Jolanta Zalejska-Fiolka

Beta-carotene reduces oxidative stress, improves glutathione metabolism and modifies antioxidant defense systems in lead-exposed workers.

The aim of this study was to determine whether beta-carotene administration reduces oxidative stress and influences antioxidant, mainly glutathione-related, defense systems in workers chronically exposed to lead. The population consisted of two randomly divided groups of healthy male volunteers exposed to lead. Workers in the first group (reference group) were not administered any antioxidants, while workers in the second group (CAR group) were treated orally with 10mg of beta-carotene once a day for 12weeks. Biochemical analysis included measuring markers of lead-exposure and oxidative stress in addition to the levels and activities of selected antioxidants. After treatment, levels of malondialdehyde, lipid hydroperoxides and lipofuscin significantly decreased compared with the reference group. However, the level of glutathione significantly increased compared with the baseline. Treatment with beta-carotene also resulted in significantly decreased glutathione peroxidase activity compared with the reference group, while the activities of other glutathione-related enzymes and of superoxide dismutase were not significantly changed. However, the activities of glucose-6-phosphate dehydrogenase and catalase, as well as the level of alpha-tocopherol, were significantly higher after treatment compared with the baseline. Despite controversy over the antioxidant properties of beta-carotene in vivo, our findings showed reduced oxidative stress after beta-carotene supplementation in chronic lead poisoning.

Influence of sodium fluoride and caffeine on the kidney function and free-radical processes in that organ in adult rats

An experiment was carried out on Sprague-Dawley rats (adult males) that for 50 days were administered, in the drinking water, NaF and NaF with caffeine (doses, respectively: 4.9 mg of NaF/kg body mass/24 h and 3 mg of caffeine/kg body mass/24 h). Disturbances were noted in the functioning of kidneys, which were, particularly noticeable after the administration of NaF with caffeine. Changes in the functioning of kidneys were also confirmed by such parameters as the level of creatinine, urea, protein, and calcium. Modifications of the enzymatic antioxidative system (superoxide dismutase, catalase, and glutathione peroxidase) and lipid peroxidation (malondialdehyde) were also observed. Changes in the contents of the above parameters as well as pathomorphological examinations suggest increased diuresis, resulting in dehydration of the rats examined.

The effect of lead-induced oxidative stress on blood viscosity and rheological properties of erythrocytes in lead exposed humans.

Lead-induced oxidative stress has been identified as the essential factor in lead poisoning pathogenesis. Therefore, the present study examined the association between occupational lead exposure and blood rheological parameters with respect to malondialdehyde (a lipid peroxidation product), lipofuscin, and glutathione concentrations in erythrocytes. The examined group included 283 healthy male employees of lead-zinc works. In brief, 129 workers were classified as the low-exposure group, while the high-exposure group was composed of 154 workers. The mean blood levels of lead and zinc-protoporphyrin and the mean urine concentrations of delta-aminolevulinic acid were used as exposure markers. The control group consisted of 73 healthy male administrative workers. Whole blood viscosity was elevated in both exposure subgroups compared with the control group. Erythrocyte aggregability increased significantly; although the increase was greater in the low exposure group. Erythrocyte deformability decreased in both subgroups. The levels of malondialdehyde and lipofuscin were significantly elevated, whereas the glutathione content decreased. In conclusion, occupational exposure to lead may induce oxidative stress in erythrocytes. This stress elevates whole blood viscosity and disturbs erythrocyte aggregability and deformability. There is a dose-effect relationship between lead levels and blood rheological parameters.

Effect of treatment with N-acetylcysteine on non-enzymatic antioxidant reserves and lipid peroxidation in workers exposed to lead

