PON1 activity and total oxidant status in patients with active pulmonary tuberculosis

Oxidative stress and anti-oxidant status in children with sepsis

BACKGROUND

Sepsis is a life-threating cause in childhood ages. The recognition and treatment early are significant for decreasing mortality. Sepsis has many factors and various biomarkers function in the pathogenesis, the stress indicators oxidants increased and antioxidants decreased. The objective of our study was to investigate the levels of thiol disulfides with and without sepsis in a pediatric intensive care unit (PICU).

MATERIALS AND METHODS

A cohort study was conducted between October 2022 and March 2023 at the PICU, comprising 64 with sepsis and 62 children without sepsis. Blood samples from sepsis and the control group were collected and centrifuged. Subsequently, the samples were stored at -80 °C until the day of the experiment. Once the requisite number of patients had been enrolled, the thiol-disulfide values in the collected samples were analysed in accordance with the ELISA kit method.

RESULTS

The research parameters investigated, namely total oxidant status, plasma 8-OHdG, total-native thiol and native/total thiol percent ratio, were found to be considerably elevated in the sepsis group in comparison to the control (p < 0.05). Furthermore, the oxidative stress parameters investigated (total antioxidant status, paraoxonase 1 activity, disulfide, disulfide/native thiol percent ratio, disulfide/total thiol percent ratio) were found to be significantly lower in the sepsis group than in control (p < 0.05).

CONCLUSIONS

In our study as well, we detected all antioxidant parameters are low and oxidant parameters are statistically significantly higher in sepsis. Our study posits that thiol-disulfide levels have the potential to serve as a diagnostic tool in conjunction with traditional established biomarkers of inflammation in critically ill children in the PICU who are being treated for sepsis.

CLINICAL TRIAL REGISTRATION

Not applicable.

Paraoxonase-1: How a xenobiotic detoxifying enzyme has become an actor in the pathophysiology of infectious diseases and cancer

Both infectious and non-infectious diseases can share common molecular mechanisms, including oxidative stress and inflammation. External factors, such as bacterial or viral infections, excessive calorie intake, inadequate nutrients, or environmental factors, can cause metabolic disorders, resulting in an imbalance between free radical production and natural antioxidant systems. These factors may lead to the production of free radicals that can oxidize lipids, proteins, and nucleic acids, causing metabolic alterations that influence the pathogenesis of the disease. The relationship between oxidation and inflammation is crucial, as they both contribute to the development of cellular pathology. Paraoxonase 1 (PON1) is a vital enzyme in regulating these processes. PON1 is an enzyme that is bound to high-density lipoproteins and protects the organism against oxidative stress and toxic substances. It breaks down lipid peroxides in lipoproteins and cells, enhances the protection of high-density lipoproteins against different infectious agents, and is a critical component of the innate immune system. Impaired PON1 function can affect cellular homeostasis pathways and cause metabolically driven chronic inflammatory states. Therefore, understanding these relationships can help to improve treatments and identify new therapeutic targets. This review also examines the advantages and disadvantages of measuring serum PON1 levels in clinical settings, providing insight into the potential clinical use of this enzyme.

On the Role of Paraoxonase-1 and Chemokine Ligand 2 (C-C motif) in Metabolic Alterations Linked to Inflammation and Disease. A 2021 Update

Infectious and many non-infectious diseases share common molecular mechanisms. Among them, oxidative stress and the subsequent inflammatory reaction are of particular note. Metabolic disorders induced by external agents, be they bacterial or viral pathogens, excessive calorie intake, poor-quality nutrients, or environmental factors produce an imbalance between the production of free radicals and endogenous antioxidant systems; the consequence being the oxidation of lipids, proteins, and nucleic acids. Oxidation and inflammation are closely related, and whether oxidative stress and inflammation represent the causes or consequences of cellular pathology, both produce metabolic alterations that influence the pathogenesis of the disease. In this review, we highlight two key molecules in the regulation of these processes: Paraoxonase-1 (PON1) and chemokine (C-C motif) ligand 2 (CCL2). PON1 is an enzyme bound to high-density lipoproteins. It breaks down lipid peroxides in lipoproteins and cells, participates in the protection conferred by HDL against different infectious agents, and is considered part of the innate immune system. With PON1 deficiency, CCL2 production increases, inducing migration and infiltration of immune cells in target tissues and disturbing normal metabolic function. This disruption involves pathways controlling cellular homeostasis as well as metabolically-driven chronic inflammatory states. Hence, an understanding of these relationships would help improve treatments and, as well, identify new therapeutic targets.

