Lyudmila V. Stepanova

BACKGROUND: The negative impact of environmental factors affects human health, leading to an increase in disease rates associated with unfavorable living conditions. Assessing environmental quality remains highly relevant, as each major industrial center has its own regional characteristics. AIM: To compare the cationic and anionic composition and types of saliva microcrystallization in residents of major industrial centers, using Omsk and Krasnoyarsk as examples. MATERIALS AND METHODS: A cross-sectional study was conducted using saliva samples from residents of Omsk (n = 82) and Krasnoyarsk (n = 86), aged 18–22 years. All samples were analyzed for ammonium, potassium, sodium, magnesium, calcium, chlorides, sulfates, fluorides, and phosphates using capillary electrophoresis, and the types of saliva microcrystallization were compared. Statistical analysis was performed using nonparametric methods, including the Mann–Whitney test for two-group comparisons and the Kruskal–Wallis test for comparisons involving three or more groups. RESULTS: Significant regional differences were observed for all parameters except sulfate concentration in saliva. Residents of Krasnoyarsk had higher levels of ammonium, potassium, calcium, and all anions in their saliva compared to those from Omsk, whereas sodium and magnesium concentrations were higher in Omsk residents. In all parameters except calcium, increased concentrations were observed in male subgroups, regardless of region. No differences in saliva microcrystallization patterns were identified between the two cities. CONCLUSION: The element concentrations in saliva differ between residents of Omsk and Krasnoyarsk. When planning studies using saliva as a biological substrate, it is essential to consider regional factors that influence its composition, which are determined by varying geochemical and industrial factors. Therefore, it is necessary to refine the normal reference values for saliva parameters specific to each city.

This paper proposes bioluminescent enzymatic assay of saliva as a non-invasive method for monitoring the functional state of the body. The value of luminescence intensity from coupled enzyme-based reaction catalyzed by NADH:FMN oxidoreductase and luciferase, when exposed to saliva, served as an indicator of the state of the body of workers at work. The absence of a significant difference between profiles of bioluminescence before and after the shift and no changes in biochemical, physical and chemical parameters of saliva indicated that the bodies had adapted to a workload. An increased bioluminescent intensity value is typical for workers in a state of chronic fatigue, a decreased one points to the presence of chronic diseases and bad habits. The dependence of the bioluminescent intensity value on the concentration of lactate, lipid peroxidation products, ionic and mineral composition, the values of free radical oxidation and antiradical protection was identified. Thus, the dependence of the saliva constituents on conditions of life and health status of workers can be identified using bioluminescent enzyme bioassay that is suitable for rapid monitoring of the body at work.

The saliva of athletes participating in anaerobic (track and field athletes) or aerobic (swimmers) physical activity was studied. Saliva sample was collected before (control) and after the workout. It was found that physical activity significantly increased the salivary total protein concentration and pH values in the athletes. The activity of catalase in saliva was significantly increased only after aerobic, but not anaerobic exercise performance. The bioluminescent indicator of athletes’ saliva is significantly higher during aerobic workout than anaerobic exercise. Salivary biomarkers such as lactate concentration, catalase activity, total protein concentration, calcium, potassium, magnesium ions, and the amide IV group may have a significant effect on the enhancement of light emission in a bioluminescent assay based on a system of coupled enzymatic reaction. The amide IV group and the presence of the salivary oligosaccharides, polysaccharides, phosphatase, and phospholipids in athletes during anaerobic physical activity can eliminate bioluminescence more efficiently than the concentration of triene conjugates and the amide II group in the saliva of athletes involved in aerobic exercises. Thus, significant biomarkers for the measurement of the physiological status of athletes who engaged in aerobic or anaerobic physical activity have been identified in saliva, these biomarkers can influence the integrated response of the bioluminescent enzymatic biotest. The change in the integrated bioluminescent indicator of athletes' saliva depending on the type of physical exertion can be used in sports medicine to prevent physical overload.

