Analytical aspects of antioxidants and free radical activity in clinical biochemistry

Soda intake influences phenotype, antioxidants and inflammatory status in high protein-fed wistar rats

An increasing population of people, especially young adults who exercise, consume high protein diets along with carbonated drinks. While there are numerous studies on the effect of high protein diets, there is a need to understand how protein diets in combination with carbonated drinks impact physiology. In order to assess these effects on wistar rats' phenotype, antioxidants and inflammatory profiles, 64 wistar rats were divided into dietary groups of 8 male and 8 female animals each. The animals were fed standard diet as control (chow), chow and carbonated soda, a high protein diet (48.1% energy from protein) and a high protein diet with carbonated soda according to their groups. Body measurements, blood glucose levels, serum insulin levels, lipid peroxidation, antioxidant activity, adipokines and inflammatory markers concentrations were all determined. At the end of the study, body measurements, inflammatory markers and adipokine concentration were increased in animals fed the high protein diet and high protein-soda diet. There was a decrease in antioxidant and lipid peroxidation levels in protein fed male and female animals but those fed protein in combination with soda had increased lipid peroxidation levels. In conclusion, high protein diet in combination with carbonated soda impacts physiology differently from a high protein diet alone, and may stimulate weight gain, oxidative stress and HPD-related inflammation in Wistar rats.

Personalized redox medicine in inflammatory bowel diseases: an emerging role for HIF-1α and NRF2 as therapeutic targets

Inflammatory bowel diseases (IBD), encompassing Crohn's disease (CD) and ulcerative colitis (UC), are intimately associated with inflammation and overproduction of reactive oxygen species (ROS). Temporal and inter-individual variabilities in disease activity and response to therapy pose significant challenges to diagnosis and patient care. Discovery and validation of truly integrative biomarkers would benefit from embracing redox metabolomics approaches with prioritization of central regulatory hubs. We here make a case for applying a personalized redox medicine approach that aims to selectively inhibit pathological overproduction and/or altered expression of specific enzymatic sources of ROS without compromising physiological function. To this end, improved 'clinical-omics integration' may help to better understand which particular redox signaling pathways are disrupted in what patient. Pharmacological interventions capable of activating endogenous antioxidant defense systems may represent viable therapeutic options to restore local/systemic redox status, with HIF-1α and NRF2 holding particular promise in this context. Achieving the implementation of clinically meaningful mechanism-based biomarkers requires development of easy-to-use, robust and cost-effective tools for secure diagnosis and monitoring of treatment efficacy. Ultimately, matching redox-directed pharmacological interventions to individual patient phenotypes using predictive biomarkers may offer new opportunities to break the therapeutic ceiling in IBD.

Histone deacetylase inhibitor givinostat has ameliorative effect in the colitis model

Purpose:

To investigate the effect of givinostat treatment in acetic acid-induced ulcerative colitis model in rats.

Methods:

Thirty male Wistar albino rats were used. Rats were randomly divided into three equal groups, and colitis was induced on 20 rats by rectal administration of %4 solutions of acetic acid. Twenty rats with colitis were randomly divided into two groups. %0.9 NaCl (saline) solution was administered intraperitoneally to the first group of rats (saline group, n=10) at the dose of 1 mL/kg/day. Givinostat was administered intraperitoneally to the second group rats (Givinostat group, n=10) at the dose of 5 mg/kg/day. Samples were collected for biochemical analysis. Colon was removed for histopathological and biochemical examinations.

Results:

Plasma tumor necrosis factor-α (TNF-α), pentraxin-3 (PTX-3), and malondialdehyde levels were significantly decreased in the givinostat group compared to the saline group (p<0.05, p<0.001, and p<0.001 respectively; p<0.001, p<0.001, and p<0.001, respectively). Colon TNF-α and prostaglandin F2 alpha (PGF-2) levels were significantly decreased (p<0.05, and p<0.001, respectively). The givinostat group had a significantly lower histologic score than saline group (p<0.001, and p<0.001, respectively).

Conclusions:

Givinostat, a good protector and regenerator of tissue and an anti-inflammatory agent, may be involved in the treatment of colitis in the future.

Oxidative Stress and Redox-Modulating Therapeutics in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is associated with the production of reactive species that target cysteine redox switches in proteins, thereby affecting gene regulation, DNA damage, ion transport, intermediary metabolism, and mitochondrial function. Precursors of reactive species are derived from organic and inorganic compounds and their cofactors, including amino acids, vitamins, oxygen, nitrite, and sulfate. Nutrition and the gut microbiome fuel this process to a significant extent. The production of reactive species in IBD is reflected by a reduction in systemic free thiols, the major components of the antioxidant machinery. Systemic free thiols are amenable to nutritional or therapeutic intervention. This opens up future avenues for therapeutic modulation of redox status in IBD.

Experimental and clinical study of the efficacy of medicines containing omega-3 and 6 polyunsaturated fatty acids, in the treatment of inflammatory skin diseases

Introduction: Over the recent years, the attention of scientists regarding the search for alternative means of treatment, including local therapy, of inflammatory skin diseases, has been focused in recent years on medicines containing omega-3 and 6 polyunsaturated fatty acids (PUFA).

Objectives: to substantiate the feasibility of using medicines containing omega-3 and 6 polyunsaturated fatty acids and antioxidants in the treatment of inflammatory skin diseases.

