Protein Carbonyl Content Levels Research Articles

Mitigating effects of antioxidant properties of Artemisia campestris leaf extract on hyperlipidemia, advanced glycation end products and oxidative stress in alloxan-induced diabetic rats

Artemisia campestris is used as antivenom and anti-inflammatory Tunisian folk medicine. Recently, increased oxidative stress was shown to play an important role in the etiology and pathogenesis of diabetes mellitus and its complications. This study was designed to examine the effects of A. campestris leaf aqueous extract (Ac) on alloxan-induced diabetic rats by measuring glycemia, lipid profile, lipid peroxidation (MDA), protein carbonyl content (PCO), advanced oxidation protein products (AOPP), activities of both non-enzymatic and enzymatic antioxidants. Results of our study showed an increase in blood glucose levels, total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-c), a decrease in high-density lipoprotein cholesterol (HDL-c) level and disturbed antioxidant enzyme activities (CAT, SOD, GPx) in the pancreatic tissue of diabetic rats. Furthermore, MDA, PCO and AOPP were elevated in the pancreas of the diabetic rats. The administration of Ac to diabetic rats at a dose of 200mgkg−1bw resulted in a significant reduction in glycemia, TC, TG, LDL-c, pancreas LPO, PCO and AOPP levels, CAT and GPx activities associated with an elevation of GSH content and SOD activity in comparison with diabetic group. We conclude that A. campestris aqueous extract may be effective for correcting hyperglycemia and preventing diabetic complications.

Protective effect of Asystasia gangetica reduced oxidative damage in the small intestine of streptozotocin-induced diabetic rats

Oxidative stress plays an important role in the pathogenesis of various diabetic complications and small intestine is vulnerable to damage resulting in morphological and functional changes. In this study, the effects of Asystasia gangetica leaf extract (AGLE) on oxidative stress status in small intestine of diabetic rats were examined. The leaves of Asystasia gangetica was extracted with 70% ethanol. Oral administration of AGLE once daily (100 mg/kg and 200 mg/kg b.w.) for 28 days to diabetic rats significantly (P < 0.05) increased antioxidant levels of catalase, superoxide dismutase, glutathione peroxidase, glutathione, GSSH, carbohydrate metabolizing enzyme, glucose-6-phosphate dehydrogenase. The increased levels of protein carbonyl content, lipid peroxidation and xanthine oxidase/xanthine dehydrogenase in diabetic rats were reverted back to near normal levels on treatment with AGLE. Both doses of AGLE offered significant activity (P < 0.01) against oxidative damage and were comparable with standard, glibenclamide. The results revealed the occurrence of oxidative stress in small intestine during diabetes and suggest the potential of AGLE as an antioxidant in protecting the tissue defense system against oxidative damage in streptozotocin-induced diabetes.

Protective Effect of the Nuclear Factor Kappa B Inhibitor Pyrrolidine Dithiocarbamate in Lung Injury in Rats with Streptozotocin-Induced Diabetes

Background: Diabetes mellitus (DM) causes debilitating complications and, as a result, diabetics frequently require intensive care. Although lungs are not thought to be affected primarily by DM, an increasing number of studies indicate physiological and structural abnormalities in diabetic lungs. Objectives: Pyrrolidine dithiocarbamate (PDTC) is a metal chelator and a potent inhibitor of NF-ĸB. Keeping in mind that NF-ĸB activation may be crucial in end-organ injury due to DM, we studied the role of PDTC on the inhibition of NF-ĸB activation and its effects on possible lung injury in rats with streptozotocin-induced DM. Methods: 36 Sprague-Dawley rats were allocated into 4 groups: diabetes, diabetes + PDTC, control and control + PDTC. At the end of 10 weeks, rats were sacrificed and their lungs were taken for histopathological and immunohistochemical evaluation [for NF-ĸB (p65) and endothelial nitric oxide (eNOS) immunoreactivities]. Protein carbonyl content (PCC), superoxide dismutase (SOD) and reduced glutathione (GSH) activities were measured. Results: Histopathologically, basal membranes were thickened and there was intense inflammatory reaction in diabetic lungs. However, the PDTC group, in which there were poor positive expressions of eNOS and p65 activity compared to diabetes group, revealed fewer inflammatory changes. PCC levels in diabetic lungs were higher, but SOD and GSH activities were lower. However, measurements of these parameters in the PDTC group and controls gave similar results. Conclusion: Lungs are exposed to changes induced by oxidative stress in diabetes through NF-ĸB activation and PDTC seems to be useful to prevent diabetic lung injury.

