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Insights into the Management of Chronic Hepatitis in Children-From Oxidative Stress to Antioxidant Therapy. Int J Mol Sci 2024; 25:3908. [PMID: 38612717 PMCID: PMC11011982 DOI: 10.3390/ijms25073908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 03/22/2024] [Accepted: 03/29/2024] [Indexed: 04/14/2024] Open
Abstract
Recent research has generated awareness of the existence of various pathophysiological pathways that contribute to the development of chronic diseases; thus, pro-oxidative factors have been accepted as significant contributors to the emergence of a wide range of diseases, from inflammatory to malignant. Redox homeostasis is especially crucial in liver pathology, as disturbances at this level have been linked to a variety of chronic diseases. Hepatitis is an umbrella term used to describe liver inflammation, which is the foundation of this disease regardless of its cause. Chronic hepatitis produces both oxidative stress generated by hepatocyte inflammation and viral inoculation. The majority of hepatitis in children is caused by a virus, and current studies reveal that 60-80% of cases become chronic, with many young patients still at risk of advancing liver damage. This review intends to emphasize the relevance of understanding these pathological redox pathways, as well as the need to update therapeutic strategies in chronic liver pathology, considering the beneficial effects of antioxidants.
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Metabolic Dysfunction-Associated Fatty Liver Disease and Chronic Viral Hepatitis: The Interlink. Pathogens 2024; 13:68. [PMID: 38251375 PMCID: PMC10821334 DOI: 10.3390/pathogens13010068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 01/05/2024] [Accepted: 01/07/2024] [Indexed: 01/23/2024] Open
Abstract
Metabolic dysfunction-associated fatty liver disease (MAFLD) has now affected nearly one-third of the global population and has become the number one cause of chronic liver disease in the world because of the obesity pandemic. Chronic hepatitis resulting from hepatitis B virus (HBV) and hepatitis C virus (HCV) remain significant challenges to liver health even in the 21st century. The co-existence of MAFLD and chronic viral hepatitis can markedly alter the disease course of individual diseases and can complicate the management of each of these disorders. A thorough understanding of the pathobiological interactions between MAFLD and these two chronic viral infections is crucial for appropriately managing these patients. In this comprehensive clinical review, we discuss the various mechanisms of chronic viral hepatitis-mediated metabolic dysfunction and the impact of MAFLD on the progression of liver disease.
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The Role of Glutathione in Selected Viral Diseases. Antioxidants (Basel) 2023; 12:1325. [PMID: 37507865 PMCID: PMC10376684 DOI: 10.3390/antiox12071325] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/20/2023] [Accepted: 06/21/2023] [Indexed: 07/30/2023] Open
Abstract
During inflammatory processes, immunocompetent cells are exposed to substantial amounts of free radicals and toxic compounds. Glutathione is a cysteine-containing tripeptide that is an important and ubiquitous antioxidant molecule produced in human organs. The intracellular content of GSH regulates the detoxifying capacity of cells, as well as the inflammatory and immune response. GSH is particularly important in the liver, where it serves as the major non-protein thiol involved in cellular antioxidant defense. There are numerous causes of hepatitis. The inflammation of the liver can be caused by a variety of infectious viruses. The relationship between oxidative stress and the hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis E virus (HEV) infection is not fully known. The aim of this study was to examine the relationship between hepatotropic viruses and glutathione status, including reduced glutathione (GSH) and oxidized glutathione (GSSG), as well as antioxidant enzymes, e.g., glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST) in liver diseases.
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Therapeutic mechanisms and beneficial effects of non-antidiabetic drugs in chronic liver diseases. Clin Mol Hepatol 2022; 28:425-472. [PMID: 35850495 PMCID: PMC9293616 DOI: 10.3350/cmh.2022.0186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 06/29/2022] [Indexed: 11/05/2022] Open
Abstract
The global burden of chronic liver disease (CLD) is substantial. Due to the limited indication of and accessibility to antiviral therapy in viral hepatitis and lack of effective pharmacological treatment in nonalcoholic fatty liver disease, the beneficial effects of antidiabetics and non-antidiabetics in clinical practice have been continuously investigated in patients with CLD. In this narrative review, we focused on non-antidiabetic drugs, including ursodeoxycholic acid, silymarin, dimethyl4,4'-dimethoxy-5,6,5',6'-dimethylenedixoybiphenyl-2,2'-dicarboxylate, L-ornithine L-aspartate, branched chain amino acids, statin, probiotics, vitamin E, and aspirin, and summarized their beneficial effects in CLD. Based on the antioxidant, anti-inflammatory properties, and regulatory functions in glucose or lipid metabolism, several non-antidiabetic drugs have shown beneficial effects in improving liver histology, aminotransferase level, and metabolic parameters and reducing risks of hepatocellular carcinoma and mortality, without significant safety concerns, in patients with CLD. Although the effect as the centerpiece management in patients with CLD is not robust, the use of these non-antidiabetic drugs might be potentially beneficial as an adjuvant or combined treatment strategy.
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Metabolic and nutritional triggers associated with increased risk of liver complications in SARS-CoV-2. World J Hepatol 2022; 14:80-97. [PMID: 35126841 PMCID: PMC8790394 DOI: 10.4254/wjh.v14.i1.80] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/28/2021] [Accepted: 12/23/2021] [Indexed: 02/06/2023] Open
Abstract
Obesity, diabetes, cardiovascular and respiratory diseases, cancer and smoking are risk factors for negative outcomes in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which can quickly induce severe respiratory failure in 5% of cases. Coronavirus disease-associated liver injury may occur during progression of SARS-CoV-2 in patients with or without pre-existing liver disease, and damage to the liver parenchyma can be caused by infection of hepatocytes. Cirrhosis patients may be particularly vulnerable to SARS-CoV-2 if suffering with cirrhosis-associated immune dysfunction. Furthermore, pharmacotherapies including macrolide or quinolone antibiotics and steroids can also induce liver damage. In this review we addressed nutritional status and nutritional interventions in severe SARS-CoV-2 liver patients. As guidelines for SARS-CoV-2 in intensive care (IC) specifically are not yet available, strategies for management of sepsis and SARS are suggested in SARS-CoV-2. Early enteral nutrition (EN) should be started soon after IC admission, preferably employing iso-osmolar polymeric formula with initial protein content at 0.8 g/kg per day progressively increasing up to 1.3 g/kg per day and enriched with fish oil at 0.1 g/kg per day to 0.2 g/kg per day. Monitoring is necessary to identify signs of intolerance, hemodynamic instability and metabolic disorders, and transition to parenteral nutrition should not be delayed when energy and protein targets cannot be met via EN. Nutrients including vitamins A, C, D, E, B6, B12, folic acid, zinc, selenium and ω-3 fatty acids have in isolation or in combination shown beneficial effects upon immune function and inflammation modulation. Cautious and monitored supplementation up to upper limits may be beneficial in management strategies for SARS-CoV-2 liver patients.
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Changes in Glutathione Content in Liver Diseases: An Update. Antioxidants (Basel) 2021; 10:364. [PMID: 33670839 PMCID: PMC7997318 DOI: 10.3390/antiox10030364] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 02/22/2021] [Accepted: 02/24/2021] [Indexed: 02/07/2023] Open
Abstract
Glutathione (GSH), a tripeptide particularly concentrated in the liver, is the most important thiol reducing agent involved in the modulation of redox processes. It has also been demonstrated that GSH cannot be considered only as a mere free radical scavenger but that it takes part in the network governing the choice between survival, necrosis and apoptosis as well as in altering the function of signal transduction and transcription factor molecules. The purpose of the present review is to provide an overview on the molecular biology of the GSH system; therefore, GSH synthesis, metabolism and regulation will be reviewed. The multiple GSH functions will be described, as well as the importance of GSH compartmentalization into distinct subcellular pools and inter-organ transfer. Furthermore, we will highlight the close relationship existing between GSH content and the pathogenesis of liver disease, such as non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), chronic cholestatic injury, ischemia/reperfusion damage, hepatitis C virus (HCV), hepatitis B virus (HBV) and hepatocellular carcinoma. Finally, the potential therapeutic benefits of GSH and GSH-related medications, will be described for each liver disorder taken into account.
