Abstract
Over the last decades, significant progress has been made in studying agonistic and antagonistic hematopoietic peptides. The main disadvantage of this class of peptides is their low stability with noninvasive administration methods, which limits the widespread use of hematopoiesis-regulated peptide drugs in medical practice. The aim of this work is to study novel peptidomimetics with hematopoietic activity sustained in invasive and oral administration. The activity of the leading compound cyclopeptide Cyclo-[Glu(Ile)-Glu(Trp)] (CP-88) was compared to that of the pharmaceutical preparation Stemokin in stimulating the population of committed colony-forming cells in intact and irradiated mice. CP-88 peptide increases the relative number of CD34+ cells in the blood and bone marrow, leading to expanded hematopoietic stem cells. CP-88 peptide, applied 48 h before bone marrow extraction, stimulates the population of committed colony-forming cells in the normal bone marrow by 33-37% above the normal level. In recipient mice injected with irradiated bone marrow, this peptide was restored practically to normal levels of colony-forming cells in a wide range of doses at intraperitoneal and oral administration. The toxicological results conclude that in humans, considering interspecies extrapolation, the CP-88 peptide can be practically safe with a single and course administration in doses of up to 100 μg/kg. The results of this investigation underscore the significant potential of CP-88 peptide as a hematopoiesis-regulated drug and instill optimism for its future application in medical practice.