Ursodeoxycholic acid-induced changes of plasma and urinary bile acids in patients with primary biliary cirrhosis

Oral Vancomycin, Ursodeoxycholic Acid, or No Therapy for Pediatric Primary Sclerosing Cholangitis: A Matched Analysis

BACKGROUND AND AIMS

Many children with primary sclerosing cholangitis (PSC) receive oral vancomycin therapy (OVT) or ursodeoxycholic acid (UDCA). There is a paucity of data on whether these medications improve outcomes.

APPROACH AND RESULTS

We analyzed retrospective data from the Pediatric PSC Consortium. Children treated with OVT were matched 1:1:1 to those treated with UDCA or managed with observation (no treatment) based on the closest propensity score, ensuring similar baseline characteristics. Two hundred sixty-four patients (88 each with OVT, UDCA, or observation) had matching propensity scores and were similar in demographics, phenotype, immunosuppression, baseline biochemistry, and hepatic fibrosis. After 1 year in an intention-to-treat analysis, all outcome metrics were similar regardless of treatment group. In OVT, UDCA, and untreated groups, respectively: Gamma-glutamyltransferase normalized in 53%, 49%, and 52% (P = not significant [NS]), liver fibrosis stage was improved in 20%, 13%, and 18% and worsened in 11%, 29%, and 18% (P = NS), and the 5-year probability of liver transplant listing was 21%, 10%, and 12% (P = NS). Favorable outcome was associated with having a mild phenotype of PSC and minimal hepatic fibrosis.

CONCLUSIONS

We presented the largest-ever description of outcomes on OVT in PSC and compared them to carefully matched patients on UDCA or no therapy. Neither OVT nor UDCA showed improvement in outcomes compared to a strategy of observation. Patients progressed to end-stage liver disease at similar rates. Spontaneous normalization of biochemistry is common in children receiving no therapy, particularly in the majority of children with a mild phenotype and an early stage of disease. Placebo-controlled treatment trials are needed to identify effective treatments for pediatric PSC.

An insight into primary biliary cholangitis and its recent advances in treatment: semi-synthetic analogs to combat ursodeoxycholic-acid resistance

INTRODUCTION

Primary biliary cholangitis (PBC) is a chronic cholestatic liver disease which on progression causes cirrhosis; various studies also suggested that several diseases can co-exist in patients. In existing depiction of disease PBC, apart from entire use of ursodeoxycholic acid (UDCA), several patients need to step forward to liver-transplantation or death due to resistance or non-responder with UDCA monotherapy.

AREAS COVERED

To overcome this non-respondent treatment, novel bile acid semi-synthetic analogs have been identified which shows their potency against for farnesoid X receptor and transmembrane G protein-coupled receptor-5 which are identified as target for many developing analogs which have desirable pharmacokinetic profiles.

EXPERT OPINION

A range of studies suggests that adding semisynthetic analogs in therapeutic regime improves liver biochemistries in patients with suboptimal response to UDCA. Thus, the aspire of this review is to abridge and compare therapeutic value and current markets affirm of various bile acids semi-synthetic analogs which certainly are having promising effects in PBC monotherapy or in pooled treatment with UDCA for PBC.

Direct Amplification of Tissue Factor:Factor VIIa Procoagulant Activity by Bile Acids Drives Intrahepatic Coagulation

OBJECTIVE

Regulation of TF (tissue factor):FVIIa (coagulation factor VIIa) complex procoagulant activity is especially critical in tissues where plasma can contact TF-expressing cells. One example is the liver, where hepatocytes are routinely exposed to plasma because of the fenestrated sinusoidal endothelium. Although liver-associated TF contributes to coagulation, the mechanisms controlling the TF:FVIIa complex activity in this tissue are not known. Approach and Results: Common bile duct ligation in mice triggered rapid hepatocyte TF-dependent intrahepatic coagulation coincident with increased plasma bile acids, which occurred at a time before observable liver damage. Similarly, plasma TAT (thrombin-antithrombin) levels increased in cholestatic patients without concurrent hepatocellular injury. Pathologically relevant concentrations of the bile acid glycochenodeoxycholic acid rapidly increased hepatocyte TF-dependent procoagulant activity in vitro, independent of de novo TF synthesis and necrotic or apoptotic cell death. Glycochenodeoxycholic acid increased hepatocyte TF activity even in the presence of the phosphatidylserine-blocking protein lactadherin. Interestingly, glycochenodeoxycholic acid and taurochenodeoxycholic acid increased the procoagulant activity of the TF:FVIIa complex relipidated in unilamellar phosphatidylcholine vesicles, which was linked to an apparent decrease in the K_m for FX (coagulation factor X). Notably, the zwitterionic detergent 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate, a bile acid structural analog, did not increase relipidated TF:FVIIa activity. Bile acids directly enhanced factor X activation by recombinant soluble TF:FVIIa complex but had no effect on FVIIa alone.

CONCLUSIONS

The results indicate that bile acids directly accelerate TF:FVIIa-driven coagulation reactions, suggesting a novel mechanism whereby elevation in a physiological mediator can directly increase TF:FVIIa procoagulant activity.

Ursodeoxycholic Acid Therapy in Pediatric Primary Sclerosing Cholangitis: Predictors of Gamma Glutamyltransferase Normalization and Favorable Clinical Course

OBJECTIVE

To investigate patient factors predictive of gamma glutamyltransferase (GGT) normalization following ursodeoxycholic acid (UDCA) therapy in children with primary sclerosing cholangitis.

STUDY DESIGN

We retrospectively reviewed patient records at 46 centers. We included patients with a baseline serum GGT level ≥50 IU/L at diagnosis of primary sclerosing cholangitis who initiated UDCA therapy within 1 month and continued therapy for at least 1 year. We defined "normalization" as a GGT level <50 IU/L without experiencing portal hypertensive or dominant stricture events, liver transplantation, or death during the first year.

RESULTS

We identified 263 patients, median age 12.1 years at diagnosis, treated with UDCA at a median dose of 15 mg/kg/d. Normalization occurred in 46%. Patients with normalization had a lower prevalence of Crohn's disease, lower total bilirubin level, lower aspartate aminotransferase to platelet ratio index, greater platelet count, and greater serum albumin level at diagnosis. The 5-year survival with native liver was 99% in those patients who achieved normalization vs 77% in those who did not.

CONCLUSIONS

Less than one-half of the patients treated with UDCA have a complete GGT normalization in the first year after diagnosis, but this subset of patients has a favorable 5-year outcome. Normalization is less likely in patients with a Crohn's disease phenotype or a laboratory profile suggestive of more advanced hepatobiliary fibrosis. Patients who do not achieve normalization could reasonably stop UDCA, as they are likely not receiving clinical benefit. Alternative treatments with improved efficacy are needed, particularly for patients with already-advanced disease.

Prohibitin 1 suppresses liver cancer tumorigenesis in mice and human hepatocellular and cholangiocarcinoma cells

Prohibitin 1 (PHB1) is best known as a mitochondrial chaperone, and its role in cancer is conflicting. Mice lacking methionine adenosyltransferase α1 (MATα1) have lower PHB1 expression, and we reported that c-MYC interacts directly with both proteins. Furthermore, c-MYC and MATα1 exert opposing effects on liver cancer growth, prompting us to examine the interplay between PHB1, MATα1, and c-MYC and PHB1's role in liver tumorigenesis. We found that PHB1 is highly expressed in normal hepatocytes and bile duct epithelial cells and down-regulated in most human hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA). In HCC and CCA cells, PHB1 expression correlates inversely with growth. PHB1 and MAT1A positively regulate each other's expression, whereas PHB1 negatively regulates the expression of c-MYC, MAFG, and c-MAF. Both PHB1 and MATα1 heterodimerize with MAX, bind to the E-box element, and repress E-box promoter activity. PHB1 promoter contains a repressive E-box element and is occupied mainly by MAX, MNT, and MATα1 in nonmalignant cholangiocytes and noncancerous tissues that switched to c-MYC, c-MAF, and MAFG in cancer cells and human HCC/CCA. All 8-month-old liver-specific Phb1 knockout mice developed HCC, and one developed CCA. Five-month-old Phb1 heterozygotes, but not Phb1 flox mice, developed aberrant bile duct proliferation; and one developed CCA 3.5 months after left and median bile duct ligation. Phb1 heterozygotes had a more profound fall in the expression of glutathione synthetic enzymes and higher hepatic oxidative stress following left and median bile duct ligation.

CONCLUSION

We have identified that PHB1, down-regulated in most human HCC and CCA, heterodimerizes with MAX to repress the E-box and positively regulates MAT1A while suppressing c-MYC, MAFG, and c-MAF expression; in mice, reduced PHB1 expression predisposes to the development of cholestasis-induced CCA. (Hepatology 2017;65:1249-1266).

