Phloretin alleviates doxorubicin-induced cardiotoxicity through regulating Hif3a transcription via targeting transcription factor Fos.

BACKGROUND: Doxorubicin (Dox), a chemotherapeutic agent known for its efficacy, has been associated with the development of severe cardiotoxicity, commonly referred to as doxorubicin-induced cardiotoxicity (DIC). The role and mechanism of action of phloretin (Phl) in cardiovascular diseases are well-established; however, its specific function and underlying mechanism in the context of DIC have yet to be fully elucidated. OBJECTIVE: This research aimed to uncover the protective effect of Phl against DIC in vivo and in vitro, while also providing a comprehensive understanding of the underlying mechanisms involved. METHODS: DIC cell and murine models were established. The action targets and mechanism of Phl against DIC were comprehensively examined by systematic network pharmacology, molecular docking, transcriptomics technologies, transcription factor (TF) prediction, and experimental validation. RESULTS: Phl relieved Dox-induced cell apoptosis in vitro and in vivo. Through network pharmacology analysis, a total of 554 co-targeted genes of Phl and Dox were identified. Enrichment analysis revealed several key pathways including the PI3K-Akt signaling pathway, Apoptosis, and the IL-17 signaling pathway. Protein-protein interaction (PPI) analysis identified 24 core co-targeted genes, such as Fos, Jun, Hif1a, which were predicted to bind well to Phl based on molecular docking. Transcriptomics analysis was performed to identify the top 20 differentially expressed genes (DEGs), and 202 transcription factors (TFs) were predicted for these DEGs. Among these TFs, 10 TFs (Fos, Jun, Hif1a, etc.) are also the co-targeted genes, and 3 TFs (Fos, Jun, Hif1a) are also the core co-targeted genes. Further experiments validated the finding that Phl reduced the elevated levels of Hif3a (one of the top 20 DEGs) and Fos (one of Hif3a's predicted TFs) induced by Dox. Moreover, the interaction between Fos protein and the Hif3a promoter was confirmed through luciferase reporter assays. CONCLUSION: Phl actively targeted and down-regulated the Fos protein to inhibit its binding to the promoter region of Hif3a, thereby providing protection against DIC.

Bioinformatics and network pharmacology analysis of DWYG capsule for improving liver regeneration: identification of active compounds and mechanisms.

Aimed to explore the mechanisms and targets of Diwu Yanggan Capsule (DWYG), a traditional Chinese medicine in liver regeneration, we used the TCMSP to obtain the active ingredients and targets of DWYG and the GEO database to obtain the DEGs related to liver regeneration. We also searched for liver regeneration-related genes in disease databases and integrated them with the herbal and GEO data to screen for potential targets of DWYG in liver regeneration. Enrichment analysis using R language and molecular docking of the key targets and active ingredients were constructed. We found 73 potential targets of DWYG in liver regeneration and revealed that DWYG may act through pathways such as MAPK, TNF, and IL-17. We also found that quercetin was a major component of DWYG with low binding energy to three key targets. Our results suggest that DWYG can facilitate liver regeneration and quercetin may be its core ingredient.

The pharmacology and mechanisms of traditional Chinese medicine in promoting liver regeneration: A new therapeutic option.

BACKGROUND: The liver is renowned for its remarkable regenerative capacity to restore its structure, size and function after various types of liver injury. However, in patients with end-stage liver disease, the regenerative capacity is inhibited and liver transplantation is the only option. Considering the limitations of liver transplantation, promoting liver regeneration is suggested as a new therapeutic strategy for liver disease. Traditional Chinese medicine (TCM) has a long history of preventing and treating various liver diseases, and some of them have been proven to be effective in promoting liver regeneration, suggesting the therapeutic potential in liver diseases. PURPOSE: This review aims to summarize the molecular mechanisms of liver regeneration and the pro-regenerative activity and mechanism of TCM formulas, extracts and active ingredients. METHODS: We conducted a systematic search in PubMed, Web of Science and the Cochrane Library databases using "TCM", "liver regeneration" or their synonyms as keywords, and classified and summarized the retrieved literature. The PRISMA guidelines were followed. RESULTS: Forty-one research articles met the themes of this review and previous critical studies were also reviewed to provide essential background information. Current evidences indicate that various TCM formulas, extracts and active ingredients have the effect on stimulating liver regeneration through modulating JAK/STAT, Hippo, PI3K/Akt and other signaling pathways. Besides, the mechanisms of liver regeneration, the limitation of existing studies and the application prospect of TCM to promote liver regeneration are also outlined and discussed in this review. CONCLUSION: This review supports TCM as new potential therapeutic options for promoting liver regeneration and repair of the failing liver, although extensive pharmacokinetic and toxicological studies, as well as elaborate clinical trials, are still needed to demonstrate safety and efficacy.

