Effects of dietary supplements on the space radiation-induced reduction in total antioxidant status in CBA mice

In the present study, the total antioxidant status was used as a biomarker to evaluate oxidative stress induced by proton, HZE-particle and gamma radiation in CBA mice. The results demonstrated that the plasma level of TAS was significantly decreased (P < 0.05) in CBA mice after exposure to a 50-cGy dose of radiation from HZE particles or a 3-Gy dose of radiation from protons or gamma rays. Diet supplementation with Bowman-Birk Inhibitor Concentrate (BBIC), L-selenomethionine (L-SeM), or a combination of N-acetyl cysteine, sodium ascorbate, co-enzyme Q10 (CoQ10), alpha-lipoic acid, L-SeM and vitamin E succinate could partially or completely prevent the reduction in the plasma level of TAS in CBA mice exposed to proton or HZE-particle radiation. The selected antioxidant combination with or without CoQ10 has a comparable protective effect on the gamma-radiation-induced drop in TAS in CBA mice. These results indicate that BBIC, L-SeM and the selected antioxidant combinations may serve as countermeasures for space radiation-induced adverse biological effects.     

Antioxidant capacity of seminal plasma measured by TAS Randox

BACKGROUND: An imbalance between reactive oxygen species (ROS) generation in sperm and antioxidant capacity of seminal plasma has been linked to male infertility. The antioxidant power of biological fluids can be evaluated either by measurement of individual antioxidants or total antioxidant capacity (TAC). The aim of this study was to assess whether TAS Randox can also be used for seminal plasma antioxidant capacity estimation. MATERIAL AND METHODS: Freshly thawed aliquots of seminal plasma and blood serum of 38 males from infertile couples and 24 healthy normospermic controls were simultaneously assayed using TAS Randox reagents on the Hitachi Modular P800 Analyzer. Semen analysis was performed according to WHO guidelines. ROS in fresh sperm suspension in phosphate buffered saline was measured by chemiluminescence immediately after separation of seminal plasma. RESULTS: Semen analysis showed that in our study group only 14 males were normospermic and 24 males had mostly combined pathologies. The medians for ROS production were similar in both the study and the control groups (4850 and 5450 RLU/min, resp). Seminal plasma TAS levels were significantly lower (p<0.02) in the study group while blood serum TAS levels were similar in both groups. A significant positive correlation (p<0.05) between TAS in seminal plasma and serum was found, seminal plasma levels being on average 1.4 times higher. CONCLUSIONS: The TAS Randox kit may be used for clinical studies intended to identify decreased antioxidant power in the seminal fluid of infertile men.     

Quasi-total-body exposure to an oxygen-ozone mixture in a sauna cabin

We have investigated the effects of quasi-total-body exposure of healthy volunteers to either an oxygen-ozone mixture (O(2)-O(3)) or to oxygen (O(2)) alone during a short period in a sauna cabin. The subjects underwent both an experimental and a control examination, separated by a 3.5-month interval. Body mass, blood pressure, body temperature changes, electrocardiograms, venous blood gas and haemocytometric analyses, total antioxidant status and plasma levels of protein thiol groups, thiobarbituric acid reactive substances (TBARS), plasma cytokine, hepatic enzymes and creatine were determined before, immediately after the 20-min period in the cabin and then 0.5, 1.0 and 24 h afterwards. We observed statistically significant variations of body temperature, venous partial pressure of O(2) values, TBARS and plasma levels of interleukin 8, particularly after O(2)-O(3) exposure. The increase in TBARS plasma levels concomitant with protein oxidation has been tentatively interpreted as being attributable to the transcutaneous passage of some reactive O(2) species, which should be considered if this approach is to be used as a biological response modifier. However, in the present study no adverse effects were noted after one session.     

