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Comparative Study 2006; 27(Suppl 2): 112-115 PubMed PMID: 17159793 Citation  Keywords:  Adult, Aged, Aged, 80 and over, DNA Damage, Diet, Female, Fruit, Humans, Male, Malondialdehyde:blood, Middle Aged, Mineral Fibers:toxicity, Occupational Diseases:prevention & control, Oxidative Stress, Vegetables, Vitamins:blood,.   

OBJECTIVES: In humans, epidemiological evidence suggests that increased consumption of fruits and vegetables can substantially enhance the protection against many common types of cancer.

METHODS & RESULTS: A molecular epidemiological study in 3 Slovak factories producing asbestos, glass fibres and rockwool was conducted. Altogether 388 subjects (239 exposed, 148 controls) were investigated. Food frequency questionnaire was used to ascertain nutrient intake and compared to plasma levels of selected micronutrients, as well as to markers of oxidative stress (MDA, oxidative DNA damage and DNA repair) and antioxidant protection. We found a negative correlation between MDA concentrations and consumption of fruits (p=0.05) and vegetables (p=0.05) in all control subjects. Intake of fruits (p=0.05), vegetables (p=0.01), milk (p=0.01) and cereals (p=0.05) inversely correlated with oxidative DNA damage (net FPG) in all subjects investigated. There was a negative correlation between the intake of fruits (p=0.05) and vegetables (p=0.01) in all exposed subjects.

CONCLUSIONS: Our results suggest that well balanced food consumption with higher fruits and vegetables intake has a protective effect against oxidative damage....

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Comparative Study 2006; 27(Suppl 2): 65-68 PubMed PMID: 17159782 Citation  Keywords:  Asphyxia Neonatorum:blood, Delivery, Obstetric, Glutathione Peroxidase:blood, Humans, Infant, Newborn, Malondialdehyde:blood, Oxidative Stress, Stress, Physiological:blood, Superoxide Dismutase:blood, Term Birth:blood,.   

OBJECTIVES: In healthy term newborns (HTN) to determine on the 1st and 5th day of life the activity of total antioxidant capacity (TAS), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GPX) and to compare the values with the group of asphyxiated term newborns (ATN).

PATIENTS/METHODS: The series consisted of 15 HTN and 24 ATN. In both groups TAS, MDA, GPX and SOD were investigated.

RESULTS: Reference values in HTN (1st/5th day of life) for TAS were 0.52+/-0.03/0.49+/-0.04 mmol/l, for MDA 0.72+/-0.07/1.08+/-0.09 micromol/l, for SOD 594.20+/-16.47/591.23+/-14.14 Ug/Hb and for GPX 25.48+/-1.32/25.98+/-1.20 Ug/Hb. In a group of ATN the obtained values were (1st/5th day of life): TAS 1.1+/-0.08/0.98+/-0.08 mmol/l, MDA 2.08+/-0.22/2.21+/-0.34 micromol/l, SOD 509.18+/-26.8/564.49+/-36.4 Ug/Hb and GPX 30.2+/-1.9/32.45+/-2.69 Ug/Hb.

CONCLUSIONS: Statistically significant differences were found on the 1st and 5th day of life between the two groups investigated in values of MDA (**p<0.01) and TAS (**p<0.01). Increased values of MDA in the group of ATN on the 1st and 5th day of life confirmed the presence of lipoperoxidation. The obtained values of TAS on the 1st and 5th day of life in the group of ATN were surprisingly higher than in HTN. The increase of TAS in ATN could point to a certain ability of ATN to prevent the damage of balance between overproduction of MDA and antioxidants. The results of SOD and GPX activity were not statistically significant, yet they are indicative of the biochemical reaction of the organism of term newborns to asphyxia....

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Comparative Study 2006; 27(5): 615-621 PubMed PMID: 17159817 Citation  Keywords:  Adult, Epitopes:immunology, Fatigue Syndrome, Chronic:blood, Fatty Acids:immunology, Female, Humans, Immunoglobulin M:blood, Male, Middle Aged, Oxidative Stress:immunology, Proteins:immunology, Reactive Nitrogen Species:immunology, Reactive Oxygen Species.   

: There is now some evidence that chronic fatigue syndrome (CFS) is accompanied by signs of oxidative stress and by a decreased antioxidant status. The aim of the present study was to examine whether CFS is accompanied by an immune response to neoepitopes of a variety of modified lipids and proteins indicating damage caused by oxidative and nitrosative stress. Toward this end we examined serum antibodies to fatty acids (oleic, palmitic and myristic acid), by-products of lipid peroxidation, i.e. azelaic acid and malondialdehyde (MDA), acetylcholine, S-farnesyl-L-cysteine, and N-oxide modified amino-acids in 14 patients with CFS, 14 subjects with partial CFS and 11 normal controls. We found that the prevalences and mean values for the serum IgM levels directed against oleic, palmitic and myristic acid, MDA, azelaic acid, S-farnesyl-L-cysteine, and the N-oxide derivates, nitro-tyrosine, nitro-phenylalanine, nitro-arginine, nitro-tryptophan, and nitro-cysteinyl were significantly greater in CFS patients than in normal controls, whereas patients with partial CFS took up an intermediate position. There were significant and positive correlations between the serum IgM levels directed against fatty acids, MDA and azelaic acid and the above N-oxide-derivates and the severity of illness (as measured by the FibroFatigue scale) and symptoms, such as aches and pain, muscular tension and fatigue. The results show that CFS is characterized by an IgM-related immune response directed against disrupted lipid membrane components, by-products of lipid peroxidation, S-farnesyl-L-cysteine, and NO-modified amino-acids, which are normally not detected by the immune system but due to oxidative and nitrosative damage have become immunogenic....

