Arylesterase Enzyme Research Articles

The Effect of Age on the Paraoxonase and Arylesterase Activity of Pregnant Mothers and Their Infants

The study aimed to research the effect of maternal age at pregnancy on the paraoxonase (PON) and arylesterase activity levels of mothers and infants. The study comprised 30 mothers aged more than 35 years and their infants, and 30 mothers aged under 25 years and their infants. All pregnancies had been of 38-42 weeks with normal spontaneous vaginal birth. PON and arylesterase activities were measured using paraoxon and phenylacetate substrates. When the PON and arylesterase enzyme activities were compared, the PON and arylesterase activity of the mothers aged more than 35 years was found to be statistically significantly lower compared to that of the mothers aged under 25 years (P = 0.006 and P = 0.03, respectively), while there was no statistically significant difference in PON and arylesterase enzyme activity between the two groups of infants (P > 0.05). While the PON and arylesterase enzyme activity of the mothers aged more than 35 years was found to be significantly lower compared to that of the mothers aged under 25 years, there was no statistical significance between the infants. This can be explained by the reduced PON and arylesterase enzyme activity during pregnancies at an older age, although this did not affect the PON and arylesterase enzyme activity of the infants.

Increased Oxidant Stress and Inflammation in Patients with Chronic Schizophrenia

Background: Several lines of evidence, including postmortem studies, suggest increased oxidative stress and inflammation in patients with schizophrenia. Alteration of oxidative stress markers has been reported in schizoprenia studies, but with inconsistent results. Oxidized low-density lipoproteins (oxLDL) have been reported to be capable of eliciting neurocytotoxicity. On the other hand, paraoxonase (PON1), an arylesterase(ARE), plays a role in protection against oxidative modifications of LDL and is considered to be one of the antioxidant enzymes. There are no studies showing the changes in oxidative stress and inflammation together, nor the activities of PON1 and ARE in schizophrenic patients. In this study, we examined PON1, ARE activities and oxidative/anti-oxidative markers in patients with chronic schizophrenia and healthy controls. Methods: We recruited 30 male chronic schizophrenic patients and 30 male healthy control subjects and examined C-reactive protein(CRP), fibrinogen, PON1, ARE and plasma total antioxidant status (TAS) and total oxidant status (TOS), oxidative stress index(OSI) in both groups. Schizophrenia symptoms were assessed using the positive and negative syndrome scale (PANSS). The related routine lipid profile parameters including HDL were also examined. Results: Patients had significantly higher CRP, fibrinogen, TOS and OSI levels; but the patients and control subjects did not differ on activities of the antioxidant enzymes PON1 and ARE. Interestingly, there were not any group differences in the lipid profile parameters except the triglyceride levels, that increased significantly in the patient group. Conclusions: In the present study, reporting the ARE activities besides the PON1 activities in schizophrenic patients for the first time, we showed that PON1 and ARE enzyme activities were not statistically different in patients with chronic schizophrenia. This study provides additional evidence of increased oxidative stress and inflammation in chronic schizophrenia, but no alterations in the antioxidant status were observed. Our results suggest that other mechanisms than the high density lipoprotein(HDL)-disfunctionality, namely decreases in PON1 or ARE enzyme activities, are more important in oxidative or antioxidative pathophysiological processes in schizophrenia.

Cu/Zn-superoxide dismutase, paraoxonase and arylesterase activities and malondialdehyde levels in patients with familial mediterranean fever

