According to the WHO, the secondary form of hematopoietic-depressive status increases the risk of death in people with oncological, infectious, and hormonal diseases. The choice of drugs that stimulate the hematopoietic activity of B-lymphopoiesis is limited. The current leucopoiesis drugs have a number of side effects: thymic preparations stimulate the production of PGE2, which causes chronic inflammation and various autoimmune diseases through the differentiation of T helper 1 (Th1) cells, the proliferation of Th17 cells, and the production of IL-22 from Th22 cells through EP2 and EP4 receptors; cytokine preparations can cause uncontrolled immune reactions and impaired contractility of smooth and cardiac muscles; drugs based on nucleic acids can stimulate the division of all cells, including bacterial and cancerous ones. The use of oligonucleotides such as ribozymes and antisense oligodeoxynucleotides (AS-ODNs) shows promise as therapeutic moieties, but faces a number of challenges such as nuclease sensitivity, off-target effects, and efficient delivery. The search for substances that stimulate B-lymphopoiesis among ionic compounds was motivated by the discovery of the unique properties of lidocaine docusate, one of the first ionic liquid forms of the known drugs. The lidocaine docusate (protonated form of lidocaine (2-(diethylamino)-N-(2,6-dimethylphenyl) acetamide + docusate-anion (dioctylsulfosuccinate))) suppresses the division of pheochromocytoma cells and activates immunity in rats. The trimecaine-based ionic compound (TIC) demonstrates high B-lymphopoiesis-stimulating activity. The TIC compound stimulates an increase in the volume of transitional B cells, which play an important role for further differentiation and formation of a sufficient number of mature B1 cells and mature B2 cells, where mature B2 cells make up the bulk of the functional population of B lymphocytes. The TIC compound most strongly stimulated the restoration of the number of marginal zone B cells, follicular B cells, and activated germinal center B cells after the cytotoxic emptying of the follicular centers of the spleen induced cyclophosphamide. It significantly exceeds the activity of the comparison drug methyluracil. The TIC compound does not affect the level of pro-B, pre-B-I, or pre-B-II bone marrow cells, which prevents the risk of the formation of immature functionally defective cells.

Leukopenia remains a major clinical challenge associated with infectious diseases, oncological therapies, autoimmune disorders, and metabolic and iatrogenic conditions. Insufficient leukopoiesis not only increases susceptibility to infections but also limits the intensity and continuity of anticancer and immunosuppressive treatments. Targeted stimulation of leukopoiesis therefore represents a critical therapeutic strategy in modern biomedicine. This narrative review summarizes pharmacological and biotechnological approaches to leukopoiesis stimulation based on an analysis of peer-reviewed literature from major biomedical databases. Emphasis was placed on molecular mechanisms of action, clinical positioning, and translational potential of leukopoiesis-modulating agents. Current leukopoiesis-stimulating strategies encompass cytokine-based therapies, bone marrow-derived peptides, thymic and microbial immunomodulators, nucleic acid-based agents, plant-derived compounds, and chemically synthesized small molecules. Classical colony-stimulating factors remain the cornerstone of clinical practice; however, their limitations, including adverse effects and restricted spectrum of action, have driven the development of alternative approaches. Emerging strategies increasingly target specific regulatory nodes of hematopoiesis, including bone marrow stromal interactions, transcription factor signaling, chemokine receptor pathways, and immune cell differentiation programs. Advances in the understanding of leukopoiesis regulation have expanded therapeutic opportunities beyond conventional growth factor administration. Pharmacological and biotechnological targeting of leukopoiesis holds promise for improving clinical outcomes in patients with leukopenia of diverse etiologies. Future progress in this field will depend on the integration of mechanistic insights with clinical evidence to enable more selective, effective, and safer leukopoiesis-stimulating therapies.

A novel inclusion complex of a fluorinated pyrazolopiperidine derivative (5-benzyl-7-(2-fluorobenzylidene)-2,3-bis(2-fluorophenyl)-3,3a,4,5,6,7-hexahydro-2H-pyrazolo [4,3-c]pyridine hydrochloride, PP·HCl) with β-cyclodextrin (PPβCD) was designed, synthesized, and characterized as a potential therapeutic agent for chemotherapy-induced myelosuppression and lymphopenia. Encapsulation of PP within β-cyclodextrin increased aqueous solubility by approximately 3.4-fold and improved dissolution rate by 2.8-fold compared with the free compound. Structural analysis using IR, ^1H/^13C NMR, and TLC confirmed the formation of a stable 1:1 host–guest complex, and the disappearance of free PP signals further supported complete encapsulation. In vivo evaluation in a cyclophosphamide-induced myelosuppression model demonstrated that PPβCD accelerated hematopoietic recovery, restoring leukocyte and erythrocyte counts 35–40% faster than methyluracil, without any signs of systemic toxicity. These findings indicate that β-cyclodextrin complexation significantly enhances solubility, dissolution, and biological efficacy of the pyrazolopiperidine scaffold, supporting further preclinical development of PPβCD as a supportive therapy for chemotherapy-related hematological complications.

