Total Radical-trapping Potential Research Articles

The Influence of Selected Insecticides on the Oxidative Response of Atta sexdens (Myrmicinae, Attini) Workers

Reactive oxygen species (ROS) are generated as products of normal cellular metabolic activities; however, the use of pesticides to control leafcutter ants leads to unbalanced ROS production. We evaluated the effects of two insecticides (fipronil, sulfluramid) and metallic insecticide complex (magnesium complex [Mg(hesp)2(phen)] (1)) on the superoxide dismutase (SOD), glutathione (GSH) and the overall antioxidant capacity using two different methodologies: total radical-trapping potential (TRAP) and oxygen radical absorbance capacity (ORAC). Media workers of Atta sexdens (C. Linnaeus) were exposed to the insecticides for 24 h, 48 h, 72 h and 96 h before their fat bodies were dissected for analysis. The results showed that although the sulfluramid may cause the production of ROS, its slow action in the organism does not lead to oxidative stress. There is a rise in oxidative stress in workers of leafcutter ants treated with fipronil because SOD significantly increased when compared to the control group. On the other hand, Mg1-complex suppressed both GSH and SOD, indicating that the immune system may be affected by Mg1-complex, which has a delayed activity ideal for its use in chemical pest control. Both TRAP and ORAC evaluated total antioxidant capacities; however, ORAC proved to be a more sensitive method. In conclusion, the Mg1-complex is a new compound that should be further investigated as a potential replacement for fipronil and sulfluramid in pest control.

A Novel Pathway Phenotype of Temporal Lobe Epilepsy and Comorbid Psychiatric Disorders: Results of Precision Nomothetic Medicine.

No precision medicine models of temporal lobe epilepsy (TLE) and associated mental comorbidities have been developed to date. This observational study aimed to develop a precision nomothetic, data-driven comorbid TLE model with endophenotype classes and pathway phenotypes that may have prognostic and therapeutical implications. We recruited forty healthy controls and 108 TLE patients for this research and assessed TLE and psychopathology (PP) features as well as oxidative stress (OSTOX, e.g., malondialdehyde or MDA, lipid hydroperoxides, and advanced oxidation protein products) and antioxidant (paraoxonase 1 or PON1 status, -SH groups, and total radical trapping potential or TRAP) biomarkers. A large part (57.2%) of the variance in a latent vector (LV) extracted from the above TLE and PP features was explained by these OSTOX and antioxidant biomarkers. The PON1 Q192R genetic variant showed indirect effects on this LV, which were completely mediated by PON1 activity and MDA. Factor analysis showed that a common core could be extracted from TLE, PP, OSTOX and antioxidant scores, indicating that these features are manifestations of a common underlying construct, i.e., a novel pathway phenotype of TLE. Based on the latter, we constructed a new phenotype class that is characterized by increased severity of TLE, PP and OSTOX features and lowered antioxidant defenses. A large part of the variance in episode frequency was explained by increased MDA, lowered antioxidant, and nitric oxide metabolite levels. In conclusion, (a) PP symptoms belong to the TLE phenome, and the signal increased severity; and (b) cumulative effects of aldehyde formation and lowered antioxidants determine epileptogenic kindling.

고콜레스테롤혈증 ApoE Knockout 마우스에서 기능성 수정과의 지질과산화 및 산화적 DNA 손상 억제 효과

The recipe for sujeonggwa, a Korean traditional sweet drink containing cinnamon, ginger, sugar, or honey, was modified by replacing sugar with alternative sweeteners (stevia or short-chain frutooligosaccharide (scFOS)) in order to improve the health functionality of sujeonggwa. The aim of this study was to evaluate the effects of modified sujeonggwa on lipid peroxidation and oxidized DNA damage in diet-induced hypercholesterolemic ApoE knockout mice. Hypercholesterolemia was induced in 6-week-old male mice by administration of a high cholesterol diet (1.25% cholesterol, 0.5% cholic acid, and 10% coconut oil) for 4 weeks, after which mice were divided into five groups: sucrose solution-fed control group, sujeonggwa containing sucrose group, sucrose+stevia group, su- crose+stevia+scFOS group, and commercially available sujeonggwa group as a positive control. After 6 weeks, su- jeonggwa supplementation resulted in reduced hepatic thiobarbituric acid reactive substances (TBARS), regardless of sweetener type. However, reduction of hepatic TBARS by commercially available sujeonggwa was insignificant. Both endogenous and H2O2-induced DNA damage in hepatocytes and splenocytes were significantly reduced only in the sujeonggwa containing stevia group compared to the sucrose-fed control group. There were no significant effects of sujeonggwa supplementation on total radical trapping potential, lipid peroxidation, or DNA damage in blood. These results suggest that sujeonggwa has protective effects against hepatic lipid peroxidation and DNA damage in hepatocytes or splenocytes from diet-induced hypercholesterolemic ApoE knockout mice, and the type of sweetener should be modified to improve the health benefits of sujeonggwa.

