Glycyrrhetinic acid pretreatment attenuates liver ischemia/reperfusion injury via inhibiting TLR4 signaling cascade in mice

Piperine attenuates hepatic ischemia/reperfusion injury via suppressing the TLR4 signaling cascade in mice

Piperine, the major active substance in black pepper, has been shown to have anti-inflammatory and antioxidant effects in several ischemic diseases. However, the role of piperine in hepatic ischemia/reperfusion injury (HIRI) and its underlying mechanisms remain unclear. In this study, the mice were administered piperine (30 mg/kg) intragastric administration before surgery. After 24 h of hepatic ischemia-reperfusion, liver histopathological evaluation, serum transaminase measurements, and TUNEL analysis were performed. The infiltration of inflammatory cells and production of inflammatory mediators in the liver tissue were determined by immunofluorescence and immunohistochemical staining. The protein levels of toll-like receptor 4 (TLR4) and related proteins such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), interleukin-1 receptor-associated kinase 1 (IRAK1), p65, and p38 were detected by western blotting. The results showed that plasma aminotransferase (ALT), aspartate aminotransferase (AST), hepatocyte apoptosis, oxidative stress, and inflammatory cell infiltration significantly increased in HIRI mice. Piperine pretreatment notably repaired liver function, improved the histopathology and apoptosis of liver cells, alleviated oxidative stress injury, and reduced inflammatory cell infiltration. Further analysis showed that piperine attenuated tumor necrosis factor-a (TNF-α) and interleukin 6 (IL-6) production and reduced TLR4 activation and phosphorylation of IRAK1, p38, and NF-κB in HIRI. Piperine has a protective effect against HIRI through the TLR4/IRAK1/NF-κB signaling pathway and may be a safer option for future clinical treatment and prevention of ischemia-related diseases.

Novel anti-inflammatory peptide alleviates liver ischemia-reperfusion injury

Ischemia-reperfusion injury (IRI) remains an unavoidable challenge in liver surgery, with macrophages playing a critical role in its pathogenesis. However, the mechanisms by which macrophages regulate the pathogenesis of IRI are not well understood. Through a target-guided screening approach, we identified a small 3 kDa peptide (SjDX5-271) from various schistosome egg-derived peptides that induced M2 macrophage polarization. SjDX5-271 treatment protected mice against liver IRI by promoting M2 macrophage polarization, and this protective effect was abrogated when the macrophages were depleted. Transcriptomic sequencing showed that the TLR signaling pathway was significantly inhibited in macrophages from the SjDX5-271 treatment group. We further identified that SjDX5-271 promoted M2 macrophage polarization by inhibiting the TLR4/MyD88/NF-κB signaling pathway and alleviated hepatic inflammation in liver IRI. Collectively, SjDX5-271 exhibited some promising therapeutic effects in IRI and represented a novel therapeutic approach, potentially applicable to other immune-related diseases. The current study demonstrates the potential of new biologics from the parasite, enhances our understanding of host-parasite interplay, and provides a blueprint for future therapies for immune-related diseases.

Elucidating Cuproptosis-Associated Genes in the Progression from Nash to HCC Using Bulk and Single-Cell RNA Sequencing Analyses and Experimental Validation

Background and Objectives: Non-alcoholic steatohepatitis (NASH) is a significant risk factor for hepatocellular carcinoma (HCC) development. Timely treatment during the NASH stage is essential to minimize the possibility of disease progression to HCC. Cuproptosis is a newly identified form of cellular death that could impact the progression of various diseases and cancers. Materials and Methods: Transcriptome and single-cell sequencing datasets were utilized to investigate the role of cuproptosis-related genes (CRGs) in NASH progression to HCC. FDX1, LIPT1, and PDHP were identified as CRGs in NASH patients, and FDX1, DBT, GCSH, SLC31A1, and DLAT were identified as CRGs in patients with NASH progressing to HCC. FDX1 was found to play a significant role in both NASH patients and patients with NASH progressing to HCC. This study constructed cuproptosis-related clusters (CRCs) using the Nonnegative Matrix Factorization algorithm, and they were linked to fatty acid metabolism and the PPAR signaling pathway in both NASH CRCs and HCC CRCs. The Weighted Correlation Network Analysis algorithm identified CRP, CRC, TAT, CXCL10, and ACTA1 as highly relevant genes in NASH CRCs and HCC CRCs. The expression of FDX1 was validated in both mouse models and human NASH samples. Results: The investigation highlights FDX1 as a pivotal CRG in both NASH and NASH progression to HCC. The comprehensive characterization of CRGs sheds light on their potential biofunctional importance in the context of NASH and HCC. Our experimental results show that FDX1 expression was significantly increased in NASH patients. Conclusions: The present study identified key CRGs, revealing their potential impact on NASH and HCC. Meanwhile, targeting FDX1 may prevent the progression of NASH to HCC.

