Plasma Thiol Levels Research Articles

Neutrophils as a source of factors that increase the length of the inflammatory phase of wound healing in patients with type 2 diabetes mellitus

Oxidative stress and neutrophil activation leading to an increase in myeloperoxidase (MPO), elastase and neutrophil extracellular trap (NET) levels in blood are considered as pathogenic mechanisms responsible for the development of extremity damage in people with type 2 diabetes mellitus (T2DM). The aim of this study was to analyze the relationship between factors, associated with neutrophil activation, and the length of the initial phase of wound healing (the inflammatory phase) in T2DM patients. Patients were divided retrospectively into three groups depending on the damage extent: group 1 (wound on toe) < group 2 (wound on foot) < group 3 (wound on lower leg). Compared to the control group (healthy volunteers), T2DM patients at admission to hospital had significantly (p<0.05) increased levels of blood glucose and glycated hemoglobin (groups 1-3), ESR (groups 1 and 3), blood neutrophil count (groups 2 and 3), plasma MPO concentration (groups 1-3) and blood NET concentration (group 3) and decreased levels of plasma thiols (groups 1-3) and erythrocyte glutathione peroxidase activity (groups 2 and 3). The length of hospital stay after surgical procedures corresponded to the length of the inflammatory phase of the wound healing process and correlated with the number of blood neutrophils in patients before surgery (r=0.72, p<0.05). Leukocytic intoxication index depended on wound area (r=0.59, p<0.05), and it was significantly higher for groups 2 and 3 compared to the control group and group 1. The neutrophil count before surgery in T2DM patients with damage in the lower extremities correlated with the length of the inflammatory phase of wound healing. The correlation found can be attributed to an increase in extracellular MPO and NETs, which, in its turn, results from the activation and degranulation of neutrophils and netosis. Thus, the duration of the inflammatory phase of wound healing depends on specific aspects of systemic inflammation increasing oxidative/halogenative stress and intoxication.

Thiol/disulfide homeostasis in patients with ankylosing spondylitis.

Ankylosing spondylitis (AS) is a chronic inflammatory disease. In many inflammatory diseases, increased production of pro-inflammatory cytokines is associated with an increase in oxidative stress mediators. Thiol/disulfide homeostasis is a marker for oxidative stress. The aim of this study was to examine the dynamic thiol/disulfide homeostasis in AS. Sixty-nine patients with AS and 60 age- and sex-matched controls were included in the study. The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and visual analogue scale (VAS) were used to determine the disease activity. Native thiol, total thiol, and disulfide levels were measured with a novel automated method recently described by Erel and Neselioglu. The aforementioned method is also optionally manual spectrophotometric assay. The total thiol levels were significantly lower in the AS group compared with the control group (p = 0.03). When the patients were divided into active (n = 35) and inactive (n = 34) subgroups using BASDAI scores, the native plasma thiol and total thiol levels were significantly lower in the active AS patients compared to the inactive AS patients (p = 0.02, p = 0.03 respectively). There was a negative correlation between the plasma native thiol levels and VAS, BASDAI scores. Thiol/disulfide homeostasis may be used for elucidating the effects of oxidative stress in AS. Understanding the role of thiol/disulfide homeostasis in AS might provide new therapeutic intervention strategies for patients.

Plasma thiols and thiol-disulfide homeostasis in patients with isolated coronary artery ectasia

Background and aimsThiol/disulfide homeostasis has an important role in the antioxidant defense system. Oxidative stress may contribute to the pathogenesis of coronary artery ectasia. The aim of this study was to evaluate plasma thiol levels and thiol/disulfide homeostasis in patients with isolated coronary artery ectasia. MethodsForty-one patients with isolated coronary artery ectasia and 72 patients with normal coronary arteries were included in the study. Markis classification and number of ectatic coronary arteries were recorded. Plasma total thiol levels, native thiol levels and disulfide levels were measured. Thiol/disulfide homeostasis was appraised by calculating thiol/disulfide ratio. ResultsPlasma native thiol levels were significantly lower (336.9 (252.9–374.1) vs. 353.1 (327.0–380.0), p = 0.041) and disulfide levels were significantly higher (18.9 ± 6.3 vs. 16.6 ± 3.4, p = 0.014) in patients with coronary artery ectasia than control patients. Both native thiol/disulfide and total thiol/disulfide ratio was significantly lower in the coronary artery ectasia group (p < 0.001). Multivariate logistic regression analysis revealed that native thiol levels, disulfide levels and native thiol/disulfide ratio were independently associated with the presence of coronary artery ectasia. Thiol/disulfide ratio was not different according to number of ectatic coronary arteries and there was no association between thiol/disulfide ratio and Markis classification. ConclusionsPlasma thiol/disulfide homeostasis is altered in patients with coronary artery ectasia.