Effects of Radiation on Protein Oxidation and Lipid Peroxidation in the Brain Tissue

Radiation produces reactive oxygen species that modify macromolecules such as protein and lipid by oxidation and act in many pathological processes, causing serious damage to the brain. This study sought to evaluate the effects of radiation and the protective effect of N-acetylcysteine (NAC) on the brain tissue of guinea pigs based on the levels of lipid peroxidation and protein oxidation. Thirty-two guinea pigs were divided into groups of eight animals each: control group (group I); radiation group (group II); NAC group (group III), and NAC administered before radiation exposure group; (group IV). Guinea pigs in groups II and IV were exposed to Co 60 radiotherapy using the Source-Axis-Distance = 80 technique. The levels of protein carbonyl content and malondialdehyde (MDA), which is a marker for lipid peroxidation, were investigated by the Evans-Levine and Uchiyama-Mihara methods, respectively. The protein carbonyl and MDA levels of group II were significantly greater than those of group I ( P < .01). The protein carbonyl and MDA levels of group IV were lower than those of group II. The difference between the MDA levels of group IV and group II was significant ( P < .01); however, the difference in protein carbonyl levels between the two groups was not significant. The results indicated that radiation increased protein oxidation and lipid peroxidation in the brain, and NAC administration before radiation exposure may aid in the treatment by decreasing protein and lipid oxidation.

Reversal of the Mitochondrial Phenotype and Slow Development of Oxidative Biomarkers of Aging in Long-lived Mclk1+/− Mice

Although there is a consensus that mitochondrial function is somehow linked to the aging process, the exact role played by mitochondria in this process remains unresolved. The discovery that reduced activity of the mitochondrial enzyme CLK-1/MCLK1 (also known as COQ7) extends lifespan in both Caenorhabditis elegans and mice has provided a genetic model to test mitochondrial theories of aging. We have recently shown that the mitochondria of young, long-lived, Mclk1(+/-) mice are dysfunctional, exhibiting reduced energy metabolism and a substantial increase in oxidative stress. Here we demonstrate that this altered mitochondrial condition in young animals paradoxically results in an almost complete protection from the age-dependent loss of mitochondrial function as well as in a significant attenuation of the rate of development of oxidative biomarkers of aging. Moreover, we show that reduction in MCLK1 levels can also gradually prevent the deterioration of mitochondrial function and associated increase of global oxidative stress that is normally observed in Sod2(+/-) mutants. We hypothesize that the mitochondrial dysfunction observed in young Mclk1(+/-) mutants induces a physiological state that ultimately allows for their slow rate of aging. Thus, our study provides for a unique vertebrate model in which an initial alteration in a specific mitochondrial function is linked to long term beneficial effects on biomarkers of aging and, furthermore, provides for new evidence which indicates that mitochondrial oxidative stress is not causal to aging.

