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1.
Essential elements, mainly selenium and zinc, were involved in protection against oxidative stress in cells. Oxidation could lead to the formation of free radicals that have been implicated in the pathogenesis of many diseases, including leukemia. Leukemia is a neoplastic disease that is susceptible to antioxidant enzyme and essential elements alterations. This study was undertaken to examine the levels of essential elements, antioxidant enzymes activities, and their relationships with different types of leukemia. Serum selenium, zinc, and copper concentrations, red blood cell glutathione peroxidase (GPx) activities, plasma Cu−Zn superoxide dismutase (Cu−Zn SOD) activities and lipid peroxidation (LPO) levels were determined in 49 patients with different types of leukemia before initial treatment. Serum selenium and zinc concentrations were lower in leukemia patients than those of controls (p<0.01). Serum copper concentration was higher in leukemia patients than that of controls (p<0.01). The activities GPx and Cu−Zn SOD were significantly increased in leukemia patients, especially with acute leukemia (AL), acute lymphoid leukemia (ALL), and acute nonlymphoid leukemia (ANLL) (p<0.05), whereas no difference was found between those of chronic myelogeneous leukemia and the controls. The levels of LPO were normal as controls. Serum selenium concentration was not correlated with GPx, and serum levels of zinc and copper were not related to Cu−Zn SOD. Serum zinc levels had a negative correlation with the absolute peripheral blast cells, whereas serum copper had a positive correlation with the absolute peripheral blast cells. Increased GPx and Cu−Zn SOD activities and normal levels of LPO, which were a protective responses, were an indicator of mild oxidative stress; it mights indicate that the essentials elements alterations in leukemia patients were mostly dependent on tumor activity. Changes of their levels demonstrated that there are low selenium, zinc, and high copper status in leukemia patients. The decrease of plasma zinc and increase of the Cu/Zn ratio could be the index that showed an unfavorable prognosis of acute leukemia.  相似文献   

2.
《Free radical research》2013,47(12):1187-1194
Abstract

Background: Modifications of oxidative stress are reported in hepatitis C. The relationship between insulin resistance (IR), steatosis and oxidative stress is not established. Materials and methods: One hundred and eighty-seven HCV-RNA patients were assessed by determination of biochemical, metabolic and viral features, HOMA-IR and morphological alterations. In the 52-non-3 genotypes sub-group and 35 healthy individuals, thiobarbituric acid (TBARS), total glutathione (total-GSH), vitamins C and E, lycopene, β-carotene, glutathione peroxidase (GPx), catalase and superoxide dismutase were determined. Results: In non-3 genotype patients, steatosis was associated with higher values of BMI, HOMA-IR and triglycerides. In the 52-HCV sub-group, values of TBARS, GPx and total-GSH differ from the control group. Despite these, differences could not be observed according to the presence of steatosis, patients with IR presented significant differences regarding total-GSH (p=0.019), β-carotene (p=0.006), lycopene (p=0.005) and GPx (p=0.009). Conclusion: In non-3 genotype HCV carries, IR, and not steatosis, is associated with modifications in serum levels of oxidative stress.  相似文献   

3.
The objective of this study was to determine whether systemic inflammatory and oxidative stress marker concentrations correlate with pericardial and intrathoracic fat volumes. Participants of the Framingham Offspring Study (n = 1,175, 53% women, mean age 59 ± 9 years) had pericardial and intrathoracic fat volumes assessed by multidetector computed tomography (MDCT) scans, and provided fasting blood and urine samples to measure concentrations of 14 inflammatory markers: C‐reactive protein (CRP), interleukin‐6, monocyte chemoattractant protein‐1 (MCP‐1), CD40 ligand, fibrinogen, intracellular adhesion molecule‐1, lipoprotein‐associated phospholipase A2 activity and mass, myeloperoxidase, osteoprotegerin, P‐selectin, tumor necrosis factor‐α, tumor necrosis factor receptor‐2, and urinary isoprostanes. Multivariable linear regression models were used to determine the association of log‐transformed inflammatory marker concentrations with fat volumes, using fat volume as the dependent variable. Due to smaller sample sizes, models were rerun after adding urinary isoprostanes (n = 961) and tumor necrosis factor‐α (n = 813) to the marker panel. Upon backward elimination, four of the biomarkers correlated positively with each fat depot: CRP (P < 0.0001 for each fat depot), interleukin‐6 (P < 0.05 for each fat depot), MCP‐1 (P < 0.01 for each fat depot), and urinary isoprostanes (P < 0.01 for pericardial fat; P < 0.001 for intrathoracic fat). Even after adjusting for BMI, waist circumference (WC), and abdominal visceral fat, CRP (P = 0.0001) and urinary isoprostanes (P = 0.02) demonstrated significant positive associations with intrathoracic fat, but not with pericardial fat. Multiple markers of inflammation and oxidative stress correlated with pericardial and intrathoracic fat volumes, extending the known association between regional adiposity and inflammation and oxidative stress.  相似文献   