Methods:The studies were carried out on 224 conventional white rats of the Wistar line in compliance with the international principles of the European Convention for the Protection of Vertebrates. A burn injury was used to cause experimental simple irritant contact dermatitis. After trying various treatment options with using Omegaven, histopathological examinations of 18 fragments of affected skin of white rats with cross sections stained with hematoxylin–eosin and pikrofuxin by Van Gieson’s method. The state of lipid peroxidation (LPO) in blood and affected skin was evaluated in the animals. One hundred forty-six patients with inflammatory skin diseases (dermatitis simple irritant contact, allergic contact dermatitis, atopic dermatitis, neurodermatitis, psoriasis, cutaneous mastocytosis in children) were observed. In treatment, there were used medicines with omega-3 and 6 PUFA or an antioxidant medicines.

Results and discussion: Skin reactions of dermatitis simple irritant contact in rats after burn injury were evaluated at different points of time. The observations showed higher efficacy of medicines containing PUFA than standard anti-inflammatory agents in the treatment of simple irritant contact dermatitis. Histopathological examination of the skin of white rats with simple irritant contact dermatitis after the 11-day treatment revealed that the expression and composition of the cellular reaction in the lesions with a predominating lymphocytes and macrophages (mainly cell response) differ significantly from those trated with Radevit ointment (segmented neutrophil leukocytes, eosinophils – delay in the acute phase of inflammation). There was identified a smaller thickness (up to 1/3) of the strips of granulation tissue under the actively proliferating cells of the epidermis. It was possible to demonstrate the superiority with respect to reducing the activity of LPO medicines containing omega-3 and 6 PUFA, over those with anti-inflammatory action. The clinical observations of patients showed high efficacy of the local treatment with medicines containing omega-3 and 6 PUFA, or antioxidant.

Conclusion: For the first time, the mechanism of implementing an anti-inflammatory effect of the experimental medicines containing omega-3 and 6 polyunsaturated fatty acids (Omegaven, Vitamin F99 cream rich), – an antioxidant effect - when treating simple irritant contact dermatitis when treating simple irritant contact dermatitis; that is the weakening of the severity of oxidative stress. For the first time, the greatest contribution of an increased activity of catalase to the weakening of oxidative stress in the affected skin is shown.

Probiotic yeast Kluyveromyces marxianus CIDCA 8154 shows anti-inflammatory and anti-oxidative stress properties in in vivo models

Inflammatory bowel diseases (IBDs) are complex affections with increasing incidence worldwide. Multiple factors are involved in the development and maintenance of the symptoms including enhanced oxidative stress in intestinal mucosa. The conventional therapeutic approaches for IBDs are based on the use anti-inflammatory drugs with important collateral effects and partial efficacy. In the present work we tested the anti-inflammatory capacity of Kluyveromyces marxianus CIDCA 8154 in different models. In vitro, we showed that the pretreatment of epithelial cells with the yeast reduce the levels of intracellular reactive oxygen species. Furthermore, in a murine model of trinitro benzene sulfonic acid-induced colitis, yeast-treated animals showed a reduced histopathological score (P<0.05) and lower levels of circulating interleukin 6 (P<0.05). The capacity to modulate oxidative stress in vivo was assessed using a Caenorhabditis elegans model. The yeast was able to protect the nematodes from oxidative stress by modulating the SKN-1 transcription factor trough the DAF-2 pathway. These results indicate that K. marxianus CIDCA 8154 could control the intestinal inflammation and cellular oxidative stress. Deciphering the mechanisms of action of different probiotics might be useful for the rational formulation of polymicrobial products containing microorganisms targeting different anti-inflammatory pathways.

Evaluation of oxidative stress biomarkers in patients with fixed orthodontic appliances

AIM

The aim of this study was to examine the changes in the levels of interleukine-1 beta (IL-1 β ), tumor necrosis factor alpha (TNF- α ), malondialdehyde (MDA), nitric oxide (NO), and 8-hydroxydeoxyguanosine (8-OHdG) in saliva and IL-1 β , TNF- α , and NO in gingival crevicular fluid (GCF) samples of patients with fixed orthodontic appliances.

MATERIAL AND METHOD

The subject population consisted of 50 volunteers who were in need of orthodontic treatment with fixed orthodontic appliances. GCF and saliva samples were obtained from all individuals before treatment, at 1st month of treatment and at 6th month of treatment. Periodontal clinical parameters were measured. Samples were investigated to detect IL-1 β , TNF- α , and 8-OHdG levels using ELISA method and NO and MDA levels using spectrophotometric method.

RESULTS

Since IL-1 β level detected in GCF at the 6th month of orthodontic treatment is statistically significant according to baseline (P < 0.05), all other biochemical parameters detected both in saliva and in GCF did not show any significant change at any measurement periods.

CONCLUSION

Orthodontic tooth movement and orthodontic materials used in orthodontic treatment do not lead to a change above the physiological limits that is suggestive of oxidative damage in both GCF and saliva.

[Oxidative stress in Crohn's disease]

Crohn's disease (CD) is characterized by transmural inflammation that is most frequently located in the region of the terminal ileum. Although the physiopathological mechanisms of the disease are not yet well defined, the unregulated immune response is associated with high production of reactive oxygen species (ROS). These elements are associated with complex systems known as antioxidant defenses, whose function is ROS regulation, thereby preventing the harmful effects of these elements. However, the presence of an imbalance between ROS production and ROS elimination by antioxidants has been widely described and leads to oxidative stress. In this article, we describe the most significant findings on oxidative stress in the intestinal mucosa and peripheral blood.

