Neuroprotective effect of mesna (2-mercaptoethane sulfonate) against spinal cord ischemia/reperfusion injury in rabbits.

Although the precise mechanism by which ischemia/reperfusion injury occurs in the spinal cord remains unclear, it is evident that free oxygen radicals and apoptosis play major roles in the destruction of membrane lipids, damage to DNA and cell death. The apoptotic process involves activation of the caspase-3 cascade. Although it is widely used as a protective agent against cell injury, it is unknown whether mesna (2-mercaptoethane sulfonate) ameliorates neuronal ischemic injury. The aim of this study was to determine the effect of mesna on caspase-3 activity in a rabbit model. Adult rabbits underwent spinal cord ischemic injury via occlusion of the abdominal aorta for 20 min. Twenty-four hours after ischemia, spinal cord samples were obtained and tissue caspase-3 activity was measured. Rabbits that had been given a single dose of 150 mg/kg mesna had decreased caspase-3 activity in the spinal cord following ischemia/reperfusion injury, indicating a protective effect. However, caspase-3 activity was lower in rabbits given methylprednisolone than in those given mesna, indicating that methylprednisolone has the stronger protective effect of the two agents.

Oxidant stress due to non ionic low osmolar contrast medium in rat kidney.

BACKGROUND & OBJECTIVES: Contrast media may cause contrast-induced nephropathy (CIN) in risk group. This study was taken up to establish possible effects of non ionic low osmolar contrast medium administration on oxidant/antioxidant status and nitric oxide (NO) levels in rat kidney tissues. METHODS: Fourteen female, 14 wk old Wistar-albino rats were divided into 2 groups of 7 rats each (control and contrast groups). Non ionic low osmolar contrast medium was administered iv to the animals in the contrast group. The day after, animals were sacrificed and malondialdehyde (MDA) and NO levels and activities of antioxidant [superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT)] and oxidant [xanthine oxidase (XO)] enzymes were measured in kidney tissues. Serum creatinine levels were measured to evaluate kidney functions. RESULTS: Contrast medium administration caused an increase in MDA levels and a decrease in NO levels in kidney tissues. INTERPRETATION & CONCLUSIONS: The results suggest that non ionic low osmolar contrast medium administration leads to accelerated oxidant reactions and decreased NO level in rat kidney tissues. Further studies need to be done to assess the role of these changes in CIN.

High-cholesterol diet increases xanthine oxidase and decreases nitric oxide synthase activities in erythrocytes from rats.

The aim of this study was to investigate the effects of a high-cholesterol diet on oxidant/antioxidant status and nitric oxide synthase (NOS) activity in erythrocytes from rats. Sixteen Sprague-Dawley-type albino male rats were used in the study. The rats were randomly divided into 2 groups: the control group (group 1) was fed a standard rat diet, and the treated group (group 2) was fed a high-cholesterol diet (4% cholesterol, 1% cholic acid, and 0.5% thiouracil) in addition to standard pellet rat diet for 3 months. At the end of the study period, blood samples were obtained from the rats under ether anesthesia. Oxidant (malondialdehyde level, sensitivity to oxidation value, and xanthine oxidase [XO] activity) and antioxidant parameters (antioxidant potential value, superoxide dismutase, catalase, and glutathione peroxidase activities) were studied in erythrocyte preparations. Activities of erythrocyte NOS and arginase enzymes and serum total cholesterol levels were also measured. We observed that serum total cholesterol levels, erythrocyte XO activities, and sensitivity to oxidation values significantly increased in group 2 (cholesterol fed) compared with the control group (group 1). Erythrocyte NOS activities were also found to decrease in group 2. In conclusion, our results suggest that cholesterol feeding causes an increase in XO activity and a decrease in NOS activity in the erythrocytes from rats. The increase in XO activity may render the erythrocyte membranes sensitive to oxidant stress, and the decrease in NOS activity in the erythrocytes may increase cardiovascular disease risk via reduced endothelial relaxation.

Malondialdehyde and nitric oxide levels in erythrocytes from patients with systemic sclerosis.

OBJECTIVE: To investigate malondialdehyde (MDA) and nitric oxide (NO) levels in the erythrocytes from patients with systemic sclerosis (SSc). SUBJECTS AND METHODS: Twenty-nine patients diagnosed as having SSc and 16 volunteer healthy subjects (as control group) participated in the study. Fasting blood samples were obtained from the patients and healthy subjects in anticoagulated tubes (with EDTA), and the erythrocytes were separated. The MDA and NO levels were measured in the erythrocyte sediments by the spectrophotometric method. RESULTS: The levels of MDA and NO were elevated in the erythrocyte sediments of the patients as compared to those of the control group (1.037 +/- 0.125 vs. 0.951 +/- 0.114 mumol/g Hb, respectively, p = 0.047 for MDA, and 0.340 +/- 0.071 vs. 0.209 +/- 0.074 mmol/g Hb, respectively, p < 0.001 for NO). A weak positive correlation was also observed between MDA and NO levels (r = 0.30, p = 0.15 in the patient group, and r = 0.27, p = 0.49 in the control group). CONCLUSIONS: Our results show higher levels of MDA and NO in the erythrocytes of patients with SSc than normal subjects.

