Antioxidant status and glutathione metabolism in peripheral blood mononuclear cells from patients with chronic hepatitis C

The Role of Glutathione in Selected Viral Diseases

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.

Biopharmaceutical, preclinical pharmacokinetic and pharmaco-dynamic investigations of an orally administered novel 3-nbutylphthalide prodrug for ischemic stroke treatment

Ischemic stroke (IS) has been contributing in leading causes of disability and death worldwide and the cases are still increasing. In China, naturally sourced compound 3-n-butylphthalide (NBP) is widely applied in clinical practice for IS treatment with established evidences of efficacy and safety. However, NBP is an oily liquid at room temperature and has no active brain targeting ability, quite limiting its broader application in clinical practice. Via intravenous injection (i.v.) a prodrug compound (DB1) we previously developed deriving from NBP had dramatically enhanced the pharmacological effects, where however, this i.v. route still discount future patient compliance. As druggability of DB1 in oral administration has yet to be elaborated, the current study intended to systemically investigate its biopharmaceutical properties, so as to further consider clinical applicability of DB1 oral preparations. Additionally, pharmacokinetics and pharmacodynamics of DB1 via oral administered route were also studied, illustrating broad potential of further DB1 medicine development. After the derivation, aqueous solubility of DB1 improved 3∼400 folds compared with NBP in various pH media, and n-octanol/water partition coefficient kept in the range of 0∼2. In situ single-pass intestinal perfusion on rats showed effective permeability coefficient of DB1 over 10^-2 cm/s. In contrast to NBP, oral administration of DB1 could display significant enhanced bioavailability in rats and achieve increased accumulation in brain tissues. As expected, DB1 effectively alleviated oxidative stress damage and reduced infarct volume on ischemia/reperfusion (I/R) modeled rats, resulting in reduced mortality. Additionally, this new prodrug did not add any safety concerns based on NBP. Therefore, biopharmaceutical results and preclinical pharmacodynamic evidences support the conclusion that an oral administration of DB1 may have a good potential for clinical IS treatment.

Enteroviral 2B Interacts with VDAC3 to Regulate Reactive Oxygen Species Generation That Is Essential to Viral Replication

Enterovirus (EV) 71 caused episodes of outbreaks in China and Southeast Asia during the last few decades. We have previously reported that EV71 induces reactive oxygen species (ROS). However, the underlying mechanism remains elusive. Co-immunoprecipitation-proteomic analysis revealed that enteroviral 2B protein interacted with mitochondrial voltage-dependent anion channel 3 (VDAC3). Knockdown (KD) of VDAC3 expression specifically inhibited enteroviral replication. Single-round viral replication was also inhibited in KD cells, suggesting that VDAC3 plays an essential role in replication. Consistent with this, VDAC3 gene KD significantly reduced the EV71-induced mitochondrial ROS generation. Exogenous 2B expression could induce the mitochondrial ROS generation that was significantly reduced in VDAC3-KD cells or in the Mito-TEMPO-treated cells. Moreover, VDAC3 appears to be necessary for regulation of antioxidant metabolism. VDAC3 gene KD led to the enhancement of such pathways as hypotaurine/taurine synthesis in the infected cells. Taken together, these findings suggest that 2B and VDAC3 interact to enhance mitochondrial ROS generation, which promotes viral replication.

Effect of Silymarin as an Adjunct Therapy in Combination with Sofosbuvir and Ribavirin in Hepatitis C Patients: A Miniature Clinical Trial

Silymarin is proclaimed to be a blend of flavonolignans or phytochemicals. An era of new generation of direct-acting antivirals (DAAs) has commenced to have facet effect in swaying of the hepatitis C virus (HCV). Nonetheless, this therapy has serious side effects that jeopardize its efficacy. This study is aimed at probing the effects of ribavirin (RBV) and sofosbuvir (SOF) along with silymarin as an adjunct therapy on hematological parameters and markers of obscured oxidative stress. The effect of DAAs along with silymarin was also examined on variable sex hormone level and liver function markers such as alanine aminotransferase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), and bilirubin. The study was followed to determine viral load and viral genotypes. A total of 30 patients were randomly divided into two equal groups comprising the control group (n = 15) and treatment group (n = 15). The control group was solely administered with DAAs (SOF and RBV; 400 mg/800 mg each/day). Conversely, the treatment group was dispensed with DAAs, but with adjunct therapy of silymarin (400 mg/day) along with DAAs (400/800 mg/day) over period of 8 weeks. Sampling of blood was performed at pre- and posttreatment levels for the evaluation of different propound parameters. Our data showed that silymarin adjunct therapy enhances the efficiency of DAAs. A decrease in menace level of liver markers such as ALT, ALP, AST, and bilirubin was observed (p > 0.05). The adjunct therapy concurrently also demonstrated an ameliorative effect on hematological indices and oxidative markers, for instance, SOD, TAS, GSH, GSSG, and MDA (p < 0.05), diminishing latent viral load. The silymarin administration was also found to revamp the fluster level of sex hormones. Our outcomes provide evidence that systematic administration of silymarin effectively remits deviant levels of hematological, serological, hormonal, and antioxidant markers. This demonstrates a possibly unique role of silymarin in mitigating hepatitis C.

Direct-acting antivirals restore systemic redox homeostasis in chronic HCV patients

Chronic hepatitis C therapy has completely changed in the last years due to the availability of direct-acting antivirals (DAAs). Removing the virus may be not enough since chronic infection deeply modifies immune system and cellular metabolism along decades of inflammation. Oxidative stress plays a significant role in maintaining systemic inflammation during chronic HCV infection. Other than removing the virus, effective therapy could counteract oxidative stress. This study investigated the impact of DAA treatment on circulating markers of oxidative stress and antioxidant defence in a cohort of patients affected by chronic hepatitis C. To this, an observational study on 196 patients who started therapy with DAA for HCV-related hepatitis was performed. Patients were assessed at baseline, 4 weeks after the initiation of therapy (4wks), at the end of treatment (EoT), and 12 weeks after the EoT (SVR12). Circulating oxidative stress was determined by measuring serum hydroxynonenal (HNE)- and malondialdehyde (MDA)-protein adducts, and 8-hydroxydeoxyguanosine (8-OHdG). Antioxidant status was evaluated by measuring the enzymatic activity and mRNA expression of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in peripheral blood mononuclear cells. We observed a reduction of serum 8-OHdG at 4wks, while the circulating level of both HNE- and MDA-protein adducts diminished at EoT; all these markers persisted low at SVR12. On the other side, we reported an increase in the enzymatic activity of all the antioxidant enzymes in PBMC at EoT and SVR12. Taking into account circulating 8-OHdG and antioxidant enzyme activities, patients with high fibrosis stage were those that had the most benefit from DAA therapy. To conclude, this study indicates that treatment with DAAs improves the circulating redox status of patients affected by chronic hepatitis C. This positive impact of DAA therapy may be related to its effectiveness on cutting down viremia and pro-inflammatory markers.

