Protective effects of n-Butanol extract and iridoid glycosides of Veronica ciliata Fisch. Against ANIT-induced cholestatic liver injury in mice

Exploration of the Combined Mechanism of Direct and Indirect Effects of Paeoniflorin in the Treatment of Cholestasis

Cholestasis is a multifactorial hepatobiliary disorder, characterized by obstruction of bile flow and accumulation of bile, which in turn causes damage to liver cells and other tissues. In severe cases, it can result in the development of life-threatening conditions, including cirrhosis and liver cancer. Paeoniflorin (PF) has been demonstrated to possess favourable therapeutic potential for the treatment of cholestasis. The objective of this research was to examine the molecular mechanism of PF in the treatment of ANIT-induced cholestasis and to propose novel avenues for further research on the pharmacological effects of PF. In vivo and in vitro models of cholestasis were developed. The histopathological changes in the bile ducts and liver were evaluated through the use of hematoxylin and eosin (HE) staining. The extent of apoptosis was evaluated through the use of immunofluorescence (IF), immunoblotting (WB), and electron microscopy. The JNK signalling pathway was identified as the direct mechanism of action of PF through the utilisation of HuProt™ 20 K chips and other technologies. The present study demonstrated that PF markedly alleviated liver injury in an ANIT-induced cholestasis model. Specifically, PF was observed to attenuate cholestasis-induced liver injury by reducing the abnormal elevation of liver function indices and suppressing the expression of inflammatory mediators. Furthermore, PF exhibited anti-apoptotic properties in both in vivo and in vitro experiments, thereby mitigating cholestasis-induced hepatocyte apoptosis. These protective effects are attributable to the fact that PF exerts its action through direct interaction with the JNK pathway. It has been demonstrated that PF is capable of binding directly to MAPK8 (JNK1) and MAPK9 (JNK2), thereby inhibiting JNK activation and reducing apoptosis. With regard to the protection of bile ducts, PF may indirectly inhibit hepatocyte apoptosis by maintaining the structural integrity and tight junctions of bile duct cells. PF improved cholestasis by inhibiting hepatocyte apoptosis directly by targeting the JNK signaling pathway and indirectly inhibited hepatocyte apoptosis by improving the tight junctions of bile duct cells to regulate the bile duct microenvironment.

Pirfenidone ameliorates ANIT-induced cholestatic liver injury via modulation of FXR, NF-кB/TNF-α, and Wnt/GSK-3β/β-catenin signaling pathways

Cholestasis is a hepatobiliary disorder characterized by the excessive accumulation of toxic bile acids in hepatocytes, leading to cholestatic liver injury (CLI) through multiple pathogenic inflammatory pathways. Currently, there are limited therapeutic options for the management of cholestasis and associated CLI; therefore, new options are urgently needed. Pirfenidone (PF), an oral bioavailable pyridone analog, is used for the treatment of idiopathic pulmonary fibrosis. PF has recently demonstrated diverse potential therapeutic activities against different pathologies. Accordingly, the present study adopted the α-naphthyl isothiocyanate (ANIT)-induced CLI model in mice to explore the potential protective impact of PF and investigate the underlying mechanisms of action. PF intervention markedly reduced the serum levels of ALT, AST, LDH, total bilirubin, and total bile acids, which was accompanied by a remarkable amelioration of histopathological lesions induced by ANIT. PF also protected the mice against ANIT-induced redox imbalance in the liver, represented by reduced MDA levels and elevated GSH and SOD activities. Mechanistically, PF inhibited ANIT-induced downregulated expressions of the farnesoid X receptor (FXR), as well as the bile salt export pump (BSEP) and the multidrug resistance-associated protein 2 (MRP2) bile acid efflux channels. PF further repressed ANIT-induced NF-κB activation and TNF-α and IL-6 production. These beneficial effects were associated with its ability to dose-dependently inhibit Wnt/GSK-3β/β-catenin/cyclin D1 signaling. Collectively, PF protects against ANIT-induced CLI in mice, demonstrating powerful antioxidant and anti-inflammatory activities as well as an ability to oppose BA homeostasis disorder. These protective effects are primarily mediated by modulating the interplay between FXR, NF-κB/TNF-α/IL-6, and Wnt/β-catenin signaling pathways.

Targeting SIRT1/AMPK/Nrf2/NF-кB by sitagliptin protects against oxidative stress-mediated ER stress and inflammation during ANIT-induced cholestatic liver injury

Intrahepatic cholestasis is a common clinical form of hepatobiliary injury characterized by the intrahepatic accumulation of toxic bile acids. Besides its antidiabetic activity, the dipeptidyl peptidase IV inhibitor sitagliptin (SG) has been recently assigned diverse pharmacological activities and therapeutic potential against different disorders owing to its emerging antioxidant and anti-inflammatory properties. The current study explored the potential hepatoprotective effect of SG on α-naphthyl isothiocyanate (ANIT)-induced cholestatic liver injury (CLI) in mice and investigate its possible targeted signaling pathways. Mice received SG (10 and 20 mg/kg) for four consecutive days, two days before and after a single oral administration of ANIT (75 mg/kg). Our results revealed that SG administration remarkably prevented ANIT-induced histopathological lesions in the liver and maintained hepatic functions and oxidative/antioxidant balance. Ultimately, SG counteracted the inflammatory response in the liver, as indicated by the marked suppression of hepatic expression of NF-κB, TNF-α, and IL-6. Moreover, it inhibited the endoplasmic reticulum (ER) stress response in the liver. These beneficial effects of SG were accompanied by upregulation of SIRT1, p-AMPK, and Nrf2 expressions while downregulating keap1 expression in the liver. In conclusion, this study is the first to demonstrate the ability of SG to protect against ANIT-induced CLI through modulating multiple signaling cascades, including SIRT1/AMPK, Nrf2/keap1, and NF-кB, which resulted in enhanced antioxidant capacity and repressed inflammatory and ER stress responses in the liver.

