Arbutin Alleviates the Liver Injury of α-Naphthylisothiocyanate-induced Cholestasis Through Farnesoid X Receptor Activation

Cholestasis is a kind of stressful syndrome along with liver toxicity, which has been demonstrated to be related to fibrosis, cirrhosis, even cholangiocellular or hepatocellular carcinomas. Cholestasis usually caused by the dysregulated metabolism of bile acids that possess high cellular toxicity and synthesized by cholesterol in the liver to undergo enterohepatic circulation. In cholestasis, the accumulation of bile acids in the liver causes biliary and hepatocyte injury, oxidative stress, and inflammation. The farnesoid X receptor (FXR) is regarded as a bile acid–activated receptor that regulates a network of genes involved in bile acid metabolism, providing a new therapeutic target to treat cholestatic diseases. Arbutin is a glycosylated hydroquinone isolated from medicinal plants in the genus Arctostaphylos, which has a variety of potentially pharmacological properties, such as anti-inflammatory, antihyperlipidemic, antiviral, antihyperglycemic, and antioxidant activity. However, the mechanistic contributions of arbutin to alleviate liver injury of cholestasis, especially its role on bile acid homeostasis via nuclear receptors, have not been fully elucidated. In this study, we demonstrate that arbutin has a protective effect on α-naphthylisothiocyanate–induced cholestasis via upregulation of the levels of FXR and downstream enzymes associated with bile acid homeostasis such as Bsep, Ntcp, and Sult2a1, as well as Ugt1a1. Furthermore, the regulation of these functional proteins related to bile acid homeostasis by arbutin could be alleviated by FXR silencing in L-02 cells. In conclusion, a protective effect could be supported by arbutin to alleviate ANIT-induced cholestatic liver toxicity, which was partly through the FXR pathway, suggesting arbutin may be a potential chemical molecule for the cholestatic disease.

Metabolomic Analysis Reveals the Therapeutic Effects of MBT1805, a Novel Pan-Peroxisome Proliferator-Activated Receptor Agonist, on α-Naphthylisothiocyanate-Induced Cholestasis in Mice

Background and Aims: Therapeutic drugs that are used to treat cholestatic liver disease are limited; however, the results of clinical trials on primary biliary cholangitis treatment targeting peroxisome proliferator-activated receptors (PPARs) are encouraging. In this study, we aimed to identify the effects of MBT1805, a novel balanced PPARα/γ/δ agonist, on cholestasis induced by α-naphthylisothiocyanate (ANIT) and elucidate the underlying mechanisms through untargeted and bile acid-targeted metabolomic analysis.

Methods: Levels of serum biochemical indicators (transaminase, aspartate transaminase, alkaline phosphatase, and total bilirubin) and liver histopathology were analyzed to evaluate the therapeutic effects of MBT1805 on ANIT-induced cholestasis in C57BL/6 mice. Untargeted and bile acid-targeted metabolomic analysis of liver tissues was performed using ultrahigh-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MC/MC). qRT-PCR and Western blot analysis were carried out to measure the expression of key enzymes and transporters regulating bile acid synthesis, biotransformation, and transport.

Results: MBT1805 significantly improved abnormal levels of liver biochemical indicators and gallbladder enlargement induced by ANIT. Histopathological analysis showed that MBT1805 effectively relieved ANIT-induced necrosis, vacuolation, and inflammatory infiltration. Untargeted metabolomic analysis identified 27 metabolites that were involved in the primary biliary acid biosynthesis pathway. In addition, bile acid-targeted metabolomics showed that MBT1805 could alleviate the abnormal bile acid content and composition induced by ANIT. Furthermore, qRT-PCR and Western blot results confirmed that MBT1805 could effectively regulate bile acid synthesis, biotransformation, and transport which helps relieve cholestasis.

Conclusions: MBT1805 is a potential candidate drug for cholestasis, with a balanced PPARα/γ/δ activation effect.

Metabolomics analysis delineates the therapeutic effects of Huangqi decoction and astragalosides on α-naphthylisothiocyanate (ANIT) -induced cholestasis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Cholestasis caused by bile secretion and excretion disorders is a serious manifestation of liver disease. With limited treatment methods, it affects millions of people worldwide. Huangqi decoction (HQD), an effective traditional Chinese medicine, is used to treat chronic cholestatic liver diseases. However, the action mechanisms of it were not fully elucidated.

