Publications (23)45.86 Total impact
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Article: I405V and TaqIB polymorphisms of the cholesteryl ester transfer protein and their relation to serum lipid and lipoprotein levels in a Turkish population.
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ABSTRACT: Cholesteryl ester transfer protein (CETP) plays a central role in high-density lipoprotein (HDL) metabolism. Genetic polymorphisms of the CETP gene can influence levels of serum lipoproteins. It has been reported that mean HDL-cholesterol (HDL-C) concentrations are low in Turkish population. Thus, we investigated the frequencies of the common I405V and TaqIB polymorphisms of the CETP gene and their relation to serum lipid and lipoprotein levels in a Turkish population. The variant allele frequencies of I405V and TaqIB polymorphisms of the CETP gene were found to be 0.38 and 0.46, respectively and similar to some of the European populations. Subjects for the VV genotype of I405V polymorphism had higher HDL-C levels than did II subjects. The covariance analysis showed that gender and triglyceride (TG) levels have an effect on the association of HDL-C and I405V polymorphism. In conclusion, our results indicate that I405V polymorphism may affect the HDL-C levels in Turkish population. The association of this polymorphism and HDL-C levels could be modified by other factors, such as gender and TG levels.Cell Biochemistry and Function 01/2009; 27(2):76-80. · 1.77 Impact Factor -
Article: Effect of heme oxygenase-1 induction by octreotide on TNBS-induced colitis.
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ABSTRACT: Ulcerative colitis is a chronic inflammatory disease of the colon and rectum. Although the precise etiology of ulcerative colitis remains unknown, it is believed to involve an abnormal host response to endogenous or environmental antigens, genetic factors, and oxidative damage. The aim of the present study was to investigate whether heme oxygenase-1 (HO-1) induction by octreotide could protect against oxidative and inflammatory damage from induced colitis. Rats received octreotide 50 microg/kg per day intraperitoneally for 5 days before 2,4,6 trinitrobenzene sulfonic acid (TNBS) solution administration and for 15 days following TNBS solution administration. Rats were killed on day 21, and colonic malondialdehyde (MDA) levels, glutathione (GSH) levels and HO-1 expression were measured. Nuclear factor (NF)-kappaB and HO-1 expression was evaluated by immunohistochemical examination of the colonic tissue. Rats with TNBS-induced colitis had significantly increased colonic MDA levels and HO-1 expression in comparison to the control group. Octreotide treatment was associated with increased HO-1 expression and GSH levels, but decreased MDA levels. Histopathological examination revealed that the intestinal mucosal structure was preserved in the octreotide-treated group. In addition, treatment with octreotide significantly increased HO-1 expression and decreased NF-kappaB expression by immunohistochemistry when compared to the TNBS-induced colitis group. Octreotide appears to have protective effects against colonic damage in TNBS-induced colitis. This protective effect is, in part, mediated by modification of the inflammatory response and the induction of HO-1 expression.Journal of Gastroenterology and Hepatology 12/2007; 22(11):1852-8. · 2.87 Impact Factor -
Article: Effect of heme oxygenase‐1 induction by octreotide on TNBS‐induced colitis
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ABSTRACT: Background and Aim: Ulcerative colitis is a chronic inflammatory disease of the colon and rectum. Although the precise etiology of ulcerative colitis remains unknown, it is believed to involve an abnormal host response to endogenous or environmental antigens, genetic factors, and oxidative damage. The aim of the present study was to investigate whether heme oxygenase-1 (HO-1) induction by octreotide could protect against oxidative and inflammatory damage from induced colitis.Methods: Rats received octreotide 50 µg/kg per day intraperitoneally for 5 days before 2,4,6 trinitrobenzene sulfonic acid (TNBS) solution administration and for 15 days following TNBS solution administration. Rats were killed on day 21, and colonic malondialdehyde (MDA) levels, glutathione (GSH) levels and HO-1 expression were measured. Nuclear factor (NF)-κB and HO-1 expression was evaluated by immunohistochemical examination of the colonic tissue.Results: Rats with TNBS-induced colitis had significantly increased colonic MDA levels and HO-1 expression in comparison to the control group. Octreotide treatment was associated with increased HO-1 expression and GSH levels, but decreased MDA levels. Histopathological examination revealed that the intestinal mucosal structure was preserved in the octreotide-treated group. In addition, treatment with octreotide significantly increased HO-1 expression and decreased NF-κB expression by immunohistochemistry when compared to the TNBS-induced colitis group.Conclusion: Octreotide appears to have protective effects against colonic damage in TNBS-induced colitis. This protective effect is, in part, mediated by modification of the inflammatory response and the induction of HO-1 expression.Journal of Gastroenterology and Hepatology 10/2007; 22(11):1852 - 1858. · 2.87 Impact Factor -
Article: The role of heat shock protein 70 (Hsp 70) in male infertility: is it a line of defense against sperm DNA fragmentation?
