Paraoxonase 1 Arylesterase Activity Research Articles

Usefulness of the Measurement of Serum Paraoxonase-1 Arylesterase Activity in the Diagnoses of COVID-19.

The development of inexpensive, fast, and reliable screening tests for COVID-19 is, as yet, an unmet need. The present study was aimed at evaluating the usefulness of serum arylesterase activity of paraoxonase-1 (PON1) measurement as a screening test in patients with different severity levels of COVID-19 infection. We included 615 COVID-19-positive patients who were classified as asymptomatic, mildly symptomatic, severely symptomatic, or fatally symptomatic. Results were compared with 50 healthy volunteers, 330 patients with cancer, and 343 with morbid obesity. Results showed PON1 activity greatly decreased in COVID-19 compared to healthy volunteers; a receiver operating characteristics plot showed a high diagnostic accuracy. The degree of COVID-19 severity did not influence PON1 levels. Our results indicated that PON1 determination was efficient for disease diagnosis, but not for prognosis. Furthermore, patients with obesity or cancer presented alterations similar to those of COVID-19 patients. As such, elevated levels of PON1 indicate the absence of COVID-19, but low levels may be present in various other chronic diseases. The assay is fast and inexpensive. We suggest that PON1 measurement could be used as an initial, high cut-off point screening method, while lower values should be confirmed with the more expensive nucleic acid amplification test.

Occupational exposure to pesticides in farmworkers and the oxidative markers.

Organophosphate (OPPs) and organochlorine pesticides (OCPs) are the two predominant forms of pesticides extensively used all around the world and are being reconsidered as environmental pollutants. The current study sought to assess the role of socioeconomic factors on the level of pesticides residues and the oxidative effects of exposure to OPPs and OCPs among the farmworkers of southeast Iran. In this cross-sectional study, 192 farmworkers and 74 non-farmworkers (controls) were involved. Gas chromatography (GC) was performed to measure the serum levels of organochlorine chemicals (2,4-DDT, 4,4-DDT, 2,4-DDE, 4,4-DDE, α-HCH, β-HCH, and γ-HCH). Furthermore, acetylcholinesterase (AChE) activity, arylesterase activity of paraoxonase-1 (PON-1), and several oxidative stress (OS) markers were assessed. In addition, the impact of several parameters such as home to farm distance, education level, ventilation status, and personal protective equipment (PPE) on pesticide levels was analyzed. The levels of OCPs in the farmworkers were significantly higher than the control subjects. In addition, AChE activity, arylesterase activity of PON-1, and total antioxidant capacity in farmworkers were significantly less, and MDA levels were higher than the controls. Education level was associated with farmworkers' protective behavior. The current findings suggested that some phased out OCPs can still be measured in human samples in the southeast of Iran. Furthermore, the current study demonstrated that exposure to OCPs and OPPs was accompanied by adverse consequences regarding OS parameters and subsequent health problems. In addition, the findings of the present study suggest that improving farmworkers' education might be associated with reduced exposure to pesticides and less adverse health effects.

Paraoxonase-1 (PON-1) Arylesterase Activity Levels in Patients with Coronary Artery Disease: A Meta-Analysis.

Aim To review and compare the PON-1 arylesterase activity between coronary artery disease (CAD) and non-CAD patients. Methods Data were obtained by searching MEDLINE and Scopus for all investigations published between January 1, 2000 and March 1, 2021 comparing PON-1 arylesterase activity between CAD and controls. Results Twenty studies, based on 5417 patients, met the inclusion criteria and were included in the analysis. A random effect model revealed that PON-1 arylesterase activity was significantly lower in the CAD group compared to controls (SMD = –0.587, 95%CI = −0.776 to -0.339, p < 0.0001, I2 = 92.3%). In CAD patients, the PON-1 arylesterase activity was significantly higher among CAD patients without diabetes mellitus (DM) compared to those with diabetes (SMD: 0.235, 95% CI: 0.014 to 0.456, p = 0.03, I2 = 0%). Conclusions PON-1 activity is significantly lower in CAD patients, and those without DM presented a significantly higher PON-1 arylesterase activity.

