Vitamins C and E protect isolated cardiomyocytes against oxidative damage

Vitamin C as a treatment for organ failure in sepsis

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection, with a high morbidity and mortality rate. Exogenous vitamin C supplementation is a potential therapeutic option for the treatment of multi-organ dysfunction in sepsis due to the significantly lower levels of vitamin C in the circulating blood of sepsis patients compared to healthy subjects and the importance of vitamin C in many of the physiological processes of sepsis. Vitamin C may influence the function of numerous organs and systems, including the heart, lungs, kidneys, brain, and immune defences, by reducing oxidative stress, inhibiting inflammatory factor surges, regulating the synthesis of various mediators and hormones, and enhancing immune cell function. With the development of multiple clinical randomized controlled trials, the outcomes of vitamin C treatment for critically ill patients have been discussed anew. This review's objectives are to provide an overview of how vitamin C affects various organ functions in sepsis and to illustrate how it affects each organ. Understanding the pharmacological mechanism of vitamin C and the organ damage caused by sepsis may help to clarify the conditions and clinical applications of vitamin C.

Anthropometric and Dietary Factors as Predictors of DNA Damage in Obese Women

Enhanced DNA damage and disturbances in DNA repair mechanisms are reported to be involved in the pathogenesis of chronic diseases like obesity, atherosclerosis, metabolic syndrome, diabetes, and cancer. The aim of the present study was to evaluate whether anthropometric factors and dietary habits are related to endogenous DNA damage. One hundred and fourteen premenopausal, apparently healthy women were included in the study: 88 obese individuals and 26 controls. The comet assay was used to measure basal DNA damage. Biochemical measurements included lipids, apolipoproteinAI, fasting insulin, glucose, and C-reactive protein high sensitivity (CRP-hs). Dietary intakes were assessed by 3-day food records. The mean level of DNA damage was almost two times higher in obese than in non-obese women (p < 0.001). Regression modeling showed that body mass index (BMI), daily intakes of energy, and vitamin C are key predictors of variance in basal DNA damage. Our data demonstrate the impact of obesity-associated inflammation on DNA damage and indicate that regardless of obesity, the level of DNA damage can be reduced by adequate intakes of vitamins C and E. It suggests that particular attention should be paid to the content of antioxidants in the diet of obese people and further studies are needed to modify dietary guidelines to prevent DNA damage in obese individuals.

Biologically active constituents of the secretome of human W8B2+ cardiac stem cells

The benefits of adult stem cells for repair of the heart have been attributed to the repertoire of salutary paracrine activities they appear to exert. We previously isolated human W8B2⁺ cardiac stem cells (CSCs) and found they powerfully influence cardiomyocytes and endothelial cells to collectively promote cardiac repair and regeneration. Here, the complexity of the W8B2⁺ CSC secretomes was characterised and examined in more detail. Using ion exchange chromatography to separate soluble proteins based on their net surface charge, the secreted factors responsible for the pro-survival activity of W8B2⁺ CSCs were found within the low and medium cation fractions. In addition to the soluble proteins, extracellular vesicles generated from W8B2⁺ CSCs not only exhibited pro-survival and pro-angiogenic activities, but also promoted proliferation of neonatal cardiomyocytes. These extracellular vesicles contain a cargo of proteins, mRNA and primary microRNA precursors that are enriched in exosomes and are capable of modulating collectively many of the cellular pathways involved in protein metabolism, cell growth, as well as cellular responses to stress and organisation of the extracellular matrix. Thus the W8B2⁺ CSC secretome contains a multitude of bioactive paracrine factors we have now characterised, that might well be harnessed for therapeutic application for cardiac repair and regeneration.

