Management of nonalcoholic steatohepatitis: an analytic review

Pharmacological therapy of nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH), unlike simple steatosis, is a potentially progressive disease. Various types of drugs have been explored for the treatment of NASH. We reviewed the various therapies available, with particular emphasis on their efficacy for the improvement of hepatic fibrosis. Treatments for NASH included lipase-inhibiting agents, drugs that target components of metabolic syndrome, antioxidants, liver cytoprotectants, and suppressors of inflammatory cytokines. Alanine transaminase levels were significantly decreased and the grade of histologic features other than fibrosis was significantly improved in more than 75% of treatment arms across studies, yet the stage of liver fibrosis was significantly improved in less than 30% of treatment arms. Recently, drugs such as peroxisome proliferator-activated receptor-γ agonists have received attention for their anti-fibrotic effect. However, due to a lack of large-scale, high quality, long-term clinical trials, the utility of any particular treatment for NASH is not yet clear. Further clinical studies are needed to evaluate the efficacy and safety of individual drugs.

Polaprezinc attenuates liver fibrosis in a mouse model of non-alcoholic steatohepatitis

BACKGROUND AND AIM

The effect of polaprezinc, a zinc-carnosine chelate compound, on the development of non-alcoholic steatohepatitis (NASH) was investigated in dietary methionine and choline deficient (MCD) mice.

METHODS

Mice were fed the MCD diet with or without polaprezinc (2.2 g/kg diet) for 10 weeks. Liver histopathology, triglyceride and lipid peroxide levels, and the expression of genes linked to fibrosis were then assessed.

RESULTS

MCD mice developed steatohepatitis accompanied by mild fibrosis with an increase in lipid peroxidation, hepatic stellate cell (HSC) activation, and the augmented mRNA expression of tumor necrosis factor-alpha, transforming growth factor-beta1 and procollagen alpha1(I). The mRNA expression levels of matrix metalloproteinase (MMP)-2 and tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 were also enhanced. Histopathologically, polaprezinc supplementation did not influence the development of steatosis but it apparently attenuated fibrosis. Polaprezinc slightly reduced lipid peroxidation and suppressed HSC activation as well as the mRNA expression of pro-inflammatory cytokines. Polaprezinc affected the MCD diet-enhanced expression of TIMP-1 even when administered relatively late.

CONCLUSION

These results suggest that polaprezinc attenuates fibrosis in NASH by reducing inflammation and lipid peroxidation and, during a later phase, promoting fibrolysis via the inhibition of TIMP expression in the liver. Further investigation is required to clarify the clinical efficacy of polaprezinc in patients with NASH.

The effect of QuYuHuaTanTongLuo Decoction on the non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is the most common cause of cryptogenic cirrhosis, is becoming more prevalent in China. However, there is as yet no clearly established therapy for reversing fatty liver. Our aim is to explore the effect of traditional Chinese herbs QuYuHuaTanTongLuo Decoction (QYHTTLD) on non-alcoholic steatohepatitis. Sixty-nine non-alcoholic steatohepatitis patients were randomly divided into two groups. One group of 35 patients were treated by QYHTTLD, another group of 34 patients were treated by Ursodeoxycholic acid (UDCA). The TNF-alpha, IL-8, MDA level, SOD activity and liver function, as well as B ultrasonic image were detected before and after being treated. The results showed: after 6 months treatment, MBI of the treatment group was obviously decreased (p<0.05). The levels of TC, TG and LDL-C were significantly decreased whereas the level of HDL-C increased (p<0.01, p<0.05, p<0.05, and p<0.05, respectively) in the treatment group, the levels of TC, TG, LDL-C and HDL-C had no significant difference in the control group (p>0.05). The levels of TNF-alpha, IL-8 and MDA were significantly decreased whereas SOD activity was significantly increased (p<0.01, p<0.05, p<0.01, and p<0.01, respectively) in the treatment group, the level of MDA was significantly decreased in the control group (p<0.05). B ultrasonic images were ameliorated in different degree (p<0.01 and p<0.01, respectively). Both QYHTTLD and UDCA had the effect in improving the scores of symptoms and signs of patients, however, the difference value of the scores in treatment group were significantly higher than that in control group after being treated for 6 months (p<0.05).