Protective effects of cordycepin pretreatment against liver ischemia/reperfusion injury in mice

INTRODUCTION

Cordycepin has been reported to exhibit hepatic protective and anti-inflammatory properties. Here, we investigated the role of cordycepin in ischemia/reperfusion (IR)-induced liver injury in a mouse model.

METHODS

Mice were pretreated with cordycepin by gavage for 3 weeks, followed by the establishment of the IR modeling. Liver injury, Suzuki's histological grading, hepatic apoptosis, and inflammatory responses were evaluated by biochemical and pathological analysis.

RESULTS

It was found that Cordycepin pretreatment at 50 mg/kg for 3 weeks attenuated IR-induced liver injury, as reflected by the significant decrease of the levels of aspartate aminotransferase, alanine transaminase, lactate dehydrogenase, and low-density lipoprotein. Cordycepin pretreatment also reduced histopathological changes, attenuated hepatocyte apoptosis, inflammatory responses in the livers of IR mice. Mechanically, toll-like receptor 4/nuclear factor kappa-B signaling in liver tissues was inhibited by Cordycepin pretreatment.

CONCLUSIONS

In conclusion, Cordycepin pretreatment protects IR-induced liver injury, which demonstrates its potential for the treatment of IR in the liver.

Glycyrrhetinic acid proliposomes mediated by mannosylated ligand: Preparation, physicochemical characterization, environmental stability and bioactivity evaluation

Glycyrrhetinic acid is a bioactive compound extracted from licorice that exhibits inhibition effect on various cancers. However, its hydrophobicity results in low bioavailability that limits application. We aim to overcome this barrier, the present research was performed to prepare glycyrrhetinic acid proliposomes mediated mannosylated ligand (mannose-diester lauric diacid-cholesterol, MDC) and to evaluate its physicochemical characterizations, environmental stability and bioactivity. In preliminary optimization studies of glycyrrhetinic acid proliposomes mediated MDC (MDC-GA-PL), four optimum operating parameters, cryoprotectant of glucose and mannitol, the mixed cryoprotectant ratio (glucose/mannitol) of 1:1, a cryoprotectant/egg phosphatidylcholine mass ratio of 10/1, and -60 ℃ pre-freezing temperature, were obtained after investigation. Under the optimum lyophilization conditions, MDC-GA-PL was freeze-dried and reconstituted proliposomes were characterized. These proliposomes showed that MDC-GA-PL were well-dispersible spherical particles with an average particle size of 120.80 nm, a polydispersity index about 0.095, a zeta potential of -33.15 mV, encapsulation efficiency of 85.9% and drug loading of 6.38%. In vitro drug release study showed that glycyrrhetinic acid release of MDC-GA-PL conforms to the Higuchi release model. In addition, these proliposomes were stable during six months at 4 ℃. Moreover, acute toxicity assay revealed no substantial safety concern for MDC-GA-PL. Finally, in vitro bioactivity of proliposomes was evaluated. Cytotoxicity effect and apoptosis efficiency of MDC-GA-PL by HepG2 cells was significantly higher than that of glycyrrhetinic acid proliposomes without MDC, demonstrating that MDC has a desirable effect on liver target. Overall, we have reason to believe that MDC-GA-PL would be a promising target delivery to improve therapeutic against hepatic diseases.

