Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P30044 (antioxidant enzyme)
 8,037 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Paraoxonase is a serum enzyme with an anti-oxidant function, protecting low density lipoproteins (LDL) from oxidative modifications. Diabetic patients are suggested to be at greater risk of oxidative stress, which may contribute to the significantly higher incidence of vascular disease in this population. Less efficient protection mechanisms may be one feature of the greater susceptibility to oxidation in diabetes. In this context, the present study examined the hypothesis that serum paraoxonase is reduced in type 1 (insulin-dependent) diabetic patients and that the reduction can affect the anti-oxidant capacity of HDL. Serum paraoxonase concentrations and activities were compared in type 1 patients and first degree, non-diabetic relatives with particular attention paid to the confounding effects of paraoxonase gene polymorphisms. In addition, the ability of HDL-paraoxonase to protect low density lipoproteins from oxidation was analysed in an in vitro system. Serum concentrations and enzyme activities of paraoxonase were significantly lower in type 1 patients compared to non-diabetic, first degree relatives. The differences were independent of promoter and coding region polymorphisms, which influence serum concentrations and activities of the enzyme. Overall, paraoxonase concentrations were a mean 13.3+/-4.5% lower (P<0.02) in type 1 patients. Specific activities did not differ between diabetic and non-diabetic groups. The concentration ratios of LDL cholesterol:paraoxonase (1.37+/-0.51 vs. 1.18+/-0.37, P=0.003) and apolipoprotein B:paraoxonase (0.84+/-0.33 vs. 0.71+/-0.40; P=0.012) were significantly higher in diabetic patients, consistent with a reduced capacity to protect LDL from oxidation. In vitro oxidation studies showed that a significantly higher level of lipid hydroperoxides was generated in LDL in the presence of HDL, containing paraoxonase levels equivalent to those of type 1 patients, compared to HDL containing paraoxonase levels equivalent to those of control subjects (mean difference 8.1%, P<0.05). The study demonstrates that serum concentrations of the antioxidant enzyme paraoxonase are significantly lower in type 1 (insulin-dependent) diabetic patients compared to non-diabetic, first-degree relatives, independently of known gene polymorphisms. Concentrations are reduced to an extent that can affect its anti-oxidant capacity. The results are consistent with the contention that modifications to serum paraoxonase in type 1 patients can increase risk of lipoprotein oxidation and, consequently, risk of vascular disease.
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PMID:Serum paraoxonase is reduced in type 1 diabetic patients compared to non-diabetic, first degree relatives; influence on the ability of HDL to protect LDL from oxidation. 1122 46

We examined levels of malondialdehyde (MDA) (an end-product of lipid peroxidation) and paraoxonase (PON1) (an antioxidant enzyme) activity and PON1 phenotypes in people who were exposed to ionizing radiation for different time periods and doses. A total of 78 individuals (mean age 34 +/- 7 years) were included in the study. Fifty-one of them were radiology workers whereas the control group was composed of 27 healthy volunteers who had never worked in a radiology-related job. Paraoxon was used as substrate for measurement of PON1 activity levels (basal and NaCl-stimulated). Phenylacetate was used as substrate for measurement of arylesterase activity levels. Cumulative levels of serum NaCl-stimulated PON1/arylesterase activities were utilized for phenotypic differentiation. In radiology workers, three different phenotypes were determined based on paraoxonase/arylesterase ratio. The ratios were 1.09 +/- 0.30 for AA (homozygote low activity); 2.91 +/- 1.07 for AB (heterozygote activity) and 4.97 +/- 1.21 for BB (homozygote high activity). There was a statistically meaningful negative correlation between serum MDA levels and PON1 activity levels in all phenotypes (p < 0.05). PON1 activity levels were found to be 25-35% lower in people who were exposed to long-term ( > 5 years) radiation compared to controls. There was no statistically significant correlation between serum arylesterase activity and MDA levels in these subjects (r = -0.185, p > 0.05). PON1 activity levels were decreased whereas serum MDA levels were increased in individuals exposed to radiation for a long period. PON phenotypes of people employed in jobs which expose them to radiation should be determined and based on these findings they should be advised to avoid risk factors inducing oxidative stress, such as smoking, and to consume foods rich in vitamins and trace elements to increase their antioxidant capacity.
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PMID:Levels of paraoxonase and arylesterase activities and malondialdehyde in workers exposed to ionizing radiation. 1462 76

