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.

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.

Biotransformation and nitroglycerin-induced effects on antioxidative defense system in rat erythrocytes and reticulocytes.

The effects of nitroglycerin (glyceryl trinitrate - GTN) are mediated by liberated nitric oxide (NO) and formed reactive nitrogen species, which induces oxidative stress during biotransformation in red blood cells (RBCs). The aim of this study was to evaluate effects of GTN on antioxidative defense system (AOS) in rat erythrocytes (without) and reticulocytes (with functional mitochondria). Rat erythrocyte and reticulocyte-rich RBC suspensions were aerobically incubated (2 h, 37°C) without (control) or in the presence of different concentrations of GTN (0.1-1.5 mM). After incubation, concentrations of non-enzymatic components of AOS, activities of antioxidative enzymes and oxidative pentose phosphate (OPP) pathway activity were followed in RBC suspensions. In rat reticulocytes, GTN decreased the activity of mitochondrial MnSOD and increased the activity of CuZnSOD. In rat RBCs, GTN induced increase of Vit E concentration (at high doses), but decreased glutathione content and activities of all glutathione-dependent antioxidative enzymes; the OPP pathway activity significantly increased. GTN biotransformation and induction of oxidative stress were followed by general disbalance of antioxidative capacities in both kinds of RBCs. We suggest that oxidative stress, MnSOD inhibition and depletion of glutathione pool in response to GTN treatment lead to decreased bioavailability of NO after GTN biotransformation in rat reticulocytes.

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.

Effects of acute in vivo cisplatin and selenium treatment on hematological and oxidative stress parameters in red blood cells of rats.

Although cisplatin (cisPt) is one of the most often used cytotoxic drugs in the treatment of cancer, its clinical application is associated with nephrotoxicity and a cumulative anemia. In this study, we evaluated posible protective effects of selenium (Se) on hematological and oxidative stress parameters in rats, acutely treated with cisPt. Four groups of Wistar albino rats included control rats, cisPt-treated (7.5 mg/kg of body weight of cisPt, i.p.), Se-treated (6 mg/kg of body weight of Na(2)SeO(4), i.p.), and Se and cisPt co-treated rats. The rats were killed 72 h after treatment; hematological and oxidative stress parameters were followed in red blood cells. The results showed depletion in platelet number induced by high acute doses of cisPt and strong utilization of reduced glutathione, resulting in elevation of GSSG/2 GSH ratio. Se treatment was followed by stimulated erythropoiesis, increased lipid peroxidation, and GSH depletion. Se and cisPt co-treatment were followed by stimulated erythropoiesis and significant recovery of reduced glutathione status when compared with cisPt-treated rats. In conclusion, acute doses of Se and cisPt primarily act as pro-oxidants. CisPt influenced antioxidative properties of exogenous Se and their synergistic effects may partially participate in protection against cisPt-induced toxicity.

Cadmium-induced lipid peroxidation and changes in antioxidant defense system in the rat testes: protective role of coenzyme Q(10) and vitamin E.

The aim of this study was to investigate the protective role of coenzyme Q(10) (CoQ(10), 20mg/kg) and Vitamin E (Vit E, 20 IU/kg) alone or in combination against cadmium (Cd, 0.4 mg/kg) induced lipid peroxidation and changes in antioxidant defense system in the rat testes. The obtained results showed that Cd increased lipid peroxidation in the testes, suggesting that Cd-induced oxidative stress, while CoQ(10) and Vit E treatment reversed this change to control values. Acute intoxication with Cd was followed by significantly decreased activity of antioxidant enzymes (SOD, CAT, GSH-Px, GR and GST). Vitamins C and E concentrations also significantly declined in Cd-exposed rat testes. Treatment with CoQ(10) and Vit E reversed Cd-induced alterations of antioxidant defense system and significantly prevented Cd-induced testes damage. These results suggest that both CoQ(10) and Vit E function as a potent antioxidant in protection of rats testes against the oxidative stress induced by Cd.

