network contained all targets of licorice ingredients and PQ, which displayed the two redox regulatory enzymatic group modules cytochrome P450 (CYP450) and Nrf2 via a score-related graphic theoretic clustering algorithm in silico. According to ADME properties, glycyrol, isolicoflavonol, licochalcone A, 18beta-glycyrrhetinic acid, and licoisoflavone A were employed due to their oral bioavailability (OB) ≥ 30%, drug-likeness (DL) ≥ 0.1, and being highly associated with CYP450 and Nrf2 pathways, as potential activators to halt PQ-induced cells death in vitro. Both 3A4 inhibitor and silenced Nrf2 gene decreased the alexipharmic effects of those ingredients significantly. All these disclosed the detoxification and antioxidation effects of licorice on acute lung injury induced by PQ, and glycyrol, isolicoflavonol, licochalcone A, 18beta-glycyrrhetinic acid, and licoisoflavone A upregulated CYP450 and Nrf2 pathways underlying the alexipharmic mechanisms of licorice.

Neuroprotective effects of isoliquiritigenin against cognitive impairment via suppression of synaptic dysfunction, neuronal injury, and neuroinflammation in rats with kainic acid-induced seizures

Epileptogenesis is a dynamic process initiated by insults to brain and commonly accompanied by cognitive impairment. Isoliquiritigenin (ISL), a flavonoid in licorice, has a broad spectrum of biological effects including anti-inflammatory and antioxidant activities. However, the protective effects of ISL against cognitive impairment in epileptic processes and the underlying molecular mechanism are not well understood. To address these questions, we established an reproducible seizure model by intracerebroventricular injection of kainic acid (KA) in 21-day-old rats; ISL was intraperitoneally administered three times prior to KA injection, and changes in cognitive function; synaptic plasticity; neuronal injury; number of glial cells; and expression of pro-inflammatory cytokines and nuclear factor-like (NRF)2 signaling and NACHT, LRR, and PYD domains-containing protein (NLRP)3 inflammasome components in the hippocampus were examined. Rats with KA-induced seizures showed longer average escape latency and decreases in the number of platform crossings and average time spent in the target quadrant in the Morris water maze; ISL pretreatment reversed this decline in cognitive impairment and increased the protein levels of synaptophysin, postsynaptic density-95 and brain-derived neurotrophic factor while reducing the number of Fluoro Jade B-positive cells, microglia, and astrocytes; cleaved-Caspase-3 and -9 protein levels; and tumor necrosis factor-α, interleukin (IL)-1β, and IL-18 production. It also enhanced the nuclear localization of NRF2, hemeoxygenase-1, and NAD(P)H:quinone oxidoreductase (NQO) 1, and reversed the upregulation of NLRP3 inflammasome components NLRP3 and Caspase-1 induced by KA injection. Thus, ISL protects against cognitive impairment in KA-induced epileptic processes possibly through regulation of NRF2 signaling and the NLRP3 inflammasome pathway.

Isoliquiritigenin exerts antioxidant activity in Caenorhabditis elegans via insulin-like signaling pathway and SKN-1

BACKGROUND

Glycyrrhiza uralensis is a well-known medicinal plant. Different therapeutic effects have been reported for its secondary metabolites, including neuroprotective activity. Antioxidant properties have also been documented for some of its compounds and it could be a possible mechanism of neuroprotection.

PURPOSE

The present study was conducted to investigate the antioxidant effect and underlying pathways of G. uralensis and its main compounds.

METHODS

The experiments were conducted with Caenorhabditis elegans, a simple in vivo model, widely used in this context. The methanol extract of G. uralensis and its main compounds isoliquiritigenin, liquiritigenin, glycyrrhizic acid, and glycyrrhetinic acid were tested for their effects on heat shock protein expression under mild oxidative stress and survival rate under lethal oxidative stress. To clarify the underlying pathways, the effect on the transcription factors DAF-16, SKN-1, and HSF-1 was tested.

RESULTS

Isoliquiritigenin was the most potent compound in both assays, leading to a 31% decrease in expression of the stress marker heat shock protein and an 87% increase in survival rate. It significantly activated DAF-16 and SKN-1, but not HSF-1.

