Zuzana Országhová

Antioxidant systems in polymorphonuclear leucocytes of Type 2 diabetes mellitus.

Aims To examine the effect of Type 2 diabetes mellitus (DM) on enzymes of importance for oxygen‐dependent killing of microorganisms by leucocytes.

Probiotics and vitamin C for the prevention of respiratory tract infections in children attending preschool: a randomised controlled pilot study

Background:This pilot study investigates the efficacy of a probiotic consortium (Lab4) in combination with vitamin C on the prevention of respiratory tract infections in children attending preschool facilities.Subjects/methods:In a double-blind, randomised, placebo-controlled pilot study with children aged 3–6 years, 57 received 1.25 × 1010 colony-forming units of Lactobacillus acidophilus CUL21 (NCIMB 30156), Lactobacillus acidophilus CUL60 (NCIMB 30157), Bifidobacterium bifidum CUL20 (NCIMB 30153) and Bifidobacterium animalis subsp. lactis CUL34 (NCIMB 30172) plus 50 mg vitamin C or a placebo daily for 6 months.Results:Significant reductions in the incidence rate of upper respiratory tract infection (URTI; 33%, P=0.002), the number of days with URTI symptoms (mean difference: −21.0, 95% confidence interval (CI):−35.9, −6.0, P=0.006) and the incidence rate of absence from preschool (30%, P=0.007) were observed in the active group compared with the placebo. The number of days of use of antibiotics, painkillers, cough medicine or nasal sprays was lower in the active group and reached significance for use of cough medicine (mean difference: −6.6, 95% CI: −12.9, −0.3, P=0.040). No significant differences were observed in the incidence rate ratio or duration of lower respiratory tract infection or in the levels of plasma cytokines, salivary immunoglobulin A or urinary metabolites.Conclusions:Supplementation with a probiotic/vitamin C combination may be beneficial in the prevention and management of URTIs.

Effect of natural polyphenols (Pycnogenol) on oxidative stress markers in children suffering from Crohn's disease – a pilot study

Abstract Crohns disease (CD) is a nonspecific, chronic inflammatory disease of the gastrointestinal tract. It is supposed that in etiopathogenesis oxidative stress (OS) plays a role. However, its precise role in the active and non-active states of disease is not known yet. We conducted a pilot study focusing on the relationship between OS of CD in remission and the possibility to influence clinical parameters and markers of OS by polyphenolic extract, Pycnogenol® (Pyc). Compared to 15 healthy controls 15 pediatric CD patients (all were in remission according to their disease activity index – PCDAI) had reduced the activity of Cu/Zn-superoxide dismutase (SOD) and increased the oxidative damage to proteins. We found negative correlations between markers of inflammation (calprotectin, CRP) as well as between PCDAI and total antioxidant capacity (TAC). Activities of antioxidant enzymes, SOD, and glutathione peroxidase (GPX) negatively correlated with calprotectin and PCDAI. Pyc (2 mg/kg) positively influenced the parameters of OS in CD patients after 10 weeks of administration.

The effect of natural polyphenols on the oxidative stress markers in patients with diabetic nephropathy.

BACKGROUND Nephropathy remains a significant cause of morbidity and mortality in the diabetic population and is the leading cause of end-stage renal failure, hence kidney transplantations. As a result of the diabetic milieu, increased generation of reactive oxygen species is thought to play a key role in the progression of diabetic nephropathy. Aim of this study was to evaluate the effect of Pycnogenol (Pyc), the extract from Pinus pinaster, on the level of glucose, advanced glycation end products (AGE) and oxidative stress markers in patients with Diabetic nephropathy (DN). SUBJECT AND METHODS To double blind randomised placebo controlled exploratory study were enrolled 20 men with DN received daily Pyc (120mg) or a placebo. Patients were investigated before, one and three months after Pyc administration and after termination of drugs supplementation. RESULTS The level of glucose, AGEs, malondialdehyde (MDA), 8-isoprostanes (8-Iso), as well as protein carbonyls (PC) were increased in comparison to control group. We have found lower level of glucose, AGEs, MDA and 8-Iso after 3 months of Pyc administration in comparison to the beginning state and to placebo group, but these results did not reach significance. CP and TAS were not affected. CONCLUSION Our data allow us to conclude that Pycnogenoladministration reduces oxidative damage to lipids rather through the decreased glucose level than through the influence of antioxidant capacity of plasma. This study was supported by grant Ministry of Health 2012/8-ukba-8.

Influence of oak wood polyphenols on cysteine, homocysteine and glutathione total levels and PON1 activities in human adult volunteers - a pilot study.

