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Journal Article 2009; 30(Suppl 1): 128-132 PubMed PMID: 20027158 Citation  Keywords:  Absorption, Animals, Cattle, Centrifugation, Collagen Type I:chemistry, Electrophoresis, Polyacrylamide Gel, Humans, Hydrogen Peroxide:chemistry, Hydroxyl Radical:chemistry, Luminescence, Oxidation-Reduction, Phagocytes:metabolism, Platelet Aggregation, P.   

OBJECTIVES: The effects of non-modified and oxidatively modified calf skin collagen type I on platelet aggregation and the oxidative burst of phagocytes were examined in the framework of a general hypothesis that collagen, platelets and phagocytes cooperate to modulate the oxidative burst of phagocytes and the extent of oxidative stress.

MATERIALS AND METHODS: Calf skin collagen type I was subjected to oxidative modification by hydrogen peroxide or hydroxyl radical. Thermal denaturation of collagen was performed in a spectrophotometer equipped with a temperature gradient device. The aggregation of isolated human platelets obtained after differential centrifugation was measured using a dual-channel aggregometer. The production of reactive oxygen species by human whole blood phagocytes was evaluated by luminol-enhanced chemiluminescence.

RESULTS: Oxidative modification of collagen samples was characterized by a decrease in denaturation transition temperature. Oxidatively modified samples showed a modified SDS-PAGE pattern, evidencing a significant destruction of the collagen. All oxidatively modified collagen samples, independent of the oxidation treatment applied, lost their platelet-aggregating and phagocyte oxidative burst-inducing activity.

CONCLUSION: The results suggest that reactive oxygen species were able to modify collagen. On the other hand, oxidatively modified collagen lost its activating properties towards platelets and phagocytes....

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Journal Article 2008; 29(5): 779-783 PubMed PMID: 18987604 Citation  Keywords:  Adenosine Triphosphate:metabolism, Adrenergic beta-Antagonists:pharmacology, Carbazoles:pharmacology, Cell Differentiation:drug effects, Cell Proliferation:drug effects, Fluorometry, Granulocytes:drug effects, HL-60 Cells, Humans, Luminescence, Nitric Oxi.   

OBJECTIVES: The generation of reactive oxygen species (ROS) by phagocytes is one of the irreplaceable microbicidal tools of innate immunity. It has been reported in our previous studies that short-term treatment by carvedilol ex vivo inhibits ROS generation. The purpose of this study was to investigate the long-term effect of carvedilol on phagocytes.

METHODS: Human leukemia HL-60 cells differentiated into granulocyte-like cells were used as the model. Final concentrations of carvedilol were 0.1-100 micromol/l. The production of ROS by HL-60 cells was measured using luminol-enhanced chemiluminescence (CL).

RESULTS: Carvedilol in concentrations 0.1-10 micromol/l did not exhibit any toxic effect on cells (measured using bioluminescent bacteria Photorhabdus luminescens subsp. thracensis). One hour's treatment with 10 micromol/l carvedilol significantly decreased both spontaneous and activated CL of cells. Conversely, no inhibitory effects on CL were observed in 10 micromol/l carvedilol after 48 h incubation; lower concentrations of carvedilol even slightly increased the CL activity of HL-60 cells. A significant increase in spontaneous CL activity was detected in cells incubated with 10 micromol/l carvedilol in comparison with the control. Powerful antioxidative properties of carvedilol against peroxyl radical (ORAC assay) were proved. No scavenging of nitric oxide (electrochemical method) was observed.

CONCLUSIONS: Long-term influence of carvedilol can induce an increase in the generation of phagocyte-derived ROS and potentially also other inflammatory mediators. The increased ROS production is compensated for by antioxidative properties of carvedilol although the increased production of inflammatory mediators could affect the proper function of immune system....

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Journal Article 2008; 29(5): 794-797 PubMed PMID: 18987603 Citation  Keywords:  Animals, Diptera:physiology, Humans, Larva, Luminescence, Male, Neutrophils:drug effects, Peroxidase:metabolism, Salivary Glands:physiology, Superoxides:metabolism, Tissue Extracts:pharmacology, Zymosan,.   

OBJECTIVES: There is incomplete information about host immune response to maggot therapy, nowadays increasingly used to clean chronic wounds from necrotic debris and infection. Maggots are applied to the wound during the inflammatory phase. At the same time neutrophils infiltrate the inflammatory site as the first defense line of the organism. Myeloperoxidase (MPO) and reactive oxygen species, generated during the respiratory burst by neutrophils, are the key players participating in microbial killing as well as in signalling pathways.

AIM: We studied the effect of an extract from salivary glands (SGE) of Lucilia sericata (L. sericata) on opsonized zymosan stimulated whole blood chemiluminescence (CL), superoxide generation and MPO release from human neutrophils.