CONCLUSION

The present study identified isoliquiritigenin as the most active antioxidant compound in G. uralensis. It exerts its effect by activating the transcription factors DAF-16/FOXO and SKN-1/Nrf2 which regulate many genes, including those which code for proteins of antioxidative response. This implicates isoliquiritigenin as a possible supplement drug against oxidative stress especially in neurodegenerative diseases.

Quercetin and kaempferol increase the intestinal absorption of isorhamnetin coexisting in Elaeagnus rhamnoides (L.) A. Nelson (Elaeagnaceae) extracts via regulating multidrug resistance-associated protein 2

BACKGROUND

Isorhamnetin (IS) is a flavonoid component with many biological activities such as antioxidant, anti-inflammatory, and anticancer, which is also the main active component in total flavones of Elaeagnus rhamnoides (L.) A. Nelson (Elaeagnaceae) (TFH); however, the interaction between IS and other components in TFH is unclear.

PURPOSE

The aim of the present study was to investigate the enhancement of quercetin (QU) or kaempferol (KA) on the intestinal absorption of IS coexisting in TFH, and then preliminarily illuminate the related mechanisms.

METHODS

Firstly, the intestinal absorption of IS in the presence or absence of QU or KA was conducted by in vivo pharmacokinetics model, in situ single-pass intestinal perfusion model (SPIP), and MDCK II-MRP2 monolayer cell model to confirm the enhancement of QU or KA on IS absorption. Secondly, the effects of multidrug resistance-associated protein 2 (MRP2) inhibitors on the IS intestinal absorption were investigated to ascertain the mediation of MRP2 on IS absorption. Finally, the effects of QU or KA on MRP2 activity, protein expression, and mRNA level were performed by SPIP, everted-gut sacs, western blotting, and real-time polymerase chain reaction experiments to elucidate the related mechanisms.

RESULTS

QU or KA increased IS intestinal absorption according to the increased AUC_0-96h, C_max, and P_eff of IS after co-administrated with QU or KA to rats; the oral absorption of IS was mediated by MRP2 based on the facts that the average plasma concentration, AUC_0-96h, and P_eff of IS were increased when co-administrated with PR or MK571 (MRP2 inhibitors) as well as the P_ratio(BL/AP) of IS was decreased by MK571 in MDCK II-MRP2 cell monolayer; the activity, protein expression, and mRNA level of MRP2 were inhibited or down-regulated by QU or KA because of the increased P_eff of MRP2 substrate calcein (CA) and the down-regulated relative protein and mRNA intensity after co-treated with QU or KA.

CONCLUSION

QU and KA increased the intestinal absorption of IS in TFH by regulating the activity and expression of MRP2, which provides useful information for the investigation of the transporter-mediated interaction of flavonoid components in herbal extracts.

Phytochemical and Pharmacological Role of Liquiritigenin and Isoliquiritigenin From Radix Glycyrrhizae in Human Health and Disease Models

The increasing lifespan in developed countries results in age-associated chronic diseases. Biological aging is a complex process associated with accumulated cellular damage by environmental or genetic factors with increasing age. Aging results in marked changes in brain structure and function. Age-related neurodegenerative diseases and disorders (NDDs) represent an ever-growing socioeconomic challenge and lead to an overall reduction in quality of life around the world. Alzheimer’s disease (AD) and Parkinson’s disease (PD) are most common degenerative neurological disorders of the central nervous system (CNS) in aging process. The low levels of acetylcholine and dopamine are major neuropathological feature of NDDs in addition to oxidative stress, intracellular calcium ion imbalance, mitochondrial dysfunction, ubiquitin-proteasome system impairment and endoplasmic reticulum stress. Current treatments minimally influence these diseases and are ineffective in curing the multifunctional pathological mechanisms. Synthetic neuroprotective agents sometimes have negative reactions as an adverse effect in humans. Recently, numerous ethnobotanical studies have reported that herbal medicines for the treatment or prevention of NDDs are significantly better than synthetic drug treatment. Medicinal herbs have traditionally been used around the world for centuries. Radix Glycyrrhizae (RG) is the dried roots and rhizomes of Glycyrrhiza uralensis or G. glabra or G. inflata from the Leguminosae/Fabaceae family. It has been used for centuries in traditional medicine as a life enhancer, for the treatment of coughs and influenza, and for detoxification. Diverse chemical constituents from RG have reported including flavanones, chalcones, triterpenoid saponins, coumarines, and other glycosides. Among them, flavanone liquiritigenin (LG) and its precursor and isomer chalcone isoliquiritigenin (ILG) are the main bioactive constituents of RG. In the present review, we summarize evidence in the literature on the structure and phytochemical properties and pharmacological applications of LG and ILG in age-related diseases to establish new therapeutics to improve human health and lifespan.