AIM OF THE STUDY

We aim to investigate the therapeutic effect of HQD, and its active component, astragalosides, against α-naphthylisothiocyanate (ANIT)-induced cholestasis in rats based on targeted metabolomics analysis and revel the potential mechanism.

MATERIALS AND METHODS

The therapeutic effect of HQD and astragalosides on ANIT-induced cholestasis model rats were evaluated by serum biochemical analysis. Liver damage was identified by histopathology. The levels of bile acids (BAs) and free fatty acids (FFAs) in serum and liver tissues were measured by ultra-high performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-TQMS). qRT-PCR and Western blot analysis were used to measure the expression of nuclear hormone receptor, membrane receptor and BA transporter protein in cholestatic rats before and after HQD and astragalosides treatment.

RESULTS

The obtained data showed that the administration of ANIT caused obvious cholestasis with significantly increased intrahepatic retention of hydrophobic BAs and altered FFAs, which were consistent with the liver histopathological and serum biochemical findings. HQD and astragalosides treatment were able to attenuate ANIT-induced BAs and FFAs perturbation, ameliorate the impaired liver function, histopathological ductular reaction, and lipid peroxidation damage by ANIT. Elevated mRNA and protein expression of transporters related to BA metabolism and genes related to lipogenesis and lipid oxidation metabolism in cholestasis were attenuated or normalized by HQD and astragalosides treatment.

CONCLUSIONS

Intervention by ANIT can significantly change the homeostasis of BAs and FFAs. HQD and astragalosides exerted a hepatoprotective effect against cholestatic liver injury by restoring the altered BA and FFA metabolism through the improvement of BA transporter, nucleus hormone receptor, and membrane receptor.

Dehydrodiconiferyl alcohol, a lignan from Herpetospermum pedunculosum, alleviates cholestasis by activating pathways associated with the farnesoid X receptor

BACKGROUND

In our previous study, we demonstrated the hepatoprotective effect of Herpetospermum pedunculosum in cholestatic rats. A bioassay-guided study also led to the identification and isolation of a lignan, dihydrodiconiferyl alcohol (DA) from the seeds of H. pedunculosum.

PURPOSE

To investigate whether DA could alleviate cholestasis and determine the mechanisms underlying such action.

METHODS

Male Sprague-Dawley (SD) rats were administered with DA (10, 20 or 40 mg/kg) intragastrically once daily for 7 days prior to treatment with α-naphthylisothiocyanate (ANIT) (60 mg/kg). We then evaluated the levels of a range of serum indicators, determined bile flow, and carried out histopathological analyses. Western blotting was then used to investigate the levels of inflammatory mediators and the Farnesoid X Receptor (FXR), proteins involved in the downstream biosynthesis of bile acids, and a range of transport proteins. Molecular docking was used to simulate the interaction between DA and FXR. Cell viability of human hepatocytes (L-02) cells was determined by MTT. Then, we treated guggulsterone-inhibited L-02 cells, Si-FXR L-02 cells, and FXR-overexpression cells with the FXR agonist GW4064 (6 μM) or DA (25, 50 and 100 μM) for 24 h before detecting gene and protein expression by RT-PCR and western blotting, respectively.

RESULTS

DA significantly attenuated ANIT-induced cholestasis in SD rats by reducing liver function indicators in the serum, increasing bile flow, improving the recovery of histopathological injuries in the liver, and by alleviating pro-inflammatory cytokines in the liver. DA also increased the expression levels of FXR and altered the levels of downstream proteins in the liver tissues, thus indicating that DA might alleviate cholestasis by regulating the FXR. Molecular docking simulations predicted that DA was as an agonist of FXR. In vitro mechanical studies further showed that DA increased the mRNA and protein expression levels of FXR, Small Heterodimer Partner 1/2, Bile Salt Export Pump, Multidrug Resistance-associated Protein 2, and Na+/taurocholate Co-transporting Polypeptide, in both guggulsterone-inhibited and Si-FXR L-02 cells. Moreover, DA enhanced the mRNA and protein expression of FXR, and its downstream genes and proteins, in L-02 cells containing an FXR-overexpression plasmid.

CONCLUSION

DA may represent an effective agonist for FXR has significant therapeutic potential for the treatment of cholestatic liver injury.