Ionic high-osmolar contrast medium causes oxidant stress in kidney tissue: partial protective role of ascorbic acid.

It has been known that contrast medium may cause contrast-induced nephropathy in risk groups. This study sought to establish possible effects of ionic high-osmolar contrast medium administration with or without antecedent cisplatin treatment on oxidant/antioxidant status in rat kidney tissues, as well as to investigate a possible protective role of antioxidant ascorbic acid in this regard. Thirty-five female, 14-week-old Wistar-albino rats were used in this study. They were divided into five groups of seven rats (sham, contrast, contrast + ascorbic acid, contrast + cisplatin, and contrast + cisplatin + ascorbic acid). Ascorbic acid was given in a dose of 250 mg/kg/day orally throughout the study period, and cisplatin (10 mg/kg) as a single i.v. dose on the fourth day. Ionic high-osmolar contrast medium (3 gr/kg iodine as a single dose) was administered by i.v. route on the fifth day. After the animals were sacrificed on the sixth day, their kidney tissues were removed surgically to be used in the analyses. Malondialdehyde (MDA) level and activities of antioxidant (superoxide dismutase [SOD], glutathione peroxidase [GSH-Px] and catalase [CAT]) and oxidant (xanthine oxidase [XO]) enzymes were measured in these samples. Serum urea and creatinine levels were measured to evaluate kidney functions. Histopathological investigation of the tissues was also performed. It was observed that contrast medium administration caused increases in MDA levels in the kidney tissues, either alone or together with antecedent cisplatin treatment. However, ascorbic acid prevented the increases in MDA levels in the kidney tissues. Histopathological findings revealed that ionic high-osmolar contrast medium administration alone led to mild acute structural damage, but contrast medium administration together with antecedent cisplatin usage caused severe tubular necrosis. Ascorbic acid supplementation prevented these changes, to a great extent. The results suggest that ionic high-osmolar contrast medium administration, either alone or together with antecedent cisplatin treatment, leads to accelerated oxidative reactions in rat kidney tissues, and ascorbic acid protects in part the kidney tissues against this oxidant stress.

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.

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 Electromagnetic Radiation Use on Oxidant/Antioxidant Status and DNA Turn-over Enzyme Activities in Erythrocytes and Heart, Kidney, Liver, and Ovary Tissues From Rats: Possible Protective Role of Vitamin C.

ABSTRACT In this study, the aim was to investigate possible effects of Electromagnetic Radiation (EMR) use on oxidant and antioxidant status in erythrocytes and kidney, heart, liver, and ovary tissues from rats, and possible protective role of vitamin C. For this aim, 40 Wistar albino female rats were used throughout the study. The treatment group was exposed to EMR in a frequency of 900 MHz, the EMR plus vitamin C group was exposed to the same EMR frequency and given vitamin C (250 mg/kg/day) orally for 4 weeks. There were 10 animals in each group including control and vitamin C groups. At the end of the study period, blood samples were obtained from the animals to get erythrocyte sediments. Then the animals were sacrificed and heart, kidney, liver, and ovary tissues were removed. Malondialdehyde (MDA) levels and superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), xanthine oxidase (XO), and adenosine deaminase (ADA) enzyme activities were measured in the tissues and erythrocytes. It was observed that MDA level, XO, and GSH-Px activities significantly increased in the EMR group as compared with those of the control group in the erythrocytes. In the kidney tissues, it was found that MDA level and CAT activity significantly increased, whereas XO and ADA activities decreased in the cellular phone group as compared with those of the control group. However, in the heart tissues it was observed that MDA level, ADA, and XO activities significantly decreased in the cellular phone group as compared with those of the control group. The results suggest that EMR at the frequency generated by a cell phone causes oxidative stress and peroxidation in the erythrocytes and kidney tissues from rats. In the erythrocytes, vitamin C seems to make partial protection against the oxidant stress.

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.

Reduced antioxidant potential & sensitivity to oxidation in plasma low density lipoprotein fraction in type 2 diabetes mellitus patients.

