Arylesterase Activity Research Articles

Paraoxonase and arylesterase activities in adults with vitamin B12 deficiency

Objective: The purpose of this study was to investigate paraoxonase (PON) and arylesterase (ARES) enzyme activity in adults with vitamin B12 deficiency, and specific changes in the activities of these enzymes following vitamin B12 treatment.Methods: A total of 46 patients with vitamin B12 deficiency (aged 18–82 years) and 45 healthy volunteer controls (aged 19–64 years) participated in this study. Venous blood samples were collected, and serum vitamin B12, homocysteine (HCY), methylmalonic acid, PON1, and ARES levels were measured.Results: Paired comparison showed that pre- and post-treatment values for PON and ARES were similar between patients and controls (both P > 0.05). There was no statistically significant relationship between patients’ pre-/post-treatment PON or HCY levels and serum vitamin B12 levels, compared with those of the control group (P > 0.05).Discussion: The results of the present study do not support the hypothesis that the antioxidant enzymes PON and ARES have an underlying role in vitamin B12 deficiency and related hyperhomocysteinemia. Our findings suggest that PON and ARES do not play a role in the systemic effects of vitamin B12 deficiency.

Postprandial Paraoxonase 1 Activity Following Consumption of Recommended Amounts of Mixed Meals in Healthy Males.

Postprandial lipid level increases induce oxidative stress, which is involved in atherogenesis. The antioxidant properties of paraoxonase 1 (PON1) have attracted attention. However, changes in postprandial PON1 levels differ across prior studies, and changes in PON1 lactonase activity, potentially relevant to PON1 physiology, after the consumption of ordinary meals are unknown. Herein we evaluated postprandial serum lipid levels and PON1 changes following mixed-meal consumption of the amounts recommended for ordinary meals. Nine healthy male volunteers consumed three different meals in a randomized cross-over design. The test meals were as follows: S, white rice; SMF, S with fat-containing protein-rich main dishes; and SMFV: SMF with vegetable dishes. The serum lipid concentrations and PON1 lactonase and arylesterase activities were determined during a three-hour period after the consumption of these meals. The postprandial triglyceride levels were higher after consuming the SMF and SMFV meals than after consuming the S meal. Despite postprandial high-density lipoprotein cholesterol being unchanged, PON1 lactonase activity was decreased, while PON1 arylesterase activity was increased in the postprandial state after all test meals. Postprandial changes in lactonase and arylesterase activities did not differ among the test meals. Inverse changes in PON1 lactonase and arylesterase activities were observed after consuming recommended ordinary meals. This observation provides useful information for choosing PON1 species as postprandial markers.

The Early Effect of Carotid Artery Stenting on Antioxidant Capacity and Oxidative Stress in Patients with Carotid Artery Stenosis.

The treatment of carotid artery stenosis is associated with the risk of complications, which may include stroke after carotid artery stenting (CAS) and myocardial infarction after carotid endarterectomy (CEA). The imbalance between prooxidative mechanisms and antioxidant capacity creates a milieu of factors, which may increase the risk of complications after endovascular procedures. We have examined 43 consecutive patients with carotid artery stenosis. Sera were analyzed for the activity of paraoxonase (PON) and arylesterase (ARE), sulfhydryl groups (SG), malondialdehyde (MDA), and conjugated dienes (CD) concentrations by means of spectrophotometric methods before and next day after CAS. We have found lowered PON (P = 0.0032), increase in ARE activity (P = 0.0058), and decrease in sulfhydryl groups concentration (P = 0.0267). No effect on absolute MDA and CD concentrations was observed. The degree of carotid artery stenosis correlated negatively with PON/ARE ratio after CAS (r S = −0.507, P = 0.0268). To conclude, CAS influences both enzymatic (differently, PON and ARE activity) and nonenzymatic antioxidant defense. Females are more susceptible to lipid peroxidation after CAS. PON/ARE ratio after CAS correlated with the degree of carotid artery stenosis. The changes (deltas) in ARE activity, SG, and MDA concentrations correlated with the severity of neurological deficit and disability.