Development of a validated HPLC method for the simultaneous determination of flavonoids in Cuscuta chinensis Lam. by ultra-violet detection

BACKGROUND

Cuscuta species known as dodder, have been used in traditional medicine of eastern and southern Asian countries as liver and kidney tonic. Flavonoids are considered as the main biologically active constituents in Cuscuta plants especially in C. chinensis Lam.

OBJECTIVE

In the present study, a fast, simple and reliable method for the simultaneous determination and quantization of C. chinensis flavonols including hyperoside, rutin, isorhamnetin and kaempferol has been developed.

MATERIALS AND METHODS

The chromatographic separation was carried out on a reversed phase ACE 5 C18 with eluting at a flow rate of 1 ml/min using a gradient with O-phosphoric acid 0.25% : acetonitrile for 42 min. UV spectra were collected across the range of 200-900 nm, extracting 360 nm for the chromatograms. The method was validated according to linearity, selectivity, precision, recovery, LOD and LOQ.

RESULTS

The method was selective for determination of rutin, hyperoside, isorhamnetin and kampferol. The calibration graphs of flavonols were linear with r2 > 0.999. RSDs% of intra- and inter-day precisions were found 1.3&3.4 for rutin, 1.5&2.8 for hyperoside, 1.3&3.3 for isorhamnetin and 1.7 & 2.9 for kaempferol which were satisfactory. LODs and LOQs were calculated as 1.73 & 8.19 for rutin, 0.09 & 4.19 for hyperoside, 2.09 & 6.3 for isorhamnetin and 0.18 & 0.56 for kaempferol. The recovery averages of above-mentioned flavonols were 90.3%, 97.4%, 98.7% and 90.0%, respectively.

CONCLUSION

The simplicity of the method makes it highly valuable for quality control of C. chinensis according to quantization of flavonols.

Involvement of oxidative stress and mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in inflammatory bowel disease

The pathophysiology of inflammatory bowel disease involves excessive immune effects of inflammatory cells against gut microbes. In genetically predisposed individuals, these effects are considered to contribute to the initiation and perpetuation of mucosal injury. Oxidative stress is a fundamental tissue-destructive mechanisms that can occur due to the reactive oxygen species and reactive nitrogen metabolites which are released in abundance from numerous inflammatory cells that have extravasated from lymphatics and blood vessels to the lamina propria. This extravasation is mediated by interactions between adhesion molecules including mucosal addressin cell adhesion molecule-1 and vascular cell adhesion molecule-1 on the surface of lymphocytes or neutrophils and their ligands on endothelial cells. Thus, reactive oxygen species and adhesion molecules play an important role in the development of inflammatory bowel disease. The present review focuses on the involvement of oxidative stress and adhesion molecules, in particular mucosal addressin cell adhesion molecule-1, in inflammatory bowel disease.

The effects of one-step self-etch adhesives on the induction of oxidative stress and production of TGF-beta1 and BMP-2 by human gingival fibroblasts

The aim of this study was to evaluate and compare the effects of two self-etch adhesive materials on the induction of oxidative stress and production of transforming growth factor-beta1 (TGF-beta1) and bone morphogenetic protein-2 (BMP-2) by cultured human gingival fibroblasts (HGF). Inflammation-free attached gingiva was obtained from healthy donors under informed consent. Following 24- and 72-h exposure of HGF to two different elutes of the test materials, cell viability was determined using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Lipid peroxidation, a major indicator of oxidative stress, was measured by the thiobarbituric acid reactive substance (TBARS) assay. TGF-beta1 and BMP-2 levels in cell-free culture media were determined by enzyme-linked immunosorbent assay (ELISA). Cell viability of the test groups was significantly lower than those of control at 24 and 72 h (P < 0.001), but showed an increase at 72 h (P < 0.001). The TBARS levels of both test groups were significantly greater than that of control (P < 0.05), and displayed similar values at 72 h (P > 0.05). For both materials, the levels of TGF-beta1 and BMP-2 were significantly greater than that of control (P < 0.05). Both test groups showed increased TGF-beta1 levels. These results indicate that the tested self-etch adhesives might be capable of inducing production of TGF-beta1 and BMP-2 in cultured HGF, despite their cytotoxic and oxidative stress-producing potential.

Advanced oxidation protein products: a novel marker of oxidative stress in ulcerative colitis

BACKGROUND/GOALS

The etiology and pathogenesis of chronic inflammatory bowel diseases are still poorly understood. Oxidative stress takes place in the pathogenesis of ulcerative colitis (UC) and advanced oxidation protein products (AOPP) are accepted as a novel marker of oxidative stress. There are no data concerning whether AOPP may be used as a simple serum marker to assess the disease activity, predict severity of the disease course in UC.

STUDY

In this study, we determine the importance of neutrophil activation and the role of oxidative stress in the pathogenesis of UC, by quantification of AOPP and total thiol levels as markers of oxidative protein damage, malondialdehyde levels as a marker of lipid peroxidation, and myeloperoxidase activity as a marker of neutrophil activation in patients with UC.

RESULTS

Serum levels of AOPP, thiol, myeloperoxidase activity, and malondialdehyde were found as increased in UC group compared with controls (P=0.004, 0.047, 0.001, and 0.001 respectively).

CONCLUSIONS

Our finding of increased levels of plasma AOPP levels supports the presence of oxidative stress and protein oxidation in UC and this marker may be used as a simple serum marker to assess disease activity, predict the severity of disease course, and perhaps response to therapy.

