A randomized controlled trial of high-dose ursodesoxycholic acid for nonalcoholic steatohepatitis

Effects of ursodeoxycholic acid therapy on carotid intima media thickness, apolipoprotein A1, apolipoprotein B, and apolipoprotein B/A1 ratio in nonalcoholic steatohepatitis

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is a prevalent liver disease that is increasingly being associated with cardiovascular disease. Ursodeoxycholic acid (UDCA) may have antioxidant and anti-inflammatory activities, and may reduce liver injury in NASH. To date, no studies have assessed the efficacy of UDCA in carotid intima media thickness (CIMT), serum lipids, apolipoprotein A1 (apo A), apolipoprotein B (apo B), and apolipoprotein B/A1 (apo B/A1) ratios in patients with NASH.

PATIENTS AND METHODS

In this prospective study, 30 patients with biopsy-proven NASH and 25 healthy adults as a control group were evaluated. None of the participants had diabetes, hypertension, or hyperlipidemia. Patients with NASH received UDCA 15 mg/kg/day for 6 months. BMI, waist circumference, homeostasis model assessment, lipids, apo A1, apo B, apo B/A1 ratios, and CIMT were analyzed before and after the treatment period.

RESULTS

At the end of the study, there were no statistically significant changes in BMI or waist circumference. Liver enzymes decreased gradually. The homeostasis model assessment decreased from 3.4 ± 1.89 to 2.06 ± 1.68 (P < 0.001). No significant changes in the mean triglyceride, total cholesterol, low-density lipoprotein, or apo B levels were observed. The mean high-density lipoprotein (42.9 ± 7.1 vs. 45.5 ± 9.8; P = 0.037) and apo A1 (127.6 ± 17.7 vs. 135.9 ± 22.2; P = 0.02) increased significantly. Apo B/A1 ratios tended to decrease, but this decrease was not statistically significant. The mean CIMT decreased significantly (0.56 ± 0.15 vs. 0.47 ± 0.12; P = 0.001).

CONCLUSION

UDCA treatment in NASH patients resulted in statistically significant reductions in the mean CIMT over a 6-month period. We believe that this benefit of UDCA may have resulted from decreased insulin resistance and increased serum high-density lipoprotein-apo A1 levels. However, larger, longer-term studies are needed to confirm this effect of UDCA in NASH.

The combination of ezetimibe and ursodiol promotes fecal sterol excretion and reveals a G5G8-independent pathway for cholesterol elimination

Previous studies suggest an interdependent relationship between liver and intestine for cholesterol elimination from the body. We hypothesized that a combination of ursodiol (Urso) and ezetimibe (EZ) could increase biliary secretion and reduce cholesterol reabsorption, respectively, to promote cholesterol excretion. Treatment with Urso increased hepatic ABCG5 ABCG8 (G5G8) protein and both biliary and fecal sterols in a dose-dependent manner. To determine whether the drug combination (Urso-EZ) further increased cholesterol excretion, mice were treated with Urso alone or in combination with two doses of EZ. EZ produced an additive and dose-dependent increase in fecal neutral sterol (FNS) elimination in the presence of Urso. Finally, we sequentially treated wide-type and G5G8-deficient mice with Urso and Urso-EZ to determine the extent to which these effects were G5G8 dependent. Although biliary and FNS were invariably lower in G5G8 KO mice, the relative increase in FNS following treatment with Urso alone or the Urso-EZ combination was not affected by genotype. In conclusion, Urso increases G5G8, biliary cholesterol secretion, and FNS and acts additively with EZ to promote fecal sterol excretion. However, the stimulatory effect of these agents was not G5G8 dependent.

4Ps medicine of the fatty liver: the research model of predictive, preventive, personalized and participatory medicine-recommendations for facing obesity, fatty liver and fibrosis epidemics

Relationship between adipose tissue and fatty liver, and its possible evolution in fibrosis, is supported by clinical and research experience. Given the multifactorial pathogenesis of non-alcoholic fatty liver disease (NAFLD), treatments for various contributory risk factors have been proposed; however, there is no single validated therapy or drug association recommended for all cases which can stand alone. Mechanisms, diagnostics, prevention and treatment of obesity, fatty liver and insulin resistance are displayed along with recommendations and position points. Evidences and practice can get sustainable and cost-benefit valuable outcomes by participatory interventions. These recommendations can be enhanced by comprehensive research projects, addressed to societal issues and innovation, market appeal and industry development, cultural acceptance and sustainability. The basis of participatory medicine is a greater widespread awareness of a condition which is both a disease and an easy documented and inclusive clue for associated diseases and unhealthy lifestyle. This model is suitable for addressing prevention and useful for monitoring improvement, worsening and adherence with non-invasive imaging tools which allow targeted approaches. The latter include health psychology and nutritional and physical exercise prescription expertise disseminated by continuous medical education but, more important, by concrete curricula for training undergraduate and postgraduate students. It is possible and recommended to do it by early formal teaching of ultrasound imaging procedures and of practical lifestyle intervention strategies, including approaches aimed to healthier fashion suggestions. Guidelines and requirements of research project funding calls should be addressed also to NAFLD and allied conditions and should encompass the goal of training by research and the inclusion of participatory medicine topics. A deeper awareness of ethics of competences in health professionals and the articulation of knowledge, expertise and skills of medical doctors, dieticians, health psychologists and sport and physical exercise graduates are the necessary strategy for detectin a suboptimal health status and achieving realistically beneficial lifestyle changes. “The devil has put a penalty on all things we enjoy in life. Either we suffer in health or we suffer in soul or we get fat” (Albert Einstein); the task of medical research and intervention is to make possible to enjoy life also without things that make sufferance in health and souls and which excessively increase body fat.

Lack of efficacy of an inhibitor of PDE4 in phase 1 and 2 trials of patients with nonalcoholic steatohepatitis

BACKGROUND & AIMS

ASP9831 is a phosphodiesterase-4 inhibitor developed to treat nonalcoholic steatohepatitis (NASH); it showed potent anti-inflammatory and antifibrotic effects in preclinical studies. We evaluated the efficacy and safety of ASP9831 in patients with NASH.

METHODS

In a phase 1 trial, we determined the optimal therapeutic window of ASP9831 in healthy volunteers and evaluated 2 doses (50 and 100 mg) in patients with NASH. Based on the positive outcomes of the phase 1 study, we performed a phase 2 trial to compare the biochemical effects of ASP9831 vs placebo. Patients with NASH were assigned randomly to groups given either 50 mg (n = 33) or 100 mg (n = 33) ASP9831 twice daily, or placebo (n = 30), for 12 weeks. The primary end point was the mean percentage change, from baseline to the end of ASP9831 administration, in serum level of alanine aminotransferase (ALT); secondary outcomes included changes in aspartate aminotransferase (AST) levels, ratio of AST:ALT, and various biomarkers of NASH.

RESULTS

After 12 weeks of administration, there was no significant change in mean serum levels of ALT (P = .42) or AST (P = .20) or other biomarkers in any group, and no significant differences were observed among groups. Most adverse events were mild; gastrointestinal disorders occurred more frequently in the ASP9831 groups than the placebo group.

