Iron is an essential element for living organisms. However, as it is a transition metal, it can participate in Fenton reaction resulting in generation of free radicals and oxidative damage to tissues. Antioxidants may prevent possible iron toxicity by chelating free iron or scavenging free radicals. Falvonoids are naturally occurring substances that are capable of formation of complexes with metals, including iron. T h e y have been show to possess antioxidant activity, which depends on molecular complexity of numerous types of flavonoids, e.g. quercetin and silibinin. Bisphosphonates are synthetic drugs used to treat various metabolic diseases of bones. Their principál effect is an inhibition of osteclast activity leading to a decreased bone resorption. Bisphosphonates have been however shown to exert some antioxidant activity in in vitro experiments, too. The aim of this PhD thesis was to investigate the role of iron in toxicity of other metals (cadmium) and the effect of flavonoids (quercetin and silibinin) and bisphosphonates (clodronate, etidronate and risedronate) on iron-induced oxidative damage in vivo. Experiments were performed in male mice (CD-1, Charles River, 25-35 body weight). Iron was administered intraperitoneally or in the diet. Cadmium was administered subcutaneously. Flavonoids and...

Iron is an essential element for living organisms. However, as it is a transition metal, it can participate in Fenton reaction resulting in generation of free radicals and oxidative damage to tissues. Antioxidants may prevent possible iron toxicity by chelating free iron or scavenging free radicals. Falvonoids are naturally occurring substances that are capable of formation of complexes with metals, including iron. T h e y have been show to possess antioxidant activity, which depends on molecular complexity of numerous types of flavonoids, e.g. quercetin and silibinin. Bisphosphonates are synthetic drugs used to treat various metabolic diseases of bones. Their principál effect is an inhibition of osteclast activity leading to a decreased bone resorption. Bisphosphonates have been however shown to exert some antioxidant activity in in vitro experiments, too. The aim of this PhD thesis was to investigate the role of iron in toxicity of other metals (cadmium) and the effect of flavonoids (quercetin and silibinin) and bisphosphonates (clodronate, etidronate and risedronate) on iron-induced oxidative damage in vivo. Experiments were performed in male mice (CD-1, Charles River, 25-35 body weight). Iron was administered intraperitoneally or in the diet. Cadmium was administered subcutaneously. Flavonoids and...

The author deals with oxidative stress and its effects on the pathogenesis of various diseases including the development of insulin resistance. The work is divided in the usual way overview of current knowledge on the issues, methods, results, discussion and conclusions. Part of this work is to describe an animal experiment in the waking state, whose introduction to our department was one of the tasks of this graduate work.

Charles University University of Porto Faculty of Pharmacy in Hradec Králové Faculty of Pharmacy Department of Pharmacology and Toxicology Department of Biological Sciences Student: Karolína Zubatá Supervisor: doc. PharmDr. Martina Čečková, Ph.D. Consultants: Susana Rocha, Ph.D., prof. Alice Santos-Silva, Ph.D. Title of diploma thesis: Oxidative stress biomarkers of the erythrocyte in the newborn - a follow-up study Increased levels of oxidative stress (OS) have been described in healthy, full-term newborns as a consequence of the drastic changes introduced by birth and by the exposure to extrauterine environment. Our intention was to examine the OS levels in red blood cells (RBCs) of neonates and to further understand the changes that the newborn organism undergoes with its newly- acquired autonomy as this knowledge is limited and there are no reference values. Umbilical cord blood samples were collected from a small population of newborns (n = 8) and several hematological and biochemistry parameters were evaluated. Our experimental data consist of OS biomarkers measurements performed in different fractions of blood (RBC membrane, total RBCs and plasma): membrane bound hemoglobin (MBH), lipid peroxidation (LPO), quantification of catalase (CAT) and glutathione peroxidase (GPx) activities,...

The author deals with oxidative stress and its effects on the pathogenesis of various diseases including the development of insulin resistance. The work is divided in the usual way overview of current knowledge on the issues, methods, results, discussion and conclusions. Part of this work is to describe an animal experiment in the waking state, whose introduction to our department was one of the tasks of this graduate work.

