Biomedical subjects

Aysun Bay Karabulut

Publications and source records attributed to Aysun Bay Karabulut.

15 recordsLinked to original sources

PubMed2006

Resveratrol, a red wine constituent polyphenol, protects gastric tissue against the oxidative stress in cholestatic rats.

This experimental study was designed to determine the effects of resveratrol on the level of malondialdehyde (MDA), reduced glutathione (GSH), and nitric oxide (NO) in gastric tissue after bile duct ligation (BDL). Swiss albino rats were divided into three groups: Group 1, sham (n = 7); Group 2, BDL (BDL only group; n = 7); and Group 3, BDL plus resveratrol (n = 7). Animals in the resveratrol group were treated with 10 mg/kg resveratrol (i.p.) once a day throughout 28 days. In the resveratrol group, levels of MDA and NO in gastric tissue were significantly lower than in the BDL-only group (P < 0.001). The level of GSH in the resveratrol group was significantly higher than in the BDL-only group (P < 0.001). The present study demonstrates that intraperitoneal administration of resveratrol maintains antioxidant defenses and reduces oxidative gastric damage. This effect of resveratrol may be useful to preserve gastric tissue under oxidative stress due to cholestasis.

Animals↗

PubMed2006

House dust-mites: effect on antioxidant enzyme activities.

BACKGROUND: House dust-mites are potent allergens of the indoor environment and are common inhabitants of houses worldwide. Free radicals are constantly produced by cells, mostly as reactive oxygen species. Once produced, free radicals are removed by antioxidant defenses, including the enzymes SOD, GPx, and CAT. MATERIAL/METHODS: The aim was to describe the importance of the antioxidant enzymes SOD, GPx, and CAT co-acting in hunan cells against toxic reactive oxygen species and their relationship with pathophysiological processes in stubjects who have dust-mites in their homes. RESULTS: The activities of erythrocyte GPx and SOD in skin-test-positive (dust-mite-positive/negative) patients were significantly lower than those in dust-mite- and skin-test-negative controls (p < 0.05). Among the skin-test-positive patients, SOD activity was found to be lower in dust-mite-positive than in dust-mite-negative patients (p < 0.05). There was not a statistically significant difference between the CAT levels of skin-test-positive (dust-mite-positive/negative) patients and dust-mite- and skin-test-negative controls (p > 0.05). CONCLUSIONS: This study clearly shows that dust-mite depresses the activities of SOD, GPx, and, to a small extent, CAT; which influence cellular reducing capacity and consequently may increase asthma risk more than other allergens.

Adolescent↗

PubMed2005

Protective effect of melatonin against oxidative stress on adhesion formation in the rat cecum and uterine horn model.

This experimental study was designed to evaluate the degree of adhesion formation and peritoneal tissue levels of malondialdehyde (MDA), reduced glutathione (GSH) and nitric oxide (NO) and the effect of melatonin on these metabolites in a postoperative intraperitoneal adhesion formation model in rats. Thirty adult female Wistar albino rats were subjected to standardized lesions by cecal and uterine horn abrasion and were randomly divided into three groups. Control rats were treated with 5% ethanol. Melatonin treated rats received 4 mg/kg melatonin before closure and for 10 consecutive days intraperitoneally after surgery. Rats in the sham operation group underwent a surgical procedure similar to the other groups however the peritoneal abrasion was not performed. On postoperative day 10 relaparatomy was performed. After the assessment of the adhesions, the rats in each group were sacrificed and peritoneal tissues were harvested to determine the tissue levels of MDA, GSH and NO activity. Adhesion formation scores in the melatonin group were significantly lower than that of control and sham group (p<0.01 and p<0.02, respectively). Tissue levels of MDA and NO were significantly lower in the melatonin treated rats when compared with control and sham groups. The levels of GSH in the melatonin treated rats were significantly higher than those of control and sham groups (p<0.01). The results demonstrate that in this experimental model, intraperitoneal administration of melatonin decreases the extent of peritoneal adhesions and causes a decrease in MDA and NO and an increase in GSH levels.

Animals↗

PubMed2005

Protective effect of resveratrol against oxidative stress in cholestasis.