Recent Advances Regarding the Molecular Mechanisms of Triterpenic Acids: A Review (Part II)

Triterpenic acids are a widespread class of phytocompounds which have been found to possess valuable therapeutic properties such as anticancer, anti-inflammatory, hepatoprotective, cardioprotective, antidiabetic, neuroprotective, lipolytic, antiviral, and antiparasitic effects. They are a subclass of triterpenes bearing a characteristic lipophilic structure that imprints unfavorable in vivo properties which subsequently limit their applications. The early investigation of the mechanism of action (MOA) of a drug candidate can provide valuable information regarding the possible side effects and drug interactions that may occur after administration. The current paper aimed to summarize the most recent (last 5 years) studies regarding the MOA of betulinic acid, boswellic acid, glycyrrhetinic acid, madecassic acid, moronic acid, and pomolic acid in order to provide scientists with updated and accessible material on the topic that could contribute to the development of future studies; the paper stands as the sequel of our previously published paper regarding the MOA of triterpenic acids with therapeutic value. The recent literature published on the topic has highlighted the role of triterpenic acids in several signaling pathways including PI3/AKT/mTOR, TNF-alpha/NF-kappa B, JNK-p38, HIF-α/AMPK, and Grb2/Sos/Ras/MAPK, which trigger their various biological activities.

18β-Glycyrrhetinic Acid Protects against Cholestatic Liver Injury in Bile Duct-Ligated Rats

18β-Glycyrrhetinic acid is a nutraceutical agent with promising hepatoprotective effects. Its protective mechanisms against cholestatic liver injury were further investigated in a rodent model of extrahepatic cholestasis caused by Bile Duct Ligation (BDL) in rats. The daily oral administration of 18β-Glycyrrhetinic acid improved liver histology, serum biochemicals, ductular reaction, oxidative stress, inflammation, apoptosis, impaired autophagy, and fibrosis. 18β-Glycyrrhetinic acid alleviated the BDL-induced hepatic and systemic retention of bile acids, matrix-producing cell activation, hepatic collagen deposition, Transforming Growth Factor beta-1/Smad activation, malondialdehyde elevation, glutathione reduction, High Mobility Group Box-1/Toll-Like Receptor-4 activation, NF-κB activation, inflammatory cell infiltration/accumulation, Interleukin-1β expression, Signal Transducer and Activator of Transcription-1 activation, Endoplasmic Reticulum stress, impairment autophagy, and caspase 3 activation. Conversely, the protein expression of Sirt1, Farnesoid X Receptor, nuclear NF-E2-Related Factor-2, Transcription Factor EB, bile acid efflux transporters, and LC3-II, as well as the protein phosphorylation of AMP-Activated Protein Kinase, was promoted in 18β-Glycyrrhetinic acid-treated BDL rats. The hepatoprotective effects of 18β-Glycyrrhetinic acid in the present investigation correlated well with co-activation and possible interactions among Sirt, FXR, and Nrf2. The concurrent or concomitant activation of Sirt1, FXR, and Nrf2 not only restored the homeostatic regulation of bile acid metabolism, but also alleviated oxidative stress, inflammation, apoptosis, impaired autophagy, and fibrosis.

Curculigoside mitigates hepatic ischemia/reperfusion-induced oxidative stress, inflammation, and apoptosis via activation of the Nrf-2/HO-1 pathway

Curculigoside has been shown to decrease oxidative stress and inflammatory reactions in many disorders, but its effects during hepatic ischemia-reperfusion injury (IRI) remain unknown. This research aims to determine the protective role and the potential mechanism of action of curculigoside in hepatic IRI. Here, a well-established rat model of partial warm IRI was constructed; serum ALT/AST and H&E staining were employed to assay the extent of liver injury; the superoxide dismutase, malondialdehyde, IL-6, and TNF-α contents were determined using the corresponding kits; the apoptosis index was evaluated by TUNEL staining; and the expression of Nrf-2, HO-1, and apoptosis-associated proteins was detected by qRT-PCR and Western blotting. The results showed that curculigoside pretreatment effectively mitigated hepatic IRI, as demonstrated by decreases in the levels of serum aminotransferases, hepatocellular necrosis and apoptosis, oxidative stress markers, infiltration of inflammatory cells, and secretion of proinflammatory cytokines. Mechanistically, the expression of Nrf-2 and HO-1 was greatly suppressed by hepatic IRI and reactivated by curculigoside. Furthermore, cotreatment with ML-385, an inhibitor of Nrf-2, counteracted the protective effect of curculigoside against hepatic IRI. The results of our study show that curculigoside plays a protective role in hepatic IRI by inhibiting oxidative stress, inflammation, and apoptosis and that its effects may be associated with activation of the Nrf-2/HO-1 pathway.

