Determination of superoxide dismutase and glutathione peroxidase activities in blood of healthy pediatric subjects

Effects of Five Prebiotics on Growth, Antioxidant Capacity, Non-Specific Immunity, Stress Resistance, and Disease Resistance of Juvenile Hybrid Grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂)

To explore the short-term health benefits of five prebiotics on hybrid grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂), six experimental groups fed with different diets (basal diet, diet control (CON); basal diet + 0.2% fructooligosaccharide (FOS), diet FOS; basal diet + 0.5% chitosan, diet chitosan (CTS); basal diet + 0.2% mannan-oligosaccharide (MOS), diet MOS; basal diet + 0.1% β-glucan (GLU), Diet GLU; basal diet + 0.05% xylooligosaccharide (XOS), diet XOS) were set up, and a 4-week feeding trial was conducted. MOS and XOS significantly improved the growth of hybrid grouper compared to the CON group (p < 0.05). Antioxidant enzyme assay showed that the activity of glutathione peroxidase (GPx) was significantly enhanced in the MOS group, and the content of malondialdehyde (MDA) in the XOS group was significantly lower than in the CON group (p < 0.05). The catalase (CAT) activities were significantly enhanced in all prebiotic-supplemented groups compared with the CON group (p < 0.05). Non-specific immunity assay showed that the activities of alkaline phosphatase (AKP) and lysozyme (LZM) were significantly increased in all prebiotic-supplemented groups compared with the CON group (p < 0.05). The total protein content in the XOS group was significantly increased (p < 0.05), and the albumin (ALB) activity in the MOS group was more significantly increased than that in the CON group. Histological examination of the intestine revealed that muscle thickness was significantly increased in all prebiotic-supplemented groups compared to the CON group (p < 0.05). Villi length, villi width, muscle thickness all increased significantly in the MOS group (p < 0.05). In addition, the crowding stress and ammonia nitrogen stress experiments revealed that the survival rates of the MOS and XOS groups after stresses were significantly higher than those of the CON group (p < 0.05). Though MOS and XOS exhibited similar anti-stress effects, the antioxidant and non-specific immunity parameters they regulated were not the same, indicating that the specific mechanisms of MOS and XOS's anti-stress effects were probably different. After being challenged with Vibrio harvey, MOS and GLU groups showed significantly higher post-challenge survival rates than the CON group (p < 0.05). These findings indicated that among the five prebiotics, MOS and XOS showed the best overall short-term beneficial effects and could be considered promising short-term feed additives to improve the stress resistance of juvenile hybrid grouper.

Assessment of Wheat Germ Oil Role in the Prevention of Induced Breast Cancer in Rats

Breast cancer is the most predominant cause of death in women globally. The current study was performed to evaluate the possible protective role of wheat germ oil (WGO), wheat germ powder (WGP), and vitamin E (Vit E) against breast carcinoma induced by the environmental carcinogen 7,12-dimethylbenz[a]anthracene (DMBA) in Sprague Dawely albino rats. Eighty female rats were divided into eight groups, each of ten rats. All protective agents were taken 21 days prior to DMBA treatment. Group I served as the normal control. Group II received Vit E (100 mg/kg BW/d) by gavage. Group III was fed a 20% WGP enriched basal diet. Group IV received WGO (270 mg/kg BW/d) by gavage. Group V received DMBA (50 mg/kg body weight/subcutaneous injection). Group VI received Vit E + DMBA. Group VII received WGP + DMBA. Group VIII received WGO + DMBA. The investigation focused on bodyweights, complete blood picture (CBC), cancer antigen 15.3 (CA15.3), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), and histopathological and immunohistochemical analyses. Results showed that all cancer protective agents significantly improved CBC parameters, proliferating cell nuclear antigen (PCNA), and the histopathology picture, with the best improvement in the WGO group. In addition, WGO, WGP, and Vit E decreased the CA15.3 and MDA levels and elevated both the SOD and CAT levels compared to the DMBA group. Consequently, supplementation with WGO, WGP, and Vit E protects against lipid peroxidation and oxidative stress and reduces breast cancer.