Mechanistic studies on the alleviation of ANIT-induced cholestatic liver injury by Polygala fallax Hemsl. polysaccharides

ETHNOPHARMACOLOGICAL RELEVANCE

Polygala fallax Hemsl. is a traditional folk medicine commonly used by ethnic minorities in the Guangxi Zhuang Autonomous Region, and has a traditional application in the treatment of liver disease. Polygala fallax Hemsl. polysaccharides (PFPs) are of interest for their potential health benefits.

AIM OF THIS STUDY

This study explored the impact of PFPs on a mouse model of cholestatic liver injury (CLI) induced by alpha-naphthyl isothiocyanate (ANIT), as well as the potential mechanisms.

MATERIALS AND METHODS

A mouse CLI model was constructed using ANIT (80 mg/kg) and intervened with different doses of PFPs or ursodeoxycholic acid. Their serum biochemical indices, hepatic oxidative stress indices, and hepatic pathological characteristics were investigated. Then RNA sequencing was performed on liver tissues to identify differentially expressed genes and signaling pathways and to elucidate the mechanism of liver protection by PFPs. Finally, Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were used to verify the differentially expressed genes.

RESULTS

Data analyses showed that PFPs reduced the levels of liver function-related biochemical indices, such as ALT, AST, AKP, TBA, DBIL, and TBIL. PFPs up-regulated the activities of SOD and GSH, down-regulated the contents of MDA, inhibited the release of IL-1β, IL-6, and TNF-α, or promoted IL-10. Pathologic characterization of the liver revealed that PFPs reduced hepatocyte apoptosis or necrosis. The RNA sequencing indicated that the genes with differential expression were primarily enriched for the biosynthesis of primary bile acids, secretion or transportation of bile, the reactive oxygen species in chemical carcinogenesis, and the NF-kappa B signaling pathway. In addition, the results of qRT-PCR and Western blotting analysis were consistent with those of RNA sequencing analysis.

CONCLUSIONS

In summary, this study showed that PFPs improved intrahepatic cholestasis and alleviated liver damage through the modulation of primary bile acid production, Control of protein expression related to bile secretion or transportation, decrease in inflammatory reactions, and inhibition of oxidative pressure. As a result, PFPs might offer a hopeful ethnic dietary approach for managing intrahepatic cholestasis.

A Transcriptomic and Metabolomic Study on the Biosynthesis of Iridoids in Phlomoides rotata from the Qinghai-Tibet Plateau

Phlomoides rotata is a traditional Chinese herbal medicine that grows in the Qinghai-Tibet Plateau region at a 3100-5000 m altitude. Iridoid compounds are the main active compounds of the P. rotata used as medical ingredients and display anti-inflammatory, analgesic, and hepatoprotective properties. To better understand the biological mechanisms of iridoid compounds in this species, we performed a comprehensive analysis of the transcriptome and metabolome of P. rotata leaves from four different regions (3540-4270 m). Global metabolome profiling detected 575 metabolites, and 455 differentially accumulated metabolites (DAMs) were detected in P. rotata leaves from the four regions. Eight major DAMs related to iridoid metabolism in P. rotata leaves were investigated: shanzhiside methyl ester, 8-epideoxyloganic acid, barlerin, shanzhiside, geniposide, agnuside, feretoside, and catalpin. In addition, five soil physical and chemical indicators in P. rotata rhizosphere soils were analyzed. Four significant positive correlations were observed between alkaline nitrogen and geniposide, exchangeable calcium and geniposide, available potassium and shanzhiside, and available phosphorus and shanzhiside methyl ester. The transcriptome data showed 12 P. rotata cDNA libraries with 74.46 Gb of clean data, which formed 29,833 unigenes. Moreover, 78.91% of the unigenes were annotated using the eight public databases. Forty-one candidate genes representing 23 enzymes involved in the biosynthesis of iridoid compounds were identified in P. rotata leaves. Moreover, the DXS1, IDI1, 8-HGO1, and G10H2 genes associated with iridoid biosynthesis were specifically expressed in P. rotata. The integration of transcriptome and metabolome analyses highlights the crucial role of soil physical and chemical indicators and major gene expression related to iridoid metabolism pathways in P. rotata from different areas. Our findings provide a theoretical foundation for exploring the molecular mechanisms underlying iridoid compound accumulation in P. rotata.

Activation of Nrf2/HO-1 signaling pathway exacerbates cholestatic liver injury

Nuclear factor erythroid 2-related factor-2 (Nrf2) antioxidant signaling is involved in liver protection, but this generalization overlooks conflicting studies indicating that Nrf2 effects are not necessarily hepatoprotective. The role of Nrf2/heme oxygenase-1 (HO-1) in cholestatic liver injury (CLI) remains poorly defined. Here, we report that Nrf2/HO-1 activation exacerbates liver injury rather than exerting a protective effect in CLI. Inhibiting HO-1 or ameliorating bilirubin transport alleviates liver injury in CLI models. Nrf2 knockout confers hepatoprotection in CLI mice, whereas in non-CLI mice, Nrf2 knockout aggravates liver damage. In the CLI setting, oxidative stress activates Nrf2/HO-1, leads to bilirubin accumulation, and impairs mitochondrial function. High levels of bilirubin reciprocally upregulate the activation of Nrf2 and HO-1, while antioxidant and mitochondrial-targeted SOD2 overexpression attenuate bilirubin toxicity. The expression of Nrf2 and HO-1 is elevated in serum of patients with CLI. These results reveal an unrecognized function of Nrf2 signaling in exacerbating liver injury in cholestatic disease.

