Kinetics of Glycoxidation of Bovine Serum Albumin by Glucose, Fructose and Ribose and Its Prevention by Food Components

The aim of this study was to compare the kinetics of the glycoxidation of bovine serum albumin (BSA) as a model protein by three sugars: glucose, fructose and ribose, using fluorometric measurements of the content of advanced glycation end products (AGEs), protein-bound fructosamine, dityrosine, N'-formylkynurenine, kynurenine, tryptophan, the content of advanced oxidation protein products (AOPP), protein carbonyl groups, as well as thiol groups. Moreover, the levels of glycoalbumin and AGEs were determined by using an enzyme-linked immunosorbent assay. Based on the kinetic results, the optimal incubation time for studies of the modification of the glycoxidation rate by additives was chosen, and the effects of 25 compounds of natural origin on the glycoxidation of BSA induced by various sugars were examined. The same compounds were found to have different effects on glycoxidation induced by various sugars, which suggests caution in extrapolation from experiments based on one sugar to other sugars. From among the compounds tested, the most effective inhibitors of glycoxidation were: polyphenols, pyridoxine and 1-cyano-4- hydroxycinnamic acid.The study has been supported by Grant 2011/01/M/NZ3/02065 from the Polish National Science Center and performed within the COST (European Cooperation in Science and Technology) action CM1001

Kinetics of Glycoxidation of Bovine Serum Albumin by Methylglyoxal and Glyoxal and its Prevention by Various Compounds

The aim of this study was to compare several methods for measurement of bovine serum albumin (BSA) modification by glycoxidation with reactive dicarbonyl compounds (methylglyoxal ‒ MGO and glyoxal ‒ GO), for studies of the kinetics of this process and to compare the effects of 19 selected compounds on BSA glycation by the aldehydes. The results confirm the higher reactivity of MGO with respect to GO and point to the usefulness of AGE, dityrosine and N′-formylkynurenine fluorescence for monitoring glycation and evaluation of protection against glycation. Different extent of protection against glycation induced by MGO and GO was found for many compounds, probably reflecting effects on various stages of the glycation process. Polyphenols (genistein, naringin and ellagic acid) were found to protect against aldehyde-induced glycation; 1-cyano-4-hydroxycinnamic acid was also an effective protector.The study has been supported by Grant 2011/01/M/NZ3/02065 from the Polish National Science Center. We are indebted to J. Skolimowski for the synthesis of nitroxide

Oxidative Modification of Proteins in Pediatric Cystic Fibrosis with Bacterial Infections

Pseudomonas aeruginosa and Staphylococcus aureus cause chronic lung infection in cystic fibrosis (CF) patients, inducing chronic oxidative stress. Several markers of plasma protein oxidative damage and glycoxidation and activities of erythrocyte antioxidant enzymes have been compared in stable CF patients chronically infected with Pseudomonas aeruginosa ( = 12) and Staphylococcus aureus ( = 10) in relation to healthy subjects ( = 11). Concentration of nitric oxide was also measured in the exhaled air from the lower respiratory tract of patients with CF. Elevated glycophore (4.22 ± 0.91 and 4.19 ± 1.04 versus control 3.18 ± 0.53 fluorescence units (FU)/mg protein; < 0.05) and carbonyl group levels (1.9 ± 0.64, 1.87 ± 0.45 versus control 0.94 ± 0.19 nmol/mg protein; < 0.05) as well as increased glutathione S-transferase activity (2.51 ± 0.88 and 2.57 ± 0.79 U/g Hb versus 0.77 ± 0.16 U/g Hb; < 0.05) were noted in Pseudomonas aeruginosa and Staphylococcus aureus infected CF. Kynurenine level (4.91 ± 1.22 versus 3.89 ± 0.54 FU/mg protein; < 0.05) was elevated only in Staphylococcus aureus infected CF. These results confirm oxidative stress in CF and demonstrate the usefulness of the glycophore level and protein carbonyl groups as markers of oxidative modifications of plasma proteins in this diseaseThe study has been supported by the Polish Ministry of Science and Higher Education with an Iuventus Plus Grant IP201104797

Bioleptin as a useful marker of metabolic status in children with diabetes mellitus type 1

IntroductionThe purpose of our study was tomeasure the level of leptin and biologically active leptin (bioLEP) in children with type 1 diabetes, depending on the duration of diabetes and its degree of metabolic control.MethodsThe study included 94 children (58 boys and 36 girls). In a group of children with diabetes, 40 patients were newly diagnosed with type 1 diabetes, 40 children who have diabetes for more than a year (20 with good metabolic control and 20 with poor metabolic control). The control group consisted of 14 healthy children. The serum level of leptin and bioLEP was measured using a sandwich enzyme-linked immunosorbent assay. To our knowledge, this is the first study to describe bioLEP levels among diabetic children with different forms of disease control.ResultsLower levels of leptin were found in children with diabetes compared to healthy children. Furthermore, we found a statistically higher concentration of leptin in the group of children with newly diagnosed diabetes compared to children from the diabetic group with poor metabolic control and lower than healthy children (11.19 vs. 7.84 and 20.94 ng/mL). Moreover, children in the metabolically well-controlled group had statistically lower levels of this hormone (5.11 ng/mL) than healthy children. Leptin concentrations differed significantly between underweight, overweight, and obese children.DiscussionIn our study, the level of bioLEP differed significantly between children in the newly diagnosed diabetes group and children in the long-term, poorly controlled diabetes group and healthy controls. Despite many studies published in recent years, many aspects of leptin secretion, action, and mechanisms of its influence on carbohydrate and fat metabolism are still to be clarified. In our opinion, studies evaluating the status of bioLEP in diabetes can also contribute to a better understanding of the mechanisms regulating metabolism