Arylesterase activity of paraoxonase 1 in patients with primary hypertension

Abstract Introduction Paraoxonase 1 is an enzyme associated with high-density lipoprotein fraction and is considered to present antioxidant activity. Objectives The aim of the study was to assess the arylesterase activity of paraoxonase 1 (PON1) in the serum of patients with hypertension, due to effect of therapy and before treatment. Patients and Methods. The study was conducted in 76 patients with primary hypertension and 28 volunteers for the control group. Hypertensive subjects were assigned to one of three groups: well controlled (n=25), poorly controlled (n=26), and newly diagnosed before therapy (n=25) hypertension. We evaluated metabolic parameters in all participants using routine laboratory methods, as well as arylesterase activity of PON1. Results The four study groups differed with arylesterase activity of PON1 and the highest levels were found in patients with well controlled hypertension and the lowest in newly diagnosed. All patients diagnosed with hypertension presented negative correlations between PON1 and systolic and diastolic blood pressure. Conclusions Effective treatment of hypertension could result in increased PON1 activity, despite unfavorable homocysteine concentrations in blood. Untreated hypertension might decrease activity of PON.

The Increase in Paraoxonase 1 Is Associated With Decrease in Left Ventricular Volume in Kidney Transplant Recipients.

Background: Patients on dialysis have impaired cardiac function, in part due to increased fluid volume and ventricular stress. Restored kidney function through transplantation reduces left ventricular volume in both systole and diastole. We previously reported that the decrease in NT-proB-type natriuretic peptide (NT-proBNP) was associated with a decrease in adiponectin. Paraoxonase 1 (PON1) has been inversely associated with cardiovascular outcomes. We now report the association of changes in PON1 with changes in left ventricular volume and left ventricular mass after kidney transplantation.Design: Patients on dialysis were assessed at baseline and 12 months after kidney transplantation (n = 38). A comparison group of patients on dialysis who were not expected to receive a transplant in the next 24 months were studied (n = 43) to determine if the change of PON1 with kidney transplantation achieved a significance greater than that due to biologic variation. Left ventricular volume and mass were determined by cardiac magnetic resonance imaging. PON1 was measured by arylesterase activity and by mass.Results: PON1 mass and activity were not different between the groups at baseline. Both PON1 mass and activity were increased post-kidney transplantation (p < 0.0001 for change). The change in PON1 mass (p = 0.0062) and PON1 arylesterase activity (p = 0.0254) were inversely correlated with the change in NT-proBNP for patients receiving a kidney transplant. However, only the change in the PON1 mass, and not the change in PON1 arylesterase, was inversely correlated with the change in left ventricular volume (ml/m2.7) (p = 0.0146 and 0.0114 for diastolic and systolic, respectively) and with the change in hemoglobin (p = 0.0042).Conclusion: Both PON1 mass and arylesterase activity are increased by kidney transplantation. The increase in PON1 mass is consistent with a novel relationship to the increase in hemoglobin and decrease in left ventricular volume and NT-proBNP seen when kidney function is restored.

Abnormal paraoxonase-1 (PON1) enzyme activity in idiopathic inflammatory myopathies.

Patients with idiopathic inflammatory myopathies (IIM) have severe vascular involvement, which contributes to disease morbidity and mortality. Paraoxonase-1 (PON1) is a high-density lipoprotein (HDL) associated protein that protects the vascular endothelium from oxidative injury and damage. The current work assessed the functional and genetic determinants of PON1 activity in IIM patients. A total of 184 IIM patients and 112 healthy controls (HC) were included. PON1 enzyme activity was assessed by paraoxonase, arylesterase and lactonase assays, and the Q192R PON1 single nucleotide polymorphism (SNP) was analysed. Multivariate regression models examined associations of PON1 activity with IIM diagnosis and myositis disease outcomes. The arylesterase and lactonase activities of PON1 were significantly lower in IIM patients compared with HC. Higher myositis disease activity, the presence of severe IIM-associated interstitial lung disease (ILD), and the presence of MDA5 or anti-synthetase antibodies were significantly associated with lower PON1 activity. The PON1 Q192R polymorphism was strongly linked to the paraoxonase activity of PON1 in IIM, and patients with the PON1 QQ genotype had better IIM disease outcomes compared with patients with the QR or RR genotypes. The arylesterase and lactonase activities of PON1 are significantly impaired in IIM patients compared with HC, and inversely associate with IIM disease activity and the presence of severe ILD. The PON1 QQ genotype associates with more favourable disease outcomes in IIM patients. Large prospective studies are needed to further evaluate the role of PON1 and PON1 genetic polymorphisms in the development and propagation of IIM and IIM-ILD.

