Magnesium isoglycyrrhizinate inhibits inflammatory response through STAT3 pathway to protect remnant liver function

Glycyrrhizin and the Related Preparations: An Inspiring Resource for the Treatment of Liver Diseases

Liver diseases and their related complications endanger the health of millions of people worldwide. The prevention and treatment of liver diseases are still serious challenges both in China and globally. With the improvement of living standards, the prevalence of metabolic liver diseases, including non-alcoholic fatty liver disease and alcoholic liver disease, has increased at an alarming rate, resulting in more cases of end-stage liver disease. Therefore, the discovery of novel therapeutic drugs for the treatment of liver diseases is urgently needed. Glycyrrhizin (GL), a triterpene glycoside from the roots of licorice plants, possesses a wide range of pharmacological and biological activities. Currently, GL preparations (GLPs) have certain advantages in the treatment of liver diseases, with good clinical effects and fewer adverse reactions, and have shown broad application prospects through multitargeting therapeutic mechanisms, including antisteatotic, anti-oxidative stress, anti-inflammatory, immunoregulatory, antifibrotic, anticancer, and drug interaction activities. This review summarizes the currently known biological activities of GLPs and their medical applications in the treatment of liver diseases, and highlights the potential of these preparations as promising therapeutic options and their alluring prospects for the treatment of liver diseases.

Integrating Metabolomics and Network Pharmacology to Decipher the Hepatoprotective Effect Mechanisms of Magnesium Isoglycyrrhizinate Injection

This study aimed to explore the liver protective effects of a fourth-generation glycyrrhizic acid product (magnesium isoglycyrrhizinate injection, MII) in the treatment of mice with drug-induced liver injury-specifically, to determine its effects on plasma metabolites. Moreover, the possible mechanism of its intervention in lipid metabolism and amino acid metabolism through the liver protective effect was preliminarily explored, combined with network pharmacology. The liver injury model of mice was established using acetaminophen (APAP). The protective effect of MII on the mice model was evaluated using pathological tissue sections and biochemical indices such as alanine transaminase (ALT), aspartate aminotransferase (AST), and superoxide dismutase (SOD). Metabolomics analysis of plasma was performed using the UHPLC-QTOF/MS technique to screen for potential biomarkers and enriched metabolic pathways. The potential targets and pathways of MII were predicted by network pharmacology, and the mechanism was verified by Western blot analysis. MII significantly improved the pathological liver changes in mice with liver injury. The content of ALT and AST was decreased, and the activity of SOD was increased significantly (p < 0.05, 0.01). A total of 29 potential biomarkers were identified in the metabolomics analysis, mainly involving seven pathways, such as lipid metabolism and amino acid metabolism. A total of 44 intersection targets of MII in the treatment of liver injury were obtained by network pharmacology, involving lipid metabolism and other related pathways. Western blot analysis results showed that MII could significantly reduce the expression of JAK2 and STAT3. MII can effectively ameliorate liver injury in modeled mice through related pathways such as lipid metabolism and amino acid metabolism. This study could provide not only a scientific basis for the elucidation of the mechanism of action of MII in exerting a hepatoprotective effect, but also a reference for its rational clinical application.

Magnesium and Liver Metabolism Through the Lifespan

Within the organism, the liver is the main organ responsible for metabolic homeostasis and xenobiotic transformation. To maintain an adequate liver weight-to-bodyweight ratio, this organ has an extraordinary regenerative capacity and is able to respond to an acute insult or partial hepatectomy. Maintenance of hepatic homeostasis is crucial for the proper functioning of the liver, and in this context, adequate nutrition with macro- and micronutrient intake is mandatory. Among all known macro-minerals, magnesium has a key role in energy metabolism and in metabolic and signaling pathways that maintain liver function and physiology throughout its life span. In the present review, the cation is reported as a potential key molecule during embryogenesis, liver regeneration, and aging. The exact role of the cation during liver formation and regeneration is not fully understood due to its unclear role in the activation and inhibition of those processes, and further research in a developmental context is needed. As individuals age, they may develop hypomagnesemia, a condition that aggravates the characteristic alterations. Additionally, risk of developing liver pathologies increases with age, and hypomagnesemia may be a contributing factor. Therefore, magnesium loss must be prevented by adequate intake of magnesium-rich foods such as seeds, nuts, spinach, or rice to prevent age-related hepatic alterations and contribute to the maintenance of hepatic homeostasis. Since magnesium-rich sources include a variety of foods, a varied and balanced diet can meet both macronutrient and micronutrient needs.

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.

Short-term outcomes of perioperative glucocorticoid administration in patients undergoing liver surgery: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

The purpose of this systematic review and meta-analysis was to investigate whether glucocorticoid might be beneficial after hepatectomy.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Embase, Cochrane Library and Web of Science.

ELIGIBILITY CRITERIA

We included studies assessing the efficacy of perioperative glucocorticoid administration in patients undergoing liver surgery.

