Characterization of the antioxidant profile of human saliva in peri-implant health and disease.

OBJECTIVES: Peri-implant disease is considered to be an inflammatory disease, but many aspects of its pathogenesis remain unknown. At present, peri-implant disease is considered to be initiated and perpetuated by a small group of predominantly Gram-negative, anaerobic, or micro-aerophilic bacteria that colonize the subgingival area. Bacteria cause the observed tissue destruction directly by toxic products and indirectly by activating host defence systems, i.e. inflammation. A variety of molecular species appears in the inflamed tissues, among them are reactive species such as free radicals and reactive oxygen species (ROS). The purpose of this study was to assess levels of various antioxidants in saliva to identify differences between the saliva of patients with healthy peri-implant tissues and patients with peri-implant disease, and to examine whether the whole saliva of those with peri-implant disease conditions might have lower levels of antioxidants than that of healthy individuals. MATERIALS AND METHODS: Thirty healthy adult volunteers (14 men and 16 women) with implant-supported overdentures (Ankylos Biofunctional Implants) were selected from the group of patients from Tallinn Dental Clinic. Biochemical and clinical parameters evaluated were the following ones: the levels of urate, ascorbate, myeloperoxidase in saliva, total antioxidant status of saliva, pocket probing depth (mm), gingival index (0, 1, 2, or 3), and bleeding on probing (0 or 1). RESULTS AND CONCLUSION: Total antioxidant status (TAS) of saliva and concentration of uric acid and ascorbate, which are the main salivary antioxidants, are significantly decreased in patients with peri-implant disease. TAS in healthy subjects was 0.41+/-0.10 for resting saliva and 0.31+/-0.09 for stimulated saliva; in diseased subjects TAS was 0.19+/-0.07 and 0.12+/-0.03, respectively. In healthy subjects, the concentration of urate was 307.2+/-78.06 microM/l in resting saliva and 241.5+/-89.09 microM/l in stimulated saliva. In diseased patients, the concentration of urate was 120+/-36.13 and 91.60+/-39.35 microM/l, respectively. The concentration of ascorbate did not differ in resting and stimulated saliva. In healthy subjects, it was 2.79+/-0.81 mg/l and in diseased subjects, it was 1.54+/-0.30 mg/l. This may indicate that excessive ROS production in peri-implant disease is leading to the situation of excessive oxidative stress, which may be an important factor contributing the destruction of peri-implant tissues. The importance of these findings may be the better understanding of the processes involved in the pathogenesis of peri-implant disease and that the treatment of peri-implant disease may involve adjuvant anti-oxidants supplementation together with cumulative interceptive supportive therapy concept introduced by Mombelli & Lang.

Correlations between clinical parameters and interleukin-6 and interleukin-10 levels in saliva from totally edentulous patients with peri-implant disease.

PURPOSE: The purpose of the present study was (1) to assess the relationship between clinical parameters and concentrations of the proinflammatory cytokine IL-6 and the anti-inflammatory cytokine IL-10 in the saliva of totally edentulous patients with implant-supported overdentures; (2) to assess whether estimation of IL-6 and IL-10 levels in saliva could be a useful laboratory tool to detect changes preceding serious clinical complications. MATERIALS AND METHODS: Thirty healthy adult volunteers (14 men and 16 women) with implant-supported overdentures were recruited from Tallinn Dental Clinic. The biochemical and clinical parameters evaluated were the levels of IL-6 and IL-10 in saliva, pocket probing depth (mm), Gingival Index (0,1, 2, or 3), and bleeding on probing (0 or 1). RESULTS: The level of IL-6 in saliva in the peri-implant disease group was significantly elevated compared to the healthy group. IL-10 could be detected only in the saliva of patients with peri-implant disease, and it did not appear at detectable amounts in saliva of healthy controls. In addition, the levels of IL-6 and IL-10 in peri-implant disease group were positively correlated with clinical parameters. CONCLUSIONS: These data suggest that a significant relationship exists between the amount of a proinflammatory cytokine (IL-6) and the inflammatory response in peri-implant tissue. The results also suggest that IL-6 and IL-10 could be used as markers of peri-implant disease together and that the level of the latter cytokine gives additional information about the potency of an organism's integrated immune response for maintenance of inflammatory balance.

Correlation of peri-implant health and myeloperoxidase levels: a cross-sectional clinical study.

OBJECTIVES: At present, there are no diagnostic tools that permit early detection of peri-implantitis. The purpose of this cross-sectional study was to evaluate the correlation of myeloperoxidase (MPO) levels with traditional periodontal clinical parameters around dental implants including peri-implant pocket probing depth (PPD), gingival index (GI) and bleeding on probing (BOP), since MPO has been associated with destruction of periodontal tissues. MATERIAL AND METHODS: Twenty-four healthy adult volunteers (9 men and 15 women) with 64 Ankylos Biofunctional implants (DentsplyFriadent, Mannheim, Germany) were recruited from Tallinn Dental Clinic. Biochemical and clinical parameters evaluated were the following ones: the level of MPO in the peri-implant sulcus fluid (PISF) (an analog for gingival crevicular fluid in natural teeth), PPD (mm), GI (0,1,2 or 3), and BOP (0 or 1). RESULTS AND CONCLUSION: In comparison to the clinically healthy implants, total amounts of MPO were significantly higher in PISF collected around implants with inflammatory lesions. In addition, the levels of MPO were correlated with the clinical parameters. The results confirm the similarity of the inflammatory response of tissues surrounding implants and natural teeth, and suggest that MPO could be promising marker of inflammation around dental implants.