Cholestatic models induced by lithocholic acid and α‑naphthylisothiocyanate: Different etiological mechanisms for liver injury but shared JNK/STAT3 signaling

α‑naphthylisothiocyanate (ANIT) is used to induce intrahepatic cholestasis and it is frequently used for investigations into the disease mechanism. The lithocholic acid (LCA) cholestatic model has also been extensively used in various studies; however, to the best of our knowledge, a comparative study determining the hepatotoxic mechanisms induced by these two models has not been previously conducted. In the present study, ICR mice were treated with ANIT or LCA to induce cholestatic liver injury. Biochemical analysis was used to determine the serum. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and total bile acid (TBA) levels, and histopathological assessment was used to examine the liver tissue. Metabolomic analysis was used for the serum biomarker identification. Reverse transcription‑quantitative PCR analysis and western blotting were used to analyze the inflammation biomarkers. The serum metabolome of the ANIT group clustered away from of the LCA group, which was demonstrated by the different modifications of the BA components. ALP level was found to be preferentially increased in the ANIT group from 24 to 48 h. Total BA levels was only increased in the ANIT group at 24 h. In contrast, AST and ALT activity levels were preferentially increased in the LCA group. The bile ducts in the hepatic tissues of the ANIT group were observed to be severely dilated, whereas the presence of edematous hepatocytes around the necrotic lesions and neutrophil infiltration were identified in the LCA group. The expression levels of cholesterol 7α‑hydroxylase and sterol 12α‑hydroxylase genes were significantly downregulated in the ANIT group compared with the LCA group, where a stronger adaptation of BA metabolism was supported by major differences in the concentration of the BA components. Despite the aforementioned etiological differences in the cholestasis induced by each treatment, the activation of the JNK/STAT3 signaling pathway was similar between the two cholestatic models. In conclusion, these data suggested that the liver injury induced by ANIT may be cholestatic, while the liver injury caused in the LCA model may be hepatocellular. Moreover, the downstream cholestatic liver injury in both models was indicated to be mediated by the JNK/STAT3 signaling pathway.

TianJiu therapy for α-naphthyl isothiocyanate-induced intrahepatic cholestasis in rats treated with fresh Ranunculus sceleratus L

ETHNOPHARMACOLOGICAL RELEVANCE

TianJiu (TJ) therapy, one type of cold moxibustion, applies to specific acupuncture points with herbal patches of hot nature, providing a constant irritant to the skin until the presence of hyperemia and blistering. Traditional and clinical reports suggest that TJ is an effective therapy for the treatment of jaundice with fresh Ranunculus sceleratus L. (RS), in which protoanemonin is one of the main irritant constituents. However, the therapeutic effect of TJ treatment with fresh RS against intrahepatic cholestasis has not been studied in animal experiments.

AIM OF THE STUDY

Present study was undertaken to investigate the effect of TJ treatment with fresh RS against intrahepatic cholestasis in rats and provide an experimental basis for the underlying mechanism of TJ therapy.

MATERIALS AND METHODS

Male intrahepatic cholestatic Sprague-Dawley rats induced by 2% α-naphthylisothiocyanate (ANIT, 80 mg/kg B.W.) were treated by TJ therapy with fresh RS. The levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), direct bilirubin (DBIL), total bilirubin (TBIL), total bile acid (TBA), hepatic malondialdehyde (MDA) and nitric monoxide (NO), as well as hepatic body ratio, bile flow and hepatic histopathological assay were measured and evaluated to investigate the therapeutic effect of TJ treatment with fresh RS. Phytochemical analysis of fresh and dried RS was performed by gas chromatography-mass spectrometer (GC-MS).

RESULTS

After TJ treatment with fresh RS, the abnormally elevated levels of serum AST, ALT, ALP, DBIL, TBIL and TBA, as well as hepatic MDA and NO at 108 h were reduced significantly (versus model group, P < 0.01). The hepatic body ratio, bile flow and hepatic pathological change of cholestatic rats at 108 h in TJ group were restored when compared with those of model group. Thirty-one compounds including lactones, flavonoids and phenolic acids were identified and determined by GC-MS analysis. The content of protoanemonin in fresh RS (9.49%) was about 25-fold higher than that in dried RS (0.38%).

