Depletion Of Antioxidant System Research Articles

Effect of exogenous microflora of the hepatobiliary system on the biochemical composition of bile and lipid peroxidation processes of somatic cell membranes in chronic opisthorchiasis

It has been epidemiologically established that the rate of primary cholangiocarcinomas increases greatly in the ObIrtysh basin which is hyperendemic for helminth Opisthorchis felineus in comparison with other regions where the population is not infested. In this connection chronic opisthorchiasis is considered as facultative liver precancer. The study of cholangiocarcinogenesis mechanisms will allow developing pathogenetic approaches to prevention of this tumor. Aim of the study was to investigate the significance of microbiota of the hepatobiliary tract of chronic opisthorchiasis patients in changing of biochemical composition of bile and investigation of its biological influence on somatic cells membrane. Material and methods. Objects of research: bacteria; inbred mice infected by opisthorchis; samples of bile, cultures of human embryo fibroblasts and splenocytes of inbred mice in vitro; blood plasma; standard primary and secondary bile acids. We studied: species of bacteria colonizing bile ducts; quantitative and qualitative composition of bile acids, and level of diene conjugates and malondialdehyde in duct bile samples; biological activity of bile on processes of lipid peroxidation of cell membranes in vitro; influence of bile and lipid peroxidation products on cytomembrane permeability; activity of antioxidant systems of the body. Results and discussion. It was found out, that bile of patients with chronic opisthorchiasis in majority of cases (77.0 %) was infected by different species of bacteria. In 30.0 % of cases certain types of intestinal bacteria (Proteus vulgaris, P. mirabilis, Citrobacter freundii, Bacteroides alcaligues faecalis, Clostridium, Streptococcus faecalis, Escherichia coli) change biochemical composition of duct bile – deconjugated primary and secondary bile acids and also high level of total bile acids are detected. Bile of the above biochemical composition, against the background of depletion of antioxidant system, induces activation of cell membrane lipid peroxidation processes and significantly increases their permeability to toxic components of bile. These processes are promotor in cholangiocarcinogenesis.

THE INFLUENCE OF VAGINAL SUPPOSITORIES “MELANIZOL” ON THE SYSTEM OF LPO-AOS IN CONDITION OF MODEL OF A NONSPECIFIC VAGINITIS IN RATS

It is known that almost any pathology is accompanied by an imbalance of the lipid peroxidation (LPO) and the antioxidant system (AOS), and diseases of the female reproductive system are no exception. Thus, modern therapies of nonspecific vaginitis (NV) should include drugs with an antioxidant effect in the complex treatment, because the role of the LPO-AOS system in the mechanism for the development of NV is great. This problem can be solved by new complex drug with plant material with a wide spectrum of action. Aim. The aim of our research was to study the effect of new vaginal suppositories “Melanizol”, containing metronidazole and tea tree oil on the system of LPO-AOS on a model of nonspecific vaginitis in rats. Materials and methods. The study object was the new vaginal suppositories “Melanizol”. As reference drugs there were taken suppositories “Gravagin” and “Hippophaes oleum suppositories”. The study has been carried out on the model of experimental nonspecific (irritative) vaginitis caused in rats by the mixture of turpentine oil and dimethyl sulfoxide. Blood serum and vaginal tissue were used as the material for the study. Thiobarbituric acid-active products (TBA-AP) were determined as the component of a lipid peroxidation. The catalase (CAT), the superoxide dismutase (SOD) and the reduced glutathione (G-SH) were determined as the component of an antioxidant system. Results and discussion. On the background of experimental vaginitis in serum and in vaginal tissue homogenate in rats, significant changes in indicators of the LPO-AOS were noted. Change of these indicators show a systemic response of the body to pathological changes in the vagina, which is manifested in the depletion of AOS and activation of the LPO. The vaginal suppositories “Melanizol” in the study on the model of nonspecific (irritative) vaginitis in rats showed an antioxidant effect. Suppositories “Melanizol” significantly reduce the level of TBA-AP, interfering with lipid peroxidation processes, and restore the level of G-SH, as well as the activity of SOD and catalase in the blood and in the vaginal homogenate, helping to protect the cell membranes. Suppositories “Melanizol” significantly exceed the reference suppositories “Gravagin” and are not inferior to the reference drug “Hippophaes oleum suppositories” in activity to reduce the level of TBA-AP, and to restore the level of G-SH, as well as restoration the activity of SOD and CAT. Antioxidant activity of vaginal suppositories “Melanizol” can be explained by the presence of tea tree oil and metronidazole in their composition, which is confirmed by literature data. Conclusions. The conducted researches have shown that the new vaginal suppositories “Melanizol” demonstrated antioxidation activity. Results of this experiment allow us to recommend them for the further studies as medication for the treatment of nonspecific vaginitis.

Implication of Oxidative Stress in Small Intestine Disorders, Constipation and Diarrhea: A Mini Review

Diarrhea pathophysiology and constipation are multifactorial gastrointestinal (GI) disorders characterized by intestinal peristalsis disruption of and an irregularity in secretion/absorption process. Oxidative stress, as an imbalance in prooxidants/antioxidants, has recently been recognized as a significant player in these GI disturbances. In this respect, numerous studies were performed and have shown that the deleterious effects on GI tract were accompanied by accumulation of oxidants and depletion of antioxidant system. Antioxidant remedy is necessary in scavenging free radicals and reactive oxygen species preventing oxidative stress-induced GI interruptions.