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Comparative Study 2006; 27(5): 595-599 PubMed PMID: 17159816 Citation  Keywords:  Animals, Antioxidants:pharmacology, Antithyroid Agents:pharmacology, Diet, Dose-Response Relationship, Drug, Kidney:chemistry, Liver:chemistry, Lung:chemistry, Male, Oxidative Stress:drug effects, Potassium Iodide:administration & dosage, Propylthiouracil.   

OBJECTIVES: Iodide administration to animals, living in iodine-deficient areas, can induce oxidative processes in the thyroid gland and increase concentration of lipid peroxidation (LPO). Propylthiouracil (PTU)--a well-known antithyroid drug--may also act as an antioxidant. There are some reports, which consider the protective ability of this drug against LPO. The goal of the study was to evaluate oxidative processes and the protective role of PTU in three rat organs during treatment with pharmacological doses of iodide.

MATERIAL AND METHODS: Schiff's bases (SB) concentrations (a parameter of oxidative stress) were measured in liver, lung and kidney homogenates of male Wistar rats. For 2 weeks the animals received iodides in their diet in the following concentrations: Group 1--Controls (standard diet, approx. 0.7 mg of potassium iodide per kg; KI/kg); Group 2--diet containing 0.25 mg KI/kg; Group 3--diet with 4.0 mg KI/kg; Group 4--diet with 8.0 mg KI/kg. Group 5--standard diet with 0.1% of PTU in drinking water for two weeks. Subsequent tree groups (6-8) received KI in their diet in doses as above, respectively, together with PTU.

RESULTS: We noted increased SB levels in the lungs and in the liver, compared to those observed in the control group. We also found decreased SB concentrations in liver and lung homogenates after the administration of PTU but, unexpectedly, the level of SB increased in kidney homogenates of all the groups.

CONCLUSIONS: The results of this study indicate that iodine is involved in oxidative processes in different organs and PTU protects against iodine-induced oxidative stress....

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Comparative Study 2005; 26(6): 806-810 PubMed PMID: 16380687 Citation  Keywords:  Animals, Glutathione:metabolism, Hyperthyroidism:chemically induced, Kidney:metabolism, Lipid Peroxidation, Male, Malondialdehyde:metabolism, Melatonin:metabolism, Oxidative Stress:physiology, Rats, Rats, Sprague-Dawley, Testis:metabolism, Thyroxine,.   

OBJECTIVE: The present study aimed at determining how 3-week intraperitoneal melatonin administration affected oxidative stress caused by experimental hyperthyroidism.

MATERIALS AND METHODS: The study was conducted on 30 male rats of Sprague-Dawley species. The experimental animals were divided to 3 groups (control, hyperthyroidism and hyperthyroidism+melatonin). The supplementation was continued for 3 weeks after which the animals were sacrificed and tissue malondyaldehyde (MDA) and glutathione (GSH) levels were determined.

RESULTS: MDA levels in kidney and testis tissues in hyperthyroidism group were higher than those in control and hyperthyroidism+melatonin administered groups (p<0.001) and levels in hyperthyroidism+melatonin administered group were higher than those in the control group (p<0.001). The highest GSH levels were obtained in hyperthyroidism+melatonin-administered group (p<0.001) and GSH levels in hyperthyroidism group were higher than those in the control group (p<0.001).

CONCLUSION: Results of the study demonstrate that hyperthyroidism induced by 3-week L-thyroxine administration increased oxidative stress in kidney and testis tissues and that although melatonin administration inhibited this stress to a certain extent, it could not bring the stress down to the level in controls....

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Comparative Study 2004; 25(1-2): 70-74 PubMed PMID: 15159686 Citation  Keywords:  Animal Feed, Animals, Antioxidants:physiology, Brain:metabolism, Dose-Response Relationship, Drug, Iodides:administration & dosage, Liver:metabolism, Lung:metabolism, Male, Melatonin:physiology, Oxidative Stress:physiology, Rats, Rats, Wistar, Schiff Base.   

