Liver disease in Europe

Bioassay guided fractionation, isolation and characterization of hepatotherapeutic 1, 3-di-ortho-galloyl quinic acid from the methanol extract of the leaves of Pterocarpus santalinoides

ETHNOPHARMACOLOGICAL RELEVANCE

Leaf extracts of Pterocarpus santalinoides DC are traditionally used to ameliorate ageing-related ailments such as heart and liver diseases, and have been reported to be protective against toxic injuries to the liver.

AIM OF THE STUDY

This study aimed to isolate and characterize the hepatoprotective/hepatotherapeutic principle in the methanol leaf extract of P. santalinoides.

MATERIALS AND METHODS

Fresh leaves of P. santalinoides were dried under shade and ground into powder. The ground leaves (2 Kg) were extracted with 80% methanol by maceration. Fractionation was carried out using column and thin layer chromatography techniques. Bioassay of fractions and sub-fractions was done using carbon tetrachloride (CCl₄)-induced hepatotoxicity model in albino rats. Phytochemical analysis was carried out on the active compound. Characterization and structural elucidation of the active compound using high performance liquid chromatography and nuclear magnetic resonance spectroscopy was done.

RESULTS

Extraction yielded 260 g dry extract. Six fractions (F1, F2, F3, F4, F5 and F6) were obtained after column and thin layer chromatography, with F6 (R_f = 0.78; Yield = 2.13 g) being the most active hepatotherapeutic fraction that significantly (p < 0.05) lowered serum ALT activity and increased serum albumin levels in CCl₄-induced hepatopathy in albino rats. Further separation of F6 yielded four sub-fractions (F6_1, F6₂, F6₃ and F6₄), of which F6₁ with an R_f of 0.85 and a yield of 30.0 mg was isolated as the active hepatotherapeutic compound. Stiasny and ferric chloride test of F6₁ showed the presence of tannins in the fraction. Characterization of F6₁ revealed 1, 3-di-ortho-galloyl quinic acid.

CONCLUSION

The hepatoprotective/hepatotherapeutic principle in the methanol extract of the leaves of P. santalinoides was identified as 1, 3-di-ortho-galloyl quinic acid.

Latest developments in the imaging of fibrotic liver disease

According to the World Health Organization, liver cirrhosis accounted for 1.8% of all deaths in Europe, causing about 170,000 deaths per year. Approximately 29 million persons in the EU suffer from chronic liver disease and this trend is on the rise. Liver disease is the EU's fifth most common cause of death accounting for at least one in six deaths. Early detection and monitoring of fibrosis has the potential to direct management of these chronic liver diseases and avert morbidity and mortality. Although the available techniques are in their infancy and the very early stages of fibrosis are difficult to detect, there have been significant advances in imaging over the last decade that has resulted in the use of these new imaging techniques being introduced into the patient pathway. This review explores the accuracies of these imaging techniques, their role in the management of patients, and the potential for the future.

TLR3/4 signaling is mediated via the NFκB-CXCR4/7 pathway in human alcoholic hepatitis and non-alcoholic steatohepatitis which formed Mallory-Denk bodies

Activation of Toll-like receptor (TLR) signaling which stimulates inflammatory and proliferative pathways is the key element in the pathogenesis of Mallory-Denk bodies (MDBs) in mice fed DDC. However, little is known as to how TLR signaling is regulated in MDB formation during chronic liver disease development. The first systematic study of TLR signaling pathway transcript regulation in human archived formalin-fixed, paraffin-embedded (FFPE) liver biopsies with MDB formation is presented here. When compared to the activation of Toll-like signaling in alcoholic hepatitis (AH) and non-alcoholic steatohepatitis (NASH) patients, striking similarities and obvious differences were observed. Similar TLRs (TLR3 and TLR4, etc.), TLR downstream adaptors (MyD88 and TRIF, etc.) and transcript factors (NFκB and IRF7, etc.) were all upregulated in the patients' livers. MyD88, TLR3 and TLR4 were significantly induced in the livers of AH and NASH compared to normal subjects, while TRIF and IRF7 mRNA were only slightly upregulated in AH patients. This is a different pathway from the induction of the TLR4-MyD88-independent pathway in the AH and NASH patients with MDBs present. Importantly, chemokine receptor 4 and 7 (CXCR4/7) mRNAs were found to be induced in the patients livers in FAT10 positive hepatocytes. The CXCR7 pathway was significantly upregulated in patients with AH and the CXCR4 was markedly upregulated in patients with NASH, indicating that CXCR4/7 is crucial in liver MDB formation. This data constitutes the first demonstration of the upregulation of the MyD88-dependent TLR4/NFκB pathway in AH and NASH where MDBs formed, via the NFκB-CXCR4/7 pathway, and provides further insight into the mechanism of MDB formation in human liver diseases.

