Blood micronutrient, oxidative stress, and viral load in patients with chronic hepatitis C

Linkage of some trace elements, peripheral blood lymphocytes, inflammation, and oxidative stress in patients undergoing either hemodialysis or peritoneal dialysis

BACKGROUND

Changes in essential trace elements may affect the inflammatory and immunological state of patients on hemodialysis (HD) or peritoneal dialysis (PD). Therefore, we aimed to determine trace element content and markers of oxidative stress, inflammation, and immune status in HD and PD patients and to assess the relationships among these parameters.

METHODS

Patients on either HD (n = 20) or PD (n = 20) and age-, sex-, body mass index-matched healthy individuals (n = 20) were enrolled in the study. The trace elements zinc, copper, selenium, and iron; markers of oxidative stress thiobarbituric acid reactive substances (TBARS) and protein carbonyl levels; activities of antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase; percentages of CD3 T lymphocytes and the subsets CD4 and CD8; the CD4/CD8 ratio; and C-reactive protein (CRP) were measured.

RESULTS

All dialysis patients had low levels of albumin and hemoglobin. Significantly decreased percentages of CD3 and CD4 T lymphocytes and increased levels of CRP, TBARS, and carbonyl compounds were observed in HD patients. HD patients also had elevated erythrocyte SOD, lower GPx and catalase activities, and decreased levels of Se, Zn, and Fe in comparison to PD patients and healthy subjects. In addition, CRP was positively associated with TBARS and carbonyl levels, but was significantly inversely associated with Zn and Se levels. Positive correlations were found between T lymphocyte CD3 and CD4 percentages and Zn, Se, and Fe levels.

CONCLUSIONS

There were significant decreases in T lymphocyte-related immunological regulation and increased inflammation and oxidative stress in dialysis patients. Essential trace element status was independently related to immune status, inflammation, and oxidative damage.

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.

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-alpha (TNF-alpha), interferon-gamma (IFN-gamma) 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-alpha 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-gamma 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.

Metabolic investigations in patients with hepatitis B and C

AIM: To investigate the similarities and dissimilarities in patients with hepatitis B and hepatitis C, clinically and metabolically.

METHODS: Fifty patients with hepatitis B virus and hepatitis C virus infection were included in this study, along with fifty healthy controls for comparison purposes. Intravenous blood (10 mL) samples from patients and healthy subjects were collected and made to clot before serum was separated and immediately levels of the enzymes, alkaline phosphatase (ALK), creatinine phosphokinase (CPK), lactate dehydrogenase (LDH), serum glutamate oxaloacetate transaminase (s-GOT) and serum glutamate pyruvate transaminase (s-GPT) were determined by a kit method. For total content of each metal the serum samples were analyzed using atomic absorption spectrophotometry. Levels of cholesterol, triglycerides, urea, creatinine and uric acid were determined using a kit method on Microlab 300.

RESULTS: Serum magnesium and copper levels remained unchanged, whereas the concentration of zinc decreased and iron increased significantly in both groups of patients. Total antioxidant activity was significantly decreased in both hepatitis B and C. Among the enzymes analyzed, ALK, s-GPT, LDH and s-GOT were all significantly increased in both patients with hepatitis B and C whereas CPK was significantly decreased in patients with hepatitis B and remained unchanged in patients with hepatitis C.

CONCLUSION: The information accumulated by this study will help provide a better understanding of involved metabolic processes in order to design appropriate therapeutic approaches for treating these patients, so they can recover and lead normal lives.

Relative and combined effects of chronic alcohol consumption and HCV infection on serum zinc, copper, and selenium

In alcoholic hepatitis, Kupffer cells are activated by intestinal gram-bacteria, leading to cytokine production and free radicals release, which, enhancing cytokine secretion, create a positive feedback loop which contributes to liver inflammation. Free radicals also damage the liver in chronic hepatitis C virus (HCV) infection, a condition frequently associated to alcohol consumption. In both situations, activity of antioxidant enzymes and of its cofactors zinc (Zn), selenium (Se), and copper (Cu) is important. This study was performed to assess the relative and combined effects of chronic alcoholism and HCV infection on serum Se, Zn, and Cu, and its relation with serum malondialdehyde (MDA) and tumor necrosis factor-α, interferon-γ, and interleukins (IL) 4, 6, and 8, in 19 HCV- alcoholic patients, 12 HCV+ alcoholic patients, nine HCV+ non-alcoholic patients, and 20 controls. Serum Zn and Se were lower in both HCV+ and HCV- alcoholic patients, whereas serum Cu was lower in HCV+ individuals. Serum Zn and Se were related to liver function derangement. MDA levels were higher in alcoholics, but no relation was observed between trace elements and MDA or cytokines, so that our results do not support a relevant role of the analyzed trace elements in the pathogenesis of chronic liver disease.