Enhanced Efficacy of Direct-Acting Antivirals in Hepatitis C Patients by Coadministration of Black Cumin and Ascorbate as Antioxidant Adjuvants

The widespread adaptation of a new generation of direct-acting antiviral agents (DAAs) unveils a superlative effect in the eradication of the hepatitis C virus (HCV). However, this therapy has been reported to exhibit vigorous side effects that pose a risk in fleet recovery. This study was conducted to investigate the efficacy of DAAs: sofosbuvir (SOF) and ribavirin (RBV), along with black cumin (BLC) and ascorbate (ASC), as adjuvants on hematological parameters; oxidative stress markers such as total antioxidant status (TAS), superoxide dismutase (SOD), reduced (GSH) and oxidized (GSSG) glutathione (GSH), gamma-glutamyl transferase (GGT), and malondialdehyde (MDA); liver function markers such as aspartate transaminase (AST), alanine aminotransferase (ALT), bilirubin, and alkaline phosphatase (ALP); and viral load with determined genotypes. HCV-infected patients (n = 30) were randomly divided into two equal groups: control group (n = 15) and treatment group (n = 15). The control group was subjected only to SOF and RBV (400 mg each/day). Synergistically, the treatment group was administered with adjuvant therapy of BLC (250 mg/day) and ASC (1000 mg/day) along with DAAs (400 mg each/day) for 8 weeks. All selected patients were subjected to sampling at pre- and posttreatment stages for the assessment of defined parameters. The data revealed that the BLC/ASC adjuvant therapy boosted the efficacy of DAAs by reducing the elevated levels of liver markers such as AST, ALT, ALP, and bilirubin in the treatment group compared with those in the control group (P > 0.05). The adjuvant therapy synchronously showed an ameliorating effect on hematological parameters. The SOF/RBV with adjuvant therapy also demonstrated an increasing effect in the activity of SOD, TAS, and GSH and a decreasing effect for GSSG, GGT, and malondialdehyde (MDA; P > 0.05) followed by curtailing a RT-PCR-quantified viral load. Our findings provide evidence that systemic administration of BLC/ASC efficiently alleviates hematological, serological, and antioxidant markers as well as the viral load in hepatitis C patients. This highlights a potentially novel role of BLC and ASC in palliating hepatitis C.

Selenium, Selenoproteins and Viral Infection

Reactive oxygen species (ROS) are frequently produced during viral infections. Generation of these ROS can be both beneficial and detrimental for many cellular functions. When overwhelming the antioxidant defense system, the excess of ROS induces oxidative stress. Viral infections lead to diseases characterized by a broad spectrum of clinical symptoms, with oxidative stress being one of their hallmarks. In many cases, ROS can, in turn, enhance viral replication leading to an amplification loop. Another important parameter for viral replication and pathogenicity is the nutritional status of the host. Viral infection simultaneously increases the demand for micronutrients and causes their loss, which leads to a deficiency that can be compensated by micronutrient supplementation. Among the nutrients implicated in viral infection, selenium (Se) has an important role in antioxidant defense, redox signaling and redox homeostasis. Most of biological activities of selenium is performed through its incorporation as a rare amino acid selenocysteine in the essential family of selenoproteins. Selenium deficiency, which is the main regulator of selenoprotein expression, has been associated with the pathogenicity of several viruses. In addition, several selenoprotein members, including glutathione peroxidases (GPX), thioredoxin reductases (TXNRD) seemed important in different models of viral replication. Finally, the formal identification of viral selenoproteins in the genome of molluscum contagiosum and fowlpox viruses demonstrated the importance of selenoproteins in viral cycle.

Endoplasmic reticulum-associated degradation potentiates the infectivity of influenza A virus by regulating the host redox state

During influenza A virus (IAV) infection, significant effects of oxidative stress often emerge due to the disruption of the redox balance. Reactive oxygen species (ROS) generated during IAV infection have been known to exert various effects on both the virus and host tissue. However, the mechanisms underlying the accumulation of ROS and their physiological significance in IAV infection have been extensively studied but remain to be fully understood. Here, we show that the levels of Sp1, a key controller of Cu-Zn superoxide dismutase (SOD1) gene expression, and SOD1 are mainly dependent upon the activity of X-box-binding protein 1 (XBP1), which is a downstream factor of the endoplasmic reticulum (ER) transmembrane sensor inositol-requiring enzyme 1 (IRE1) during ER stress. In IRE1-deficient mouse embryo fibroblasts (MEFs) or A549 human lung cells treated with XBP1 siRNA, IAV-induced Sp1 loss was mitigated. However, overexpression of the spliced form of XBP1 in IRE1-deficient MEFs resulted in a further decrease in Sp1 levels, whereas the unspliced form showed no significant differences. Treatment with proteasome inhibitor MG132 markedly inhibited the IRE1/XBP1-mediated loss of Sp1 and SOD, suggesting the involvement of proteasome-dependent ER-associated degradation (ERAD). The increase in SOD1 levels with the expression of siRNA-targeting p97, a central component of the ubiquitin-proteasome system, supports the major role of the ERAD process in IAV-mediated SOD1 loss. In addition, ROS generation due to IAV infection was attenuated in cells lacking either IRE1 or JNK. These results reveal the important roles of both IRE1/XBP1-mediated ERAD and the JNK pathway in IAV infection. Interestingly, the increase in ROS due to IAV infection is correlated with the increase in the virus titer in vitro and in vivo. However, 4-phenylbutyrate (4-PBA), an inhibitor of ER stress signaling, weakened the effect of IAV infection on SOD1 loss in a dose-dependent manner. Furthermore, the treatment of mice with 4-PBA efficiently attenuated ROS generation and ER stress in lung tissue and eventually lowered the IAV titer. These results strongly suggest that the ERAD process plays a major role in IAV infection, thus making it a potential target for antiviral drug therapy.

Antiviral effect of baicalin phospholipid complex against duck hepatitis A virus type 1

Duck hepatitis A virus type 1 (DHAV-1) is one of the main pathogens of ducklings and causes a high mortality rate. Baicalin (BA) has potent antiviral effect, but the solubility is very poor. In order to increase the absorption, solubility, and pharmacological activity, the phospholipid complex was used to modify BA in present study. Therefore, BA phospholipid complex (BAPC) was prepared. The anti-DHAV-1 abilities of BA and BAPC in vitro was evaluated by cell counting kit-8 and reverse transcription quantitative PCR. The curative effects of BA and BAPC on ducklings which were infected by DHAV-1 in addition to the ALT and AST levels were also detected. The results indicated the anti-DHAV-1 ability of BAPC was stronger than that of BA both in vitro and in vivo. To explore the anti-DHAV-1 mechanism, the influence of BAPC on DHAV-1 adsorption, replication, and release was studied. Furthermore, the anti-oxidative and immuno-enhancing abilities of BAPC in the treatment of infected ducklings were also determined. The results showed BAPC inhibited DHAV-1 adsorption, replication and release. Furthermore, it played anti-oxidative and immno-enhancing roles in the treatment, and the immno-enhancing role was crucial to the treatment.