Differences in innate immune signaling between alcoholic and non-alcoholic steatohepatitis

The similar histopathological characteristics of alcoholic steatohepatitis (ASH) and non-alcoholic steatohepatitis (NASH), and the crucial role of the innate immune response in both conditions may lead to the assumption that ASH and NASH represent the same pathophysiological entities caused by different risk factors. In this review paper, we elaborate on the pathophysiological differences between these two entities and highlight the disease-specific involvement of signaling molecules downstream of the Toll-like receptor 4, and the differential mechanism by which the inflammasome contributes to ASH versus NASH. Our findings emphasize that ASH and NASH have disease-specific mechanisms and therefore represent distinct biological entities. Further studies are needed to dissect the emerging differences in pathogenesis of these two conditions.

Toll-like receptors in liver disease

Activation of inflammatory signaling pathways is of central importance in the pathogenesis of alcoholic liver disease (ALD) and nonalcoholic steatohepatitis (NASH). Recent studies demonstrated that Toll-like receptors, the sensors of microbial and endogenous danger signals, are expressed and activated in innate immune cells as well as in parenchymal cells in the liver and thereby contribute to ALD and NASH. In this review, we emphasize the importance of gut-derived endotoxin and its recognition by TLR4 in the liver. The significance of TLR-induced intracellular signaling pathways and cytokine production as well as the contribution of individual cell types to the inflammation is evaluated. The contribution of TLR signaling to the induction of liver fibrosis and to the progression of liver pathology mediated by viral pathogens is reviewed in the context of ALD and NASH.

Galectin-3-binding protein: a serological and histological assessment in accordance with hepatitis C-related liver fibrosis

OBJECTIVES

Invasive liver biopsy is the current method for the assessment of liver fibrosis. In search of noninvasive alternatives, galectin-3-binding protein (G3BP) was introduced as a candidate-marker of hepatitis C-related fibrosis based on serum proteomics. We investigated the role of G3BP as a single-marker of significant fibrosis and cirrhosis by serology and histology and studied the effect of glycosylation on antibody-affinity in hepatitis C and alcoholic cirrhosis.

METHODS

Sera and available biopsies of hepatitis C patients with various fibrosis-grades and patients with alcoholic cirrhosis were used for G3BP-measurements by enzyme-linked immunosorbent assay and immunohistochemistry, respectively. Glycosylation-effect was analyzed by western blot. Data was analyzed in accordance to fibrosis.

RESULTS

G3BP-levels (mean+/-standard deviation) were increased during cirrhosis (22.7+/-10.1 microg/ml) compared to mild (11.3+/-6.4 microg/ml) and moderate fibrosis (13.4+/-8.3 microg/ml) (P<0.001; P=0.004, respectively). Receiver operator characteristic curves showed areas under the curve of 0.68, 0.75 and 0.81 for detection of significant fibrosis, severe fibrosis, and cirrhosis, respectively. Similar findings in hepatic G3BP expression were obtained, in which cirrhosis was associated with diffuse, parenchymal expression (P=0.002). The observed difference between hepatitis C and alcoholic cirrhosis (13.5+/-9.0 microg/ml) (P=0.009) could not be explained by glycosylation.

CONCLUSION

Our recent findings confirm our initial proteome results on serological and histological level as well as the role of G3BP as a marker of hepatitis C-related fibrosis, especially cirrhosis. Implication of this protein in future multi-marker study should be considered.

The burden and recent epidemiological changes of the main chronic liver diseases in a Greek referral tertiary centre

OBJECTIVE

To investigate the burden and recent epidemiological changes of the main chronic liver diseases in a Greek referral tertiary centre.

METHODS

We evaluated the main epidemiological characteristics of 1080 consecutive adult patients, seen at our outpatient liver clinic between 2002 and 2007, with chronic hepatitis B (HBV) and/or C (HCV) virus infection, alcoholic liver disease (ALD) or nonalcoholic fatty liver disease (NAFLD). Our patient population was divided into two groups in relation to the time of the first visit (period A: 2002-2004, period B: 2005-2007).

RESULTS

Among our patient population, 86.1% had chronic HBV and/or HCV infection (chronic HCV alone: 44.9%), 9.2% NAFLD and 4.8% ALD. From period A to B, there was a decrease in chronic HBV cases (44.0 vs. 37.8%, P = 0.045) with immigrants being responsible for 35.5% of them and being more frequent in period B than A (39.7 vs. 30.5%, P = 0.046). In chronic hepatitis B, hepatitis B e antigen-positive patients, who were more frequent immigrants compared with hepatitis B e antigen-negative patients (65.5 vs. 29.5%, P = 0.001), increased from period A to B (8.0 vs. 17.6%, P = 0.045). Intravenous drug use was reported by 41.2% of HCV patients with its proportion increasing from period A to B (32.5 vs. 47.4%, P = 0.002). Decompensated cirrhosis was present in 67, 10, 11 and 3% of patients with ALD, HBV, HCV and NAFLD, respectively.