[Ursodeoxycholic acid: A therapeutic niche in an internist's practice]

The paper shows more than 40 years' experience with ursodeoxycholic acid (UDCA) used as a drug; during this period it has demonstrated its rather high clinical efficacy. Due to the range of its inherent pleiotropic (choleretic, cytoprotective, immunomodulatory, antiapoptotic, hypocholesterolemic, and litholytic) properties, UDCA has a broad spectrum of therapeutic activity. The paper considers the issues associated with the mechanism of action and with the clinical effects of this bile acid. It gives the results of the most important randomized controlled trials determining currently the evidence base for the efficiency and safety of using UDCA in the clinical picture of visceral diseases.

Epigallocatechin 3-gallate ameliorates bile duct ligation induced liver injury in mice by modulation of mitochondrial oxidative stress and inflammation

Cholestatic liver fibrosis was achieved by bile duct ligation (BDL) in mice. Liver injury associated with BDL for 15 days included significant reactive oxygen/nitrogen species generation, liver inflammation, cell death and fibrosis. Administration of Epigallocatechin 3-Gallate (EGCG) in animals reduced liver fibrosis involving parenchymal cells in BDL model. EGCG attenuated BDL-induced gene expression of pro-fibrotic markers (Collagen, Fibronectin, alpha 2 smooth muscle actin or SMA and connective tissue growth factor or CTGF), mitochondrial oxidative stress, cell death marker (DNA fragmentation and PARP activity), NFκB activity and pro-inflammatory cytokines (TNFα, MIP1α, IL1β, and MIP2). EGCG also improved BDL induced damages of mitochondrial electron transport chain complexes and antioxidant defense enzymes such as glutathione peroxidase and manganese superoxide dismutase. EGCG also attenuated hydrogen peroxide induced cell death in hepatocytes in vitro and alleviate stellate cells mediated fibrosis through TIMP1, SMA, Collagen 1 and Fibronectin in vitro. In conclusion, the reactive oxygen/nitrogen species generated from mitochondria plays critical pathogenetic role in the progression of liver inflammation and fibrosis and this study indicate that EGCG might be beneficial for reducing liver inflammation and fibrosis.

Ursodeoxycholic acid for primary biliary cirrhosis

BACKGROUND

Ursodeoxycholic acid is administered to patients with primary biliary cirrhosis, a chronic progressive inflammatory autoimmune-mediated liver disease with unknown aetiology. Despite its controversial effects, the U.S. Food and Drug Administration has approved its usage for primary biliary cirrhosis.

OBJECTIVES

To assess the beneficial and harmful effects of ursodeoxycholic acid in patients with primary biliary cirrhosis.

SEARCH METHODS

We searched for eligible randomised trials in The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, LILACS, Clinicaltrials.gov, and the WHO International Clinical Trials Registry Platform. The literature search was performed until January 2012.

SELECTION CRITERIA

Randomised clinical trials assessing the beneficial and harmful effects of ursodeoxycholic acid versus placebo or 'no intervention' in patients with primary biliary cirrhosis.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data. Continuous data were analysed using mean difference (MD) and standardised mean difference (SMD). Dichotomous data were analysed using risk ratio (RR). Meta-analyses were conducted using both a random-effects model and a fixed-effect model, with 95% confidence intervals (CI). Random-effects model meta-regression was used to assess the effects of covariates across the trials. Trial sequential analysis was used to assess risk of random errors (play of chance). Risks of bias (systematic error) in the included trials were assessed according to Cochrane methodology bias domains.

MAIN RESULTS

Sixteen randomised clinical trials with 1447 patients with primary biliary cirrhosis were included. One trial had low risk of bias, and the remaining fifteen had high risk of bias. Fourteen trials compared ursodeoxycholic acid with placebo and two trials compared ursodeoxycholic acid with 'no intervention'. The percentage of patients with advanced primary biliary cirrhosis at baseline varied from 15% to 83%, with a median of 51%. The duration of the trials varied from 3 to 92 months, with a median of 24 months. The results showed no significant difference in effect between ursodeoxycholic acid and placebo or 'no intervention' on all-cause mortality (45/699 (6.4%) versus 46/692 (6.6%); RR 0.97, 95% CI 0.67 to 1.42, I² = 0%; 14 trials); on all-cause mortality or liver transplantation (86/713 (12.1%) versus 89/706 (12.6%); RR 0.96, 95% CI 0.74 to 1.25, I² = 15%; 15 trials); on serious adverse events (94/695 (13.5%) versus 107/687 (15.6%); RR 0.87, 95% CI 0.68 to 1.12, I² = 23%; 14 trials); or on non-serious adverse events (27/643 (4.2%) versus 18/634 (2.8%); RR 1.46, 95% CI 0.83 to 2.56, I² = 0%; 12 trials). The random-effects model meta-regression showed that the risk of bias of the trials, disease severity of patients at entry, ursodeoxycholic acid dosage, and trial duration were not significantly associated with the intervention effects on all-cause mortality, or on all-cause mortality or liver transplantation. Ursodeoxycholic acid did not influence the number of patients with pruritus (168/321 (52.3%) versus 166/309 (53.7%); RR 0.96, 95% CI 0.84 to 1.09, I² = 0%; 6 trials) or with fatigue (170/252 (64.9%) versus 174/244 (71.3%); RR 0.90, 95% CI 0.81 to 1.00, I² = 62%; 4 trials). Two trials reported the number of patients with jaundice and showed a significant effect of ursodeoxycholic acid versus placebo or no intervention in a fixed-effect meta-analysis (5/99 (5.1%) versus 15/99 (15.2%); RR 0.35, 95% CI 0.14 to 0.90, I² = 51%; 2 trials). The result was not supported by the random-effects meta-analysis (RR 0.56, 95% CI 0.06 to 4.95). Portal pressure, varices, bleeding varices, ascites, and hepatic encephalopathy were not significantly affected by ursodeoxycholic acid. Ursodeoxycholic acid significantly decreased serum bilirubin concentration (MD -8.69 µmol/l, 95% CI -13.90 to -3.48, I² = 0%; 881 patients; 9 trials) and activity of serum alkaline phosphatases (MD -257.09 U/L, 95% CI -306.25 to -207.92, I² = 0%; 754 patients, 9 trials) compared with placebo or no intervention. These results were supported by trial sequential analysis. Ursodeoxycholic acid also seemed to improve serum levels of gamma-glutamyltransferase, aminotransferases, total cholesterol, and plasma immunoglobulin M concentration. Ursodeoxycholic acid seemed to have a beneficial effect on worsening of histological stage (random; 66/281 (23.5%) versus 103/270 (38.2%); RR 0.62, 95% CI 0.44 to 0.88, I² = 35%; 7 trials).

AUTHORS' CONCLUSIONS

This systematic review did not demonstrate any significant benefits of ursodeoxycholic acid on all-cause mortality, all-cause mortality or liver transplantation, pruritus, or fatigue in patients with primary biliary cirrhosis. Ursodeoxycholic acid seemed to have a beneficial effect on liver biochemistry measures and on histological progression compared with the control group. All but one of the included trials had high risk of bias, and there are risks of outcome reporting bias and risks of random errors as well. Randomised trials with low risk of bias and low risks of random errors examining the effects of ursodeoxycholic acid for primary biliary cirrhosis are needed.

Effect of bile duct ligation on bile acid composition in mouse serum and liver

BACKGROUND

Cholestatic liver diseases can be caused by genetic defects, drug toxicities, hepatobiliary malignancies or obstruction of the biliary tract. Cholestasis leads to accumulation of bile acids (BAs) in hepatocytes. Direct toxicity of BAs is currently the most accepted hypothesis for cholestatic liver injury. However, information on which bile acids are actually accumulating during cholestasis is limited.

AIM

To assess the BA composition in liver and serum after bile duct ligation (BDL) in male C57Bl/6 mice between 6 h and 14 days and evaluate toxicity of the most abundant BAs.

RESULTS

Bile acid concentrations increased in liver (27-fold) and serum (1400-fold) within 6 h after surgery and remained elevated up to 14 days. BAs in livers of BDL mice became more hydrophilic than sham controls, mainly because of increased 6β-hydroxylation and taurine conjugation. Among the eight unconjugated and 16 conjugated BAs identified in serum and liver, only taurocholic acid (TCA), β-muricholic acid (βMCA) and TβMCA were substantially elevated representing >95% of these BAs over the entire time course. Although glycochenodeoxycholic acid and other conjugated BAs increased in BDL animals, the changes were several orders of magnitude lower compared with TCA, βMCA and TβMCA. A mixture of these BAs did not cause apoptosis or necrosis, but induced inflammatory gene expression in cultured murine hepatocytes.

CONCLUSION

The concentrations of cytotoxic BAs are insufficient to cause hepatocellular injury. In contrast, TCA, βMCA and TβMCA are able to induce pro-inflammatory mediators in hepatocytes. Thus, BAs act as inflammagens and not as cytotoxic mediators after BDL in mice.

