营养干预对骨髓移植病人抗氧化力及脂质过氧化的影响

目的探讨外源性补充抗氧化性维生素对骨髓移植病人抗氧化力及脂质过氧化的影响。方法将19名骨髓移植病人随机分为实验和对照组,实验组在预处理前给予维生素C(300 mg/d)和维生素E(600 mg/d),对照组不予补充,其余处理两者相同。测定移植前后两组病人的血浆总抗氧化力、丙二醛、全血谷胱甘肽过氧化物酶及红细胞超氧化物歧化酶水平。结果(1)移植前后实验组血浆总抗氧化力、谷胱甘肽过氧化物酶和红细胞超氧化物歧化酶值一直处于正常或正常值附近,对照组则低于正常值,两组相比有显著差异;(2)移植后实验组丙二醛值很快降至正常,对照组则一直处于较高水平,两组有显著差异。结论移植前外源性补充抗氧化性维生素可提高骨髓移植病人机体的抗氧化力,减少了脂质过氧化物的产生,有效缓解移植前大剂量放、化疗对病人机体造成的高氧化胁迫压力。     

抗氧化性维生素与男性生殖

生殖系统内过多的活性氧 (ROS)产生可导致精子膜脂质过氧化损伤 ,而抗氧化性维生素对于清除ROS 避免精子脂质过氧化损伤具有一定保护作用。本文就抗氧化性维生素在男性生殖中的作用及其在男性不育治疗等方面进行了综述     

The heat shock/oxidative stress connection

Involvement of free-radical oxidations in the aging process has been a topic of interest since Harman's original contribution. Because of the close association between aging and Alzheimer disease (AD) and the qualitative similarity in the neuropathology of both conditions, it has been proposed by many investigators that oxidative stress may be important in AD. If such modality of injury was indeed involved, one should expect to find markers of oxidation and heat shock (since free radicals are key mediators of heat-shock induction) in brains of patients with AD. In fact, several studies documented abnormal expression of antioxidant enzymes and heat-shock proteins (HSP) along with other markers of oxidation in AD brains. We showed that abnormally expressed antioxidant enzymes are topographically associated with senile plaques and neurofibrillary tangles, and that the activity of these enzymes is (contrary to what one would expect) markedly reduced. These findings have recently been confirmed by other investigators. Despite a large amount of evidence that suggests an association between oxidative stress and the pathogenesis of AD, it is not yet known whether oxidative stress is a cause or consequence of the disorder. Future research efforts regarding the oxidative stress hypothesis of AD should include attempts, at generating AD pathology by oxidative means in laboratory animals, determining the role and integrity of the heat-shock response in AD, as well as that of various antioxidant systems, growth factors, and hormones with antioxidant and neuroprotective properties.     

Reduced progression of atherosclerosis in apolipoprotein E-deficient mice treated with lacidipine is associated with a decreased susceptibility of low-density lipoprotein to oxidation

A study has been carried out in the apolipoprotein (apo) E-deficient mouse to investigate the activity of lacidipine (a calcium antagonist with antioxidant properties) in inhibiting the development of atherosclerotic lesions; of particular interest were changes in the susceptibility of low-density lipoproteins (LDL) to oxidation. Mice receiving a Western-type diet to accelerate the development of atherosclerosis were treated orally with vehicle or lacidipine at 3 or 10 mg/kg/day for 8 weeks. Lacidipine treatment (at 3 or 10 mg/kg) had no effect on the plasma lipid profile. However, a significant (P < 0.01) dose-related reduction of 43 and 50% of the aortic lesion area in respect to vehicle-treated mice was observed. Moreover, the resistance of mouse plasma LDL to undergo lipid peroxidation was significantly (P < 0.01) increased in apo E-deficient mice treated with lacidipine. The native LDL-like particle, derived from apo E-deficient mice treated with lacidipine, contained significantly lower concentrations of malonyldialdehyde than the vehicle-treated control group (P < 0.01). After exposure to human umbilical vein endothelial cells, LDL-like particle vitamin E levels (expressed as area under the curve; AUC), were significantly higher (P < 0.01) in both the 3 and 10 mg/kg lacidipine-treated groups, in comparison with the vehicle-treated control animals. We conclude that lacidipine reduced the extent of the atherosclerotic area in hypercholesterolaemic apo E-deficient mice, and that this reduction may be associated with the capacity of the drug to decrease the susceptibility of LDL to oxidation.     

The antioxidant properties of histamine receptor blockers: a comparative study in a model system

Antioxidant activities of seven histamine receptor blockers are compared using a model system of multilayer liposomes, chemiluminescence analysis, and 2-thiobarbituric acidreactive substance assay. According to a decrease in the antioxidant activity, the drugs can be arranged as follows: diprazine, suprastin, tavegil, diazoline, dimedrol, phencarol, and ranitidine. The possible mechanisms of the antioxidant activity and the significance of the antioxidant properties of these drugs for experimental research and clinical practice are discussed. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, No. 12, pp. 638–641, December, 1996     

Alterations of plasma antioxidants and mitochondrial DNA mutation in hair follicles of smokers

The effects of long-term smoking on mitochondrial DNA (mtDNA) deletions in hair follicles were investigated in subjects with different antioxidant capacity. Twenty-two male smokers with a smoking index of greater than 5 pack-years and without any known systemic diseases were recruited for this study. Forty healthy nonsmoking males were included as controls. We found that the concentrations of ascorbate and alpha-tocopherol and the activities of glutathione S-transferase (GST) and glutathione peroxidase in blood plasma were significantly decreased in smokers. The levels of glutathione and protein thiols in whole blood and the incidence of a 4,977 bp deletion of mtDNA (dmtDNA) in hair follicles were significantly increased in smokers. A significantly higher incidence of the 4,977 bp dmtDNA was found in smokers with plasma GST activity less than 5.66 U/l (OR = 7.2, P = 0.020). Using multiple covariate ANOVA and logistic regression, we found that age and low plasma GST activity were the only two risk factors for the 4,977 bp dmtDNA. These results suggest that smoking depletes antioxidants and causes mtDNA deletions and that plasma GST may play an important role in the preservation of the mitochondrial genome in tissue cells of smokers.     

