Biological and medical value of antioxidant protection system of the human body

2021 ◽  
Vol 90 (1) ◽  
pp. 21-32
Author(s):  
O.M. Kovalyova ◽  
T.M. Pasiieshvili

The article is devoted to the antioxidant system of the human body in the context of biological and medical significance. The classification of antioxidants in terms of their physical and chemical properties, bioorganic compounds, biochemical effects, mechanisms of implementation of antioxidant protection is presented. The given processes of extreme radical oxidation and mechanisms of antioxidant defense in physiological and pathological conditions. The characteristics of the components of the glutathione system, namely glutathione and enzymes – glutathione peroxidase, glutathione reductase and glutathione transferase are presented. Much attention is paid to manganese superoxide dismutase, an antiradical defense enzyme, as a fundamental regulator of cell proliferation, a mediator of metabolism and apoptosis. Interpretation of changes in the antioxidant enzyme of mitochondrial origin from a prognostic point of view is interpreted on the basis of the results of clinical observations carried out by scientists in various human diseases. The expediency of determining manganese superoxide dismutase in clinical practice for the diagnostic search for the direction of the pathological process, the timely detection of complications and the appointment of adequate therapy is emphasized. Keywords: antioxidant system, classification, glutathione system, manganese superoxide dismutase.

Introduction. In recent years, there has been an increase in the prevalence of gastroesophageal reflux disease and autoimmune thyroiditis in young people. This is associated with a hereditary predisposition, viral diseases, which are often recorded in children's and adolescent groups, the unreasonable use of a large number of drugs, as well as the influence of various negative environmental factors, instability of the autonomic nervous system, eating disorders, the presence of bad habits, chronic stress and others. The aim of the work was to investigate the state of total antioxidant status and the content of biomarkers of the second phase of detoxification of xenobiotics - manganese superoxide dismutase and glutathione peroxidase in young people with gastroesophageal reflux disease and autoimmune thyroiditis. Materials and methods. To achieve this goal, 120 patients with a combined course of gastroesophageal reflux disease (GERD) and autoimmune thyroiditis (AIT) were examined, which made up the main group and two comparison groups: with isolated GERD (45 people) and AIT (42 patients). All patients were students of various universities and were between the ages of 18 and 25. Duration of the disease did not exceed 3 years. The total antioxidant status as an indicator of the first phase of defense and the levels of mitochondrial manganese superoxide dismutase and glutathione peroxidase – the second phase of antioxidant defense was determined. Results. The study showed that in all surveyed groups there was a decrease of total antioxidant status, which characterizes the first phase of the antioxidant defense system. Changes in the first phase of antioxidant defense affect the indicators of the second level of the system, which became the basis for studying the activity of mitochondrial manganese superoxide dismutase. Thus, the value of this indicator in all examined individuals exceeded the norm, which confirmed the inclusion of the second controlling phase of antioxidant system into the pathological process. At the same time, an increase inhibition of the glutathione defense link, the second phase of xenobiotic detoxification, were diagnosed. Conclusions. Negative changes occur in the enzyme system of the first line of antioxidant system in patients with GERD and AIT which may be the result of an unfavorable autoimmune background. Control over the work of antioxidant system moves to the second phase of the system, manifested by an increase in the content of mitochondrial manganese superoxide dismutase and inhibition of the activity of glutathione peroxidase in patients with a combination of GERD and AIT.


Author(s):  
L. K. Parkhomenko ◽  
◽  
L. A. Strashok ◽  
S. I. Turchina ◽  
G. V. Kosovtsova ◽  
...  

Recently, interest in the problem of free radical oxidation in biological membranes, which is directly related to both the normal functioning of cells and the occurrence, course and outcome of many pathological conditions, has increased again in clinical medicine. The aim was to determine the role and impact of antioxidant defense in boys with hypoandrogenism. The study involved 75 adolescents with hypoandrogenism aged 13–18 years, who underwent a complex of clinical and laboratory examinations. All patients were conducted complex of anthropometric research and determination of the degree of delayed puberty, laboratory and instrumental examination. Free radical oxidation was determined by the levels of malondialdehyde, conjugated dienes, carbonated proteins, superoxide dismutase and catalase in the serum, and restored glutathione and glutathione peroxidase in whole blood. Based on their determination, the coefficient of oxidative stress was calculated. Statistical processing of results was performed using parametric and nonparametric methods. The study of indicators of the free radical oxidation process found that adolescents with hypoandrogenism have multidirectional changes in the oxidation of proteins and lipids, namely: the level of conjugated dienes increases, the concentration of malondialdehyde remains at the level of the control group, and the level of carbonated proteins tends to decrease. As for the activity of antioxidant protection enzymes, a significant decrease in the level of glutathione peroxidase was detected, while the level of superoxide dismutase and catalase remained at the level of normative indicators. Oxidative stress accompanies and is one of the pathogenetic links in the formation or maintenance of the state of hypoandrogenism in boys. This requires the use of antioxidants, the complex of which must be selected individually.


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