Diazinon-induced brain toxicity and protection by vitamins E plus C

Diazinon (DI) is a widely used pesticide in agriculture, resulting in environmental deleterious effects on neural systems. The current study was performed to investigate the effects of treatment with vitamins E plus C on brain toxicity, which is possibly induced by DI. Twenty-one male rats were divided into three groups (n = 7/group) as follows: (1) control group (C); (2) DI-treated group (DI); (3) DI + vitamins E plus C-treated group (DI + Vit). In order to examine lipid peroxidation and antioxidant status in rats, the level of malondialdehyde (MDA), activities of two free radical scavanging enzymes superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) have been studied in brain of rat. The results showed that treatment with DI induced significant (p < 0.05) increases in the level of serum MDA in rat brain. The vitamins E plus C combination reduced lipid peroxidation in rat brain. The activity of SOD level was significantly higher in DI + Vit group, compared to the control group. GSH-Px, SOD and CAT values were not significantly different in the DI group than in control. Oxidative stress contributes to DI-induced brain toxicity. Our results suggested that vitamins E plus C combination may have a protective effect on DI-induced brain toxicity.     

Moderate exercise combined with dietary vitamins C and E counteracts oxidative stress in the kidney and lens of streptozotocin-induced diabetic-rat

Oxidative stress has a key role in the pathogenesis of diabetes-induced cataract formation and nephropathy. Daily moderate exercise and vitamins C and E (VCE) supplementation can be beneficial to diabetes due to reducing blood glucose and free radical production. The aim of this study was to analyze the effect of moderate exercise with vitamin VCE on lipid peroxidation (LP) and antioxidative systems in the kidneys and lens of streptozotocin-induced diabetic rats. Forty female Wistar rats were used. They were randomly divided into four groups. The first and second groups were used as control and diabetic groups. The third group was the diabetic-exercise group. VCE-supplemented feed was given to diabetic-exercise rats constituting the fourth group. Animals in the exercised groups were moderately exercised daily on a treadmill for three weeks (five days a week). Diabetes was induced on day zero of exercise. Body weights in the four groups were recorded weekly. Lens and kidney samples were taken from all animals on day 20. Glutathione peroxidase (GSH-Px), reduced glutathione (GSH), vitamin E, and beta-carotene levels in kidney and lens, albumin in plasma, and body weight were significantly lower in the diabetic group than in the control group, whereas there was a significant increase in LP of kidney and lens as well as plasma glucose, urea, and creatinine levels in the diabetic group. The decrease in antioxidant enzymes, vitamins, and albumin and the increase in LP and glucose levels in diabetic rats were significantly improved with exercise and VCE supplementation. In the diabetic animals, the decreased beta-carotene and vitamins A levels in kidney did not improve through exercise only, although their levels were increased by exercise plus VCE supplementation. In conclusion, these data demonstrate that lipid peroxidation increases in the lens and kidney of diabetic animals and this could be due to decreases in antioxidant vitamins and enzymes. However, dietary VCE with moderate exercise may strengthen the antioxidant defense system through the reduction of ROS and blood glucose levels. The VCE supplementations with exercise may play a role in preventing the development of diabetic nephropathy and cataract formation in diabetic animals.     

Vitamin E reduces glucocorticoid-induced oxidative stress in rat skeletal muscle

The purpose of this study was to investigate the effect of vitamin E on oxidative stress in the skeletal muscle of glucocorticoid-treated rats. Male Sprague-Dawley rats (5 weeks of age) were fed a basal diet or a diet supplemented with vitamin E (5,000 mg DL-alpha-tocopheryl acetate/kg diet) for 10 d. The rats of both diet groups received subcutaneous injections of corticosterone (CTC) (0, 25, and 100 mg/kg body weight/d) during the final 4 d. Weights of the extensor digitorum longus and gastrocnemius (GAST) muscles were dose-dependently reduced by CTC. However, the muscle weight losses in rats fed the vitamin E diet were smaller than those in rats fed the basal diet. Protein carbonyl content in the GAST muscle, which was determined as an index of oxidatively modified protein, was increased by 100 mg of CTC, and the increment was significantly (p < 0.01) reduced by vitamin E supplement. Hyperglycemia was induced by 100 mg of CTC, but it was not affected by vitamin E. Lipid peroxide (TBARS) in plasma and in GAST muscle was elevated by 100 mg of CTC, and vitamin E significantly (p < 0.001) suppressed the formation of TBARS in the muscle. The change in TBARS paralleled that in protein carbonyl. These results show that CTC leads to oxidative stress in rat skeletal muscles and that vitamin E has roles in reducing the oxidative stress which causes muscle atrophy.     