The presence of the metabolic syndrome (World Health Organization definition) and its association with lipoprotein abnormalities suggestive of greater susceptibility to oxidative stress have been analyzed in patients with angiographically defined coronary artery disease. The odds ratio for the presence of the metabolic syndrome was significantly higher in coronary artery disease-positive patients (P < 0.001). The metabolic syndrome was also associated with more severe coronary disease (P < 0.01). Patients with the metabolic syndrome had significantly decreased low-density lipoprotein-cholesterol/apolipoprotein B and high-density lipoprotein-cholesterol/apolipoprotein AI ratios, indicative of the presence of small, dense lipoprotein particles. The syndrome was also associated with reduced concentrations and activities of the antioxidant enzyme, paraoxonase-1. The metabolic syndrome is characterized by smaller, denser lipoprotein particles that increase their susceptibility to oxidative modifications and diminished serum paraoxonase-1, which is a major determinant of the antioxidant capacity of high-density lipoproteins. These may be contributory factors to the increased presence and severity of coronary disease in such patients.
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PMID:Small, dense lipoprotein particles and reduced paraoxonase-1 in patients with the metabolic syndrome. 1568 41

This study was designed to evaluate the oxidative and antioxidative status in patients with ulcerative colitis by detecting antioxidant enzyme paraoxonase 1 activity together with the level of a well-known marker of oxidative stress, malondialdehyde. Serum paraoxonase 1 activity and malondialdehyde levels were analysed in 30 patients with ulcerative colitis and 30 controls using a spectrophotometric method; correlation analysis was made between these variables. Serum malondialdehyde levels were higher in the ulcerative colitis group (median: 2.5, range: 0.5-9.4 nmol ml(-1)) than among the controls (median:1.1, range: 0.5-2.3 nmol ml(-1); p < 0.001) whereas paraoxonase 1 activities were lower in the ulcerative colitis group (median: 158.4, range: 61.6-264.1 U l(-1)) than in the control group (median: 233.3, range: 114.4-431.0 U l(-1); p < 0.001). There was no correlation between serum malondialdehyde level, paraoxonase 1 activity and disease activity. (1) Increased reactive oxygen metabolites levels in ulcerative colitis may result in a pro-oxidation environment, which in turn could result in decreased antioxidant paraoxonase 1 activity and increased malondialdehyde levels, (2) increased cytokines may be a possible cause of decreased paraoxonase 1 activity and (3) decreased serum paraoxonase 1 activity may be a part of an inflammatory response.
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PMID:Serum paraoxonase 1 activity and malondialdehyde levels in patients with ulcerative colitis. 1583 Mar 98

The antioxidant enzyme paraoxonase 1 is a marker of oxidative stress and has been implicated in the pathogenesis of preeclampsia. Our objective was to determine if an association exists between low paraoxonase 1 activity at midgestation and the development of preeclampsia. We conducted a case-control study of 50 women with preeclampsia and 101 women with uncomplicated term deliveries. Maternal serum collected at 15 to 20 weeks was used to measure paraoxonase 1 activity using two substrates: paraoxon and phenylacetate (arylesterase activity). The groups did not differ with respect to maternal demographics. Paraoxonase 1 activity (paraoxon) was significantly higher in women with preeclampsia compared with controls (19.4 +/- 9.4 versus 15.6 +/- 8.0 change in absorbance per minute (dA/min), P = 0.009). When stratified by disease severity, paraoxonase 1 activity (paraoxon) was highest in women with severe preeclampsia (21.6 +/- 9.1 versus 15.6 +/- 8.0 dA/min, P = 0.002). We observed a trend toward higher arylesterase activity in women with preeclampsia compared with controls (0.343 +/- 0.07 versus 0.323 +/- 0.06 dA/min, P = 0.06). Midgestational paraoxonase 1 activity is higher in women with preeclampsia before clinical signs of the disease are present. Prospective studies are needed to determine the significance of paraoxonase 1 in the pathogenesis of preeclampsia.
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PMID:Association of midgestational paraoxonase 1 activity with pregnancies complicated by preeclampsia. 1968 20