Serum paraoxonase 1 activity in patients with iron deficiency anemia.

IntroductionIn this study we aimed to detect paraoxonase 1 (PON-1) activity in iron deficiency anemia (IDA) and to compare it with healthy controls by observing the change after iron therapy.Material and methodsIn this study, 50 adult patients with IDA and 40 healthy subjects were enrolled. All patients were analyzed at the beginning and after treatment according to laboratory assessments.ResultsMean paraoxonase and arylesterase activities in the iron deficiency anemia group were significantly lower than mean activities of the control group (102.4 ±19.2 U/l and 163.3 ±13.68 U/l, respectively and 157.3 ±26.4 U/l and 256.1 ±24.6 U/l, respectively; p = 0.0001 for both). Paraoxonase and arylesterase activities significantly increased after treatment for IDA (143.2 ±13.9 and 197.6 ±27.9 U/l, respectively, p = 0.0001). Mean activities after treatment with iron were significantly lower than mean activities in the control group (p = 0.002; p = 0.0001 respectively).ConclusionsParaoxonase and arylesterase activities in patients with IDA significantly increased after treatment with iron therapy. In adults IDA may also be one of the factors associated with increased risk of atherosclerosis.

Effects of Paraoxonase 1 gene polymorphisms on organophosphate insecticide metabolism in Japanese pest control workers.

Paraoxonase 1 (PON1) in serum detoxifies organophosphate (OP) insecticides by hydrolysis. The present cross-sectional study aimed to clarify the relationship between PON1 single nucleotide polymorphisms (SNPs) and enzyme activities or OP metabolite concentrations in urine of workers occupationally exposed to low-level OPs. Among 283 workers in 10 pest control companies located in central Japan who underwent checkups, 230 subjects (male 199, female 31, average age 38.9 ± 11.1 years old) participated in the study. Q192R and L55M polymorphisms were determined by TaqMan assay. PON1 activity was measured using fenitrothion (FNT) oxon, chlorpyrifos-methyl (CPM) oxon, chlorpyrifos (CP) oxon, and phenyl acetate as substrates. Urinary OP metabolite concentrations were measured with gas chromatography-mass spectrometry. The maximum differences in enzyme activities between individuals were 64.6-, 6.3-, 7.7-, and 2.0-fold for FNT oxonase, CPM oxonase, CP oxonase, and arylesterase (ARE), respectively. The activities of CPM oxonase and ARE in workers having the RR genotype were 53.5% and 18.2% lower than in those with the QQ genotype, respectively. CP oxonase activity was 15.0% lower in those having the M allele (LM + MM compared with LL). Urinary metabolite concentrations were not associated with PON1 polymorphisms, but negative associations were observed between the concentrations and activities of FNT oxonase and ARE. While PON1 SNPs can explain differences in catalytic activities toward some OPs, differences in urinary concentrations of OP metabolites are not attributable to PON1 SNPs but instead are attributable to its serum activities. Its serum activities might be more sensitive biomarkers for estimation of individual susceptibility to OP toxicities.

Bovine Paraoxonase-1 Activity in Oxidative Stress

Association of serum paraoxonase (PON) activity and oxidative stress in dairy cows as well as the relation between PON activity and HDL-c concentration were studied. A significantly lower PON and arylesterase (ARE) activities (P˂ 0.05) was found in cows with oxidative stress (parasitic and mastitic animals) compared to clinically healthy cows. Serum glutathione peroxidase (GPX) activity and malondialdehyde (MDA) level were also markedly reduced in cows with oxidative stress where as the serum HDL-c, LDL-c and cholesterol concentration showed significant reduction than the values in healthy cows. The results indicate a higher serum TAG and vLDL-c values in normal cows than in oxidative stress cases. The total protein content, albumin and globulin concentrations were showed slightly lower values in oxidative stress than in normal cows. A decrease serum PON activity may lead to reduction of anti oxidative protection during marked oxidative stress.

