Melatonin has been shown to play a role in antioxidative defence. We therefore studied its effect on oxidative damage to the rat cerebral cortex evoked by painful stimulation and immobilization-induced stress. Moreover, the effect of melatonin on chronic pain perception was examined. Rats were injected with either a high dose of melatonin (100 mg/kg i.p.) or a vehicle for five days and were subjected to painful stimulation or immobilization stress 30 min after the treatment. To determine the degree of oxidative stress, the levels of free radicals, thiobarbituric acid reactive substances (TBARS) as indicators of lipid peroxidation and glutathione peroxidase (GSHPx) were estimated in somatosensory cortex. Pain perception was measured by the tail-flick and plantar test. Melatonin reduced the level of TBARS previously increased by painful stimulation. Melatonin also exhibited a slight analgesic effect in those animals exposed to painful stimulation but its role in free radical scavenging did not contribute to this effect., I. Pekárková, S. Parara, V. Holeček, P. Stopka, L. Trefil, J. Racek, R. Rokyta., and Obsahuje bibliografii
The aim of this study was to assess the influence of regular daily consumption of white wine on oxidative stress and cardiovascular risk markers. Forty-two healthy male volunteers consumed 375 ml of white wine daily. Each participant provided three venous blood samples (before wine consumption, following the wine consumption period and again a month later). Levels of superoxide dismutase, glutathione peroxidase, reduced glutathione, total antioxidant capacity, total cholesterol, HDL-cholesterol, apolipoprotein A I, apolipoprotein B, triglycerides, paraoxonase 1, C-reactive protein, homocysteine, thiobarbituric acid reactive substances (TBARS) and advanced oxidation protein products (AOPP) were measured. Immediately following the month of white wine consumption there was a significant increase in HDL-cholesterol (p<0.0001), paraoxonase 1 (p<0.001), glutathione peroxidase (p<0.001) and reduced glutathione (p<0.01) levels, a decrease in superoxide dismutase activities (p<0.0001), and a decrease in oxidation protein products (p<0.001) and TBARS (p<0.05) concentrations. However, there was also a clear increase in homocysteine (p<0.0001) after a month of white wine consumption. The results of our non-placebo controlled trial suggest that regular daily white wine consumption is associated not only with both antioxidative and antiatherogenic effects but also with a potentially proatherogenic increase of homocysteine concentrations. and D. Rajdl, J. Racek, L. Trefil, K. Siala.
Ultraviolet-radiation exerts a well-known role in the development of various ocular diseases and may contribute to the progress of age-related macular degeneration. Therefore, the use of compounds able to protect the eyes from UV-induced cellular damage is challenging. The aim of this study has been to test the protective effects of an antioxidant topical formulation against UV-induced damage in rabbit eyes. Twelve male rabbits were used. Animals were divided into 4 groups of 3 animals each. Control group (CG) did not receive any irradiation and/or eye drop. The other three experimental groups were treated as follows: the first group received only UVR irradiation for 30 min, without eye drop supplementation (Irradiation group, IG), the second (G30) and the third (G60) groups received UV irradiation for 30’ and 60’, respectively, and eye drop supplementation (riboflavin, d-α-tocopheryl polyethylene glycol, proline, glycine, lysine and leucine solution) every 15 min for three hours. In the IG group a significant increase of oxidized glutathione (GSSG) and hydrogen peroxide (H2O2) was recorded in the aqueous humor, whereas ascorbic acid levels were significantly lower when compared to control eyes. In the groups exposed to UVR rays for 30 min, and treated with the topical antioxidant formulation, the GSSG, H2O2 and ascorbic acid levels were similar to those recorded in controls, whereas in the G60 group the three markers significantly differ from control group. In the lens, a significant decrease of alpha tocopherol and total antioxidant capacity (TAC) was recorded in IG-animals as compared to control group, whereas malondialdehyde (MDA) levels were significantly higher in UV-induced eye than in control eyes. In the G30 groups the alpha tocopherol, MDA and TAC levels do not significantly differ from those recorded in controls, whereas in the G60 group these three markers significantly differ from control group. Present findings demonstrate that topical treatment with the antioxidant formulation used herein protects ocular structures from oxidative stress induced by UV exposure in in vivo animal model, F. Vizzarri, M. Palazzo, S. Bartollino, D. Casamassima, B. Parolini, P. Troiano, C. Caruso, C. Costagliola., and Obsahuje bibliografii