DATA EXTRACTION AND SYNTHESIS

Four data bases were retrieved for all randomised controlled trials. We considered postoperative complications, hospital stay and postoperative chemistry evaluations as outcomes. Pooled effects of dichotomic variables were expressed as relative risk (RR) with a 95% CI. The mean difference was used for continuous variables and an inverse variance statistical method was adopted.

RESULTS

Fourteen studies with 1205 patients were included. Lower risk of overall complications was associated with glucocorticoid (RR, 0.77; 95% CI 0.64 to 0.92), while no difference was found in hospital stay (RR, 0.02; 95% CI -0.47 to 0.51). There were also improvements in postoperative chemistry evaluations including interleukin 6 on day 1 and 3, C reactive protein on day 1, 2 and 3, international normalised ratio on day 2, total bilirubin on day 1, 2, 3 and 5, albumin on day 1.

CONCLUSION

Current evidence indicated that perioperative glucocorticoid administration for patients undergoing hepatectomy reduced the risk of overall complications with inhibited postoperative inflammatory response and improved postoperative liver function.

PROSPERO REGISTRATION NUMBER

CRD42022307533.

Magnesium isoglycyrrhizinate attenuates acute alcohol-induced hepatic steatosis in a zebrafish model by regulating lipid metabolism and ER stress

Background

Alcoholism is a well-known risk factor for liver injury and is one of the major causes of hepatic steatosis worldwide. Although many drugs have been reported to have protective effects against acute alcohol-induced hepatotoxicity, there is limited available treatment for alcoholic liver disease (ALD), indicating an urgent need for effective therapeutic options. Herein, we first reported the protective effects of magnesium isoglycyrrhizinate (MgIG) on acute alcohol-induced hepatic steatosis and its related mechanisms in a zebrafish model.

Methods

Alcohol was administered directly to embryo medium at 5 days post-fertilization (dpf) for up to 32 h. MgIG was given to the larvae 2 h before the administration of alcohol and then cotreated with alcohol starting at 5 dpf. Oil red O staining was used to determine the incidence of steatosis, and pathological features of the liver were assessed by hematoxylin–eosin staining. Biological indexes, total cholesterol (TC) and triacylglycerol (TG) were detected in the livers of zebrafish larvae. Morphological changes in the livers of zebrafish larvae were observed using liver-specific EGFP transgenic zebrafish (Tg(lfabp10a:eGFP)). The expression levels of critical molecules related to endoplasmic reticulum (ER) stress and lipid metabolism were detected by qRT–PCR, whole-mount in situ hybridization and western blotting.

Results

Alcohol-treated larvae developed hepatomegaly and steatosis after 32 h of exposure. We found that MgIG improved hepatomegaly and reduced the incidence of steatosis in a dose-dependent manner by oil red O staining and diminished deposits of alcohol-induced fat droplets by histologic analysis. Moreover, MgIG significantly decreased the levels of TC and TG in the livers of zebrafish larvae. Furthermore, the expression levels of critical genes involved in ER stress (atf6, irela, bip, chop) and the key enzymes regulating lipid metabolism (acc1, fasn, hmgcs1 and hmgcra) were significantly higher in the alcohol-treated group than in the control group. However, in the MgIG plus alcohol-treated group, the expression of these genes was markedly decreased compared with that in the alcohol-treated group. Whole-mount in situ hybridization and western blotting also showed that MgIG had an effect on the expression levels of critical genes and proteins involved in lipid metabolism and ER stress. Our results revealed that MgIG could markedly regulate these genes and protect the liver from ER stress and lipid metabolism disorders.

Conclusions

Our study is the first to demonstrate that MgIG could protect the liver from acute alcohol stimulation by ameliorating the disorder of lipid metabolism and regulating ER stress in zebrafish larvae.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-022-00655-7.

Detoxification strategies of triptolide based on drug combinations and targeted delivery methods

Tripterygium wilfordii Hook f. has a long history of use in Chinese medicine. Triptolide (TP), as its main pharmacological component, has been widely explored in various diseases, including systemic lupus erythematosus, rheumatoid arthritis and cancer. However, due to its poor water solubility, limited therapeutic range and multi-organ toxicity, TP's clinical application has been greatly hampered. To improve its clinical potential, many attenuated drug combinations have been developed based on its toxicity mechanism and targeted delivery systems aimed at its water-solubility and structure. This review, conducted a systematic review of TP detoxification strategies including drug combination detoxification strategies from metabolic and toxic mechanisms, as well as drug delivery detoxification strategies from the prodrug strategy and nanotechnology. Many detoxification strategies have demonstrated promising potential in vitro and in vivo due to previous extensive studies on TP. Therefore, summarizing and discussing TP detoxification strategies for clinical problems can serve as a reference for developing novel TP detoxification strategies, and provide opportunities for future clinical applications.

Magnesium isoglycyrrhizinate prevents cadmium-induced activation of JNK and apoptotic hepatocyte death by reversing ROS-inactivated PP2A

OBJECTIVES

Cadmium (Cd) induces reactive oxygen species (ROS)-mediated hepatocyte apoptosis and consequential liver disorders. This study aimed to investigate the effect of magnesium isoglycyrrhizinate (MgIG) on Cd-induced hepatotoxicity.

