Effect of polysaccharides from calendula flores on the morpho functional features of the thymus and selenium reactions in rats under swimming stress

Abstract

Relevance. The widespread occurrence of stress factors has stimulated an active study of their experimental models, such as traumatic, thermal and other types of stress, in order to find effective methods of protection and prevention of their negative consequences. Research shows that stress causes significant changes in the immune system and hematopoietic organs, which requires a deep understanding of the mechanisms of adaptation. A particularly promising area is the study of natural adaptogens, such as pectin from calendula inflorescences (CF), which can help protect the body. Expanding the evidence base of their effectiveness is important for developing new methods of dealing with stress and its complications.

Materials and methods. The object of the study was male Wistar rats, divided into three groups: (I) intact; (II) subjected to swimming stress; and (III) receiving a CF solution (i.p., at a dose of 0.1 g/kg body weight) daily after each episode of swimming stress.In the experiment, the method of forced swimming, intraperitoneal injection of CF or saline solution, and histological and morphometric studies of the thymus and spleen were used. The study complied with the requirements of ethics and standards of laboratory practice.

Results. Swimming stress caused a significant decrease in thymus mass, especially on the 3rd day, followed by a slight recovery by the 7th day, which was more pronounced with the introduction of CF. Histological studies have shown that stress led to the destruction of the thymus structure, loss of boundaries between layers and the appearance of signs of involution, the introduction of CF mitigated the changes. Similar changes were observed in the spleen, where on day 3 there was a decrease in weight and volume of white pulp, with a gradual recovery at a later date. The content of lymphocytes in the peripheral blood decreased, which indicated a decrease in the immune response.

Conclusions. Regular administration of calendula polysaccharide solution during swimming stress in rats slows down thymus involution, stabilizes its structure, accelerates spleen recovery, and reduces lymphocytopenia during swimming stress.