Association of oxidative stress with clinical characteristics in patients with rheumatoid arthritis.

BACKGROUND: Few studies examining the association between oxidative stress and clinical parameters or disease activity in patients with rheumatoid arthritis (RA) are available. Therefore, the objective of this study was to test whether oxidative stress has any association with clinical parameters and disease activity in patients with RA. MATERIALS AND METHODS: In this post hoc cross-sectional study, 45 patients with RA treated with traditional disease-modifying antirheumatic drugs (DMARDs) ± low-dose glucocorticoids ± nonsteroidal analgesics for at least 3 months were analysed. Oxidative stress parameters were malondialdehyde (MDA), superoxide dismutase (SOD), antioxidant potential (AOP) and nonenzymatic superoxide radical scavenger activity (NSSA). Clinical parameters were pain, patient global assessment, physician global assessment, Health Assessment Questionnaire (HAQ), and disease activity score (DAS28). RESULTS: Plasma NSSA levels were significantly inversely correlated with tender joints count (r = -.304; P = .042), swollen joints count (r = -.342; P = .021) and DAS28 (r = -.396; P = .009). There were no significant correlations between MDA/SOD/AOP and any of clinical parameters or DAS28 (P > .05 for all). Multiple regression analysis revealed that NSSA was an independent variable of DAS28 (ß=-.243, P = .016). CONCLUSION: The preliminary results demonstrate that plasma NSSA levels were inversely correlated with tender and swollen joints count and DAS28 and that NSSA was independently associated with DAS28, in patients with RA treated with traditional DMARDs; and provide initial support that NSSA may be used as a biomarker of disease activity in patients with RA.

Effect of spa therapy with saline balneotherapy on oxidant/antioxidant status in patients with rheumatoid arthritis: a single-blind randomized controlled trial.

Oxidative stress has been shown to play a contributory role in the pathogenesis of rheumatoid arthritis (RA). Recent studies have provided evidence for antioxidant properties of spa therapy. The purpose of this study is to investigate whether spa therapy with saline balneotherapy has any influence on the oxidant/antioxidant status in patients with RA and to assess clinical effects of spa therapy. In this investigator-blind randomized controlled trial, we randomly assigned 50 patients in a 1:1 ratio to spa therapy plus standard drug treatment (spa group) or standard drug treatment alone (control group). Spa group followed a 2-week course of spa therapy regimen consisting of a total of 12 balneotherapy sessions in a thermal mineral water pool at 36-37 °C for 20 min every day except Sunday. All clinical and biochemical parameters were assessed at baseline and after spa therapy (2 weeks). The clinical parameters were pain intensity, patient global assessment, physician global assessment, Health Assessment Questionnaire disability index (HAQ-DI), Disease Activity Score for 28-joints based on erythrocyte sedimentation rate (DAS28-4[ESR]). Oxidative status parameters were malondialdehyde (MDA), nonenzymatic superoxide radical scavenger activity (NSSA), antioxidant potential (AOP), and superoxide dismutase (SOD). The NSSA levels were increased significantly in the spa group (p = 0.003) but not in the control group (p = 0.509); and there was a trend in favor of spa therapy for improvements in NSSA levels compared to control (p = 0.091). Significant clinical improvement was found in the spa group compared to the control in terms of patient global assessment (p = 0.011), physician global assessment (p = 0.043), function (HAQ-DI) (p = 0.037), disease activity (DAS28-4[ESR]) (0.044) and swollen joint count (0.009), and a trend toward improvement in pain scores (0.057). Spa therapy with saline balneotherapy exerts antioxidant effect in patients with RA as reflected by the increase in NSSA levels after spa therapy; whether this antioxidant effect contributes to the clinical improvements observed remains to be verified.

Circulating and myometrial markers of oxidative stress in pregnant women with fetal growth restriction.