CONCLUSION

At Greek tertiary centres, chronic viral hepatitis remains responsible for most chronic liver disease cases, but its epidemiology is changing owing to immigrants and intravenous drug users.

The global impact of hepatic fibrosis and end-stage liver disease

Hepatic fibrosis is an integral part in the progression of chronic liver disease, ultimately leading to cirrhosis and hepatocellular carcinoma. Globally, alcohol consumption, hepatitis B (HBV) and hepatitis C (HCV) have been the main causes of cirrhosis. More recently, the increasing prevalence of obesity and the metabolic syndrome has resulted in increasing incidence of cirrhosis secondary to nonalcoholic fatty liver disease (NAFLD), especially in developed countries. Chronic liver disease and cirrhosis are important causes of morbidity and mortality in the world. Moreover, the burden of chronic liver disease is projected to increase, due in part to the increasing prevalence of end-stage liver disease and HCC secondary to NAFLD and HCV.

Proteomics in liver fibrosis is more than meets the eye

Liver fibrosis is a serious health issue for many liver patients and is currently diagnosed using liver biopsy. The erroneous nature of this technique urges the search for better, noninvasive alternatives. In this regard, proteomics has been described as a useful biomarker discovery tool and has become increasingly applied in the study of liver fibrosis. Experimental and clinical studies have already provided deeper insights in the molecular pathways of liver fibrosis and even confirmed previous findings. Recent advances in proteomic strategies and tools enable multiple fractionation, multiple protein identifications and parallel analyses of multiple samples. Despite its increasing popularity, proteomics still faces certain pitfalls concerning preanalytical variability, protein coverage and statistic reliability. Proteomics is still evolving, but will undoubtedly contribute to a better understanding of the basics of the pathology and certainly offer opportunities in liver fibrosis diagnostics and therapeutics.

Liver biochemistry profile, significance and endoscopic management of biliary tract complications post orthotopic liver transplantation

AIM: To correlate the significance of liver biochemical tests in diagnosing post orthotopic liver transplantation (OLT) biliary complications and to study their profile before and after endoscopic therapy.

METHODS: Patients who developed biliary complications were analysed in detail for the clinical information, laboratory tests, treatment offered, response to it, follow up and outcomes. The profile of liver enzymes was determined. The safety, efficacy and outcomes of endoscopic retrograde cholangiography (ERC) were also analysed.

RESULTS: 40 patients required ERC for 70 biliary complications. GGT was found to be > 3 times (388.1 ± 70.9 U/mL vs 168.5 ± 34.2 U/L, P = 0.007) and SAP > 2 times (345.1 ± 59.1 U/L vs 152.7 ± 21.4 U/L, P = 0.003) the immediate post OLT values. Most frequent complication was isolated anastomotic strictures in 28 (40%). Sustained success was achieved in 26 (81%) patients.

CONCLUSION: Biliary complications still remain an important problem post OLT. SAP and GGT can be used as early, non-invasive markers for diagnosis and also to assess the adequacy of therapy. Endoscopic management is usually effective in treating the majority of these biliary complications.

Increased protein glycation in cirrhosis and therapeutic strategies to prevent it

Glycation of liver proteins by reactive aldehydes formed from the metabolism of ethanol and lipid peroxidation has been implicated in the development of both alcoholic and nonalcoholic liver cirrhosis. Modified proteins are targeted to the proteasome for proteolysis. Release of glycation-free adducts into the circulation may provide a diagnostic "signature" of hepatic protein damage. We quantitatively screened protein glycation, oxidation, and nitrosation adduct residues and free adducts in portal, hepatic, and peripheral venous blood plasma of cirrhotic patients; we also screened the hepatic and peripheral venous blood plasma of control subjects by liquid chromatography-mass spectrometry. There was a remarkable 14-16-fold increase of glyoxal-derived, hydroimidazolone-free adduct in portal and hepatic venous plasma of cirrhotic patients with respect to normal controls. There was only a twofold increase of glycation adduct residues in plasma proteins in cirrhotic patients, which was attributed mainly to decreased albumin turnover. Therapeutic strategies to decrease dicarbonyl compounds may be beneficial, such as dicarbonyl scavengers, glutathione repleting agents, and high-dose thiamine therapy.