The Effects of Pterostilbene on Neutrophil Activity in Experimental Model of Arthritis

It has been demonstrated that pterostilbene inhibits reactive oxygen species production in neutrophils in vitro. However, little is known about its effects on neutrophils during inflammation in vivo. In this study, the effect of pterostilbene on neutrophil activity was investigated in experimental arthritis model. Lewis rats were injected by a single intradermal injection of heat-killed Mycobacterium butyricum in Freund's adjuvant to develop arthritis. Another group of arthritic animals received pterostilbene 30 mg/kg, daily, p.o. The number and activity of neutrophils in blood were measured on a weekly basis during the whole experiment. Moreover, the total radical trapping potential in plasma was measured at the end of the experiment. In the pterostilbene treated arthritic group, the treatment significantly lowered the number of neutrophils in blood on days 14 and 21 without significant downregulation of neutrophil oxidative burst. Pterostilbene nonsignificantly increased total radical trapping potential in arthritic animals. These results indicate that the promising effects of pterostilbene on reactive oxygen species operate by different mechanisms in vitro and in the animal model of inflammation. In conclusion, the positive effects of pterostilbene in the model of arthritis may be attributed to regulation of neutrophil number.

Effects of Chronic Restraint Stress and 17-β-Estradiol Replacement on Oxidative Stress in the Spinal Cord of Ovariectomized Female Rats

Previous studies have shown sex-specific oxidative changes in spinal cord of rats submitted to chronic stress, which may be due to gonadal hormones. Here, we assessed total radical-trapping potential (TRAP), superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and lipid peroxidation (evaluated by the TBARS test) in the spinal cord of ovariectomized (OVX) female rats. Female rats were subjected to OVX, and half of the animals received estradiol replacement. Animals were subdivided into controls and chronically stressed (for 40 days). Our findings demonstrate that chronic stress decreased TRAP, and increased SOD activity in spinal cord homogenates from ovariectomized female rats and had no effect on GPx activity. On the other hand, groups receiving 17β-estradiol replacement presented a decreased GPx activity, but no alteration in TRAP and in SOD activity. No differences in the TBARS test were found in any of the groups analyzed. In conclusion, our results support the idea that chronic stress induces an imbalance between SOD and GPx activities, additionally decreasing TRAP. Estradiol replacement did not reverse the effects of chronic stress, but induced a decrease in GPx activity. Therefore, estradiol replacement in ovariectomized chronically stressed rats could make the spinal cord more susceptible to oxidative injury.

Interactions Between Chronic Stress and Chronic Consumption of Caffeine on the Enzymatic Antioxidant System

We studied the effect of chronic caffeine on parameters related to oxidative stress in different brain regions of stressed and non-stressed rats. Wistar rats were divided into three groups: control (receiving water), caffeine 0.3 g/L and caffeine 1.0 g/L (in the drinking water). These groups were subdivided into non-stressed and stressed (repeated restraint stress during 40 days). Lipid peroxide levels and the total radical-trapping potential were assessed, as well as antioxidant enzyme activities superoxide dismutase, gluthatione peroxidase, and catalase in hippocampus, striatum and cerebral cortex. Results showed interactions between stress and caffeine, especially in the cerebral cortex, since caffeine increased the activity of some antioxidant enzymes, but not in stressed animals. We concluded that chronic administration of caffeine led, in some cases, to increased activity of antioxidant enzymes. However, these effects were not observed in the stressed animals.