Biphasic Effect of Curcuminoids on Oxidation of Postprandial Chylomicrons.

Chylomicrons are large, triglyceride-rich lipoproteins that transport dietary lipids and lipophilic micronutrients through the lymphatic system and into the venous circulation. They therefore represent a valuable means of investigating the bioavailability of a range of bioactive molecules. Curcuminoids have a complex reputation, with most in vitro studies suggesting a beneficial effect (e.g., as an antioxidant), while in vivo work is often, at best, equivocal. We have prepared a curcuminoid extract from fresh turmeric and investigated the transfer of curcuminoids to chylomicrons by rapid ultracentrifugation. We subsequently characterized the chylomicrons in terms of their susceptibility to oxidation. There was a dose-dependent relationship between the curcuminoid level in chylomicrons and decreased levels of preformed lipid hydroperoxides (P < .05), which was broadly mirrored by paraoxonase arylesterase activity. At lower dosages (1000-3000 mg), curcuminoids protected chylomicrons against copper(II)-mediated oxidation, but at higher levels (4000-5000 mg), a pro-oxidant effect was observed. In conclusion, we report a clear biphasic (hormetic) effect of curcuminoids on lipid oxidation, which supports the theory that low dosages of bioactive compounds can have beneficial effects, while higher dosages may have an equivocal or negative impact on the disease.

Paraoxonase in women with hypertension of different reproductive age. Relationship with cardio-metabolic risk factors

Annotation. Paraoxonase is a high-density lipoprotein-associated pleiotropic enzyme able to detoxify proatherogenic compounds such as oxi-low-density-lipoproteins and homocysteine-thiolactone. Low paraoxonase activity is likely to be involved in the development of cardiovascular diseases. The aim of the study – to investigate the relationship between paraoxonase activity, structural and functional markers of the heart and blood vessels, cardio-metabolic risk factors in women with hypertension of different reproductive age. The study included 193 women aged 32-70 years (55.4±0.68 years) with essential stage II hypertension. The control group consisted of 46 healthy women. The arylesterase activity of paraoxonase (EC 3.1.1.2) in blood serum was determined by spectrophotometric method. Statistical processing of the obtained results was performed in the application package SPSS22 (© SPSS Inc.). The mean and standard error of the mean (M ± m) were calculated. Student's t-test was used. Pearson correlation analysis was performed at p &lt;0.05. It was found that in women with hypertension there was a significant decrease (16%) in serum paraoxonase activity, compared with healthy women. Low paraoxonase activity was registered in 33.3% of premenopausal patients and 56.7% of postmenopausal patients (p˂0.05) and was associated with serum estradiol levels (r=0.33, 0.41, p&lt;0.05). Low paraoxonase activity was associated with aberrant levels of lipids, homocysteine, obesity, metabolic syndrome, increased left ventricular mass index and carotid intima-media thickness, decreased brachial artery endothelium-dependent vasodilation. Thus, the decrease in serum paraoxonase activity in women with hypertension is related with the reproductive age of patients and the development of unfavorable metabolic, structural and functional changes in the heart and blood vessels.

Pesticide exposure and related health problems among farmworkers' children: a case-control study in southeast Iran.