Formulated Chinese Medicine Shaoyao Gancao Tang Reduces Tau Aggregation and Exerts Neuroprotection through Anti-Oxidation and Anti-Inflammation

Misfolded tau proteins induce accumulation of free radicals and promote neuroinflammation by activating microglia-releasing proinflammatory cytokines, leading to neuronal cell death. Traditional Chinese herbal medicines (CHMs) have been widely used in clinical practice to treat neurodegenerative diseases associated with oxidative stress and neuroinflammation. This study examined the neuroprotection effects of formulated CHMs Bai-Shao (made of Paeonia lactiflora), Gan-Cao (made of Glycyrrhiza uralensis), and Shaoyao Gancao Tang (SG-Tang, made of P. lactiflora and G. uralensis at 1 : 1 ratio) in cell model of tauopathy. Our results showed that SG-Tang displayed a greater antioxidative and antiaggregation effect than Bai-Shao and Gan-Cao and a stronger anti-inflammatory activity than Bai-Shao but similar to Gan-Cao. In inducible 293/SH-SY5Y cells expressing proaggregant human tau repeat domain (ΔK280 tau_RD), SG-Tang reduced tau misfolding and reactive oxygen species (ROS) level in ΔK280 tau_RD 293 cells and promoted neurite outgrowth in ΔK280 tau_RD SH-SY5Y cells. Furthermore, SG-Tang displayed anti-inflammatory effects by reducing nitric oxide (NO) production in mouse BV-2 microglia and increased cell viability of ΔK280 tau_RD-expressing SH-SY5Y cells inflamed by BV-2 conditioned medium. To uncover the neuroprotective mechanisms of SG-Tang, apoptosis protein array analysis of inflamed tau expressing SH-SY5Y cells was conducted and the suppression of proapoptotic proteins was confirmed. In conclusion, SG-Tang displays neuroprotection by exerting antioxidative and anti-inflammatory activities to suppress neuronal apoptosis in human tau cell models. The study results lay the base for future applications of SG-Tang on tau animal models to validate its effect of reducing tau misfolding and potential disease modification.

Isoliquiritigenin alleviated the Ang II-induced hypertensive renal injury through suppressing inflammation cytokines and oxidative stress-induced apoptosis via Nrf2 and NF-κB pathways

PURPOSE

Hypertensive renal injury plays important role in the pathogenesis of end-stage nephropathy and the need for dialysis. Isoliquiritigenin (ISL) is a natural compound with antioxidant and anti-inflammatory activities. In this study, the protective effects of ISL on Angiotensin II (Ang II)- induced apoptosis, inflammation and extracellular matrix production in HK-2 cells were observed and its mechanisms were elucidated.

METHODS

Cell survival was determined with MTT assay. Cell cycle and apoptosis was assessed with flow cytometric analysis. The production of cytokines including IL-1β and TNF-α were evaluated with Elisa. Western blotting assay was used to determine protein levels of apoptosis related signaling, oxidative stress, NF-κB and ECM related molecules. mRNA levels of fibronectin and collagen Ⅳ were detected by RT-qPCR.

RESULTS

Ang II significantly inhibited cell survival, induced cell cycle arrest and enhanced cell apoptosis. However, the above effects were markedly alleviated by ISL treatment in a dose-dependent manner. In addition, Ang II significantly induced oxidative stress and NF-κB signaling activation, as well as inflammatory cytokines release. In contrast, these effects were remarkably reversed by ISL via regulation of Nrf2. Notably, Ang II also triggered generation of extracellular matrix, including fibronectin and collagen Ⅳ, which was abolished upon ISL treatment.

CONCLUSIONS

Taken together, ISL alleviated the Ang II-induced hypertensive renal injury through suppressing inflammation cytokines, excessive deposition of extracellular matrix and oxidative stress-induced apoptosis via Nrf2 and NF-κB pathways. Our findings provided the evidences for exploring the possible mechanism of hypertensive renal injury pathogenesis and identifying novel therapeutic targets.