Protective effects of glycoursodeoxycholic acid in Barrett's esophagus cells

Barrett's esophagus (BE) is a premalignant condition associated with the development of esophageal adenocarcinoma (EAC). Previous studies have implicated hydrophobic bile acids and gastric acid in BE and EAC pathogenesis. In this study, we tested the hypothesis that DNA damage, cytotoxicity and oxidative stress induced by bile acids and gastric acid can be attenuated by the cytoprotective, hydrophilic bile acid glycoursodeoxycholic acid (GUDCA). Non-dysplastic BE cells were exposed for 10 min to pH 4 and/or bile acid cocktail or to pH 4 and a modified cocktail consisting of a mixture of bile acids and GUDCA. DNA damage was evaluated by the comet assay; cell viability and proliferation were measured by trypan blue staining and the MTS assay; reactive oxygen species (ROS) were measured using hydroethidium staining; oxidative DNA/RNA damage was detected by immunostaining with antibody against 8-OH-dG; thiol levels were measured by 5-chloromethylfluorescein diacetate (CMFDA) staining; and the expression of antioxidant proteins was evaluated by western blotting. DNA damage and oxidative stress were significantly increased, while thiol levels were decreased in BE cells treated with pH 4 and bile acid cocktail compared with cells treated with pH 4 alone or untreated cells. Bile acids and low pH also significantly decreased cell proliferation. Expression of the antioxidant enzymes, MnSOD and CuZnSOD, was elevated in the cells treated with bile acids and low pH. When GUDCA was included in the medium, all these effects of pH 4 and bile acids were markedly reduced. In conclusion, treatment of BE cells with acidified medium and a bile acid cocktail at physiologically relevant concentrations induces DNA damage, cytotoxicity, and ROS. The cytoprotective bile acid, GUDCA, inhibits these deleterious effects by inhibiting oxidative stress.

Bile acids in treatment of ocular disease

Bear bile has been included in Asian pharmacopeias for thousands of years in treatment of several diseases, ranging from sore throat to hemorrhoids. The hydrophilic bile acids tauroursodeoxycholic acid (TUDCA) and ursodeoxycholic acid (UDCA) are the major bile acids of bear bile. Both of these are available as synthetic formulations and are approved by the health administrations of several countries for treatment of cirrhosis and gallstones. This review briefly covers the use of bear bile in Traditional Chinese Medicine, bile acid physiology, approved use of UDCA and TUDCA in Western medicine, and recent research exploring their neuroprotective properties, including in models of ocular disease.

Ursodeoxycholic acid reduces CpG-induced IgM production in patients with primary biliary cirrhosis

AIM

Ursodeoxycholic acid (UDCA) treatment reduces IgM serum levels in patients with primary biliary cirrhosis (PBC) without affecting serum antimitochondrial antibody (AMA) titers. We previously reported that PBC-associated hyper-IgM is secondary to a disease-specific hyperproduction following bacterial stimulation by B cells.

METHODS

We isolated peripheral blood mononuclear cells (PBMC) from patients with PBC and controls and evaluated whether bacterial CpG challenge in the presence of UDCA at concentrations consistent with those achieved in treated patients led to changes in total IgM, IgG-AMA, and IgM-AMA production. Further, p65 phosphorylation and CD38 cell expression were analyzed as measures of activation of the NF-kB signaling pathway and B cell subsets, respectively.

RESULTS

UDCA significantly reduced CpG-induced total IgM and IgM-AMA production, but had no impact on IgG-AMA production. UDCA also significantly reduced the activation ofnaïve and IgM memory, but not IgG memory, B cells, as represented by CD38 expression levels. Further, p65 phosphorylation was significantly reduced in the presence of UDCA.

CONCLUSION

UDCA reduces total and IgM-AMA production in PBMC from patients with PBC by downregulating B cell activation and NF-kB signaling. These data ultimately suggest novel mechanisms of action for UDCA in chronic autoimmune cholestasis.

Bile Acid sulfation: a pathway of bile acid elimination and detoxification

Sulfotransferase-2A1 catalyzes the formation of bile acid-sulfates (BA-sulfates). Sulfation of BAs increases their solubility, decreases their intestinal absorption, and enhances their fecal and urinary excretion. BA-sulfates are also less toxic than their unsulfated counterparts. Therefore, sulfation is an important detoxification pathway of BAs. Major species differences in BA sulfation exist. In humans, only a small proportion of BAs in bile and serum are sulfated, whereas more than 70% of BAs in urine are sulfated, indicating their efficient elimination in urine. The formation of BA-sulfates increases during cholestatic diseases. Therefore, sulfation may play an important role in maintaining BA homeostasis under pathologic conditions. Farnesoid X receptor, pregnane X receptor, constitutive androstane receptor, and vitamin D receptor are potential nuclear receptors that may be involved in the regulation of BA sulfation. This review highlights current knowledge about the enzymes and transporters involved in the formation and elimination of BA-sulfates, the effect of sulfation on the pharmacologic and toxicologic properties of BAs, the role of BA sulfation in cholestatic diseases, and the regulation of BA sulfation.

Dietary glycine blunts liver injury after bile duct ligation in rats

AIM: To investigate the effects of (dietary) glycine against oxidant-induced injury caused by bile duct ligation (BDL).

METHODS: Either a diet containing 5% glycine or a standard diet was fed to male Sprague-Dawley (SD) rats. Three days later, BDL or sham-operation was performed. Rats were sacrificed 1 to 3 d after BDL. The influence of deoxycholic acid (DCA) in the presence or absence of glycine on liver cells was determined by measurement of calcium and chloride influx in cultivated Kupffer cells and lactate dehydrogenase (LDH) activity was determined in the supernatant of cultivated hepatocytes.

RESULTS: Serum alanine transaminase levels increased to about 600 U/L 1 d after BDL. However, enzyme release was blunted by about two third in rats receiving glycine. Release of the alkaline phosphatase and aspartate aminotransferase was also blocked significantly in the group fed glycine. Focal necrosis was observed 2 d after BDL. Glycine partially blocked the histopathological changes. Incubation of Kupffer cells with DCA led to increased intracellular calcium that could be blocked by incubation with glycine. However, systemic blockage of Kupffer cells with gadolinium chloride had no effects on transaminase release. Incubation of isolated hepatocytes with DCA led to a significant release of LDH after 4 h. This release was largely blocked when incubation with glycine was performed.

CONCLUSION: These data indicate that glycine significantly decreased liver injury, most likely by a direct effect on hepatocytes. Kupffer cells do not appear to play an important role in the pathological changes caused by cholestasis.

Ursodeoxycholic acid for primary biliary cirrhosis

BACKGROUND

Primary biliary cirrhosis is an uncommon autoimmune liver disease with unknown aetiology. Ursodeoxycholic acid (UDCA) has been used for primary biliary cirrhosis, but the effects remain controversial.

OBJECTIVES

To evaluate the benefits and harms of UDCA on patients with primary biliary cirrhosis against placebo or no intervention.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials on The Cochrane Library, MEDLINE, EMBASE, SCI-EXPANDED, The Chinese Biomedical CD Database, LILACS, and the references of identified studies. The last search was performed in January 2007.

SELECTION CRITERIA

Randomised clinical trials evaluating UDCA versus placebo or no intervention in patients with primary biliary cirrhosis.

DATA COLLECTION AND ANALYSIS

The primary outcomes were mortality and mortality or liver transplantation. Binary outcomes were reported as odds ratio (OR) or relative risk (RR) and continuous outcomes as weighted mean difference, all with 95% confidence intervals (CI). Meta-regression was used to investigate the associations between UDCA effects and quality of the trial, UDCA dose, trial duration, and patient's severity of primary biliary cirrhosis. We also used Bayesian meta-analytic approach to estimate the UDCA effect as sensitivity analysis.

MAIN RESULTS

Sixteen randomised clinical trials evaluating UDCA against placebo or no intervention were identified. Data from three trials have been updated. Nearly half of the trials had high risk of bias. The combined results demonstrated no significant effects favouring UDCA on mortality (OR 0.97, 95% CI 0.67 to 1.42) and mortality or liver transplantation (RR 0.92, 95% CI 0.71 to 1.21). The findings were supported by the Bayesian meta-analyses. UDCA did not improve pruritus, fatigue, autoimmune conditions, liver histology, or portal pressure. UDCA seemed to improve biochemical variables, like serum bilirubin, ascites, and jaundice, but the findings were based on few trials with sparse data. The use of UDCA is significantly associated with adverse events, mainly weight gain.

AUTHORS' CONCLUSIONS

This systematic review did not demonstrate any benefit of UDCA on mortality and mortality or liver transplantation of patients with primary biliary cirrhosis. The few beneficial effects could not be due to random errors or outcome reporting bias.

