Effect of <i>Phlojodicarpus sibiricus</i> on the subpopulation profile of blood cells and thymus of mice with a simulated tumor

The present study concerned the effect of Phlojodicarpus sibiricus extract on immune response in melanoma model induced by the B16 cells in C57Black/6 mice. The aim of our work was to evaluate the immunomodulatory properties of this plant extract in the context of oncogenesis. To achieve this goal, an experiment was conducted with three groups of mice: a control group of healthy animals, a group with induced melanoma receiving the extract, and a non-treated melanoma group. Melanoma malignancy was modeled by injecting a suspension of B16 cells, and the extract of Phlojodicarpus sibiricus was administered orally after the first signs of developing melanoma. Changes in lymphocyte subpopulation profile of blood and thymus were assessed using flow cytometry with specific monoclonal antibody markers for T lymphocytes, T helper cells, T killer cells, B lymphocytes, NK cells, and T regulatory cells. The results obtained did not reach statistical significance (p 0.05). However, certain trends were observed in the thymus, where a decreased content of T regulatory cells and NK cells was noted in the group receiving the extract compared to the melanoma group. This reduction may indicate a potential influence of the extract on the antitumor immune response, whereas changes in the ratio of T helper/T killer cells suggest possible regulation of cellular immunity. The reduction in B lymphocyte levels may reflect a shift in immune response from humoral to cell-mediated pattern, which could be beneficial in the context of tumor pathology. The extract of Phlojodicarpus sibiricus appears to modulate melanoma development, suggesting a potential for further research in immunomodulation and anti-tumor therapy. The study has revealed a reduced level of T regulatory cells and NK cells in the extract group, thus suggesting a diminished antitumor immune response. Moreover, a decline in B lymphocytes suggests a shift from humoral to cell-mediated immunity. These findings highlight the potential activity of extract as an immunomodulating agent. However, further research is necessary to confirm these effects. Mechanistic analysis of the extract action would be crucial, particularly, the ways of lymphocyte activation and apoptosis regulation.