CONCLUSION

QYHTTLD is effective for treating non-alcoholic steatohepatitis, and its effect seems to relate with the ways of QYHTTL down-regulating inflammation cytokine IL-8 level and relieving lipid peroxidation of liver.

Importance of cytokines, oxidative stress and expression of BCL-2 in the pathogenesis of non-alcoholic steatohepatitis

OBJECTIVE

Non-alcoholic steatohepatitis (NASH) is a form of chronic hepatitis. The pathogenesis of NASH has been dealt with in only a few studies and so it has not been clearly identified yet. The purpose of this study was to investigate the roles of TNF-alpha, TGF-beta, IL-6, IL-8, malondialdehyde (MDA), nitric oxide (NO) and the expression of Bcl-2 and Bax in the pathogenesis of NASH.

MATERIAL AND METHODS

The study included 92 patients, 57 of whom were diagnosed with biopsy-proven NASH, 13 with biopsy-proven hepatosteatosis and 22 with ultrasonography-diagnosed hepatosteatosis. Serum levels of TNF-alpha, TGF-beta, IL-6 and IL-8 were measured using the ELISA method. The plasma levels of NO were studied using the Griess method. Expressions of Bcl-2 and Bax were examined in paraffin blocks of liver biopsy materials by means of immunohistochemical-staining. MDA levels were measured using the thiobarbituric acid method.

RESULTS

No significant difference was found in the levels of TNF-alpha, TGF-beta, IL-6 or NO between the three groups (p>0.05). No difference was found in expression of Bcl-2 and expression of Bax between the biopsy-proven NASH and biopsy-proven hepatosteatosis groups (p>0.05). In the NASH group, the levels of IL-8 and MDA were found to be higher than those in the hepatosteatosis groups (p<0.05).

CONCLUSIONS

The elevated levels of MDA may indicate the relationship between oxidative stress and NASH. Furthermore, IL-8 was found to be higher in the NASH group than in the hepatosteatosis group, demonstrating the importance of inflammation in the pathogenesis of NASH.

Non-invasive markers to predict the liver fibrosis in non-alcoholic fatty liver disease

BACKGROUND/AIM

The aim of this study was to find a non-invasive marker, which could predict liver fibrosis without the need of liver biopsy in non-alcoholic steatohepatitis (NASH).

PATIENTS/METHODS

Fifty patients were included. All patients had one or more conditions that characterize the metabolic syndrome and histological proven NASH. Hyaluronic acid (HA), leptin (LT) and laminin (LN) were determined from serum withdrawn at the day of biopsy.

RESULTS

Patients were divided into two groups according to the histological findings. The first group consisted of 23 patients with NASH and fibrosis and the second group had 27 patients with NASH, ballooned cells, without fibrosis. Subjects with NASH and fibrosis had statistically significantly higher HA and LN than those with NASH without fibrosis, P<0.001, respectively. In contrast, there was no statistically significant difference between the levels of serum LT in the two groups. The stage of liver fibrosis in the 23 patients of group 1 was related only to the values of hyaluronic acid (P<0.001) and not to the ones of LT and LN.

CONCLUSION

Measurement of hyaluronic acid could be a predictive factor of the presence and stage of liver fibrosis in NASH. LN could be used to diagnose liver fibrosis but has no value in staging.

A pilot study of atorvastatin treatment in dyslipemid, non-alcoholic fatty liver patients

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) encompasses a wide spectrum of liver injury. Currently, there are no proven effective therapies available. Atorvastatin is a new 3-hydroxy-3-metylglutaryl coenzyme A reductase inhibitor that reduces lipid serum levels.

AIM

To evaluate the effectiveness and safety of atorvastatin in dyslipemid, non-alcoholic fatty liver patients.

PATIENTS AND METHODS

We prospectively enrolled 25 patients with NAFLD; 22 of them completed the study. Body mass index, serum lipids, liver function tests and liver density assessed by echography were measured at baseline and after 1, 3, 6, 9 and 12 months of treatment. Normalization of transaminases and/or improvement in liver density were treatment end points. Patients received atorvastatin (10-80 mg/daily) according to basal serum choleresterol levels; additionally, they were given standard weight-loss counselling and encouraged to follow a low fat diet.