Relationship between oxidative stress and embryotoxicity of hydrosalpingeal fluid

BACKGROUND: Oxidative stress mechanisms are involved in the pathophysiology of many reproductive disorders. The objective of this study was to characterize oxidative stress parameters in hydrosalpingeal fluid (HSF) and examine their possible role in early embryo development. METHODS AND RESULTS: HSF was aspirated at laparoscopic salpingectomy in 11 infertile women. Reactive oxygen species (ROS), total (non-enzymatic) antioxidant capacity (TAC) and lipid peroxidation (LPO) were assayed. Two-cell mouse embryos were incubated with 25, 50 or 75% HSF and the blastocyst development rate was observed. ROS was detected in five of 11 (45%) HSF samples with a mean of 4.2 x 10(4) c.p.m. LPO was detected in all samples at a mean (+/- SD) value of 5575.4 +/- 6091.9 micromol/l malonaldehyde. The mean blastocyst development rate at 25, 5+/- 0 and 75% HSF and in the control group was 88.9 +/- 9.4, 65.7 +/- 19.1, 45.7 +/- 5.7 and 96.7% respectively (P < 0.0001). The blastocyst development rate was positively correlated to ROS concentrations (P < 0.02) but was not significantly related to LPO. CONCLUSIONS: The blastocyst development rate decreased with increasing concentrations of HSF. For the first time, the presence of ROS, LPO and TAC activity in human HSF was characterized. A possible role of oxidative stress in the embryotoxicity of HSF is suggested.     

Mutagenicity,antioxidant potential,and antimutagenic activity against hydrogen peroxide of cashew (Anacardium occidentale) apple juice and cajuina

Fresh and processed cashew (Anacardium occidentale) apple juice (CAJ) are among the most popular drinks in Brazil. Besides their nutritional benefits, these juices have antibacterial and antitumor potential. The chemical constituents of both the fresh juice and the processed juice (cajuina) were analyzed and characterized as complex mixtures containing high concentrations of vitamin C, various carotenoids, phenolic compounds, and metals. In the present study, these beverages exhibited direct and rat liver S9-mediated mutagenicity in the Salmonella/microsome assay with strains TA97a, TA98, and TA100, which detect frameshifts and base pair substitution. No mutagenicity was observed with strain TA102, which detects oxidative and alkylating mutagens and active forms of oxygen. Both CAJ and cajuina showed antioxidant activity as determined by a total radical-trapping potential assay. To test whether this antioxidant potential might result in antimutagenesis, we used a variation of the Salmonella/microsome assay that included pre-, co-, and posttreatment of hydrogen peroxide-exposed Salmonella typhimurium strain TA102 with the juices. CAJ and cajuina protected strain TA102 against mutation by oxidative damage in co- and posttreatments. The antimutagenic effects during cotreatment with hydrogen peroxide may be due to scavenging free radicals and complexing extracellular mutagenic compounds. The protective effects in posttreatment may be due to stimulation of repair and/or reversion of DNA damage. The results indicate that CAJ and cajuina have mutagenic, radical-trapping, antimutagenic, and comutagenic activity and that these properties can be related to the chemical constituents of the juices.     

Dietary Habits,Selenium, Copper,Zinc and Total Antioxidant Status in Serum in Relation to Cognitive Functions of Patients with Alzheimer’s Disease

Oxidative stress plays a crucial role in the neurodegenerative process and can impair cognitive functions. In the prevention of Alzheimer’s disease (AD), an adequate consumption of dietary antioxidants may be a major factor. The objective of the study was to estimate selenium (Se), copper (Cu), zinc (Zn), and total antioxidant status (TAS) in the serum of patients with AD in relation to their cognitive functions and dietary habits. A total of 110 patients (aged 54–93 years) with early or moderate AD, as well as 60 healthy people (aged 52–83 years) were studied. The severity of the disease was assessed using the mini-mental state examination (MMSE) scale. Food-frequency questionnaires were implemented to collect the dietary data. The concentrations of Se, Cu and Zn in the sera were determined by the atomic absorption spectrometry method. TAS was estimated spectrophotometrically using ready-made kits (Randox). Significantly lower concentrations of Se, Zn and TAS, and higher Cu:Zn ratio in the serum of patients with AD, compared to healthy people, were observed. A low correlation between the MMSE score and TAS in the serum of AD patients and significantly higher MMSE values in patients with TAS above the reference range were also noted. In patients with serum Cu concentration above the norm, significantly lower MMSE values were found. Selected dietary habits such as the frequency of consumption of various food products had a significant impact on the concentration of the assessed parameters in the serum of people with AD.