Ginsenoside Rg1 alleviates ANIT-induced cholestatic liver injury by inhibiting hepatic inflammation and oxidative stress via SIRT1 activation

ETHNOPHARMACOLOGICAL RELEVANCE

Ginseng (Panax ginseng C. A. Mey) is a common traditional Chinese medicine used for anti-inflammation, treating colitis, type 2 diabetes, diarrhea, and recovering hepatobiliary function. Ginsenosides, the main active components isolated from ginseng, possess liver and gallbladder diseases therapeutic potential.

AIMS OF THE STUDY

Cholestatic liver injury (CLI) is a liver disease induced by intrahepatic accumulation of toxic bile acids and currently lacks clinically effective drugs. Our previous study found that ginsenosides alleviated CLI by activating sirtuin 1 (SIRT1), but the effective ingredients and the underlying mechanism have not been clarified. This study aimed to identify an effective ingredient with the most significant activation effect on SIRT1 from the five major monomer saponins of ginsenosides: Rb1, Rd, Rg1, 20s-Rg3, and Rc further explore its protective effects on CLI, and elaborate its underlying mechanism.

MATERIALS AND METHODS

Discovery Studio 3.0 was used to conduct molecular docking between monomer saponins and SIRT1, and further detect the influence of monomer saponins on SIRT1 activity in vitro. Finally, it was determined that Rg1 had the most significant stimulative effect on SIRT1, and the hepatoprotective activity of Rg1 in CLI was explored in vivo. Wild-type mice were intragastrically α-naphthylisothiocyanate (ANIT) to establish an experimental model of intrahepatic cholestasis and Rg1 intervention, and then liver injury and cholestasis related indexes were detected. In addition, Liver-specific SIRT1 gene knockout (SIRT1-/-) mice were administered with ANIT and/or Rg1 to further investigate the mechanism of action of Rg1.

RESULTS

The results of molecular docking and in vitro experiments showed that all the five ginsenoside monomers could bind to the active site of SIRT1 and promote SIRT1 activity in HepG2 cells. Among them, Rg1 exhibited the most significant stimulation of SIRT1 activity in cholestasis. Besides, it could ameliorate ANIT-induced inflammation and oxidative stress in HepG2 cells. Therefore, we investigated the hepatoprotective effect and mechanism of Rg1 on CLI. Results showed that Rg1 reversed the ANIT-induced increase in biochemical parameters, improved liver pathological injury, and decreased liver lipid accumulation, reactive oxygen species and pro-inflammatory factor levels. Mechanistically, Rg1 induced SIRT1 expression, followed by promoted the activity of Nrf2 and suppressed the activation of NF-κB. Interestingly, the hepatoprotective effect of Rg1 was blocked in SIRT1-/- mice.

CONCLUSION

Rg1 mitigated ANIT-induced CLI via upregulating SIRT1 expression, and our results suggested that Rg1 is a candidate compound for treating CLI.

Exploring the Potential Mechanisms of Action of Gentiana Veitchiorum Hemsl. Extract in the Treatment of Cholestasis using UPLC-MS/MS, Systematic Network Pharmacology, and Molecular Docking

INTRODUCTION

Gentiana veitchiorum Hemsl. (GV) has a long history in Tibetan medicine for treating hepatobiliary disease cholestasis. However, the mechanisms mediating its efficacy in treating cholestasis have yet to be determined.

AIM

To elucidate the mechanisms of action of GV in the treatment of cholestasis, an integrated approach combining ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis with network pharmacology was established.

MATERIALS AND METHODS

A comprehensive analysis of the chemical composition of GV was achieved by UPLC-MS/MS. Subsequently, a network pharmacology method that integrated target prediction, a protein-protein interaction (PPI) network, gene set enrichment analysis, and a component- target-pathway network was established, and finally, molecular docking and experiments in vitro were conducted to verify the predicted results.

RESULTS

Twenty compounds that were extracted from GV were identified by UPLC-MS/MS analysis. Core proteins such as AKT1, TNF, and IL6 were obtained through screening in the Network pharmacology PPI network. The Kyoto Encyclopedia of the Genome (KEGG) pathway predicted that GV could treat cholestasis by acting on signaling pathways such as TNF/IL-17 / PI3K-Akt. Network pharmacology suggested that GV might exert a therapeutic effect on cholestasis by regulating the expression levels of inflammatory mediators, and the results were further confirmed by the subsequent construction of an LPS-induced RAW 264.7 cell model.

CONCLUSIONS

In this study, UPLC-MS/MS analysis, network pharmacology, and experiment validation were used to explore potential mechanisms of action of GV in the treatment of cholestasis.

Down-regulation of connexin 43 contributes to structure and function of pulmonary artery in nicotine-administered mice

Dysregulated connexin signaling is implicated in the pathophysiology of pulmonary artery hypertension (PAH). Nicotine affects pulmonary vascular remodeling. However, the potential mechanistic link between connexin signaling and nicotine-induced pulmonary artery remodeling remains unclear. We aimed to investigate the role of connexin 43 (Cx43) in pulmonary artery remodeling in nicotine-administered C57BL/6 J wild-type (WT) and Cx43 heterozygous (Cx43^+/-) mice. Hemodynamic parameters and right ventricle pathology were assessed in the mice. Serum biochemical indices of hepatic and renal function were measured. The RT-PCR, immunofluorescence, and western blotting were conducted to evaluate Cx43 mRNA and protein levels. We performed histological staining to identify pulmonary arteries. Wire myography was used to examine contraction and relaxation responses in the pulmonary arteries. Pulmonary vascular permeability was assessed through Evans blue staining. Compared with the WT group, the Cx43^+/- group showed lower Cx43 mRNA and protein expression in the pulmonary arteries (P < 0.01). Nicotine treatment significantly increased Cx43 expression (P < 0.01) and induced morphological changes in the pulmonary arteries (P < 0.01). Our findings suggest that Cx43 plays a crucial role in pulmonary artery reactivity and permeability in mice. Furthermore, downregulation of Cx43 expression may contribute to alterations in pulmonary artery structure and function.

