Combined supplementation of folic acid and vitamin E diminishes diabetes-induced embryotoxicity in rats

BACKGROUND: Oxidative stress and enhanced apoptosis may be involved in the induction of embryonic dysmorphogenesis in diabetic pregnancy. Administration of folic acid or vitamin E diminishes embryonic dysmorphogenesis. We aimed to evaluate the effect of combined treatment with folic acid and vitamin E on the disturbed development in embryos of diabetic rats. METHODS: Pregnant nondiabetic and diabetic rats were treated with daily injections of 15 mg/kg folic acid or with 5% vitamin E in the diet. A third group received combined treatment. Day 10 and day 11 embryos were evaluated for development and apoptotic profile. RESULTS: We found increased malformations, resorptions, and profound growth retardation in embryos of diabetic rats compared to control embryos. Vitamin E or folic acid alone, or the 2 compounds combined, normalized embryonic demise. Maternal diabetes caused decreased nuclear factor-kappaB (NF-kappaB) activity and B-cell lymphoma 2 (Bcl-2) protein level, and increased Bcl-2-associated x proteins (Bax) in embryos. Supplementation of vitamin E alone normalized the Bax protein level in a diabetic environment. Administration of folic acid to diabetic rats increased NF-kappaB activity and Bcl-2 protein level. Combined treatment normalized Bcl-2 and Bax protein level in a diabetic environment. CONCLUSIONS: Combined supplementation of folic acid and vitamin E to pregnant diabetic rats diminished diabetes-induced malformations and resorptions, concomitant with normalization of apoptotic protein levels. No treatment completely abolished the embryonic demise; therefore, other mechanisms than oxidative stress and apoptosis are likely to be involved in diabetic embryopathy.     

Enhanced testicular antioxidant capacity in streptozotocin-induced diabetic rats

Diabetes mellitus is associated with diabetic impairment of testicular function, ultimately leading to reduced fertility. Its etiology may involve oxidative damage by reactive oxygen substances, and protection against this damage can be offered by antioxidant supplementation. The aim of this study was to investigate the effects of intraperitoneal administration of vitamin C and E, selenium (Se), and vitamin E plus Se (COM) on concentrations of lipid peroxide (as malondialdehyde; MDA), reduced glutathione (GSH), and vitamin E concentrations and glutathione peroxidase (GSH-Px) activity in the testes of rats with diabetes induced by streptozotocin (STZ). Sixty groups were used (10 animals each) and these animals were initially allocated to two groups: control group and diabetic group. The diabetic group was subdivided into five groups as follows: diabetic control (DC), vitamin E, Se, COM, and vitamin C. Animals in the DC group and vitamin C, vitamin E, Se, and COM groups were made diabetic by the injection of STZ on 4 d after an injection of vitamins C and E, Se, and COM. Those vitamins and Se were also administered for 21 consecutive days. The MDA, vitamin E, GSH levels, and GSH-Px activities in testes were determined. Although the vitamin E concentration was higher in the control than in the DC group, the MDA levels were found to be lower in the control than in the DC group. The MDA levels in the testes samples of vitamin C, vitamin E, Se, and COM groups were lower than the DC group. However, GSH-Px activity and GSH levels in the testes were not significantly different between the control and DC groups. Vitamin E concentrations in the vitamin C, vitamin E, Se, and COM groups and GSH levels and GSH-Px activities in the Se, COM, and vitamin C groups were higher than either the control or DC group. The results indicate that reactive oxygen substances may be involved in possible testicular complications in diabetes of rats. Administration of vitamins C and E and Se reduced the testicular lipid peroxidation; these vitamins and Se had significant protective effects on testes of rats against oxidative damage in diabetes. Abstract of the study was presented at the conference Trace Elements in Men and Animals-11. June 2–6, 2002; Dr. Naziroğlu has been awarded a TEMA11 Investigative Scientist Award.     

Effect of cadmium on antioxidant status in alloxane-induced diabetic rats

Fifty-two healthy Swiss Male Albino rats aged two mo were used in this study. They were divided into four groups: control (C), diabetic (D), cadmium (Cd), and diabetic+Cd (D+Cd) groups. Diabetic condition was induced in D and D+Cd groups by administration of alloxane (5 mg/100 g). After this treatment, CD and D+Cd groups were injected with CdCl₂ ip (2 mg/kg/wk). At the end of the 2-mo experimental period, thiobarbituric acid reactive substances (TBARS), plasma and erythrocyte selenium (SE), plasma ceruloplasmin (Cp), and vitamin E (vit E) were determined in four groups of rats. The erythrocyte Se was lower in the experimental groups than in the controls. Plasma Se was significantly decreased in the D and D+Cd groups compared with the control group. Plasma Cp was unaltered. Plasma vit E was significantly decreased in Cd group in comparison with the C, D, and D+Cd groups.     

