Tiiu Vihalemm

Two antioxidative lactobacilli strains as promising probiotics.

Two antioxidative strains tentatively identified as Lactobacillus fermentum, E-3 and E-18, were isolated from intestinal microflora of a healthy child. Survival time of these strains in the presence of reactive oxygen species (ROS), like hydrogen peroxide, superoxide anions and hydroxyl radicals, was significantly increased compared with a non-antioxidative strain, and also was quite similar to a highly ROS resistant strain of Salmonella typhimurium. E-3 and E-8 contain a remarkable level of glutathione, express Mn-SOD, which is important for the prevention of lipid peroxidation, and secrete hydrogen peroxide. Their significant antimicrobial activity combined with antioxidative properties may serve as defensive principles in the intestinal microbial ecosystem and overcome exo- and endogenous oxidative stress.

The Cerebrocortical Areas in Normal Brain Aging and in Alzheimer's Disease: Noticeable Differences in the Lipid Peroxidation Level and in Antioxidant Defense

The markers of oxidative stress were measured in four cerebrocortical regions of Alzheimers disease (AD) and age-matched control brains. In controls the levels of diene conjugates (DC) and lipid peroxides (LOOH) were significantly higher in the sensory postcentral and occipital primary cortex than in the temporal inferior or frontal inferior cortex. The antioxidant capacity (AOC) was highest in the temporal, and GSH in the frontal inferior cortex. The highest activity of superoxide dismutase (SOD) and catalase (CAT) was found in the occipital primary cortex. Compared with controls, significantly higher level of DC and LOOH and attenuated AOC were evident in AD temporal inferior cortex. In AD frontal inferior cortex moderate increase in LOOH was associated with positive correlation between SOD activity and counts of senile plaques. Our data suggest that in AD cerebral cortex, the oxidative stress is expressed in the reducing sequence: temporal inferior cortex > frontal inferior cortex > sensory postcentral cortex ≃ occipital primary cortex, corresponding to the histopathological spreading of AD from the associative to primary cortical areas.

Acute immune response in respect to exercise-induced oxidative stress

The relationship between exhaustive exercise, oxidative stress, the protective capacity of the antioxidant defense system and cellular immune response has been determined. Exhaustive exercise in well-trained young men (n=19)-induced leukocytosis, decreased proportion of activated-lymphocyte subsets (CD4+ and CD8+) expressing CD69, decreased lymphocyte mitogenic response to concanavalin A (ConA) and phytohemagglutinin (PHA), increased lipid peroxidation, increased total antioxidant status (TAS) and catalase activity, immediately after exercise. Suppressed blood concentration of T-lymphocyte subsets (CD3+, CD4+, CD8+, NK), increased TAS and blood total glutathione (TGSH) in early recovery period (30 min after exercise) were found. Strong positive correlation was observed between TGSH and lymphocyte mitogenic response to ConA and PHA (r=0.85 and 0.85, respectively) immediately after exercise. Moderate positive correlation was observed between TAS and lymphocyte mitogenic response to PHA (r=0.59) immediately after exercise as well as between TAS and lymphocyte mitogenic response to PHA and ConA (r=0.69 and 0.54, respectively). Moderate to weak correlation was observed between TAS and conjugated dienes with exercise (r=0.66) as well as in 30-min recovery (r=0.50). After a short-term bout of exhaustive exercise, immune system was characterized by acute phase response, which was accompanied with oxidative stress. Suppression of the cellular immunity 30 min after exercise shows that this period is not enough for recovery after exhaustive exercise. The results suggest the interactions between exercise-induced oxidative stress and immune response.

Beneficial effects of water-based exercise in patients with chronic kidney disease.

The possible beneficial effect of regular aquatic exercise on cardiorespiratory, renal lipid parameters and oxidative stress status was studied in patients with mild to moderate renal failure. The exercise group did low-intensity aerobic exercise in the pool during a period of 12 weeks, twice a week, with sessions lasting for 30 min. Matched control participants remained sedentary. The results showed that in the exercise group all cardiorespiratory functional parameters improved and resting blood pressure lowered significantly. Proteinuria and cystatin-C were diminished significantly and glomerular filtration rate was enhanced. To evaluate the changes in oxidative stress status in the serum, products of lipid peroxidation (LPO) and serum glutathione values were measured. LPO was reduced significantly and reduced glutathione levels showed significant improvement after the exercise-conditioning programme. In the control group the data either remained the same or worsened in the same period of time. In conclusion, regular water-based exercise has beneficial effects on the cardiorespiratory, renal functional parameters and oxidative stress status in patients with moderate renal failure, and can be used in the complex rehabilitation of chronic renal failure patients, together with blood pressure control, dietary consultation, encouragement and education to prevent physical worsening and to postpone cardiovascular and renal atherosclerotic complications.

