Antioxidant activity of whey protein fractions isolated by gel exclusion chromatography an protease treatment

Whey proteins were isolated from whey powder by a combination of gel exclusion chromatography and protease (pepsin or trypsin) treatment. Whey solution (6 g/dl) was applied to Sephadex G-200 column chromatography and three fractions were obtained. Gel electrophoresis (SDS-PAGE) was used to identify the fractions; the first one contained immunooglobulins and bovine serum albumin, the second contained P-lactoglobulin and a-lactalbumin whereas the third fraction contained small peptides. We have also subjected the whey filtrate to proteases (pepsin and trypsin). Treatment with proteases showed that P-lactoglobulin can be obtained after hydrolysis of the second fraction with pepsin. When the whey filtrate was treated with pepsin and then applied to Sephadex G-200 column chromatography three fractions were obtained; the first one was bovine serum albumin, the second was beta-lactoglobulin and the third fraction contained small peptides. After trypsin treatment only two fractions were obtained; the first one was serum albumin and the second fraction was an alpha-lactalbumin rich fraction. We have determined the antioxidant activity of the fractions using an assay based on the measurement of superoxide radical scavenging activity. Our results showed that among the three fractions, the first fraction had the highest superoxide radical scavenging activity. Also, protease treatment of the second fraction resulted in an increase in the antioxidant activity. (c) 2007 Elsevier B.V. All rights reserved

Role of oxidative stress, factors affecting vascular physiopathology and inflammation in the pathogenesis of migraine disease

Amaç: Çalışmamızda migren tanısı konmuş hastalar ile sağlıklı kontrol grubu arasında oksidatif stres, damar fizyopatolojisi ve_x000D_ enflamasyon biyobelirteçleri açısından bir fark olup olmadığının araştırılması amaçlandı._x000D_ Materyal ve Metod: SBÜ Ümraniye Eğitim Araştırma Hastanesi Nöroloji Polikliniğine başvuran, 18 - 49 yaş arasında olup migren_x000D_ tanı kriterlerine uyan ve sistemik herhangi bir hastalığı olmayan 27 hasta ile 27 sağlıklı kişiden kan ve idrar örnekleri alındı._x000D_ İdrarda malondialdehit, eritrositlerde glutatyon, glutatyonla ilgili enzimler, süperoksit dismutaz, katalaz, malondialdehit ve_x000D_ protein karbonilleri, plazmada malondialdehit, bilirubin, ürik asit ve albümin gibi oksidatif stres biyobelirteçlerine, damar_x000D_ fizyopatolojisi biyobelirteçlerinden trombosit ve fibrinojene, enflamasyon biyobelirteçlerinden ise interkökin (IL) 1β, IL6, IL10,_x000D_ tümör nekrozis faktör (TNF) α, c reaktif protein (CRP) ve ferritin düzeyleri ölçüldü._x000D_ Bulgular: Hasta grubunda glutatyon ve glutatyonla ilgili enzimlerin yanında süperoksit dismutaz ve katalaz değerleri kontrol_x000D_ grubuna kıyasla istatistiksel olarak anlamlı düşük (p<0,001) bulundu. Plazma albümin düzeylerinde gruplar arasında istatistiksel_x000D_ fark görülmedi. Ürik asit ve total bilirubin düzeylerinde ise hasta grubundaki düzeyler istatistiksel olarak anlamlı yüksek (p<0,001)_x000D_ bulundu. Benzer şekilde oksidatif hasar belirteçleri olan protein karbonilleri ile plazma, eritrosit ve idrar malondialdehit düzeyleri_x000D_ hasta grubunda istatistiksel olarak anlamlı yüksek (p<0,001) bulundu. Damar fizyopatolojisi belirteçlerinden trombosit sayısı ve_x000D_ fibrinojen düzeylerinin hasta grubunda anlamlı olarak arttığı (p<0,001) gözlendi. Enflamasyon belirteçlerinden IL1β, IL6, IL10 ve_x000D_ TNFα düzeyleri hasta grubunda istatistiksel olarak anlamlı yüksek (p<0,001) bulunurken, CRP ve ferritin düzeyleri düşüktü._x000D_ Sonuç: Migren hastalarında oksidatif stres, damar fizyopatolojisi ve enflamasyon belirteçleri birlikte değerlendirildiğinde,_x000D_ hastalardaki baskılanan ve azalan antioksidan düzeylerinin oksidatif stresi arttırdığı dolayısıyla enflamasyon ve damar_x000D_ fizyopatolojisi değişikliklerine neden olduğu sonucuna varıldı.Background: We compared oxidative stress, vascular pathophysiology, and inflammation markers of migraine patients with_x000D_ healthy volunteers._x000D_ Materials and Methods: Blood and urine samples were obtained from 27 healthy individuals and 27 patients with a diagnosis_x000D_ of migraine who applied to Neurology Outpatient Clinics of Umraniye Research and Training Hospital. Participants were aged_x000D_ between 18 – 49 years. Patients had their diagnosis established prior to the study, and the volunteers in the control group had_x000D_ no systemic disease or relevant disorders. Urine samples were tested for malondialdehyde while erythrocytes were investigated_x000D_ for glutathione, glutathione related enzymes, superoxide dismutase, catalase, malondialdehyde, and protein carbonyls. Plasma_x000D_ samples were analyzed for malondialdehyde, bilirubin, uric acid, and albumin as oxidative stress parameters. Thrombocyte_x000D_ count and fibrinogen levels were measured for vascular physiopathology, and interleukin (IL)1β, IL6, IL10, tumor necrosis factor_x000D_ (TNF)α, CRP, and ferritin were used as inflammation markers._x000D_ Results: In addition to glutathione and glutathione-related enzymes, superoxide dismutase and catalase values were found to_x000D_ be statistically significantly lower (p<0.001) in the patient group. Albumin levels were similar in both groups, whereas uric acid_x000D_ and bilirubin levels were significantly higher (p<0.001) in the patient group. Similarly, protein carbonyls, which are oxidative_x000D_ damage markers, as well as urine, plasma, and erythrocyte malondialdehyde levels were significantly higher (p<0.001) in the_x000D_ patient group. Thrombocyte count and fibrinogen levels, both of which are vascular physiopathology markers, were found to_x000D_ increase in the patient group (p<0.001). The participants in the patient group had significantly higher (p<0.001) levels of IL1β,_x000D_ IL6, IL10, and TNFα as inflammation markers, on the other hand, CRP and ferritin levels were lower._x000D_ Conclusions: Considering oxidative stress, vascular physiopathology, and inflammation markers as a whole, we suggest that_x000D_ patients with migraine had increased oxidative stress due to suppressed and decreased levels of antioxidants and consequently_x000D_ had inflammatory and vascular changes