4.
Objective: The aim of this study was to determine the implication of xanthine oxidase (XO) in the exercise-induced muscle oxidative stress and muscle dysfunction of these patients.

Methods: A randomized, crossover and double-blind study was conducted in nine severe COPD patients, who performed a localized quadriceps endurance test after oral treatment with allopurinol, a XO inhibitor or placebo. Redox status was studied in arterial and venous femoral blood before and after the endurance test.

Results: In placebo condition, muscle exercise resulted in a significant increase in AOPP and isoprostanes, with a significant increase in the venoarterial difference (v-a) in isoprostanes after exercise as compared with before (p<0.05). In contrast, allopurinol treatment prevented the elevation in AOPP levels and v-a isoprostanes after exercise. However, no significant improvement in quadriceps muscle endurance was observed, but allopurinol treatment seemed to preserve muscle strength properties.

Conclusion: This study demonstrates that XO is implicated in the exercise-induced muscle oxidative stress of COPD patients. Allopurinol administration seemed to improve only some muscle properties. Therefore other sources of muscle oxidative stress should be implicated in muscle dysfunction observed in these patients.  相似文献   

5.
Abstract

Objectives

Knowledge about the role of oxidative stress in human diseases, including cardiovascular system disorders, emphasizes the need for reliable markers of oxidative stress. Here, we evaluated the levels of the novel marker ischemia-modified albumin (IMA), albumin-adjusted IMA (adj-IMA), and the IMA/serum albumin ratio (IMAR) in patients with chronic ischemic heart failure (CIHF).

Methods

A total of 55 patients with CIHF and 40 age- and sex-matched healthy individuals were included in the study. Serum levels of IMA, total antioxidant status, and total oxidant status were analyzed, and the adj-IMA level, IMAR, and oxidative stress index were calculated.

Results

Serum IMA, IMAR, total oxidant status levels, and oxidative stress index were significantly higher in patients with CIHF than in the controls (all P < 0.0001), whereas albumin and total antioxidant status levels were significantly lower in the CIHF patients (P < 0.0001 and P = 0.0004, respectively). However, there was no significant difference in serum adj-IMA levels between the groups (P = 0.8).

Discussion

We observed impaired oxidant/antioxidant status in favor of oxidative stress in CIHF patients. Oxidative stress may be a key factor in the development of hypoalbuminemia in CIHF. Further studies are needed to establish the relationships among IMA, albumin, and redox balance in CIHF.  相似文献   