Beetroot Nanoencapsulation in Flavored Beverage and its Effect as Hepatoprotective Agent in Rats

&lt;b&gt;Background and Objective:&lt;/b&gt; Beetroot juice is a biological antioxidant and acts as health-promoting minerals as well as soluble fibres and vitamins. This study aimed to encapsulate the Beetroot Juice Powder (BJP) by the conjugate sodium caseinate (NaCas) and Maltodextrin (MD) to protect it from environmental conditions. Produced flavoured acid beverage using BJP encapsulated using conjugates. &lt;b&gt;Materials and Methods:&lt;/b&gt; Nano-encapsulation of BJP (20, 30, 40 mg g&lt;sup&gt;&lt;/sup&gt;&lt;sup&gt;1&lt;/sup&gt;) and determine the encapsulation efficiency, size and zeta potential. Rats were divided into 4 groups as follows, negative control, positive control and 2 test groups that received free BJP or encapsulated BJP. All rats except the negative control group were injected with CCl&lt;sub&gt;4&lt;/sub&gt; twice a week. &lt;b&gt;Results:&lt;/b&gt; The NaCas-MD conjugate has the advantage over the NaCas-MD complex of higher stability and BJP binding, also showing high encapsulation efficiency (>93.75%) of different levels of BJP. The flavoured beverage from the addition of BJP encapsulated by conjugate has better sensory and technological properties than fortified with BJP in the complex. Injection with CCl&lt;sub&gt;4&lt;/sub&gt; leads to a decrease in body weight, serum parameters including, protein, albumin, GSH, CAT and SOD, also increase ALT, AST, ALP and liver weight. Moreover, a variable pathological alteration in liver tissue was found. At the end of the experiment receiving encapsulated beetroot juice led to improvement in all above body and liver weight, all biochemical parameters and histopathological elevation. &lt;b&gt;Conclusion:&lt;/b&gt; Thus, it could be concluded that flavoured beverage containing BJP encapsulated by conjugate is of acceptable quality and high antioxidant activity. Also, it has a remarkable protective effect against acute hepatotoxicity.

Effect of a Shock Micro-Cycle on Biochemical Markers in University Soccer Players

This study aimed to examine various biochemical biomarkers changes during a shock micro-cycle in soccer players from a university team. The study had 22 players (age: 22 ± 3 years; body mass: 68.6 ± 7.1 kg; height: 1.73 ± 0.07 m). The study measured total cholesterol (TC), triglycerides (TG), cholesterol linked to high-density lipoproteins (HDL), low-density lipoproteins (LDL), very low density lipoproteins (VLDL), arterial index (AI), creatine kinase (CK), glutamate-oxalacetate-transaminase (GOT), glutamate-pyruvate-transaminase (GPT), creatinine (Cr), catalase (CAT), superoxide dismutase (SOD), cytokines IL6 and TNFα, total antioxidant capacity (Cap antiox tot), hemolysis percentage and glomerular filtration rate (GFR); measurements were conducted during a shock micro-cycle. The lipid profile variables had no statistical significance when compared on day 1 with day 14. Except for TNFα, the other biomarkers compared with day one had progressive increments until day seven, with a subsequent reduction on day 14; however, none of the biomarkers returned to baseline values despite this decrease. The data shown herein suggest the need to research these biomarkers in distinct types of mesocycles, exercise, intensity, load, and duration to diminish fatigue and improve athlete performance.

Prenatal Hypoxia and Placental Oxidative Stress: Insights from Animal Models to Clinical Evidences

Hypoxia is a common form of intrauterine stress characterized by exposure to low oxygen concentrations. Gestational hypoxia is associated with the generation of reactive oxygen species. Increase in oxidative stress is responsible for damage to proteins, lipids and DNA with consequent impairment of normal cellular functions. The purpose of this review is to propose a summary of preclinical and clinical evidences designed to outline the correlation between fetal hypoxia and oxidative stress. The results of the studies described show that increases of oxidative stress in the placenta is responsible for changes in fetal development. Specifically, oxidative stress plays a key role in vascular, cardiac and neurological disease and reproductive function dysfunctions. Moreover, the different finding suggests that the prenatal hypoxia-induced oxidative stress is associated with pregnancy complications, responsible for changes in fetal programming. In this way, fetal hypoxia predisposes the offspring to congenital anomalies and chronic diseases in future life. Several antioxidant agents, such as melatonin, erythropoietin, vitamin C, resveratrol and hydrogen, shown potential protective effects in prenatal hypoxia. However, future investigations will be needed to allow the implementation of these antioxidants in clinical practice for the promotion of health in early intrauterine life, in fetuses and children.