AIM: The objective of this study was to identify the relationship between fetal growth restriction (FGR) and oxidative stress. The mechanisms that protect against oxidative stress in the local microenvironment were investigated by comparing the activities of the markers, both in the circulation and myometrium. MATERIALS AND METHODS: Myometrial tissue and serum levels of malondialdehyde (MDA), xanthine oxidase (XO), catalase (CAT) and superoxide dismutase (SOD) markers were measured in 20 FGR and 20 healthy pregnancies. RESULTS: The mean duration of gestation at delivery was shorter (P = 0003) and the mean birthweight was lower P < 0001) in the FGR study group compared with the control group, as expected. While MDA and CAT concentrations were higher in the serum (P < 0.02 and P < 0.01, respectively), but lower in the myometrial samples (P < 0.01) in the FGR versus the control group, XO and myometrial SOD values were comparable in both groups. CONCLUSIONS: Although our data demonstrated that FGR is associated with oxidative stress, the exact role and mechanism of the oxidant and antioxidant imbalance is obscure. We speculate that despite limited local synthesis of CAT, effective and efficient removal of MDA in the uterine environment explains high MDA and CAT serum concentrations in women with FGR. Alternatively, a well-functioning myometrial system could rescue the fetus from reactive oxygen species, as demonstrated by lowered MDA and depleted CAT resulting from hyperconsumption. Elevated serum MDA and CAT levels in the serum may reflect the 'spillover' of these markers from the uterus to the circulation.

The cellular immunity and oxidative stress markers in early pregnancy loss.

OBJECTIVE: We investigated whether changes in cellular immunity and oxidative stress in pregnancy have any association with spontaneous miscarriage. MATERIAL AND METHODS: Circulating adenosine deaminase (ADA) activity as a marker of cellular immunity and malondialdehyde (MDA) and catalase (CAT), glutathione peroxidase (GPx) as markers of T lymphocyte activation and parameters of oxidative stress and antioxidant defense were compared between 40 women with early pregnancy loss and another 40 women with ungoing healthy pregnancy. RESULTS: Women with miscarriage had higher serum ADA and GPx levels when compared with women with normal pregnancy (p = 0.034 and p < 0.001, respectively). Although serum MDA level was slightly higher in women with miscarriage, the difference was not significant (p = 0.083). CAT levels were alike in both groups. CONCLUSION: We have demonstrated an increased cellular immunity and perhaps a compensated oxidative stress related to increased antioxidant activation in women with early spontaneous pregnancy loss.

A Turkish 3-center study evaluation of serum folic acid and vitamin B12 levels in Alzheimer disease.

BACKGROUND/AIM: Alzheimer disease, a common proteopathy of advanced age, is characterized by cortical atrophy, neuron degeneration, neuronal loss, and accumulation of extracellular amyloid ß plaques. We aimed to investigate serum vitamin B12 and folic acid levels in Alzheimer disease and other dementia patients, as a potential screening test to detect presymptomatic Alzheimer disease in Turkish patients. MATERIALS AND METHODS: We evaluated folic acid and vitamin B12 levels in Alzheimer disease patients as well as in other dementia and geriatric patients from Ankara, Dokuz Eylül, and Çukurova university hospitals; 290 female and male geriatric subjects were enrolled. Vitamin B12 and folic acid levels were measured using Roche E170 and Beckman Coulter DXI 800 immunoassays (chemiluminescence) according to the manufacturers' guideline in all centers. RESULTS: We evaluated the results of folic acid and vitamin B12 in Alzheimer disease, other dementias and geriatric patients. No significant difference between the groups regarding the routine control of biochemical parameters was observed. CONCLUSION: Currently, serum folic and vitamin B12 levels are not diagnostically reliable tests for screening presymptomatic Alzheimer disease. However, the results may statistically be significant if we increase the sample size.

L-arginine pathway in neonates with meconium-stained amniotic fluid.

OBJECTIVE: To study the arginase, nitric oxide synthase and nitric oxide pathways associated with passage of meconium. STUDY DESIGN: Cord blood samples were collected from 20 newborns with meconium-stained amniotic fluid (MSAF) and from 23 newborns with clear amniotic fluid. Cord blood pH, arginase, nitric oxide synthase and nitric oxide levels were compared between the groups. RESULT: The differences between the arginase and nitric oxide measurements of the newborns with MSAF and those with clear amniotic fluid were significant. In the MSAF group arginase levels were significantly lower (p=0.007) and nitric oxide levels were significantly higher (p=0.032) than the clear amniotic fluid group. CONCLUSION: Hypoxia may be involved in the pathogenesis of meconium passage due to decreased arginase and increased nitric oxide levels.