The Use of Thiol/Disulfide as a Novel Marker in Premature Ovarian Failure

The study aimed to compare the dynamic thiol/disulfide homeostasis between patients with premature ovarian failure (POF) and healthy women. A total of 77 women, 40 POF and 37 healthy controls, were recruited from a university hospital between December 2013 and June 2015. Blood samples were taken from patients to evaluate follicle stimulating hormone (FSH), luteinizing hormone, estradiol and thiol/disulfide levels. A new, fully automated method was used to measure plasma thiol, total thiol and disulfide levels. Disulfide levels, disulfide/native thiol and disulfide/total thiol ratios were significantly increased, native thiol/total thiol levels were significantly decreased in POF patients compared to controls (p < 0.001). FSH was negatively correlated with native thiol and native thiol/total thiol levels and positively with disulfide, disulfide/native thiol, and disulfide/total thiol levels. This is the first study demonstrating the thiol/disulfide homeostasis in women with POF and may help us understanding the pathophysiology.

Comparative Assessment of the Effects of Hatha Yoga and Physical Exercise on Biochemical Functions in Perimenopausal Women.

Menopause is a transitional phase in which some women experience discomfort, while others may exhibit variety of symptoms. The power of yoga therapy in relieving stress, enhancing health, improving fitness and managing symptoms of a variety of disorders is remarkable. The current study was designed to study the effect of Hatha yoga therapy and regular physical exercise on the Fasting Blood Sugar (FBS), Glycated Haemoglobin (GHB), Thyroid Stimulating Hormone (TSH), serum cortisol and total plasma thiol levels in perimenopausal women. The study included 216 women with perimenopausal symptoms, 111 in test group (Hatha yoga) and 105 in control group (physical exercise). The duration of intervention was 45 minutes every day for 12 weeks. Blood samples were collected in the pre and post intervention period. Statistical significance was defined as p<0.05. FBS and GHB (p≤0.05) showed a significant decrease after yoga therapy. Cortisol levels significantly (p≤0.05) increased in the post intervention period in the control group. However, it is maintained in the test group between the two time periods. The total plasma thiols level showed a rise in the post intervention period, significant rise (p≤0.001) in control group but not significant in the test group. The TSH levels were not altered in any group. It is concluded that exercise helps in maintaining the sugar levels but calming effects of yoga practice is important in relieving stress and enhancing health in perimenopausal women.

The association between plasma thiol levels and left ventricular diastolic dysfunction in patient with hypertension

The balance of oxidant and antioxidant status plays an important role in the left ventricular diastolic dysfunction (LVDD) in patients with hypertension (HT). Thiol is an important part of antioxidant system in the body. The aim of this study was to investigate the relationship between plasma thiol levels and LVDD in patients with HT. A total of 138 patients with newly diagnosed essential hypertensive and 20 age-gender matched subjects as control group enrolled in the study. After echocardiographic assessment, the hypertensive patients were divided into three groups: Group 1: without LVDD (n = 41); group 2: with LVDD grade 1 (n = 57); and group 3: with LVDD grade 2 (n = 40). Plasma thiol, lipid and glucose levels were measured in all subjects. Plasma thiol levels were significantly different between the groups (all of p < 0.05). While the lowest thiol level was in the group 3, the highest level was in the control group. The presence of LVDD was correlated with age, systolic and diastolic blood pressure, thiol levels, and history of coronary artery disease and hyperlipidemia (all of p < 0.05). Age and thiol were however independent predictors of LVDD in multivariate analyses (β = 0.318, p < 0.001, and β = − 0.314, p < 0.001, respectively). ROC-curve analysis revealed that thiol levels over 163 μmol/L predict LVDD in hypertensive patients with 75% sensitivity and 70% specificity (AUC = 0.783; 95% CI: 0.714–0.852). Plasma thiol is an independent predictor for the presence of LVDD. This suggests that thiol plays a role in the pathogenesis of diastolic function. Increased thiol levels may provide protection against the development of diastolic dysfunction.

