Dynamics of Bone Disease Biomarkers Dickkopf-1 and Sclerostin in Patients with Multiple Myeloma

Dickkopf-1 (DKK-1) and sclerostin are essential Wnt/β-catenin pathway inhibitors, playing an important role in multiple myeloma bone disease (MBD). We aimed to examine the serum DKK-1 and sclerostin variations in newly diagnosed multiple myeloma (NDMM) patients at diagnosis and in the course of therapy, including autologous stem cell transplantation (ASCT). This study included 41 NDMM-patients and 33 controls. MBD was assessed by whole-body low-dose computed tomography. DKK-1 and sclerostin were assayed by commercial ELISA kits. At diagnosis, NDMM-patients revealed significantly higher DKK-1 and sclerostin values (p < 0.0001), showing dependence on disease stage (lowest in ISS-I and highest in ISS-III: p < 0.0012 and p < 0.025, respectively, for both proteins). Bone lesions revealed significant positive correlation with both DKK-1 (p < 0.05) and sclerostin (p < 0.0001). In the course of therapy, significant reduction, more prominent after ASCT, was observed for both parameters in each treatment point compared to the baseline (p < 0.0001). Markedly lower sclerostin (p < 0.01) and DKK-1 (p < 0.05) values were observed in patients with complete and very good partial response compared to those with partial response, stable, or progressive disease. Sclerostin and DKK-1 in NDMM patients reflect the MBD severity and the effect of therapy. Both proteins could represent a novel tool for better disease monitoring and effectiveness of therapy.

Sambucus ebulus (Elderberry) Fruits Modulate Inflammation and Complement System Activity in Humans

Sambucus ebulus (SE) fruits are used for immune stimulation and amelioration of gastrointestinal inflammatory conditions. Currently, there is no scientific evidence of their effects on various aspects of the immune response mechanisms in humans. The purpose of this study was to evaluate the immunomodulatory potential of SE fruit infusion intake in healthy humans. Anthocyanin content was determined with UPLC-ESI-MS/MS. Fifty-three volunteers enrolled in a 4-week SE infusion intake intervention. Blood count, serum total protein, Interleukin 1 beta (IL-1β), Interleukin 6 (IL-6), Tumor Necrosis Factor Alpha (TNFα), High-sensitivity C-reactive protein (hs-CRP), C3, and C4 levels were measured on automatic analyzers, and Interleukin 8 (IL-8) was measured manually with an ELISA kit. Cyanidin-3-O-galactoside (48.15 mg/g DW), followed by cyaniding-3-sambubioside (43.41 ± 1.07 mg/g DW), were the most abundant anthocyanins in SE samples. A significant decrease in total protein (2.82%), IL-6 (20.15%), TNFα (5.38%), IL-8 (5.50%), C3 (4.16%), and C4 (14.29%) was established in the whole group. Total protein, IL-8, TNFα, and C4 decreased in women (3.11%, 4.76%, 5.09%, and 11.11%), and IL-6 decreased (40.61%) in men. Hb (1.20%) and hematocrit (1.55%) levels decreased in the whole group and in the women group (1.61% and 2.20%). SE fruits exert immune-modulatory activity as revealed by decreased pro-inflammatory status and complement activity markers in healthy volunteers after a 4-week intervention.

New Insights into the Research of Bioactive Compounds from Plant Origins with Nutraceutical and Pharmaceutical Potential

Plant bioactive compounds are essential for human health due to their multiple biological effects, such as antioxidant, anticarcinogenic, antiallergenic, anti-inflammatory, antimutagenic, and antimicrobial activities, which can have beneficial effects on various noncommunicable diseases, such as autoimmune, inflammatory, cardiovascular, cancer, metabolic, and neurodegenerative diseases [...].

