İmge B. Ergüder

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 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 obsewrved 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.

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.

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.

Citrate Levels in Fresh Tomato Juice: A Possible Dietary Alternative to Traditional Citrate Supplementation in Stone-Forming Patients

OBJECTIVES To detect citrate levels in fresh tomato juice, to reveal whether it can be studied for prevention of recurrent hypocitraturic nephrolithiasis. METHODS Juices of tomato, orange, lemon, and mandarin were extracted and blended with a hand blender, and 10 samples of 100 mL were taken from each. Citrate, oxalate, calcium, phosphorus, magnesium, sodium, potassium, chloride, and pH levels were examined in these. The same variables were re-evaluated after the samples were stored at +4 degrees C for 1 week. RESULTS In fresh tomato juice, higher citrate and magnesium levels as well as lower sodium and oxalate levels were detected as compared with the other juices. No differences were observed with regard to all variables among fresh orange, lemon, and mandarin juices. The level of citrate in the fresh tomato juice was higher at a statistically significant level than that in tomato juice that was stored for 1 week. The amount of oxalate increased in stored tomato juice. CONCLUSIONS Fresh tomato juice is considered a rich source of citrate. Furthermore, a high level of magnesium and a low level of sodium and oxalate content were detected in fresh tomato juice, the usability of which in recurrent hypocitraturic nephrolithiasis can be investigated in clinical studies.

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.

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 bood 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.

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.

Effects of cholesterol supplementation on antioxidant enzyme activities in rat hepatic tissues: possible implications of hepatic paraoxonase in atherogenesis

BACKGROUND AND AIM The effects of cholesterol supplementation on antioxidant enzyme activities were investigated hepatic tissue taken from Sprague Dawley rats. METHODS AND REULTS: The study involved 14 male Sprague Dawley rats: seven fed a normal laboratory diet and seven a normal diet plus cholesterol (3.6 g/kg/day) for three months, during which blood samples were obtained to measure serum cholesterol levels. At the end of the 3-month period, the livers were surgically removed in order to measure antioxidant enzyme activities (superoxide dismutase, catalase, glutathione peroxidase and paraoxonase-1). At the end of the study period, serum total cholesterol and HDL-cholesterol levels were significantly higher in the cholesterol-fed group than the control group. There were no significant between-group differences in hepatic superoxide dismutase, catalase and glutathione peroxidase activities, but there was a significant decrease in hepatic paraoxonase-1 activity in the cholesterol-fed group. CONCLUSIONS Cholesterol supplementation significantly decreases paraoxonase-1 activity in rat liver tissue without changing the activities of other antioxidant enzymes. These results suggest that cholesterol significantly suppresses hepatic paraoxonase-1 synthesis. It seems that the decreased paraoxinase-1 activity in the plasma HDL-fraction of atherosclerotic patients is associated with suppressed liver synthesis. A reduction in paraoxonase-1 activity may therefore lead to the more intensive exposure of LDL to oxidant attacks.