6.
Oxidative stress leads to lipid peroxidation and may contribute to the pathogenesis of lesions in multiple sclerosis (MS), an autoimmune disease characterized by inflammatory as well as degenerative phenomena. Isoprostanes are prostaglandin-like compounds which are formed by free radical catalysed peroxidation of arachidonic acid esterified in membrane phospholipids. They are a new class of sensitive specific markers for in vivo lipid peroxidation. In this study 26 patients (15 females and 11 males; mean age 48.2 ± 15.2 year; mean disease duration 10.0 ± 6.5 year) with secondary progressive MS (SPMS) and 12 healthy controls were enrolled. In patients with multiple sclerosis the lipid peroxidation as the level of urine isoprostanes and the level of thiobarbituric acid reactive species (TBARS) in plasma were estimated. Moreover, we estimated the total antioxidative status (TAS) in plasma. It was found that the urine isoprostanes level was over 6-fold elevated in patients with SPMS than in control (P < 0.001). In SPMS patients TBARS level was also statistically higher than in controls (P < 0.01). However, we did not observed any difference of TAS level in serum between SPMS patients and controls (P > 0.05). In patients with SPMS the lipid peroxidation and oxidative stress measured as the increased level of isoprostanes was observed. Thus, we suggest that the level of isoprostanes may be used as non-invasive marker for a determination of oxidative stress what in turn, together with clinical symptoms, may determine an specific antioxidative therapy in SPMS patients.  相似文献   

7.
Abstract

This study aimed to evaluate the organelle-specific antioxidant/pro-oxidant actions of clinically important dietary antioxidants against oxidative stress. An in vitro cellular model was employed to investigate the antioxidant/pro-oxidant effects of various concentrations (1, 10 and 100 μM) of ascorbic acid, α-tocopherol and β-carotene during H2O2-induced oxidative stress. Damage to nuclear and mitochondrial genomes was analyzed by quantitative polymerase chain reaction and oxidation of membrane lipids was measured via colorimetric assays. The key findings were: (i) dietary antioxidants conferred a dose-dependent protective effect (with a pro-oxidant shift at higher concentrations); (ii) the protection conferred to different sub-cellular organelles is highly specific to the dietary antioxidant; (iii) the mtDNA is highly sensitive to oxidative attack compared to nDNA (P < 0.05); and (iv) mtDNA protection conferred by dietary antioxidants was required to improve protection against oxidative-induced cell death. This study shows that antioxidant-induced protection of mtDNA is an important target for future oxidative stress therapies.  相似文献   

8.
《Free radical research》2013,47(9):692-698
Abstract

Intake of antioxidants from the diet has been recognized to have beneficial health effects, but the potential benefit of taking antioxidants such as β-carotene as supplements is controversial. The aim of the present study was to evaluate the potential protective effects of a physiologically relevant concentration (2 μM) of β-carotene on the DNA damaging effects of catechol in mouse lymphoma L5178Y cells. Two different exposure protocols were used: simultaneous exposure to β-carotene and catechol for 3 h; and exposure to catechol for 3 h after 18 h pre-treatment with the vitamin. DNA damage was evaluated using the comet assay (employing one procedure for general damage, and another procedure, which also included oxidative DNA damage). Independent of exposure protocol and procedure for comet assay, β-carotene did not increase the basal level of DNA damage. However, at the highest concentration of catechol (1 mM), β-carotene was found to clearly increase the level of catechol-induced DNA damage, especially in the pre-treated cells. Interestingly, an opposite effect was observed at lower concentrations of catechol, but the β-carotene related reduction of catechol-induced genotoxicity was significant (P < 0.05) only for the procedure including oxidative damage induced by 0.5 mM catechol. Taken together our results indicate that β- carotene can both reduce and enhance the DNA damaging effects of a genotoxic agent such as catechol. This indicates that it is the level of catechol-induced DNA damage that seems to determine whether β-carotene should be regarded as a beneficial or detrimental agent when it comes to its use as a dietary supplement.  相似文献   

9.
《Biomarkers》2013,18(2):154-158
Abstract

Oxidative stress biomarkers may have a role in the future to assist clinical decisions regarding the use of antioxidant therapies and their efficacy. The aims of this study were to evaluate the within and between-individual variability of plasma oxidative stress biomarkers and investigate factors affecting their variability. Plasma F2-isoprostanes and protein carbonyls were measured in 14 hemodialysis patients every 2 weeks for 10 weeks. Within-individual coefficients of variation (CVs) were isoprostanes?=?30.4% (range?=?6.1–66.7%) and protein carbonyls?=?16.3% (8.4–29.5%). Between-individual CVs were isoprostanes?=?34.4% (28.9–40.2%) and protein carbonyls?=?19.5% (15.6–24.5%). There were no significant (p?>?0.05) relationships between the oxidative stress biomarkers and dietary antioxidant intake, medications, clinical and demographic parameters.  相似文献   