Short-Term High-Dose Vitamin C and E Supplementation Attenuates Muscle Damage and Inflammatory Responses to Repeated Taekwondo Competitions: A Randomized Placebo-Controlled Trial

Background: Exercise-induced muscle damage during intensive sport events is a very common issue in sport medicine. Therefore, the purpose is to investigate the effects of short-term high-dose vitamin C and E supplementation on muscle damage, hemolysis, and inflammatory responses to simulated competitive Olympic Taekwondo (TKD) matches in elite athletes. Methods: Using a randomized placebo-controlled and double-blind study design, eighteen elite male TKD athletes were weight-matched and randomly assigned into either a vitamin C and E group (Vit C+E; N = 9) or placebo group (PLA; N = 9). Vit C+E or PLA supplements were taken daily (Vit C+E: 2000 mg/d vitamin C; 1400 U/d vitamin E) for 4 days (3 days before and on competition day) before taking part in 4 consecutive TKD matches on a single day. Plasma samples were obtained before each match and 24-hours after the first match for determination of markers of muscle damage, hemolysis, and systemic inflammatory state. Results: Myoglobin was lower in the Vit C+E group, compared to PLA, during the match day (area under curve, AUC -47.0% vs. PLA, p = 0.021). Plasma creatine kinase was lower in the Vit C+E group (AUC -57.5% vs. PLA, p = 0.017) and hemolysis was lower in the Vit C+E group (AUC -40.5% vs. PLA, p = 0.034). Conclusions: We demonstrated that short-term (4-days) vitamin C and E supplementation effectively attenuated exercise-induced tissue damage and inflammatory response during and after successive TKD matches.

Cardiotoxicity in rats induced by methidathion and ameliorating effect of vitamins E and C

We have examined the effect of subchronic methidathion (MD) administration on heart damage, and have evaluated possible ameliorating effects of a combination of vitamins E and C against MD toxicity. The experimental groups were: control group, rats treated with 5 mg/kg MD and rats treated with 5 mg/kg body weight MD plus vitamin E and vitamin C (MD+Vit). The groups were given MD by gavage 5 days a week for four weeks at a dose level of 5 mg/kg/day (MD and MD+Vit) by using corn oil as the vehicle. Vitamin E and vitamin C were injected at doses of 50 mg/kg i.m. and 20 mg/kg i.p., respectively, after the treatment with MD in the MD+Vit group. The levels of malondialdehyde (MDA) were determined in the heart tissue, and the levels of cardiac troponin I (TnI) in serum. An autoanalyser was used to determine the serum activities of cholinesterase (ChE). Histopathological examination was carried out in the heart tissue. MDA significantly increased in the MD group as compared to controls (P <0.01). When MD was given concurrently with vitamins E and C, the increase in MDA was significantly less (P <0.01). ChE activity significantly decreased in the MD group as compared to controls (P <-0.01). When MD was given concurrently with vitamins E and C, the decrease in ChE activity was significantly higher (P <-0.05). The serum TnI levels significantly increased in the MD group as compared to controls (P <-0.01). When MD was given concurrently with vitamins E and C, the increase in the serum TnI was significantly less (P <-0.01). MD caused the diffuse loss of striation and myocytolysis of the cardiomyocytes, whereas the combination of vitamins E and C caused a significant decrease in these effects of MD. In conclusion, subchronic MD administration caused heart damage and, in addition, treatment with a combination of vitamins E and C after the administration of MD reduced heart damage caused by MD.

Monosodium glutamate induced testicular toxicity and the possible ameliorative role of vitamin E or selenium in male rats

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Monosodium glutamate induced testicular damage due to oxidative stress.

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Using of selenium and/or vitamin E to alleviate the toxicity of monosodium glutamate especially on testis.

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Increasing of MDA levels in MSG treated group while reduction in SOD, CAT and GPx activities.