Chronic hepatitis C: quantitative EPR analysis of nitrogen oxide and copper in patients' blood

Measurements of nitrogen oxide and copper in the blood of 57 patients with chronic viral hepatitis C was carried out before antiviral therapy by electron paramagnetic resonance on a Radiopan EPR spectrometer. The results indicate elevated levels of nitrogen oxide and copper in the blood of these patients in comparison with normal subjects. Comparison of these findings with the results of a previous analysis of redox status of patients with chronic viral hepatitis C indicate that this disease is characterized by a significant pro-oxidant shift in the realization of redox processes and disorders in the metal ligand homeostasis (at least as regards copper).

Glucose-6-phosphate dehydrogenase deficiency enhances enterovirus 71 infection

Variations in the cellular microenvironment affect the host's susceptibility to pathogens. Using glucose-6-phosphate dehydrogenase (G6PD)-deficient fibroblasts as a model, this study demonstrated that the cellular redox status affects infectivity as well as the outcome of enterovirus 71 (EV71) infection. Compared with their normal counterparts, G6PD-deficient cells supported EV71 replication more efficiently and showed greater cytopathic effect and loss of viability. Mechanistically, viral infection led to increased oxidative stress, as indicated by increased dichlorofluorescein fluorescence and a diminished ratio of glutathione (GSH) to its disulfide form (GSSG), with the effect being greater in G6PD-deficient cells. Exogenous expression of active G6PD in the deficient cells, which increased the intracellular GSH : GSSG ratio, suppressed the generation of viral progeny. Consistent with this, treatment with N-acetylcysteine offered resistance to EV71 propagation and a cytoprotective effect on the infected cells. These findings support the notion that G6PD status, and thus redox balance, is an important determinant of enteroviral infection.

Selenium in food and the human body: a review

Selenium levels in soil generally reflect its presence in food and the Se levels in human populations. Se food content is influenced by geographical location, seasonal changes, protein content and food processing. Periodic monitoring of Se levels in soil and food is necessary. Diet is the major Se source and approximately 80% of dietary Se is absorbed depending on the type of food consumed. Se bioavailability varies according to the Se source and nutritional status of the subject, being significantly higher for organic forms of Se. Se supplements can be beneficial for subjects living in regions with very low environmental levels of Se. Several strategies have been followed: (1) employment of Se-enriched fertilizers; (2) supplementation of farm animals with Se; (3) consumption of multimicronutrient supplements with Se. Nevertheless, detailed investigations of possible interactions between Se supplements and other food components and their influence on Se bioavailability are needed. Suppliers also need to provide more information on the specific type of Se used in supplements. In addition, research is lacking on the mechanisms through which Se is involved in hepatocyte damage during hepatopathies. Although Se potential as an antioxidant for the prevention of cardiovascular diseases (CVD) is promising, additional long-term intervention trials are necessary. As a result, indiscriminate Se supplements cannot be reliably recommended for the prevention of CVD in human beings. Some interesting findings reported an association of Se intake with a reduced prevalence and risk for prostate and colon cancer. However, random trials for other cancer types are inconclusive. As a final conclusion, the general population should be warned against the employment of Se supplements for prevention of hepatopathies, cardiovascular or cancer diseases, because benefits of Se supplementation are still uncertain, and their indiscriminate use could generate an increased risk of Se toxicity.

The influence of selenium substitution on microcirculation and glutathione metabolism after warm liver ischemia/reperfusion in a rat model

Ischemia/reperfusion (I/R) injury is a variable yet unavoidable complication in liver surgery and transplantation. Selenium-dependent glutathione-peroxidases (GPx) and selenoproteins function as antioxidant defense systems. One target in preventing I/R injury is enhancing the capacity of endogenous redox defense. It was the aim of this study to analyze the effects of selenium substitution on liver microcirculation, hepatocellular injury and glutathione status in a model of partial warm liver ischemia in the rat. Sodium selenite was administered in three different dosages i.v.: 0.125 microg/g, 0.25 microg/g and 0.375 microg/g body weight and compared to an untreated control group (each n=10). Intravital microscopy was performed after 70 min of partial warm liver ischemia and 90 min of reperfusion. Liver tissue and plasma samples were taken at the end of the experiment for laboratory analysis. Microcirculation improved significantly in all therapy groups in contrast to control animals. ALT levels decreased significantly whereas malondialdehyde levels remained unchanged. In liver tissue, selenium supplementation caused an increase in the amount of total and reduced glutathione without changes in oxidized glutathione. This effect is likely mediated by selenite itself and selenoprotein P rather than by modulating GPx activity. We were able to show that selenite substitution has an immediate protective effect on I/R injury after warm hepatic ischemia by acting as a radical scavenger and preserving the antioxidative capacity of the liver.