BACKGROUND: We investigated the protective role of resveratrol in rat liver injuries induced by chronic biliary obstruction. MATERIALS AND METHODS: Secondary biliary cirrhosis was induced by bile duct ligation for 28 days. Swiss albino rats were divided into the three following groups: group 1: sham (n = 7); group 2: bile duct ligation (n = 7); group 3: bile duct ligation plus resveratrol (n = 7). Bile duct ligation plus resveratrol group received 10 mg/kg dose of resveratrol intraperitoneally daily for 28 days. Liver damage and cholestasis were determined by the biochemical and the pathologic examination. RESULTS: The present data showed a decrease in both plasma bilirubin levels and aspartate aminotransferase and alanine aminotransferase levels in the resveratrol-treated rats, when compared with bile duct ligation group (P < 0.05). In the resveratrol-treated rats, tissue levels of malondialdehyde and nitric oxide were significantly lower than that of the bile duct ligation (P < 0.002). The levels of glutathione in resveratrol-treated rats were significantly higher than that in bile duct ligation group (P < 0.004). The levels of interleukin-1alpha, interleukin-6, and tumor necrosis factor-alpha in resveratrol group were significantly lower than that in bile duct ligation group (P < 0.004, P < 0.001, P < 0.001, respectively). Administration of resveratrol in the rats with biliary obstruction resulted in inhibition of ductular proliferation and lymphocytic inflammation. CONCLUSION: The present study demonstrates that intraperitoneal administration of resveratrol in bile duct ligated rats maintained antioxidant defenses and reduces liver oxidative damage and ductular proliferation. This effect of resveratrol may be useful in the preservation of liver function in cholestasis.

Alanine Transaminase↗

PubMed2005

A comparative study of superoxide dismutase, catalase, and glutathione peroxidase activities and nitrate levels in vitiligo patients.

BACKGROUND: Several groups have shown the involvement of oxidative stress in the pathophysiology of vitiligo. METHODS: In this study, we examined the erythrocyte and plasma activities of glutathione peroxidase and Cu/Zn superoxide dismutase, plasma nitrite/nitrate levels, and erythrocyte catalase activity in 23 vitiligo patients and 25 controls. RESULTS: The results show that erythrocyte superoxide dismutase activity and plasma nitrite/nitrate levels are high in vitiligo patients. CONCLUSIONS: Our study confirms that oxidative stress is involved in the pathophysiology of vitiligo, as indicated by the high levels of erythrocyte superoxide dismutase activity and plasma nitrite/nitrate.

Adolescent↗

PubMed2005

Effect of the treatment of brucellosis on leukocyte superoxide dismutase activity and plasma nitric oxide level.

BACKGROUND: The mechanisms by which brucellae evade intracellular killing by polymorphonuclear leukocytes are incompletely understood. In this study, we evaluated changes of leukocyte superoxide dismutase (SOD) activity and plasma total nitrite as an indicator of nitric oxide (NO) levels during brucellosis therapy. METHODS: Thirty-two patients with acute brucellosis, 27 patients with chronic brucellosis and 30 healthy controls were included in the study. Patients with acute brucellosis were tested for leukocyte SOD activity and plasma total nitrite levels before, during (21st day), and at the end (45th day) of the combined therapy of rifampicin and doxycycline. The same parameters were also investigated in chronic cases and controls. RESULTS: The SOD activities were lower in patients with acute brucellosis before therapy compared with those 21 and 45 days after starting therapy (P < 0.001). In contrast, total nitrite levels did not change significantly (P > 0.05). CONCLUSIONS: In the present study, leukocyte SOD activity was found to be decreased in patients with acute brucellosis. Enzyme activity was increased by treatment, finally reaching the activity of healthy controls. Using an antioxidant agent in addition to classical antimicrobial therapy for acute brucellosis might be a therapeutic approach.

Acute Disease↗

PubMed2005

Protective effect of resveratrol against renal oxidative stress in cholestasis.