Damage of molecules as a consequence of oxidative stress has been implicated in the pathogenes is of chronic diseases related to aging. Diet is a key environmental factor affecting the incidence of many chronic diseases. Antioxidant substances in diet enhance the DNA, lipid and protein protection by increasing the scavenging of free radicals. Products of oxidative damage of DNA (DNA strand breaks with oxidized purines or oxidized pyrimidines), lipids (conjugated dienes of fatty acids) and proteins (carbonyls) in relation to nutrition (vegetarian diet vs. non-vegetarian, traditional mixed diet) were measured in young women aged 20-30 years (46 vegetarians, 48 non-vegetarians) vs. older women aged 60-70 years (33 vegetarians, 34 non-vegetarians). In young subjects, no differences in values of oxidative damage as well as plasma values of antioxidative vitamins (C, β-carotene) were observed between vegetarian and non-vegetarian groups. In older vegetarian group significantly reduced values of DNA breaks with oxidized purines, DNA breaks with oxidized pyrimidines and lipid peroxidation and on the other hand, significantly increased plasma values of vitamin C and β-carotene were found compared to the respective non-vegetarian group. Significant age dependences of measured parameters (increase in all oxidative damage products and decrease in plasma vitamin concentrations in older women) were noted only in non-vegetarians. Vegetarian values of older women vs. young women were similar or non-significantly changed. The results suggest that increase of oxidative damage in aging may be prevented by vegetarian nutrition., M. Krajčovičová-Kudláčková, M. Valachovičová, V. Pauková, M. Dušinská., and Obsahuje bibliografii a bibliografické odkazy
The effects of exogenous sodium nitroprusside (SNP), as nitric oxide donor, and spermidine (Spd) on growth and photosynthetic characteristics of Bakraii seedlings (Citrus reticulata x Citrus limetta) were studied under NaCl stress. In citrus plants, SNP- and Spd-induced growth improvement was found to be associated with reduced electrolyte leakage, malondialdehyde, hydrogen peroxide content, and leaf Na+ and Cl- concentration. However, we found increased leaf Ca2+, Mg2+, and K+ concentrations, relative water content, chlorophyll fluorescence parameters, antioxidant enzyme activities, such as ascorbate peroxidase, catalase, superoxide dismutase and peroxidase, as well as higher photosynthetic rate, intercellular CO2 concentration, stomatal conductance, and transpiration rate under saline regime. Foliar application of SNP and Spd alone mitigated the adverse effect of salinity, while the combined application proved to be even more effective., D. Khoshbakht, M. R. Asghari, M. Haghighi., and Obsahuje bibliografii
The effects of NaCl treatment were analysed in two species of considerably different resistance. In glycophyte, the content of ascorbate decreased but lipophilic antioxidants (α-tocopherol, plastochromanol, and hydroxy-plastochromanol) increased due to 150 mM NaCl. In halophyte, 300 mM NaCl caused a significant increase in hydrophilic antioxidants (ascorbate, total glutathione) but not in the lipophilic antioxidants. The redox states of plastoquinone (PQ) and P700 were also differently modulated by salinity in both species, as illustrated by an increased oxidation of these components in glycophyte. The presented data suggest that E. salsugineum was able to avoid a harmful singlet oxygen production at PSII, which might be, at least in part, attributed to the induction of the ascorbate-glutathione cycle. Another important cue of a high salinity resistance of this species might be the ability to sustain a highly reduced states of PQ pool and P700 under stress, which however, drastically affect the NADPH yield., M. Wiciarz, E. Niewiadomska, J. Kruk., and Obsahuje bibliografii
Because insulin resistance is inevitably associated with cardiovascular complications, there is a need to further investigate the potential involvement of oxidative stress and the cyclo-oxygenase (COX) pathway in the vascular modifications associated to this pathological context. Endothelial function was evaluated in control and fructose-fed rats (FFR) by i) in vitro study of endothelium-dependent an d-independent relaxations of aortic rings, and ii) in vivo telemetric evaluation of pressor response to norepinephrine. After 9 weeks of diet, FFR displayed hypertriglyceridemia, hyperinsulin emia and exaggerated response to glucose overload. Aortic rings from control rats and FFR exhibited comparable endothelium-dependent relaxations to Ach. In the presence of indomethacin , relaxations were significantly reduced. FFR showed exaggerated pressor responses to norepinephrine