In this study, alterations in antioxidant enzyme activities and malondialdehyde (MDA) levels in the serum samples of patients with familial Mediterranean fever (FMF), an autosomal recessive disease characterized by recurrent episodes of peritonitis, pleuritis, arthritis and fever, were investigated and compared with those of age- and sex-matched healthy controls. Twenty-five patients with FMF undergoing colchicine therapy at doses of 1-1.5 mg and 25 age- and sex-matched healthy controls were included in the study. In the patients with FMF and control subjects, the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level were measured. Cu/Zn-superoxide dismutase (Cu/Zn-SOD), paraoxonase-1 (PON-1) and arylesterase (ARE) enzyme activities and MDA levels as a production of lipid peroxidation were evaluated using the appropriate methods. No statistically significant differences in the serum levels of ESR, CRP, Cu/Zn-SOD, MDA and PON-1 between the groups were observed (p>0.05). Serum ARE activity was significantly decreased in the patients with FMF compared with the control subjects (p<0.01). In conclusion, some abnormalities in the antioxidant defense system and lipid peroxidation may be observed in FMF patients during attack-free periods. However, further long-term studies on the subject are needed to explore altered lipid peroxidation and antioxidant defense mechanisms in patients with FMF (Tab. 1, Fig. 1, Ref. 35).

The Effect of Antioxidants Supplement on Lipid Peroxidation and Serum Aryl Esterase Enzyme in Rheumatoid Arthritis Patients

Problem statement: Rheumatoid Arthritis (RA) is one of the common autoimmune diseases with unknown etiology that its prevalence ratio in females to males is 3:1. It has been suggested that serum antioxidant levels is reduced and lipid peroxidation is increased due to oxidative stress. According to a recent research, antioxidant supplements may play an important role in controlling oxidative stress. The aim of this study is to investigate the effect of antioxidants supplement on serum Aryl Esterase Enzyme (ARE) and serum Malondialdehyde (MDA) in RA patients. Approach: A pre-post study was conducted in a 3 month period on 40 female RA patients which receiving daily one SelenPlus capsule (selenium 50 mcg, zinc 8 mg, vitamin A 400 mcg, vitamin C 125 mg and vitamin E 40 mg). About 5 mL venous blood sample was taken from all participants and serum levels of ARE and MDA were measured spectrophotometerically. Distribution of the variables were assessed using histogram with normal curve as well as Kolmogrov-Smirnov test and Data were analyzed with paired t test for differences between pre-post data using SPSS software version 13.5. Results: Out of 40 patients, 39 completed the study. In comparison with the baseline, we found significant differences between serum aryl esterase and malondialdehyde values before and after intervention. The 3-month supplementation resulted in increasing ARE activity (p<0.001) and reduction of MDA levels (p<0.001). Conclusion: The antioxidantssupplement for 3 months resulted in significant improvement in ARE activity and reduction of lipid peroxidation marker and may be helpful in RA treatment.

Serum paraoxonase enzyme activity and oxidative stress in obese subjects

Obesity is an important risk factor for atherosclerotic cardiovascular disease. Paraoxonase-1 (PON1) may play a significant role in the prevention of obesity-related accelerated atherosclerosis by hydrolyzing lipid peroxides in oxidized low-density lipoproteins. The aim of this study was to evaluate PON1 and arylesterase enzyme activities and lipid hydroperoxide (LOOH) levels, and to investigate whether there is increased susceptibility to atherogenesis in obese subjects, which might be reflected by increased oxidative stress and decreased PON1 activity. We also aimed to investigate the association between PON1 activity and body mass index (BMI) in this patient group. The study involved 25 obese subjects and 23 controls. Serum PON1 and arylesterase activity was measured spectrophotometrically. LOOH levels were measured by the FOX-2 assay. Serum basal/salt-stimulated PON1 and arylesterase activities were significantly lower in obese subjects than in controls (P <0.001 for both enzymes), while LOOH levels were significantly higher (P <0.001). BMI was significantly correlated with PON1, arylesterase and LOOH levels (P <0.001, r = -0.720; P <0.001, r = -0.634; P <0.001, r = 0.491; respectively). Serum high-density lipoprotein (HDL) levels were positively correlated with PON1 activity (r = 0.347, P <0.05). Our results indicate that obese subjects have increased oxidative stress and decreased PON1 activity, which might contribute to accelerated atherosclerosis. A decrease in PON1 activity seems positively correlated with BMI and inversely correlated with HDL levels.