RESULTS

All 22 patients (14 men, mean age 47 +/- 10 years) had high cholesterol levels at baseline and 11 (44%) also presented high trygliceride levels. After 6 months of treatment, eight patients (36.3%) presented normal transaminase levels. The remaining patients continued treatment for 12 months when 20% of patients presented with normal transaminase levels, while the other patients showed a 10% reduction in basal levels. Mean cholesterol levels were 268.5 +/- 44.2 and 186.8 +/- 14.4 mg/dL before and after treatment, respectively (P < 0.05). The mean body mass index was 27.4 +/- 3.1 at baseline and 26.3 +/- 2.8 kg/cm2 at the end of treatment (P > 0.05). No side effects were reported.

CONCLUSIONS

Serum aminotransferase and lipid levels were reduced significantly in all patients with atorvastatin treatment. Therapy with atorvastatin in NAFLD patients with hyperlipidemia was found to be both effective and safe.

Effects of bezafibrate, PPAR pan-agonist, and GW501516, PPARδ agonist, on development of steatohepatitis in mice fed a methionine- and choline-deficient diet

We evaluated the effects of bezafibrate, a peroxisome proliferator-activated receptor (PPAR) pan-agonist, and GW501516, a PPARdelta agonist, on mice fed a methionine- and choline-deficient (MCD) diet, a model of non-alcholic steatohepatitis (NASH), to investigate (a) the efficacy of bezafibrate against non-alcholic steatohepatitis and (b) the relation between non-alcholic steatohepatitis and the functional role of PPARdelta. Bezafibrate (50 or 100 mg/kg/day) and GW501516 (10 mg/kg/day) were administered by gavage once a day for 5 weeks. Hepatic lipid contents, plasma triglyceride, high density lipoprotein (HDL)-cholesterol and alanine aminotransferase (ALT) concentrations were evaluated, as were histopathological changes in the liver and hepatic mRNA expression levels. Bezafibrate and GW501516 inhibited the MCD-diet-induced elevations of hepatic triglyceride and thiobarbituric acid-reactants contents and the histopathological increases in fatty droplets within hepatocytes, liver inflammation and number of activated hepatic stellate cells. In this model, bezafibrate and GW501516 increased the levels of hepatic mRNAs associated with fatty acid beta-oxidation [acyl-CoA oxidase (ACO), carnitine palmitoyltransferase-1 (CPT-1), liver-fatty acid binding protein (L-FABP) and peroxisomal ketothiolase], and reduced the levels of those associated with inflammatory cytokines or chemokine [transforming growth factor (TGF)-beta1, interleukin (IL)-6, IL-1beta, monocyte chemoattractant protein (MCP)-1, tumor necrosis factor (TNF) alpha and nuclear factor (NF)-kappaB1]. In addition, bezafibrate characteristically reduced the elevation in the level of plasma ALT, but enhanced that in plasma adiponectin and increased the mRNA expression levels of its receptors (adiponectin receptors 1 and 2). These results suggest that (a) bezafibrate (especially) and GW501516 might improve hepatic steatosis via an improvement in fatty acid beta-oxidation and a direct prevention of inflammation, (b) treatment with a PPARdelta agonist might improve non-alcholic steatohepatitis, (c) bezafibrate may improve non-alcholic steatohepatitis via activation not only of PPARalpha but also of PPARdelta, because bezafibrate is a PPAR pan-agonist.

Effects of oligofructose on glucose and lipid metabolism in patients with nonalcoholic steatohepatitis: results of a pilot study

OBJECTIVE

In experimental animals, recent results suggest that the addition of inulin-type fructans such as oligofructose (OFS) in the diet decreases triacylglycerol accumulation in the liver tissue. Therefore, we have investigated the effect of daily ingestion of OFS in seven patients with nonalcoholic steatohepatitis (NASH), confirmed by liver biopsies.