Dyslipidemia in patients with glycogen storage disease types Ia (GSD Ia) and III (GSD III) does not lead to premature atherosclerosis. The aim of this study was to investigate the association among serum copper (Cu), zinc (Zn), iron (Fe), and selenium (Se) concentrations, and their carrier proteins: ceruloplasmin, albumin, and related antioxidant enzyme activities [superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), paraoxonase (PON), and arylesterase (ARYL)] in 20 GSD Ia and 14 III patients compared to age and sex matched 20 healthy subjects. Erythrocyte oxidative stress was measured by erythrocyte thiobarbituric acid reactive substances (eTBARSs). Hypertriglyceridemia [333 (36-890)mg/dL] in GSD Ia and hypercholesterolemia with elevated LDL-cholesterol [188 (91-313)mg/dL] and decreased HDL-cholesterol [32(23-58)mg/dL] levels in GSD III were found. Serum Cu, Fe, and Zn showed no significant differences between groups. However, Se 60 (54-94), 81 (57-127) microg/L, ceruloplasmin 21 (10-90), 27 (23-65) microg/L, and albumin 2.4 (1.7-5.1), 2.8 (1.8-4.06)g/dL levels were decreased in GSD Ia and III groups, respectively, in comparison with the controls [Se 110 (60-136) microg/L, ceruloplasmin 72 (32-94) microg/L, and albumin 4.4 (4-4.8)g/dL)]. In spite of high oxidative stress in erythrocyte detected by elevated eTBARS/Hb levels in GSD group [674.8 (454.6-948.2) for GSD Ia, 636.3 (460.9-842.1) for GSD III, and 525.6 (449.2-612.6)], the activities of CAT, SOD, ARYL, and PON in GSD patients were not different from the controls. GPx activity was decreased in GSD Ia [3.7 (1.8-7.1)U/mL] and GSD III [4.2 (2.2-8.6)U/mL] compared with healthy controls [7.1 (2.9-16.2)U/mL]. In conclusion, this study supplied the data for trace elements, their carrier, and antioxidative enzymes in the patients with GSD Ia and III. The trace elements and anti-oxidative enzyme levels in GSD patients failed to explain the atherosclerotic escape phenomenon reported in these patients.
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PMID:An association among iron, copper, zinc, and selenium, and antioxidative status in dyslipidemic pediatric patients with glycogen storage disease types IA and III. 2012 79

Chronic otitis media usually presents with a benign tumor-like lesion of the temporal bone known as a cholesteatoma. The role of oxidative stress in the pathogenesis of chronic otitis media and cholesteatoma has not yet been fully explored. Therefore, the aim of this study was to investigate the oxidative stress markers and antioxidant enzymes in patients with cholesteatomatous and noncholesteatomatous chronic otitis media and in healthy subjects. A prospective controlled trial was performed on cholesteatomatous and noncholesteatomatous chronic otitis media patients in a tertiary referral center in a university hospital. A total of 75 subjects, including 25 cholesteatomatous and 25 noncholesteatomatous chronic otitis media patients and 25 healthy subjects participated in this study. Serum total oxidant status (TOS) and oxidative stress index (OSI) levels were significantly increased in the patient groups with or without cholesteatoma compared with the control group. Serum total antioxidant status (TAS) levels and Paraoxonase and arylesterase activity were significantly lower in the patient groups with or without cholesteatoma compared with the control group. Serum TOS and OSI levels were lower in the noncholesteatomatous group, whereas serum TAS levels were higher compared with the cholesteatomatous group. Serum arylesterase activity was significantly lower in the noncholesteatomatous group compared with the control group. The results of this study reveal that in cholesteatoma cases, the oxidative stress and antioxidant enzyme imbalance were more significant than in cases of chronic otitis media without cholesteatoma.
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PMID:Oxidative stress in chronic otitis media. 2271 Oct 4

