Antioxidant activity of blood plasma of mountain Altai's aborigines Russian and Kazakh nationality of low and medium height altitude areas

Due to the points about dependence antioxidant activity of organism of human on a nationality, climatic conditions, quality of nutrition are scanty under study a estimate antioxidant activity of blood plasma of Altai's low and medium height altitude aborigines. As a result there has been discovered a dependence of antioxidant activity of blood plasma more upon age and at least geographical and climatic conditions, sex and quality of nutrition.     

Selenium and malondialdehyde content and glutathione peroxidase activity in maternal and umbilical cord blood and amniotic fluid

Placenta tissue may be a major source of lipid peroxidation products in pregnancy. It was proven that placental peroxidation activity increases with gestation. Selenium (Se), as an essential constituent of glutathione peroxidase (GSH-Px), takes part in the reduction of hydrogen peroxides and lipid peroxides. Malondialdehyde (MDA) is a major breakdown product split off from lipid peroxides. In this study, Se and MDA content and GSH-Px activity were measured in blood and plasma taken from 20 apparently healthy nonpregnant women between 19 and 38 yr of age and from 115 unselected pregnant women between 17 and 45 yr of age (35 in the first trimester, 22 in the second trimester, 38 in the third trimester, and 20 within 2 d of delivery). Samples of umbilical cord blood and amniotic fluid were taken from women in the second and third trimesters and at delivery. The Se content was measured by atomic absorption spectrometry (AAS), plasma MDA concentration by thiobarbituric acid reaction, and Se-dependent GSH-Px spectrometrically. Blood and plasma Se contents of nonpregnant women were below those considered adequate, indicating low selenium intake. In comparison to nonpregnant women, pregnant women had significantly decreased whole-blood and plasma Se levels in the second and third trimesters and at delivery. The significant drop of whole-blood SeGSH-Px activity was observed in the first trimester of pregnancy and its lower activity was maintained until delivery. A significant drop in plasma SeGSH-Px activity occurred in the second trimester and attained the minimal level at delivery. The Se level and SeGSH-Px activity in maternal and umbilical cord blood were at similar levels. Amniotic-fluid SeGSH-Px activity was nondetectable or exceptionally low and its Se content remained unchanged during pregnancy. Plasma levels of MDA were significantly decreased in the second and third trimesters and at delivery. The fetal blood plasma at birth had a lower MDA level compared to the levels of MDA of their mothers at delivery. A low, but significant inverse correlation existed between blood SeGSH-Px activity and plasma MDA content and between plasma Se and plasma MDA contents during pregnancy. A significant decrease of Se and SeGSH-Px activities (antioxidant enzyme) in both blood and plasma suggests a possible drop in total antioxidant status during pregnancy. Elevated MDA plasma levels might be the result of increased lipid peroxidation in placental tissue during pregnancy.     

Antioxidant activity of blood plasma of south Altai's indigenous population of low and medium height altitude areas

Due to the fact that age change theories are still under discussion a study has been conducted on the estimation of antioxidant and antiradical activity of blood plasma. For the experiment was taken a homogeneous group of people which separate populations differ in geographical and climatic parameters of their living conditions. As a result there has been discovered a dependence of Altaians' antioxidant system upon geographical and climatic conditions, and age.     

Impaired plasma nitric oxide availability and extracellular superoxide dismutase activity in healthy humans with advancing age

This study is aimed to verify the modifications of extracellular superoxide dismutase (EC-SOD) activity and its potential involvement on the mechanism responsible for the impairment of plasma nitric oxide (NO) availability occurring with advancing age in healthy humans. For this purpose, plasma samples were drawn from 40 healthy men, aged 20-92 years, in fasting state and used for measurements of stable end-product nitrite/nitrate (NOx), as expression of NO availability, EC-SOD activity, thiobarbituric acid reactive substances (TBARS) as marker of lipid peroxidation, Trolox equivalent antioxidant capacity (TEAC) as a measure of plasma total antioxidant capacity, and in vitro susceptibility of low density lipoprotein (LDL) to copper-mediated oxidation, evaluated as lag time. As indicated by our results, advancing age was significantly related to decreased plasma values of NOx (r = -0.877, P < 0.001), EC-SOD activity (r = -0.888, P < 0.001), TEAC (r = -0.647, P < 0.001) and lag time (r = -0.621, P < 0.001) as well as to an increased plasma amount of TBARS (r = 0.858, P < 0.001). NOx plasma level resulted independently predicted by EC-SOD activity and age. EC-SOD activity, in turn, was determined by age and TEAC. Taken together, findings of the present study give further insight into the mechanism related to age-associated endothelial dysfunction, indicating that the decreased EC-SOD activity may be involved in the progressive reduction of plasma NO availability with advancing age through the age-related impairment of oxidant/antioxidant balance.     