Hyperoside prevents doxorubicin-induced cardiotoxicity by inhibiting NOXs/ROS/NLRP3 inflammasome signaling pathway.

Clinical application of doxorubicin (Dox) in cancer chemotherapy is limited by its cardiotoxicity. Present study aimed to demonstrate the effect and mechanism of hyperoside in Dox-induced cardiotoxicity. C57BL/6 mice were injected with 12 mg/kg of Dox, and 1 µM Dox was exposed to primary cardiomyocytes. Cardiac function was evaluated by echocardiographic and myocardial enzyme levels. Cardiomyocyts apoptosis was analyzed by TUNEL staining and flow cytometry. Network pharmacology and molecular docking were utilized to explore potential targets of hyperoside. Protein expressions were detected by western blot and enzyme activities were determined by colorimetry. Cardiac dysfunction and cardiomyocyte apoptosis induced by Dox were attenuated by hyperoside. Mechanism of hyperoside was mainly related to "oxidative stress" pathway. Hyperoside exhibited strong binding activities with nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs, the main source of ROS in cardiomyocytes) and cyclooxygenases (COXs). Experiments proved that hyperoside suppressed the ROS generation and the elevated activities of NOXs and COXs induced by Dox. Dox also triggered the activation of NLRP3 inflammasome, which was reversed by hyperoside. Hyperoside bound to NOXs and COXs, which prevents Dox-induced cardiotoxicity by inhibiting NOXs/ROS/NLRP3 inflammasome signaling pathway. Hyperoside holds promise as a therapeutic strategy for Dox-induced cardiotoxicity.

Comparative effectiveness of glycyrrhizic acid preparations aimed at improving liver function of patients with chronic hepatitis B: A network meta-analysis of 53 randomized controlled trials.

BACKGROUND AND OBJECTIVES: Entecavir (ETV) has disadvantages, such as poor improvement in liver function, during the treatment of Chronic hepatitis B (CHB). Thus ETV is often used in clinical therapy with glycyrrhizic acid (GA) preparations. However, due to the lack of reliable and direct clinical studies, it remains controversial whether glycyrrhizic acid preparations have the best efficacy in CHB. Therefore, we aimed to compare and rank the different GA preparations in the treatment of CHB using network meta-analysis (NMA). METHODS: We systematically searched MEDLINE, EMBASE, Cochrane Library, Web of Science, China national knowledge internet (CNKI), Wanfang, VIP, and SinoMed databases as of August 4, 2022. Literature was screened according to predefined inclusion and exclusion criteria to extract meaningful information. A Bayesian approach was used for random effects model network meta-analysis, and Stata 17 software was used for data analysis. RESULTS: From 1074 papers, we included 53 relevant randomized clinical trials (RCTs). For the primary outcome, we used the overall effective rate in assessing the effectiveness of treatment for CHB (31 RCTs including 3007 patients): CGI, CGT, DGC and MgIGI significantly reduced the incidence of overall response compared to controls (RRs range from 1.16 to 1.24); SUCRA results showed that MgIGI was the best (SUCRA 0.923). In terms of secondary outcomes, we assessed the effect of treatment for CHB according to the level of reduction in ALT and AST: for ALT (37 RCTs including 3752 patients), CGI, CGT, DGC, DGI and MgIGI significantly improved liver function index compared to controls (MD range from 14.65 to 20.41); SUCRA results showed that CGI was the best (SUCRA 0.87); for AST, GI, CGT, DGC, DGI and MgIGI significantly improved liver function index compared to the control group (MD range from 17.46 to 24.42); SUCRA results showed that MgIGI was the best (SUCRA 0.871). CONCLUSION: In this study, we verified that the combination of GA and Entecavir is more effective than entecavir monotherapy in the treatment of hepatitis B. MgIGI and CGI showed clinically significant effects on liver function recovery compared with other GA preparations. MgIGI appeared to be the best choice among all GA preparations for the treatment of CHB. Our study provides some references for the treatment of CHB.