Effect of short-term, high-dose methylprednisolone on oxidative stress in children with acute immune thrombocytopenia.

BackgroundImmune thrombocytopenia (ITP) is the most common cause of acquired childhood thrombocytopenia and is characterized by increased immune-mediated destruction of circulating thrombocytes. Oxidative damage may be involved in ITP pathogenesis; paraoxonase (PON) and arylesterase (ARE) enzymes are closely associated with the cellular antioxidant system. We investigated the effect of short-term high-dose methylprednisolone (HDMP) treatment on the total oxidant status (TOS), total antioxidant capacity (TAC), oxidative stress index (OSI), and PON and ARE enzymatic activity in children with acute ITP.MethodsThirty children with acute ITP constituted the study group and 30 healthy children constituted the control group. Children with acute ITP were treated with HDMP: 30 mg/kg for 3 days, then 20 mg/kg for 4 days. The TOS, TAC, OSI, PON, and ARE levels were determined before and after 7 days of HDMP treatment.ResultsThe TAC level (P<0.001), and PON (P<0.001) and ARE (P=0.001) activities were lower and the TOS (P=0.003) and OSI (P<0.001) levels were higher in children with acute ITP than those in healthy children in the control group. We also observed statistically significant increases in the TAC (P<0.01), PON (P<0.001) and ARE levels (P=0.001) and decreases in the TOS (P<0.05) and OSI levels (P<0.05) with 7 days of HDMP treatment compared to their values before treatment.ConclusionOur study demonstrated increased oxidative stress (OSI and TOC) and decreased antioxidant capacity (TAC), PON, and ARE in ITP patients and that steroid treatment could be effective in reducing the oxidative stress.

Distribution of Paraoxonase-1 Enzyme Activity in Some Sheep Organs

PON-1 (aryldialkylphosphatase) is an esterase enzyme synthesized by the liver and released into the serum where it is associated with HDL lipoprotein. This study aimed to detect the distribution of PON1 in ram liver, kidney and rumen in addition to GPx and SOD. PON1 paraoxonase activity was detected in liver (1.74�0.10), kidney (1.42�0.04), while it was not detected in rumen. PON1 arylesterase activity was detected in liver (0.26�0.01), kidney (0.25�0.02), while it was not detected in rumen. GPx activity was detected in liver (135.9�2.52), kidney (11.2�0.42), SOD activity was detected in liver (693.39�7.58), kidney (676.72�4.86), while it was not detected in rumen. PON1 is positively correlated to GPx and SOD, while it is negatively correlated to MDA.

Serum Paraoxonase Activity and Malondialdehyde Serum Concentrations Remain Unaffected in Response to Hydroxyurea Therapy in β-Thalassemia Patients.

β-Thalassemia is the most common hereditary disorder characterized by reduced production of β-globin chains of hemoglobin A (HbA). In recent years, hydroxyurea (HU) has shown promising therapeutic benefits in patients with β-thalassemia by fetal hemoglobin augmentation. We have analyzed effects of hydroxyurea treatment on oxidative stress in β-thalassemia patients by assessing activities of paraoxonase (PON) and arylesterase along with malondialdehyde (MDA) and total reactive oxygen species (ROS) concentrations. Blood samples from 159 individuals including 56 HU-treated and 58 untreated β-thalassemia patients and 45 healthy controls were analyzed. PON activity was found to be highest in healthy individuals (177.76 ± 4.44 U/mL) as compared to treated (52.67 ± 3.65 U/mL) and untreated (55.11 ± 3.26 U/mL) patients. A similar trend was observed in the case of arylesterase activity in normal, β-thalassemia-treated, and untreated (210.0 ± 11.25 U/mL, 163.03 ± 9.04 U/mL, 139.77 ± 10.10 U/mL) subjects. Serum MDA concentrations (2.59 ± 0.09 nmol/mL, 2.45 ± 0.08 nmol/mL, and 1.15 ± 0.05 nmol/mL) and total ROS concentrations (3.73 ± 0.20 nmol/mL, 3.54 ± 0.23 nmol/mL, and 2.45 ± 0.14 nmol/mL) were significantly elevated in both groups (untreated and treated) as compared to healthy individuals (P < .01). Oxidative stress was found to be markedly elevated in β-thalassemia patients as compared to healthy controls. Insignificant differences were, however, observed in mean concentrations of PON1 paraoxonase and arylesterase activities, serum MDA concentration and total ROS concentrations between HU-treated and untreated patients. We propose that HU therapy alone seems to be ineffective in managing oxidative stress and is likely to offer a better clinical outcome when supplemented with efficient iron chelation therapy and antioxidants.