Influence of vitamin E on the levels of fatty acids and MDA in some tissues of diabetic rats

This study was performed to determine whether vitamin E supplementation in streptozotocin-induced diabetic rats treated with insulin could affect the levels of fatty acid composition and malondialdehyde (MDA) of brain, liver and muscle tissues. Thirty Wistar albino rats were used during the experiments. They were randomly divided into three groups, each consisting of six individuals. The first group was diabetic, the second was control, and the third was diabetic but fed vitamin E. The level of stearic acid in brain tissues decreased (p<0.05) in the second and the third groups as compared to the first group. The percentage of arachidonic and polyunsaturated fatty acids slightly decreased (p<0.05) in the diabetic group in comparison to the second and third groups. The proportion of docosahexaenoic acid significantly increased (p<0.01) in the second and third groups in contrast to the first group. The level of docosatrienoic was slightly higher (p<0.05) in the third group than in other groups. In the liver tissues, the proportion of stearic, oleic and total monounsaturated fatty acids was slightly higher (p<0.05) in the first group than in the other groups. The level of arachidonic, docosahexaenoic, unsaturated and total polyunsaturated fatty acid slightly increased (p<0.05) in the second and third groups as compared to the first group. The level of myristic and stearic acids in muscle tissue slightly increased (p<0.05) in the first group as compared to the second and third groups. The proportion of arachidonic, docosahexaenoic and unsaturated fatty acids slightly increased (p<0.05) in the second and third groups relative to the first group. The amount of MDA was slightly higher in the diabetic group than in the other groups in all tissues. The results indicate that vitamin E supplementation, in experimental diabetes could play a role in controlling the oxidative status and altered fatty acid metabolism in tissues, thereby maintaining favourable fatty acid distribution in the tissues affected by diabetic complications.     

Protective role of intraperitoneally administered vitamins C and E and selenium on the levels of lipid peroxidation in the lens of rats made diabetic with streptozotocin

The aim of this work was to determine the protective effects of intraperitoneally administered vitamins C and E and selenium on the lipid peroxidation (MDA), glutathione peroxidase (GSH-Px), reduced glutathione (rGSH) activities in the lens of rats induced diabetic with streptozotocin (STZ). Lenses in the diabetic control group had a slightly higher mean level of MDA compared with lenses of the vitamin E and selenium groups, although the mean levels of MDA were significantly lower in control, combination, and vitamin C groups than in the diabetic control group (p < 0.05 andp < 0.01). However, MDA levels were significantly lower in vitamin C, vitamin E, and combination groups than in controls (p < 0.01). The GSH-Px activities of lenses were significantly higher in vitamin C-, vitamin E- and selenium-injected groups than that in the diabetic control group (p < 0.01), whereas, the activity of GSH-Px was significantly lower in the diabetic control group than in the control group. In addition, the rGSH content was seen to decrease only in the vitamin C group compared to both control and diabetic control groups (p < 0.05). In conclusion, the results from these experiments indicate that vitamins C and E and selenium can protect the lens against oxidative damage, but the effect of vitamin C appears to be much greater than that of vitamin E and selenium.     

Beneficial effect of vitamin E on the metabolic parameters of diabetic rats

The role of vitamin E in the pathogenesis of diabetes mellitus is unknown. The purpose of this study was to examine the effect of oral administration of vitamin E on some of the metabolic parameters of experimental diabetic rats. Diabetes was induced by intraperitoneal injection of streptozotocin (60 mg/kg body weight at 12 weeks of age). Vitamin E (0.2, 0.4, 0.8 mg/kg body weight) was administered orally for a period of 3 weeks to normal and diabetic Wistar rats. In some experiments, Vitamin E was given either before or after the induction of diabetes mellitus. Blood glucose level and weight were recorded for each rat in different groups on a weekly basis. Oral glucose tolerance test (OGTT) was performed on fasted normal, diabetic and vitamin E treated rats at the end of the experiment. Vitamin E significantly (p < 0.01) reduced blood glucose levels in experimental diabetes mellitus at all doses as compared to untreated rats. Vitamin E induced weight loss in normal as well as in diabetic rats. The beneficial effect of vitamin E on the hyperglycaemia of diabetic rats was dose-dependent. Moreover, vitamin E also improved OGTT in diabetic rats compared to untreated diabetics. In conclusion, vitamin E may play a role in glucose metabolism and thus be a useful adjuvant therapy in type I diabetes. (Mol Cell Biochem 261: 35–42, 2004)     