Monosodium glutamate (MSG) has been recognized as flavor enhancer that adversely affects male reproductive systems. The present study was carried out to evaluate the potential protective role of vitamin E (vit E) or selenium against MSG induced oxidative stress and histopathological changes in testis tissues of rats. Mature male Wistar rats weighing 150–200 g BW were allocated to evenly twelve groups each group of ten animals, the first group was maintained as control group, the 2nd, 3rd and 4th groups were administered MSG in three different dose levels (low, medium and high) (6, 17.5 and 60 mg/kg BW), the 5th and 6th groups were given vit E in two doses (low and high) (150 and 200 mg/kg), the 7th and 8th groups were administered selenium in two doses (low and high) (0.25 and 1 mg/kg) daily via gavage for a period of 30 days. Meanwhile the 9th and 10th groups were given combinations of MSG (high dose) and vit E while, the 11th and 12th groups were given MSG (high dose) plus selenium in two recommended doses for each one. Monosodium glutamate caused an elevation in lipid peroxidation level parallel with significant decline in SOD, CAT as well as GPx activities in testis tissues. Administration of vit E or selenium to MSG-treated groups declined lipid peroxidation, increased SOD, CAT, GPx activities. Selenium or vit E significantly reduced MSG induced histopathological changes by the entire restoration of the histological structures and the testicular antioxidant status to great extent in treated rats. In conclusion, supplementation of selenium or vit E could ameliorate the MSG induced testicular toxicity to great extent and reduce the oxidative stress on testis tissues.

Vitamin C revisited

This narrative review summarizes the role of vitamin C in mitigating oxidative injury-induced microcirculatory impairment and associated organ failure in ischemia/reperfusion or sepsis. Preclinical studies show that high-dose vitamin C can prevent or restore microcirculatory flow impairment by inhibiting activation of nicotinamide adenine dinucleotide phosphate-oxidase and inducible nitric oxide synthase, augmenting tetrahydrobiopterin, preventing uncoupling of oxidative phosphorylation, and decreasing the formation of superoxide and peroxynitrite, and by directly scavenging superoxide. Vitamin C can additionally restore vascular responsiveness to vasoconstrictors, preserve endothelial barrier by maintaining cyclic guanylate phosphatase and occludin phosphorylation and preventing apoptosis. Finally, high-dose vitamin C can augment antibacterial defense. These protective effects against overwhelming oxidative stress due to ischemia/reperfusion, sepsis or burn seems to mitigate organ injury and dysfunction, and promote recovery after cardiac revascularization and in critically ill patients, in the latter partially in combination with other antioxidants. Of note, several questions remain to be solved, including optimal dose, timing and combination of vitamin C with other antioxidants. The combination obviously offers a synergistic effect and seems reasonable during sustained critical illness. High-dose vitamin C, however, provides a cheap, strong and multifaceted antioxidant, especially robust for resuscitation of the circulation. Vitamin C given as early as possible after the injurious event, or before if feasible, seems most effective. The latter could be considered at the start of cardiac surgery, organ transplant or major gastrointestinal surgery. Preoperative supplementation should consider the inhibiting effect of vitamin C on ischemic preconditioning. In critically ill patients, future research should focus on the use of short-term high-dose intravenous vitamin C as a resuscitation drug, to intervene as early as possible in the oxidant cascade in order to optimize macrocirculation and microcirculation and limit cellular injury.

Effect of intravenous administration of antioxidants alone and in combination on myocardial reperfusion injury in an experimental pig model

BACKGROUND

Several antioxidants have been found to have conflicting results in attenuating myocardial reperfusion injury. These studies were done primarily in experimental protocols that did not approximate clinical situations.

OBJECTIVE

The aim of this study was to test the efficacy of 3 different antioxidants (ascorbic acid [AA], desferrioxamine, and N-acetylcysteine [NAC]) administered IV alone and in combination in a closed-chest pig model.