Serum paraoxonase-1 activity and risk of incident cardiovascular disease: The PREVEND study and meta-analysis of prospective population studies

BackgroundParaoxonase-1 (PON-1) has been suggested to be associated with cardiovascular disease (CVD) risk, however, aspects of the association, such as shape and independence from conventional risk factors are still uncertain. We aimed to assess the association of PON-1 with CVD risk and determine its potential utility for CVD risk prediction. MethodsPON-1 was measured as its arylesterase activity at baseline in the PREVEND prospective study of 6902 participants. ResultsDuring a mean follow-up of 9.3 years, 730 CVD events were recorded. Serum PON-1 was weakly correlated with several cardiovascular risk markers including high-density lipoprotein cholesterol (HDL-C) (r = 0.18; P < 0.001) and was approximately log-linearly associated with CVD risk. In analyses adjusted for conventional risk factors, the hazard ratio (95% CI) for CVD per 1 standard deviation (SD) increase in loge PON-1 was 0.92 (0.85–0.99; P = 0.020), which remained persistent after additional adjustment for potential confounders 0.93 (0.86–0.99; P = 0.037). The association was attenuated on further adjustment for HDL-C 0.95 (0.88–1.02; P = 0.153). In a meta-analysis of 6 population-based prospective studies involving 15 064 participants and 2958 incident CVD outcomes, the pooled multivariable adjusted (including HDL-C) relative risk (95% CI) for CVD was 0.95 (0.90–1.02; P = 0.138) per 1 SD increase in PON-1 values. Adding PON-1 to a CVD risk prediction model containing conventional risk factors did not improve the C-index or net reclassification. ConclusionsThere is an approximately log-linear inverse association between PON-1 activity and CVD risk, which is partly dependent on HDL-C levels. In addition, serum PON-1 activity provides no significant improvement in CVD risk assessment beyond conventional CVD risk factors.

Paraoxonase-1 activity is positively related to phospholipid transfer protein activity in type 2 diabetes mellitus: Role of large HDL particles

ObjectivesHigh density lipoprotein (HDL)-associated paraoxonase-1 (PON-1) exerts anti-oxidative properties, whereas phospholipid transfer protein (PLTP) is able to convert mature HDL into larger and smaller HDL particles. Here we tested associations of PON-1 with PLTP in type 2 diabetes mellitus (T2DM), a condition characterized by lower PON-1 activity and higher PLTP activity. Design and methodsSerum PON-1 (arylesterase activity), plasma PLTP activity (liposome-vesicle HDL system), and (apo)lipoproteins were measured in 81 T2DM subjects (mean age 59±9years; 31 women; no insulin treatment). In 48 participants, HDL subfractions were measured by nuclear magnetic resonance spectroscopy. ResultsIn univariate correlation analysis, PON-1 activity was positively related to PLTP activity (r=0.348, p=0.001). PLTP activity was positively related to blood pressure, body mass index and triglycerides, whereas PON-1 activity was positively to HDL cholesterol and apoA-I (p<0.05 to <0.01 for each). Both PLTP activity and PON-I activity were positively related to large HDL particles (r=0.379, p=0.008 and r=0.411, p=0.004, respectively). In multivariable linear regression analysis, PON-1 activity was associated with PLTP activity independent of clinical covariates and HDL cholesterol or apoA-I (β=0.340, p=0.001 and β=0.320, p=0.003, respectively). The association of PON-1 activity with PLTP activity was lost in analysis which included large HDL particles (large HDL: β=0.411, p=0.004). ConclusionsPON-1 activity is positively related to PLTP activity in T2DM, raising the possibility that PLTP could act to maintain PON-1. This association may in part be attributable to a common relationship of PON-1 and PLTP with large HDL particles.

