Assessment of paraoxonase 1 activity and malondialdehyde levels in patients with rheumatoid arthritis

Malondialdehyde Serum Levels in a Full Characterized Series of 430 Rheumatoid Arthritis Patients

Background. Oxidative stress has been involved in the pathogenesis of rheumatoid arthritis (RA). The serum malondialdehyde (MDA) level is a reliable biomarker of oxidative stress status. In the present work, we aimed to analyze how a comprehensive characterization of the disease characteristics in RA, including a lipid profile, insulin resistance, and subclinical atherosclerosis, relates to serum MDA levels. Methods. In a cross-sectional study that included 430 RA patients, serum MDA levels were evaluated. Multivariable analysis was performed to examine the relationship of MDA with disease activity scores and disease characteristics, including subclinical carotid atherosclerosis, a comprehensive lipid molecule profile, and indices of insulin resistance and beta cell function indices. Results. The erythrocyte sedimentation rate (ESR) showed a significant and positive relationship with MDA. However, this did not occur for other acute phase reactants such as C-reactive protein or interleukin-6. Although the DAS28-ESR score (Disease Activity Score in 28 joints) had a positive and significant association with MDA serum levels, other disease activity scores that do not use the erythrocyte sedimentation rate in their formula did not show a significant relationship with MDA. Other disease characteristics, such as disease duration and the existence of rheumatoid factor and antibodies against citrullinated protein, were not related to serum MDA levels. This also occurred for lipid profiles, insulin resistance indices, and subclinical carotid atherosclerosis, for which no associations with circulating MDA were found. Conclusions. The disease characteristics are not related to circulating MDA levels in patients with RA.

The effects of dietary essential fatty acid ratios and energy level on growth performance, lipid metabolism, and inflammation in grow-finish pigs

The objective of this study was to investigate the effects of dietary metabolizable energy (ME) level and the ratio of linoleic acid:α-linolenic acid (LA:ALA) on the growth performance, lipid metabolism, circulatory and joint inflammatory status, and synovial fluid proteome of grow-finish pigs. A total of 224 pigs (BW = 41.5 ± 6.1 kg; PIC Genus 337 × 1050, Hendersonville, TN) were randomly assigned to either a high (3.55 Mcal/kg; HE) or low (3.29 Mcal/kg; LE) ME dietary treatment with a high (23:1) or low (12:1) LA:ALA in a 2 × 2 factorial arrangement. Diets were fed across three 28-d phases. Pigs were housed either four barrows or four gilts per pen. Blood samples were collected on days 0, 21, 42, and 84. Synovial fluid was collected from the hock and carpus joints on days 0 and 84. Liver and adipose tissue samples were collected on day 84. Data were analyzed as repeated measures using PROC MIXED (SAS 9.4) with pen as the experimental unit and energy level, essential fatty acid ratio, sex, phase, and their interactions as fixed effects. Compared to LE, HE increased days 28, 56, and 84 body weight (BW; P = 0.005). For the overall period, HE increased average daily gain (ADG) compared to LE (P < 0.001) and improved feed efficiency (P = 0.001), while LE increased feed intake compared to HE (P < 0.001). Gilts receiving diets with low LA:ALA had similar final BW to barrows receiving a low LA:ALA at days 28, 56, and 84 (P = 0.024), resulting from improved overall days 0-84 ADG compared to gilts receiving the high LA:ALA (P = 0.031). In the liver, HE decreased the mRNA abundance of acetyl CoA carboxylase (ACACA; P = 0.004), cluster of differentiation 36 (P = 0.034), and tended to decrease fatty acid synthase (FASN; P = 0.056). In adipose tissue, HE decreased ACACA (P = 0.001) and FASN (P = 0.017). Plasma inflammatory markers C-reactive protein (CRP) and tumor necrosis factor-α (TNFα) were reduced on day 84 compared to day 0 (P ≤ 0.014). In the hock and carpus synovial fluid, LE tended to reduce CRP and TNFα (P ≤ 0.096). Hock and carpus synovial fluid CRP were also reduced on day 84 compared to day 0 (P = 0.001). Age of the pig impacted serum and hock synovial fluid protein abundance, but not energy level, LA:ALA, or their interactions (P < 0.05). To conclude, the high and low LA:ALA ratios utilized in this study can be fed at varying energy levels without impacting growth. Additionally, LA:ALA ratios can differentially impact the growth of barrows and gilts.

Evaluation of thiol/disulfide homeostasis in rheumatoid arthritis and disease activity

BACKGROUND

It has been suggested that the deterioration in the antioxidant defense system due to thiols may cause the pro-oxidant/antioxidant imbalance seen in rheumatoid arthritis (RA). This study was conducted to evaluate thiol/disulfide (-SH/-SS) homeostasis in patients with RA compared to healthy controls, and to validate the limited number of studies examining the relationship between Disease Activity Score-28 (DAS28) and thiol parameters.

METHOD

A total of 100 individuals (mean age: 46.3 ± 12.03) consisting of 86 females and 14 males were included in the RA group, and a total of 100 individuals (mean age: 43.3 ± 10.96 years) consisting of 78 females and 22 males were included in the control group. DAS28 was used to assess RA disease activity. -SH/-SS homeostasis parameters were measured using the automated spectrophotometric method described by Erel and Neselioğlu.

RESULTS

While native thiol (-SH) (p:0.001), total thiol (-SH + -SS) (p < 0.0001) levels and -SH\(-SS + -SH) ratio (p: 0.018) were lower in the RA group compared to the healthy controls, disulfide (-SS) level (p: 0.005)), -SS\-SH (p: 0.001) and -SS\(-SS + -SH) (p: 0.002) ratios were found to be higher. In the control group and the group in remission (defined by DAS28 < 2.6), the median values of -SH (p:0.002) and -SS + -SH (p:0.0008) were found to be significantly higher, and the median value of -SS (p: 0.001) was found to be lower compared to the other DAS28 groups. While a negative correlation was found between DAS28 and -SH (r: -0.243, p: 0.007), a positive correlation was found between DAS28 and -SS (r: 0.316, p: 0.0003), -SS\-SH (r:0.229, p: 0.002) and -SS\(-SS + -SH) (r: 0.285, p: 0.0009).

CONCLUSIONS

The plasma thiol antioxidant pool was decreased in RA compared to healthy controls and those with active disease compared to those in remission.