Total antioxidant levels are low during active TB and rise with anti-tuberculosis therapy

In tuberculosis, oxidative stress is a result of tissue inflammation, poor dietary intake of micronutrients due to illness, free radical burst from activated macrophages, and anti-tuberculosis drugs. These free radicals may in turn contribute towards pulmonary inflammation if not neutralized by antioxidants. The total antioxidant status (TAS) of individuals is a function of dietary, enzymatic, and other systemic antioxidants and is therefore an indicator of the free radical load. Our aim was to evaluate the TAS of healthy and M. tuberculosis-infected persons from a high TB incidence community, as well as tuberculosis patients at various stages of antituberculosis drug treatment and to correlate results with plasma micronutrient levels. Blood plasma samples from TB infected patients and following antituberculosis drug treatment were assayed for TAS, vitamins A, E and Zinc. Statistical analysis of results was by one-way ANOVA and the Tukey multiple comparison post test. Active TB patients showed a significantly lower TAS (P < 0.001) compared to the community controls. We also show that TAS values increase during therapy. Results correlated with micronutrients vitamin A and zinc but vitamin E remained unaffected. We suggest that total antioxidant status of TB patients should be considered for more effective disease control and that diets low in antioxidants may render individuals susceptible to tuberculosis.     

The effects of short-term training on platelet functions and total antioxidant capacity in rats

The purpose of the present study was to investigate the effect of short-term endurance training on plasma total antioxidant status (TAS) and on in vitro platelet aggregation and ATP release. Blood samples were collected from the abdominal aorta of rats following short-term treadmill exercise (25 m/min, 0 % grade, 30 min) for three consecutive days, as well as in non-exercised control group. Platelet aggregation and platelet ATP release were evaluated by impedance and bioluminescence techniques, respectively. Plasma TAS was measured spectrophotometrically. Plasma TAS was higher and ADP-induced platelet ATP release was lower in the short-term training group with respect to the control group (p<0.001). Significant negative correlation (r = -0.56, p<0.05) was found between plasma TAS and ADP-induced platelet ATP release. Neither ADP- and collagen-induced maximum aggregation rate nor collagen-induced platelet ATP release were significantly different between the groups. According to these results, short-term training caused an alteration in platelet functions limited to the secretion response, which may be related to the oxidant/antioxidant balance changes favoring the antioxidants. The improved plasma total antioxidant capacity was possibly sufficient to prevent exercise-induced oxidative damage, and the adaptive response of platelets might be associated with enhanced antioxidant status.     

Diallyl sulfide--a flavour component from garlic (Allium sativum) attenuates lipid peroxidation in mice infected with Trichinella spiralis.

We investigated the antioxidant capacity of diallyl sulfide (DAS) in the course of experimental trichinellosis in C3H mice. For this purpose, the mice were orally infected with either Trichinella spiralis larvae (300 larvae/mouse) or treated per os with normal saline (control), and 12 hrs later, they were treated per os with DAS (200 mg/kg b.w) daily for 5 or 20 days. On day 5 and 35 of the post-infection period (5 and 35 dpi), thiobarbituric-acid reactive substances (TBARS) in the small intestinal mucosa and diaphragm samples and the total antioxidant status (TAS) of blood were determined. Trichinella spiralis increased TBARS and decreased TAS in the intestinal phase of invasion. However, in the muscular phase mice, neither TBARS nor TAS was found to be different from those of the control. Diallyl sulfide has been shown to decrease TBARS and the agent did not have any effect(s) on the total antioxidant status of blood in Trichinella-infected mice. The results suggest that diallyl sulfide may be an effective antioxidant candidate and may therefore play a significant role in the defense against lipid peroxidation in trichinellosis.     

