Effect of avian bursa of Fabricius extract on the compensatory potential of bone marrow, spleen, and thymus cells in cyclophosphamide-induced mice

Malignant neoplasms often arise under immunodeficiency conditions. However, anticancer chemotherapeutic drugs can also cause the development or aggravate immunodeficiency by affecting the bone marrow function. Previous studies have shown that the bioorganocomplex obtained from the chickens’ Fabricius bursa has an antioxidant and immunotropic effect. The aim of this research was to investigate the protective mechanism of the bioorganocomplex “Bursanatal” upon cyclophosphamide-induced immunosuppression in the bone marrow, thymus, spleen of C57Bl/6 mice. Immunodeficient state was induced with single cyclophosphamide injection (200 mg/kg). Histological, morphometric, radiological methods have been used, as well as immunohistochemical staining of the spleen and thymus with CD45 and CD3 antibodies. The studies showed that cyclophosphamide injection affects both peripheral blood and bone marrow. Moreover, neutrophilic, basophilic and erythroid precursor cells are less sensitive to the cyclophosphamide. Subsequently, on the 8 th day their compensatory hyperplasia has been observed. The use of mentioned bioorganocomplex was accompanied by increased counts of leukocytes, erythrocytes and hemoglobin in peripheral blood. Bone marrow cellularity also enriched, associated with active division and maturation of erythroid, myeloid, and lymphoid cells. Bioorganocomplex administration causes a significant decrease of the red pulp area in spleen of mice with cyclophosphamide-induced immunodeficiency. Activation of extramedullary hematopoiesis was found in spleen of treated mice, i.e., the number of colony-forming hematopoietic progenitors was increased. It was also noted that the reactive center areas in the white pulp were reduced, with a significant increase of CD3 + cell contents in red and white pulp under the “Bursanatal” treatment. At the same time, the preparation did not affect thymus pathomorphology.