METHODS: Formation of reactive oxygen species in whole blood was determined by luminol-enhanced CL. superoxide generation was measured as superoxide dismutase inhibitable reduction of cytochrome c, MPO activity as the oxidation of o-dianisidine in the presence of hydrogen peroxide.

RESULTS: Crude SG extract of L. sericata had no significant effect either on superoxide generation and MPO release from isolated unstimulated human neutrophils or on activity of isolated enzymes. Crude SG extract of L. sericata in the highest concentration used significantly decreased opsonized zymosan (0.5 mg/ml) stimulated blood CL, superoxide generation and MPO release.

CONCLUSION: On the basis of our results as well as from the literature we suggest that the beneficial effects of maggot therapy might involve the decrease of generation and release of proinflammatory factors, while neither phagocytosis nor subsequent apoptosis is disturbed....

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Journal Article 2008; 29(5): 802-805 PubMed PMID: 18987580 Citation  Keywords:  Adenosine Triphosphate:metabolism, Antioxidants:pharmacology, Cell Survival:drug effects, Dose-Response Relationship, Drug, Humans, Luminescence, Neutrophils:drug effects, Reactive Oxygen Species:metabolism, Stilbenes:pharmacology, Structure-Activity Rela.   

OBJECTIVES: Oxidative stress is related to a number of autoimmune diseases, e.g. rheumatoid arthritis, cancer, etc. The main source of pathologically working reactive oxygen species (ROS) are activated polymorphonuclear leukocytes (PMNL).

OBJECTIVE: There are some papers comparing structure - pharmacological efficiency relationship of vegetal substances from the stilbenoid group. We compared the effect of trans-resveratrol, which is well-known by its antioxidative activity, with the effect of pinosylvin and pterostilbene.

METHODS: Luminol-enhanced chemiluminescence (CL) was used to study the antioxidative action. The effect was observed in whole blood and in isolated PMNL. The concentrations of substances tested were 0.01-100 microM. Due to the different abilities of luminol and isoluminol to pass through the cell membrane, we studied the effect of the substances tested on intracellular and extracellular ROS. To stimulate the production of ROS we used phorbol-myristate-acetate (PMA), which activates PMNL via protein kinase C.

RESULTS: Resveratrol, pinosylvin and pterostilbene inhibited significantly the CL of whole blood and extra- and intracellular CL of isolated PMNL in a dosedependent manner. Depending on different functional groups of the stilbene molecule, resveratrol inhibited CL of whole blood and isolated PMNL, whereas pinosylvin influenced mainly intracellular CL and pterostilbene extracellular CL.

CONCLUSION: The presence of different functional groups in the molecules of stilbenoids influence their antioxidative effect. Modification of these functional groups may result in derivatives with required antioxidative properties, targeting mainly extracellular ROS which are responsible for tissue damage during chronic inflammation....

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Comparative Study 2006; 27(Suppl 2): 141-143 PubMed PMID: 17159800 Citation  Keywords:  Brompheniramine:pharmacology, Chlorpheniramine:pharmacology, Extracellular Fluid:metabolism, Histamine H1 Antagonists:pharmacology, Humans, Intracellular Fluid:metabolism, Luminescence, Neutrophils:drug effects, Pheniramine:pharmacology, Reactive Oxygen S.   

BACKGROUND: Allergic inflammation was found to be accompanied by activation of neutrophils. Since this resulted in increased formation of reactive oxygen species, the antioxidative activity of antiallergic drugs was considered to decrease the risk of tissue damage. However, if the drug-induced inhibition of radical formation occurred intracellularly, it could disturb regulation of neutrophil functions and decrease bactericidal activity of these cells. Separate analysis of extra- and intracellular activity of antioxidative drugs is thus of particular importance.

OBJECTIVE: To differentiate the effects of three antiallergic H1-antihistamine drugs (pheniramine, chlor- and brompheniramine) on radical formation outside and inside human neutrophils.

METHODS: Formation of reactive oxygen species was determined in vitro using the chemiluminescence method. The chemiluminescence signal, initiated by phorbol-12-myristate-13-acetate, was enhanced either with isoluminol (extracellular) or with luminol in the presence of extracellular scavengers, superoxide dismutase and catalase (intracellular).

RESULTS: The antihistamines tested displayed dual activity - they inhibited the extracellular and potentiated the intracellular chemiluminescence. Chlor- and brompheniramine were found to be more effective than pheniramine.