Role of the antioxidant ascorbate in hibernation and warming from hibernation

Ground squirrels tolerate up to 90% reductions in cerebral blood flow during hibernation as well as rapid reperfusion upon periodic arousal from torpor without apparent neurological damage. Thus, hibernation is studied as a model of tolerance to cerebral ischemia and other types of brain injury. Metabolic suppression likely plays a primary adaptive role that allows hibernating species to tolerate dramatic fluctuations in blood flow. Several other aspects of hibernation physiology are also consistent with tolerance to ischemia and reperfusion suggesting that multiple neuroprotective adaptations may work in concert during hibernation. The purpose of the present work is to review evidence for enhanced antioxidant defense systems during hibernation, with a focus on ascorbate, and discuss potential roles of these antioxidants during hibernation. In concert with dramatic decreases in blood flow, nutrient and oxygen delivery, plasma concentrations of the antioxidant ascorbate [(Asc)p] increase 3-5-fold during hibernation. In contrast, during re-warming, [Asc]p declines at a relatively rapid rate that peaks at the time of maximal O(2) consumption. This peak in O(2) consumption also coincides with a brief rise in plasma urate concentration consistent with a surge in reactive oxygen species production. Overall, data suggest that elevated concentration of plasma ascorbate is poised for distribution to metabolically active tissues during the surge in oxidative metabolism that accompanies re-warming during hibernation. This pool of ascorbate, as well as increased expression of other antioxidant defense systems, may protect vulnerable tissues from oxidative stress during hibernation and re-warming from hibernation. Better understanding of the role of ascorbate in hibernation may guide use of ascorbate and other antioxidants in treatment of stroke, head trauma and neurodegenerative disease.     

Functional analysis of Asb-1 using genetic modification in mice

The Asbs are a family of ankyrin repeat proteins that, along with four other protein families, contain a C-terminal SOCS box motif, which was first identified in the suppressor of cytokine signaling (SOCS) proteins. While it is clear that the SOCS proteins are involved in the negative regulation of cytokine signaling, the biological roles of the other SOCS box-containing families are unknown. We have investigated Asb-1 function by generating mice that lack this protein, as well as mice that overexpress full-length or truncated Asb-1 in a wide range of tissues. Although Asb-1 is expressed in multiple organs, including the hematopoietic compartment in wild-type mice, Asb-1(-/-) mice develop normally and exhibit no anomalies of mature blood cells or their progenitors. While most organs in these mice appear normal, the testes of Asb-1(-/-) mice display a diminution of spermatogenesis with less complete filling of seminiferous tubules. In contrast, the widespread overexpression of Asb-1 in the mouse has no apparent deleterious effects.     

Protective effect of L-cysteine and glutathione on rat brain Na+,K+-ATPase inhibition induced by free radicals

The aim of this study was to investigate whether the preincubation of brain homogenates with L-phenylalanine (Phe), L-cysteine (Cys) or reduced glutathione (GSH) could reverse the free radical effects on Na+,K+-ATPase activity. Two well established systems were used for the production of free radicals: 1) FeSO4 (84 microM) plus ascorbic acid (400 microM) and 2) FeSO4, ascorbic acid and H2O2 (1 mM) for 10 min at 37 degrees C in homogenates of adult rat whole brain. Changes in brain Na+,K+-ATPase activity and total antioxidant status (TAS) were studied in the presence of each system separately, with or without Phe, Cys or GSH. TAS value reflects the amount of free radicals and the capacity of the antioxidant enzymes to limit the free radicals in the homogenate. Na+,K+-ATPase was inhibited by 35-50% and TAS value was decreased by 50-60% by both systems of free radical production. The enzymatic inhibition was completely reversed and TAS value increased by 150-180% when brain homogenates were preincubated with 0.83 mM Cys or GSH. However, this Na+,K+-ATPase inhibition was not affected by 1.80 mM Phe, which produced a 45-50% increase in TAS value. It is suggested that the antioxidant action of Cys and GSH may be due to the binding of free radicals to sulfhydryl groups of the molecule, so that free radicals cannot induce Na+,K+-ATPase inhibition. Moreover, Cys and GSH could regulate towards normal values the neural excitability and metabolic energy production, which may be disturbed by free radical action on Na+,K+-ATPase.     