Antioxidants alleviate electric field-induced effects on lung tissue based on assays of heme oxygenase-1, protein carbonyl content, malondialdehyde, nitric oxide, and hydroxyproline

In order to test whether antioxidants have beneficiary effects on electric field induced damage, we determined the pulmonary levels of heme oxygenase-1 (HO-1), protein carbonyl content (PCO), malondialdehyde (MDA), nitric oxide (NO) and hydroxyproline (HP) under extremely low frequency (ELF) electric (E) field exposure (50 Hz, 12 kV/m, 7 days/for 8 h/day). While PCO levels significantly increased ( p < 0.05), insignificant changes ( p > 0.05) were observed in HO-1, MDA, NO and HP levels for electric field exposure groups compared to the control group. We have not observed any significant change in these parameters on the electric field group compared to the group where NAC and EGCG were separately applied along with electric field. However, during our previous studies, we have concluded that NAC and EGCG are potent antioxidants and we believe that new studies should be established by way of setting up different experimental conditions.

α-Lipoic acid and ebselen prevent ischemia/reperfusion injury in the rat intestine

Reactive oxygen species (ROS) and reactive nitrogen species (RNS), generated during tissue reperfusion, are characteristic of ischemia/reperfusion (I/R) injury. We conducted this study to evaluate the protective effect of alpha-lipoic acid (alpha-LA) and ebselen against intestinal I/R injury. Forty Sprague-Dawley rats were divided into five groups: a sham-operated group; an I/R group, subjected to intestinal ischemia for 45 min and reperfusion for 3 days; an I/R+alpha-LA group; an I/R+ebselen group; and an I/R+alpha-LA+ebselen group. We collected ileal specimens, to measure the tissue levels of malondialdehyde (MDA), protein carbonyl content (PCC), superoxide dismutase (SOD), and glutathione peroxidase (GPx), and to evaluate the histologic changes. There was a significant decrease in SOD and GPx levels, with an increase in MDA and PCC levels and intestinal mucosal injury in the intestinal I/R group (P<0.05). Superoxide dismutase and GPx levels were significantly higher, MDA and PCC levels were significantly lower, and intestinal injury was significantly less severe in the I/R+alpha-LA+ebselen group than in the I/R group (P<0.05). Although shortened villi and epithelial lifting were seen in the I/R group, only slight mucosal injury was seen in the treatment groups. alpha-Lipoic acid and ebselen played an important role in attenuating I/R injury of the intestine by scavenging ROS and RNS.

The efficacy of ozone therapy in experimental caustic esophageal burn

Introduction Ozone has been proposed as an antioxidant enzyme activator, immunomodulator and cellular metabolic activator. This study was designed to investigate the efficacy of ozone therapy in the prevention of esophageal damage and stricture formation developed after esophageal caustic injuries in the rat. Materials and Methods Forty-five rats were allocated into three groups; sham-operated, un-treatment and treatment groups. Caustic esophageal burn was created by instilling 15% NaOH in the distal esophagus. The rats were left untreated or treated with 1 mg/kg/day ozone intraperitoneally. All rats were sacrificed at 28 days. Efficacy of the treatment was assessed by measuring the stenosis index (SI) and histopathologic damage score, and biochemically by determining tissue hydroxyproline content (HP), superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA) and protein carbonyl content (PCC) in esophageal homogenates. Results Whereas seven (47%) rats died in the un-treatment group, all rats in the sham-operated and the treatment group survived during the study. SI, the histopathologic damage score, was significantly lower in the ozone-therapy group than the un-treatment group. HP levels were significantly higher in the un-treatment group than the group treated with ozone. Caustic esophageal burn increased MDA and PCC levels and also decreased SOD and GPx enzyme activities. In contrast, ozone therapy decreased the elevated MDA and PCC levels and also increased the reduced SOD and GPx enzyme activities. Conclusion Ozone has a preventive effect in the development of fibrosis by decreasing tissue damage and increasing the antioxidant enzyme activity in an experimental model of corrosive esophageal injury.