METHODS

L02 and AML-12 cells were used to study MgIG hepatoprotective effects. Cd-evoked apoptosis, ROS and protein phosphatase 2A (PP2A)/c-Jun N-terminal kinase (JNK) cascade disruption were analysed by cell viability assay, 6-diamidino-2-phenylindole (DAPI) and TdT-mediated dUTP Nick-End Labeling (TUNEL) staining, ROS imaging and Western blotting. Pharmacological and genetic approaches were used to explore the mechanisms.

KEY FINDINGS

We show that MgIG attenuated Cd-evoked hepatocyte apoptosis by blocking JNK pathway. Pre-treatment with SP600125 or ectopic expression of dominant-negative c-Jun enhanced MgIG's anti-apoptotic effects. Further investigation found that MgIG rescued Cd-inactivated PP2A. Inhibition of PP2A activity by okadaic acid attenuated the MgIG's inhibition of the Cd-stimulated JNK pathway and apoptosis; in contrast, overexpression of PP2A strengthened the MgIG effects. In addition, MgIG blocked Cd-induced ROS generation. Eliminating ROS by N-acetyl-l-cysteine abrogated Cd-induced PP2A-JNK pathway disruption and concurrently reinforced MgIG-conferred protective effects, which could be further slightly strengthened by PP2A overexpression.

CONCLUSIONS

Our findings indicate that MgIG is a promising hepatoprotective agent for the prevention of Cd-induced hepatic injury by mitigating ROS-inactivated PP2A, thus preventing JNK activation and hepatocyte apoptosis.

Magnesium Isoglycyrrhizinate Induces an Inhibitory Effect on Progression and Epithelial-Mesenchymal Transition of Laryngeal Cancer via the NF-κB/Twist Signaling

Background

Magnesium isoglycyrrhizinate (MI) was extracted from roots of the plant Glycyrrhiza glabra, which displays multiple pharmacological activities such as anti-inflammation, anti-apoptosis, and anti-tumor. Here, we aimed to investigate the effect of MI on the progression and epithelial–mesenchymal transition (EMT) of laryngeal cancer.

Methods

Forty laryngeal cancer clinical samples were used. The role of MI in the proliferation of laryngeal cancer cells was assessed by MTT assay, Edu assay and colony formation assay. The function of MI in the migration and invasion of laryngeal cancer cells was tested by transwell assays. The effect of MI on apoptosis of laryngeal cancer cells was determined by cell apoptosis assay. The impact of MI on tumor growth in vivo was analyzed by tumorigenicity analysis using Balb/c nude mice. qPCR and Western blot analysis were performed to measure the expression levels of gene and protein, respectively.

Results

We identified that EMT-related transcription factor Twist was significantly elevated in the laryngeal cancer tissues. The expression of Twist was also enhanced in the human laryngeal carcinoma HEP-2 cells compared with that in the primary laryngeal epithelial cells. The high expression of Twist was remarkably correlated with poor overall survival of patients with laryngeal cancer. Meanwhile, our data revealed that MI reduced cell proliferation, migration and invasion and enhanced apoptosis of laryngeal cancer cells in vitro. Moreover, MI decreased transcriptional activation and the expression levels of NF-κB and Twist, and alleviated EMT in vitro and in vivo. MI remarkably inhibited tumor growth and EMT of laryngeal cancer cells in vivo.

Conclusion

MI restrains the progression of laryngeal cancer and induces an inhibitory effect on EMT in laryngeal cancer by modulating the NF-κB/Twist signaling. Our finding provides new insights into the mechanism by which MI inhibits laryngeal carcinoma development, enriching the understanding of the anti-tumor function of MI.

Magnesium isoglycyrrhizinate ameliorates concanavalin A-induced liver injury via the p38 and JNK MAPK pathway

CONTEXT

Acute liver failure is a serious disease caused by a variety of factors, and immunological injury is an important pathological process. Comprehensive liver treatment efficacy is poor, and the mortality rate is high. Magnesium isoglycyrrhizinate (MgIG) is a new glycyrrhizin drug extracted from the traditional Chinese medicine licorice. The mechanism by which MgIG regulates ConcanavalinA (ConA)-induced immunological liver injury in mice is not completely clear.

MATERIALS AND METHODS

Immunological liver injury was induced in mice by ConA injection, and the inflammatory macrophages model was induced by lipopolysaccharide (LPS). MgIG was administered 30 min prior to ConA and LPS treatment. The mice in the different groups were sacrificed 12 h after treatment, and macrophages were measured at 30 min, 1 h, and 2 h after induction. Macrophages, liver, and blood samples were then collected for analysis.

RESULTS

After drug administration, the MgIG group showed a marked decrease in serum transaminase levels, reduced apoptosis and hepatic inflammatory responses compared to the ConA group. Furthermore, there was a significant reduction in inflammatory cytokine levels in the serum and liver tissue. In vitro, the expression of inflammatory cytokines was distinctly reduced after MgIG administration. In addition, MgIG pretreatment reduced the expression of inflammatory cytokines and regulated the phosphorylation of p38 and JNK proteins in the MAPK pathway.