CONCLUSIONS

Despite a relevant mechanism of action, ASP9831 did not significantly alter the biochemical markers of NASH, compared with placebo, in a clinical trial. This highlights the difficulties of developing therapeutics for NASH and the need for more extensive preclinical testing of mechanisms of potential drug candidates. Clinicaltrialsregister.eu: 2005-001687-31; EudraCT numbers: 2007-002114-19.

Non-alcoholic fatty liver disease: what the clinician needs to know

Non-alcoholic fatty liver disease (NAFLD) is the most frequent cause of liver disease in the Western world. Furthermore, it is increasing worldwide, paralleling the obesity pandemic. Though highly frequent, only about one fifth of affected subjects are at risk of developing the progressive form of the disease, non-alcoholic steatohepatitis with fibrosis. Even in the latter, liver disease is slowly progressive, though, since it is so prevalent, it is already the third cause of liver transplantation in the United States, and it is predicted to get to the top of the ranking in few years. Of relevance, fatty liver is also associated with increased overall mortality and particularly increased cardiovascular mortality. The literature and amount of published papers on NAFLD is increasing as fast as its prevalence, which makes it difficult to keep updated in this topic. This review aims to summarize the latest knowledge on NAFLD, in order to help clinicians understanding its pathogenesis and advances on diagnosis and treatment.

Ursodeoxycholic acid ameliorates fructose-induced metabolic syndrome in rats

The metabolic syndrome (MS) is characterized by insulin resistance, dyslipidemia and hypertension. It is associated with increased risk of cardiovascular diseases and type-2 diabetes. Consumption of fructose is linked to increased prevalence of MS. Ursodeoxycholic acid (UDCA) is a steroid bile acid with antioxidant, anti-inflammatory activities and has been shown to improve insulin resistance. The current study aims to investigate the effect of UDCA (150 mg/kg) on MS induced in rats by fructose administration (10%) in drinking water for 12 weeks. The effects of UDCA were compared to fenofibrate (100 mg/kg), an agonist of PPAR-α receptors. Treatment with UDCA or fenofibrate started from the 6^th week after fructose administration once daily. Fructose administration resulted in significant increase in body weight, elevations of blood glucose, serum insulin, cholesterol, triglycerides, advanced glycation end products (AGEs), uric acid levels, insulin resistance index and blood pressure compared to control rats. Moreover, fructose increased oxidative stress in aortic tissues indicated by significant increases of malondialdehyde (MDA), expression of iNOS and reduction of reduced glutathione (GSH) content. These disturbances were associated with decreased eNOS expression, increased infiltration of leukocytes and loss of aortic vascular elasticity. Treatment with UDCA successfully ameliorated the deleterious effects of fructose. The protective effect of UDCA could be attributed to its ability to decrease uric acid level, improve insulin resistance and diminish oxidative stress in vascular tissues. These results might support possible clinical application of UDCA in MS patients especially those present with liver diseases, taking into account its tolerability and safety. However, further investigations on human subjects are needed before the clinical application of UDCA for this indication.

Advances in research of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) refers to a clinicopathologic syndrome characterized by a spectrum of histological abnormalities such as hepatocyte fatty degeneration and liver inflammation, not including those caused by alcohol and other specific factors. NAFLD is a heredity, environmental, metabolic disease, and its spectrum ranges from nonalcoholic fatty liver to nonalcoholic steatohepatitis and liver cirrhosis.

Modern approach to the clinical management of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common and emerging form of chronic liver disease worldwide. It includes a wide spectrum of liver diseases ranging from simple fatty liver to steatohepatitis, which may progress to cirrhosis, liver cancer, and liver mortality. Common metabolic diseases, which are well established cardiovascular risk factors, have been associated to NAFLD and cardiovascular disease is the single most important cause of morbidity and mortality in this patient population. The pathogenesis of NAFLD appears multifactorial and many mechanisms have been proposed as possible causes of fatty liver infiltration. Management of fatty liver has become a major challenge to healthcare systems as the consequence of the increasing rates of obesity worldwide. First-line management focuses on lifestyle modifications. Moderate weight reduction either by dietary restriction or by increased habitual physical activity is safe and highly recommended. Several therapeutic interventions have been proposed. These include insulin sensitizer agents, lipid lowering drugs, antioxidants such as vitamin E and supplementation of vitamin D₃. However, therapeutic strategies have been largely empirical so far, and experimental trials have mostly been carried out in uncontrolled settings with small sample sizes. Metabolic conditions such as diabetes mellitus, obesity, hypertension and hyperlipidemia, should be strongly considered and a multidisciplinary approach should be personalized for individual patients. Treatment of co-morbidities should be regarded as of paramount importance in the management of these patients. The purpose of this review is to examine different approaches for the clinical management of non-alcoholic fatty liver disease.

A possible role of chenodeoxycholic acid and glycine-conjugated bile acids in fibrotic steatohepatitis in a dietary rat model

BACKGROUND AND AIMS

Our previous study indicated that hepatic bile acids (BAs) may have deposited and stimulated the pathogenesis of a high fat-cholesterol (HFC) diet-induced fibrotic steatohepatitis in stroke-prone spontaneously hypertensive 5/Dmcr rats, based on dysregulated BA homeostasis pathways. We aimed to further characterize BA profiles in liver and evaluate their relationships to liver injury using this model.

METHODS

Hepatic 21 BA levels were determined by ultra-performance liquid chromatography-tandem mass spectrometry, and their correlations with macrovesicular steatosis score, serum alanine aminotransferase (ALT) level and quantified fibrotic area were assessed using Spearman and Pearson correlations.

RESULTS

Compared to control, BAs highly accumulated in HFC-fed rat liver at 2 weeks: cholic acid (CA), deoxycholic acid (DCA) and chenodeoxycholic acid (CDCA) were major species, thereafter, levels of CA and DCA declined, but CDCA species persistently increased, which induced a decrease in total CA/total CDCA ratio at 8 and 14 weeks. CDCA species positively, while total CA/total CDCA negatively, correlated with macrovesicular steatosis score, serum ALT and quantified fibrotic area. Unlike control, total ursodeoxycholic acid was minor in HFC-fed rat liver, and inversely correlated to aforementioned indicators of liver injury; total glyco-BAs, rather than tauro-BAs, were predominant in HFC-fed rat liver, and positively correlated with macrovesicular steatosis score. Moreover, its ratio to total tauro-BAs positively correlated with each parameter of liver injury, while inverse associations were detected for total tauro-BAs.

CONCLUSIONS

Hepatic BA accumulation may potentiate liver disease. CDCA and glyco-BAs play a more important role in the pathogenesis of fibrotic steatohepatitis.

Management of fatty liver disease with the metabolic syndrome

Non-alcoholic fatty liver disease (NAFLD) is the liver disease of this century, increasing in parallel with obesity, insulin resistance and the metabolic syndrome. NAFLD can be seen as a component of the metabolic syndrome, and as such, contributing as a risk factor for cardiovascular disease. In fact, these patients die more often from cardiovascular disease than from direct consequences of liver disease. In this review, we will summarize the data that link NAFLD as a central player in this dysmetabolism, as well as the evidence for appropriate therapy, in order to improve not only liver disease prognosis, but also the overall prognosis and risk of mortality, with particular focus on cardiovascular risk.

