Increased oxidative stress associated with the severity of the liver disease in various forms of hepatitis B virus infection

Protective Role of Sirtuin3 (SIRT3) in Oxidative Stress Mediated by Hepatitis B Virus X Protein Expression

Background/Aim

The hepatitis B virus (HBV) infection is accompanied by the induction of oxidative stress, especially mediated by HBV X protein (HBx). Oxidative stress has been implicated in a series of pathological states, such as DNA damage, cell survival and apoptosis. However, the host factor by which cells protect themselves under this oxidative stress is poorly understood.

Methodology/Principal Findings

In this study, we first confirmed that HBV infection significantly induced oxidative stress. Moreover, viral protein HBx plays a major role in the oxidative stress induced by HBV. Importantly, we found that mitochondrial protein SIRT3 overexpression could decrease reactive oxygen species (ROS) induced by HBx while SIRT3 knockdown increased HBx-induced ROS. Importantly, SIRT3 overexpression abolished oxidative damage of HBx-expressing cells as evidenced by γH₂AX and AP sites measurements. In contrast, SIRT3 knockdown promoted HBx-induced oxidative damage. In addition, we also observed that oxidant H₂O₂ markedly promoted HBV replication while the antioxidant N-acetyl-L-cysteine (NAC) inhibited HBV replication. Significantly, SIRT3 overexpression inhibited HBV replication by reducing cellular ROS level.

Conclusions/Significance

Collectively, these data suggest HBx expression induces oxidative stress, which promotes cellular oxidative damage and viral replication during HBV pathogenesis. Mitochondrial protein SIRT3 protected HBx expressing-cells from oxidative damage and inhibited HBV replication possibly by decreased cellular ROS level. These studies shed new light on the physiological significance of SIRT3 on HBx-induced oxidative stress, which can contribute to the liver pathogenesis.

Superoxide Dismutase 1 Protects Hepatocytes from Type I Interferon-Driven Oxidative Damage

Tissue damage caused by viral hepatitis is a major cause of morbidity and mortality worldwide. Using a mouse model of viral hepatitis, we identified virus-induced early transcriptional changes in the redox pathways in the liver, including downregulation of superoxide dismutase 1 (Sod1). Sod1(-/-) mice exhibited increased inflammation and aggravated liver damage upon viral infection, which was independent of T and NK cells and could be ameliorated by antioxidant treatment. Type I interferon (IFN-I) led to a downregulation of Sod1 and caused oxidative liver damage in Sod1(-/-) and wild-type mice. Genetic and pharmacological ablation of the IFN-I signaling pathway protected against virus-induced liver damage. These results delineate IFN-I mediated oxidative stress as a key mediator of virus-induced liver damage and describe a mechanism of innate-immunity-driven pathology, linking IFN-I signaling with antioxidant host defense and infection-associated tissue damage. VIDEO ABSTRACT.

Protective Effect of Micronized Purified Flavonoid Fraction on Ischemia/Reperfusion Injury of Rat Liver

BACKGROUND

Flavonoids have been subjected to considerable investigation because of its antioxidant and anti-inflammatory properties. However, there is no previously reported study about its effect on hepatic ischemia/reperfusion (I/R). We investigated the effects of micronized purified flavonoid fraction (MPFF) on hepatic I/R injury in rats.

METHODS

Thirty rats were recruited in the study as follows: group A, sham operation (n = 10); group B, I/R (n = 10); and group C, I/R+MPFF (n = 10). In group C, rats received (80 mg/kg/day) MPFF by gavage for 3 days before surgery, 30 minutes before ischemia and just before the reperfusion. Blood samples were taken, and serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) levels were measured to assess liver functions. Liver tissues were taken for histological evaluation and to determine the total antioxidant capacity (TAC), catalase (CAT), total oxidant status (TOS), oxidative stress index (OSI), and myeloperoxidase (MPO).

RESULTS

The present data showed a decrease in AST, ALT, and LDH levels in the MPFF-treated rats when compared with I/R group rats (P < .001 for all). In the MPFF-treated rats, tissue levels of TOS, OSI, and MPO were significantly lower than those in the I/R group (P < .01, P < .001, and P < .05, respectively). Increases in TAC and CAT levels were statistically significant in the MPFF-treated rats compared with the I/R group (P = .01 for both). On the other hand, MPFF attenuated histological alterations that were induced by I/R.

CONCLUSIONS

The present study demonstrates that MPFF ameliorates I/R-induced liver damage, probably through antioxidant and anti-inflammatory properties.

Methylation of the Glutathione-S-Transferase P1 Gene Promoter Is Associated with Oxidative Stress in Patients with Chronic Hepatitis B

Glutathione-S-transferase P1 (GSTP1) and glutathione-S-transferase M3 (GSTM3) catalyze the glutathione-related clearance of xenobiotics. The methylation of these gene promoters was associated with oxidative stress that induced liver damage. This study aims to explore the relationship among GSTP1 and GSTM3 methylation, DNA methyltransferases (DNMTs) expression, and oxidative stress in patients with chronic hepatitis B (CHB). We retrospectively enrolled 153 patients with CHB and 40 healthy controls (HCs). The GSTP1 and GSTM3 methylation status, DNMTs mRNA levels in peripheral mononuclear cells (PBMCs) and TNF-α and malondialdehyde (MDA) levels in plasma were detected. GSTP1 methylation was significantly higher in patients with CHB than HCs (P = 0.047). Patients with HBeAg-positive CHB showed significantly higher GSTP1 methylation than those with HBeAg-negative CHB (P = 0.017) and HCs (P = 0.007). No significant difference was observed between GSTP1 methylation in HBeAg-negative CHB and HCs (P = 0.191). DNMT1 and DNMT3a mRNA levels were significantly higher in participants with GSTP1 methylation than those without. In patients with CHB, the degree of GSTP1 promoter methylation was significantly correlated with DNMT1 mRNA, DNMT3a mRNA, TNF-α, MDA, HBeAg, ALT, AST and TBIL. In contrast, no significant difference was found between GSTM3 methylation in patients with CHB and HCs (P = 0.079). Meanwhile, no significant difference could be observed between GSTM3 promoter methylation in patients with HBeAg-positive CHB and HBeAg-negative CHB (P = 0.146). Therefore, this study demonstrated that GSTP1 hypermethylation was associated with DNMT1, DNMT3a overexpression and oxidative stress in patients with HBeAg-positive CHB.