Effect of systemically administered low potassium dextran solution on oxidative stress in a rat model of lung ischemia

Systemic administration of the low-potassium dextran solution on the peripheral oxidative stress was evaluated in an animal model of lung ischemia-reperfusion in rats. In one experiment, male Wistar rats were divided into two groups (n=5): one received intravenous saline, whereas in the other the animals were given intravenous low potassium dextran solution. In another experiment, male Wistar rats were divided into four groups (n=5): control, ischemia, saline and low potassium dextran. Except for the control animals, all groups were submitted to left hilar clamping for 30 min, followed by reperfusion for 30 min. Saline or low potassium dextran was administered intravenously immediately before clamp removal. In the first experiment there were no significant differences in lipid peroxidation. Total radical trapping potential measurements showed a significant increase in animals receiving low potassium dextran; in the second experiment, there was an increase in lipid peroxidation in both saline and ischemia groups compared to controls, and low potassium dextran. Low potassium dextran group showed an increase in total radical trapping potential measurements compared to all other groups. Ischemia-reperfusion injury mediated by reactive oxygen species was attenuated by the systemic use of low potassium dextran in this animal model of ischemia-reperfusion of the lung.

The antioxidant profile of three different peaches cultivars (Prunus persica) and their short-term effect on antioxidant status in human

Total polyphenols, carotenoids and vitamin C were assessed in three different peaches cultivars (Prunus persica): ‘Luisa Berselli’ (LB), ‘Stark Earlyglo’ (SE) and ‘Maria Serena’ (MS). Total antioxidant capacity of fruits and plasma antioxidant activity after ingestion of fruits were determined as Trolox equivalent antioxidant capacity (TEAC) and as plasma total radical-trapping potential (TRAP) respectively. The amount of polyphenols, carotenoids and vitamin C resulted to be generally similar in the three cultivars. TEAC, measured from harvest to 7 days postharvest, resulted to be influenced mainly by vitamin C content, whereas polyphenols and carotenoids seemed to play a secondary role. Although TEAC was similar in the three cultivars, only LB significantly increased the TRAP in human plasma at 1, 2 and 4 h after ingestion of peaches. Sugar moiety, condensed and glycoside phenols are suggested to be involved in the higher effect on plasma TRAP of LB.

A Manganese porphyrin suppresses oxidative stress and extends the life span of streptozotocin-diabetic rats

Enhanced oxidative stress due to hyperglycemia has been implicated in diabetic complications and is considered a major cause of cell and tissue damage. The aim of the present study was to investigate whether synthetic manganese porphyrin, Mn(III) 5,10,15,20-tetrakis(N-methylpyridinium-2-yl)porphyrin (MnTM-2-PyP5+) can ameliorate diabetes-induced oxidative stress and affect life span of diabetic rats.Diabetes was induced by a single (60 mg/kg) intraperitoneal injection of streptozotocin in male Wistar rats. Oxidative stress was monitored by measuring malondialdehyde levels (MDA) in blood plasma and erythrocytes using HPLC. The antioxidant status was assessed by measuring the total radical-trapping potential (TRAP) of blood plasma. Life span of the animals was used as an indication of the overall effect of MnTM-2-PyP5+. MnTM-2-PyP5+ was administered subcutaneously at 1 mg/kg for the duration of the experiment, five times/week followed by one week of rest.Diabetes increased plasma and erythrocyte levels of MDA and decreased TRAP. MnTM-2-PyP5+ had no effect on blood glucose and glycosylated hemoglobin, but significantly increased TRAP and lowered MDA. This Mn porphyrin decreased mortality and markedly extended the life span of the diabetic animals.MnTM-2-PyP5+ suppressed diabetes-induced oxidative stress, which presumably accounts for its beneficial effect on the life span of the diabetic rats. The results indicate that Mn(III) N-alkylpyridylporphyrins can be used as potent therapeutic agents in diabetes.

Repeated Restraint Stress Induces Oxidative Damage in Rat Hippocampus

It has been shown that emotional stress may induce oxidative damage, and considerably change the balance between pro-oxidant and antioxidant factors in the brain. The aim of this study was to verify the effect of repeated restraint stress (RRS; 1 h/day during 40 days) on several parameters of oxidative stress in the hippocampus of adult Wistar rats. We evaluated the lipid peroxide levels (assessed by TBARS levels), the production of free radicals (evaluated by the DCF test), the total radical-trapping potential (TRAP) and the total antioxidant reactivity (TAR) levels, and antioxidant enzyme activities (SOD, GPx and CAT) in hippocampus of rats. The results showed that RRS induced an increase in TBARS levels and in GPx activity, while TAR was reduced. We concluded that RRS induces oxidative stress in the rat hippocampus, and that these alterations may contribute to the deleterious effects observed after prolonged stress.