Liquiritin alleviates alpha-naphthylisothiocyanate-induced intrahepatic cholestasis through the Sirt1/FXR/Nrf2 pathway

Liquiritin (LQ) is an important monomer active component in flavonoids of licorice. The objective of this study was to evaluate the hepatoprotective effects of LQ in cholestatic mice. LQ (40 or 80 mg/kg) was intragastrically administered to mice once daily for 6 days, and mice were treated intragastrically with a single dosage of ANIT (75 mg/kg) on the 5th day. On the 7th day, mice were sacrificed to collect blood and livers. The mRNA and protein levels were determined by qRT-PCR and western blot assay. We also conducted systematical assessments of miRNAs expression profiles in the liver. LQ ameliorated ANIT-induced cholestatic liver injury, as evidenced by reduced serum biochemical markers and attenuated pathological changes in liver. Pretreatment of LQ reduced the increase of malondialdehyde, TNF-α, and IL-1β induced by ANIT. Moreover, ANIT suppressed the expression of Sirt1 and FXR in liver tissue, which was weakened in the LQ pre-treatment group. LQ enhanced the nuclear expression of Nrf2, which was increased in the ANIT group. LQ also increased the mRNA expressions of bile acid transporters Bsep, Ntcp, Mrp3, and Mrp4. Furthermore, a miRNA deep sequencing analysis revealed that LQ had a global regulatory effect on the hepatic miRNA expression. Kyoto Encyclopedia of Genes and Genomes functional enrichment analysis showed that the differentially expressed miRNAs were mainly related to metabolic pathways, endocytosis, and MAPK signaling pathway. Collectively, LQ attenuated hepatotoxicity and cholestasis by regulating the expression of Sirt1/FXR/Nrf2 and the bile acid transporters, indicating that LQ might be an effective approach for cholestatic liver diseases.

Oliveria decumbens Extract Exhibits Hepatoprotective Effects Against Bile Duct Ligation-Induced Liver Injury in Rats by Reducing Oxidative Stress

Background: Cholestasis is described as a disease in which bile flow from the liver is reduced or stopped, and due to its oxidative effects, irreversible consequences may occur. Due to the remarkable antioxidant properties of Oliveria decumbens (OD) and the contribution of oxidants to the progression of bile duct ligation (BDL)-induced cholestasis, Objectives: This research aimed to examine how the OD ethanolic extract affected liver damage and oxidant-antioxidant balance markers in BDL-induced cholestasis. Methods: Forty male Wistar rats weighing 200 - 250 g were used. Cholestasis was induced using the BDL approach. The rats were categorized into four groups: Group 1, sham control (SC); group 2, cholestatic; group 3, SC + OD; and group 4, cholestatic + OD. A dose of OD ethanolic extract was administered orally (500 mg/kg/day) to rats for seven days. Seven days following surgery, the rats’ blood samples were collected; after sacrifice, a part of the liver tissue was isolated. A histopathological examination was performed, while the rest was stored at -70°C in liquid nitrogen. Heparin-containing tubes were used to gather blood samples. In plasma and hepatic tissue, biochemical tests, histopathological evaluations, and oxidative stress markers staining levels were performed. Results: Our findings showed that OD could effectively reduce liver injury by reducing the activity of liver function enzymes (AST and ALP). At the same time, it did not affect total bilirubin and protein. Bile duct ligation-induced hepatic markers of protein oxidation (PCO) and reactive nitrogen species (NO) were significantly decreased by OD, and it also promoted liver antioxidant capacity by enhancing superoxide dismutase (SOD) activities. Moreover, OD treatment prevented liver bile duct proliferative changes in histopathologic analysis. Conclusions: Our study confirmed that OD exerts substantial hepatoprotective activities against BDL-induced cholestasis by improving liver damage markers and regulating oxidative stress. It may be a beneficial therapeutic agent for managing cholestasis. Bioassay-guided isolation and identification of bioactive OD secondary metabolites can further direct the discovery of potential natural-based drug candidates.

Quercetin potentiates the hepatoprotective effect of sildenafil and/or pentoxifylline against intrahepatic cholestasis: Role of Nrf2/ARE, TLR4/NF-κB, and NLRP3/IL-1β signaling pathways

AIM

Intrahepatic cholestasis is a common pathological condition of several types of liver disorders. In this study, we aimed to investigate the regulatory effects of quercetin (QU) on selected phosphodiesterase inhibitors against alpha-naphthyl isothiocyanate (ANIT)-induced acute intrahepatic cholestasis.

METHODS

Cholestasis was induced in Wistar albino rats by ANIT as a single dose (60 mg/kg; P·O.). QU (50 mg/kg, daily, P·O.), sildenafil (Sild; 10 mg/kg, twice daily, P·O.), and pentoxifylline (PTX; 50 mg/kg, daily, P.O.) were evaluated either alone or in combinations for 10 days for their antioxidant, anti-inflammatory, and anti-pyroptotic effects.

RESULTS

ANIT produced a prominent intrahepatic cholestasis as evidenced by a significant alteration in liver functions, histological structure, inflammatory response, and oxidative stress biomarkers. Furthermore, up-regulation of NF-κB-p65, TLR4, NLRP3, cleaved caspase-1, IKK-β, and IL-1β concurrently with down-regulation of Nrf-2, HO-1, and PPAR-γ expressions were observed after ANIT. QU, Sild, or PTX treatment significantly alleviated the disturbance induced by ANIT. These findings were further supported by the improvement in histopathological features. Additionally, co-administration of QU with Sild or PTX significantly improved liver defects due to ANIT as compared to the individual drugs.