State of the art: treatment of nonalcoholic steatohepatitis

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease is the most common cause of chronic liver disease in Western countries, and consists of a spectrum of histopathological changes that range in severity from simple steatosis to steatohepatitis to cirrhosis. The use of pharmacological agents as adjunctive therapy to lifestyle modification is crucial, because weight loss is often difficult to achieve and maintain. The purpose of this review is to analyze the most recent literature pertaining to current therapies for nonalcoholic steatohepatitis (NASH), as there are currently no Food and Drug Administration-approved medications.

RECENT FINDINGS

Recent studies suggest that vitamin E may improve liver histology in NASH without affecting insulin resistance; however, long-term risks remain to be studied. Pioglitazone is beneficial in improving liver histology and insulin resistance, but is associated with weight gain. Emerging data suggest that pentoxifylline may also be beneficial in improving serum aminotransferase and liver histology in patients with biopsy-proven NASH.

SUMMARY

Ongoing research evaluating potential pharmacological agents for NASH is critical, because these patients are at an increased risk for cirrhosis and hepatocellular carcinoma. The current therapies being used for the treatment of NASH include the use of vitamin E and pioglitazone, in addition to dietary counseling and regular exercise.

The role of medications for the management of patients with NAFLD

The article is intended to provide an overview of the strengths and limits of controlled trials of pharmacologic treatment of nonalcoholic fatty liver disease. No drug has so far been approved, although validated on histologic outcomes. Several new drugs are under scrutiny, acting with different mechanisms along the chain of events from fatty liver to fibrosis, cirrhosis, and hepatocellular carcinoma. The article investigates which drug, if any, should be preferred for a tailored intervention in individual patients, according to age, comorbidities, and disease severity, and if treatment should be continued lifelong, to prevent disease progression and long-term occurrence of cirrhosis.

Systematic review with meta-analysis: non-alcoholic steatohepatitis - a case for personalised treatment based on pathogenic targets

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is an umbrella term, which encompasses simple steatosis and non-alcoholic steatohepatitis (NASH). The entire spectrum of NAFLD has been associated with metabolic syndrome. NASH is associated with increased mortality compared with that of the general population. Many therapeutic options for NASH have been studied. However, there is very little evidence supporting the efficacy of most regimens for the treatment of NASH.

AIM

To provide a review focusing on the current therapeutic options available for patients with NASH as well as to briefly introduce possible future interventions.

METHODS

A MEDLINE, Pubmed and Cochrane Review database search using a combination of keywords, which included non-alcoholic fatty liver disease, non-alcoholic hepatic steatosis, NAFLD, NASH, treatment, therapeutics, vitamin E, orlistat and bariatric surgery. An overall summary of the articles was developed for each section of discussion in this review.

RESULTS

NASH associated with metabolic syndrome can progress advanced fibrosis and cirrhosis. Weight loss and lifestyle modification have been shown to improve NASH. Other medications used for weight loss and metabolic syndrome have been evaluated, such as orlistat, metformin and thiazolidinediones. Alternative regimens using ursodeoxycholic acid, statins and probiotics as well as bariatric surgery have been evaluated, but have not been recommended as first-line treatment for NASH. Vitamin E for NASH patients without diabetes seems to be promising. The lack of effective treatment for NASH suggests the heterogeneity of patients presenting with the NASH phenotype. The best treatment strategy for these patients may be to identify their pathogenic target and develop personalised treatment protocols.

CONCLUSIONS

Currently, there are few options available for the management of NASH. Future targeted treatment strategies based on the pathogenic pathways may be needed to develop effective treatment for patients with NASH.

Review of treatment options for nonalcoholic fatty liver disease

Although the future of NAFLD and NASH treatment has many promising agents, clinicians are currently faced with limited options with an emphasis on lifestyle modification. Figs. 1 and 2 summarize current practices for the diagnosis and treatment of NAFLD with the understanding that each patient's treatment must be customized to their comorbidities, exercise tolerance, and willingness to comply with therapy.

Free radical biology for medicine: learning from nonalcoholic fatty liver disease

Reactive oxygen species, when released under controlled conditions and limited amounts, contribute to cellular proliferation, senescence, and survival by acting as signaling intermediates. In past decades there has been an epidemic diffusion of nonalcoholic fatty liver disease (NAFLD) that represents the result of the impairment of lipid metabolism, redox imbalance, and insulin resistance in the liver. To date, most studies and reviews have been focused on the molecular mechanisms by which fatty liver progresses to steatohepatitis, but the processes leading toward the development of hepatic steatosis in NAFLD are not fully understood yet. Several nuclear receptors, such as peroxisome proliferator-activated receptors (PPARs) α/γ/δ, PPARγ coactivators 1α and 1β, sterol-regulatory element-binding proteins, AMP-activated protein kinase, liver-X-receptors, and farnesoid-X-receptor, play key roles in the regulation of lipid homeostasis during the pathogenesis of NAFLD. These nuclear receptors may act as redox sensors and may modulate various metabolic pathways in response to specific molecules that act as ligands. It is conceivable that a redox-dependent modulation of lipid metabolism, nuclear receptor-mediated, could cause the development of hepatic steatosis and insulin resistance. Thus, this network may represent a potential therapeutic target for the treatment and prevention of hepatic steatosis and its progression to steatohepatitis. This review summarizes the redox-dependent factors that contribute to metabolism alterations in fatty liver with a focus on the redox control of nuclear receptors in normal liver as well as in NAFLD.

Pharmacological agents for nonalcoholic steatohepatitis

The rationale for specific pharmacologic therapy in nonalcoholic steatohepatitis (NASH) is determined by the potential for disease progression and the difficulties, in many patients, to successfully implement diet and lifestyle changes in the long term. Because they correct insulin resistance, insulin-sensitizing agents are attractive candidates for the treatment of NASH. However, two randomized studies have shown that vitamin E, despite having no effect on insulin sensitivity, achieves interesting histological and biochemical efficacy. This review provides an insight into the therapeutic efficacy and safety issues of different pharmacological agents tested in human NASH.

An active metabolite of oltipraz (M2) increases mitochondrial fuel oxidation and inhibits lipogenesis in the liver by dually activating AMPK

BACKGROUND AND PURPOSE

Oltipraz, a cancer chemopreventive agent, has an anti-steatotic effect via liver X receptor-α (LXRα) inhibition. Here we have assessed the biological activity of a major metabolite of oltipraz (M2) against liver steatosis and steatohepatitis and the underlying mechanism(s).

EXPERIMENTAL APPROACH

Blood biochemistry and histopathology were assessed in high-fat diet (HFD)-fed mice treated with M2. An in vitroHepG2 cell model was used to study the mechanism of action. Immunoblotting, real-time PCR and luciferase reporter assays were performed to measure target protein or gene expression levels.

KEY RESULTS

M2 treatment inhibited HFD-induced steatohepatitis and diminished oxidative stress in liver. It increased expression of genes encoding proteins involved in mitochondrial fuel oxidation. Mitochondrial DNA content and oxygen consumption rate were enhanced. Moreover, M2 treatment repressed activity of LXRα and induction of its target genes, indicating anti-lipogenic effects. M2 activated AMP-activated protein kinase (AMPK). Inhibition of AMPK by over-expression of dominant negative AMPK (DN-AMPK) or by Compound C prevented M2 from inducing genes for fatty acid oxidation and repressed sterol regulatory element binding protein-1c (SREBP-1c) expression. M2 activated liver kinase B1 (LKB1) and increased the AMP/ATP ratio. LKB1 knockdown failed to reverse target protein modulations or AMPK activation by M2, supporting the proposal that both LKB1 and increased AMP/ATP ratio contribute to its anti-steatotic effect.