Potential toxicity of cyanogenic glycoside amygdalin and bitter apricot seed in rabbits-Health status evaluation

Amygdalin is one of the most studied secondary metabolites of Prunus genus. It is a cyanogenic glycoside which was initially obtained from the bitter almonds seeds and is a major component of the seeds of plants, such as apricots, almonds, peaches, apples and other rosaceous plants. The views of scientists on the use of amygdalin have been contradictory for many years, partly because toxicokinetics and metabolism of amygdalin still have not been adequately explored. The present in vivo study was designed to reveal whether pure amygdalin intramuscularly injected or apricot seeds oral consumption induce changes in overall health status of rabbit as a biological model. A total of 60 adult rabbits were randomly divided into five groups. The control group received no amygdalin while the two experimental groups E1 and E2 received a daily intramuscular injection of amygdalin at doses 0.6 and 3.0 mg/kg bw. The experimental groups E3 and E4 were fed crushed bitter apricot seeds (Prunus armeniaca L.), at doses 60 and 300 mg/kg bw, mixed with commercial feed for rabbits. Blood collection was carried out after 14 days. Biochemical, haematological and antioxidant enzymes activity analysis were performed and statistically evaluated. A short-term amygdalin administration had negligible impact on biochemical parameters-mainly level of urea, bilirubin, cholesterol. Haematological profile of rabbits was influenced very slightly-non-significant platelet count and platelet percentage increase, erythrocytes count and haemoglobin decrease. SOD activity of rabbits decreased significantly (p > 0.05) after apricot seeds consumption (102.3 U/ml) in comparison to control (117.4 U/ml). Differences might be connected to diverse metabolism by different administration routes and at the same time by the presence of other substances in apricot seeds (phytosterols, polyphenols, fatty acids). However, a short-term consumption had only slight effect on health status of rabbits and at recommended doses did not represent risk for their health.

The Role of Oxidative Stress in the Pathomechanism of Congenital Malformations

Congenital anomalies are significant causes of mortality and morbidity in infancy and childhood. Embryogenesis requires specific signaling pathways to regulate cell proliferation and differentiation. These signaling pathways are sensitive to endogenous and exogenous agents able to produce several structural changes of the developing fetus. Oxidative stress, due to an imbalance between the production of reactive oxygen species and antioxidant defenses, disrupts signaling pathways with a causative role in birth defects. This review provides a basis for understanding the role of oxidative stress in the pathomechanism of congenital malformations, discussing the mechanisms related to some congenital malformations. New insights in the knowledge of pathomechanism of oxidative stress-related congenital malformations, according to experimental and human studies, represent the basis of possible clinical applications in screening, prevention, and therapies.

Selenium Status in Patients with Turner Syndrome: a Biochemical Assessment Related with Body Composition

Studies about selenium status in patients with Turner syndrome (TS) are non-existent in the literature. The aim of this study was to evaluate selenium status in patients with TS, while considering the different ages of the studied population and the relation with body composition. In total, 33 patients with TS were evaluated and grouped according to their developmental stages (children, adolescents, and adults). Selenium concentrations in their plasma, erythrocytes, urine, and nails were determined by using hydride generation atomic absorption spectrometry and erythrocyte glutathione peroxidase activity were measured by using Randox commercial kits. Additionally, height, weight, body fat percentage, waist circumference, and waist-height ratio were measured to characterize the patients. No differences in the selenium concentrations in the plasma, erythrocyte, urine, and nails or in the glutathione peroxidase activity were observed among the age groups (p > 0.05). The evaluated selenium levels were less than the established normal ones. The patients with larger waist circumference, body fat percentage, body mass index, and waist-height ratio showed lower glutathione peroxidase enzyme activity (p = 0.023). The present study shows that most patients with TS are deficient in selenium and that those with a greater accumulation of body fat have a lower GPx activity.

Importance of internal mammary artery perfusion in cardiac ischemia and reperfusion

Purpose: Our purpose was to investigate the changes in antioxidant defense systems due to internal mammary artery (IMA) perfusion during coronary artery bypass graft (CABG) operations in which proximal anastomoses were completed under partial bypass with the aid of a side-biting clamp.