BACKGROUND/AIMS: This experimental study was designed to evaluate histological changes of the kidney and renal tissue levels of malondialdehyde (MDA), reduced glutathione (GSH), and nitric oxide (NO) and the effect of resveratrol on these metabolites after bile duct ligation in rats. METHODS: Secondary biliary cirrhosis was induced by bile duct ligation for 28 days. Swiss albino rats were divided into three groups. Group 1: Sham (n=7), Group 2: Bile duct ligation (n=7), Group 3: Bile duct ligation plus resveratrol (n=7). Bile duct ligation (BDL) plus resveratrol group received 10 mgr/kg dose of resveratrol intraperitoneally daily throughout 28 days. Kidney tissues were harvested to determine the tissue levels of MDA, GSH, and NO activity. Liver and kidney tissues were removed for light microscopic evaluation. RESULTS: Cholestasis was determined by biochemical and pathologic examination. In the resveratrol-treated rats, levels of MDA were significantly lower than those of the BDL group (p < 0.04). The levels of GSH in the resveratrol-treated rats were significantly higher than those in the BDL group (p < 0.01). The levels of NO in the resveratrol group were significantly lower than those in the BDL group (p < 0.01). CONCLUSION: The present study demonstrates that intraperitoneal administration of resveratrol in bile duct ligated rats maintains antioxidant defenses and reduces kidney oxidative damage. This effect of resveratrol may be useful in the preservation of renal oxidative stress in cholestasis.

Animals↗

PubMed2004

Interferon-alpha reduces the development of experimental necrotizing enterocolitis.

Cytokines had important role in the pathogenesis of necrotizing enterocolitis (NEC). The aim of this study is to investigate if IFN-alpha has a prophylaxic effect on experimental NEC development in newborn rat pups. Twenty eight Wistar Albino newborn rat pups were divided into three groups. Control group rats were breast-fed, NEC group and interferon (IFN) group rat pups were hand-fed with premature newborn formula. IFN-alpha was administered subcutaneously at a dose of 50,000 IU/rat/day in IFN group. NEC was induced experimentally by cold stress twice a day in IFN and NEC groups. On the fourth day, the rats were killed, and all the intestine were removed to determine the tissue level of malonaldehyde (MDA) and histologic changes. The microscopic lesions in the NEC group rats were virtually the same as those seen in neonatal NEC, with severe separation of submucosa and/or lamina propria, loss of villi and in some cases necrosis to extention the muscularis. In contrast, in the rats treated with IFN, lesions were moderate separation of submucosa and/or lamina propria, edema in submucosal and muscular layers. Intestinal injury score and MDA levels in NEC group were significantly higher than in the IFN group (P<0.05). In conclusion it was suggested that IFN-alpha was effective in reducing the severity of NEC in rat pups.

Animals↗

PubMed2004

Hydrophobic nature of rat lymph chylomicrons.

BACKGROUND: A typical molecular structure of a lipoprotein is composed of hydrophobic lipids at the core and hydrophilic apolipoprotein side chains and lipid head groups at the surface. Some of the hydrophobic characteristics of rat lymph chylomicrons were investigated. METHODS: Thoracic duct was cannulated and lymph was collected overnight. Chylomicrons (>100 nm) were isolated by ultracentrifugation at 4 x 10(6)xg min. Since particle aggregation is a characteristic of hydrophobic nature of lipoproteins, as an index of aggregation, the turbidity generated by vortexing and storage of chylomicrons was measured spectrophotometrically at 680 nm. We also assessed the ability of chylomicrons to interact with five different hydrophobic interaction chromatography (HIC) media. RESULTS: Neither shaking nor prolonged storage at 4 degrees C produced an increase in the optical density of chylomicron solution indicating no aggregation took place. Typical elution profiles of chylomicrons through octyl, phenyl (high substance) and butyl sepharose columns showed two peaks. Peak I material emerged with 4 mol/l NaCl in a position corresponding to the void volume and peak II material eluted with water. Phenyl sepharose (high performance) media exhibited the maximum binding strength towards chylomicrons among the five different media. In the case of phenyl sepharose (low substance) column, an additional material was eluted with 3 mol/l NaCl between peaks I and II. These results indicate the heterogeneity of chylomicron surface hydrophobicity. CONCLUSION: Since particle aggregation is a characteristics of hydrophobicity of lipoproteins and believed to be an underlying cause of atherosclerosis, fractionation of lipoproteins by hydrophobic interaction chromatography may introduce a new approach into the assessment of lipoprotein atherogeneicity.

