Hematoprotective effects and antioxidant properties of ß-glucan and vitamin C against acetaminophen-induced toxicity: an experimental study in rats.

Acetaminophen is widely used as an over-the-counter analgesic and antipyretic drug. The aim of the present study was to investigate the pro-oxidative effects of acetaminophen (300 mg/kg/day i.p.) and antioxidative effects of ß-glucan (4 mg/kg/day i.p.) and/or vitamin C (100 mg/kg/day i.p.) on the blood parameters of treated rats. After 3 days of treatment, hematological and parameters of redox status were measured. Exposure of rats to acetaminophen caused significant changes in some hematological parameters and the glutathione redox cycle, leading to an increased concentration of oxidative stress parameters and the formation of lipid peroxidation, while the activities of antioxidant enzymes were decreased. Administration of ß-glucan and/or vitamin C reduced lipid peroxidation and restored the levels of examined hematological and oxidative stress parameters and improved the activities of antioxidant enzymes. Obtained results demonstrated that acetaminophen has significant pro-oxidative effects and may disrupt redox balance in blood of rats, while the combination of ß-glucan and/or vitamin C amplified the antioxidant defense potential and exhibited a strong hematoprotective activity against acetaminophen-induced toxicity. Therefore, ß-glucan and vitamin C co-treatment may be a promising therapeutic option for the treatment of acute acetaminophen hematotoxicity.

Do different diets affect oxidative stress biomarkers and metal bioaccumulation in two snake species?

In this study we examined possible differences in heavy metal accumulation and oxidative stress parameters in the liver and muscle of two semi-aquatic snakes: grass snake (Natrix natrix) and dice snake (N. tessellata), that inhabit the same environment but differ in prey diversity. The obtained results revealed some interspecies, inter-tissue, prey-snake and prey-prey differences in heavy metal concentrations. Grass snakes pray contained significantly higher concentrations of Al, Cr and Fe as compared to food of dice snakes. Both investigated snakes accumulated generally lower concentrations of metals than their prey, indicating that they are not at risk of contaminant biomagnification. A significant interspecies difference in accumulation was observed only for Cu and Mn concentrations. On the other hand, analysis of oxidative stress biomarkers showed clear differences between the investigated snake species and the two investigated tissues. The liver of grass snake had increased superoxide dismutase, glutathione reductase and glutathione-S-transferase activities in comparison to dice snake. In muscle, a reverse trend was observed for the activities of these three enzymes, as well as for glutathione peroxidase activity. The higher number of significant correlations observed between oxidative stress biomarkers and heavy metal concentrations in grass snake points to upregulation of the antioxidative system (AOS), which resulted in a lower TBARS concentration. Results show that while the investigated snake species did not differ significantly in the accumulated metals, their defense mechanisms were different. This reveals the complexity of the AOS and points to the cooperation of different AOS components in individuals from natural populations.

Comparative assessment of the antioxidative defense system in subadult and adult anurans: A lesson from the Bufotes viridis toad.

During their complex life cycle, anurans are faced with various physiological and biochemical demands that can result in increased free radical production. The antioxidative system (AOS), assumes a central role in protection from oxidative stress, and increased knowledge of its response would allow us to identify and quantify underlying costs of free radical production. In this study, we compared the patterns and levels of integration of the AOS during two life stages of Bufotes viridis toads from natural populations: young, fully developed, reproductively inactive subadults and reproductively active adults. All examined parameters (SOD, CAT, GSH-Px, GR, GST, GSH and SH groups) were measured in the liver, skin and muscle. The obtained results showed that: (1) subadult individuals possessed a more integrated AOS (a higher index of integration and number of significant correlations), based mostly on the coordinated action of SOD-CAT; (2) adult individuals used the GSH-Px/GSH system; (3) all examined tissues exhibited similar patterns of variation of AOS parameters; (4) significant correlations between the AOS and biometric parameters. Our results indicate that adult and subadult toads differed in the way they processed free radicals, implying that adults may be more susceptible to oxidative damage. The knowledge from this study will contribute to a better understanding of the AOS and how its activity is modulated in natural populations of anurans throughout their life.

Prooxidant effects of chronic exposure to deltamethrin in green toad Bufotes viridis.