Optimization of polymyxin B regimens for the treatment of carbapenem-resistant organism nosocomial pneumonia: a real-world prospective study.

BACKGROUND: Polymyxin B is the first-line therapy for Carbapenem-resistant organism (CRO) nosocomial pneumonia. However, clinical data for its pharmacokinetic/pharmacodynamic (PK/PD) relationship are limited. This study aimed to investigate the relationship between polymyxin B exposure and efficacy for the treatment of CRO pneumonia in critically ill patients, and to optimize the individual dosing regimens. METHODS: Patients treated with polymyxin B for CRO pneumonia were enrolled. Blood samples were assayed using a validated high-performance liquid chromatography-tandem mass spectrometry method. Population PK analysis and Monte Carlo simulation were performed using Phoenix NLME software. Logistic regression analyses and receiver operating characteristic (ROC) curve were employed to identify the significant predictors and PK/PD indices of polymyxin B efficacy. RESULTS: A total of 105 patients were included, and the population PK model was developed based on 295 plasma concentrations. AUCss,24 h/MIC (AOR = 0.97, 95% CI 0.95-0.99, p = 0.009), daily dose (AOR = 0.98, 95% CI 0.97-0.99, p = 0.028), and combination of inhaled polymyxin B (AOR = 0.32, 95% CI 0.11-0.94, p = 0.039) were independent risk factors for polymyxin B efficacy. ROC curve showed that AUCss,24 h/MIC is the most predictive PK/PD index of polymyxin B for the treatment of nosocomial pneumonia caused by CRO, and the optimal cutoff point value was 66.9 in patients receiving combination therapy with another antimicrobial. Model-based simulation suggests that the maintaining daily dose of 75 and 100 mg Q12 h could achieve ≥ 90% PTA of this clinical target at MIC values ≤ 0.5 and 1 mg/L, respectively. For patients unable to achieve the target concentration by intravenous administration, adjunctive inhalation of polymyxin B would be beneficial. CONCLUSIONS: For CRO pneumonia, daily dose of 75 and 100 mg Q12 h was recommended for clinical efficacy. Inhalation of polymyxin B is beneficial for patients who cannot achieve the target concentration by intravenous administration.

Glycyrrhiza uralensis Fisch. and its active components mitigate Semen Strychni-induced neurotoxicity through regulating high mobility group box 1 (HMGB1) translocation.

Semen Strychni has long been used for the treatment of rheumatoid arthritis, facioplegia and myasthenia gravis due to its anti-inflammation and anti-nociceptive properties in China. However, the fatal neurotoxicity of Semen Strychni has limited its wider clinical application. To investigate the acute toxicity induced by Semen Strychni and the detoxification of liquorice, we evaluated inflammation, oxidative stress and the translocation of high mobility group box 1 (HMGB1) in rats. As a result, there were obvious oxidative stress and inflammation in hippocampus after the Semen Strychni extracts (STR) treatment in rats. Liquorice extracts (LE) and its three active monomers - glycyrrhizic acid (GA), liquiritigenin (LIQ), isoliquiritigenin (ISL) showed the potential for mitigating STR-induced neurotoxicity. HMGB1 levels in cytoplasm and serum and the levels of two downstream receptors RAGE and TLR4 were significantly increased after STR treatment. Through using LE and the monomers, the nucleocytoplasmic transport and release of HMGB1 were inhibited. In addition, the binding between HMGB1 and TLR4 was weakened in detoxification groups comparing with the STR group. Taken together, these findings indicated that liquorice and its active components alleviated acute neurotoxicity induced by Semen Strychni partly via HMGB1-related pathway.