Naringenin in combination with vitamins C and E potentially protects oxidative stress-mediated hepatic injury in cadmium-intoxicated rats

Cadmium (Cd)-induced oxidative stress and hepatic injury is one of the major outcomes of chronic Cd toxicity, which can be ameliorated by numerous antioxidants. The present study was undertaken to find the therapeutic efficacy of naringenin (NGN) plus vitamins C and E on Cd-induced oxidative hepatotoxicity in Wistar rats. It has been noticed that Cd intoxication significantly elevates the levels of serum hepatic marker enzymes such as alanine amino transferase, aspartate amino transferase, alkaline phosphatase, lactate dehydrogenase, γ glutamyl transferase, total bilirubin, and hepatic thiobarbituric acid reactive substances, lipid hydroperoxides, conjugated dienes and protein carbonyls. In addition, Cd also decreases the activities of hepatic enzymatic antioxidants superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, glutathione reductase and glucose-6-phosphate dehydrogenase and the levels of non-enzymatic antioxidants total sulphydryl groups, reduced glutathione, vitamins C and E and histopathological changes in liver. Treatment with NGN and vitamins C and E in combination more significantly improved the altered biochemical and histopathological changes in the liver of Cd-intoxicated rats than the NGN or vitamins C and E treatment alone. Conclusion: The present data suggest that combined administration of NGN with vitamins C and E proved to be more beneficial in the treatment of Cd-hepatotoxicity than NGN treatment alone.     

Interactions between vitamins C and E in human subjects

Despite convincing in vitro evidence, a vitamin C-E interaction has not been confirmed in vivo. This study was designed to examine the effects of supplementation with either vitamin C or E on their respective plasma concentrations, other antioxidants, lipids and some haemostatic variables. Fasting blood was collected before and after intervention from thirty healthy adults in a double-blinded crossover study. Baselines for measured variables were established after 2 weeks of placebo supplementation, followed by daily supplementation with 73.5 mg RRR-alpha-tocopherol acetate or 500 mg ascorbic acid, and placebo, for 6 weeks. A 2 month washout preceded supplement crossover. Mean values showed that plasma lipid standardised alpha-tocopherol increased with ascorbic acid supplementation: from 4.09 (sem 0.51) to 4.53 (sem 0.66) micromol/mmol total cholesterol plus triacylglycerol (P < 0.05), and plasma ascorbic acid increased from 62.8 (sem 14.9) to 101.3 (sem 22. 2) micromol/l (P < 0.005). Supplementation with (RRR)-alpha-tocopherol acetate increased plasma alpha-tocopherol from 26.8 (sem 3.9) to 32.2 (sem 3.8) micromol/l (P < 0.05), and lipid-standardised alpha-tocopherol from 4.12 (sem 0.48) to 5.38 (sem 0.52) micromol/mmol (P < 0.001). Mean plasma ascorbic acid also increased with vitamin E supplementation, from 64.4 (sem 13.3) to 76. 4 (sem 18.4) micromol/l (P < 0.05). Plasma ferric reducing (antioxidant) power and glutathione peroxidase (U/g haemoglobin) increased in both groups, while urate, total cholesterol and triacylglycerol levels decreased (P < 0.05 throughout). Results are supportive of an in vivo interaction between vitamins C and E.     

