Bile duct ligation in rats induces biliary expression of cytokine-induced neutrophil chemoattractant

BACKGROUND & AIMS: Bile duct obstruction causes neutrophilic inflammation of the liver and leads to hepatic fibrosis. In obstructive liver disease, the localization of neutrophils in portal tracts suggests that cells within this region produce neutrophil chemoattractants. In this study, we investigated whether bile duct obstruction in rats induces portal expression of cytokine-induced neutrophil chemoattractant (CINC). METHODS: Rats underwent bile duct ligation for 3 hours to 8 days. CINC regulation was examined in vivo at various intervals by immunohistochemistry, ribonuclease protection, and in situ hybridization. CINC production was also investigated in cell culture, in response to putative stimuli from obstructed liver. RESULTS: Bile duct ligation caused neutrophilic infiltration of the liver within 3 hours. CINC was also rapidly induced, with specific expression identified in biliary cells. Rat intrahepatic biliary cells produced CINC constitutively in culture; when exposed to cholestatic bile, they showed a 12-fold increase in CINC secretion. The effect of bile was not attributable to toxicity or to dissolved cytokines or endotoxin. Mechanical strain, designed to mimic the stretching of biliary cells during obstruction, did not induce CINC. CONCLUSIONS: Biliary cells contribute to hepatic inflammation during cholestasis by producing neutrophil chemoattractants. A major stimulus to biliary chemoattractant production in vivo may be bile itself.     

Infiltrating neutrophils in bile duct-ligated livers do not promote hepatic fibrosis

Bile duct obstruction causes rapid infiltration of neutrophils into the liver and leads ultimately to hepatic fibrosis. In this study, we assessed whether neutrophils play an active role in the pathogenesis of hepatic fibrosis under conditions of biliary obstruction. We performed bile duct ligation (BDL) on rats, some of which were depleted of neutrophils by means of an anti-neutrophil antiserum. Rats treated with the antiserum had 48% fewer neutrophils than control rats. Despite this, they showed no difference in either bile duct proliferation or hepatic fibrogenesis after BDL compared with control rats. In a second set of experiments, we performed BDL on mice with an underlying defect in neutrophil function due to transgenic expression of interleukin-8. Mice with neutrophil dysfunction deposited less (−22%) collagen in their livers after BDL than wild-type mice, but the difference was not statistically significant. In summary, data from two independent rodent models indicate that infiltrating neutrophils do not influence hepatic fibrogenesis following bile duct obstruction. The findings suggest that neutrophils play little if any role in the immunomodulation of liver fibrosis.     

α-Melanocyte-Stimulating Hormone Gene Transfer Attenuates Inflammation after Bile Duct Ligation in the Rat

Cholestasis occurs in a wide variety of human liver diseases, and hepatocellular injury is an invariant feature of cholestasis causing liver dysfunction and inflammation, promoting fibrogenesis, and ultimately leading to liver failure. α-Melanocyte-stimulating hormone (α-MSH) is a potent anti-inflammatory agent in many models of inflammation, suggesting that it inhibits a critical step common to different forms of inflammation. The aim of this study was to investigate whether the gene transfer of α-MSH could attenuate hepatic inflammation after bile duct ligation in the rat. Studies were performed in bile duct-ligated (BDL) rats. Hydrodynamic-based gene transfection with α-MSH plasmid via rapid tail vein injection was performed 30 min after ligation of bile duct. The endpoints were studied as markers of inflammation 7 days after bile duct ligation. α-MSH expression in liver via a single administration of naked plasmid was demonstrated. Liver inflammation index, including neutrophil infiltration and serum alanine aminotransferase, were significantly reduced in α-MSH gene transfer rats. Markers for liver inflammation, including expression of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and inducible NO synthase (iNOS) mRNA, as assessed by real-time PCR, were also attenuated by α-MSH gene therapy. Expression of iNOS protein in liver diminished after α-MSH gene transfer. Consistent with these data, hepatic stellate cells (HSC) and Kupffer cells were markedly inhibited in α-MSH gene-treated rats. Our findings show that gene transfer of α-MSH could attenuate hepatic inflammation after bile duct ligation in the rat.     