Spectrophotometric assays for evaluation of Reactive Oxygen Species (ROS) in serum: general concepts and applications in dogs and humans

Reactive oxygen species (ROS) are reactive compounds derived from oxygen. In biological systems, an excessive amount of ROS can cause oxidative damage to biological macromolecules being involved in different diseases. Several assays have been developed in the last 30 years for ROS evaluation. The objective of this article will be to provide an update about the spectrophotometric methods currently used in the assessment of ROS in serum. The chemical basis of four different techniques will be reviewed, and examples of their possible applications will be provided. A particular emphasis about the practical applications of these assays in the dog will be made, but selected information about their use in humans will also be presented for comparative purposes, following a One-Health approach. The information about the spectrophotometric assays presented in this paper should be interpreted with caution once limited information about them is available yet, and further studies should be performed to clarify what they measure and their clinical application. Ideally, when applied to evaluate a sample's oxidative status, they should be incorporated in a panel of analytes where other oxidants, antioxidants, and biomarkers of inflammation were also included.

Oxidative stress and phenotype frequencies of paraoxonase-1 in teratozoospermia

Oxidative stress causes infertility in men by affecting especially sperm morphology. The aim of the study was to examine the frequencies of paraoxonase-1 (PON1) phenotypes and the serum PON1, arylesterase, total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index, catalase and thiol levels in teratozoospermic infertile men and normospermic fertile men. The study included 184 teratozoospermic infertile men and 72 normospermic fertile men. The double substrate method was employed to determine the phenotype distribution of PON1. The evaluation of sperm morphology was made in accordance with the Kruger's criteria. TAS, catalase and thiol levels were determined to be significantly lower in teratozoospermic infertile men compared to normospermic fertile men. A significant change was not observed in the levels of TOS, PON1 and arylesterase. There was a positive correlation between catalase and thiol levels and sperm morphology. While there were significantly more teratozoospermic men with AA phenotypes compared to normospermic men, there were significantly more persons with AB and BB phenotypes in normospermic men than in teratozoospermic men. As far as we know, such a study was conducted for the first time and suggests that PON1 phenotypic distribution may play a significant role in sterile males because of impaired sperm morphology.

Associations of lipoprotein subclasses and oxidative stress status in pulmonary and pulmonary plus extrapulmonary sarcoidosis

Background: Sarcoidosis is an inflammatory disease with pulmonary and extrapulmonary manifestations. In such pathologic conditions, increased oxidative stress and rearrangement of high-density lipoprotein (HDL) and low-density lipoprotein (LDL) may occur. Objective: This study evaluated association of oxidative stress and lipoprotein subclasses in severe forms of pulmonary and pulmonary plus extrapulmonary sarcoidosis. Methods: Lipid parameters, LDL and HDL subclass distributions, high-sensitivity C-reactive protein (hsCRP), serum amyloid A (SAA), paraoxonase 1 (PON1), malondialdehyde (MDA), total-oxidant status (TOS), sulfhydryl (SH) groups, pro-oxidant anti-oxidant balance (PAB) were determined in 77 patients (53 isolated pulmonary and 24 pulmonary plus extrapulmonary) and 139 controls. Results: Both pulmonary and extrapulmonary sarcoidosis patients had significantly higher levels of triglycerides and TOS (P<0.05) and more LDL II, LDL III, LDL IVA particles (P<0.01), but lower HDL size, SH groups (P<0.001), PON1 activity and less LDL I subclasses (P<0.05) than controls. In isolated pulmonary disease, HDL-cholesterol (P<0.01) was significantly lower whereas proportions of HDL 3a and PAB were significantly higher (P<0.05) when compared with the control group. PON1 was significantly higher in pulmonary than in combined pulmonary-extrapulmonary disease (P<0.05). In pulmonary sarcoidosis, TOS and PON1 correlated significantly with small-sized HDL particles (P<0.05). Conclusions: Both patient groups were characterized by adverse lipoprotein profile and elevated oxidative stress. In isolated pulmonary group significant associations of oxidative stress and HDL particles distribution was demonstrated. Pulmonary sarcoidosis was associated with higher PON1 activity and rearrangement of LDL particles did not depend on disease localization. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 198-205).