维生素C对香烟烟雾的氧化应激作用的影响

目的　了解维生素C(VC)对香烟烟雾溶液 (CSS)作用下的大鼠淋巴细胞产生氧化应激的影响。方法　将香烟烟雾溶液作用于经VC预处理的大鼠淋巴细胞 ,用 2’ ,7’ -二乙酰二氯荧光素 (DCFH -DA)检测细胞内活性氧自由基 (ROS)水平 ,用彗星实验评价DNA的损伤状况 ,同时检测细胞内超氧化物歧化酶 (SOD)活性和脂质过氧化物(LPO)水平。结果　 8× 10 -3 支 /mlCSS作用下大鼠淋巴细胞内ROS和LPO水平增高 ,DNA损伤增强 ,SOD活性降低。用 5 0 μmol/LVC干预后 ,与相应非干预组相比细胞内ROS和LPO水平降低 ,DNA损伤减轻 ,SOD活性增强 ,且均有显著性差异。结论　 5 0 μmol/LVC能保护大鼠淋巴细胞 ,减轻CSS导致的氧化应激。     

The effects of diazinon on lipid peroxidation and antioxidant enzymes in rat erythrocytes: role of vitamins E and C

Reactive oxygen species caused by organophosphates may be involved in the toxicity of various pesticides. Therefore, in this study, we aimed to investigate the effects of acute exposure to organophosphate insecticide diazinon (DI) and possible ameliorating role of vitamins E and C, with the following parameters: lipid peroxidation (LPO) and the activity of the glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) in rat erythrocytes. The experimental groups were arranged as control group, DI-treated group (DI) and DI + vitamin E + vitamin C-treated group (DI + Vit). DI + Vit groups were treated orally with a single dose of 335 mg/kg DI body weight. Vitamins E and C were injected at doses of 150 mg/kg body weight intramuscular (in) and 200 mg/kg body weight intraperitoneal (ip), respectively, 30 min after the treatment of DI in DI + Vit group. Blood samples were taken 24 h after the DI. The results showed that DI administration caused to increase in LPO and the activities of SOD and GSH-Px enzymes in erythrocytes. Also, the combination of vitamins E and C decreased LPO and the activities of GSH-Px and SOD compared with the DI group. In conclusion, although treating rats with single dose DI increases LPO and antioxidant enzyme activities in erythrocytes, vitamins C and E combination can reduce LPO caused by DI.     

Fallopian damage induced by organophosphate insecticide methyl parathion, and protective effect of vitamins E and C on ultrastructural changes in rats

The aim of the present study was to examine the effects of subchronic methyl parathion (MP) administration on lipid peroxidation and fallopian tube damage, and to evaluate the preventive effects of the use of vitamins E and C against toxicity. The experimental groups were: rats treated with corn oil (control group), with 5 mg/kg MP and with 5 mg/kg body weight MP plus vitamins E and C (MP + Vit). The groups were given MP by oral gavage for five days a week for four weeks at a daily dose of 5 mg/kg (MP and MP + Vit) using corn oil as a vehicle. Vitamins E and C were injected at doses of 50 mg/kg intramuscularly and 20 mg/kg intraperitoneally, respectively, just after the treatment with MP in the MP + Vit group. The levels of malondialdehyde (MDA) were determined in rat plasma. Electron microscopic ultrastuructural and histopathological changes in the fallopian tissue were examined. MDA levels were higher in the MP group than in the control group, and lower in the MP + Vit group than in the MP group. MP led to deletions in microvilli and marked loss in kinocillia of surface epithelium. But these marked histopathological findings decreased in the MP + Vit group. Multiple doses of MP administration caused some damage in the fallopian tube, and treatment with vitamins E and C after MP could reduce this effect.     

