Eriocalyxin B confers radioprotection of hematopoietic stem and progenitor cells via granulocyte colony-stimulating factor induction.

Ionizing radiation induces injury in multiple organs, particularly in the hematopoietic system; however, the implementation of effective preventive measures for hematopoietic acute radiation syndrome (H-ARS) is still limited. In this study, we investigated the radioprotective effects of a natural diterpenoid, eriocalyxin B (EriB), on hematopoietic injury associated with ARS in mice exposed to total body irradiation (TBI). The results suggested that EriB effectively provides radioprotection against hematopoietic injury, as evidenced by improved survival, increased peripheral blood recovery, and accelerated regeneration of hematopoietic stem and progenitor cells (HSPCs) in irradiated mice. EriB also protects against radiation-induced persistent bone marrow suppression and augments hematopoietic reconstitution potential even at two months after irradiation. Further results demonstrated that EriB is capable of effectively reducing ROS levels, thereby safeguarding HSPCs from apoptosis and DNA damage after irradiation exposure. Importantly, EriB protects against radiation-induced hematopoietic injury, at least in part through the induction of G-CSF. Finally, EriB had no radioprotective effect on post-radiation Raji lymphoma cells in mice after irradiation. These findings suggest that the natural product EriB may be a promising candidate for protection against HSPC injury after radiation exposure.