Astragalus Polysaccharide Promotes Hematopoiesis in an Irradiated Mouse Model and Reduces Apoptosis of Hematopoietic Cells

Background: Huangqi (the dried root of Radix Astragali) is a notable Chinese herb that has been used to promote hematopoiesis for centuries. Astragalus polysaccharide (ASPS), a bioactive constituent extracted from Radix Astragali, may play an essential role for hematopoiesis. The objective of this study is to investigate the hematopoietic effects of ASPS in mouse models and explore underlying mechanism, which provides scientific basis for future applications.

Methods: An irradiation-induced myelosuppressive mouse model and colony-forming unit (CFU) assays were used to determine the in vivo hematopoietic effects of ASPS. The anti-apoptotic effects of ASPS were also examined by using annexin V, caspase-3, and JC-1 assays with flow cytometry in HL-60 cells.

Results: In the myelosuppressed mouse model, ASPS enhanced the recovery of platelet and red blood cell at day 21, and white blood cell at day 14. ASPS also promoted the CFU formation of all lineages (MK, GM, E, GEMM and F). Morphological study of bone marrow revealed that as compared to the control group, tri-lineage hematopoiesis was preserved in the ASPS- and TPO-treated group. Overall cellularity (MTC/area) of ASPS-treated group was similar to that of TPO. Furthermore, in-vitro study showed that 100 μg/ml of ASPS had maximum effect on CFU formation. ASPS also reduced apoptosis via inhibiting mitochondrial/Caspase-3 signal pathway.

Conclusions: ASPS may promote hematopoiesis in irradiated myelosuppressive mice by enhancing hematopoietic proliferation and inhibiting apoptosis of hematopoietic cells.