Metabolic Activation of the Toxic Natural Products From Herbal and Dietary Supplements Leading to Toxicities.

Currently, herbal and dietary supplements have been widely applied to prevent and treat various diseases. However, the potential toxicities and adverse reactions of herbal and dietary supplements have been increasingly reported, and have gradually attracted widespread attention from clinical pharmacists and physicians. Metabolic activation of specific natural products from herbal and dietary supplements is mediated by hepatic cytochrome P450 or intestinal bacteria, and generates chemical reactive/toxic metabolites that bind to cellular reduced glutathione or macromolecules, and form reactive metabolites-glutathione/protein/DNA adducts, and these protein/DNA adducts can result in toxicities. The present review focuses on the relation between metabolic activation and toxicities of natural products, and provides updated, comprehensive and critical comment on the toxic mechanisms of reactive metabolites. The key inductive role of metabolic activation in toxicity is highlighted, and frequently toxic functional groups of toxic natural products were summarized. The biotransformation of drug cytochrome P450 or intestinal bacteria involved in metabolic activation were clarified, the reactive metabolites-protein adducts were selected as biomarkers for predicting toxicity. And finally, further perspectives between metabolic activation and toxicities of natural products from herbal and dietary supplements are discussed, to provide a reference for the reasonable and safe usage of herbal and dietary supplements.

Network Pharmacology Prediction and Molecular Docking-Based Strategy to Discover the Potential Pharmacological Mechanism of Huai Hua San Against Ulcerative Colitis.

BACKGROUND: Huai Hua San (HHS), a famous Traditional Chinese Medicine (TCM) formula, has been widely applied in treating ulcerative colitis (UC). However, the interaction of bioactives from HHS with the targets involved in UC has not been elucidated yet. AIM: A network pharmacology-based approach combined with molecular docking and in vitro validation was performed to determine the bioactives, key targets, and potential pharmacological mechanism of HHS against UC. MATERIALS AND METHODS: Bioactives and potential targets of HHS, as well as UC-related targets, were retrieved from public databases. Crucial bioactive ingredients, potential targets, and signaling pathways were acquired through bioinformatics analysis, including protein-protein interaction (PPI), as well as the Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Subsequently, molecular docking was carried out to predict the combination of active compounds with core targets. Lastly, in vitro experiments were conducted to further verify the findings. RESULTS: A total of 28 bioactive ingredients of HHS and 421 HHS-UC-related targets were screened. Bioinformatics analysis revealed that quercetin, luteolin, and nobiletin may be potential candidate agents. JUN, TP53, and ESR1 could become potential therapeutic targets. PI3K-AKT signaling pathway might play an important role in HHS against UC. Moreover, molecular docking suggested that quercetin, luteolin, and nobiletin combined well with JUN, TP53, and ESR1, respectively. Cell experiments showed that the most important ingredient of HHS, quercetin, could inhibit the levels of inflammatory factors and phosphorylated c-Jun, as well as PI3K-Akt signaling pathway in LPS-induced RAW264.7 cells, which further confirmed the prediction by network pharmacology strategy and molecular docking. CONCLUSION: Our results comprehensively illustrated the bioactives, potential targets, and molecular mechanism of HHS against UC. It also provided a promising strategy to uncover the scientific basis and therapeutic mechanism of TCM formulae in treating diseases.