Oxidative stress, a trigger of hepatitis C and B virus-induced liver carcinogenesis

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.

Brown propolis attenuates cerebral ischemia-induced oxidative damage via affecting antioxidant enzyme system in mice

Oxidative stress plays a critical role in ischemic brain injury. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) are the enzymes underlying the endogenous antioxidant mechanisms affected by stroke and are considered as oxidative stress biomarkers. Brown propolis (BP) is a bioactive natural product with a set of biological activities that in turn may differ depending on the area from which the substance is originated. The aim of this study was to investigate the effect of water-extracted brown propolis (WEBPs), from two regions of Iran, against cerebral ischemia-induced oxidative injury in a mouse model of stroke. Experimentally, the chemical characterization and total polyphenol content were determined using GC/MS and Folin-Ciocalteu assay respectively. Seventy-two adult male mice were randomly divided into the surgical sham group, control group (treated with vehicle), and four groups of WEBPs-treated animals. The WEBPs were administered at the doses of 100 and 200mg/kg IP, during four different time points. Oxidative stress biomarkers (SOD and GPx activity, SOD/GPx ratio), lipid peroxidation (LPO) index (malondialdehyde content) and infarct volume were measured 48h post stroke. Behavioral tests were evaluated 24 and 48h after stroke. WEBPs treatment resulted in significant restoration of antioxidant enzymes activity and a subsequent decrease in LPO as well as the infarct volume compared to the control group. Sensory-motor impairment and neurological deficits were improved significantly as well. These results indicate that Iranian BP confers neuroprotection on the stroke-induced neuronal damage via an antioxidant mechanism which seems to be mediated by the endogenous antioxidant system.

Oxidative stress and age-related changes in T cells: is thalassemia a model of accelerated immune system aging?

Iron overload in β-thalassemia major occurs mainly due to blood transfusion, an essential treatment for β-thalassemia major patients, which results in oxidative stress. It has been thought that oxidative stress causes elevation of immune system senescent cells. Under this condition, cells normally enhance in aging, which is referred to as premature immunosenescence. Because there is no animal model for immunosenescence, most knowledge on the immunosenescence pattern is based on induction of immunosenescence. In this review, we describe iron overload and oxidative stress in β-thalassemia major patients and how they make these patients a suitable human model for immunosenescence. We also consider oxidative stress in some kinds of chronic virus infections, which induce changes in the immune system similar to β-thalassemia major. In conclusion, a therapeutic approach used to improve the immune system in such chronic virus diseases, may change the immunosenescence state and make life conditions better for β-thalassemia major patients.

Curcumin, Silybin Phytosome(®) and α-R-Lipoic Acid Mitigate Chronic Hepatitis in Rat by Inhibiting Oxidative Stress and Inflammatory Cytokines Production

Chronic hepatitis is recognized as a worldwide health problem that gradually progresses towards cirrhosis and hepatocellular carcinoma. Despite the large number of experiments using animal models for allergic hepatitis, it is still difficult to produce a picture of chronic hepatitis. Therefore, this study was conducted to introduce an animal model approximating to the mechanism of chronicity in human hepatitis. The study also aimed to examine the hepatoprotective effects of curcumin, silybin phytosome(®) and α-R-lipoic acid against thioacetamide (TAA)-induced chronic hepatitis in rat model. TAA was administered intraperitoneally at a dose of 200 mg/kg three times weekly for 4 weeks. At the end of this period, a group of rats was killed to assess the development of chronic hepatitis in comparison with their respective control group. TAA administration was then discontinued, and the remaining animals were subsequently allocated into four groups. Group 1 was left untreated, whereas groups 2-4 were allowed to receive daily oral doses of curcumin, silybin phytosome(®) or α-R-lipoic acid, respectively, for 7 weeks. Increases in hepatic levels of malondialdehyde associated with TAA administration were inhibited in groups receiving supplements. Furthermore, glutathione depletion, collagen deposition, macrophage activation and nuclear factor κappa-B expression as well as tumour necrosis factor-α and interleukin-6 levels were significantly decreased in response to supplements administration. Serological analysis of liver function and liver histopathological examination reinforced the results. The above evidence collectively indicates that the antioxidant and anti-inflammatory activities of curcumin, silybin phytosome(®) and α-R-lipoic acid may confer therapeutic efficacy against chronic hepatitis.

Glutathione S-Transferase M1 and T1 Gene Polymorphisms and the Outcome of Chronic Hepatitis C Virus Infection in Egyptian Patients

We analysed the distribution of GSTM1 and GSTT1 gene polymorphisms in Egyptian patients with chronic hepatitis C, and investigated their relationship to the clinical outcome of chronic hepatitis C virus (HCV) infection. This study included 169 patients with chronic HCV infection and 145 healthy and matched controls.GSTM1 and GSTT1 polymorphisms were genotyped by multiplex polymerase chain reaction. Individual GSTM1 null and GSTT1 null genotypes were more frequent in patients versus control subjects [OR, 4 (95% CI, 2.5-6.4); P ˂ 0.001] and [OR, 1.7 (95% CI, 1.1-2.6); P = 0.025], respectively. The patient group showed a higher frequency of the combined GSTM1/GSTT1 double-null genotype than the control group [OR, 1.8 (95% CI, 1.1-2.9); P = 0.016]. The distribution frequencies of the combined GSTM1/GSTT1 double-null genotype were significantly different [OR, 0.5 (95% CI, 0.25-0.99); P = 0.049] between F0-F3 and F4. There were no significant differences between the two groups with regard to other genotypes. The combined GSTM1/GSTT1 double-null genotype was significantly increased in Child-Pugh C patients in comparison to Child-Pugh A+B (P = 0.02). There was no significant difference between different classes with regard to other genotypes. In conclusion, we identified an association between the combined GSTM1/GSTT1 double-null genotype and advanced liver fibrosis and outcome of chronic HCV infection in Egyptian patients.

The role of cellular oxidoreductases in viral entry and virus infection-associated oxidative stress: potential therapeutic applications

INTRODUCTION

Cellular oxidoreductases catalyze thiol/disulfide exchange reactions in susceptible proteins and contribute to the cellular defense against oxidative stress. Oxidoreductases and oxidative stress are also involved in viral infections. In this overview, different aspects of the role of cellular oxidoreductases and oxidative stress during viral infections are discussed from a chemotherapeutic viewpoint.

AREAS COVERED

Entry of enveloped viruses into their target cells is triggered by the interaction of viral envelope glycoproteins with cellular (co)receptor(s) and depends on obligatory conformational changes in these viral envelope glycoproteins and/or cellular receptors. For some viruses, these conformational changes are mediated by cell surface-associated cellular oxidoreductases, which mediate disulfide bridge reductions in viral envelope glycoprotein(s). Therefore, targeting these oxidoreductases using oxidoreductase inhibitors might yield an interesting strategy to block viral entry of these viruses. Furthermore, since viral infections are often associated with systemic oxidative stress, contributing to disease progression, the enhancement of the cellular antioxidant defense systems might have potential as an adjuvant antiviral strategy, slowing down disease progression.