Tissue-type plasminogen activator deficiency exacerbates cholestatic liver injury in mice

Recent studies demonstrating a role for plasminogen activator inhibitor (PAI)-1 in cholestatic liver disease in mice suggested that tissue-type plasminogen activator (tPA) or urokinase plasminogen activator (uPA) might be important after biliary tract obstruction. We now demonstrate that blocking tPA exacerbates liver injury after bile duct ligation (BDL). tPA deficient mice have increased bile infarcts, increased TUNEL positive cells, increased neutrophil infiltration, reduced hepatocyte proliferation and reduced ductular reaction 72 hours after BDL compared to wild type mice. In addition, the protective and proliferative effects of plasminogen activator inhibitor 1 (PAI-1) deficiency after BDL are dramatically blocked by the tPA inhibitor tPA-STOP. One potential mechanism for these effects is that both tPA deficiency and tPA-STOP reduce hepatocyte growth factor (HGF) activation and c-Met phosphorylation in the liver after BDL. In support of this hypothesis, HGF treatment reverses the effects of tPA deficiency in mice. Furthermore, preferential tPA activation in areas of injury after BDL might occur because fibrin accumulates in bile infarcts and activates tPA. CONCLUSION: tPA inactivation accelerates liver injury after BDL and reduces HGF activation. These data suggest that strategies to increase HGF activation might be protective in liver diseases with biliary tract obstruction even without increased HGF production.     

Role of alphavbeta6 integrin in acute biliary fibrosis

Acute biliary obstruction leads to periductal myofibroblasts and fibrosis, the origin of which is uncertain. Our study provides new information on this question in mice and humans. We show that bile duct obstruction induces a striking increase in cholangiocyte alphavbeta6 integrin and that expression of this integrin is directly linked to fibrogenesis through activation of transforming growth factor beta (TGF-beta). Administration of blocking antibody to alphavbeta6 significantly reduces the extent of acute fibrosis after bile duct ligation. Moreover, in beta6-null mice subjected to the injury, fibrosis is reduced by 50% relative to that seen in wild-type mice, whereas inflammation occurs to the same extent. The data indicate that alphavbeta6, rather than inflammation, is linked to fibrogenesis. It is known that alphavbeta6 binds latent TGF-beta and that binding results in release of active TGFbeta. Consistent with this, intracellular signaling from the TGFbeta receptor is increased after bile duct ligation in wild-type mice but not in beta6(-/-) mice, and a competitive inhibitor of the TGFbeta receptor type II blocks fibrosis to the same extent as antibody to alphavbeta6. In a survey of human liver disease, expression of alphavbeta6 is increased in acute, but not chronic, biliary injury and is localized to cholangiocyte-like cells. CONCLUSION: Cholangiocytes respond to acute bile duct obstruction with markedly increased expression of alphavbeta6 integrin, which is closely linked to periductal fibrogenesis. The findings provide a rationale for the use of inhibitors of alphavbeta6 integrin or TGFbeta for down-regulating fibrosis in the setting of acute or ongoing biliary injury.     

Loss of MMP 13 attenuates murine hepatic injury and fibrosis during cholestasis

Cholestasis occurs in a variety of clinical settings and often results in liver injury and secondary biliary fibrosis. Several matrix metalloproteinases (MMPs) are upregulated in the liver during cholestasis. The function of the major interstitial collagenase, MMP-13, in the initial phase of liver fibrosis is unknown. The aim of this study was to evaluate the role of MMP-13 during the development of cholestasis-induced liver fibrosis by comparing wild-type and MMP-13-deficient mice. Cholestasis was induced by bile duct ligation (BDL) for 5 days or 3 weeks. Activation and proliferation of hepatic stellate cells (HSCs) were detected by immunohistochemistry. Expression of MMP-13 mRNA increased significantly in BDL livers of WT mice. After BDL for 3 weeks liver fibrosis was suppressed in MMP-13-deficient mice versus WT animals. Activation and proliferation of HSCs were also suppressed in livers of MMP-13-deficient mice after BDL. To clarify the mechanism of this suppression, samples from 5-day BDL mice were used for evaluation of liver injury. Compared with those in WT animals, serum ALT and the number of hepatic neutrophils were reduced in MMP-13-deficient mice. Increased expression of the mRNA of inflammatory mediators such as tumor necrosis factor-alpha (TNF-alpha) was significantly suppressed in livers of MMP-13-deficient mice. Upregulation of fibrogenic markers, for example, transforming growth factor beta1 (TGF-beta1), was also significantly suppressed in livers of MMP-13-deficient mice versus in WT mice. In conclusion, distinct from the known function of interstitial collagenase to reduce liver fibrosis by degrading the extracellular matrix, MMP-13 contributes to accelerating fibrogenesis in cholestatic livers by mediating the initial inflammation of the liver.     