Ozone causes lipid peroxidation but little antioxidant depletion in exercising and nonexercising hamsters.

Ozone (O(3)), a major component of urban air pollution, is a strong oxidizing agent that can cause lung injury and inflammation. In the present study, we investigated the effect of inhalation of O(3) on levels of F(2)-isoprostanes in bronchoalveolar lavage fluid (BALF) and on levels of antioxidants in the BALF and plasma of hamsters. Because antioxidants, including urate, ascorbate, GSH, and vitamin E, defend the lungs by reacting with oxidizing agents, we expected to find a decrease in antioxidant levels after O(3) exposure. Similarly, we expected an increase in the levels of F(2)-isoprostanes, which are lipid peroxidation products. Exposure to 1.0 or 3.0 parts/million (ppm) O(3) for 6 h resulted in an increase in BALF neutrophil numbers, an indicator of acute inflammation, as well as elevation of BALF F(2)-isoprostanes. The higher dose of O(3) caused an increase in the BALF level of urate and a decrease in the plasma level of ascorbate, but 1.0 ppm O(3) had no effect on BALF or plasma antioxidant levels. Exposure to 0.12 ppm O(3) had no effect on BALF neutrophils or F(2)-isoprostanes nor on BALF and plasma antioxidants. We also investigated the effect of O(3) exposure of hamsters during exercise on F(2)-isoprostane and antioxidant levels. We found that exposure to 1.0 ppm O(3) during 1 h of exercise on a laddermill increased BALF levels of F(2)-isoprostanes but had no effect on BALF neutrophils or on BALF and plasma antioxidants. These results indicate that O(3) induces inflammation and biomolecule oxidation in the lungs, whereas extracellular antioxidant levels are relatively unchanged.     

服食黑蒜可有效维持长跑运动员抗氧化能力并缓解发炎情况

为探讨服食黑蒜对长跑运动员的抗氧化与抗发炎作用,本研究招募8位大学生长跑运动员为受试者,采用双盲交叉实验分别进行14 d黑蒜或安慰剂服食,并在第15天进行10 000 m运动测试。通过采集服食前与运动后运动员的血液,并对超氧化歧化酶(SOD)、总抗氧化状态(TAS)、谷胱甘肽过氧化酶(GPx)等氧化能力指标与肌酸激酶(CK)、乳酸脱氢酶(LDH)、超敏C-反应蛋白(hs-CRP)、白细胞数(WBC)等发炎指标进行分析,本研究发现在10 000 m运动测试后,黑蒜组体内抗氧化参数显著低于安慰剂组,发炎情况中白细胞数指标在黑蒜组中显著低于安慰剂组。本研究表明,服食黑蒜可以显著降低抗氧化指标SOD、TAS与GPx活性及白细胞数量,有效维持体内抗氧化能力及降低运动后发炎情况。     

Total Antioxidant Status Correlates with Cognitive Impairment in Patients with Recurrent Depressive Disorder

Depressive disorder is a multifactorial diseases, that one of the typical feature are cognitive impairments. The aim of this study was to determine the total antioxidant status (TAS) in patients with recurrent depressive disorder (rDD) and to define relationship between plasma levels of TAS and the cognitive performance. Design and methods: the study comprised 74 subjects: patients with rDD (n = 45) and healthy subjects (n = 29). Cognitive function assessment was based on: Trail Making Test, The Stroop Test, Verbal Fluency Test and Auditory Verbal Learning Test. Statistically significant differences were found in the intensity of depression symptoms, measured by the Hamilton Depression Rating Scale (HDRS) on therapy onset versus the examination results after 8 weeks of treatment (p < 0.001). The level of TAS was substantially higher in patients with rDD (p = 0.01). For rDD patients, elevated TAS levels were associated with worse cognitive test performance. The higher was the concentration of plasma TAS, the greater was the severity of depressive symptoms measured by HDRS before and after pharmacotherapy. (1) Higher concentration of plasma TAS in rDD patients is associated with the severity of depressive symptoms. (2) Elevated levels of plasma TAS are related to impairment of short-term declarative memory, long-term declarative-memory, verbal fluency and working memory.     