Comparison of stored umbilical cord blood and adult donor blood: transfusion feasibility.

OBJECTIVE: This study aimed to compare the storage properties of red blood cell (RBC) concentrates of umbilical cordblood (UCB) and adult donor blood (ADB), and to evaluate the feasibility of UCB-RBC concentrate as an autologoussource for blood transfusion in very low birth weight (VLBW) preterm neonates. MATERIAL AND METHODS: In all, 30 newborn (10 preterm, 20 full term) UCB and 31 ADB units were collected.RBC concentrates were stored and compared with regard to pH, potassium (K(+)), 2,3-biphosphoglycerate (2-3-BPG),adenosine tri-phosphate (ATP), plasma Hb, and bacterial contamination on d 1, 21, and 35 of storage. RESULTS: The K(+) level increased with time and differed significantly between storage d 1 and 21, and between storaged 1 and 35 in both the UCB and ADB units. Initial and d 21 K(+) levels were higher in the UCB units than in the ADBunits. The 2,3-BPG level did not differ significantly between the UCB-PRC and ADB-PRC samples. After 35 d of storageboth UCB-PRC and ADB-PRC samples exhibited significant differences from the initial free Hb, intracellular ATP, andpH values. Significant differences in intracellular ATP and pH were also observed between the UCB-PRC and ADB-PRCsamples. CONCLUSION: The volume of harvested and prepared UCB-PRC can be used for some of the blood transfusions requiredduring the neonatal period and thus may decrease the number of allogeneic transfusions, especially in preterm newborns.The hematological and biochemical changes that occurred in UCB during storage were comparable with those observedin ADB, and do not pose a risk to the immature metabolism of neonates. UCB-RPC prepared and stored under standardconditions can be a safe alternative RBC source for transfusions in VLBW newborns.

Cardioprotective roles of aged garlic extract, grape seed proanthocyanidin, and hazelnut on doxorubicin-induced cardiotoxicity.

Doxorubicin (DXR) is a chemotherapeutic agent used effectively in the treatment of several childhood malignancies. During treatment, cardiotoxicity caused by cell damage due to the free oxygen radicals that are generated is a major limiting factor. This study was undertaken to determine whether DXR-induced cardiotoxicity could be prevented by natural foods with antioxidant properties such as aged garlic extract (AGEX), grape seed proanthocyanidin (PA), and hazelnut. Wistar albino male rats were assigned randomly to 9 groups each consisting of 15 rats. AGEX, PA, and hazelnut groups received these antioxidants in addition to their standard rat diet. They were also treated with cumulative intraperitoneal (i.p.) injections according to 2 different regimens: either a high-dose of 15 mg/kg DXR (3.75 mg/kg per week for 4 weeks) or a low-dose of 7.5 mg/kg DXR (1.875 mg/kg per week for 4 weeks). The control group received i.p. 0.9% saline. AGEX, PA, or hazelnut supplements were given orally to the groups for a 6-week period starting 1 week before the DXR treatment and ending 1 week after the treatment. One week after the last DXR injection, heart tissue samples were analyzed to determine malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and xanthine oxidase (XO) levels, and serum samples were taken for creatine kinase (CK). There were no significant changes in MDA levels among the control, DXR-treated groups, or supplemented groups that received additional natural antioxidant foods. SOD enzyme levels were decreased in rats treated with DXR. PA prevented the decrease at low doses of DXR. DXR treatment decreased CAT enzyme levels, but additional PA and hazelnut consumption increased these levels at low cumulative doses. XO enzyme levels were decreased in AGEX and hazelnut groups, but PA prevented the decrease. CK levels were elevated after DXR administration, indicating myocardial injury, but PA significantly reversed this. Although there were no differences histopathologically between AGEX, PA, and hazelnut groups, the protective effects of AGEX and PA were evident in electron microscopy. In conclusion, the positive effects of natural antioxidant foods on the prevention of DXR-induced cardiac injury could not be clearly shown on the basis of antioxidant enzymes. However, the electron microscopic changes clearly demonstrated the protective effects of AGEX and PA. The supplementation of these antioxidant foods over longer periods may show more definitive results. Human studies with different doses are needed to evaluate the effects of these foods on the human heart.