Effects of propolis, caffeic acid phenethyl ester, and pollen on renal injury in hypertensive rat: An experimental and theoretical approach

The objective of this study was to evaluate the antioxidant effects of propolis, caffeic acid phenethyl ester (CAPE; active compound in propolis), and pollen on biochemical oxidative stress biomarkers in rat kidney tissue inhibited by Nω -nitro-L-arginine methyl ester (L-NAME). The biomarkers evaluated were paraoxonase (PON1), oxidative stress index (OSI), total antioxidant status (TAS), total oxidant status (TOS), asymmetric dimethylarginine (ADMA), and nuclear factor kappa B (NF-κB). TAS levels and PON1 activity were significantly decreased in kidney tissue samples in the L-NAME-treated group (P < 0.05). The levels of TAS and PONI were higher in the L-NAME plus propolis, CAPE, and pollen groups compared with the L-NAME-treated group. TOS, ADMA, and NF-κB levels were significantly increased in the kidney tissue samples of the L-NAME-treated group (P < 0.05). However, these parameters were significantly lower in the L-NAME plus propolis, CAPE, and pollen groups (P < 0.05) compared with rats administered L-NAME alone (P < 0.05). Furthermore, the binding energy of CAPE within catalytic domain of glutathione reductase (GR) enzyme as well as its inhibitory mechanism was determined using molecular modeling approaches. In conclusion, experimental and theoretical data suggested that oxidative alterations occurring in the kidney tissue of chronic hypertensive rats may be prevented via active compound of propolis, CAPE administration.

Paraoxonases and infectious diseases

The paraoxonases (PON1, PON2 and PON3) are an enzyme family with a high structural homology. All of them have lactonase activity and degrade lipid peroxides in lipoproteins and cells. As such, they play a role in protection against oxidation and inflammation. Infectious diseases are often associated with oxidative stress and an inflammatory response. Infection and inflammation trigger a cascade of reactions in the host, known as the acute-phase response. This response is associated with dramatic changes in serum proteins and lipoproteins, including a decrease in serum PON1 activity. These alterations have clinical consequences for the infected patient, including an increased risk for cardiovascular diseases, and an impaired protection against the formation of antibiotic-resistant bacterial biofilms. Several studies have investigated the value of serum PON1 measurement as a biomarker of the infection process. Low serum PON1 activities are associated with poor survival in patients with severe sepsis. In addition, preliminary studies suggest that serum PON1 concentration and/or enzyme activity may be useful as markers of acute concomitant infection in patients with an indwelling central venous catheter. Investigating the associations between paraoxonases and infectious diseases is a recent, and productive, line of research.

Total antioxidant, total oxidant and serum paraoxonase levels according to lipid administration method in parenterally fed premature infants

OBJECTIVE

The aim of our study was to determine whether lipid solutions delivered separately or in mixture with total parenteral nutrition (TPN) solutions effect the balance between oxidant and antioxidant levels in premature infants.

METHODS

A total of 60 preterm newborns who were delivered at their 30-34 gestational weeks and received TPN were included in the study. Premature newborns were randomized into two groups based on the delivery method of the lipid solution, separately (Group 1) or in mixture with TPN solutions (Group 2). Total antioxidant status (TAS), total oxidant status (TOS) and paraoxonase (PON-1) levels were analyzed in both blood samples, and oxidative stress index (OSI) was also calculated.