Phytochemical Composition, Anti-Inflammatory and ER Stress-Reducing Potential of Sambucus ebulus L. Fruit Extract

Sambucus ebulus L. (SE) fruits are used for their immunostimulation, hematopoietic and antiviral potential. Recently, we focused on analyzing the mechanism underlying SE fruit aqueous extract's (FAE) immunomodulation and anti-inflammatory activities, with attention to its endoplasmic reticulum (ER) stress-reducing potential. J774A.1 macrophages were treated with SE FAE alone or in conditions of lipopolysaccharides (LPS) stimulation. Using GC-MS and LC-MS/MS, its phytochemical composition was analyzed. To measure transcription and protein levels, we used qPCR and Western blot, respectively. The prevailing phytochemicals in SE FAE were hydroxycinnamic acids, proanthocyanidins and anthocyanins. The content of some amino acids, organic acids, alcohols, fatty acids and esters were newly reported. Extracts exerted an immunostimulation potential by stimulating IL-6, TNFα, Ccl2, COX2 and iNOS transcription, without inducing ER stress. SE FAE suppressed the LPS-induced transcription of inflammation related genes (IL-1β, IL-6, TNFα, Ccl2, Icam-1, Fabp4, COX2, iNOS, Noxo1, IL-1ra, Sirt-1) and reduced the protein levels of iNOS, peIF2α, ATF6α and CHOP. The effects were comparable to that of salicylic acid. SE suppresses LPS-stimulated inflammatory markers on the transcription and translation levels. Targeting ER stress is possibly another mechanism underlying its anti-inflammatory potential. These findings reveal the potential of SE fruits as a beneficial therapeutic of inflammation and ER stress-related pathological conditions.

Vitamin D Status in Patients with Atrial Fibrillation and Heart Failure - Is there a Link?

BACKGROUND

The disturbed pleiotropic functions of vitamin D are related to numerous chronic non-skeletal diseases. The role of vitamin D insufficiency/deficiency in cardiovascular diseases (CVD) is controversial. Therefore, the aim was to study the vitamin D status in CVD patients and to reveal possible relationships with CVD risk factors.

METHODS

This prospective study includes 93 individuals devided into two groups - patients with CVD (n = 49) and patients at risk for CVD (n = 44) served as controls. The CVD-patients were stratified into AF-group - with paroxysmal or persistent atrial fibrillation and HF-group - with heart failure with preserved ejection fraction, in sinus rhythm. Vitamin D status was assessed by measurement of serum 25-hydroxy-vitamin D (25OHD) using liquid chromatography with mass detection. Gene expression of the regulatory enzyme of vitamin D metabolism, 1-alfa-hydroxylase (CYP27B1), was evaluated by two-step real-time qPCR. Coronary artery calcium scans were performed and coronary artery calcium score (CACS) was calculated. Routine biochemical parameters were extracted from the medical documentation. Standard statistical methods (descriptive statistics, unpaired Student's t-test, one-way ANOVA, simple and multiple linear regression analyses) were applied. Statistical significance was considered at p < 0.05.

RESULTS

Serum 25OHD levels of the controls were higher than those of the CVD-patients (37.36 ± 15.10 ng/mL vs. 27.70 ± 11.80 ng/mL, p = 0.008). The vitamin D status worsened with the severity of CVD pathology: significant decrease of 25OHD levels was found in the AF-group (29.56 ± 11.76 ng/mL, p = 0.044) and HF-group (24.47 ± 11.61 ng/mL, p = 0.003) vs. controls (37.36 ± 15.10 ng/mL). Significant reduction in circulating vitamin D levels with the increase of CACS (p = 0.007) was also observed. Linear regression analysis revealed significant negative association for serum 25OHD with CACS for both the entire studied group (p = 0.008) and for CVD patients (p = 0.049). The gene expression of CYP27B1 was down regulated with both the severity of CVD pathology (p = 0.05) and coronary calcium accumulation (p = 0.08). Moreover, we found a significant positive relationship (p = 0.041) between serum 25OHD levels and CYP27B1 gene expression.

CONCLUSIONS

Vitamin D deficiency may be an independent cardiovascular risk factor associated with the severity of CVD pathology and increased coronary calcium deposition. The mechanism by which vitamin D itself can affect cardiovascular outcomes remains to be clarified.