CONCLUSIONS

TJ treatment with fresh RS exhibited good therapeutic effect on ANIT-induced intrahepatic cholestasis in rats, which may be due to the attenuated oxidative stress in the liver tissue. It is rational for the ancients to choose fresh RS as TJ herbal patches because of its abundant protoanemonin with the character of irritant. The qualitative and quantitative results of GC-MS analysis provided the chemical basis of TJ therapy with fresh RS, which can be regarded as a simple and efficient method for the treatment of cholestasis hepatitis.

Targeted Metabolomics Reveals a Protective Role for Basal PPARα in Cholestasis Induced by α-Naphthylisothiocyanate

α-Naphthylisothiocyanate (ANIT) is an experimental agent used to induce intrahepatic cholestasis. The Ppara-null mouse line is widely employed to explore the physiological and pathological roles of PPARα. However, little is known about how PPARα influences the hepatotoxicity of ANIT. In the present study, wild-type and Ppara-null mice were orally treated with ANIT to induce cholestasis. The serum metabolome of wild-type mice segregated from that of the Ppara-null mice, driven by changes of bile acid (BA) metabolites. Alkaline phosphatase and total BAs were elevated preferentially in Ppara-null mice, which correlated with changes in Cyp7a1, Cyp8b1, Mrp3, Cyp3a11, Cyp2b10, Ugt1a2, and Ugt1a5 genes and showed cross-talk between basal PPARα and potentially adaptive pathways. Il6, Tnfa, and target genes in the STAT3 pathway ( Socs3, Fga, Fgb, and Fgg) were up-regulated in Ppara-null mice but not in wild-type mice. The JNK pathway was activated in both mouse lines, while NF-κB and STAT3 were activated only in Ppara-null mice. These data suggest protection against cholestasis by basal PPARα involves regulation of BA metabolism and inhibition of NF-κB/STAT3 signaling. Considering studies on the protective effects of both basal and activated PPARα, caution should be exercised when one attempts to draw conclusions in which the PPARα is modified by genetic manipulation, fasting, or activation in pharmacological and toxicological studies.

Dioscin Protects ANIT-Induced Intrahepatic Cholestasis Through Regulating Transporters, Apoptosis and Oxidative Stress

Intrahepatic cholestasis, a clinical syndrome, is caused by excessive accumulation of bile acids in body and liver. Proper regulation of bile acids in liver cells is critical for liver injury. We previously reported the effects of dioscin against α-naphthylisothio- cyanate (ANIT)-induced cholestasis in rats. However, the pharmacological and mechanism data are limited. In our work, the animals of rats and mice, and Sandwich-cultured hepatocytes (SCHs) were caused by ANIT, and dioscin was used for the treatment. The results showed that dioscin markedly altered relative liver weights, restored ALT, AST, ALP, TBIL, GSH, GSH-Px, MDA, SOD levels, and rehabilitated ROS level and cell apoptosis. In mechanism study, dioscin not only significantly regulated the protein levels of Ntcp, OAT1, OCT1, Bsep and Mrp2 to accelerate bile acids excretion, but also regulated the expression levels of Bak, Bcl-xl, Bcl-2, Bax, Caspase 3 and Caspase 9 in vivo and in vitro to improve apoptosis. In addition, dioscin markedly inhibited PI3K/Akt pathway and up-regulated the levels of Nrf2, GCLc, GCLm, NQO1 and HO-1 against oxidative stress (OS) caused by bile acids. These results were further validated by inhibition of PI3K and Akt using the inhibitors of wortmannin and perifosine in SCHs. Our data showed that dioscin had good action against ANIT-caused intrahepatic cholestasis through regulating transporters, apoptosis and OS. This natural product can be considered as one active compound to treat intrahepatic cholestasis in the future.

Protective effects of petroleum ether extracts of Herpetospermum caudigerum against α-naphthylisothiocyanate-induced acute cholestasis of rats

ETHNOPHARMACOLOGICAL RELEVANCE

The ripe seeds of Herpetospermum caudigerum have been used in Tibetan folk medicine for treatment of bile or liver diseases including jaundice, hepatitis, intumescences or inflammation. Previously reports suggested that the seed oil and some lignans from H. caudigerum exhibited protective effects against carbon tetrachloride (CCl₄)-induced hepatic damage in rats, which may be related to their free radical scavenging effect. However, the protective effect of H. caudigerum against cholestasis is still not revealed. The aim of the present study was to investigate the pharmacological effect and the chemical constituents of the petroleum ether extract (PEE) derived from H. caudigerum against α-naphthylisothiocyanate (ANIT)-induced acute cholestasis in rats.