Diabetes and prediabetes in patients with hepatitis B residing in North America

Diabetes is associated with liver disease progression and increased hepatocellular carcinoma risk, but factors associated with diabetes in patients with chronic hepatitis B virus (HBV) infection in North America are unknown. We aimed to determine factors predictive of diabetes and impaired fasting glucose (IFG) in a large HBV-infected multiethnic cohort. Adults with chronic HBV not receiving antiviral therapy were enrolled from 21 centers in North America. Diabetes was defined by history/medication use or fasting glucose≥126 mg/dL and IFG as fasting glucose 100-125 mg/dL. Of 882 patients included, 47.2% were female, 71.3% Asian, 83.7% foreign born, median age was 44 years, and median body mass index BMI 24.3 kg/m2. In this cohort, 26.0% were hepatitis B envelope antigen (HBeAg) positive, 43.9% had HBV DNA≥20,000 IU/mL, and 26.7% alanine aminotransferase (ALT)≥2× upper limit of normal (≥40 U/L women, ≥60 U/L men). Overall, 12.5% had diabetes and 7.8% IFG. The combined prevalence of diabetes or IFG was highest among blacks (36.7%) and those either born in the United States/Canada or foreign born with migration>20 years ago (25.5%). Obesity (odds ratio [OR]: 2.13), hyperlipidemia (OR, 4.13), hypertension (OR, 3.67), high ALT level (OR, 1.86), and family history of diabetes (OR, 3.43) were associated with diabetes. Factors associated with IFG were obesity (OR, 4.13) and hypertension (OR, 3.27), but also HBeAg positivity (OR, 0.39). Recent migration was negatively associated with diabetes among non-Asians (OR, 0.30).

CONCLUSIONS

Diabetes is more prevalent in HBV-infected North American adults than the general population and is associated with known metabolic risk factors and liver damage, as determined by ALT levels. Among the foreign born, longer duration of North America residence predicted diabetes risk in non-Asians. These results highlight the opportunities for interventions to prevent diabetes especially among at-risk ethnic groups with HBV.

Effect of L-ornithine L-aspartate on Liver Injury Due to Acute Ethyl Alcohol Intoxication in Rats

OBJECTIVE

Ethyl alcohol is a substance that is widely used worldwide and known to exert toxic effects on liver. In this study, we aimed to examine the effect of L-ornithine L-aspartate (LOLA) on the toxicity of a single dose of ethyl alcohol in rats.

SUBJECTS AND METHOD

We used 32 randomly selected male Sprague-Dawley rats weighing 200-250 g. The rats were grouped into four groups with each group containing eight rats: Group 1: the control group, Group 2: the ethyl alcohol group, Group 3: the LOLA group and Group 4: the ethyl alcohol+LOLA group. Ethyl alcohol was administered orally through a nasogastric tube at a dose of 6 g/kg after diluting with distilled water. One hour after ethyl alcohol administration, LOLA was administered to pre-specified groups orally through a nasogastric tube at a dose of 200 mg/kg after diluting with distilled water. Liver tissue and blood samples were obtained from all rats 24 hours later to study total antioxidant capacity (TAC), total oxidant status (TOS) and oxidative stress index (OSI) levels in liver samples, and aspartate aminotransferase (AST), alanine transferase (ALT), TAC, TOS and OSI levels in blood samples.

RESULTS

Serum TAC, TOS and OSI levels were higher in the groups that were administered ethyl alcohol. In addition, tissue TAC level was higher and TOS and OSI levels were lower in groups that were given ethyl alcohol. No significant changes were observed in serum and tissue TAC, TOS, OSI, ALT and AST levels in the LOLA administered groups.

CONCLUSION

This study showed that LOLA was not biochemically effective and exerts no oxidative stress reducing activity in liver injury due to acute ethyl alcohol toxicity.

Thymoquinone protects end organs from abdominal aorta ischemia/reperfusion injury in a rat model

Introduction

Previous studies have demonstrated that thymoquinone has protective effects against ischemia reperfusion injury to various organs like lungs, kidneys and liver in different experimental models.

Objective

We aimed to determine whether thymoquinone has favorable effects on lung, renal, heart tissues and oxidative stress in abdominal aorta ischemia-reperfusion injury.

Methods

Thirty rats were divided into three groups as sham (n=10), control (n=10) and thymoquinone (TQ) treatment group (n=10). Control and TQ-treatment groups underwent abdominal aorta ischemia for 45 minutes followed by a 120-min period of reperfusion. In the TQ-treatment group, thymoquinone was given 5 minutes. before reperfusion at a dose of 20 mg/kg via an intraperitoneal route. Total antioxidant capacity, total oxidative status (TOS), and oxidative stress index (OSI) in blood serum were measured and lung, kidney, and heart tissue histopathology were evaluated with light microscopy.

Results

Total oxidative status and oxidative stress index activity in blood samples were statistically higher in the control group compared to the sham and TQ-treatment groups (P<0.001 for TOS and OSI). Control group injury scores were statistically higher compared to sham and TQ-treatment groups (P<0.001 for all comparisons).

Conclusion

Thymoquinone administered intraperitoneally was effective in reducing oxidative stress and histopathologic injury in an acute abdominal aorta ischemia-reperfusion rat model.

Serum paraoxonase activity, total thiols levels, and oxidative status in patients with acute brucellosis

It is well known that paraoxonase-1 (PON1) activity may decrease during the course of infection and inflammation. The aim of this study was to investigate serum PON1 activity, oxidative status, and thiols levels in patients with acute brucellosis. In addition, we investigated the PON1 phenotype in patients with acute brucellosis. Thirty patients with acute brucellosis and 35 healthy controls were enrolled. Serum paraoxonase and arylesterase activities, thiols levels, lipid hydroperoxide levels, total antioxidant capacity (TAC), total oxidant status (TOS) and oxidative stress index (OSI) were determined. Serum basal and salt-stimulated paraoxonase-arylesterase activities, TAC levels and thiols levels were significantly lower in patients with acute brucellosis than controls (for all, p < 0.05), while LOOH levels, TOS levels, and OSI values were significantly higher (for all, p < 0.05). We concluded that oxidative stress is increased, while serum PON1 activity is decreased in patients with acute brucellosis. These results indicate that lower PON1 activity is associated with oxidant-antioxidant imbalance.

The protective effect of goji berry extract in ischemic reperfusion in testis torsion

This study investigated whether goji berry extract (GBE), a known antioxidant, reduces ischemic reperfusion injury when administered to rats exposed to experimental testis torsion. A total of 32 Sprague-Dawley male rats were randomized into 4 groups, including the control (sham), goji, torsion, and torsion-goji groups. The treatment groups received intraperitoneal GBE prior to torsion. The left testes of the animals were subjected to torsion via 5 hours of ischemia and 6 hours of reperfusion. TAC (total antioxidant capacity), TOS (total oxidant status) and OSI (oxidative stress index) levels were calculated. Approximately 5-μm-thick sections were stained with hematoxylin-eosin (H&E) and examined under a light microscope. Statistical analyses were performed with the SPSS 15 software package. The mean serum TAC level was significantly increased in Groups 2 and 4 compared with Groups 1 and 3 in biochemical analyses (for both P < 0.001). The mean serum TOS level was significantly increased in Group 3 compared with Groups 1, 2, and 4 (P < 0.001, P < 0.001, and P = 0.003, respectively). Comparison of the groups with regard to histopathological examination revealed that Group 4 exhibited a significantly higher rate of hemorrhage and congestion compared with Groups 1 and 2 (P = 0.038). The groups did not differ significantly with respect to degeneration. Ischemic reperfusion injury associated with testis torsion was reduced by the antioxidant effect of GBE. Further experimental and clinical studies are needed to confirm the agent's efficacy for this indication.

Hepatitis B virus infection, diabetes mellitus, and their synergism for cholangiocarcinoma development: A case-control study in Korea

AIM: To identify possible risk factors and their synergism for cholangiocarcinoma development.