Liposomal chrysin attenuates hepatic ischaemia-reperfusion injury: possible mechanism via inhibiting NLRP3 inflammasome

OBJECTIVES

The chrysin has properties of low aqueous solubility, bioavailability and absorption, and its effect on hepatic ischaemia-reperfusion (HIR) remains unclear. Thus, we prepared a liposomal chrysin (LC) and explored its effect and potential mechanism on HIR.

METHODS

A thin-film dispersion method was used to prepare LC, and a mouse HIR model was used. Mice were pre-treated with LC (100 mg/kg) or placebo by gavage feeding at 16.5 h, 8.5 h, 0.5 h before modelling.

RESULTS

The average particle sizes, polydispersity index, zeta potential, encapsulation efficiency and drug loading of LC were 129 ± 13.53 nm, 0.265 ± 0.021, -34.46 ± 4.14 mV, 95.03 ± 2.17%, 16.4 ± 0.8%. The concentration of chrysin in plasma and liver tissue by LC administration increased 2.54 times and 1.45 times. LC pre-treatment reduced HIR-induced liver injury and inhibited cell apoptosis. Besides, LC pre-treatment decreased reactive oxygen species and malondialdehyde and inhibited the inflammation response indicated by lower IL-6, TNF-α, infiltration of neutrophils. Further, LC pre-treatment significantly decreased NLRP3 activation, evidenced by reduced cleaved caspase-3, NLRP3, ASC, cleaved caspase-1 and IL-1β expression.

CONCLUSIONS

LC has good biocompatibility, and it could attenuate HIR-induced injury. Its mechanism was associated with NLRP3 inflammasome inhibition, and LC might be an effective drug for treating and preventing HIR-induced injury.

Resveratrol modulates Toxoplasma gondii infection induced liver injury by intervening in the HMGB1/TLR4/NF-κB signaling pathway

Toxoplasma gondii (T. gondii) is an obligate intracellular parasite that can cause liver diseases in the host, including hepatitis and hepatomegaly. High mobility group box 1 (HMGB1) is the main inflammatory mediator causing cell injury or necrosis. HMGB1 binds to toll like receptor 4 (TLR4), then activates the nuclear factor-κB (NF-κB) signaling pathway, which promotes the release of inflammatory factors. Our previous studies showed that HMGB1 mediated TLR4/NF-κB signaling pathway plays an important role in liver injury induced by T. gondii infection. Resveratrol (RSV) is a small polyphenol, which has anti-inflammatory, anti-cancer, anti-T. gondii effect. However, the effect of RSV on liver injury caused by T. gondii infection is unclear. This study used the RH strain tachyzoites of T. gondii to infect murine liver line, NCTC-1469 cells to establish an in vitro model and acute infection of mice for the in vivo model to explore the protective effect of RSV on liver injury induced by T. gondii infection. The results showed that RSV inhibited the proliferation of T. gondii in the liver, reduced the alanine aminotransferase/aspartate aminotransferase levels and pathological liver damage. Additionally, RSV inhibited the production of tumor necrosis factor-α, inducible nitric oxide synthase and HMGB1 by interfering with the TLR4/NF-κB signaling pathway. These results indicate that RSV can protect liver injury caused by T. gondii infection by intervening in the HMGB1/TLR4/NF-κB signaling pathway. This study will provide a theoretical basis for RSV treatment of T. gondii infection induced liver injury.

Augmenter of liver regeneration ameliorates ischemia-reperfusion injury in steatotic liver via inhibition of the TLR4/NF-κB pathway

Hepatocytes from donors with preexisting hepatic steatosis exhibited increased sensitivity to ischemia-reperfusion injury (IRI) during liver transplantation. Augmenter of liver regeneration (ALR) protected the liver against IRI, but the mechanism was not clarified. Therefore, the hypothesis that ALR attenuated IRI in steatotic liver by inhibition of inflammation and downregulation of the Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) pathway was examined. C57BL/6 mice were subjected to a methionine-choline-deficient (MCD) diet to induce liver steatosis. Mice were transfected with ALR-containing adenovirus 3 days prior to partial warm hepatic IRI. After 30 min of ischemia and 6 h of reperfusion injury, liver function, hepatic injury, the inflammatory response and TLR4/NF-κB signaling pathway activation were assessed. ALR maintained liver function and alleviated hepatic injury as indicated by the decreased levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), preserved hepatic structure and reduced apoptosis. ALR also reduced the IRI-induced inflammatory response by suppressing Kupffer cell activation, inhibiting neutrophil chemotaxis and reducing inflammatory cytokine production. Further investigation using reverse transcription-quantitative PCR, western blotting and immunohistochemistry revealed that ALR reduced TLR4/NF-κB signaling pathway activation, which led to a decreased synthesis of inflammatory cytokines. ALR functioned as a regulator of the IRI-induced inflammatory response by suppressing the TLR4/NF-κB pathway, which supports the use of ALR in therapeutic applications for fatty liver transplantation.