Association between Paraoxonase/Arylesterase Activity of Serum PON-1 Enzyme and Rheumatoid Arthritis: A Systematic Review and Meta-Analysis

Background: A decrease in serum paraoxonase (PON-1) and arylesterase (ARE) activity has been reported in rheumatoid arthritis (RA) patients and linked to chronic inflammation and impaired antioxidant defense. Methods: A systematic review and meta-analysis were performed to critically appraise the current evidence on plasma/serum concentrations of PON-1 and ARE activity in RA patients and healthy controls. The Web of Science, PubMed, Scopus, and Google Scholar databases were searched from inception to November 2021. We used random-effects meta-analysis. The risk of bias was estimated using the Joanna Briggs Institute Critical Appraisal Checklist tool. The certainty of the evidence was assessed with GRADE. The study complied with the PRISMA statements and was registered in PROSPERO (CRD42022345380). Results: Seventeen studies reported PON-1 activity (1144 RA patients, 797 controls) and ten reported ARE activity (1367 RA patients, 1037 controls). RA patients had significantly lower PON-1 (SMD = −1.32, 95% CI −1.94 to −0.70; p < 0.001) and ARE activity (SMD = −0.91, 95% CI −1.37 to −0.46; p < 0.001). There was substantial heterogeneity (PON, I2 97%; ARE, 95.7%, p < 0.001 for both). There was no publication bias. The pooled SMD values did not significantly change after sensitivity analysis. The certainty of the evidence was very low due to the observational nature of the studies and the large heterogeneity. Conclusion: Our meta-analysis has shown that both serum PON-1 and ARE activity are significantly lower in RA patients, suggesting a deficit in antioxidant defense mechanisms in this disease.

Ameliorative effect of cerium oxide nanoparticles against Freund’s complete adjuvant-induced arthritis

Aim: To assess the mechanistic effects of cerium oxide nanoparticles (CONPs) on Freund’s complete adjuvant (FCA)-induced rheumatoid arthritis in rats. Methods: CONPs were characterized and evaluated in vitro (RAW 264.7 macrophages) and in vivo (FCA-induced rheumatoid arthritis model). Results: In vitro treatment with CONPs significantly reduced lipopolysaccharide-induced oxidative stress (as evident from dichlorodihydrofluorescein diacetate staining), diminished mitochondrial stress (as observed with tetraethylbenzimidazolylcarbocyanine iodide staining) and reduced superoxide radicals. In vivo, CONPs exhibited anti-rheumatoid arthritis activity, as evident from results of paw volume, x-ray, clinical scoring, levels of cytokines (IL-17, IL-1β, TNF-α and TGF-β1) and histology. Conclusion: We provide preclinical proof that CONPs may be a novel futuristic nanoparticle-based approach for therapy of rheumatoid arthritis.

A systematic review of preclinical studies on the efficacy of taurine for the treatment of rheumatoid arthritis

Due to the undesirable effects of conventional medical therapies prescribed for rheumatoid arthritis (RA), complementary therapies, especially nutritional agents, have recently gained great attention. Recent animal and in vitro researches have shown benefits of taurine (Tau), a sulfur-containing amino acid, in RA and suggest that Tau may be a therapeutic candidate in RA; however, no systematic review exists regarding Tau and RA. Accordingly, this paper systematically reviewed the available researches regarding Tau and RA and plausible underlying mechanisms. We searched electronic databases like Scopus, WOS, PubMed, Embase, ProQuest, Cochrane Library, and a search engine Google Scholar until December 2020 and we have applied search alert services to detect related papers published after the primary search. We did not have any restriction in publication date and/or language. We found no clinical study; thus we considered related animal and in vitro researches. Furthermore, we checked the citations or references of these researches and grey literature to detect possible studies. We did not consider reviews, book chapters, conference abstracts, and articles about Tau in health problems other than RA. Eighteen articles were entered in present systematic review. Animal and in vitro researches showed that Tau either directly or indirectly (via Tau derivatives such as Tau-chloramine, Tau-bromamine, taurochenodeoxycholic acid, and taurolidine) could control RA by different mechanisms such as reducing inflammation, suppressing oxidative stress, and inducing apoptosis. This review serves convincing clues about the efficacy of Tau in RA and explains the importance of additional clinical investigations.

Evaluation of the effect of hydroalcoholic and flavonoid-enriched extracts of Dracocephalum kotschyi on indomethacin-induced gastric ulcer in rats

Background and purpose:

Dracocephalum kotschyi (Zaringiah) is a fragrant wild medicinal plant found in Iran. Traditionally, it is used for the treatment of rheumatism, asthma, and gastrointestinal ailments. So far no investigation has been done on the beneficial or side effects of D. kotschyi on peptic ulcer. Therefore, this research was performed to find out whether D. kotschyi extract would induce peptic ulcer or could alleviate existing peptic ulcer.

Experimental approach:

Effect of hydroalcoholic (DKHE) and flavonoid extracts (DKFE) of D. kotschyi were determined in normal or indomethacin-induced gastric ulcer rats (n = 6) and compared with the vehicle and ranitidine treated controls. All the treatments were carried out orally and 24 h later the stomach mucus was visually examined for peptic ulcers. A section of the stomach was taken for microscopic histopathological examinations while another section of the stomach was used for measurement of myeloperoxidase (MPO) and malondialdehyde (MDA) activities.

Findings/Results:

Oral administration of the DKHE and DKFE alone, did not cause any sign of gastric ulcer induction. The D. kotschyi extracts not only didn’t aggravate the induced ulcer but also significantly prevented the severity of gastric ulcer induction by indomethacin. In addition, DKHE and DKFE inhibited MPO (up to 58.2%) and MDA (up to 44.2%) activities indicating their anti-inflammatory and antioxidant potential action on the stomach-induced ulcer.

Conclusion and implication:

Usage of D. kotschyi extracts is not associated with gastric ulcer induction and its co-administration with NSAIDs would be beneficial for controlling both the inflammation and preventing gastric ulcer in diseases such as rheumatism.

Association between rs662 (A > G) and rs854560 (A > T) polymorphisms in PON1 gene and the susceptibility for psoriasis in mestizo population of Western Mexico

Psoriasis is a chronic, autoimmune skin disease. In psoriasis, PON1 activity is diminished and peroxidation biomarkers are elevated. The most studied PON1 polymorphisms are rs662 (A > G) and rs854560 (A > T), which have been associated with the antioxidant activity of PON1, risk of cardiovascular diseases and psoriasis development. The aim of this study, was to determine the association of rs662 (A > G) and rs854560 (A > T) PON1 polymorphisms with psoriasis susceptibility in Western Mexico population. In this case-control study, we included 104 psoriasis patients and 124 control subjects. The genotyping of polymorphisms rs662 (A > G) and rs854560 (A > T) of PON1 was carried out by PCR-RFLPs. The lipid profiles were quantified by enzymatic colorimetric method, and PON1 activity was determined by spectrophotometry. The lipid profile levels, except HDL-C and atherogenic index, were higher in patients vs. controls. Patients presented lower paraoxonase and arylesterase activity. The G allele of rs662 (A > G) is associated with risk for psoriasis, while the T allele of rs854560 (A > T) is associated with low susceptibility to psoriasis. The AG haplotype was more frequent within the patient group (p < 0.05). The AA and AG genotypes of rs662 (A > G) and TT and AA genotypes of rs854560 (A > T) are associated with lower PONase and ARE activity in patients vs. controls. Patients with the G allele of rs662 (G > A) and T alleles of rs854560 (A > T) show significant differences in the lipid levels in comparison to controls. These results suggest that carriers of G allele of rs662 (A > G) present a greater susceptibility to psoriasis.