Drug- and chemical-induced cholestasis

Cholestasis caused by medicinal and chemical agents is an increasingly well-recognized cause of liver disease. Clinical drug-induced cholestatic syndromes producing jaundice and bile duct injury can mimic extrahepatic biliary obstruction, primary biliary cirrhosis, and sclerosing cholangitis, among others. This article updates the various forms of drug-induced cholestasis, focusing on the clinicopathologic features of this form of hepatic injury and on the known or putative mechanisms by which drugs and chemicals lead to cholestasis.     

Transcriptional profiling after bile duct ligation identifies PAI-1 as a contributor to cholestatic injury in mice

Extrahepatic cholestasis leads to complex injury and repair processes that result in bile infarct formation, neutrophil infiltration, cholangiocyte and hepatocyte proliferation, extracellular matrix remodeling, and fibrosis. To identify early molecular mechanisms of injury and repair after bile duct obstruction, microarray analysis was performed on liver tissue 24 hours after bile duct ligation (BDL) or sham surgery. The most upregulated gene identified encodes plasminogen activator inhibitor 1 (PAI-1, Serpine 1), a protease inhibitor that blocks urokinase plasminogen activator (uPA) and tissue-type plasminogen activator (tPA) activity. Because PAI-1, uPA, and tPA influence growth factor and cytokine processing as well as extracellular matrix remodeling, we evaluated the role of PAI-1 in cholestatic liver injury by comparing the injury and repair processes in wild-type (WT) and PAI-1-deficient (PAI-1-/-) mice after BDL. PAI-1-/- mice had fewer and smaller bile infarcts, less neutrophil infiltration, and higher levels of cholangiocyte and hepatocyte proliferation than WT animals after BDL. Furthermore, PAI-1-/- mice had higher levels of tPA activation and mature hepatocyte growth factor (HGF) after BDL than WT mice, suggesting that PAI-1 effects on HGF activation critically influence cholestatic liver injury. This was further supported by elevated levels of c-Met and Akt phosphorylation in PAI-1-/- mice after BDL. In conclusion, PAI-1 deficiency reduces liver injury after BDL in mice. These data suggest that inhibiting PAI-1 might attenuate liver injury in cholestatic liver diseases.     

High adiponectin in chronic liver disease and cholestasis suggests biliary route of adiponectin excretion in vivo

BACKGROUND/AIMS: Models of fatty liver diseases and fibrosis suggest a hepatoprotective effect of adiponectin, an adipocyte-derived hormone with antidiabetic, antiobesity, antiatherogenic and anti-inflammatory effects. METHODS: We studied adiponectin serum levels in 111 chronic liver disease (CLD) patients and 226 healthy controls and the impact of cholestasis on adiponectin by bile duct ligation experiments in mice. RESULTS: Adiponectin was significantly elevated in CLD, and correlated with stage of liver cirrhosis, liver cell injury, e.g. aminotransferase activity, and inflammatory markers, but not with liver synthesis capacity, insulin sensitivity (HOMA index) or clinical complications. As patients with biliary liver diseases and cholestasis exhibited the highest adiponectin levels, we experimentally investigated a potential biliary route of adiponectin excretion. Following bile duct ligation in mice adiponectin levels rapidly increased without affecting hepatic adiponectin gene expression. Also, adiponectin was detectable in human bile. High adiponectin concentrations were associated with severe cholangitis and/or cholestasis on liver histology. CONCLUSIONS: Adiponectin is elevated in chronic liver disease and correlates with inflammation and liver damage. High adiponectin levels after bile duct ligation in mice and in human bile from cholestatic patients suggest that biliary secretion is involved in adiponectin clearance and that adiponectin could serve as a novel marker indicating cholestasis in liver cirrhosis.     