Efficacy of Complex Phytoadaptogens as an Adjunct to Non-surgical Treatment of Chronic Periodontitis: A Randomized Clinical Trial

Background:

Many herbal formulas are used in dentistry in the complex treatment and prevention of periodontitis, but it is not always possible to achieve a long-term remission and stimulate regeneration of periodontal structures.

Aim:

The aim of this randomized clinical trial was to assess the efficacy of chronotherapy with complex phytoadaptogens (CFA) as an adjunct to non-surgical periodontal treatment (NSPT) and to achieve long-term remission.

Materials and Methods:

Forty systemically healthy patients with chronic generalized periodontitis (probing pocket depth ≥5 mm) were randomly divided into two groups: patients in one group received treatment with NSPT alone (group 2), whereas patients in another group received CFA in addition to NSPT (group 3). Twenty individuals with healthy periodontium (group 1) composed a control group. The clinical outcomes, Simplified Oral Hygiene Index (OHI-S), Sulcus Bleeding Index (SBI), Periodontal Index (PI), and Doppler ultrasound results, were assessed on baseline, after treatment, and 6 months after treatment.

Results:

There was a statistically significant difference between groups 2 and 3, in favor of group 3 in terms of microcirculation parameters—S (P = 0.03), M (P = 0.02), D (P = 0.03), and RI (P = 0.005); indicators of PI (P = 0.005), SBI (P = 0.03), and OHI-S (P = 0.006) were closer to the normal values during 6-month follow-up. Also there was a statistical difference (P < 0.05) at all time points compared with controls, for several parameters in intragroup comparison.

Conclusion:

The data obtained confirm the hypothesis that CFA application in chronic periodontitis treatment is more than appropriate for long-term prevention due to their immunomodulatory, anti-inflammatory, antioxidant, stress-limiting, chronotropic effects.

Research progress on the protective effects of licorice-derived 18β-glycyrrhetinic acid against liver injury

The first description of the medical use of licorice appeared in "Shennong Bencao Jing", one of the well-known Chinese herbal medicine classic books dated back to 220-280 AD. As one of the most commonly prescribed Chinese herbal medicine, licorice is known as "Guo Lao", meaning "a national treasure" in China. Modern pharmacological investigations have confirmed that licorice possesses a number of biological activities, such as antioxidation, anti-inflammatory, antiviral, immune regulation, and liver protection. 18β-glycyrrhetinic acid is one of the most extensively studied active integrants of licorice. Here, we provide an overview of the protective effects of 18β-glycyrrhetinic acid against various acute and chronic liver diseases observed in experimental models, and summarize its pharmacological effects and potential toxic/side effects at higher doses. We also make additional comments on the important areas that may warrant further research to support appropriate clinical applications of 18β-glycyrrhetinic acid and avoid potential risks.

SIRT1 alleviates hepatic ischemia-reperfusion injury via the miR-182-mediated XBP1/NLRP3 pathway

The hepatoprotection of histone deacetylase sirtuin 1 (SIRT1) has been identified to attenuate ischemia-reperfusion (IR)-triggered inflammation and liver damage. This study was performed to characterize the function of SIRT1 in hepatic IR injury. In in vivo assays on liver-specific knockout mice of SIRT1, we first validated the effect of SIRT1 knockout on liver damage and XBP1/NLRP3 inflammasome activation. Next, we examined whether knockdown of XBP1/NLRP3 or miR-182 agomir could reverse the effect of SIRT1 knockout. In in vitro assays, NCTC1469 cells subjected to hypoxia/reoxygenation (H/R) were transduced with small interfering RNA (siRNA)/activator of SIRT1 or miR-182 agomir to confirm the effect of SIRT1 on NCTC1469 cell behaviors as well as the regulation of miR-182 and the XBP1/NLRP3 signaling pathway. Hepatic IR injury was appreciably aggravated in SIRT1 knockout mice, and SIRT1 knockdown abolished the inhibition of XBP1/NLRP3 inflammasome activation, which was reversed by NLRP3 knockdown, XBP1 knockdown, or miR-182 agomir. Mechanistically, miR-182 expression was positively regulated by SIRT1 in hepatic IR injury in mice, and miR-182 inhibited the expression of XBP1 by binding to the 3' untranslated region (UTR) of XBP1. The histone deacetylase SIRT1 inhibits the downstream XBP1/NLRP3 inflammatory pathway by activating miR-182, thus alleviating hepatic IR injury in mice.