Expression of bile acid synthesis and detoxification enzymes and the alternative bile acid efflux pump MRP4 in patients with primary biliary cirrhosis

BACKGROUND

Bile acid synthesis, transport and metabolism are markedly altered in experimental cholestasis. Whether such coordinated regulation exists in human cholestatic diseases is unclear. We therefore investigated expression of genes for bile acid synthesis, detoxification and alternative basolateral export and regulatory nuclear factors in primary biliary cirrhosis (PBC).

MATERIAL/METHODS

Hepatic CYP7A1, CYP27A1, CYP8B1 (bile acid synthesis), CYP3A4 (hydroxylation), SULT2A1 (sulphation), UGT2B4/2B7 (glucuronidation), MRP4 (basolateral export), farnesoid X receptor (FXR), retinoid X receptor (RXR), short heterodimer partner (SHP), hepatocyte nuclear factor 1alpha (HNF1alpha) and HNF4alpha expression was determined in 11 patients with late-stage PBC and this was compared with non-cholestatic controls.

RESULTS

CYP7A1 mRNA was repressed in PBC to 10-20% of controls, while CYP27 and CYP8B1 mRNA remained unchanged. SULT2A1, UGT2B4/2B7 and CYP3A4 mRNA levels were unaltered or only mildly reduced in PBC. MRP4 protein levels were induced three-fold in PBC, whereas mRNA levels remained unchanged. Expression levels of FXR, RXR, SHP, PXR, CAR, HNF1alpha and HNF4alpha were moderately reduced in PBC without reaching statistical significance.

SUMMARY/CONCLUSIONS

Repression of bile acid synthesis and induction of basolateral bile acid export may represent adaptive mechanisms to limit bile acid burden in chronic cholestasis. As these changes do not sufficiently counteract cholestatic liver damage, future therapeutic strategies should aim at stimulation of bile acid detoxification pathways.

Heme oxygenase-1 overexpression increases liver injury after bile duct ligation in rats

AIM: To investigate the effects of heme oxygenase-1 (HO-1) against oxidant-induced injury caused by bile duct ligation (BDL).

METHODS: Either cobalt protoporphyrin (CoPP), a HO-1 inducer, or saline were injected intraperitoneally in male SD-rats. Three days later, BDL or sham-operations were performed. Rats were sacrificed 3 wk after BDL and livers were harvested for histology. Fibrosis was evaluated by sirius red staining and image analysis. Alpha-smooth muscular actin, which indicates activation of stellate cells, was detected by immunohistochemical staining, and cytokine and collagen-Iα (Col-Iα) mRNA expression was detected using RNase protection assays.

RESULTS: Serum alanine transaminase increased 8-fold above normal levels one day after BDL. Surprisingly, enzyme release was not reduced in rats receiving CoPP. Liver fibrosis was evaluated 3 wk after BDL and the sirius red-positive area was found to be increased to about 7.8%. However, in CoPP pretreated rats sirius red-positive areas were increased to about 11.7% after BDL. Collagen-Iα and TGF-β mRNA increased significantly by BDL. Again, this effect was increased by HO-1 overexpression.

CONCLUSION: Hepatic fibrosis due to BDL is not reduced by the HO-1 inducer CoPP. In contrast, HO-1 overexpression increases liver injury in rats under conditions of experimental chronic cholestasis.

Chenodeoxycholic acid and taurochenodexycholic acid induce anti-apoptotic cIAP-1 expression in human hepatocytes

BACKGROUND AND AIMS

Increased concentration of endogenous bile acids in the liver correlates with clinical features of cholestatic liver diseases. Recently, it was reported that non-toxic hydrophobic bile acid activated a survival signaling pathway via phosphatidylinositol 3 (PI3) kinase in hepatocytes. However, whether bile acid induces inhibitors of apoptosis protein (IAPs) directly in human hepatocytes remains unknown. This study investigated effects of bile acids on cIAP-1, cIAP-2 and XIAP expression in hepatocytes.

METHODS

Human fetal hepatocytes and HepG2 cells were treated with free or conjugated chenodeoxycholic acid (CDCA) or ursodeoxycholic acid in the presence or absence of several inhibitors. Reverse transcriptase-polymerase chain reaction and Western blot analyses were performed for mRNA and protein expressions, respectively, of IAPs. Luciferase assay was used to investigate transcriptional activity of nuclear factor (NF)-kappaB.

RESULTS

Chenodeoxycholic acid up-regulated both mRNA and protein expressions of cIAP-1. In particular, taurochenodeoxycholic acid (TCDCA), but not glycochenodeoxycholic acid (GCDCA), induced cIAP-1 mRNA expression. In contrast, cIAP-2 and XIAP mRNA expressions were not influenced by CDCA. Moreover, CDCA-induced cIAP-1 mRNA expression was inhibited completely by calphostin C and SB203580, but not by wortmannin. Luciferase assay showed that CDCA and TCDCA activated NF-kappaB-driven transcriptional activity.

CONCLUSION

It was shown that CDCA induced cIAP-1 expression in hepatocytes through protein kinase C- and p38 mitogen-activated protein kinase-mediated pathway. Especially, TCDCA, but not GCDCA, increased cIAP-1 mRNA expression and NF-kappaB-regulated transcriptional activity. Therefore, it is suggested that CDCA and TCDCA themselves have an inhibitory potential against apoptosis through the cIAP-1-survival signaling pathway, in addition to PI3 kinase-dependent pathway.

Human UDP-glucuronosyltransferase (UGT)1A3 enzyme conjugates chenodeoxycholic acid in the liver

Chenodeoxycholic acid (CDCA) is a liver-formed detergent and plays an important role in the control of cholesterol homeostasis. During cholestasis, toxic bile acids (BA) accumulate in hepatocytes causing damage and consequent impairment of their function. Glucuronidation, a conjugation reaction catalyzed by UDP-glucuronosyltransferase (UGT) enzymes, is considered an important metabolic pathway for hepatic BA. This study identifies the human UGT1A3 enzyme as the major enzyme responsible for the hepatic formation of the acyl CDCA-24glucuronide (CDCA-24G). Kinetic analyses revealed that human liver and UGT1A3 catalyze the formation of CDCA-24G with similar K(m) values of 10.6 to 18.6 mumol/L, respectively. In addition, electrophoretic mobility shift assays and transient transfection experiments revealed that glucuronidation reduces the ability of CDCA to act as an activator of the nuclear farnesoid X-receptor (FXR). Finally, we observed that treatment of human hepatocytes with fibrates increases the expression and activity of UGT1A3, whereas CDCA has no effect. In conclusion, UGT1A3 is the main UGT enzyme for the hepatic formation of CDCA-24G and glucuronidation inhibits the ability of CDCA to act as an FXR activator. In vitro data also suggest that fibrates may favor the formation of bile acid glucuronides in cholestatic patients.

Ursodeoxycholic acid and superoxide anion

AIM: To investigate the ability of ursodeoxycholic acid (UDCA) to scavenge superoxide anion (O2^-).

METHODS: We assessed the ability of UDCA to scavenge (O2^-) generated by xanthine-xanthine oxidase (X-XO) in a cell-free system and its effect on the rate of O2^--induced ascorbic acid (AA) oxidation in hepatic post-mitochondrial supernatants.

RESULTS: UDCA at a concentration as high as 1 mmol/L did not impair the ability of the X-XO system to generate O2^-, but could scavenge O2^- at concentrations of 0.5 and 1 mmol/L, and decrease the rate of AA oxidation at a concentration of 100 µmol/L.

CONCLUSION: UDCA can scavenge O2^-, an action that may be beneficial to patients with primary biliary cirrhosis.

Ursodeoxycholic acid inhibits endothelin-1 production in human vascular endothelial cells

Endothelin-1 is known to be implicated in the pathogenesis of hepatobiliary diseases such as cirrhosis, especially in portal hypertension. This study aimed to investigate the effects of ursodeoxycholic acid on endothelin-1 production in human endothelial cells. The effects of ursodeoxycholic acid and its conjugates (tauroursodeoxycholic and glycoursodeoxycholic acids) on endothelin-1 production as well as nitric oxide (NO) in human umbilical vein endothelial cells (HUVECs) were examined. The production of endothelin-1 and nitric oxide in culture medium was measured using enzyme-linked immunosorbent assay (ELISA) and the Griess method, respectively. Endothelin-1 and endothelial nitric oxide synthase (eNOS) mRNA expression were investigated by real-time quantitative reverse transcriptase/polymerase chain reaction (RT-PCR). Ursodeoxycholic acid (30-1000 microM) inhibited endothelin-1 production in a concentration-dependent manner, and ursodeoxycholic acid at concentrations higher than 300 microM increased nitric oxide production in culture medium. The conjugates of ursodeoxycholic acid also increased nitric oxide production and decreased endothelin-1 production, which was less effective than ursodeoxycholic acid. N-nitro-L-arginine-mythel-ester (L-NAME), a nitric oxide synthase (NOS) inhibitor, suppressed the ursodeoxycholic acid-induced nitric oxide production, but it did not antagonize the inhibitory effects of ursodeoxycholic acid on endothelin-1 production. Ursodeoxycholic acid also induced a concentration-dependent decrease in endothelin-1 mRNA expression without significant changes in eNOS mRNA expression. These results provide novel evidence that ursodeoxycholic acid inhibits endothelin-1 production in human endothelial cells, but nitric oxide is not responsible for the inhibitory effect of ursodeoxycholic acid on endothelin-1. Thus, ursodeoxycholic acid therapy may prevent the development of several pathogenesis such as portal hypertension observed in patients with cirrhosis due to the improvement of endothelial function.

