Blood cell superoxide dismutase and enolase activities as markers of alcoholic and nonalcoholic liver diseases

Identification of serum insulin-like growth factor binding protein 1 as diagnostic biomarker for early-stage alcohol-induced liver disease

Background

Alcohol consumption is a major cause of liver disease in humans. The use and monitoring of biomarkers associated with early, pre-clinical stages of alcohol-induced liver disease (pre-ALD) could facilitate diagnosis and treatment, leading to improved outcomes.

Methods

We investigated the pathological, transcriptomic and protein changes in early stages of pre-ALD in mice fed the Lieber-Decarli liquid diet with or without alcohol for four months to identify biomarkers for the early stage of alcohol induced liver injury. Mice were sampled after 1, 2 and 4 months treatment.

Results

Pathological examination revealed a modest increase in fatty liver changes in alcohol-treated mice. Transcriptomics revealed gene alterations at all time points. Most notably, the Igfbp1 (Insulin-Like Growth Factor Binding Protein 1) was selected as the best candidate gene for early detection of liver damage since it showed early and continuously enhanced induction during the treatment course. Consistent with the microarray data, both Igfbp1mRNA expression in the liver tissue and the IGFBP1 serum protein levels showed progressive and significant increases over the course of pre-ALD development.

Conclusions

The results suggest that in conjunction with other tests, serum IGFBPI protein could provide an easily measured biomarker for early detection of alcohol-induced liver injury in humans.

Antioxidative status of patients with alcoholic liver disease in southeastern Taiwan

AIM: To investigate the antioxidative status of patients with alcoholic liver disease (ALD) in southeastern Taiwan.

METHODS: Our study comprised 27 patients with ALD recruited from Taitung Mackay Memorial Hospital, located in southeastern Taiwan. Patients with ALD included 12 non-aborigines (12 men) and 15 aborigines (11 men and 4 women). According to the severity of ALD, patients with ALD included 10 with hepatitis (9 men and 1 woman) and 17 with cirrhosis (14 men and 3 women). Twenty-two age- and gender-matched healthy adults served as the control group in this study. Venous blood (10 mL) of each subject was drawn into EDTA-containing tubes after 8 h overnight fasting.

RESULTS: Compared to the control group, patients with ALD showed significantly lower erythrocytic catalase (11.1 ± 0.7 U/mg Hb vs 8.0 ± 0.7 U/mg Hb, P < 0.05) and superoxide dismutase (9.5 ± 1.6 U/mg Hb vs 3.0 ± 0.2 U/mg Hb, P < 0.05) activities. Furthermore, the erythrocytic reduced glutathione/oxidized glutathione ratio was significantly lower in ALD patients than that in the control group (38.1 ± 5.4 vs 15.7 ± 1.9, P < 0.05). The results revealed that patients with ALD experienced more oxidative stress than those in the control group. The non-aboriginal, but not the aboriginal, ALD group had higher erythrocytic glutathione peroxidase (GPX) activity than that in the control group (46.1 ± 7.8 U/g Hb vs 27.9 ± 2.2 U/g Hb, P < 0.05). Hepatitis, but not cirrhosis, ALD patients had higher erythrocytic GPX activity than that in the control group (44.3 ± 8.6 U/g Hb vs 27.9 ± 2.2 U/g Hb, P < 0.05).

CONCLUSION: Our results indicate that both ethnicity and the severity of ALD may cause different erythrocytic antioxidative enzyme activities especially GPX activity.

Occupational exposure to mineral fibres. Biomarkers of oxidative damage and antioxidant defence and associations with DNA damage and repair