Genetic polymorphism in the manganese superoxide dismutase gene is associated with an increased risk for hepatocellular carcinoma in HCV-infected Moroccan patients

Hepatocellular carcinoma (HCC) ranks among the 10 most common cancers worldwide. The main risk factors for its development are hepatitis B and C virus infections. Hepatitis B and C viruses induce chronic inflammation and oxidative stress that could predispose a cell to mutagenesis and proliferation. Manganese superoxide dismutase (MnSOD) catalyses the detoxification of free radicals, thus playing a crucial role in the protection against damage. A valine (Val) to alanine (Ala) substitution at amino acid 9, mapping within the mitochondrion-targeting sequence of the MnSOD gene, has been associated with an increased cancer risk. The aim of our study was to investigate a possible association of the Val/Ala-MnSOD polymorphism and HCC development in Moroccan patients. Genotypes were determined by means of PCR and RFLP analysis in 96 patients with HCC and 222 control subjects matched for age, sex, and ethnicity. Homozygous Ala/Ala carriers were 31% in the cases and 18% in the controls, which corresponds to an odds ratio (OR) of 2.89, with a 95% confidence interval (CI) of 1.47-5.68. Stratification into subgroups based on HCV infection status revealed an even more increased risk for homozygous Ala/Ala carriers with hepatitis C infection (38.2% in the cases versus 14.8% in the control subjects OR, 5.09; 95% CI, 1.76-14.66). Our findings provide further evidence of an association between the Ala-9Val MnSOD polymorphism and HCC occurrence in hepatitis C virus-infected Moroccan patients.

Redox regulation of hepatitis C in nonalcoholic and alcoholic liver

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.

Interactions among infections, nutrients and xenobiotics

During recent years there have been several incidents in which symptoms of disease have been linked to consumption of food contaminated by chemical substances (e.g., 2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD). Furthermore, outbreaks of infections in food-producing animals have attracted major attention regarding the safety of consumers, e.g., Bovine Spongiform Encephalitis (BSE) and influenza in chicken. As shown for several xenobiotics in an increasing number of experimental studies, even low-dose xenobiotic exposure may impair immune function over time, as well as microorganism virulence, resulting in more severe infectious diseases and associated complications. Moreover, during ongoing infection, xenobiotic uptake and distribution are often changed resulting in increased toxic insult to the host. The interactions among infectious agents, nutrients, and xenobiotics have thus become a developing concern and new avenue of research in food toxicology as well as in food-borne diseases. From a health perspective, in the risk assessment of xenobiotics in our food and environment, synergistic effects among microorganisms, nutrients, and xenobiotics will have to be considered. Otherwise, such effects may gradually change the disease panorama in society.

Zinc and the liver: an active interaction

Zinc is an essential trace element, exerting important antioxidant, anti-inflammatory, and antiapoptotic effects. It affects growth and development and participates in processes such as aging and cancer induction. The liver is important for the regulation of zinc homeostasis, while zinc is necessary for proper liver function. Decreased zinc levels have been implicated in both acute and chronic liver disease states, and zinc deficiency has been implicated in the pathogenesis of liver diseases. Zinc supplementation offers protection in experimental animal models of acute and chronic liver injury, but these hepatoprotective properties have not been fully elucidated. In the present review, data on zinc homeostasis, its implication in the pathogenesis of liver diseases, and its effect on acute and chronic liver diseases are presented. It is concluded that zinc could protect against liver diseases, although up to now the underlying pathophysiology of zinc and liver interactions have not been defined.

Influence of Glucose in the Dialysate on the Activity of Erythrocyte-Glutathione-Peroxidase and Blood Selenium Concentration in Hemodialyzed Patients

BACKGROUND

The aim of the study was to show the influence of glucose in the dialysate on the intensity of oxidative stress, activity of glutathione peroxidase (GSHPx) and concentration of selenium in patients undergoing regular hemodialysis.

METHODS

The study was comprised of 85 patients hemodialyzed with dialysate containing glucose [HD-g(+)] or not containing glucose [HD-g(-)], patients with chronic renal failure on conservative treatment and control group. The concentrations of the products of reaction with thiobarbituric acid (TBARS), concentration of selenium in erythrocytes and plasma, concentration of copper in erythrocytes and the activity of GSHPx were determined.