Effects of aqueous green tea extract on activities of DNA turn-over enzymes in cancerous and non-cancerous human gastric and colon tissues.

AIM: The purpose of this study was to investigate possible effects of green tea extract on the activities of DNA turn-over enzymes, namely adenosine deaminase (ADA) and xanthine oxidase (XO) in gastric and colon tissues from patients with stomach and colon cancer. MATERIALS AND METHODS: Six cancerous and 6 non-cancerous adjacent human gastric tissues, and 7 cancerous and 7 non-cancerous adjacent colon tissues obtained surgically were treated with aqueous green tea extract at 3 different concentrations for 1 hour, and then ADA and XO activities were measured. RESULTS: In all of the tissues, XO activities were found to elevate after treatment with green tea extract. Additionally, ADA activity was found to be inhibited in the cancerous gastric tissues by the green tea extract. Elevated XO and reduced ADA activities due to treatment with green tea extract may lower salvage pathway activity and lead to inhibition in carcinogenesis. CONCLUSION: Our data suggest that green tea may support the medical treatment of stomach and colon cancer.

Effects of garlic consumption on plasma and erythrocyte antioxidant parameters in elderly subjects.

BACKGROUND: The oxidative stress theory of aging is one of the most widely acknowledged theories of aging. The intake of fruits and vegetables with antioxidant power is associated with a reduced incidence of many chronic diseases of aging. OBJECTIVE: The effects of ingesting garlic on plasma and erythrocyte antioxidant parameters of elderly subjects were investigated in this study. METHODS: 13 subjects (mean age 70.69 +/- 4.23) participated in the study. They ingested garlic at the daily dose of 0.1 g/kg b.w. for 1 month. Before and after this period, fasting blood samples were obtained, and oxidant [malondialdehyde (MDA) and xanthine oxidase (XO)] and antioxidant [superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT)] parameters were studied in erythrocytes, and MDA levels were studied in plasma samples obtained from the subjects. Routine blood biochemical parameters were also measured in blood samples. RESULTS: In the plasma fraction and erythrocyte hemolysate, MDA levels were found to be significantly lower, but erythrocyte GSH-Px and SOD activities were significantly higher in the second samples relative to the first ones. XO activity was found to be lower in the second samples, but this decrease was not statistically meaningful. LDL cholesterol was found to be significantly lower in the second samples relative to the first ones. CONCLUSION: Our results show that ingestion of garlic leads to significantly lowered plasma and erythrocyte MDA levels and to increased activities of some antioxidant enzymes, which indicates that consumption of garlic decreases oxidation reactions. It is quite possible that reduced peroxidation processes due to garlic consumption may play a part in some of the beneficial effects of garlic in elderly subjects.

Oxidant/antioxidant status and vitamin A levels in children infected with varicella.

AIM: Varicella is a childhood disease, with its highest incidence being found in children aged 1 to 9 years. The aim of this study was to investigate the plasma oxidant and antioxidant status in Turkish children with varicella infection. METHODS: The study population consisted of 29 children infected with varicella recruited from the Department of Pediatrics at Baskent University Hospital in Ankara, Turkey. The control group consisted of 20 age-matched children from the same region who were apparently otherwise healthy. After overnight fasting, venous blood samples were obtained and transferred to heparinized tubes. Plasma malondialdehyde and vitamin A levels were measured in both groups. RESULTS: The plasma malondialdehyde levels were higher in children in the infected group than they were in children in the control group. However, there were no statistically significant differences in plasma vitamin A levels between the groups. CONCLUSION: This study suggests that oxidant stress causes significant peroxidation, and the antioxidant defence system is affected in varicella infection. Antioxidant supplementation may yield beneficial results in these patients. Further studies are needed to determine the positive effects of vitamin A supplementation in patients with varicella infections.

Activities of xanthine oxidase and superoxide dismutase enzymes in rat intestinal tissues in sepsis.