Oxidative stress reflects an imbalance between antioxidants and pro-oxidants. Many diseases like atherosclerosis or heart failure are involved in oxidative stress. Increased oxidative stress is one of the potential contributing factors to aging. The aim of this study was to monitor the total thiol levels as markers of oxidative stress in 20 healthy volunteers after polyphenols intake (extract from the French oak wood Quercus robur - Robuvit® (300 mg/day)). Polyphenols are known as biomodulators with antioxidant activities. Homocysteine, cysteine and glutathione total levels were determined by using HPLC with electrochemical detection. The activity of the antioxidant enzyme paraoxonase-1 toward two substrates was determined by spectrophotometry. The level of thiol compounds and paraoxonase-1 activities were controlled after run-in (week 0), intervention (week 4) and washout (week 6) period. After the intervention period the results showed that Robuvit® had no significant influence on glutathione level (p = 0.382) and paraoxonase activities towards both, arylester and lactone substrates. On the other hand, homocysteine and cysteine levels decreased significantly (p = 0.029; p < 0.001, respectively). The negative correlation between paraoxonase lactonase activity and homocysteine level was noticed. This confirms that paraoxonase might play an important role in homocysteine-thiolactone metabolism.

Effect of the French Oak Wood Extract Robuvit on Markers of Oxidative Stress and Activity of Antioxidant Enzymes in Healthy Volunteers: A Pilot Study

We examined in vitro antioxidant capacity of polyphenolic extract obtained from the wood of oak Quercus robur (QR), Robuvit, using TEAC (Trolox equivalent antioxidant capacity) method and the effect of its intake on markers of oxidative stress, activity of antioxidant enzymes, and total antioxidant capacity in plasma of 20 healthy volunteers. Markers of oxidative damage to proteins, DNA, and lipids and activities of Cu/Zn-superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were determined in the erythrocytes. We have found an in vitro antioxidant capacity of Robuvit of 6.37 micromole Trolox equivalent/mg of Robuvit. One month intake of Robuvit in daily dose of 300 mg has significantly decreased the serum level of advanced oxidation protein products (AOPP) and lipid peroxides (LP). Significantly increased activities of SOD and CAT as well as total antioxidant capacity of plasma after one month intake of Robuvit have been shown. In conclusion, we have demonstrated for the first time that the intake of Robuvit is associated with decrease of markers of oxidative stress and increase of activity of antioxidant enzymes and total antioxidant capacity of plasma in vivo.

Effects of N1-methylnicotinamide on oxidative and glycooxidative stress markers in rats with streptozotocin-induced diabetes mellitus

Abstract Objectives This study was focused on the monitoring how the anti-inflammatory substance, N1-methylnicotinamide (MNA), could influence oxidation and glycooxidation stress markers in rats under conditions of streptozotocin (STZ)-induced diabetes mellitus. Methods Diabetes mellitus was induced in 60 male Wistar rats by intraperitoneal injection of STZ and after 7 days diabetic animals were allocated to five groups according to the dose of MNA administered for 7 weeks. The degree of DNA damage in lymphocytes, as well as advanced glycation endproducts (AGEs), protein carbonyls, lipid peroxides, and total antioxidant capacity (TEAC) in plasma were measured. Results Glycation damage to proteins (represented by AGEs level) was significantly increased in all diabetic groups compared to untreated non-diabetic animals. MNA did not affect TEAC of plasma in any group of diabetic rats. Supplementation of diabetic rats with MNA at the dose of 200 mg/kg resulted in decreased protein carbonyls (from 0.0818 ± 0.0091 to 0.0558 ± 0.0044 nmol/mg proteins; P < 0.05, n = 15) and DNA oxidation, reflected by the levels of 8-oxoG (0.6302 ± 0.085 vs. 0.9213 ± 0.108 8-oxoG/106 G; P < 0.05, n = 15), compared to untreated diabetic animals. Discussion Our results demonstrated that MNA at suitable concentrations could influence oxidative modifications of proteins and DNA.

An Effect of Oak‐Wood Extract (Robuvit®) on Energy State of Healthy Adults—A Pilot Study

The purpose of our study was to examine the psychological benefits of the treatment with Robuvit® (Horphag Research Ltd.) – polyphenolic extract obtained from the wood of oak Quercus robur – on the healthy elderly individuals using energy subscale scores of the Activation – Deactivation Adjective Check List. Analysis was focused on the comparison of pre‐post treatment effect of Robuvit on symptoms of fatigue. In the total group of volunteers, significant increase of average question scores was found in three of four subscales of feelings (energy, tiredness, and tension) after 4 weeks of Robuvit administration. Effects of extract were observed mainly after stratification of total group of volunteers according to the level of feeling at the pre‐treatment questionnaire. Our results demonstrate positive effect of Robuvit on mental and energy level in healthy human without any unwanted side effects.