Role of MicroRNA-155 in Triptolide-induced hepatotoxicity via the Nrf2-Dependent pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Triptolide (TP), the main bioactive and toxic ingredient of Tripterygium wilfordii Hook F, causes severe toxicity, particularly for hepatotoxicity. However, the underlying mechanisms for its hepatotoxicity are not entirely clear. AIM OF THE STUDY: The purpose of the study was to explore the role of miR-155, a microRNA closely related to various liver injuries and a regulator of the nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant pathway, in TP-induced liver injury in vitro and in vivo. MATERIALS AND METHODS: First, in vitro L02 cells were treated with different concentrations of TP. The protein levels of Nrf2 and its downstream genes Heme oxygenase1 (HO-1) were determined by Western blot. The mRNA expression of miR-155, Nrf2, NAD(P)H: quinone oxidoreductase 1 (NQO1) and HO-1 were measured using qRT-PCR. And we transfected miR-155 inhibitor and miminc before TP treatment to determine the mRNA and/or protein levels of miR-155, Nrf2 and HO-1. Then, we further confirmed the interaction between miR-155 and Nrf2 pathway in TP-induced hepatic injury in BALB/C mice. The degree of liver injury was determined by HE staining and serum biochemical. The mRNA expression of miR-155 was examined with qRT-PCR and Nrf2 and HO-1 gene expression in liver were evaluated by immunohistochemistry and/or Western blot. RESULTS: The results showed that TP significantly induced the expression of miR-155 both in L02 cells and in rodents liver tissue, and the inhibition of miR-155 could mitigate the hepatic damages caused by TP. Further experiments demonstrated that the inhibition of miR-155 reversed the down-regulation of Nrf2 and HO-1 by TP, while the miR-155 mimic enhanced the effects of TP. Animal experiments also showed that the inhibition of miR-155 by miR-155 antagomir reversed the decrease of Nrf2 induced by TP administration. CONCLUSIONS: These results indicated that miR-155 played an important role in TP-induced hepatotoxicity by regulating the Nrf2 signaling pathway.

Antioxidant Effect of Polygonatum sibiricum Polysaccharides in D-Galactose-Induced Heart Aging Mice.

Polygonatum sibiricum polysaccharides (PSP), the extract of Polygonatum sibiricum, are demonstrated to exhibit a wide range of pharmacological activities. A recent study reported that PSP alleviated the aging of the kidney and meninges. However, the effect of PSP on heart aging remains unclear. The present study is aimed at investigating the protection of PSP on D-galactose- (D-gal-) induced heart aging. Results showed that irregularly arranged cardiac muscle fibers were observed in heart tissues of D-gal-treated mice, and the levels of cardiac troponin T (cTnT), creatine kinase (CK), p21, and p53 were increased after D-gal treatment. D-gal-induced heart aging and injury can be attenuated by oral administration of PSP. Moreover, PSP also decreased reactive oxygen species (ROS) and malondialdehyde (MDA) and increased the level of superoxide dismutase (SOD) in the hearts of D-gal-treated mice. DNA damages and lipid peroxidation induced by oxidative stress were also inhibited by PSP as indicated by reduced levels of 8-hydroxydeoxyguanosine (8-OHdG) and 4-hydroxy-2-nonenal (4-HNE). Collectively, PSP attenuated D-gal-induced heart aging via inhibiting oxidative stress, suggesting that PSP might serve as a potential effective Chinese herbal active constituent for antiaging therapy.

Identification and analysis of components in Shen-Fu-Shu granule extract and in rat plasma after oral administration by UPLC-ESI/Q-TOF-MS.

BACKGROUND AND OBJECTIVES: Shen-Fu-Shu granule is traditional Chinese herb formula for acute and chronic renal failure. This work was aimed to identify the compounds in Shen-Fu-Shu granule extract and absorbed compounds in rat plasma following oral administration of Shen-Fu-Shu granule. METHODS: A high-resolution and high-sensitivity ultra-performance liquid chromatography with electrospray ionization quadrupole time-of-flight tandem mass spectrometry in positive and negative ion mode were established. The methodology of plasma pharmacochemistry was adopted to analyze the herbal components in vivo. A post-acquisition data processing software UNIFI could automatically, rapidly and accurately achieve the qualitative analysis of the chemical components in Shen-Fu-Shu granule extract and the absorbed components (and their metabolites) in rat plasma after oral administration of Shen-Fu-Shu granule. RESULTS: Combined with fragments and structure information of LC-Q-TOF-MS, a total of 264 compounds were detected and identified in Shen-Fu-Shu granule extract, while 66 absorbed components (including 38 prototype compounds and 28 metabolites) in plasma were discovered or tentatively characterized in rat plasma. CONCLUSIONS: This study offers a systematically applicable approach for rapid screening and identification of absorbed components derived from multi-herb prescription. It is helpful for understanding the material basis of its therapeutic effects and provides useful information for further study of mechanism of action of Shen-Fu-Shu granule.