Improved effects of viral gene delivery of human uPA plus biliodigestive anastomosis induce recovery from experimental biliary cirrhosis

Gene therapy may represent a new avenue for the development of multimodal treatment for diverse forms of cirrhosis. This study explores the potential benefits of combining adenovirus-mediated human urokinase-plasminogen activator (AdHuPA) gene delivery and biliodigestive anastomosis to enhance the therapeutic efficacy of each treatment alone for cholestatic disorders resulting in secondary biliary cirrhosis. In an experimental model of secondary biliary cirrhosis, application of 6 x 10(11) vp/kg AdHuPA adenovirus vector resulted in 25.8% liver fibrosis reduction and some improvement in liver histology. The relief of bile cholestasis by a surgical procedure (biliodigestive anastomosis) combined with AdHuPA hepatic gene delivery rendered a synergistic effect, with a substantial 56.9 to 42.9% fibrosis decrease. AdHuPA transduction resulted in clear-cut expression of human uPA protein detected by immunohistochemistry and induction of up-regulation in the expression of metalloproteinases MMP-3, MMP-9, and MMP-2. Importantly, functional hepatic tests, specifically direct bilirubin, were improved. Also, hepatic cell regeneration, rearrangement of hepatic architecture, ascites, and gastric varices improved in cirrhotic rats treated with AdHuPA but not in counterpart AdGFP cirrhotic animals. We believe this might represent a novel therapeutic strategy for human cholestatic diseases.

Systematic review: ursodeoxycholic acid--adverse effects and drug interactions

BACKGROUND

Ursodeoxycholic acid is increasingly being used for the treatment of chronic cholestatic liver diseases. It appears to be generally well tolerated, but a systematic review on drug safety is lacking.

AIM

As experimental data suggest a role of bile acids in the regulation of hepatic drug metabolism at both the transcriptional and post-transcriptional level, the literature was screened for adverse drug reactions and drug interactions related to ursodeoxycholic acid.

METHODS

A systematic review of the literature was performed using a refined search strategy to evaluate the adverse effects of ursodeoxycholic acid and its interactions with other drugs.

RESULTS

Ursodeoxycholic acid caused diarrhoea in a small proportion of patients. Rare skin reactions were due to drug adjuvants rather than the active substance. Decompensation of liver cirrhosis was reported after the administration of ursodeoxycholic acid in single cases of end-stage primary biliary cirrhosis. Recurrent right upper quadrant abdominal pain was incidentally observed. The absorption of ursodeoxycholic acid was impaired by colestyramine, colestimide, colestipol, aluminium hydroxide and smectite. Metabolic drug interactions were reported for the cytochrome P4503A substrates, ciclosporin, nitrendipine and dapsone.

CONCLUSIONS

Ursodeoxycholic acid is generally well tolerated. Drug absorption interactions with anion exchange resins deserve consideration. Metabolic interactions with compounds metabolized by cytochrome P4503A are to be expected.

Inhibitory effects of ursodeoxycholic acid on the induction of nitric oxide synthase in vascular smooth muscle cells

The expression of inducible nitric oxide synthase (iNOS) and the resultant increased nitric oxide production are associated with endotoxemia and atherosclerotic lesions observed in transplant hearts or balloon-injured artery. Ursodeoxycholic acid has been shown to have cardiovascular protective effects, such as inhibition of the development of transplant arteriosclerosis, but its mechanism remains unclear. Here, we investigated the effects of ursodeoxycholic acid on nitric oxide production and the expression of iNOS in vascular smooth muscle cells isolated from adult rat aorta and rabbit coronary artery. Nitrite released from cells in the culture medium was measured with the Griess reaction. iNOS mRNA and protein were measured by Northern and Western blot analyses. Treatment with ursodeoxycholic acid (30-1000 microM) significantly inhibited lipopolysaccharide plus interferon-gamma-induced nitric oxide production in a concentration-dependent manner, but ursodeoxycholic acid showed only small inhibitory effects on nitric oxide production that had already been induced by lipopolysaccharide plus interferon-gamma. Ursodeoxycholic acid by itself did not affect basal nitric oxide production. Ursodeoxycholic acid also suppressed lipopolysaccharide plus interferon-gamma-induced expression of iNOS mRNA and protein. Ursodeoxycholic acid had the most potent inhibitory effect among various kinds of bile acids examined, i.e. chenodeoxycholic acid, deoxycholic acid, cholic acid and conjugated bile acids such as tauroursodeoxycholic acid. These results suggest that ursodeoxycholic acid inhibits the induction of iNOS and then nitric oxide production in aortic and coronary artery smooth muscle cells, suggesting a possible mechanism for the cardiovascular protective effect of ursodeoxycholic acid under various pathophysiological conditions such as endotoxemia and atherosclerosis.

Fibrates suppress chenodeoxycholic acid-induced RANTES expression through inhibition of NF-kappaB activation

Fibrates, hypolipidemic agents, are reported to be effective in treatment of primary biliary cirrhosis. However, the mechanism involved in therapeutic benefits of fibrates in primary biliary cirrhosis remains unknown. In contrast, hepatic regulated upon activation, normal T-cell expressed and secreted (RANTES) is increased in patients with primary biliary cirrhosis and bile acids up-regulate RANTES expression in hepatocytes. The role of fibrates in bile acid-induced RANTES expression was investigated in human hepatoma cells; 100 microM of bezafibrate and fenofibrate decreased expression of chenodeoxycholic acid-induced RANTES mRNA and protein. In addition, luciferase enzyme assay using RANTES promoter-luciferase reporter plasmid revealed that 100 microM of bezafibrate and fenofibrate transcriptionally reduced chenodeoxycholic acid-induced RANTES gene expression. Moreover, bezafibrate clearly repressed DNA-binding activity of nuclear factor-kappaB (NF-kappaB) induced by chenodeoxycholic acid. Therefore, fibrates might be inhibitory agents of inflammatory cell migration by RANTES to the liver in patients with primary biliary cirrhosis, possibly indicating that fibrates are therapeutic agents in primary biliary cirrhosis.

Viral gene delivery of superoxide dismutase attenuates experimental cholestasis-induced liver fibrosis in the rat

Hydrophobic bile acids lead to generation of oxygen free radicals in mitochondria. Accordingly, this study investigated if gene delivery of superoxide dismutase (SOD) would reduce hepatic injury caused by experimental cholestasis. Rats were given adenovirus (Ad; 3 x 10(9) p.f.u., i.v.) carrying the bacterial control gene lacZ, mitochondrial Mn-SOD or cytosolic Cu/Zn-SOD genes 3 days before bile duct ligation. Both Mn- and Cu/Zn-SOD activity was increased in the liver about four-fold 3 days after viral infection. Serum alanine transaminase increased to about 710 U/l after bile duct ligation, which was blunted by about 70% in rats receiving Ad-Mn-SOD, but by only 30% in rats receiving Ad-Cu/Zn-SOD. Bile duct ligation caused focal necrosis, apoptosis and fibrosis in the liver and increased collagen alpha1 mRNA about 20-fold. These effects were reduced significantly by Ad-Mn-SOD, but not by Ad-Cu/Zn-SOD. In addition, bile duct ligation increased 4-hydroxynonenal, a product of lipid peroxidation, activated NF-kappaB and increased synthesis of TNF(alpha) and TGF-beta. These effects were also blunted significantly by Ad-Mn-SOD, but not by Ad-Cu/Zn-SOD. Taken together, it is concluded that cholestasis causes liver injury by mechanisms involving mitochondrial oxidative stress. Gene delivery of mitochondrial Mn-SOD blocks formation of oxygen radicals and production of toxic cytokines thereby minimizing liver injury caused by cholestasis.

Ursodeoxycholic acid for primary biliary cirrhosis

BACKGROUND

Primary biliary cirrhosis is a rare autoimmune liver disease and an effective treatment has been difficult to establish. Some randomised clinical trials have found an effect of ursodeoxycholic acid for primary biliary cirrhosis.

OBJECTIVES

Evaluate the beneficial effects and adverse effects of peroral ursodeoxycholic acid for primary biliary cirrhosis versus placebo or no intervention.

SEARCH STRATEGY

The Controlled Trials Register of The Cochrane Hepato-Biliary Group, The Cochrane Library, MEDLINE, EMBASE and the full text of the identified studies were searched until April 2001. The electronic searches were done by entering the search terms 'ursodeoxycholic acid', 'UDCA', 'primary biliary cirrhosis', and 'PBC'.