Whey proteins: targets of oxidation, or mediators of redox protection

Bovine whey proteins are highly valued dairy ingredients. This is primarily due to their amino acid content, digestibility, bioactivities and their processing characteristics. One of the reported bioactivities of whey proteins is antioxidant activity. Numerous dietary intervention trials with humans and animals indicate that consumption of whey products can modulate redox biomarkers to reduce oxidative stress. This bioactivity has in part been assigned to whey peptides using a range of biochemical or cellular assays in vitro. Superimposing whey peptide sequences from gastrointestinal samples, with whey peptides proven to be antioxidant in vitro, allows us to propose peptides from whey likely to exhibit antioxidant activity in the diet. However, whey proteins themselves are targets of oxidation during processing particularly when exposed to high thermal loads and/or extensive processing (e.g. infant formula manufacture). Oxidative damage of whey proteins can be selective with regard to the residues that are modified and are associated with the degree of protein unfolding, with alpha-Lactalbumin more susceptible than beta-Lactoglobulin. Such oxidative damage may have adverse effects on human health. This review summarises how whey proteins can modulate cellular redox pathways and conversely how whey proteins can be oxidised during processing. Given the extensive processing steps that whey proteins are often subjected to, we conclude that oxidation during processing is likely to compromise the positive health attributes associated with whey proteins

Plasma homocysteine and aminothiol levels in idiopathic epilepsy patients receiving antiepileptic drugs

Objective: Homocysteine is a sulfur containing amino acid that is formed during methionine metabolism. Patients under long-term antiepileptic drug treatment often have hyperhomocysteinemia. These patients have low levels of serum folate, vitamin B12 and vitamin B6, all of which are associated with homocysteine metabolism. We have investigated the effects of valproic acid and new generation antiepileptic drugs (lamotrigine and levetiracetam) on plasma levels of homocysteine and aminothiols as well as serum vitamin B12 and folic acid. Materials and methods: Forty-seven idiopathic epileptic patients on antiepileptic drugs were compared with 38 age-matched healthy controls. Commercial immuno-assay methods were used for vitamin B12 and folic acid analyses. Homocysteine, cysteine, cysteinylglycine and glutathione levels were determined by high performance liquid chromatography. Results: There was no significant difference in patient and control values in terms of vitamin B12, folic acid and homocysteine. Valproic acid and lamotrigine seemed to effect aminothiol redox status. Glutathione levels of epileptic patients receiving valproic acid and lamotrigine were higher than controls. Conclusion: Our results suggest that redox homeostasis may be impaired and glutathione synthesis increased in response to the oxidative stress caused by antiepileptic drug use