Pesticide-induced oxidative stress, as one of mechanism of toxicity, has been a focus of toxicological research. However, there is a lack of data for certain pesticides-oxidative stress effects especially on terrestrial amphibians. This study evaluates the prooxidative effects of orally administered insecticide deltamethrin (DM) in some tissues of the terrestrial toad Bufotes viridis. Toads were randomly divided and assigned to a control group and a test group that was orally exposed to the pesticide (5 mg/kg of body weight/daily) for 21 days. Animals were euthanized from each group on days 7, 14, and 21, and the liver, leg muscle, ventral skin, and gastrointestinal tissue (GIT) were dissected and used for analysis. From battery of investigated antioxidant components, superoxide dismutase (SOD) was the most differentiate parameter in all examined tissues. For the period of prolonged exposure to pesticide, antioxidative strategy of Bufotes viridis was based on SOD utilization in attempt to maintain the oxidative disbalance at acceptable level. The integrated biomarker response (IBR) as the measure of the overall biochemical response to DM exposure revealed that the group exposed for 21 days had the highest response. Our work has offered valuable data ensuring evidence that toads exposed to deltamethrin developed adaptive reactions that were tissue-specific and that DM-generated systemic toxicity was time-dependent. The present work showed that oxidative stress has significant role in pesticide-induced toxicity and contributes to better understanding of ecotoxicological risk in the terrestrial amphibians exposed to DM.

Oxidative cost of interspecific hybridization: a case study of two Triturus species and their hybrids.

Oxidative stress has most recently been suggested as one of the possible mechanisms responsible for reduced fitness of hybrids. To explore possible oxidative cost of hybridization, we examined anti-oxidant defence system parameters (superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, glutathione reductase, glutathione, SH groups), their interconnectedness (index of integration) and levels of oxidative damage [concentrations of lipid peroxides, TBARS (thiobarbituric acid reactive substances)] in laboratory-reared newt species, Triturus macedonicus and T. ivanbureschi, and their hybrid. Our results showed that parental species differed in anti-oxidant defence system parameters, but not in the levels of integration of the whole system and oxidative damage. Individuals of T. ivanbureschi had higher activities of superoxide dismutase, glutathione S-transferase and concentrations of glutathione. Hybrid individuals of crested newts displayed higher levels of the anti-oxidant defence system (higher superoxide dismutase, catalase, glutathione peroxidase activities and concentrations of SH groups), and a lower overall correlation of anti-oxidant system (lower index of integration) in comparison with both parental species, suggesting that they may possess a less efficient anti-oxidant defence system and a higher investment in maintaining oxidative balance. The higher investment in the anti-oxidant system could divert limited resources away from other functions and affect further hybrid fitness. The presented findings contribute to a better understanding of the anti-oxidant defence system of crested newts and their interspecies differences, and support the hypothesis that oxidative stress is one of the costs of interspecific hybridization.

Role of selenium and vitamin C in mitigating oxidative stress induced by fenitrothion in rat liver.

Excessive use of organophosphate insecticides, including fenitrothion (FNT) can cause detrimental consequences in non-target organisms. Selenium (Se) and vitamin C (Vit C) possess protective abilities against various toxic compounds due to their antioxidative properties. Accordingly, the aim of the present study was to examine the possible ameliorative effects of Se and Vit C in hepatotoxicity induced by FNT. For the purpose of this study, male Wistar albino rats were divided into control and groups treated with Se (0.5 mg/kg b.w, as Na2SeO3) and Vit C (100 mg/kg b.w), FNT (20 mg/kg b.w) and FNT in cotreatment with Se and Vit C for 30 days. The current data showed a reduction in absolute and relative liver weight after FNT administration. Increased activities of liver enzymes (AST, ALT, ALP, LDH and GGT) indicated liver damage. FNT alone caused significant alterations in biochemical parameters (glucose and total bilirubin). Elevation in LPO level along with decreased activities of antioxidant enzymes (SOD, CAT, GSH-Px) and GSH content reflected the presence of oxidative stress. Coadministration of FNT with Se and Vit C exhibited hepatoprotective role confirmed by reduction of oxidative stress levels and restoration in the values of examined parameters. Because of their beneficial effects, Se and Vit C may be used in reducing injuries caused by pesticides.