Adenosine Deaminase as a Useful Biomarker for Diagnosis and Monitoring of Inflammatory Bowel Disease

BACKGROUND

Inflammatory bowel disease (IBD) is a multifactorial immunologically mediated disorder characterized by repeated cycles of exacerbations and remissions. Diagnosis and monitoring of ulcerative colitis (UC) and Crohn's disease (CD) as common types of IBD require the usage of unpleasant invasive methods such as colonoscopy and cross-sectional imaging. Development of a non-invasive biomarker panel including different inflammatory parameters for evaluation of various aspects of gut inflammation and disease course is a priority task. In addition to the well-known inflammatory markers serum C-reactive protein (CRP) and fecal calprotectin (FC), adenosine deaminase (ADA) could be a promising candidate-biomarker. ADA has been shown to increase in several inflammatory conditions, but little is known about its significance in IBD. This preliminary research aims to study the serum levels of ADA in IBD patients and to evaluate its ability to adequately reflect the gut inflammatory process.

METHODS

Fifty-four IBD patients (40 with UC and 14 with CD) and 50 controls were enrolled in the study. Routine laboratory parameters such as white blood cells (WBC) count, erythrocyte sedimentation rate (ESR), and CRP were used. The specific biomarker for intestinal inflammation FC was measured by sandwich immunoassay (BÜHLMANN) and ADA activity - by two-step enzyme method (BioSystems).

RESULTS

The median [IQR: 25th - 75th percentile] ADA values in IBD patients were significantly higher than those in the controls (18.7 U/L [15.4 - 22.5] vs. 9.10 U/L [7.1 - 11.2] respectively; p < 0.0001). A significant difference was obtained when comparing median ADA values in patients with active disease (20.4 [17.8 - 25.3] U/L) with those in patients with mild form of the disease or in remission (15.3 [13.0 - 16.0]; p < 0.0001). A strong positive correlation between ADA and FC (r = 0.63; p < 0.0001) and moderate positive correlation between ADA and CRP (r = 0.46; p < 0.001) were observed. ROC-curve analysis revealed good ability of ADA to discriminate not only IBD patients from healthy individuals, but also patients with active disease and those in remission/mild form.

CONCLUSIONS

The present study revealed that ADA levels were significantly increased in IBD patients. Together with FC and CRP, ADA could be used as an effective biomarker for assessment of intestinal inflammation and as a potential indicator for disease activity.

ASYMPTOMATIC HYPERURICEMIA AS A POTENTIAL METABOLIC RISK FACTOR FOR CORONARY ARTERY CALCIFICATION IN PATIENTS WITH ATRIAL FIBRILLATION OR HEART FAILURE

Purpose: To assess the role of asymptomatic hyperuricemia for the presence and severity of coronary arterial calcium (CAC) in adults with different cardiovascular (CV) pathology and its association with conventional CV risk factors. Material/Methods: Adults (n=81) of both genders were divided into controls: with moderate- to high risk without known CVD; AF-group: CVD-patients with paroxysmal or persistent atrial fibrillation in sinus rhythm, HF–group: heart failure subjects with preserved ejection fraction. A structured interview was performed at admittance for evaluation of the classical CVD risk factors. CAC score (CACS) was determined by multislice computed tomography. Routine laboratory parameters, including uric acid (UA), were extracted from medical documentation. Descriptive statistics, Mann-Whitney U-test, one-way ANOVA, chi-square test, Spearman's correlation, and multiple linear regression analysis were applied. The predictive power of serum UA was evaluated using receiver operating characteristic (ROC) analysis. Statistical significance was considered at p<0.05. Results: Serum UA was significantly higher in subjects with CACS=1-99AU (p=0.030), and with CACS≥100AU (p=0.067) vs. patients without CACS. Within the UA tertiles, highest CACS was found in the tertile with highest serum UA. UA revealed positive relation with CACS (r=0.35, p=0.002), age (r=0.25, p=0.027), body mass index (0.27, p=0.017), waist circumference (r=0.44, p<0.0001), triglycerides (r=0.29, p=0.001), and creatinine (r=0.54, p<0.0001). Multiple linear regression analysis revealed significant association between UA as dependent variable and waist circumference (β=0.63, p=0.061), serum triglycerides (β=0.37, p=0.028), creatinine levels (β=0.45, p<0.0001). Conclusions: Asymptomatic hyperuricaemia could be an important metabolic factor negatively affecting the chronic cardio-vascular pathology besides the conventional risk factors.

