The effects of resveratrol on oxidant/antioxidant systems and their cofactors in rats.

BACKGROUND: Resveratrol, which belongs to a class of polyphenolic compounds called stilbenes, is proposed to have anti-aging effects. OBJECTIVES: This research has focused on the effects of resveratrol on oxidant/antioxidant systems and also copper and zinc concentrations in rats. MATERIAL AND METHODS: The control group consisted of 12 male Wistar albino rats, 10-12 weeks of age, weighing approximately 284 g. The experimental group consisted of 12 male Wistar albino rats, in the same age, weighing 282 g. Before the experimental procedure, a training period was performed for control and experimental groups, systolic arterial blood pressures and heart rates were recorded. Body weights were measured also. The experimental group was administered resveratrol (20 mg/kg) in drinking water for six weeks. At the end of the study, blood glucose levels, red cell superoxide dismutase (SOD), catalase activities, copper, zinc concentrations in plasma and red cells, also, malondialdehyde (MDA) concentrations in plasma were determined in both groups. RESULTS: At the end of the study, statistically significant increases in SOD and catalase activities, and also in plasma copper and red cell zinc concentrations and statistically significant decreases in body weight, blood glucose, blood pressure, lipid peroxidation product MDA concentration and plasma zinc, red cell copper concentrations were found in resveratrol administered group. CONCLUSIONS: Resveratrol administration affected oxidant/antioxidant systems and their cofactors significantly.

The effect of K-ATP channel blockage during erythropoietin treatment in renal ischemia-reperfusion injury.

ATP dependent K channels (K-ATP) take part in the Erythropoietin (EPO) induced cardioprotection but these channel activations have role in cytoprotective role of EPO in the renal ischemia reperfusion (IR) damage is still unknown. For this purpose rats were pretreated with EPO (500 IU/kg) and/or K-ATP channel blocker glibenclamide (40 mM/kg) i.p. before bilateral renal IR damage. Renal tissues were used for histological examination and measurement of caspase-3 and TNF-alpha levels. Renal functions were evaluated by glomerular filtration rate (GFR) fractional excretion of sodium (FENa) and potassium (FEK). Renal TNF-alpha and caspase-3 levels were decreased in both glibenclamide and EPO-treated IR rats compared to untreated rats. The protection afforded by the pretreatment with EPO alone was greater than that of administering glibenclamide alone. Application of glibenclamide at the same time partly abolished the cytoprotective effect of EPO treatment. K-ATP mediated cytoprotection is not the main mechanism of protective effect of EPO.

Pretreatment effect of resveratrol on streptozotocin-induced diabetes in rats.

This study was planned to investigate the pretreatment effect of resveratrol on streptozotocin-induced diabetic rats. The control group consisted of 10 male albino Sprague-Dawley rats, 10-12 weeks of age, weighing approximately 295 g. The first experimental group consisted of 15 albino Sprague-Dawley rats, 10-12 weeks of age, weighing approximately 305 g. This group was administered streptozotocin (55 mg/kg, intraperitoneally). The second experimental group (n = 15) was administered resveratrol (0.5 ml/day) 10 days before streptozotocin induction. A training period was performed for all groups before the experimental procedure, and systolic arterial blood pressures and heart rates were recorded daily. At the end of the 10th day, blood samples of control and experimental groups were drawn. Total nitrite, nitrite, nitrate, malondialdehyde (MDA), copper, and zinc concentrations in plasma were measured both in control and experimental groups. Additionally, superoxide dismutase, catalase activities, and copper and zinc concentrations in red cell were determined in each group. At the end of the study, increases in catalase activity, nitric oxide level, and zinc concentrations and decreases in lipid peroxidation product MDA and copper concentrations were found in the resveratrol-pretreated diabetic group when compared to the diabetic group.

Resveratrol: is there any effect on healthy subject?

This preliminary study was planned to investigate the effects of resveratrol on oxidative-nitrosative stress markers and on trace element concentrations in blood and on circulatory system parameters in rats. Twenty-five Sprague-Dawley male rats, 10-12 weeks old, with mean body weight of 295 g were used in the study. Administration of resveratrol (0.5 ml/day) was performed in experimental group in 10 days. In control (n = 10) and in experimental groups (n = 15), after 1 week training period, systolic arterial blood pressures and heart rates were recorded daily. At the end of the tenth day, blood samples of control and experimental groups were drawn. Total nitrite, nitrite, nitrate, malondialdehyde, copper, zinc concentrations in plasma, superoxide dismutase, and catalase activities and copper, zinc concentrations in red cell were determined both in control and experimental groups. Alterations in oxidative and nitrosative stress markers, trace element concentrations, and circulatory system parameters in experimental group compared to controls were observed. The results of this study were discussed according to the effect of resveratrol.