RESULTS

Thirty cases from both groups were included in the study. Statistically significant decrease in the level of TAS and increase in the level of PON-1 were detected at 72 h of TPN therapy in both groups (p < 0.05). Statistically significant decrease in both TOS and OSI levels were observed in Group 2 (p < 0.05). In association with these findings, any statistically significant intergroup difference was not detected in both parameters regarding oxidant balance (p > 0.05).

CONCLUSION

Our study showed that according to lipid administration method any difference for oxidant-antioxidant balance was not detected.

Oxidative stress in otosclerosis

OBJECTIVES

Otosclerosis is a disease involving abnormal bone turnover in the human otic capsule that results in hearing loss. Several hypotheses have been suggested for the etiopathogenesis of otosclerosis; however, its etiology remains unclear.

METHODS

This study evaluated the correlation between otosclerosis and levels of paraoxonase-1 (PON1), arylesterase, total antioxidant status, total oxidant status (TOS), oxidative stress index (OSI), total sulfhydryl (-SH) groups, lipid hydroperoxide, and ceruloplasmin in the serum of otosclerosis patients and healthy subjects with respect to oxidative stress.

RESULTS

In our study, TOS and OSI levels were higher in the otosclerosis patients than in the controls. The PON1 levels showed that oxidative stress was severe, and as a result, antioxidants were consumed and depleted.

DISCUSSION

When an imbalance between oxygen free radical production and antioxidative defense mechanisms occurs, reactive oxygen species levels may increase, which in turn may damage cells and tissues through the peroxidation of phospholipid membrane structures. The body initially responds with increased antioxidant production, but if the oxidative stress is severe, decreased antioxidant levels may result. This study reports expression levels of oxidative stress species in otosclerosis patients.

Respiratory effects of sulfur mustard exposure, similarities and differences with asthma and COPD

CONTEXT

Previous research has found relationships between sulfur mustard (SM) toxicity and its adverse effects.

OBJECTIVE

SM is highly toxic to the respiratory system, leading to hacking cough, rhinorrheachest tightness, acute pharyngitis and laryngitis, chronic bronchitis and lung fibrosis. In this review, based on the scientific literature, we provide an updated summary of information on SM exposures and their differences with asthma and COPD.

METHOD

Information of this review was obtained by searching Medline/PubMed, ScienceDirect, Scopus, Google Scholar, ISI Web of Knowledge and Chemical Abstracts.

RESULTS

SM exposure can decrease pulmonary function tests (PFTs) values. In addition, inflammatory cell accumulation in the respiratory tract and increased expression of some pro-inflammatory cytokines including tumor necrosis factor-α (TNFα), IL-1a, IL-1β, and reactive oxygen radicals due to SM exposure have been shown. Matrix metalloproteinase (MMP) which degrade extracellular matrix proteins, contributing to inflammatory cell recruitment, tissue injury and fibrosis are also up-regulated in the lung after SM exposure. In the lung, SM exposure also can cause serious pathological changes including airway inflammation, parenchymal tissue destruction and airway obstruction which can lead to asthma or chronic obstructive pulmonary disease (COPD). Following SM poisoning, DNA damage, apoptosis and autophagy are observed in the lung along with the increased expression of activated caspases and DNA repair enzymes.

CONCLUSION

In the present article, respiratory symptoms, changes in PFTs, lung pathology and lung inflammation due to SM exposure and the similarities and differences between them and those observed in asthma and COPD were reviewed.

Total antioxidant and total oxidant states, and serum paraoxonase-1 in neonatal sepsis

BACKGROUND

Paraoxonase-1 (PON-1) is an enzyme with a glycoprotein structure that depends on calcium and which is located in serum high-density lipoprotein (HDL). The aim of this study was to evaluate PON-1, and oxidant/antioxidant state, before and after treatment for neonatal sepsis, and to determine the usability of PON-1 in neonatal sepsis treatment.