Paraoxonase 1 Phenotype and Protein N-Homocysteinylation in Patients with Rheumatoid Arthritis: Implications for Cardiovascular Disease

Paraoxonase 1 (PON1) is the high density lipoprotein-associated esterase which inhibits the development of atherosclerosis by metabolizing lipid peroxidation products as well as hydrolyzing proatherogenic metabolite of homocysteine (Hcy), Hcy thiolactone, which otherwise reacts with lysine groups of proteins, thus forming N-Hcy-protein in a process referred to as protein N-homocysteinylation. Rheumatoid arthritis (RA) is the chronic inflammatory autoimmune disease associated with increased risk of cardiovascular complications, but the underlying mechanisms are incompletely understood. We examined PON1 status and N-homocysteinylation of serum proteins in patients with RA. Blood was collected from 74 RA patients and 70 control subjects. PON1 activity was measured toward synthetic (paraoxon, phenyl acetate) and natural (Hcy thiolactone) substrates. PON1 protein concentration was measured by ELISA. Total Hcy as well as N-Hcy-protein were measured in serum as well. PON1 activity toward Hcy thiolactone was lower in RA patients than in control subjects which was accompanied by increased concentration of N-Hcy-protein despite normal total Hcy concentration. PON1 protein concentration was unchanged in the RA group, but the specific enzyme activity was reduced. When RA patients were categorized according to the DAS28-ESR score, PON1 concentration and enzymatic activity were lower whereas N-Hcy-protein was higher in those with high disease activity. PON1 activity and Hcy thiolactone were correlated with DAS28-ESR score and myeloperoxidase concentration. In conclusion, RA is associated with deficiency of PON1 activity and increased protein N-homocyseinylation which may contribute to accelerated development of cardiovascular diseases.

PON-1 haplotype (-108C>T, L55M, and Q192R) modulates the serum levels and activity PONase promoting an atherogenic lipid profile in rheumatoid arthritis patients

INTRODUCTION/OBJECTIVE

Paraoxonase 1 (PON1) promotes antioxidant and antiatherogenic activity related to the hydrolysis of oxidized lipids of low-density lipoproteins. In rheumatoid arthritis (RA) patients, it has been reported that low PON1 activity is related to an impaired lipid profile, increasing cardiovascular risk (CVR). The goal of this study was to analyze the effect of common PON1 polymorphisms and haplotypes on enzymatic activity, PON1 serum levels (PON1s), and lipid parameters related to atherogenic profile in RA patients.

METHODS

A cross-sectional study was carried out on 250 Mexican patients with RA. The lipid profile was determined by colorimetric tests. The PON1 activity (CMPAase) was measured by spectrophotometry. The levels of PON1s were determined by ELISA, and the polymorphisms in the PON-1 gene (-108C>T, L55M, and Q192R) were genotyped by the PCR-RFLP method. The haplotypes were estimated and statistical analysis was performed.

RESULTS

The median of the CMPAase activity and PON1 levels was 13.91 U/mL and 24.75 ng/mL, respectively. The CMPAase activity was significantly lower in carriers of -108TT and 192QQ genotypes (β = - 4.09, P = 0.001 and β = - 3.73, P = 0.002, respectively); moreover, the PON1 levels were lower in 192Q allele carriers (P < 0.01). The TLQ haplotype was associated with CMPAase activity < 13.91 U/mL (OR = 2.29, P < 0.001), as well as with levels of PON1s < 24.75 ng/mL (OR = 1.65, P = 0.017). In this study, the CMPAase activity (< 13.91 U/mL) showed a positive association with lower levels of high-density lipoprotein cholesterol (HDL-c; < 40/50 mg/dL), and with a triglycerides/HDL-c ratio > 3%, and a total cholesterol/HDL-c ratio > 4.5/5%, all representatives of an atherogenic risk lipid profile.

CONCLUSIONS

PON1 polymorphisms modulate the CMPAase activity and PON1 levels in Mexican patients with RA. The CMPAase activity < 13.91 U/mL is associated with an atherogenic lipid profile, independently of inflammation markers and treatment with anti-rheumatic drugs. Key Points •The haplotype TLQ is a marker for low PONase activity in rheumatoid arthritis. •The haplotype TLQ is a marker for low PON1 serum levels in rheumatoid arthritis. •The enzymatic PON1 activity represents the best marker for an atherogenic lipid profile in rheumatoid arthritis, in comparison with PON1 levels. •The haplotype TLQ is a marker of low PON1 activity, levels of PON1s, and atherogenic lipid profile, independent of treatment therapy in rheumatoid arthritis.

Carotid plaques in adult rheumatoid arthritis patients; association with paroxonase 1 enzymatic activity and Q192R paroxonase 1 gene polymorphism

Paroxonase 1 (PON 1) enzymatic activity and Q192R PON polymorphism has been implicated with greater cardiovascular risk in general population. Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized with increased inflammatory markers leading to increased cardiovascular morbidity. The aim of the work was to study association between PON1 enzymatic activity & gene polymorphism with carotid plaques in RA patients. This case-control study was carried out at Zagazig University Hospitals on 99 subjects divided randomly into two groups; 48 RA patients and 51 controls. RA patients fulfilled the revised 2010 EULAR/ACR classification criteria of RA. All patients were subjected to history taking, clinical evaluation, laboratory investigations & plain X-rays. Carotid intima-media thickness (CIMT) and PON1 enzyme assay & genotyping were done for both groups. PON1 enzyme levels were significantly higher in patients than controls. Also, there was a significant negative correlation of PON1 enzyme activity with increased CIMT & plaques. The cut-off value of PON1 enzyme level that had the highest CVD prediction was 4.2 U/ml. Although PON1 genotyping was insignificantly different between patients and controls, patients with QQ genotype had the lowest PON1 activity then patients with QR genotype then RR genotype. In RA patients, decreased serum PON1 enzymatic activity and QQ genotyping of Q192R PON polymorphism was associated with increased CIMT & plaques. Serum PON1 could be a good marker for atherosclerosis prediction in RA patients at cutoff 4.2 U/ml.