Effect of an inhibitor of nitric oxide production on Cu-Zn/SOD and its cofactors in diabetic rats.

The aim of this study was to investigate the effect of an inhibitor of nitric oxide production, N(omega)-nitro-L-arginine methyl esther (L-NAME) on Cu-Zn/SOD (superoxide dismutase) enzyme activity and copper and zinc concentrations in diabetes-induced rats. The control group consisted of 12 male albino Sprague-Dawley rats, 10-12 wk of age and weighing 300 g. Twenty-six albino Sprague-Dawley rats, 10-12 wk of age and weighing 315 g, constituted the experimental group. The experimental group was divided into two groups. The first group (n=12) constituted streptozotocininduced (55 mg/kg, intraperitoneally) diabetic rats and the second group (n=14) was administered L-NAME (1 mg/kg/d) after streptozotocin induction. For determination of Cu-Zn/SOD activity, spectrophotometry was used. Zinc and copper concentrations were determined by atomic absorption spectrophotometry. Results showed that Cu-Zn/SOD activity was increased significantly in both experimental groups compared to controls, and the increase in the second group was higher than in the first group (p<0.01, p<0.01, p<0.05). Plazma zinc concentration was increased in the second group when compared with controls (p<0.05). Plasma copper was decreased significantly in the second group compared to controls and the first group (p<0.001, p<0.001). Red cell copper concentration was decreased significantly in the first group compared to controls (p<0.05). This study showed that L-NAME administration has ensured an additive effect on the antioxidant defense system, which was proved by the increase in Cu-Zn/SOD activity. This increase might have a protective effect against tissue damage in the acute period, with corresponding changes in zinc and copper concentrations.

Effects of plasma nitric oxide levels on platelet activation in single donor apheresis and random donor concentrates.

P-selectin is an useful marker to determine platelet activation and nitric oxide inhibits platelet activation, secretion, adhesion and aggregation. The aim of this study was to investigate the relationship between nitric oxide and P-selectin values in both single donor apheresis and random donor platelet concentrates. According to the results of this study, we found that the best platelet concentrate is freshly prepared single donor apheresis concentrate and it is important to prevent activation at the beginning of the donation. Nitric oxide, which is synthesized from platelets during the storage period, is not sufficient to prevent platelet activation.

Effects of subacute boric acid administration on rat kidney tissue.

BACKGROUND/AIMS: Boron is used in manufacturing processes and numerous consumer products. Clarification of boron toxicity is important because of industrial and consumer exposure to boron and boron-containing compounds. The aim of this study was to observe effects of subacute boric acid administration on rat kidney tissue. MATERIALS AND METHODS: A total of 96 male albino Sprague-Dawley rats were used in this study. Seventy-two rats were selected for the experimental group and 24 rats constituted the control group. Experimental group rats were divided into three groups for exposure to three different doses of orally administered boric acid (100-275-400 mg/kg/day). Kidney tissues were removed at the 10th, 30th, and 45th day after sacrificing the rats. Kidney weights, kidney boron concentration and histopathological changes were determined. RESULTS: In the experimental group, a significant accumulation of boron in kidney tissue was seen, but there was a significant drop in boron concentration on the 45th day compared with the 30th day. Histopathological degenerative changes were observed especially in the proximal tubule cells that were dose- and time-dependent. CONCLUSION: Subacute boric acid exposure caused dose-dependent histopathological changes in kidney tissue.

Comparison of the plasma and hernia sac tissue copper levels in direct and indirect inguinal hernia patients.

Although the inguinal hernia is among the most commonly encountered and well-described health problems all over the world, the etiology is still controversial. The aim of this study was to compare the plasma and hernia sac tissue copper levels in direct and indirect inguinal hernia patients. Plasma and hernia sac tissue copper levels obtained from patients operated under spinal anesthesia with primary direct (group I, n = 55, 45 male, mean age = 45.68 yr) and indirect (group II, n = 55, 40 male, mean age = 38.57 yr) hernias were detected by atomic absorption spectrophotometer. Significantly lower plasma and hernia sac tissue copper levels were detected in group I in comparison to group II (p < 0.001). Both plasma and hernia sac tissue copper levels were significantly lower in males when we compare the patients according to their sex characteristics, including both direct and indirect hernia groups (p < 0.05 and p < 0.01, respectively). Age was not a significant factor. The plasma and hernia sac tissue copper levels were significantly lower in direct hernia patients in comparison to indirect hernia patients. Copper is a cofactor of lysyl oxidase, an important enzyme in collagen tissue metabolism, so there might be a defect in the collagen synthesis of direct hernia patients because of the decreased activity of the lysyl oxidase. Further investigations are necessary to clarify this concept.