METHODS: A hospital-based, case-control study in which we included 276 cholangiocarcinoma patients [193 extrahepatic cholangiocarcinoma (ECC) and 83 intrahepatic cholangiocarcinoma (ICC)], diagnosed at a training hospital in Korea between 2007 and 2013, and 552 healthy controls matched 2:1 for age, sex, and date of diagnosis. Risk factors for cholangiocarcinoma and possible synergism between those factors were evaluated using conditional logistic regression and synergism index, respectively.

RESULTS: There was an association between cholangiocarcinoma and hepatitis B virus (HBV) infection, diabetes mellitus (DM), cholecystolithiasis, choledocholithiasis, and hepatolithiasis, with the adjusted odds ratios (AORs) of 4.1, 2.6, 1.7, 12.4, and 39.9, respectively. Synergistic interaction on the additive model was investigated between HBV infection and DM (AOR = 12.2; 95%CI: 1.9-80.1). In the subgroup analyses, cholecystolithiasis, choledocholithiasis, hepatolithiasis, and DM were significant risk factors for ECC (AOR = 2.0, 18.1, 14.9, and 2.0, respectively), whereas choledocholithiasis, hepatolithiasis, HBV infection, and DM were risk factors for ICC (AOR = 8.6, 157.4, 5.3 and 4.9, respectively). Synergistic interaction was also observed between HBV infection and DM (OR = 22.7; 95%CI: 2.4-214.1). However, there was no synergistic interaction between other significant risk factors for cholangiocarcinoma.

CONCLUSION: In this Korean study, HBV infection and DM were found to exert independent and synergistic effects on the risk for cholangiocarcinoma, including ICC. Exploring the underlying mechanisms for such synergy may lead to the development of cholangiocarcinoma prevention strategies in high-risk individuals.

An overview of new biomolecular pathways in pathogen-related cancers

Cancer molecular pathways are combinations of metabolic processes deregulated in neoplastic cells. Besides pathways specific to tissues from which cancers originate, common neoplastic traits are present among most tumors. Hanahan and Weinberg have described the most critical 'hallmarks' shared by many cancer types. In recent years, cancer stem cell specific properties and pathways have also been identified. Other altered pathways are peculiar of cancer type and cancer stage, even in different cancer stem cell types. In pathogen-related tumors, the alteration of inflammatory and immunologic response along with impairment of cell cycle control represents key molecular events of tumor progression. This article summarizes the recent discoveries of new altered pathways in cancer and their importance in cancer diagnosis and tailored therapies.

Urotensin-II level and its association with oxidative stress in early diabetic nephropathy

OBJECTIVE

Diabetic nephropathy is the most common cause of end stage renal failure. Early treatment of diabetic nephropathy depends on understanding the underlying mechanisms of the disease. In this study we investigated the role of U-II in early nephropathy and ıts association with oxidative stress, paraoxonase (PON)-1 and arylesterase.

RESEARCH DESIGN AND METHODS

Twenty-three diabetic patients with microalbuminuria, 23 diabetic patients with normoalbuminuria and 25 healthy individuals were enrolled in the study. Serum total antioxidant status (TAS), total oxidant status (TOS), PON-1, arylesterase, and urotensin-II (U-II) levels were measured. Oxidative stress index (OSI) percent ratio of TOS to TAS level was accepted as OSI.

RESULTS

Serum U-II levels were higher in the microalbuminuric diabetes group compared to the normoalbuminuric diabetic group and the healthy control group (p=0.009 and p=0.0001, respectively). Normoalbuminuric diabetic group's U-II levels were significantly higher compared to those of the healthy control group (p=0.0001). Correlation analysis yielded that plasma U-II levels are negatively correlated to TAS, arylesterase, and PON-1 levels (r=-0.395, p=0.001; r=-0.291, p=0.014; and r=-0.279, p=0.018, respectively) and that they had a positive correlation with OSI levels (r=0.312, p=0.008). These associations were confirmed in the multiple regression analysis. The results of multiple logistic regression analysis showed that oxidative stress is important in the development of microalbuminuria.

CONCLUSION

The data of this study reveal that increased serum U-II has a role in the development of diabetic nephropathy. This effect of U-II may be related to high levels oxidative stress parameters.

Protective effects of carvacrol against methotrexate-induced testicular toxicity in rats

To investigate the effect of carvacrol (CAR) on methotrexate (MTX)-induced testis damage in rats. Twenty-four male rats were equally divided into three groups: group I control treatment; group II MTX-treated; group III MTX + CAR-treated. A single dose of CAR was administered intraperitoneally to group III on the first day of the experiment and a single dose of MTX was administered intraperitoneally to groups II and III on the second day of the experiment. The total duration of the experiment was 8 days. Blood samples and testis tissue were obtained from each animal for the measurement of malondialdehyde (MDA), Total oxidant status (TOS), Total Antioxidant Status (TAS), and Oxidative stress index (OSI). Light microscopy was used to complete the histopathological examination of testis specimens from each animal. Analysis of serum and testis sampled revealed that MDA, TOS and OSI levels were significantly greater in the group receiving MTX alone relative to the control treated animals while the TAS level was significantly reduced in the MTX group when compared with the control group. The administration of CAR was associated with significantly decreased MDA, TOS, and OSI levels and increased TAS levels relative to the rats treated with MTX alone. All of these quantitative values demonstrate that CAR alleviates deleterious effects of MTX on testicular tissue. Use of antioxidants such as CAR may protect germ cells against oxidative stress and apoptosis when used in combination with MTX.

Serum prolidase activity and oxidant-antioxidant status in children with chronic hepatitis B virus infection

BACKGROUND

Chronic hepatitis B (CHB) is a global health problem that can result in serious complications associated with collagen degradation. Prolidase is a specific imidodipeptidase that plays an important role in the breakdown of collagen. The aim of this study was to investigate prolidase activity and oxidant-antioxidant status in children with CHB.

METHODS

This prospective case control study includes 38 patients with CHB, 31 patients with inactive hepatitis B (IHB), and 29 healthy matched control subjects. Serum prolidase enzyme activity (SPEA), total antioxidant capacity (TAC), total oxidative activity (TOA), and malondialdehyde (MDA) level were measured and oxidative stress index (OSI) was calculated for each group.

RESULTS

Patients with CHB had significantly higher SPEA levels (207.82 ± 186.80 IU/L) than did the controls (58.6 ± 38.1 IU/L) and IHB patients (67.1 ± 39.9) (p < 0.001). CHB patients also had significantly higher TOA (45.0 ± 19.9 vs. 29.4 ± 11.7 (μmolH2O2 Eq./L), p = 0.005), OSI (33.1 ± 21.4 vs. 17.5 ± 10.2, p = 0.002) and MDA (13.4 ± 4.0 vs. 7.8 ± 2.6 μm/L, p < 0.001) values compared with the controls. TOA (32.0 ± 10.0) and OSI (15.4 ± 11.0) values of IHB patients were significantly lower than those of CHB patients (p < 0.05). SPEA had significant correlations with HBV- DNA and ALT values (r =0.514 and r =0.454, p < 0.001).

CONCLUSION

Our results suggest that prolidase activity can be considered as a reliable marker for CHB and increased oxidative stress appears to be related to chronicity of the disease.