Erythrocyte susceptibility to oxidative stress and antioxidant status in patients with type 1 diabetes

In this study, malondialdehyde (MDA) level as an index of erythrocyte susceptibility to oxidative stress and antioxidant defense system (glutathione level (GSH), glutathione peroxidase enzyme activity (GPx) in erythrocytes and ferric reducing ability of plasma (FRAP) as the total plasma antioxidant capacity were measured in 35 patients with type 1 diabetes and 28 age and sex-matched normal subjects. MDA level was significantly elevated in diabetic patients (650.9+/-144.3 nmol/g versus 476.5+/-138.5 nmol/g Hb, P<0.001). The level of MDA was positively correlated with duration of diabetes (r= 0.29, P<0.05) and HbA(1C) (r= 0.39, P<0.05) and negatively with FRAP (r= -0.3, P<0.05). The level of GSH and FRAP were lower in patients than controls (7.05+/-1.6 micromol/g versus 8.24+/-0.9 micromol/g Hb, and 389.05+/-82.3 micromol/l versus 520.4+/-124.1 micromol/l, respectively, P<0.001). GPx activity was not significantly different between the two groups. GSH and FRAP were negatively correlated with HbA(1C) (r= -0.334, P<0.01 and r= -0.5, P<0.01, respectively). In conclusion, there seems to be an increased susceptibility to oxidative stress and decreased antioxidant defense in patients with type 1 diabetes, which may be due to poor glycemic control.

Gingival crevicular fluid prostaglandin E(2) and thiobarbituric acid reactive substance levels in smokers and non-smokers with chronic periodontitis following phase I periodontal therapy and adjunctive use of flurbiprofen

BACKGROUND

It has been established that smoking is an important risk factor for the initiation and progression of chronic periodontitis (CP). This study investigates the effects of phase I periodontal therapy and adjunctive flurbiprofen administration on prostaglandin E(2) (PGE(2)) and thiobarbituric acid reactive substance (TBARS) levels in gingival crevicular fluid (GCF) samples from smoker and non-smoker patients with CP.

METHODS

Twenty-one non-smoker and 21 smoker patients with CP were divided into four groups according to treatment modalities. Group 1 (non-smokers with CP) and group 3 (smokers with CP) patients received daily 100-mg flurbiprofen tablets in a 2 x 1 regimen for 10 days together with scaling and root planing (SRP). Patients in group 2 (non-smokers with CP) and group 4 (smokers with CP) received placebo tablets in a 2 x 1 regimen for 10 days together with SRP. Plaque index (PI), gingival index (GI), probing depth (PD), and clinical attachment level (CAL) measurements were recorded and GCF samples were collected at baseline and on day 10 of drug intake from each sampling area by a single examiner who was unaware of the treatment modality. Assays for GCF PGE(2) and TBARS were carried out by an enzyme-linked immunosorbent assay and fluorometric method, respectively.

RESULTS

All groups showed statistically significant reductions in PI and GI scores following the phase I periodontal treatment on day 10 (P <0.05), but no statistical differences were observed in PD and CAL scores after the therapy. In groups 1 and 2, the reduction of GCF PGE(2) and TBARS levels were not significant after the therapy compared to baseline levels. In group 3, GCF PGE(2) and TBARS levels exhibited a statistically significant decrease (P <0.05) after the therapy. Group 4 showed significant reductions (P <0.05) in GCF PGE(2) levels after the therapy. No statistically significant reductions were observed in group 4 with regard to GCF TBARS levels. When groups 1 and 3 were compared according to GCF TBARS levels after the therapy, a more statistically significant reduction was observed in group 3 (P = 0.001).

CONCLUSION

These results suggest that additional flurbiprofen administration may have more inhibitory effects on GCF levels of PGE(2) and TBARS in the groups of smokers compared to non-smokers with CP.

Effects of pistachio nuts consumption on plasma lipid profile and oxidative status in healthy volunteers

BACKGROUND AND AIM

Effects of pistachio nuts consumption on plasma lipid profile and oxidative status were investigated in healthy volunteers with normal lipid levels.

METHODS AND RESULTS

The study was conducted in 24 healthy men and 20 healthy women. All subjects consumed their regular diets during a 1-week period. After this period, half of the subjects (12 men and 10 women, mean age 32.8 +/- 6.7 years) were randomized to a regular diet group and the other half (12 men and 10 women, mean age 33.4 +/- 7.2 years) were randomized to a pistachio group which involved substituting pistachio nuts for 20% of their daily caloric intake for 3 weeks. Plasma total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride, malondialdehyde (MDA) and antioxidant potential (AOP) were measured before and after the dietary modification from all the subjects. After 3 weeks, with the pistachio diet, the mean plasma total cholesterol, MDA levels and, total cholesterol/HDL and LDL/HDL ratios were found to be significantly decreased (P < 0.05, P < 0.05, P < 0.001 and P < 0.01, respectively); on the contrary, HDL and AOP levels, and AOP/MDA ratios were significantly increased (P < 0.001, P < 0.05 and P < 0.01, respectively). Triglyceride and LDL levels also decreased but this was not statistically significant (P > 0.05).

CONCLUSION

These results indicated that consumption of pistachio nuts decreased oxidative stress, and improved total cholesterol and HDL levels in healthy volunteers.