RESULTS

GSHPx had significantly higher activity in HD-g(-) group before HD than in control group. In HD-g(+) group before hemodialysis, the activity of GSHPx was significantly lower than in the control group. After HD, the activity showed a statistically significant increase. In both hemodialyzed groups, selenium concentration before hemodialysis both in plasma and erythrocytes was significantly lower, compared to control group. In the group of patients with CRF on conservative treatment, selenium concentration in RBC was significantly higher, compared to concentrations obtained in other groups except for control group. The increase of copper concentration in erythrocytes was accompanied by the increase of oxidative stress and increase of TBARS concentration. The opposite relationship was observed for selenium-its concentration was inversely correlated to copper concentration.

CONCLUSIONS

In both groups of hemodialyzed patients, hemodialysis caused the increase of GSHPx in erythrocyte activity and increase of plasma and erythrocyte selenium concentration.

Effect of iron depletion on serum markers of fibrogenesis, oxidative stress and serum liver enzymes in chronic hepatitis C: results of a pilot study

BACKGROUND

Hepatic iron deposition has been associated with decreased response to interferon-alpha monotherapy, and has been speculated to contribute to disease progression in chronic hepatitis C (CHC). We performed this study to evaluate the effect of iron depletion on biochemical and virologic markers, and markers of lipid peroxidation and fibrogenesis.

MATERIALS AND METHODS

Eighteen patients with CHC who did not have a virologic response to interferon monotherapy underwent weekly phlebotomies until iron depletion (serum ferritin <50 ng/ml). Serum levels of alanine transaminase (ALT), hepatitis C virus-RNA, transferrin saturation, ferritin, 8-isoprostane, hyaluronic acid, amino-terminal procollagen III peptide and YKL-40 were measured before and after iron depletion.

RESULTS

There was a statistically significant reduction of serum ALT, transferrin saturation and serum ferritin after iron depletion (range 4-11 phlebotomies). Serum ALT returned to normal after iron depletion in four (22%) patients. There was a significant reduction in serum procollagen III peptide level among patients who achieved biochemical response. No significant reduction was noted in serum levels of other markers.

CONCLUSIONS

Iron depletion was associated with a biochemical response in 22% of patients who did not respond to interferon monotherapy. There was a significant reduction in a key marker of fibrogenesis among patients with biochemical response. These data support longer-term studies of iron depletion in CHC.

Redox modulation of the hepatitis C virus replication complex is calcium dependent

Reactive species and perturbation of the redox balance have been implicated in the pathogenesis of many viral diseases, including hepatitis C. Previously, we made a surprising discovery that concentrations of H(2)O(2) that are nontoxic to host cells disrupted the hepatitis C virus (HCV) replication complex (RC) in Huh7 human hepatoma cells in a manner that suggested signaling. Here, we show that H(2)O(2) and interferon-gamma have comparable effects on the HCV subgenomic and genomic RNA replication in Huh7 cells. H(2)O(2) induced a gradual rise in the intracellular calcium concentration ([Ca(2+)](i)). Both rapid and sustained suppression of HCV RNA replication by H(2)O(2) depended on this calcium elevation. The peroxide-induced [Ca(2+)](i) elevation was independent of extracellular calcium and derived, at least in part, from the endoplasmic reticulum. Likewise, the suppression of the HCV RC by H(2)O(2) was independent of extracellular calcium but required an intracellular calcium source. Other agents that elevated [Ca(2+)](i) could also suppress the HCV RC, suggesting that calcium elevation might be sufficient to suppress HCV RNA replication. In conclusion, oxidants may modulate the HCV RC through calcium. Effects on the infectivity and the morphogenesis of HCV remain to be determined. These findings suggest possible regulatory roles for redox and calcium signaling during viral infections.

Mechanisms of liver injury. III. Oxidative stress in the pathogenesis of hepatitis C virus

Hepatitis C virus (HCV) is a major cause of viral hepatitis that can progress to hepatic fibrosis, steatosis, hepatocellular carcinoma, and liver failure. HCV infection is characterized by a systemic oxidative stress that is most likely caused by a combination of chronic inflammation, iron overload, liver damage, and proteins encoded by HCV. The increased generation of reactive oxygen and nitrogen species, together with the decreased antioxidant defense, promotes the development and progression of hepatic and extrahepatic complications of HCV infection. This review discusses the possible mechanisms of HCV-induced oxidative stress and its role in HCV pathogenesis.