Attention Deficit Hyperactivity Disorder and oxidative stress: A short term follow up study

In this study, we aimed to investigate total antioxidative status (TAS) and total oxidative status (TOS) of plasma and antioxidant enzymes such as paraoxonase (PON), stimulated paraoxonase (SPON), arylesterase (ARES) and thiols in plasma of children and adolescents with Attention Deficit Hyperactivity Disorder (ADHD). In the second step. this study aimed to reveal the possible effects of ADHD treatment on these parameters. Fifty-six patients with ADHD and 52 healthy controls were involved in this study. Venous blood samples were collected and oxidative and antioxidative parameter's were studied. In the second phase of the study, blood samples were taken from patients using medication. Pre-treatment oxidative stress index (OSI) values and the plasma TOS levels of the patients with ADHD were statistically higher than those of the control group. The plasma thiol levels of the patients with ADHD were significantly lower than the control group. The post-treatment plasma antioxidative parameter's levels were significantly higher than the pre-treatment levels. The post-treatment oxidative stress index value was significantly lower than the pre-treatment value. Therefore, oxidative metabolism was found to be impaired in children and adolescents with ADHD. It was also determined that methylphenidate repairs the oxidative balance by increasing antioxidant defence mechanisms.

Advanced oxidation protein products, total thiol levels and total oxidant/antioxidant status in patients with nash.

In this study we aim to evaluate the relationship of advanced oxidation protein products (AOPP), total thiol, total antioxidant status (TAS), total oxidant status (TOS) levels and oxidative stress index (OSI) in patients with nonalcoholic steatohepatitis (NASH). A total of 28 patients with NASH and 19 age-and-gender-matched healthy subjects were enrolled in the study as control group. Plasma AOPP and thiol levels were determined by spectrophotometric methods. Plasma TAS and TOS levels were measured using commercially available kits and OSI was calculated. Plasma AOPP (256.7 vs. 125.8 μmol/L) and TOS levels (8.9 vs. 5.9 μmol H2O2 equiv/L) were higher in patients with NASH than the controls (p<0.019 and p<0.041 respectively). Plasma total thiol levels (235.0 vs. 291.6 μmol/L) were lower in patients with NASH than the controls (p<0.001). TAS levels (1.14 vs. 1.14 mmol Trolox equiv/L) were not significantly different in patients with NASH than the controls (p>0.900). OSI values (8.0 vs. 5.5) were higher in patients with NASH than the controls (p<0.039). Our findings indicate that oxidative stress increases in patients with NASH as shown by increases in TOS level. We think effective antioxidant therapy to inhibit protein oxidation and also to increase of TAS and total thiol levels may be a therapeutic option in patients with NASH who have under increased oxidative stress.

Plasma thiols levels in Alzheimer's disease mice under diet-induced hyperhomocysteinemia: effect of S-adenosylmethionine and superoxide-dismutase supplementation.

Widely confirmed reports were published on association between hyperhomocysteinemia, B vitamin deficiency, oxidative stress, and amyloid-β in Alzheimer's disease (AD). Homocysteine, cysteine, cysteinylglycine and glutathione are metabolically interrelated thiols that may be potential indicators of health status and disease risk; they all participate in the metabolic pathway of homocysteine. Previous data obtained in one of our laboratories showed that B vitamin deficiency induced exacerbation of AD-like features in TgCRND8 AD mice; these effects were counteracted by S-adenosylmethionine (SAM) supplementation, through the modulation of DNA methylation and antioxidant pathways. Since the cellular response to oxidative stress typically involves alteration in thiols content, a rapid and sensitive HPLC method with fluorescence detection was here used to evaluate the effect of SAM and superoxide-dismutase (SOD) supplementation on thiols level in plasma, in TgCRND8 mice. The quantitative data obtained from HPLC analysis of mice plasma samples showed significant decrease of thiols level when the B vitamin deficient diet was supplemented with SAM + SOD and SOD alone, the latter showing the greatest effect. All these considerations point out the measurement of plasma thiols concentration as a powerful tool of relevance for all clinical purposes involving the evaluation of oxidative stress. The coupling of HPLC with fluorimetric detection, here used, provided a strong method sensitivity allowing thiols determination at very low levels.