—The saliva of athletes with anaerobic (track and field athletes) and aerobic (swimmers) physical loads was studied. Saliva was collected before (in a state of physical rest) and after training. It was found that physical load significantly increased the concentration of total protein in saliva and the activity of hydrogen ions (pH) in the saliva. Catalase activity in saliva was significantly increased only after aerobic physical load, as opposed to anaerobic load. The bioluminescent saliva index was significantly increased for athletes engaged in aerobic physical load compared to that for an anaerobic load. Saliva biomarkers such as the concentration of lactate and total protein, catalase activity, concentration of calcium, potassium, and magnesium ions, as well as the content of group IV amides, had a significant effect on the enhancement of light emission in a bioluminescent two-enzyme reaction. The content of group IV amides and a complex of oligosaccharides, polysaccharides, phosphatase, and phospholipids in the saliva of athletes engaged in anaerobic physical load could more strongly inhibit bioluminescent glow than the concentration of triene conjugates and the content of group II amides in the saliva of athletes engaged in aerobic physical load. Thus, significant biomarkers of the physiological state of the body have been identified in the saliva of athletes engaged in aerobic or anaerobic physical loads, which were able to affect the integral response of a bioluminescent enzymatic biotest. A change in the integral bioluminescent saliva index, depending on the type of physical load for an athlete, can be used in sports medicine to prevent physical overloads.

A bioluminescence enzymatic assay of saliva was proposed as a noninvasive method to monitor the functional state of the body. The luminescence intensity from coupled enzymatic reactions catalyzed by NADH:FMN oxidoreductase and luciferase on exposure to saliva served as an indicator of the body state of workers at work. The absence of a significant difference between bioluminescence values measured before and after a shift with no changes in biochemical, physical, and chemical parameters of saliva suggested adaptation to a workload. An increased bioluminescence intensity was typical for workers in a state of chronic fatigue; a decreased intensity was observed in workers with chronic diseases and harmful habits. Bioluminescence intensity was found to depend on the concentrations of lactate and lipid peroxidation products, the ionic and mineral composition, and parameters of free radical oxidation and antiradical protection. Thus, the dependence of the saliva constituents on the life conditions and health status of workers can be detected using the bioluminescence enzymatic bioassay, which is suitable for rapid occupational monitoring.

The purpose of the work was to find optimal conditions for bioluminescent enzymatic analysis of saliva (based on the use of NADH:FMN oxidoreductase + luciferase) and then to determine the biological effect of using bioluminescence assay of saliva to study the physiological state of the body under normal and pathological conditions. The saliva of snowboarders and students were studied in the “rest–training” model. The saliva of patients diagnosed with acute pharyngitis was examined in the “sick–healthy” model. Bioluminescence assay was performed with a lyophilized and immobilized bi‐enzyme system using cuvette, plate, and portable luminometers. The concentrations of secretory immunoglobulin A (sIgA) and cortisol were determined by enzyme immunoassay, and the total protein content was measured by spectrophotometric method. The activity of the bioluminescent system enzymes increased as the amount and volume of saliva in the sample was decreased. The cuvette and plate luminometers were sensitive to changes in the luminescence intensity in saliva assay. Luminescence intensity correlated with the concentrations of sIgA and cortisol. The integrated bioluminescent index for saliva was reduced in the “rest–training” model and increased in the “sick–healthy” model. Thus, the non‐invasive bioluminescent saliva analysis may be a promising tool for assessing the health of the population.

Bioluminescent testing of saliva of sports horses sampled before and after physical exercise was carried out using a bioenzyme reaction catalyzed by NADH:FMN-oxidoreductase and bacterial luciferase. The inhibitory effect of saliva on the intensity of the glow was shown, which depended on an increase in the pH of saliva after muscle work. A decrease in the integral bioluminescent indicator during low-intensity muscle work correlated with the content of total protein and glucose in the blood serum. An increase in the bioluminescent indicator at high intensity was due to a decrease in creatinine or an increase in aspartate aminotransferase and is interrelated with an increase in heart rate. It is shown for the first time that the inhibition of bioluminescent glow can be an indicator of the functional state of a horse in training, which can be used in sports horse breeding to prevent overloads.