Administration of glycyrrhetinic acid reinforces therapeutic effects of mesenchymal stem cell-derived exosome against acute liver ischemia-reperfusion injury

Recent studies have shown that mesenchymal stem cell‐derived exosome could attenuate ischaemia‐reperfusion (I/R) injury by suppressing inflammatory response in the liver. Glycyrrhetinic acid was also shown to be capable of repressing the TLR4 signalling pathway. However, it remains to be explored as whether the combined administration of mesenchyma stem cell (MSC)‐derived exosome and glycyrrhetinic acid (GA) could increase their therapeutic effects on I/R injury. Western blot was performed to evaluate the expression of proteins associated with inflammatory response in THP‐1 cells and I/R rat models treated under different conditions. Flow cytometry was carried out to analyse the proportions of different subtypes of peripheral blood cells in I/R rats. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured to assess the liver injury in I/R rats. Combined treatment with MSC‐derived exosome and GA effectively maintained the expression of key proteins involved in inflammatory response in LPS stimulated THP‐1 cells and THP‐1 cells treated under hypoxia conditions. In the established of I/R rat models, GA administration reinforced the therapeutic efficiency of MSC‐derived exosomes by maintaining the proportion of different subgroups of peripheral blood cells, decreasing the concentration of ALT and AST, and restoring the expression of dysregulated proteins associated with inflammation. Our results demonstrated that treatment with exosomes derived from mesenchymal stem cells (MSCs) attenuated liver I/R injury, while the pre‐treatment with GA may further promote the therapeutic effect of mesenchymal stem cell‐derived exosome against acute liver ischaemia‐reperfusion injury.

Assessment of Ankaferd Blood Stopper in experimental liver ischemia reperfusion injury

BACKGROUND/AIM

To investigate possible protective effects of Ankaferd Blood Stopper® (ABS) in an experimental liver ischemia reperfusion injury (IRI) model.

MATERIALS AND METHODS

The study was carried out on 30 female rats separated into 3 groups as sham, control (IRI), and treatment (IRI + ABS) groups. In the IRI + ABS group, 0.5 mL/day ABS was given for 7 days before surgery. In the IRI and IRI + ABS groups, the hepatic pedicle was clamped for 30 min to apply ischemia. Then, after opening the clamp, 90-min reperfusion of the liver was provided. Blood and liver tissue samples were taken for biochemical and histopathological analyses.

RESULTS

Compared to the sham group, the IRI group had significantly higher levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total oxidant status (TOS), malondialdehyde (MDA), fluorescent oxidant products (FOP) and lower expression of albumin and total antioxidant status (TAS) (P < 0.05). Compared to the IRI group, the IRI+ABS group showed lower expression of AST, ALT, TOS, MDA and FOP and higher expression of albumin and TAS (P < 0.05). In the histopathological analysis, congestion scores were statistically significantly lower in the IRI + ABS group than in the IRI group.

CONCLUSIONS

ABS has a strong hepatoprotective effect due to its antioxidant and antiinflammatory effects and could therefore be used as a potential therapeutic agent for IRI.