BACKGROUND: The aim of this study was to elucidate a possible source of oxidant stress in experimental sepsis. METHODS: For this aim, 32 Sprague-Dawley type rats were used in the study. After all the animals underwent laparotomy, nonlethal cecum ligation and puncture (CLP) technique was used to create an experimental sepsis model in two groups (CLP-6 and CLP-48 groups). Rats in the other groups (Sham operated) were used as controls. Animals in the control-6 and CLP-6 groups were killed 6 hours after the beginning of the study whereas the other animals were killed 48 hours after the beginning. Part of the terminal ileum of each animal was removed to be used in the measurements of xanthine oxidase and superoxide dismutase enzyme activities. RESULTS: Xanthine oxidase activity in the CLP-48 group was found to increase significantly as compared with that of the control-48 group, but superoxide dismutase activity did not change. No significant changes, however, were observed between analysis parameters in the terminal ileum tissues when obtained 6 hours after the beginning of sepsis. CONCLUSION: Our results suggest that increased xanthine oxidase activity is one of the leading factors for the oxidant stress in the late phase of sepsis.

Effects of apple consumption on plasma and erythrocyte antioxidant parameters in elderly subjects.

The effects of apple consumption on plasma and erythrocyte antioxidant parameters of elderly subjects were investigated in this study. Fifteen elderly subjects (mean age 71.86 +/- 4.17) participated in the study. They consumed an apple a day for 1 month. Before and after this period, fasting blood samples were obtained, and oxidant (malondialdehyde [MDA]) and antioxidant (superoxide dismutase [SOD], glutathione peroxidase [GSH-Px], catalase [CAT], and antioxidant potential [AOP]) parameters were studied. MDA and AOP levels were studied in plasma, and SOD, GSH-Px, and CAT activities and MDA levels were measured in the erythrocytes. In the erythrocytes, GSH-Px and SOD activities were found to be higher (p < .001 and p < .01), but MDA levels were lower in the second samples relative to the first ones. In the plasma, AOP value was found to be higher in the second samples relative to first ones (p < .001). No differences were found, however, between the routine blood parameters such as total cholesterol, low-density lipoprotein cholesterol, very-low-density lipoprotein cholesterol, high-density-lipoprotein cholesterol, and triglyceride levels. The results show that consumption of apple leads to significant increases in the activities of some antioxidant enzymes and in the antioxidant potential values of the blood, and that decreases oxidation reactions in the body in significant amount. It is quite possible that reduced peroxidation processes owing to consumption of this fruit may play a part in some of their beneficial effects in the elderly subjects.

Oxidant and antioxidant status of Turkish marasmic children: a single center study.

The aim of this study was to investigate plasma oxidant and antioxidant status in Turkish marasmic children. The study population consisted of 38 marasmic children (group I) and 28 age-matched children (group II) who were apparently well, with weight-forage >80% of the standards in the same region. After overnight fasting, venous blood samples were drawn and immediately transferred to heparinized and normal tubes. Plasma antioxidant potential (AOP), and malondialdehyde (MDA) levels were measured in both groups. The plasma MDA levels were found to be higher in group I than in group II. However, plasma AOP values were lower in group I than in group II. The present study suggests that AOP is reduced due to an impaired antioxidant system in the plasma of malnourished patients. This oxidant stress causes significant peroxidation. Also, the antioxidant defense system of the patients is deteriorated in marasmus.

Black grape and garlic extracts protect against cyclosporine a nephrotoxicity.

The aim of this study was to determine if the natural antioxidant foods, dried black grape and garlic, protect against cyclosporine nephrotoxicity. Forty-two Sprague-Dawley rats were given Cyclosporine A (CsA) orally for 10 days, with the antioxidant food supplementation begun 3 days before CsA treatment and continued during the study period (totaling 13 days). In each group (control, CsA alone, CsA plus black grape, CsA plus aqueous garlic extract, aqueous garlic extract alone and black grape alone), there were 7 animals. At the end of the study period, the animals were sacrificed; their kidneys were removed and prepared for biochemical and histopathological investigations. Oxidant (xanthine oxidase enzyme and malondialdehyde) and antioxidant (superoxide dismutase, glutathione peroxidase and catalase enzymes) parameters were measured in the kidney tissues of the groups. Histopathological examinations of the tissues were also performed. It has been found that CsA creates oxidant load to the kidneys through both xanthine oxidase activation and impaired antioxidant defense system, which accelerates oxidation reactions in the kidney tissue. Supplementation with either dried black grape or aqueous garlic extract led to reduced malondialdehyde level in the kidney tissue possibly, by preventing oxidant reactions. In conclusion, the results suggest that impaired oxidant/antioxidant balance may play part in the CsA-induced nephrotoxicity, and some foods with high antioxidant power may ameliorate this toxicity, in agreement with studies with antioxidant vitamins.