Free radicals, lipid peroxidation and the antioxidant system in the blood of cows and newborn calves around calving

The oxidative stress of birth in cattle (Bos taurus) was evaluated by measuring steady state concentration of free radicals in whole blood, rate of lipid peroxidation and activity of antioxidant enzymes in erythrocytes, antioxidant capacity of blood plasma in 14 calves at birth and four times after birth until 3 weeks of age and also in their mothers at calving. The same parameters were also measured in 58 dairy cows before calving, at parturition and after calving. Free radical concentration in the blood of newborn calves was higher than in cows confirming that birth means oxidative stress for calves. Red blood cell malondialdehyde in calves was the highest at birth and following the first solid feed intake at the third week. Superoxide dismutase activity increased in calves during the first three weeks of life. Ferric reducing ability of plasma was higher in calves at birth than in cows and decreased thereafter. Higher superoxide dismutase activity in red blood cells and lower ferric reducing ability of plasma in dairy cows was found at calving compared to the average of all pre- and post-calving results. We conclude that the blood of newborn calves is well prepared to deal with the oxidative stress of birth, and that such a stress is present even when some fingerprint markers of redox imbalance show no apparent alterations. Stress of calving has minor effects on the antioxidant system of cows.     

Antioxidant activity of blood plasma in Altai aborigines

Because little is known about the dependence of the antioxidant activity (AOA) of the body on the environment and type of diet, the AOA of blood plasma in low-hill and middle-hill Altai aborigines has been evaluated. It has been found that the AOA of blood plasma is more dependent on age and less dependent on the environment, sex, and type of diet.     

Antioxidative effect of the N-stearoylethanolamine in the heart tissue and blood plasma of rats under doxorubicin treatment

The influence of N-stearoylethanolamine on the alterated antioxidant enzyme activity in the heart tissue and blood plasma of rats under the doxorubicin treatment was investigated. It was shown that doxorubicin administration caused the decrease of antioxidant enzymes activity (superoxide dismutase and glutathione peroxidase) in the heart tissue. Administration of the NSE promoted the partial normalization of these enzymes activity. It was shown that doxorubicin treatment caused the increase of the urea and creatinine level in the blood plasma of experimental animals. The NSE administration normalized the level of the urea and did not affect creatinine level.     

Antioxidant defense and trace element imbalance in patients with postradiation syndrome

More than 6000 residents of Latvia were involved in recovery work in Chernobyl. They were healthy men exposed to substantial ionizing radiation (0.01–0.5 Gy). Now, these recovery workers suffer from “postradiation syndrome”: dizziness and poor memory, headache, local pains, and so forth. The biochemical mechanism of “postradiation syndrome” has not been completely established. In this Phase I study, we have investigated how exposure to radiation impacts antioxidative defense and trace element concentrations in the blood of recovery workers. Thirty-five patients with postradiation syndrome (men, age range 33–50 yr) and 15 healthy men similar in age as control subjects were studied for the effects on plasma chemiluminescence, the activity of antioxidant enzymes, and the concentration of ceruloplasmin and concentrations of selenium (Se), zinc (Zn), and copper (Cu) in blood. The results revealed that plasma chemiluminescence was significantly increased (3.5-fold to 5.5-fold), the activity of catalase in erythrocytes was significantly elevated, and the activity of glutathione peroxidase in plasma was significantly reduced in examined patients. Concentrations of Zn and Cu were significantly higher and the concentration of Se was lower in these patients. We conclude that the patients exposed to ionizing radiation have diminished blood antioxidant defense associated with pronounced Se deficiency and imbalance of Zn and Cu. Presented in part on the SFRR (Europe) Summer Meeting in Dresden, July 2–5, 1999.     