Monosialoganglioside Increases Catalase Activity in Cerebral Cortex of Rats

Monosialoganglioside (GM1) is a neuroprotective agent that has been reported to scavenge free radicals generated during reperfusion and to protect receptors and enzymes from oxidative damage. However, only a few studies have attempted to investigate the effects of GM1 on enzymatic antioxidant defenses of the brain. In the present study, we evaluate the effects of the systemic administration of GM1 on the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), and on spontaneous chemiluminescence and total radical-trapping potential (TRAP) in cerebral cortex of rats ex vivo. The effects of GM1 on CAT activity and spontaneous chemiluminescence in vitro were also determined.Animals received two injections of GM1 (50 mg/kg, i.p.) or saline (0.85% NaCl, i.p.) spaced 24 h apart. Thirty minutes after the second injection the animals were sacrificed and enzyme activities and spontaneous chemiluminescence and TRAP were measured in cell-free homogenates. GM1 administration reduced spontaneous chemiluminescence and increased catalase activity ex vivo, but had no effect on TRAP, SOD or GSH-Px activities. GM1, at high concentrations, reduced CAT activity in vitro. We suggest that the antioxidant activity of GM1 ganglioside in the cerebral cortex may be due to an increased catalase activity.

Lipid peroxidation and total radical-trapping potential of the lungs of rats submitted to chronic and sub-chronic stress.

Exposure to stress induces a cluster of physiological and behavioral changes in an effort to maintain the homeostasis of the organism. Long-term exposure to stress, however, has detrimental effects on several cell functions such as the impairment of antioxidant defenses leading to oxidative damage. Oxidative stress is a central feature of many diseases. The lungs are particularly susceptible to lesions by free radicals and pulmonary antioxidant defenses are extensively distributed and include both enzymatic and non-enzymatic systems. The aim of the present study was to determine lipid peroxidation and total radical-trapping potential (TRAP) changes in lungs of rats submitted to different models of chronic stress. Adult male Wistar rats weighing 180-230 g were submitted to different stressors (variable stress, N = 7) or repeated restraint stress for 15 (N = 10) or 40 days (N = 6) and compared to control groups (N = 10 each). Lipid peroxidation levels were assessed by thiobarbituric acid reactive substances (TBARS), and TRAP was measured by the decrease in luminescence using the 2-2'-azo-bis(2-amidinopropane)-luminol system. Chronic variable stress induced a 51% increase in oxidative stress in lungs (control group: 0.037 +/- 0.002; variable stress: 0.056 +/- 0.007, P < 0.01). No difference in TBARS was observed after chronic restraint stress, but a significant 57% increase in TRAP was presented by the group repeatedly restrained for 15 days (control group: 2.48 +/- 0.42; stressed: 3.65 +/- 0.16, P < 0.05). We conclude that different stressors induce different effects on the oxidative status of the organism.

Mutagenicity, antioxidant potential, and antimutagenic activity against hydrogen peroxide of cashew (Anacardium occidentale) apple juice and cajuina.

Fresh and processed cashew (Anacardium occidentale) apple juice (CAJ) are among the most popular drinks in Brazil. Besides their nutritional benefits, these juices have antibacterial and antitumor potential. The chemical constituents of both the fresh juice and the processed juice (cajuina) were analyzed and characterized as complex mixtures containing high concentrations of vitamin C, various carotenoids, phenolic compounds, and metals. In the present study, these beverages exhibited direct and rat liver S9-mediated mutagenicity in the Salmonella/microsome assay with strains TA97a, TA98, and TA100, which detect frameshifts and base pair substitution. No mutagenicity was observed with strain TA102, which detects oxidative and alkylating mutagens and active forms of oxygen. Both CAJ and cajuina showed antioxidant activity as determined by a total radical-trapping potential assay. To test whether this antioxidant potential might result in antimutagenesis, we used a variation of the Salmonella/microsome assay that included pre-, co-, and posttreatment of hydrogen peroxide-exposed Salmonella typhimurium strain TA102 with the juices. CAJ and cajuina protected strain TA102 against mutation by oxidative damage in co- and posttreatments. The antimutagenic effects during cotreatment with hydrogen peroxide may be due to scavenging free radicals and complexing extracellular mutagenic compounds. The protective effects in posttreatment may be due to stimulation of repair and/or reversion of DNA damage. The results indicate that CAJ and cajuina have mutagenic, radical-trapping, antimutagenic, and comutagenic activity and that these properties can be related to the chemical constituents of the juices.

Juice and phenolic fractions of the berry Aristotelia chilensis inhibit LDL oxidation in vitro and protect human endothelial cells against oxidative stress.