Low Serum Paraoxonase-1 Lactonase and Arylesterase Activities in Obese Children and Adolescents

Abstract Serum paraoxonase-1 (PON1) binds mainly to high density lipoproteins (HDLs) and protects low density lipoproteins (LDLs) against oxidation. While paraoxonase and arylesterase activities are traditionally assayed, lactonase activity, accounting for protection against LDL oxidation, was less investigated in obese children and adolescents. Therefore, we aimed to measure lactonase, paraoxonase and arylesterase activities, oxidized LDL (ox-LDL) and malondialdehyde (MDA) levels in obese children and adolescents. Study population included 68 children (35 obese and 33 normal-weight). Arylesterase and paraoxonase activities were assayed spectrophotometrically. Lactonase activity, ox-LDL and MDA levels were measured using a pH-sensitive colorimetric assay, an ELISA technique and a fluorimetric method, respectively. The lipid profile was assessed by common methods. Lactonase and arylesterase activities were decreased in the presence of obesity. MDA, but not ox-LDL levels, showed significant differences between groups. Multiple regression analysis identified a reciprocal relationship and a possible association between lactonase and arylesterase activities and obesity.

Fluvastatin Decreases Oxidative Stress in Kidney Transplant Patients

ObjectiveOxidative stress has been suggested to have a pivotal role in the development of cardiovascular disease in kidney transplant patients (KTPs). The effects of fluvastatin on oxidative status in KTPs have not been well evaluated. The aim of the present study was to evaluate the effects of fluvastatin on oxidative status by investigating erythrocyte superoxide dismutase (SOD), erythrocyte glutathione peroxidase (GPx), serum paraoxonase (PON1), and serum arylesterase (ARE), along with lipid peroxidation products, serum malonldialdehyde, and apolipoprotein B malondialdehyde (ApoB MDA). MethodsEighteen KTPs were included in the present study. Blood samples were obtained after 1 night's fast. Erythrocyte SOD, erythrocyte GPx, serum PON1, serum ARE, serum MDA, and ApoB MDA were measured using methods described previously. Paired-sample t test was used for comparing the changes from week 0 to week 4 of parameters that might be associated with fluvastatin treatment. ResultsThe present study has shown that erythrocyte SOD and GPx, and serum PON1 and ARE activities increased at the fourth week of the statin treatment. Furthermore an increase in the antioxidant enzymes following fluvastatin may be a clue for the antioxidant effects of this drug. Four weeks of fluvastatin long-acting tablets 80 mg/day led to a decrease in plasma Apo-MDA and MDA levels. ConclusionThe findings of the present study demonstrate that fluvastatin 80 mg long-acting tablets may be used safely for 4 weeks and decrease atherogenic lipoproteins in KTPs. Furthermore, after 4 weeks of fluvastatin treatment, the levels of antioxidant parameters increased and oxidative parameters decreased. Further placebo-controlled treatment studies would be helpful to evaluate the effects of fluvastatin on oxidant and antioxidant parameters including PON1 in patients with KT.