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ABSTRACT: To clarify the role of heat shock protein 70 (Hsp 70) and its relation with DNA damage in male infertility. Prospective study. Andrology laboratory of Istanbul Medical Faculty. Semen samples from 37 infertile men and 13 fertile men (as controls). The percentage of DNA fragmentation was assayed with the use of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL). Sperm Hsp 70 expression was determined by using Western blot analysis. Both the percentages of sperm DNA fragmentation and Hsp 70 expression were correlated with semen analysis parameters. TUNEL-positive spermatozoa in the infertile group (18.7% for asthenospermics and 13.0% for oligoasthenospermics) were higher than the fertile group (4.9%). Significant inverse correlations were detected between percentage of TUNEL-positive cells and both concentration (r = -0.487) and motility (r = -0.377) of spermatozoa. No expression of Hsp 70 was observed in azospermic group, whereas Hsp 70 levels were found increased significantly in infertile group (U = 62 for asthenospermics and U = 38 for oligoasthenospermics) compared to fertile group as analyzed by using Mann-Whitney U Wilcoxon rank sum test. Furthermore, significant positive correlation was found between percentage of TUNEL-positive cells and Hsp 70 expression (r = 0.357). Hsp 70 expression may have been increased as a protective mechanism against apoptosis in spermatozoa of infertile men.Fertility and sterility 10/2007; 90(2):322-7. · 3.97 Impact Factor -
Article: The effect of heme oxygenase-1 induction by glutamine on TNBS-induced colitis. The effect of glutamine on TNBS colitis.
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ABSTRACT: Inflammatory bowel disease is a multifactorial inflammatory disease of the colon and rectum with an unknown etiology. In the present study, we aimed to investigate whether heme oxygenase-1 (HO-1) induction by glutamine could protect colitis-induced damage from oxidative, inflammatory, and apoptotic damage. The rats were divided into four groups. Group 1 had TNBS colitis alone, group 2 had TNBS-induced colitis and glutamine 1 g/kg/day intragastric gavage for 3 days before TNBS solution administration and 15 days following TNBS solution administration, group 3 had glutamine alone 1 g/kg/day intragastric gavage for 18 days before being killed, and group 4 had isotonic saline solution alone 1 cm3/rat intragastric gavage for 18 days before being killed. Colonic malondialdehyde (MDA) levels, glutathione (GSH) levels, caspase-3 activities, and HO-1 expressions of the killed rats were measured. Nuclear factor kappa B (NF-kappaB) and HO-1 expression were evaluated by immunohistochemical examination of the colonic tissue. TNBS-induced colitis significantly increased the colonic MDA levels, caspase-3 activities, and HO-1 expression in comparison to the control group. Glutamine treatment was associated with increased HO-1 expression and GSH levels and decreased MDA levels and caspase-3 activity. Histopathological examination revealed that the intestinal mucosal structure was preserved in the glutamine-treated group. In addition to this, treatment with glutamine significantly increased HO-1 expression and decreased NF-kappaB expression by immunohistochemistry when compared to the TNBS-induced colitis group. Glutamine reduced colonic damage in TNBS-induced colitis. The mechanism of the protection associated with glutamine was due to antioxidant, antiapoptotic, anti-inflammatory, and HO-1 induction effects.International Journal of Colorectal Disease 07/2007; 22(6):591-9. · 2.38 Impact Factor -
Article: Nitrotyrosine formation and heme oxygenase-1 expression in endotoxemic cirrhotic rats.