The extract from the plant Galega officinalis containing the guanidine derivative galegin has been used in the treatment of diabetes-associated complications since middle ages. Nevertheless, the positive effects of the treatment were often overweight by the adverse side effects. Some sixty years ago guanidin was replaced by the less toxic synthetic biguanide derivatives - metformin, phenphormin and buformin, the latter two being withdrawn due to the unacceptable risk of fatal lactate acidosis. Metformin is still widely used antidiabetics and belongs to the first choice drugs in the treatment of type 2 diabetes. Phenphormin is now gaining renewed attention with regard to its antineoplastic properties. Despite its long-term clinical use the mechanism of biguanides action is not fully understood yet. At present it is generally accepted that the core of its antihyperglycemic effect lays in the inhibition of hepatic gluconeogenesis. In contrast, there is less consensus regarding the particular metabolic pathway or target that are responsible for the metformin-induced attenuation of gluconeogenesis. For a long time, a hot candidate for metformin target in the cell was AMP-activated kinase (AMPK) but the metformin effect was proved also in mice carrying the dominant negative mutation of AMPK α subunit. Quite...

The hypothesis that experimental manipulations increasing life span correlate to reduced physical activity and reduced molecular oxidative damage was tested. We used three longevity phenotypes of males and females of Pyrrhocoris apterus, diapause insects, reproductive insects and insect with ablation of the corpus allatum, an endocrine gland producing juvenile hormone. Protein carbonyl content in thoracic muscles was used as an index of molecular oxidative modification.

This thesis is focused on the study of glycosphingolipids in the rat liver in different types of cholestasis and the effect of oxidative stress on changes in the composition and localization of gangliosides. First, it was necessary to optimize the immunochemical detection of glycosphingolipids. GM1 ganglioside was selected as a representative of a large glycolipid family. We found that minimum water content in the fixing solution was a key condition for fixation of histological sections. Optimized method of GM1 detection was subsequently used in in vivo experiments. We have demonstrated that estrogen-induced cholestasis characterized by high concentrations of bile acids and increased oxidative stress caused changes in the synthesis and distribution of liver gangliosides. HMOX induction is associated with a reduction in oxidative stress level and accompanied by normalization in GSL content. In experiments with obstructive cholestasis, we found that changes in the distribution and synthesis of gangliosides were not strictly specific to a particular type of cholestasis. We assume that it represents a general mechanism of hepatoprotection. We also confirmed the important role of bilirubin, product of HMOX reaction, in protection of hepatocytes against oxidative damage caused by high concentrations of...

This thesis is focused on the study of glycosphingolipids in the rat liver in different types of cholestasis and the effect of oxidative stress on changes in the composition and localization of gangliosides. First, it was necessary to optimize the immunochemical detection of glycosphingolipids. GM1 ganglioside was selected as a representative of a large glycolipid family. We found that minimum water content in the fixing solution was a key condition for fixation of histological sections. Optimized method of GM1 detection was subsequently used in in vivo experiments. We have demonstrated that estrogen-induced cholestasis characterized by high concentrations of bile acids and increased oxidative stress caused changes in the synthesis and distribution of liver gangliosides. HMOX induction is associated with a reduction in oxidative stress level and accompanied by normalization in GSL content. In experiments with obstructive cholestasis, we found that changes in the distribution and synthesis of gangliosides were not strictly specific to a particular type of cholestasis. We assume that it represents a general mechanism of hepatoprotection. We also confirmed the important role of bilirubin, product of HMOX reaction, in protection of hepatocytes against oxidative damage caused by high concentrations of...

The aim of this study was to evaluate the relationship of oxidative stress (OS) marker s in exhaled breath condensate (EBC) in adult patients with cystic fibrosis (CF) to the severity of lung disease, nutritional status and systemic antioxidants and inflammatory markers, as well as to short - and medium - term development of pulmonary function and nutritional status, and finally to assess the response to treatment with inhaled corticosteroids (ICS). Methods: CF patients were examined in a stable phase of the disease during routine outpatient controls. EBC was collected using E C oScreen device (J aeger) in CF patients and in control group members. Nitrites and nitrates and 8 - isoprostane were examined using liquid chromatography and competitive enzyme immunoanalysis, respectively, in EBC as OS markers. Demographic data including the dominant pathogen of airway colonization and ICS treatment were recorded in CF patients. Lung function tests, chest X-ray s, nutritional statuses and systemic antioxidants and inflammatory markers were also examined using standard methods. The values of OS markers in EBC in patients with CF were compared with the control group and correlated to clinical parameters. Lung function tests and nutritional status es in CF patients were examined in one, three and five years intervals...