Material and Method: Twenty-five patients to be studied were divided into two groups according to the criterion of whether during proximal anastomoses left internal mammary artery (LIMA) perfusion was applied ( n = 15, LIMA group) or not ( n = 10, non-LIMA group). The erythrocyte catalase (CAT), superoxide dismutase (SOD), serum lipid peroxidation (LPO) products and whole blood reduced glutathione (GSH) levels were measured in the blood samples taken from the coronary sinus before cardiopulmonary bypass (CPB) (t1), before declamping (t2), at the 5th min after declamping (t3), at the 5th (t4) and 15th (t5) min after removing the side-biting clamp.

Results: While erythrocyte CAT enzyme activity decreases in both groups after the basal measurements, no significant difference was detected between the groups. Although the GSH levels did not differ at t1, t2 and t3, they were found to be higher in the LIMA group at t4 ( p = 0.006) and t5 ( p = 0.021). The erythrocyte SOD enzyme activity decreased after the basal measurements in both groups, but this reduction was less in the LIMA group at t4 ( p= 0.034) and t5 ( p = 0.018) compared to the other group. LPO products rose in both groups when reperfusion started after declamping. The levels of LPO products were significantly higher at t4 and t5 in the non-LIMA group than the other group ( p = 0.011 and p = 0.008).

Conclusion: If proximal anastomoses of coronary grafts are completed under partial bypass, permitting LIMA perfusion during this procedure will be beneficial to antioxidant defense systems.

Melatonin actions on ovaprim (synthetic GnRH and domperidone)-induced oocyte maturation in carp

The major objective of the present study was to demonstrate the actions of exogenous melatonin on ovaprim (synthetic GnRH and domperidone)-induced final oocyte maturation focusing on the oxidative status of pre-ovulatory follicles in the carpCatla catla. Accordingly, gravid carp during the early spawning phase of the reproductive cycle were injected with melatonin and/or ovaprim at different time intervals or luzindole (a pharmacological blocker of melatonin receptors) before their administration. We studied their effects on the latency period, the rate of germinal vesicle breakdown (GVBD; a visual marker of final oocyte maturation) in oocytes, and the levels of maturation-promoting factor (MPF), as well as oxidative stress, different antioxidants, melatonin and MT1 melatonin receptor protein in the extracts of pre-ovulatory follicles. Notably, melatonin treatment 2 h before the injection of ovaprim resulted in the shortest latency period as well as the highest rate of GVBD and MPF formation. Exogenous melatonin, irrespective of the injection schedule, caused a significant reduction in intra-follicular oxidative stress and an increase in the levels of both enzymatic and non-enzymatic antioxidants, melatonin and its receptor protein. Concentrations of ovarian melatonin in each fish exhibited a significant negative correlation with the level of oxidative stress, but a positive correlation with the rate of GVBD and the activity/level of different antioxidants. However, no significant effects of melatonin and/or ovaprim were detected in luzindole-pretreated carp. Collectively, the present study provides the first evidence that melatonin pretreatment in carp ameliorates ovaprim actions on the process of final oocyte maturation by the formation of MPF and alleviates oxidative stress in pre-ovulatory follicles by stimulating different antioxidants.

Biochemical impact of soccer: an analysis of hormonal, muscle damage, and redox markers during the season

This study aimed to analyze changes in performance, muscle function, and stress-related biochemical markers in professional soccer players (n = 14) at 4 timepoints (3 for performance and 4 for stress-related biochemical markers) during the soccer season [Formula: see text] preseason (E1), midseason (E2), end of the season (E3) [Formula: see text] and after the end of the recovery period (E4). Performance in 5- and 30-m sprints, countermovement jump, and agility, and maximal isokinetic knee extension and knee flexion strength were measured (E1 to E3). We observed increased in-season levels of myoglobin (E2 > E1 and E4; p < 0.05), a higher testosterone/cortisol ratio (T/C), and increased levels of creatine kinase (CK), C-reactive protein, superoxide dismutase (SOD), protein sulfhydryls (-SH), and malondialdehyde (E2 and E3 > E1 and E4; p < 0.05). Lower cortisol concentrations (E3 < E1 and E4; p < 0.05) and glutathione reductase activity (E3 < E2 and E4; p < 0.05) were observed at the end of the season. T/C, CK, SOD, -SH, and malondialdehyde decreased during the off-season, and cortisol and glutathione reductase increased (E3 < E4; p < 0.05). Agility increased in E2 and E3 (p < 0.01). Significant correlations were found during the season between hormonal and muscle function parameters (r = 0.56-0.86; p < 0.05). In addition, in E2, significant associations were observed between match-accumulated time (MATE2; minutes played by each player during the competition period), performance, and hormonal and redox parameters (r = 0.456-0.615; p < 0.05). In conclusion, this study shows that soccer players face significant changes in biomarkers of physiologic strain (muscle damage and oxidative stress-related markers) during the season, but values return to normal during the off-season. Additionally, MAT influences physical, hormonal, and oxidative stress-related parameters in professional soccer players.