Therapeutic Effects ofTeucrium poliumExtract on Oxidative Stress in Pancreas of Streptozotocin-Induced Diabetic Rats

Increased oxidative stress is a widely accepted factor in the development and progression of diabetes and its complications. In this study, we evaluated the antioxidative potential of Teucrium polium (Family Lamiaceae) aqueous extract for protecting rat pancreatic tissue against streptozotocin (STZ)-induced oxidative stress. Diabetes was induced in rats by intraperitoneal injections of at a single dose of STZ at 40 mg/kg. The crude extract (equivalent to 0.5 g of plant powder/kg of body weight) was administered orally (intragastrically) to a group of STZ diabetic rats for 30 consecutive days. Changes in antioxidant status were evaluated by determining catalase (CAT) and superoxide dismutase (SOD) activities and the level of reduced glutathione (GSH) in pancreatic tissue. In addition, serum nitric oxide (NO) concentration, pancreatic tissue malondialdehyde (MDA) (an index of lipid peroxidation) level, and reliable markers of protein oxidation such as protein carbonyl content (PCO) and advanced oxidation protein products (AOPP) were also determined. Under diabetic conditions, blood glucose level, serum NO concentration, and pancreatic MDA, PCO, and AOPP levels were all increased. The diabetic rats also exhibited pancreatic GSH depletion along with significant reductions in activities of CAT and SOD. Rats treated with T. polium extract had significantly higher GSH levels along with enhanced CAT and SOD activities in pancreatic tissue. In addition to suppressed blood glucose levels, serum NO, pancreatic MDA, PCO, and AOPP levels were all lower than in the diabetic group. Our results strongly support the proposal that antioxidative activity of T. polium occurs by quenching the extent of lipid and protein oxidation. Based on these observations, it is concluded that T. polium may have protective effect(s) on pancreatic tissue in STZ-induced oxidative stress due to its high antioxidative potential.

Effect of 3-amino benzamide, a poly(adenosine diphosphate-ribose) polymerase inhibitor, in experimental caustic esophageal burn

Introduction The enzyme poly(adenosine diphosphate-ribose) polymerase affects the repair of DNA in damaged cells. However, its activation in damaged cells can lead to adenosine triphosphate depletion and death. This study was designed to investigate the efficacy of 3-amino benzamide (3-AB), a poly(adenosine diphosphate-ribose) polymerase inhibitor, on the prevention of esophageal damage and stricture-formation development after esophageal caustic injuries in rat. Materials and Methods Forty-five rats were allocated into 3 groups: sham-operated, untreated, and treated groups. Caustic esophageal burn was created by instilling 15% NaOH to the distal esophagus. The rats were left untreated or treated with 3-AB 10 mg/kg per day intraperitoneally. All rats were killed on the 28th day. Efficacy of the treatment was assessed by measuring the stenosis index and histopathologic damage score and biochemically by determining tissue hydroxyproline content, superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA), and protein carbonyl content (PCC) in esophageal homogenates. Results Treatment with 3-AB decreased the stenosis index and histopathologic damage score seen in caustic esophageal burn rats. Hydroxyproline level was significantly higher in the untreated group as compared with the group treated with 3-AB. Caustic esophageal burn increased MDA and PCC levels and also decreased SOD and GPx enzyme activities. On the contrary, 3-AB treatment decreased the elevated MDA and PCC levels and also increased the reduced SOD and GPx enzyme activities. Conclusion 3-Amino benzamide has a preventive effect in the development of fibrosis by decreasing tissue damage and increasing the antioxidant enzyme activity in an experimental model of corrosive esophagitis in rats.

Erdosteine and Ebselen As Useful Agents in Intestinal Ischemia/Reperfusion Injury