EXPERT OPINION

Promising antiviral data were obtained for both strategies. However, potential pitfalls have also been identified for these strategies, indicating that it is important to carefully assess the benefits versus risks of these antiviral strategies.

RNA Viruses: ROS-Mediated Cell Death

Reactive oxygen species (ROS) are well known for being both beneficial and deleterious. The main thrust of this review is to investigate the role of ROS in ribonucleic acid (RNA) virus pathogenesis. Much evidences has accumulated over the past decade, suggesting that patients infected with RNA viruses are under chronic oxidative stress. Changes to the body's antioxidant defense system, in relation to SOD, ascorbic acid, selenium, carotenoids, and glutathione, have been reported in various tissues of RNA-virus infected patients. This review focuses on RNA viruses and retroviruses, giving particular attention to the human influenza virus, Hepatitis c virus (HCV), human immunodeficiency virus (HIV), and the aquatic Betanodavirus. Oxidative stress via RNA virus infections can contribute to several aspects of viral disease pathogenesis including apoptosis, loss of immune function, viral replication, inflammatory response, and loss of body weight. We focus on how ROS production is correlated with host cell death. Moreover, ROS may play an important role as a signal molecule in the regulation of viral replication and organelle function, potentially providing new insights in the prevention and treatment of RNA viruses and retrovirus infections.

Polymorphic differences in SOD-2 may influence HCV viral clearance

Hepatitis C virus (HCV) is a pathogen causing chronic hepatitis, cirrhosis, and liver cancer occurring in about 3% of the world's population. Most individuals infected with HCV develop persistent viremia. Oxidative stress may play an important role in the pathogenesis of a number of diseases including HCV infection and diabetes mellitus. Polymorphisms in the antioxidant genes may determine cellular oxidative stress levels as a primary pathogenic role in HCV and/or in its complications. Patients with HCV and normal, healthy controls were investigated for a superoxide dismutase (SOD-2) polymorphism in the mitochondrial targeting sequence with Ala/Val (C-9T) substitution. Polymorphisms in antioxidant gene SOD-2 were carried out by PCR, restriction fragment length polymorphism assays and by polyacrylamide gel electrophoresis. For the SOD-2 polymorphism, the RNA positive group showed a higher percentage of "CT" genotype than the RNA negative group (89.3% vs. 66.1%, P = 0.001, χ(2)  = 11.9). The RNA negative group had more TT genotypes than the RNA positive group (27.4% vs. 6.80%, P = 0.01, χ(2)  = 11.6). The exposed uninfected group had an increased frequency of the "CT" genotype (86.2% vs. 66.1%, P = 0.02, χ(2)  = 5.5). The RNA positives had a higher frequency of the "CT" from the normal controls (72.1% vs. 89.2%, P = 0.005, χ(2)  = 7.8).

Effects of α-tocopherol and ascorbic acid in the severity and management of traumatic brain injury in albino rats

Background:

Traumatic brain injury (TBI) is accompanied by substantial accumulation of biomarkers of oxidative stress and depletion of antioxidants reserve which initiate chain reactions that damage brain cells. The present study investigated the role of ascorbic acid and α-tocopherol on the severity and management of TBI in rats.

Materials and Methods:

Wistar rats were subjected to closed head injury using an accelerated impact device. Rats were administered 45 mg/kg and 60 mg/kg body weight of ascorbic acid, α-tocopherol or a combination of the two vitamins for 2 weeks pre- and post injury. Blood and brain tissue homogenates were analyzed for vitamin C, vitamin E, malondialdehyde, superoxide dismutase, and creatine kinase activities.

Results:

The results indicated that TBI caused significant (P < 0.05) decreased in vitamins C and E levels in the blood and brain tissue of TBI-untreated rats. The activities of superoxide dismutase in TBI rats were markedly reduced when compared with non traumatized control and showed a tendency to increased following supplementation with vitamins C and E. Supplementation of the vitamins significantly (P < 0.05) reduced malondialdehyde in the treatment groups compared with the TBI-untreated group.

Conclusion:

The study indicated that pre and post treatment with ascorbic acid and α-tocopherol reduced oxidative stress induced by brain injury and effectively reduced mortality rate in rats.

Interactions Between Hepatitis C Virus and Mitochondria: Impact on Pathogenesis and Innate Immunity

Hepatitis C virus (HCV) causes a persistent chronic infection of hepatocytes resulting in progressive fibrosis and carcinogenesis. Abnormalities in mitochondria are prominent features of clinical disease where ultrastructural changes, alterations in electron transport, and excess reactive oxygen species (ROS) production occur. These mitochondrial abnormalities correlate with disease severity and resolve with viral eradication. Multiple viral proteins, particularly core and NS3/4a bind to mitochondria. The core and NS5a proteins primarily cause ER stress, ER Ca²⁺ release and enhance direct transfer of Ca²⁺ from ER to mitochondria. This results in electron transport changes, increased ROS production and sensitivity to mitochondrial permeability transition and cell death. The viral protease, NS3/4a, binds to mitochondria as well where it cleaves an important signaling adapter, MAVS, thus preventing viral clearance by endogenous interferon production. This review discusses the mechanisms by which HCV causes mitochondrial changes and consequences of these for disease.

Peripheral type I interferon receptor correlated with oxidative stress in chronic hepatitis B virus infection

Type I interferon receptor (IFNAR) has been involved in the progression of chronic hepatitis B (CHB). Oxidative stress is also associated with hepatitis B virus (HBV) infection and might contribute to the structure and function of protein synthesis including the IFNAR family. This study was aimed to determine the possible associations between oxidative stress and peripheral IFNAR expression in chronic HBV infection. Fifty-four CHB patients and 31 liver cirrhosis (LC) patients were consecutively collected, as well as 11 healthy subjects as controls. Expression levels of IFNAR1 and IFNAR2 in peripheral blood lymphocytes and monocytes were measured by flow cytometry. IFNAR1 and IFNAR2c mRNA were detected by real-time reverse transcription-polymerase chain reaction. Levels of plasma-soluble IFNAR and oxidative stress parameters, including xanthine oxidase (XOD), malondialdehyde (MDA), glutathione (GSH), glutathione S-transferase (GST), and glutathione peroxidase (GSH-Px) were detected by enzyme linked immunosorbent assay (ELISA). The frequencies of IFNAR1 and IFNAR2 in lymphocytes and monocytes were significantly increased in CHB and LC patients than in healthy controls. Expression levels of IFNAR1 and IFNAR2c mRNA and plasma-soluble IFNAR level in CHB and LC patients were upregulated compared with healthy controls. Mean fluorescence intensity (MFI) of IFNAR2 in monocytes of CHB patients was higher than that in LC patients. Levels of plasma XOD, MDA, and GST were significantly increased in CHB and LC patients compared with healthy controls. Meanwhile, GSH and GSH-Px in CHB and LC patients were decreased than that in healthy controls. Furthermore, plasma MDA, GSH, and GST levels in CHB patients were higher than that in LC patients. In CHB patients, plasma GST level was negatively correlated with MFI of IFNAR2 in lymphocytes. Our results suggested that oxidative stress play an important role in the regulation of IFNAR in chronic HBV infection.