Betulinic acid negates oxidative lung injury in surgical sepsis model

BackgroundSepsis commonly progresses to acute lung injury and is associated with high morbidity and mortality. Septic acute lung injury is characterized by severe oxidative stress response, remained refractory to present therapies, and new therapies need to be developed to improve further clinical outcomes. We determined the effect of betulinic acid (BA) on oxidative lung injury in mice using cecal ligation and puncture (CLP) model. Materials and methodsFive groups of mice (six in each group) received three pretreatments at 24-h interval before surgery. Surgery was done 1 h after last dosing. Sham and CLP control group mice received vehicle. BA was administered to other three groups of mice at 3, 10, and 30 mg/kg dose. Lung and plasma samples were collected for analysis by sacrificing the mice at 18 h of surgery. ResultsCompared with sham, CLP significantly increased total protein, nitrite, malondialdehyde, isoprostane, superoxide, protein carbonyl, oxidative stress index, inducible nitric oxide synthase protein, and histopathologic changes and reduced the superoxide dismutase, catalase activity, and total thiol levels in lungs and plasma, which were restored by BA pretreatment. ConclusionsBA pretreatment decreased the levels of oxidants, increased the levels of antioxidants in lungs and plasma thereby reducing the oxidative lung injury in CLP mice. Additionally, BA was found to scavenge the superoxide and nitric oxide radical in vitro. Thus, BA is suggested to be effective in treatment of oxidative lung injury in sepsis.

Antioxidant Effect of Grape Seed Proanthocyanidin Extract against Potassium Dichromate Induced Oxidative DNA Damage in Small Intestine of Adult Male Albino Rats

Background: Chromium usage is increasing worldwide. Oral exposure to hexavalent chromium Cr (VI) in animals and humans causes various health hazards. Cr (VI) compounds are classified as class I human carcinogens. Antioxidants were reported to inhibit chemical carcinogenesis. Grape seed proanthocyanidin extract (GSPE), naturally occurring compounds, have antioxidant, anti-inflammatory, anti-allergic and anti-tumor activities. Objectives: Accordingly, this work was conducted to investigate the antioxidant effect of GSPE against oxidative DNA damage induced by potassium dichromate on small intestine of adult male albino rats through biochemical and microscopic study. Study design: Forty adult male albino rats were included in this study and divided into four equal groups. Group I served as control group. Group II received 100mg/kg/day GSPE. Group III was treated with 15mg/kg/day potassium dichromate. Group IV received both K dichromate and GSPE in their previous doses. All animals were treated orally by syringe feeding method for two months. Body weight, plasma and tissue malondialdehyde (MDA) and total thiol (T-SH) of all studied groups were measured. In addition, light microscopic examination of small intestine using hematoxylin and eosin stains and immunostaining for detection of p53 positive cells as well as scanning electron microscopic examination were carried out. Results: The current study showed that adult male albino rats treated orally with potassium dichromate showed decrease in body weight, significant increase in plasma and intestinal tissue MDA and significant decrease in plasma and intestinal tissue thiol level. All these changes were associated with severe histological alterations in the wall of the small intestine especially the duodenum with significant increase of p53 positive cells. GSPE were found to counteract the toxic effect of potassium dichromate by attenuating oxidative stress and DNA damage. Conclusion: It is concluded that GSPE is promising as an agent that can potentially reduce K dichromate induced toxic effects in small intestine through its antioxidant effect.

Changes in plasma thiol levels induced by different phases of treatment in breast cancer; the role of commercial extract from black chokeberry

Different low-molecular-weight thiols, including glutathione, cysteine, and cysteinylglycine are physiological free radical scavengers. On the other hand, homocysteine may play a role as an oxidant. The aim of our present study was to establish in vitro the effects of the commercial extract of Aronia melanocarpa (Aronox(®)) on the amount of selected low-molecular-weight thiols and the activity of antioxidative enzymes (superoxide dismutase, glutathione peroxidase, and glutathione reductase) in plasma obtained from patients with invasive breast cancer during different phases of treatment [before or after the surgery and patients after different phases of chemotherapy (doxorubicin and cyclophosphamide)] and from healthy subjects. Patients were hospitalized in Department of Oncological Surgery and Department of Chemotherapy, Medical University of Lodz, Poland. The level of low-molecular-weight thiols was determined by high-performance liquid chromatography. We observed that in the presence of the Aronia extract changes in amount of thiols in plasma from breast cancer patients (at all tested groups) were significantly reduced. Our results showed that tested commercial extract reduced modifications of antioxidative enzymes activity in plasma from patients during different phases of treatment, but this effect was not statistical significant. Our results suggest that the Aronia extract supplementation in breast cancer patients has a beneficial effect on thiols concentration in plasma. Plasma, as reported in this work, could be used as an experimental model to evaluate the beneficial action of plant supplements, including phenolic extracts on thiols or other molecules during different phases of treatment.