Nevirapine modulation of paraoxonase-1 in the liver: An in vitro three-model approach

IntroductionNevirapine is associated with severe hepatotoxicity, through the formation of reactive metabolites. Paraoxonase-1 (PON-1) is a promiscuous enzyme involved in the metabolism of xeno- and endobiotics and proposed as a biomarker of hepatotoxicity. The aim of this work was to explore the effects of nevirapine and its phase I metabolites, 2-hydroxy-nevirapine and 12-hydroxy-nevirapine, on PON-1 activities. Material and methods2D and 3D primary cultures of rat hepatocytes, and also HepG2 2D cell cultures, were exposed to nevirapine, 2-hydroxy-nevirapine, and 12-hydroxy-nevirapine. The paraoxonase (POase), arylesterase (AREase) and lactonase (LACase) activities of PON-1 were quantified. ResultsEffects of nevirapine and its metabolites were only observed in the 3D cell model. Both nevirapine and 12-hydroxy-nevirapine increased POase (p<0.05, p<0.01) and LACase activities (p<0.05, p<0.001). The AREase activity was increased only upon 12-hydroxy-nevirapine exposure (p<0.01). These modulatory effects were observed at 300μM concentrations of nevirapine and 12-hydroxy-nevirapine. ConclusionsThe formation of 12-hydroxy-nevirapine seems to be the main factor responsible for the increase of PON-1 activities induced by nevirapine exposure. This effect was only observed in the 3D model, suggesting that an in vivo-like system is necessary for this modulation to occur. The present data suggest that the 3D model is a more suitable in vitro model than the conventional ones to explore drug effects on PON-1.

Abstract 13809: Serial Paraoxonase-1-associated Serum Arylesterase Activity and Outcomes in Ambulatory Patients With Heart Failure

Introduction: Decreased arylesterase (ArylE) activity of paraoxonase-1, a HDL-associated protein with anti-inflammatory and antioxidant properties, has been associated with increased risk of cardiac events in ischemic heart failure (HF) patients. However, the change of ArylE activity over time and its association with HF adverse outcomes has not been reported. Methods: We examined the association between baseline and follow up serum ArylE activity and HF outcomes (death, cardiac transplantation or ventricular assist device implantation) in 304 patients with HF enrolled in the Atlanta Cardiomyopathy Consortium, a prospective cohort study in the metropolitan Atlanta GA area from 1/2008 to 7/2009. ArylE activity was assessed on enrollment for all patients, and for 152 patients after 1 year of follow up. Significant drop in ArylE activity on follow up was defined as a drop of ≥25% vs. baseline levels. Results: In our population (age 56.5±12 years, male 63.9%, CAD 39.1%, EF 30±15 %), mean baseline and follow up ArylE activity levels were 110.5 ± 29.8 μmol/min/ml and 105.2±27.7 μmol/min/ml, respectively. Mean ArylE activity change between follow up and baseline levels was -5.9 ± 28.6 μmol/min/ml, p = 0.015. After mean follow up of 2.8 ± 1.1 years, 53 events were reported. Low baseline ArylE activity was associated with increased risk of adverse HF outcomes [HR (95CI%) for lowest tertile vs highest tertile of 2.6 (1.3-5.5), p=0.01] (Figure A). This association remained significant after adjustment for age, gender, diabetes, creatinine clearance and CAD. Patients who had significant drop in ArylE activity (≥25% of baseline levels, n=18), had significantly increased risk of HF events [HR(95%CI) of 4.9 (1.6-14.6), p=0.005], even after adjustment for baseline levels of ArylE activity (Figure B). Conclusions: Reduced baseline ArylE activity and decreased levels on follow up are associated with adverse outcomes in stable outpatients with HF.