HCV and oxidative stress in the liver

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.

Biomarkers of peripheral muscle fatigue during exercise

BACKGROUND

Biomarkers of peripheral muscle fatigue (BPMFs) are used to offer insights into mechanisms of exhaustion during exercise in order to detect abnormal fatigue or to detect defective metabolic pathways. This review aims at describing recent advances and future perspectives concerning the most important biomarkers of muscle fatigue during exercise.

RESULTS

BPMFs are classified according to the mechanism of fatigue related to adenosine-triphosphate-metabolism, acidosis, or oxidative-metabolism. Muscle fatigue is also related to an immunological response. impaired calcium handling, disturbances in bioenergetic pathways, and genetic responses. The immunological and genetic response may make the muscle susceptible to fatigue but may not directly cause muscle fatigue. Production of BPMFs is predominantly dependent on the type of exercise. BPMFs need to change as a function of the process being monitored, be stable without appreciable diurnal variations, correlate well with exercise intensity, and be present in detectable amounts in easily accessible biological fluids. The most well-known BPMFs are serum lactate and interleukin-6. The most widely applied clinical application is screening for defective oxidative metabolism in mitochondrial disorders by means of the lactate stress test. The clinical relevance of most other BPMFs, however, is under debate, since they often depend on age, gender, physical fitness, the energy supply during exercise, the type of exercise needed to produce the BPMF, and whether healthy or diseased subjects are investigated.

CONCLUSIONS

Though the role of BPMFs during fatigue is poorly understood, measuring BPMFs under specific, standardised conditions appears to be helpful for assessing biological states or processes during exercise and fatigue.

Cu/Zn superoxide dismutase (SOD1) induction is implicated in the antioxidative and antiviral activity of acetylsalicylic acid in HCV-expressing cells

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.

Antioxidant supplementation attenuates oxidative stress in chronic hepatitis C patients

Reactive oxygen species (ROS) overgeneration is involved in the pathogenesis of hepatitis C. The aim of this study was to evaluate the antioxidant status in the blood of HCV infected patients treated or not with standard therapy before and after supplementation of vitamins E, C and zinc. Biomarkers of oxidative stress were evaluated in the blood of three groups of patients: group 1 - controls; group 2 - HCV patients without treatment examined before and after a daily antioxidant supplementation (vitamin E 800 mg, C 500 mg and zinc 40 mg) for 6 months; and group 3 - HCV patients treated with pegylated interferon combined with ribavirin, also examined before and after the same antioxidant supplementation. Before antiviral treatment HCV patients showed enhanced superoxide dismutase, catalase and glutathione peroxidase activities and decreased glutathione reductase activity, while lipoperoxidation was increased and reduced glutathione showed decreased levels compared to controls. Treatment with standard therapy enhanced the activities of catalase and glutathione S-transferase, increased contents of protein carbonyl and promoted further reduced glutathione depletion. After antioxidant supplementation, decreased catalase and glutathione S-transferase activities, decreased lipoperoxidation in group 2, and increased reduced glutathione contents in both supplemented groups were detected. Before antioxidant supplementation, alanine aminotransferase and gamma glutamyl transferase contents showed significant increases in group 2.

CONCLUSION

Untreated HCV patients and also those treated with the standard therapy are coping with a systemic oxidative stress. The antioxidant supplementation conferred an antioxidant protection to both supplemented groups attenuating oxidation processes related to the disease.

Serum metabolomics reveals γ-glutamyl dipeptides as biomarkers for discrimination among different forms of liver disease

BACKGROUND & AIMS

We applied a metabolome profiling approach to serum samples obtained from patients with different liver diseases, to discover noninvasive and reliable biomarkers for rapid-screening diagnosis of liver diseases.

METHODS

Using capillary electrophoresis and liquid chromatography mass spectrometry, we analyzed low molecular weight metabolites in a total of 248 serum samples obtained from patients with nine types of liver disease and healthy controls.

RESULTS

We found that γ-glutamyl dipeptides, which were biosynthesized through a reaction with γ-glutamylcysteine synthetase, were indicative of the production of reduced glutathione, and that measurement of their levels could distinguish among different liver diseases. Multiple logistic regression models facilitated the discrimination between specific and other liver diseases and yielded high areas under receiver-operating characteristic curves. The area under the curve values in training and independent validation data were 0.952 and 0.967 in healthy controls, 0.817 and 0.849 in drug-induced liver injury, 0.754 and 0.763 in asymptomatic hepatitis B virus infection, 0.820 and 0.762 in chronic hepatitis B, 0.972 and 0.895 in hepatitis C with persistently normal alanine transaminase, 0.917 and 0.707 in chronic hepatitis C, 0.803 and 0.993 in cirrhosis type C, and 0.762 and 0.803 in hepatocellular carcinoma, respectively. Several γ-glutamyl dipeptides also manifested potential for differentiating between nonalcoholic steatohepatitis and simple steatosis.

CONCLUSIONS

γ-Glutamyl dipeptides are novel biomarkers for liver diseases, and varying levels of individual or groups of these peptides have the power to discriminate among different forms of hepatic disease.

Correlation between promoter methylation of glutathione-S-tranferase P1 and oxidative stress in acute-on-chronic hepatitis B liver failure

Promoter methylation of glutathione-S-transferase P1 (GSTP1) may be involved in liver damage caused by oxidative stress in acute-on-chronic hepatitis B-induced liver failure (ACHBLF). This study aimed to explore GSTP1 promoter methylation status and oxidative stress in such patients. DNA was extracted from peripheral blood mononuclear cells (PBMCs) of patients with acute-on-chronic liver hepatitis B-induced liver failure, chronic hepatitis B (CHB) and normal controls, followed by sodium-bisulfite treatment and methylation-specific PCR (MSP) analysis. Plasma malondialdehyde (MDA) adducts levels were detected by enzyme-linked immunosorbent assay as oxidative stress marker. Model for end-stage liver disease (MELD) score was employed to estimate the severity of the liver failure. Eleven of 35 patients with acute-on-chronic liver failure and 3 of 35 patients with stab le hepatitis B displayed GSTP1 promoter methylation, and the difference was significant (χ2)  = 5.71, P = 0.02). No differences in standard liver function tests were found in patients with acute-on-chronic liver failure with and without GSTP1 promoter methylation although the levels of total bilirubin were greater in those with methylation. The levels of MDA adducts were significantly higher in patients with liver failure when compared to those with CHB (12.44 ± 5.38 pmol/mg vs 8.42 ± 5.49 pmol/mg, P < 0.01), and in the patients with liver failure who had promoter methylation the levels were higher than in those who did not (15.2 ± 4.68 pmol/mg vs 11.17 ± 5.29 pmol/mg, P < 0.01). The MELD score was not significantly different between methylated and unmethylated patients with liver failure (P > 0.05), although MDA adducts were correlated with MELD scores in patients with acute-on-chronic liver failure (r = 0.579, P < 0.01). GSTP1 promoter methylation may facilitate oxidative stress-associated liver damage in ACHBLF, and oxidative stress is correlated with ACHBLF severity.