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Current Trends of Essential Trace Elements in Patients with Chronic Liver Diseases. Nutrients 2020; 12:nu12072084. [PMID: 32674425 PMCID: PMC7400835 DOI: 10.3390/nu12072084] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/16/2020] [Accepted: 06/29/2020] [Indexed: 02/06/2023] Open
Abstract
Essential trace elements play crucial roles in the maintenance of health, since they are involved in many metabolic pathways. A deficiency or an excess of some trace elements, including zinc, selenium, iron, and copper, frequently causes these metabolic disorders such as impaired glucose tolerance and dyslipidemia. The liver largely regulates most of the metabolism of trace elements, and accordingly, an impairment of liver functions can result in numerous metabolic disorders. The administration or depletion of these trace elements can improve such metabolic disorders and liver dysfunction. Recent advances in molecular biological techniques have helped to elucidate the putative mechanisms by which liver disorders evoke metabolic abnormalities that are due to deficiencies or excesses of these trace elements. A genome-wide association study revealed that a genetic polymorphism affected the metabolism of a specific trace element. Gut dysbiosis was also responsible for impairment of the metabolism of a trace element. This review focuses on the current trends of four trace elements in chronic liver diseases, including chronic hepatitis, liver cirrhosis, nonalcoholic fatty liver disease, and autoimmune liver diseases. The novel mechanisms by which the trace elements participated in the pathogenesis of the chronic liver diseases are also mentioned.
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Oxidative stress, a trigger of hepatitis C and B virus-induced liver carcinogenesis. Oncotarget 2018; 8:3895-3932. [PMID: 27965466 PMCID: PMC5354803 DOI: 10.18632/oncotarget.13904] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 12/05/2016] [Indexed: 12/11/2022] Open
Abstract
Virally induced liver cancer usually evolves over long periods of time in the context of a strongly oxidative microenvironment, characterized by chronic liver inflammation and regeneration processes. They ultimately lead to oncogenic mutations in many cellular signaling cascades that drive cell growth and proliferation. Oxidative stress, induced by hepatitis viruses, therefore is one of the factors that drives the neoplastic transformation process in the liver. This review summarizes current knowledge on oxidative stress and oxidative stress responses induced by human hepatitis B and C viruses. It focuses on the molecular mechanisms by which these viruses activate cellular enzymes/systems that generate or scavenge reactive oxygen species (ROS) and control cellular redox homeostasis. The impact of an altered cellular redox homeostasis on the initiation and establishment of chronic viral infection, as well as on the course and outcome of liver fibrosis and hepatocarcinogenesis will be discussed The review neither discusses reactive nitrogen species, although their metabolism is interferes with that of ROS, nor antioxidants as potential therapeutic remedies against viral infections, both subjects meriting an independent review.
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S-adenosyl-L-methionine modifies antioxidant-enzymes, glutathione-biosynthesis and methionine adenosyltransferases-1/2 in hepatitis C virus-expressing cells. World J Gastroenterol 2016; 22:3746-3757. [PMID: 27076759 PMCID: PMC4814737 DOI: 10.3748/wjg.v22.i14.3746] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Revised: 02/14/2016] [Accepted: 03/02/2016] [Indexed: 02/06/2023] Open
Abstract
AIM: To elucidate the mechanism(s) by which S-adenosyl-L-methionine (SAM) decreases hepatitis C virus (HCV) expression.
METHODS: We examined the effects of SAM on viral expression using an HCV subgenomic replicon cell culture system. Huh7 HCV-replicon cells were treated with 1 mmol/L SAM for different times (24-72 h), then total RNA and proteins were isolated. cDNA was synthesized and real time-PCR was achieved to quantify HCV-RNA, superoxide dismutase 1 and 2 (SOD-1, SOD-2) catalase, thioredoxin 1, methionine adenosyltransferase 1A and 2A (MAT1A, MAT2A) expression, and GAPDH and RPS18 as endogenous genes. Expression of cellular and viral protein was evaluated by western-blot analysis using antibodies vs HCV-NS5A, SOD-1, SOD-2, catalase, thioredoxin-1, MAT1A, MAT2A, GAPDH and actin. Total glutathione levels were measured at different times by Ellman’s recycling method (0-24 h). Reactive oxidative species (ROS) levels were quantified by the dichlorofluorescein assay (0-48 h); Pyrrolidin dithiocarbamate (PDTC) was tested as an antioxidant control and H2O2 as a positive oxidant agent.
RESULTS: SAM exposition decreased HCV-RNA levels 50%-70% compared to non-treated controls (24-72 h). SAM induced a synergic antiviral effect with standard IFN treatment but it was independent of IFN signaling. In addition, 1 mmol/L SAM exposition did not modify viral RNA stability, but it needs cellular translation machinery in order to decrease HCV expression. Total glutathione levels increased upon SAM treatment in HCV-replicon cells. Transcriptional antioxidant enzyme expression (SOD-1, SOD-2 and thioredoxin-1) was increased at different times but interestingly, there was no significant change in ROS levels upon SAM treatment, contrary to what was detected with PDTC treatment, where an average 40% reduction was observed in exposed cells. There was a turnover from MAT1A/MAT2A, since MAT1A expression was increased (2.5 fold-times at 48 h) and MAT2A was diminished (from 24 h) upon SAM treatment at both the transcriptional and translational level.
CONCLUSION: A likely mechanism(s) by which SAM diminish HCV expression could involve modulating antioxidant enzymes, restoring biosynthesis of glutathione and switching MAT1/MAT2 turnover in HCV expressing cells.
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Mangosteen xanthones suppress hepatitis C virus genome replication. Virus Genes 2014; 49:208-22. [PMID: 24986787 DOI: 10.1007/s11262-014-1098-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 06/16/2014] [Indexed: 02/06/2023]
Abstract
Hepatitis C virus (HCV) is a hepatotropic single-stranded RNA virus. HCV infection is causally linked with development of liver cirrhosis and hepatocellular carcinoma. Enhanced production of reactive oxygen species by HCV has been implicated to play an important role in HCV-induced pathogenesis. Mangosteen has been widely used as a traditional medicine as well as a dietary supplement ,thanks to its powerful anti-oxidant effect. In the present study, we demonstrated that the ethanol extract from mangosteen fruit peels (MG-EtOH) is able to block HCV genome replication using HCV genotype 1b Bart79I subgenomic (EC50 5.1 μg/mL) and genotype 2a J6/JFH-1 infectious replicon systems (EC50 3.8 μg/mL). We found that inhibition of HCV replication by MG-EtOH led to subsequent down-regulation of expression of HCV proteins. Interestingly, MG-EtOH exhibited a modest inhibitory effect on in vitro RNA polymerase activity of NS5B. Among a number of xanthones compounds identified within this MG-EtOH, we discovered α-MG (EC50 6.3 μM) and γ-MG (EC50 2.7 μM) as two major single molecules responsible for suppression of HCV replication. This finding will provide a valuable molecular basis to further develop mangosteen as an important dietary supplement to combat HCV-induced liver diseases.
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Bush Sophora Root polysaccharide and its sulfate can scavenge free radicals resulted from duck virus hepatitis. Int J Biol Macromol 2014; 66:186-93. [DOI: 10.1016/j.ijbiomac.2014.02.038] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 02/13/2014] [Accepted: 02/17/2014] [Indexed: 12/18/2022]
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Complementary and alternative medications in hepatitis C infection. World J Hepatol 2014; 6:9-16. [PMID: 24653790 PMCID: PMC3953807 DOI: 10.4254/wjh.v6.i1.9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 12/22/2013] [Accepted: 01/06/2014] [Indexed: 02/06/2023] Open
Abstract
Chronic hepatitis C (CHC) infection affects almost 3% of the global population and can lead to cirrhosis, liver failure, and hepatocellular carcinoma in a significant number of those infected. Until recently, the only treatments available were pegylated interferon and ribavirin, which traditionally were not very effective and have considerable side effects. For this reason, interest in complementary and alternative medications (CAM) in the management of hepatitis C has been investigated. Some CAM has demonstrated therapeutic potential in chronic hepatitis C treatment. Unfortunately, some CAM has been shown to have the potential to cause drug-induced liver injury. This article will review and evaluate many of the natural molecules that interact with the hepatitis C virus (HCV) life cycle and discuss their potential use and safety in HCV therapy, as well as highlight some important interactions between medical and complementary treatments.