Oral administration of alpha-lipoic acid did not affect lipid peroxidation and antioxidant biomarkers in rheumatoid arthritis patients

Abstract. Rheumatoid arthritis (RA) is a chronic inflammatory disease in which oxidative stress could play a substantial pathological role. Alpha-lipoic acid (ALA) has been known as a “universal” and “ideal” antioxidant. The purpose of this study was to investigate the effects of oral administration of Alpha-lipoic acid (ALA) on lipid peroxidation and antioxidant biomarkers in Rheumatoid arthritis (RA) patients. The study was a randomized, double-blinded, placebo-controlled clinical trial. 70 RA patients were randomized 1:1 to two groups using blocked randomization method and received 1200 mg/day ALA or placebo for 8 weeks. Fasting blood samples were obtained before and after the intervention to analyze total antioxidant capacity (TAC), antioxidant enzymes [superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and arylesterase (ARE) activities] and malondialdehyde (MDA). We observed significant increase in serum TAC (0.11 mmol/L; p=0.033) and ARE (13.76 U/mL; p=0.046) and significant decline in MDA (−0.36 nmol/L; p=0.002), in ALA group. However, these changes in ALA-treated group were not statistically significant when compared with placebo-treated group (p > 0.05). Also, within- and between-group differences of whole blood SOD and GSH-Px were not statistically significant (p > 0.05). In conclusion, unexpectedly, ALA therapy did not affect the oxidative status of RA patients in the present clinical trial. It seems that more comprehensive clinical trials in RA patients are still warranted to clarify the effectiveness of ALA which has been known as a potent antioxidant.

Effect of Eicosapentaenoic Acid Supplementation on Paraoxonase 2 Gene Expression in Patients with Type 2 Diabetes Mellitus: a Randomized Double-blind Clinical Trial

Type 2 diabetes mellitus (T2DM) is recognized as one of the most prevalent metabolic diseases, and it is mostly associated with oxidative stress, atherosclerosis and dyslipidemia. Paraoxonase 2 (PON2) due to its antioxidant properties may play a role in the atherosclerosis development. Although long-chain omega-3 polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA) have been shown to reduce the risk of cardiovascular disease, the exact mechanism of action is still unknown. Our goal in this study was to determine the effect of EPA administration on gene expression of PON2 in patients with T2DM. Present study was a randomized, controlled double-blind trial. Thirty-six patients with T2DM were randomly allocated to receive 2 g/day EPA (n = 18) or placebo (n = 18) for 8 weeks. There were no significant differences between 2 groups concerning demographic or biochemical variables, and dietary intakes as well (p > 0.05). However, patients received EPA showed a significant increase in the gene expression of PON2 compared with placebo group (p = 0.027). In addition, high-density lipoprotein cholesterol increased and fasting blood sugar decreased significantly after EPA supplementation compared with control group. Taken together, supplementation with 2 g/day EPA could be atheroprotective via the upregulation of PON2 in patients with T2DM.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03258840.

Association between serum malondialdehyde levels and depression during early methamphetamine withdrawal

Some evidence suggested that malondialdehyde (MDA) as a marker of oxidative stress played an important part in modulating the activities of depression. Methamphetamine (METH) dependence often lead to depression that may associate with MDA. In this study, our purpose was to explore the association between serum MDA levels and depression during METH withdrawal. 179 METH-dependent patients were recruited in this study and 144 (80.4%) finished the assessment. We measured serum MDA at 532 nm spectrophotometrically at admission. The short form of the Beck Depression Inventory (BDI-13) was used to evaluate depression symptoms. Patients were identified to have depression symptoms with the BDI score ≥ 8. As a result, 89 (61.8%) of the remaining 144 METH-dependent patients were identified to have depression symptoms. Patients with depression symptoms showed significantly higher serum MDA levels than non-depression patients (3.42 ± 1.60 nmol/ml vs. 2.43 ± 1.25 nmol/ml; p <  0.001). After controlling for potential confounding variables in our logistic model, serum MDA levels were independently associated with the development of depression during early METH withdrawal (OR =1.952, 95% CI, 1.414-2.694, p < 0.001). Furthermore, our study found a positive association between Beck Depression Inventor (BDI) score in early METH abstinence and serum MDA levels (r =0.185; p =  0.026). Our results indicated that higher serum MDA levels were related to higher risk of depression symptoms during early METH withdrawal.

Correlation of High-Density Lipoprotein-Associated Paraoxonase 1 Activity With Systemic Inflammation, Disease Activity, and Cardiovascular Risk Factors in Psoriatic Disease

OBJECTIVE

To compare the activity of high-density lipoprotein (HDL)-associated paraoxonase 1 (PON1) in patients with psoriasis (PsO) and patients with psoriatic arthritis (PsA), and to evaluate the association of PON1 activity with the extent of disease activity and severity of the cardiovascular disease (CVD) burden in these patients.

METHODS

Serum levels of paraoxonase and arylesterase activity (both measures of PON1 function in humans) were measured in patients with PsA (n = 198, 51.0% male) and patients with PsO (n = 145, 50.3% male) who were enrolled in a longitudinal psoriatic disease biorepository. Data on PsA disease activity (using the Disease Activity Score in 28 joints [DAS28], Clinical Disease Activity Index, and painful/swollen joint counts), preexistent CVD and CVD risk factors (including diabetes, dyslipidemia, hypertension, and smoking), Framingham Risk Scores for CVD, quality of life measures, and laboratory test findings (erythrocyte sedimentation rate, C-reactive protein level, and lipid profiles) were recorded.

RESULTS

Serum arylesterase activities were significantly lower in patients with PsO and patients with PsA (mean ± SD 111.1 ± 25.5 μmoles/minute/ml and 124.4 ± 33.4 μmoles/minute/ml, respectively) compared to healthy controls (144.3 ± 33.4 μmoles/minute/ml) (each P < 0.001 versus healthy controls). Serum arylesterase activity decreased in parallel with increasing levels of disease activity (DAS28 scores, P = 0.012), older age (P = 0.013), higher body mass index (P = 0.042), greater incidence of metabolic syndrome (P = 0.004) and hypertension (P = 0.014), and worsening Framingham Risk Scores (P = 0.001). However, no correlation was seen between serum arylesterase activity and the extent of disease activity or CVD burden in patients with PsO. Serum paraoxonase activity trended lower both in patients with PsO and in patients with PsA (each P = 0.073 versus healthy controls). However, no association was seen between serum paraoxonase activity and the extent of disease activity or CVD burden in either of the patient cohorts.

CONCLUSION

PON1 activity is decreased in psoriatic diseases. In the PsA cohort, decreases in arylesterase activity correlated with increasing severity of joint disease and CVD burden. Arylesterase activity, as compared to paraoxonase activity, appeared to serve as a more sensitive predictor of preexisting CV risk factors in the PsA cohort. However, this correlation was not observed in the PsO population.

