Objective      To investigate the effect of total saponins of Panax ginseng (TSPG) on irradiationinduced bone marrow hematopoietic cell injury and senescence.        Methods      Forty male C57BL/6 mice were divided into four groups including a control group

an irradiation (IR) group

an IR+T50 group (TSPG 50 mg/kg) and an IR+T200 group (TSPG 200 mg/kg). The mice were pretreated with TSPG for 3 days

then were irradiated by 6.5 Gy X-ray

and were further treated with TSPG for 7 days. Blood routine examination

bone marrow mononuclear cell (BM-MNC) counting and hematopoietic cell colony forming unit (CFU) counting were performed. The cell cycle of BM-MNC was determined by flow cytometry

and the senescence of cells from CFU was evaluated by senescence-associated β-galactosidase (SA-β-gal) staining and the expression of p16

Ink4a

protein.       Results      Compared with the IR group

the numbers of white blood cell (WBC) (2.19±0.87)

BM-MNC and CFU significantly increased in the IR+T200 group (P0.05)

but the red blood cells and platelets showed no significant changes. The numbers of the cells at G

1

phase decreased in a dose-dependent manner

and the cells from the CFU of the IR+T200 group exhibited a decreased expression of SA-β-gal and p16

Ink4a

(P0.05).       Conclusion      TSPG 200 mg/kg may alleviate irradiation-induced bone marrow hematopoietic cell injury and senescence.