Radical Exchange Reactions between Vitamin E, Vitamin C and Phospholipids in Autoxidizing Polyunsaturated Lipids

Antioxidant reactions of mixtures of vitamin E, vitamin C and phospholipids in autoxidizing lipids at 90°C have been studied by ESR spectroscopy. When the phospholipid contained a tertiary amine (e.g. phosphatidylcholine), the vitamin C and the vitamin E radicals were successively observed as these two vitamins were sequentially oxidised during lipid oxidation. In the presence of the primary amine contained in phosphatidylserine, the vitamin E oxidation was delayed for a few hours. In this case neither the vitamin C, nor the vitamin E radicals but a nitroxide radical derived from the phospholipid was observed. Similar results to those obtained with PS were obtained in the presence of either phospha-tidylethanolamine or soybean lecithin. The participation in the radical reactions of phospholipids possessing a primary amine can therefore explain the synergistic effect of these phospholipids in a mixture of vitamins E and C.     

Dietary vitamin C and E modulates oxidative stress induced-kidney and lens injury in diabetic aged male rats through modulating glucose homeostasis and antioxidant systems

Diabetes induces oxidative stress in aged human and rat, although daily supplementation of vitamins C and E (VCE) can be beneficial to aged diabetic rats by reducing free radical production. The aim of the present study was to evaluate whether dietary VCE supplementation relieves oxidative stress in streptozotocin (STZ)-induced diabetic in aged rats. Thirty aged rats were randomly divided into three groups. The first group was used as a control. The second group was made diabetic using a single dose of intraperitoneal STZ. VCE-supplemented feed was given to aged diabetic rats constituting the third group. On the 21st day of the experiment, blood, lens and kidney samples were taken from all animals. Glutathione peroxidase (GSH-Px) activity in lens and kidney, reduced glutathione (GSH), vitamin E and β-carotene concentrations in kidney were lower in the diabetic group than in the control whereas plasma glucose, urea and creatinine, and kidney and lens peroxidation (LP) levels were higher in the diabetic group than in the control. However, kidney and lens LP levels, and plasma glucose, urea and creatinine values were decreased by VCE supplementation. Lens and kidney GSH-Px activity, kidney GSH, vitamin E and β-carotene concentrations and erythrocyte counts were increased by VCE treatment. Kidney weights, vitamin A, haemoglobin, hematocrit, leukocyte and platelets values were not changed by diabetes and/or VCE supplementation. VCE ameliorated also diabetes-induced histopathological changes in kidney. In conclusion, we observed that VCE supplementation is beneficial towards kidney and lens of aged diabetic rats by modulating oxidative and antioxidant systems.     

Antioxidant effect of carnosine treatment on renal oxidative stress in streptozotocin-induced diabetic rats

Nitric oxide (NO) plays a significant role in the development of diabetic nephropathy. We investigated the effects of an antioxidant, carnosine, on streptozotocin (STZ)-induced renal injury in diabetic rats. We used four groups of eight rats: group 1, control; group 2, carnosine treated; group 3, untreated diabetic; group 4, carnosine treated diabetic. Kidneys were removed and processed, and sections were stained with periodic acid-Schiff (PAS) and subjected to eNOS immunohistochemistry. Examination by light microscopy revealed degenerated glomeruli, thickened basement membrane and glycogen accumulation in the tubules of diabetic kidneys. Carnosine treatment prevented the renal morphological damage caused by diabetes. Moreover, administration of carnosine decreased somewhat the oxidative damage of diabetic nephropathy. Appropriate doses of carnosine might be a useful therapeutic option to reduce oxidative stress and associated renal injury in diabetes mellitus.     