The effect of red grape seed extract on serum paraoxonase activity in patients with mild to moderate hyperlipidemia

CONTEXT AND OBJECTIVE

Red grape seed extract (RGSE) contains oligomeric proanthocyanidin complexes as a class of flavonoids. These compounds are potent antioxidants and exert many health-promoting effects. This study aimed to determine the effects of RGSE on serum levels of triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein AI (apo-AI) levels and paraoxonase (PON) activity in patients with mild to moderate hyperlipidemia (MMH).

DESIGN AND SETTINGS

A randomized double-blind placebo-controlled clinical trial was conducted at Shahid-Modarres Hospital (Tehran, Iran) and Tabriz University of Medical Sciences. Seventy MMH patients were randomly assigned to receive treatment (200 mg/day of RGSE) or placebo for eight weeks.

RESULTS

Significant elevation in serum levels of apo-AI (P = 0.001), HDL-C (P = 0.001) and PON activity (P = 0.001) and marked decreases in concentrations of TC (P = 0.015), TG (P = 0.011) and LDL-C (P = 0.014) were found in the cases. PON activity was significantly correlated with apo-AI (r = 0.270; P < 0.01) and HDL-C (r = 0.45; P < 0.001). Significant differences between the RGSE and control groups (before and after treatment) for TC (P = 0.001), TG (P = 0.001), PON (P = 0.03), apo-AI (P = 0.001) and LDL-C (P = 0.002) were seen.

CONCLUSION

It is possible that RGSE increases PON activity mostly through increasing HDL-C and apo-AI levels in MMH patients. It may thus have potential beneficial effects in preventing oxidative stress and atherosclerosis in these patients.

Is 4-Hydroxynonenal a Predictive Parameter for the Development of Joint Erosion in Patients With Rheumatoid Arthritis?

Objectives

This study aims to evaluate serum 4-hydroxynonenal (4-HNE) levels and its clinical and radiological significance in patients with rheumatoid arthritis (RA).

Patients and methods

The study included 40 patients (8 males, 32 females; mean age 51.4±11.2 years; range 24 to 72 years) with RA and 30 healthy controls (8 males, 32 females; mean age 53.0±11.7 years; range 24 to 72 years. Serum 4-HNE levels were measured using sandwich enzyme-linked immunosorbent assay method. Patients with disease activity score 28 ≤3.2 and >3.2 were allocated into low and high/moderate disease activity groups, respectively. Additionally, patients were divided into two groups as early RA (disease duration ≤2 years) and established RA (disease duration ≥2 years). Functional disability was evaluated using health assessment questionnaire. Radiographs were scored using the modified Larsen scoring.

Results

Serum 4-HNE levels in patients with RA were significantly higher than controls (p=0.001). Serum 4-HNE levels did not correlate with laboratory or clinical parameters of disease activity including erythrocyte sedimentation rate, C-reactive protein, disease activity score 28, and health assessment questionnaire. Serum 4-HNE levels were higher in patients with established RA than patients with early RA (r=0.487, p=0.001). Besides, modified Larsen score which indicates structural damage correlated significantly with serum 4-HNE levels (p=0.001).

Conclusion

These results indicate that serum 4-HNE levels may be used as an indicator for structural damage such as erosions in the early stage of RA; however, they are not efficient to monitor disease activity.

Paraoxonase and arylesterase levels in autoimmune thyroid diseases

OBJECTIVE

The aim of this study was to evaluate serum paraoxonase-1 (PON1) activity and its association with oxidative stress in autoimmune thyroid disease (AITD).

METHODS

A total of 50 patients with AITD, including 25 with Hashimoto's thyroiditis and 25 with Graves' disease were enrolled. The control group comprised 27 healthy subjects. Blood samples were obtained in the euthyroid period and 3 months after initiation of medical treatment. Serum samples from patients with AITD and the healthy control group were analyzed for basal PON1, salt-stimulated PON1, and arylesterase (ARE) activities, along with lipid hydroperoxide (LOOH) and total free sulfhydryl (-SH) levels.

RESULTS

Serum PON1 activities and -SH levels were significantly lower (P < 0.001, for each), whereas LOOH levels were significantly higher (P < 0.001, for each) in patients with AITD, compared to the control group. We observed no significant differences in ARE levels between the patient and healthy control groups (P > 0.05). PON1 activity was positively correlated with -SH (r = 0.522, P < 0.001) and negatively correlated with LOOH (r = -0.487, P < 0.001). PON1 phenotype distribution of the subjects was not significantly different among the three groups (P = 0.961).

CONCLUSIONS

Serum PON1 activity is decreased in patients with AITD, and correlated positively with -SH, a well-known antioxidant, and negatively with LOOH, an index of lipid oxidation.

Total oxidative stress, paraoxonase and arylesterase levels at patients with pseudoexfoliation syndrome and pseudoexfoliative glaucoma

AIM

To investigate the oxidative stress status of the aqueous humor and serum of patients with pseudoexfoliation (PEX) syndrome and pseudoexfoliative glaucoma (PEG) and to measure paraoxonase (PON) and arylesterase (ARE) levels.

METHODS

A total of 78 patients were enrolled in the study, with 26 patients in each separate group. The patients were divided into three groups: the first group entailed PEX syndrome patients, while the second group consisted of patients with PEG and the third group involved patients with no additional systemic diseases, other than the diagnosis of cataract as control. Total oxidative stress (TOS), total antioxidant capacity (TAC), PON, and ARE levels in aqueous humor and serum were measured.

RESULTS

TAC, PON and arylesterase levels in aqueous humor and serum of the PEX syndrome and PEG patients were significantly decreased compared with control group (P<0.05). TOS values were higher in patients with PEX syndrome and PEG than controls (P<0.05). TAC, PON and ARE levels of aqueous humor did not differ significantly between the PEX syndrome and PEG groups.

CONCLUSION

These findings are potentially of significance and add to the growing body of evidence for oxidative stress in PEX syndrome and PEG. Decreased antioxidant defense and increased oxidative stress system may play an important role in the pathogenesis of PEX syndrome and PEG.