10.
BackgroundIntraluminal thrombus (ILT) formation plays a significant role in the progression of infrarenal abdominal aortic aneurysms (AAA). Potentially, as ILT thickness increases the availability of trace elements in the aneurysm wall could decrease thereby leading to oxidative stress and intensifying pro-inflammatory cytokine generation.AimTo determine if thrombus thickness is related to the concentration of trace elements in the wall of infrarenal AAA.Patients and methodsThe concentrations of trace elements in the wall of the aneurysm sack and ILT obtained from 19 consecutive patients during surgery for infrarenal AAA were determined using emission spectrometry.ResultsThe concentrations of magnesium, zinc, manganese, and lead in the wall of AAA were significantly greater than in the ILT. Only the concentration of copper was lower in the AAA wall compared with the thrombus. The concentration of calcium, phosphorus, zinc, lead, copper, and magnesium increased with ILT thickness. The concentrations of no other trace elements in the wall of AAA were found to be related to the ILT thickness.ConclusionsIntraluminal thrombus thickness is not associated with a lower concentration of trace elements in the wall of the infrarenal AAA. Thus, the intraluminal thrombus participates in the progression of AAA by mechanisms independent of trace element supply to the wall of the aneurysm sack.  相似文献   

11.
Both anemia and zinc deficiency are commonly observed in patients with chronic uremia. Oxidative stress of red blood cells (RBC) has been suggested to participate in the development of anemia in these patients with chronic uremia due to reduced life span of RBC. Whether zinc deficiency aggravates the effect of oxidative stress on RBC of chronic uremia is still not understood. We thus performed the study to determine the influence of zinc deficiency on the oxidative stress of RBC in uremic rats. Zinc deficiency was induced by long-term dietary zinc deficiency. Five-sixth nephrectomy (5/6 Nx) was used to produce chronic uremia. Experiment was carried out in the following five groups: normal control (NL), chronic uremia (Nx), chronic uremia + dietary zinc deficiency (Nx-D), Nx-D + zinc supplement (Nx-DZ) and Chronic uremia + pair-fed (Nx-PF). Osmotic fragility and lipid peroxidation of RBC were used to evaluate the oxidative stress of RBC. Five weeks after 5/6 nephrectomy (Nx), 5/6 Nx rats present a syndrome of uremia to elevate the levels of plasma creatinine and urea, and reduce the level of plasma zinc (1.12 +/- 0.08 vs 1.35 +/- 0.05 ug/ml). But they does not find to produce anemia and to increase osmotic fragility and lipid peroxidation in RBC. Dietary zinc deficiency in Nx-D group produced severe anorexia and reduced plasma zinc and selenium levels and the activity of RBC-GPX. Yet in Nx-D rats, osmotic fragility and susceptibility of lipid peroxidation in red cells did not increase, because of the increase of plasma copper level (1.85 +/- 0.3 vs 1.41 +/- 0.05 microg/ml) and RBC-SOD activity (1.95 +/- 0.27 vs 0.78 +/- 0.05 unit/g Hb). Zinc supplement in Nx-D rats (Nx-DZ group) recovered the appetite and normalized the levels of plasma zinc, copper and selenium. Food restriction in 5/6 Nx rats (Nx-PF group) decreased plasma copper level and increased osmotic fragility of RBC and elevated the susceptibility of lipid peroxidation after stressing RBC with H2O2 Because Nx-PF rats presented a lower RBC-SOD activity (0.44 +/- 0.11 vs 0.78 +/- 0.05 unit/g Hb) and a lower plasma copper level. We further found a positive relationship (r=0. 802,p<0.01) between plasma copper level and RBC-SOD activity in normal and uremic rats. This study suggests that RBC-SOD activity may play an important role in preventing RBC oxidative stress. Plasma copper level may be a marker of RBC-SOD activity. We conclude, in chronic uremia, zinc deficiency doses not result in RBC oxidative stress as plasma copper level is normal, but may affect the absorption of intestinal nutrition.  相似文献   