SELECTION CRITERIA

Randomised clinical trials evaluating ursodeoxycholic acid administered perorally at any dose versus placebo or no intervention in patients with primary biliary cirrhosis diagnosed by any method. Only trials using an adequate method for randomisation were included, regardless of blinding and language.

DATA COLLECTION AND ANALYSIS

The methodologic quality of the randomised clinical trials was evaluated by components and the Jadad-score. The following outcomes were extracted: mortality, liver transplantation, pruritus, other clinical symptoms (jaundice, portal pressure, (bleeding) oesophageal varices, ascites, hepatic encephalopathy, hepato-renal syndrome, autoimmune conditions), liver biochemistry, liver function, liver biopsy findings, quality of life, and adverse events. All analyses were performed according to the intention-to-treat method.

MAIN RESULTS

A total of 16 randomised clinical trials evaluating ursodeoxycholic acid against placebo (n = 15) or no intervention (n = 1) in 1422 patients were identified. The median Jadad-score was 3 (range 1-5). A number of trials described as double blind had problems with the blinding. Neither mortality (odds ratio = 0.94; 95% confidence interval (CI) 0.60 to 1.48), liver transplantation (odds ratio = 0.83; 95% CI 0.52 to 1.32), mortality or liver transplantation (odds ratio = 0.90; 95% CI 0.65 to 1.26), pruritus, fatigue, autoimmune conditions, quality of life, liver histology, or portal pressure were significantly affected by ursodeoxycholic acid (given in doses of 8-15 mg/kg/day for three months to five years). However, ursodeoxycholic acid significantly (P < 0.05) reduced ascites, jaundice, and biochemical variables such as serum bilirubin and liver enzymes. Ursodeoxycholic acid was not significantly associated with adverse events. Including data after patients had been switched onto open label ursodeoxycholic acid confirmed the findings regarding the lack of a significant effect of ursodeoxycholic acid on mortality and mortality or liver transplantation. A significant (P = 0.04) effect was, however, observed on the incidence of liver transplantation (odds ratio = 0.68; 95% CI 0.48 to 0.98).

REVIEWER'S CONCLUSIONS

Ursodeoxycholic acid has a marginal therapeutic effect for primary biliary cirrhosis. On the positive side, ursodeoxycholic acid has few side effects. The general usage of ursodeoxycholic acid for primary biliary cirrhosis needs reevaluation.

Bile acids regulate RANTES gene expression through its cognate NF-kappaB binding sites

Regulated upon activation, normal T-cells expressed and secreted (RANTES) mainly migrates memory type CD4+ T-lymphocytes to inflamed tissues. In this study, we examined effects of bile acids on RANTES gene expression in human hepatoma cells. Upon stimulation with hydrophobic bile acids, RANTES proteins were clearly increased. Semiquantitative RT-PCR analysis revealed that chenodeoxycholic acid (CDCA) induced RANTES mRNA expression. Moreover, RANTES was transcriptionally induced in two hepatoma cell lines by CDCA, presumably via its cognate NF-kappaB binding sites in the RANTES promoter. Electrophoretic mobility shift assay revealed that hydrophobic bile acids induced DNA-binding activity of NF-kappaB. Additionally, the magnitude of inducibility was closely associated with the hydrophobicity of bile acids. In conclusion, we might indicate that bile acids induced RANTES gene expression in human hepatoma cells, possibly suggesting that bile acids play an important role in migration of inflammatory cells by RANTES to the liver in patients with primary biliary cirrhosis.

Micronuclei induction, cell cycle delay and apoptosis as markers of cellular stress caused by ursodeoxycholic acid in human lymphocytes

Ursodeoxycholic acid (UDCA) is a bile acid (BA) used for cholesterol gallstone dissolution. Since epidemiological evidence indicates that BAs can be involved in the etiology of colorectal cancer, we investigated the effects of UDCA and its physiologically produced taurine conjugate tauroursodeoxycholic acid (TUDCA) on human lymphocyte cultures in terms of genetic damage in the form of micronuclei (MN) production, cell cycle modifications and induction of apoptosis. With respect to controls, treatment with UDCA (from 10 microg/ml) caused a dose-related increase in MN, whereas TUDCA caused no significant increase (up to 1000 microg/ml). Fluorescence in situ hybridization (FISH) analysis using pancentromeric probes suggested that UDCA exerts aneugenic activity. Bromodeoxyuridine/Hoechst flow cytometry showed that both BA significantly inhibit cell cycle progression (UDCA at 100 microg/ml, and TUDCA, more markedly at 300-1000 microg/ml). Neither UDCA nor TUDCA affected induction of apoptosis, as evaluated by the Annexin-V-Fluos assay. We conclude that UDCA is potentially genotoxic. However, taking into account the characteristics of other physiological BA, our findings are in line with the concept that long-term UDCA treatment may be safely administered. The multi-assay approach reported here could be useful in the toxicological evaluation of newly developed BA analogs as candidates for pharmacological use.

Differences in the efficacy of ursodeoxycholic acid and bile acid metabolism between viral liver diseases and primary biliary cirrhosis

AIM AND METHODS

The effects of ursodeoxycholic acid (UDCA, 600 mg/day) on liver function test values, and serum and urinary bile acids levels in hepatitis C virus-related chronic hepatitis (CH, n = 39) and liver cirrhosis (LC, n = 25), and in primary biliary cirrhosis (PBC, n = 25) were compared.

RESULTS

The percentages of improvement in alanine transaminase (ALT) and gamma-glutamyl transpeptidase (gamma-GTP) in CH were almost the same in LC. The rates of improvement in ALT in PBC were negatively correlated with histological stages in the liver. Total serum bile acid levels in LC rose to the same extent as in CH, but the increases in PBC were significantly smaller at stages 3-4 than stages 1-2. The urinary levels of hydroxylated metabolites of UDCA only slightly increased in LC, but they increased significantly at PBC stages 3-4.

CONCLUSIONS

The efficacy of UDCA was preserved in LC, but diminished at PBC stages 3-4. The poor enrichment of UDCA in the bile acid pool and extensive biotransformation of UDCA may cause the limited efficacy of UDCA in the cirrhotic stage of PBC.

Use of ursodeoxycholic acid in liver diseases

Ursodeoxycholic acid is currently the only established drug for the treatment of chronic cholestatic liver diseases. It has cytoprotective, anti-apoptotic, membrane stabilizing, anti-oxidative and immunomodulatory effects. Prolonged administration of ursodeoxycholic acid in patients with primary biliary cirrhosis (PBC) is associated with survival benefit and a delaying of liver transplantation. There is evidence that it might even prevent progression of the histologic stage of PBC. It also has a beneficial effect on primary sclerosing cholangitis, intrahepatic cholestasis of pregnancy, liver disease associated with cystic fibrosis, chronic graft versus host disease, total parenteral nutrition associated cholestasis and various pediatric cholestatic liver diseases. In the present review the current knowledge about the mechanisms of the action and role of ursodeoxycholic acid in the treatment of various liver diseases has been discussed.

Acute hepatitis A: combination of the relapsing and the cholestatic forms, two rare variants

Here we present an unusual case of a 23-year-old, otherwise healthy man who had a biphasic form of viral hepatitis A with a combination of two variants, the relapsing and cholestatic forms. One month after resolution of the first phase of acute hepatitis A, he was readmitted with jaundice and intense pruritus. During hospitalization, his serum bilirubin level increased to 50.2 mg/dL, with a slight increase in the other levels of liver enzymes. He was treated with ursodeoxycholic acid and later with corticosteroid therapy, resulting in resolution of symptoms and improvement of his liver function tests after 2 weeks. Medication therapy seems to be justified in markedly symptomatic patients with relapsing hepatitis.

Effect of silymarin on biliary bile salt secretion in the rat

The effect of the hepatoprotector silymarin on bile secretion, with particular regard to bile salt secretion, was studied in Wistar rats. Silymarin (25, 50, 100, and 150 mg/kg/day, i.p., for 5 days) induced a dose-dependent increase in bile flow and bile salt secretion, the maximal effect being reached at a dose of 100 mg/kg/day (+17 and +49%, for bile flow and bile salt output, respectively; P < 0.05). Assessment of bile salt composition in bile revealed that stimulation of the bile salt secretion was accounted for mainly by an increase in the biliary secretion of beta-muricholate and, to a lesser extent, of alpha-muricholate, chenodeoxycholate, ursodeoxycholate, and deoxycholate. The maximum secretory rate (T(m)) of bile salts, as assessed by infusing the non-hepatotoxic bile salt tauroursodeoxycholate i.v. at stepwise-increasing rates, was not influenced by silymarin. The flavonolignan also increased the endogenous bile salt pool size (+53%, P < 0.05) and biliary bile acid excretion after bile acid pool depletion (+54%, P < 0.05), a measure of de novo bile salt synthesis. These results suggest that silymarin increases the biliary excretion and the endogenous pool of bile salts by stimulating the synthesis, among others, of hepatoprotective bile salts, such as beta-muricholate and ursodeoxycholate.