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ABSTRACT: Endotoxemia increases hepatic toxicity and mortality in cirrhosis. Because the mechanism of augmented hepatotoxicity in endotoxemic cirrhotic rats is still unclear, we wanted to investigate whether oxidative and nitrosative stress play a causative role in lipopolysaccharide (LPS)-treated cirrhotic rats. Liver cirrhosis was produced by the administration of thioacetamide (0.3 g/L of tap water) for a period of 3 months in rats. At the end of this period, cirrhotic rats were sacrificed 6 h after LPS injection (5 mg/kg, intraperitoneally). Serum transaminase activities, plasma total nitrite and nitrotyrosine (NT) levels as well as hepatic lipid peroxides, NT formation and heme oxygenase 1 (HO-1) expression were determined. LPS administration to cirrhotic rats caused further increases in serum transaminase activities, and plasma total nitrite and NT levels as well as hepatic lipid peroxide levels as compared to cirrhotic rats. Hepatic NT formation and HO-1 expression were also found to be increased in LPS-injected cirrhotic rats. Our results indicate that increased oxidative and nitrosative stress may have a synergistic effect in LPS-augmented hepatotoxicity in cirrhotic rats.Archives of Medical Research 02/2007; 38(1):28-33. · 1.88 Impact Factor -
Article: The effect of octreotide on pancreatic damage in TNBS-induced colitis.
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ABSTRACT: Inflammatory bowel disease, a chronic condition of the intestine, is associated with numerous extraintestinal manifestations, including pancreatitis. This study investigated the effect of octreotide administration on oxidative damage in a rat model of colitis induced by 2,4,6-trini-trobenzene sulfonic (TNBS) acid. Colonic and pancreatic malondialdehyde and glutathione levels are indicators of oxidative damage, and TNBS-induced colitis significantly increased the colonic and pancreatic malondialdehyde levels and decreased glutathione levels. Octreotide treatment was associated with decreased malondialdehyde levels and increased glutathione levels in the colonic and pancreatic tissue. The colonic mucosal structure was preserved and pancreatic inflammation decreased in rats treated with octreotide. Octreotide also significantly decreased nuclear factor-kB expression by immunohisto-chemistry in the colonic and pancreatic tissue compared with TNBS-induced colitis group. Octreotide appears to have protective effects against TNBS-induced colonic and pancreatic damage. These results imply the reduction in mucosal damage owing to the anti-inflammatory and antioxidant effects of octreotide.Surgical Innovation 07/2006; 13(2):102-8. · 2.13 Impact Factor -
Article: The effect of heme oxygenase-1 induction by glutamine on radiation-induced intestinal damage: the effect of heme oxygenase-1 on radiation enteritis.
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ABSTRACT: Radiation enteritis is a significant clinical problem in patients receiving ionizing radiation directed at the abdomen or pelvis. The small intestine is the most radiosensitive gastrointestinal organ. Myeloperoxidase (MPO) activity and malondialdehyde (MDA) levels of the small intestine were measured to determine the oxidative damage caused by radiation. In addition, caspase-3 activity of the small intestine was measured to define the degree of apoptosis. The present study was undertaken to investigate the effect of glutamine administration on heme oxygenase-1 (HO-1) expression of the radiation enteritis model. Rats received 1 g/kg/d glutamine (HO-1-inducer) for 7 days before irradiation and continued for 3 days after irradiation. Zn-prothoporphyin (Zn-PP) 40 micromol/kg was delivered subcutaneously for 1 day before irradiation. Intestinal MPO activities and MDA levels are indicators of oxidative damage, whereas caspase-3 activities show the degree of apoptosis of the small intestine. At histopathologic examination, terminal ileum tissue was analyzed for morphologic changes. Also, the nuclear factor-kappa (NF-kappa) expression level of the terminal ileum was determined with immunohistochemistry methods to show the mucosal inflammatory process. Irradiation significantly increased the intestinal MPO and caspase-3 activities, MDA levels, and HO-1 expression in comparison with the sham group. Glutamine treatment was associated with increased HO-1 expression, decreased MPO activity, caspase-3 activity, and MDA levels. Inhibition of HO-1 activity by Zn-PP completely eliminated the protective effects of glutamine. Histopathologic examination showed that the intestinal mucosal structure was preserved in the glutamine-treated group. In the irradiation group, NF-kappaB overexpression was detected. NF-kappaB positivity was strongest in the intestine of animals in the radiation alone group and the Zn-PP-treated irradiation group. Glutamine appears to have protective effects against radiation-induced intestinal damage. This protective effect is mediated in part by the induction of HO-1 activity because inhibition of Zn-PP resulted in the complete abolishment of the protective effect of glutamine.The American Journal of Surgery 05/2006; 191(4):503-9. · 2.78 Impact Factor -
Article: The effect of taurine or betaine pretreatment on hepatotoxicity and prooxidant status induced by lipopolysaccharide treatment in the liver of rats.