The ameliorating effects of selenium and vitamin C against fenitrothion-induced blood toxicity in Wistar rats.

Fenitrothion is widely used organophosphate pesticide in agriculture and health programs, but besides, it causes several toxic effects. The present study was designed to evaluate the possible protective effects of selenium (0.5mg/kg b.w.) and vitamin C (100mg/kg b.w) on altered haematological, biochemical and oxidative stress parameters in the blood of rats orally treated with fenitrothion (20mg/kg b.w) for 30days. Fenitrothion caused changes in body weight, food and water intake, and some haematological and biochemical parameters. Fenitrothion altered the glutathione redox status (GSH and GSSG) and decreased activity of antioxidant enzymes (GSH-Px, GST, SOD and CAT), leading to a lipid peroxidation. Selenium and vitamin C, by improving the activity of antioxidants, reduced oxidative stress and a lipid peroxidation, maintaining the values of examined parameters to optimal levels. Therefore, selenium and vitamin C could be useful in providing protection of exposed non-target organisms including people from fenitrothion.

Antioxidative and haematoprotective activity of coenzyme Q10 and vitamin E against cadmium-induced oxidative stress in Wistar rats.

Cadmium (Cd) is a major environmental pollutant, which exerts adverse effects mainly by inducing oxidative stress. Coenzyme Q10 (CoQ10) and vitamin E (VE), naturally occurring antioxidants, improve health condition by inactivating free radicals and enhancing antioxidative defence. The aim of our study was to investigate the protective role of CoQ10 and/or VE pretreatment against Cd-induced haematotoxicity. Wistar albino rats were intramuscularly injected with CoQ10 (20 mg/kg b.w.) and/or VE (20 IU/kg b.w.) or with saline (control group). After 24 h, Cd was injected intraperitoneally (0.4 mg/kg b.w.) and 1 day after, animals were sacrificed. Acute Cd intoxication caused significant changes in haematological and biochemical parameters and altered the glutathione cycle, leading to the formation of lipid peroxidation, while the concentrations and activities of antioxidants (vitamins C and E, superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase) were decreased. CoQ10 and/or VE significantly maintained these values to near-normal levels, afforded additional protection by reducing lipid peroxidation and improved the levels of antioxidants in the blood. Plasma CoQ10 and VE levels negatively correlated with oxidative damage parameters while positively correlated with antioxidative defence parameters. Regarding their effects, CoQ10 and VE were in synergistic interaction. The present study suggested that CoQ10 and VE combination may be beneficial in protecting from Cd-induced haematotoxicity and may be used as a preventive against acute Cd intoxication of exposed people.

Oxidative stress parameters in two Pelophylax esculentus complex frogs during pre- and post-hibernation: Arousal vs heavy metals.

In spring, frogs from temperate regions are faced with arousal-induced oxidative stress and exposure to various xenobiotics from the environment. The question is whether pollutants can significantly modify the antioxidative defense system (AOS) response of hibernators during recovery from hibernation. If this assumption is true, we would then expect different patterns of seasonal variations in the AOS between individuals exposed to different levels of pollution. To examine this assumption, we determined the relationship between seasonal variations of accumulated metals and AOS parameters in the skin and muscle of two frog species from the Pelophylax esculentus complex (P. ridibundus and P. esculentus) inhabiting two localities (the Danube-Tisza-Danube canal and the Ponjavica River) with different levels of pollution during pre- and post-hibernation periods, respectively autumn and spring. Our results showed that even though there were differences in the concentrations of accumulated metals and AOS parameters between localities and species, the frogs displayed almost the same patterns of AOS variations during seasons, with a higher AOS response observed in spring. The parameters SH groups, GSH, GR and SOD had been contributed most rather than others. Our findings indicate that oxidative stress during the post-hibernation period was mainly caused by the organisms' recovery from hibernation, as the result of natural selection acting on the AOS, and that the accumulated metals did not significantly modify the AOS response. The present study provides new insight into the biological and physiological cellular responses of frogs to arousal stress.