CONCLUSION AND IMPLICATIONS

M2 inhibited liver steatosis and steatohepatitis by enhancing mitochondrial fuel oxidation and inhibiting lipogenesis. These effects reflected activation of AMPK elicited by increases in LKB1 activity and AMP/ATP ratio.

Ursodeoxycholic acid inhibits liver X receptor α-mediated hepatic lipogenesis via induction of the nuclear corepressor SMILE

Small heterodimer partner interacting leucine zipper protein (SMILE) has been identified as a nuclear corepressor of the nuclear receptor (NRs) family. Here, we examined the role of SMILE in the regulation of nuclear receptor liver X receptor (LXR)-mediated sterol regulatory element binding protein-1c (SREBP-1c) gene expression. We found that SMILE inhibited T0901317 (T7)-induced transcriptional activity of LXR, which functions as a major regulator of lipid metabolism by inducing SREBP-1c, fatty acid synthase (FAS), and acetyl-CoA carboxylase (ACC) gene expression. Moreover, we demonstrated that SMILE physically interacts with LXR and represses T7-induced LXR transcriptional activity by competing with coactivator SRC-1. Adenoviral overexpression of SMILE (Ad-SMILE) attenuated fat accumulation and lipogenic gene induction in the liver of T7 administered or of high fat diet (HFD)-fed mice. Furthermore, we investigated the mechanism by which ursodeoxycholic acid (UDCA) inhibits LXR-induced lipogenic gene expression. Interestingly, UDCA treatment significantly increased SMILE promoter activity and gene expression in an adenosine monophosphate-activated kinase-dependent manner. Furthermore, UDCA treatment repressed T7-induced SREBP-1c, FAS, and ACC protein levels, whereas knockdown of endogenous SMILE gene expression by adenovirus SMILE shRNA (Ad-shSMILE) significantly reversed UDCA-mediated repression of SREBP-1c, FAS, and ACC protein levels. Collectively, these results demonstrate that UDCA activates SMILE gene expression through adenosine monophosphate-activated kinase phosphorylation, which leads to repression of LXR-mediated hepatic lipogenic enzyme gene expression.

Pharmacological agents for NASH

NASH is a common liver disease that increases liver-related mortality and reduces survival. The need for optimal management of NASH is therefore a priority for today's practicing hepatologist. The rationale for specific pharmacological therapy for NASH is based on the potential for disease progression and the difficulties that many patients have successfully implementing, in the long term, diet and lifestyle changes. Even in those that succeed, limited evidence exists that severe liver injury in patients with NASH can be reversed by diet and lifestyle measures alone. This Review provides a personal and critical assessment of the histological efficacy and safety of agents tested in randomized trials in patients with NASH.

Involvement of free radicals and oxidative stress in NAFLD/NASH

Non-alcoholic fatty liver disease (NAFLD) is now the most common liver disease affecting high proportion of the population worldwide. NAFLD encompasses a large spectrum of conditions ranging from fatty liver to non-alcoholic steatohepatitis (NASH), which can progress to cirrhosis and cancer. NAFLD is considered as a multifactorial disease in relation to the pathogenic mechanisms. Oxidative stress has been implicated in the pathogenesis of NAFLD and NASH and the involvement of reactive oxygen species (ROS) has been suggested. Many studies show the association between the levels of lipid oxidation products and disease state. However, often neither oxidative stress nor ROS has been characterized, despite oxidative stress is mediated by multiple active species by different mechanisms and the same lipid oxidation products are produced by different active species. Further, the effects of various antioxidants have been assessed in human and animal studies, but the effects of drugs are determined by the type of active species, suggesting the importance of characterizing the active species involved. This review article is focused on the role of free radicals and free radical-mediated lipid peroxidation in the pathogenesis of NAFLD and NASH, taking characteristic features of free radical-mediated oxidation into consideration. The detailed analysis of lipid oxidation products shows the involvement of free radicals in the pathogenesis of NAFLD and NASH. Potential beneficial effects of antioxidants such as vitamin E are discussed.

From NAFLD in clinical practice to answers from guidelines

This review of the literature consists of three sections. First, papers concerning non-alcoholic fatty liver disease (NAFLD) awareness among the general population, general practitioners, and liver and non-liver specialists were retrieved and analyzed to highlight the perception of disease, verify knowledge of current recommendations, and identify the main difficulties experienced in clinical practice. Next, position papers and clinical practice guidelines issued by International and National Hepatological Scientific Societies were identified and critically assessed in order to pinpoint the areas of convergence/difference. Finally, practical suggestions on NAFLD diagnosis and management in daily practice are provided and the open questions highlighted.

The role of ursodeoxycholic acid in non-alcoholic steatohepatitis: a systematic review

Background

Non-alcoholic steatohepatitis (NASH) is a condition that occurs during the progression of non-alcoholic fatty liver disease. Effective therapy for NASH is still lacking. In this study, we investigated the effects of Ursodeoxycholic acid (UDCA) in the treatment of NASH.

Methods

Western and Chinese databases were searched by independent investigators using appropriate MESH headings to identify randomized, controlled Western and Chinese clinical trials, published between January 1990 and October 2012, testing the effects of UDCA in patients with NASH. Patient characteristics and trial endpoints were analyzed, with quality assessment according to widely acknowledged criteria. P < 0.05 was defined as statistically significant in all trials.

Results

Twelve qualified randomized clinical trials, including six from China and involving 1160 subjects, were selected. Seven of these trials assessed the effects of UDCA Monotherapy, with the other five testing combinations of UDCA with vitamin E, polyene phosphatidylcholine, silymarin, glycyrrhizin and tiopronin. The duration of therapy ranged from 3 to 24 months, with two studies using high doses of UDCA (23–35 mg/kg/d). The average quality point was 2.69, and was significantly lower in articles from China than in those from Western countries (2.2 ± 0.4 vs. 3.8 ± 1.1, respectively, p < 0.05). UDCA Monotherapy significantly improved liver function in five studies and improved steatosis and fibrosis in two studies. All five studies assessing UDCA combination therapy showed significant improvements liver function, while two studies also improved steatosis and inflammation. One study of high-dose UDCA showed significant improvements in ALT, γGT and liver fibrosis, whereas the other study showed no significant change in ALT and liver pathology.

Conclusions

UDCA therapy is effective in NASH, especially when combined with other drugs. However, the low quality of these studies and the heterogeneity of their results precluded further meta-analysis. Additional carefully designed clinical trials are needed, especially in China.

Vitamin D and nonalcoholic fatty liver disease (NAFLD): is it more than just an association?

Vitamin D is a secosteroid with known effects on calcium homeostasis that has recently been shown to have other significant functions regarding immune modulation, cell differentiation and proliferation, and the inflammatory response. As our understanding of the many functions of vitamin D has grown, the presence of vitamin D deficiency (VDD) has become more evident in Western populations. Concomitantly, nonalcoholic fatty liver disease (NAFLD) has become the most common cause of chronic liver disease. NAFLD and VDD are often found together, and while this is not unexpected, given their similar associations with obesity and sedentary lifestyle, a growing body of evidence points to a closely linked and potentially causative relationship between VDD and NAFLD. The epidemiologic association between VDD and NAFLD as well as the role of VDD in the pathogenesis of NAFLD and the available evidence on the clinical utility of vitamin D replacement in NAFLD populations are discussed.