SIGNIFICANCE

Combined QU with Sild or PTX exhibited promising hepatoprotective effects and anti-cholestatic properties through modulation of Nrf2/ARE, TLR4/NF- κB, and NLRP3/IL-1β signaling pathways.

Transcriptome and Gut Microbiota Profiling Analysis of ANIT-Induced Cholestasis and the Effects of Da-Huang-Xiao-Shi Decoction Intervention

Cholestasis is characterized by bile acid (BA) circulation disorders, which is usually related to damage of hepatocyte barrier function. Currently, patients with cholestasis face several obstacles in seeking diagnosis and therapy. Da-Huang-Xiao-Shi decoction (DHXSD) is an ancient classic formula that has been used clinically for cholestasis treatment. Nevertheless, the underlying biological activities and therapeutic mechanisms remain unclear. In this study, an alpha-naphthylisothiocyanate (ANIT)-induced cholestasis rat model was established to examine the anticholestatic effects of DHXSD using histopathological and molecular analyses. Transcriptomic analysis combined with 16S rRNA gene sequencing analysis was systematically applied to study the mechanism of action of DHXSD. Simultaneously, the effect of DHXSD on gut microbiota, short-chain fatty acids (SCFAs), and intestinal barrier function were evaluated based on the ANIT-induced cholestasis model in rats. The results showed that DHXSD effectively attenuated ANIT-induced cholestasis by reducing liver function indicators (alanine transaminase [ALT], P < 0.05; alkaline phosphatase [ALP], P < 0.05; total bile acid [TBA], P < 0.01; γ-glutamyl transpeptidase [GGT], P < 0.001) and levels of hepatotoxicity-related enzymes (P < 0.05), thus improving the recovery of histopathological injuries, and regulating levels of inflammatory cytokines (P < 0.05). In addition, 16S rRNA gene sequencing analysis combined with intestinal barrier function analysis revealed that the DHXSD significantly ameliorated ANIT-induced gut microbiota dysbiosis. Significantly altered genes in the model and treatment groups were screened using transcriptomic analysis. Sixty-eight genes and four microbial genera were simultaneously altered with opposing trends in variation after ANIT and DHXSD treatments. We built a framework for predicting targets and host-microbe interaction mechanisms, as well as identifying alternative treatment for cholestasis, which should be validated further for clinical application. In conclusion, DHXSD appears to be a promising agent for protection against liver injury. IMPORTANCE Cholestasis is a serious manifestation of liver diseases resulting in liver injury, fibrosis, and liver failure with limited therapies. To date, only ursodeoxycholic acid (UDCA) has been approved by the U.S. Food and Drug Administration for the treatment of cholestasis. However, approximately one-third of patients with cholestasis are unresponsive to UDCA. Therefore, it is urgent to search for appropriate therapeutic agents for restoring stoppage status of the bile components to treat cholestasis. In this study, we investigated how the microbiome and transcriptome data sets correlated with each other to clarify the role of microbiome alterations in host metabolism. In combination, this research offers potential molecular biomarkers that should be validated for more accurate diagnosis of cholestasis and the clinical utilisation of gut microbiota as a target for treatment.

Kuhuang injection exerts a protective effect by activating PPAR-γ in an in vitro model of chlorpromazine-induced cholestatic liver injury constructed by tissue engineering

CONTEXT

Kuhuang (KH) injection is a widely used anticholestatic drug in the clinic and the mechanisms are still unclear.

OBJECTIVE

This study uses a new 3D tissue-engineered (TE) liver platform to study the ability of kuhuang to ameliorate liver injury induced by chlorpromazine (CPZ) and the possible mechanisms involved.

MATERIALS AND METHODS

The TE livers (n = 25) were divided into 5 groups (n = 5 livers/group) as 3D, 3D + CPZ, 3D + CPZ + KH, 3D + CPZ + GW9662 (a PPARγ inhibitor) and 3D + CPZ + KH + GW9662. The treatments with kuhuang (1 mg/mL) and GW9662 (10 μmol/L) were given to the desired groups on the 7th day of the experimental process. 20 μmol/L CPZ was added on the 8th day.

RESULTS

According to the 2D experimental results, the minimum effective concentration of kuhuang is 10 μg/mL and the optimal effective concentration is 1 mg/mL. Kuhuang ameliorated tissue damage in the TE livers both in terms of tissue structure and culture supernatant. Kuhuang significantly reduced TBA accumulation (38%) and downregulated CYP7A1 (38%) and CYP8B1 (79%). It reduced hepatic levels of ROS (14%), MDA (27%) but increased the levels of GSH (41%), SOD (12%), BSEP (4.4-fold), and MRP2 (74%). Moreover, kuhuang downregulated DR5 (99%) but increased the mRNA expression of PPARγ (4-fold). Molecular docking analyses determined the bioactivity of the active compounds of kuhuang through their specific bindings to PPARγ.

CONCLUSIONS

Kuhuang could alleviate CPZ-induced cholestatic liver injury by activating PPARγ to reduce oxidative stress. Applying kuhuang for the treatment of CPZ-induced liver injury could be suggested.