Sublethal effects of the pyrethroid insecticide deltamethrin on oxidative stress parameters in green toad (Bufotes viridis L.).

Pyrethroids are synthetic insecticides widely used in agriculture, public health, and veterinary medicine. Deltamethrin, a type II pyrethroid insecticide, has attracted particular attention because of its frequent use. The mechanisms of the toxicity of most pesticides (including pyrethroids) in nontarget organisms is linked to the production of free radicals, oxidative stress induction, increased lipid peroxidation, and disruption of the total antioxidant potential. The aim of the present study was to investigate the effects of acute toxicity of 3 different concentrations (8, 16, and 32 mg/kg body wt) of orally applied deltamethrin after 96 h of treatment. Some of the front-line oxidative stress parameters as well as cholinesterase (ChE) activity and cytochrome P4501A (CYP1A) expression in the liver, muscle, skin, and gastrointestinal tissue of the adult green toad Bufotes viridis were determined. Compared with the control group, the activity of catalase and glutathione reductase was increased in the liver and skin, while the concentration of sulfhydryl groups was reduced. In the liver and muscle, concentrations of thiobarbituric reactive substances were increased, as well as liver CYP1A expression. In the muscle and skin, glutathione-S-transferase activity was higher in treated toads. The oxidative stress parameters examined were affected by different deltamethrin concentrations. We conclude that the assessed parameters represent good biomarkers of pesticide-induced oxidative stress. Environ Toxicol Chem 2017;36:2814-2822. © 2017 SETAC.

Comparative study of oxidative stress parameters and acetylcholinesterase activity in the liver of Pelophylax esculentus complex frogs.

Comparative activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), the phase II biotransformation enzyme glutathione-S-transferase (GST), the concentrations of total glutathione (GSH), sulfhydryl groups (-SH) and the activity of the neurotoxicity biomarker acetylcholinesterase (AChE) were investigated in the livers of species belonging to the Pelophylax esculentus "complex" (parental species Pelophylax ridibundus, Pelophylax lessonae, and their hybrid Pelophylax kl. esculentus) from the wetland, Obedska bara in Serbia. The condition factor (CF) and hepato somatic index (HSI) were also calculated. All three species were caught at same locality and were exposed to the same environmental conditions. Liver SOD activity was lower in P. ridibundus than in P. kl. esculentus and P. lessonae; higher activities of CAT, GR and GST were observed in P. kl. esculentus frogs as compared to their parental species. The activity of GSH-Px was significantly lower in P. kl. esculentus. The activity of AChE was increased in P. lessonae as compared to P. kl. esculentus and P. ridibundus. Similar concentrations of GSH and -SH groups were observed in all investigated species. P. kl. esculentus had a higher CF, while the HSI was lower when compared to the parental species. Our findings suggest that the parental species (P. ridibundus and P. lessonae) possess more similar antioxidative responses to environmental conditions than the hybrid species P. kl. esculentus. The obtained results improve our understanding of the biology and physiology of these three closely related species.

Oxidative stress biomarkers, cholinesterase activity and biotransformation enzymes in the liver of dice snake (Natrix tessellata Laurenti) during pre-hibernation and post-hibernation: A possible correlation with heavy metals in the environment.

We investigated in the liver of dice snakes during pre- and post-hibernation changes in the following antioxidant parameters: total, manganese and copper zinc containing superoxide dismutases (Tot SOD, MnSOD, CuZn SOD, respectively), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and the concentrations of total glutathione (GSH) and sulfhydryl groups (-SH). In addition, we examined the expression of phase I biotransformation enzyme cytochrome P4501A (CYP1A) and the activity of phase II biotransformation enzyme glutathioneS-transferase (GST), the level of lipid peroxidation (by measuring the thiobarbituric acid-reactive substances (TBARS)), cholinesterase activity (ChE) and metallothionein expression (MT). We also measured the concentrations of heavy metals, including Al, Cd, As, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb and Zn in the water and snake liver during both periods. During the post-hibernation period, the activities of Tot SOD, CuZn SOD and GST and the concentration of GSH were significantly decreased, while GSH-Px and GR activities, the concentrations of -SH groups and TBARS were significantly increased. The activities of Mn SOD, CAT and ChE, and the relative amounts of CYP1A and MT did not significantly change during the investigated periods. The observed differences in the examined parameters probably represent adaptive physiological responses to sudden changes in tissue oxygenation during arousal from hibernation. Our findings also indicate that the accumulated metals modulated the responses of the examined parameters during the investigated periods.