Anti-Inflammatory and Antioxidant Effect of Eucommia ulmoides Polysaccharide in Hepatic Ischemia-Reperfusion Injury by Regulating ROS and the TLR-4-NF-κB Pathway

Eucommia ulmoides polysaccharide (EUP) has been shown to have anti-inflammatory and antioxidant effects. However, the mechanism underlying these effects has rarely been reported, and whether EUP can reduce liver injury in hepatic ischemia-reperfusion injury (HIRI) has not been reported. In this study, 40 Sprague-Dawley (SD) rats were randomly divided into 5 groups: the sham group, ischemia-reperfusion (I/R) group, and three EUP pretreatment groups (320 mg/kg, 160 mg/kg, and 80 mg/kg). SD rats were pretreated with EUP by gavage once a day prior to I/R injury for 10 days. Except for the sham group, blood flow in the middle and left liver lobes was blocked in all the other groups, resulting in 70% liver ischemia, and the ischemia and reperfusion times were 1 h and 4 h, respectively. Ischemic liver tissue and serum were obtained to detect biochemical markers and liver histopathological damage. Compared with the I/R group, after EUP pretreatment, serum alanine aminotransferase, aspartate aminotransferase, tumor necrosis factor-α, and interleukin-1β levels were significantly decreased, malondialdehyde levels in liver tissues were significantly decreased, superoxide dismutase levels were significantly increased, and the area of liver necrosis was notably reduced. To understand the specific mechanism involved, we determined the levels of Toll-like receptor- (TLR-) 4-nuclear factor-kappaB (NF-κB) pathway-associated proteins in vivo and in vitro. The data showed that EUP can reduce liver damage by decreasing ROS levels and inhibiting TLR-4-NF-κB pathway activation and may be a promising drug in liver surgery to prevent HIRI.

Novel 3'-Substituted-1',2',4'-Oxadiazole Derivatives of 18βH-Glycyrrhetinic Acid and Their O-Acylated Amidoximes: Synthesis and Evaluation of Antitumor and Anti-Inflammatory Potential In Vitro and In Vivo

A series of novel 18βH-glycyrrhetinic acid (GA) derivatives containing 3'-(alkyl/phenyl/pyridin(-2″, -3″, and -4″)-yl)-1',2',4'-oxadiazole moieties at the C-30 position were synthesized by condensation of triterpenoid's carboxyl group with corresponding amidoximes and further cyclization. Screening of the cytotoxicity of novel GA derivatives on a panel of tumor cell lines showed that the 3-acetoxy triterpenoid intermediates-O-acylated amidoxime 3a-h-display better solubility under bioassay conditions and more pronounced cytotoxicity compared to their 1',2',4'-oxadiazole analogs 4f-h (median IC50 = 7.0 and 49.7 µM, respectively). Subsequent replacement of the 3-acetoxy group by the hydroxyl group of pyridin(-2″, 3″, and -4″)-yl-1',2',4'-oxadiazole-bearing GA derivatives produced compounds 5f-h, showing the most pronounced selective toxicity toward tumor cells (median selectivity index (SI) > 12.1). Further detailed analysis of the antitumor activity of hit derivative 5f revealed its marked proapoptotic activity and inhibitory effects on clonogenicity and motility of HeLa cervical carcinoma cells in vitro, and the metastatic growth of B16 melanoma in vivo. Additionally, the comprehensive in silico study revealed intermediate 3d, bearing the tert-butyl moiety in O-acylated amidoxime, as a potent anti-inflammatory candidate, which was able to effectively inhibit inflammatory response induced by IFNγ in macrophages in vitro and carrageenan in murine models in vivo, probably by primary interactions with active sites of MMP9, neutrophil elastase, and thrombin. Taken together, our findings provide a basis for a better understanding of the structure-activity relationship of 1',2',4'-oxadiazole-containing triterpenoids and reveal two hit molecules with pronounced antitumor (5f) and anti-inflammatory (3d) activities.

Glycyrrhetinic acid alleviates hepatic inflammation injury in viral hepatitis disease via a HMGB1-TLR4 signaling pathway

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Licorice defect in TCM recipes leads to the hepatotoxicity in administrated mice.

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GA inhibits viral hepatitis by suppressing HMGB1 release and cytokine activity.

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GA treatment effect on infected mice is similar with HMGB1 neutralizing antibody.

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HMGB1-TLR4 axis is involved in murine hepatic injury during MHV infection.