12.
Plasma essential trace elements, selenium, copper, zinc, and iron concentrations and the levels of immunoregulatory cytokines, interleukin-1β (IL-1β), interleukin-2 receptor (IL-2r), IL-6, IL-8, and tumor necrosis factor-α (TNF-α) were evaluated in patients with cutaneous leishmaniasis (CL) to investigate a possible role of these cytokines on selenium, zinc, copper, and iron homeostasis in CL patients. Plasma albumin levels were measured as an index of nutritional status. Plasma selenium, zinc, and iron concentrations, and IL-2r levels were significantly lower, and copper concentrations and IL-1β, IL-8, IL-6 and TNF-α levels were significantly higher in patients with CL than those of healthy controls. There was no significant difference in plasma albumin levels between two groups. There were positive important correlations between plasma selenium and IL-2r, copper and IL-6, and copper and IL-1β, and negative correlations between selenium and IL-8, iron and TNF-α, and zinc and IL-1β contents in patients with CL. Our results showed that plasma trace element contents change in patients with CL. These changes may not be a result of a specific deficiency from dietary inadequacies or imbalances, but, probably, a result of a part of the defense strategies of an organism that is regulated by immunoregulatory cytokines.  相似文献   

13.
Approximately 12% of Americans do not consume the estimated average requirement for zinc and could be at risk for zinc deficiency. Since zinc has proposed antioxidant function, inadequate zinc consumption may lead to an enhanced susceptibility to oxidative stress through several mechanisms, including altered antioxidant defenses. In this study, we hypothesized that dietary zinc restriction would result in lower antioxidant status and increased oxidative damage. We fed weanling Sprague-Dawley rats (n=12 per group) a zinc-adequate (50 mg/kg of zinc) diet, a zinc-deficient (<0.05 mg/kg of zinc) diet or a pair-fed diet for 3 weeks and then assessed their antioxidant status and oxidative stress parameters. Rats were zinc deficient as indicated by a significant (P<.05) reduction in body weight (49%) and 19% lower (P<.05) hepatic zinc (20.6+/-2.1 mg/kg) as compared with zinc-adequate rats (24.6+/-2.2 mg/kg). Zinc deficiency resulted in elevated (P<.05) plasma F(2) isoprostanes. Zinc deficiency-mediated oxidative stress was accompanied by a 20% decrease (P<.05) in the ferritin-reducing ability of plasma assay and a 50% reduction in plasma uric acid (P<.05). No significant change in plasma ascorbic acid or in plasma alpha-tocopherol and gamma-tocopherol was observed. However, hepatic alpha-tocopherol and gamma-tocopherol concentrations were decreased by 38% and 27% (P<.05), respectively, as compared with those in zinc-adequate rats. Hepatic alpha-tocopherol transfer protein levels were unaltered (P>.05) by zinc deficiency, but cytochrome P450 (CYP) 4F2 protein levels were elevated (P<.05) as compared with those in zinc-adequate rats. Collectively, zinc deficiency increased oxidative stress, which may be partially explained by increased CYP activity and reductions in hepatic alpha-tocopherol and gamma-tocopherol and in plasma uric acid.  相似文献   

14.
Zhang  Rong-Rong  Wang  Ya-Hui  Li  Tong  Tan  Guo-Fei  Tao  Jian-Ping  Su  Xiao-Jun  Xu  Zhi-Sheng  Tian  Yong-Sheng  Xiong  Ai-Sheng 《Protoplasma》2021,258(2):379-390