Antioxidant status and proteolytic-antiproteolytic balance in colorectal cancer

Free radicals participate in the development of cancer. When the antioxidant defence system is not longer capable to destroy free radicals they may cause lipid and protein oxidation. Lipid peroxidation products also modify proteins. In such a situation the proteolytic-antiproteolytic balance existing in the blood may be changed. Therefore the aim of this study was to examine the correlation between antioxidant status and activity of proteolytic enzymes and their inhibitors in cases of colorectal cancer. This study included 55 patients with colorectal cancer. The blood was taken before surgery and plasma was collected. Total antioxidant status, the levels of lipid peroxidation products (malondialdehyde and 4-hydroxynonenal) and activity of cathepsin G, elastase and their inhibitors (alpha-1-antitrypsin and alpha-2-macroglobulin) were determined in plasma. It was shown that during the development of cancer total antioxidant status was signficantly decreased while lipid peroxidation products were increased. Activity of alpha-2-macroglobulin was decreased and activity of determined enzymes was not significantly changed. The observed changes indicate a shift in proteolytic-antiproteolytic balance which may enhance carcinogenesis.     

Investigation of antioxidant enzymes in children with autistic disorder

Impaired antioxidant mechanisms are unable to inactivate free radicals that may induce a number of pathophysiological processes and result in cell injury. Thus, any abnormality in antioxidant defence systems could affect neurodevelopmental processes and could have an important role in the etiology of autistic disorder. The plasma levels of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD), and erythrocyte levels of GSH-Px were investigated in 45 autistic children and compared with 41 normal controls. Levels of erythrocyte SOD, erythrocyte and plasma GSH-Px were assayed spectrophotometrically. Activities of erythrocyte SOD, erythrocyte and plasma GSH-Px in autistic children were significantly lower than normals. These results indicate that autistic children have low levels of activity of blood antioxidant enzyme systems; if similar abnormalities are present in brain, free radical accumulation could damage brain tissue.     

Experimental investigation of some systemic effects of nitric oxide inhalation

The goal of this work was to study the influence of nitric oxide inhalation on parameters of blood proand antioxidant systems in rats under both an intact condition and experimental thermal injury. We studied 40 Wistar rats that were divided into four equal groups. The intact group was subjected to no manipulation exñept a single blood sampling, main group I was subjected to inhalation of a air mixture containing 20 ppm of nitric oxide for 10 days, the control group was subjected to thermal injury and conventional treatment, and main group II was subjected to thermal injury and daily inhalation of nitric oxide (20 ppm) for 10 days. We studied the intensity of lipid peroxidation in the blood plasma, the total antioxidant activity, the peroxide resistance of erythrocytes, the level of malondialdehyde in the blood plasma and erythrocytes, and the activity of superoxide dismutase. It was shown that daily inhalations of a mixture containing a low concentration of nitric oxide (20 ppm) modified blood oxidative metabolism in healthy and burned rats. We hypothesized that the activation of lipid peroxidation in erythrocytes accompanied by a pronounced increase in the catalytic activity of superoxide dismutase is a unified response of healthy and burned rats to exogenous nitric oxide exposure. We also observed a moderate prooxidant effect in the blood plasma of healthy animals comparable to that in the erythrocytes of these rats. In the case of thermal injury, oxidative stress tended to be corrected after the end of the course of inhalation.     