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ABSTRACT: Taurine or betaine have been reported to have antioxidative potential and inhibit Kupffer cell activation. These effects may play an important role in their hepatoprotective effects. Therefore, they may also have protective effects in lipopolysaccharide hepatotoxicity by both inhibiting Kupffer cell activation and behaving as antioxidants. The prophylactic efficiency of taurine or betaine pretreatment for the prevention of peroxidative changes induced by lipopolysaccharide treatment in the rat liver was investigated. Lipopolysaccharide (10 mg/kg intraperitoneally) was given to rats pretreated with taurine (1.5%, w/v) or betaine (1.5%, w/v) in drinking water for 4 weeks and plasma transaminase activities as well as hepatic malondialdehyde, diene conjugate (DC), glutathione, alpha-tocopherol and ascorbic acid levels, and superoxide dismutase (SOD) and glutathione peroxidase activities were determined. Significant increases in plasma transaminase activities and hepatic malondialdehyde and DC levels and decreases in hepatic glutathione and alpha-tocopherol levels and SOD and glutathione peroxidase activities were observed 6 h after lipopolysaccharide treatment. This treatment did not alter ascorbic acid levels in the liver compared with controls. Taurine or betaine pretreatment in lipopolysaccharide-injected rats caused significant decreases in plasma transaminase activities and hepatic malondialdehyde and DC levels, and significant increases in glutathione and alpha-tocopherol (not betaine) levels without changing ascorbic acid levels and SOD and glutathione peroxidase activities in the liver. Our findings clearly indicate that taurine or betaine pretreatment was effective in the prevention of lipopolysaccharide-induced hepatotoxicity and prooxidant status.European Journal of Gastroenterology & Hepatology 10/2005; 17(9):917-21. · 1.76 Impact Factor -
Article: Mitochondrial Lipid Peroxides and Antioxidant Enzymes in Colorectal Adenocarcinoma Tissues
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ABSTRACT: Lipid peroxide levels and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and glutathione transferase (GST) activities were investigated in mitochondrial fractions obtained from tumorous and nontumorous colorectal tissues of fourteen patients with colon and rectum cancer. Histopathological evaluations, including type, stage, necrosis and lymphocyte infiltration were also performed for each patient. The activities of SOD, GSH-Px and GST were increased significantly, but lipid peroxide levels remained unchanged in mitochondria obtained from tumors compared to adjacent normal tissues of subjects with colorectal cancer. When the patients were grouped according to their histopathological evaluation, such as type, stage, necrosis and lymphocyte infiltration, no relationship was observed between the histopathological results and the mitochondrial lipid peroxidation or antioxidant enzyme activities.Cancer Science 08/2005; 91(12):1258 - 1263. · 3.33 Impact Factor -
Article: Increased LDL+VLDL oxidizability and plasma homocysteine levels in chronic alcoholic patients.
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ABSTRACT: The purpose of this study was to investigate the effect of heavy alcohol consumption on peroxidation status in apolipoprotein B-containing lipoproteins (LDL+VLDL) and plasma as well as plasma homocysteine (HC) levels in patients with chronic alcoholism who drank raki, a national Turkish beverage. For this reason, endogenous diene conjugate (DC) and lipid hydroperoxide (LOOH) levels and lag phase, maximum DC formation and propagation rate following copper induction were measured in apolipoprotein B-containing lipoproteins (LDL+VLDL) isolated by precipitation with dextrane sulfate and MgCl2 from plasma. In addition, serum malondialdehyde (MDA), DC, HC, folate and vitamin B12 levels as well as paraoxonase activity were determined. Serum MDA and DC levels were higher in heavy raki drinkers compared to control subjects. Significant increases in endogenous DC and LOOH levels in LDL+VLDL together with shortened lag phase were also observed in patients. In addition, HDL-cholesterol, HC and vitamin B12 levels and HDL-associated paraoxonase activity were found to be higher, but folate levels to be lower in serum of heavy raki consumers. In conclusion, our results indicate that increases in LDL+VLDL oxidizability and plasma HC levels may enhance the susceptibility to vascular diseases in heavy raki drinkers.Journal of Nutritional Science and Vitaminology 05/2005; 51(2):99-103. · 1.20 Impact Factor -
Article: Hazelnut oil administration reduces aortic cholesterol accumulation and lipid peroxides in the plasma, liver, and aorta of rabbits fed a high-cholesterol diet.