DESIGN

They received 16 g/day OFS or maltodextrine (placebo) for 8 weeks in a randomized double-blind crossover design. Energy intake, body composition, liver steatosis and blood parameters were analysed after 4 and 8 weeks of dietary supplementation.

RESULTS

Compared to placebo, OFS decreased significantly serum aminotransferases, aspartate aminotransferase after 8 weeks, and insulin level after 4 weeks, but this could not be related to significant effect on plasma lipids.

CONCLUSION

This pilot study supports the putative interest of OFS in the management of liver diseases associated with abnormal lipid accumulation in humans.

Tratamiento médico de la hepatopatía grasa no alcohólica primaria

The need for an effective and safe medical treatment of nonalcoholic fatty liver disease is urgent due to its high prevalence and progressive character. At the moment, therapeutic strategies are largely empirical and based on the control of associated clinical conditions (especially obesity, type 2 diabetes mellitus, and hypertriglyceridemia) and the use of some specific drugs (insulin sensitizing agents, cytoprotectives, antioxidants, and anticytokines) as an attempt to counteract known elements of the pathogenesis. None of these specifics measures have been found to display enough evidence to recommend their clinical use. It is indispensable to join efforts in coordinated networks to define, as soon as possible, the best treatment and the best time to start it.

Relation of hemochromatosis with hepatocellular carcinoma: epidemiology, natural history, pathophysiology, screening, treatment, and prevention

HH is a common inherited disorder of iron metabolism affecting about 1 out of 250 individuals of Northern European decent. Many of these patients do not have evident phenotypic expression and do not develop significant iron loading. Some patients, however, develop progressive iron overload and cirrhosis. These individuals are at risk of developing HCC. Cirrhotics with hemochromatosis should undergo regular screening for HCC. If HCC is identified early, treatment with either resection or liver transplantation is optimal. Palliative measures, including ablative therapy and chemoembolization, can be used. With increasing clinical recognition,hemochromatosis should be diagnosed earlier and progression to cirrhosis and HCC should be minimized.

Identification of novel molecular candidates for fatty liver in the hyperlipidemic mouse model, HcB19

The inbred HcB19 mouse strain expresses a truncated form of thioredoxin interacting protein and is phenotypically characterized by fatty liver and elevated plasma triglycerides and VLDL. Recently, these mice have been proposed as an animal model for familial combined hyperlipidemia. The aim of the present study was identification of hepatic proteins specifically associated with the presence of fatty liver. Eighteen differential proteins were detected in whole-liver homogenate from HcB19, or the parental strain C3H, using 2D electrophoresis, and 11 of those were successfully identified by mass spectrometry. Five of the identified differential proteins were mitochondrial, two peroxisomal, two cytosolic, and two secretory. Four differential proteins were novel in the fatty liver proteome [i.e., aconitase, succinate dehydrogenase, propionyl CoA carboxylase alpha chain (PCCA), and 3-hydroxyanthranilate 3,4 dioxygenase (3HAAO)]. Of these, PCCA and 3HAAO are of particular interest because of their known functions in nicotinic acid metabolism (3HAAO) and ketogenesis (PCCA). We have newly identified several differential proteins in the hepatic proteome of mice with fatty liver, including PCCA and 3HAAO, and confirmed differential expression of previously reported proteins. These individual proteins, PCCA and 3HAAO, can be important in development of fatty liver or in the expression of hyperlipidemia.

Association of nonalcoholic fatty liver disease with insulin resistance: is OGTT indicated in nonalcoholic fatty liver disease?

Nonalcoholic fatty liver disease (NAFLD) is frequently associated with type 2 diabetes mellitus, obesity, and dyslipidemia. We tested the hypothesis that there may be an association between NAFLD and insulin resistance (IR); and its correlation with glucose tolerance status of subjects who aren't known patients with diabetes. One hundred and seventy-six consecutive patients with elevated serum aminotransferase levels and bright liver were evaluated. Sixty-two patients were excluded from the study. Age, gender, height, weight, body mass index, waist circumferences, and family history of diabetes were recorded. Fasting plasma glucose, insulin, lipid profile were measured. A standard oral glucose tolerance test (OGTT) was performed and the index of IR was calculated according to the HOMA method. Patients with a normal glucose tolerance formed group 1 (64 patients) and patients with impaired or diabetic glucose tolerance group 2 (50 patients). Age, female sex, family history of type 2 diabetes, fasting insulin, fasting plasma glucose and HOMA-R index were statistically significantly different between the groups. Although the subjects in the study are not known patients with diabetes, the prevalence of impaired or diabetic glucose tolerance was prominent. In conclusion, performing OGTT in cases with nonalcoholic fatty liver disease may be useful for early screening of diabetes mellitus.