An LC-MS/MS method for determination of bioactive components of liquorice and Semen Strychni in rat plasma: Application to a pharmacokinetics study.

Semen Strychni is known for its treatment of rheumatic arthritis with a low therapeutic index. Liquorice contributes a lot in herb detoxification according to the traditional Chinese medicine theory. A simple, rapid, and sensitive liquid chromatography-mass spectrometric method (LC-MS) was developed and validated for simultaneous determination of main bioactive ingredients in liquorice and Semen Strychni in rat plasma. Using moclobemide and cyproterone acetate as the internal standards, the analytes were pretreated via protein precipitation with methanol. An Ultimate AQ-C18 column (3.0 µm, 3.0 × 100 mm) was employed for chromatographic separation, combining with gradient elution. The mobile phase consisted of 0.07% formic acid and 0.12% ammonium acetate in aqueous phase (A) and acetonitrile in organic phase (B). The elution program was as follows: 0-0.5 min, 20% B; 0.5-1 min, 20-60% B; 1-7 min, 60-85% B; and 7-7.5 min, returned to 20% B, then continued to 12 min. Selected reaction monitoring was performed in both positive and negative ESI. Positive mode was adopted for detection of strychnine, brucine, and moclobemide, while negative mode was used for glycyrrhizic acid, glycyrrhetinic acid, liquiritigenin, isoliquiritigenin, liquiritin, and cyproterone acetate. The method was validated for specificity, linearity, matrix effect, recovery, precision, accuracy, and stability. The results show that this method is sensitive, accurate and robust for biological matrix analysis. Moreover, the proposed method was applied to a pharmacokinetic study in Sprague-Dawley rats for investigating the mechanism of which liquorice detoxifies Semen Strychni.

The Ethanol Extract of Licorice (Glycyrrhiza uralensis) Protects against Triptolide-Induced Oxidative Stress through Activation of Nrf2.

To investigate the potential role of nuclear factor erythroid 2-related factor 2 (Nrf2) in licorice ethanol extract (LEE) against triptolide- (TP-) induced hepatotoxicity, HepG2 cells were exposed to LEE (30, 60, and 90 mg·L-1) for 12 h and then treated with TP (50 nM) for 24 h. Besides, an acute liver injury model was established in ICR mice by a single dose of TP (1.0 mg·kg-1, i.p.). Relevant oxidant and antioxidant mediators were analyzed. TP led to an obvious oxidative stress as evidenced by increasing levels of ROS and decreasing GSH contents in HepG2 cells. In vitro results were likely to hold true in in vivo experiments. LEE protected against TP-induced oxidative stress in both in vitro and in vivo conditions. Furthermore, the decreased level of Nrf2 in the TP-treated group was observed. The mRNA levels of downstream genes decreased as well in ICR mice liver, whereas they increased in HepG2 cells. In contrast, LEE pretreatment significantly increased the level of Nrf2 and its downstream genes. LEE protects against TP-induced oxidative stress partly via the activation of Nrf2 pathway.

Danshen modulates Nrf2-mediated signaling pathway in cisplatin-induced renal injury.