Serum paraoxonase and arylesterase activities in patients with chronic otitis media

Objectives: Paraoxonase-1 (PON1) prevents oxidative stress by inhibiting the oxidation of cell membrane lipids by the reactive oxygen species that form during acute and chronic inflammation. The aim of this study was to investigate serum PON1 activity and oxidative stress in patients with chronic otitis media (COM).Methods: Fifty consecutive patients with COM and 55 controls were enrolled in the present study. The patients were divided into two groups according to the presence of cholesteatoma. The serum PON1 arylesterase activities and lipid hydroperoxide (LOOH) levels were determined.Results: Serum paraoxonase and arylesterase activities were significantly lower in the COM patients than in the controls (P < 0.001 for all comparisons), whereas the LOOH levels were significantly higher (P < 0.001).Discussion: These results indicated that a lower level of PON1 activity was associated with an oxidant–antioxidant imbalance. In addition, decreased PON1 activity may play an important role in the pathophysiology of COM.

Glucomannan and glucomannan plus spirulina added to pork significantly block dietary cholesterol effects on lipoproteinemia, arylesterase activity, and CYP7A1 expression in Zucker fa/fa rats.

Zucker fa/fa rats easily develop dyslipidemia and obesity. Restructured pork (RP) is a suitable matrix for including functional ingredients. The effects of glucomannan- RP or glucomannan plus spirulina-enriched RP on plasma lipid/lipoprotein levels, cytochrome P450 7A1 (CYP7A1) expression, and arylesterase activity in growing fa/fa rats fed high-energy, high-fat cholesterol-enriched diets were tested. Groups of six rats each received diet containing 15% control-RP (C), 15% glucomannan-RP diet (G), 15% glucomannan + spirulina-RP diet (GS), and same diets enriched with 2.4% cholesterol and 0.49% cholic acid (cholesterol-enriched control (HC), cholesterol-enriched glucomannan (HG), and cholesterol-enriched glucomannan + spirulina (HGS) diets) over a 7-week period. C diet induced obesity, severe hyperglycemia, moderate hypercholesterolemia, and hypertriglyceridemia. Those facts were not significantly modified by G or GS diets. G diet increased CYP7A1 expression but decreased the total cholesterol/high density lipoproteins (HDL)-cholesterol ratio (p < 0.05) vs. C diet. GS vs. G diet increased (p < 0.05) CYP7A1 expression. HC vs. C diet reduced food intake, body weight gain, and plasma glucose (p < 0.01) but increased cholesterolemia (p < 0.01), lipidemia (plasma cholesterol plus triglycerides) (p < 0.001), cholesterol/triglyceride ratio in very low density lipoproteins (VLDL), and HDL (p < 0.05), cholesterol transported by VLDL and intermediate density lipoproteins (IDL) + low density lipoproteins (LDL), total cholesterol/HDL-cholesterol ratio and CYP7A1 expression (at least p < 0.05). HG and HGS diets vs. HC noticeably reduced lipidemia (p < 0.001), normalized VLDL and IDL + LDL lipid composition, and increased CYP7A1 expression (p < 0.01) but did not modify the cholesterol/HDL-cholesterol ratio. HGS vs. HG decreased triglyceridemia, the triglyceride-glucose (TyG) index and increased arylesterase/HDL-cholesterol activity (p < 0.05). In conclusion, G- and GS-RP act as functional foods and notably blocked the dietary cholesterol effects. In addition, HGS-RP improved the glucomannan hypolipidemic effects, increased arylesterase/HDL-cholesterol activity, and decreased insulin resistance.

PON1 as a model for integration of genetic, epigenetic, and expression data on candidate susceptibility genes.