METHODS

Farm-raised domestic male pigs (aged 3-5 months, weight of 30-35 kg) were assigned to 1 of 5 groups to receive treatment as follows: group A, AA 100 mg/kg; group B, desferrioxamine 60 mg/kg; group C, a loading dose of NAC 100 mg/kg for 20 minutes and a 20-mg/kg maintenance dose; group D, all 3 drugs in combination; and group E, normal saline (control group). The infusion of all drugs was started 15 minutes before and completed 5 minutes after reperfusion, except for the administration of NAC, which was terminated 60 minutes postreperfusion. Myocardial ischemia (45 minutes) and reperfusion (210 minutes) were achieved percutaneously by circumflex artery balloon occlusion. Ejection fraction, left ventricular end-diastolic pressure (LVEDP), flow in the infarcted artery, and all ventricular arrhythmias were recorded. Oxidative stress was estimated by serial measurements of thiobarbituric acid reactive substance (TBARS) concentration in coronary sinus blood. Infarct size was assessed as a percentage of the area at risk (I/R ratio) using the tetrazolium red staining method.

RESULTS

The 25 pigs were divided into 5 groups of 5 pigs each. No significant between-group differences were found in I/R ratio or in oxidative stress (as measured by TBARS concentration). Group C developed significantly more ventricular atrhythmias than the control group (80% vs 0%, P = 0.02). No other differences among groups were found. LVEDP was significantly elevated in all treatment groups (mean LVEDP difference [SD] for group A, 6.0 [1.6] mm Hg; group B, 17.6 [1.9] mm Hg; group C, 3.6 [1.7] mm Hg; group D, 6.8 [3.2] and group E, 5.4 [3.4] mm Hg). LVEDP elevation was found to be significantly higher in group B compared with all the other groups (all, P < 0.001). No significant between-group differences were found in the other parameters measured.

CONCLUSION

In this experimental pig model, the antioxidants AA, desferrioxamine, and NAC administered alone or in combination did not reduce the deleterious effects of reperfusion injury and specifically the extent of myocardial necrosis.

Differential effects of vitamins E and C and carotenoids on growth, resistance to oxidative stress, fledging success and plumage colouration in wild great tits

Oxidative stress is the imbalance between the production of reactive species and antioxidants, which causes damage to lipids, proteins and DNA. Antioxidants, like vitamins and carotenoids, can limit oxidative damage and can therefore regulate the trade-off between growth, which is a period of high reactive species production, and self-maintenance. However, the role of carotenoids as antioxidants in vivo has been debated, and it has been suggested that carotenoid-based signals indicate the availability of non-pigmentary antioxidants (e.g. vitamins) that protect carotenoids from oxidation, known as the 'protection hypothesis'. To evaluate the importance of vitamins versus carotenoids as antioxidants during growth and to test the protection hypothesis, we supplemented nestling great tits, Parus major, 3, 5 and 7 days after hatching with a single dose of carotenoids and/or vitamins in a 2×2 full-factorial design. We subsequently measured body condition, antioxidant capacity, oxidative damage, fledging success and plumage reflectance. Vitamins enhanced antioxidant capacity, but did not affect oxidative damage. Vitamin-treated nestlings had higher growth rates and higher probability of fledging. In contrast, carotenoids did not affect any of these traits. Furthermore, carotenoid-based colouration increased over the breeding season in nestlings that received vitamins only. This study shows that vitamins are limiting for growth rate and fledging success, and suggests that vitamins could regulate the trade-off between growth and self-maintenance in favour of the former. Moreover, our results are consistent with the idea that carotenoids are minor antioxidants in birds, but they do not support the protection hypothesis.

Rationale for antioxidant supplementation in sarcopenia

Sarcopenia is an age-related clinical condition characterized by the progressive loss of motor units and wasting of muscle fibers resulting in decreased muscle function. The molecular mechanisms leading to sarcopenia are not completely identified, but the increased oxidative damage occurring in muscle cells during the course of aging represents one of the most accepted underlying pathways. In fact, skeletal muscle is a highly oxygenated tissue and the generation of reactive oxygen species is particularly enhanced in both contracting and at rest conditions. It has been suggested that oral antioxidant supplementation may contribute at reducing indices of oxidative stress both in animal and human models by reinforcing the natural endogenous defenses. Aim of the present paper is to discuss present evidence related to possible benefits of oral antioxidants in the prevention and treatment of sarcopenia.