Carotenoids are liposoluble pigments found in plant chromoplasts that are responsible for the yellow, orange, and red colors of carrot taproots. Drought is one of the main stress factors affecting carrot growth. Carotenoids play important roles in drought resistance in higher plants. In the present work, the carotenoid contents in three different-colored carrot cultivars, ‘Kurodagosun’ (orange), ‘Benhongjinshi’ (red), and ‘Qitouhuang’ (yellow), were determined by ultra-high-performance liquid chromatography (UPLC) after 15% polyethylene glycol (PEG) 6000 treatment. Real-time fluorescence quantitative PCR (RT-qPCR) was then used to determine the expression levels of carotenoid synthesis- and degradation-related genes. Increases in β-carotene content in ‘Qitouhuang’ taproots under drought stress were found to be related to the expression levels of DcPSY2 and DcLCYB. Increases in lutein and decreases in α-carotene content in ‘Qitouhuang’ and ‘Kurodagosun’ under PEG treatment may be related to the expression levels of DcCYP97A3, DcCHXE, and DcCHXB1. The expression levels of DcNCED1 and DcNCED2 in the three cultivars significantly increased, thus suggesting that NCED genes could respond to drought stress. Analysis of the growth status and carotenoid contents of carrots under PEG treatment indicated that the orange cultivar ‘Kurodagosun’ has better adaptability to drought stress than the other cultivars and that β-carotene and lutein may be involved in the stress resistance process of carrot.

  相似文献   

15.
Abstract

Introduction: Although it is uncertain how the hepatitis C virus (HCV) core protein influences hepatic oxidative stress after partial hepatectomy and common bile duct ligation (CBDL) this may be crucial for the prognosis of patients with HCV infection who have undergone hepatic resection, or who have complications due to a biliary tract obstruction.

Materials and methods: A group of double transgenic mice (DTM) that express both the tetracycline transactivator (tTA) and the HCV core, with conditional, acute expression of the HCV core in the context of the mature liver were subjected to 43% partial hepatectomy and CBDL. The levels of thioredoxin-1, thiobarbituric acid reactive substances (TBARS), and 4-hydroxynonenal (4-HNE) were evaluated in liver samples taken 3 days after the operations.

Results: The DTM had significantly higher TBARS levels than mice that were transgenic for only tTA (i.e. single transgenic mice; STM) and non-transgenic mice (NTM) after a sham laparotomy, CBDL and partial hepatectomy. Of the DTM, the TBARS levels were higher in female mice than in males after a sham laparotomy (P = 0.02) and CBDL (P = 0.0001). 4-HNE staining data were compatible with these results. Furthermore, male DTM exhibited higher levels of thioredoxin-1 than female DTM after sham laparotomy (P = 0.012) and CBDL (P = 0.008).

Conclusions: The HCV core increases hepatic oxidative stress in vivo and female DTM are more vulnerable to the oxidative stress caused by acute core expression with, or without, CBDL. The fact that the female DTM had lower thioredoxin-1 levels may account for this observation.  相似文献   

16.
《Free radical research》2013,47(5):650-680
Abstract

β-Carotene, the precursor of vitamin A, possesses pronounced radical scavenging properties. This has centered the attention on β-carotene dietary supplementation in healthcare as well as in the therapy of degenerative disorders and several cancer types. However, two intervention trials with β-carotene have revealed adverse effects on two proband groups, that is, cigarette smokers and asbestos-exposed workers. Beside other causative reasons, the detrimental effects observed have been related to the oxidation products of β-carotene. Their generation originates in the polyene structure of β-carotene that is beneficial for radical scavenging, but is also prone to oxidation. Depending on the dominant degradation mechanism, bond cleavage might occur either randomly or at defined positions of the conjugated electron system, resulting in a diversity of cleavage products (CPs).

Due to their instability and hydrophobicity, the handling of standards and real samples containing β-carotene and related CPs requires preventive measures during specimen preparation, analyte extraction, and final analysis, to avoid artificial degradation and to preserve the initial analyte portfolio. This review critically discusses different preparation strategies of standards and treatment solutions, and also addresses their protection from oxidation. Additionally, in vitro oxidation strategies for the generation of oxidative model compounds are surveyed. Extraction methods are discussed for volatile and non-volatile CPs individually. Gas chromatography (GC), (ultra)high performance liquid chromatography (U)HPLC, and capillary electrochromatography (CEC) are reviewed as analytical tools for final analyte analysis. For identity confirmation of analytes, mass spectrometry (MS) is indispensable, and the appropriate ionization principles are comprehensively discussed. The final sections cover analysis of real samples and aspects of quality assurance, namely matrix effects and method validation.  相似文献   