The effects of amifostine and dexamethasone on brain tissue lipid peroxidation during oxygen treatment of carbon monoxide-poisoned rats.

The mechanisms of injury of, and methods of treating patients with, carbon monoxide (CO) poisoning are poorly understood. Besides the hypoxic degenerative effects of CO, reoxygenation injury may play an important role. Amifostine (Ami), which is most often used in radiotherapy for its tissue protective characteristics, may offer benefits. In this study, investigators evaluated the effectiveness of various treatments in a CO-poisoned rat model. A total of 36 Wistar rats were randomly assigned to 1 of 6 groups (n=6 each), including control and poisoned groups exposed to CO at 2000 ppm (v/v) for 1 h, followed by various 1-h treatments: group C (control), group COair (ambient air), group CO-NBO (normobaric 100% oxygen), group CO-HBO (hyperbaric oxygen with 3 atmospheres absolute [3 ATA]), group CO-NBO-Ami (normobaric oxygen with intraperitoneal [i.p.] injection of amifostine 250 mg/kg body weight [bw]), and group CO-70O (70% O2 and 5% CO2 with dexamethasone 10 mg/kg bw, i.p.). Blood gas analysis, carboxyhemoglobin determination, brain tissue lipid peroxidation, and glutathione peroxidase (GSHPx), superoxide dismutase (SOD), lactate dehydrogenase (LDH), and creatine kinase (CK) activities were evaluated. Carboxyhemoglobin concentration in the air-treated group was 44+/-2%; it decreased to the control level with all oxygen treatments. Brain tissue GSH-Px and SOD measurements did not change. The activity of LDH in group CO-HBO and the activities of LDH and CK in group CO-70O were similar to those of group C. Lipid peroxides were high in ambient air and normobaric oxygen, but HBO, amifostine with oxygen, or 70% O2 reduced these to control levels (P<.05).

Cisplatin impairs antioxidant system and causes oxidation in rat kidney tissues: possible protective roles of natural antioxidant foods.

This study aims to elucidate the molecular mechanism(s) of cisplatin nephrotoxicity and the possible protective effects of antioxidant food supplementation on this toxicity. Twenty eight rats were used throughout the study. Cisplatin was administered intraperitoneally (i.p.) in a single dose (10 mg kg(-1)). Antioxidant food supplementation was started 3 days before cisplatin treatment. In each group (control, cisplatin, cisplatin plus dried black grape and cisplatin plus tomato juice), there were seven animals. Rats were killed 72 h after treatment. The kidneys were removed and prepared for biochemical and histopathological investigations. Oxidant (sensitivity to oxidation, xanthine oxidase enzyme and malondialdehyde level) and antioxidant (superoxide dismutase, glutathione peroxidase and catalase enzymes, and antioxidant potential value) parameters were measured in kidney tissues of the groups. Histopathological examination was also performed. Significant decreases were measured in the renal activities of catalase and glutathione peroxidase enzymes. There was, however, a significant increase in the activity of xanthine oxidase enzyme in the cisplatin-treated animals compared with the control group. The kidney tissue malondialdehyde levels were found to be increased, but sensitivity to oxidation and antioxidant potential values to be decreased in the cisplatin group. In the food supplemented groups, it has been observed that black grape eliminated oxidant stress by increasing antioxidant potential, but tomato did not. Histopathological examination results also revealed significant damage in the kidney tissues from the cisplatin-treated rats. In the black grape group, significant improvements were observed compared with the cisplatin group. In the tomato group, there were also some improvements but to a lesser degree compared with the black grape group. The results suggest that cisplatin treatment causes significant oxidant load to the kidneys through both xanthine oxidase activation and impaired antioxidant defense system, which resulted in accelerated oxidation reactions in the kidney tissue. It is proposed that supplementation of some foods such as black grape which has resveratrol as an antioxidant can provide significant protection against cisplatin nephrotoxicity.

Methotrexate causes oxidative stress in rat kidney tissues.