Animals↗

PubMed2004

Altered diurnal variation of nitric oxide production in patients with panic disorder.

The aim of this prospective study was to investigate the diurnal change in serum nitric oxide (NO) levels in active and remission phases of patients with panic disorder. This study included 15 patients fulfilling the criteria for panic disorder of Diagnostic and Statistical Manual of Mental Disorders--Fourth Edition and 15 healthy controls matched for age and sex. All patients were receiving a selective serotonin reuptake inhibitor at therapeutic doses. The serum nitrite and nitrate levels of subjects were determined at 10:00 a.m. after overnight fasting and at 3:00 p.m. 2 hours after lunch. NO levels of all patients measured in the morning were significantly higher than those of controls. The patients were also divided into active and remission groups according to clinical status and Panic Agoraphobia Scale's cut-off point. There were no statistically significant differences in serum nitrite and nitrate levels of the active group between the 10:00 a.m. and 3:00 p.m. measurements. In contrast, statistically significant differences were found in the serum levels of nitrite (p<0.05) and nitrate (p<0.05) in the remission group. Notably, the afternoon nitrite and nitrate levels of the remission group were higher than those of the morning levels as seen in control subjects. Thus, diurnal variation of NO production is altered in patients with panic disorder but is resumed in the remission phase. The present study suggests that serum NO levels are a good marker for evaluation of panic disorder.

Agoraphobia↗

PubMedDate not supplied

Maternal and fetal plasma adenosine deaminase, xanthine oxidase and malondialdehyde levels in pre-eclampsia.

The aim of this study was to evaluate maternal-fetal plasma adenosine deaminase, xanthine oxidase (ADA, XO) activity and malondialdehyde (MDA) levels and the relationship between them in pre-eclampsia. Maternal and umbilical cord whole blood samples were taken from 29 pre-eclamptic and 33 normal pregnants. The plasma ADA, XO activities as well as MDA levels were assayed by spectrophotometric methods. MDA levels and ADA, XO activities were found to be higher in maternal and fetal plasma in pre-eclamptics than in normal pregnancy. The differences were statistically significant between groups (p < 0.05). Increased maternal-fetal plasma XO and ADA activities, as a marker of immunological disorder, may be related to the pathogenesis of pre-eclampsia. In addition, increased MDA levels may be a reflection of increased oxidative stress in pre-eclamptics and their fetuses.

Adenosine Deaminase↗

PubMedDate not supplied

Protective effect of aminoguanidine against oxidative stress in an experimental peritoneal adhesion model in rats.

Postoperative intraperitoneal adhesion formation is a major cause of intestinal obstruction, pain and infertility. This experimental study was designed to evaluate the degree of adhesion formation and peritoneal tissue levels of malondialdehyde (MDA), reduced glutathione (GSH) and total nitrite and nitrate (NO) and the effect of aminoguanidine (AG) on these metabolite values after postoperative intraperitoneal adhesion formation in rats. A total of 21 adult male Wistar albino rats were randomly divided into three groups. Control rats were untreated; the AG group received AG 200 mg kg(-1) i.p. for 10 consecutive days intraperitoneally after surgery. The sham group was given 0.9% NaCl. The rats were killed on postoperative day 10. The peritoneal tissues were harvested to determine the tissue levels of MDA, GSH, and NO activity. For light microscopic evaluation, the cecum was removed. Adhesion formation scores in the AG group were significantly lower than those of the control and sham groups (p < 0.017, p < 0.026 respectively). In the AG-treated rats, tissue levels of MDA and NO were significantly lower than in the control group (p < 0.017). The levels of GSH in aminoguanidine-treated rats were significantly higher than those of the control group (p < 0.01). The severity of the inflammation was more prominent in the control group compared with the AG-injected rats. The results demonstrate that in this experimental model, intraperitoneal administration of aminoguanidine decreases the incidence and extent of peritoneal adhesions and causes a decrease in MDA and NO and an increase in GSH values.

Animals↗

PubMedDate not supplied

The effect of resveratrol on surgery-induced peritoneal adhesions in an experimental model.