Protective effects of ethyl pyruvate in cisplatin-induced nephrotoxicity

This study was performed to investigate the effect of ethyl pyruvate on changes in renal functions and oxidative stress related renal injury caused by cisplatin (cis-dichlorodiammine platinum-II; CDDP). Male Wistar albino rats were divided into four groups (n = 8): (1) control group (1 ml Ringer's lactate solution i.p.); (2) ethyl pyruvate (EP) group (50 mg/kg Ringer's EP solution (REPS) i.p.); (3) cisplatin group (a single dose of cisplatin (5 mg/kg, i.p.); and (4) cisplatin + EP group (a single dose of cisplatin (5 mg/kg, i.p.) + REPS 50 mg/kg/day, i.p.) for five days. At the sixth day, kidneys of rats were mounted to a Langendorff apparatus. Renal perfusion pressures were recorded. Blood samples were taken for serum urea, creatinine, total oxidant status (TOS), total antioxidant status (TAS) and oxidative stres index (OSI) evaluations. Kidney tissues were obtained for malondialdehyde (MDA) analyses and histopathological examination. Perfusion pressures, serum urea, creatinine, TOS, OSI and tissue MDA levels were found significantly higher, whereas TAS was notably lower in cisplatin group. Histopathological examination showed apparent renal paranchymal injury in cisplatin group. In cisplatin + REPS group, perfusion pressures, serum urea, creatinine and tissue MDA levels were decreased. Moreover, EP co-administration provided less inflammatory cell infiltration, tubular dilatation, whereas TOS, TAS and OSI improved significantly versus cisplatin group. These findings show that EP has protective effects against cisplatin nephrotoxicity.

Carvacrol and pomegranate extract in treating methotrexate-induced lung oxidative injury in rats

Background

This study was designed to evaluate the effects of carvacrol (CRV) and pomegranate extract (PE) on methotrexate (MTX)-induced lung injury in rats.

Material/Methods

A total of 32 male rats were subdivided into 4 groups: control (group I), MTX treated (group II), MTX+CRV treated (group III), and MTX+PE treated (group IV). A single dose of 73 mg/kg CRV was administered intraperitoneally to rats in group III on Day 1 of the investigation. To group IV, a dose of 225 mg/kg of PE was administered via orogastric gavage once daily over 7 days. A single dose of 20 mg/kg of MTX was given intraperitoneally to groups II, III, and IV on Day 2. The total duration of experiment was 8 days. Malondialdehyde (MDA), total oxidant status (TOS), total antioxidant capacity (TAC), and oxidative stress index (OSI) were measured from rat lung tissues and cardiac blood samples.

Results

Serum and lung specimen analyses demonstrated that MDA, TOS, and OSI levels were significantly greater in group II relative to controls. Conversely, the TAC level was significantly reduced in group II when compared to the control group. Pre-administering either CRV or PE was associated with decreased MDA, TOS, and OSI levels and increased TAC levels compared to rats treated with MTX alone. Histopathological examination revealed that lung injury was less severe in group III and IV relative to group II.

Conclusions

MTX treatment results in rat lung oxidative damage that is partially counteracted by pretreatment with either CRV or PE.

Role of Nrf2 in chronic liver disease

Nuclear erythroid 2-related factor 2 (Nrf2) is a central regulator of antioxidative response elements-mediated gene expression. It has a significant role in adaptive responses to oxidative stress by interacting with the antioxidant response element, which induces the expression of a variety of downstream targets aimed at cytoprotection. Previous studies suggested oxidative stress and associated damage could represent a common link between different forms of diseases. Oxidative stress has been implicated in various liver diseases, including viral hepatitis, nonalcoholic fatty liver disease/steatohepatitis, alcoholic liver disease and drug-induced liver injury. Nrf2 activation is initiated by oxidative or electrophilic stress, and aids in the detoxification and elimination of potentially harmful exogenous chemicals and their metabolites. The expression of Nrf2 has been observed throughout human tissue, with high expression in detoxification organs, especially the liver. Thus, Nrf2 may serve as a major regulator of several cellular defense associated pathways by which hepatic cells combat oxidative stress. We review the relevant literature concerning the crucial role of Nrf2 and its signaling pathways against oxidative stress to protect hepatic cell from oxidative damage during development of common chronic liver diseases. We also review the use of Nrf2 as a therapeutic target to prevent and treat liver diseases.

The protective effects of pomegranate extracts against renal ischemia-reperfusion injury in male rats

Aim:

To evaluate the possible protective effect of pomegranate extract (PE) on rats following renal ischemia–reperfusion (I/R) injury.

Materials and Methods:

Twenty-four Wistar rats were divided into three groups. Sham group underwent laparotomy then waited for 45 minutes without ischemia. I/R group were subjected to left renal ischemia for 45 minutes followed by 60 minutes of reperfusion. I/R + PE group were subjected to the same renal I/R as the I/R group were also given 225 mg/kg PE peroral 30 minutes prior to the ischemia. Malondialdehyde (MDA), total antioxidant capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) were determined on the blood samples and kidney tissues. Histopathological analyses were conducted on the kidney tissues.

Results:

Serum TAC levels were significantly decreased in I/R group when compared with S group (P = 0.001). Serum MDA levels were increased in I/R group; however, it was not statistically significant. In rat kidney tissues, TOS levels and OSI index were significantly increased after I/R injury, while TAC levels were decreased. In I/R + PE group, PE reversed the negative effects of I/R injury. PE pretreatment was effective in decreasing tubular necrosis score.

Conclusion:

PE pretreatment ameliorated the oxidative damage and histopathological changes occurring following renal I/R injury.

'Liver let die': oxidative DNA damage and hepatotropic viruses

Chronic infections by the hepatotropic viruses hepatitis B virus (HBV) and hepatitis C virus (HCV) are major risk factors for the development of hepatocellular carcinoma (HCC). It is estimated that more than 700,000 individuals per year die from HCC, and around 80 % of HCC is attributable to HBV or HCV infection. Despite the clear clinical importance of virus-associated HCC, the underlying molecular mechanisms remain largely elusive. Oxidative stress, in particular DNA lesions associated with oxidative damage, play a major contributory role in carcinogenesis, and are strongly linked to the development of many cancers, including HCC. A large body of evidence demonstrates that both HBV and HCV induce hepatic oxidative stress, with increased oxidative DNA damage being observed both in infected individuals and in murine models of infection. Here, we review the impact of HBV and HCV on the incidence and repair of oxidative DNA damage. We begin by giving a brief overview of oxidative stress and the repair of DNA lesions induced by oxidative stress. We then review in detail the evidence surrounding the mechanisms by which both viruses stimulate oxidative stress, before focusing on how the viral proteins themselves may perturb the cellular response to oxidative DNA damage, impacting upon genome stability and thus hepatocarcinogenesis.

Renal effects of NO-inhibition in patients with cirrhosis vs. healthy controls: a randomized placebo-controlled crossover study

BACKGROUND

Nitric oxide (NO) is an important regulator of renal hemodynamics and sodium excretion. Systemic and splanchnic NO-synthesis is increased in liver cirrhosis contributing to the characteristic hyperdynamic circulation. The significance of renal NO in human cirrhosis is not clear.