Reactive oxygen and nitrogen species generated during reperfusion of the tissue are characteristic of ischemia/reperfusion (I/R) injury. The purpose of the present study was to investigate whether erdosteine and ebselen, molecules with antioxidant properties and peroxynitrite scavenging capability, respectively, can reduce oxidative stress and histological damage in the rat small bowel subjected to mesenteric I/R injury. Forty Sprague-Dawley rats were divided into five groups equally: sham, I/R, I/R plus erdosteine, I/R plus ebselen, and I/R plus erdosteine and ebselen. Intestinal ischemia for 45 min and reperfusion for 3 d were carried out. Ileal specimens were obtained to determine the tissue levels of malondialdehide (MDA), protein carbonyl content (PCC), superoxide dismutase (SOD), glutathione peroxidase (GPx), nitrite/nitrate (NO(x)) level and histological changes. Intestinal I/R resulted in increased tissue MDA, PCC, and NO(x) levels and decreased SOD and GPx activities. Both erdosteine and ebselen alone significantly decreased MDA, PCC, and NO(x) levels and increased antioxidant enzymes activities, but all values were different from control. These changes almost returned to control values in the group treated with erdostein and ebselen. Histopathologically, the intestinal injury in rats treated with erdosteine and ebselen as well as combination were less than I/R group. Both erdosteine and ebselen were able to attenuate I/R injury of the intestine via inhibition of lipid peroxidation and protein oxidation, maintenance of antioxidant, and free radical scavenger properties. Nevertheless, combination treatment showed more promising results, suggesting that scavenging peroxynitrite nearby antioxidant activity is important in preventing intestinal I/R injury.

The effect of hemodialysis on accelerated atherosclerosis in diabetic patients: correlation of carotid artery intima-media thickness with oxidative stress

Objective Both diabetes and hemodialysis (HD) are associated with increased oxidative stress. The aim of this study was to clarify the effect of maintenance HD on oxidative stress parameters in diabetic patients and to explore any relation between carotid artery intima-media thickness (CIMT) and oxidative stress markers. Methods Twenty Type 2 diabetic patients undergoing chronic maintenance HD, 20 type 2 diabetic patients with normal renal function, and 20 age- and sex-matched healthy subjects were included. Serum thiobarbituric acid reactive substances (TBARS), protein carbonyl content (PCO), and nitrite/nitrate levels were determined as oxidative stress markers. Serum vitamin E, plasma sulfhydryl (P-SH), erythrocyte glutathione (GSH) levels, and superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities were measured as antioxidants. CIMT was assessed by carotid artery ultrasonography. Results Both diabetic patient groups had enhanced oxidative stress indicated by higher levels of TBARS, PCO, and nitrate/nitrite and lower activities of SOD, CAT, and GPx compared to controls. Diabetic patients undergoing HD had significantly higher CIMT ( P=.001) and higher levels of nitrite/nitrate ( P=.05), PCO ( P=.03), and GSH ( P=.04) but significantly lower levels of P-SH ( P<.001), serum vitamin E ( P=.04), SOD ( P=.02), CAT ( P=.001), and GPx ( P=.006) compared to diabetic patients with normal renal functions. There were significant negative correlations between CIMT and SOD ( r=−0.50, P<.001), CAT ( r=−0.41, P=.003), and P-SH levels ( r=−0.51, P<.001) and significant positive correlation between CIMT and nitrite/nitrate levels ( r=0.41, P=.003) and TBARS ( r=0.35, P=.02). Linear regression analysis showed TBARS was significantly and positively correlated with CIMT ( P=.04), while SOD and P-SH were significantly and negatively correlated with CIMT ( P=.05 and P=.02, respectively). Conclusions Hemodialysis exacerbates oxidative stress and disturbances in antioxidant enzymes in diabetic patients. Serum nitrite/nitrate and TBARS can be used as positive determinants, while erythrocyte SOD, CAT activities, and P-SH level can be used as negative determinants of atherosclerosis assessed by CIMT in diabetic patients.

Hepatitis B virus infection contributes to oxidative stress in a population exposed to aflatoxin B1 and high-risk for hepatocellular carcinoma

Biomarkers of hepatitis B virus (HBV) infection, aflatoxin B1 (AFB1) exposure and oxidative stress were detected in 71 hepatocellular carcinoma (HCC) patients and 694 controls from southern China. Plasma level of AFB1-albumin-adducts (AAA) and protein carbonyl content (PCC) were significantly higher in the 71 HCC cases than in any age/gender matched HBV sero-status groups (p<0.001). HCC patients positive for the p53-249 G-T mutation had a marginally higher level of PCC than those negative for the mutation (p=0.077). HBV infection had a prominent influence on the association between AFB1 exposure and oxidative stress biomarkers in the controls. Our study indicates a significant contribution from HBV infection to oxidative stress in a population with AFB1 exposure which might substantially increase risk for HCC in this region.