Protective effects of quercetin and vitamin C against nicotine-induced toxicity in the blood of Wistar rats.

Nicotine is a potential inducer of oxidative stress, through which it can damage numerous biological molecules. The aim of our study was to investigate the prooxidative effects of nicotine and protective (additive or synergistic) effects of quercetin and vitamin C in the blood of experimental animals, to determine whether the combination of these antioxidants might be beneficial for clinical purposes. Wistar albino rats were receiving intraperitoneal nicotine injection (0.75 mg kg-1 per day) or saline (control group) or nicotine plus quercetin (40 mg kg-1 per day) and vitamin C (100 mg kg-1 per day) for three consecutive days. On day 4, we determined their blood lipid profile, liver enzymes, oxidative stress parameters, and antioxidative system parameters. Compared to untreated control, nicotine significantly increased total cholesterol, LDLcholesterol, triglycerides, liver enzymes (alanine transaminase, aspartate transaminase, and lactate dehydrogenase) and oxidative stress parameters (superoxide anion, hydrogen peroxide, and lipid peroxide) and decreased HDL-cholesterol, glutathione, and superoxide dismutase/catalase activity. Quercetin + vitamin C reversed these values significantly compared to the nicotine alone group. Our results confirm that nicotine has significant prooxidative effects that may disrupt the redox balance and show that the quercetin + vitamin C combination supports antioxidant defence mechanisms with strong haematoprotective activity against nicotine-induced toxicity. In practical terms, this means that a diet rich in vitamin C and quercetin could prevent nicotine-induced toxicity and could also be useful in the supportive care of people exposed to nicotine.

Bioaccumulation and effects of metals on oxidative stress and neurotoxicity parameters in the frogs from the Pelophylax esculentus complex.

Metals are involved in the formation of reactive oxygen species and can induce oxidative stress. The aim of this study was to assess the effects of several metals on oxidative stress in the skin and muscle of the Pelophylax esculentus "complex" frogs (parental species Pelophylax ridibundus, Pelophylax lessonae, and their hybrid Pelophylax esculentus) that inhabit the wetland Obedska Bara in Serbia, and the potential use of these species as bioindicator organisms in biomonitoring studies. The biomarkers of oxidative stress (SOD, CAT, GSH-Px, GR, GST activities and GSH, SH concentrations) and cholinesterase activity were investigated. The concentrations of nine metals (Fe, Cu, Zn, As, Cd, Cr, Hg, Ni, and Pb) were measured in the water and tissues. Correlations were established between metals and biomarkers in the tissues. The results of metal accumulation distinguished the skin of P. lessonae and muscle of P. ridibundus from other P. esculentus complex species. The oxidative stress biomarkers observed in P. ridibundus and P. esculentus had greater similarity than in P. lessonae. The P. lessonae displayed the highest number of correlations between biomarkers and metals. The results of tissue responses revealed that skin was more susceptible to metal-induced oxidative stress, with only exception of As. In the light of these findings, we can suggest the use of P. esculentus complex species as a biomonitoring species in studies of metal accumulation and metal-induced oxidative stress, but with special emphasis on P. lessonae.

Biomarkers of oxidative stress and metal accumulation in marsh frog (Pelophylax ridibundus).