Efficacy and safety of the farnesoid X receptor agonist obeticholic acid in patients with type 2 diabetes and nonalcoholic fatty liver disease

BACKGROUND & AIMS

Obeticholic acid (OCA; INT-747, 6α-ethyl-chenodeoxycholic acid) is a semisynthetic derivative of the primary human bile acid chenodeoxycholic acid, the natural agonist of the farnesoid X receptor, which is a nuclear hormone receptor that regulates glucose and lipid metabolism. In animal models, OCA decreases insulin resistance and hepatic steatosis.

METHODS

We performed a double-blind, placebo-controlled, proof-of-concept study to evaluate the effects of OCA on insulin sensitivity in patients with nonalcoholic fatty liver disease and type 2 diabetes mellitus. Patients were randomly assigned to groups given placebo (n = 23), 25 mg OCA (n = 20), or 50 mg OCA (n = 21) once daily for 6 weeks. A 2-stage hyperinsulinemic-euglycemic insulin clamp was used to measure insulin sensitivity before and after the 6-week treatment period. We also measured levels of liver enzymes, lipid analytes, fibroblast growth factor 19, 7α-hydroxy-4-cholesten-3-one (a BA precursor), endogenous bile acids, and markers of liver fibrosis.

RESULTS

When patients were given a low-dose insulin infusion, insulin sensitivity increased by 28.0% from baseline in the group treated with 25 mg OCA (P = .019) and 20.1% from baseline in the group treated with 50 mg OCA (P = .060). Insulin sensitivity increased by 24.5% (P = .011) in combined OCA groups, whereas it decreased by 5.5% in the placebo group. A similar pattern was observed in patients given a high-dose insulin infusion. The OCA groups had significant reductions in levels of γ-glutamyltransferase and alanine aminotransferase and dose-related weight loss. They also had increased serum levels of low-density lipoprotein cholesterol and fibroblast growth factor 19, associated with decreased levels of 7α-hydroxy-4-cholesten-3-one and endogenous bile acids, indicating activation of farnesoid X receptor. Markers of liver fibrosis decreased significantly in the group treated with 25 mg OCA. Adverse experiences were similar among groups.

CONCLUSIONS

In this phase 2 trial, administration of 25 or 50 mg OCA for 6 weeks was well tolerated, increased insulin sensitivity, and reduced markers of liver inflammation and fibrosis in patients with type 2 diabetes mellitus and nonalcoholic fatty liver disease. Longer and larger studies are warranted. ClinicalTrials.gov, Number: NCT00501592.

Ursodeoxycholyl lysophosphatidylethanolamide inhibits lipoapoptosis by shifting fatty acid pools toward monosaturated and polyunsaturated fatty acids in mouse hepatocytes

Ursodeoxycholyl lysophosphatidylethanolamide (UDCA-LPE) is a hepatoprotectant in inhibiting apoptosis, inflammation, and hyperlipidemia in mouse models of nonalcoholic steatohepatitis (NASH). We studied the ability of UDCA-LPE to inhibit palmitate (Pal)-induced apoptosis in primary hepatocytes and delineate cytoprotective mechanisms. We showed that lipoprotection by UDCA-LPE was mediated by cAMP and was associated with increases in triglycerides (TGs) and phospholipids (PLs). An inhibitor of cAMP-effector protein kinase A partially reversed the protective effects of UDCA-LPE. Lipidomic analyses of fatty acids and PL composition revealed a shift of lipid metabolism from saturated Pal to monounsaturated and polyunsaturated fatty acids, mainly, oleate, docosapentaenoate, and docosahexaenoate. The latter two ω-3 fatty acids were particularly found in phosphatidylcholine and phosphatidylserine pools. The catalysis of Pal by stearoyl-CoA desaturase-1 (SCD-1) is a known mechanism for the channeling of Pal away from apoptosis. SCD-1 protein was upregulated during UDCA-LPE lipoprotection. SCD-1 knockdown of Pal-treated cells showed further increased apoptosis, and the extent of UDCA-LPE protection was reduced. Thus, the major mechanism of UDCA-LPE lipoprotection involved a metabolic shift from toxic saturated toward cytoprotective unsaturated fatty acids in part via SCD-1. UDCA-LPE may thus be a therapeutic agent for treatment of NASH by altering distinct pools of fatty acids for storage into TGs and PLs, and the latter may protect lipotoxicity at the membrane levels.

Efficacy of ursodesoxycholic acid in treatment of nonalcoholic fatty liver disease: A meta-analysis

AIM: To evaluate the efficacy and safety of ursodesoxycholic acid in the treatment of nonalcoholic fatty liver disease (NAFLD).

METHODS: Randomized controlled clinical trials comparing the efficacy of ursodesoxycholic acid alone or in combination with other drugs versus other drugs or placebo alone in the treatment of NAFLD were retrieved by searching PubMed, Embase, OVID, Cochrane Library , CNKI, and Wanfang database. Review Manager 5.0 was used for meta-analysis.

RESULTS: Compared to the ursodesoxycholic acid monotherapy group, the drug combination group had significantly improved total effective rate (RR = 1.23, 95%CI: 1.07-1.41, P = 0.004) and decreased serum levels of TC (WMD = -1.69, 95%CI: -2.77--0.62, P = 0.002), TG (WMD = -1.01, 95%CI: -1.59--0.43, P = 0.0006), ALT (WMD = -22.65, 95%CI: -35.27--10.04, P = 0.0004), and AST (WMD =- 21.93, 95%CI: -23.74--20.12, P < 0.00001). The decrease in GGT was significant in both the ursodesoxycholic acid monotherapy group and drug combination group (WMD = -21.96, 95%CI: -35.73--8.18, P = 0.002; WMD = -28.80, 95%CI: -51.85--5.76, P = 0.01). There was no statistically significant difference in the incidence of adverse reactions (RR = 2.26, 95%CI: 0.88-5.83, P = 0.09).

CONCLUSION: Ursodesoxycholic acid is effective and safe in the management of NAFLD, and better efficacy can be achieved when it is combined with other positive agents.

Role of mitochondria in HIV infection and associated metabolic disorders: focus on nonalcoholic fatty liver disease and lipodystrophy syndrome

Highly active antiretroviral therapy (HAART) has considerably improved the prognosis of HIV-infected patients. However, prolonged use of HAART has been related to long-term adverse events that can compromise patient health such as HIV-associated lipodystrophy syndrome (HALS) and nonalcoholic fatty liver disease (NAFLD). There is consistent evidence for a central role of mitochondrial dysfunction in these pathologies. Nucleotide reverse transcriptase inhibitors (NRTIs) have been described to be mainly responsible for mitochondrial dysfunction in adipose tissue and liver although nonnucleoside transcriptase inhibitors (NNRTIs) or protease inhibitors (PIs) have also showed mitochondrial toxicity, which is a major concern for the selection and the long-term adherence to a particular therapy. Several mechanisms explain these deleterious effects of HAART on mitochondria, and evidence points to other mechanisms beyond the “Pol-γ hypothesis.” HIV infection has also direct effects on mitochondria. In addition to the negative effects described for HIV itself and/or HAART on mitochondria, HIV-infected patients are more prone to develop a premature aging and, therefore, to present an increased oxidative state that could lead to the development of these metabolic disturbances observed in HIV-infected patients.