Measurement of activity and concentration of paraoxonase 1 (PON-1) in seminal plasma and identification of PON-2 in the sperm of boar ejaculates

This study revealed and characterised the presence of the antioxidant enzymes paraoxonase (PON) type 1 (PON-1, extracellular) and type 2 (PON-2, intracellular) in boar semen. To evaluate PON-1, an entire ejaculate from each of ten boars was collected and the seminal plasma was harvested after double centrifugation (1,500g for 10 min). Seminal plasma was analysed for concentration as well as enzymatic activity of PON-1 and total cholesterol levels. Seminal-plasma PON-1 concentration ranged from 0.961 to 1.670 ng/ml while its enzymatic activity ranged from 0.056 to 0.400 IU/ml, which represent individual variance. Seminal-plasma PON-1 concentration and enzymatic activity were negatively correlated (r = -0.763; P < 0.01). The activity of seminal-plasma PON-1 negatively correlated with ejaculate volume (r = -0.726, P < 0.05), but positively correlated with sperm concentration (r = 0.654, P < 0.05). Total seminal-plasma cholesterol concentration positively correlated with PON-1 activity (r = 0.773; P < 0.01), but negatively correlated with PON-1 concentration (r = -0.709; P < 0.05). The presence of intracellular PON-2 was determined via immunocytochemistry in spermatozoa derived from artificial insemination. PON-2 localised to the post-acrosomal area of the sperm head and principal piece of the tail in membrane-intact spermatozoa. In summary, PON is present in boar semen, with PON-1 at low levels in seminal plasma and PON-2 within the spermatozoa. Further studies are needed to characterise the relationship between antioxidant PONs with sperm and other seminal-plasma parameters.

Anti-cyclic citrullinated peptide antibodies and paraoxonase-1 polymorphism in rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is the most common chronic inflammatory joint disease, with a worldwide prevalence of 0.5% to 1%. Anti-cyclic citrullinated peptide antibody (anti-CCP-2 Ab) is a marker of choice for diagnosing early and late RA. Anti-oxidant enzymes activity decreases in RA patients. Till now, the relationship between the rheumatoid factor (RF) and anti-CCP-2 Ab, anti-oxidant activity and polymorphism of paraoxenase-1 (PON-1) 192 Q/R in patients with RA has not been investigated. In this study, we aimed to determine the serum level of RF and anti-CCP-2 Ab, PON-1 activity and 192 Q/R polymorphism and arylesterase (ARE) activity in patients with RA. Also, we studied RA markers in different genotypes of PON-1 of RA patients.

Methods

A total of 120 RA patients and 90 healthy persons were subjected to full clinical examinations and routine laboratory tests. PON-1 and ARE activities were determined using an enzymatic spectrophotometric method. PON-1 192 gene polymorphism was determined using polymerase chain reaction based restriction fragment analysis. RF was measured by immunoturbidimetry method and anti-CCP-2 Ab was assayed by enzyme-linked immunosorbent assay (ELISA). Statistical analysis was performed using SPSS for windows 20.0.

Results

The sensitivity and specificity of anti-CCP-2 Ab for the diagnosis of RA were 76.2% and 100% respectively. PON-1 and ARE activities were statistically lower (P <0.001) in the RA group compared to the control group. A negative correlation between RF and anti-CCP-2 Ab levels and PON-1 and ARE activities was found. No significant difference in the genotype distribution between RA patients and healthy persons was detected. RF and anti-CCP-2 Ab levels were higher in RA patients carried RR genotype than in those carried QQ genotype.

Conclusion

High RF and anti-CCP-2 antibody serum levels were found to be associated with decreased PON-1 and ARE activities with no correlation between PON-1 polymorphism and serum levels of RF and anti-CCP-2 Ab in patients with RA. These results may indicate an implication between antioxidant enzymes activity and serum levels of RF and anti-CCP-2 Ab.

Muscle wasting in rheumatoid arthritis: The role of oxidative stress

Rheumatoid arthritis (RA), the commonest inflammatory arthritis, is a debilitating disease leading to functional and social disability. In addition to the joints, RA affects several other tissues of the body including the muscle. RA patients have significantly less muscle mass compared to the general population. Several theories have been proposed to explain this. High grade inflammation, a central component in the pathophysiology of the disease, has long been proposed as the key driver of muscle wasting. More recent findings however, indicate that inflammation on its own cannot fully explain the high prevalence of muscle wasting in RA. Thus, the contribution of other potential confounders, such as nutrition and physical activity, has also been studied. Results indicate that they play a significant role in muscle wasting in RA, but again neither of these factors seems to be able to fully explain the condition. Oxidative stress is one of the major mechanisms thought to contribute to the development and progression of RA but its potential contribution to muscle wasting in these patients has received limited attention. Oxidative stress has been shown to promote muscle wasting in healthy populations and people with several chronic conditions. Moreover, all of the aforementioned potential contributors to muscle wasting in RA (i.e., inflammation, nutrition, and physical activity) may promote pro- or anti-oxidative mechanisms. This review aims to highlight the importance of oxidative stress as a driving mechanism for muscle wasting in RA and discusses potential interventions that may promote muscle regeneration via reduction in oxidative stress.

Soy protein, genistein, and daidzein improve serum paraoxonase activity and lipid profiles in rheumatoid arthritis in rats

In this study, we investigated the effects of genistein, daidzein, and soy protein on paraoxonase and arylesterase activity, malondialdehyde (MDA) levels, and lipid profiles of arthritic rats in vivo and the results were compared with that of dexamethasone. Seventy-two female Sprague-Dawley rats were divided into six groups: healthy control, animals with collagen-induced arthritis (CIA), CIA-soy protein (7 g/kg)-treated rats, CIA-genistein (20 mg/kg)-treated animals, CIA-daidzein (20 mg/kg)-treated rats, and CIA-dexamethasone (1 mg/kg)-treated rats. Rheumatoid arthritis was induced using collagen type II and the treatments were carried out by daily gavages feedings for 50 days. The paraoxonase activity in serum was measured spectrophotometrically using paraoxon and phenylacetate as substrates. Serum MDA and lipids levels were determined using enzymatic colorimetric methods. Arthritis-induced decreases in paraoxonase and arylesterase activity was restored after treatment with soy protein and isoflavones (P<.05). MDA concentrations were lower after treatment with all tested compounds. However, only soy protein could partially improve the lipid profile.