Long-term effects of ursodeoxycholic acid in primary biliary cirrhosis: results of a double-blind controlled multicentric trial. UDCA-Cooperative Group from the Spanish Association for the Study of the Liver

BACKGROUND/AIM

The aim of this study was to assess the efficacy of ursodeoxycholic acid (UDCA) for primary biliary cirrhosis in a randomized, double-blind placebo-controlled trial.

METHODS

Consecutive patients (n=192) were randomized to receive 14-16 mg UDCA/kg/day or placebo. Patients underwent a complete history, physical examination, liver chemistries, immunological determinations and liver biopsy at entry and at the end of the trial, which lasted for at least 2 years. Patients were seen every 3 months and the median follow-up was 3.4 years (range 0.3 to 6.1 years).

RESULTS

Patients receiving UDCA (99) or placebo (93) were comparable with regard to age, sex, biochemical parameters and liver histology. UDCA treatment was associated with decreases in alkaline phosphatase, gammaglutamyl transferase, alanine aminotransferase, and cholesterol levels, effects which were conspicuous after 3 months of treatment and remained similar during the follow-up. During the study 31 patients (10 receiving UDCA and 21 placebo) discontinued the trial because of noncompliance (n=11), voluntary withdrawal (n=19) or adverse effects (n=1). Treatment failure (death or liver transplantation) was observed in 17 patients receiving UDCA and in 11 patients receiving placebo. Times to death or liver transplantation and to clinical complications were not significantly different in patients receiving UDCA or placebo. Histological analysis indicates that UDCA improved portal inflammation and prevented histological stage progression. By contrast, histological stage as well as ductular proliferation and ductopenia progressed in patients receiving placebo.

CONCLUSIONS

Although UDCA treatment did not significantly affect time to death or liver transplantation and to clinical complications, the effects on both cholestasis and liver histology suggest that UDCA is safe and may be useful for preventing the progression of primary biliary cirrhosis.

Ursodeoxycholic acid as adjunctive therapy for problematic type 1 autoimmune hepatitis: a randomized placebo-controlled treatment trial

To evaluate the efficacy of ursodeoxycholic acid as adjunctive therapy in type 1 autoimmune hepatitis, 37 patients who had experienced treatment failure, repeated relapse, or incomplete response were randomized to ursodeoxycholic acid (13-15 mg/kg daily) or placebo for 6 months in addition to their usual corticosteroid schedule. Serum aspartate transaminase (70% vs. 31%, P =.04) and alkaline phosphatase (47% vs. 7%, P =.02) levels improved more commonly in the 21 patients randomized to ursodeoxycholic acid. Mean serum levels, however, were similar before and after the treatment period. The frequency of dose reduction or corticosteroid withdrawal was comparable in both groups (29% versus 31%, P >.9), and clinical improvement (48% vs. 44%, P >.9) or its absence (52% vs. 56%, P >.9) occurred as commonly in patients receiving ursodeoxycholic acid or placebo. The modified histological activity score (3.5 +/- 0.8 vs. 3. 5 +/- 0.9) and the modified fibrosis score (2.4 +/- 0.4 vs. 2.4 +/- 0.4) were similar before and after treatment with ursodeoxycholic acid and no different than after placebo therapy. We conclude that ursodeoxycholic acid can improve certain laboratory tests in problematic patients with type 1 autoimmune hepatitis when administered adjunctively for 6 months. Short-term therapy, however, does not facilitate reduction in the dose of corticosteroids or its withdrawal, affect clinical outcome, or reduce histological activity.

A pilot study on the hemodynamic effect of short-term ursodeoxycholic acid therapy in patients with stable liver cirrhosis

OBJECTIVE

Total serum bile acid concentrations are elevated in individuals with liver disease. Ursodeoxycholic acid (UDCA) therapy in such patients results in a further significant rise in plasma levels to the extent that it becomes the major circulating bile acid. In laboratory animals, bile acids, such as taurocholic acid, have also been shown to possess a diuretic-like action, as they can promote diuresis, natriuresis, and kaliuresis by inhibiting tubular sodium reabsorption. The aim of the present study was to assess the effect of 1 month's UDCA therapy on cardiovascular function in cirrhotic patients.

METHODS

Two groups of patients with cirrhosis were studied, six with primary biliary cirrhosis (PBC) and six with postnecrotic liver cirrhosis (PNC). Cardiovascular function was assessed by determination of blood pressure, heart rate, and by two-dimensional and pulsed Doppler echocardiography.

RESULTS

In PBC patients, 1 month's treatment with UDCA significantly reduced diastolic volume without changing systolic, diastolic, and mean blood pressures, heart rate, systolic and stroke volumes, ejection fraction, cardiac output, and systemic vascular resistance. In PNC patients, UDCA significantly reduced cardiac output, with a tendency to reduce left ventricular volumes, without any changes in systolic, diastolic, and mean blood pressures.

CONCLUSIONS

UDCA caused reductions in diastolic volume in the PBC patients and cardiac output in the PNC patients. Such reductions are not unlike that seen in individuals treated with diuretics. This diuretic-like action deserves further study, particularly in cirrhotic patients who are also being treated with diuretics or show evidence of cardiac myopathy.

Review article: mechanisms of action and therapeutic applications of ursodeoxycholic acid in chronic liver diseases

Ursodeoxycholic acid (ursodiol) is a non-toxic, hydrophilic bile acid used to treat predominantly cholestatic liver disorders. Better understanding of the cellular and molecular mechanisms of action of ursodeoxycholic acid has helped to elucidate its cytoprotective, anti-apoptotic, immunomodulatory and choleretic effects. Ursodeoxycholic acid prolongs survival in primary biliary cirrhosis and it improves biochemical parameters of cholestasis in various other cholestatic disorders including primary sclerosing cholangitis, intrahepatic cholestasis of pregnancy, cystic fibrosis and total parenteral nutrition-induced cholestasis. However, a positive effect on survival remains to be established in these diseases. Ursodeoxycholic acid is of unproven efficacy in non-cholestatic disorders such as acute rejection after liver transplantation, non-alcoholic steatohepatitis, alcoholic liver disease and chronic viral hepatitis. This review outlines the present knowledge of the modes of action of ursodeoxycholic acid, and presents data from clinical trials on its use in chronic liver diseases.

Biliary bile acids in primary biliary cirrhosis: effect of ursodeoxycholic acid

Bile acid composition in fasting duodenal bile was assessed at entry and at 2 years in patients with primary biliary cirrhosis (PBC) enrolled in a randomized, double-blind, placebo-controlled trial of ursodeoxycholic acid (UDCA) (10-12 mg/kg/d) taken as a single bedtime dose. Specimens were analyzed by a high-pressure liquid chromatography method that had been validated against gas chromatography. Percent composition in bile (mean +/- SD) for 98 patients at entry for cholic (CA), chenodeoxycholic (CDCA), deoxycholic (DCA), lithocholic (LCA), and ursodeoxycholic (UDCA) acids, respectively, were 57.4 +/- 18.6, 31.5 +/- 15.5, 8.0 +/- 9.3, 0.3 +/- 1.0, and 0.6 +/- 0.9. Values for CA were increased, whereas those for CDCA, DCA, LCA, and UDCA were decreased when compared with values in normal persons. Bile acid composition of the major bile acids did not change after 2 years on placebo medication. By contrast, in patients receiving UDCA for 2 years, bile became enriched with UDCA on average to 40.1%, and significant decreases were noted for CA (to 32.2%) and CDCA (to 19.5%). No change in percent composition was observed for DCA and LCA. Percent composition at entry and changes in composition after 2 years on UDCA were similar in patients with varying severity of PBC. In patients whose bile was not enriched in UDCA (entry and placebo-treated specimens), CA, CDCA, DCA, and the small amount of UDCA found in some of these specimens were conjugated to a greater extent with glycine (52%-64%) than with taurine (36%-48%). Treatment with UDCA caused the proportion of all endogenous bile acids conjugated with glycine to increase to 69% to 78%, while the proportion conjugated with taurine (22%-31%) fell (P <.05). Administered UDCA was also conjugated predominantly with glycine (87%).