CONCLUSION

These findings demonstrated that MgIG protects against ConA-induced immunological liver injury by markedly alleviating liver inflammation, and this provides guidance for the clinical amelioration of liver inflammation induced by immunological factors.

Magnesium isoglycyrrhizinate alleviates fructose-induced liver oxidative stress and inflammatory injury through suppressing NOXs

Excessive fructose intake is a risk factor for liver oxidative stress injury. Magnesium isoglycyrrhizinate as a hepatoprotective agent is used to treat liver diseases in clinic. However, its antioxidant effects and the underlying potential mechanisms are still not clearly understood. In this study, magnesium isoglycyrrhizinate was found to alleviate liver oxidative stress and inflammatory injury in fructose-fed rats. Magnesium isoglycyrrhizinate suppressed hepatic reactive oxygen species overproduction (0.97 ± 0.04 a.u. versus 1.34 ± 0.07 a.u.) in fructose-fed rats by down-regulating mRNA and protein levels of nicotinamide adenine dinucleotide phosphate oxidase (NOX) 1, NOX2 and NOX4, resulting in reduction of interleukin-1β (IL-1β) levels (1.13 ± 0.09 a.u. versus 1.97 ± 0.12 a.u.). Similarly, magnesium isoglycyrrhizinate reduced reactive oxygen species overproduction (1.07 ± 0.02 a.u. versus 1.35 ± 0.06 a.u.) and IL-1β levels (1.14 ± 0.09 a.u. versus 1.66 ± 0.07 a.u.) in fructose-exposed HepG2 cells. Furthermore, data from treatment of reactive oxygen species inhibitor N-acetyl-L-cysteine or NOXs inhibitor diphenyleneiodonium in fructose-exposed HepG2 cells showed that fructose enhanced NOX1, NOX2 and NOX4 expression to increase reactive oxygen species generation, causing oxidative stress and inflammation, more importantly, these disturbances were significantly attenuated by magnesium isoglycyrrhizinate. The molecular mechanisms underpinning these effects suggest that magnesium isoglycyrrhizinate may inhibit NOX1, NOX2 and NOX4 expression to reduce reactive oxygen species generation, subsequently prevent liver oxidative stress injury under high fructose condition. Thus, the blockade of NOX1, NOX2 and NOX4 expression by magnesium isoglycyrrhizinate may be the potential therapeutic approach for improving fructose-induced liver injury in clinic.

The hepatoprotective effects of XCHD and MgIG against methotrexate-induced liver injury and inflammation in rats through suppressing the activation of AIM2 inflammasomes

BACKGROUND

Recent studies have shown that drug-induced liver injury may be related to the immune response activated by drugs. A cytosolic dsDNA inflammasome called absent in melanoma 2 (AIM2) was found to be associated with aseptic inflammation. The present study aimed to explore the effects of on the liver injury and inflammation in methotrexate (Mtx)-induced rats.

METHODS

Sprague Dawley (SD) rats were selected and classified into 4 groups randomly, includes control group, Mtx group, Mtx-Xiaochaihu decoction (XCHD) group and Mtx-magnesium isoglycyrrhizinate (MgIG) group. Light microscopy was used to examine histological specimens after hematoxylin-eosin (HE) staining. The AST levels in liver tissue and blood serum ALT in the rats were assessed with enzyme linked immunosorbent assay (ELISA). Then AIM2 expression and inflammatory factors, including caspase-1, IL-18, and IL-1β, in the liver biopsy specimens of rats were detected by immunohistochemistry. Furthermore, the correlation between inflammatory and AIM2 expression factors was comprehensively analyzed.

RESULTS

Functional and structural hepatotoxicity can be caused by the exposure to Mtx, which was supported by the improved biochemical marker levels and the worse histopathological changes in liver tissue. Compared with the Mtx group, the levels of liver enzymes ALT and AST, histological deterioration in the liver tissues were effectively decreased by XCHD and MgIG treatment, respectively. In addition, the expression of AIM2, caspase-1 and IL-1β was observably higher in the Mtx group, which was apparently inhibited in the Mtx-XCHD and Mtx-MgIG groups. There was no obvious change in IL-18 expression among four groups. AIM2 expression were positively associated with the severity of liver inflammation and had a higher relevance with caspase-1 expression.

CONCLUSIONS

AIM2 inflammasome in hepatocytes has a significant effect on the development of Mtx-induced liver injury, which can be ameliorated by both XCHD and MgIG treatment. The latent mechanism and potential signal pathway require further study.