Antioxidative enzyme and glutathione S-transferase activities in diabetic rats exposed to long-term ASA treatment

Low-dose acetylsalicylic acid (ASA) treatment is a standard therapeutic approach in diabetes mellitus for prevention of long-term vascular complications. The aim of the present work was to investigate the effect of long-term ASA administration in experimental diabetes on activities of some liver enzymes: glutathione peroxidase (GSHPx), catalase, glucose-6-phosphate dehydrogenase (G6PDH) and glutathione S-transferase (GST). Blood glucose, glycated hemoglobin, as well as plasma ALT and AST activities increased in rats with streptozotocin-induced experimental diabetes. The long-term hyperglycemia resulted in decreased activities of GSHPx (by 26%), catalase (by 34%), GST (by 38%) and G6PDH (by 27%) in diabetic animals. We did not observe increased accumulation of membrane lipid peroxidation products or altered levels of reduced glutathione in livers. The linear correlation between blood glucose and glycated hemoglobin in diabetic animals was distorted upon ASA treatment, which was likely due to a chemical competition between nonenzymatic protein glycosylation and protein acetylation. The long-term ASA administration partially reversed the decrease in GSHPx activity, but did not influence the activities of catalase and GST in diabetic rats. Otherwise, some decrease in these parameters was noted in ASA-treated nondiabetic animals. Increased ASA-induced G6PDH activity was recorded in both diabetic and nondiabetic rats. While both glycation due to diabetic hyperglycemia and ASA-mediated acetylation had very similar effects on the activities of all studied enzymes but G6PDH, we conclude that non-enzymatic modification by either glucose or ASA may be a common mechanism of the observed convergence.     

Changes in liver gangliosides in streptozotocin-induced diabetic rats

Diabetes mellitus is associated with various structural and functional liver abnormalities that affect the glycogen and lipid metabolisms. The effects of streptozotocin-induced diabetes and of insulin supplementation to Sprague-Dawley diabetic rats on ganglioside patterns in liver were determined. Diabetic livers showed a tendency to hepatomegaly 3 weeks after STZ-induction of diabetes. The concentration of total gangliosides in diabetic and non-diabetic livers was similar, but the concentration of total gangliosides in the liver of insulin-stabilized rats was slightly increased. Bidimensional TLC chromatographic analysis of gangliosides isolated from normal diabetic and insulin-stabilized diabetic livers showed quantitative and qualitative changes. In comparison with normal controls, the densitometric analyses of diabetic liver ganglioside patterns had increased amounts of GM3, GM1, GD1b, and GT1b gangliosides, while GM2 could not be detected. The hepatic ganglioside pattern of insulin-stabilized diabetic rats was partially restored, resembling the profile of normal rats. The activity of GalNAcT, GalT-2 and SialT-4 transferases was measured in liver microsomal fractions of the different groups of animals. Diabetic rats showed an increased activity of GalNAcT and a decrease in the activity of GalT-2 and SialT-4 compared with the controls. The enzymatic activities found in insulin-treated rats showed a tendency to return to the values observed in normal control animals. The results evidenced that streptozotocin-induced diabetes affects the liver ganglioside pattern and the ganglioside synthesis enzyme activity. The alterations found in ganglioside metabolism could represent one of the earliest changes associated with the diabetic pathology.     

Antioxidant properties of drugs used in Type 2 diabetes management: could they contribute to,confound or conceal effects of antioxidant therapy?

Objectives: This is a narrative review, investigating the antioxidant properties of drugs used in the management of diabetes, and discusses whether these antioxidant effects contribute to, confound, or conceal the effects of antioxidant therapy.Methods: A systematic search for articles reporting trials, or observational studies on the antioxidant effect of drugs used in the treatment of diabetes in humans or animals was performed using Web of Science, PubMed, and Ovid. Data were extracted, including data on a number of subjects, type of treatment (and duration) received, and primary and secondary outcomes. The primary outcomes were reporting on changes in biomarkers of antioxidants concentrations and secondary outcomes were reporting on changes in biomarkers of oxidative stress. Results: Diabetes Mellitus is a disease characterized by increased oxidative stress. It is often accompanied by a spectrum of other metabolic disturbances, including elevated plasma lipids, elevated uric acid, hypertension, endothelial dysfunction, and central obesity. This review shows evidence that some of the drugs in diabetes management have both in vivo and in vitro antioxidant properties through mechanisms such as scavenging free radicals and upregulating antioxidant gene expression. Conclusion: Pharmaceutical agents used in the treatment of type 2 diabetes has been shown to exert an antioxidant effect..     

