[Anthocyanins as an element of nutritional support for athletes: effects and molecular mechanisms of action].

Antioxidants are among the common components of sports nutrition designed to counteract oxidative stress that develops during intense physical activity. One of the promising antioxidants are anthocyanins which belong to polyphenolic compounds of plant origin (class of flavonoids). The purpose of the research was to analyze the results of prospective controlled studies on the effect of anthocyanins on physical performance, and to consider the possible molecular mechanisms of their action. Material and methods. Sources were searched in PubMed, Google Scholar, and CyberLeninka databases of peer-reviewed scientific literature without restrictions on the year of publication using the following keywords: anthocyanins, physical performance, recovery, sport and exercise nutrition, oxidative stress, inflammation. Results. The main data set on the effects of anthocyanins in athletes was obtained using extracts of blackcurrant and Montmorency tart cherry. Volunteers received anthocyanins at a dose of 86-547 mg per day for 1 to 10 days with subsequent evaluation of their performance in cycling, running and fitness activities. The possibility of favorable effect of anthocyanins on physical performance and acceleration of its recovery after exertion has been shown. The source, dose and duration of intake did not significantly influence the established effects of anthocyanins. Acting as exogenous regulators of metabolism, anthocyanins can activate several mechanisms of performance enhancement, including influence on antioxidant and immune status and apoptosis intensity. Anthocyanins prevent the formation of reactive oxygen species, neutralize electrophilic compounds by direct interaction or through activation of Nrf2 factor, which regulates the transcription of antioxidant enzyme genes. The basis of the anti-inflammatory action of anthocyanins is their ability to inhibit MARK and NF-κB mediated signal transduction. Inclusion of bilberry and blackcurrant extract in the diet prevented the intensification of myocyte apoptosis and suppression of cellular immunity induced by exhausting exercise. An additional mechanism of anthocyanin action on physical performance may be an increase in blood supply of organs and tissues due to vascular dilation caused by activation of endothelial nitric oxide synthase. Conclusion. The intake of plant extracts with a high anthocyanin content can increase physical performance and improve recovery after physical exertion, which may be due to the antioxidant and anti-inflammatory effects of anthocyanins, their ability to regulate apoptosis processes and improve blood supply to organs and tissues.

[Bioactive compounds anthocyanins as a factor in the nutritional recovery of the body's adaptive potential after intense physical activity in the experiment: assessment of immunological and hematological indicators of adaptation].

Restoring the adaptive potential of an athlete is of paramount importance not only for the implementation of his training and competitive activities, but also for maintaining health. One of the leading place in complex recovery programs in sports is given to full-fledged optimal nutrition, which provides for meeting the body's requirements not only in energy, macro- and micronutrients, but also in minor bioactive compounds. The use of anthocyanin-containing products is a promising strategy for the normalization of metabolic and immune disorders that develop as a result of intense physical and neuro-emotional stress not only in athletes, but also in other groups of people exposed to these factors, including military personnel undergoing training in conditions close to combat. This determines the relevance of this study. The aim of the research was to study the effect of an anthocyanin-enriched diet on hematological profile and cellular immunity in rats after intense physical activity. Material and methods. The experiment was carried out for 4 weeks on 4 groups of male Wistar rats with an initial body weight of ~300 g. The motor activity of the animals of the 1st (control) and 2nd groups was limited by the standard keeping animals in the vivarium, while physically active rats of the 3rd and 4th groups received additional physical activity - training on a treadmill. Before the end of the experiment, the animals of 3rd and 4th groups were given debilitating physical activity on a treadmill (until the rats refused to continue the exercise). Rats of all 4 groups received a standard semi-synthetic diet, water ad libitum. Animals in 2nd and 4th groups were additionally fed blueberry and blackcurrant extract (30% anthocyanins) as part of the diet at a daily dose of 15 mg anthocyanins/kg body weight. Hematological parameters were determined on a Coulter ACT TM 5 diff OV hematological analyzer. Expression of CD45R, CD3, CD4, CD8a, CD161 receptors on rat peripheral blood lymphocytes was determined by direct immunofluorescent staining of whole blood cells using a panel of monoclonal antibodies conjugated with fluorescent dyes: APC, FITC, PE. The measurements were carried out on an FC-500 flow cytometer. Results. Intense physical activity in rats of the 3rd group did not lead to a significant change in erythrocyte parameters compared with the control group. Enrichment of the diet with blueberry and black currant extract (the 2nd and the 4th groups) provided a significant (p<0.05) increase in blood content of hemoglobin (Hb) (150.7±0.9 and 154.4±2.0 vs 145.4±0.9 g/l in control), hematocrit (44.95±0.21 and 46.18±0.64 vs 43.78±0.32%) and the average content of Hb in erythrocytes (18.00±0.20 and 18.03±0.24 vs 17.35±0.24 pg). The absolute content of leukocytes and other cellular elements of the leukocyte formula, as well as leukocyte indices in rats of the experimental groups didn't significantly differ from those of the control rats, which confirms the absence of an inflammatory process. Intense physical activity and anthocyanin enrichment of the diet didn't have a significant effect on rat platelet parameters. Enrichment of the diet of rats of the 4th group with blueberry and black currant extract led to the activation of cellular immunity, as evidenced by a significant (p<0.01) increase in the percentage (from the total content of T-lymphocytes) of T-helpers (70.13 ±1.34 vs 63.75±0.99%) and a decrease in the relative content of cytotoxic T-lymphocytes (28.65±1.38 vs 34.71±0.95%) in comparison with those in rats of the 3rd group and at the level of the trend (р<0.1) - from the 1st group indexes (66.87±1.20 and 31.87±1.26%, accordingly). Intense physical activity led to a decrease in immunoregulatory index in rats of the 3rd group (1.86±0.07) compared with the control (2.13±0.12) (p<0.1), and in animals of the 4th group this indicator was significantly higher (2.50±0.14, p<0.05). In animals of the 3rd group a statistically significant (p<0.05) decrease in the relative content of NK cells in peripheral blood was found compared to the control. Enrichment of the diet of physically active rats with blueberry and black currant extract led to a significant (p<0.05) increase in the percentage of NK cells compared to this indicator in rats of the 3rd group (4.87±0.75 vs 2.08±0.18%) and had no significant difference with the indicator in rats of the control group (4.32±0.98%). Conclusion. The enrichment of the rats' diet with blueberry and blackcurrant extract containing a daily dose of 15 mg of anthocyanins per kg of body weight provides an increase in blood Hb content, hematocrit and the average content Hb in erythrocytes. It has been established that intense physical activity induces the cellular immunity suppression. The activating effect of anthocyanins on adaptive cellular immunity and NK cells, which are lymphocytes of innate immunity, was revealed. The data obtained indicate the effectiveness of the use of bioactive compounds (anthocyanins) to increase the adaptive potential of the organism.