Oxidative modification of low-density lipoprotein (LDL) particles is a key event in the development of atherosclerosis. Oxidized LDL induces oxidative stress and modifies gene expression in endothelial cells. Berries constitute a rich dietary source of phenolic antioxidants. We found that the endemic Chilean berry Aristotelia chilensis (ach) has higher phenol content and scores better for total radical-trapping potential and total antioxidant reactivity in in vitro antioxidant capacity tests, when compared to different commercial berries. The juice of ach is also effective in inhibiting copper-induced LDL oxidation. In human endothelial cell cultures, the addition of ach juice significantly protects from hydrogen peroxide-induced intracellular oxidative stress and is dose-dependent. The aqueous, anthocyanin-rich fraction of ach juice accounts for most of ach's antioxidant properties. These results show that ach is a rich source of phenolics with high antioxidant capacity and suggest that it may have antiatherogenic properties.

Myocardial oxidative stress and antioxidants in hypertension as a result of nitric oxide synthase inhibition.

Rats were made hypertensive by the administration of the nitric oxide synthase inhibitor nitro-L-arginine (LNA, 2.74 mmol/L) in drinking water for 7 d. Hearts from hemodynamically assessed animals were analyzed for lipid peroxidation (LPO), gamma-glutamylcysteine-synthetase (gamma-GCS), glutathione disulfide reductase (GR), glutathione peroxidase (GSHPx), catalase (CAT), superoxide dismutase (SOD), and total radical trapping potential (TRAP) activities. LNA treatment increased the mean arterial blood pressure by 46% and the heart rate by 22% without changing plasma renin activity. LNA treatment resulted in a 30% increase in LPO. gamma-GCS was reduced by 48% and GR by 36% in the cardiac tissue of hypertensive rats as compared to controls. The activity of nonselenium GSHPx was reduced by 27%, and selenium-dependent GSHPx activity in the heart was not affected by LNA treatment. In hypertensive rats, SOD activity was increased by 16%, and CAT was decreased by 46%. TRAP was lower (27%) in the myocardium of hypertensive rats than in that of controls. These data suggest that LNA-induced hypertension is associated with increased myocardial oxidative stress.

Oxidative stress evaluation in diabetes.

Over the recent years, researches have focused their attention on the pathologic role of free radicals in a variety of diseases, among which the most important are atherosclerosis, cancer, and diabetes. The set of intracellular and extracellular conditions that leads to chemical or metabolic generation of reactive species is termed "oxidative stress." The susceptibility to oxidative stress is a function of the overall balance between the factors that exert oxidative stress and those that exhibit antioxidant capability. There is currently great interest in the potential contribution of increased oxidative stress to the development of complications in diabetes mellitus. Direct measurement of oxidative stress in vivo is a very complex question, because free radicals are highly reactive, have a very short life, and are present in very low concentrations. Thus, indirect methods, used for measuring secondary products of oxidative stress, are rather unspecific and may give conflicting data. Nitrotyrosine detection in plasma and tissues may be a useful method to demonstrate peroxynitrite-mediated damage. The total radical-trapping potential (TRAP) in plasma represents a more reliable estimation of serum antioxidant capability than the measurement of each known antioxidant. The detection of increased levels of oxidation products in tissue and biological fluids is important to investigate the relation between free radical production and the development of pathology. This hypothesis suggests the possibility of a therapeutic intervention with antioxidant agents. The identification of a useful marker to assess the effect of antioxidants on oxidative stress seems to be mandatory.

Effect of chronic variate stress on thiobarbituric-acid reactive species and on total radical-trapping potential in distinct regions of rat brain.

It has been suggested that oxidative stress is involved in aging and neuropathologic disorders. In addition, chronic stress and high corticosterone levels are suggested to induce neuronal death. The aim of this study is to verify the effect of chronic variate stress on lipoperoxidation and on the total radical-trapping potential (TRAP) in hippocampus, hypothalamus and cerebral cortex. Adult male Wistar rats were submitted to different stressors during 40 days. Lipid peroxide levels were assessed by the thiobarbituric acid reactive species (TBARS) reaction, and TRAP was measured by the decrease in luminescence using the 2-2'-azo-bis(2-amidinopropane)-luminol system. The results showed that in cerebral cortex homogenates chronic stress induces an increase in oxidative stress. In hypothalamus a decreased lipoperoxidation was observed, however TRAP showed no difference. In hippocampus no difference was observed. We concluded that prolonged stress induces oxidative stress which varies selectively with the brain region.