[Non-alcoholic fatty liver disease and steatohepatitis]

Non-alcoholic fatty liver disease and non-alcoholic steatohepatitis, the hepatic manifestations of metabolic syndrome with close association with inzulin resistance and obesity, are the most common liver diseases, affecting up to a third of the population worldwide. They confer increased risk for hepatocellular carcinoma as well as cardiovascular diseases. The review aims to summarize advances in epidemiology, pathogenesis and clinical management of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis. Besides liver biopsy and biomarkers, a novel non-invasive diagnostic tool the called "controlled attenuation parameter" measuring the attenuation of ultrasound generated by the transient elastography transducer, can quantitatively assess the hepatic fat content and differentiate between steatosis grades. At the same time, liver stiffness (fibrosis) can also be evaluated. The authors present their own results obtained with the latter procedure. In non-alcoholic fatty liver disease, the lifestyle intervention, weight loss, diet and exercise supported by cognitive behavioural therapy represent the basis of management. Components of metabolic syndrome (obesity, dyslipidaemia, diabetes and arterial hypertension) have to be treated. Although there is no approved pharmacological therapy for NASH, it seems that long lasting administration of vitamin E in association with high dose ursodeoxycholic acid may be beneficial. In addition, omega-3 polyunsaturated fatty acid substitution can also decrease liver fat, however, the optimal dose is not known yet. Further controlled clinical studies are warranted to establish the real value of any suggested treatment modalities for non-alcoholic fatty liver disease and non-alcoholic steatohepatitis, although these are in experimental phase yet.

Role of thiazolidinediones, insulin sensitizers, in non-alcoholic fatty liver disease

The prevalence of metabolic syndrome, obesity and insulin resistance has become an epidemic in the world. A strong association exists between metabolic syndrome and non-alcoholic fatty liver disease (NAFLD), though the etiology of NAFLD is still unclear. This close association leads to numerous clinical studies to investigate the effects of insulin sensitizers, thiazolidinediones (TZDs), on hepatic fat accumulation. Thiazolidinediones affect glucose and lipid metabolism in insulin-sensitive tissues, which in turn reduces the lipid content in the liver by modulating several mediators. In the present review, we discuss key modulators - adiponectin and sirtulin-adenosine monophosphate activated protein kinase signaling - as the mechanisms responsible for NAFLD related to metabolic syndrome.

Serum biomarkers in nonalcoholic steatohepatitis: value for assessing drug effects?

Nonalcoholic steatohepatitis (NASH) is a common chronic liver disease throughout the world. In the USA, approximately 3-5% of the population are affected, and the prevalence of this condition is increasing. NASH is associated with an increased risk of liver-related morbidity, such as cirrhosis and fibrosis, as well as cardiovascular disease, and in spite of several clinical studies investigating putative new drugs, no approved treatment is currently available. This is partly due to the nature of the disease. NASH is a complex, slowly progressing disease, and confirmatory clinical trials have long treatment durations and require invasive end points (a liver biopsy). Such invasive assessments are only accepted in confirmatory trials; clinical studies in the exploratory clinical development phase must rely on noninvasive biomarkers as the primary end point. Experimental and clinical research continues to achieve validation and qualification of biomarkers in NASH, which will hopefully assist the development of new treatments for NASH patients.

Evolving therapies for liver fibrosis

Fibrosis is an intrinsic response to chronic injury, maintaining organ integrity when extensive necrosis or apoptosis occurs. With protracted damage, fibrosis can progress toward excessive scarring and organ failure, as in liver cirrhosis. To date, antifibrotic treatment of fibrosis represents an unconquered area for drug development, with enormous potential but also high risks. Preclinical research has yielded numerous targets for antifibrotic agents, some of which have entered early-phase clinical studies, but progress has been hampered due to the relative lack of sensitive and specific biomarkers to measure fibrosis progression or reversal. Here we focus on antifibrotic approaches for liver that address specific cell types and functional units that orchestrate fibrotic wound healing responses and have a sound preclinical database or antifibrotic activity in early clinical trials. We also touch upon relevant clinical study endpoints, optimal study design, and developments in fibrosis imaging and biomarkers.

Decreased hepatotoxic bile acid composition and altered synthesis in progressive human nonalcoholic fatty liver disease

Bile acids (BAs) have many physiological roles and exhibit both toxic and protective influences within the liver. Alterations in the BA profile may be the result of disease induced liver injury. Nonalcoholic fatty liver disease (NAFLD) is a prevalent form of chronic liver disease characterized by the pathophysiological progression from simple steatosis to nonalcoholic steatohepatitis (NASH). The hypothesis of this study is that the 'classical' (neutral) and 'alternative' (acidic) BA synthesis pathways are altered together with hepatic BA composition during progression of human NAFLD. This study employed the use of transcriptomic and metabolomic assays to study the hepatic toxicologic BA profile in progressive human NAFLD. Individual human liver samples diagnosed as normal, steatosis, and NASH were utilized in the assays. The transcriptomic analysis of 70 BA genes revealed an enrichment of downregulated BA metabolism and transcription factor/receptor genes in livers diagnosed as NASH. Increased mRNA expression of BAAT and CYP7B1 was observed in contrast to decreased CYP8B1 expression in NASH samples. The BA metabolomic profile of NASH livers exhibited an increase in taurine together with elevated levels of conjugated BA species, taurocholic acid (TCA) and taurodeoxycholic acid (TDCA). Conversely, cholic acid (CA) and glycodeoxycholic acid (GDCA) were decreased in NASH liver. These findings reveal a potential shift toward the alternative pathway of BA synthesis during NASH, mediated by increased mRNA and protein expression of CYP7B1. Overall, the transcriptomic changes of BA synthesis pathway enzymes together with altered hepatic BA composition signify an attempt by the liver to reduce hepatotoxicity during disease progression to NASH.

Diabetes and nonalcoholic Fatty liver disease: a pathogenic duo

Recent data increasingly support a complex interplay between the metabolic condition diabetes mellitus and the pathologically defined nonalcoholic fatty liver disease (NAFLD). NAFLD predicts the development of type 2 diabetes and vice versa, and each condition may serve as a progression factor for the other. Although the association of diabetes and NAFLD is likely to be partly the result of a "common soil," it is also probable that diabetes interacts with NAFLD through specific pathogenic mechanisms. In particular, through interrelated metabolic pathways currently only partly understood, diabetes appears to accelerate the progression of NAFLD to nonalcoholic steatohepatitis, defined by the presence of necroinflammation, with varying degrees of liver fibrosis. In the research setting, obstacles that have made the identification of clinically significant NAFLD, and particularly nonalcoholic steatohepatitis, difficult are being addressed with the use of new imaging techniques combined with risk algorithms derived from peripheral blood profiling. These techniques are likely to be used in the diabetes population in the near future. This review examines the pathogenic links between NAFLD and diabetes by exploring the epidemiological evidence in humans and also through newer animal models. Emerging technology to help screen noninvasively for differing pathological forms of NAFLD and the potential role of preventive and therapeutic approaches for NAFLD in the setting of diabetes are also examined.