Efeito da administração de uma dieta enteral com antioxidantes sobre as concentrações plasmáticas de tióis totais, carbonilas de proteínas e malondialdeído após acidente vascular cerebral

OBJETIVO: Avaliar o efeito da administração de uma dieta enteral industrializada com antioxidantes sobre as concentrações plasmáticas de tióis totais, carbonilas de proteínas e malondialdeído em pacientes após acidente vascular cerebral. MÉTODOS: A amostra foi constituída de 14 pacientes de um hospital geral que iniciaram nutrição enteral 48 horas após o evento. Falência múltipla, insuficiência hepática, obesidade mórbida e diabetes Mellitus associados foram critérios de exclusão. A dieta industrializada ofertada por gotejamento contínuo, com uso de bombas infusoras, continha mix de carotenoides, vitaminas C, E e minerais Se, Zn e Cu em sua formulação. As amostras de sangue foram coletadas antes do início da administração da dieta e após cinco dias de início da dieta enteral, somente de pacientes que tivessem recebido o volume necessário para completar o gasto energético total. Tióis plasmáticos e carbonilas de proteína foram determinados por meio do Reagente de Ellman e pela reação com dinitrofenilhidrazina respectivamente. O malondialdeído foi obtido pela determinação de substâncias reativas do ácido tiobarbitúrico. RESULTADOS: A média de idade foi M=70,3, DP=14,1 anos. Todos receberam acima de 100% da Dietary Reference Intakes para nutrientes antioxidantes, que não ultrapassaram os limites superiores toleráveis de ingestão. Não houve alteração da concentração de tióis, mas houve aumento da formação de carbonilas de proteínas (p=0,034). Nos pacientes entubados, esse marcador mostrou-se significativamente maior (p=0,048) após administração da dieta. Não houve diferença nas concentrações de malondialdeído após a oferta de antioxidantes dietéticos. CONCLUSÃO: A análise de biomarcadores não demonstrou redução do estresse oxidativo após administração de dieta enteral industrializada com antioxidantes.

Oxidative stress and antioxidant status in prostate cancer patients: Relation to Gleason score, treatment and bone metastasis

Over the last decade, epidemiological, experimental and clinical studies have implicated oxidative stress in the development and progression of prostate cancer. In the present study, we evaluated the oxidative status and antioxidant defense in patients with prostate cancer (PCa) taking into consideration: treatment, Gleason score and bone metastasis. For this, we measured concentrations of plasmatic thiobarbituric acid reactive substances (TBARS), serum protein carbonylation, whole blood catalase (CAT) and superoxide dismutase (SOD) activities, as well as the plasma and erythrocyte thiol levels and serum vitamin C and E concentration. This study was performed on 55 patients with PCa and 55 healthy men. TBARS levels and serum protein carbonylation were higher in PCa patients than in controls and altered levels of antioxidants were found in these patients. CAT activity was decreased and SOD activity was higher in PCa patients when compared with controls. Non-protein thiol levels were increased, however, serum vitamin C and vitamin E content were reduced in PCa patients when compared with controls. In addition, different parameters analyzed in PCa patients based on metastasis, treatment and Gleason score showed changes in oxidative stress biomarkers and antioxidant defenses. These findings may indicate an imbalance in the oxidant/antioxidant status, supporting the idea that oxidative stress plays a role in PCa, moreover, the oxidative profile appear to be modified by bone metastasis, treatment and Gleason score.

Antioxidant biomarkers and food intake in elderly women.