CONCLUSION: Compared to other H1-antihistamines (such as dithiaden or loratadine, active both extra- and intracellularly), the observed inhibition caused by the pheniramines tested was unique since it occurred selectively outside neutrophils. This might indicate the ability of these drugs to minimise toxic effects of extracellular radicals without affecting intracellular oxidant production involved in regulation of neutrophil functions and in microbial killing....

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Comparative Study 2006; 27(1-2): 85-88 PubMed PMID: 16648782 Citation  Keywords:  Adolescent, Adult, Aged, Anticonvulsants:adverse effects, Carbamazepine:adverse effects, Cardiovascular Diseases:blood, Epilepsy:blood, Female, Folic Acid:blood, Humans, Immunoassay, Luminescence, Male, Middle Aged, Phenytoin:adverse effects, Valproic Aci.   

PURPOSE: Previous studies showed an association between the blood levels of folate and vitamin B(12) and the risk for cardiovascular disease. The aim of this study is to investigate the effect of chronic use of phenytoin, carbamazepine or valproate monotherapy on the plasma levels of folate and B(12), and to compare folate and B(12) levels in epileptic patients with or without cardiovasular disorders.

METHODS: The study was conducted in the outpatient neurology clinic at Bahrain Defence Force (BDF) Hospital between January-July, 2005. Medical information was obtained by interviewing the patients and examining their hospital records. Blood folate and vitamin B(12) were measured by Immulite immunoanalysis assay using chemoluminescence.

RESULTS: A total of 26 consecutive outpatients (17 males, 9 females) were recruited in the study. Their mean age +/- SD was 38.2 +/- 20.1 year (range 15-77 year). Five (19.2%) had complex partial epilepsy and the remainder had tonic-clonic seizures. They had epilepsy for 15.7 +/- 8.1 years (range 2-35 years). Thirteen of them used phenytoin, nine carbamazepine and four used valproate. The duration of the treatment (years), dose (mg/day) and serum concentration (micromol/l) were 18.3 +/- 10.6, 376.9 +/- 180.4, 41.6 +/- 25.6, for phenytoin, 14.5 +/- 11.7, 422.2 +/- 175.0, 31.1 +/- 15.9 for carbamazepine and 18.3 +/- 6.3, 400, 567.7 +/- 78.1 for valproate, respectively. Eleven (42.3%) had established cardiovascular disorders such as hypertension, myocardial infarction or stroke. The mean level of plasma folate (12.94 +/- 6.76 ng/ml) and B12 (484.94 +/- 191.25 pg/ml) in epileptic patients with cardiovascular disorders compared to their values (11.27 +/- 5.84), (514.49 +/- 225.31) respectively in epileptics with no cardiovascular disorders were not statistically significant in the two groups.

CONCLUSION: In epileptic patients on chronic therapy with phenytoin, carbamazepine or valproate folate and B(12) levels were not different in patients with or without cardiovascular disorders....

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Journal Article 2005; 26(5): 515-520 PubMed PMID: 16264408 Citation  Keywords:  Adrenal Medulla:physiopathology, Adrenocorticotropic Hormone:blood, Animals, Cold Temperature, Corticosterone:blood, Epinephrine:blood, Luminescence, Male, Norepinephrine:blood, Pituitary-Adrenal System:physiopathology, Rats, Rats, Wistar, Restraint, Phys.   

OBJECTIVE: The effects of three different long-term (21 days) stresses: isolation(LTI), forced swimming (LTS) and isolation accompanied by forced swimming (LTI+LTS) on the level of plasma noradrenaline (NA), adrenaline (A), corticosterone (CORT) and adrenocorticotropic hormone (ACTH), both under basal conditions and in response to short-term immobilization and cold as heterotypic additional stressors, were compared.

METHODS: Plasma NA and A were assayed by the radioenzymatic method. Plasma CORT was measured using RIA kits. Plasma ACTH was determined by chemiluminescent method.

RESULTS: LTI produced a significant elevation of basal plasma CORT and ACTH, while basal plasma NA and A concentrations remained unchanged. Combination of long-term isolation and forced swimming, produced a significant elevation of basal plasma ACTH content only, while LTS did not influence the basal level of this hormone. When LTI rats were exposed to immobilization and cold, a significant elevation of plasma NA and A level was recorded. In LTS and LTI+LTS groups of rats exposed to immobilization or cold, increased plasma NA and A levels were observed, but this increase was lower in comparison with that found in LTI rats. No difference in plasma CORT content between the three long-term stressed groups of animals was observed, while plasma ACTH level was significantly more elevated in LTS and LTI+LTS than in LTI rats.

CONCLUSION: Based on these results, it may be concluded that LTI as a psychosocial stress represents a stronger stressor than LTS. Also, daily short-term (15 min, 21 days) swimming stress seems to attenuate the effect of long-term isolation on the activity of sympatho-adrenomedullary system....

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