Seasonal changes in antioxidant defence systems in seminal plasma and fluids of the boar reproductive tract

This study aimed to analyze seasonal variations in the antioxidant defence systems of the seminal plasma and fluids of the cauda epididymis and vesicular glands of the boar. The analyzed antioxidants included superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and total L-glutathione (GSH+GSSG). Seasonal changes in total protein content and total antioxidant status (TAS) of the seminal plasma and reproductive fluids were also analyzed. Compared with the spring-summer period, total protein content in the seminal plasma was significantly higher during the autumn-winter period. Among the antioxidants analyzed, only SOD activity showed marked seasonal variations, being significantly higher during the spring-summer period. Likewise, the fluid of the cauda epididymis exhibited greater SOD and CAT activity during the spring-summer period, whereas TAS levels were markedly higher during the autumn-winter period. Neither GPx activity nor total GSH+GSSG content in the cauda epididymal fluid was significantly affected by the seasonal periods. The vesicular gland fluid exhibited an approximately 4-fold greater level of SOD activity during the autumn-winter period, as compared with the spring-summer period. By contrast, greater CAT and GPx activity, and a higher level of total GSH+GSSG were observed in the vesicular gland fluid during the spring-summer period. In conclusion, the findings of this study indicate that seasonal variations could have varying effects on the antioxidant defence systems in the seminal plasma and fluids of the boar reproductive tract.     

Garlic supplementation prevents oxidative DNA damage in essential hypertension

Oxygen-free radicals and other oxygen/nitrogen species are constantly generated in the human body. Most are intercepted by antioxidant defences and perform useful metabolic roles, whereas others escape to damage biomolecules like DNA, lipids and proteins. Garlic has been shown to contain antioxidant phytochemicals that prevent oxidative damage. These include unique water-soluble organosulphur compounds, lipid-soluble organosulphur compounds and flavonoids. Therefore, in the present study, we have tried to explore the antioxidant effect of garlic supplementation on oxidative stress-induced DNA damage, nitric oxide (NO) and superoxide generation and on the total antioxidant status (TAS) in patients of essential hypertension (EH). Twenty patients of EH as diagnosed by JNC VI criteria (Group I) and 20 age and sex-matched normotensive controls (Group II) were enrolled in the study. Both groups were given garlic pearls (GP) in a dose of 250 mg per day for 2 months. Baseline samples were taken at the start of the study, i.e. 0 day, and thereafter 2 months follow-up. 8-Hydroxy-2′-deoxyguanosine (8-OHdG), lipids, lipid peroxidation (MDA), NO and antioxidant vitamins A, E and C were determined. A moderate decline in blood pressure (BP) and a significant reduction in 8-OHdG, NO levels and lipid peroxidation were observed in Group I subjects with GP supplementation. Further, a significant increase in vitamin levels and TAS was also observed in this group as compared to the control subjects. These findings point out the beneficial effects of garlic supplementation in reducing blood pressure and counteracting oxidative stress, and thereby, offering cardioprotection in essential hypertensives.     