AIMS

In order to clarify the role of NO in the regulation of renal hemodynamics and sodium excretion in human cirrhosis, we studied the effects of N(G)-monomethyl-L-arginine (L-NMMA) - a nonselective NO-inhibitor - on blood pressure (MAP), heart rate (HR), GFR, RPF, UNa × V, FENa, FELi and plasma levels of renin, angII, aldo, ANP, BNP and cGMP in 13 patients with cirrhosis (Child gr.A: 8; Child gr.B+C: 5) and 13 healthy controls.

METHODS

The study was randomized and placebo-controlled. Renal hemodynamics were assessed by measuring renal clearance of (51) Cr-EDTA and (125) I-Hippuran for GFR and RPF, respectively.

RESULTS

L-NMMA induced a similar, significant increase in MAP in both groups and a more pronounced relative decrease in HR in the CIR group (P = 0.0209, anova). L-NMMA did not change GFR in any group, but RPF decreased significantly in both groups, but most pronouncedly in CIR (P = 0.0478, anova). FENa decreased significantly in both groups after l-NMMA, but the response was again most pronounced in the CIR group (P = 0.0270, anova). All parameters remained stable after placebo. No significant differences were observed between the effects of L-NMMA in Child gr.A vs. Child gr. B+C patients.

CONCLUSION

The data supports the hypothesis that renal NO is enhanced in human cirrhosis.

Serum prolidase enzyme activity and oxidative stress levels in patients with acute hemorrhagic stroke

BACKGROUND

It has been indicated that oxidative damage contributes to secondary brain injury in both ischemic and hemorrhagic stroke patients. Collagen is a major component of the extracellular matrix, and prolidase plays a role in collagen synthesis. The aim of this study was to evaluate the serum prolidase activity, nitric oxide (NO) levels, total antioxidant capacity (TAC) and total oxidant status (TOS) in patients with acute hemorrhagic stroke.

METHODS

Twenty-five patients with acute hemorrhagic stroke and 25 controls were enrolled. Serum prolidase activity, catalase activity, NO levels, TAC and TOS were measured spectrophotometrically. Oxidative stress index (OSI) was calculated.

RESULTS

Serum TAC levels and catalase activity were significantly lower in acute hemorrhagic stroke patients than controls (both, p < 0.001), while NO levels, TOS levels, OSI values and prolidase activity were significantly higher (all, p < 0.01). When patients with acute hemorrhagic stroke were divided according to gender, no differences were observed between females and males in respect to serum prolidase enzyme activity, NO levels, TAC levels, TOS levels and OSI values (all, p > 0.05).

CONCLUSIONS

Findings from the study suggest an association between increased oxidative stress levels, decreased antioxidant levels and increased prolidase enzyme activity in patients with acute hemorrhagic stroke compared with controls. More studies are needed to elucidate mechanistic pathways on oxidative stress in patients with acute hemorrhagic stroke.

Serum prolidase enzyme activity and oxidative status in patients with fibromyalgia

OBJECTIVE

This study was performed to investigate serum prolidase enzyme activity and oxidative stress in patients diagnosed with fibromyalgia (FM).

METHODS

The study population consisted of 40 patients with a previous diagnosis of FM and 30 healthy subjects. We measured serum prolidase enzyme activity, total antioxidant status (TAS), total oxidative status (TOS), oxidative stress index (OSI), and paraoxonase-1 (PON-1) levels.

RESULTS

On average, FM patients were diagnosed within 3.2 years of symptom onset, and patients had a mean of 14 tender points. There were no significant differences between patients and controls in age, body mass index, serum TAS, or PON-1 levels. However, patients with FM demonstrated higher serum prolidase activity, TOS, and OSI than the control group. Serum prolidase activity was positively correlated with serum TOS, OSI, and visual analog scale pain and fatigue scores. No correlation was found between serum prolidase activity and FM duration or the average number of tender points.

DISCUSSION

Our results demonstrate a previously unreported association between serum prolidase enzyme activity and FM. Increased prolidase activity may contribute to the pathogenesis of FM, and measuring serum prolidase enzyme activity may be a useful FM biomarker.

Serum prolidase enzyme activity and oxidative status in patients with Behçet's disease

OBJECTIVES

To assess serum prolidase enzyme activity and oxidative stress in patients with Behçet's disease (BD).

METHODS

The study population consisted of BD patients (n = 42) and healthy participants (n = 29). BD patients were classified as active (n = 18) or inactive (n = 24) according to disease activity. Serum prolidase enzyme activity, total antioxidant status (TAS), total oxidative status (TOS), oxidative stress index (OSI), and malondialdehyde (MDA) levels were measured.

RESULTS

In BD patients with active disease, serum prolidase activity was significantly higher compared with the inactive and control participants. Serum prolidase activity was also significantly higher in all BD patients in comparison with controls. Serum prolidase activity was also positively correlated with OSI, C-reactive protein, and active BD. MDA, TOS, and OSI levels were all significantly higher in the BD group when compared with the healthy control participants. Serum TAS levels were significantly lower in BD patients in comparison with healthy controls.

CONCLUSION

High prolidase activity may indicate critical biological activities relevant to pathological events in BD, and this activity may be a biological indicator of disease. Further studies are needed to verify these findings.

Progress in understanding role of diabetes mellitus in the development of hepatitis virus-related hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. Hepatitis B or hepatitis C virus infection has been considered the most important etiologic factor for human HCC. Recently, it has been suggested that diabetes mellitus is a risk factor for HCC, and that insulin resistance as a critical component of diabetes mellitus pathogenesis may be involved in the occurrence of hepatitis virus-related HCC. Since IRS-1-Ser312 is a molecule that is involved in the pathogenesis of both hepatitis C virus and diabetes mellitus, IRS-1 or ROS may play a role in the development of HCC associated with diabetes mellitus and hepatitis B virus. Hence, diabetes mellitus and hepatitis virus not only are independent risk factors for HCC but also interact with each other to contribute to the development of this malignancy.

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.

Assessment of the serum paraoxonase activity and oxidant/antioxidant status in patients with recurrent aphthous stomatitis

OBJECTIVES

Several studies have indicated that recurrent aphthous stomatitis (RAS) is associated with oxidative stress. The aim of this study was to investigate serum paraoxonase (PON) activity and oxidant/antioxidant status in patients with RAS.

DESIGN AND METHODS

Thirty-one patients with RAS and 31 healthy controls were enrolled. Serum PON1 and arylesterase activities, total antioxidant capacity, total oxidant status, and oxidative stress index were determined.

RESULTS

Serum total antioxidant capacity levels, PON1, and arylesterase activities were significantly lower in RAS than controls (P < 0.001), while total oxidant status levels and oxidative stress index were significantly higher (P < 0.001). PON1 activity had a significant correlation with high-density lipoprotein cholesterol only (r = 0.482, P < 0.05), while there were no correlations with other lipids (P > 0.05) in patients with RAS.

CONCLUSIONS

Our results indicate that RAS is associated with decreased PON1 activity and increased oxidative stress that plays a crucial role in the pathogenesis of RAS. Further studies on a larger number of patients are needed to verify these results.