Viusid, a nutritional supplement, increases survival and reduces disease progression in HCV-related decompensated cirrhosis: a randomised and controlled trial

OBJECTIVES

Viusid is a nutritional supplement with recognised antioxidant and immunomodulatory properties which could have beneficial effects on cirrhosis-related clinical outcomes such as survival, disease progression and development of hepatocellular carcinoma (HCC). This study evaluated the efficacy and safety of viusid in patients with HCV-related decompensated cirrhosis.

DESIGN

A randomised double-blind and placebo-controlled study was conducted in a tertiary care academic centre (National Institute of Gastroenterology, Havana, Cuba). The authors randomly assigned 100 patients with HCV-related decompensated cirrhosis to receive viusid (three oral sachets daily, n=50) or placebo (n=50) during 96 weeks. The primary outcome of the study was overall survival at 96 weeks, and the secondary outcomes included time to disease progression, time to HCC diagnosis, time to worsening of the prognostic scoring systems Child-Pugh and Model for End-Stage Liver Disease, and time to a new occurrence or relapse for each one of the main clinical complications secondary to portal hypertension at 96 weeks.

RESULTS

Viusid led to a significant improvement in overall survival (90%) versus placebo (74%) (HR 0.27, 95% CI 0.08 to 0.92; p=0.036). A similar improvement in disease progression was seen in viusid-treated patients (28%), compared with placebo-treated patients (48%) (HR 0.47, 95% CI 0.22 to 0.89; p=0.044). However, the beneficial effects of viusid were wholly observed among patients with Child-Pugh classes B or C, but not among patients with Child-Pugh class A. The cumulative incidence of HCC was significantly reduced in patients treated with viusid (2%) as compared with placebo (12%) (HR 0.15, 95% CI 0.019 to 0.90; p=0.046). Viusid was well tolerated.

CONCLUSIONS

The results indicate that treatment with viusid leads to a notable improvement in overall clinical outcomes such as survival, disease progression and development of HCC in patients with HCV-related decompensated cirrhosis. Trial registration number http://ClinicalTrials.gov (NCT00502086).

Characteristic expression pattern of oxidative stress in livers with cryptogenic hepatocellular carcinoma

The mechanism responsible for the development of hepatocellular carcinoma (HCC) in the setting of oxidative stress has yet to be clearly defined. We studied the role of oxidative stress in hepatocarcinogenesis in subjects without underlying chronic viral hepatitis. The subjects were 24 patients negative for serum hepatitis B surface antigen and hepatitis C antibody tests, who underwent hepatic resection for HCC (Group N). Subjects were excluded if diagnosed with liver disease predisposing to HCC. Immunohistochemical staining for oxidative stress-related markers was performed on non-cancerous liver regions. Resected liver tissues adjacent to HCC from 24 patients with chronic hepatitis B (Group B) and 21 patients with chronic hepatitis C (Group C) were also examined. The percentage of 8-hydroxydeoxyguanosine-positive hepatocytes in Group N was significantly lower than that in Group B and that in the combined population of Groups B and C. The percentage of the area positive for 4-hydroxynonenal in Group N was significantly higher than that in Groups B or C. Meanwhile, the percentage of the area positive for manganese superoxide dismutase in Group N was not different from that in Groups B and C. In conclusion, the mechanism of hepatocarcinogenesis through oxidative stress for patients without known liver disease predisposing to HCC may differ from that for patients with chronic viral hepatitis.

Increased mitochondrial superoxide dismutase expression and lowered production of reactive oxygen species during rotavirus infection

Rotaviruses are responsible for severe diarrhea in infants and substantial economic losses in animal husbandry worldwide. We investigated the oxidant/antioxidant status in rotavirus-infected human colon adenocarcinoma (Caco-2) cell line. Our results show that within the initial 48 h of infection the expression of the mitochondrial superoxide dismutase (MnSOD) is significantly increased, which correlates with a decrease in reactive oxygen species production, and with a lack of cellular glutathione depletion. During this period the mitochondria display a hyperpolarization of the inner membrane, which leads to an increased mitochondrial membrane potential. No increase in apoptosis was detected in the infected cultures. In contrast to many viral infections which cause redox imbalance in host cells, the described virus-host interaction suggests that rotavirus infection does not lead to an induction of oxidative stress, possibly to prolong cell survival and to allow for accumulation of viral particles before cell destruction and virus release.

Antioxidant and immunomodulatory effects of Viusid in patients with chronic hepatitis C

AIM: To investigate the efficacy of Viusid, a nutritional supplement, as an antioxidant and an immunomodulator in patients with chronic hepatitis C.

METHODS: Sixty patients with chronic hepatitis C who were non-responders to standard antiviral treatment were randomly assigned to receive Viusid (3 sachets daily, n = 30) or placebo (n = 30) for 24 wk. The primary outcome was the change in serum malondialdehyde and 4-hydroxyalkenals (lipid peroxidation products). Secondary outcomes were changes in serum tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ) and interleukin-10 (IL-10).

RESULTS: Statistically significant reductions in serum 4-hydroxyalkenals and malondialdehyde levels were observed in both groups in comparison with pretreatment values, but the patients who received Viusid showed a more marked reduction as compared with the control group (P = 0.001). TNF-α levels significantly increased from 6.9 to 16.2 pg/mL (P < 0.01) in the patients who received placebo in comparison with almost unchanged levels, from 6.6 to 7.1 pg/mL (P = 0.26), in the patients treated with Viusid (P = 0.001). In addition, IL-10 levels were markedly increased in the patients treated with Viusid (from 2.6 to 8.3 pg/mL, P = 0.04) in contrast to the patients assigned to placebo (from 2.8 to 4.1 pg/mL, P = 0.09) (P = 0.01). Likewise, the administration of Viusid markedly increased mean IFN-γ levels from 1.92 to 2.89 pg/mL (P < 0.001) in comparison with a reduction in mean levels from 1.80 to 1.68 pg/mL (P = 0.70) in the placebo group (P < 0.0001). Viusid administration was well tolerated.

CONCLUSION: Our results indicate that treatment with Viusid leads to a notable improvement of oxidative stress and immunological parameters in patients with chronic hepatitis C.