Recent genome- and epigenome-wide studies demonstrate that the DNA methylation is controlled in part by genetics, highlighting the importance of integrating genetic and epigenetic data. To better understand molecular mechanisms affecting gene expression, we used the candidate susceptibility gene paraoxonase 1 (PON1) as a model to assess associations of PON1 genetic polymorphisms with DNA methylation and arylesterase activity, a marker of PON1 expression. PON1 has been associated with susceptibility to obesity, cardiovascular disease, and pesticide exposure. In this study, we assessed DNA methylation in 18 CpG sites located along PON1 shores, shelves, and its CpG island in blood specimens collected from newborns and 9-year-old children participating (n = 449) in the CHAMACOS birth cohort study. The promoter polymorphism, PON1-108, was strongly associated with methylation, particularly for CpG sites located near the CpG island (P << 0.0005). Among newborns, these relationships were even more pronounced after adjusting for blood cell composition. We also observed significant decreases in arylesterase activity with increased methylation at the same nine CpG sites at both ages. Using causal mediation analysis, we found statistically significant indirect effects of methylation (β(95% confidence interval): 6.9(1.5, 12.4)) providing evidence that DNA methylation mediates the relationship between PON1-108 genotype and PON1 expression. Our findings show that integration of genetic, epigenetic, and expression data can shed light on the functional mechanisms involving genetic and epigenetic regulation of candidate susceptibility genes like PON1.

First-episode psychosis is associated with oxidative stress: Effects of short-term antipsychotic treatment.

In the present study, our aim was to investigate the oxidative-antioxidative systems in unmedicated first-episode psychosis (FEP) patients at the beginning and after short-term treatment. This study consisted of 29 patients who experienced an FEP and 25 control subjects. In order to investigate the oxidative status, we determined plasma malondialdehyde (MDA) levels, oxidizability of red blood cells, oxidation and oxidizability of apolipoprotein B-containing lipoproteins (apo B-basal MDA and apo B-ΔMDA). In order to evaluate the antioxidative defense, we measured serum total antioxidative capacity, uric acid, albumin, total bilirubin and vitamin E levels and serum paraoxonase/arylesterase, whole blood glutathione peroxidase (GPx) and red blood cell superoxide dismutase activities before and after 6 weeks of treatment in patients with FEP. Plasma MDA and apo B-basal MDA levels and red blood cell superoxide dismutase activity were significantly higher and serum arylesterase and whole blood-GPx activities were lower in the FEP group than those of the healthy control group. There were not any significant changes in the oxidative and antioxidative system parameters (except increased vitamin E levels) after treatment. The results of this study suggest that FEP is accompanied by oxidative stress. However, further studies are needed to clarify the role of oxidative stress in the physiopathologic mechanisms of FEP, so that oxidative and antioxidative system parameters can be used in the management of these patients. In accordance with psychiatric evaluation, for a better management, patients with FEP may require a multidisciplinary approach, including oxidative and antioxidative system parameters.

Serum paraoxonase and arylesterase activities of paraoxonase-1 (PON-1), mild cognitive impairment, and 2-year conversion to dementia: A pilot study.

Converging lines of evidence suggest that paraoxonase-1 (PON-1) may confer protection against inflammatory and oxidative challenge which, in turn, plays a key-role in the onset and progression of dementia. The aim of this study was to evaluate whether serum PON-1 paraoxonase/arylesterase activities might predict the clinical conversion of mild cognitive impairment (MCI) to late-onset Alzheimer's disease (LOAD) or vascular dementia (VAD). Serum paraoxonase and arylesterase activities were measured by spectrophotometric assays at baseline in 141 MCI patients (median age: 77 years; interquartile range 71-81) and in 78 healthy controls (median age: 76 years; interquartile range 73-79). After 2 years of follow-up, 86 MCI remained stable (MCI/MCI), 34 converted to LOAD (MCI/LOAD), whereas 21 converted to VAD (MCI/VAD). Baseline arylesterase activity was lower in all MCI groups compared with controls (all p < 0.01), whereas paraoxonase activity was lower in MCI/VAD group compared to controls (p < 0.05) and MCI/MCI patients (p = 0.009). Low paraoxonase and arylesterase activities (I quartile) were associated to higher risk of conversion to VAD (OR: 3.74, 95% CI: 1.37-10.25 and OR: 3.16, 95% CI: 1.17-8.56, respectively). Our results suggest that in MCI patients low PON-1 activity might contribute to identify individuals susceptible to develop vascular dementia.