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An evidence-based systematic review of vitamin A by the natural standard research collaboration. J Diet Suppl 2013; 9:299-416. [PMID: 23157584 DOI: 10.3109/19390211.2012.736721] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
An evidence-based systematic review of vitamin A by the Natural Standard Research Collaboration consolidates the safety and efficacy data available in the scientific literature using a validated and reproducible grading rationale. This paper includes written and statistical analysis of clinical trials, plus a compilation of expert opinion, folkloric precedent, history, pharmacology, kinetics/dynamics, interactions, adverse effects, toxicology, and dosing.
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Abstract
Hepatitis C virus (HCV) is the etiological agent accounting for chronic liver disease in approximately 2-3% of the population worldwide. HCV infection often leads to liver fibrosis and cirrhosis, various metabolic alterations including steatosis, insulin and interferon resistance or iron overload, and development of hepatocellular carcinoma or non-Hodgkin lymphoma. Multiple molecular mechanisms that trigger the emergence and development of each of these pathogenic processes have been identified so far. One of these involves marked induction of a reactive oxygen species (ROS) in infected cells leading to oxidative stress. To date, markers of oxidative stress were observed both in chronic hepatitis C patients and in various in vitro systems, including replicons or stable cell lines expressing viral proteins. The search for ROS sources in HCV-infected cells revealed several mechanisms of ROS production and thus a number of cellular proteins have become targets for future studies. Furthermore, during last several years it has been shown that HCV modifies antioxidant defense mechanisms. The aim of this review is to summarize the present state of art in the field and to try to predict directions for future studies.
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The effect of increased oxidative stress and ferritin in reducing the effectiveness of therapy in chronic hepatitis C patients. Clin Biochem 2012; 45:1389-93. [PMID: 22760008 DOI: 10.1016/j.clinbiochem.2012.06.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 06/20/2012] [Accepted: 06/22/2012] [Indexed: 01/31/2023]
Abstract
BACKGROUND/AIM Chronic hepatitis C (CHC) patients have higher oxidative stress and ferritin than healthy individuals. However, the level of oxidative stress in CHC patients during treatment with peginterferon alpha-2a and ribavirin is not clear. The aims of our study are to investigate changes of thiobarbituric acid reactive substances (TBARS; indicated oxidative stress), total antioxidant status (TAS) and ferritin in CHC patients during therapy and to identify the correlation of these factors and the effectiveness of therapy. METHODS Sixty CHC patients were selected and were prescribed 180 μg of peginteferon alpha-2a once a week and a daily dose of 1000 to 1200 mg ribavirin for 6 months. Throughout the treatment course, blood samples were taken to determine TBARS, TAS, and liver inflammation profiles including ferritin, aspartate transaminase (AST) and alanine transaminase (ALT). RESULTS The level of TBARS increased before the 12th week of therapy. Additionally, the levels of TBARS were higher in non-rapid virological response (RVR) patients compared with RVR (p<0.01) in baseline and therapy at the 24th week. TAS was lower during therapy than at baseline. Levels of TAS were significantly higher in sustained virological response (SVR) patients than in non-SVR (p<0.01) in the 4th week post-therapy. We also found a positive correlation between the level of ferritin and liver inflammation during treatment (p<0.01). The levels of ferritin and ALT were lower in SVR than in non-SVR patients in the 4th week of post-therapy (p<0.01). CONCLUSIONS This study indicated that decreased ferritin, decreased TBARS and increased TAS status may improve the efficacy of treatment.
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Cu/Zn superoxide dismutase (SOD1) induction is implicated in the antioxidative and antiviral activity of acetylsalicylic acid in HCV-expressing cells. Am J Physiol Gastrointest Liver Physiol 2012; 302:G1264-73. [PMID: 22442156 DOI: 10.1152/ajpgi.00237.2011] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We evaluated the participation of oxidative stress in the negative regulation of hepatitis C virus (HCV)-RNA induced by acetylsalicylic acid (ASA). We used the HCV subgenomic replicon cell system that stably expresses HCV-nonstructural proteins (Huh7 HCV replicon cells) and the parental cell line. Cells were exposed to 4 mM ASA at different times (12-72 h), and pyrrolidine dithiocarbamate (PDTC) was used as an antioxidant control. Reactive oxygen species (ROS) production, oxidized protein levels, cytosolic superoxide dismutase (Cu/Zn-SOD), and glutathione peroxidase (GPx) activity were measured to evaluate oxidative stress. In addition, viral RNA and prostaglandin (PGE(2)) levels were determined. We observed that ASA treatment decreased ROS production and oxidized protein levels in a time-dependent fashion in both parental and HCV replicon cells with a greater extent in the latter. Similar results were found with PDTC exposure. Average GPx activity was decreased, whereas a striking increase was observed in average cytosolic SOD activity at 48 and 72 h in both cells exposed to ASA, compared with untreated cells. HCV replicon cells showed higher levels of Cu/Zn-SOD expression (mRNA and protein) with ASA treatment (48 and 72 h), whereas NS5A protein levels showed decreased expression. In addition, we found that inhibition of SOD1 expression reversed the effect of ASA. Interestingly, PDTC downregulated HCV-RNA expression (55%) and PGE(2) (60%) levels, imitating ASA exposure. These results suggest that ASA treatment could reduce cellular oxidative stress markers and modify Cu/Zn-SOD expression, a phenomenon that may contribute to the mechanisms involved in HCV downregulation.
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Oxidative stress, endogenous antioxidants, alcohol, and hepatitis C: pathogenic interactions and therapeutic considerations. Free Radic Biol Med 2012; 52:1135-50. [PMID: 22306508 DOI: 10.1016/j.freeradbiomed.2012.01.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 01/04/2012] [Accepted: 01/12/2012] [Indexed: 12/16/2022]
Abstract
Hepatitis C virus (HCV) is a blood-borne pathogen that was identified as an etiologic agent of non-A, non-B hepatitis in 1989. HCV is estimated to have infected at least 170 million people worldwide. The majority of patients infected with HCV do not clear the virus and become chronically infected, and chronic HCV infection increases the risk for hepatic steatosis, cirrhosis, and hepatocellular carcinoma. HCV induces oxidative/nitrosative stress from multiple sources, including inducible nitric oxide synthase, the mitochondrial electron transport chain, hepatocyte NAD(P)H oxidases, and inflammation, while decreasing glutathione. The cumulative oxidative burden is likely to promote both hepatic and extrahepatic conditions precipitated by HCV through a combination of local and more distal effects of reactive species, and clinical, animal, and in vitro studies strongly point to a role of oxidative/nitrosative stress in HCV-induced pathogenesis. Oxidative stress and hepatopathogenesis induced by HCV are exacerbated by even low doses of alcohol. Alcohol and reactive species may have other effects on hepatitis C patients such as modulation of the host immune system, viral replication, and positive selection of HCV sequence variants that contribute to antiviral resistance. This review summarizes the current understanding of redox interactions of HCV, outlining key experimental findings, directions for future research, and potential applications to therapy.