Vitamin E and C supplementation reduces oxidative stress, improves antioxidant enzymes and positive muscle work in chronically loaded muscles of aged rats

Aging is associated with increased oxidative stress. Muscle levels of oxidative stress are further elevated with exercise. The purpose of this study was to determine if dietary antioxidant supplementation would improve muscle function and cellular markers of oxidative stress in response to chronic repetitive loading in aging. The dorsiflexors of the left limb of aged and young adult Fischer 344 Brown×Norway rats were loaded 3 times weekly for 4.5 weeks using 80 maximal stretch-shortening contractions per session. The contra-lateral limb served as the intra-animal control. The rats were randomly assigned to a diet supplemented with Vitamin E and Vitamin C or normal non-supplemented rat chow. Biomarkers of oxidative stress were measured in the tibialis anterior muscle. Repetitive loading exercise increased maximal isometric force, negative work and positive work in the dorsiflexors of young adult rats. Only positive work increased in the aged animals that were supplemented with Vitamin E and C. Markers of oxidative stress (H(2)O(2), total GSH, GSH/GSSG ratio, malondialdehyde and 8-OHdG) increased in the tibialis anterior muscles from aged and young adult animals with repetitive loading, but Vitamin E and C supplements attenuated this increase. MnSOD activity increased with supplementation in the young adult animals. CuZnSOD and catalase activity increased with supplementation in young adult and aged animals and GPx activity increased with exercise in the non-supplemented young adult and aged animals. The increased levels of endogenous antioxidant enzymes after Vitamin E and C supplementation appear to be regulated by post-transcriptional modifications that are affected differently by age, exercise, and supplementation. These data suggest that antioxidant supplementation improves indices of oxidative stress associated with repetitive loading exercise and aging and improves the positive work output of muscles in aged rodents.

Use of vitamins C and E as a prophylactic therapy to prevent postoperative atrial fibrillation

Oxidative stress has been strongly involved in the underlying mechanism of atrial fibrillation, particularly in the arrhythmia occurring in patients undergoing cardiac surgery with extracorporeal circulation (postoperative atrial fibrillation). The ischemia/reperfusion injury thus occurring in the myocardial tissue contributes to the development of tissue remodeling, thought to be responsible for the functional heart impairment. Consequently, structural changes due to the cardiac tissue biomolecules attack by reactive oxygen and/or nitrogen species could account for functional changes in ion channels, transporters, membrane conductance, cytosolic transduction signals, and other events, all associated with the occurrence of arrhythmic consequences. The lack of success and significant side effects of anti-arrhythmic drugs have given rise to attempts aimed to develop alternative novel pharmacologic treatments. On this line, the biological properties of the antioxidant vitamins C and E suggest that they could decrease the vulnerability of the heart to the oxidative damage. Nevertheless, very few studies to assess their anti-arrhythmic effects have been reported in humans. The clinical and experimental evidence supporting the view that the pharmacological use of antioxidant vitamins could contribute to prevent postoperative atrial fibrillation is presented.

Oxidative damage of workers in secondary metal recovery plants affected by smoking status and joining the smelting work