Glutamine fructose-6-phosphate amidotransferase (GFAT) gene expression and activity in patients with type 2 diabetes: Inter-relationships with hyperglycaemia and oxidative stress

Objective: Cell culture and animal model studies have strongly suggested a role for the rate-limiting enzyme for hexosamine biosynthesis, glutamine:fructose-6-phosphate amidotransferase (GFAT) in insulin resistance. However, there are very few clinical studies and none on Asian Indians, a high-risk group for type 2 diabetes (T2DM), which examined the role of GFAT in insulin resistance and T2DM. Design and method: The study group comprised of T2DM subjects without any complications ( n = 25) and control non-diabetic subjects ( n = 23). GFAT mRNA expression and activity were measured by semi-quantitative RT-PCR and fluorimetry, respectively. Oxidative damage was assessed in plasma by the extent of lipid peroxidation [thiobarbituric acid reactive substances (TBARS)] and protein carbonyl content (PCO) using standard methods. Result: The mean (± SE) GFAT activity was significantly higher in diabetic (30.22 ± 2.40 pM/mg protein/min) compared to control subjects (20.10 ± 1.12 pM/mg protein/min) ( p < 0.001). Plasma levels of diabetic patients also exhibited increased lipid peroxidation and protein carbonylation. GFAT activity was positively correlated ( p < 0.005) with GFAT mRNA, HbA 1c, insulin resistance (HOMA-IR), postprandial plasma glucose and levels of TBARS and PCO. In multiple logistic regression analysis, the association between GFAT activity and T2DM persisted even after adjusting for age, gender, BMI and HOMA-IR (OR = 1.202, p = 0.026). Conclusion: Increased GFAT activity appears to be associated with insulin resistance, postprandial hyperglycaemia and oxidative stress in T2DM and may point towards a potential pathway amenable for therapeutic intervention.

Is correction for protein concentration appropriate for protein adduct dosimetry? Hypothesis and clues from an aflatoxin B1‐exposed population

Protein adducts are useful biomarkers for assessing exposure, metabolism and risk of carcinogens. Aflatoxin B1-albumin adducts (AAA) and protein carbonyl content (PCC) have long been used for assessing aflatoxin exposure and oxidative stress to proteins, and the quantitative data are almost exclusively expressed per mg protein. Given the large variation in protein concentrations in plasma among populations, this may not be the most appropriate method. The objective was to test the hypothesis that AAA and PCC should be expressed per mL plasma in population studies. AAA and PCC were analyzed among 402 subjects from three regions of China with a gradient in hepatocellular carcinoma (HCC) mortality ranging from 21 to 97 per 100,000. When biomarker values were expressed per mL plasma, the AAA level was significantly associated with plasma PCC (r = 0.262, P < 0.001), and adjusted levels of AAA and PCC paralleled HCC mortalities in the three regions, suggesting a role for aflatoxin-related oxidative stress in hepatocarcinogenesis in this population. In addition, there were statistically significant associations between both protein biomarkers, expressed per mL plasma, and the levels of alanine aminotransferase and aspartate aminotransferase in hepatitis B virus-infected subjects, suggesting roles for aflatoxin exposure, oxidative stress and hepatitis B virus infection in the development of HCC. The present data suggest that interindividual variation in plasma protein concentration may influence the dosimetry and relevant interpretation of protein biomarkers.