Magnolol Prevents Acute Alcoholic Liver Damage by Activating PI3K/Nrf2/PPARγ and Inhibiting NLRP3 Signaling Pathway

Alcoholic liver damage (ALD) is a toxic liver damage caused by excessive drinking. Oxidative stress is one of the most crucial pathogenic factors leading to ALD. Magnolol is one of the main active constituents of traditional Chinese medicine Magnolia officinalis, which has been reported to possess many pharmacological effects including anti-inflammatory, anti-oxidant, and anti-tumor. However, the effects of magnolol on ALD remain unclear. In this study, we firstly evaluated the protective effects of magnolol on ALD, and then tried to clarify the mechanism underlying the pharmacological activities. AST, ALT, GSH-Px, and SOD were detected by respective kits. Histopathological changes of liver tissue were analyzed by H&E staining. The activities of PI3K, Nrf2, and NLRP3 signaling pathways activation were detected by western blotting analysis. It was showed that alcohol-induced ALT and AST levels were significantly reduced by magnolol, but the antioxidant enzymes of GSH-Px and SOD levels were significantly increased. Magnolol attenuated alcohol-induced pathologic damage such as decreasing hepatic cord swelling, hepatocyte necrosis, and inflammatory cell infiltration. Furthermore, it was found that magnolol inhibited oxidative stress through up-regulating the activities of HO-1, Nrf2, and PPARγ and the phosphorylation of PI3K and AKT. And magnolol also decreased inflammatory response by inhibiting the activation of NLRP3inflammasome, caspase-1, and caspase-3 signaling pathway. Above results showed that magnolol could prevent alcoholic liver damage, and the underlying mechanism was through activating PI3K/Nrf2/PPARγ signaling pathways as well as inhibiting NLRP3 inflammasome, which also suggested magnolol might be used as a potential drug for ALD.

Microvesicles Derived from TGF-β1 Stimulated Hepatic Stellate Cells Aggravate Hepatocellular Injury

Hepatic stellate cells (HSCs) are liver-specific cells playing critical roles in liver physiological and pathophysiological processes. Transforming growth factor-β1 (TGF-β1) is an inflammatory cytokine secreted by both hepatocytes and HSCs. We have previously shown that microvesicles (MVs) derived from quiescent HSCs protect hepatocyte functions. In this study, we investigated the effects of MVs released from TGF-β1-stimulated HSCs (HSC-MVs) on xenobiotic-injured hepatocytes. Two hepatocyte cell lines (BRL-3A and HL-7702) were treated with N-acetyl-p-aminophenol or H₂O₂ to build the injury models. Different concentrations of HSC-MVs were used to coculture with injured hepatocytes. MTT, Hochest33258 staining, and flow cytometry were used to determine their effects on the viability and apoptosis of hepatocytes. Liver injury indicators, alanine aminotransferase (ALT) and aspartate amino transferase (AST), were assessed by enzyme-linked immune sorbent assay kits. The phosphoinositide 3-kinase (PI3K) activator (740Y-P) and extracelluar signal regulated kinase (Erk)1/2 activator (platelet-derived growth factor-BB) were used for pathway analysis. The expression levels of p-PI3K/PI3K, p-Akt/Akt, and activated caspase-3 were measured by western blot. Results showed that (i) HSC-MVs dose dependently impaired the viability of hepatocytes in both injury models, (ii) moreover, HSC-MVs dose dependently increased the apoptosis in those cell models, (iii) HSC-MVs also elevated the levels of ALT and AST in the coculture media, and (iv) these effects were accompanied by a decrease in p-PI3K/PI3K and p-Akt/Akt, which could be partially abolished by 740Y-P. Meanwhile, the proapoptotic effect of HSC-MVs was associated with p-Erk1/2/Erk1/2 downregulation and activated caspase-3 upregulation, and could be inhibited by Erk1/2 activation. Our findings demonstrate that HSC-MVs are involved in inflammatory hepatocytes injury probably through the PI3K/Akt, Erk1/2, and caspase-3 pathways.

Magnesium isoglycyrrhizinate ameliorates high fructose-induced liver fibrosis in rat by increasing miR-375-3p to suppress JAK2/STAT3 pathway and TGF-β1/Smad signaling

Increasing evidence has demonstrated that excessive fructose intake induces liver fibrosis. Epithelial-mesenchymal transition (EMT) driven by transforming growth factor-β1 (TGF-β1)/mothers against decapentaplegic homolog (Smad) signaling activation promotes the occurrence and development of liver fibrosis. Magnesium isoglycyrrhizinate is clinically used as a hepatoprotective agent to treat liver fibrosis, but its underlying molecular mechanism has not been identified. Using a rat model, we found that high fructose intake reduced microRNA (miR)-375-3p expression and activated the janus-activating kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) cascade and TGF-β1/Smad signaling, which is consistent with the EMT and liver fibrosis. To further verify these observations, BRL-3A cells and/or primary rat hepatocytes were exposed to high fructose and/or transfected with a miR-375-3p mimic or inhibitor or treated with a JAK2 inhibitor, and we found that the low expression of miR-375-3p could induce the JAK2/STAT3 pathway to activate TGF-β1/Smad signaling and promote the EMT. Magnesium isoglycyrrhizinate was found to ameliorate high fructose-induced EMT and liver fibrosis in rats. More importantly, magnesium isoglycyrrhizinate increased miR-375-3p expression to suppress the JAK2/STAT3 pathway and TGF-β1/Smad signaling in these animal and cell models. This study provides evidence showing that magnesium isoglycyrrhizinate attenuates liver fibrosis associated with a high fructose diet.

