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Öğe The effect of L-carnitine on nitric oxide metabolism in streptozotocin-induced diabetic rats(Walter De Gruyter Gmbh, 2014) Ozgun, Gulben Sayilan; Ozgun, Eray; Eskiocak, Sevgi; Sut, NecdetObjective: The aim of this study is to investigate the effect of L-carnitine on plasma and liver nitric oxide metabolism in streptozotocin-induced diabetic rats. Methods: Sprague Dawley female rats were divided randomly into following groups: control, L-carnitine, diabetes and diabetes+L-carnitine. Diabetes and diabetes+L-carnitine groups were intra-peritonally injected with a single dose of streptozotocin (40 mg/kg) prepared in the citrate buffer (pH 4.5). Other groups were injected with only citrate buffer. 72 hours after the streptozotocin injection, L-carnitine (500 mg/kg/day) was given intraperitoneally to L-carnitine and diabetes+L-carnitine groups for 15 days. Physiological saline was given intraperitoneally to the other groups for 15 days. Blood sugar (at 72 hours and the end of experiment), liver nitric oxide and inducible nitric oxide synthase, plasma nitric oxide and nitrotyrosine levels were measured. Results: Blood glucose levels in diabetic groups were higher compared with other groups. Percentage change of blood glucose in diabetes+L-carnitine group was lower compared with other groups. Also diabetes+L-carnitine group's plasma nitric oxide levels were higher than control group. Plasma nitrotyrosine levels of L-carnitine injected groups were lower than diabetes group. There was no significant difference between the levels of liver inducible nitric oxide synthase and nitric oxide in groups. Conclusion: As a result, our study showed that plasma and liver nitric oxide and liver inducible nitric oxide synthase levels aren't changed significantly but plasma nitrotyrosine levels are increased at the end of 15th day of experimental diabetes. On the other hand, our results also showed that L-carnitine causes an increase in plasma nitric oxide levels and a decrease in plasma nitrotyrosine levels whereas it has no effect on liver nitric oxide and inducible nitric oxide synthase levels.Öğe Effect of L-carnitine on serum paraoxonase, arylesterase and lactonase activities and oxidative status in experimental colitis(Walter De Gruyter Gmbh, 2013) Ozgun, Eray; Ozgun, Gulben Sayilan; Eskiocak, Sevgi; Yalcin, Omer; Gokmen, Selma SuerAim: Oxidative stress plays an important role in the pathogenesis of inflammatory bowel disease. We investigated antioxidant L-carnitine effect on activities of paraoxonase 1 enzyme which is also synthesized in colon and oxidative status in experimental colitis. Material and Methods: Wistar albino female rats were divided into four groups randomly: control, colitis, pre-treatment and treatment groups. To induce colitis, single dose of 1 mL acetic acid (%4) was given intrarectally to colitis, pre-treatment and treatment groups. Single dose of 500 mg/kg L-carnitine was given intraperitoneally 1 hour before inducing colitis to pre-treatment group and 24 hours after inducing colitis to treatment group. All groups were sacrificied 48 hours after intrarectally administration. Existence of colitis was confirmed by histopathological changes. Paraoxonase, arylesterase and lactonase activities, total oxidant and antioxidant status, malondialdehyde, and total sialic acid were measured in serum. Oxidative stress index was calculated from the formula. Results: While serum malondialdehyde, total sialic acid, total oxidant status and oxidative stress index were significantly elevated, serum paraoxonase, arylesterase and lactonase activities and total antioxidant status were significantly decreased in acetic-acid induced experimental colitis. In acetic-acid induced experimental colitis, L-carnitine caused a significant decrease in serum malondialdehyde, total sialic acid, total oxidant status and oxidative stress index but a significant increase in serum arylesterase and lactonase activities of treatment group only. Conclusion: L-Carnitine has an increasing effect on serum arylesterase and lactonase activities and decreasing effect on oxidative stress in acetic acid-induced experimental colitis. Therefore, L-carnitine may be useful for the treatment of inflammatory bowel disease.