Effects of selenium on endothelial dysfunction and metabolic profile in low dose streptozotocin induced diabetic rats fed a high fat diet

Endothelial dysfunction develops as a result of oxidative stress and is responsible for diabetic vascular complications. We investigated the effects of selenium on endothelial dysfunction and oxidative stress in type 2 diabetic rats. Male Wistar rats were divided into five groups: controls, untreated diabetics, and diabetics treated with 180, 300, 500 mcg/kg selenium each day. Diabetes was induced by a single intraperitoneal injection of low dose streptozotocin to rats fed a high fat diet. Endothelium-dependent and -independent relaxations were measured in the thoracic aorta. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and endothelial nitric oxide synthase (eNOS) mRNA expressions were analyzed using real-time polymerase chain reaction (RT-PCR). Fasting blood glucose, lipid profile, lipid oxidation, insulin and nitric oxide were measured in blood samples. Malondialdehyde, superoxide dismutase, catalase and glutathione peroxidase levels were measured in liver samples. RT-PCR showed that selenium reversed increased NADPH oxidase expression and decreased eNOS expression to control levels. Selenium also improved the impairment of endothelium-dependent vasorelaxation in the diabetic aorta. Selenium treatment significantly decreased blood glucose, cholesterol and triglyceride levels, and enhanced the antioxidant status in diabetic rats. Our findings suggest that selenium restores a normal metabolic profile and ameliorates vascular responses and endothelial dysfunction in diabetes by regulating antioxidant enzyme and nitric oxide release.     

Antioxidant enzymatic defense in salivary glands of streptozotocin‐induced diabetic rats: a temporal study

Hyperglycemia induces overproduction of superoxide and it is related to diabetic complications. In this study, we analyzed the antioxidant enzymatic defense and the lipid peroxidation of rat salivary glands in six different periods of diabetic condition. Ninety‐six rats were divided into 12 groups: C7/14/21/28/45/60 (non‐diabetic animals) and D7/14/21/28/45/60 (diabetic animals). Diabetes was induced by streptozotocin and the rats were euthanized after 7, 14, 21, 28, 45, or 60 days. Their parotid (PA) and submandibular (SM) glands were removed soon after the sacrifice and the total protein and malondialdehyde (MDA) concentrations, as well as, the superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activities were determined. Twenty‐one days after the diabetes induction, the SM glands showed an increase in SOD, CAT, and GPx activities, as well as, MDA concentration. Concerning the PA glands, an increase in the CAT activity and MDA content was observed throughout the observation period. The results suggest that diabetes can cause alterations on the salivary glands and that PA and SM glands react differently when exposed to diabetes condition. However, no impairment of antioxidant system was observed in the group whose diabetic condition had been induced 60 days earlier, herein named 60‐day group. Copyright © 2010 John Wiley & Sons, Ltd.     

Changes in the Level of Sialic Acid in Plasma,Brain and Liver of Inherently Scorbutic Rats during Vitamin C and E Deficiencies

The plasma level of sialic acid (NeuAc) in inherently scorbutic [Osteogenic Disorder Shionogi (ODS)] rats was increased by 21 days of vitamin C deficiency and simultaneous vitamins C and E deficiency. The brain content of NeuAc was decreased by deficiencies of these vitamins. The NeuAc level in the liver was not affected significantly by these deficiencies.     

Dexpanthenol reduces diabetic nephropathy and renal oxidative stress in rats

Hyperglycemia increases reactive oxygen species (ROS) and the resulting oxidative stress contributes to the development of diabetic complications. Dexpanthenol (Dxp) is the biological active form of pantothenic acid. We investigated whether Dxp administration could decrease oxidative stress as a way to treat renal complications of diabetes mellitus (DM). Thirty-two male Wistar albino rats were divided into four groups: control, Dxp, DM and DM + Dxp. Experimental diabetes was induced by a single dose of streptozotocin (STZ). After administration of STZ, the DM + Dxp group was administered 500 mg/kg Dxp intraperitoneally every day for 6 weeks. At the end of the study, blood glucose levels were measured and rats were sacrificed. Kidneys were embedded in paraffin, sectioned and stained with hematoxylin and eosin, and periodic acid-Schiff. The mean malondialdehyde levels, glutathione peroxidase, superoxide dismutase and catalase activities, and total antioxidant and total oxidant status also were measured. The control group was normal in histological appearance. We observed congestion, inflammation, glomerulosclerosis, tubular desquamation, loss of villi and hydropic degeneration in tubule cells in the DM group. Indicators of oxidative stress were elevated and antioxidant activity was reduced in the DM group compared to controls. In the DM + Dxp group, oxidative stress was decreased, antioxidant activity was increased and histopathological changes were reduced compared to the DM group. We found that Dxp exhibited ameliorative effects on STZ induced diabetic nephropathy by increasing antioxidant activity.     