Paeoniflorin alleviates 17α-ethinylestradiol-induced cholestasis via the farnesoid X receptor-mediated bile acid homeostasis signaling pathway in rats

Cholestasis, characterized by disturbance of bile formation, is a common pathological condition that can induce several serious liver diseases. As a kind of trigger, estrogen-induced cholestasis belongs to drug-induced cholestasis. Paeoniflorin is the most abundant bioactive constituent in Paeonia lactiflora Pall., Paeonia suffruticosa Andr., or Paeonia veitchii Lynch, a widely used herbal medicine for treating hepatic disease over centuries in China. However, the pharmacologic effect and mechanism of paeoniflorin on estrogen-induced cholestasis remain unclear. In this experiment, the pharmacological effect of paeoniflorin on EE-induced cholestasis in rats was evaluated comprehensively for the first time. Ultra-high-performance liquid chromatography coupled with Q-Exactive orbitrap mass spectrometer was used to monitor the variation of bile acid levels and composition. It was demonstrated that paeoniflorin alleviated 17α-ethinylestradiol (EE)-induced cholestasis dose-dependently, characterized by a decrease of serum biochemical indexes, recovery of bile flow, amelioration of hepatic and ileal histopathology, and reduction of oxidative stress. In addition, paeoniflorin intervention restored EE-disrupted bile acid homeostasis in enterohepatic circulation. Further mechanism studies using western blot, quantitative Real-Time PCR, and immunohistochemical showed that paeoniflorin could upregulate hepatic efflux transporters expression but downregulate hepatic uptake transporter expression. Meanwhile, paeoniflorin reduced bile acids synthesis by repressing cholesterol 7α-hydroxylase in hepatocytes. Paeoniflorin affected the above transporters and enzyme via activation of a nuclear receptor, farnesoid X receptor (FXR), which was recognized as a vital regulator for maintaining bile acid homeostasis. In conclusion, paeoniflorin alleviated EE-induced cholestasis and maintained bile acid homeostasis via FXR-mediated regulation of bile acids transporters and synthesis enzyme. The findings indicated that paeoniflorin might exert a potential therapeutic medicine for estrogen-induced cholestasis.

Protective Effect of Rhus chinensis Mill. Fruits on 3,5-Diethoxycarbonyl-1,4-Dihydrocollidine-Induced Cholestasis in Mice via Ameliorating Oxidative Stress and Inflammation

This study focused on the preventive effects of the extracts of Rhus chinensis Mill. (RCM) fruits on cholestasis induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) in mice. The results showed that RCM extracts could significantly ameliorate DDC-induced cholestasis via multiple mechanisms, including (1) alleviating liver damage via enhancing antioxidant capacity, such as increasing the contents of glutathione, superoxide dismutase, and catalase and inhibiting the levels of malondialdehyde; (2) preventing liver inflammation by suppressing NF-κB pathway and reducing proinflammatory cytokines secretion (e.g., tumor necrosis factor-α, interleukin-1β, and interleukin-6); (3) inhibiting liver fibrosis and collagen deposition by regulating the expression of transforming growth factor-β and α-smooth muscle actin; (4) modulating abnormal bile acid metabolism through increasing the expression of bile salt export pump and multidrug resistance-associated protein 2. This study was the first to elucidate the potential preventive effect of RCM extracts on DDC-induced cholestasis in mice from multiple pathways, which suggested that RCM fruits could be considered as a potential dietary supplement to prevent cholestasis.

San-Huang-Chai-Zhu Formula Ameliorates Liver Injury in Intrahepatic Cholestasis through Suppressing SIRT1/PGC-1α-Regulated Mitochondrial Oxidative Stress

Background

Chinese herbal formulae possess promising applications in treating intrahepatic cholestasis.

Objective

Our study aims to explore the protective effect of the San-Huang-Chai-Zhu formula (SHCZF) on liver injury in intrahepatic cholestasis (IC) and investigate the underlying mechanism related to mitochondrial oxidative stress.

Methods

An IC rat model was established by α-naphthyl isothiocyanate induction. Hepatic histomorphology was observed through hematoxylin and eosin staining. Levels of biochemical indexes of hepatic function and oxidative stress were determined by an enzyme-linked immunosorbent assay. Cell apoptosis in liver tissues was detected by the TUNEL assay. The mRNA expression of mtDNA, SIRT1, and PGC-1α was measured by qRT-PCR, and the protein expression of Bax, Bcl-2, caspase-3, SIRT1, and PGC-1α was determined by Western blotting.

Results

SHCZF treatment attenuated liver injury in IC. Levels of hepatic function parameters were decreased after SHCZF administration. In addition, the decreased level of malondialdehyde (MDA) and the increased levels of superoxide dismutase (SOD), glutathione (GSH), and adenosine triphosphate (ATP) in hepatic mitochondria confirmed that SHCZF could attenuate oxidative stress in IC. SHCZF treatment also reduced the apoptosis in the liver tissues of IC rats. Furthermore, SHCZF administration upregulated the expression of mtDNA, SIRT1, and PGC-1α in IC.

Conclusions

SHCZF exerts a protective effect on liver injury in IC via alleviating SIRT1/PGC-1α-regulated mitochondrial oxidative stress.

Protective Effect of Hedyotis diffusa Willd. Ethanol Extract on Isoniazid-Induced Liver Injury in the Zebrafish Model

Objective

Methods

Results

Conclusion

Neutrophil membrane-mimicking nanodecoys with intrinsic anti-inflammatory properties alleviate sepsis-induced acute liver injury and lethality in a mouse endotoxemia model

Sepsis-induced acute liver injury often develops in the early stages of sepsis and can exacerbate the pathology by contributing to multiple organ dysfunction and increasing lethality. No specific therapies for sepsis-induced liver injury are currently available; therefore, effective countermeasures are urgently needed. Considering the crucial role of neutrophils in sepsis-induced liver injury, herein, neutrophil membrane-mimicking nanodecoys (NM) were explored as a biomimetic nanomedicine for the treatment of sepsis-associated liver injury. NM administration exhibited excellent biocompatibility and dramatically decreased the plasma levels of inflammatory cytokines and liver injury biomarkers, including aspartate aminotransferase, alanine aminotransferase, and direct bilirubin, in a sepsis mouse model. NM treatment also reduced hepatic malondialdehyde content, myeloperoxidase activity, and histological injury, and ultimately improved survival in the septic mice. Further in vitro studies showed that NM treatment neutralized the neutrophil chemokines and inflammatory mediators and directly mitigated neutrophil chemotaxis and adhesion. Additionally, NM also markedly weakened lipopolysaccharide-induced reactive oxygen species generation, cyclooxygenase-2 expression, nitric oxide secretion, and subsequent hepatocyte injury. Thus, this study provides a promising therapeutic strategy for the management of sepsis-induced acute liver injury.