АНТИОКСИДАНТНАЯ ЗАЩИТА И ОСОБЕННОСТИ ПЕРЕКИСНОГО ОКИСЛЕНИЯ ЛИПИДОВ ПРИ БРОНХИАЛЬНОЙ АСТМЕ У ДЕТЕЙ

Objective: To research peculiarities of the lipid peroxidation and antioxidant system in children with bronchial asthma.Methods: It has taken the results of the research in 56 children aged from 5 to 14 years, who suffered with bronchial asthma (BA). Along with the general clinical examination, spirometry were used to identify respiratory function, and malondialdehyde (MDA) and superoxide dismutase contents in blood serum were analyzed. Results: Spirometry in all BA patients from attack of disease up to attack-free interval showed increasing of forced expiratory volume in 1 second (from 61.5±3.70% to 84.3±5.33%) and maximum voluntary ventilation (from 59.1±4.21% to 81.7±6.31%), and decreasing of residual volume (from 117.4±6.01% to 93.1±5.25%) . Biochemical studies revealed increase in the content of MDA (3.2±0.04), reduced activity of superoxide dismutase (10.7±0.2) and reduced content of ascorbic acid (57.6±0.28) in blood serum in children with BA. Conclusion: At the time of attacks in children lipid peroxidation processes are intensified and followed by increasing development of lipid peroxidation products (MDA), depletion of antioxidant system in blood serum, lower activity of superoxide dismutase, and increased sialic acid, which facilitates development of immune-inflammatory process in the bronchopulmonary system. Administration of Mexidol in children with BA led to earlier elimination of the key clinical and paraclinical implications such as: elimination of asthma attacks, disappearance of pulmonary rale, improved respiratory function parameters, and indicators of lipid peroxidation and antioxidant system in the blood serum. Keywords: Bronchial asthma, children, lipid peroxidation, antioxidants.

Oxidative stress and modification of synaptic proteins in hippocampus after traumatic brain injury

Oxidative stress, an imbalance between oxidants and antioxidants, contributes to the pathogenesis of traumatic brain injury (TBI). Oxidative neurodegeneration is a key mediator of exacerbated morphological responses and deficits in behavioral recoveries. The present study assessed early hippocampal sequential imbalance to possibly enhance antioxidant therapy. Young adult male Sprague–Dawley rats were subjected to a unilateral moderate cortical contusion. At various times post-TBI, animals were killed and the hippocampus was analyzed for antioxidants (GSH, GSSG, glutathione peroxidase, glutathione reductase, glutathione- S-transferase, glucose-6-phosphate dehydrogenase, superoxide dismutase, and catalase) and oxidants (acrolein, 4-hydroxynonenal, protein carbonyl, and 3-nitrotyrosine). Synaptic markers (synapsin I, postsynaptic density protein 95, synapse-associated protein 97, growth-associated protein 43) were also analyzed. All values were compared with those for sham-operated animals. Significant time-dependent changes in antioxidants were observed as early as 3 h posttrauma and paralleled increases in oxidants (4-hydroxynonenal, acrolein, and protein carbonyl), with peak values obtained at 24–48 h. Time-dependent changes in synaptic proteins (synapsin I, postsynaptic density protein 95, and synapse-associated protein 97) occurred well after levels of oxidants peaked. These results indicate that depletion of antioxidant systems following trauma could adversely affect synaptic function and plasticity. Early onset of oxidative stress suggests that the initial therapeutic window following TBI appears to be relatively short, and it may be necessary to stagger selective types of antioxidant therapy to target specific oxidative components.

A Time Course of Contusion-Induced Oxidative Stress and Synaptic Proteins in Cortex in a Rat Model of TBI

An imbalance between oxidants and antioxidants has been postulated to lead to oxidative damage in traumatic brain injury (TBI). Oxidative neurodegeneration is a key mediator of exacerbated morphological responses and deficits in behavioral recoveries. The present study was designed to delineate the early temporal sequence of this imbalance in order to enhance possible antioxidant therapy. Young adult male Sprague-Dawley rats were subjected to a unilateral moderate cortical contusion. At various times post-trauma (3, 6, 12, 24, 48, 72, and 96 h), animals were killed and the cortex analyzed for enzymatic and non-enzymatic oxidative stress markers. Fresh tissues were prepared for biochemical analysis of several antioxidants (glutathione [GSH], glutathione peroxidase [GPx], glutathione reductase [GR], glutathione-S-transferase [GST], and thiobarbituric acid reactive substances [TBARS]). Synaptic markers Synapsin-I, PSD-95, SAP-97 and GAP-43 were analyzed by Western blot with antibodies directed against them. All activity levels were compared to sham-operated animals. Activity of antioxidant enzymes and GSH clearly demonstrate a significant time-dependent increase in oxidative stress. Changes in pre- and post-synaptic proteins (Synapsin-I and PSD-95) occur early (24 h), whereas SAP-97 levels demonstrate a protracted reduction. These results indicate that depletion of antioxidant systems following trauma could adversely affect synaptic function and plasticity. Because of the observed differences in the time-course of various markers, it may be necessary to stagger selective types of anti-oxidant therapy to target specific oxidative components. The initial therapeutic window following TBI appears relatively short since oxidative damage occurs as early as 3 h.