Increased levels of total oxidant status and decreased activity of arylesterase in migraineurs

Objectives There is strong evidence associating migraine with a variety of comorbid disorders, including cardiovascular disease and stroke, in which oxidative stress seems to be an important underlying mechanism. The aim of the study was to investigate in migraineurs the body oxidant/antioxidant balance and paraoxonase enzyme activities as a measure of HDL functionality. Design and methods Oxidative stress index, total oxidant status and antioxidant status were examined in addition to the paraoxonase and arylesterase enzyme activities in sixty-two migraineurs and fifty healthy control subjects. Results Serum arylesterase activities were significantly lower in migraineurs (p = 0.0065), whereas total oxidant status was higher in patients compared to the controls (p = 0.0035). Conclusions This preliminary study showed that oxidative/antioxidative balance shifted towards the oxidative status in migraine. Moreover, the results also suggested that decreased arylesterase activities might be associated with HDL-related disfunction.

Serum paraoxonase and arylesterase activities in various forms of hepatitis B virus infection.

The aim of this study was to determine and evaluate the activity of paraoxonase and arylesterase enzymes in various clinical forms of hepatitis B infection and to investigate the correlation between these parameters and chronic disease course/fibrosis. Overall, 40 patients diagnosed as hepatitis B carriers (CIHBV), 40 chronic active hepatitis B (CAHBV) patients, and 40 healthy adults (control group) between 18 and 65 years of age were enrolled the study. Serum paraoxonase and arylesterase activities were measured spectrophotometrically. Their activities were significantly lower in patients with CAHBV compared with CIHBV patients or with control group patients (P<0.001). There was a negative correlation between alanine aminotransferase levels and the activity of paraoxonase and arylesterase (r = -0.38, P = 0.001 and r = -0.28, P = 0.002, respectively). A statistically significant negative correlation was found between arylesterase activity in the sera of CAHBV patients and HBV DNA levels (ρ = -0.33, P = 0.03). On the contrary, no correlation was found between paraoxonase levels and HBV DNA levels (P>0.05). The histology activity index of CAHBV patients did not correlate with paraoxonase and arylesterase activities (P>0.05). In light of these findings, it may be assumed that during the progression of an inactive hepatitis B carrier to being actively infected, reduced paraoxonase and arylesterase activities may be observed.

Evaluation of serum paraoxonase and arylesterase activities in ankylosing spondylitis patients

OBJECTIVESThe aim of this study was to investigate the activities of serum paraoxonase and arylesterase in patients with ankylosing spondylitis with respect to those of healthy controls, to assess whether these enzyme levels are related to disease activity and functional capacity.METHODSThe study included 32 patients with ankylosing spondylitis whose diagnoses were made according to the modified New York criteria as well as 25 healthy controls matched for age and sex. The Bath Ankylosing Spondylitis Disease Activity Index and the Bath Ankylosing Spondylitis Functional Index were applied to the ankylosing spondylitis patients. As laboratory parameters, the erythrocyte sedimentation rate and serum C-reactive protein level were measured in patients and control subjects. Paraoxonase and arylesterase enzyme activities were measured using appropriate methods.RESULTSNo statistically significant differences (p>0.05) were found between the ankylosing spondylitis patients and controls in terms of serum paraoxonase or arylesterase levels. Furthermore, there was no correlation between clinical and laboratory parameters in patients with ankylosing spondylitis.CONCLUSIONSerum paraoxonase and arylesterase levels in ankylosing spondylitis patients may not differ from those of healthy controls, and there is no significant correlation between antioxidant parameters and the Bath Ankylosing Spondylitis Disease Activity Index or Bath Ankylosing Spondylitis Functional Index scores in ankylosing spondylitis patients. Further research is needed to provide deeper understanding of this disease.