To investigate the relationship between antioxidant biomarkers and food intake in elderly women. Cross-sectional study. Recreation Center for the Elderly in the city of Itajaí, Santa Catarina, Brazil. 73 elderly women with an average age of 71 years, 93% caucasian, average body weight 68.7 ± 13.1 kg and average BMI 28.5 ± 2.3 kg/m². Nutritional status was assessed based on the Body Mass Index (BMI). Data on food intake were obtained by applying the 24h diet recall method in three non-consecutive days, including Sunday. The assessment of antioxidant biomarkers was performed based on tests for total plasma thiols and phenolic compounds. The linear regression analysis was used to assess the effect of the consumption of food groups on antioxidant biomarkers. A positive association was found between thiols and intake of carotenoid-rich vegetables (p=0.03), oils, fats and oilseeds (p=0.03); a negative association was observed between total concentrations of phenolic compounds and intake of cereals (p=0.04). The intake of foods from the carotenoid-rich vegetables, oils, fats and oilseeds food groups increased the levels of plasma thiols, and the intake of foods from the group of cereals decreased the plasma concentration of phenols. Studies should be conducted to investigate the association between the intake of antioxidant-rich foods and the plasma antioxidant profile, as a way to protect against the aging process.

Inhibition of the formation of advanced glycation end products by thymoquinone

The inhibitory activity of thymoquinone, a major quinone from black seeds (Nigella sativa) against the formation of advanced glycation end products was studied using the hemoglobin-δ-gluconolactone, human serum albumin–glucose, and the N-acetyl-glycyl-lysine methyl ester–ribose assays. A comparison was made with the inhibitory activity of aminoguanidine. The cytotoxicity of thymoquinone was studied by the release of lactate dehydrogenase from platelets and the levels of plasma thiols. At 20μM, thymoquinone inhibited 39% of hemoglobin glycation, 82% of post-Amadori glycation products, reduced methyglyoxal-mediated human serum albumin glycation by 68%, inhibited 78% of late glycation end products. Aminoguanidine at 10mM was less effective than thymoquinone. The IC50 for thymoquinone and aminoguanidine were 7.2μM and 1.25mM, respectively. Thymoquinone at 20–50μM was not toxic to platelet lactate dehydrogenase and plasma thiols. The potential of thymoquinone in food applications is discussed.

Genetic Dysregulation of Glutathione Synthesis Predicts Alteration of Plasma Thiol Redox Status in Schizophrenia

Genetic studies have shown an association between schizophrenia and a GAG trinucleotide repeat (TNR) polymorphism in the catalytic subunit (GCLC) of the glutamate cysteine ligase (GCL), the key enzyme for glutathione (GSH) synthesis. The present study was aimed at analyzing the influence of a GSH dysregulation of genetic origin on plasma thiols (total cysteine, homocysteine, and cysteine-glycine) and other free amino acid levels as well as fibroblast cultures GSH levels. Plasma thiols levels were also compared between patients and controls. As compared with patients with a low-risk GCLC GAG TNR genotype, patients with a high-risk genotype, having an impaired GSH synthesis, displayed a decrease of fibroblast GSH and plasma total cysteine levels, and an increase of the oxidized form of cysteine (cystine) content. Increased levels of plasma free serine, glutamine, citrulline, and arginine were also observed in the high-risk genotype. Taken together, the high-risk genotypes were associated with a subgroup of schizophrenia characterized by altered plasma thiols and free amino acid levels that reflect a dysregulation of redox control and an increased susceptibility to oxidative stress. This altered pattern potentially contributes to the development of a biomarker profile useful for early diagnosis and monitoring the effectiveness of novel drugs targeting redox dysregulation in schizophrenia.

Association between Biomarkers of Carbonyl Stress with Increased Systemic Inflammatory Response in Different Stages of Chronic Kidney Disease and after Renal Transplantation