To understand the effect of metals on the marsh frog Pelophylax ridibundus and the possible environment-induced changes in oxidative stress enzymes, we determined the concentrations of 18 metals: Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Ga, Hg, In, Li, Mn, Ni, Pb, Sr, and Zn, in the tissues (liver, skin, and muscle) and water samples collected from different locations in Serbia. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), glutathione S-transferase (GST), acetylcholinesterase (AChE), and changes in concentrations of reduced glutathione (GSH) and sulfhydryl groups (SH) were analyzed in the tissues of the sampled frogs. The concentrations of Al, Cd, Co, Cr, Cu, Fe, Ga, Hg, and Ni were highest in the liver, whereas those of Ba, Ca, Li, Mn, Pb, Sr, and Zn were highest in the skin. Hg correlated positively with liver SOD (in frogs from Danube-Tisza-Danube Canal (DTD)), muscle CAT (DTD), and muscle GST Ponjavica River (PO); Pb demonstrated a strong positive correlation with liver GR in frogs from Mt. Fruska Gora (FG); Cd only exhibited a positive correlation with AChE in the skin of frogs from DTD. In the skin, Zn correlated positively with AChE (DTD), SH groups (PO), and CAT (FG), and negatively with CAT, GST, and SH in the liver of frogs from DTD. Examination of these oxidative stress biomarkers, together with analysis of metal accumulation in the liver and skin of marsh frogs, provides a powerful tool for the assessment of metal pollution.

Antioxidative responses of the tissues of two wild populations of Pelophylax kl. esculentus frogs to heavy metal pollution.

Heavy metal pollution of the aquatic environment is of great concern worldwide. Heavy metals are capable of inducing oxidative stress by increasing the formation of reactive oxygen species (ROS), and directly affecting the antioxidant defense system (AOS) in living organisms. The frog Pelophylax kl. esculentus is a semiaquatic species with semipermeable skin and a complex lifecycle, and represents a potentially useful bioindicator organism. The aim of this study was to investigate the accumulation of several heavy metals (Cd, Co, Cr, Cu, Fe, Hg, Ni, Pb and Zn), and their effects on selected parameters of the AOS, including the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), phase II biotransformation enzyme glutathione-S-transferase (GST), the total glutathione (GSH) contents and sulfhydryl (SH) group concentrations, as well as cholinesterases (ChEs) activities in the liver, skin and muscle of P. kl. esculentus. Frog samples were collected at two sites (the Danube-Tisza-Danube canal (DTDC) and the river Ponjavica) in Serbia, which are characterized by different levels of metal pollution. Differences between the metal contents in different tissues showed that the skin of frogs from the DTDC accumulated statistically higher concentrations of Cd, Cu, Pb and Zn, while only the Fe concentration was lower. No significant differences between metal concentrations in muscle tissues of frogs from the DTDC and Ponjavica were observed. Examination of the parameters of the AOS revealed that frogs from the DTDC had higher concentrations of GSH in the liver and of SH groups in the skin and muscle, whereas the activities of the antioxidative enzymes SOD, GHS-Px and GR in the liver and of GR in the skin were lower than in frogs from the Ponjavica. The relationship between metal concentrations and AOS parameters showed the highest number of correlations with GSH, GR and CAT, and with Ni, Zn, Hg, Cr and Cd. Based on the results in this study, we concluded that increased concentrations of heavy metals in frog tissues can alter the AOS, which leads to higher concentrations of GSH and SH groups and lower activities of antioxidative enzymes. The response of the AOS to metal pollutants allowed us to make a distinction between different frog tissues, and to conclude that the liver and skin are more suitable for assessing metal-induced oxidative stress in frogs than muscle.

Antioxidative enzymes in irradiated rat brain-indicators of different regional radiosensitivity.

PURPOSE: Previously, we examined manganese superoxide dismutase (MnSOD), copper-zinc superoxide dismutase (CuZnSOD), and catalase (CAT) activities in rat brain irradiated with 2 or 3 Gy of γ-rays. The results indicated that lower MnSOD activity and inducibility found in hippocampus might explain higher radiosensitivity of this brain region. Thus, in this study, we wanted to determine changes of MnSOD, CuZnSOD, and CAT activities after dose of 5 Gy and to find out if differences in MnSOD activity are caused by changes in its expression. METHODS: Heads of 4-day-old female rats were irradiated with γ-rays, using (60)Co. Animals were sacrificed 1/24 h after exposure. Hippocampus and cortex tissues were prepared for enzyme activity measurements and Western blot analysis. RESULTS: One hour after exposure, γ-rays significantly decreased MnSOD activity in both examined brain regions. Twenty-four hours later, MnSOD recovery showed dose and regional dependence. It was weaker at higher doses and in hippocampal region. MnSOD expression changed in the similar manner as MnSOD activity only at lower doses of γ-rays. In both examined brain regions, gamma radiation significantly decreased CuZnSOD activity and did not change activity of CAT. CONCLUSIONS: Our results confirmed that MnSOD plays an important role in different regional radiosensitivity but also showed that depending on dose, radiation affects MnSOD level by utterly different mechanisms. Postradiation changes of CuZnSOD and CAT are not regionally specific and therefore, cannot account for the different radiosensitivity of the hippocampus and cortex.