BACKGROUND & OBJECTIVES: The aim of this study was to investigate LDL oxidation in the ethiopathogenesis of diabetes mellitus. Diabetes mellitus a disease caused due to severe insulin dysfunction, is associated with lipid and protein metabolic disorders. METHODS: A total of 90 type 2 diabetes patients were grouped according to their glycoted haemoglobin (HbA1c) values as regulated (<5.7%), poorly regulated (5.7 - 7.7%) and unregulated (>7.7%). Further, a healthy control group of 37 individuals was included for comparison in terms of sensitivity of low density lipoprotein (LDL) to oxidation and measurements of antioxidant potential (AOP). A heparin - citrate precipitation method was used to obtain LDL from the serum samples of patients and control groups. The LDL fractions were exposed to oxidation with CuSO4 and sensitivity to oxidation was evaluated. Ten patients each from regulated and unregulated groups, and 10 healthy controls were examined for antioxidant potential. RESULTS: The sensitivity of LDL fraction to oxidation was significantly lower in all diabetic groups compared to the control group. AOP was significantly decreased in unregulated diabetic group compared to the control group. INTERPRETATION & CONCLUSION: We hypothesize that oxidant stress increases in diabetes mellitus and oxidant defense systems weaken during the chronic course of the illness. Due to decreased antioxidant potential, that probably shortens the LDL oxidation lag phase, the sensitivity to oxidation appears to be lower in diabetes mellitus patients.

Oxidant/antioxidant status of placenta, blood, and cord blood samples from pregnant women supplemented with iron.

OBJECTIVE: In this study, it was aimed to investigate oxidant/antioxidant status in placenta and in blood and cord blood samples from pregnant women supplemented with iron during pregnancy. METHODS: For this purpose, 27 pregnant women at admission for delivery participated in the study. Fifteen of them did not take iron tablets and the others took oral iron supplements during pregnancy. Following delivery, part of the placenta and blood and cord blood samples were taken from the mothers. In these samples, oxidant parameters (malondialdehyde [MDA] levels and xanthine oxidase [XO] activities) and antioxidant parameters (antioxidant potential [AOP] values, superoxide dismutase [SOD], catalase [CAT] and glutathione peroxidase [GSH-Px] activities) were studied. RESULTS: It was found that MDA level and SOD activities increased significantly in the placentas from the iron-supplemented group as compared with those from the control group. We also observed that activities of SOD and XO enzymes in maternal erythrocytes, XO in cord blood erythrocytes and GSH-Px activities in cord blood plasma decreased significantly. However, activities of CAT and GSH-Px enzymes in cord blood erythrocytes and MDA levels in maternal plasma increased in the iron-supplemented group as compared with those from the control group. CONCLUSION: Increased MDA levels in the maternal plasma and the placenta in the iron-supplemented group suggests that iron supplementation may contribute to increased oxidative stress in women taking iron supplements during pregnancy.

Short-term effects of smoking cessation on blood antioxidant parameters and paraoxonase activity in healthy asymptomatic long-term cigarette smokers.

The aim of this study was to compare short-term effects of smoking cessation on blood oxidant/antioxidant status, cholesterol levels, and paraoxonase activity. Sixteen healthy, asymptomatic long-term cigarette smokers (mean age: 35 +/- 9 yr) participated in the study in the smoking cessation program. After and before smoking cessation, subjects were examined for oxidant/antioxidant status, cholesterol level, paraoxonase activity, breath carbon monoxide levels, and blood carboxyhemoglobin values. When compared to previous values, subjects were revealed statistically significant decreases in malondialdehyde and carbon monoxide levels 4 wk after smoking cessation. The ratio of high-density lipoprotein (HDL) low-density lipoprotein (LDL) cholesterol was found to be increased. Significantly increased to paraoxonase activity was also observed in the blood samples obtained after cigarette cessation period. It was concluded that all these changes observed after smoking cessation might be of importance in the reduction of cardiovascular risk parameters in the smokers.

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.

Effects of black grape extract on activities of DNA turn-over enzymes in cancerous and non cancerous human colon tissues.

Effects of extract of dried whole black grape including seed on adenosine deaminase (ADA), 5' nucleotidase (5'NT) and xanthine oxidase (XO) enzymes were investigated in cancerous and non-cancerous human colon tissues. Enzyme activities were measured in 20 colon tissues, 10 from cancerous region and 10 from non cancerous region with and without pre incubation with black grape extract. ADA and 5'NT activities were found increased and that of the XO decreased in the cancerous tissues relative to non cancerous ones. After incubation period with black grape extract for 12 h, ADA and 5'NT activities were found to be significantly lowered but that of XO unchanged in both cancerous and non cancerous tissues. Results suggest that ADA and 5'NT activities increase but XO activity decreases in cancerous human colon tissues, which may provide advantage to the cancerous tissues in obtaining new nucleotides for rapid DNA synthesis through accelerated salvage pathway activity. Black grape extract makes significant inhibition on the ADA and 5'NT activities of cancerous and non cancerous colon tissues, thereby eliminating this advantage of cancer cells, which might be the basis for the beneficial effect of black grape in some kinds of human cancers.