Background: Chronic kidney disease (CKD) is characterized by progressive kidney dysfunction accompanied by accumulation of uremic toxins and a potential disequilibrium between the redox status and the generation of prooxidants, resulting in oxidative stress and chronic inflammation which is associated with complications (particularly cardiovascular disease) in this population. We aimed to analyze the concentration of total plasma thiols (indicator of antioxidant capacity) and the protein carbonyl content (a marker of carbonyl stress) in relation to kidney function and inflammation in a group of patients with CKD. Patients and Methods: A group of 68 patients with CKD (stages 2–5; mean age 57 ± 12 years, 46% male, 34% diabetics) and another group of 21 patients who underwent living donor kidney transplantation (mean age 36 ± 17 years, 50% male, 10% diabetics, and 9 ± 2 months after renal transplantation) were included in the study. Total plasma thiol and protein carbonyl levels were determined by the DTNB and DNPH methods, respectively, and were adjusted to the plasma albumin concentrations. Plasma levels of fibrinogen and C-reactive protein (CRP) were measured by routine methods and used as markers of inflammation. Results: Mean glomerular filtration rate (GFR) was 48 ml/min, and there was a positive correlation between GFR and thiol (r = 0.25, p < 0.05) and a negative correlation between GFR and carbonyl (r = –0.26, p < 0.05), fibrinogen (r = –0.45, p < 0.0001) and CRP (r = –0.14, p = ns). Carbonyl strongly correlated with CRP (0.49, p < 0.0001) and fibrinogen (0.30, p < 0.01). There was a significant reduction in plasma carbonyl after renal transplantation (1.4 ± 0.4 nmol/mg albumin), compared with the levels before the procedure (2.0 ± 1.4 nmol/mg albumin, p < 0.05), which parallels an improvement in thiol levels (15 ± 4 vs. 21 ± 5 nmol/mg albumin, p < 0.001). In addition, there was a significant correlation between CRP and carbonyl after the transplantation (r = 0.65; p < 0.005). Conclusion: We observed that patients with CKD present an altered redox status and increased signs of carbonyl stress and inflammatory activity as kidney function deteriorates, which was partially but significantly improved after renal transplantation. These findings indicate the importance of renal function in the complications of CKD related to oxidative stress and inflammation.

Bioavailability of Vitamins E and C: Does Helicobacter pylori Infection Play a Role?

Background: While the association between bioavailability of vitamins E and C and Helicobacter pylori infection has been extensively researched in gastritis and gastric cancer patients, little is known about this relationship in asymptomatic adults. Aim: To investigate the effect of H. pylori infection on bioavailability of vitamins E and C in asymptomatic adults. Methods: Volunteers from the University of Toronto, aged 18–45 years, were screened, for their H. pylori infection status. H. pylori-negative (n = 32) and asymptomatic H. pylori-positive (n = 27) participants received vitamin C (500 mg) and vitamin E (400 IU) supplements daily for 28 days. Plasma vitamins C, E and thiols concentrations were assessed before (baseline) and after supplementation. Results: Postsupplementation plasma levels of vitamin C and E were significantly higher than presupplementation levels in both groups. Yet, changes in plasma vitamins E and C were not significantly different between the two groups [vitamin C (µmol/l): 13.97 ± 16.86 vs. 20.87 ± 27.66, p > 0.05; vitamin E (µmol/l): 15.52 ± 9.4 vs. 14.47 ± 15.77; p > 0.05 for H. pylori-negative and H. pylori-positive groups, respectively]. In addition, no significant difference was found in plasma thiols levels between groups (p > 0.05). Conclusion: These findings suggest that H. pylori does not influence antioxidants bioavailability in its asymptomatic stages of infection until a factor or combination of factors triggers the inflammation cascade which may lead to increased oxidative stress and possibly reduced bioavailability of vitamins E and C.

Effect of aronia on thiol levels in plasma of breast cancer patients

AbstractThe various specific biomarkers of oxidative stress in plasma from patients with breast cancer, as well as biomarkers (the level of lipid hydroperoxides, conjugated dienes, thiobarbituric acid reactive substances) have been described. The aim of our present study was to evaluate the amount of low-molecular-weight thiols (which are physiological free radical scavengers) and establish the effects of the extract from A. melanocarpa on the amount of these thiols in plasma obtained from patients with invasive breast cancer, patients with benign breast diseases and from healthy volunteers. We observed in patients the higher amounts of homocysteine in plasma from patients in comparison to plasma from the control group; however the total level of glutathione, cysteine, cysteinylglycine, and the amount of thiols in reduced and oxidized forms was changed (e.g., in patients, the decrease of glutathione and cysteine reached about 50% of total values). Moreover, we showed that in the presence of the extract of A. melanocarpa (50 µg/mL, 5 min, 37°C), changes in amount of thiols in plasma from patients with invasive breast cancer and patients with benign breast diseases were significantly reduced in vitro. Considering the data presented in this study, we suggest that the extract from A. melanocarpa has an effect on thiol metabolism and the levels of all tested thiols observed in plasma obtained from breast cancer patients.