The protective effect of curcumin on ischemia-reperfusion injury in rat ovary

BACKGROUND

To evaluate the protective effects of curcumin in experimental ischemia and ischemia/reperfusion (I/R) injury of rat ovaries.

METHODS

Forty-eight female adult Wistar Albino rats were used. Rats divided into six groups and designed: Sham, Torsion, Detorsion, Sham + Curcumin, Torsion + Curcumin, and Detorsion + Curcumin. Except for the Sham and Sham + Curcumin group, all groups were performed to bilateral adnexal torsion for 3 h. Bilateral adnexal detorsion was implemented in the Detorsion and Detorsion + Curcumin groups. The injection of curcumin was intraperitoneally achieved 30 min before the sham, torsion and detorsion.

RESULTS

Total oxidant status levels (TOS), oxidative stress index (OSI) and histologic scores values of ovarian tissue were higher in the torsion and detorsion groups than the sham group (p < 0.05). There was a strong correlation between the total histologic scores of I/R injury and the OSI (r = 0.809, p < 0.001). By the use of curcumin, a significant decrease was established in the mean levels of oxidant markers and histopathologic scores of the ovarian tissues.

CONCLUSIONS

Administration of curcumin is effective in reversing tissue damage induced by ischemia-reperfusion injury in ovarian torsion.

Effect of hydrogen-rich water on oxidative stress, liver function, and viral load in patients with chronic hepatitis B

OBJECTIVE

To investigate effects of hydrogen-rich water (HRW) on oxidative stress, liver function and HBV DNA in patients with chronic hepatitis B (CHB).

METHODS

Sixty patients with CHB were randomly assigned into routine treatment group or hydrogen treatment group in which patients received routine treatment alone or additional oral HRW (1200-1800 mL/day, twice daily), respectively, for 6 consecutive weeks. Serum oxidative stress, liver function, and HBV DNA level were detected before and after treatment. Thirty healthy subjects served as controls.

RESULTS

When compared with controls, oxidative stress was obvious in CHB patients, and the liver function also significantly impaired. After treatment, the oxidative stress remained unchanged in routine treatment group, but markedly improved in hydrogen treatment group. The liver function was improved significantly and the HBV DNA reduced markedly after corresponding treatments. Although a significant difference was noted in the oxidative stress between two groups after treatment, the liver function and HBV DNA level were comparable after treatment and both had improved tendencies.

CONCLUSION

HRW significantly attenuates oxidative stress in CHB patients, but further study with long-term treatment is required to confirm the effect of HRW on liver function and HBV DNA level.

Serum paraoxonase activity and oxidative status in subjects with alopecia areata

INTRODUCTION

Previous studies have suggested that oxidative stress may play an important role in the pathogenesis of alopecia areata (AA) but these reports are limited and conflicting.

OBJECTIVES

The aim of this study was to investigate serum paraoxonase-1 (PON1) activity and oxidative status in subjects with AA.

MATERIALS AND METHODS

Thirty-nine subjects with AA and 39 healthy controls were enrolled. Serum PON1 activity, total antioxidant capacity (TAC), total oxidant status (TOS) and oxidative stress index (OSI) were determined.

RESULTS

Serum TAC levels and PON1 activity were significantly lower in the subjects with AA than controls (p = 0.038, p = 0.001, respectively), whereas TOS levels and OSI were significantly higher (both, p = 0.001) in the subjects with AA.

CONCLUSIONS

Our results suggest that reduced PON1 activity may be related to increased oxidant and decreased antioxidant levels. These data indicated that oxidant/antioxidant imbalance may play a role in the etiopathogenesis of AA.

Glutathione S-transferase P1 correlated with oxidative stress in hepatocellular carcinoma

BACKGROUND

Glutathione-S-transferase P1 (GSTP1) is an important phase II enzyme that can protect cells from oxidative stress in various human cancers. However, few clinical studies were undertaken on the relationship between GSTP1 and oxidative stress in hepatocellular carcinoma (HCC). The present study was therefore aimed to evaluate the potential associations between GSTP1 and oxidative stress in HCC patients.

METHODS

The GSTP1 expression in peripheral blood mononuclear cells (PBMCs) was determined by flow cytometry from 38 HCC patients and 38 chronic hepatitis B (CHB) patients. The GSTP1 mRNA level in PBMCs was determined by real-time quantitative polymerase chain reaction. Enzyme-linked-immunosorbent-assay (ELISA) was performed to measure the oxidative stress status, including plasma levels of malondialdehyde (MDA), xanthine oxidase (XOD), reduced glutathione hormone (GSH) and glutathione-S-transferases (GST).

RESULTS

Significantly decreased GSTP1 protein expression was found in HCC patients than in CHB patients (P<0.05). The GSTP1 mRNA expression of HCC patients was also decreased compared with CHB patients (P<0.05). MDA and XOD levels were significantly higher in HCC patients than in CHB patients, while plasma GSH and GST levels were statistically lower in HCC patients than in CHB patients. GSTP1 expression level was correlated with plasma levels of MDA (P<0.01), XOD (P = 0.01) and GSH (P< 0.01), GST (P< 0.01).

CONCLUSION

We demonstrated that the reduced GSTP1 expression might contribute to oxidative stress in the development of HCC from CHB.

Does the MRI or MRI contrast medium gadopentetate dimeglumine change the oxidant and antioxidant status in humans?

BACKGROUND

It has become evident that gadolinium-based contrast agents (GBCA) may have nephrotoxic potential. Oxidative stress is one of the most important pathways in the pathogenesis of iodinated contrast-induced nephropathy.

PURPOSE

To investigate the effects of static magnetic fields and gadopentetate dimeglumine (Magnevist(®)) on oxidant/antioxidant status via measurement of total antioxidant capacity (TAC), total oxidant status (TOS), and serum malondialdehide (MDA).

MATERIAL AND METHODS

Two age- and sex-matched groups of patients not under oxidative stress conditions that underwent magnetic resonance imaging (MRI) were recruited to this study. While contrast-enhanced (Magnevist(®), 0.2 mmol/kg) MRI was performed in group 1, MRI without GBCA was performed in group 2. Fasting blood glucose, C-reactive protein, serum creatinine, liver enzymes, uric acid, and lipid parameters were examined in all patients. Peripheral venous blood samples in order to determine TAC, TOS, and MDA were collected before and 6, 24, and 72 h after the MRI procedures. The TOS:TAC ratio was used as the oxidative stress index (OSI). Patients were followed up to 72 h.

RESULTS

There were no significant changes in serum TAC, TOS, and MDA levels (Δ(serum TAC), Δ(serum TOS), and Δ(MDA)) in either group 6, 24, or 72 h after the procedures (P > 0.05). Furthermore, OSI did not change after the procedures in either group (P > 0.05).

CONCLUSION

Magnetic field and gadopentetate dimeglumine (Magnevist(®)) do not change the oxidant or antioxidant status at a dose of 0.2 mmol/kg.