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ABSTRACT: Hazelnut oil (HO) is rich in monounsaturated fatty acids and antioxidants. We wanted to investigate the effect of HO on lipid levels and prooxidant-antioxidant status in rabbits fed a high-cholesterol (HC) diet. An HC diet caused significant increases in lipids and lipid peroxide levels in the plasma, liver, and aorta together with histopathological atherosclerotic changes in the aorta. Glutathione levels, glutathione peroxidase, and glutathione transferase activities decreased significantly, but superoxide dismutase activity and vitamin E and C levels remained unchanged in the livers of rabbits following HC diet. HO supplementation reduced plasma, liver, and aorta lipid peroxide levels and aorta cholesterol levels together with amelioration in atherosclerotic lesions in the aortas of rabbits fed an HC diet, without any decreasing effect on cholesterol levels in the plasma or liver. HO did not alter the antioxidant system in the liver in the HC group. Our findings indicate that HO reduced oxidative stress and cholesterol accumulation in the aortas of rabbits fed an HC diet.Bioscience Biotechnology and Biochemistry 11/2004; 68(10):2050-7. · 1.28 Impact Factor -
Article: Methionine supplementation did not augment oxidative stress, atherosclerotic changes and hepatotoxicity induced by high cholesterol diet in C57BL/6J mice.
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ABSTRACT: The purpose of this study was to investigate the effect of a high-methionine plus cholesterol diet (HM+HC) on plasma, erythrocyte, liver and aorta lipid, lipid peroxide levels, and the liver antioxidant system, as well as hepatic and aortic histopathology in CS 7BL/6J mice, and to compare these results to those observed following administration of a high-methionine (HM) or high-cholesterol diet (HC) alone. Mice were fed diets containing 1.5% methionine, 1.5%, cholesterol and 0.5% cholic acid, or a combination of the two diets, for 4 mo. The HM diet did not alter cholesterol or diene conjugate (DC) levels in the plasma or aorta, but this diet caused increases in cholesterol, triglyceride, malondialdehyde (MDA) and DC levels and a decrease in a-tocopherol levels without any change in the levels of glutathione and ascorbic acid or the activities of superoxide dismutase, glutathione peroxidase and glutathione transferase in the liver of mice. However, the HC diet alone was found to further increase cholesterol, triglyceride. MDA and DC levels in the plasma and liver together with changes in hepatic antioxidant system elements, but aortic cholesterol and DC levels remained unchanged as compared to the control group. There were no changes in blood hemoglobin and erythrocyte MDA levels or erythrocyte hemolysis values in both the HM and HC groups. However, the parameters related to lipid and lipid peroxide and antioxidant systems did not change in the plasma or tissues of the HM+HC and HC groups. Only plasma cholesterol was observed to increase in the HM+HC group as compared to the HC group. In addition, histopathological findings in the liver and aorta were similar in the HC and HM+HC groups. In conclusion, our results indicate that the addition of methionine to the HC diet did not augment oxidative stress, hepatotoxicity or atherosclerotic changes induced by the HC diet in mice.Journal of Nutritional Science and Vitaminology 09/2004; 50(4):258-64. · 1.20 Impact Factor -
Article: Heme oxygenase induction protects liver against oxidative stress in x-irradiated aged rats.
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ABSTRACT: We studied the effect of total body X-ray irradiation on the heme oxygenase-1 (HO-1) induction in the livers of young and aged rats. For this purpose, male rats were irradiated with a dose of 17 Gy. The animals were killed 5 h after irradiation. HO-1 protein expression was found to be increased two fold in aged rat liver, but lipid peroxide levels had decreased significantly where no change was observed either in inducible nitric oxide synthase protein expression or in glutathione levels. Contradictory results with respect to HO-1 and lipid peroxidation levels were obtained in the livers of young animals. These results suggest that the additional oxidative stress produced in irradiated rats may be compensated by HO-1 induction as decreased lipid peroxide levels were shown in the livers of aged animals.Biogerontology 02/2004; 5(2):99-105. · 3.34 Impact Factor -
Article: Age-related increases in plasma malondialdehyde and protein carbonyl levels and lymphocyte DNA damage in elderly subjects.