Neuromuscular function, hormonal and redox status and muscle damage of professional soccer players after a high-level competitive match

The main aim was to analyse the impact of an official match on hormonal and redox status, muscle damage and inflammation and neuromuscular function. Seven high-level male soccer players from the same team performed an official match and data were collected 72 h before, 24, 48 and 72 h post-match. Plasma testosterone/cortisol ratio (T/C), creatine kinase (CK), superoxide dismutase (SOD), glutathione peroxidase (GPX) and reductase (GR) activities, myoglobin (Mb), C-reactive protein (CRP), uric acid (UA), protein sulfhydryls (-SH), malondialdehyde (MDA) concentrations and total antioxidant status (TAS) were measured. Sprint, jump and change of direction performance, and maximal isokinetic knee extension and flexion were obtained as neuromuscular functional parameters. Cortisol increased and T/C decreased until 48 h recovery (P < 0.05). Mb, CRP and -SH (P < 0.05) increased at 24 h and CK, TAS, SOD and MDA (P < 0.05) increased up to 48 h recovery. GR increased and GPX decreased at 24 h recovery (P < 0.05). Jump performance decreased 24 h post-match (P < 0.05), but no significant alterations in sprint, change of direction and muscle strength were observed. In conclusion, an official match resulted in changes in plasma biomarkers until 48 h of recovery period, without major impact on performance.

Validation of a surgical technique for rat intestinal irradiation: potential side effects prevention by dietary grape phenolics

AIMS

This study evaluates and defines the histological and biochemical consequences of irradiation on the Hauer-Jensen intestinal model and investigates the potential effects of dietary polyphenols.

MAIN METHODS

Sprague-Dawley rats were orchiectomized, and an ileal loop was transposed to the left part of the scrotum, then irradiated 2 weeks after surgery with a single dose of 21 Gy (4.49 Gy/min). Four groups of rats received either phenolic extracts from grape seeds (EGS) and from red wine (ACYS, EGT), or pure quercetin 3-O-β-glucoside (Q3G), for 5 days before the irradiation and were sacrificed 2 weeks after. Antioxidant enzyme activities, i.e. superoxide dismutase (SOD) and glutathione peroxidase activity (GSHPx), and oxidative markers such as myeloperoxidase activity (MPO) and thiobarbituric acid reactive substances (MDA) were measured as well as cytokine-induced neutrophil chemoattractant level (CINC-1), a chemokine involved in inflammation.

KEY FINDINGS

Irradiated rats exhibited a high radiation injury score (RIS) with a thickened serosa, mucosal loss and ulceration, and epithelial atypicality. Intestinal MPO activity and CINC-1 concentration were significantly increased in irradiated animals (60 and 66 %, respectively). Higher plasma MDA levels (58 %) and SOD activity (32 %) were accompanied by a reduced GSHPx activity (79 %). However, feeding phenolic extracts remarkably reduced levels of blood SOD activity (34 % on average), intestinal CINC-1 (25-75 % range) and MPO activity (36-84 %). Except for Q3G, phenolics preserved the intestinal structure.

SIGNIFICANCE

These findings show that irradiation triggers an inflammation, and an oxidative stress by disturbing the pro-oxidant/antioxidant balance and indicate that phenolics supply exerts preventive effects against radio-induced intestinal impairment.

Can apricot kernels fatty acids delay the atrophied hepatocytes from progression to fibrosis in dimethylnitrosamine (DMN)-induced liver injury in rats?

Background and aims

The present study was aimed to analyze the chemical composition of ground apricot kernel (GAK) and examine its effect on hepatic fibrosis in vivo induced by dimethylnitrosamine (DMN) in rats.