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Chronic Hepatitis. Integr Med (Encinitas) 2012. [DOI: 10.1016/b978-1-4377-1793-8.00019-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Ethanol and reactive species increase basal sequence heterogeneity of hepatitis C virus and produce variants with reduced susceptibility to antivirals. PLoS One 2011; 6:e27436. [PMID: 22087316 PMCID: PMC3210796 DOI: 10.1371/journal.pone.0027436] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 10/17/2011] [Indexed: 02/07/2023] Open
Abstract
Hepatitis C virus (HCV) exhibits a high level of genetic variability, and variants with reduced susceptibility to antivirals can occur even before treatment begins. In addition, alcohol decreases efficacy of antiviral therapy and increases sequence heterogeneity of HCV RNA but how ethanol affects HCV sequence is unknown. Ethanol metabolism and HCV infection increase the level of reactive species that can alter cell metabolism, modify signaling, and potentially act as mutagen to the viral RNA. Therefore, we investigated whether ethanol and reactive species affected the basal sequence variability of HCV RNA in hepatocytes. Human hepatoma cells supporting a continuous replication of genotype 1b HCV RNA (Con1, AJ242652) were exposed to ethanol, acetaldehyde, hydrogen peroxide, or L-buthionine-S,R-sulfoximine (BSO) that decreases intracellular glutathione as seen in patients. Then, NS5A region was sequenced and compared with genotype 1b HCV sequences in the database. Ethanol and BSO elevated nucleotide and amino acid substitution rates of HCV RNA by 4-18 folds within 48 hrs which were accompanied by oxidative RNA damage. Iron chelator and glutathione ester decreased both RNA damage and mutation rates. Furthermore, infectious HCV and HCV core gene were sufficient to induce oxidative RNA damage even in the absence of ethanol or BSO. Interestingly, the dn/ds ratio and percentage of sites undergoing positive selection increased with ethanol and BSO, resulting in an increased detection of NS5A variants with reduced susceptibility to interferon alpha, cyclosporine, and ribavirin and others implicated in immune tolerance and modulation of viral replication. Therefore, alcohol is likely to synergize with virus-induced oxidative/nitrosative stress to modulate the basal mutation rate of HCV. Positive selection induced by alcohol and reactive species may contribute to antiviral resistance.
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Abstract
Oxidative stress is commonly associated with a number of liver diseases and is thought to play a role in the pathogenesis of chronic hepatitis C, alcoholic liver disease, non-alcoholic steatohepatitis (NASH), haemochromatosis and Wilson's disease. Antioxidant therapy has thus been considered to have the possibility of beneficial effects in the management of these liver diseases. Despite this promise, antioxidants have produced mixed results in a number of clinical trials of efficacy. This review summarizes the results of clinical trials of antioxidants as sole or adjuvant therapy of chronic hepatitis C, alcoholic liver disease and non-alcoholic steatohepatitis (NASH). Overall, the most promising results to date are for vitamin E therapy of NASH but some encouraging results have been obtained with antioxidant therapy of acute alcoholic hepatitis as well. Despite evidence for small reductions of serum alanine aminotransferase, there is as yet no convincing evidence that antioxidant therapy itself is beneficial to patients with chronic hepatitis C. Problems such as small sample size, short follow up duration, inadequate endpoints, failure to demonstrate tissue delivery and antioxidant efficacy, and heterogeneous nature of the 'antioxidant' compounds used have complicated interpretation of results of the clinical studies. These limitations and their implications for future trial design are discussed.
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Coinfection with hepatitis C virus, oxidative stress and antioxidant status in HIV-positive drug users in Miami. HIV Med 2011; 12:78-86. [PMID: 20500231 DOI: 10.1111/j.1468-1293.2010.00849.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND The pathogenesis of HIV/hepatitis C virus (HCV) coinfection is poorly understood. We examined markers of oxidative stress, plasma antioxidants and liver disease in HIV/HCV-coinfected and HIV-monoinfected adults. METHODS Demographics, medical history, and proof of infection with HIV, hepatitis A virus (HAV), hepatitis B virus (HBV) and HCV were obtained. HIV viral load, CD4 cell count, complete blood count (CBC), complete metabolic panel, lipid profile, and plasma concentrations of zinc, selenium, and vitamins A and E were determined. Malondialdehyde (MDA) and glutathione peroxidase concentrations were obtained as measures of oxidative stress. Aminotransferase to platelet ratio index (APRI) and fibrosis index (FIB-4) markers were calculated. RESULTS Significant differences were found between HIV/HCV-coinfected and HIV-monoinfected participants in levels of alanine aminotransferase (ALT) (mean±standard deviation: 51.4±50.6 vs. 31.9±43.1 U/L, respectively; P=0.014), aspartate aminotransferase (AST) (56.2±40.9 vs. 34.4±30.2 U/L; P<0.001), APRI (0.52±0.37 vs. 0.255±0.145; P=0.0001), FIB-4 (1.64±.0.91 vs. 1.03±0.11; P=0.0015) and plasma albumin (3.74±0.65 vs. 3.94±0.52 g/dL; P=0.038). There were no significant differences in CD4 cell count, HIV viral load or antiretroviral therapy (ART) between groups. Mean MDA was significantly higher (1.897±0.835 vs. 1.344± 0.223 nmol/mL, respectively; P=0.006) and plasma antioxidant concentrations were significantly lower [vitamin A, 39.5 ± 14.1 vs. 52.4±16.2 μg/dL, respectively (P=0.0004); vitamin E, 8.29±2.1 vs. 9.89±4.5 μg/mL (P=0.043); zinc, 0.61±0.14 vs. 0.67±0.15 mg/L (P=0.016)] in the HIV/HCV-coinfected participants than in the HIV-monoinfected participants, and these differences remained significant after adjusting for age, gender, CD4 cell count, HIV viral load, injecting drug use and race. There were no significant differences in glutathione peroxidase concentration, selenium concentration, body mass index (BMI), alcohol use or tobacco use between groups. Glutathione peroxidase concentration significantly increased as liver disease advanced, as measured by APRI (β=0.00118; P=0.0082) and FIB-4 (β=0.0029; P=0.0177). Vitamin A concentration significantly decreased (β=-0.00581; P=0.0417) as APRI increased. CONCLUSION HIV/HCV coinfection is associated with increased oxidative stress and decreased plasma antioxidant concentrations compared with HIV monoinfection. Research is needed to determine whether antioxidant supplementation delays liver disease in HIV/HCV coinfection.
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Lipid Peroxidation in Acute Respiratory Distress Syndrome and Liver Failure. J Surg Res 2011; 168:243-52. [DOI: 10.1016/j.jss.2009.10.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2009] [Revised: 09/07/2009] [Accepted: 10/19/2009] [Indexed: 12/12/2022]
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Abstract
BACKGROUND Several liver diseases have been associated with oxidative stress. Accordingly, antioxidants have been suggested as potential therapeutics for various liver diseases. The evidence supporting these suggestions is equivocal. OBJECTIVES To assess the benefits and harms of antioxidant supplements for patients with liver diseases. SEARCH STRATEGY We searched The Cochrane Library, MEDLINE, EMBASE, LILACS, the Science Citation Index Expanded, and Conference Proceedings Citation Index-Science to January 2011. We scanned bibliographies of relevant publications and asked experts and pharmaceutical companies for additional trials. SELECTION CRITERIA We considered for inclusion randomised trials that compared antioxidant supplements (beta-carotene, vitamin A, C, E, and selenium) versus placebo or no intervention for autoimmune liver diseases, viral hepatitis, alcoholic liver disease, and cirrhosis (any aetiology). DATA COLLECTION AND ANALYSIS Four authors independently selected trials for inclusion and extracted data. Outcome measures were all-cause mortality, liver-related mortality, liver-related morbidity, biochemical indices at maximum follow-up in the individual trials as well as adverse events, quality-of-life measures, and cost-effectiveness. For patients with hepatitis B or C we also considered end of treatment and sustained virological response. We conducted random-effects and fixed-effect meta-analyses. Results were presented as relative risks (RR) or mean differences (MD), both with 95% confidence intervals (CI). MAIN RESULTS Twenty randomised trials with 1225 participants were included. The trials assessed beta-carotene (3 trials), vitamin A (2 trials), vitamin C (9 trials), vitamin E (15 trials), and selenium (8 trials). The majority of the trials had high risk of bias and showed heterogeneity. Overall, the assessed antioxidant supplements had no significant effect on all-cause mortality (relative risk [RR] 0.84, 95% confidence interval [CI] 0.60 to 1.19, I(2) = 0%), or liver-related mortality (RR 0.89, 95% CI 0.39 to 2.05, I(2) = 37%). Stratification according to the type of liver disease did not affect noticeably the results. Antioxidant supplements significantly increased activity of gamma glutamyl transpeptidase (MD 24.21 IU/l, 95% CI 6.67 to 41.75, I(2) = 0%). AUTHORS' CONCLUSIONS We found no evidence to support or refute antioxidant supplements in patients with liver disease. Antioxidant supplements may increase liver enzyme activity.
