The effect of an experimental biological immunostimulant on the cytokine profile and complement system in rats

The studies were conducted to substantiate the safety and immunoregulatory efficacy of Immunocol-vet through a quantitative assessment of the dynamics of proinflammatory and anti-inflammatory cytokines and complement components, confirming the absence of hyperinflammatory potential while maintaining the functional activity of the immune response. The experiments were performed in 2025-2026 on 5 groups (15 animals each) of Wistar albino rats (weight 200 ± 10 g). The experimental design included studying the following options: intact control, pyrogenal, polyacrylic acid (PAC), Escherichia coli anatoxin, Immunocol-vet (a combination of pyrogenal, PAC, and anatoxin). The drugs were administered intramuscularly at 0.2 ml three times (days 1, 3, and 7). Blood was collected on days 3, 7 and 10 (before the next administration) with subsequent enzyme immunoassay of immunological markers (cytokines IL-2, IL-4, IL-6, IL-10, IL-1β, TNF-α and complement components C3, C5). On day 3, Immunocol-vet maintained IL-4 at the control level (16.71 vs. 18.18 pg/ml), pyrogenal reduced it to 1.5 pg/ml with an increase in IL-10 to 27.4 pg/ml. By day 7, pyrogenal induced a peak of IL-6 (14.35 pg/ml) and a decrease in IL-4 to 0.17 pg/ml and C5 to 0.27 ng/ml. In the presence of Immunocol-vet, on the 7 th day, IL-6 remained minimal (0.05 pg/ml), IL-4 remained at a functional level (4.37 pg/ml), and IL-1β was effectively suppressed (0.83 pg/ml). On the 10 th day, Immunocol-vet restored IL-4 to control values (9.66 pg/ml versus the control of 9.47 pg/ml) and increased IL-2 to 13.42 pg/ml. The TNF-α indicator in the group receiving Immunocol-vet by the 10th day was 120.18 pg/ml and was lower than the control (145.61 pg/ml), while in the group receiving pyrogenal, its value reached a maximum for the entire experiment (196.55 pg/ml). Immunocol-vet exhibits immunoregulatory properties: the combination of components (pyrogenal, PAK, and toxoid) ensures an early immune response followed by physiological inhibition of the inflammatory cascade, preservation of the Th2 component (IL-4), and control of pyrogenic IL-1β without the risk of developing hyperinflammation or early immunosuppression.