A paucity of unusual trihydroxy bile acids in the urine of patients with severe liver diseases

To clarify the relationship between the occurrence of unusual trihydroxy bile acids, namely hyocholic acid, ursocholic acid (UCA), and omega-muricholic acid (omega-MCA) in urine and liver disease severity, urinary bile acids were analyzed by gas-liquid chromatography in acute and late phases of acute hepatitis and before and after ursodeoxycholic acid (UDCA) loading in healthy adults and liver cirrhosis patients. In 11 patients with acute hepatitis, the occurrence rates and amounts of unusual trihydroxy bile acids were increased in the late (recovery) phase, as compared with those in the early phase. In 10 patients with severe acute hepatitis who had prothrombin times exceeding 16 seconds, these bile acids had completely disappeared from the urine in the early phase but reappeared in the late phase in those who had a good outcome, though never in a patient who died. After UDCA administration for a week, the amounts of unusual bile acids, especially UCA and omega-MCA, which are thought to be synthesized through 12 alpha- and 6 alpha-hydroxylations, respectively, from UDCA, were clearly increased in 10 healthy adults but only slightly changed in 10 patients with liver cirrhosis. In conclusion, hepatic hydroxylations of dihydroxy bile acids as a detoxification reaction were impaired in severe liver diseases, which may play a role in the intensification and perpetuation of hepatocellular injuries.

Mechanism of hepatoprotective action of bile salts in liver disease

Ursodeoxycholic acid (UDCA) improves liver enzymes and in many instances liver histology in cholestatic liver diseases such as primary biliary cirrhosis and primary sclerosing cholangitis. Besides classic cholestatic diseases, UDCA also improves liver biochemistry in alcoholic liver disease and in chronic viral hepatitis C. The main target of UDCA treatment, however, is cholestasis, and consequently the mechanisms responsible for the beneficial effects in these diseases are of interest, and are discussed in detail in this article.

Gas chromatography of bile acids

Bile acids, the end products of cholesterol metabolism in the liver, are of vital importance in the tissue distribution of cholesterol. Abnormalities in cholesterol biosynthesis or metabolism are often reflected in the proportions, concentrations and conjugation of bile acids in various tissues and determination of bile acids in these tissues is important in the diagnosis of hepatobiliary diseases. Several methods for quantitative determination of bile acids in biological fluids are known and have been reviewed. In this review, we have discussed the gas-chromatographic method for determination of bile acids with special reference to bile acid quantitation in plasma, bile, urine and stool.

Differences in the metabolism and disposition of ursodeoxycholic acid and of its taurine-conjugated species in patients with primary biliary cirrhosis

The clinical effectiveness of ursodeoxycholate in the treatment of liver disease may be limited by its poor absorption and extensive biotransformation. Because in vitro and in vivo studies suggest that the more hydrophilic bile acid tauroursodeoxycholate has greater beneficial effects than ursodeoxycholate, we have compared for the first time the absorption, metabolism, and clinical responses to these bile acids in patients with primary biliary cirrhosis (PBC). Twelve female patients with PBC were sequentially administered tauroursodeoxycholate and ursodeoxycholate (750 mg/d for 2 months) in a randomized, cross-over study. Bile acids were measured in serum, duodenal bile, urine, and feces by gas chromatography-mass spectrometry (GC-MS). Biliary ursodeoxycholate enrichment was higher during tauroursodeoxycholate administration (32.6% vs. 29.2% during ursodeoxycholate; P <.05). Lithocholic acid concentration was consistently higher in all biological fluids during ursodeoxycholate administration. Fecal bile acid excretion was the major route of elimination of both bile acids; ursodeoxycholate accounted for 8% and 23% of the total fecal bile acids during tauroursodeoxycholate and ursodeoxycholate administration, respectively (P <.05). Tauroursodeoxycholate was better absorbed than ursodeoxycholate, and, although it was partially deconjugated and reconjugated with glycine, it underwent reduced biotransformation to more hydrophobic metabolites. This comparative study suggests that tauroursodeoxycholate has significant advantages over ursodeoxycholate that may be of benefit for long-term therapy in PBC.

Effect of bile acids on fibroblast proliferation and viability

PURPOSE

To examine the in vitro effects of bile acids and salts on the viability, growth and morphology of human Tenon's capsule fibroblasts.

METHODS

Human Tenon's capsule fibroblasts were grown from explants in culture and used between passages 3 and 5. Fibroblasts (n = 3) were treated in triplicate with deoxycholic acid (DA), sodium deoxycholate (NaD) and cholic acid (CA) at concentrations between 50 microM and 1 mM. Cell viability and growth were assessed with trypan blue staining and haemocytometer counting, and a colorimetric (MTT) assay. Morphology was assessed with light microscopy and cresyl violet staining.

RESULTS

A dose-dependent decrease in viability was observed following bile acid treatment (24 and 48 h) where the effects of DA > NaD > CA. The LD50 values at 48 h for DA, NaD and CA were 300 microM, 400 microM and 720 microM respectively. Cell growth following bile acid treatment was reduced compared with controls. Fibroblasts treated with bile acids displayed a loss of normal spindle-shaped morphology and multiple processes, some with varicosities, extended from many cells. These changes were dose-dependent, and at higher concentrations cells became detached and were non-viable (trypan-blue-positive). Extensive cell death was observed in cultures treated with DA 400 microM, NaD 500 microM and CA 800 microM.

CONCLUSIONS

Lower doses of bile acids and salts reduced in vitro fibroblast growth associated with morphological changes; higher doses induced fibroblast cytotoxicity. These observations suggest that bile acids and salts, in particular DA, may be useful in regulating wound fibrosis following trabeculectomy surgery.

Relationship between biliary and serum bile acids and response to ursodeoxycholic acid in patients with primary biliary cirrhosis

OBJECTIVE

Ursodeoxycholic acid (UDCA) improves liver biochemistries and enriches the bile with UDCA in patients with primary biliary cirrhosis. The aim of this study was to determine whether the degree of enrichment of bile correlated with that of serum and whether either of these measures correlated with improvement in measures of liver disease.

METHODS

In a randomized study, biliary and serum bile acid analyses were performed at entry and after 2 yr of UDCA or placebo.

RESULTS

The percentage of ursodeoxycholic acid in bile increased by 42% in the UDCA group (n = 61) compared with 8% in the placebo group (n = 57) (p < 0.0001). Measurement of serum bile acids in 32 patients (18 ursodeoxycholic acid, 14 placebo) indicated that at 2 yr, ursodeoxycholic acid comprised 65% of serum bile acids in the treated group and 7% in the placebo group. Agreement between bile and serum was fair (r = 0.75, p < or = 0.00002) because in some patients, plasma but not biliary bile acids were enriched with UDCA. Changes in biliary ursodeoxycholic acid correlated significantly but weakly with the changes in serum alkaline phosphatase, AST, bilirubin, and in Mayo risk score. Correlations between changes in serum bile acid composition and biochemical measures of disease activity were even weaker.

CONCLUSION

The measurement of biliary bile acids is superior to that of serum bile acids for assessing the compliance and changes in the circulating bile acids in patients receiving ursodeoxycholic acid for the treatment of primary biliary cirrhosis. Furthermore, measures to further increase the proportion of ursodeoxycholic acid in circulating bile acids should be explored.

The inhibitory effect of ursodeoxycholic acid and pentoxifylline on platelet derived growth factor-stimulated proliferation is distinct from an effect by cyclic AMP

This study assessed the ability of ursodeoxycholic acid (UDCA) and one of its metabolites, tauroursodeoxycholic acid (TUDCA), to inhibit platelet derived growth factor (PDGF) stimulated fibroproliferation and compared these results to the effect of pentoxifylline and its metabolite-1 [1-(5-hydroxyhexyl)-3,7-dimethylxanthine] and assessed the potential role of cyclic AMP in this process. Fibroproliferative activity was measured by the tritiated thymidine uptake assay in human fibroblast cultures. All four compounds: pentoxifylline, metabolite-1, UDCA and TUDCA inhibited the fibroproliferative activity stimulated by PDGF (8 ng/ml). Incubation of fibroblasts with dibutyryl cyclic AMP reduced proliferation stimulated by PDGF suggesting that the PDGF stimulated proliferation was sensitive to inhibition by a membrane permeable analogue of cyclic AMP. Incubation of myofibroblasts with dibutyryl cyclic AMP significantly inhibited PDGF stimulated proliferation suggesting that cyclic AMP can regulate PDGF stimulated proliferation in the myofibroblast. To determine if the effect of pentoxifylline on fibroproliferation was mediated by cyclic AMP, we used dideoxyadenosine, a potent inhibitor of adenylyl cyclase. The effect of pentoxifylline on fibroproliferation was not prevented by dideoxyadenosine, which inhibits formation of cyclic AMP, thus suggesting that the inhibitory effect of pentoxifylline on PDGF-stimulated proliferation of fibroblasts was not mediated by cyclic AMP, arguing against a role for cyclic AMP in this process. Combinations of UDCA (250 microM) plus pentoxifylline (120 microM) or UDCA (250 microM) plus TUDCA (250 microM) inhibited fibroproliferative activity stimulated by PDGF to a greater extent than either drug alone. As UDCA has been reported to decrease cyclic AMP these results argue against a role for cyclic AMP in this process. Finally the results suggest that UDCA may inhibit PDGF-stimulated proliferation via an inhibition of C-kinase.