Protective effects of vitamins C and E against hepatotoxicity induced by methyl parathion in rats

Male rats were given vitamins C+E, methyl parathion, or both daily via gavage for seven weeks. Body weight was decreased while liver weight increased significantly at the end of fourth and seventh weeks in the methyl parathion- and methyl parathion plus vitamin-treated groups. Serum total protein, albumin, triglyceride, low density lipoprotein-cholesterol (VLDL-cholesterol) levels decreased, and serum alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl-transferase (GGT), lactate dehydrogenase (LDH), and total cholesterol levels increased significantly in the methyl parathion- and the methyl parathion plus vitamin-treated rats. There was a statistically significant difference for all biochemical parameters when the methyl parathion plus vitamin-treated group was compared with methyl parathion-treated group. In electron microscopic investigation, cytopathological alterations were observed in hepatocytes of the methyl parathion- and the methyl parathion plus vitamin-treated rats. As a result, methyl parathion-induced hepatotoxicity is reduced by vitamins C+E, but vitamins C+E did not provide complete protection.     

Carotenoids and vitamins C and E in the prevention of cardiovascular disease

Atherosclerotic cardiovascular diseases (CVD) are a major source of mortality and morbidity in the general population. Oxidative modification of low-density lipoprotein cholesterol (LDL-C) represents the most important determinant factor in the development and progression of atherosclerotic lesions. Oxidative damage and the production of free radicals (FRs) in the endothelium are some of the main factors involved in the pathogenesis of the atherosclerotic process that causes CVD. Appropriate nutritional practices are of central importance in managing risk and treatment of CVD; in fact, many current guidelines for a healthy general population contain nutritional recommendations to reduce the risk of these diseases. Observational studies of vitamins C and E, the most prevalent natural antioxidant vitamins, suggest that supplemental use of these vitamins may lower the risk for coronary events. Despite these data, several large, randomized controlled trials have failed to confirm the benefits of vitamin C and E in cardiovascular prevention. The aim of this review is to examine the published studies regarding the effect of vitamins (C and E) and beta-carotene supplementation in the prevention of CVD due to atherosclerosis.     

The effects of methidathion on liver: role of vitamins E and C

Methidathion (MD) is one of the most widely used organophosphate insecticides (OPIs) for public health programmes and agricultural purposes. However it causes side effects such as liver disorders. We examined the ameliorating effects of a combination of vitamins E and C against MD induced liver toxicity in rats. MD was given orally with a single dose of 8 mg/kg body weight at 0 h. Vitamin E and vitamin C were injected 30 min after the treatment of MD at doses of 150 mg/kg body weight i.m. and 200 mg/kg body weight i.p., respectively. Liver tissue samples were taken 24 h after the MD administration. In MD treated group, some histopathological changes like infiltration with mononuclear cells at parenchymal tissue, sinusoidal dilatation, focal necrotic areas, granular degeneration and picnotic nuclei in the hepatocytes were observed. The severity of these lesions was reduced by administration of vitamins. It is concluded that MD caused liver damage and single-dose treatment with a combination therapy of vitamins E and C after the administration of MD can reduce the toxic effects of MD on liver tissue of rats.     

Plasma antioxidants and coronary heart disease: vitamins C and E, and selenium

The possibility of a relation between plasma antioxidants such as vitamins C and E and selenium, and mortality from coronary heart disease (CHD) was examined. A cross-sectional survey was undertaken of random population samples of apparently healthy middle-aged men in four European regions with differing mortalities from CHD [rate/100,000 for men aged 40-49]: north Karelia (eastern Finland) (n = 99) [212/100,000]; south-west Finland (n = 85) [146/100,000]; Scotland (n = 131) [140/100,000]; and south Italy (n = 80) [43/100,000]. Median (5th-95th percentile) plasma vitamin C concentrations were lower in Scotland: 18.2 (5.7-61.3) microM than in other regions: north Karelia 28.4 (6.2-85.2); south-west Finland 33.5 (5.7-76.6); south Italy 38.0 (10.2-69.8) microM (P less than 0.001). The median levels in the four areas did not however reflect the regional CHD mortality rates. Regional differences in plasma vitamin E levels were also observed: Scottish levels were low 20.0 (12.1-29.3) microM (P less than 0.001) and did not differ between the other areas: 23.0 (16.7-35.1), 22.5 (13.7-31.6) and 23.9 (15.6-41.3) microM respectively. The vitamin E gradient could be explained in part by differences in serum cholesterol. However, cholesterol-adjusted vitamin E levels were low in the three high CHD areas: Scotland 3.41 (2.41-4.62); north Karelia 3.53 (2.67-5.18); south-west Finland 3.53 (2.58-4.92); Italy 4.81 (3.25-5.99) mumol/mmol cholesterol (P less than 0.001). Cholesterol-adjusted vitamin E was not lower in north Karelia, the higher CHD mortality area in Finland. Serum selenium values also varied with the area examined and reported low levels in Finland were confirmed. Nevertheless, selenium levels did not correlate with the reported mortality rates of CHD. Thus in our small cross-cultural study the evidence did not support our hypothesis that plasma antioxidants explain regional differences in CHD mortality.     

