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ABSTRACT: The purpose of the present study was to investigate the effect of lipoic acid on lipid peroxidation, nitric oxide production, and visual evoked potentials (VEPs) in rats exposed to chronic restraint stress and to examine whether lipoic acid could prevent VEP alterations that occurred in stress together with lipid peroxidation. Forty male wistar rats, aged three months, were used in the present study. They were equally divided into four groups: control (C), the group treated with lipoic acid (L), the group exposed to restraint stress (S), and the group exposed to stress and treated with lipoic acid (LS). Chronic restraint stress was applied for 21 days (1 h/day) and lipoic acid (100 mg/kg/day) was injected intraperitonally to the L and LS groups for the same period. Brain and retina TBARS levels were significantly increased in the S group compared with the C group. Lipoic acid reduced retina and brain TBARS levels in the L and LS groups compared with their corresponding control groups. Restraint stress significantly increased nitrite and nitrate levels in both brain and retina in the stress group with respect to the control group. Lipoic acid produced a significant decrease in brain and retina nitrite and nitrate levels of the L and LS groups comparing with their corresponding control groups. All latencies of VEP components were prolonged in the S group with respect to the C group. The study found significant correlations between VEPs latencies and TBARS and nitrite and nitrate levels of retina and brain. Lipoic acid decreased the latencies of all VEP components in the LS group whereas it did not affect them in the L group with respect to their control groups. In summary, lipoic acid treatment was found effective in preventing VEP and TBARS alterations caused by stress.
International Journal of Neuroscience 01/2008; 117(12):1691-706. · 0.97 Impact Factor
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ABSTRACT: The aim of this study was determination and comparison of the levels of myeloperoxidase (MPO), xanthine oxidase (XO), and superoxide dismutase (SOD) in gastric mucosa of children who were infected and noninfected with Helicobacter pylori (HP). The MPO, and XO enzyme activities were detected via kinetic measurement, and the MPO, XO and SOD enzyme protein levels were detected via Western blot, in antral mucosa specimens of 43 patients who underwent upper gastrointestinal endoscopy with various indications. The diagnosis of HP infection was made with a positive rapid urease test and histopathologic detection. MPO activity and enzyme protein levels were measured in 14 [8 HP (+) and 6 HP (-)], and in 9 [5 HP (+) and 4 HP (-)] while XO activity and enzyme protein levels were measured in 16 [10 HP (+) and 6 HP (-)] and in 9 [5 HP (+) and 4 HP (-)] patients, respectively. SOD protein level was detected in 13 [7 HP (+) and 6 HP (-)] patients. Of 43 patients 25 were HP (+) and 18 were HP (-). MPO activities were 75.6 +/- 40.5 and 98.8 +/- 44.1 U/g. protein (p = 0.302) while XO activities were 0.5 +/- 0.3 and 0.4 +/- 0.2 U/g. protein in HP (+) and HP (-) patients, respectively (p = 0.625). Measured enzyme protein levels of MPO, XO and SOD were found statistically indifferent in HP (+) and HP (-) patients (p = 0.327, p = 0.086, and p = 0.775, respectively). The results of this study revealed that, MPO, XO and SOD conditions in gastric mucosa alone were not affected from HP presence. That's why MPO, XO, and SOD may not have important roles in the pathogenesis of HP related gastric disease in children.
Molecular and Cellular Biochemistry 11/2006; 290(1-2):125-30. · 2.06 Impact Factor
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ABSTRACT: The aim of this study was to evaluate the effect of chronic restraint stress and alpha-lipoic acid (LA) administration on lipid peroxidation and antioxidant enzyme activities in rat peripheral organs.
Forty male wistar rats, aged 3 months were randomized to one of the following groups: control, restraint stress, LA treated and restraint stress+LA treated. Chronic restraint stress was applied for 21 days (1h/day) and LA (100 mg/kg/day) was administered intraperitoneally for the same period.
Restraint stress had no statistically significant effect on lipid peroxidation, copper/zinc superoxide dismutase (Cu/Zn SOD), catalase (CAT) and glutathione peroxidase (GPx) activity in rat liver and heart, when compared to the control group. Lipid peroxidation, determined by measuring malondialdehyde (MDA) levels, was found to be increased in the kidney of restraint stress treated rats, compared to controls. Restraint stress-induced lipid peroxidation in the kidney was significantly decreased via LA treatment. Administration of LA also enhanced GPx and decreased Cu/Zn SOD activity in rat kidney, liver and heart, compared to the control group.