Nonalcoholic fatty liver disease: an emerging threat to obese and diabetic individuals

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in the Western world and its incidence is increasing rapidly. NAFLD is a spectrum ranging from simple steatosis, which is relatively benign hepatically, to nonalcoholic steatohepatitis (NASH), which can progress to cirrhosis. Obesity, insulin resistance, type 2 diabetes mellitus, and dyslipidemia are the most important risk factors for NAFLD. Due to heavy enrichment with metabolic risk factors, individuals with NAFLD are at significantly higher risk for cardiovascular disease. Individuals with NAFLD have higher incidence of type 2 diabetes. The diagnosis of NAFLD requires imaging evidence of hepatic steatosis in the absence of competing etiologies including significant alcohol consumption. Liver biopsy remains the gold standard for diagnosing NASH and for determining prognosis. Weight loss remains a cornerstone of treatment. Weight loss of ∼5% is believed to improve steatosis, whereas ∼10% weight loss is necessary to improve steatohepatitis. A number of pharmacologic therapies have been investigated to treat NASH, and agents such as vitamin E and thiazolidinediones have shown promise in select patient subgroups.

Pharmacologic therapy for nonalcoholic fatty liver disease in adults

Nonalcoholic fatty liver disease (NAFLD) is characterized by the accumulation of triglycerides in hepatocytes in the absence of excessive alcohol intake, ranging in severity from simple steatosis to nonalcoholic steatohepatitis (NASH). Nonalcoholic steatohepatitis can ultimately progress to cirrhosis and hepatocellular carcinoma. NAFLD is associated with cardiometabolic risk factors and is the most common chronic liver disease among adults in the Western Hemisphere. Although simple steatosis is generally considered a self-limiting disease, evidence suggests an increased risk of cardiovascular disease, and, less conclusively, mortality, among individuals with NAFLD and/or NASH. The current standard of care for the treatment of patients with NAFLD focuses on lifestyle interventions, particularly diet and exercise. There is a lack of consensus regarding the most effective and appropriate pharmacologic therapy. A PubMed search was conducted using the medical subject heading terms "fatty liver" and "steatohepatitis." This review focuses on the current pharmacologic options available for treating adults with NAFLD and/or NASH. Continued investigation of drugs or combinations that improve NAFLD progression is crucial. Clinicians, particularly pharmacists, must take an active role in identification and appropriate selection of pharmacotherapy for NAFLD.

Incretin secretion stimulated by ursodeoxycholic acid in healthy subjects

Bile acids play an important role in post-prandial glucose metabolism by stimulating release of glucagon-like peptide-1 (GLP-1) via the G-protein-coupled receptor TGR5, which is expressed in intestinal L cells. Thus, bile acid sequestrants are expected to stimulate secretion of endogenous GLP-1 through TGR5. We investigated incretin and insulin secretion after a meal with and without ursodeoxycholic acid (UDCA), a widely used therapeutic agent in liver diseases, in 7 non-diabetic Japanese subjects. We found that UDCA intake resulted in higher GLP-1 secretion (area under the curve [AUC] of 0–60 min after meal without UDCA, 450 ± 162 mmol·min/l; with UDCA, 649 ± 232 mmol·min/l, P = 0.046) and lower blood glucose (AUC of 0–60 min without UDCA, 7191 ± 250 mg·min/dl; with UDCA, 6716 ± 189 mg·min/dl, P = 0.001) , although we did not find statistically significant insulin increase by UDCA intake (AUC of 0–60 min without UDCA, 1551 ± 418 μU·min/ml; with UDCA, 1941 ± 246 μU·min/ml, P = 0.065). These results suggest that UDCA increases bile-induced GLP-1 secretion. Ours is the first report showing increased GLP-1 secretion and decreased blood glucose in response to UDCA.

Nonalcoholic fatty liver disease and the metabolic syndrome: clinical implications and treatment

The prevalence of nonalcoholic fatty liver disease (NAFLD) is expected to rise along with the global obesity epidemic. As NAFLD is the most common cause of chronic liver disease in the United States, it has become a major health concern. It affects all ethnicities, with the highest prevalence among the Hispanic population. Individuals with nonalcoholic steatohepatitis (NASH), the more serious form of NAFLD, are at increased risk of developing cirrhosis, hepatic decompensation, and hepatocellular carcinoma. Since NAFLD is intricately associated with the metabolic syndrome and insulin resistance, increased risk of cardiovascular disease and mortality become a real concern. It has recently been shown that current nutrition trends, such as increased consumption of high-fructose corn syrup and certain types of fats, may have an important role in the increased NAFLD prevalence. As there are no ideal treatment options available for NAFLD, a multifaceted treatment approach should be tailored to each individual patient.

Bile acid transporters and regulatory nuclear receptors in the liver and beyond

Bile acid (BA) transporters are critical for maintenance of the enterohepatic BA circulation where BAs exert their multiple physiological functions including stimulation of bile flow, intestinal absorption of lipophilic nutrients, solubilization and excretion of cholesterol, as well as antimicrobial and metabolic effects. Tight regulation of BA transporters via nuclear receptors is necessary to maintain proper BA homeostasis. Hereditary and acquired defects of BA transporters are involved in the pathogenesis of several hepatobiliary disorders including cholestasis, gallstones, fatty liver disease and liver cancer, but also play a role in intestinal and metabolic disorders beyond the liver. Thus, pharmacological modification of BA transporters and their regulatory nuclear receptors opens novel treatment strategies for a wide range of disorders.

miR-34a/SIRT1/p53 is suppressed by ursodeoxycholic acid in the rat liver and activated by disease severity in human non-alcoholic fatty liver disease

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) comprises a spectrum of stages from simple steatosis to non-alcoholic steatohepatitis (NASH). However, disease pathogenesis remains largely unknown. microRNA (miRNA or miR) expression has recently been reported to be altered in human NASH, and modulated by ursodeoxycholic acid (UDCA) in the rat liver. Here, we aimed at evaluating the miR-34a/Sirtuin 1(SIRT1)/p53 pro-apoptotic pathway in human NAFLD, and to elucidate its function and modulation by UDCA in the rat liver and primary rat hepatocytes.

METHODS

Liver biopsies were obtained from NAFLD morbid obese patients undergoing bariatric surgery. Rat livers were collected from animals fed a 0.4% UDCA diets. Primary rat hepatocytes were incubated with bile acids or free fatty acids (FFAs) and transfected with a specific miRNA-34a precursor and/or with a p53 overexpression plasmid. p53 transcriptional activity was assessed by ELISA and target reporter constructs.

RESULTS

miR-34a, apoptosis and acetylated p53 increased with disease severity, while SIRT1 diminished in the NAFLD liver. UDCA inhibited the miR-34a/SIRT1/p53 pathway in the rat liver in vivo and in primary rat hepatocytes. miR-34a overexpression confirmed its targeting by UDCA, which prevented miR-34a-dependent repression of SIRT1, p53 acetylation, and apoptosis. Augmented apoptosis by FFAs in miR-34a overexpressing cells was also inhibited by UDCA. Finally, p53 overexpression activated miR-34a/SIRT1/p53, which in turn was inhibited by UDCA, via decreased p53 transcriptional activity.

CONCLUSIONS

Our results support a link between liver cell apoptosis and miR-34a/SIRT1/p53 signaling, specifically modulated by UDCA, and NAFLD severity. Potential endogenous modulators of NAFLD pathogenesis may ultimately provide new tools for therapeutic intervention.