Antioxidant protective effects of lactitol against endotoxemia in patients with chronic viral hepatitis

Although antiviral drugs are widely used in the clinic, progression to liver cirrhosis and hepatocellular carcinoma cannot yet be entirely prevented. The aim of this study was to determine the effects of lactitol in chronic viral hepatitis patients with endotoxemia. Ninety-four patients with chronic viral hepatitis were separated into two groups based on plasma endotoxin levels: one group with endotoxemia (≥ 45 ng/l, n=60) and one group without endotoxemia (<45 ng/l, n=34). Sixty patients with gut-derived endotoxemia were randomly and evenly divided into a lactitol treatment group and a control group. Plasma endotoxin levels in patients with chronic viral hepatitis exhibited a negative correlation with superoxide dismutase (SOD) activity (P<0.001) and a positive correlation with levels of malondialdehyde (MDA) (P<0.001). The levels of SOD in the lactitol-treated group increased (P<0.01), while the levels of MDA decreased (P<0.01). Plasma endotoxin levels decreased (P<0.01) and the number of lactobacilli and bifidobacteria in the intestinal tract increased (P<0.01 for all). These results suggest that lactitol administration is capable of reducing injury caused by oxidants through regulating intestinal flora and decreasing gut-derived endotoxemia in patients with chronic viral hepatitis.

Ellagic acid ameliorates lung injury after intestinal ischemia-reperfusion

Background:

The aim of this study was to investigate the possible protective role of antioxidant treatment with ellagic acid (EA) on lung injury after intestinal ischemia-reperfusion (I/R) injury using biochemical and histopatological approaches.

Materials and Methods:

Forty rats were divided into four groups as control, control + EA, I/R, and I/R + EA. The control and control + EA groups were also anesthetized and subjected to laparotomy, but without clamp application. The control + EA and I/R + EA groups were given EA (85 mg/kg) orally prior to experiment. The I/R and I/R + EA groups underwent 30 minutes of intestinal ischemia and 1 hour of reperfusion. In all groups, serum total antioxidant capacity (TAC) and malondialdehyde (MDA) levels were determined. TAC, total oxidative status (TOS), and oxidative stress index (OSI) in lung tissue were measured. Lung tissue histopathology was also evaluated by light microscopy.

Results:

TAC levels were higher in control, EA, and I/R + EA groups while TOS, OSI, and MDA levels were lower in these groups compared with I/R group. Serum MDA levels were significantly higher in I/R + EA group than that of control group. Lung tissue TAC levels were lower in I/R + EA group while OSI values were higher in that groups compared with EA group. Histological tissue damage was milder in the EA treatment group than in the I/R group.

Conclusion:

These results suggest that EA treatment protected the rats lung tissue against intestinal I/R injury.

Methylation of the glutathione-S-transferase M3 gene promoter is associated with oxidative stress in acute-on-chronic hepatitis B liver failure

Chronic hepatitis B (CHB) is a major cause for liver disease worldwide, ranking as the first cause for liver cirrhosis and hepatocellular carcinoma. Acute-on-chronic hepatitis B liver failure (ACHBLF) is most commonly caused by acute severe exacerbation during CHB virus infection. The pathophysiology of ACHBLF is still poorly understood. Glutathione-S-transferase (GST) M3 belongs to GSTs superfamily and it has been demonstrated to contribute to oxidative stress-mediated liver damage. The present study was aimed to determine the potential association between GSTM3 promoter methylation and oxidative stress in ACHBLF patients. Thirty ACHBLF patients, 30 CHB patients and 10 healthy controls were included in this study. Methylation of GSTM3 promoter was determined using methylation-specific PCR (MSP) method. Plasma biomarkers for oxidative stress including malondialdehyde (MDA) and GST were detected by enzyme-linked immunosorbent assay (ELISA). Model for end-stage liver disease (MELD) scoring system was used for predicting the severity and prognosis of liver failure. ACHBLF patients had significant higher GSTM3 promoter methylation rate than CHB patients (30% versus 6.7%, χ(2) = 5.455, P = 0.020). Plasma MDA and GST levels were significantly increased in ACHBLF patients compared with CHB patients. Meanwhile, MDA, MELD scores and mortality rate were significantly higher in methylated group than those in unmethylated group of ACHBLF patients. Furthermore, plasma MDA levels were positively correlated with MELD scores of ACHBLF (r = 0.588, P = 0.001). In conclusion, the methylation of GSTM3 promoter may contribute to oxidative stress-associated liver damage and correlate with the disease severity in ACHBLF.

Oxidative stress and liver disease

In humans, oxidative stress and antioxidant defenses are the sum of a complicated network of enzymatic and non-enzymatic processes. Depending on the stage and severity of diseases, a patient's antioxidant armamentarium may increase as an appropriate response to an oxidant challenge, whereas others may decrease as an indication of unbalanced consumption. In some cases, the formation of reactive oxygen species is a requisite and healthy event. In fact, free radicals can affect intracellular signal transduction and gene regulation, resulting in cytokine production essential to the inflammatory process. In many other cases, especially liver diseases, excessive oxidative stress undoubtedly contributes to the progression and pathological findings of disease and serves as a prognostic indicator. Reactive oxygen species are highly reactive molecules that are naturally generated in small amounts through metabolism and could damage cellular molecules such as lipids, proteins or DNA. Oxidative stress plays a major role in many liver diseases. In this review, we summarize the biological character of free radicals and some antioxidants, and the related methods of analysis. Then, we discusses the association of oxidative stress to many types of liver diseases.

Relationship of oxidative stress in hepatitis B infection activity with HBV DNA and fibrosis

BACKGROUND

The aim of this study was to evaluate oxidative stress in various clinical forms of hepatitis B infection and to investigate its role in the development of the chronic form of the disease.

METHODS

Ninety-three patients with inactive hepatitis B surface antigen (HbsAg) carrier state (IHBCS), 65 patients with chronic hepatitis B infection (CHB), and 42 healthy adults were included in the study. The following values were measured and compared in patient groups: total antioxidant status (TAS), total oxidative stress (TOS), oxidative stress index (OSI), sulfhydryl (SH), lipid peroxidation (LOOH), catalase (CAT), and ceruloplasmin. In patients with chronic hepatitis B, these values were compared with HBV DNA and fibrosis levels.

RESULTS

ALT, TOS, LOOH, and OSI levels were higher in the CHB group compared to the other groups (P<0.001). Catalase levels increased in the CHB and IHBCS groups compared to the control group (P<0.001). Total aminooxidant and ceruloplasmin levels were found to be lowest in the CHB group and highest in the control group (P<0.001). Sulfhyrdyl was higher in the control group compared to the other groups (P<0.001). In the CHB group, there was no correlation between the HBV DNA and OSI (P>0.05).

CONCLUSIONS

These finding suggested that oxidative stress is associated with hepatitis B activity.

Oxidant and antioxidant parameters in patients with Brucella canis

OBJECTIVES

The aim of this study was to evaluate the oxidative status in patient with Brucella canis (B. canis) and healthy controls by measurement of total antioxidant capacity (TAC) and total oxidant capacity (TOS), and calculation of oxidative stress index (OSI).

DESIGN AND METHODS

Six patients with B. canis and 6 healthy control subjects were included in this study. Diagnosis of B. canis was made by rapid slide agglutination test (RSAT) and Modified Plate Agglutination Test (MPAT). The serum samples of B. canis positive patients and controls were used for measurement of TAC and TOS levels.