A link between bilirubin levels and atrial fibrillation recurrence after catheter ablation

BACKGROUND

Bilirubin is associated with different cardiovascular diseases. The relationship between bilirubin and atrial fibrillation (AF) remains unclear. The aim of this study is to determine the association between bilirubin and AF recurrence after catheter ablation.

METHODS

A total of 212 patients who received AF ablation were retrospectively studied. The total bilirubin level, clinical characteristics, and echocardiographic findings were analyzed to predict the outcome of AF ablations.

RESULTS

During a mean follow-up period of 12.2 ± 5.8 months, 61 (28.8%) patients had AF recurrence after catheter ablation. The patients with AF recurrence had a larger left atrial (LA) diameter (39.8 ± 6.3 versus 36.7 ± 5.8 mm; p = 0.001) and higher total bilirubin levels (0.82 ± 0.37 versus 0.63 ± 0.29 mg/dL; p < 0.001) than those without recurrence. The patients with recurrence had higher direct and indirect bilirubin levels than patients without recurrence. The total bilirubin level remained an independent predictor of AF recurrence after multivariate analysis (odds ratio, 4.95; 95% CI, 1.65-14.83; p = 0.004). We identified a cut point of the total bilirubin level for predicting AF recurrence by receiver operator characteristic curve (cut point, 0.7 mg/dL; area under the curve, 0.65; p < 0.001). The total bilirubin levels were positively correlated with the neutrophil counts. However, there were no associations among the total bilirubin level, left atrial (LA) diameter, and voltage.

CONCLUSION

Higher serum bilirubin levels were associated with AF recurrence in paroxysmal AF patients following catheter ablation.

Magnesium isoglycyrrhizinate suppresses LPS-induced inflammation and oxidative stress through inhibiting NF-κB and MAPK pathways in RAW264.7 cells

Magnesium Isoglycyrrhizinate (MgIG), a novel molecular compound extracted from licorice root, has exhibited greater anti-inflammatory activity and hepatic protection than glycyrrhizin and β-glycyrrhizic acid. In this study, we investigated the anti-inflammatory effect and the potential mechanism of MgIG on Lipopolysaccharide (LPS)-treated RAW264.7 cells. MgIG down-regulated LPS-induced pro-inflammatory mediators and enzymes in LPS-treated RAW264.7 cells, including TNF-α, IL-6, IL-1β, IL-8, NO and iNOS. The generation of reactive oxygen species (ROS) in LPS-treated RAW264.7 cells was also reduced. MgIG attenuated NF-κB translocation by inhibiting IKK phosphorylation and IκB-α degradation. Simultaneously, MgIG also inhibited LPS-induced activation of MAPKs, including p38, JNK and ERK1/2. Taken together, these results suggest that MgIG suppresses inflammation by blocking NF-κB and MAPK signaling pathways, and down-regulates ROS generation and inflammatory mediators.

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.

Magnesium Isoglycyrrhizinate Ameliorates Fibrosis and Disrupts TGF-β-Mediated SMAD Pathway in Activated Hepatic Stellate Cell Line LX2

Liver fibrosis is a histological change often attributed to the activation of hepatic stellate cells (HSCs) and the excessive formation of scar tissues in the liver. Advanced stages of the disease frequently lead to cirrhosis. Magnesium isoglycyrrhizinate (MgIG) has been accepted as a hepatoprotective drug with the potential of alleviating inflammatory conditions and thus promote liver recovery from viral- or drug-induced injury. While MgIG has been empirically integrated into the clinics to treat some liver diseases, its anti-fibrotic effect and the associated mechanisms remain poorly characterized. Herein, we demonstrated that 1 mg/ml MgIG attenuated the production of αSMA and collagen-1 in activated HSCs using TGF-β1-induced human HSCs LX2 as the fibrotic cell model. We found that MgIG exerts an inhibitory effect on the TGF-β-SMAD signaling pathway by arresting the binding of downstream transcription factors SMAD2/3 and SMAD4. Furthermore, MgIG was shown to suppress proliferation and induce senescence of activated LX2 cells. Protein expression of p27 and enzymatic activity of senescence-associated β-galactosidase were elevated upon exposure to MgIG. In addition, we observed that exposure of activated LX2 cells to MgIG reduces TGF-β-induced apoptosis. Interestingly, a lower toxicity profile was observed when human fetal hepatocytes LO2 were exposed to the same concentration and duration of the drug, suggesting the specificity of MgIG effect toward activated HSCs. Overall, hepatoprotective concentrations of MgIG is shown to exert a direct effect on liver fibrosis through inhibiting TGF-β-signaling, in which SMAD2/3 pathway could be one of the mechanisms responsible for the fibrotic response, thereby restoring the surviving cells toward a more quiescent phenotype. This provides critical mechanistic insights to support an otherwise empirical therapy.