Pharmacological influence on processes of adjuvant arthritis: Effect of the combination of an antioxidant active substance with methotrexate

Oxygen metabolism has an important role in the pathogenesis of rheumatoid arthritis. A certain correlation was observed between oxidative stress, arthritis and the immune system. Reactive oxygen species produced in the course of cellular oxidative phosphorylation and by activated phagocytic cells during oxidative burst, exceed the physiological buffering capacity and result in oxidative stress. The excessive production of ROS can damage protein, lipids, nucleic acids, and matrix components. Patients with rheumatoid arthritis have an altered antioxidant defense capacity barrier. In the present study the effect of substances with antioxidative properties, i.e. pinosylvin and carnosine, was determined in monotherapy for the treatment of adjuvant arthritis (AA). Moreover carnosine was evaluated in combination therapy with methotrexate. Rats with AA were administered first pinosylvin (30 mg/kg body mass daily per os), second carnosine (150 mg/kg body mass daily per os) in monotherapy for a period of 28 days. Further, rats with AA were administered methotrexate (0.3 mg/kg body mass 2-times weekly per os), and a combination of methotrexate+carnosine, with the carnosine dose being the same as in the previous experiment. Parameters, i.e. changes in hind paw volume and arthritic score were determined in rats as indicators of destructive arthritis-associated clinical changes. Plasmatic levels of TBARS and lag time of Fe²⁺-induced lipid peroxidation (tau-FeLP) in plasma and brain were specified as markers of oxidation. Plasmatic level of CRP and activity of γ-glutamyltransferase (GGT) in spleen and joint were used as inflammation markers. In comparison to pinosylvin, administration of carnosine monotherapy led to a significant decrease in the majority of the parameters studied. In the combination treatment with methotrexate+carnosine most parameters monitored were improved more remarkably than by methotrexate alone. Carnosine can increase the disease-modifying effect of methotrexate treatment in rat AA.

Potential of ayurgenomics approach in complex trait research: leads from a pilot study on rheumatoid arthritis

Background

Inconsistent results across association studies including Genome-wide association, have posed a major challenge in complex disease genetics. Of the several factors which contribute to this, phenotypic heterogeneity is a serious limitation encountered in modern medicine. On the other hand, Ayurveda, a holistic Indian traditional system of medicine, enables subgrouping of individuals into three major categories namely Vata, Pitta and Kapha, based on their physical and mental constitution, referred to as Prakriti. We hypothesised that conditioning association studies on prior risk, predictable in Ayurveda, will uncover much more variance and potentially open up more predictive health.

Objectives and Methods

Identification of genetic susceptibility markers by combining the prakriti based subgrouping of individuals with genetic analysis tools was attempted in a Rheumatoid arthritis (RA) cohort. Association of 21 markers from commonly implicated inflammatory and oxidative stress pathways was tested using a case-control approach in a total cohort comprising 325 cases and 356 controls and in the three subgroups separately. We also tested few postulates of Ayurveda on the disease characteristics in different prakriti groups using clinico-genetic data.

Results

Inflammatory genes like IL1β (C-C-C haplotype, p = 0.0005, OR = 3.09) and CD40 (rs4810485 allelic, p = 0.04, OR = 2.27) seem to be the determinants in Vata subgroup whereas oxidative stress pathway genes are observed in Pitta (SOD3 rs699473, p = 0.004, OR = 1.83; rs2536512 p = 0.005; OR = 1.88 and PON1 rs662, p = 0.04, OR = 1.53) and Kapha (SOD3 rs2536512, genotypic, p = 0.02, OR = 2.39) subgroups. Fixed effect analysis of the associated markers from CD40, SOD3 and TNFα with genotype X prakriti interaction terms suggests heterogeneity of effects within the subgroups. Further, disease characteristics such as severity was most pronounced in Vata group.

Conclusions

This exploratory study suggests discrete causal pathways for RA etiology in prakriti based subgroups, thereby, validating concepts of prakriti and personalized medicine in Ayurveda. Ayurgenomics approach holds promise for biomarker discovery in complex diseases.

Atherosclerosis and rheumatoid arthritis: more than a simple association

In the last decades a large amount of evidence linked rheumatoid arthritis (RA) to atherosclerosis. In fact, RA patients have an increased risk of cardiovascular events that is not fully explained by other classic cardiovascular risk factors. RA and atherosclerosis may share several common pathomechanisms and inflammation undoubtedly plays a primary role. The proinflammatory cytokines such as tumor necrosis factor alpha and interleukin-6, involved in the pathogenesis of RA, are also independently predictive of subsequent cardiovascular disease (CVD). In RA, inflammation alters HDL constituents and the concentration of LDL and HDL, thus facilitating atherosclerosis and CVD events. On the other hand, also the increase of oxidative processes, frequently observed in RA, induces atherosclerosis. Interestingly, some genetic polymorphisms associated with RA occurrence enhance atherosclerosis, however, other polymorphisms associated with RA susceptibility do not increase CVD risk. Several other mechanisms may influence atherosclerotic processes in RA. Moreover, atherosclerosis may be directly mediated also by underlying autoimmune processes, and indirectly by the occurrence of metabolic syndrome and impaired physical activity. Finally, the effects of RA therapies on cardiovascular system in general and on atherosclerosis in particular are really wide and different. However, the starting point of every RA treatment is that disease control, or better remission, is the best way we have for the reduction of CVD occurrence.

The concentration of thiobarbituric acid reactive substances (TBARS) and paraoxonase activity in blood of patients with osteoarthrosis after endoprosthesis implantation

Background

The aim of this study was to evaluate the concentration of malondialdehyde (MDA) in erythrocytes and in blood plasma and the activity of blood paraoxonase (PON1) of patients with osteoarthrosis (OA) submitted to endoprosthesis implantation for evaluating oxidative stress.

Material/Methods

Study was conducted on 55 patients with OA and on 54 total movement-efficient volunteers. The material for the study was venous blood plasma, serum and erythrocytes.

Results

Increased concentration of MDAe before surgery was observed in the group of men and in patients with a degenerative process affecting hip joints. After an implantation of endoprosthesis, MDAe decreased to the level observed in the control groups. In the study group MDA concentration in plasma was slightly lower before surgery, and after an operation it reached the value of the parameter of the reference groups. Regardless of sex or age, paraoxonase activity was almost twice as high in almost all subgroups as in the reference group. A positive correlation between PON 1 activity and MDAe concentration was demonstrated both before and after surgery in the group of men.

Conclusions

The increase of PON1 activity in patients’ serum in relation to the control groups indicates a probable pathogenic role of the increased formation of reactive oxygen species in the course of OA and may suggest acute inflammation of the synovial joint. The high level of PON 1 activity after endoprosthesis implantation indicates that surgical treatment may additionally stimulate ROS generation. MDAe concentration indicate more intensive process of lipid peroxidation in the elderly.