The effect of polyphenolic extract from pine bark, Pycnogenol on the level of glutathione in children suffering from attention deficit hyperactivity disorder (ADHD)

Attention deficit hyperactivity disorder (ADHD) belongs to the neurodevelopmental disorders characterized by impulsivity, distractibility and hyperactivity. In the pathogenesis of ADHD genetic and non-genetic factors play an important role. It is assumed that one of non-genetic factors should be oxidative stress. Pycnogenol, an extract from the pine bark, consists of bioflavonoids, catechins, procyanidins and phenolic acids. Pycnogenol acts as powerful antioxidant, chelating agent; it stimulates the activities of some enzymes, like SOD, eNOS, and exhibits other biological activities. AIM: The aim of this randomized, double-blind, placebo-controlled trial was to investigate the influence of administered Pycnogenol or placebo on the level of reduced (GSH) and oxidized (GSSG) glutathione in children suffering from ADHD and on total antioxidant status (TAS). This is the first investigation of the redox glutathione state in relation to ADHD. RESULTS: One month of Pycnogenol administration (1 mg/kg body weight/day) caused a significant decrease in GSSG and a highly significant increase in GSH levels as well as improvement of GSH/GSSG ratio in comparison to a group of patients taking a placebo. TAS in children with ADHD was decreased in comparison with reference values. Pycnogenol administration normalizes TAS of ADHD children.     

Isoflavone genistein-8-c-glycoside prevents the oxidative damages in structure and function of rat liver microsomal membranes

Bioflavonoids (polyhydroxyphenols) are ubiquitous components of plants, fruits and vegetables; these compounds are efficient scavengers of free oxygen radicals and peroxides. The aim of this study was to investigate the antioxidant and radioprotective effects of genistein-8-C-glicoside (G8CG), an isoflavone, isolated from the flowers of Lipinus luteusl L. G8CG prevents dose-dependently the destruction of the cytochrome P-450 and its conversion to an inactive form cytochrome P-420, inhibits membrane lipid peroxidation and membrane SH-group oxidation in isolated rat liver microsomal membranes under tert-butylhydroperoxide-induced oxidative stress. Single whole-body gamma-irradiation (1 Gy) of rats results in blood plasma and liver microsomal membrane lipid peroxidation, impairments of microsomal membrane structure and function. Rat treatment with G8CG (75 mg/kg) developed the clear protective effect, stabilized membrane structure and improved the parameters of the monooxygenase function. We can conclude that G8CG can be used as antioxidant and radioprotective agent.     

N-Acetylcysteine and Selenium Modulate Oxidative Stress,Antioxidant Vitamin and Cytokine Values in Traumatic Brain Injury-Induced Rats

It has been suggested that oxidative stress plays an important role in the pathophysiology of traumatic brain injury (TBI). N-acetylcysteine (NAC) and selenium (Se) display neuroprotective activities mediated at least in part by their antioxidant and anti-inflammatory properties although there is no report on oxidative stress, antioxidant vitamin, interleukin-1 beta (IL)-1β and IL-4 levels in brain and blood of TBI-induced rats. We investigated effects of NAC and Se administration on physical injury-induced brain toxicity in rats. Thirty-six male Sprague–Dawley rats were equally divided into four groups. First and second groups were used as control and TBI groups, respectively. NAC and Se were administrated to rats constituting third and forth groups at 1, 24, 48 and 72 h after TBI induction, respectively. At the end of 72 h, plasma, erythrocytes and brain cortex samples were taken. TBI resulted in significant increase in brain cortex, erythrocytes and plasma lipid peroxidation, total oxidant status (TOS) in brain cortex, and plasma IL-1β values although brain cortex vitamin A, β-carotene, vitamin C, vitamin E, reduced glutathione (GSH) and total antioxidant status (TAS) values, and plasma vitamin E concentrations, plasma IL-4 level and brain cortex and erythrocyte glutathione peroxidase (GSH-Px) activities decreased by TBI. The lipid peroxidation and IL-1β values were decreased by NAC and Se treatments. Plasma IL-4, brain cortex GSH, TAS, vitamin C and vitamin E values were increased by NAC and Se treatments although the brain cortex vitamin A and erythrocyte GSH-Px values were increased through NAC only. In conclusion, NAC and Se caused protective effects on the TBI-induced oxidative brain injury and interleukin production by inhibiting free radical production, regulation of cytokine-dependent processes and supporting antioxidant redox system.     