Differential effects of acetaminophen on enzymatic and non-enzymatic antioxidant factors and plasma total antioxidant capacity in developing and adult rats

Recently we reported that ferric reducing ability of plasma (FRAP) assay, as an index of total antioxidant activity, increases in growing rats in response to high dose of vitamin K. In this study, it was found that acetaminophen (APAP) can cause elevation in FRAP in suckling and adult rats. This study was initiated to assess the contribution of individual antioxidant factors on elevation in FRAP. A surge in FRAP, 1 h after high dose APAP (250 or 450 mg/kg BW) administration was recorded in both young as well as adults. Whereas, low dose drug (25 mg/kg) failed to alter FRAP in both the age groups. Time-course studies show that drug-dependent elevation in FRAP begin rapidly, reaching a maximum at 1 h (> 500%). Increased FRAP was associated with a marked increase (∼14-fold) in plasma bilirubin, 6 h after drug administration at 450 mg/kg only in suckling rats. Similarly, APAP-related increase in superoxide dismutase activity in erythrocytes was limited to young rats of both the age groups. Other factors measured during this period viz., plasma uric acid, bilirubin and total protein together with catalase activity of erythrocytes remained unchanged in treated rats. Under these circumstances, APAP-related depletion in liver glutathione was almost similar in both the age groups. During a 12 h study, the concentration of lipid peroxidation products, in liver of treated groups remained within the levels of respective controls. The endpoint hepatotoxic effects of APAP was almost similar in both the age groups, suggesting that like adults, immature rats can cope with toxic effects of APAP owing to their drug-dependent induction in certain antioxidant factors.     

Antioxidant status of ewe's blood during pregnancy and lactation

Antioxidant status of ewe's blood during pregnancy and lactation was studied. It is revealed that the lipid peroxidation in erythrocytes is decreased, whereas in blood plasma is increased in the middle pregnancy, reaching the maximum shortly before peak of progesterone production. The activities of antioxidant enzymes are increased at the end of pregnancy, when the level of progesterone in blood is maximal. The positive correlation between plasma progesterone level and activity of erythrocyte superoxide dismutase (p < 0.01), between plasma cortisol concentration and total antioxidant capacity of blood plasma (p < 0.05) are revealed. It is shown, that the activities of antioxidant enzymes reach a maximum in the critical periods of pregnancy, providing the protection of the maternal organism and the fetus against negative influence of free radicals. The positive correlation between a level of hormones and separate parameters of antioxidant system in blood allows to assume, that progesterone participates in the regulation of enzymatic part of the antioxidant system, while cortisol is implicated in the regulation of the non-enzymatic component of this system in ewes.     

Regulation of Free Radical Processes by Delta-Sleep Inducing Peptide in Rat Tissues under Cold Stress

An intraperitoneal injection of an exogenous delta-sleep inducing peptide (DSIP) at a dose of 12 g/100 g body weight shifted the prooxidant–antioxidant balance of free radical process (FRP) in tissues and erythrocytes of rats: the activities of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) and the concentrations of antioxidants (reduced glutathione in particular) increased. The DSIP stimulated the myeloperoxidase activity in blood neutrophils and had no effect on the activity of xanthine oxidase, a prooxidant enzyme, in the brain and liver. Cold stress displaced the prooxidant–antioxidant balance by increasing the xanthine oxidase activity in tissues and decreasing the myeloperoxidase activity in blood neutrophils; it also inhibited the enzyme antioxidant activities in tissues and erythrocytes that was neutralized by an increased ceruloplasmin activity in blood plasma and by an elevated level of antioxidants in rat blood and tissues. Preliminary administration of DSIP to animals exposed to cold stress restored the prooxidant–antioxidant balance: it normalized the myeloperoxidase activity in blood neutrophils, decreased the xanthine oxidase activity, and increased the activity of antioxidant enzymes in tissues and erythrocytes restoring the antioxidant level. The molecular regulation mechanism of free radical processes by DSIP in tissues under stressful conditions is discussed.     