According to WHO, the acquired secondary form of hematopoietic-depressive states increases the risk of death in people with cancer, infectious, and hormonal diseases. The choice of drugs that stimulate the proliferative activity of bone marrow cells is limited. The stimulus to the search for hematopoietic-stimulating compounds among pyridine derivatives was the manifestation of the activity of the cerebroprotective drug Mexidol (2-ethyl-6-methyl-3-hydroxypyridine succinate) to restore the granulocytes and B-lymphocytes homeostasis in clinical practice. The hematopoietic-stimulating activity of the newly synthesized compound Complex of 5-benzyl-7-(o-fluorobenzylidene)-2,3-bis(o-fluorophenyl)-3,3a,4,5,6,7-hexahydro-2H-pyrazolo [4,3-c]pyridine complex with β-cyclodextrin (BIV) was studied on a model of cyclophosphamide-induced myelodepression in C57BL6/J mouse line. The BIV compound demonstrated a stimulating effect on the process of restoring the level of Ly-6G⁺ Ly-6C⁺ granulocytes, monocytes/macrophages, CD19⁺ B-lymphocytes in the bone marrow, exceeding the activity of the reference drug Methyluracil. The BIV compound did not affect on the proliferative activity of c-kit (CD117⁺)-expressing cells, CD3e⁺ pre-T-lymphocytic cells and Ter-119⁺ erythroid cells in the bone marrow. The total number of bone marrow myelokaryocytes in the experimental groups was significantly higher than in the intact group. The pronounced hematopoietic-stimulating effect of the BIV compound gives in the future the prospect of development as a drug used for the treatment of B-lymphocytic and granulocytic-macrophage hematopoietic-depressive states.

Background: Cyclophosphamide is widely used in oncology, autoimmune disorders, and transplantation-related conditioning or post-transplant immunosuppression. However, its therapeutic value is limited by hematopoietic and lymphoid toxicity, including leukopenia, neutropenia, anemia, thrombocytopenia, bone marrow suppression, thymic injury, and prolonged impairment of T-cell recovery. These effects may occur after pulsed intravenous administration, high-dose regimens used in transplantation or severe refractory disease, and continuous low-dose/metronomic exposure. Therefore, there is a medical need for pharmacological agents capable of compensating cyclophosphamide-induced hematopoietic and lymphopoietic suppression without causing uncontrolled stimulation of early progenitor cells. Aim: To evaluate the hematopoietic and T-lymphopoiesis-stimulating activity of BIV under cyclophosphamide-induced hematopoietic and T-lymphopoietic suppression. Methods: Cyclophosphamide-induced hematopoietic- and T-lymphopoiesis-suppressive models were established on laboratory albinos rats and C57BL6/J mice. Peripheral blood hematological indices in rats were measured using hematology analyzers. Hematopoietic stem cells, thymocyte subsets, Th _act , T _reg , T _mem , CTL cell populations, and erythroid cells from the bone marrow, thymus, and spleen were analyzed by flow cytometry. Statistical analysis was performed using one-way ANOVA (p < 0.05). Results: In rats with CPh-induced hematopoietic suppression, BIV supported partial recovery of erythrocyte and hemoglobin parameters and improved leukopoietic indices under CPh-induced hematopoietic suppression. The β-cyclodextrin complex of 5-benzyl-7-(o-fluorobenzylidene)-2,3-bis(o-fluorophenyl)-3,3a,4,5,6, 7-hexahydro-2H-pyrazolo[4,3-c]pyridine (BIV) demonstrated a consistent moderate activity in restoring the overall level of CD3ε+CD19− T lymphocytes in the bone marrow and thymus. In the bone marrow, BIV uniformly increased the reduced levels of CD3ε+CD19− T lymphocytes and CD3ε+CD44 ⁺ T _mem memory T cells to physiological normal values. In the spleen, BIV restored the decreased levels of CD25+FoxP3+ T _reg regulatory lymphocytes and CD28 ⁺ CD44 ⁺ T _mem memory T cells to physiological normal levels, while reducing the elevated levels of CD3ε+CD8a+ CTL cytotoxic T lymphocytes and CD4 ⁺ CD25 ⁺ Th _act activated helper T cells to values corresponding to the physiological norm. Conclusion: BIV demonstrated notable hematopoietic- and T-lymphopoiesis-modulating activity. The compound partially restored erythropoiesis as well as central and peripheral T-lymphopoiesis, while providing balanced regulation of cytotoxic, regulatory, and memory T-cell subsets in cyclophosphamide-induced T-lymphopoiesis-suppressive models. Several evaluated T-lymphocyte subpopulations approached or returned to physiological control levels under the experimental conditions, although full translational validation requires further pharmacological and toxicological investigation.