Serum copper and zinc concentrations in patients with chronic hepatitis C.

The aim of this study was to measure the alterations in serum trace elements, including zinc and copper in patients with chronic hepatitis C and to compare them with the results of healthy individuals. Seventeen patients with chronic hepatitis C and 17 healthy individuals were included in this study. Serum zinc and cooper concentrations were measured by using atomic absorption spectrophotometer of patients with chronic hepatitis C and the results were statistically compared with those of healthy individuals. Serum zinc concentrations were 105.6+/-22.8 microg/dl in patients with chronic hepatitis C and 94.41+/-19 microg/dl in healthy controls, respectively. Serum copper concentrations were 103.17+/-20.8 microg/dl in patients with chronic hepatitis C and 90.8+/-14.3 microg/dl in healthy subjects, respectively. Serum zinc and copper concentrations were not found statistically different in patients with chronic hepatitis C compared with those of healthy individuals (p>0.05). In conclusion, serum trace element concentrations did not show statistical alterations in patients with chronic hepatitis C compared to healthy subjects.

Serum copper and zinc concentrations in patients with chronic hepatitis B.

The aim of this study was to measure the alterations in serum trace elements, including zinc and copper in patients with chronic hepatitis and to compare with the results of healthy individuals. The serum zinc and copper concentrations were measured by using atomic absorption spectrophotometer in sera of patients with chronic hepatitis and statistically compared with those of healthy individuals. One hundred and five subjects, 71 patients with chronic hepatitis B (46 asymptomatic carriers, 25 chronic active hepatitis B) and 34 healthy individuals were included in this study. Sera of patients with chronic hepatitis and statistically compared with those of healthy individuals. Serum zinc concentrations were 104+/-24.98 microg/dl in asymptomatic carriers, 97+/-16.03 microg/dl in chronic active hepatitis and 108+/-21.07 in healthy controls, respectively. Serum copper concentrations were 88+/-17.8 microg/dl in asymptomatic carriers, 86+/-20.02 microg/dl in patients with chronic active hepatitis B and 88+/-13.59 microg/dl in healthy controls, respectively. Serum zinc and copper concentrations were not statistically different in patients with chronic hepatitis B compared with those of healthy individuals (p>0.05). Serum trace element concentrations did not show statistical alterations in patients with chronic hepatitis B compared with healthy subjects.

Serum copper and zinc concentrations in patients with brucellosis.

The aim of this study was to measure the alterations in serum trace element concentrations, including zinc (Zn) and copper (Cu) in patients with brucellosis and to compare them with the results of healthy individuals. Seventy-five subjects, 60 patients with brucellosis and 15 healthy individuals were included in this study. The serum Zn and Cu concentrations were measured by using atomic absorbtion spectrophotometer in sera of patients with brucellosis and statistically compared with those of healthy individuals. Serum Cu concentration was found to be significantly higher in patients with brucellosis than that of healthy individual (130.5+/-24.7, 96+/-8.65 microg/dl, respectively) (p < 0.01). Serum Zn concentration was lower in patients with brucellosis than those of healthy subjects (79.5 +/-13.5 and 83+/-5.59 microg/dl, respectively) (p < 0.01). Serum trace element concentrations showed significant alterations in patients with brucellosis compared with healthy subjects.

Superoxide dismutase activity and zinc and copper concentrations in growth retardation.

The aim of this study was to determine the effects of oral zinc treatment on red cell copper/zinc-superoxide dismutase (Cu/Zn-SOD) activity and zinc and copper concentrations in growth retardation. Thirty-five patients, average age of 11 yr, were selected. The control group consisted of 10 healthy children whose average age was 10 yr. Superoxide dismutase activity was determined by spectrophotometer. Copper and zinc concentrations were measured by an atomic absorption spectrophotometer. The activity of Cu/Zn-SOD before zinc treatment was higher than the controls (p<0.001). There was a decrease in Cu/Zn-SOD activity after zinc treatment (p<0.001) and the values after treatment were still higher than the controls (p<0.001). Plasma zinc concentrations before zinc treatment were lower than controls (p<0.01). After treatment, there was an increase in plasma zinc concentrations compared to controls and the patients' values before zinc treatment, respectively (p<0.001, p<0.001). After zinc treatment, plasma copper concentrations were decreased significantly (p<0.01). An increase in red cell zinc concentration (p<0.01) and a decrease in copper concentration (p<0.001), which were statistically significant, were seen after zinc treatment. The results suggested that there were significant alterations in Cu/Zn-SOD activity and zinc and copper concentrations during growth retardation. With zinc treatment, these parameters appeared to approach normal values.

Antioxidant superoxide dismutase activity in obese children.