The Potential Protective Effect of Iridoid Glycosides Isolated From Osmanthus fragrans Seeds Against the Development of Immune Liver Injury in Mice

Objective: The iridoid glycosides were extracted and separated from Osmanthus fragrans seeds, and the potential protective effect of Osmanthus fragrans seed extract on concanavalin A-induced immune liver injury in mice was studied.

Methods:Osmanthus fragrans seeds were extracted by 95% ethanol reflux. Then, the iridoid glycosides were enriched by extraction refined through petroleum ether (60°C–90°C), ethyl acetate, and water-saturated n-butanol in sequence, so as to purify the n-butanol part (Osmanthus fragrans seed’s n-butanol extraction, OFSN) by macroporous resin. Specnuezhenide and Nuezhenoside G13 were used as the reference substances to determine the concentration of iridoid glycosides by HPLC. On this basis, a mouse immune liver injury model was established by tail intravenous concanavalin A (20 mg/kg); the contents of serum ALT, AST, IFN-γ, and TNF-α and the contents of liver tissue MDA and SOD were determined; the pathological changes of the liver by HE staining were observed; and the expression levels of p38MAPK and p-p38mapk in liver tissue were detected by WB.

Results: The linearity, precision, repeatability, recovery, and stability of HPLC all met the requirements by validating with the methodology. The contents of Specnuezhenide and Nuezhenoside G13 in the n-butanol extracts were 39.20% and 39.88%, respectively. Actually, their contents can reach up to 82.56% and 87.9% after being purified by macroporous resin. The results of animal experiments show that OFSN could significantly reduce the liver and spleen index, reduce the ALT and AST contents in plasma and the MDA content in liver tissue, and then increase the SOD content. Besides, OFSN could also reduce the plasma IFN-γ and TNF-α levels. The HE staining result indicates that the pathological changes in the liver tissues of mice treated with OFSN are alleviated to different degrees while the WB result suggests that OFSN could significantly inhibit the expression of p-p38mapk.

Conclusion:Osmanthus fragrans seeds are rich in iridoid glycosides, which has a good protective effect on mouse immune liver injury caused by concanavalin A. The mechanism may be related to inhibiting the phosphorylation of p38MAPK, inhibiting the release of inflammatory mediators, improving the antioxidant capacity of liver cells, and weakening the occurrence of lipid peroxidation.

Glycyrrhetinic Acid Protects α-Naphthylisothiocyanate- Induced Cholestasis Through Regulating Transporters, Inflammation and Apoptosis

Glycyrrhetinic acid (GA), the active metabolic product of Glycyrrhizin (GL) that is the main ingredient of licorice, was reported to protect against α-naphthylisothiocyanate (ANIT)- induced cholestasis. However, its protective mechanism remains unclear. In our work, the cholestatic liver injury in mice was caused by ANIT and GA was used for the treatment. We assessed cholestatic liver injury specific indexes, histopathological changes, bile acid transporters, inflammation and apoptosis. The results of liver biochemical index and histopathological examination showed that GA markedly attenuated ANIT-induced liver injury. Mechanism research suggested that GA could activate the expression of farnesoid x receptor (FXR) and its downstream bile acids transporters Na+/taurocholate co-transporting polypeptide (NTCP), bile salt export pump (BSEP) and multidrug resistance-associated protein 2 (MRP2), as well as the nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream proteins MRP3, MRP4. These transporters play a vital role in mediating bile acid homeostasis in hepatocytes. Moreover, GA could significantly inhibit the ANIT-induced activation of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) inflammatory pathway and the increase of tumor necrosis factor-α (TNF-α) concentration in serum. Also, GA protected against ANIT-induced mitochondrial apoptosis by regulating the expression of Bcl-2, Bax, cleaved caspase 3 and cleaved caspase 9. In conclusion, GA alleviates the hepatotoxicity caused by ANIT by regulating bile acids transporters, inflammation and apoptosis, which suggests that GA may be a potential therapeutic agent for cholestasis.

Heme Oxygenase-1 Induction by Cobalt Protoporphyrin Ameliorates Cholestatic Liver Disease in a Xenobiotic-Induced Murine Model

Cholestatic liver diseases can progress to end-stage liver disease and reduce patients' quality of life. Although their underlying mechanisms are still incompletely elucidated, oxidative stress is considered to be a key contributor to these diseases. Heme oxygenase-1 (HO-1) is a cytoprotective enzyme that displays antioxidant action. It has been found that this enzyme plays a protective role against various inflammatory diseases. However, the role of HO-1 in cholestatic liver diseases has not yet been investigated. Here, we examined whether pharmacological induction of HO-1 by cobalt protoporphyrin (CoPP) ameliorates cholestatic liver injury. To this end, a murine model of 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) diet feeding was used. Administration of CoPP ameliorated liver damage and cholestasis with HO-1 upregulation in DDC diet-fed mice. Induction of HO-1 by CoPP suppressed the DDC diet-induced oxidative stress and hepatocyte apoptosis. In addition, CoPP attenuated cytokine production and inflammatory cell infiltration. Furthermore, deposition of the extracellular matrix and expression of fibrosis-related genes after DDC feeding were also decreased by CoPP. HO-1 induction decreased the number of myofibroblasts and inhibited the transforming growth factor-β pathway. Altogether, these data suggest that the pharmacological induction of HO-1 ameliorates cholestatic liver disease by suppressing oxidative stress, hepatocyte apoptosis, and inflammation.