Bioluminescent testing of saliva of sports horses, selected before and after physical exercise, was carried out using a coupled enzyme reaction catalyzed by NADH:FMN-oxidoreductase and bacterial luciferase. The inhibitory effect of saliva on the intensity of the light emission was shown, which depended on an increase in the pH of saliva after muscle work. A decrease in the integral bioluminescent index after low-intensity muscular work correlated with the content of total protein and glucose in the blood an serum increase in the bioluminescent index at high intensity was due to a decrease in creatinine or an increase in aspartate aminotransferase and is corelated with an increase in heart rate. It has been shown for the first time that the inhibition of bioluminescence can be an indicator of the functional state of a horse in training, which can be used in sports horse breeding to prevent overloads.

The paper considers the creation of a diagnostic system based on morphological and biophysical indicators that allows us to understand the influence of the climatic component, as well as stress factors on the general physiological state of young people for further correction of preventive measures and preservation of the health of the peoples of the Far North. The aim of the study is a comprehensive assessment of the health of young people living in the Far North based on the results of bioluminescent saliva activity, stress-emotional state obtained before and after intense mental stress, as well as anthropometric and bioimpedance indicators. 117 students of the Medical Institute of Surgut State University took part in the survey at a young age (18-23 years) during the educational process (rest) and during the examination session (mental load) in the first half of the year of study (autumn-winter 2021). The stress-emotional state was assessed using the Spielberger-Khanin test, the functional state of students They were studied using bioluminescent salivary fluid testing, anthropometric and bioimpedance methods. Samples were obtained by spitting unstimulated saliva into a test tube. As a result of the study, regional features of the physique of young people were revealed, which indicates the formation of a phenotype adapted to living conditions in the northern region. The relationship between the stress-emotional status of adolescents and the level of inhibition of the bioluminescent enzymatic system by saliva samples taken before and after mental stress was shown. The value of the residual glow had an increased indicator for the state of rest and significantly reduced the intensity of the bioluminescent glow under mental stress. The methodological development obtained in the future will make it possible to effectively manage the methods and methods of diagnosing young people, taking into account the influence of external factors, climatic zones and conditions.

Th e aim of the research was to evaluate the possibilities of using saliva as an indicator of mental and physical stress in the bioluminescent method. Material and methods. Th e object of the study was the saliva of schoolchildren (15-16 years old, n=15), students (19-20 years old, Krasnoyarsk State Medical University and Surgut State University, n=227) and athletes (19-20 years old, n=25). Saliva sampling was performed before and aft er muscle tension and psycho-emotional stress. Th e bacterial bioenzyme system NADH:FMN-oxidoreductase + luciferase was used as a test system. Th e residual glow intensity was used as an integral indicator of body fatigue [1, 2]. Results. It shows the greatest fatigue of schoolchildren aft er mental stress and the least fatigue aft er physical exertion. Boys got tired aft er physical exertion, girls aft er mental exertion. Physical activity tired the excellent schoolchildren. Mental stress caused fatigue of the good schoolchildren. Th e fatigue of students during the study session was revealed, regardless of the region of residence and the component composition of saliva. Students had the same index of stress resistance regardless of the state of rest or mental stress. Indicators of situational and personal anxiety were higher among students from the northern regions. For the fi rst time, the least fatigue of highly qualifi ed athletes was shown during high-intensity physical activity, which distinguishes them from low-skilled athletes. Th e concentration of lactate in the saliva of athletes increased with fatigue. Conclusion. Mental and physical overload aff ect schoolchildren regardless of their academic performance and length of study. Psychological or emotional stress causes fatigue of the students’ body, regardless of the component composition of their saliva and the region of residence. Physical (muscular) tension of varying intensity tires the body of highly qualifi ed athletes to a lesser extent, which makes it possible to reveal their high stress resistance to overloads. Th us, saliva can serve as an indicator of mental and physical stress in the bioluminescent method. It is planned to develop new express methods for pre-trip inspections of railway employees.