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.

Allergic contact dermatitis is accompanied by severe abnormal changes in antioxidativity of blood.

We investigated whether the oxidative stress (OS) caused by skin inflammation could reflect in the blood, in a 21-year-old female student sensitized to nickel, colophony and abitole with often relapsing allergic contact dermatitis (ACD). As glutathione redox ratio was increased in the blood not only during the relapse but also in the beginning of remission phase, we prescribed natural medical preparations of d-alpha-tocopherol (in the first week 100 mg three times a day followed by 100 mg/day) and ascorbic acid (200 mg/day) for 25 days to her. After using antioxidants in the remission period, one of the principal OS markers-the glutathione redox ratio reached the normal physiological level. In this report, we showed that during acute extensive ACD OS is expressed in the blood and simultaneous supplementation of d-alpha-tocopherol and ascorbic acid might reduce systemic OS.

Nickel sulphate and epoxy resin: differences in iron status and glutathione redox ration at the time of patch testing.

The reactive patch test reaction is a useful model to characterize oxidative stress in acute allergic contact dermatitis. This model was used to study oxidative stress in the skin of individuals allergic to nickel and epoxy resin. The study included six and five patients, respectively, whose skin was simultaneously biopsied from a positive patch test site and from an apparently healthy area. The biopsies were homogenized and used for determination of iron content, unbound iron binding capacity, diene conjugate levels, and glutathione redox ratio. A positive test reaction to 5% nickel sulphate was accompanied by 2.5-fold increase in iron level as compared to apparently healthy skin (P<0.1). The percentage saturation of iron-binding capacity and the glutathione redox ratio were significantly increased (P<0.01 and P<0.05, respectively). Reactive patch test responses to 1% epoxy resin were not accompanied by clear alterations in iron status or glutathione redox ratio. Our investigation showed that apart from oxidative burst caused by accumulation of inflammatory cells, hapten properties might also influence the oxidative stress status of the skin. The high incidence of nickel allergy may be attributed, at least in part, to the influence of nickel ions on the glutathione redox ratio and iron status of the skin.

Antioxidative probiotic fermented goats' milk decreases oxidative stress-mediated atherogenicity in human subjects.

The increasing interest in a healthy diet is stimulating innovative development of novel scientific products in the food industry. The viable lactic acid bacteria in fermented milk products, such as yoghurt, have been associated with increased lactose tolerance, a well-balanced intestinal microflora, antimicrobial activity, stimulation of the immune system and antitumoural, anticholesterolaemic and antioxidative properties in human subjects. Recently, we have studied a human Lactobacillus spp. strain that possesses antioxidative activity. The aim of the present pilot study was to develop goats' milk fermented with the human antioxidative lactobacilli strain, Lactobacillus fermentum ME-3, and to test the effect of the fermented probiotic goats' milk on oxidative stress markers (including markers for atherosclerosis) in human blood and urine and on the gut microflora. Twenty-one healthy subjects were assigned to two treatment groups: goats' milk group and fermented goats' milk group (150 g/d) for a period of 21 d. Consumption of fermented goats' milk improved anti-atherogenicity in healthy subjects: it prolonged resistance of the lipoprotein fraction to oxidation, lowered levels of peroxidized lipoproteins, oxidized LDL, 8-isoprostanes and glutathione redox ratio, and enhanced total antioxidative activity. The consumption of fermented goats' milk also altered both the prevalence and proportion of lactic acid bacteria species in the gut microflora of the subjects. We conclude that the goats' milk fermented with our special antioxidative lactobacilli strain Lactobacillus fermentum ME-3 exhibits anti-atherogenic effects.

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.

Oxidative stress before and after exercise conditioning in patients following surgical revascularization of the myocardium.

The main purpose of the study was to evaluate changes in the extent of oxidative stress and its associations with the indices of cardiorespiratory reserve and functional capacity in 35 patients enrolled in a 12-week exercise conditioning programme 2-4 weeks after surgical revascularization of the myocardium. The following markers of oxidative stress were measured spectrophotometrically before and after the programme: lipid peroxidation products (thiobarbituric acid reactive substances, diene conjugates and lipid hydroperoxide) and markers of blood antioxidant status (blood glutathione markers, blood antioxidative capacity and lag phase of low-density lipoprotein (LDL)). To evaluate the functional indices of the cardiorespiratory system the patients underwent bicycle cardiopulmonary testing before entering and after completing the programme. On the basis of peak oxygen consumption (peak VO2) +/- 1 SD, three subgroups with different aerobic capacity were identified: >/=19 ml/min per kg (GR I, n = 7), 11-19 ml/min per kg (GR II, n = 24) and

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.