MATERIALS AND METHODS

Male cholestatic Sprague-Dawley (SD) rats induced by ANIT (60mg/kg) were orally administered with PEE (350, 700 and 1400mg/kg). Levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), γ-Glutamyl transpeptidase (γ-GTP), total bilirubin (TBIL), direct bilirubin (DBIL) and total bile acid (TBA), as well as bile flow, and histopathological assay were evaluated. Hepatic malondialdehyde (MDA), myeloperoxidase (MPO), superoxide dismutase (SOD), glutathione S-transferase (GST), and nitric monoxide (NO) in liver were measured to explore the possible protective mechanisms. Phytochemical analysis of PEE was performed by gas chromatography-mass spectrometer (GC-MS).

RESULTS

PEE have exhibited significant and dose-dependent protective effect on ANIT-induced liver injury by reduce the increases in serum levels of ALT, AST, ALP, γ-GTP, TBIL, DBIL and TBA, restore the bile flow in cholestatic rats, and reduce the severity of the pathological tissue damage induced by ANIT. Hepatic MDA, MPO and NO contents in liver tissue were reduced, while SOD and GST activities were elevated in liver tissue. 49 compounds were detected and 39 of them were identified by GC-MS analysis, in which long-chain fatty acids were the main constituents.

CONCLUSIONS

PEE exhibited a dose-dependently protective effect on ANIT-induced liver injury in cholestatic rats with the potential mechanism of attenuated oxidative stress in the liver tissue, and the possible active compounds were long-chain fatty acids.

Chlorogenic acid inhibits cholestatic liver injury induced by α-naphthylisothiocyanate: involvement of STAT3 and NFκB signalling regulation

OBJECTIVES

Chlorogenic acid (CGA) is one of the most widely consumed polyphenols in diets and is recognized to be a natural hepatoprotective agent. Here, we evaluated the protective effect and the potential mechanism of CGA against ɑ-naphthylisothiocyanate (ANIT)-induced cholestasis and liver injury.

METHODS

Twenty-five male 129/Sv mice were administered with CGA, and ANIT challenge was performed at 75 mg/kg on the 4th day. Blood was collected and subjected to biochemical analysis; the liver tissues were examined using histopathological analysis and signalling pathways.

KEY FINDINGS

Chlorogenic acid almost totally attenuated the ANIT-induced liver damage and cholestasis, compared with the ANIT group. Dose of 50 mg/kg of CGA significantly prevented ANIT-induced changes in serum levels of alanine aminotransferase, alkaline phosphatases, total bile acid, direct bilirubin, indirect bilirubin (5.3-, 6.3-, 18.8-, 158-, 41.4-fold, P<0.001) and aspartate aminotransferase (4.6-fold, P<0.01). Expressions of the altered bile acid metabolism and transport-related genes were normalized by cotreatment with CGA. The expressions of interleukin 6, tumour necrosis factor-α and suppressor of cytokine signalling 3 were found to be significantly decreased (1.2-fold, ns; 11.0-fold, P<0.01; 4.4-fold, P<0.05) in the CGA/ANIT group. Western blot revealed that CGA inhibited the activation and expression of signal transducer and activator of transcription 3 and NFκB.

CONCLUSIONS

These data suggest that CGA inhibits both ANIT-induced intrahepatic cholestasis and the liver injury. This protective effect involves down-regulation of STAT3 and NFκB signalling.

Geniposidic acid protected against ANIT-induced hepatotoxity and acute intrahepatic cholestasis, due to Fxr-mediated regulation of Bsep and Mrp2

ETHNOPHARMACOLOGICAL RELEVANCE

Geniposidic acid (GPA) is the main constituent of Gardenia jasminoides Ellis (Rubiaceae), which has long been used to treat inflammation, jaundice and hepatic disorders. The cholagogic effect of Gardenia jasminoides Ellis (Rubiaceae) and GPA have been widely reported, but the underlying occurrence mechanism remains unclear.