In vivo T-lymphocyte activation and transient reduction of viral replication in macaques infected with simian immunodeficiency virus

While it is well established that cellular activation can increase human immunodeficiency virus (HIV) replication in T lymphocytes, it is also clear that both activated CD8+ and CD4+ T lymphocytes mediate anti-HIV activity. To assess the relative importance of these contrary effects on HIV replication in vivo, we evaluated the consequences of Mycobacterium bovis BCG and staphylococcal enterotoxin B (SEB) inoculation in vivo in rhesus monkeys chronically infected with simian immunodeficiency virus of macaques (SIVmac). BCG inoculation induced as much as a 2.5-log reduction of plasma and intracellular SIV RNA in SIVmac-infected monkeys. This down-regulation of virus replication persisted as long as 4 weeks after BCG inoculation. Similarly, SEB injection resulted in up to a 3-log decrease in plasma and intracellular SIV RNA in SIVmac-infected macaques. Interestingly, the short-term reduction of viremia in these monkeys correlated with the peak in vivo production of SEB- and BCG-induced cytokine responses. However, no long-term clinical benefit was observed in the SIVmac-infected macaques. These studies provide in vivo evidence that potent T-cell stimulation driven by antigens other than the virus itself can, under some circumstances, mediate short-term reduction of viremia in AIDS virus-infected individuals.     

Measuring circulating antioxidants in wild birds

Antioxidants protect against free radical damage, which is associated with various age-related pathologies. Antioxidants are also an important buffer against the respiratory burst of the immune system. This protection presumably has costs and therefore might underlie important life-history trade-offs. Studying such trade-offs in a comparative context requires field-applicable methods for assessing antioxidant capacity in wild animals. Here, we present modifications to a simple spectrophotometric assay (the TEAC or TAS assay) that can be applied to miniscule amounts of blood plasma to determine circulating antioxidant capacity. Additionally, uric acid, the most abundant circulating antioxidant, should be measured independently. Uric acid in birds is derived from amino acid catabolism, perhaps incidentally to its antioxidant function. The assay was validated in experimental studies on chickens showing effects of diet on antioxidant capacity, and in field measurements on 92 species of birds, which demonstrate substantial species differences in constitutive antioxidant capacity. Furthermore, most wild birds demonstrate a dramatic change in antioxidant capacity due to stress. These results show that this technique detects variation appropriate for both interspecific and intraspecific studies, and that antioxidants and uric acid change in response to conditions of interest to field ecologists, such as diet and stress.     

Cyclosporine A induced changes to plasma and erythrocyte antioxidant defences

Organ transplant recipients develop pronounced cardiovascular disease, and decreased antioxidant capacity in plasma and erythrocytes is associated with the pathogenesis of this disease. These experiments tested the hypothesis that the immunosuppressant cyclosporine A (CsA) alters erythrocyte redox balance and reduces plasma antioxidant capacity. Female Sprague-Dawley rats were randomly assigned to a control or CsA treated group. Treatment animals received 25 mg/kg/day of CsA via intraperitoneal injection for 18 days. Control rats were injected with the same volume of the vehicle. Three hours after the final CsA injection, rats were exsanguinated and plasma analysed for total antioxidant status (TAS), alpha-tocopherol, malondialdehyde (MDA), and creatinine. Erythrocytes were analysed for superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and glucose-6-phosphate dehydrogenase (G6PD) activities, alpha-tocopherol, and MDA. CsA administration resulted in a significant (P < 0.05) decrease in plasma TAS and significant increases (P < 0.05) in plasma creatinine and MDA. Erythrocyte CAT was significantly (P < 0.05) increased in CsA treated rats compared to controls. There were no significant differences (P > 0.05) in erythrocyte SOD, GPX, G6PD, alpha-tocopherol or MDA between groups. In summary, CsA alters erythrocyte antioxidant defence and decreases plasma total antioxidant capacity.