Danshen, an efficacious agent for cardiovascular diseases, has been found to play an essential role in kidney injury. In the present study, the effect of Danshen on cisplatin-induced renal dysfunction was investigated in a mouse model. Danshen was administered to mice at a dose of 3 g/kg 4 days before and 3 days after cisplatin treatment. A single intraperitoneal injection of 20 mg/kg cisplatin was used to induce nephrotoxicity. The mice were sacrificed 72 h after cisplatin intoxication. Biochemical parameters including serum creatinine and blood urea nitrogen were analyzed. Histopathological changes of kidney tissues were detected using HE staining. Antioxidant enzymes (GSH-Px and SOD) and peroxidative product (MDA) were detected. Protein expressions of Nrf2 and its target genes including HO-1 and NQO1 were measured by Western blotting. The results showed that pretreatment with Danshen significantly reduced serum creatinine and blood urea nitrogen in the cisplatin-treated mice. Histopathological examination showed that Danshen mitigated the renal damage induced by cisplatin. Moreover, Danshen restored the activities of antioxidant enzymes (GSH-Px and SOD) and normalized the MDA contents in renal tissues. Western blotting revealed that Danshen enhanced the expressions of Nrf2 and its target genes in cisplatin-exposed mice. It was suggested that Danshen protects against the cisplatin-induced renal impairment in the mice, which is potentially associated with the upregulation of Nrf2-mediated signaling pathway.

Glycyrrhetinic Acid Accelerates the Clearance of Triptolide through P-gp In Vitro.

Triptolide (TP) is an active ingredient isolated from Tripterygium wilfordii Hook. f. (TWHF), which is a traditional herbal medicine widely used for the treatment of rheumatoid arthritis and autoimmune disease in the clinic. However, its adverse reactions of hepatotoxicity and nephrotoxicity have been frequently reported which limited its clinical application. The aim of this study was to investigate the mechanism of glycyrrhetinic acid (GA) effecting on the elimination of TP in HK-2 cells and the role of the efflux transporters of P-gp and multidrug resistance-associated proteins (MRPs) in this process. An ultra performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS) analytical method was established to determine the intracellular concentration of TP. In order to study the role of efflux transporters of P-gp and MRPs in GA impacting on the accumulation of TP, the inhibitors of efflux transporters (P-gp: verapamil; MRPs: MK571) were used in this study. The results showed that GA could enhance the elimination of TP and reduce the TP accumulation in HK-2 cells. Verapamil and MK571 could increase the intracellular concentration of TP; in addition, GA co-incubation with verapamil significantly increased the TP cellular concentration compared with the control group. In conclusion, GA could reduce the accumulation of TP in HK-2 cells, which was related to P-gp. This is probably one of the mechanisms that TP combined with GA to detoxify its toxicity. Copyright © 2017 John Wiley & Sons, Ltd.

The Protective Effects of Isoliquiritigenin and Glycyrrhetinic Acid against Triptolide-Induced Oxidative Stress in HepG2 Cells Involve Nrf2 Activation.

Triptolide (TP), an active ingredient of Tripterygium wilfordii Hook f., possesses a wide range of biological activities. Oxidative stress likely plays a role in TP-induced hepatotoxicity. Isoliquiritigenin (ISL) and glycyrrhetinic acid (GA) are potent hepatoprotection agents. The aim of the present study was to investigate whether Nrf2 pathway is associated with the protective effects of ISL and GA against TP-induced oxidative stress or not. HepG2 cells were treated with TP (50 nM) for 24 h after pretreatment with ISL and GA (5, 10, and 20 µM) for 12 h and 24 h, respectively. The results demonstrated that TP treatment significantly increased ROS levels and decreased GSH levels. Both ISL and GA pretreatment decreased ROS and meanwhile enhanced intracellular GSH content. Additionally, TP treatment obviously decreased the protein expression of Nrf2 and its target genes including HO-1 and MRP2 except NQO1. Moreover, both ISL and GA displayed activities as inducers of Nrf2 and increased the expression of HO-1, NQO1, and MRP2. Taken together the current data confirmed that ISL and GA could activate the Nrf2 antioxidant response in HepG2 cells, increasing the expression of its target genes which may be partly associated with their protective effects in TP-induced oxidative stress.

Progress on mechanism of Tripterygium wilfordii-induced liver injury and detoxification mechanism of licorice.