Metabolomic analysis in ophthalmology

Modern science takes into account phenotype complexity and establishes approaches to track changes on every possible level. Many "omics" studies have been developed over the last decade. Metabolomic analysis enables dynamic measurement of the metabolic response of a living system to a variety of stimuli or genetic modifications. Important targets of metabolomics is biomarker development and translation to the clinic for personalized diagnosis and a greater understanding of disease pathogenesis. The current review highlights the major aspects of metabolomic analysis and its applications for the identification of relevant predictive, diagnostic and prognostic biomarkers for some ocular diseases including dry eye, keratoconus, retinal diseases, macular degeneration, and glaucoma. To date, possible biomarker candidates for dry eye disease are lipid metabolites and androgens, for keratoconus cytokeratins, urea, citrate cycle, and oxidative stress metabolites. Palmitoylcarnitine, sphingolipids, vitamin D related metabolites, and steroid precursors may be used for distinguishing glaucoma patients from healthy controls. Dysregulation of amino acid and carnitine metabolism is critical in the development and progression of diabetic retinopathy. Further work is needed to discover and validate metabolic biomarkers as a powerful tool for understanding the molecular mechanisms of ocular diseases, to provide knowledge on their etiology and pathophysiology and opportunities for personalized clinical intervention at an early stage.

Diets rich in saturated fat and fructose induce anxiety and depression-like behaviours in the rat: is there a role for lipid peroxidation?

Epidemiological studies reveal associations between obesity/metabolic syndrome and mood disorders. We assessed behavioural changes in rats fed diets enriched in fat and fructose in different proportions and correlated the observed alterations with biochemical changes induced by the diets. Three groups of rats were used as follows: control (C) animals fed regular rat chow, rats fed high-fat diet (HF) and rats fed high-fat and high-fructose diet (HFHF). HF and HFHF animals were also given a 10% fructose solution as drinking water. Behavioural and biochemical parameters were determined. Anxiety was measured by the open-field and the social interaction test. Depression-like behaviour was evaluated by the forced swimming test. The object recognition test was utilized to assess effects on memory. Diet-exposed animals displayed signs of anxiety in the open-field (HF rats had reduced central time; HFHF rats had reduced number of central entries) and in the social interaction test (decreased time of interaction in HF group). In the forced swimming test, the immobility time was prolonged in the HFHF group. While different measures of anxiety scores correlated with visceral adiposity and dyslipidemia, results from both social interaction and forced swimming tests were significantly associated with lipid peroxidation, which in turn also correlated with the metabolic parameters. The experimental diets did not affect the object recognition memory. Both experimental diets induced metabolic derangements in rats and provoked similar anxiety- and depression-like behaviours. Lipid peroxidation seems to play a role in translating diet-induced metabolic alterations into behavioural disorders.

Serum 25-hydroxy vitamin D levels in Bulgarian patients with prostate cancer: a pilot study

BACKGROUND

The antiproliferative effect of the active form of vitamin D on cancer cells and its ability to induce cell differentiation and suppression of tumor-induced angiogenesis in the last decade has provoked enormous research for the elucidation of its role in the prevention of different types of cancer and in slowing down the malignancy progression. The aim of the present pilot study was to determine the circulating 25-hydroxy vitamin D (25OHD) levels in Bulgarian prostate cancer (PCa) patients and to investigate their relationship with various determinants associated with the severity and progression of the disease.

METHODS

A total of 53 male patients (mean age 67.0 ± 7.1 years) with clinical suspicion for PCa were enrolled in the study. All patients were subjected to systemic transrectal ultrasound-guided tru-cut prostate biopsies (10 cores at least). Detected tumors were graded using the Gleason grading system. Prostate specific antigen (PSA) serum levels were measured immunochemically. The 25OHD assay was performed by a validated HPLC-UV method. Other covariates (BMI, age, family history of PCa) were collected by interview at the time of hospitalization. One-way ANOVA with Kruskal Wallis statistics was used for comparison of medians of different parameters. The level of significance was set at p < 0.05.