Insulin resistance and not steatosis is associated with modifications in oxidative stress markers in chronic hepatitis C, non-3 genotype

BACKGROUND

Modifications of oxidative stress are reported in hepatitis C. The relationship between insulin resistance (IR), steatosis and oxidative stress is not established.

MATERIALS AND METHODS

One hundred and eighty-seven HCV-RNA patients were assessed by determination of biochemical, metabolic and viral features, HOMA-IR and morphological alterations. In the 52-non-3 genotypes sub-group and 35 healthy individuals, thiobarbituric acid (TBARS), total glutathione (total-GSH), vitamins C and E, lycopene, beta-carotene, glutathione peroxidase (GPx), catalase and superoxide dismutase were determined.

RESULTS

In non-3 genotype patients, steatosis was associated with higher values of BMI, HOMA-IR and triglycerides. In the 52-HCV sub-group, values of TBARS, GPx and total-GSH differ from the control group. Despite these, differences could not be observed according to the presence of steatosis, patients with IR presented significant differences regarding total-GSH (p=0.019), beta-carotene (p=0.006), lycopene (p=0.005) and GPx (p=0.009).

CONCLUSION

In non-3 genotype HCV carries, IR, and not steatosis, is associated with modifications in serum levels of oxidative stress.

Hydroxyoctadecadienoic acid as a potential biomarker for oxidative stress in patients with chronic hepatitis C

BACKGROUND AND AIM

The possible involvement of oxidative stress in hepatitis C virus (HCV)-induced liver damage and hepatocarcinogenesis has been reported. We have recently developed a novel method to measure total hydroxyoctadecadienoic acid (tHODE) and have proposed its usefulness as a biomarker for lipid peroxidation. The present study was undertaken to evaluate oxidative stress in HCV-infected liver diseases by several potential oxidative stress markers including tHODE and further to validate the biomarkers for evaluating the efficacy of iron reduction therapy.

METHODS

Total hydroxyoctadecadienoic acid, total 8-iso-prostagrandin F(2alpha) (t8-iso-PGF(2alpha)), selenoprotein P and other antioxidant compounds were measured in the plasma and erythrocytes obtained from 42 healthy controls and 78 HCV patients. Plasma levels of biomarkers and antioxidants were also assessed during the iron reduction therapy for 16 weeks in 12 HCV patients.

RESULTS

The concentrations of tHODE in the plasma and erythrocytes and t8-iso-PGF(2alpha) in the plasma of chronic HCV-infected patients were significantly higher than those of healthy controls. Plasma levels of vitamin E and vitamin C of HCV-infected patients were lower than those of the controls. Furthermore, the plasma tHODE significantly correlated with serum aminotransferases and type IV collagen-7S domain in chronic HCV-infected patients. During the iron reduction therapy, the plasma levels of tHODE but not t8-iso-PGF(2alpha) decreased and inversely its stereo-isomer ratio (ZE/EE) increased in parallel with the decreases of serum alanine aminotransferase, ferritin and alpha-fetoprotein.

CONCLUSION

The levels of tHODE in chronic HCV-infected patients can be a useful biomarker for the evaluation of oxidative stress in chronic hepatitis C.

Cellular immune response to infection by different genotypes of hepatitis C virus

The present study aimed to estimate the cellular immune response to infection by different HCV genotypes in some Egyptian patients with chronic liver disease. HCV-RNA and HCV genotypes were conducted using type-specific primers to amplify the core region of HCV genome. The levels of IFN-gamma and TNF-alpha, PIIINP, SOD enzyme were also determined. The results showed that genotype 4 was the prevalent one (88.57%).Genotype 3 was found mixed with genotype 2 and 4 (11.42% and 34.28% respectively). Genotype 1 was absent from patients under study. No significant differences were observed in the level of IFN-gamma interferon, SOD enzyme and ALT enzyme between those genotypes. On the other hand the level of TNF-alpha was greatly increased in patients infected with mixed HCV genotypes 3, 4 compared with patients with genotype 4 and those infected with mixed genotypes 2, 3. Otherwise PIIINP was decreased significantly of the same group compared with other groups.

Fibroblast protein profile analysis highlights the role of oxidative stress and vitamin K recycling in the pathogenesis of pseudoxanthoma elasticum

Pseudoxanthoma elasticum (PXE) is a genetic disorder associated to mutations in the ABCC6 gene; however, the pathogenetic mechanisms leading to elastic fibre calcifications and to clinical manifestations are still unknown. Dermal fibroblasts, directly involved in the production of the extracellular milieu, have been isolated from healthy subjects and from patients affected by PXE, cultured in vitro and characterized for their ability to produce reactive oxygen species, for structural and functional properties of their cell membranes, for changes in their protein profile. Data demonstrate that oxidative stress has profound and endurable consequences on PXE fibroblast phenotype being responsible for: reduced levels of global DNA methylation, increased amount of carbonylated proteins and of lipid peroxidation products, altered structural properties of cell membranes, modified protein expression. Data shed new light on the pathogenetic pathways in PXE, by identifying a network of proteins affecting elastic fibre calcification through inefficient vitamin K recycling, and highlight the role of differentially expressed proteins as targets for validating the efficacy of future therapeutic strategies aiming to delay and/or revert the pathologic phenotype of PXE fibroblasts. Moreover, data open new perspectives for investigating PXE-like phenotypes in the absence of ABCC6 mutations.

Oxidant and antioxidant of arylesterase and paraoxonase as biomarkers in patients with hepatitis C virus

OBJECTIVES

Oxidative stress plays a role in the pathogenesis in patients with HCV infection. The objective of this study was to evaluate oxidant and antioxidant biomarkers in patients with HCV.

DESIGN AND METHODS

Serum malonaldehyde (MDA) and nitric oxide (NO) levels and the activities of myeloperoxidase (MPO), arylesterase (AE) and paraoxonase-1 (PON1) were determined in 23 chronic and 21 cirrhotic patients with HCV and 21 healthy subjects.

RESULTS

Cirrhotic patients with HCV had higher serum NO level and MPO activity while lower AE and PON1 activities than the chronic. Significant inverse correlation was observed between MDA and PON1 activity in patients with HCV. The most significant HCV biomarker was MDA, AE, NO and PON1. The best combined ones for sensitivity, specificity were MDA+albumin, PON1+AST, and PON1+albumin.

CONCLUSIONS

The use of the MDA, MPO, AE, NO and PON1 as biomarkers might be useful tools, helping in the monitoring of patients with HCV.

[Effects of supplementation with the antioxidant flavonoid, silymarin, in chronic hepatitis C patients treated with peg-interferon + ribavirin. A placebo-controlled double blind study]

Since oxidative stress may play a pathogenetic role in chronic hepatitis C, and sustained virological response to antiviral therapy is limited in HCV1 genotype infection, a double blind study was performed in HCV1 patients treated with pegylated interferon + ribavirin, to assess the efficacy of supplementation with the antioxidant flavonoid silymarin.