Exercise-induced oxidative stress leads hemolysis in sedentary but not trained humans

Intravascular hemolysis is one of the most emphasized mechanisms for destruction of erythrocytes during and after physical activity. Exercise-induced oxidative stress has been proposed among the different factors for explaining exercise-induced hemolysis. The validity of oxidative stress following exhaustive cycling exercise on erythrocyte damage was investigated in sedentary and trained subjects before and after antioxidant vitamin treatment (A, C, and E) for 2 mo. Exercise induced a significant increase in thiobarbituric acid-reactive substance and protein carbonyl content levels in sedentary subjects and resulted in an increase of osmotic fragility and decrease in deformability of erythrocytes, accompanied by signs for intravascular hemolysis (increase in plasma hemoglobin concentration and decrease in haptoglobulin levels). Administration of antioxidant vitamins for 2 mo prevented exercise-induced oxidative stress (thiobarbituric acid-reactive substance, protein carbonyl content) and deleterious effects of exhaustive exercise on erythrocytes in sedentary subjects. Trained subjects' erythrocyte responses to exercise were different from those of sedentary subjects before antioxidant vitamin treatment. Osmotic fragility and deformability of erythrocytes, plasma hemoglobin concentration, and haptoglobulin levels were not changed after exercise, although the increased oxidative stress was observed in trained subjects. After antioxidant vitamin treatment, functional and structural parameters of erythrocytes were not altered in the trained group, but exercise-induced oxidative stress was prevented. Increased percentage of young erythrocyte populations was determined in trained subjects by density separation of erythrocytes. These findings suggest that the exercise-induced oxidative stress may contribute to exercise-induced hemolysis in sedentary humans.

Suppressive effects of dietary curcumin on the increased activity of renal ornithine decarboxylase in mice treated with a renal carcinogen, ferric nitrilotriacetate

Curcumin, a natural, biologically active compound extracted from rhizomes of Curcuma species, has been shown to act as a biological response modifier in various disorders. We have reported previously that the dietary supplementation of curcumin enhances the activities of antioxidant and phase II metabolizing enzymes in mice (M. Iqbal, S.D. Sharma, Y. Okazaki, M. Fujisawa, S. Okada, Dietary supplementation of curcumin enhances antioxidant and phase II metabolizing enzymes in ddY mice: possible role in protection against chemical carcinogenesis and toxicity, Pharmacol and Toxicol. 92 (2003) 33_38.) and inhibits ferric nitrilotriacetate (Fe-NTA) induced oxidative injury of lipids and DNA in vitro (M. Iqbal, Y. Okazaki, S. Okada, In vitro curcumin modulates Ferric Nitrilotriacetate (Fe-NTA) and hydrogen peroxide (H(2)O(2))-induced peroxidation of microsomal membrane lipids and DNA damage, Teratogenesis Carcinogenesis and Mutagenesis Supplement 23 (2003) 151-160.). In our present study, Fe-NTA, a known complete renal carcinogen, which generate ROS in vivo, was given intraperitoneally to mice and curcumin was tested for its ability to inhibits oxidative stress and the activity of ornithine decarboxylase (ODC) as well as histopathological changes in the kidney. Substantial changes in glutathione, antioxidant enzymes as well as changes in phase II metabolizing enzymes were observed in the kidney at 12 h after treatment with Fe-NTA (9.0 mg Fe/kg body weight). Effect of oxidative stress induced by Fe-NTA were also demonstrated by the increase in lipid peroxidation as monitored by formation of thiobarbituric acid-reactive substances and 4-hydroxy-2-nonenal (HNE)-modified proteins in kidney. Likewise, the level of protein carbonyl contents, an indicator of protein oxidation was also increased after Fe-NTA administration. However, the changes in these parameters were restored to normal in curcumin-pretreated mice. The ODC activity in the kidney was significantly increased by Fe-NTA, while the increased ODC activity induced by Fe-NTA was normalized in curcumin-pretreated mice. In addition, curcumin pretreatment almost completely prevented kidney biomolecules from oxidative damage and protected the tissue against observed histopathological alterations.