The presented data shows that LA is a protective agent against restraint stress--the inducer of lipid peroxidation in the kidney. These findings also suggest that LA-induced changes in antioxidant enzyme activities in rat peripheral organs may contribute to their versatile effects observed in vivo.
Pharmacological Research 10/2006; 54(3):247-52. · 4.44 Impact Factor
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ABSTRACT: Intravenous nitroglycerin (GTN) has been used as an anti-ischemic agent for the therapy of unstable and post-infarction angina. Nitric oxide (NO) and S-nitrosothiols constitute the biologically active species formed via nitroglycerin bioactivation. Increased levels of reactive oxygen species can diminish the therapeutic action of organic nitrates by scavenging donated NO and oxidizing tissue thiols important in nitrate biotransformation. Studies reported here show that the red cell activity of antioxidant enzymes, catalase and glutathione peroxidase, are significantly decreased after intravenous nitroglycerin treatment. Catalase activity (739.6 +/- 92.3 k/gHb) decreased to 440.1 +/- 111.9 and 459.8 +/- 130.7 k/gHb after 1 and 24 hr GTN infusion, respectively. Similarly, glutathione peroxidase activity (5.8 +/- 1.8 U/gHb) decreased to 3.2 +/- 1.7 and 3.8 +/- 1.1 U/g Hb after 1 and 24 hr GTN infusion, respectively. The reported decrease in antioxidant enzyme activities can lead to an oxidant milieu and contribute to the generation of nitrate tolerance.
Journal of Enzyme Inhibition and Medicinal Chemistry 07/2005; 20(3):293-6. · 1.62 Impact Factor
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ABSTRACT: Sodium metabisulfite (Na2S2O5) is used as an antioxidant and antimicrobial agent in a variety of drugs and functions as a preservative in many food preparations. In addition to their antioxidant activity, sulfites oxidize to sulfite radicals (SO3-) initiating lipid peroxidation. This study was performed to elucidate the effect of subchronic Na2S2O5 (520 mg/kg/day) ingestion on hepatic and renal antioxidant enzyme activities and lipid peroxidation in albino rats. The antioxidant effect of l-carnitine was also tested in rats treated with Na2S2O5. Plasma uric acid levels were monitored in all rats included in the study. Malondialdehyde (MDA) levels significantly increased in Na2S2O5 treated rats vs. controls, with kidney values of 2.21+/-0.21 vs. 1.22+/-0.35 and liver values of 79.85+/-19.5 vs. 31.36+/-5.0 nmol/mg protein, respectively. Selenium-glutathione peroxidase (GPx) activity was significantly increased in Na2S2O5 treated rats vs. controls, with kidney values of 38.22+/-2.21 vs. 8.09+/-0.76 and liver values of 31.11+/-6.37 vs. 11.70+/-1.02 U/g protein, respectively. Sodium metabisulfite treatment increased plasma uric acid levels in rats that were included in the study. No protective effect of l-carnitine was observed against lipid peroxidation in both liver and kidneys of rats treated with Na2S2O5. The presented data confirm the prooxidant activity of sulfites and suggest that increased GPx activity and plasma uric acid levels may partially reduce the observed renal and hepatocellular oxidative damage caused via the ingestion of sulfites.
Regulatory Toxicology and Pharmacology 07/2005; 42(1):77-82. · 2.43 Impact Factor
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ABSTRACT: Fifty-two healthy Swiss Male Albino rats aged two mo were used in this study. They were divided into four groups: control
(C), diabetic (D), cadmium (Cd), and diabetic+Cd (D+Cd) groups. Diabetic condition was induced in D and D+Cd groups by administration
of alloxane (5 mg/100 g). After this treatment, CD and D+Cd groups were injected with CdCl2 ip (2 mg/kg/wk). At the end of the 2-mo experimental period, thiobarbituric acid reactive substances (TBARS), plasma and
erythrocyte selenium (SE), plasma ceruloplasmin (Cp), and vitamin E (vit E) were determined in four groups of rats.
The erythrocyte Se was lower in the experimental groups than in the controls. Plasma Se was significantly decreased in the
D and D+Cd groups compared with the control group. Plasma Cp was unaltered. Plasma vit E was significantly decreased in Cd
group in comparison with the C, D, and D+Cd groups.
Biological Trace Element Research 04/1997; 57(2):105-114. · 1.92 Impact Factor