METHODS

A total of 35 neonatal sepsis patients and 35 healthy controls were included in the study. Activity of PON-1, total oxidant state (TOS) and total antioxidant state (TAS) were measured and oxidative stress index (OSI) was calculated.

RESULTS

In the neonatal sepsis patients, pre-treatment TAS, TOS and OSI were significantly higher than the post-treatment levels (P < 0.0001, P < 0.0001 and P < 0.0001, respectively), and PON-1 was significantly lower (P < 0.0001). Similarly, pre-treatment TAS, TOS and OSI in the sepsis group were also significantly higher than in the control group (P < 0.0001, P < 0.0001 and P < 0.0001, respectively) and PON-1 was significantly lower (P < 0.0001). Post-treatment TAS in the sepsis group was significantly higher than in the control group (P = 0.009), whereas post-treatment TOS, OSI and PON-1 in the sepsis group were not significantly different to the control group (P = 0.078, P = 0.597 and P = 0.086, respectively).

CONCLUSION

Low serum PON-1 was found in neonatal sepsis. Serum PON-1 is thought to be a useful biomarker to evaluate the effectiveness of treatment and recovery in neonatal sepsis.

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.

Discovery and identification of serum potential biomarkers for pulmonary tuberculosis using iTRAQ-coupled two-dimensional LC-MS/MS

Pulmonary tuberculosis (TB) caused by Mycobacterium tuberculosis is a chronic disease. Currently, there are no sufficiently validated biomarkers for early diagnosis of TB infection. In this study, a panel of potential serum biomarkers was identified between patients with pulmonary TB and healthy controls by using iTRAQ-coupled 2D LC-MS/MS technique. Among 100 differentially expressed proteins screened, 45 proteins were upregulated (>1.25-fold at p < 0.05) and 55 proteins were downregulated (<0.8-fold at p < 0.05) in the TB serum. Bioinformatics analysis revealed that the differentially expressed proteins were related to the response to stimulus, the metabolic and immune system processes. The significantly differential expression of apolipoprotein CII (APOCII), CD5 antigen-like (CD5L), hyaluronan-binding protein 2 (HABP2), and retinol-binding protein 4 (RBP4) was further confirmed using immunoblotting and ELISA analysis. By forward stepwise multivariate regression analysis, a panel of serum biomarkers including APOCII, CD5L, and RBP4 was obtained to form the disease diagnostic model. The receiver operation characteristic curve of the diagnostic model was 0.98 (sensitivity = 93.42%, specificity = 92.86%). In conclusion, APOCII, CD5L, HABP2, and RBP4 may be potential protein biomarkers of pulmonary TB. Our research provides useful data for early diagnosis of TB.

Serum paraoxonase 1 activity and oxidative stress in pediatric patients with pulmonary tuberculosis

OBJECTIVES

The aim of this study was to determine the oxidative stress and paraoxonase 1 (PON1) levels in children with pulmonary tuberculosis (TB) compared to healthy controls, and to examine the association of demographical with oxidative stress.

SUBJECTS AND METHODS

Forty children diagnosed with pulmonary TB and 40 age- and gender-matched healthy controls were enrolled in the study. Serum total antioxidant status (TAS), total oxidant status (TOS) and PON1 levels were measured. The oxidative stress index (OSI) was calculated to indicate the degree of oxidative stress.

RESULTS

The TAS levels were lower (1.73 ± 0.5 vs. 2.54 ± 1.2 μmol Trolox Eq/l) while TOS levels were significantly higher (26.9 ± 14.4 vs. 13.4 ± 7.7 μmol H2O2 Eq/l) in the TB group than in the controls (p < 0.001). The OSI was significantly higher in the TB group than in the controls (21.2 ± 5.1 vs. 6.5 ± 4.9 units, p = 0.006). Serum PON1 levels were significantly lower in the TB group than in the controls (14.2 ± 13.2 vs. 28.4 ± 17.3 U/l, p < 0.001). The lower PON1 levels correlated with TAS and OSI levels but not with anthropometric parameters (r = 0.264, p = 0.018 and r = -0.255, p = 0.023, respectively).