Licorice root extract and magnesium isoglycyrrhizinate protect against triptolide-induced hepatotoxicity via up-regulation of the Nrf2 pathway

Triptolide, the predominant biologically active component of the Chinese herb Tripterygium wilfordii Hook f., possesses numerous pharmacological activities, including anti-inflammatory, anti-fertility, anti-neoplastic, and immunosuppressive effects. However, toxicity and severe adverse effects, particularly hepatotoxicity, limit the clinical application of triptolide. Licorice root extract contains various bioactive compounds and is potent hepatoprotective. Magnesium isoglycyrrhizinate, a magnesium salt of the 18α-glycyrrhizic acid stereoisomer of glycyrrhizic acid, is used clinically in China to treat chronic viral hepatitis and acute drug-induced liver injury. The aim of this study was to investigate the role of the factor erythroid 2-related factor 2 pathway in the protective effects of LE and MIG against triptolide-induced hepatotoxicity. Hepatotoxicity models were established in L-02 cells and rats using triptolide, and the protective effects of LE and MIG were investigated in vitro and in vivo, respectively. LE and MIG significantly protected against triptolide-induced cytotoxicity. Additionally, triptolide decreased the mRNA and protein levels of Nrf2 and down-regulated Nrf2 target genes, including UGT1A, BSEP, and MRP2, while pretreatment with LE and MIG reversed these effects. Finally, Nrf2-involved antioxidant responses were activated in the presence of LE and MIG.

Ginnalin A from Kujin tea (Acer tataricum subsp. ginnala) exhibits a colorectal cancer chemoprevention effect via activation of the Nrf2/HO-1 signaling pathway

Ginnalin A (also known as acertannin) is one of the most important phenolic compounds of several beverage Acer plants. In this study, it is reported for the first time that ginnalin A is an activator of the Nrf2 signaling pathway in human colon cancer cells. Ginnalin A, isolated from the leaves of Acer tataricum subsp. ginnala, exhibited promising preventive activity against colon cancer cells (HCT116, SW480 and SW620) with IC50 values of 24.8 μM, 22.0 μM and 39.7 μM, respectively. In addition, it significantly reduced the colony formation of these cells. Flow cytometry analysis indicated that ginnalin A suppressed cancer proliferation via the induction of cell cycle arrest at the S-phase. Real time PCR analysis demonstrated that ginnalin A can upregulate the mRNA expression levels of Nrf2-related antioxidant genes Nrf2, HO-1 and NQO1. Western blotting analysis revealed that ginnalin A promoted the Nrf2 nuclear translocation and upregulated the proteins Nrf2, HO-1 and NQO1. Moreover, the upregulation of p62 and the inhibition of Keap1 were also found by Western blotting analysis. Therefore, the activation of the Nrf2 signaling pathway was probably induced through the upregulation of p62 and the inhibition of Keap1.

Licorice ethanol extract improves symptoms of polycytic ovary syndrome in Letrozole-induced female rats

BACKGROUND

Licorice (Glycyrrhizae radix et rhizome, GRR) has long been used as an ingredient in Korean traditional medicinal herbal formulas for various metabolic and reproductive diseases. Polycystic ovary syndrome (PCOS) is a common endocrine disorder in premenopausal women. In the present study, we examined the effects of GRR extract on PCOS-like symptoms in female rats.

METHODS

Symptoms of PCOS were induced by Letrozole treatment for 4 weeks in 6-week-old female SD rats, after which the effects of GRR extract on recovery of normal hormonal levels and polycystic ovaries were assessed. Serum levels of luteinizing hormone (LH), follicular-stimulating hormone (FSH), LH/FSH ratio, and follicular cysts were evaluated, followed by the expression levels of known follicular phase markers such as Kitl, Cyp11a1, and Ptgs2.

RESULTS

The serum level of FSH was reduced only in the Lestrozole treatment group (PCOS), whereas significant recovery of FSH level was observed in the Letrozole and GRR co-treatment group (PCOS + GRR). Serum LH levels were not altered in any of the groups. Furthermore, the LH/FSH ratio (known biomarker for PCOS) was elevated only in the Letrozole treatment group (PCOS), whereas it was significantly reduced in the Letrozole and GRR co-treatment group (PCOS + GRR). For histological changes, follicular cysts, antral follicles, and increased thickness of the theca- and granulosa layers were observed in the PCOS group, whereas these alterations were remarkably reversed by GRR treatment.