There are no published studies examining the effects of N-acetylcysteine (NAC) administration on the non-enzymatic defence systems in humans exposed to lead. In view of this, it was decided to measure the levels of uric acid (UA), albumin, bilirubin and alpha-tocopherol before and after treatment with NAC. An estimation was also made of the degree of oxidative stress by measuring the ferric reducing ability of plasma (FRAP), the levels of conjugated dienes (CD) and lipid hydroperoxides (LHP). Male employees who worked with lead were randomized into two groups. The first group included workers who were not administered any drugs (n=49), while the second group (n=122) consisted of workers who were treated with NAC at three different doses (200 mg, 400 mg and 800 mg) for 12 weeks. The administration of NAC (400 mg, 800 mg) resulted in significant decreases in the LHP levels. Similarly, a strong tendency toward lower levels of CD was observed in the same groups. The UA levels were significantly lower only in the group receiving the 200 mg dose of NAC. However, the alpha-tocopherol levels were significantly elevated after treatment with NAC (400 mg, 800 mg). NAC administration did not significantly affect the levels of bilirubin and albumin, but a tendency toward higher values was observed for FRAP. NAC reduced the extent of lipid peroxidation in a dose-dependent manner. Elevated concentrations of alpha-tocopherol may have enhanced the beneficial effects of NAC. Treatment with NAC may contribute to the restoration of non-enzymatic antioxidant reserves when administered to lead-exposed workers.

The metabolism of carbohydrates and lipid peroxidation in lead-exposed workers:

The present study was undertaken to estimate the effect of occupational exposure to lead on the blood concentration of glucose and several enzymes involved in glycolysis, the citric acid cycle, and the pentose phosphate pathway. To estimate the degree of lipid peroxidation, the concentrations of conjugated dienes were determined. The examined group included 145 healthy male employees of lead–zinc works. Taking into account the mean blood lead levels, the examined group was divided into two subgroups. The control group was composed of 36 healthy male administrative workers. The markers of lead exposure were significantly elevated in both subgroups when compared with the controls. There were no significant changes in fasting glucose concentration and fructose-1,6-bisphosphate aldolase activity in the study population. The concentration of conjugated dienes was significantly higher in both subgroups, whereas the activity of malate dehydrogenase was significantly higher only in the group with higher exposure. The activities of lactate dehydrogenase and sorbitol dehydrogenase were significantly decreased in the examined subgroups. The activity of glucose-6-phosphate dehydrogenase decreased significantly in the group with higher exposure and could be the cause of the elevated concentrations of conjugated dienes. It is possible to conclude that lead interferes with carbohydrate metabolism, but compensatory mechanisms seem to be efficient, as glucose homeostasis in lead-exposed workers was not disturbed.

The influence of macro and trace elements on sperm quality.

The aim of this study was to examine the association between combined concentrations of macro and trace elements and markers of oxidative stress and antioxidative defense system function together with selected cytokine levels. Based on the combined medians of the seminal plasma levels of calcium, magnesium, zinc, copper, iron, and selenium, the study subjects (88 fertile male volunteers) were divided into the following two subgroups: the Me-L group (low level of metals) and the Me-H group (high level of metals). There was a tendency toward reduced motility in the Me-H group compared to that in the Me-L group. The total protein, albumin, and total oxidation status (TOS) levels were significantly higher in the Me-H group than in the Me-L group. The total superoxide dismutase (SOD), Mn-SOD, and CuZn-SOD, activity in spermatozoa were significantly lower in the Me-H group than in the Me-L group. In seminal plasma, the Mn-SOD activity was significantly higher in the Me-H group, whereas the CuZn-SOD activity was significantly lower. Additionally, the activity levels of glutathione peroxidase (GPx) and glutathione-S-transferase (GST) were lower in the Me-H group. The medians of IL-1β, IL-10, and IL-12 were significantly higher in the Me-H group than in the Me-L group, whereas the medians of IL-2, IL-5, and IL-13 were significantly lower. Higher levels of macro and trace elements in the seminal plasma of fertile males may be associated with decreased motility. Higher levels of the examined metals are associated with elevated oxidative stress accompanied by decreased activities of some of the antioxidant enzymes and increased pro-inflammatory cytokine levels.

Oxidative stress in the red blood cells of patients with primary open-angle glaucoma

BACKGROUND This study was designed to examine oxidative and antioxidative changes in the red blood cells (RBCs) of patients presenting with glaucomatous degeneration. METHODS The experimental design was a case-control study of strictly selected patients who required antiglaucomatous surgery during primary open-angle glaucoma despite relatively regulated intraocular pressure (IOP) (POAG group, n = 30) and patients who underwent an operation for nonpathological cataracts (cataract group, n = 25). The activities of total superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT), as well as the concentration of malondialdehyde (MDA), were measured. Glaucomatous damage was estimated from a transient pattern electroretinogram. RESULTS Significant increases in GPX (p = 0.026) and CAT (p = 0.000) activity were noted in the RBCs of POAG patients compared to those of cataract patients. Although SOD was elevated in patients with POAG, the differences compared to cataract controls were not significant (p = 0.079). MDA concentrations were significantly increased in the glaucoma group compared to the cataract controls. CONCLUSION An oxidative disorder primarily represented by catalase upregulation was observed during the course of glaucoma.