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Abstract
Hepatitis B virus (HBV)- and hepatitis C virus (HCV)-related chronic infections represent a major health problem worldwide. Although the efficacy of HBV and HCV treatment has improved, several important problems remain. Current recommended antiviral treatments are associated with considerable expense, adverse effects and poor efficacy in some patients. Thus, several alternative approaches have been attempted. To review the clinical experiences investigating the use of lipid- and water-soluble vitamins in the treatment of HBV- and HCV-related chronic infections, PubMed, the Cochrane Library, MEDLINE and EMBASE were searched for clinical studies on the use of vitamins in the treatment of HBV- and HCV-related hepatitis, alone or in combination with other antiviral options. Different randomised clinical trials and small case series have evaluated the potential virological and/or biochemical effects of several vitamins. The heterogeneous study designs and populations, the small number of patients enrolled, the weakness of endpoints and the different treatment schedules and follow-up periods make the results largely inconclusive. Only well-designed randomised controlled trials with well-selected endpoints will ascertain whether vitamins have any role in chronic viral hepatitis. Until such time, the use of vitamins cannot be recommended as a therapy for patients with chronic hepatitis B or C.
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Abstract
BACKGROUND Several liver diseases have been associated with oxidative stress. Accordingly, antioxidants have been suggested as potential therapeutics for various liver diseases. The evidence supporting these suggestions is equivocal. AIM To assess the benefits and harms of antioxidant supplements for patients with liver diseases. METHODS We identified trials through electronic and manual searches until August 2009. We included randomized trials comparing antioxidant supplements (beta-carotene, vitamin A, C, E and selenium) vs. placebo or no intervention for autoimmune liver diseases, viral hepatitis, alcoholic liver disease and cirrhosis (any aetiology). Random-effects and fixed-effect meta-analyses were conducted. Results were presented as relative risks (RR), or mean difference (MD), both with 95% confidence intervals (CI). RESULTS Twenty randomized trials with 1225 participants were included. The trials assessed beta-carotene (3 trials), vitamin A (2 trials), vitamin C (9 trials), vitamin E (15 trials) and selenium (8 trials). The majority of the trials had high risk of bias and showed heterogeneity. Overall, the assessed antioxidant supplements had no significant effect on all-cause mortality [relative risk (RR) 0.84, 95% confidence interval (CI) 0.60-1.19, I(2) = 0%] or liver-related mortality (RR 0.89, 95% CI 0.39-2.05, I(2) = 37%). Stratification according to the type of liver disease assessed did not affect the conclusions. Antioxidant supplements significantly increased the activity of gamma glutamyl transpeptidase (MD 24.21 IU/L, 95% CI 6.67-41.75, I(2) = 0%). CONCLUSIONS We found no evidence to support or refute antioxidant supplements in patients with liver disease. Antioxidant supplements may increase liver enzymes.
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Plasma levels of trace elements have an implication on interferon treatment of children with chronic hepatitis B infection. Biol Trace Elem Res 2010; 135:153-61. [PMID: 19727570 DOI: 10.1007/s12011-009-8507-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2009] [Accepted: 08/17/2009] [Indexed: 10/20/2022]
Abstract
This study evaluated the plasma levels of trace elements in children with chronic hepatitis B virus (HBV) infection and assessed whether they can be a factor that affects the response to interferon alpha (IFN-alpha) treatment. The study included 35 cases (ten girls, 25 boys) aged 3-13 years with chronic HBV infection and the control group. Plasma levels of copper (Cu), manganese (Mn), molybdenum (Mo), selenium (Se), and zinc (Zn) were measured before IFN-alpha treatment and biochemical, virological, and histopathologic response to treatment were assessed. Children were followed for at least 15 months. Although plasma Cu levels showed no difference between the groups, Mn, Mo, Se, and Zn levels were significantly lower in the study group before treatment. Fourteen cases (40%) showed biochemical response; 17 (48.6%) showed virological response; 16 (47.6%) showed histopathologic response, and ten (28.6%) showed response according to all three parameters. Plasma Cu and Mn levels of patients with triple response showed no difference; but Mo, Se, and Zn levels were significantly lower (p < 0.001) in the study group. No difference was observed between responders and nonresponders (p > 0.05). Plasma levels of Mn, Mo, Se, and Zn are lower in children with chronic HBV infection compared to healthy children. The pretreatment levels of these elements did not show difference between responders and nonresponders to IFN-alpha.
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Hepatic lipid peroxidation and antioxidant micronutrients in hepatitis virus C liver recipients with and without disease recurrence. Transplant Proc 2010; 41:3800-5. [PMID: 19917391 DOI: 10.1016/j.transproceed.2009.06.185] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2009] [Accepted: 06/24/2009] [Indexed: 12/31/2022]
Abstract
BACKGROUND Hepatitis C virus (HCV) reinfection after liver transplantation is universal and progresses to cirrhosis in 10% to 30% of patients. Several risk factors are associated with progression. Oxidative stress may be involved because it has a role in the pathogenesis of HCV. OBJECTIVE To determine whether HCV liver recipients with disease recurrence are more oxidatively stressed than those with no recurrence. METHODS Measurements were performed at 12 months posttransplantation, and in a subgroup of patients at 6 months. Liver lipid peroxidation (LPO), antioxidant potential, plasma vitamin E, retinol, and vitamin C were measured. Demographic data, pretransplantation viral load, anthropometry, and 3-day food records were also obtained. Data were log-transformed; analysis was performed using the independent t test, Pearson correlation, and multivariate regression analysis. RESULTS Recipients of HCV livers with recurrence (n = 21) had higher liver LPO (mean [SEM] micromoles of malondialdehyde per gram of liver tissue, 1.66 [0.28]) vs those with no recurrence (n = 16; 0.88 [0.13]) (P = .02). A significant relationship was found between liver LPO and HCV recurrence, and this significance continued when accounting for pretransplantation viral load and donor age. Six patients with recurrence and 11 with no recurrence also had measurements obtained at 6 months posttransplantation. Those with recurrence at 12 months had significantly higher hepatic LPO at 6 months (1.86 [0.62]) compared with those with no recurrence (0.75 [0.14]) (P = .04). CONCLUSIONS Recipients of HCV livers with recurrence are more oxidatively stressed at 6 and 12 months compared with those with no recurrence. Accounting for viral load and donor age, oxidative stress was independently associated with recurrence. More research is needed to confirm this association.
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Therapeutic use of cytoprotective agents in canine and feline hepatobiliary disease. Vet Clin North Am Small Anim Pract 2010; 39:631-52. [PMID: 19524797 DOI: 10.1016/j.cvsm.2009.02.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Many medicinal, nutraceutical, and botanic extracts have been used as cytoprotective agents in liver disease. This article explains the mechanisms of action, pertinent pharmacokinetics, side effects, and clinical indications for the use of S-adenosylmethionine, N-acetylcysteine, ursodeoxycholic acid, silymarin, and vitamin E. The literature pertaining to in vitro studies, laboratory animal models, and human and veterinary clinical trials is reviewed with regards to the efficacy and use of these cytoprotective agents in hepatobiliary disease.