Links between Disease Severity, Bacterial Infections and Oxidative Stress in Cystic Fibrosis

Cystic fibrosis (CF) is one of the most common, yet fatal genetic diseases in Caucasians. The presence of a defective CF transmembrane conductance regulator and the massive neutrophils influx into the airways contribute to an imbalance in epithelial cell processes and extracellular fluids and lead to excessive production of reactive oxygen species and intensification of oxidative stress. The study included 16 controls and 42 participants with CF aged 10 to 38. The products of protein oxidation, total antioxidant capacity (TAC) and markers of lipid peroxidation were estimated in the serum of the subjects. Furthermore, we compared the level of oxidative stress in patients with CF according to the severity of disease and type of bacterial infection. Thiol groups and serum TAC decreased significantly in patients with CF (p &lt; 0.05). Elevated levels of 3-nitrotyrosine, malondialdehyde and 8-isoprostane were observed in CF subjects (p &lt; 0.05). Furthermore, as the severity of the disease increased, there was a decrease in the thiol groups and TAC levels, as well as an increase in the concentration of 3-nitrotyrosine and 8-isoprostane. CF participants infected with Pseudomonas aeruginosa had elevated 3-nitrotyrosine concentration levels (p &lt; 0.05), while those infected with Staphylococcus aureus noted a decrease in thiol groups (p &lt; 0.05). Elevated levels of oxidative stress markers were found in the serum of CF patients. Furthermore, oxidative stress progressively increased over the years and along with the severity of the disease. The presence of bacterial infection with P. aeruginosa or S. aureus had a slight effect on oxidative stress, while co-infection by two species did not affect the level of oxidative stress

Influence of food-derived advanced glycation end products on health

Introduction. Advanced glycation end products (AGEs) are compounds formed endogenously in the human body. Besides this source of AGEs, they also exist in food and can be generated during cooking. Enhanced endogenous generation and intake of dietary AGEs have physiological impact on human health and are associated with progression of many diseases, including diabetes and its complications. Aim. The purpose of this review is to the present the current state of knowledge about the various negative effects of advanced glycation end products on human health. Materials and methods. This study is based on analysis of literature reporting the content of AGEs in food and high or low AGEs dietary interventions in human and animal subjects. Results. Literature data present databases gathering description of AGEs determinations in various types of food. Conclusions. Excessive consumption of AGEs-rich products, especially abundant in protein and fat or cooked for a long time at high temperature, may contribute to the deterioration of human health, including development of hypertension, insulin resistance, and diabetic complications

Influence of food-derived advanced glycation end products on health

Introduction. Advanced glycation end products (AGEs) are compounds formed endogenously in the human body. Besides this source of AGEs, they also exist in food and can be generated during cooking. Enhanced endogenous generation and intake of dietary AGEs have physiological impact on human health and are associated with progression of many diseases, including diabetes and its complications. Aim. The purpose of this review is to the present the current state of knowledge about the various negative effects of advanced glycation end products on human health. Materials and methods. This study is based on analysis of literature reporting the content of AGEs in food and high or low AGEs dietary interventions in human and animal subjects. Results. Literature data present databases gathering description of AGEs determinations in various types of food. Conclusions. Excessive consumption of AGEs-rich products, especially abundant in protein and fat or cooked for a long time at high temperature, may contribute to the deterioration of human health, including development of hypertension, insulin resistance, and diabetic complications

Fractional Exhaled Nitric Oxide in Teenagers and Adults with Atopic Dermatitis

Fractional exhaled nitric oxide (FeNO) is a non-invasive biomarker of eosinophilic airway inflammation and therapeutic response to corticosteroid treatment of respiratory diseases. Atopic dermatitis (AD), one of the most common allergic conditions of the skin, is a factor influencing the increase of FeNO. The main aim of this study was to determine differences between levels of FeNO in patients with AD and healthy controls as measured by an electrochemical analyzer. In total, 54 teenagers and adults with AD were recruited and compared with 34 healthy volunteers. The measurements of FeNO were taken using the Hyp&rsquo;Air FeNO in participants. FeNO was statistically significantly higher in patients with AD than in healthy controls (60.5 &plusmn; 35.1 vs. 14.8 &plusmn; 5.1 ppb, p &lt; 0.001). We found a strong positive significant correlation between FeNO and the number of positive skin prick tests among AD patients (R = 0.754, p &lt; 0.001). There was no correlation between FeNO and duration of disease as well as SCORAD index among patients. Moreover, we also found no FeNO difference between the mild and moderate forms of AD. The presence of AD and the increasing number of positive skin prick tests increase FeNO, so the results of this measurement should be interpreted with caution in patients with respiratory diseases suffering from AD