PATIENTS AND METHODS

Thirty-two naive HCV1 positive patients with biopsy proven chronic hepatitis C, to be treated with pegylated interferon + ribavirin, have been randomized: group A): 16 patients have been given the antiviral therapy for 6-12 months plus placebo for the first 3 months; group B): 16 patients have been treated with pegylated interferon + ribavirin for 6-12 months plus silymarin, 2 x 166 mg/day, was given for 3 months. Serum alanine aminotransferase and HCV-RNA levels as well as parameters of oxidative stress such as plasma or red blood cell hemolysate, malondialdehyde, superoxide dismutase, glutathione peroxidase, catalase and myeloperoxidase were determined after 0, 1, 3, 6 and 12 months during the treatment. Sustained virological response as undetectable serum HCV RNA was evaluated 24 weeks after the end of therapy.

RESULTS

In the silymarin group, a more rapid decrease in the malondialdehyde level as well as a marked decrease in superoxide dismutase and an increase in myeloperoxidase activity after month 12 were found, alanine aminotransferase normalized in 6/16 (vs control 9/16) cases, and sustained virological response occurred in 3/16 (vs 7/16) patients.

DISCUSSION/CONCLUSION

Although silymarin supportation to antiviral therapy improved oxidative stress, it was able to affect favourably neither the alanine aminotransferase nor the sustained virological response. These contradictory findings may be related to randomization bias as patients in study group B had more negative predictors of response: they were older with higher fibrosis score and even with more severe pretreatment baseline oxidative stress. Regarding the recently published in vitro experiments with silybinin on HCV replication as well as the newest convincing clinical observations, we do suggest further studies with more than three times higher doses of silymarin in controlled trials to assess the value of this supplementation in antivirally treated HCV patients.

Manganese superoxide dismutase activity and incidence of hepatocellular carcinoma in patients with Child-Pugh class A liver cirrhosis: a 7-year follow-up study

AIMS

To evaluate possible modifications in the manganese superoxide dismutase (MnSOD) activity during neoplastic transformation of a cirrhotic liver and to find out whether its assessment may have predictive value to identify cirrhotic patients at a higher risk of hepatocellular carcinoma (HCC).

METHODS

Seventy-one consecutive subjects with Child-Pugh class A liver cirrhosis were recruited. At the time of enrolment, HCC was diagnosed in 20 cirrhotic patients. The 51 cirrhotic patients without HCC were followed up for the occurrence of tumour by 6-monthly screening for 7 years. During follow-up, 16 patients developed HCC. Seventy healthy subjects formed the control group. MnSOD activity was assayed spectrophotometrically.

RESULTS

Serum MnSOD activity was significantly lower in 70 healthy subjects compared with 51 cirrhotic patients and 20 cirrhotic patients with HCC. Cirrhotic patients who developed HCC during follow-up showed significantly higher values of MnSOD activity than HCC-free patients. The best cut-off of MnSOD activity was 0.40 U/ml. At this cut-off, chi2 analysis revealed that MnSOD activity was significantly different between the HCC-free cirrhotic patients and cirrhotic patients who developed HCC.

CONCLUSION

The present findings suggest that during neoplastic transformation of cirrhotic liver, an increase in MnSOD activity may occur already during the precancerous phase, making this enzyme a probable malignancy-associated parameter.

Viusid, a nutritional supplement, in combination with interferon alpha-2b and ribavirin in patients with chronic hepatitis C

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.

The effect of antioxidant supplementation on hepatitis C viral load, transaminases and oxidative status: a randomized trial among chronic hepatitis C virus-infected patients

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.

Oxidative stress and antioxidant defense in patients with chronic hepatitis C patients before and after pegylated interferon alfa-2b plus ribavirin therapy

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.

Mitochondrial oxidative stress in the lungs of cystic fibrosis transmembrane conductance regulator protein mutant mice

Cystic fibrosis is a fatal genetic disorder involving dysfunction of the cystic fibrosis transmembrane regulator protein (CFTR) resulting in progressive respiratory failure. Previous studies indicate that CFTR regulates cellular glutathione (GSH) transport and that dysfunctional CFTR is associated with chronic pulmonary oxidative stress. The cause and the source of this oxidative stress remain unknown. The current study examines the role of the mitochondria in CFTR-mediated pulmonary oxidative stress. Mitochondrial GSH levels and markers of DNA and protein oxidation were assessed in the lung mitochondria from CFTR-knockout mice. In addition, in vitro models using human CFTR-sufficient and -deficient lung epithelial cells were also employed. Mitochondrial GSH levels were found to be decreased up to 85% in CFTR-knockout mice, and 43% in human lung epithelial cells deficient in CFTR. A concomitant 29% increase in the oxidation of mitochondrial DNA, and a 30% loss of aconitase activity confirmed the existence of a mitochondrial oxidative stress. Flow cytometry revealed significantly elevated levels of cellular reactive oxygen species (ROS) in CFTR-deficient human lung cells. These studies suggest that dysfunctional CFTR leads to an increase in the level of ROS and mitochondrial oxidative stress. This oxidative stress, however, appears to be a consequence of lower mitochondrial GSH levels and not increased oxidation of GSH. Further studies are needed to determine how CFTR deficiency contributes to mitochondrial oxidative stress and the role this plays in CFTR-mediated lung pathophysiology.

Expression of oxidative stress-related molecules in circulating leukocytes and urine in patients with chronic viral hepatitis

AIMS

Oxidative stress plays a role in pathogenesis of chronic viral hepatitis. Expression of oxidative stress-related molecules remains to be clarified.

METHODS

4-hydroxy-2-nonenal (4-HNE), 4-hydroxy-2-hexenal (4-HHE), catalase, superoxide dismutase-1 (SOD-1), glutathione peroxidase-1, thioredoxin (TRX) in leukocytes and urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) were examined in 164 persons, including 130 chronic viral hepatitis patients and 34 normal individuals, by Western blot analysis and enzyme-linked immunosorbent assay, respectively. Hepatic expression of these proteins was immunohistochemically examined in 12 patients with chronic viral hepatitis, compared with three persons without liver damage.

RESULTS

The 4-HNE/beta-actin ratios in chronic viral hepatitis were significantly higher than those in normal individuals (P<0.01), and were significantly correlated with asparate aminotransferase (AST) and alanine aminotransferase (ALT) (P<0.01, each). The catalase/beta-actin and SOD-1/beta-actin ratios in chronic viral hepatitis were higher than those in normal individuals, and were significantly correlated with 4-HNE/beta-actin ratios (P<0.01, each). Hepatic expression of 4-HNE, 4-HHE, catalase, SOD-1 and TRX in chronic viral hepatitis was higher than that without liver damage. Urinary excretion of 8-OHdG was not changed in chronic viral hepatitis.

CONCLUSIONS

The results of the present study suggest that expression of oxidative stress-related molecules in leukocytes is upregulated in relation to serum aminotransferase levels.