Relation of elevated serum alanine aminotransferase activity with iron and antioxidant levels in the United States

BACKGROUND & AIMS

Oxidative stress is thought to play a role in liver injury. Hepatic iron may promote liver injury, whereas antioxidant vitamins and minerals may inhibit it, but few clinical studies have examined such relationships. We analyzed the associations of serum iron measures and antioxidant concentrations with abnormal serum alanine transaminase (ALT) activity in a large, national, population-based study.

METHODS

A total of 13,605 adult participants in the third U.S. National Health and Nutrition Examination Survey (NHANES III), 1988-1994, underwent phlebotomy. Exclusions included excessive alcohol consumption, hepatitis B and C, and iron overload.

RESULTS

Elevated ALT levels were found in 3.1% of the population. In univariate analysis, factors associated with abnormal ALT levels (P < 0.05) included higher transferrin saturation and iron and selenium concentrations, and lower vitamin C, alpha and beta carotene, and lutein/zeaxanthin concentrations. In multivariate logistic regression analyses, elevated ALT level was associated positively with increasing deciles of transferrin saturation (odds ratio [OR] per decile, 1.10; 95% confidence interval [CI], 1.03-1.18) and iron concentration (OR, 1.13; 95% CI, 1.06-1.21). Abnormal ALT level was associated negatively with increasing deciles of alpha carotene (OR, 0.82; 95% CI, 0.72-0.94), beta carotene (OR, 0.91; 95% CI, 0.86-0.96), beta cryptoxanthin (OR, 0.91; 95% CI, 0.84-0.99), lutein/zeaxanthin (OR, 0.90; 95% CI, 0.84-0.96), and a variable combining the 5 carotenoid measures (OR, 0.89; 95% CI, 0.83-0.95). Vitamin C was associated inversely, but only at the highest concentrations.

CONCLUSIONS

In this large, national, population-based study, the risk for apparent liver injury was associated with increased iron and decreased antioxidants, particularly carotenoids.

Iron as a co-morbid factor in nonhemochromatotic liver disease

Heavy iron overload, in both primary and secondary hemochromatosis, may cause fibrosis of parenchymal organs, especially the liver. The toxicity of iron is believed to involve increased oxidative stress, with iron-catalyzed production of reactive oxygen species causing oxidative damage to lipids, proteins, and nucleic acids. Lesser degrees of hepatic iron deposition are also associated with, and seem to be risk factors for, certain nonhemochromatotic liver diseases. Porphyria cutanea tarda is associated with hepatic iron overload and responds to iron-reduction therapy. Results of recent studies have demonstrated high prevalences (about 60%-80%) of HFE gene mutations in patients with porphyria cutanea tarda. Chronic hepatitis C is another risk factor for porphyria cutanea tarda. Other recent evidence indicates that the prevalence of HFE gene mutations is increased in chronic viral hepatitis and that patients with chronic hepatitis C harboring especially the C282Y mutation are more likely to suffer from advanced hepatic fibrosis or cirrhosis and to do so at younger ages. A role for modest iron overload in increasing severity of alcohol-induced liver disease has been well established from results of experimental studies. However, it is currently unresolved whether mild-to-moderate hepatic iron deposition or heterozygosity for the C282Y mutation plays a role in human alcoholic liver disease or in nonalcoholic fatty liver disease or nonalcoholic steatohepatitis. There is persuasive evidence that iron reduction decreases insulin resistance, and it likely also decreases oxidative stress, two key pathogenic features of nonalcoholic fatty liver disease/nonalcoholic steatohepatitis. Iron loading has also been described after portosystemic shunts and in end-stage liver disease.