Dietary fat type affects vitamins C and E and biomarkers of oxidative status in peripheral and brain tissues of golden Syrian hamsters

Oxidative stress is an important trigger in the complex chain of events leading to neurodegenerative diseases. On the other hand, dietary fatty acids play an essential role in brain function. The objectives of this study were to assess the effect of dietary fat type on vitamin C and vitamin E (alpha-and gamma-tocopherol) concentrations in peripheral and brain tissues and its effect on 8-epiPGF(2)alpha (F(2)-isoprostanes). Male Golden Syrian hamsters (n = 120, 8 wk old) were fed diets enriched in butter, hydrogenated fat (margarine), and canola and soybean oils. After 12 wk, hamsters were deprived of food, anesthetized with isoflurane, and killed via terminal exsanguination. Analyses of vitamins C, E, and 8-epiPGF(2)alpha were performed in peripheral tissues and brain. Hamsters consuming the margarine-enriched diet had lower (P < 0.05) vitamin C and alpha-tocopherol concentrations in liver, plasma, and brain, and higher (P < 0.02) plasma 8-epiPGF(2)alpha than groups fed the butter, and the canola and soybean oil diets. Liver and plasma gamma-tocopherol concentration was higher (P < 0.001) among the groups fed the soybean- and margarine-enriched diets compared with the other groups. alpha-Tocopherol was higher (P < 0.05) and 8-epiPGF(2)alpha lower (P < 0.01) among the groups fed the canola and soybean oil diets compared with the other groups. Across the groups, an inverse correlation between plasma levels of vitamin C and 8-epiPGF(2)alpha (r = -0.37, P = 0.03) and a positive correlation between plasma levels of vitamin C and alpha-tocopherol were observed (r = 0.341, P = 0.003). Hamsters fed the butter-enriched diet had a higher (P < 0.03) plasma uric acid concentration than the other groups. The results of this study provide new evidence concerning the effect of dietary fat on antioxidant status, which is important for the maintenance of good health.     

Effect of vitamins C and E supplementation on Helicobacter pylori eradication: a meta-analysis

Vitamins C and E can act as potent antioxidants to reduce the damage caused by reactive oxygen species in gastric mucosa. Whether vitamin supplements for Helicobacter pylori eradication regimen could improve the rate of eradication remains uncertain. Therefore, we performed a meta-analysis to evaluate the efficacy of vitamins C and E supplementation for the eradication of H. pylori. Searches were conducted in the databases PubMed, EMBASE and Cochrane Library. Randomised controlled trials (RCT) that fulfilled the inclusion criteria and addressed the clinical questions of this analysis were further assessed. Of the six RCT included, five had a low methodological quality. Of the six RCT, three compared the efficacy of the eradication regimen v. eradication regimen plus vitamins C and E. The result of the meta-analysis showed a non-significant difference in the eradication rate of H. pylori between the two groups (risk ratio (RR) 0·93, P = 0·76). Another three RCT compared the eradication regimen v. eradication regimen plus vitamin C only, and there too there was no significant difference in the eradication rate (RR 0·83, P = 0·32). In conclusion, vitamins C and/or E supplements to the H. pylori eradication regimen could not improve the eradication rate. However, currently available data do not draw a definitive conclusion about the effectiveness of antioxidant vitamins on H. pylori eradication, owing to the small sample size and low-to-moderate methodological quality.     