In Taiwan, secondary copper smelters and zinc recovery plants primarily utilize recovering metal from scrap and dross, and handles mostly fly ash and slag with high temperature to produce ZnO from the iron and steel industry. The materials may contain organic impurities, such as plastic and organic chloride chemicals, and amounts of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) are produced during the smelting process. Therefore, secondary metal recovery industries are major emission sources of PCDD/Fs, which may have been demonstrated to elicit oxidative stress and to involve the production of plasma malondialdehyde (MDA). Many studies have also indicated that the intake of antioxidants, smoking, age and exposure to environmental pollutants may be implicated to DNA damage or lipid peroxidation. This study therefore aims to elucidate the roles of occupational exposure like joining the smelting work, age, smoking and alcohol status, and antioxidant intake on oxidative damage in secondary metal recovery workers in Taiwan. 73 workers were recruited from 2 secondary metal recovery plants. The analysis of 8-hydroxydeoxyguanosine (8-OH-dG) in urine, DNA strand breakage (comet assay) and lipid peroxidation (MDA) in blood samples were completed for all of the workers. The results showed that the older subjects exhibited significantly lower levels of 8-OH-dG and MDA than younger subjects. Our investigation also showed that working departments were in related to plasma MDA and DNA strand breakage levels of nonsmokers, however, the observation become negligible in smokers. And it is implicated that cigarette type might affect 8-OH-dG levels in secondary metal recovery workers. Since, adding to results above, the MDA level in production workers was significantly higher than those in managerial departments, it is important for the employers to make efforts on improving occupational environments or serving protective equipments to protect workers in secondary metal recovery factories.

Prevention of atrial fibrillation following cardiac surgery: basis for a novel therapeutic strategy based on non-hypoxic myocardial preconditioning

Atrial fibrillation is the most common complication of cardiac surgical procedures performed with cardiopulmonary bypass. It contributes to increased hospital length of stay and treatment costs. At present, preventive strategies offer only suboptimal benefits, despite improvements in anesthesia, surgical technique, and medical therapy. The pathogenesis of postoperative atrial fibrillation is considered to be multifactorial. However oxidative stress is a major contributory factor representing the unavoidable consequences of ischemia/reperfusion cycle occurring in this setting. Considerable evidence suggests the involvement of reactive oxygen species (ROS) in the pathogenic mechanism of this arrhythmia. Interestingly, the deleterious consequences of high ROS exposure, such as inflammation, cell death (apoptosis/necrosis) or fibrosis, may be abrogated by a myocardial preconditioning process caused by previous exposure to moderate ROS concentration known to trigger survival response mechanisms. The latter condition may be created by n-3 PUFA supplementation that could give rise to an adaptive response characterized by increased expression of myocardial antioxidant enzymes and/or anti-apoptotic pathways. In addition, a further reinforcement of myocardial antioxidant defenses could be obtained through vitamins C and E supplementation, an intervention also known to diminish enzymatic ROS production. Based on this paradigm, this review presents clinical and experimental evidence supporting the pathophysiological and molecular basis for a novel therapeutic approach aimed to diminish the incidence of postoperative atrial fibrillation through a non-hypoxic preconditioning plus a reinforcement of the antioxidant defense system in the myocardial tissue.

Aprotinin ameliorates ischemia/reperfusion injury in a rat hind limb model

The aim of the study was to investigate the protective effect of aprotinin in a rat hind limb ischemia/reperfusion (I/R) model. A well-known antioxidant, alpha-tocopherol, was also tested for comparison. Ischemia was induced for 4 h by vascular clamping of the iliac arteries of 24 Sprague-Dawley rats, followed by 1 h of reperfusion. Muscle injury was evaluated in three groups: a saline group, an alpha-tocopherol group and an aprotinin group. Blood pH, pO2, pCO2, HCO3, creatine kinase (CPK), lactate dehyrogenase (LDH) and thiobarbituric acid reactive substances (TBARS) as well as muscle TBARS were measured at the end of the reperfusion. Muscle tissue samples were taken for histological examination. alpha-Tocopherol and aprotinin groups showed a significant amelioration of plasma CPK (p=0.002, p=0.002), LDH (p=0.004, p=0.004) and muscle tissue TBARS (p=0.001, p=0.001) compared with the control. Plasma TBARS were significantly lower in the aprotinin group compared with the control (p=0.017). Also, tissue TBARS was significantly lower in the aprotinin group than the alpha-tocopherol group (p<0.001). Neutrophil infiltration was less prominent in the alpha-tocopherol and aprotinin groups compared to the control (p=0.006, p=0.001). These results suggest that aprotinin, a potent anti-inflammatory drug, is more useful than alpha-tocopherol, a powerful antioxidant, for attenuating muscle injury after I/R.