AIM OF THE STUDY

This investigation was designed to evaluate the hepatoprotection effect and potential mechanisms of GPA derived from Gardenia jasminoides Ellis (Rubiaceae) on fighting against α-naphthylisothiocyanate (ANIT) caused liver injury with acute intrahepatic cholestasis.

MATERIALS AND METHODS

Sprague-Dawley (SD) rats were intragastrically (i.g.) administered with the GPA (100, 50 and 25mg/kg B.W. every 24h) for seven consecutive days, and then they were treated with ANIT (i.g. 65mg/kg once in the 5th day) which induced liver injury with acute intrahepatic cholestasis. Serum and bile biochemical analysis, bile flow rate and liver histopathology were measured to evaluate the protective effect of GPA fight against ANIT treatment. The protein and mRNA expression levels of farnesoid X receptor (Fxr), bile-salt export pump (Bsep), multidrug resistance associated protein2 (Mrp2), were evaluated to study the effect of liver protection about GPA against ANIT induced hepatotoxicity and underlying mechanisms.

RESULTS

Some abnormalities were observed on ANIT treated rats including weight loss, reduced food intake and hair turned yellow. Obtained results demonstrated that at dose 100 and 50mg/kg B.W. (P<0.01) and 25mg/kg B.W. (P<0.05) of GPA pretreated dramatically prevented ANIT induced decreased in bile flow rate. Compared with ANIT treated group, the results of bile biochemical parameters about total bile acid (TBA) was increased by GPA at groups with any dose (P<0.01), glutathione (GSH) was increased significantly at high dose (P<0.01) and medium dose (P<0.05), total bilirubin (TB) was increased at high and medium dose (P<0.05), direct bilirubin (DB) was only increased at high dose (P<0.01). Serum levels of glutamic-Oxalacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), γ-glutamyltranspeptidase (γ-GT), TB, DB and TBA in comparison with ANIT treated group (P<0.01) were reduced by GPA (between 100 and 50mg/kg B.W.) pretreatment. Histopathology of the liver tissue showed that pathological damages and hepatic portal area filled with bile were relieved after GPA pretreatment compared with ANIT treated group. The protein and mRNA expression of Fxr, Bsep and Mrp2 were decreased in ANIT treated group. On the contrary, the protein and mRNA of Fxr, Bsep and Mrp2 were up regulated significantly pretreatment by GPA at dose of high and medium groups. On protein level of Bsep and Mrp2 the result shown no statistical difference in GPA (25mg/kg B.W.), but it was not same shown in mRNA level.

CONCLUSION

The results of this investigation have demonstrated that the GPA exerts a dose dependent hepatoprotection effect on ANIT induced liver damage with acute intrahepatic cholestasis in rats, which may due to Fxr mediated regulation of bile transporters like Bsep and Mrp2.

Evaluation of the protective effect of Rhei Radix et Rhizoma against α-naphthylisothiocyanate induced liver injury based on metabolic profile of bile acids

ETHNOPHARMACOLOGICAL RELEVANCE

To evaluate the hepatoprotective effect of the root and rhizome of Rhubarb (Rhei Radix et Rhizoma) against α-naphthylisothiocyanate (ANIT)-induced liver injury using metabolic profile of bile acids (BAs) along with biochemical parameters and histological alterations.

MATERIALS AND METHODS

Ultra-performance liquid chromatography coupled with quadrupole mass spectrometry (UPLC-MS) was applied to determinate the concentration of BAs, which was followed by multivariate statistical analysis of Principal Component Analysis (PCA) and Partial Least Squares Discriminate Analysis (PLS-DA).

RESULTS

Based on PCA results, three groups (Vehicle group, ANIT group and RhO+ANIT group) were clearly distinguished. Tauro-cholic acid (TCA), tauro-hyodesoxycholic acid (THDCA), glyco-cholic acid (GCA), and glyco-chenodeoxycholic acid (GCDCA) were proved to be the most important markers corresponding to ANIT-induced liver injury and protection provided by Rhubarb, which is further confirmed by PLS-DA. A correlation was found between the foregoing BAs and biochemical parameters including serum aspartate aminotransferase (ALT) and aspartate aminotransferase (AST), which confirmed that TCA, THDAC, GCA, and GCDCA could be considered as sensitive biomarkers.

CONCLUSION

The variance of the BAs contents can be used to evaluate ANIT-induced hepatotoxicity caused by ANIT and protective effects of Rhubarb. It also lays the foundation for the further research on the mechanisms of cholestasis as well as the therapeutic effect of Rhubarb.