Influence of selenomethionine and vitamin E on the antioxidative system in animals with experimentally induced hypercholesterolemia

The aim of this study was to investigate the effect of combined therapy of vitamin E and selenomethionine to pro/ antioxidant status in experimental hypercholesterolemia. Thirty male rabbits were included in the study and randomized into five groups consisting of the control group (standard diet) and four experimental groups staying on a diet rich in cholesterol (0.5 g/100 g diet): cholesterol group and groups supplemented cholesterol with selenomethionine (12.5 μg/kg body mass/24 h) or vitamin E (10 mg of Dl-α-tocopherol/kg body mass/24 h) or combination of the above antioxidants for 3 mo. The activity of superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT) as well as the concentration of malondialdehyde (MDA) was estimated in the blood during every month of experiment. Increased activity of SOD and GPX with a decreased concentration of MDA in comparison to the cholesterol diet was found mainly in the combination of study antioxidants. The supplementation of the cholesterol diet with combined doses of vitamin E and selenomethionine appears to prevent the lesions induced by experimental hypercholesterolemia much more efficiently than single doses of the above.

Magnesium and selected parameters of the non-enzymatic antioxidant and immune systems and oxidative stress intensity in the seminal plasma of fertile males

INTRODUCTION The present study investigated associations between environmental exposure to magnesium (Mg) and the levels of oxidative stress parameters and selected cytokines, and the antioxidant defense system in the seminal plasma of fertile males. MATERIALS AND METHODS The study population consisted of 57 healthy, non-smoking, fertile men from the southern region of Poland. Based on the median magnesium levels in seminal plasma, subjects were divided into two groups: those with low (Mg-L) and high (Mg-H) magnesium concentrations. RESULTS Differences were not observed between the Mg-L and Mg-H groups as regards semen volume, pH, count, motility, or morphology of sperm cells. In the Mg-H group, cholesterol levels were significantly higher (77%) compared with the Mg-L group: however, γ-glutamyltranspeptidase activity was significantly lower (21%). The values of total oxidant status were significantly different between the two groups, with 78% higher values observed in the Mg-H group compared with the Mg-L group, whereas malondialdehyde levels did not differ significantly. The values for total antioxidant capacity and uric acid levels were significantly lower in the Mg-H group compared with the Mg-L group (14% and 17%, respectively). However, levels of bilirubin, albumin, thiol groups and α-tocopherol were significantly higher in the Mg-H group (71%, 44%, 35% and 47%, respectively). CONCLUSION No associations between Mg levels in the seminal plasma of fertile males and standard semen parameters were found. However, Mg levels may be associated with altered function of the non-enzymatic antioxidant system.

Effect of Selected Dietary Compounds on Extracellular Superoxide Dismutase in the Vitreous of Chinchillas

Purpose: The purpose of this study was to evaluate the effect of diet on the extracellular superoxide dismutase (EC-SOD) activity in the vitreous of chinchillas. Methods: Seventy-eight male chinchillas were randomly divided into 7 subgroups: controls, receiving a standard basal diet, and 6 experimental groups additionally receiving 10% nonoxidized and 10% oxidized olive oil, a garlic extract and lipoic acid in their diet. The activities of EC-SOD were measured. Results: The highest EC-SOD activity was similar in the controls [2.17 ± 0.27 nitric units (NU)/mg protein] and in rabbits fed oxidized olive oil (2.29 ± 0.31 NU/mg protein; p = 0.519). Nonoxidized olive oil appeared to be the strongest antioxidant component of diet (1.58 ± 0.20 NU/mg protein) as compared with the subgroups above (p = 0.008 and p = 0.012, respectively). Administration of garlic and lipoic acid decreased the SOD activity only inthe groups fed oxidized olive oil (p = 0.014). Conclusions: The SOD activity in laboratory animals is possibly modulated by diet. Work will be continued to extrapolate these results to humans.