[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.