Study on the antioxidant status of vitiligo patients of different age groups in Baroda

One of the major hypotheses in the pathogenesis of vitiligo is the oxidative stress hypothesis. Pollution plays a major role in the production of free radicals. Gujarat, a highly industrialized state in India has a high prevalence of vitiligo patients. No previous studies were done on the age-dependent antioxidant status of vitiligo patients in Baroda city, Gujarat. Blood samples were collected from vitiligo patients of different age groups (5-15, 16-25, 26-35, 36-45 yr) and from age matched healthy volunteers. Antioxidant enzymes in blood such as catalase, superoxide dismutase, glutathione peroxidase and non-enzymatic antioxidants such as reduced glutathione and plasma vitamin E were estimated. Lipid peroxidation levels in erythrocytes and the reducing equivalent system, i.e. glucose-6-phosphate dehydrogenase were also measured. Significant increase in superoxide dismutase activity and lipid peroxidation levels in erythrocytes was observed in all age groups of vitiligo patients as compared with age-matched healthy controls, wherein an increase of 55% (P < 0.02) was observed in superoxide dismutase activity and lipid peroxidation levels in 36-45 yr age group. Whole blood glutathione levels, erythrocyte glutathione peroxidase and glucose-6-phosphate dehydrogenase activity were decreased significantly, whereas erythrocyte catalase activity and plasma vitamin E levels were not different in vitiligo patients as compared with age-matched healthy controls. No specific age group showed a significant difference. This is the first report on the age-dependent antioxidant status of vitiligo patients in Baroda. The disease affects individuals of any age group as shown in this study and systemic oxidative stress might precipitate the pathogenesis of vitiligo in susceptible patients.     

Whole blood glutathione peroxidase and erythrocyte superoxide dismutase activities, serum trace elements (Se, Cu, Zn) and cardiovascular risk factors in subjects from the city of Ponta Delgada, Island of San Miguel, The Azores Archipelago, Portugal

Activities of whole blood glutathione peroxidase (GSH-Px) and erythrocyte superoxide dismutase (SOD) and serum levels of selenium (Se), copper (Cu) and zinc (Zn) were measured in 118 apparently healthy subjects aged 20-60 years from the city of Ponta Delgada, Island of San Miguel, The Azores Archipelago, Portugal. Data were analysed by age/gender, lipid profile and blood pressure as cardiovascular risk factors searching for their relevance when assessing reference values for antioxidant biomarkers. GSH-Px was in the same range, but SOD was significantly lower than in other Portuguese populations. Neither activity differed with gender. GSH-Px activity increased with age, namely in normolipidemic men versus the hyperlipidemic group in which a decrease was observed. This suggests a progressive impairment of GSH-Px with age caused by an enhanced production of oxidant species in hyperlipidemia. GSH-Px was 30% lower in male hypertensives versus normotensives. SOD activity did not relate to age or blood pressure but was 17% higher in the hyperlipidemic men versus the normolipidemic group, suggesting a better antioxidant protection by SOD than by GSH-Px in hyperlipidemia and hypertension. Se was higher in men versus women, particularly in the older subjects, and partly related to hyperlipidemia. Zn levels showed a similar dependency on gender, not related to age or lipid profile. Cu levels were much higher in women than in men in all age or lipid profile classes and decreased in hyperlipidemia. They were lowered with age in both genders, particularly in normolipidemic women. The present research therefore suggests that hyperlipidemia and hypertension do affect antioxidant status and should be considered when assessing antioxidant biomarkers in blood.     

Whole blood glutathione peroxidase and erythrocyte superoxide dismutase activities,serum trace elements (Se,Cu, Zn) and cardiovascular risk factors in subjects from the city of Ponta Delgada,Island of San Miguel,The Azores Archipelago,Portugal

Activities of whole blood glutathione peroxidase (GSH-Px) and erythrocyte superoxide dismutase (SOD) and serum levels of selenium (Se), copper (Cu) and zinc (Zn) were measured in 118 apparently healthy subjects aged 20–60 years from the city of Ponta Delgada, Island of San Miguel, The Azores Archipelago, Portugal. Data were analysed by age/gender, lipid profile and blood pressure as cardiovascular risk factors searching for their relevance when assessing reference values for antioxidant biomarkers. GSH-Px was in the same range, but SOD was significantly lower than in other Portuguese populations. Neither activity differed with gender. GSH-Px activity increased with age, namely in normolipidemic men versus the hyperlipidemic group in which a decrease was observed. This suggests a progressive impairment of GSH-Px with age caused by an enhanced production of oxidant species in hyperlipidemia. GSH-Px was 30% lower in male hypertensives versus normotensives. SOD activity did not relate to age or blood pressure but was 17% higher in the hyperlipidemic men versus the normolipidemic group, suggesting a better antioxidant protection by SOD than by GSH-Px in hyperlipidemia and hypertension. Se was higher in men versus women, particularly in the older subjects, and partly related to hyperlipidemia. Zn levels showed a similar dependency on gender, not related to age or lipid profile. Cu levels were much higher in women than in men in all age or lipid profile classes and decreased in hyperlipidemia. They were lowered with age in both genders, particularly in normolipidemic women. The present research therefore suggests that hyperlipidemia and hypertension do affect antioxidant status and should be considered when assessing antioxidant biomarkers in blood.     