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ABSTRACT: Increased oxidative stress has been hypothesized to play an important role in the aging process. A role for oxidative damage in normal aging is supported by studies in experimental animals, but there is limited evidence in humans. To investigate the relationship between the oxidative stress and aging in humans, we determined lipid and protein oxidation in plasma as well as DNA damage in lymphocytes in young and elderly subjects. 55 healthy subjects were divided into young (21-40 years) and elderly (61-85 years) groups. Plasma malondialdehyde (MDA), protein carbonyl (PC) levels, and grade of DNA damage in lymphocytes using comet assay as well as total ferric reducing antioxidant power (FRAP) in plasma were determined in young and elderly subjects. Plasma MDA and PC levels were found to be increased in plasma of elderly subjects as compared to young subjects. Increases in endogenous and H2O2-induced DNA damage were also observed in lymphocytes of elderly subjects. In addition, we detected a significant decrease in FRAP values in elderly subjects. Plasma MDA, PC levels and endogenous and H2O2-induced DNA damage were positively correlated with aging, but negatively with FRAP values. We evaluated MDA, PC levels and lymphocyte DNA damage altogether in both young and elderly subjects for the first time. The results of this study strongly support the presence of increased oxidative stress in elderly subjects.Clinical Biochemistry 08/2003; 36(5):397-400. · 2.08 Impact Factor -
Article: Influence on hazelnut oil administration on peroxidation status of erythrocytes and apolipoprotein B 100-containing lipoproteins in rabbits fed on a high cholesterol diet.
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ABSTRACT: Hazelnut oil (HO) is rich in monounsaturated fatty acids (MUFA). The effect of a high cholesterol (HC) diet with and without HO on lipids and lipid peroxide levels in plasma, apolipoprotein B 100-containing lipoproteins (VLDL + LDL), and erythrocytes as well as hematological data was investigated in rabbits. A HC diet caused significant increases in lipid peroxide levels in plasma and apo B-containing lipoproteins together with histopathological atherosclerotic findings in aorta. In addition, this diet resulted in hemolytic anemia associated with increased endogenous diene conjugate (DC) levels, but H(2)O(2)-induced malondialdehyde (MDA) levels remained unchanged in erythrocytes. HO supplementation reduced lipid peroxide levels in plasma and apolipoprotein B 100-containing lipoproteins as well as aortic atherosclerotic lesions in rabbits fed an HC diet without any decreasing effect on lipid levels. In addition, HO was found to reduce hemolytic anemia together with significant decreases in DC and H(2)O(2)-induced MDA levels.Journal of Agricultural and Food Chemistry 07/2003; 51(13):3905-9. · 2.82 Impact Factor -
Article: Effects of added dietary taurine on erythrocyte lipids and oxidative stress in rabbits fed a high cholesterol diet.
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ABSTRACT: Lipid peroxidation leads to damage of polyunsaturated fatty acids of membrane phospholipids. The contribution of oxidative stress to hypercholesterolemia-induced hemolytic anemia and the effects of addition of taurine on erythrocyte lipid composition, oxidative stress, and hematological data were studied in rabbits fed on a high cholesterol (HC) diet (1%, w/w) for 2 months. The effects of taurine on erythrocyte hemolysis and H2O2-induced lipid peroxidation were investigated in normal rabbit erythrocytes in vitro. The HC diet resulted in increases in plasma lipids and lipid peroxide levels as well as increases in cholesterol levels and the cholesterol:phospholipid ratio in the erythrocytes. This diet caused a hemolytic anemia, but lipid peroxide levels remained unchanged in the erythrocytes of the rabbits. Taurine (2.5%, w/w) added to the food has an ameliorating effect on plasma lipids and lipid peroxide levels in rabbits fed on a HC diet. This treatment also caused decreases in elevated erythrocyte cholesterol levels and cholesterol:phospholipid ratio due to the HC diet, but it did not prevent the hemolytic anemia and did not change erythrocyte lipid peroxide levels. In addition, in an in vitro study, taurine did not protect erythrocytes against H2O2-induced hemolysis or lipid peroxidation. These results show that the HC diet causes hemolytic anemia without any changes in erythrocyte lipid peroxidation, and taurine treatment was not effective against hemolytic anemia caused by the HC diet.Bioscience Biotechnology and Biochemistry 01/2003; 66(12):2701-5. · 1.28 Impact Factor -
Article: Hepatic mitochondrial prooxidant and antioxidant status in ethanol-induced liver injury in rats.