Saikokeishito Extract Exerts a Therapeutic Effect on alpha-Naphthylisothiocyanate-Induced Liver Injury in Rats through Attenuation of Enhanced Neutrophil Infiltration and Oxidative Stress in the Liver Tissue

We examined whether Saikokeishito extract (TJ-10), a traditional Japanese herbal medicine, exerts a therapeutic effect on alpha-naphthylisothiocyanate (ANIT)-induced liver injury in rats through attenuation of enhanced neutrophil infiltration and oxidative stress in the liver tissue. In rats treated once with ANIT (75 mg/kg, i.p.), liver injury with cholestasis occurred 24 h after treatment and progressed at 48 h. When ANIT-treated rats orally received TJ-10 (0.26, 1.3 or 2.6 g/kg) at 24 h after the treatment, progressive liver injury with cholestasis was significantly attenuated at 48 h after the treatment at the dose of 1.3 or 2.6 g/kg. At 24 h after ANIT treatment, increases in hepatic lipid peroxide and reduced glutathione contents and myeloperoxidase activity occurred with decreases in hepatic superoxide dismutase and glutathione reductase activities. At 48 h after ANIT treatment, these changes except for reduced glutathione were enhanced with decreases in catalase, Se-glutathione peroxidase, and glucose-6-phosphate dehydrogenase activities. TJ-10 (1.3 or 2.6 g/kg) post-administered to ANIT-treated rats attenuated these changes found at 48 h after the treatment significantly. These results indicate that TJ-10 exerts a therapeutic effect on ANIT-induced liver injury in rats possibly through attenuation of enhanced neutrophil infiltration and oxidative stress in the liver tissue.

Protective effects of Moutan Cortex Radicis against acute hepatotoxicity

This study evaluated the potential beneficial effect of Moutan Cortex Radicis (MCR) in a murine model of carbon tetrachloride (CCl(4))-, D-galactosamine (GalN)- and α-naphthylisothiocyanate (ANIT)-induced liver injury. Acute hepatotoxicity was induced by intraperitoneal injection of CCl(4) (10 µL/kg), GalN (700 mg/kg), and ANIT (40 mg/kg). Animals received MCR (30, 100, and 300 mg/kg ) orally at 48, 24, and 2 h before and 6 h after administration of CCl(4), GalN, and ANIT. Serum activities of aminotransferase were significantly higher at 24 h after CCl(4) or GalN treatment. These changes were attenuated by MCR. Histopathological analysis revealed multiple and extensive areas of portal inflammation, hepatocellular necrosis, and an increase in inflammatory cell infiltration. These changes were inhibited by MCR. Serum total bilirubin concentration increased and bile flow decreased significantly 48 h after ANIT treatment, which was attenuated by MCR. Our results suggest that MCR has a protective effect on acute liver injury.

Tissue factor-dependent coagulation contributes to alpha-naphthylisothiocyanate-induced cholestatic liver injury in mice

Separation of concentrated bile acids from hepatic parenchymal cells is a key function of the bile duct epithelial cells (BDECs) that form intrahepatic bile ducts. Using coimmunostaining, we found that tissue factor (TF), the principal activator of coagulation, colocalized with cytokeratin 19, a marker of BDECs in the adult mouse liver. BDEC injury induced by xenobiotics such as alpha-naphthylisothiocyanate (ANIT) causes cholestasis, inflammation, and hepatocellular injury. We tested the hypothesis that acute ANIT-induced cholestatic hepatitis is associated with TF-dependent activation of coagulation and determined the role of TF in ANIT hepatotoxicity. Treatment of mice with ANIT (60 mg/kg) caused multifocal hepatic necrosis and significantly increased serum biomarkers of cholestasis and hepatic parenchymal cell injury. ANIT treatment also significantly increased liver TF expression and activity. ANIT-induced activation of the coagulation cascade was shown by increased plasma thrombin-antithrombin levels and significant deposition of fibrin within the necrotic foci. ANIT-induced coagulation and liver injury were reduced in low-TF mice, which express 1% of normal TF levels. The results indicate that ANIT-induced liver injury is accompanied by TF-dependent activation of the coagulation cascade and that TF contributes to the progression of injury during acute cholestatic hepatitis.