In order to study the effect of mineral wool exposure on oxidative DNA damage and lipid peroxidation, an epidemiological study was conducted in a mineral wool factory in Slovakia. Altogether 141 subjects were investigated (21-58 years old), 43 controls (20 men and 23 women: 27 non-smokers, 16 smokers) and 98 exposed (75 men and 23 women: 61 non-smokers, 37 smokers). We found higher malondialdehyde (MDA) levels in the group of all exposed workers (P = 0.025) and in exposed non-smokers (P = 0.003) and a significantly suppressed activity of ceruloplasmin oxidase (P = 0.02, P < 0.02, respectively) and catalase (CAT) (P = 0.04, P = 0.01, respectively) in these groups. The activity of glutathione S-transferase (GST) was affected by exposure to mineral wool; levels were significantly lower in all exposed subjects (P = 0.04), in the exposed non-smokers (P = 0.03) and in exposed men (P < 0.01). Concentrations of vitamin C in plasma and the ferric-reducing activity of plasma (FRAP) were not affected by the mineral wool exposure. There was a significant negative correlation between the activity of glutathione peroxidase (GPX) and MDA in the whole group (P < 0.01) and in the exposed group and between CAT activity and MDA in all subjects (P < 0.01). GST activity correlated inversely with oxidized pyrimidines in lymphocyte DNA, in almost all subgroups. We found significant negative correlations between DNA repair and GPX in all subjects (P = 0.03) as well as in control men (P < 0.03) and between DNA repair and CAT in all control subjects (P < 0.02) and in control men (P < 0.01). Interestingly, we found a positive correlation between DNA repair and MDA in all subjects (P < 0.01) and in all exposed subjects (P < 0.03). The presented results indicate that mineral wool exposure induces an increase in oxidative damage to biomolecules especially in the group of male non-smokers. However, optimal levels of antioxidants could have a protective effect. Biomarkers such as MDA, antioxidant enzymes and antioxidant vitamins measured in blood may be useful biomarkers of oxidative stress and antioxidant protection. We do not recommend FRAP as a marker of antioxidant status as interference from other constituents can provide false or confusing results. Our study supports the idea that there might also be other mechanisms by which antioxidant enzymes (especially GST) protect cells against oxidative DNA damage.

Oxidative status in patients with alcohol dependence: a clinical study in Taiwan

The aim of this study is to examine the relationship between alcohol dependence and oxidative status. The biochemical parameters and antioxidants status were measured among 28 patients with alcohol dependence. Nineteen healthy persons without drinking problem were recruited as the control subjects. The activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyltransferase (gamma-GT), and levels of cholesterol, triglyceride (TG), and uric acid were significantly increased in the specimen of patients compared with control. Serum malondialdehyde (MDA) levels of the patients were found to be significantly increased compared with controls and decreased after abstinence. Superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities were, respectively, 86% and 37% lower in alcoholic patients. After 14 d of abstinence, SOD activity was significantly reduced by 85%, CAT by 52%, and GPX by 54%, whereas no change was found in activity of glutathione reductase (GR). The duration of alcohol dependence is significantly correlated with the levels of MDA. In addition, the activity of CAT was significantly correlated with MDA levels. The results of this study suggest that oxidative stress occurred during alcohol dependence and subsequently affected the antioxidants mechanisms.

Blood antioxidant levels in patients with alcoholic liver disease correlate with the degree of liver impairment and are not specific to alcoholic liver injury itself

BACKGROUND

Enhanced production of reactive oxygen species may play a pathogenic role in alcoholic liver injury.

AIMS

To investigate whether various antioxidant parameters in blood are affected in different stages of alcoholic liver disease and how specific the changes are relative to non-alcoholic cirrhosis.

METHODS

Patients with alcohol abuse without cirrhosis (n=14), with alcoholic cirrhosis [Child-Pugh scores A (n=9), B (n=5) and C (n=18)] and with non-alcoholic cirrhosis [Child-Pugh score C (n=6)] and healthy controls (n=13) were studied. Levels of reduced glutathione and glutathione peroxidase activity in blood, erythrocytic superoxide dismutase activity and carotenoids, alpha-tocopherol and malondialdehyde in plasma were measured.

RESULTS

Levels of reduced glutathione were significantly decreased in Child-Pugh score C cirrhotics, alcoholic or not in origin, whereas oxidized glutathione and glutathione peroxidase activity were not affected. Superoxide dismutase activity and alpha-tocopherol levels were not significantly different in the various groups. Carotenoid levels were significantly lower in alcoholic cirrhotics (Child-Pugh score C) vs. controls. Malondialdehyde levels were elevated only in cirrhotics Child-Pugh score C, alcoholic or non-alcoholic.

CONCLUSIONS

Levels of reduced glutathione and malondialdehyde reflect the degree of liver impairment, more than the relation with alcohol intake. Decreases in several antioxidant levels are not specific to alcoholic liver injury.

Laboratory markers of ethanol intake and abuse: a critical appraisal

Laboratory markers for ethanol intake and abuse and chronic alcoholism currently in use have been critically reviewed. The merits and pitfalls of each test have been evaluated. The clinical use of the new test of carbohydrate-deficient transferrin has been particularly emphasized. Carbohydrate-deficient transferrin currently provides the highest specificity and sensitivity of all commonly used markers of alcoholism.