Polymorphisms in the PON gene cluster are associated with Alzheimer disease

Paraoxonase is an arylesterase enzyme that is expressed in the liver and found in the circulation in association with apoA1 and the high-density lipoprotein, and prevents the accumulation of oxidized lipids in low-density lipoproteins in vitro. Common polymorphisms in genes encoding paraoxonase are established risk factors in a variety of vascular disorders including coronary artery disease and carotid artery stenosis, but their association with Alzheimer disease (AD) is controversial. We tested the association of 29 SNPs in PON1, PON2 and PON3 with AD in 730 Caucasian and 467 African American participants of the MIRAGE Study, an ongoing multi-center family-based genetic epidemiology study of AD. Eight SNPs were associated with AD in the African American families (0.0001< or =P< or =0.04) and two SNPs were associated with AD in Caucasian families (0.01< or =P< or =0.04). Of note, the pattern of association for the PON1 promoter SNP -161[C/T] was the same in both ethnic groups (P=0.006). Haplotype analysis using sliding windows revealed 11 contiguous SNP combinations spanning the three PON genes with significant global test scores (0.006< or =P< or =0.04) in the two ethnic groups combined. The most significantly associated haplotype comprised SNPs in the region spanning the -161[C/T] SNP (P=0.00009). Our results demonstrate association between AD and variants in the PON gene cluster in Caucasians and African Americans.

Effect of six candidate genes on early aging in a French population.

The objective of this study was to examine the association between an aging indicator previously defined from a nationwide population study, and lipids and apolipoproteins, angiotensin converting enzyme, paraoxonase activities, and six candidate genes related to the aging process. Two hundred and fifty-six healthy Caucasian men (69.8 +/- 4.0 years) were included in the study. Total cholesterol, triglycerides, HDL-cholesterol, lipoprotein(a), apolipoprotein A1, B and E concentrations, and the activities of paraoxonase, arylesterase, and angiotensin-converting enzymes were determined by standardized laboratory methods. A multiplex assay was used to genotype the studied polymorphisms: apolipoprotein E, lipoprotein lipase, paraoxonase, methylenetetrahydrofolate reductase, cystathionine beta-synthase and angiotensin-converting enzymes. Paraoxonase polymorphism at codon 192 (Gln/Arg) was the only one significantly associated with the aging indicator, Gln homozygotes being more advanced in aging compared with Arg allele carriers. It was also observed that the aging indicator was positively correlated with serum concentrations of total cholesterol, triglycerides and apolipoprotein B, and negatively with the activities of basal and stimulated paraoxonase and arylesterase. Multiple regression analysis showed that triglycerides and basal paraoxonase activity explain 13.6% of the variance of the aging indicator. Triglyceride concentration and paraoxonase gene and activities may contribute to the aging process. Taking into account the smallness of the sample size, and the poor level of significance due to the im-plication of paraoxonase polymorphism at codon 192, these results need to be verified in further studies on a greater number of subjects.

Biocompatibility studies with perfluorochemical oxygen carriers.

The effects of injecting either a novel perfluorodecalin (FDC)-based emulsion or various perfluorochemical (PFC) oils on liver cytochromes P-450 (P-450) and aryl esterase (LAE) enzymes in male rats have been studied. Mean P-450 concentration increased (P less than 0.05) following injection of the novel emulsion or FDC. In contrast, LAE increased in response to injection of FDC (P less than 0.05) and the C-16 oil, perfluoroperhydrofluoranthrene (P less than 0.01), added to stabilize the emulsion. No corresponding changes in either P-450 or LAE occurred in rats injected with either perfluorotripropylamine, perfluorotributylamine or perfluorooctylbromide. The "sleeping time" of animals injected with the pentobarbital-based anaesthetic, Equithesin, following pretreatment with the novel emulsion was lower (P less than 0.05) than in saline-injected controls. The results are discussed in relation to the effects of PFCs on liver metabolic functions.