Öğe Effect of lipoic acid on paraoxonase-1 and paraoxonase-3 protein levels, mRNA expression and arylesterase activity in liver hepatoma cells(General Physiol And Biophysics, 2017) Ozgun, Eray; Ozgun, Gulben Sayilan; Tabakcioglu, Kiymet; Gokmen, Selma Suer; Sut, Necdet; Eskiocak, SevgiParaoxonase-1 (PON1) and paraoxonase-3 (PON3) are anti-atherosclerotic enzymes, synthesized primarily in liver and bound to HDL in circulation. The aim of the present study was to investigate the effects of therapeutic doses of lipoic acid on PON1 and PON3 protein levels, mRNA expression and arylesterase activity in liver. We treated HepG2 cells with 10, 40 and 200 mu M lipoic acid for 72 h. Cell viability was evaluated by 3-(4,5-dimethy1-2-thiazoly1)-2,5-dipheny1-2Htetrazolium bromide assay. PON1 and PON3 protein levels were measured by Western blotting, their mRNA expression was measured by quantitative PCR and arylesterase activity was measured spectrophotometrically. 200 mu M lipoic acid caused a significant increase on PON1 and PON3 protein levels and arylesterase activity as compared with control, 10 mu M and 40 mu M lipoic acid treated cells. 200 mu M lipoic acid also caused a significant decrease on PON1 mRNA expression whereas on a significant increase PON3 mRNA expression as compared with control, 10 mu M and 40 mu M lipoic acid-treated cells. Our study showed that although lip oic acid up-regulates PON3 but down-regulates PON1 mRNA expression, it increases both PON1 and PON3 protein levels and arylesterase activity in HepG2 cells. We can report that lipoic acid may be useful for preventing atherosclerosis at therapeutic doses.Öğe The effects of L-carnitine on acetaminophen induced hepatotoxicity in rats(Walter De Gruyter Gmbh, 2013) Aktas, Ozgur; Eskiocak, Sevgi; Ozgun, Gulben Sayilan; Yalcin, Omer; Sut, NecdetObjective: The aim of this study was to investigate the protective effect of L-carnitine against to liver damage caused by lipid peroxidation and oxidative stress in toxic hepatitis induced by acetaminophen. Materials and Methods: Wister-albino male rats were divided into three groups randomly: control, toxic hepatitis, and L-carnitine groups. To introduce a toxic hepatitis, single dose of acetaminophen (300 mg/kg) dissolved in warm saline was given intraperitoneally to toxic hepatitis and L-carnitine groups. A single dose of L-carnitine (500 mg/kg) was given intraperitoneally to L-carnitine group five minutes after introducing to toxic hepatitits. A single dose of warm saline was given intraperitoneally to control group. Results: In toxic hepatitis group, serum alanine and aspartate aminotransferase and plasma and liver malondialdehyde levels were higher whereas plasma Gc-globulin, whole blood and liver glutathione levels, erythrocyte and liver catalase activities and erythrocyte glutathione peroxidase activity were lower as compared to control group. In L-carnitine group, serum alanine and aspartate aminotransferase and plasma and liver malondialdehyde levels were lower whereas whole blood and liver glutathione levels, erythrocyte and liver catalase activities and erythrocyte glutathione peroxidase activity were higher as compared to toxic hepatitis group. There was no significant change between plasma Gc-Globulin levels of these groups. Histopathological changes in toxic hepatitis group were more prominent than those found in L-carnitine group. Conclusion: L-Carnitine has a protective effect against to liver damage caused by lipid peroxidation and oxidative stress in toxic hepatitis induced by acetaminopfen in rats.Öğe The Effects of L-Carnitine on Protein Oxidation of Streptozotocin-Induced Diabetic Rats(Walter De Gruyter Gmbh, 2010) Ozgun, Gulben Sayilan; Eskiocak, Sevgi; Sut, NecdetIt has been reported that there is a significant protein oxidation resulted from oxidative damage in patients with diabetes mellitus. The aim of this study is to investigate the effects of L-carnitine which has antioxidant activity on protein oxidation seen in diabetes. In the study, twenty adult male rats of Wistar strain were randomly divided into three groups as follows: control (n=5), diabetes (n=8) and L-carnitine+diabetes groups (n=7). Diabetes and L-carnitine+diabetes groups were intraperitonally injected with a single dose of 50 mg/kg streptozotocin prepared in the citrate buffer (pH 4.5). Control group was injected with only citrate buffer. 72 hours after the streptozotocin injection, L-carnitine was given intraperitonally (500 mg/kg/day) to L-carnitine+diabetes groups for 15 days. Physiological saline was given intraperitonally to other groups for 15 days. The levels of blood sugar (at 72 hours and 2(nd) week) and kidney tissue advanced oxidation protein products of diabetes and L-carnitine+diabetes groups were higher than those in control group (p<0.001, p<0.05 and p<0.01; respectively). Kidney protein carbonyl level of diabetes group was higher when compared with the control group and L-carnitine+diabetes group (p<0.01 for both). There was a significant positive correlation between kidney tissue total and protein thiol levels in all groups. As a result; we can report that L-carnitine partially prevents protein oxidation seen in diabetes mellitus.