Which is more effective in the prevention of renal ischemia–reperfusion-induced oxidative injury in the early period in mice: interleukin (IL)-10 or anti-IL-12?

Objectives: Ischemia–reperfusion (I–R) injury induces production of reactive oxygen species (ROS) and some inflammatory mediators like tumor necrosis factor (TNF). We compared the effects of IL-10 and anti IL-12 antibody (Ab) on TNF-α production and oxidative stress markers. We also searched for which one, anti IL-12 or IL-10, is superior in the prevention of I–R induced oxidative stress. Design and methods: The animals were divided into four groups: control ( n = 5), I–R ( n = 5), I–R + IL-10 ( n = 5), I–R + anti IL-12 Ab ( n = 5). Mice were subjected to renal ischemia by clamping the left pedicle for 45 min, and were then reperfused for 1 h. Results: Under conditions of IL-12 blockade and IL-10 treatment, I–R-induced tissue TNF-α levels were significantly reduced ( P < 0.01). IL-10 treatment decreased I–R-induced thiobarbituric acid reactive substances (TBARS) and protein carbonyl content levels ( P < 0.05). After IL-10 treatment, decrease in tissue reduced glutathione (GSH) levels were prevented. Renal superoxide dismutase (SOD) and catalase (CAT) activities were observed to be decreased after I–R. IL-10 treatment increased both SOD and CAT activities over control values ( P < 0.05). Conclusion: These data indicated that IL-10 treatment may be more effective than anti-IL-12 treatment in the prevention of renal I–R-induced oxidative injury in the early period.

Protective role of superoxide dismutases against ionizing radiation in yeast

The protective role of superoxide dismutases (SODs) against ionizing radiation, which generates reactive oxygen species (ROS) harmful to cellular function, was investigated in the wild-type and in mutant yeast strains lacking cytosolic CuZnSOD (sod1Δ), mitochondrial MnSOD (sod2Δ), or both SODs (sod1Δsod2Δ). Upon exposure to ionizing radiation, there was a distinct difference between these strains in regard to viability and the level of protein carbonyl content, which is the indicative marker of oxidative damage to protein, intracellular H2O2 level, as well as lipid peroxidation. When the oxidation of 2′,7′-dichlorofluorescin was used to examine the hydroperoxide production in yeast cells, the SOD mutants showed a higher degree of increase in fluorescence upon exposure to ionizing radiation as compared to wild-type cells. These results indicated that mutants deleted for SOD genes were more sensitive to ionizing radiation than isogenic wild-type cells. Induction and inactivation of other antioxidant enzymes, such as catalase, glucose 6-phosphate dehydrogenase, and glutathione reductase, were observed after their exposure to ionizing radiation both in wild-type and in mutant cells. However, wild-type cells maintained significantly higher activities of antioxidant enzymes than did mutant cells. These results suggest that both CuZnSOD and MnSOD may play a central role in protecting cells against ionizing radiation through the removal of ROS, as well as in the protection of antioxidant enzymes.

Protein oxidation in aging and age-related diseases.

Although different theories have been proposed to explain the aging process, it is generally agreed that there is a correlation between aging and the accumulation of oxidatively damaged proteins, lipids, and nucleic acids. Oxidatively modified proteins have been shown to increase as a function of age. Studies reveal an age-related increase in the level of protein carbonyl content, oxidized methionine, protein hydrophobicity, and cross-linked and glycated proteins as well as the accumulation of less active enzymes that are more susceptible to heat inactivation and proteolytic degredation. Factors that decelerate protein oxidation also increase the life span of animals and vice versa. Furthermore, a number of age-related diseases have been shown to be associated with elevated levels of oxidatively modified proteins. The chemistry of reactive oxygen species-mediated protein modification will be discussed. The accumulation of oxidatively modified proteins may reflect deficiencies in one or more parameters of a complex function that maintains a delicate balance between the presence of a multiplicity of prooxidants, antioxidants, and repair, replacement, or elimination of biologically damaged proteins.