Non-alcoholic fatty liver disease and insulin resistance: from bench to bedside

Non-alcoholic fatty liver disease (NAFLD) is now the most frequent chronic liver disease in the developed countries. There is also growing evidence from basic and clinical research that NAFLD has a strong relationship to insulin resistance, which is a key factor in the development of type 2 diabetes. The aim of this review is to summarize the recent important findings linking NAFLD and insulin resistance. Lipid accumulation, particularly of diacylglycerol, appears to be of major importance in this process. Mitochondrial dysfunction, through decreased mitochondrial biogenesis, increases oxidative stress, and ageing also plays an important role. Finally, endoplasmic reticulum stress and inflammation also probably contribute to the development of insulin resistance via mechanisms that are still not well understood. Clinical aspects of NAFLD, such as its diagnosis and management, are also investigated in this review.

Therapeutic approach of hepatic sarcoidosis

PURPOSE OF REVIEW

Surveillance of hepatic involvement in sarcoidosis has not been standardized. Therefore, management of hepatic involvement is a clinical challenge. This review analyses published data on the pharmacological treatment of hepatic sarcoidosis.

RECENT FINDINGS

Only 5-30% of patients with hepatic sarcoidosis display symptoms. Occasionally, it has a rapid progressive course with serious complications, stressing an appropriate and carefully timed therapeutic approach. Because symptomatic hepatic sarcoidosis is uncommon, therapeutic studies are scarce. Answers to the questions when to initiate which treatment are lacking. Case reports describe beneficial effects of prednisone and the augmentation of cytotoxic and anti-tumor necrotic factor-α (TNF-α) therapy. However, because of small sample sizes, no meaningful conclusions could be drawn. In symptomatic hepatic sarcoidosis patients, it is recommended to start to treat the sarcoidosis with prednisone, preceded by ursodeoxycholic acid when signs of cholestasis are present. In refractory cases or when prednisone weaning is impossible, cytotoxic drugs or anti-TNF-α therapy should be considered.

SUMMARY

This review illustrates the importance of an appropriate therapeutic approach of sarcoidosis patients with hepatic involvement. It emphasizes the need for future studies to evaluate treatment options to avoid disease progression and hepatic complications.

The efficacy of pharmacological treatment in pediatric nonalcoholic Fatty liver disease

PURPOSE

With growing number of obese children, the prevalence of nonalcoholic fatty liver disease (NAFLD) in pediatric population is increasing. Nonalcoholic steatohepatitis (NASH) is a severe form of NAFLD, and can cause morbid complications. It is important to identify patients in order to grade pathologic severities and treat those children who possibly have NASH. This study was performed to evaluate whether the pharmacological therapy is also effective as well as the body weight reduction in pediatric NAFLD.

METHODS

Among the 52 children presenting with obesity and hepatopathy, NAFLD was diagnosed through liver biopsy in 29 children, who were 7 to 14 years of age, from January 2006 to December 2011. The patients were advised to reduce their body weight through diverse methods. Medication with Ursodeoxycholic acid (UDCA) and vitamin E was performed in children whose liver functions did not improve or their weight reductions were not successful. The therapeutic effects were monitored and assessed via the biochemical profiles and the physical measurements.

RESULTS

The therapy of vitamin E and UDCA combined with body mass index (BMI) reduction showed significantly higher rate of improvement in clinical profiles, which could be seen in data of aspartate aminotransferase (AST), alanine aminotransferase (ALT), AST/ALT ratio, alkaline phosphatase, total bilirubin and γ-glutamyl transpeptidase. Children whose BMI were successfully reduced showed favorable clinical improvements without any medication, but those without BMI reduction did not show any improvement despite medications.

CONCLUSION

This study showed that the first line of therapy should be the BMI reduction in NAFLD and drug therapy combined with BMI reduction could have additive therapeutic effect in children with NAFLD.

Effects of bile duct ligation and cholic acid treatment on fatty liver in two rat models of non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease, one of the most prevalent liver disorders in Western countries, is characterized by hepatic accumulation of triglycerides. Bile acids have long been known to affect triglyceride homeostasis through a not completely understood mechanism.

AIM

To analyse the effects of two different manipulations of bile acid circulation on non-alcoholic fatty liver disease.

METHODS

Two animal models of non-alcoholic fatty liver disease were developed by either feeding rats with a choline deficient or with a high fat diet. After 4 weeks, rats were randomized to undergo either bile duct ligation, sham operation or cholic acid administration.

RESULTS

During cholestasis there was an increased CYP7A1 expression, the rate limiting enzyme in bile acid synthesis, and a reduction of hepatic concentration of oxysterols, ligands of the liver X receptors. Target genes of the liver X receptors, involved in fatty acid and triglyceride synthesis, were down-regulated in association with decreased hepatic triglyceride content and improvement of fatty liver. Administration of cholic acid, ligand of farnesoid X receptor, also had a beneficial effect on fatty liver in rats on choline deficient diet.

CONCLUSION

These results indicate that pharmacological approaches increasing the expression of CYP7A1 or stimulating farnesoid X receptor pathway could represent a promising treatment for non-alcoholic fatty liver disease.

Direct acting antivirals for the treatment of chronic viral hepatitis

The development and evaluation of antiviral agents through carefully designed clinical trials over the last 25 years have heralded a new dawn in the treatment of patients chronically infected with the hepatitis B and C viruses, but not so for the D virus (HBV, HCV, and HDV). The introduction of direct acting antivirals (DDAs) for the treatment of HBV carriers has permitted the long-term use of these compounds for the continuous suppression of viral replication, whilst in the case of HCV in combination with the standard of care [SOC, pegylated interferon (PegIFN), and ribavirin] sustained virological responses (SVRs) have been achieved with increasing frequency. Progress in the case of HDV has been slow and lacking in significant breakthroughs.This paper aims to summarise the current state of play in treatment approaches for chonic viral hepatitis patients and future perspectives.

Ursodeoxycholic acid for nonalcoholic steatohepatitis

The aim of this study was to evaluate the effects of ursodeoxycholic acid on patients with nonalcoholic steatohepatitis using meta-analysis. PubMed, EMBASE, Web of Science, Cochrane Library, Chinese Biomedical Databases, and article references were searched. We included randomized controlled trials using liver biopsy as a reference standard. We identified three eligible studies. Among histological responses, only lobular inflammation improved in the high-dose ursodeoxycholic acid subgroup compared with the control group [mean deviation (MD): -0.23 (-0.40, -0.06), P=0.008]. However, fibrosis may tend to increase [MD: 0.08 (-0.04, 0.20), P=0.17]. Among biochemical responses, γ-glutamyl transpeptidase reduction was significantly greater in the ursodeoxycholic acid group than in the placebo group, and the reduction tendency was only shown in the high-dose subgroup [MD: -35.58 (-52.60, -18.56), P<0.0001]. Serum total bilirubin increased in the high-dose ursodeoxycholic acid subgroup compared with the control group [MD: 0.43 (0.14, 0.72), P=0.004]. Ursodeoxycholic acid-treated patients did not differ significantly from control patients with regard to alanine transaminase, aspartate aminotransferase, and alkaline phosphatase activities. Adverse events were nonspecific and considered of no major clinical relevance. Ursodeoxycholic acid in monotherapy has no substantial positive effect on nonalcoholic steatohepatitis.