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Nitric oxide and redox regulation in the liver: part II. Redox biology in pathologic hepatocytes and implications for intervention. J Surg Res 2009; 167:96-112. [PMID: 20400112 DOI: 10.1016/j.jss.2009.10.006] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Indexed: 12/13/2022]
Abstract
Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are created in normal hepatocytes and are critical for normal physiologic processes, including oxidative respiration, growth, regeneration, apoptosis, and microsomal defense. When the levels of oxidation products exceed the capacity of normal antioxidant systems, oxidative stress occurs. This type of stress, in the form of ROS and RNS, can be damaging to all liver cells, including hepatocytes, Kupffer cells, stellate cells, and endothelial cells, through induction of inflammation, ischemia, fibrosis, necrosis, apoptosis, or through malignant transformation by damaging lipids, proteins, and/or DNA. In Part I of this review, we will discuss basic redox biology in the liver, including a review of ROS, RNS, and antioxidants, with a focus on nitric oxide as a common source of RNS. We will then review the evidence for oxidative stress as a mechanism of liver injury in hepatitis (alcoholic, viral, nonalcoholic). In Part II of this review, we will review oxidative stress in common pathophysiologic conditions, including ischemia/reperfusion injury, fibrosis, hepatocellular carcinoma, iron overload, Wilson's disease, sepsis, and acetaminophen overdose. Finally, biomarkers, proteomic, and antioxidant therapies will be discussed as areas for future therapeutic interventions.
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Elevated hepatic iron: a confounding factor in chronic hepatitis C. BIOCHIMICA ET BIOPHYSICA ACTA 2009; 1790:650-62. [PMID: 19393721 DOI: 10.1016/j.bbagen.2009.04.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 04/06/2009] [Accepted: 04/15/2009] [Indexed: 12/13/2022]
Abstract
Historically, iron overload in the liver has been associated with the genetic disorders hereditary hemochromatosis and thalassemia and with unusual dietary habits. More recently, elevated hepatic iron levels also have been observed in chronic hepatitis C virus (HCV) infection. Iron overload in the liver causes many changes including induction of oxidative stress, damage to lysosomes and mitochondria, altered oxidant defense systems and stimulation of hepatocyte proliferation. Chronic HCV infection causes numerous pathogenic changes in the liver including induction of endoplasmic reticulum stress, the unfolded protein response, oxidative stress, mitochondrial dysfunction and altered growth control. Understanding the molecular and cellular changes that could occur in a liver which has elevated hepatic iron levels and in which HCV replication and gene expression are ongoing has clinical relevance and represents an area of research in need of further investigation.
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Abstract
In hepatitis C virus (HCV) infection, significant hepatic steatosis or superimposed nonalcoholic steatohepatitis is associated with disease severity and poor response to antiviral therapy. Nonalcoholic fatty liver disease (NAFLD) and HCV are common causes of chronic liver disease in Western countries and are strongly linked to concurrent obesity, insulin resistance, and the metabolic syndrome. With the escalating prevalence of obesity in North America, insulin resistance and the metabolic syndrome are major public health problems that have a significant impact on morbidity and mortality associated with NAFLD and HCV. This article focuses on the current understanding of the interplay between host and viral factors that are involved in the interaction between NAFLD and HCV.
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Abstract
BACKGROUND Both nonalcoholic fatty liver disease (NAFLD) and chronic hepatitis C (CHC) are frequent causes of chronic liver disease. In recent years, there have been significant revelations as regards the relationship between NAFLD and CHC. AIM To conduct a systematic, evidence-based review of the epidemiology, pathophysiology and potential treatments of coexistent NAFLD and CHC. METHODS The terms such as hepatitis C, fatty liver, NAFLD, nonalcoholic steatohepatitis and steatosis were searched on PubMed up to January 2008. References from selected articles and pertinent abstracts were also included. RESULTS Hepatic steatosis affects up to 80% of patients with CHC and is dependent on both viral and host factors. While insulin resistance (IR) is associated with hepatic steatosis and hepatitis C virus, genotype-specific pathogenic mechanisms have been identified and are currently the focus of intense investigation in the literature. Clinical implications of concurrent NAFLD, CHC and IR include increased disease progression, elevated risk of hepatocellular carcinoma, and decreased response to antiviral therapy. CONCLUSIONS NAFLD and IR are common in patients with CHC virus infection. IR is a driving force in the development of hepatic steatosis. Because of the clinical implications of hepatic steatosis and IR in the setting of CHC, further studies evaluating treatments, which may increase response to antiviral therapy, are needed.
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Interaction of metabolic syndrome, nonalcoholic fatty liver disease and chronic hepatitis C. Expert Rev Gastroenterol Hepatol 2008; 2:207-15. [PMID: 19072356 DOI: 10.1586/17474124.2.2.207] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) has become one of the most prevalent liver diseases in the Western world. NAFLD represents a wide spectrum of histologic subgroups, with nonalcoholic steatohepatitis as the most aggressive form. The risk of developing NAFLD is strongly associated with metabolic syndrome and insulin resistance. The pathogenesis of NAFLD is a multiple-hit process resulting from hepatic fat deposition that is related to several conditions, including insulin resistance and central obesity. Additional hits, such as oxidative stress or adipocytokines produced by white adipose tissue, can further enhance liver damage leading to nonalcoholic steatohepatitis or fibrosis. Although NAFLD is often the primary liver disease of metabolic conditions, it can also exacerbate other liver diseases such as hepatitis C (HCV); indeed, more than 50% of patients with HCV have hepatic steatosis. Hepatic steatosis can be related to host factors (e.g., obesity, metabolic syndrome or insulin resistance) or to the genotype of virus (e.g., HCV genotype 3). Increasing evidence suggests that hepatic steatosis, insulin resistance and obesity in the setting of HCV have a negative impact on the efficacy of treatment and hepatic progression of fibrosis.
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Antioxidant therapy for chronic hepatitis C after failure of interferon: Results of phase II randomized, double-blind placebo controlled clinical trial. World J Gastroenterol 2007; 13:5317-23. [PMID: 17879400 PMCID: PMC4171320 DOI: 10.3748/wjg.v13.i40.5317] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To assess the safety and efficacy of antioxidant therapy for patients with chronic hepatitis C virus (HCV) infection.
METHODS: One hundred chronic HCV infection patients failed in interferon treatment were enrolled and randomly assigned to receive combined intravenous and oral antioxidants or placebo, or oral treatment alone. Primary end points were liver enzymes, HCV-RNA levels and histology.
RESULTS: Combined oral and intravenous antioxidant therapy was associated with a significant decline in ALT levels in 52% of patients who received antioxidant therapy vs 20% of patients who received placebo (P = 0.05). Histology activity index (HAI) score at the end of treatment was reduced in 48% of patients who received antioxidant therapy vs 26% of patients who received placebo (P = 0.21). HCV-RNA levels decreased by 1-log or more in 28% of patients who received antioxidant therapy vs 12% who received placebo (P = NS). In part II of the trial, oral administration of antioxidants was not associated with significant alterations in any of the end points.
CONCLUSION: Antioxidant therapy has a mild beneficial effect on the inflammatory response of chronic HCV infection patients who are non-responders to interferon. Combined antiviral and antioxidant therapy may be beneficial for these patients.
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Redox regulation of hepatitis C in nonalcoholic and alcoholic liver. Free Radic Biol Med 2007; 43:869-82. [PMID: 17697932 DOI: 10.1016/j.freeradbiomed.2007.05.036] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Revised: 05/26/2007] [Accepted: 05/30/2007] [Indexed: 12/19/2022]
Abstract
Hepatitis C virus (HCV) is an RNA virus of the Flaviviridae family that is estimated to have infected 170 million people worldwide. HCV can cause serious liver disease in humans, such as cirrhosis, steatosis, and hepatocellular carcinoma. HCV induces a state of oxidative/nitrosative stress in patients through multiple mechanisms, and this redox perturbation has been recognized as a key player in HCV-induced pathogenesis. Studies have shown that alcohol synergizes with HCV in the pathogenesis of liver disease, and part of these effects may be mediated by reactive species that are generated during hepatic metabolism of alcohol. Furthermore, reactive species and alcohol may influence HCV replication and the outcome of interferon therapy. Alcohol consumption has also been associated with increased sequence heterogeneity of the HCV RNA sequences, suggesting multiple modes of interaction between alcohol and HCV. This review summarizes the current understanding of oxidative and nitrosative stress during HCV infection and possible combined effects of HCV, alcohol, and reactive species in the pathogenesis of liver disease.