The antioxidative effect of estradiol therapy on erythrocytes in women with preeclampsia.

In the present study, we evaluated changes of both oxidative stress marker concentrations in erythrocytes and values of blood pressure, as well as their relation during short-term estradiol therapy in preeclampsia. Serum estradiol concentrations were also recorded. The results of this study showed significant decrease of mean arterial pressure (MAP) values during estradiol therapy, whereas there was no significant change in serum estradiol concentrations. Decreased concentrations of superoxide anion (O(2)(-)), hydrogen peroxide (H(2)O(2)), nitrite (NO(2)(-)), peroxynitrite (ONOO(-)) and lipid peroxide (LPO) were found during estradiol therapy in erythrocytes. No changes were found in the activity of gluthatione-S-transferase (GST). The decrease of MAP values was positively correlated with the reduction of concentrations of O(2)(-), H(2)O(2), NO(2)(-) and ONOO(-) in erythrocytes during estradiol therapy. The obtained results suggest that short-term intramuscular administration of estradiol shows antioxidative effects in erythrocytes and reduces blood pressure in preeclampsia.

Oxidative stress and changes in antioxidative defense system in erythrocytes of preeclampsia in women.

The present study was designed to investigate whether oxidative stress occurred to erythrocytes in preeclampsia and was related to disease. Indicative markers of oxidative stress and changes in antioxidant defense system were assayed in the erythrocytes of 22 healthy pregnant and 20 women with preeclampsia. Results of our work indicated high concentration of hydrogen peroxide, nitrite, peroxynitrite and lipid peroxides in preeclampsia compared to healthy pregnant women. Concentration of superoxide anion was lower in preeclamptic women. There were no differences in concentrations of vitamin E, reduced glutathione and oxidized glutathione. Activity of glutathione-S-transferase (GST) was higher while activities of superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) were lower in preeclamptic women. There were no differences in glutathione peroxidase (GSH-Px) activity between the two investigated groups. These results suggest that preeclampsia was characterized by oxidative stress and alteration of antioxidative defense system by disbalance in oxidative/antioxidative status of erythrocytes.

Antioxidant defence enzyme activities in hepatopancreas, gills and muscle of Spiny cheek crayfish (Orconectes limosus) from the River Danube.

The aim of our study was to determine the activity of antioxidant defence (AD) enzymes: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and the phase II biotransformation enzyme glutathione-S-transferase (GST) in the hepatopancreas, the gills and muscle of Spiny cheek crayfish (Orconectes limosus) from the River Danube and to compare tissue specificities of investigated enzymes. Our results indicated that both specific and total SOD activities in the hepatopancreas were lower compared to the gills and muscle. Total SOD activity in the gills was lower with respect to that in muscle. CAT and GSH-Px (both specific and total) activities were higher in the hepatopancreas compared to those in the gills and muscle. In the gills the specific and total GR activities were higher than in the hepatopancreas and muscle. The specific and total GST activities were higher in the hepatopancreas compared with the gills and muscle. Our study represents the first comprehensive report of AD enzymes in tissues of O. limosus caught in the River Danube. The noted tissue distributions of the investigated AD enzyme activities most likely reflected different metabolic activities and different responses to environmental conditions in the examined tissues.

A comparative study of the effects of molsidomine and 3-morpholinosydnonimine on the redox status of rat erythrocytes and reticulocytes.