Various human disorders are cured by the use of licorice, a key ingredient of herbal remedies. Glycyrrhizic acid (GL), a triterpenoid glycoside, is the aqueous extract from licorice root. Glycyrrhetinic acid (GA) has been reported to be a major bioactive hydrolysis product of GL and has been regarded as an anti-inflammatory agent for the treatment of a variety of inflammatory diseases, including hepatitis. However, the mechanism by which GA inhibits viral hepatic inflammatory injury is not completely understood. In this study, we found that, by consecutively treating mice with a traditional herbal recipe, licorice plays an important role in the detoxification of mice. We also employed a murine hepatitis virus (MHV) infection model to illustrate that GA treatment inhibited activation of hepatic inflammatory responses by blocking high-mobility group box 1 (HMGB1) cytokine activity. Furthermore, decreased HMGB1 levels and downstream signaling triggered by injection of a neutralizing HMGB1 antibody or TLR4 gene deficiency, also significantly protected against MHV-induced severe hepatic injury. Thus, our findings characterize GA as a hepatoprotective therapy agent in hepatic infectious disease not only by suppressing HMGB1 release and blocking HMGB1 cytokine activity, but also via an underlying viral-induced HMGB1-TLR4 immunological regulation axis that occurs during the cytokine storm. The present study provides a new therapy strategy for the treatment of acute viral hepatitis in the clinical setting.

Yinning Tablet, a hospitalized preparation of Chinese herbal formula for hyperthyroidism, ameliorates thyroid hormone-induced liver injury in rats: Regulation of mitochondria-mediated apoptotic signals

ETHNOPHARMACOLOGICAL RELEVANCE

Hyperthyroidism is closely associated with liver injury. The preliminary clinical observation suggests that Yinning Tablet, a hospitalized preparation of traditional Chinese formula for hyperthyroidism, improves not only hyperthyroidism, but also hyperthyroidism-associated liver injury.

AIM

To evaluate the effect and underlying mechanisms of Yinning Tablet on thyroid hormone-induced liver injury.

MATERIALS AND METHODS

Female rats were orally administered L-thyroxine (1 mg/kg) once daily for 60 days, and co-treated with the carefully identified Yinning Tablet extract (0.6-2.4 g/kg) during the last 30 days. Blood and liver variables were determined enzymatically, histologically, by ELISA, radioimmunoassay, Real-Time PCR or Western blot, respectively.

RESULTS

Co-treatment with the extract attenuated L-thyroxine-induced increases in serum alanine transaminase and aspartate transaminase activities, the ratio of liver weight to body weight, cytoplasmic vacuolization in hepatocytes, infiltrated inflammatory cells and confused structures in liver tissue, accompanied by attenuation of increased serum triiodo-l-thyronine concentration and hepatic deiodinase type I overexpression in rats. Importantly, Yinning Tablet suppressed L-thyroxine-triggered hepatic Bax, cleaved caspases-3, -8 and -9 protein overexpression, and Bcl-2 protein downregulation. Furthermore, the increases in cytochrome c protein expression, Ca²⁺-ATPase activity and malondialdehyde content, and decreases in activities of Na⁺/K⁺-ATPase, catalase, superoxide dismutase and glutathione peroxidase, and total antioxidant capacity in liver tissue were attenuated.

CONCLUSION

The present results suggest that Yinning Tablet ameliorates thyroid hormone-induced liver injury in rats by regulating mitochondria-mediated apoptotic signals. Our findings go insight into the pharmacological basis of the hospitalized preparation for treatment of hyperthyroidism-associated liver injury.

Rapid quantitative analysis of 18 chemical constituents in HuangQi JianZhong Tang based on UHPLC-MS

A rapid, highly sensitive, and specific analytical method using ultra-high-performance liquid chromatography-triple quadruple MS was developed to quantitatively measure 18 chemical constituents in Huangqi Jianzhong Tang (HQJZ), a famous traditional Chinese medicine formula. Chromatographic separation was performed on a Waters ACQUITY UPLC HSS T3 column (2.1 mm × 100 mm, 1.8 μm) with a gradient mobile phase (A: 0.1% aqueous formic acid and B: acetonitrile) at a flow rate of 0.25 mL/min. The chromatographic peaks of 18 components were identified by comparing with the reference compounds. Multiple reaction monitoring was employed for quantitative analysis of the components. Seven batches of HQJZ samples were analyzed with a good linear regression relationship (R² , .9978-.9993), precisions [relative standard deviation (RSD), 0.90%-3.60%], repeatability (RSD, 2.50%-4.00%), stability (RSD, 1.00%-4.00%), and recovery (96.10%-104.30%). Based on this established method, the present study offered a highly sensitive, specific, and rapid determination method for identification of 18 compounds, which greatly promoted the systemic quality control of HQJZ.