CONCLUSION

The TOS and OSI levels were higher and the TAS and PON1 levels were lower in pediatric patients with pulmonary TB when compared to healthy controls. This indicates greater oxidative stress in the patients.

Assessing the relationship of paraoxonase-1 Q192R polymorphisms and the severity of lung disease in SM-exposed patients

Late respiratory complications in patients suffering from pulmonary lesions due to sulfur mustard (SM) gas are asthma, chronic obstructive pulmonary disease and bronchiectasis. Recently PON1 antioxidant activity draws attention as the enzyme which prevents the oxidation of lipoproteins during oxidative stress. In this study we aimed to investigate PON1 192 polymorphisms and paraoxonase and arylesterase activity in the serum of SM-exposed lung disease patients. Also, we examined the detection of PON1 and apoA1 proteins in BAL fluid. 101 male patients were included who were categorized to three groups of mild, moderate and severe suffering from pulmonary lesions due to SM. Significant reduction in paraoxonase activity [Healthy: 412.46 ± 89.1 U/L, Severe: 89.66 ± 20.7 U/L] (p < 0.0001) and arylesterase activity [Healthy: 25826.4 ± 4425.23 U/L, Severe: 16760.43 ± 3814.9 U/L] (p < 0.0001) with increase in severity of disease was demonstrated statistically. With respect to the distribution of the PON1 polymorphism, the RR genotype was more frequent in severe patients [37.2%] than healthy group [10%] (p < 0.05) and no significant regression was found between genotype and PON1 activity. On the other hand, the results of PON1 and apoA1 detection illustrated that only apoA1 protein was found in BAL fluid. According to our findings it seems that increase in the stress oxidative in chemical injured veterans with pulmonary complications comes with reduction in PON1 enzyme activity and appearance of RR genotype rises up with the increase in disease severity. Since a significant correlation between enzyme activity and genotype was not observed altering these two variables with each other requires more studies.

Effects of paraoxonase 1 activity and gene polymorphisms on long-term pulmonary complications of sulfur mustard-exposed veterans

Sulfur mustard (SM) is an alkylating agent with prolonged adverse effects. The antioxidant paraoxonase 1 (PON1), an endogenous free radical scavenger, plays a protective role against oxidative stress. The possible roles of oxidative stress in the pathogenesis of SM, together with the antioxidant activity of PON1, are enough to warrant the analysis of PON1 polymorphisms and allelic variants in incapacitated veterans. PON1 55 L/M and 192 Q/R polymorphisms were assayed in 289 male veterans with severe pulmonary conditions, who were exposed to SM 20-25 years ago, and 66 gender-, age- and ethnic-matched healthy controls. As we showed previously the PON1 activity decreased significantly in veterans. However, PON1 55 L/M and 192 Q/R genotype distributions were not significantly different between the veterans and the controls. R and L allele carriers have also significantly higher basal and salt-stimulated PON1 activity than Q and M allele carriers. Paraoxonase and arylesterase activities in individuals with the QQ+(MM or LM) genotype were significantly lower than those with the (RR or QR)+LL genotype. Furthermore, basal and salt-stimulated paraoxonase activity in veterans with the (RR or QR)+LL genotype was significantly lower than that in the controls. A positive correlation has been determined between serum PON1 activity and pulmonary function test in QR/LL genotypes. Some of the veterans with RR+QR genotypes have also shown a novel missense change of Asn227Ser in exon 6 of the enzyme. This substitution is close to the binding domain of PON1 and so modifies enzyme activity.