RESULTS

Significantly lower 25OHD levels were detected in PCa patients compared to those with benign prostate hyperplasia (BPH) (p < 0.05). Patients with high grade tumors (Gleason score ≥ 7) showed significantly lower 25OHD levels, while those with low grade tumors (Gleason score < 7) revealed better 25OHD status (50.49 vs. 63.17 nmol/L, p < 0.05). A moderate negative correlation between 25OHD levels and the Gleason score was established (Spearman r = -0.46, p < 0.05). Significant seasonal variations in 25OHD levels, both for PCa and BPH patients, were detected (p < 0.01).

CONCLUSIONS

This preliminary study shows an association between 25OHD status and classical markers characterizing the severity of PCa. The results might suggest a potential beneficial role of vitamin D for PCa patients. Further prospective studies are needed to strengthen the interrelationships between 25OHD levels and variables related with PCa and to test them for causality.

Influence of dl-alpha-tocopherol acetate on indomethacin-induced gastric mucosal injury in rats

1 There is an increasing body of evidence supporting the hypothesis that antioxidants are able to reduce gastric mucosal damage induced by stressors of different origin. The aim of the present study was to investigate the influence of dl-alpha-tocopherol acetate (TA) on indomethacin-induced gastric mucosal injury in rats and a possible role for an anti-oxidative mechanism in the response. 2 TA (25, 50 and 100 mg kg(-1)) was applied intraperitoneally as a pretreatment 1 h before the subcutaneous administration of indomethacin (30 mg kg(-1)). 3 TA reduced the area of indomethacin-induced gastric ulcers, the effect being significant (P < 0.05) at the highest dose of 100 mg kg(-1). 4 Histopathological examination of rat stomach samples demonstrated that TA caused an increase in gastric mucus production and a reduction of the severity of mucosal lesions. 5 The three doses of TA prevented indomethacin-induced elevation of plasma and mucosal malondialdehyde (MDA) levels, which in TA-pretreated rats were not significantly different from the control values. Neither indomethacin treatment nor TA pretreatment had a significant influence on the gastric mucosal levels of reduced glutathione or oxidized glutathione. 6 Our results suggest that the gastroprotective effect of TA is likely to be due to increased mucus production and interference with oxidative stress development as evidenced by the decreased plasma and gastric mucosal MDA.

Impaired mitochondrial Ca2+ homeostasis in respiratory chain-deficient cells but efficient compensation of energetic disadvantage by enhanced anaerobic glycolysis due to low ATP steady state levels

Energy-producing pathways, adenine nucleotide levels, oxidative stress response and Ca(2+) homeostasis were investigated in cybrid cells incorporating two pathogenic mitochondrial DNA point mutations, 3243A>G and 3302A>G in tRNA(Leu(UUR)), as well as Rho(0) cells and compared to their parental 143B osteosarcoma cell line. All cells suffering from a severe respiratory chain deficiency were able to proliferate as fast as controls. The major defect in oxidative phosphorylation was efficiently compensated by a rise in anaerobic glycolysis, so that the total ATP production rate was preserved. This enhancement of glycolysis was enabled by a considerable decrease of cellular total adenine nucleotide pools and a concomitant shift in the AMP+ADP/ATP ratios, while the energy charge potential was still in the normal range. Further important consequences were an increased production of superoxide which, however, was neither escorted by major changes in the antioxidative defence systems nor was it leading to substantial oxidative damage. Most interestingly, the lowered mitochondrial membrane potential led to a disturbed intramitochondrial calcium homeostasis, which most likely is a major pathomechanism in mitochondrial diseases.