Detection of lead-induced oxidative stress in the rat epididymis by chemiluminescence

It has been shown that lead (Pb) is able to induce lipid peroxidation, one of the main manifestations of oxidative stress. In this study we examined the relationship between chronic Pb exposure and level of reactive oxygen species (ROS) in reproductive system tissues of sexually mature male Wistar rats. One group of animals (control, K) was allowed to drink distilled water, the second group (Pb) was allowed to drink freely 1% aqueous solution of lead acetate. Another groups had a following supplements: rats were allowed to drink distilled water containing vitamin C (vit C) at concentration of 500 mg/l or Trolox (a vitamin E analog) at concentration of 48 mg/l or vit C (500 mg/l) + Trolox (48 mg/l). The similar groups among Pb-treated animals were examined after treatment with the same vitamins and using the same vitamin doses, dissolved in 1% aqueous solution of lead acetate. In all cases the time of drinking was 6 months. It was found that lead content in samples of tissues from testis, epididymis and in a whole blood in Pb- and Pb with antioxidants treated rats was significantly elevated. Chemiluminescence (CL) emitted by the Pb-treated tissues was significantly higher when compared to the light emission by tissues isolated from the animals of control group. The increase in the CL caused by lead occurs in the following increasing order within the studied tissues: cauda of epididymis < testis < caput of epididymis (19%, 39% and 51%, respectively). Dietary vit C supplementation to the Pb-treated rats for 6 months period decreased the CL from caput of epididymis, cauda of epididymis and testis (by 43%, 24%, 39%, respectively) more effectively in comparison to the control group (35%, 17%, 33%, respectively). Also stronger quenching effect on the light emission from the above mentioned tissues after Trolox supplementation was observed in the Pb-treated group (42%, 21%, 35%, respectively) than in the control group (23%, 13%, 13% respectively). The combination of both antioxidants treatments (vit C and Trolox) did not give a higher significant quenching effect compared to the treatment with the vitamins separately. No ultrastructural changes were found in the seminiferous epithelium of Pb-treated animals. However, we found abnormalities in ultrastructure of epididymal epithelial cells and epididymal spermatozoa in rats of Pb-treated groups. These findings provide ex vivo evidence that Pb causes oxidative cellular damage in reproductive system tissues of adult male rats, which may be closely associated with the ROS production.

Combination therapy with vitamins C plus E inhibits survivin and human prostate cancer cell growth

BACKGROUND

We postulated that combinations of C and E vitamins modulate the antioxidant network and blocks survivin gene expression in androgen-responsive and non-responsive human prostate cancer cell (HPCC) lines.

METHODS

ALVA-101 and DU-145 cell growth and apoptosis were estimated using the Cell Titer 96 AQ and cell death detection ELISA. Reverse transcription-polymerase chain reaction, Western blot and electrophoretic mobility shift assay were used to quantify survivin mRNA, protein, nuclear factor kappa B (NF-kappaB), and activator protein-1 (AP-1).

RESULTS

All the tested combinations of vitamins C and E (25-100 microM, 72 hr) reduced cell growth (4-83%). Vitamin C enhanced the growth suppressive effect of vitamin E. Apoptosis was enhanced (25-45%) (vitamins = 100 microM, 24 hr). Survivin mRNA was decreased (26-29%) (vitamins = 250 microM, 24 hr), and survivin protein was decreased (>90%) (vitamins = 100 microM, 72 hr). NF-kappaB and AP-1 activities were increased (vitamins = 100 microM, 24 hr).

CONCLUSIONS

The combinations of vitamins C and E are potent inducers of apoptosis in HPCC and suppressers of surviving, an antiapoptotic factor.