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ABSTRACT: In this study, prooxidant and antioxidant status in liver homogenates and their mitochondrial fractions were investigated in both chronic and chronic plus acute ethanol-treated rats. Increases in serum transaminase activities, as well as increases in total lipid, triglyceride, malondialdehyde (MDA) and diene conjugate (DC) levels and decreases in glutathione (GSH), vitamin E and vitamin C levels, have been observed in liver homogenates following chronic ethanol treatment (20% ethanol, v/v as drinking water for 3 months), but CuZn-superoxide dismutase (CuZnSOD), glutathione peroxidase (GSH-Px) and glutathione transferase (GST) activities remained unchanged in postmitochondrial fractions. When an acute dose of ethanol (5 g/kg, i.p.) was given rats which had received ethanol chronically, serum transaminase activities and hepatic lipid and MDA and DC levels increased further, but GSH levels and antioxidant enzymes decreased more compared to the chronic ethanol-treated rats. There were no significant differences in the levels of MDA, DC and protein carbonyl and the activities of GSH-Px and GST in the hepatic mitochondrial fraction of rats following both chronic and chronic plus acute treatments. Mn-superoxide dismutase (MnSOD) activities increased in both groups, but mitochondrial GSH levels decreased only after chronic plus acute treatment. Therefore, we suggest that the increase in MnSOD activity may play an important role in the regulation of mitochondrial susceptibility against ethanol-induced oxidative stress.Biological & Pharmaceutical Bulletin 12/2002; 25(11):1482-4. · 1.66 Impact Factor -
Article: Increased lipid peroxidation in serum and low-density lipoproteins associated with aging in humans.
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ABSTRACT: This study was carried out in 140 healthy subjects who were divided into three subgroups of age: young (21-40 years), mature (41-60 years), and elderly (61-85 years) to investigate lipid peroxides and the antioxidant system in serum and low-density lipoproteins (LDL). Serum levels of cholesterol and LDL-cholesterol increased with age. The elderly group was found to have higher polyunsaturated fatty acid (PUFA) levels, thiobarbituric acid reactive substances (TBARS), diene conjugates, and lower cholesterol-adjusted vitamin E levels and antioxidant activity (AOA) as compared to the young group. No age-related difference was detected in serum vitamin C levels. Age correlated positively with serum cholesterol, LDL-cholesterol, PUFA, TBARS, diene conjugates, and negatively with cholesterol-adjusted vitamin E levels and AOA. In addition, endogenous LDL diene conjugate levels and the susceptibility of LDL to copper-induced lipid peroxidation increased in elderly subjects as compared with young subjects. In addition, positive correlations were detected between age and LDL endogenous diene conjugate levels and TBARS formation after copper incubation. However, the susceptibility of whole serum to copper-induced lipid peroxidation did not change in young and elderly subjects. Our results show that endogenous lipid peroxide levels in serum and LDL, and the susceptibility of LDL to copper-induced oxidation, increased with aging in humans.International Journal for Vitamin and Nutrition Research 11/2002; 72(5):315-20. · 0.88 Impact Factor -
Article: Taurine treatment reduces hepatic lipids and oxidative stress in chronically ethanol-treated rats.
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ABSTRACT: In this study, we evaluated whether taurine treatment has a protective effect on the prooxidant-antioxidant state following chronic ethanol treatment in rats. Rats were given water containing 20% ethanol (v/v) as drinking water for 3 months. Chronic ethanol treatment in drinking water resulted in increased oxidative stress in the liver of rats. Taurine treatment was performed by adding 1% taurine (w/v) to the drinking water plus injection (400 mg/kg body weight) intraperitoneally 3 times/week for 28 d after ethanol cessation in chronically ethanol-treatad rats. This treatment starting after ethanol cessation caused a significant decreases in serum transaminase activities and hepatic total lipid, triglyceride, malondialdehyde, and diene conjugate levels and significant increases in hepatic glutathione, vitamin E, and vitamin C levels, but did not alter the activities of superoxide dismutase, glutathione peroxidase, and glutathione transferase in the liver as compared with chronically ethanol-treated rats. Accordingly, we propose that taurine has a restorative effect on ethanol-induced hepatic damage by decreasing oxidative stress.Biological & Pharmaceutical Bulletin 10/2002; 25(9):1231-3. · 1.66 Impact Factor
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2002–2009
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Istanbul University
- • Department of Family Medicine (Istanbul Medical Faculty)
- • Department of General Surgery
İstanbul, Istanbul, Turkey
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