[Protective effect of anthocyanins on apoptosis of gastrocnemius muscle myocytes of rats after intense exercise].

Currently, in sports medicine, much attention is paid to the prevention and treatment of delayed muscle soreness syndrome (DOMS), which occurs several hours or days after unusual or intense physical activity, as well as the state of athlete overtraining. One of the main pathogenetic factors in the development of this syndrome is myocyte ultrastructural damage with apoptosis activation. Therefore, using natural antioxidants in sports nutrition for the relief of this pathology is of particular relevance. The aim of the study was to study the effect of an anthocyanin-enriched diet on apoptosis of gastrocnemius muscle myocytes of rats after intense exercise. Material and methods. The experiment was carried out for 4 weeks on 4 groups of male Wistar rats (12 animals in each, initial body weight ~300 g). Animals were divided into groups of rats (groups 1 and 2), whose motor activity was limited by standard conditions for keeping animals in vivarium, and groups of physically active rats (groups 3 and 4), which received additional physical activity - treadmill training. Before the end of the experiment, the animals of groups 3 and 4 were given debilitating (until the rats refused to continue the exercise) physical activity on a treadmill. Rats of all four groups received a standard semi-synthetic diet, water ad libitum. Animals in groups 2 and 4 were additionally given blueberry and blackcurrant extract (30% anthocyanins) as part of the diet at a daily dose of 15 mg anthocyanins/kg body weight. The intensity of apoptosis of gastrocnemius muscle myocytes was studied by flow cytometry. Cells were stained with fluorochrome-conjugated annexin V and vital dye 7-aminoactinomycin. The results are presented as the percentage of intact cells and cells at different stages of apoptosis per 100 000 counted objects in each sample. Results. The enrichment of the diet of control group rats with blueberry and black currant extract did not have a significant effect on the relative content of intact cells and the studied parameters of apoptosis of gastrocnemius muscle myocytes of rats of the 2nd group. Intense physical activity in rats of the 3rd group led to a statistically significant (p<0.05) decrease in the relative content of intact (live) cells compared with this indicator in rats of other groups (85.32±1.44 vs 90.87±0.66% - in the 1st group; 90.16±0.79% - in the 2nd group; 89.01±0.81% - in the 4th group, р<0.05). After intense physical activity in rats of the 3rd group, activation of apoptosis of gastrocnemius muscle myocytes was found, as evidenced by an increase in the relative content of objects in apoptosis compared with other groups (11.61±1.45 vs 7.88±0.60% - in the 1st group, р<0.05; 8.01±0.70% - in the 2nd group, p<0.10; 7.93±0.59% - in the 4th group р<0.05). Enrichment of the diet of exercise rats with blueberry and blackcurrant extract (4th group) had a protective effect on the intensity of the apoptosis process, the studied parameters did not differ significantly from those in rats of the control and the 2nd groups. Conclusion. The results of the study indicate the activation of the process of apoptosis of gastrocnemius muscle myocytes of rats after intense physical activity. Enrichment of rats' diet with anthocyanins from blueberry and black currant extracts ensures the restoration of the studied apoptosis parameters to the level of control group rats. In the control group of rats with normal physical activity, the addition of anthocyanins to the diet does not have a significant effect on the physiological process of apoptosis of gastrocnemius muscle myocytes. In this way, an evidence base for the effectiveness of the use of biologically active substances - anthocyanins - in sports nutrition for the restoration of skeletal muscles has been obtained.