The Past and Present of Paraoxonase Enzyme: Its Role in the Cardiovascular System and Some Diseases

Although paraoxonase is synthesized in many tissues including the heart, colon, kidneys, lungs, small intestines and brain, its major locus of synthesis is the liver. PON1 is in close association with apolipoproteins and protects LDL against oxidation. It was reported that PON1 quantities dropped to 40 times lower than normal in cardiovascular diseases and diseases like diabetes, ulcerative colitis, Crohn's disease, chronic renal failure, SLE, Behcet's disease, cancer, hepatitis B, obesity, metabolic syndrome, Alzheimer's and dementia. It is speculated that the concerning decline in serum PON1 amount results from single nucleotide polymorphism in the coding (Q192R, L55M) and promoter (T-108C) sites of the PON1 gene. Additionally, circulating amounts of PON1 are affected by vitamins, antioxidants, fatty acids, dietary factors, drugs, age and lifestyle. This collection attempts to review and examine the past and present studies of paraoxonase and its relation with the cardiovascular system and some relevant diseases.

Oxidative stress in chronic otitis media

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

Paraoxonase and arylesterase activities in children with iron deficiency anemia and vitamin B12 deficiency anemia

Paraoxonase-1 is an esterase enzyme and it has 3 types of activity, namely paraoxonase, arylesterase, and diazoxonase. It has been reported that paraoxonase-1 deficiency is related to increased susceptibility to development of atherosclerosis and cardiovascular disease. The aim of this study was to investigate serum paraoxonase and arylesterase activities in children with iron deficiency anemia and vitamin B(12) deficiency anemia. Thirty children with iron deficiency anemia, 30 children with vitamin B(12) deficiency anemia, and 40 healthy children aged 6 months to 6 years were enrolled in this study. Serum paraoxonase and arylesterase activities were measured with a spectrophotometer by using commercially available kits. Mean paraoxonase and arylesterase activities in vitamin B(12) deficiency anemia group (103 ± 73 and 102 ± 41 U/L, respectively) were significantly lower than mean activities of control group (188 ± 100 and 147 ± 34 U/L, respectively; P < .001 for both) and iron deficiency anemia group (165 ± 103 and 138 ± 39 U/L, respectively; P < .05, P < .001), whereas there were no significant differences between iron deficiency anemia and control groups (P > .05). Paraoxonase and arylesterase activities significantly increased after treatment with vitamin B(12) in vitamin B(12) deficiency anemia; however, there were no significant changes in the activities of these enzymes after iron treatment in iron deficiency anemia group. Important correlations were found between vitamin B(12) levels and both paraoxonase and arylesterase activities (r = .367, P < .001; r = .445, P < .001). Our results suggest that vitamin B(12) deficiency anemia causes important reductions in paraoxonase and arylesterase activities, and after vitamin B(12) therapy the activities of these enzymes returned to near-normal levels.

Investigation of heavy metal effects on immobilized paraoxanase by glutaraldehyde

Serum paraoxonase 1 (PON1) was purified from bovine serum using hydrophobic interaction chromotography on Sepharose 4B-coupled l-tyrosine 1-naphthylamine gel, and monitored by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Paraoxonase enzyme was immobilized using different ratios of glutaraldehyde and the maximum activity was observed with 7% glutaraldehyde. The effects of inhibition by Mn(+2), Co(+2) and Cu(+2) heavy metals on the immobilized and free enzyme activities were studied. At the optimum pH and temperature, the K(m) and V(max) kinetic values for bovine serum paraoxonase and immobilized paraoxonase towards paraoxon substrate were determined as 0.296 × 10(-3) M & 37.04 EU vs. 0.727-10(-3) M & 36.36 EU, respectively.

Paraoxonase and arylesterase activity and total oxidative/anti-oxidative status in patients with chronic adenotonsillitis

OBJECTIVES

The aim of this study was to investigate serum paraoxonase, arylesterase activities along with determination of oxidative status via measurement of total oxidant status (TOS), total antioxidant status (TAS) and oxidative stress index (OSI) in children with recurrent adenotonsillitis during pre- and post-adenotonsillectomy period and to compare results with data from healthy subjects.

METHODS

We performed a prospective controlled trial on adenoidectomy and/or tonsillectomy patients. A total of 47 subjects, including 22 patients with recurrent adenotonsillitis and 25 healthy controls were enrolled in this study. Peripheral venous blood samples were taken from patients before adenotonsillectomy and a second sample was obtained in first month postoperatively. In the control group, blood samples from healthy volunteers were collected for one time only. Serum paraoxonase, arylesterase activities, TOS, TAS and OSI levels were measured.