Portulaca oleracea methanolic extract attenuate bile duct ligation-induced acute liver injury through hepatoprotective and anti-inflammatory effects

Introduction

Cholestasis is a liver disease caused by a malfunction of the hepato-biliary system. Oxidative stress as a systemic complication is the main characteristic of cholestasis. The aim of this study was to evaluate the anti-inflammatory and hepatoprotective effects of Portulaca oleracea (PO) methanolic extract on liver dysfunction and tissue damage induced by bile duct ligation (BDL) in rats.

Materials and methods

Twenty-eight male Wistar rats were randomly divided into four groups: sham control (SC), BDL alone, SC plus 500 mg/kg methanolic extract of PO orally for 1 week, and BDL plus 500 mg/kg methanolic extract of PO orally for 1 week. After 1 week, the animals were anesthetized, and the liver and blood samples were taken from each animal. Biochemical parameters, oxidative stress biomarkers, histopathological changes, as well as the gene expression of IL-1, TNF-α, TGF-β, and α-SMA have been evaluated.

Results

The methanolic extract of PO at a dose of 500 mg/kg significantly decreased the plasma levels of aminotransferases, alkaline phosphatase as compared to BDL group (P < 0.05), while it had no significant effect on the levels of oxidative stress markers in the hepatic tissue. The plasma level of malondialdehyde and ferric-reducing antioxidant power were markedly elevated in the BDL group in comparison to SC group (P < 0.05), while treatment with PO significantly reduced these markers (P < 0.05). The administration of PO attenuated hydroxyproline content, bile duct proliferation, and inflammation score in the cholestatic liver in contrast to non-treated BDL rats (P < 0.05). Moreover, the methanolic extract of PO markedly declined the expression of TNF-α and TGF-β pro inflammatory genes in contrast to BDL rats.

Conclusions

Taken together, our findings showed that PO attenuated liver injury by decreasing liver function tests, inflammation, and hydroxyproline content. As a result, it is suggested that PO can be applied in cholestatic liver damage as a therapeutic or adjuvant agent.

Pharmacokinetic study of seven bioactive components of Xiaoyan Lidan Formula in cholestatic and control rats using UPLC-MS/MS

A rapid, sensitive, and reliable ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method has been developed to simultaneously determine the major bioactive components of Xiaoyan Lidan Formula (XYLDF) in rat plasma, using sulfamethoxazole as the internal standard (IS). The seven major bioactive components are andrographolide, dehydroandrographolide, enmein, 1-methoxicabony-β-carboline, 4,5-dimethoxy-canthin-6-one, 4-methoxy-5-hydroxy-canthin-6-one, and 1-hydroxymethyl-β-carboline. After pretreating by protein precipitation with methanol, separation was performed on a UPLC C18 column using gradient elution with a mobile phase consisting of acetonitrile and 0.1% formic acid at a flowing rate of 0.7 mL/min. Detection was performed on TSQ Quantum mass spectrometry set at the positive/negative ionization and multiple reaction monitoring (MRM) mode. The intra- and inter-day precision were less than 9.8%, whereas the intra- and inter-day accuracy were within ± 13.4%. The method was validated and applied to compare the pharmacokinetic profiles of the analytes in serum of Alpha-naphthylisothiocyanate (ANIT)-induced cholestasis and control rats after oral administration of XYLDF. The results showed remarkable differences in pharmacokinetic properties of the analytes between cholestatic (model) and control groups, thereby providing essential scientific information for better understanding of mechanism of XYLDF and a reference for its clinical applications.

TLR4-MyD88-NF-κB signaling pathway contributes to the progression of secondary hepatic injury and fibrosis in hepatolithiasis

This paper focused on evaluating the effect of TLR4-MyD88-NF-κB signaling pathway in the progression of secondary hepatic injury and fibrosis in hepatolithiasis. The levels of inflammatory factors (IL-1β, IL-6, TNF-α) and serum biochemical values (ALT, AST, Tbil, Dbil, ALP, GGT) were detected by ELISA. IHC was used to detected the expression level of TLR4 in liver tissues of hepatolithiasis patients and mice. The pathological changes of liver tissue were observed by HE staining. The levels of MyD88, NF-κB, IκB, Laminin (LN), and chitosan enzyme 3-like protein 1 (CHI3L1) were detected by western blotting. In hepatolithiasis patients, the levels of TNF-α, IL-1β, and IL-6 were distinctly raised and proteins associated with TLR4-MyD88-NF-κB signaling pathway (such as TLR4, MyD88, NF-κB, and IκB) in liver tissues were significantly up-regulated. In Bile duct ligation (BDL) model of mice, the results showed that in addition to the significant increase of inflammatory factors, liver function indexes, and fibrosis indexes in BDL mice were also significantly up-regulated. Additionally, TLR4-MyD88-NF-κB signaling pathway was activated in BDL mice. After TLR4 knockdown in BDL mice, inflammatory factors, liver function indexes, and fibrosis indexes were significantly down-regulated. TLR4-MyD88-NF-κB signaling pathway proteins were restrained. TLR4-MyD88-NF-κB signaling pathway took part in the progression of secondary hepatic injury and fibrosis in hepatolithiasis. Inhibition of TLR4-MyD88-NF-κB signaling pathway can reduce the progression of secondary hepatic injury and fibrosis in hepatolithiasis.