OBJECTIVES: Administration of iodides to animals, living in iodine-deficient areas, can induce necrosis and fibrosis of the thyroid gland. It is believed that structural and functional changes of the thyroid may be related to oxidative processes. Increased lipid peroxidation levels were reported in murine thyroid glands after high doses of iodine. Melatonin (MEL) is believed to exert its effects via electron donation to directly detoxify free radicals, such as, e.g., the highly toxic hydroxyl radical. In numerous reports related to the antioxidative action of MEL, the authors have considered the protective ability of this hormone against peroxidation of lipids. The goal of the study was to evaluate oxidative processes and the protective role of MEL in three organs of the rat (the liver, the brain, and the lungs) during treatment with different doses of iodide.

MATERIAL AND METHODS: Schiff's bases (SB) concentrations (a parameter of oxidative stress) were measured in liver, lung and brain homogenates of male Wistar rats. The animals received iodides in their diet in the following concentrations, for 2 weeks: Group 1--Controls (standard normal-iodine diet, containing approx. 0.7 mg of kalium iodide per kg; KI/kg); Group 2--diet containing 0,25 mg KI/kg; Group 3--diet with 4,0 mg KI/kg; Group 4--diet with 8,0 mg KI/kg. Group 5--standard normal-iodine diet and MEL alone in a dose of 1 mg/kg BW i.p. at 3.00 pm, every day for two weeks. Subsequent three groups (6-8) received KI in their diet in doses as above, respectively, together with MEL.

RESULTS: We noted increased levels of SB in the lungs and in the liver, when compared to those observed in controls. We also found decreased SB concentrations in liver and lung homogenates after an administration of MEL but--unexpectedly--the level of SB increased in the group with the highest dose of iodine in diet in lung homogenates. Increased levels of Schiff's bases suggest that iodine is involved in oxidative processes not only in the thyroid but also in other tissues, and MEL protects against the iodine-induced oxidative stress.

CONCLUSION: Our results confirm the differences in lipid peroxidation among the examined organs. These alterations can possibly be related to different sensitivity rates of examined tissues to oxidative damage....

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Journal Article 2003; 24(5): 293-303 PubMed PMID: 14647000 Citation  Keywords:  Animals, Humans, Oxidative Stress:physiology, Pineal Gland:physiology, Thyroid Diseases:metabolism, Thyroid Gland:metabolism,.   

: Reactive oxygen species (ROS) play an important role in physiological processes, but - when being in excess - ROS cause oxidative damage to molecules. Under physiological conditions, the production and detoxification of ROS are more-or-less balanced. Also in the thyroid, ROS and free radicals participate in physiological and pathological processes in the gland. For example, hydrogen peroxide (H2O2) is crucial for thyroid hormone biosynthesis, acting at different steps of the process. Additionally, H2O2 is believed to participate in the Wolff-Chaikoff's effect, undergoing in conditions of iodide excess in the thyroid. Much evidence has been accumulated indicating that oxidative stress is involved in pathomechanism of thyroid disease, e.g., Graves' disease, goiter formation or thyroid cancer. Melatonin (N-acetyl-5-methoxytryptamine) - the main secretory product of the pineal gland - is a well-known antioxidant and free radical scavenger, widely distributed in the organism. Mutual relationships between the pineal gland and the thyroid have - for a long time - been a subject of intensive research. The abundant to-date's evidence relates mostly to the inhibitory action of melatonin on the thyroid growth and function and - to a lesser extent - to the stimulatory effects of thyroid hormones on the pineal gland. It is highly probable that under physiological conditions melatonin and, possibly, other antioxidants regulate ROS generation for thyroid hormone synthesis. We believe that melatonin may protect against extensive oxidative damage in the course of certain thyroid disorders or in case of a harmful action of some external factors on the thyroid. Thus, oxidative damage and the protective action of antioxidants, melatonin included, may occur during both physiological and pathological processes in the thyroid, however, this assumption, requires further studies....

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Journal Article 2002; 23(Suppl 1): 39-44 PubMed PMID: 12019350 Citation  Keywords:  Animals, Anticarcinogenic Agents:pharmacology, Antioxidants:pharmacology, Carcinogens:antagonists & inhibitors, Humans, Melatonin:pharmacology, Oxidative Stress:physiology,.   

: The complex process of carcinogenesis is, to a large extent, due to oxidative stress. Numerous indicators of oxidative damage are enhanced in the result of the action of carcinogens. Several antioxidants protect, with different efficacy, against oxidative abuse, exerted by carcinogens. Recently, melatonin (N-acetyl-5-methoxytryptamine) and some other indoleamines have gained particular meaning in the defense against oxidative stress and, consequently, carcinogenesis. Some antioxidants, like ascorbic acid, play a bivalent role in the antioxidative defense, revealing, under specific conditions, prooxidative effects. Among known antioxidants, melatonin is particularly frequently applied in experimental models of anticarcinogenic action. In the numerous studies, examining several parameters of oxidative damage and using several in vitro and in vivo models, this indoleamine has been shown to protect DNA and cellular membranes from the oxidative abuse caused by carcinogens. When either preventing or decreasing the oxidative damage to macromolecules, melatonin also protects against the initiation of cancer. The protection provided by melatonin and some other antioxidants against cellular damage, due to carcinogens, make them potential therapeutic supplements in the conditions of increased cancer risk....

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