CONCLUSION

These results suggest that GRR extract inhibits the symptoms of PCOS by regulating imbalanced hormonal levels and irregular ovarian follicles.

Ultra-Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS)-Based Pharmacokinetics and Tissue Distribution Study of Koumine and the Detoxification Mechanism of Glycyrrhiza uralensis Fisch on Gelsemium elegans Benth

Gelsemium elegans Benth. (G. elegans), which is a famous Chinese folk medicine, has been commonly used to treat certain types of skin ulcers and alleviate inflammation, headaches, and cancer pain. However, the extensive clinical use of G. elegans has been greatly hampered by its toxicity. As one of the most widely used herbal medicines, Glycyrrhiza uralensis Fisch, has a unique effect on detoxification of G. elegans. In the present study, a rapid and sensitive method using ultra-liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was established and validated for determination of koumine, the most abundant molecule among the alkaloids of G. elegans, in rat plasma, tissue, and liver microsome. The developed method was successfully applied to the pharmacokinetics, tissue distribution, and in vitro metabolism study in rat with or without pre-treated Glycyrrhiza uralensis Fisch extract. Meanwhile, the expression level of CYP3A1 mRNA was analyzed to explain the detoxification mechanism of Glycyrrhiza uralensis Fisch on G. elegans. As a result, our work demonstrated that Glycyrrhiza uralensis Fisch could significantly affect the pharmacokinetics and tissue distribution of koumine in rats. The detoxification mechanism of Glycyrrhiza uralensis Fisch on G. elegans may be its cytochrome enzyme up-regulation effect.

Aconitum alkaloids, the major components of Aconitum species, affect expression of multidrug resistance-associated protein 2 and breast cancer resistance protein by activating the Nrf2-mediated signalling pathway

BACKGROUND

Aconitum alkaloids from Aconitum species are often used to treat arthritis and rheumatic diseases but have the drawback of high toxicity. Identifying their pharmacokinetic behaviour is important for the safe clinical application of Aconitum species. Efflux transporters (ETs), including P-glycoprotein (P-gp), multidrug resistance-associated protein 2 (MRP2), and breast cancer resistance protein (BCRP), have important functions in regulating the pharmacokinetic behaviours of drugs and in herb-herb or herb-drug interactions (HDIs). The Aconitum alkaloids regulate P-gp expression and function, but their effects on MRP2 and BCRP expression remain unknown.

PURPOSE

To determine the effects of three Aconitum alkaloids, aconitine (AC), benzoylaconine (BAC), and aconine, on MRP2 and BCRP.

METHODS

The levels of the protein and mRNA expression of MRP2 and BCRP in vivo and in vitro were measured via Western blotting and real-time PCR, respectively. Fluorescence signals of MRP2 and BCRP were detected via confocal fluorescence microscopy. A reporter assay using HepG2-C8 cells, which were generated by transfecting plasmids containing the antioxidant response element (ARE)-luciferin gene into HepG2 cells, was used to examine the ARE-luciferin activity. The transport activities of MRP2 and BCRP were tested via flow cytometry using substrate probes.

RESULTS

The Aconitum alkaloids significantly up-regulated MRP2 and BCRP expression, accompanied by a marked increase in nuclear factor E2-related factor-2 (Nrf2) expression in the jejunum, ileum, and colon of FVB mice, in the order AC < BAC < aconine. In the in vitro model, the Aconitum alkaloids increased MRP2 and BCRP expression in Caco-2 and LS174T cells, in the order AC < BAC < aconine. Additionally, these alkaloids promoted the translocation of Nrf2 from the cytoplasm to the nucleus and significantly increased ARE-luciferin activity in HepG2-C8 cells. Luteolin, a potent inhibitor of Nrf2, markedly prevented MRP2 and BCRP expression from being induced by the three Aconitum alkaloids. The efflux activity of MRP2 was also significantly increased in cells receiving the same treatment.

CONCLUSIONS

The tested Aconitum alkaloids significantly increased the expression of MRP2 and BCRP by activating the Nrf2-mediated signalling pathway and enhanced the efflux activity of MRP2. The potential for herb-herb interactions or HDIs exists when Aconitum species are co-administered with substrate drugs that are transported via MRP2 and BCRP. Therefore, the Aconitum alkaloids may be used as quality indicators for the herbs of Aconitum species.