Öğe Increased fibrinogen to albumin ratio in ischemic retinal vein occlusions(Sage Publications Ltd, 2017) Guclu, Hande; Ozal, Sadik A.; Gurlu, Vuslat Pelitli; Ozgun, Gulben Sayilan; Ozgun, ErayPurpose: To demonstrate the relationship between ischemia and plasma fibrinogen and serum albumin levels in cases of retinal vein occlusion (RVO). Methods: This study included 44 patients with central RVO (CRVO), 68 patients with branch RVO (BRVO), and 54 age- and sex-matched controls, for a total of 166 subjects. All of the subjects underwent full ophthalmologic examinations and complete physical examinations, including a detailed medical history and blood count, and biochemical parameters. Results: The mean fibrinogen to albumin ratios were 92.5 +/- 36.1 for the patients with CRVO, 84.5 +/- 31.5 for the patients with BRVO, and 68.4 +/- 12.2 for the control group. Overall, the patients with CRVO and patients with BRVO with ischemia had higher fibrinogen to albumin ratios and higher fibrinogen levels. Moreover, significant positive correlations were found between ischemia and the fibrinogen to albumin ratio (r = 0.732, p = 0.001) and the fibrinogen level (r = 0.669, p = 0.001). Conclusions: The fibrinogen to albumin ratio is significantly associated with ischemic RVO. Instead of complicated and invasive methods, such as a retinal angiogram, the fibrinogen to albumin ratio could be a useful initial diagnostic test to predict ischemia in RVO.Öğe Protective effects of ?-lipoic acid and L-carnitine in liver ischemia/reperfusion injury(Turkish Biochem Soc, 2014) Ozgun, Gulben Sayilan; Ozgun, Eray; Basaran, Usmit Nusret; Altaner, Semsi; Sut, Necdet; Eskiocak, SevgiObjective: Oxidative stress plays an important role in the pathogenesis of liver ischemia/reperfusion injury. Thus, antioxidant treatment can be protective against to liver ischemia/reperfusion injury. The aim of this study to investigate the effects of alpha-lipoic acid and L-carnitine on liver total oxidant status, lipid peroxidation, protein oxidation, neutrophil infiltration and hepatic necrosis in liver ischemia/reperfusion model. Methods: Wistar albino male rats were divided into four groups randomly: Sham (n=7), ischemia/reperfusion (n=7), alpha-lipoic acid (n=8) and L-carnitine (n=8). alpha-Lipoic acid (100 mg/kg) and L-carnitine (100 mg/kg) were given intraperitoneally to alpha-lipoic acid group 15 minutes before and to L-carnitine group 30 minutes before ischemia/reperfusion protocol, respectively. To induce hepatic ischemia/reperfusion injury, ischemia (60 minutes) and reperfusion (30 minutes) were applied to all groups except sham group. Total oxidant status, malondialdehyde, advanced oxidation protein products and myeloperoxidase levels were measured in ischemic lobes of liver tissues. Hepatic necrosis was scored microscopically. Results: There was no significant change in myeloperoxidase levels as an indicator of neutrophil infiltration after reperfusion procedure. Both L-carnitine and alpha-lipoic acid caused a significant decrease in hepatic necrosis. While L-carnitine prevents an increase in total oxidant status, lipid peroxidation and protein oxidation, alpha-lipoic acid prevents only an increase in lipid peroxidation of the liver in hepatic ischemia/reperfusion injury. Conclusion: As a result; we can report that L-carnitine and alpha-lipoic acid have protective effects against to hepatic ischemia/reperfusion injury.Öğe Serum osteopontin levels in patients with psoriasis vulgaris and its relation with oxidative stress(Galenos Publ House, 2023) Kilinc, Cem; Korkmaz, Selma; Ozgun, Gulben Sayilan; Ficicioglu, Sezin Kuru; Piskin, SuleymanBackground and Design: Oxidative stress is known to play a role in the etiopathogenesis of psoriasis. Recent data suggest that osteopontin (OPN) can also play a role in the pathogenesis of psoriasis. In the current study, OPN levels and oxidative stress were evaluated in patients with psoriasis.Materials and Methods: The study included 61 patients with psoriasis and 62 healthy controls. The OPN levels, total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) were measured using serum. The disease severity was evaluated using the psoriasis area and severity index (PASI).Results: No statistically significant differences in OPN, TAS, and OSI values were identified between the psoriasis and control groups. A negative correlation was found with the TAS. There was no statistically significant correlation between the PASI score and OPN, TAS, TOS, and OSI values.Conclusion: We did not find a statistically significant correlation between OPN levels and oxidative stress in patients with psoriasis. We believe that larger and more detailed studies are needed to highlight the role of OPN and oxidative stress in the etiopathogenesis of psoriasis.