Pesticides are potentially hazardous chemicals that can cause injury to human health and the environment. The purpose of this study was to evaluate organophosphate pesticides (OPPs) and organochlorine pesticides (OCPs) exposure in farmworkers' children aged 6 to 11years in Jiroft city in southeastern Iran. One hundred twenty farmworkers' children as case and 53 non-farmworkers' children aged 6 to 11years as control were selected and the serum levels of OCPs were measured by using gas chromatography in all participants. In addition, erythrocyte acetylcholinesterase (AChE) and arylesterase activity of paraoxonase-1 (PON-1) were measured to evaluate OPPs effects. Catalase (CAT), superoxide dismutase3 (SOD3), glutathione peroxidase (GPx3) activities, and the levels of serum malondialdehyde (MDA), total antioxidant capacity (TAC), nitric oxide (NO), and protein carbonyl (PC) were measured to investigate OCPs and OPPs effects on oxidative stress (OS). The serum levels of beta-HCH, 4,4 DDE, and 4,4 DDT in the case group were significantly higher than the control group. In addition, in the case group, AChE, PON-1, CAT, SOD3, and GPx3 activities and the levels TAC were significantly lower, while MDA, PC, and NO levels were significantly higher than the control group. OCPs as illegal pesticides are present in southeast Iran and children are exposed to OCPs and OPPs in the studied area. In addition, higher serum levels of pesticides may be a major contributor in OS development, as a cause of many diseases.

Arylesterase activity of paraoxonase 1 (PON1) on HDL3 and HDL2: Relationship with Q192R, C-108T, and L55M polymorphisms

BackgroundControversy exists regarding the role of the subfractions of high-density lipoproteins (HDL2 and HDL3) in cardiovascular disease. The functionality of these particles, and their protective role, is due in part to the paraoxonase 1 (PON1) presence in them. The polymorphisms rs662 (Q192R, A/G), rs854560 (L55 M, T/A), and rs705379 (C-108T) of the PON1 gene have been related to enzyme activity and, with the anti-oxidative capacity of the HDL. The objective was to determine the arylesterase PON1 activity in HDL3 and HDL2 and its relationship with the polymorphisms mentioned, in a young population. MethodsThe polymorphisms were determined through mini-sequencing (SnaPshot). The HDL subpopulations were separated via ionic precipitation, cholesterol was measured with enzymatic methods, and PON1 activity was measured through spectrophotometry. ResultsThe results show that the PON1 polymorphisms do not influence the cholesterol in the HDL. A variation between 40.02 and 43.9 mg/dL was in all the polymorphisms without significant differences. Additionally, PON1 activity in the HDL3 subfractions was greater (62.83 ± 20 kU/L) than with HDL2 (35.8 ± 20.8 kU/L) in the whole population and in all the polymorphisms (p < 0.001), and it was independent of the polymorphism and differential arylesterase activity in the Q192R polymorphism (QQ > QR > RR). Thus, 115.90 ± 30.7, 88.78 ± 21.3, 65.29 ± 10.2, respectively, for total HDL, with identical behavior for HDL3 and HDL2. ConclusionsPON1 polymorphisms do not influence the HDL-c, and the PON activity is greater in the HDL3 than in the HDL2, independent of the polymorphism, but it is necessary to delve into the functionality of these findings in different populations.

Assessment of follicular fluid paraoxonase activity with pregnancy outcomes in women undergoing IVF/ICSI

The search for a reliable marker to predict pregnancy success is not yet identified. This study aims to evaluate paraoxonase activities (PON1) in follicular fluid (FF) and their correlation with oocyte yield, fertilization, and clinical pregnancy (CP). Methods: The study included 99 women aged 22- 37 years old who were undergoing IVF/ICSI, were divided into fertile, which represents the control group consisting of 25 participants, and the infertile group, which was subdivided into 21 patients with PCOS, 26 patients with a low level of AMH, as well as 27 patients with unknown cause of infertility. The FF Basal PON1, salt stimulated PON1, and arylesterase activities were measured using the spectrophotometry method. Results: The PON1 basal activity of the PCOS group was higher (P<0.05) when compared with the control and UI groups. The PON1 arylesterase activity of the PCOS group was higher (P<0.05) when compared with control, UI, and low AMH groups. Each group showed a difference (P<0.05)in the pregnancy success in PCOS, low AMH, and UI groups but not in the control group. Conclusion: An increase in FF antioxidants seems to be a negative fertilization indicator, which may represent an adverse ovarian condition that triggered anti-oxidant behavior.