AIM: Methotrexate (MTX), a folic acid antagonist, is one of the chemotherapeutic agents widely used in the treatment of some types of cancers. Nephrotoxicity is one of the complications of MTX treatment. The aim of this study was to investigate possible effects of MTX treatment on the oxidant/antioxidant status in rat kidney tissues and enzymatic mechanisms leading to nephrotoxicity. METHODS: For this aim, 10 Sprague-Dawley type female rats of 4 weeks old were used in the study. The animals were divided into two groups randomly. Five of them were used as control, and the others were treated with MTX intravenously (60 mg/m2 of body surface area per week) for 7 weeks. At the end of this period, they were sacrificed, and kidney tissues were removed to be used in the analyses of malondialdehyde (MDA) levels, antioxidant potential (AOP) values, and superoxide dismutase, catalase, glutathione peroxidase, xanthine oxidase, adenosine deaminase, and 5' nucleotidase enzyme activities. RESULTS: There was significant increase in the MDA level in the MTX group compared with the control group (1.74+/-0.23 nmol/mg vs. 1.04+/-0.30 nmol/mg; p<0.05, respectively). There were however no meaningful differences between enzyme activities and AOP values of the groups. CONCLUSION: It has been suggested that MTX leads to oxidative stress in rat kidney tissues, which might be one of the reasons for MTX-induced nephrotoxicity.

Effects of cyclosporine on oxidant/antioxidant status in rat ovary tissues: protective role of black grape extract.

OBJECTIVES: It has been demonstrated that immunosuppressive drug cyclosporine A (CsA) increases the synthesis of reactive oxygen species (ROS) and lipid peroxidation products in vitro and in vivo studies, but its possible toxic effects in ovary tissue have not been defined yet. This study was designed to elucidate possible relation between CsA treatment and oxidant/antioxidant status in rat ovary tissue and, to determine if antioxidant supplementation is beneficial. METHODS: CsA and black grape extracts were given to rats orally for 10 days. In each group (control, CsA, CsA plus black grape and black grape alone), there were 7 animals (28 rats in total). After the animals were sacrificed, their ovaries were removed to be used in the measurement of malondialdehyde (MDA) level and activities of superoxide dismutase (SOD), catalase (CAT) and xanthine oxidase (XO) enzymes. RESULTS: In the control, CsA plus black grape and black grape alone groups, MDA levels were significantly lower than CsA group. Xanthine oxidase activities were significantly higher in CsA and CsA plus black grape groups than control group. In addition, XO activity was significantly lower in black grape alone group than all the other groups including control group. There were no significant differences in the activities of SOD and CAT enzymes between the groups. CONCLUSION: The results suggest that CsA leads to oxidant stress and peroxidation in rat ovary tissues mainly due to increased XO activity. It has been suggested that this oxidant stress and peroxidation reactions can be prevented by antioxidant food supplementation like black grape.

Peroxidation in muscle and liver tissues from fish in a contaminated river due to a petroleum refinery industry.

In this study, we aimed to investigate the possible effects of the wastewater water contamination of a petroleum industry on the oxidant/antioxidant status of muscle and liver tissues from fish in the Kizilirmak River, Kirikkale, Turkey. The antioxidant/oxidant parameters were analyzed in the muscle and liver tissues from fish in 10 km of the river above and below the industry. Malondialdehyde (MDA) and susceptibility to oxidation (SO) values were measured in the liver and muscle tissues as indexes of oxidation, and antioxidant potential (AOP), superoxide dismutase (SOD), glutathion peroxidase (GSH-Px), and catalase(CAT) activities were measured as indexes of antioxidant status. There was significant oxidation in the muscle tissue of the fish obtained in the river downstream of the industry compared to those obtained upstream of the industry. Although there were no meaningful differences between the SOD and GSH-Px activities, the AOP value and CAT activities were found to be reduced in the muscle tissues from the fish obtained downstream. In the liver tissues, the SOD and GSH-Px activities were found to be increased in the fish obtained downstream but no differences were observed in the MDA, SO, AOP, and CAT values. Our results suggest that some contaminants from the petrochemical industry cause oxidation in fish muscle tissues by impairing the antioxidant system. However, because no peroxidation was observed in the liver tissue from the downstream fish, it is possible that liver tissues have a stronger antioxidant capacity than muscle.