Effects of Khaya grandifoliola (Meliaceae) on some biochemical parameters in rats

The antimalarial activity of the crude water extract of Khaya grandifoliola (Welw) CDC (Meliaceae) stem bark in mice has been reported. The biochemical effects of the crude water extract at doses of 100, 200 and 500 mg/day were examine in plasma, liver, and heart after 7 and 21 days of administration and after a recovery period of 21 days. The extract had a significant hypoglycaemic, hypoproteinaemic and hypocholesterolaemic effect at p < 0.05 when compared to the control rats. Liver protein content and glutathione (GSH) were significantly reduced (p < 0.05) in groups treated with the extract. The concentration of free fatty acids in the plasma was not significantly reduced in groups treated with the extract. A non-significant increase in liver malondialdehyde (MDA) was observed in the extract-administered groups. After the recovery period, the values returned to levels that were not significantly different from those of the control at (p < 0.05) for all the parameters examined.

The protective role of DL-?-lipoic acid in the oxidative vulnerability triggered by A?-amyloid vaccination in mice

Recent reports indicate that beta-amyloid peptide (Abeta) vaccine based therapy for Alzheimer's disease (AD) may be on the horizon. There are however, concerns about the safety of this approach. Immunization with Abeta has several disadvantages, because it crosses the blood brain barrier and cause inflammation and neurotoxicity. The present work is aimed to study the protective effective of alpha-lipoic acid (LA) in the oxidative vulnerability of beta-amyloid in plasma, liver, spleen and brain, when Abeta fibrils are given intraperitoneally in inflammation induced mice. Result shows that reactive oxygen species (ROS) in the astrocytes of inflammation induced mice along with Abeta (IA) has shown 2.5-fold increase when compared with LA treated mice. The increased level of lipid peroxidase (LPO) (p < 0.05) and decreased antioxidant status (p < 0.05) were observed in the plasma, liver, spleen and brain of LA induced mice when compared with LA treated mice. Data shows that there were no significant changes observed between the control and LA treated mice. Our biochemical and histological results highlight that significant oxidative vulnerability was observed in IA treated mice, which was prevented by LA therapy. Our findings suggest that the antioxidant effect of LA when induced with Abeta may serve as a potent therapeutic tool for inflammatory AD models.

Antioxidant status of adult Nigerian asthmatics: implications for prognosis

Serum antioxidant status of 50 (19M, 31F) adult asthmatic patients, aged 40 to 50 yr and attending the medical outpatient clinic of the University College Hospital, Ibadan, has been assessed, by measurement of serum ascorbic acid, copper, zinc, albumin, uric acid and magnesium levels, to determine the relationship between antioxidant status and severity of bronchial asthma. Twenty-five (25) age matched adults (10M, 15F) served as controls. The test subjects were classified into two groups (1&2) based on the degree of respiratory distress. Questionnaires were also used to obtain data on subjects' fruit and vegetable intake. Fruit and vegetable intake was similar in patients and controls, 96% and 100% respectively reporting adequate intake. Copper (Cu) level was not significantly different between patients and control subjects, but was significantly higher in female asthmatics than in males (p < 0.05). Magnesium (Mg) level was also lower in asthmatics than in control subject (p < 0.001). Plasma Zinc level was not different between patients and control (p > 0.05). The levels of the other antioxidants, vitamin C, uric acid and albumin were all lower in asthmatics than in controls (p < 0.05, p < 0.001, p < 0.001) respectively. The magnesium level of group 2 (severe asthmatics) was lower than in controls (p < 0.05) unlike moderate asthmatics (group 1) which do not differ significantly from controls. These findings support the emerging concept that antioxidants are consumed in this inflammatory disease and that a corresponding increase in antioxidant supply may improve prognosis for bronchial asthma.

The role of interleukin-12, and tissue antioxidants in chronic sinusitis

BACKGROUND

The role of cytokines and reactive oxygen species formation in the pathogenesis of chronic sinusitis is still not fully understood. This work was designed to determine if patients with chronic sinusitis demonstrate altered levels of serum IL-12 and/or tissue antioxidants.

SUBJECTS AND METHODS

Mucosal biopsy specimens from the uncinate process of patients with chronic sinusitis were obtained from 52 patients using functional endoscopic sinus surgery. Normal mucosa samples were collected from 20 healthy controls. Patients' group was further classified according to computerized tomography findings into mild and severe subgroups. Serum IL-12 was estimated using enzyme immunoassay (EIA). The levels of tissue uric acid, and reduced glutathione were determined biochemically, alpha-tocopherol was measured by HPLC. Superoxide dismutase (SOD) activity was determined by spectrophotometry.

RESULTS

A significant decrease in serum IL-12, tissue alpha-tocopherol and SOD in patient group was demonstrated (p < 0.05). Tissue uric acid and reduced glutathione showed primary increase in mild subgroup followed by significant drop in severe subgroup (p < 0.05). Negative significant correlation was observed between glutathione, uric acid, and SOD, and the severity of the disease (p < 0.05) independent of the cellularity of the biopsy.

CONCLUSION

The presented data suggests a possible role of IL-12, and tissue antioxidants in development and progression of chronic sinusitis. Adjuvant antioxidant treatment may have role in achieving better prognosis of the disease.

Review article: oxidative stress as a pathogenic factor in inflammatory bowel disease--radicals or ridiculous?

Virtually all inflammatory mediators investigated to date seem to be dysregulated in the inflamed intestinal mucosa of patients with inflammatory bowel disease. However, which of these are actually involved in the initiation and perpetuation of intestinal tissue damage is still not fully understood. Amongst these mediators are the reactive oxygen metabolites, produced in large amounts by the massively infiltrating leucocytes. These reactive oxygen metabolites are believed to constitute a major tissue-destructive force and may contribute significantly to the pathogenesis of inflammatory bowel disease. This paper provides a concise overview of reactive oxygen metabolite biochemistry, the types of cell and tissue damage potentially inflicted by them, and the endogenous antioxidants which should prevent these harmful effects. An up-to-date summary of the available human experimental data suggests that reactive oxygen metabolite-mediated injury is important in both the primary and downstream secondary pathophysiological mechanisms underlying intestinal inflammation. Nonetheless, how the individual components of the mucosal antioxidant enzymatic cascade respond to inflammatory conditions is a neglected area of research. This particular aspect of intestinal mucosal oxidative stress therefore merits further study, in order to provide a sound, scientific basis for the design of antioxidant-directed treatment strategies for inflammatory bowel disease patients.