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Enhancement of intracellular gamma-tocopherol levels in cytokine-stimulated C3H 10T1/2 fibroblasts: relation to NO synthesis, isoprostane formation, and tocopherol oxidation. BMC CHEMICAL BIOLOGY 2007; 7:2. [PMID: 17608946 PMCID: PMC1931582 DOI: 10.1186/1472-6769-7-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2006] [Accepted: 07/03/2007] [Indexed: 11/17/2022]
Abstract
Background Stimulation of C3H 10T1/2 murine fibroblasts with interferon-γ(IFN) and bacterial lipopolysaccharide (LPS) generates reactive oxygen and nitrogen species leading to DNA damage, lipid oxidation, and tocopherol oxidation. The tocopherols possess unique chemical and biological properties that suggest they have important roles related to intracellular defense against radical-mediated damage. Results Despite increased levels of reactive oxidants and decreased media tocopherol, cellular levels of γ-tocopherol, but not α-tocopherol, were observed to increase significantly when cells were treated with IFN/LPS. Inhibition of nitric oxide (NO) synthesis by a specific inhibitor of inducible NO synthase (iNOS) increased both intracellular α-tocopherol and γ-tocopherol concentrations, but did not significantly alter the reduction in media tocopherol levels caused by IFN/LPS treatment. Both exposure to exogenous NO and cellular synthesis of NO in cell culture increased media levels of 8-epi-prostaglandin F2α, a marker of oxidative lipid damage, whereas inhibition of endogenous NO synthesis reduced media 8-epi-prostaglandin F2α formation to control levels. Conclusion Elevated intracellular levels of γ-tocopherol in response to the cellular inflammatory state may indicate that it serves a unique role in minimizing cellular damage resulting from endogenous NO synthesis. Results of the current study suggest that NO is an important mediator of damage within the cell, as well as in the oxidation of both α- and γ-tocopherols. The paradoxical increase in cellular tocopherol associated with the induction of NO synthesis may indicate either enhanced cellular transport/decreased export for tocopherols or recruitment of free tocopherol from tocopherol storage molecules.
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Abstract
AIM: To investigate the antifibrotic effects of peginterferon-alpha 2b and taurine on oxidative stress markers and hepatocellular apoptosis.
METHODS: Sixty rats with CCl4-induced liver fibrosis were divided into 4 groups (n = 15). Group 1 was left for spontaneous recovery (SR). Groups 2-4 received peginterferon-alpha 2b, taurine, and their combination, respectively, for four weeks. Histological fibrosis scores, histomorphometric analysis, tissue hydroxyproline, tissue MDA, GPx and SOD activities were determined. Activated stellate cells and hepatocellular apoptosis were also evaluated.
RESULTS: The degree of fibrosis decreased in all treatment groups compared to spontaneous recovery group. Taurine alone and in combination with peginterferon-alpha 2b reduced oxidative stress markers, but peginterferon-alpha 2b alone did not. Apoptotic hepatocytes and activated stellate cells were higher in groups 2-4 than in group 1. Combined taurine and peginterferon-alpha 2b further reduced fibrosis and increased activated stellate cell apoptosis, but could not improve oxidative stress more than taurine alone.
CONCLUSION: Peginterferon-alpha 2b exerts anti-fibrotic effects on rat liver fibrosis. It seems ineffective against oxidative stress in vivo. Peginterferon-alpha 2b in combination with taurine seems to be an antifibrotic strategy.
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Emerging host cell targets for hepatitis C therapy. Drug Discov Today 2007; 12:209-17. [PMID: 17331885 DOI: 10.1016/j.drudis.2007.01.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2006] [Revised: 01/03/2007] [Accepted: 01/24/2007] [Indexed: 12/23/2022]
Abstract
Chronic hepatitis C virus (HCV) infection is a major burden on humanity. The current HCV therapy has limited efficacy, and there is pressing need for new and more effective therapies. Host cell factors that are required for HCV infection, replication and/or pathogenesis represent potential therapeutic targets. Of particular interest are cellular receptors that mediate HCV entry, factors that facilitate HCV replication and assembly, and intracellular pathways involving lipid biosynthesis, oxidative stress and innate immune response. A crucial challenge now is to manipulate such cellular targets pharmacologically for chronic HCV treatment, without being limited by side effects.
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Viusid, a nutritional supplement, in combination with interferon alpha-2b and ribavirin in patients with chronic hepatitis C. Liver Int 2007; 27:247-59. [PMID: 17311621 DOI: 10.1111/j.1478-3231.2006.01411.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
BACKGROUND The pathogenesis of chronic hepatitis C (CHC) is associated to severe oxidative stress that leads to necro-inflammation and progression of fibrosis. Previous trials suggested that antioxidative therapy may have a beneficial effect. We evaluated the efficacy and safety of Viusid in combination with interferon alpha-2b (IFN alpha-2b) and ribavirin in patients with CHC. METHODS We randomly assigned 100 patients, between October 2002 and December 2004, in two arms: IFN alpha-2b (5 MU on alternate days), ribavirin at a dose of 13 mg/kg daily and Viusid (three sachets daily) vs. IFN alpha-2b (5 MU on alternate days) and ribavirin at a dose of 13 mg/kg daily. Subjects were treated for 48 weeks and then followed for an additional 24 weeks. The primary end point was the histologic response (reduction of at least two points without fibrosis worsening in the total score on the Histological Activity Index). RESULTS A significantly high proportion of patients who received combined therapy plus Viusid had a histologic response better than those patients who received IFN alpha-2b and ribavirin (57% vs. 37%, P=0.03). The patients with virologic response achieved the highest percentages of histologic response, irrespective of assigned treatment. Among non-responders, the highest reduction in the mean change from baseline score for necro-inflammatory activity (NA) and fibrosis (F) was reported in patients treated with Viusid [NA, -1.50 (Viusid), -1.20 (without Viusid); F, -0.31 (Viusid), 0.00 (without Viusid)]. Sustained normalization of serum alanine aminotransferase concentration was highest in the Viusid group compared with standard therapy (67% vs. 41%, P=0.009). The overall safety profile was similar in both groups, but interestingly, the anemia was less intense in the group with Viusid (P=0.04). CONCLUSIONS Our results suggest that triple therapy with Viusid, IFN alpha-2b and ribavirin was well tolerated and may have a beneficial effect on histologic and biochemical variables. The intensity of anemia is reduced in patients treated with Viusid.
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Chronic Hepatitis. Integr Med (Encinitas) 2007. [DOI: 10.1016/b978-1-4160-2954-0.50027-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
Liver fibrosis may be considered as a dynamic and integrated cellular response to chronic liver injury. The activation of hepatic stellate cells and the consequent deposition of large amounts of extracellular matrix play a major role in the fibrogenic process, but it has been shown that other cellular components of the liver are also involved. Although the pathogenesis of liver damage usually depends on the underlying disease, oxidative damage of biologically relevant molecules might represent a common link between different forms of chronic liver injury and hepatic fibrosis. In fact, oxidative stress-related molecules may act as mediators able to modulate all the events involved in the progression of liver fibrosis. In addition, chronic liver diseases are often associated with decreased antioxidant defenses. Although vitamin E levels have been shown to be decreased in chronic liver diseases of different etiology, the role of vitamin E supplementation in these clinical conditions is still controversial. In fact, the increased serum levels of alpha-tocopherol following vitamin E supplementation not always result in a protective effect on liver damage. In addition, clinical trials have usually been performed in small cohorts of patients, thus making definitive conclusions impossible. At present, treatment with vitamin E or other antioxidant compounds could be proposed for nonalcoholic fatty liver disease (NAFLD), the most frequent hepatic lesion in western countries which can progress to nonalcoholic steatohepatitis and cirrhosis due to the production of large amounts of oxidative stress products. However, although some studies have shown encouraging results, multicentric and long-term clinical trials are needed.