Reevaluation of Serum Arylesterase Activity in Neurodevelopmental Disorders.

Organophosphate compounds (OPs) interfere with neurodevelopment and are neurotoxic for humans and animals. They are first biotransformed to the more toxic oxon form, and then hydrolyzed to specific metabolites by the enzyme paraoxonase/arylesterase, encoded by the gene PON1 located on human chr. 7q21.3. In autism spectrum disorder (ASD) and in attention-deficit/hyperactivity disorder (ADHD), a correlation between OP exposure and disease onset has been reported. In this case-control study, we aimed to replicate our previous work showing reduced levels of serum PON1 arylesterase activity in Italian and Caucasian-American ASD samples, and to extend our analysis to other neurodevelopmental disorders, namely ADHD and developmental language disorder (DLD), also known as specific language impairment (SLI). The arylesterase activity, measured using standard spectrophotometric methods, is significantly reduced in the ADHD, and not in the ASD sample compared with the controls. Our previous results seemingly stem from spuriously high arylesterase levels in the former control sample. Finally, genotyping SNPs rs705379 and rs662 using TDI-FP, a significant effect of rs705379 alleles on the serum arylesterase activity is observed in all of the subgroups tested, regardless of diagnosis, as well as a lack of association between PON1 gene polymorphisms and ASD/ADHD susceptibility in the Italian population. In summary, the serum arylesterase activity is reduced in children and adolescents with ADHD, and this reduction is not due to the functional PON1 gene variants assessed in this study. Based on previous literature, it may more likely reflect enhanced oxidative stress than specific genetic underpinnings.

A Multi-Omics Analysis of PON1 Lactonase Activity in Relation to Human Health and Disease.

Paraoxonase 1 (PON1) enzyme has antioxidative properties and is present in mammalian blood and several other body fluids. In blood, PON1 is usually integrated into the high-density lipoprotein (HDL) cholesterol. PON1 is a highly versatile enzyme displaying diverse functions such as arylesterase, lactonase, and paraoxonase, among others. PON1 activities are usually investigated with artificial substrates, for example, dihydrocoumarin and thiobutyl butyrolactone for lactonase activity. The PON1 enzyme activities measured with different substrates tend to be falsely assumed as being equivalent in the literature, although there are poor or weak correlations among the PON1 enzyme activities with different substrates. In addition, and despite our knowledge of the factors influencing PON1 paraoxonase and arylesterase activities, there is little knowledge of PON1 lactonase activity variations and attendant mechanisms. This is important considering further that the lactonase activity is the native activity of PON1. We report here a multi-omics analysis of PON1 lactonase activity. The influence of genetic variations, particularly of single nucleotide polymorphisms and epigenetic, proteomic, and lipidomic variations on PON1 lactonase activity are reviewed. In addition, the influence of various environmental, clinical, and demographic variables on PON1 lactonase activity is discussed. Finally, we examine the associations between PON1 lactonase activity and health states and common complex diseases such as atherosclerosis, dementias, obesity, and diabetes. To the best of our knowledge, this is the first multi-omics analysis of PON1 lactonase activity with an eye to future applications in basic life sciences and translational medicine and the nuances of critically interpreting PON1 function with lactones as substrates.