Lipid peroxidation and erythrocyte antioxidant enzymes in patients with Behçet's disease

In spite of unknown etiology, it is now accepted that reactive oxygen species (ROS) produced by neutrophils may be related to the pathogenesis of Behçet's Disease (BD). The objective was to investigate whether increased production of ROS may affect erythrocyte oxidant/antioxidant system in patients with BD. The levels of malondialdehyde (MDA), one of the end products of lipid peroxidation, in plasma and erythrocyte, and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), antioxidant enzymes, in erythrocyte, also C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were measured in 22 patients in active stage of the disease and also in 30 healthy controls. Increased CRP, ESR, and MDA levels in plasma and erythrocyte and increased SOD but decreased GSH-Px activities in erythrocytes were observed in the patients, when compared to the controls. In addition, significantly positive correlations between plasma and erythrocyte MDA levels, and erythrocyte MDA-CRP, MDA-ESR, MDA-SOD, SOD-ESR and SOD-CRP levels, but negative correlation between plasma MDA and erythrocyte GSH-Px, were found in BD patients. It may be suggested that increased production of ROS in BD, as reflected by higher plasma and erythrocyte MDA levels, may impair erythrocyte membrane integrity and also may lead to the alterations in the erythrocyte antioxidant defense system, as reflected by higher SOD and lower GSH-Px activities in erythrocytes.

Assay of serum allantoin in humans by gas chromatography-mass spectrometry

BACKGROUND

The small amount of allantoin present in human serum results from free radical (FR) action on urate and may provide a stable marker of free radical activity in vivo. We describe a gas chromatography-mass spectrometry (GC-MS) assay for serum allantoin and report a reference range in healthy individuals.

METHODS

Fasting blood samples were obtained from 134 healthy middle-aged volunteers (56 men, mean age 55, range 45-72; 78 women, mean age 55, range 50-72) Allantoin was assayed using 15N(2) allantoin as an internal standard. After isolation from aqueous standards or serum by extraction onto an anion exchange column (AG-MP1), allantoin was derivatised with N-methyl-N-(tert-butyldimethylsilyl) trifluoroacetamide (MTBSTFA). Derivatives were injected onto an HP-1 column and analysed using a Mass Selective Detector with Single Ion Monitoring at 398 and 400 m/z.

RESULTS

The distribution of serum allantoin concentrations in men and women was non-Gaussian and log transformation was used for the analysis of data. Women (10.8 +/- 1.7 micromol/l (mean +/- S.D.)) had significantly lower serum allantoin levels than men (13.4 +/- 1.6 micromol/l, p=0.015). Reference ranges (95% CI) for middle-aged healthy subjects were 7.4-46.8 micromol/l (men) and 3.7-31.2 micromol/l (women).

CONCLUSION

Gas chromatography-mass spectrometry provides a reliable and accurate method for the determination of serum allantoin.

Interleukin-1beta and thiobarbituric acid reactive substance (TBARS) levels after phase I periodontal therapy in patients with chronic periodontitis

BACKGROUND

Interleukin-1beta (IL-1beta), a potent stimulator of bone resorption, has been implicated in the pathogenesis of periodontal tissue destruction. There is also a clearly defined and substantial role for free radicals or reactive oxygen species in periodontal destruction. The thiobarbituric acid reactive substances (TBARS) is a commonly applied test to measure free radical activity. The aims of this study were to investigate the amount of crevicular IL-1beta, tissue TBARS levels, and the clinical status of patients with advanced chronic periodontitis and the effect of phase I periodontal therapy on these clinical parameters and measurements.

METHODS

Twenty-five chronic periodontitis and 25 healthy control (C) patients were selected for the study. Plaque index (PI), gingival index (GI), probing depth (PD), and clinical attachment level (CAL) were recorded from each sampling area. Gingival crevicular fluid (GCF) sampling and clinical index scores were recorded at the initial examination (IE) and 6 weeks after phase I periodontal therapy (APT). Assays for GCF IL-1beta were carried out by enzyme-linked immunosorbent assay (ELISA). Gingival tissue samples were obtained from sites requiring periodontal flap surgery due to unresolved pockets to determine the tissue TBARS levels. The paired-samples t test was used to compare the IL-1beta levels and clinical parameters between IE and APT. The independent-samples t test was used to determine the significance of all parameters between IE and C, and between APT and C. The correlation among the IL-1beta levels, clinical parameters, and tissue TBARS levels was analyzed using the Pearson correlation.

RESULTS

The concentration of IL-1beta levels was not statistically different among IE, APT, and C groups, but the total amount of IL-1beta levels was statistically different among the 3 groups. While the levels of IL-1beta and the clinical parameters were reduced following phase I periodontal treatment, pretreatment IL-1beta, post-treatment IL-1beta, and TBARS levels were statistically higher in IE and APT groups than C specimens. Tissue TBARS levels in the APT group were statistically greater than controls. No correlations were noted between tissue TBARS levels and clinical parameters in the APT group. A positive statistical correlation was detected between the total IL-1beta and TBARS levels in the APT group.