Utilization of adjuvant arthritis model for evaluation of new approaches in rheumatoid arthritis therapy focused on regulation of immune processes and oxidative stress

As a number of disease-modifying anti-rheumatic drugs often have side effects at high doses and/or during long-term administration, increased efficacy without increased toxicity is expected for combination therapy of rheumatoid arthritis (RA). The safety of long-term therapy of RA is very important as patients with RA are usually treated for two or more decades. This experimental overview is focused on some promising substances and their combinations with the standard antirheumatic drug – methotrexate (Mtx) for treatment of rheumatoid arthritis. The adjuvant arthritis model in Lewis rats was used for evaluation of antiinflammatory efficacy of the substances evaluated. Mtx was administered in the oral dose of 0.3 mg/kg b.w. twice a week. Natural and synthetic antioxidants were administered in the daily oral dose of 20 mg/kg b.w for coenzyme Q₁₀ (CoQ₁₀), 150 mg/kg b.w for carnosine (Carn), 15 mg/kg b.w. for stobadine dipalmitate (Stb) and its derivative SMe1.2HCl (SMe1), and 30 mg/kg b.w. for pinosylvin (Pin) or pterostilbene (Pte). Mtx in the oral dose of 0.4 mg/kg b.w. twice a week was combined with Pin in the oral daily dose of 50 mg/kg b.w. Clinical (hind paw volume – HPV), biochemical (activity of GGT in joint and level of TBARS in plasma), and immunological (IL-1 in plasma) parameters were assessed. Our results achieved with different antioxidants in monotherapies showed a reduction of oxidative stress in adjuvant arthritis independently of the chemical structure of the compounds. Pin was the most effective antioxidant tested in decreasing HPV. All combinations tested showed a higher efficacy in affecting biochemical or immunological parameters than Mtx administered in monotherapy. The findings showed the benefit of antioxidant compounds for their use in combination therapy with methotrexate.

Effect of peroxisome proliferator-activated receptor gamma agonist (pioglitazone) and methotrexate on disease activity in rheumatoid arthritis (experimental and clinical study)

OBJECTIVE

To investigate the combined effect of both pioglitazone and methotrexate on disease activity of rheumatoid arthritis in a biphasic study; experimental and clinical.

METHODS

EXPERIMENTALLY: 50 rats were divided into 5 equal groups; controls, experimental arthritis, methorexate treated (0.1 mg/Kg daily), pioglitazone-treated (10 mg/kg daily), and methotrexate and pioglitazone treated. Clinically: forty-nine diabetic rheumatoid arthritis patients were included. Patients group consisted of 28 patients and they received pioglitazone 30 mg orally beside their usual treatment. Control group consisted of 21 patients and they continued their usual treatment plus placebo. Disease activity was assessed using DAS28 score. Patients were followed up for 3 months.

RESULTS

Pioglitazone produced a significant improvement of serum oxidative stress parameters (P < 0.05), and inflammatory cytokines in the treated arthritic group (P < 0.05). Clinically, the pioglitazone treated group showed significant improvement in DAS28 (P = 0.001) and C-reactive protein (P < 0.0001) compared to placebo group.

CONCLUSION

The concomitant use of the PPAR γ agonist pioglitazone and methotrexate appears to be promising therapeutic strategy for rheumatoid arthritis patients.

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.

Effect of atorvastatin on inflammation and modification of vascular risk factors in rheumatoid arthritis

OBJECTIVE

To investigate the effect of atorvastatin therapy on inflammation, disease activity, endothelial dysfunction, and arterial stiffness in patients with rheumatoid arthritis (RA).

METHODS

This study included 30 patients with early RA, randomly divided into 2 groups. Group 1 (n = 15) received methotrexate (MTX; 0.2 mg/kg/week; mean (15.5 ± SD 1.3) plus prednisone (10 mg/day). Group 2 (n = 15) received MTX and prednisone with the same previous doses plus atorvastatin therapy (40 mg/day). Ten healthy individuals of similar age and sex served as controls. Disease activity, lipid profile, serum malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), resistin, adiponectin, and brachial artery flow-mediated dilation (FMD) were measured before and after 6 months of treatment.

RESULTS

Atorvastatin combined with MTX therapy significantly reduced serum total cholesterol, low-density lipoprotein cholesterol, and triglycerides, and increased high-density lipoprotein cholesterol (p < 0.001). Disease activity variables, serum MDA, TNF-α, resistin, adiponectin, and FMD were significantly improved by the drug combinations (p < 0.001).

CONCLUSION

Atorvastatin therapy in patients with RA reduced disease activity and conventional and novel vascular risk factors that promote the atheromatous lesion. Therapy was also associated with concomitant improvement in endothelial function.

Lack of association between paraoxonase-1 Q192R polymorphism and rheumatoid arthritis in southeast Iran

Decreased paraoxonase-1 (PON1) activity has been associated with rheumatoid arthritis. There are two polymorphisms in serum PON1; one differs in the amino acid at position 192 (Q192R) and the other one differs at position 55 (L55M). We looked for a possible association between Q192R polymorphism and rheumatoid arthritis. The Q192R polymorphism in 88 rheumatoid arthritis patients and 78 healthy subjects was determined using tetra amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and PCR-restriction fragment length polymorphism (RFLP) methods. We found no significant differences between rheumatoid arthritis patients and control subjects regarding PON1 Q192R polymorphism. PON1 Q192R polymorphism was not found to be correlated with increased risk for rheumatoid arthritis in this Iranian population.

Paraoxonase: a multifaceted biomolecule

BACKGROUND

Paraoxonase enzyme was first identified as a protective barrier against organophosphorus poisoning. After painstaking research spanning the last three decades, the knowledge about this enzyme has increased immensely. The present review attempts to elaborate the role of paraoxonase enzyme in normal physiology as well as provide an overview of the various disorders in which the enzyme may have a role in etiopathogenesis.

METHODS

The literature was searched from the websites of the National Library of Medicine (http://www.ncbi.nlm.nih.gov/) and Pub Med Central, the U.S. National Library of Medicine's digital archive of life sciences journal literature.

RESULTS

Paraoxonase acts as an important antioxidant enzyme against oxidative stress. The enzyme has been implicated in the pathogenesis of a number of disorders including cardiovascular disorders, cancers etc.

CONCLUSIONS

A better understanding of the molecular mechanism of the enzyme along with the regulatory circuits will help us to utilize agonists to potentiate the anti oxidant actions of the enzyme.

Expression and activity of paraoxonase 1 in human cataractous lens tissue

Paraoxonase 1 (PON1) is a high-density lipoprotein-associated enzyme that is believed to be involved in the protection against oxidative stress. There is evidence that paraoxonase activity is reduced in patients with diabetes and cataract. In the current study, we analyzed mRNA expression of PON1 as well as other members of the paraoxonase family, PON2 and PON3, in human cataractous lens samples. Our results indicate that only PON1 is expressed at the gene and protein levels in human lens tissues. We quantified MDA levels and measured PON1 (paraoxonase/arylesterase) enzymatic activities in subjects suffering from cataract due to aging and diabetes. Decreased PON1 activity was more pronounced in diabetic patients (p< 0.001) compared to senile subjects, which may be due to glycation and increased oxidative insult. To examine the structural alterations that occur in response to glycation, we constructed a three-dimensional model of PON1 and its glycated variant. Glycation at Lys70 and Lys75 is predicted to cause hindrance in binding of substrate to the active site of the enzyme.