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Abstract
Hepatitis C, nonalcoholic fatty liver characterized by hepatic steatosis, and obesity inflict significant health and economic burdens on the Western world. Insulin resistance is the key player in these disease processes. Complex interplay between these conditions results in the ultimate phenotype of liver disease. This article focuses on the current understanding of host and viral interactions as well as on consequent clinical implications.
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The use of selected nutrition supplements and complementary and alternative medicine in liver disease. Nutr Clin Pract 2006; 21:255-72. [PMID: 16772543 PMCID: PMC4239999 DOI: 10.1177/0115426506021003255] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Almost all patients with liver disease, especially advanced liver disease, have some evidence of malnutrition, including mineral/vitamin deficiency. A major health trend in the United States has been the significant growth in the use of complementary and alternative medicine (CAM), including nutrition supplements and herbal agents. In the 1990s, the United States government created the National Center for Complementary and Alternative Medicine (NCCAM), as well as the Office on Dietary Supplements, to extend our knowledge in these areas. CAM users are often highly educated and frequently use CAM therapy for chronic diseases, including chronic liver disease. Indeed, most studies suggest that patients with chronic liver disease frequently use nutrition supplements and CAM agents in addition to their traditional medicines. The purpose of this review is to provide an update on the role of nutrition supplements and herbals in liver disease. This article will focus mainly on 7 selected agents (vitamin E, zinc, magnesium, S-adenosylmethionine, betaine, silymarin, and glycyrrhizin), for which there have been not only in vitro and animal studies but also human clinical trials, and we will review both potential efficacy and safety issues.
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The effect of antioxidant supplementation on hepatitis C viral load, transaminases and oxidative status: a randomized trial among chronic hepatitis C virus-infected patients. Eur J Gastroenterol Hepatol 2006; 18:985-9. [PMID: 16894312 DOI: 10.1097/01.meg.0000231746.76136.4a] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE To assess the effect of antioxidant supplementation on hepatitis C viral load, transaminases and oxidative status. METHODS We performed a randomized, placebo-controlled, double-blind trial to assess the effect of antioxidant supplementation on serum alanine aminotransferase, plasma hepatitis C viral load as well as oxidative and antioxidant markers in patients with hepatitis C virus infection. The participants received a daily dose of ascorbic acid (500 mg), D-alpha-tocopherol (945 IU) and selenium (200 microg) or placebo tablets for 6 months. RESULTS Twenty-three patients were included. During supplementation, the antioxidant group had significantly higher levels of plasma ascorbic acid and alpha-tocopherol than the placebo group and the activity of erythrocyte glutathione peroxidase had significantly increased from baseline to month 6. No differences were observed in serum alanine aminotransferase and log10-transformed plasma hepatitis C virus-RNA between the groups or changes from the baseline at any time. No consistent differences between groups or changes from the baseline with respect to erythrocyte activities of antioxidative enzymes (glutathione reductase, superoxide dismutase and catalase) or plasma levels of oxidative markers (malondialdehyde and 2-amino-adipic semialdehyde) were found. CONCLUSION Supplementation with vitamin C, E and selenium increased the antioxidant status, but had no effects on alanine aminotransferase, viral load or oxidative markers.
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Oxidative stress and antioxidant defense in patients with chronic hepatitis C patients before and after pegylated interferon alfa-2b plus ribavirin therapy. J Transl Med 2006; 4:25. [PMID: 16787540 PMCID: PMC1513604 DOI: 10.1186/1479-5876-4-25] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2006] [Accepted: 06/20/2006] [Indexed: 12/11/2022] Open
Abstract
Background Oxidative stress could play a role in pathogenesis of hepatitis C virus (HCV) infection. The aim of our study is to determine oxidant/antioxidant status of patients with chronic hepatitis C (CHC), and the effect of pegylated interferon alfa-2b plus ribavirin combination therapy on oxidative stress. Methods Nineteen patients with chronic HCV infection and 28 healthy controls were included in the study. In control and patient groups, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, erythrocyte malondialdehyde (MDA) levels, erythrocyte CuZn-superoxide dismutase (SOD), erythrocyte glutathione peroxidase (GSH-Px) activities were measured. After pegylated interferon alfa-2b and ribavirin combination therapy for 48 weeks, these parameters were measured again in the patient group. Results Serum MDA levels increased significantly in CHC patients (n:19), before the treatment when compared with healthy subjects (n:28) 9.28 ± 1.61, 4.20 ± 1.47 nmol/ml, p < 0.001 respectively. MDA concentration decreased significantly (p < 0.001) after the treatment as well as ALT, AST activity, in erythrocytes of these patients. Average antioxidant enzymes (superoxide dismutase and glutathione peroxidase) were significantly lower in erythrocytes of patients with CHC before treatment compared with the control group (both, p < 0.001). Chronic Hepatitis C patients after pegylated interferon alfa-2b and ribavirin therapy showed values of SOD, GSH-Px were significantly higher than pretreatment levels (both, p < 0.001). Conclusion Our results show that patients with chronic HCV infection are under the influence of oxidative stress associated with lower levels of antioxidant enzymes. These impairments return to level of healthy controls after pegylated interferon alfa-2b plus ribavirin combination therapy of CHC patients. Although interferon and ribavirin are not antioxidants, their antiviral capacity might reduce viral load, and inflammation, and perhaps through this mechanism might reduce virus-induced oxidative stress.
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Treatment of chronic hepatitis C in non-responsive patients with pegylated interferon associated with ribavirin and thalidomide: report of six cases of total remission. Rev Inst Med Trop Sao Paulo 2006; 48:109-12. [PMID: 16699635 DOI: 10.1590/s0036-46652006000200011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2023] Open
Abstract
Hepatitis C virus (HCV) infection is an important public health issue worldwide. It is estimated that over 170 million people are infected with the virus. The present study reports six cases in which patients did not respond to combination therapy with pegylated interferon and ribavirin. However, after the addition of thalidomide to the therapy, the patients presented negative RNA PCR. The use of thalidomide combined with pegylated interferon and ribavirin for the treatment of hepatitis C is described here for the first time in the related literature.
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Abstract
Oxidative stress is a common pathogenetic mechanism contributing to initiation and progression of hepatic damage in a variety of liver disorders. Cell damage occurs when there is an excess of reactive species derived from oxygen and nitrogen, or a defect of antioxidant molecules. Experimental research on the delicately regulated molecular strategies whereby cells control the balance between oxidant and antioxidant molecules has progressed in recent years. On the basis of this evidence, antioxidants represent a logical therapeutic strategy for the treatment of chronic liver disease. Clinical studies with large numbers of patients have not yet been performed. However, results from several pilot trials support this concept and indicate that it may be worth performing multicentre studies, particularly combining antioxidants with anti-inflammatory and/or antiviral therapy. Oxidative stress plays a pathogenetic role in liver diseases such as alcoholic liver disease, chronic viral hepatitis, autoimmune liver diseases and non-alcoholic steatohepatitis. The use of antioxidants (e.g. S-adenosylmethionine [SAMe; ademetionine], tocopherol [vitamin E], polyenylphosphatidylcholine or silymarin) has already shown promising results in some of these pathologies.
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Abstract
Pegylated interferon and ribavirin combination therapy represent the standard-of-care treatment for chronic hepatitis C, that allows to cure more than half of the patients. However, the success of this bitherapy is in balance with numerous side effects, especially hematologic and psychiatric. This review is focused on complementary treatments (erythropoietin, G-CSF, vitamin E, glutathion, ursodeoxycholic acid and antidepressants) likely to bring a benefit in maintaining adequate interferon and ribavirin dosages and in improving quality of life. This analysis has been performed by using the Medline(R) data base and with data from laboratories which commercialized these molecules. Erythropoietin, G-CSF and antidepressants are the best tools to optimize the bitherapy in its dose and its duration while privileging the quality of life of HCV-infected patients.
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