CONCLUSION

These data suggest that the levels of crevicular IL-1beta and gingival tissue TBARS are closely associated with periodontal status. This relationship may be valuable in treating and monitoring periodontal disease progression.

Method for the measurement of antioxidant activity in human fluids

AIM

To develop a new, simple, and cheap method for estimating antioxidant activity in human fluids.

METHODS

The assay measured the capacity of the biological fluids to inhibit the production of thiobarbituric acid reactive substances (TBARS) from sodium benzoate under the influence of the free oxygen radicals derived from Fenton's reaction. A solution of 1 mmol/litre uric acid was used as standard.

RESULTS

The following mean (SD) antioxidative activities were found (as uric acid) in the various biological fluids: serum, 2.04 (0.20) mmol/litre; urine, 176.5 (25.6) micromol/litre; cerebrospinal fluid, 95.0 (26.9) micromol/litre; aqueous humour oculi, 61.25 (9.9) micromol/litre; saliva, 838.5 (48.2) micromol/litre; tears, 247.0 (17.0) micromol/litre; ascites fluid, 270.0 (63.3) micromol/litre; kidney cyst fluid, 387.1 (28.1) micromol/litre. Small samples of the biological material were needed for the analyses: 10 microl of serum and 50-100 microl of other body fluids. In the sera of 48 healthy individuals there was a significant positive correlation between values obtained with the Randox method (as a reference method) and the new method proposed here (correlation coefficient, 0.8728; mean difference between methods, <0.4%).

CONCLUSIONS

This method is easy, rapid, reliable, and practical for the routine measurement of total antioxidant activity in serum and other human body fluids. Small samples of biological material are needed for the analyses and the results are comparable with the reference (Randox) method.

Antioxidant properties of carvedilol and metoprolol in heart failure: a double-blind randomized controlled trial

Animal and human studies have shown that carvedilol has significant antioxidant properties compared with other beta-blockers. The objective of this study was to determine if these antioxidant effects are detectable in patients with heart failure and to compare carvedilol with the selective beta-blocker metoprolol. Twenty-four patients with chronic heart failure were randomly assigned to receive either carvedilol or metoprolol in a double-blind control trial for 12 weeks in a University teaching hospital clinic. Blood pressure, heart rate, exercise tolerance, left ventricular ejection fraction, plasma total antioxidant status, erythrocyte superoxide dismutase, and glutathione peroxidase activities were determined at baseline and every 4 weeks up to 12 weeks. The results showed that erythrocyte superoxide dismutase and glutathione peroxidase were significantly reduced in carvedilol treated patients after 12 weeks of therapy, whereas metoprolol had no significant effect, although the clinical improvement over the short-term was similar with both drugs. Thus carvedilol, in addition to improving symptoms in heart failure, also possesses significant antioxidant properties. Whether this additional action influences long-term outcome is at present unknown.

Antioxidant and thyroid hormone status in selenium-deficient phenylketonuric and hyperphenylalaninemic patients

BACKGROUND

Subjects consuming protein-restricted diets, such as patients with phenylketonuria (PKU) or milder hyperphenylalaninemias (HPAs) are at risk of selenium deficiency. Selenium is a cofactor of the antioxidant enzyme glutathione peroxidase and of the thyroid hormone converting enzyme thyroxine deiodinase.

OBJECTIVE

Our goal was to investigate the effects of low plasma selenium on antioxidant and thyroid hormone status.

DESIGN

We assessed plasma selenium, plasma total antioxidant status and the individual components thereof, erythrocyte antioxidant status, and plasma thyroid hormones in 24 PKU and 10 HPA patients and in 42 age-matched control subjects.

RESULTS

Selenium was significantly lower in both PKU and HPA patients than in control subjects and the PKU patients had lower values than did the HPA patients. Total antioxidant status was lower in both patient groups than in the control group, whereas alpha-tocopherol, albumin, and uric acid were not significantly different among groups. Plasma selenium correlated well (r = 0.76) with erythrocyte glutathione peroxidase. PKU patients had lower glutathione peroxidase activity than did HPA patients and control subjects and lower glutathione concentrations than did control subjects. Both patient groups had lower superoxide dismutase activity than did control subjects. Free triiodothyronine was higher in both patient groups than in control subjects, whereas free thyroxine was higher in the PKU patients only. Free thyroxine and reverse triiodothyronine were inversely correlated with selenium.

CONCLUSION

Supplementation with selenium seems to be advisable for patients consuming diets low in natural protein.

Comparison of relative antioxidant activities of British medicinal plant species in vitro

We have determined the relative levels of endogenous antioxidant activity in a range of British medicinal plant species (representative of a variety of plant families, selected on the basis of their widespread use in traditional herbal medicine), via competitive scavenging of the ABTS(z.rad)(+) or O(2)(-)(z.rad) radicals in vitro. A number of plant species with appreciable levels (i.e. greater than or comparable with the activity in corresponding extracts of Ginkgo biloba or Panax ginseng, as recognised phytological sources of antioxidant activity) of antioxidant activity against the ABTS(z.rad)(+) radical were identified as potentially novel sources of free radical scavenging compounds; however none of these extracts showed measurable antioxidant activity when assayed against the O(2)(-)(z.rad) radical. It, therefore, follows that any comparative determination of antioxidant activity should clearly define the radical species and assay method employed. For those extracts showing activity against the ABTS(z.rad)(+) radical, in general, it was not possible to predict the potential antioxidant capacity of a given plant species (or the most active part of the plant) on a taxonomical basis, or from its use in traditional or modern medicine. In the longer term further characterisation of the active compounds from plant species with appreciable antioxidant activity identified in the present investigation may prove of value for treatment of disorders such as Alzheimer's disease, in which free radical induced tissue damage has been implicated.