17.
18.
Abstract

The effect of supplementation with substances having antioxidant properties on the adaptive responses of human skin fibroblasts to UV-induced oxidative stress was studied in vitro. UVR was found to induce a substantial oxidative stress in fibroblasts, resulting in an increased release of superoxide anions and an increase in lipid peroxidation (shown by an elevated malonaldehyde content). Sub-lethal doses of UVR were also found to induce adaptive responses in the fibroblast antioxidant defences, with a transient rise in catalase and superoxide dismutase activities followed by a slower, large increase in cellular glutathione content. Supplementation of the fibroblasts with the antioxidants, Trolox (a water soluble analogue of α-tocopherol), ascorbic acid or β-carotene, had differential effects on these responses. Trolox supplementation reduced the UVR-induced cellular oxidative stress and adaptive response in a predictable concentration-dependant manner. This was in contrast to ascorbic acid which increased superoxide release from fibroblasts. At low doses, ascorbate supplements also reduced the magnitude of the adaptive increases in catalase and superoxide dismutase activities and increase in glutathione content. β-Carotene had a similar effect to ascorbic acid, reducing the extent of the adaptations to UVR at lower doses while simultaneously increasing superoxide release and malonaldehyde content. These in vitro data indicate that only the vitamin E analogue suppressed UVR-induced oxidative stress in a predictable manner and suggest that common dietary antioxidants may not be equally effective in reducing the potential deleterious effects of UVR-induced oxidative stress in skin.  相似文献   

19.

Colorectal cancer (CRC) is an increasingly common medical issue affecting millions worldwide, and contribution of the body’s trace elements to CRC is arguable. The concentrations and buffered status of selenium, iron, copper, zinc, and phosphorus in blood and large intestinal tissues of CRC patients are, respectively, variable and vital for cell physiology. The aim of this study was to assess selenium, iron, copper, zinc, and phosphorus variations in blood and colorectal epithelia along with examining the expression of mismatch repair proteins in CRC patients with/without metastasis for potential diagnosis/therapy. Concentrations of selenium, iron, copper, zinc, and phosphorus in blood of healthy versus CRC patients and colorectal epithelia (adenocarcinomatous versus non-adenocarcinomatous/control) were measured in 40 CRC patients (55.87 ± 11.9 years old) with/without metastasis before surgery using ICP-OES. Mismatch repair (MMR) protein expression was analyzed through histopathological/immunohistochemistry assays, which was sparse in 5 CRC patient’s colorectal tissues (12%). Compared with healthy individuals, blood and colorectal tissue’s levels of phosphorus, copper, and iron were significantly higher in the CRC patients, and more pronounced in metastatic CRC patients; conversely, blood and colorectal tissue’s selenium levels were significantly lower in metastatic patients. Unlike blood zinc, cancerous colorectal tissue’s zinc concentration was significantly lower in CRC patients compared to healthy control cohorts. There was no significant difference on the measured elements in samples from CRC patients with MMR compared to CRC patients with MMR+. Receiver operating characteristic analysis revealed a correlation of blood iron, zinc, copper, and phosphorus to CRC, and inappropriately low levels of blood and colorectal selenium correlated with exacerbated metastasis. Altered levels of selenium, iron, copper, zinc, and phosphorus in vivo may impact the pathogenesis and detection of CRC, and their diagnostic/therapeutic potential in CRC would be revealing.

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20.
《Free radical research》2013,47(1-2):85-92
Experiments with model membranes, in which ubiquinone was incorporated, were performed in order to clarify the mechanism by which ubiquinone can prevent or control chain lipid peroxidation in biomembranes.

Comparing the behaviour of ubiquinone-containing vesicles with β-carotene containing vesicles we suggest that a possible explanation of the ubiquinone antioxidant effect could be to scavenge singlet oxygen and to affect structurally the lipid bilayer inhibiting hydroperoxide decomposition.  相似文献   

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