Kupffer cells abrogate cholestatic liver injury in mice

BACKGROUND & AIMS: Biliary obstruction and cholestasis can cause hepatocellular apoptosis and necrosis. Ligation of the common bile duct in mice provides an excellent model in which to study the underlying mechanisms. Kupffer cells play a key role in modulating the inflammatory response observed in most animal models of liver injury. This study was performed to determine the role of Kupffer cells in the injury attending cholestasis. METHODS: Mice were not treated or were rendered Kupffer cell-depleted by intravenous inoculation of multilamellar liposome-encapsulated dichloromethylene diphosphonate, the common bile duct was ligated and divided; sham-operated animals served as controls. Similarly, interleukin-6 (IL-6)-deficient and tumor necrosis factor-receptor-deficient mice underwent bile duct ligation (BDL) or sham operations. RESULTS: Serum alanine transaminase levels were increased in all BDL mice at 3 days after surgery, but were significantly higher in IL-6-deficient mice or mice rendered Kupffer cell-depleted before ligation. Histologic examination of BDL livers showed portal inflammation, neutrophil infiltration, bile duct proliferation, and hepatocellular necrosis. Photoimage analyses confirmed more necrosis in the livers of Kupffer cell-depleted and IL-6-deficient animals. Purified Kupffer cells derived from BDL animals produced more IL-6 in culture. Similarly, Kupffer cells obtained by laser capture microdissection from the livers of BDL mice expressed increased levels of IL-6 messenger RNA. Recombinant mouse IL-6 administered 1 hour before BDL completely reversed the increased liver damage assessed otherwise in Kupffer cell-depleted mice. CONCLUSIONS: These findings indicate that Kupffer cells abrogate cholestatic liver injury by cytokine-dependent mechanisms that include the production of IL-6.     

Melatonin versus vitamin E as protective treatment against oxidative stress after extra-hepatic bile duct ligation in rats

The aims of the present study were first to compare the effects of melatonin and vitamin E on the cholestasis syndrome and their protective effect on liver injury, and second, to evaluate the activity of antioxidant enzymes after treatment with these antioxidant drugs. Cholestasis was achieved in adult male Wistar rats by double ligature and section of the extra-hepatic biliary duct. Hepatic and plasma oxidative stress markers were evaluated by changes in the amount of lipid peroxides, measured as malondialdehyde (MDA) and reduced glutathione (GSH) in plasma and homogenates of hepatic tissue. Serum bilirubin, alkaline phosphatase (AP), and gamma-glutamyl-transpeptidase (GGT) were used to evaluate the severity of cholestasis, and serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were used to evaluate the hepatic injury. Both vitamin E and melatonin were administrated 1 day before and 7 days after bile duct ligation. Acute ligation of the bile duct was accompanied by a significant increased in MDA and a decrease in GSH levels in both plasma and liver, as well as a significant reduction in antioxidant enzymes activities. The overall analysis of both treatments showed that melatonin (500 microg/kg daily) offered significantly better protection against cholestasis and a superior protective effect on hepatic injury than did vitamin E (15 mg/kg daily). Although vitamin E treatment resulted in a reduction of parameters of oxidative stress, the results were significantly better after a much lower daily dose of melatonin. Moreover, melatonin treatment was associated with a significant recovery of antioxidative enzymes. In conclusion, the present paper demonstrates a correlation between the intensity of biliary tract obstruction and increased free radical generation, as well as a direct correlation between the level of oxidative stress and the biochemical markers of liver injury. Melatonin (at a much lower dose than vitamin E) was much more efficient than vitamin E in reducing the negative parameters of cholestasis, the degree of oxidative stress and provided a significantly greater hepatoprotective effect against the liver injury secondary to the acute ligation of the biliary duct.     

Ursodeoxycholic acid aggravates bile infarcts in bile duct-ligated and Mdr2 knockout mice via disruption of cholangioles