HRT and vitamins C and E do not improve coronary disease in women

Hormone replacement therapy (HRT) and antioxidant vitamin supplements (vitamins E and C) do not provide cardiovascular benefit for postmenopausal women with known coronary heart disease. Moreover, a potential for harm exists with each of the treatments. Therefore, neither should be prescribed specifically for cardiovascular benefit for postmenopausal women with coronary heart disease.     

Role of vitamin E and oxidative stress in exercise.

Reactive oxygen species (ROS) play an important role as mediators of skeletal muscle damage and inflammation after strenuous exercise. These ROS arise largely from increases in mitochondrial oxygen consumption and electron transport flux. Bouts of intense exercise are associated with increases in lipid peroxidation, generating malondialdehyde and F(2alpha)-isoprostanes, and the release of muscle enzymes like lactate dehydrogenase and creatine kinase. Dietary and enzymatic antioxidant defenses appear to play a protective role in muscle cells by reducing associated oxidative damage to lipids, nucleic acids, and protein. However, studies of the use of dietary antioxidants like vitamin E to reduce exercise-induced muscle injury have met with mixed success. The equivocal nature of these results appear to reflect a diversity of factors including the antioxidant(s) tested, the nature and timing of the exercise, the age and fitness of the subjects, and the methodology for assessing oxidative stress.     

Selenium and vitamins A, E, and C: nutrients with cancer prevention properties

It has been estimated that 35% of all cancer incidence is related to diet. The potential appears great that high intakes of various nutrients can reduce the incidence of some types of cancer. Selenium and vitamins A, C, and E, discussed in this article, have many actions and interactions that are important in relationship to the study of nutrition and cancer. Even though only a few of the necessary human trials of efficacy have been conducted, epidemiological and animal data suggest that vitamins and/or minerals act as anticarcinogens, altering cancer incidence, differentiation, and growth. Thus, they may prove useful adjuncts to conventional therapies or in cancer prevention. However, the nutrients should not be viewed as cure-alls that work alone. Adequate intake ideally should be the result of increased dietary consumption rather than supplements because as yet unidentified components found in food may prove beneficial and protective. More research is needed prior to encouraging members of the general population to increase their intakes of various nutrients, even though there is now some evidence that those nutrients may help prevent some cancers.     

Effect of hyperbaric oxygen and vitamin C and E supplementation on biomarkers of oxidative stress in healthy men

The objectives of the present study were to evaluate the effect of normobaric and hyperbaric O2 (HBO) on plasma antioxidants and biomarkers of oxidative stress in plasma and urine and to investigate the effect of a 4-week vitamin C plus E supplementation on HBO-induced oxidative stress. Nineteen healthy men were exposed to HBO (100 % O2; 240 kPa) before and after 4 weeks' supplementation with 500 mg vitamin C plus 165 mg alpha-tocopherol equivalents. Exposure to 21 % O2 at 100 kPa served as intra-individual controls (control). Samples for the analysis of plasma antioxidants and oxidative stress biomarkers were collected before and immediately after each treatment. The present results showed that when compared with 'control', a single exposure to HBO resulted in a decrease of plasma vitamin C (P = 0.027) and an increase of lipid peroxides (P = 0.0008) and urinary 8-oxo-deoxyguanosine (8-oxodG) excretion (P = 0.006). Oxidative stress was not prevented by a 4-week supplementation with vitamins C and E. HBO-induced changes in plasma parameters correlated with basal antioxidant levels. The increase of urinary 8-oxodG after HBO plus supplementation correlated negatively with vitamin E intake (P = 0.023). We concluded that in healthy men HBO caused oxidative stress, which could not be prevented by dietary vitamin C plus E supplementation. The present data support the idea that HBO is a suitable model for oxidative stress in healthy volunteers.