Methods and results

Hepatic fibrosis was induced by intraperitoneal injections of 10 mg/kg DMN for 3 consecutive days each week over a period of 4 wk. The rats were randomly assigned to five groups of nine rats each: the negative control group (NC), the hepatic fibrosis group (PC), hepatic fibrosis supplemented with GAK (0.5 mg/kg/BW/rat), hepatic fibrosis supplemented with GAK (1 mg/kg/BW/rat) and hepatic fibrosis supplemented with GAK (1.5 mg/kg/BW/rat). Rats were killed, blood was collected and livers were excised for biochemical measurements and histological examination. Results indicate that the diet supplemented with GAK led to improving liver function, lipid peroxides, and liver CAT, SOD and GSH. These results were confirmed by liver histology. Hierarchically high levels f GAK (1.5 mg/kg/BW/rat) gave the best results compared to other tested levels.

Conclusion

This study demonstrates that GAK administration specifically (1.5 mg/kg/BW/rat) can effectively improve liver fibrosis caused by DMN, and may be used as a therapeutic option and preventive measure against hepatic fibrosis. Furthermore, a human trial would be applied specially GAK is a part of Egyptian diet. The act of why high amounts of GAK was improved biochemical values compared to low or moderate levels tested in this study may be due to increase levels of oleic acid and other polyphenols in apricot kernels

Important role of oxidative stress biomarkers in Huntington's disease

This study examined global oxidative stress (GOS) and antioxidant system and their correlation with disease stage in 19 patients with HD. The results revealed an increase in oxidative stress biomarkers and a reduction in antioxidant systems in HD patients. The effects were more intense in HD1 than in HD2 patients. Additionally, carbonylated proteins and GOS were correlated with disease stage. These findings suggest that oxidative stress plays an important role in the pathogenesis of HD.

Influence of dietary lipids on the erythrocyte antioxidant status of hypercholesterolaemic children

The aim of this work was to examine the effect of dietary lipid intakes on the biomarkers of red cell antioxidant status in hypercholesterolaemic children. The study population included 34 children (18 boys and 16 girls) with cholesterol levels > or =5.2 mmol/l and 16 normolipidaemic children (9 boys and 7 girls) between 6 and 12 years of age. The status of the erythrocyte antioxidants superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and reduced glutathione (GSH) were estimated spectrophotometrically. Dietary intake was assessed by 24-h recall and seven-day records. The hypercholesterolaemic children showed a decreased activity of antioxidant enzymes in relation to the control group. There was a negative correlation between energy intake and the activity of antioxidant enzymes (SOD and CAT) and GSH levels. Cholesterol intake was inversely correlated with CAT and GPx activity and GSH levels. The intake of polyunsaturated fat was positively correlated with the GPx activity. A decrease in the fat content of the diet for 6 months was proposed and 15 children followed the diet strictly. The activities of antioxidant enzymes in these children were significantly higher after the low-fat diet; the greatest increment was noted in the activity of GPx (91% with respect to the initial values), SOD was increased by 44% and CAT by 70%. We conclude that the intake of dietary lipids can modulate the antioxidant defence system, and an excess of energy and cholesterol has a negative influence on the antioxidant enzymes.

Relationships between silicon content and glutathione peroxidase activity in tissues of rats receiving lithium in drinking water

Lithium salts are widely used in psychiatry, but their presence in organism can result in both beneficial and adverse effects. Silicon, the third most abundant trace element in humans as well as antioxidant enzyme glutathione peroxidase (GPx) play important roles in organism. The disturbance of their level can cause severe disorders. The aim of our work was to evaluate the influence of Li2CO3 administration in drinking water for a period of 4 weeks on Si content and GPx activity in the tissues of liver, kidney, brain and femoral muscle in rats. The concentrations of provided solutions were 0.7, 1.4, 2.6, 3.6, 7.1 and 10.7 mmol Li+ x dm-3. GPx activity was decreased versus control as a consequence of Li treatment, particularly in kidney and brain. This effect could be suggested to contribute to renal abnormalities which could occur during Li therapy. Si tissue level was significantly enhanced versus control in liver and femoral muscle in groups receiving high Li doses. In brain no well-marked changes were observed, whereas in kidney we observed the depletion in low-Li-groups, restoration of Si level in higher-Li-groups and unexpected decrease in the highest-Li-group. Positive correlations between Si content and GPx activity in the tissues of kidney (r = 0.677) and brain (r = 0.790) as well as negative correlation (r = -0.819) in femoral muscle were found. We consider that our results give some reason for suggesting that monitoring of silicon level in patients undergoing Li therapy could be recommended. However, more investigations should be performed, particularly regarding the relationships between Si and GPx in blood and urine Si excretion during lithium administration.