TIME COURSE OF OXIDATIVE STRESS DURING OPEN-HEART SURGERY

Oxidative stress and subsequent lipid peroxidation have been suggested as pathogenetically important for postischaemic reperfusion injury. We studied the time-course of oxidative stress in 14 adults undergoing cardiac surgery, evaluating serum levels of lipid peroxidation products--diene conjugates (DC) and basal and Fe-stimulated thiobarbituric acid reactive substances (TBARS, FeTEBARS)--as well as markers of blood antioxidant status--serum antioxidative capacity (AOC) and red blood cell glutathione (RBC-GSH) at 6 perioperative time-points. Arterial TBARS were significantly increased 15 minutes after start of cardiopulmonary bypass, 5 minutes after release of aortic cross-clamp and 15 minutes after cessation of bypass, compared with the preoperative levels (respective means 20.8, 38.5, 34.8 vs 7.5 nmol/g protein, p < 0.05). AOC had decreased at these times (means 21.3, 18.1, 23.2 vs 34.9%, p < 0.05). The TBARS changes correlated with AOC decrease (r = 0.30, p < 0.001). Changes in serum DC and RBC-GSH were not statistically significant. All lipid peroxidation parameters had returned to preoperative levels on the following morning, while antioxidative capacity remained suppressed (28.1%, p < 0.05). These data demonstrate a definite time-course of oxidative stress markers in arterial blood during open-heart surgery.

PRECONDITIONING WITH HYDROGEN PEROXIDE (H2O2) OR ISCHEMIA IN H2O2-INDUCED CARDIAC DYSFUNCTION

The possible cardioprotective effects of preconditioning by ischaemia (IPC) or a low dose of H2O2 (HPC) prior to a high dose of H2O2 was investigated. Langendorff-perfused rat hearts (n = 10 in each group) were subjected to 10 min of 140 micromol/L H2O2 and 30 min recovery after either (1) control perfusion, (2) 20 micromol/L H2O2 for 10 min, recovery 10 min, or (3) 2 x 2 min global ischaemia and 5 min reperfusion. 140 micromol/L H2O2 increased left ventricular end-diastolic pressure from 0 to 68+/-8 mmHg in controls (mean+/-SEM), which was attenuated by IPC (46+/-9 mmHg, p<0.001) and HPC (18+/-4 mmHg, p < 0.001 compared to controls, p < 0.01 compared to IPC). HPC, but not IPC, improved coronary flow (p < 0.02) and left ventricular developed pressure (p < 0.001) during recovery. Troponin T release was similar in all groups. Tissue thiobarbituric acid reactive substances, antioxidant capacity, catalase, and glutathione peroxidase were not influenced by 140 micromol/L H2O2. H2O2 decreased the level of tissue glutathione. This reduction was augmented by HPC (p <0.02) and attenuated by IPC (p < 0.02). H2O2 increased superoxide dismutase (p < 0.04). The increase was attenuated by IPC (p < 0.05), but not influenced by HPC. HPC efficiently protected cardiac function in H2O2-induced cardiac injury, while IPC had only a small protective effect. The functional protection cannot be explained by reduction of irreversible injury, attenuation of lipid peroxidation, or modification of tissue antioxidant parameters.