The level of antioxidant enzymes, plasma vitamins C and E in cement plant workers

BACKGROUND

Chronic exposure to cement dust has been reported to lead to several health problems. This study was designed to investigate the plasma oxidant and antioxidant status in cement plant workers and control subjects.

METHODS

Twenty-eight volunteer male cement plant workers and 30 volunteer office male workers (control) aged 29-54 years participated. The concentration of plasma vitamin C (P-VC), plasma vitamin E (P-VE), plasma malondialdehyde (P-MDA), and the activity of erythrocyte superoxide dismutase (E-SOD), plasma glutathione peroxidase (P-GSH-Px), and some serum biochemical parameters were measured in both groups.

RESULTS

The levels of MDA (175%), ALT (61%), and AST (39%) were significantly increased, while total RBC count (12%), Hb (11%) vitamin E (51%), C (35%), SOD (44%), and GSH-Px (51%) activities were markedly decreased, and the levels of urea, protein, and albumin triglyceride and cholesterol were almost the same in cement plant workers versus the control subjects.

CONCLUSION

Cement workers are exposed to more oxidative stress compared to control subjects. To overcome these oxidative stresses, supplementation of antioxidant vitamins, such as alpha-tocopherol and ascorbic acid, may be beneficial. In addition, proper precaution to protect workers could prevent serious health problems.

Hypercholesterolemia and hypertension have synergistic deleterious effects on coronary endothelial function

OBJECTIVE

Coronary endothelial dysfunction is associated with an increase in cardiac events. Hypercholesterolemia (HC) and hypertension (HT) are both associated with endothelial dysfunction, and their coexistence is associated with an increased incidence of cardiac events in epidemiological studies. However, pathogenic mechanisms are poorly understood. Here we studied the effects of coexisting HC and HT on coronary endothelial function.

METHODS AND RESULTS

Four groups of pigs were studied after 12 weeks of a normal diet (n=9), a 2% HC diet (n=9), HT (achieved by unilateral renal artery stenosis, n=8), or HC+HT (n=6). Coronary endothelial function was tested, in epicardial arteries and arterioles, by using organ chamber techniques. Oxidative stress was measured in coronary artery tissue. Vasodilatory response to bradykinin and calcium ionophore was significantly impaired in animals with HC+HT compared with each risk factor alone (P<0.05 for both). In animals with coexistent HC and HT, the increase in oxidative stress was more pronounced compared with each risk factor alone (P<0.05). Furthermore, chronic antioxidant supplementation significantly improved coronary artery vasoreactivity.

CONCLUSIONS

These results suggest that HC and HT have a synergistic deleterious effect on coronary endothelial function, associated with increased oxidative stress. This interaction may contribute to the increased incidence of coronary heart disease and cardiac events seen when HC and HT coexist.

Influence of intravenous vitamin E supplementation in cardiac surgery on oxidative stress: a double-blinded, randomized, controlled study

BACKGROUND

I.V. infusions of vitamin E emulsion (all-rac-alpha-tocopherol) may reduce ischaemia-reperfusion injury after elective cardiac surgery.

METHODS

Forty patients participated in a prospective, double-blind, placebo-controlled, randomized trial, receiving either placebo or four doses (270 mg each) of all-rac-alpha-tocopherol between 16 h before and 48 h after surgery. We determined plasma concentrations of vitamin E, vitamin C, malondialdehyde, creatine kinase, troponin I and interleukin 6 and other measures of clinical outcome.

RESULTS

Infusion of vitamin E caused normalization of vitamin E plasma concentrations during and after surgery, but had no effect on the early increase in malondialdehyde concentration or the decreases in antioxidative capacity and the water-soluble antioxidant vitamin C.

CONCLUSIONS

Normalization of plasma vitamin E concentrations with parenteral vitamin E emulsion does not affect biochemical markers of myocardial injury and does not affect clinical outcome after cardiac surgery.