Adhesion formation is a common cause of complications following surgery. The aim of this study was to investigate the effect of resveratrol on intra-abdominal adhesion prevention in a rat model. Twenty one Wistar-Albino rats weighing 200-250 g were assigned to three groups, of 7 rats each. After a midline laparotomy was performed, a 1 cm area of the ceacum was abraded in two of the groups. They were then given either resveratrol (Group 1), or saline (Group 2) intraperitoneally. Group 3 rats (sham operation) received no treatment, without the serosal damage. On the 14th day, the rats were killed and the adhesion score was determined according to Mazuji's adhesion grade scale. The tissue levels of malondialdehyde (MDA), nitric oxide (NO), and reduced glutathione (GSH) were measured. The mean Mazuji's adhesion grade in the resveratrol group was 1.0 +/- 0.0, in the saline group 2.57 +/- 1.51, and zero in the sham operated group (p < 0.05 between the resveratrol group and saline group comparison). The levels of MDA and NO in the resveratrol group were significantly lower than those of the saline group (p < 0.001). The level of GSH in the resveratrol group was significantly higher than in the saline and sham operated groups (p < 0.001 and p < 0.001, respectively). Introduction of resveratrol into the peritoneal cavity at the time of surgery reduced adhesion formation effectively in this model. Resveratrol probably acts through reduction of lipid peroxidation products.

Animals↗

PubMedDate not supplied

The role of oxidative stress in postoperative delirium.

AIM: This study aimed to determine a marker that predicts delirium using preoperative oxidative processes in patients undergoing cardiopulmonary bypass surgery. METHOD: Twelve of the 50 patients included in the study showed signs of delirium during postoperative follow-up. The Delirium Rating Scale was used in patients with delirium according to DSM-IV-TR in the postoperative period. Venous blood samples were obtained from the patients the day before and the day after the surgery to determine plasma antioxidant enzyme levels. RESULTS: While there were no differences in preoperative superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) levels in both groups, catalase (CAT) levels were significantly lower in the delirium group. Postoperative SOD and MDA levels were also higher in the delirium group, while the GSH-Px levels were found to be lower when compared with those during the preoperative period. In the nondelirium group, the postoperative MDA and GSH-Px levels were found to be lower than preoperative levels, and postoperative SOD levels were found to be higher than preoperative levels. CAT levels were lower in the delirium group when the pre- and postoperative levels were compared in both groups. The postoperative levels of SOD, GSH-Px and CAT in the nondelirium group and MDA in the delirium group were significantly higher than preoperative levels. CONCLUSION: Patients with low preoperative CAT levels appeared to be more susceptible to delirium than patients with higher CAT levels.

Aged↗

PubMedDate not supplied

Dust-mites: effect on lipid peroxidation.

BACKGROUND: Dust-mites are present in our homes, feed on dead exfoliated skin and other organic material. It is also known that oxidative stress may lead to cellular damage that can be confirmed by markers of cellular disruption. Oxidative stress in various infective processes has been documented. We investigated whether house dust-mites cause oxidative stress in patients. METHODS: Products of lipid peroxidation in erythrocytes and lymphocytes were assessed by measuring malondialdehyde concentration. RESULTS: Our results showed that patients who had a positive skin test for dust-mite antigens and had dust-mites present in their houses (dust-mite positive) had increased erythrocyte malondialdehyde levels (62.39 [18.56] nmol/g-Hb) compared with those who were skin test positive, dust-mite negative (45.45 [10.82]) or skin test negative, dust-mite negative (42.20 [5.68]). They also had significantly higher levels of lymphocyte malondialdehyde (4.22 [0.55] nmol/g-protein) compared with those who were skin test positive, dust-mite negative (3.46 [0.29]) or skin test negative, dust-mite negative (1.25 [0.31]; p <0.05). However, there was no statistically significant difference between the malondialdehyde levels of dust-mite negative/skin test positive and dust-mite negative/skin test negative patients. CONCLUSION: Increased malondialdehyde activity in lymphocytes and erythrocytes in the dust-mite positive/skin test positive group shows the presence of the oxidative stress in patients with dust-mite infestation.

Adolescent↗