BACKGROUND & AIMS: The effects of ursodeoxycholic acid (UDCA) in biliary obstruction are unclear. We aimed to determine the effects of UDCA in bile duct-ligated and in Mdr2 knockout (Mdr2(-/-)) mice with biliary strictures. METHODS: Mice fed UDCA (0.5% wt/wt) or a control diet were subjected to common bile duct ligation (CBDL), selective bile duct ligation (SBDL), or sham operation. UDCA was also fed to 2-month-old Mdr2(-/-) mice. Serum biochemistry, liver histology, and mortality rates were investigated. The biliary tract was studied by plastination, India ink injection, and electron microscopy. The effects of UDCA on biliary pressure were determined by cholangiomanometry. RESULTS: UDCA feeding in CBDL mice increased biliary pressure, with subsequent rupture of cholangioles and aggravation of hepatocyte necroses, resulting in significantly increased mortality. UDCA feeding in SBDL mice aggravated liver injury exclusively in the ligated lobe. Mdr2(-/-) mice developed liver lesions resembling sclerosing cholangitis characterized by biliary strictures and dilatations. UDCA induced bile infarcts in these animals. CONCLUSIONS: UDCA aggravates bile infarcts and hepatocyte necroses in mice with biliary obstruction via disruption of cholangioles as a result of increased biliary pressure caused by its choleretic action.     

Drug- and chemical-induced cholestasis

Cholestasis resulting from drugs is an increasingly recognized cause of liver disease. It produces a broad clinical-pathologic spectrum of injury that includes simple jaundice, cholestatic hepatitis, and bile duct injury that can mimic extrahepatic biliary obstruction, primary biliary cirrhosis, and sclerosing cholangitis. Although the risk of drug-induced cholestasis leading to a fatal outcome is quite rare, knowledge and recognition of the various forms of cholestatic injury assumes an importance whenever clinicians are confronted with jaundice or other manifestations of liver disease in patients receiving medicinal or chemical agents.     

Effects of warm ischemia time on biliary injury in rat liver transplantation

AIM: To investigate the effect of different secondary warm ischemia time (SWIT) on bile duct injury in liver-transplanted rats.METHODS: Forty-eight male inbred Sprague-Dawley rats were randomly assigned into four groups: a sham-operation group and three groups with secondary biliary warm ischemia time of 0 min, 10 min and 20 min. A rat model of autologous liver transplantation under ether anesthesia was established, and six rats were killed in each group and blood samples and the median lobe of the liver were collected for assay at 6 h and 24 h after hepatic arterial reperfusion.RESULTS: With prolongation of biliary warm ischemia time, the level of vascular endothelial growth factor-A was significantly decreased, and the value at 24 h was higher than that at 6 h after hepatic arterial reperfusion, but with no significant difference. The extended biliary SWIT led to a significant increase in bile duct epithelial cell apoptosis, and a decrease in the number of blood vessels, the bile duct surrounding the blood vessels and bile duct epithelial cell proliferation in the early postoperative portal area. Pathologic examinations showed that inflammation of the rat portal area was aggravated, and biliary epithelial cell injury was significantly worsened.CONCLUSION: A prolonged biliary warm ischemia time results in aggravated injury of the bile duct and the surrounding vascular plexus in rat autologous orthotopic liver transplantation.     

An analytical review of vasculobiliary injury in laparoscopic and open cholecystectomy

Objectives

Biliary injuries are frequently accompanied by vascular injuries, which may worsen the bile duct injury and cause liver ischemia. We performed an analytical review with the aim of defining vasculobiliary injury and setting out the important issues in this area.

Methods

A literature search of relevant terms was peformed using OvidSP. Bibliographies of papers were also searched to obtain older literature.

Results

Vasculobiliary injury was defined as: an injury to both a bile duct and a hepatic artery and/or portal vein; the bile duct injury may be caused by operative trauma, be ischaemic in origin or both, and may or may not be accompanied by various degrees of hepatic ischaemia. Right hepatic artery (RHA) vasculobiliary injury (VBI) is the most common variant. Injury to the RHA likely extends the biliary injury to a higher level than the gross observed mechanical injury. VBI results in slow hepatic infarction in about 10% of patients. Repair of the artery is rarely possible and the overall benefit unclear. Injuries involving the portal vein or common or proper hepatic arteries are much less common, but have more serious effects including rapid infarction of the liver.

Conclusions

Routine arteriography is recommended in patients with a biliary injury if early repair is contemplated. Consideration should be given to delaying repair of a biliary injury in patients with occlusion of the RHA. Patients with injuries to the portal vein or proper or common hepatic should be emergently referred to tertiary care centers.     

Reversible bile acid changes in bile duct obstruction and its potential for hepatocellular injury.