Prooxidative effects of aspartame on antioxidant defense status in erythrocytes of rats.

Since aspartame (L-aspartyl-L-phenylalanine methyl ester, ASP) is one of the most widely used artificial sweeteners, the aim of the present study was to investigate its effects on serum glucose and lipid levels as well as its effects on oxidative/antioxidative status in erythrocytes of rats. The experiment included two groups of animals: the control group was administered with water only, while the experimental group was orally administered with ASP (40 mg/kg b.w.) daily, for a period of six weeks. When compared with the control group, the group administrated with ASP indicated higher values of serum glucose, cholesterol and triglycerides. Significantly increased concentrations of superoxide anion (O2 .-), hydrogen peroxide (H2O2), peroxynitrite (?N??-) and lipid peroxides (LPO) were recorded in the erythrocytes of ASP treated group in comparison to the control group. In the course of chronic ASP administration, the following was observed: the concentration of reduced glutathione (GSH) and the activity of catalase (CAT) increased. Thus, these findings suggest that long-term consumption of ASP leads to hyperglycemia and hyperlipidemia, as well as to oxidative stress in erythrocytes.

Protective effects of oestradiol against cadmium-induced changes in blood parameters and oxidative damage in rats.

The aim of this study was to investigate the protective effects of oestradiol (E2, 4 mg kg-1 b.w. i.p.) against cadmium-induced (Cd, 2 mg kg-1 b.w. i.p.) blood changes in rats. Cadmium induced a significant decline in haemoglobin, haematocrit, and total erythrocyte, lymphocyte, and thrombocyte count, whereas total leukocytes and granulocytes increased. A significant increase was also observed in serum cholesterol, triglycerides, glucose, AST, and ALT activities, whereas total protein and albumin levels dropped significantly. Administration of E2 in combination with Cd alleviated most of these adverse effects. In terms of oxidative stress, Cd significantly increased oxygen-free radicals (O2 •- and H2O2) in neutrophils and lipid peroxidation in erythrocytes, whereas E2 treatment reversed these changes to control values. Acute Cd poisoning significantly lowered antioxidant enzyme (SOD and CAT) activity and the level of non-enzymatic antioxidants (GSH and vitamin E), while increasing in GSSG. Treatments with E2 reversed Cd-induced effects on the antioxidant defences and significantly lowered Cd-induced oxidative damage in erythrocytes. This study suggests that exogenous E2 effectively restores redox balance in rat erythrocytes and counters adverse haematological and biochemical effects of Cd poisoning. It also improves the antioxidant capacity of erythrocytes, acting in synergy with endogenous antioxidants.

Lipid peroxidative damage on Cisplatin exposure and alterations in antioxidant defense system in rat kidneys: a possible protective effect of selenium.

Cisplatin (Cis-diamminedichloroplatinum II, CP) is an important chemotherapeutic agent, useful in the treatment of several cancers, but with several side effects such as nephrotoxicity. The present study investigated the possible protective effect of selenium (Se) against CP-induced oxidative stress in the rat kidneys. Male Wistar albino rats were injected with a single dose of cisplatin (7 mg CP/kg b.m., i.p.) and selenium (6 mg Se/kg b.m, as Na(2)SeO(3), i.p.), alone or in combination. The obtained results showed that CP increased lipid peroxidation (LPO) and decreased reduced glutathione (GSH) concentrations, suggesting the CP-induced oxidative stress, while Se treatment reversed this change to control values. Acute intoxication of rats with CP was followed by statistically significant decreased activity of antioxidant defense enzymes: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and glutathione-S-transferase (GST). Treatment with Se reversed CP-induced alterations of antioxidant defense enzyme activities and significantly prevented the CP-induced kidney damage.