The aim of the study was to evaluate the antioxidative Cu/Zn-SOD (superoxide dismutase) response to obesity-related stress in obese children compared to a similar-aged control group. Forty-eight exogenic obese children and 11 healthy children were compared for red cell Cu/Zn-SOD, glucose, and lipid profiles and the relations between them were investigated. Antioxidant response as Cu/Zn-SOD was significantly higher in the obese group (p<0.05). Although glucose and lipid levels were statistically higher in the obese group, a certain relation with the SOD level was not established in childhood. This is the first study showing the oxidative stress caused by obesity and related antioxidative response even in the childhood period. Interventions, including diet modifications, should be kept in mind to diminish the obesity-related oxidative stress from the childhood period.

Trace element status in plasma and erythrocytes in hyperemesis gravidarum.

OBJECTIVE: To determine trace element status in plasma and erythrocytes hyperemetic women at presentation and after treatment. STUDY DESIGN: Studies were carried out on 32 women with hyperemesis gravidarum. Thirteen non-vomiting, healthy, pregnant women served as controls. Copper, zinc and magnesium concentrations in both plasma and erythrocytes were estimated before and after treatment. Independent sample t test, paired sample t test, Wilcoxon signed rank test, Mann-Whitney U test, chi2 test, Kruskall-Wallis one-way analysis of variance and Spearman's correlation study were used for statistical analysis. RESULTS: There were no significant differences between the 2 groups in erythrocyte zinc, copper and magnesium concentration. Plasma zinc levels were significantly higher (P = .006), while plasma copper levels were significantly lower (P = .001) in the study group as compared to the controls, but plasma magnesium levels were not significantly altered. Treatment brought a significant decrease in plasma zinc levels (P = .001), increase in plasma copper concentration (P = .001) but no change in erythrocyte zinc, copper or magnesium concentration. When trace element levels were grouped according to the degree of ketonuria, no significant differences were found in the 2 groups. CONCLUSION: Hyperemetic women had normal tissue zinc, copper and magnesium concentrations, and rehydration normalized the plasma zinc and copper levels. Otherwise, no significant effects on trace elements were noted.

Zinc treatment affects superoxide dismutase activity in growth retardation.

Children with growth dysfunction present complex diagnostic challenges. The purpose of this study was to determine the effects of oral zinc treatment on red cell copper/zinc superoxide dismutase (Cu/Zn-SOD) activity and copper and zinc concentrations in children with "growth retardation." Twenty-nine patients, average age of 11 yr, whose percentile was under 3% of the National Center of Health Statistics parameters were selected. For the control group, 10 children whose average age was 10 yr were included. Red cell Cu/Zn-SOD activity was determined by spectrophotometer. Red cell copper and zinc concentrations were measured by atomic absorption spectrophotometer. Red cell Cu/Zn-SOD activity was higher than the control group before zinc treatment (p<0.001). There was a decrease in the Cu/Zn-SOD activity after zinc treatment, but the mean value of the Cu/Zn-SOD activity of patients was still higher than the control values (p<0.001). After zinc treatment, there was an increase in red cell zinc concentration (p<0.01) and a decrease in copper concentration (p<0.001), which were statistically significant. The results of this study suggested that Cu/Zn-SOD activity was increased significantly during growth retardation and zinc treatment appeared to ameliorate the enzyme activity. There were also insignificant alterations in red cell copper and zinc concentrations.

Hypertension: does impaired endothelium-dependent relaxation affect superoxide scavenging?

The purpose of this study was to investigate the effects of acute nitric oxide synthase inhibition on mean arterial blood pressure, oxidative stress markers such as plasma malondialdehyde (MDA) concentration, intracellular antioxidant enzyme activities such as copper-zinc superoxide dismutase (Cu/Zn SOD) and catalase and on trace elements important for activity and stability of Cu/Zn-SOD. Wistar-Kyoto rats (approx 150 g) (n=11) were treated with Nomega-nitro-L-arginine methyl esther (L-NAME) (0.5 mg/mL) for 2 d. Age- and bodyweight-matched rats (n=10) were used for control group. Their systolic blood pressures and heart rates were recorded daily during the experimental period and also before their blood samples were drawn. Plasma MDA, plasma and red cell zinc and copper concentrations, and red cell Cu/Zn-SOD and catalase activities were determined. A progressive rise in systolic arterial blood pressure was observed compared to the control group (p<0.001). The heart rate of the experimental group was reduced on the third day (p<0.05). Plasma MDA concentration and red cell catalase activity were increased in the experimental group (p<0.001 and p<0.001, respectively). Plasma copper and red cell zinc concentrations were also increased significantly in the experimental group (p<0.001 and p<0.01, respectively). In conclusion, impairment in endothelium-derived relaxation altered mean arterial blood pressure, oxidant status, and trace element concentrations.