Tripterygium wilfordii has exihibited multiple pharmacological activities, such as anti-inflammatory, immune modulation, anti-tumor and anti-fertility. T. wilfordii have been used for the therapy of inflammation and autoimmune diseases including rheumatoid arthritis, immune complex nephritis and systemic lupus erythematosus clinically. However, it is well known that T. wilfordii has small margin between the therapeutic and toxic doses and could cause serious injury on digestive, reproductive and urogenital systems. Among all the organs, liver is one of the most remarkable targets of T. wilfordii-induced toxicities, and the damage is more serious than others. It is generally accepted that T. wilfordii-induced liver injury is a result of the combined effects of toxic elements of T. wilfordii. It is reported in several studies that the mechanism of T. wilfordii-induced liver injury may be related to lipid peroxidation, cell apoptosis and immune damage, and so on. Licorice is one of the most commonly used Chinese herbal medicine, with effects of heat- clearing and detoxicating, anti-inflammatory and hepatoprotective, reconciling various drugs, and so on. Licorice often accompany T. wilfordii in clinical application which can significantly reduce the liver injury induced by T. wilfordii. The attenuated effect is exact, but the mechanism is still a lack of in-depth study. This paper reviews the studies on T. wilfordii-induced liver injury and the related mechanism as well as licorice and other traditional Chinese medicine accompany T. wilfordii to reduce the injury in recent years, so as to provide reference for related research in the future.

[Advances in cardiovascular effects of tanshinone II(A)].

Cardiovascular diseases, like coronary heart disease and myocardial infarction, are the most common cause of death worldwide. Chinese medicines have demonstrated rich cardioprotective activities for clinical applications. Salvia miltiorrhiza, a very important component of traditional Chinese medicine, can promote blood circulation and relieve blood stasis. Salvia miltiorrhiza is widely used in treatment of cardiovascular and cerebrovascular disease such as coronary heart disease and cerebral infarction ( CI). Tanshinone II(A), the major lipophilic components extracted from the root of S. miltiorrhiza, possesses anti-atherosclerosis, anti-cardiac hypertrophy, anti-oxidant, anti-arrhythmia and so on. This paper discusses current research status of tanshinone II(A) in cardioprotective effects.

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

ETHNOPHARMACOLOGICAL RELEVANCE: Licorice (Glycyrrhizae radix), the root of Glycyrrhiza uralensis Fisch. (Leguminosae), is mainly used to moderate the characteristics of toxic herbs in Traditional Chinese Medicine, which could be partly interpreted as detoxification. However, the underlying mechanism is still not fully elucidated. Nuclear factor erythroid 2-related factor 2 (Nrf2) plays a key role in the protection against toxic xenobiotics. In our previous research, we have identified that extracts from Glycyrrhiza uralensis induced the expression of Nrf2 nuclear protein and its downstream genes. This research aims to screen the most potent Nrf2 inducer isolated from Glycyrrhiza uralensis and examine its effect on Nrf2 signaling pathway and detoxification system. MATERIALS AND METHODS: Four compounds derived from Glycyrrhiza uralensis (glycyrrhetinic acid, liquiritigenin, isoliquiritigenin and liquiritin) were screened by ARE-luciferase reporter. The most potent ARE-luciferase inducer was chosen to further examine its effect on Nrf2 and detoxification genes in HepG2 cells. The role of Nrf2-dependent mechanism was tested by using Nrf2 knockout mice (Nrf2 KO) and Nrf2 wild-type mice (Nrf2 WT). RESULTS: ARE-luciferase reporter assay showed these four compounds were all potent Nrf2 inducers, and isoliquiritigenin was the most potent inducer. Isoliquiritigenin significantly up-regulated the expression of Nrf2 and its downstream detoxification genes UDP-glucuronosyltransferase 1A1 (UGT1A1), glutamate cysteine ligase (GCL), multidrug resistance protein 2 (MRP2) and bile salt export pump (BSEP) in vitro and in vivo. Additionally, isoliquiritigenin showed Nrf2-dependent transactivation of UGT1A1, GCLC and MRP2. CONCLUSIONS: Isoliquiritigenin, isolated from Glycyrrhiza uralensis, stimulates detoxification system via Nrf2 activation, which could be a potential protective mechanism of licorice.