Correlation between theIn Vitro antioxidant activity and polyphenol content of aqueous extracts from bulgarian herbs

The water phase antioxidant activity of extracts from 23 Bulgarian medicinal plants was studied in relation to their polyphenol content in comparison with mate, black tea, honeybush and rooibos foreign species. Antioxidant activity was measured by the ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)) cation radical decolorization assay, and the total polyphenol content was assayed according to the Folin-Ciocalteu method. Five Bulgarian plant extracts exhibited higher antioxidant activity than that of mate, which is 21.7% of all Bulgarian herbs included in this study. These were Alchemilla vulgaris L. (4.79 +/- 0.14 mm), Sambucus ebulus L. (4.03 +/- 0.07 mm), Mentha spicata L. (3.90 +/- 0.03 mm), Fragaria vesca L. (3.74 +/- 0.06 mm), Crataegus monogyna Jacq. (3.63 +/- 0.05 mm). Another eight Bulgarian medicinal plant extracts exhibited an intermediate antioxidant activity - lower than that of mate and higher than that of honeybush, which makes 34.8% of all Bulgarian herbs included in the study. More than half of the herbal extracts included in the present study exhibited antioxidant activity higher than or comparable to the reference foreign plants. A positive correlation (r = 0.92) between antioxidant activity and polyphenol content was found, suggesting that the antioxidant capacity of the aqueous plant extracts is due to a great extent to their polyphenols.

Effect of Aronia melanocarpa fruit juice on indomethacin-induced gastric mucosal damage and oxidative stress in rats

Aronia melanocarpa fruits are rich in phenolic substances-mainly flavonoids from the anthocyanin subclass. The anthocyanins are water-soluble plant pigments with antioxidant, anti-inflammatory, antimicrobial, hepatoprotective, gastroprotective and other activities. We studied the effect of A. melanocarpa fruit juice (AMFJ) on indomethacin-induced gastric mucosal damage in rats and its possible relation to the oxidative status. AMFJ (5, 10 and 20 ml kg(-1)) was applied orally as a pretreatment 1 h before the subcutaneous administration of indomethacin (30 mg kg(-1)). Gastric ulcer formation was estimated morphometrically and histopathologically 4h after the indomethacin administration. Malondialdehyde (MDA) in rat plasma and gastric mucosa and also reduced glutathione (GSH) and oxidized glutathione (GSSG) in gastric mucosa were determined and used as biochemical markers of the oxidative status. AMFJ-pretreatment diminished the number and area of indomethacin-induced gastric lesions. Histopathological examination of rat stomachs demonstrated that AMFJ induced an increase in gastric mucus production and a reduction of the depth and severity of indomethacin-induced mucosal lesions. AMFJ dose-dependently reduced the elevated indomethacin plasma and gastric MDA levels and at the doses of 10 and 20 ml kg(-1) they were not significantly different from the control values. Neither indomethacin-treatment, nor AMFJ-pretreatment had a significant influence on GSH and GSSG gastric mucosal levels. These results demonstrated that indomethacin-induced gastric mucosal damage was accompanied by the development of oxidative stress, evidenced by the accumulation of MDA. AMFJ-pretreatment decreased the gastric lesions caused by indomethacin. It could be suggested that this effect of AMFJ was probably due to the increased mucus production and interference with oxidative stress development as evidenced by the decreased plasma and gastric mucosal MDA.

Hepatoprotective effect of the natural fruit juice from Aronia melanocarpa on carbon tetrachloride-induced acute liver damage in rats

The fruits of Aronia melanocarpa are rich in anthocyanins--plant pigments with anti-inflammatory and antioxidant activity. We studied the effect of the natural fruit juice from A. melanocarpa (NFJAM) on carbon tetrachloride (CCl4)-induced acute liver damage in rats. Histopathological changes such as necrosis, fatty change, ballooning degeneration and inflammatory infiltration of lymphocytes around the central veins occurred in rats following acute exposure to CCl4 (0.2 ml kg(-1), 2 days). The administration of CCl4 increased plasma aspartate transaminase (AST) and alanine transaminase (ALT) activities, induced lipid peroxidation (as measured by malondialdehyde (MDA) content in rat liver and plasma) and caused a depletion of liver reduced glutathione (GSH). NFJAM (5, 10 and 20 ml kg(-1), 4 days) dose-dependently reduced the necrotic changes in rat liver and inhibited the increase of plasma AST and ALT activities, induced by CCl4 (0.2ml kg(-1), 3rd and 4th days). NFJAM also prevented the CCl4-induced elevation of MDA formation and depletion of GSH content in rat liver.