The inhibition of Hippo/Yap signaling pathway is required for magnesium isoglycyrrhizinate to ameliorate hepatic stellate cell inflammation and activation

Liver fibrosis is a reversible pathological process accompanied by abnormal inflammation, and its end-stage cirrhosis is responsible for high morbidity and mortality worldwide. This study was to investigate the effect of Magnesium isoglycyrrhizinate (MgIG) on liver fibrosis and inflammation, and to further clarify molecular mechanism. We found that MgIG treatment significantly alleviated carbon tetrachloride (CCl₄)-induced liver fibrosis and HSC activation by regulating TGF-β signaling and MMP/TIMP systems. In addition, MgIG treatment significantly inhibited the inflammatory response of liver fibrosis in mice characterized by reduced pro-inflammatory factors expression and increased anti-inflammatory factors expression. Interestingly, experiments in vitro also showed that MgIG treatment significantly reduced the expression of hepatic stellate cell (HSC) activation markers. Besides, MgIG treatment not only inhibited the expression of pro-inflammatory factors, but also promoted the production of anti-inflammatory factors in activated HSCs. Importantly, treatment with MgIG inhibited Hippo/Yap signaling pathway, which was a potential mechanism for MgIG-induced anti-inflammatory effects. The overexpression of Hippo/Yap signaling effector YAP completely impaired MgIG-induced anti-inflammatory and anti-fibrotic effects. Taken together, these results provide novel implications to reveal the molecular mechanism of the anti-inflammatory properties induced by MgIG, by which points to the possibility of using MgIG to treat liver fibrosis.

Magnesium isoglycyrrhizinate attenuates D-galactosamine/lipopolysaccharides induced acute liver injury of rat via regulation of the p38-MAPK and NF-κB signaling pathways

CONTEXT

Acute hepatic failure involves in serious inflammatory responses and leads to a high mortality. Magnesium isoglycyrrhizinate (MgIG), a magnesium salt of 18-α glycyrrhizic acid (GA) stereoisomer, has been shown anti-inflammatory activity previously.

OBJECTIVE

This study aimed to investigate the protective effects of MgIG, a hepatocyte protective agent, on D-galactosamine and lipopolysaccharide (D-GaIN/LPS)-induced acute liver injury in rats, and meanwhile explore the molecular mechanism.

MATERIALS AND METHODS

Male Sprague-Dawley (SD) rats were injected with D-GaIN/LPS (800 mg/kgBW/10 μg/kgBW) with or without administration of MgIG (225 mg/kg once 6 h after D-GaIN/LPS injection and MgIG 45 mg/kg twice in another 12 h, intraperitoneal injection). Rats were sacrificed 24 h after D-GaIN/LPS injection, the blood and liver samples were collected for future inflammation and hepatotoxicity analyses.

RESULTS

MgIG significantly inhibited D-GaIN/LPS-induced inflammatory cytokines production and hepatotoxicity as indicated by both diagnostic indicators of liver damage [aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels] and histopathological analysis. Western blot analysis demonstrated that MgIG significantly decreased p38-mitogen activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) activation induced by D-GaIN/LPS.

CONCLUSION

The results indicated that the protective effects of MgIG on D-GaIN/LPS-induced acute liver injury might be correlated with its capacity to regulate the p38-MAPK and NF-κB signaling pathways.

Inhibition of myocardial hypertrophy by magnesium isoglycyrrhizinate through the TLR4/NF-κB signaling pathway in mice

Magnesium isoglycyrrhizinate (MgIG) is a magnesium salt of the 18-α glycyrrhizic acid stereoisomer that has exhibited hepato-protective effects and has anti-inflammatory, antioxidant, and antiviral activities. Here, we have investigated the effects and potential mechanisms of action of MgIG, with respect to myocardial fibrosis induced by isoproterenol (ISO) in mice. Mice were administered MgIG for 14days, with concurrent ISO dosing, and were sacrificed two weeks later. Lactate dehydrogenase (LDH) and creatine kinase (CK) concentrations were measured in the blood. Pathological changes in the myocardium were observed via light microscopy. In addition, the expression of the Bax and Bcl-2 genes, and the basic fibroblast growth factor (bFGF) protein were measured via an immunohistochemical method. The RNA expression of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), c-fos, and c-jun mRNA were quantified by reverse transcription-polymerase chain reaction (RT-PCR) in the myocardial tissue. The protein expression of toll-like receptor (TLR) 4, and nuclear factor kappa B (NF-κB) (p65) were measured using Western blot assays. Compared with the control group, the ISO group showed significant increases in bFGF, Bax, Bcl-2, TLR4, and NF-κB (p65) expressions, as well as increased serum levels of LDH and CK. MgIG had a protective effect on ISO-induced myocardial fibrosis, which might be ascribed, at least in part, to the inhibition of the TLR4/NF-κB (p65) signaling pathway.