Alterations in tissue glutathione antioxidant system in streptozotocin-induced diabetic rats

Changes in tissue glutathione antioxidant system in streptozotocin-induced diabetic rats for a period of 15 weeks were examined. Total glutathione level was significantly increased in kidney tissue, but were slightly decreased and increased in liver and heart tissues, respectively. The small changes in total glutathione level in the liver and heart, though not statistically significant, were associated with reciprocal alterations in the activity Of -glutamylcysteine synthetase (GCS). While the GCS activity was not changed in kidney tissue, the activity of -glutathione peroxidase was significantly increased in kidney tissue. Insulin treatment could completely or partly normalize almost all of these changes induced by diabetes. However, the decrease in hepatic glutathione S-transferases activity in diabetic rats was not reversed by the insulin treatment. The ensemble of results suggests that the diabetes-induced alterations in tissue glutathione antioxidant system may possibly reflect an inter-organ antioxidant response to a generalized increase in tissue oxidative stress associated with diabetes.Abbreviations AGES advanced glycosylation end-products - EDTA ethylenediamine tetraacetic acid - GCS -glutamylcysteine synthetase - GlyHb glycated hemoglobin - GPX Se-glutathione peroxidase - GRD glutathione reductase - GSH reduced glutathione - GSSG oxidized glutathione - GST glutathione S-transferases - SSA sulfosalicylic acid - STZ streptozotocin     

Protective role of intraperitoneally administered vitamin E and selenium in rats anesthetized with enflurane

The aim of this investigation was to determine levels of liver vitamins A and E and blood biochemical and hematological parameters in the enflurane anesthesia of rats. Fifty adult male Wistar rats were used in this study. All rats were randomly divided into five groups. The first and second groups were used as the control and anesthesia control groups, respectively, and only the placebo was intraperitoneally injected. The third group was intraperitoneally administered with vitamin E (dl/-α-tocopheryl acetate, 100 mg/kg body weight), the fourth group with Se (Na₂SeO₃ 1.5 mg/kg body weight), and the fifth group with vitamin E and Se (dl-α-tocopheryl acetate, 100 mg/kg body weight + Na₂SeO₃ 1.5 mg/kg body weight). This administration was done for three times with overday intervals and the second, third, forth, and fifth group rats were taken to enflurane anesthetise for 2 h. The liver vitamin E level was slightly lower in the anesthesia control group than in control group. However, the liver vitamin E content was significantly (p < 0.05 andp < 0.01) increased in vitamin E, Se, and combination groups, whereas the vitamin A level in liver was not statistically different. In general, plasma levels of alanine aminotransferase, creatin kinase, total bilirubin, urea, red blood cell counts, packet cell volume, and hemoglobulin values were significantly (p < 0.05 andp < 0.001) increased during the anesthesia and returned to near control values after the vitamin E plus selenium injection. However, administration of vitamin E had less effect on the hematological and biochemical parameters compared to that of selenium and their combination with vitamin E. However, the white blood cell count and levels of alkaline phosphatase, aspartate aminotransferase, total cholesterol, triglycerides, total protein, and creatinine were not statistically influenced by the anesthesia. In conclusion, we observed that plasma levels of some enzymes and metabolites were significantly increased in the enflurane anesthesia of rats, whereas the liver vitamin E levels were slightly decreased. Therefore, we observed that vitamin E and selenium have a protective effect against anesthesia complication, but the effect of selenium appears to be much greater than the vitamin E.     

Protective effect of alpha-tocopherol on oxidative stress in experimental pulmonary fibrosis in rats

The study was undertaken to investigate the influence of alpha-tocopherol (vitamin E) on malondialdehyde (MDA) and glutathione (GSH) levels and catalase (CAT) activity in lung of rats with bleomycin-induced pulmonary fibrosis (PF). Fourteen Wistar-albino rats were randomly divided into two groups of seven animals each. The first group was treated intra-tracheally with bleomycin hydrochloride (BM group); the second group was also instilled with BM but received injections of alpha-tocopherol twice a week (BM + E group). The third group was treated in the same manner with saline solution only, acting as controls (C). There were decreases in GSH level and CAT activity while an increase in MDA level in BM group was found compared to the control group (p < 0.05). Vitamin E had a regulator effect on these parameters. After administration of alpha-tocopherol, the increase in GSH level and CAT activity and the decrease in MDA level were seen in BM + E group compared to BM group (p < 0.05). Distinct histopathological changes were found in the BM group compared to the untreated rats. Less severe fibrotic lesions were also observed in the BM + E group. The results show that vitamin E is effective on the prevention of BM-induced PF, as indicated by differences in the lung levels of oxidants and antioxidants.