that were abolis hed with indomethacin. Urinary nitrites/nitrates, 8-isoprostanes and thromboxane B2 excretion levels were markedly enhanced in FFR, whereas the plasma levels of 6-keto prostaglandin F1α were unchanged. In conclusion, fructose overload in rats induced hypertriglyceridemia and insulin resistance associated with an enhanced oxidative stress. This was associated with COX pathway dysregulation which could be one of the contributors to subsequent vascular dysfunction. Consequently, reduction of oxidative stress and regulation of the COX pathway could represent new potential therapeutic strategies to limit vascular dysfunction and subsequent cardiovascular complications associated with insulin resistance., A. Outdot ... [et al.]., and Obsahuje seznam literatury
In the present study we aimed to evaluate whether oxidative stress and inflammation induced by strenuous exercise affect glycocalyx integrity and endothelial function. Twenty one young, untrained healthy men performed a maximal incremental cycling exercise - until exhaustion. Markers of glycocalyx shedding (syndecan-1, heparan sulfate and hyaluronic acid), endothelial status (nitric oxide and prostacyclin metabolites - nitrate, nitrite, 6-keto-prostaglandin F1α), oxidative stress (8-oxo-2’- deoxyguanosine) and antioxidant capacity (uric acid, nonenzymatic antioxidant capacity) as well as markers of inflammation (sVCAM-1 and sICAM-1) were analyzed in venous blood samples taken at rest and at the end of exercise. The applied strenuous exercise caused a 5-fold increase in plasma lactate and hypoxanthine concentrations (p<0.001), a fall in plasma uric acid concentration and non-enzymatic antioxidant capacity (p<10−4), accompanied by an increase (p=0.003) in sVCAM-1 concentration. Plasma 6-keto-prostaglandin F1α concentration increased (p=0.006) at exhaustion, while nitrate and nitrite concentrations were not affected. Surprisingly, no significant changes in serum syndecan-1 and heparan sulfate concentrations were observed. We have concluded, that a single bout of severe-intensity exercise is well accommodated by endothelium in young, healthy men as it neither results in evident glycocalyx disruption nor in the impairment of nitric oxide and prostacyclin production., J. Majerczak, K. Duda, S. Chlopicki, G. Bartosz, A. Zakrzewska, A. Balcerczyk, R. T. Smoleński, J. A. Zoladz., and Obsahuje bibliografii
It is known that excessive sympathetic activity and oxidative stress are enhanced in obesity. This study aimed to clarify whether exercise training (ET) attenuates sympathetic activation and oxidative stress in obesity. The obesity was induced by highfat diet (HFD) for 12 weeks. Male Sprague-Dawley rats were assigned to four groups: regular diet (RD) plus sedentary (RD-S), RD plus ET (RD-ET), HFD plus sedentary (HFD-S), and HFD plus ET (HFD-ET). The rats in RD-ET and HFD-ET groups were trained on a motorized treadmill for 60 min/day, five days/week for 8 weeks. The sympathetic activity was evaluated by the plasma norepinephrine (NE) level. The superoxide anion, malondialdehyde and F2-isoprostanes levels in serum and muscles were measured to evaluate oxidative stress. The ET prevented the increases in the body weight, arterial pressure and white adipose tissue mass in HFD rats. The NE level in plasma and oxidative stress related parameters got lower in HFD-ET group compared with HFD-S group. We have found decreased mRNA and protein levels of toll-like receptor (TLR)-2 and TLR-4 by ET in HFD rats. These findings suggest that ET may be effective for attenuating sympathetic activation and oxidative stress in diet-induced obesity., G. Li, J.-Y. Liu, H.-X. Zhang, Q. Li, S.-W. Zhang., and Obsahuje bibliografii
‘Hass‘ and ‘Fuerte‘ avocado plants were grown under well-watered or waterlogged conditions. Results indicated significant effects on the majority of the allometric parameters in waterlogged plants, with ‘Fuerte‘ displaying a more pronounced growth inhibition. Waterlogged conditions caused a progressive and simultaneous decline in net photosynthetic rate and stomatal conductance, earlier in ‘Fuerte‘ than in ‘Hass‘. Maximal potential quantum yield of PSII was unaffected by the soil water regime and/or variety and leaf water potential values in waterlogged plants were not more negative compared with control plants. ‘Fuerte‘ waterlogged plants exhibited increased contents of thiobarbituric acid reactive substances, whereas oxidative injury was not detected in ‘Hass‘. Finally, none of the two cultivars displayed valuable antioxidant potential, as evidenced by the decreased activities of the antioxidant enzymes superoxide dismutase, guaiacol peroxidase, glutathione peroxidase, and ascorbate peroxidase., G. Doupis, N. Kavroulakis, G. Psarras, I. E. Papadakis., and Obsahuje seznam literatury