The etiology of hepatocellular dysfunction resulting from chronic biliary obstruction is not clearly understood. Alterations in bile acid metabolism due to changes in microsomal cytochrome P-450 enzyme activities may have a fundamental role in cholestatic liver injury. This study examines the very early changes in both biliary bile acids and hepatic microsomal cytochrome P-450 content after bile duct obstruction in the rat and the effects of the restoration of bile flow after 3 days of biliary obstruction. We found that early induction of cytochrome P-450 may be a fundamental step in the generation of cholestatic liver injury mediated by hepatotoxic bile acids. The rapid reversal of bile acid changes with reconstituted bile flow indicate that the liver is able to quickly recover when obstruction is relieved. Characterization of this fundamental process may ultimately provide a means of modulation of cholestatic hepatotoxicity.     

Reversibility of hepatic mitochondrial damage in rats with long-term cholestasis

Background/Aims: Long-term bile duct ligation in rats is associated with secondary biliary cirrhosis and metabolic alterations, e.g. mitochondrial dysfunction. We performed the current studies to characterize the reversibility of hepatic mitochondrial dysfunction after reversing biliary obstruction by Roux-en-Y anastomosis.Methods: Rats were studied after 4 weeks of bile duct ligation, and after 5 or 14 days of reanastomosis. Control rats were pair-fed to treated rats and all rats were studied after starvation for 24 h. Mitochondria were isolated by differential centrifugation and enzyme activities determined by spectrophotometric methods.Results: In comparison to controls, plasma β-hydroxybutyrate concentrations were decreased in bile duct ligated rats (200±70 vs. 790±200 μmol/l) and remained decreased after relief of biliary obstruction. In contrast, plasma free fatty acids were not different between controls and treated rats. Oxidative metabolism of L-glutamate, succinate and duroquinol was decreased in liver mitochondria from bile duct ligated rats. After relief of biliary obstruction, the metabolism of L-glutamate and duroquinol normalized quickly, whereas succinate metabolism remained impaired. Similar results were obtained for the mitochondrial oxidases in disrupted mitochondria. The activities of complex I, II, III and V of the respiratory chain were reduced in bile duct ligated rats. After relief of biliary obstruction, complex I and III normalized quickly, whereas complex II and V remained impaired. Oxidative metabolism of long-chain fatty acids by isolated liver mitochondria was decreased in bile duct ligated rats and did not recover after relief of biliary obstruction.Conclusions: Long-term cholestasis in the rat is associated with a decrease in specific functions of liver mitochondria which recover only partially after Rouxen-Y anastomosis. The persistence of decreased mitochondrial fatty acid metabolism cannot be explained by impaired activity of the respiratory chain, but is more likely due to alterations in mitochondrial β-oxidation.     

2-Mercaptoethane sulfonate (MESNA) protects against biliary obstruction-induced oxidative damage in rats.

The aim of this study was to assess the antioxidant and antifibrotic effects of chronic administration of 2-mercaptoethane sulfonate (MESNA) on oxidative liver damage and fibrosis induced by biliary obstruction in rats. Liver fibrosis was induced in male Wistar albino rats by bile duct ligation and scission (BDL). MESNA (150mg/kg, i.p.) or saline was administered for 28 days. At the end of the experiment, rats were killed by decapitation. Serum aspartate aminotransferase (AST), and alanine aminotransferase (ALT) levels were determined to assess liver function. Tumor necrosis factor-alpha (TNF-alpha) and lactate dehidrogenase (LDH) were also assayed in serum samples. Liver tissues were taken for determination of the free radicals, hepatic malondialdehyde (MDA) levels, an end product of lipid peroxidation; glutathione (GSH) levels, a key antioxidant; myeloperoxidase (MPO) activity, as an indirect index of neutrophil infiltration. Hepatic collagen content, as a fibrosis marker was also determined. Serum AST, ALT, LDH and TNF-alpha levels were elevated in the BDL group as compared to control group, while this increase was significantly decreased by MESNA treatment. BDL caused a significant (p<0.05-0.001) decrease in GSH levels while MDA levels and MPO activity were increased in the liver tissue. These changes were reversed by MESNA treatment. Collagen contents of the liver tissue was increased by BDL (p<0.001), and reversed back to the control levels with MESNA. Since MESNA administration alleviated the BDL-induced oxidative injury of the liver and improved the hepatic functions, it seems likely that MESNA with its antioxidant and antifibrotic properties, may be of potential therapeutic value in protecting the liver fibrosis and oxidative injury due to biliary obstruction.