Acknowledgement to the 2000 Reviewers

Adam, O., München, Germany Bauer, C.P., Gaissach, Germany Berdel, D., Wesel, Germany Boeing, H., Bergholz-Rehbrücke, Germany Eder, K., Halle, Germany Elmadfa, I., Wien, Austria Erbersdobler, H., Kiel, Germany Flynn, A., Cork, Ireland Goldenberg, H., Wien, Austria Götz, M., Wien, Austria Grimm, H., Giessen, Germany Hagemeister, H., Rostock, Germany Heymsfield, G., New York, USA Krawinkel, M., Giessen, Germany Krempf, M., Nantes, France Laplace, J.P., Paris, France Lemmens, R., Wien, Austria Linseisen, J., Heidelberg, Germany Martinez, J.A., Pamplona, Spain Metges, C., Bergholz-Rehbrücke, Germany Moser, U., Basel, Switzerland Müller, M.J., Kiel, Germany Pfeuffer, E., Kiel, Germany Pietrzik, K., Bonn, Germany Pils, K., Wien, Austria Roth, H.P., Freising-Weihenstephan, Germany Rust, P., Wien, Austria Saris, W., Mastricht, Netherlands Schrezenmeir, J., Kiel, Germany Schümann, K., München, Germany Schweigert, F.J., Bergholz-Rehbrücke, Germany Seiler, W., Basel, Switzerland Thorsdottir, I., Reykjavik, Iceland Van den Berg, H., AJ Zeist, Netherlands Vasson, M.P., Clermont-Ferrand, France Vermeer, C., Mastricht, Netherlands Wernermann, J., Huddinge, Sweden Zunft, H.J., Bergholz-Rehbrücke, Germany

Could long-term alimentary iron overload have an impact on the parameters of oxidative stress? A study on the basis of a village in southern Estonia.

The effects of long-term alimentary (drinking water) iron overload on the parameters of oxidative stress were evaluated. The study group (n = 35) from a village in southern Estonia was 37.1 ± 13.3 years old, and the mean period of drinking water iron overload was 20.6 ± 9.3 years. The serum iron content was significantly higher than normal. The total iron-binding capacity of serum tended to be lowered. There was no change in the transferrin content. The parameters of lipid peroxidation like conjugated dienes and thiobarbituric acid reactive substances showed also significant differences. In addition, the red blood cell glutathione content was also decreased. The total antioxidant capacity of serum was not changed. It can be concluded from our results that a long-term alimentary iron overload results in a positive serum iron balance, which, in turn, yields an increased oxidative stress.

Successful management of mild atopic dermatitis in adults with probiotics and emollients

Atopic dermatitis is characterized by impaired skin and mucous membrane barrier function. Measures improving barrier integrity decrease the influence of environmental factors that might exacerbate inflammation. Ten adult patients with mild-to-moderate atopic dermatitis consumed for three months fermented with potent antioxidative probiotic, L. fermentum ME-3 (DSM 14241) goat milk 200 mg/day. A control group consisted of six patients, not supplemented by probiotic. All patients used emollients regularly. Skin iron levels, glutathione redox ratios (GSSG/GSH), diene conjugate (DC) amounts, blood glutathione status, oxidized low-density lipoprotein (oxLDL), and total antioxidativity was measured at the baseline and after three months. A significant decrease in skin iron levels, DC amounts, and glutathione redox ratio occurred in the probiotic-supplemented group compared to the control group (P < 0.05 for all indices). In the same group, blood levels of oxLDL decreased (p < 0.05), and GSH levels increased (P < 0.001) with concomitant improvement in the GSSG/GSH ratio. Blood antioxidativity markers also showed an improvement. The results of our study demonstrate that regular use of probiotics with antioxidative properties coupled with the use of lipid-containing emollients considerably decreases inflammation and concomitant oxidative stress in adult patients with mild-to-moderate atopic dermatitis. This effect was observed both in the skin and in the blood.

Oxidative stress status in kidney tissue after losartan and atenolol treatment in experimental renal failure.

Background/Aims: Rats with subtotal nephrectomy (5/6NPX) rapidly develop systemic hypertension and proteinuria. The aim of our study was to evaluate the changes in oxidative stress parameters after 2 and 4 weeks of treatment with renin-angiotensin system (RAS)-blocking agent losartan and beta-blocking agent atenolol in experimental chronic renal failure (CRF). Methods: After 5/6NPX, rats were immediately treated with losartan or atenolol. The lipid peroxidation (LPO) products malondialdehyde and 4-hydroxyalkenals and oxidized and reduced glutathione values were measured in the renal cortex tissue and in blood; isoprostanes in urine. Results: There were no differences in the blood pressure values, serum creatinine levels or in daily proteinuria using both antihypertensive treatments. Losartan treatment lowered significantly LPO in kidney tissue after 2 and 4 weeks of treatment compared with untreated and atenolol-treated animals and induced the decrease of excretion of isoprostanes in urine at the end of the study. There was no ameliorating impact of losartan or atenolol observed in the blood status of oxidative stress in this period of time. Conclusion: In the early period of experimental CRF, losartan treatment but not atenolol treatment induces significant decline in LPO grade in the kidney tissue of nephrectomized rats. RAS blockade in the kidney influences local tissue LPO in a much greater extent than in blood.