RESULTS

Paraoxonase, arylesterase activity, TAS and TOS levels were significantly higher in preoperative group compared to control group (P<0.001, P=0.003, 0.003 and 0.005, respectively). However, OSI level was similar in preoperative group compared to control group (P=0.25). In the post-operative group, paraoxonase, arylesterase activities, TAS and OSI levels were lower as compared to preoperative group but differences were statistically insignificant (P=0.483, 0.265, 0.149 and 0.090, respectively). TOS level in post-operative group was significantly lower than the preoperative group (P<0.001). In the post-operative group, paraoxonase and arylesterase activities were significantly higher as compared to control group (P=0.004 and 0.02, respectively). TOS and OSI levels were significantly lower in post-operative group compared to control group (P=0.001 and 0.02, respectively). However, TAS was similar between post-operative and control groups (P=0.464).

CONCLUSIONS

Based on data obtained from this study, we may state that paraoxonase, arylesterase activities with TAS, TOS and OSI levels of patients with chronic adenotonsillitis shows alterations due to oxidant/antioxidant imbalance induced by frequent infections.

Atherogenic changes of low-density lipoprotein susceptibility to oxidation, and antioxidant enzymes in pulmonary tuberculosis

OBJECTIVES

Tuberculosis remains one of the most common infectious diseases and a leading cause of mortality world wide. There is some evidence for the possible involvement of Mycobacterium tuberculosis in atherosclerosis. We aim to investigate total antioxidant capacity (TAC), red blood cell superoxide dismutase (SOD) activity, whole blood glutathione peroxidase (GPX) activity, low-density lipoprotein (LDL) susceptibility to oxidation, and malondialdehyde (MDA) levels in patients with pulmonary tuberculosis (PTB).

METHODS

Forty-five males with active PTB (case group) and 45 healthy age-matched males (control group) were enrolled in the study. TAC, SOD and GPX activities were determined by commercial ELISA kits. MDA levels were measured using the thiobarbituric acid method. LDL susceptibility to oxidation was assessed by measuring lag phase duration.

RESULTS

TAC, SOD and GPX activities, and lag phase duration in the case group were significantly lower than the control group (p=.002, p=.004, p=.008, and p=.004, respectively; independent), while the MDA levels was higher in case group (p=.024).

CONCLUSIONS

Our findings suggest a higher susceptibility of LDL to oxidation and higher levels of lipid peroxidation, and therefore, a possible higher risk of atherosclerosis in patients with PTB.

Serum paraoxonase and arylesterase activities in patients with pulmonary tuberculosis

BACKGROUND

The aim of the present study was to determine serum paraoxonase and arylesterase activities in tuberculosis, nontuberculosis pulmonary disease and healthy subjects.

MATERIALS AND METHODS

In this case-control study we determined the serum paraoxonase and arylesterase activities in 36 patients with pulmonary tuberculosis, 38 nontuberculosis pulmonary disease and 49 healthy controls.

RESULTS

The results showed that serum paraoxonase (PON) activity was significantly lower in patients with pulmonary tuberculosis (61.10±51.62IU/L) than healthy controls (98.79±68.79IU/L) (p<0.05). In addition we found that the level of PON activity was significantly lower in patients with nontuberculosis pulmonary disease (67.49±47.88IU/L) than normal individuals (p<0.05). There was no significant differences regarding PON activity between patients with pulmonary tuberculosis and nontuberculosis pulmonary disease (p>0.05). The arylesterase activity was significantly lower in patients with pulmonary tuberculosis than nontuberculosis pulmonary disease and normal subjects (p<0.05).

DISCUSSION

The lower paraoxonase and aryesterase activities in pulmonary tuberculosis patients compared to healthy subjects might be due to imbalance of oxidant/antioxidant systems in pulmonary tuberculosis patients which needs more clarification.