Magnesium isoglycyrrhizinate ameliorates doxorubicin-induced acute cardiac and hepatic toxicity via anti-oxidant and anti-apoptotic mechanisms in mice

The present study investigated the effects and potential mechanisms of action of magnesium isoglycyrrhizinate (MgIG) in doxorubicin (DOX)-treated mice. Histopathological analysis and western blot analysis were conducted in the liver and heart tissues and biochemical analysis of the serum was performed. The results revealed that MgIG (10, 20 and 40 mg/kg/day) could protect the structure and functions of the liver and heart by inhibiting the activities of the myocardial enzymes creatine kinase (CK), CK-MB and lactate dehydrogenase and the hepatic-specific enzymes aspirate aminotransferase and alanine aminotransferase, increasing the activities of the antioxidants superoxide dismutase and glutathione peroxidase, and inhibiting cellular apoptosis induced by DOX (30 mg/kg). These results demonstrate that inhibiting lipid peroxidation and reducing myocardial and hepatocyte apoptosis may be one of the mechanisms by which MgIG exhibits hepatoprotective and cardioprotective effects in DOX-treated mice.

Amelioration of Ethanol-Induced Hepatitis by Magnesium Isoglycyrrhizinate through Inhibition of Neutrophil Cell Infiltration and Oxidative Damage

Alcoholic liver disease (ALD) is a leading cause of liver-related morbidity and mortality worldwide. There is no effective treatment to prevent the disease progression. Magnesium isoglycyrrhizinate (MgIG) showed potent anti-inflammatory, antioxidant, and hepatoprotective activities and was used for treating liver diseases in Asia. In this study, we examined whether MgIG could protect mice against alcohol-induced liver injury. The newly developed chronic plus binge ethanol feeding model was used to study the role of MgIG in ALD. Serum liver enzyme levels, H&E staining, immunohistochemical staining, flow cytometric analysis, and real-time PCR were used to evaluate the liver injury and inflammation. We showed that MgIG markedly ameliorated chronic plus binge ethanol feeding liver injury, as shown by decreased serum alanine transaminase and aspartate aminotransferase levels and reduced neutrophil infiltration. The reason may be attributed to the reduced expression of proinflammatory cytokines and chemokines with the treatment of MgIG. The hepatoprotective effect of MgIG was associated with suppression of neutrophil ROS production as well as hepatocellular oxidative stress. MgIG may play a critical role in protecting against chronic plus binge ethanol feeding-induced liver injury by regulating neutrophil activity and hepatic oxidative stress.

Magnesium isoglycyrrhizinate protects against renal‑ischemia‑reperfusion injury in a rat model via anti‑inflammation, anti‑oxidation and anti‑apoptosis

The present study aimed to investigate whether magnesium isoglycyrrhizinate protects against renal ischemia‑reperfusion injury (RIRI), and to verify the underlying mechanisms. An RIRI rat model was induced by removing the right kidney, and exposing and clamping the left kidney. RIRI model rats were administered 30 mg/kg magnesium isoglycyrrhizinate for 3 days. Blood urea nitrogen (BUN) and serum creatinine levels in the blood of RIRI model rat were examined, compared with sham‑operated controls. Magnesium isoglycyrrhizinate suppressed the activities of tumor necrosis factor‑α, interleukin (IL)‑1β, IL‑6, superoxide dismutase, glutathione peroxidase, inducible nitric oxide synthase (iNOS) and caspase‑3 in RIRI model rats. Renal iNOS, matrix metalloproteinase (MMP)‑2, phosphorylated‑signal transducers and activators of transcription 3 (STAT3) and intercellular adhesion molecule‑1 (ICAM‑1) protein expression levels were suppressed by magnesium isoglycyrrhizinate treatment in RIRI model rats. These findings suggested that magnesium isoglycyrrhizinate protects RIRI via anti‑inflammatory, ‑oxidative and ‑apoptotic mechanisms in an RIRI rat model. These results implicate magnesium isoglycyrrhizinate pretreatment as a potential approach to protect against RIRI via suppression of the iNOS, ICAM‑1, MMP‑2 and STAT3 signaling pathways.

Hepatic Stellate Cell-Derived Microvesicles Prevent Hepatocytes from Injury Induced by APAP/H2O2

Hepatic stellate cells (HSCs), previously described for liver-specific mesenchymal stem cells (MSCs), appear to contribute to liver regeneration. Microvesicles (MVs) are nanoscale membrane fragments, which can regulate target cell function by transferring contents from their parent cells. The aim of this study was to investigate the effect of HSC-derived MVs on xenobiotic-induced liver injury. Rat and human hepatocytes, BRL-3A and HL-7702, were used to build hepatocytes injury models by n-acetyl-p-aminophenol n-(APAP) or H₂O₂ treatment. MVs were prepared from human and rat HSCs, LX-2, and HST-T6 and, respectively, added to injured BRL-3A and HL-7702 hepatocytes. MTT assay was utilized to determine cell proliferation. Cell apoptosis was analyzed by flow cytometry and hoechst33258 staining. Western blot was used for analyzing the expression of activated caspase-3. Liver injury indicators, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) in culture medium were also assessed. Results showed that (1) HSC-MVs derived from LX-2 and HST-T6 were positive to CD90 and annexin V surface markers; (2) HSC-MVs dose-dependently improved the viability of hepatocytes in both injury models; (3) HSC-MVs dose-dependently inhibited the APAP/H₂O₂ induced hepatocytes apoptosis and activated caspase-3 expression and leakage of LDH, ALT, and AST. Our results demonstrate that HSC-derived MVs protect hepatocytes from toxicant-induced injury.