EFFECT OF ANTIEPILEPTIC DRUGS ON ERYTHROCYTE OSMOTIC FRAGILITY AND LIPID-PEROXIDATION

Epileptic children receiving antiepileptics were studied to investigate the effect of carbamazepine and phenobarbital therapy on erythrocyte osmotic fragility and lipid peroxidation. Significant differences between the two groups were observed in erythrocyte osmotic fragility. In addition, there was a significant increase in erythrocyte malondialdehyde release in the epileptic group compared to controls. It is suggested that the use of antioxidants in addition to antiepileptic drugs may be beneficial

Cumene hydroperoxide-induced chemiluminescence in human erythrocytes: effect of antioxidants and sulfhydryl compounds

1. The time-course of cumene hydroperoxide-induced changes in lipid peroxidation, protein sulfhydryl groups and chemiluminescence intensity was determined in human erythrocytes. 2. Increase in lipid peroxidation was maximal within 60 min of incubation and was paralleled by a decrease in protein sulfhydryl groups and an increase in chemiluminescence formation. 3. A standard assay system was established to investigate the protective effects of antioxidants and scavenger compounds on cumene hydroperoxide-induced chemiluminescence formation. 4. Chain-breaking antioxidants (i.e. butylated hydroxytoluene) and sulfhydryl compounds (i.e. dithiothreitol) were able to suppress chemiluminescence formation. 5. Our results suggested that secondary free radicals, as well as sulfhydryl groups of proteins are involved in cumene hydroperoxide-induced chemiluminescence formation

Imaging Reactive Oxygen Species-Induced Modifications in Living Systems

Significance: Reactive Oxygen Species (ROS) may regulate signaling, ion channels, transcription factors, and biosynthetic processes. ROS-related diseases can be due to either a shortage or an excess of ROS. Recent Advances: Since the biological activity of ROS depends on not only concentration but also spatiotemporal distribution, real-time imaging of ROS, possibly in vivo, has become a need for scientists, with potential for clinical translation. New imaging techniques as well as new contrast agents in clinically established modalities were developed in the previous decade. Critical Issues: An ideal imaging technique should determine ROS changes with high spatio-temporal resolution, detect physiologically relevant variations in ROS concentration, and provide specificity toward different redox couples. Furthermore, for in vivo applications, bioavailability of sensors, tissue penetration, and a high signal-to-noise ratio are additional requirements to be satisfied. Future Directions: None of the presented techniques fulfill all requirements for clinical translation. The obvious way forward is to incorporate anatomical and functional imaging into a common hybrid-imaging platform

Combined effects of quercetin and curcumin on anti-inflammatory and antimicrobial parameters in vitro

In this in-vitro study, combinatory anti-inflammatory interactions between Quercetin (Q) and Curcumin (C) along with their combined antimicrobial activity against MRSA were studied. Anti-inflammatory markers of (i) COX-2 expression, (ii) NF kappa beta activation and (iii) NO levels were investigated. Antimicrobial synergy was tested by checkerboard assay. We found that, treatment with the low-concentration combination group (QC), where Q and C were combined, resulted in significant downregulation of COX-2 expression (P < 0.0001) and inhibition of NF kappa beta activation in cells (P < 0.0001), to a similar extent to that induced by higher concentrations of Q and C alone. QC treatment was also found to induce a significant reduction in NO production (P < 0.0001). QC was significantly more effective in the reduction of total NO levels when compared to Q alone (P < 0.001). Checkerboard assay indicated that the combination of Q and C provides better killing of MRSA in lower dilutions than standalone Minimum Inhibitory Concentrations. These results suggest that combining low concentrations of Q and C yield similar or better anti-inflammatory effectiveness when compared to treatment with each agent alone. Moreover, they co-operate synergistically in the context of antimicrobial activity, with an increased effectiveness when compared to Q or C alone at high concentrations

Increased plasma and erythrocyte lipid peroxidation in hyperlipidemic individuals

[No abstract available