Objective. In the present study, since PON1 is known as an HDL-associated antioxidant enzyme that inhibits the oxidative modification of LDL and oxidative stress plays a role in the pathogenesis of mesenteric ischemia, we investigated the changes in PON1 activity and lipid profile in an experimental ischemic colitis model. Methods. Forty male Wistar albino rats were divided into two groups: the control group (N = 15) and the experimental group (N = 25). All animals were anesthetized with ether and ketamine anesthesia to undergo a midline laparotomy. Ischemic colitis was induced by marginal vessel ligation in the splenic flexura (devascularization process). A sham laparotomy was performed in the control group. All animals were sacrificed on the seventh postoperative day. Oxidative stress marker (malonyldialdehyde, MDA), lipid profile, and paraoxonase (PON-1) and arylesterase activities were determined. Histopathological evaluation was done under light microscopy, after sectioning and staining with hematoxyline and eosin. Statistical analysis was conducted using Student's t-test and Mann-Whitney U test, and P < 0.05 was considered as statistically significant. Results. There was a significant decrease in both serum and tissue PON1 activity in ischemic colitis group (P < 0.01, for each). Similarly, arylesterase levels showed a parallel decrease in both tissue and serum of the experimental group (P < 0.01 and P < 0.001, retrospectively). MDA, an oxidative stress marker, was seen to increase in the experimental group (P < 0.01, tissue; P < 0.05, serum). In experimental group, there was a significant rise in serum total cholesterol and LDL levels (P < 0.001, for each). However, HDL level decreased significantly (P < 0.001). Triglycerides did not show any change between the groups (P > 0.05). Conclusions. PON1 and arylesterase play an important role in the pathophysiology of ischemic colitis.
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PMID:Paraoxonase and arylesterase activities, lipid profile, and oxidative damage in experimental ischemic colitis model. 2319 80

Increases in the generation of reactive oxygen species and decreases in antioxidant enzyme activities with aging have been reported in the prostate, and are also observed in age-related disorders such as atherosclerosis, Alzheimer's disease, and cataracts. Several studies have demonstrated that proteins are targets for reactive oxidants in cells, and that oxidized proteins accumulate during aging, oxidative stress and in some pathological conditions. However, only a limited number of studies have actually evaluated oxidative damage in relation to HDL-cholesterol-associated antioxidant enzyme activities or have assessed its relationship with prostate cancer. In this study, we examined the effect of HDL-cholesterol-associated antioxidant enzyme activities, paraoxonase1, arylesterase and new oxidative stress parameters (total oxidant status, total antioxidant status [and oxidative stress index]) in newly-diagnosed prostate cancer patients and healthy controls. There were no significant differences in oxidative stress parameters and lipid parameters between prostate cancer patients and controls, however, paraoxonase1 enzyme activity, and non-HDL-cholesterol levels were higher in prostate cancer patients than controls. The results of this study were derived from a small number of subjects, but might represent an important working hypothesis for further research in a larger number of cases to clarify the role of paraoxonase1 overproduction on the prostate and its clinical relevance.
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PMID:Enhanced HDL-cholesterol-associated anti-oxidant PON-1 activity in prostate cancer patients. 2376

Variability in the activity and function of serum paraoxonase (PON1) as an antioxidant enzyme involved in vascular disease has been observed. In this study, we investigated the enzyme activity parameters, based on the 192Q/R polymorphism, using the salt stimulation property of PON1 as an important although neglected property. In total, 172 participants, including 90 control subjects and 82 patients with ischemic stroke were enrolled. Paraoxonase activity (para), arylesterase activity (aryl) and salt-stimulated paraoxonase activity (para-Na) were measured by spectrophotometric assays. The distribution of the 192Q/R phenotypes was determined using the dual substrate method. We observed that the para-percent (percentage stimulation of paraoxonase activity by NaCl) was significantly lower in the patients than in the controls, in both the QR+RR group (p=0.01) and QQ phenotypes (p=0.001). More than the other parameters, para-percent and para-degree (para-Na-para) are affected by ischemic stroke (p<0.001). In R-containing phenotypes, significant correlations were observed between both aryl and para, with age (r=-0.364, p=0.016; and r=-0.333, p=0.029, respectively). The salt stimulation properties of PON1 activity, particularly the parameters para-percent and para-degree, could be considered more important than the prevalent activities of the enzyme, and could be better applied for the assessment of PON1 status in ischemic stroke rather than the common enzyme activities.
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PMID:The salt stimulation property of serum paraoxonase (PON1) could be a valuable factor in evaluating the enzyme status in ischemic stroke: the role of activity-determined PON1 192Q/R phenotypes. 2443 30


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