Effects of paracetamol and propacetamol on gastric mucosal damage and gastric lipid peroxidation caused by acetylsalicylic acid (ASA) in rats

We have studied the effect of paracetamol and its pro-drug propacetamol on gastric mucosal damage induced by acetylsalicylic acid (ASA) and its possible relation to changes in gastric lipid peroxidation status in rats. Paracetamol or propacetamol were administered intragastrically 1h before ASA (300 mg kg(-1)) in the following equivalent doses: 62.5, 125.0 and 250.0 mg kg(-1) or 125.0, 250.0 and 500.0 mg kg(-1), respectively. The effects of the tested agents were compared to that of prostaglandin E2 (PGE2) 15, 30 and 60 mg kg(-1). Gastric ulcer formation was estimated morphometrically 4h after ASA administration. Malondialdehyde (MDA), glutathione (reduced, GSH, and oxidized, GSSG) and uric acid (UA) were determined in gastric mucosa and blood plasma and used as biochemical markers of the oxidative status. The results showed that paracetamol (250, 125, 62.5 mg kg(-1)) and propacetamol (500, 250, 125 mg kg(-1)) diminished the area of ASA-induced gastric lesions. The effect of propacetamol was more pronounced than that of paracetamol and similar to that of PGE2. Gastric MDA increased 3-fold in the ASA-group. The tested agents reduced it by a range of 30-70%. In all pretreated groups gastric glutathione and UA levels were found higher than that of control group and lower than that of ASA-group. Paracetamol and propacetamol, as well as PGE2, diminished the lipid peroxidation in plasma to a lesser extent than in gastric mucosa, but maintained elevated levels of the selective plasma antioxidant UA. These results show that the ASA-induced gastric mucosal damage is accompanied by the development of oxidative stress, evidenced by the accumulation of MDA, and concomitant initial activation of cell antioxidant defences. As paracetamol and propacetamol tend to decrease gastric lesions caused by ASA and alter gastric mucosal MDA, glutathione and UA values in a favorable manner, it could be suggested that their effects on the gastric mucosa could be related to interference with oxidative stress development.

Increased antioxidant capacity, suppression of free radical damage and erythrocyte aggrerability after combined application of alpha-tocopherol and FC-43 perfluorocarbon emulsion in early postburn period in rats

Certain rheological disorders such as enhanced aggregation and reduced deformability of erythrocytes are closely associated with microcirculatory disturbances, decreased tissue oxygen supply and represent a major problem in severely burnt patients [1-4]. Vitamin E (alpha-tocopherol) and vitamin A (retinol) exert an important plasma antioxidant properties against free radical-induced damage [11,12]. They possess chain-breaking properties and act as synergists [13]. Plasma antioxidant capacity may be decreased in severely burnt patients as a result of the enhanced consumption and inadequate restoration of antioxidants in the conditions of activated peroxidative process [14]. Treatment with alpha-tocopherol suppresses lipid peroxidation in blood and therefore improves erythrocyte rheology [15]. Perfluorocarbon emulsions improve microcirculation and rheological blood properties [16-18] and preserve the structure and function of endothelial cells [19]. The very small particle size, low viscosity and high oxygen carrying capacity ensure their penetration into the microvasculature even under conditions of ischemia and acidosis [20, 21]. Perfluorocarbons have been reported to inhibit leukocyte activation and superoxide radical production [22]. The aim of the present study was to examine the antioxidant capacity, free radical mediated damage and erythrocyte aggregation in plasma of rats with thermal skin injury in the early postburn period and to evaluate the effect of treatment with alpha-tocopherol and FC-43 perfluorocarbon emulsion alone and in combination. We might conclude that thermal skin injury in rats reduces the antioxidant capacity, enhances free radical mediated damage and erythrocyte aggregation on the third hour after injury. The combined application of alpha-tocopherol and FC-43 perfluorocarbon emulsion immediately after thermal skin injury in rats increases plasma antioxidant capacity, decreases free radical mediated damage of erythrocytes and suppresses their aggregation on the third hour after the injury.