In vivo/in silico insight into the effect of titanium dioxide nanoparticle on serum paraoxonase 1 activity in rat

Serum paraoxonase1 (PON1) has special function in human body organism including the antioxidant and anti-atherogenic properties. In the present study, the effect of TiO2 nanoparticles on the activity and structure of the PON1 has been evaluated through in vivo and in silico methods. After treatments of the rats with different doses of TiO2 NPs, blood samples were collected and serum PON1 activity was measured by phenylacetate and paraoxon as substrate. In addition, the effects of TiO2 NP on enzyme structure were analyzed through Molecular dynamic (MD) simulation via Gromacs software package to obtain RMSD, RMSF, Rg, SASA, and secondary structures values. A significant reduction (p < 0.05) in arylesterase & paraoxonase activities of serum PON1 were monitored in Spectrometric assays when rats were treated with 150 and 200 mg/kg doses of TiO2 NPs. RMSD, RG, RMSF, and SASA values in the presence of TiO2 have been increased while RMSF values of the L1 and L2 loops (gate of the catalytic site) have been reduced. Moreover, Hydrogen bonds and secondary structure values of the enzyme decreased in the presence of TiO2 NP. All of these MD simulation results could indicate the instability of the PON1 structure bounded to TiO2 NP. TiO2 NP could cause a disturbance in the enzyme structure and function of PON1 based on the results. PON1 prevents oxidation of LDL and can delay atherosclerosis progression while in the presence of TiO2 NP these protective effects could be endangered. Communicated by Ramaswamy H. Sarma

Pesticide exposure and related health problems among family members of farmworkers in southeast Iran. A case-control study

BackgroundPesticides used in agriculture are some of the most common pollutants in the world. This study aimed to investigate the effects of Organophosphorus Pesticides (OPPs) and Organochlorine Pesticides (OCPs) on the families of farmworkers in the southeast of Iran. MethodsIn the present case-control study, 141 family members of farmworkers (as the case group) and 59 family members of non-farmworkers (as the controls) were recruited. Serum levels of OCPs such as α-HCH, β-HCH, γ-HCH, 2,4-DDE, 4,4-DDE, 2,4-DDT, and 4,4-DDT were determined. In addition, erythrocyte acetylcholinesterase (AChE) activity, malondialdehyde (MDA), total antioxidant capacity (TAC), protein carbonyl (PC), nitric oxide (NO) serum levels, arylesterase activity of paraoxonase 1 (PON-1), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activity were determined in all participants. Furthermore, distance to farmlands, education, crops, type, and the number of consumed fruits were evaluated for each individual separately. ResultsThe erythrocyte AChE activity and serum activities of GPx, SOD, and PON-1 and TAC levels were significantly decreased, whereas the concentration of MDA, PC, NO, and seven OCPs were significantly increased in the farmworkers’ families as compared to the controls. Spearman correlation and linear regression suggest that OCPs increase the oxidative stress in farmworkers’ family members. Moreover, distance, education, farming precedence, products, and ventilation had significant effects on the OCP levels and increased the odds ratio of OCP levels in farmworkers’ families. ConclusionWith regards to the data obtained in this study, it was revealed that OCPs as illegal pesticides and OPPs were higher than expected in the farmworkers’ family members. Furthermore, exposure to OCPs and OPPs, apart from the other effects on the body, leads to oxidative stress (OS) that may cause serious diseases in the exposed populations.

Influence of nutritional factors and the PON1 C(‐107)T polymorphism on paraoxonase‐1 activity in childhood

ObjectiveThe cardioprotective enzyme paraoxonase‐1 (PON1) suffers an important influence from genetic polymorphisms and nutritional factors. The aim of this study was to investigate the influence of diet, nutritional status, and the C(‐107)T polymorphism on PON1 arylesterase activity in children. MethodsThis was a cross‐sectional study with 97 children, aged between 5 and 8 years, of both genders, from a pediatric outpatient clinic in southern Brazil. A sociodemographic, behavioral, and food consumption questionnaire was applied, and anthropometric measurements and laboratory blood samples were taken. PON1 arylesterase activity was measured by phenol extinction (U/mL), and DNA extraction and analysis of the PON1 C(‐107)T polymorphism were performed. The Hardy–Weinberg equilibrium was tested with the chi‐squared test and linear regression was used to estimate PON1 activity according to four adjustment models, with an acceptable error of 5%. ResultsIn the sample, the male gender accounted for 50.5%, 39.2% were 6 years of age, 54.5% had normal weight, and 51.5% had PON1 activity below the median (90.0, 15–30U/mL). Genotype frequency was 54.6% (53/97), 31.0% (30/97), and 14.4% (14/97), respectively, for CT, CC, and TT, consistent with the Hardy–Weinberg equilibrium (p=0.22). In the regression analysis, the model that included sociodemographic variables as well as frequency of consumption of fruits, vegetables, legumes, dairy products, and beans estimated a variability of 14.8% in PON1 activity combined with the PON1 C(‐107)T polymorphism. ConclusionsDuring childhood, a good‐quality diet with greater inclusion of healthy foods was important to predict the activity of the cardioprotective enzyme PON1 combined with the C(‐107)T polymorphism of the PON1 gene.