Raw material enzymatic activity determination: a specific case for validation and comparison of analytical methods--the example of superoxide dismutase (SOD)

Implementation of ICH guideline for validation of analytical methods was tested in the case of two enzymatic assays of determination of superoxide dismutase (SOD) activity. Analytical figures of merits of two tested methods (NBT reference method and the so called WST-1 method) demonstrate the feasibility of such approach. Nevertheless specification usually admitted for physicochemical method (e.g., HPLC), needs to be clearly enlarged, for instance, up to 10% for repeatability and 20% for reproducibility. On the other hand, the cross-validation performed between the two enzymatic activity determination techniques, though based on the same principle, clearly shows that the quality of results depends on small variation in the experimental conditions. This shows that an enzymatic activity determination should be strictly related to the technique used, especially in the pharmaceutical control quality field, and confirms that analytical figures of merits are strongly function of the technique used. Finally, it was demonstrated that both NBT reference method and WST-1 method give strictly similar results.

Antioxidant enzyme activities in healthy Chinese adults: influence of age, gender and smoking

OBJECTIVE

Specific antioxidant enzymes play a vital role in regulating and maintaining oxidant species. The aim of this study was to determine these antioxidant enzyme activities (i.e. catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx)) in erythrocytes from a group of healthy Chinese subjects and to study the influence of age, gender and smoking habits on the enzyme activities.

METHODOLOGY

Chinese healthy subjects (n = 276) were grouped according to their age range, gender differences and smoking habits. Antioxidant enzyme activities were measured spectrophotometrically using standard kinetic methods.

RESULTS

There was a significant decrease in erythrocyte GPx activity in ever-smokers compared with non-smokers (47.10 +/- 1.33 mU/g haemoglobin (Hb) vs. 51.41 +/- 1.64 mU/g Hb, P < 0.05). Age-related significant increases in erythrocyte CAT and SOD activities were found in non-smokers but not in ever-smokers. There was no age-related difference in erythrocyte GPx activity in either non-smokers or ever-smokers. Among those >60 years old, erythrocyte CAT and GPx activities were significantly lower in ever-smokers than in non-smokers (29.70 +/- 3.07 mU/g Hb vs. 41.63 +/- 4.92 mU/g Hb (P < 0.05), and 47.55 +/- 2.00 mU/g Hb vs. 55.30 +/- 3.60 mU/g Hb (P < 0.05), respectively). It was also found that females had higher erythrocyte GPx activity than males but this difference did not reach significance in non-smokers.

CONCLUSION

From the results of this study, it is concluded that oxidative stress seems to be present in elderly ever-smokers among the Chinese population.

Effect of a high-altitude expedition to a Himalayan peak (Pumori, 7,161�m) on plasma and erythrocyte antioxidant profile

The effects of a high-altitude exposure were studied in six mountaineers who spent 3 weeks at an altitude range between 5,250 and 7,161 m after 1 week in an acclimatization trek (2,800-5,250 m). Blood drawn from the antecubital vein was collected at sea level 1 day before and 1 day after the expedition to analyse some haematological variables [haemoglobin (Hb), haematocrit (Htc) and red blood cell (RBC) count], erythrocyte antioxidant enzyme activity [superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (Gr)] and membrane fatty acid profile [mono-unsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), saturated fatty acids (SFA), trans fatty acids (TRANS)]. Moreover, total antioxidant status (TAS), thiobarbituric acid reactive substances (TBARS), thiol protein groups (SH), SOD, GPx and Gr were measured in plasma. High-altitude exposure induced polycythaemia, with significant increases in RBC count (5.26%), Hb concentration (4.83%) and Htc (6.26%). Furthermore, a significant increase in plasma TBARS, SOD and Gr was observed after the expedition, whereas SH, TAS and GPx decreased. Erythrocyte glutathione-cycle-related antioxidant enzyme activity was upregulated, whereas SOD activity was maintained after the expedition. In addition, despite the unchanged (MUFA+PUFA)/SFA ratio, the membrane erythrocyte fatty acid content showed a significant increase in PUFAs and a decrease in TRANS, suggesting enhanced membrane fluidity. In conclusion, it seems that high-altitude exposure, besides quantitative variations in RBC expression, induced plasma oxidative stress and damage, and significant changes in erythrocyte components, namely in antioxidant enzyme activity and membrane fatty acid profile that might modify RBC functionality.