Elevated plasma homocysteine elicits an increase in antioxidant enzyme activity

Elevated plasma homocysteine is considered to be a risk factor for cardiovascular disease. The mechanisms for this effect are not fully understood but there is some evidence for a role for reactive oxygen species (ROS). This study was conducted to explore the effects of elevated plasma total homocysteine (tHcy) concentration on activity of antioxidant enzymes in the circulation. The study group consisted of 10 patients with inherited defects of homocysteine metabolism, from whom 41 blood samples were collected over a period of six months. Blood samples were also collected from 13 of their obligate heterozygous parents. For data analysis samples were classified as those with plasma tHcy < 20 microM or > 20 microM. The activity of erythrocyte superoxide dismutase (SOD) and plasma glutathione peroxidase (GSHPx) was elevated in samples with plasma tHcy > 20 microM. Moreover, a significant correlation was demonstrated between plasma GSHPx activity, plasma glutathione peroxidase protein and plasma tHcy. III vitro studies confirmed that this observation was not due to a simple chemical enhancement of enzyme activity. Homocysteine protected GSHPx from loss of activity following incubation at 37 degrees C. A similar effect was seen with another thiol-containing amino acid, cysteine. Results suggest that elevated plasma tHcy represents an oxidative stress, resulting in an adaptive increase in activity of antioxidant enzymes in the circulation.     

Alterations in Antioxidant Enzymes During Aging in Humans

The oxidative stress theory of aging offers the best mechanistic elucidation of the aging phenomenon and other age-related diseases. The susceptibility of an individual depends on the antioxidant status of the body. In humans, the antioxidant system includes a number of antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT), nonenzymatic antioxidants such as glutathione (GSH), protein –SH, ascorbic acid, and uric acid, and dietary antioxidants. Antioxidant enzymes form the first line of defense against reactive oxygen species. In an earlier report, we showed that the plasma antioxidant potential in humans decreases as a function of age and that there are compensatory mechanisms operating in the body which are induced to maintain the antioxidant capacity during aging. In the present study, we report the relationship between human aging and antioxidant enzymes SOD and CAT; we also correlate the activity of these enzymes with the antioxidant capacity of the plasma. Our results show a significantly higher plasma SOD and CAT activity in older individuals than in younger individuals. The induction in activity of SOD and CAT during human aging may be a compensatory response of the individual to an increased oxidative stress.     

Quercetin supplementation does not alter antioxidant status in humans

Abstract

This study measured the influence of ingesting quercetin on plasma measures for oxidative stress and antioxidant capacity. Male and female subjects (n = 1002) varying in age (18–85 years) and body mass index (BMI) (16.7–52.7 kg/m²) were studied. Subjects were randomized to one of three groups using double-blinded methods: placebo, 500 mg or 1000 mg quercetin/day with 125 mg or 250 mg vitamin C/day, respectively. Pre- and post-study fasting blood samples show that plasma quercetin increased in a dose-responsive manner. The pattern of change in plasma F₂-isoprostanes, oxidized low density lipoprotein, reduced glutathione, ferric reducing ability of plasma (FRAP) and oxygen radical absorbance capacity (ORAC) did not differ between supplementation groups or after adjustment for gender, age, BMI and disease status. In summary, quercetin supplementation over 12 weeks in doses of 500 mg or 1000 mg/day significantly increased plasma quercetin levels, but had no influence on several measures of oxidative stress and antioxidant capacity.