P1591SERUM PARAOXONASE 1 ARYLESTERASE ACTIVITY AS AN ANTIOXIDANT MARKER IN DIALYSIS PATIENTS

Abstract Background and Aims Patients with chronic kidney disease (CKD) have the highest risk for cardiovascular disease associated with high-density lipoprotein deficiency, chronic inflammation and the development of oxidative stress (OS). This study aimed to investigate serum paraoxonase 1 (PON-1) arylesterase activity in patients with end-stage renal disease (ESRD) and its association with oxidative stress markers. Method We conducted a cross-sectional observational study involving 58 ESRD patients. Among them, there were 20 hemodialyses (HD) patients and 38 patients treated with peritoneal dialysis (PD). Serum PON1 arylesterase activity was determined spectrophotometrically by the number of formed phenolic complexes using phenylacetate. Also, the concentrations of malondialdehyde, serum concentrations of ceruloplasmin, thiol groups and total peroxidase activity (TPA) in erythrocyte were determined spectrophotometrically. In addition, the blood lipid spectrum (including high-density lipoproteins) was determined in all patients. The reference group consisted of 30 conditionally healthy individuals. For the statistical analysis, we used Kruskal-Wallis’s t-test and Spearman's rank correlation test. All statistical analyses were performed using MedCalc. Results Serum PON1 arylesterase activity was 6.57 kU/L in reference group versus 2.25 kU/L in HD patients and 4.26 kU/L in PD patients (p &amp;lt; 0.0001) (Fig. 1). A direct association was found between serum PON1 arylesterase activity and ceruloplasmin concentration (r = 0.38; p = 0.004) and TPA (r = 0.32; p = 0.02) in HD patients. In iddition, serum PON1 arylesterase activity was associated with high-density lipoproteins (r = 0.67; p &amp;lt; 0.0001) in PD patients (Fig. 2). Conclusion We observed a decrease in serumPON1 arylesterase activityin ESRD patients compared to the control group. The lowest level of serum PON1 arylesterase activity was determined in HD patients. Moreover, the association between serum PON1 arylesterase activity and a decrease in antioxidant blood markers was found. Our results support the hypothesis that OS is an important mediator in the progression of kidney diseases and indicates a potential antioxidant role of serum PON1 arylesterase activity in ESRD patients. We suggest using serum PON1 arylesterase activity as an antioxidant marker in dialysis patients.

Arylesterase activity of paraoxonase 1 and intensity of oxidative processes in the blood of dialysis patients

This study aimed to investigate the arylesterase activity of paraoxonase 1 (PON-1) in patients with end-stage renal disease (ESRD) and its relationship with oxidative stress markers.&#x0D; Methods. We conducted a one-time prospective observational study involving 58 ESRD patients. Among them, there were 20 hemodialyses (HD) patients and 38 patients treated with peritoneal dialysis (PD). The activity of PON-1 in serum was determined spectrophotometrically by the number of phenolic complexes formed using phenylacetate. Besides, spectrophotometrically the concentrations of malondialdehyde, serum concentrations of ceruloplasmin, thiol groups and total peroxidase activity (TPA) of erythrocyte were determined. The reference group consisted of 30 conditionally healthy individuals.&#x0D; Results. The arylesterase activity of the PON-1 in reference group was 6.57 kU/L versus 2.25 kU/L in HD patients and 4.26 kU/L in PD patients (p ˂ 0.0001). A direct correlation was found between arylesterase activity of PON-1 and ceruloplasmin concentration (p = 0.004), and TPA (p = 0.02) in HD patients. The activity of PON-1 in the serum of PD patients was associated with high-density lipoproteins (p ˂ 0.0001).&#x0D; Conclusions. We observed a decrease in the arylesterase activity of PON-1 in ESRD patients compared to the control group. The lowest activity of PON-1 is determined in HD patients. Moreover, the association of the PON-1 activity with a decrease in antioxidant blood markers was found. The enzyme activity in PD patients correlated with increased blood HDL. Further studies involving a larger dialysis cohort of patients are needed to determine the pathogenetic role of PON-1 activity in the development of cardiovascular events in ESRD patients.