After enzymic biotransformation, molsidomine (MO) acts via the metabolite 3-morpholinosydnonimine (SIN-1) through spontaneous liberation of nitric oxide (NO) and superoxide (O(2)(.-)). The aim of this study was to compare the effects of MO and its active metabolite SIN-1 on the redox status of rat erythrocytes and reticulocytes. Rat erythrocyte as well as reticulocyte-rich red blood cell (RBC) suspensions were aerobically incubated (2 h, 37 degrees C) without (control) or in the presence of different concentrations of MO or SIN-1. In rat erythrocytes, biotransformation of MO resulted in the production of NO and nitroxyl (NO(-)). Endogenous superoxide anion (O(2)(.-)) participated in peroxynitrite generation. SIN-1 simultaneously liberated NO and O(2)(.-), which formed peroxynitrite (at least in part), but the liberated NO predominantly reacted with haemoglobin, forming methaemoglobin in erythrocytes. In reticulocytes, MO and SIN-1 caused an increase in the levels of both nitrite and 3-nitrotyrosine (an indicator of peroxynitrite), whereas they decreased the level of O(2)(.-). In reticulocytes, MO was metabolized into SIN-1 which led to the generation of NO, which reacted with O(2)(.-) (endogenous or exogenous) forming reactive nitrogen species. In conclusion, there are two metabolic pathways for MO biotransformation: one causing NO and NO(-) generation predominantly in erythrocytes and the other, via SIN-1 metabolism, in reticulocytes. The main difference between the action of MO and SIN-1 was that the latter caused oxidative damage in RBCs.

Combined effects of coenzyme Q(10) and Vitamin E in cadmium induced alterations of antioxidant defense system in the rat heart.

Our study investigated the possible protective effects of coenzyme Q(10) (CoQ(10)) and Vitamin E (Vit E) alone or in combination against cadmium (Cd) induced alterations of antioxidant defense system in the rat heart. Male Wistar rats were injected with a single dose of CdCl(2) (0.4mg Cd/kg BW i.p.), CoQ(10) (20mg CoQ(10)/kg BW i.m.) and Vit E (20IU Vit E/kg BW i.m.), alone or in combination. Acute intoxication of rats with Cd were followed by significantly increased activity of antioxidant defense enzymes (CuZn SOD, GSH-Px, GST and GR), while the activity of Mn SOD was decreased in the heart. The treatment with Cd significantly decreased Vit C and Vit E concentrations. Treatment with CoQ(10) and Vit E reversed Cd-induced alterations of antioxidant defense system. The obtained results support the assumption that CoQ(10) and Vit E functions cooperatively with endogenous antioxidants and diminished toxic effects of Cd in rat heart.

[Effects of molsidomine on changes in oxidant/antioxidant status of rat erythrocytes]. / Promene oksidaciono-antioksidacionog statusa eritrocita pacova u prisustvu molsidomina.

INTRODUCTION: Molsidomine (MO) is an established drug in treatment of coronary heart disease. Considering that MO is a donor of nitric oxide (NO) and a superoxide anion radical (O2*-), which forms peroxynitrite, a very toxic radical, the aim of this study was further elucidation of molecular mechanisms of MO action, particularly effects on prooxidative-antioxidative status of rat erythrocytes. MATERIAL AND METHODS: Rat (Wistar albino, male, 250-300 g of b.m.) erythrocyte suspensions were aerobically incubated (120 min, 37 degrees C) without (control) or with MO (0.1, 0.25, 0.5, 1.0 and 1.5 mM). Concentrations of reactive oxygen species, methemoglobin, Heinz bodies, lipid peroxides, vitamins and glutathione, as well as activities of enzymes of the antioxidative defense system (AOS) were evaluated using standard techniques. RESULTS AND DISCUSSION: Molsidomine increases nitrite concentrations (indicating NO+ level), hydroxylamine (indicating NO- level), 3-nitro-tyrosine (indicating ONOO- level) and H2O2, but decreases O2*- level in a dose-dependent manner (changes are statistically significant only with high doses of molsidomine--1.0 and 1.5 mM). These alterations were followed by partial cells damage, increased formation of Heinz bodies, but there were no changes in MetHb and lipid peroxide levels. The defense response of erythrocytes to evident oxidative stress includes increased Vitamin E and Vitamin C concentrations (nonenzymatic components ofAOS), as well as decreased glutathione (reduced and oxidized) levels. Activities ofAOS enzymes remain unchanged. CONCLUSION: Experimental doses of MO induce oxidative stress in rat erythrocytes. However, the first line of AOS is successful in the cellular defence response.