Measurement of 5-hydroxy-2-aminovaleric acid as a specific marker of iron-mediated oxidation of proline and arginine side-chain residues of low-density lipoprotein apolipoprotein B-100

An alteration of apolipoprotein (apo) B-100 structure by direct oxidative modification is supposed to be an important mechanism involved in atherogenesis. There is difficulty in quantifying this type of modification owing to a lack of specific assays. We evaluated a methodology based on the oxidation of protein arginine and proline to gamma-glutamyl semialdehyde which by reduction forms 5-hydroxy-2-aminovaleric acid (HAVA). We determined HAVA by using derivatization to N(O)-ethoxycarbonyl ethyl esters and gas chromatography-mass spectrometry in different low-density lipoprotein preparations subjected to oxidative damage in the presence of iron. Results suggest that apoB-100 proline and arginine residues are highly reactive toward oxygen radicals ex vivo. Femtomole levels of HAVA can be reproducible measured. HAVA determination compares well with the measurement of carbonyl group formation used as a generally accepted but nonspecific index of protein oxidation. Thus, HAVA could prove to be a sensitive assay for studying specific modification of apoB-100.

Smoking habits and plasma lipid peroxide and vitamin E levels in never-treated first-episode patients with schizophrenia

BACKGROUND

Lipid peroxidation may be increased in schizophrenia, due to the illness, lifestyle or medication.

AIMS

To determine plasma lipid peroxide levels and serum vitamin E and A levels in first-episode never-treated people with schizophrenia and in controls.

METHOD

Thirty in-patients with a first episode of schizophrenia or schizophreniform psychosis were recruited, as were controls matched for gender, age, smoking and dietary status. Blood samples were taken, smoking status was recorded and body mass index measured.

RESULTS

There were no significant differences between patients and controls in plasma peroxide levels. Seventy-three per cent of the patients smoked. Patients who smoked had a higher mean lipid peroxide level than non-smokers. Seventy-seven per cent of patients and 70% of controls had a ratio of vitamin E to cholesterol of less than 5. Body mass index was lower in patients than in controls.

CONCLUSIONS

As a result of the high prevalence of smoking this group shows increased lipid peroxidation. Low serum ratios of vitamin E to cholesterol in both patients and controls suggest an unsatisfactory diet.

Determination of activity of antioxidants in human subjects

Evidence from biochemical and animal models suggests that nutritional antioxidants should inhibit the development of diseases such as CHD and certain cancers. This evidence is not clearly corroborated by intervention studies in human subjects, due, in part, to inadequacies in current analytical methodologies. Although in vitro assays can give useful information on the attributes required by a compound to act as an antioxidant, results may have little nutritional relevance due to limited bioavailability. The determination of antioxidants in blood is often used as a measure of antioxidant status in vivo, but may not necessarily reflect concentrations in target tissues where oxidative stress is greatest. In addition, the accumulation of antioxidants in selective tissues may not be apparent from plasma measurements. Participation in quality-control schemes for antioxidant determination by HPLC allows inter-laboratory comparison of results. Moderation of indices of oxidative damage to lipids, proteins and DNA can provide information on the effectiveness of compounds as nutritional antioxidants. However, most current methods of assessing oxidative stress are subject to confounding factors of non-oxidative origin. Assays for total antioxidant capacity in plasma differ in their type of oxidation source, target and measurement used to detect the oxidized product. They give different results, should never be used in isolation, and results should be interpreted with caution. Until more is known about the activity and metabolic fate of antioxidants, caution should be exercised in the consumption of large amounts of commercially-available antioxidant preparations.

Measures of total free radical activity in critically ill patients

OBJECTIVES

To examine the role played by free radicals during the initial phase of critical illness in patients on an Intensive Care Unit (ICU).

DESIGN AND METHODS

Serum total antioxidant status (TAS) and uric acid (UA) levels were measured in 50 patients over 18 hours to represent the initial stage of critical illness. Clinical scoring systems (APACHE II and multiple organ dysfunction scores) were used to assess the degree of organ dysfunction. Outcome was assessed according to patient survival (survivors, n = 36; non-survivors, n = 14).

RESULTS

Serum TAS was higher in non-survivors; a similar finding was demonstrated for serum UA. Levels of both biochemical markers were associated with the degree of organ function and with higher antioxidant and UA levels present in patients with more severe organ dysfunction. In addition, serum UA was significantly correlated to serum TAS and probably accounted for much of the antioxidant activity observed.

CONCLUSIONS

The increased TAS and UA levels observed may simply be a response to the degree of renal dysfunction observed as those patients with worse renal function had higher TAS and UA levels. In conclusion, measurement of serum TAS appears to be a reflection of UA concentration and results should be interpreted with caution particularly in patients who have renal dysfunction.

Assessment of status

Laboratory methods for the measurement of micronutrients are usually based upon determinations in the peripheral blood. Most are relatively insensitive, but can screen for impending acute deficiency or toxicity. The metabolic responses to disease, injury and infection may alter the laboratory findings independently of dietary supply. Methods based upon the intra-cellular biochemical function of individual micronutrients are becoming available and can detect more marginal deficiencies. The investigation of general populations for micronutrient depletions largely relies upon clinical and epidemiological evaluation of responses to controlled trials of supplementation.