The Effects of Anthocyanins and Their Microbial Metabolites on the Expression and Enzyme Activities of Paraoxonase 1, an Important Marker of HDL Function

High circulating HDL concentrations and measures of various HDL functions are inversely associated with cardiovascular disease (CVD) risk. Paraoxonase 1 (PON1) contributes to many of the athero-protective functions of HDL, such as promoting the reverse cholesterol transport process and reducing the levels of oxidized LDL. PON1 activities are influenced by several factors, the most important being diet and genetic polymorphisms. Reported data from randomized controlled trials have shown that anthocyanin consumption increased PON1 activity. However, the underlying molecular mechanisms by which anthocyanins increase PON1 activity are not understood. Therefore, the aim of this research was to investigate the ability of anthocyanins and their metabolites to increase PON1 gene expression and/or enzyme activities as potential mechanisms. The effect of the two predominant dietary anthocyanins and 18 of their recently identified microbial metabolites including their phase-II conjugates on PON1 gene expression was studied using a PON1-Huh7 stably-transfected cell line and reporter gene assay. The effects of these compounds on PON1 arylesterase and lactonase activities were investigated using two isoforms of the PON1 enzyme that are the phenotypes of the 192Q/R polymorphism. None of the compounds caused even modest changes in PON1 promoter activity (p ≥ 0.05). Further, none of the compounds at physiological concentrations caused any significant changes in the arylesterase or lactonase activity of either of the iso-enzymes. Cyanidin reduced the lactonase activity of the PON1-R192R enzyme at high concentrations (−22%, p < 0.001), but not at physiologically achievable concentrations. In conclusion, none of the data reported here support the notion that anthocyanins or their metabolites affect PON1 transactivation or enzyme activities.

Decreased Level of Nitric Oxide in Preeclamptic Pregnancy: A Relationship with PON1 Arylesterase Activity

Aims: The aim of the study was to evaluate the status and diagnostic utility of PON1. (Paraoxonase-1) Arylesterase and nitric oxide as indicator of antioxidant status in preeclampsia.&#x0D; Study Design: Analytical case control study.&#x0D; Place and Duration of Study: Sample: Department of obstretics and gynecology Department, G. M. C. Ambajogai, between July 2010 and July 2012.&#x0D; Methodology: We conducted a case-control study of 57 women with preeclampsia and 57 women with uncomplicated deliveries. We measured PON1 Arylesterase activity, Nitric oxide and lipid profile.&#x0D; Results: Serum levels of LDLc (low density lipoprotein cholesterol) are higher in cases than in controls and are statistically significant (p=0.023). However serum HDLc (high density lipoprotein cholesterol) levels are decreased significantly (p = 0.017). Serum PON1 Arylesterase showed significant decrease in cases152.68 KU/L versus controls 180.89 KU/L, p value=0.002. Serum nitric oxide also showed significant decrease in cases 22.77 ± 4.792 umol/L versus controls 25.127 umol/L, p=0.010. PON1 Arylesterase activity is found to be positively correlated with serum HDL cholesterol (r = 0.449, p value&lt; 0.001). Multivariate logistic regression analysis was done.&#x0D; Conclusion: Our observed results show decrease in the antioxidant PON1 Arylesterase activity point towards their role in the pathogenesis of Preeclampsia.