RESULTS

The TOS and OSI index were significantly higher in brucellosis positive patients than control group (p<0.001 and p<0.0001, respectively), while TAC level was found similar in patient and control groups.

CONCLUSION

Findings of this study have shown that B. canis generate low TOS and OSI index in man compared with smooth Brucella species infection. This difference may help to provide understanding about the pathogenesis of B. canis infection in man.

Paraoxonase-1 is not affected in polycystic ovary syndrome without metabolic syndrome and insulin resistance, but oxidative stress is altered

Paraoxonase-1 (PON1) activity is decreased in polycystic ovary syndrome (PCOS) having metabolic syndrome (MetS) or insulin resistance (IR). We aimed to assess PON1 activity and oxidative stress in PCOS without MetS or IR. Metabolic and hormonal parameters, high-sensitive C-reactive protein (hs-CRP), oxidative stress parameters (total antioxidant status (TAS), total oxidative stress (TOS), oxidative stress index (OSI), lipid hydroperoxide (LOOH), total free sulfhydryl (--SH) groups), PON and arylesterase were analyzed in 30 normal weighed patients with PCOS without MetS or IR and 20 normal controls. Hs-CRP, PON, arylesterase, and TAS levels of PCOS and control groups were similar. LOOH, TOS, and OSI of PCOS group were higher than in the controls (p < 0.05; p < 0.001, and p < 0.001, respectively). - SH group levels showed a positive correlation with free testosterone (fT). TOS positively correlated with free androgen index (FAI), body mass index (BMI), waist-to-hip ratio (WHR), LOOH, and OSI. This study showed that oxidative stress is increased in PCOS even in the absence of MetS or IR. PON1 activity appears not to be affected in PCOS without MetS and IR. Several metabolic and antropometric risk factors may aggravate this altered oxidative state in PCOS.

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.

Evaluation of oxidative status in patients with hyperthyroidism

Data on the antioxidant levels enzyme in patients with hyperthyroidism are limited and conflicting. Therefore, the objective of this study was to evaluate the oxidative status using an automated method in patients with hyperthyroidism. Thirty-six subjects with hyperthyroidism and 30 healthy controls were enrolled in this study. Serum oxidative status was determined via measurement of total antioxidant capacity (TAC) and total oxidant status (TOS) and calculation of oxidative stress index (OSI). Serum TAC levels were significantly lower in patients with hyperthyroidism than controls (P=0.002), while serum TOS levels and OSI values were significantly higher (P=0.008, 0.004; respectively). Serum TAC levels were correlated with TSH levels (rho=0.223, P=0.032), FT3 levels (rho=-0.434, P=0.002) and FT4 levels (rho=-0.363, P=0.003) in patients. Further, TOS levels and OSI values were correlated with TSH levels (rho=-0.245, P=0.037; rho=-0.312, P=0.011, respectively), FT3 levels (rho=0.293, P=0.017, rho=0.505, P=0.002, respectively), and FT4 levels (rho=0.302, P=0.006, rho=0.321, P=0.008, respectively) in patients. Duration of disease was significantly correlated with OSI values in patients (rho=0.420, P=0.011), while no correlation with serum TAC levels and TOS levels (P>0.05). Oxidants are increased and antioxidants are decreased in patients with hyperthyroidism; as a result, the oxidative-antioxidative balance is shifted to the oxidative side. Increased oxidative stress may play a role in the pathogenesis of hyperthyroidism. It is believed that supplementation of antioxidant vitamins such as vitamins C and E may be helpful for these patients.

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.

Association between metabolic abnormalities and HBV related hepatocelluar carcinoma in Chinese: a cross-sectional study

Background

Previous studies suggested that the abnormality of metabolism is a newly identified risk factor in HBV-related hepatocellular carcinoma (HCC). The association between metabolic factors and hepatocellular carcinoma (HCC) has not been clarified up to now. This study was conducted to investigate the prevalence of metabolic abnormalities in HCC and to probe the association between metabolic parameters and liver function as well, so as to evaluate the interactions between metabolism and the development of HBV-related HCC.

Methods

Totally 179 cases of HBV-related HCC, who were surgically treated and pathologically confirmed were enrolled. HBV carriers (n = 100) and healthy controls (n = 150) were recruited from routine physical examination during the same period. Body mass index (BMI) was obtained from medical documentation. All the metabolic-related parameters and liver function tests were determined with routine biochemical or immunological analytic methods. Malondialdehyde (MDA) and total antioxidant capacity(TAOC)were detected by chemical analytic methods. A stratified analysis was conducted according to BMI, glycated albumin (GA), free fatty acids (FFA), and the relationships between the metabolic-related parameters and liver functions were analyzed in HCC and control subjects.

Results

HCC group showed significantly high levels of mean BMI, serum glucose, low serum lipids levels than controls (P < 0.05). Acquired by stratified analysis, the higher the BMI, the higher level of insulin and homeostasis model assessment for insulin resistance (HOMA-IR) (P < 0.01) were found in HCC patients. Elevated level of MDA and γ-glutamyltransferase (GGT) were revealed in those with high serum FFA level for the first time. Strong associations between metabolic factors and liver function were shown in HCC (P < 0.05). Higher GA level was strongly associated with increased risk of cancer compared to healthy controls (OR = 9.87, 95% confidence interval: 1.86~52.29). Serum triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C) levels were negative contributory factors for HCC (OR = 0.05, 95% confidence interval: 0.01~0.27 and OR = 0.32, 95% confidence interval, 0.11~0.95: respectively).

Conclusions

Metabolic abnormalities are closely associated with the occurrence and development of HBV-related HCC. Oxidative stress and/or lipid peroxidation might be involved in the pathogenesis and acceleration of liver function impairments in HCC.

The influence of hemodialysis membrane permeability on serum paraoxonase-1 activity and oxidative status parameters

We aimed to measure oxidative stress parameters and paraoxonase-1 (PON-1) enzyme activities in chronic hemodialysis (HD) patients and to investigate whether HD membrane permeability has any influence on those measures. Forty-seven HD patients and 24 controls were enrolled. At the first step of the study, all HD patients had undergone HD treatment via "low-flux" membranes for 4 weeks. At the second step of the study, the membranes were switched to "high-flux" membranes and HD treatments were also performed via "high-flux" membranes for 4 weeks. Blood samples were withdrawn after completion of 4 weeks treatment for each membrane. Total oxidant status (TOS), total antioxidant status (TAS), and paraoxonase and arylesterase activities were measured in blood samples of the patients and the controls. TOS and oxidative stress index (OSI) of both membranes were higher than controls (all, P < 0.05), while TAS and paraoxonase and arylesterase activities were lower (all P < 0.05). Paraoxonase (P < 0.05, r = -0.437 and P < 0.05, r = -0.453, respectively) and arylesterase (P < 0.05, r = -0.333 and P < 0.05, r = -0.371, respectively) activities of "low-flux" and "high-flux" membranes were inversely correlated with OSI. There were no significant differences between "low-flux" and "high-flux" membranes in regard to oxidative stress parameters or PON-1 enzyme activities (all, P > 0.05). HD patients have increased oxidative stress and decreased serum PON-1 activities inversely correlated with oxidative stress. Membrane permeability seems to have no influence on oxidative stress parameters and PON-1 enzyme activities.