Objective: To study the influence of Yisui Shengxue granule on the cell cycle of bone morrow cells(BMCs)in mice irradiated by 60Co-γ rays

and to explore its mechanism in hematopoietic regulation. Method: Seventy-eight male Kunming mice were randomly divided into six groups

normal control group

model group

G-CSF group

low-dose

middle-dose and high-dose Yisui Shengxue granule group.Except normal control group

mice were established by 60Co-γ ray in other five groups.2 days before modeling

mice in low-dose

middle-dose and high-dose Yisui Shengxue granule group received 12

6

3 g·kg-1·d-1 Yisui Shengxue granule ig respectively

mice in other groups received the same volume distilled water.The 2nd day after modeling

mice in G-CSF group received 30 μg·kg-1·d-1 recombinant human granulocyte colony-stimulating factor by injection

mice in other groups received the same way as before modeling

the course lasted 14 days.Cell cycle distribution of BMCs was detected by flow cytometry(FCM) analysis. Result: The data showed that

compared with normal control group

the BMC population in model group and all the Yisui Shengxue granule groups obviously decreased in G0/G1 phase(all P<0.001)

significantly increased in S phase and G2/M phase(all P<0.001)

and their proliferation index (PI) were obviously elevated (all P<0.001).Compared with model group

the BMC population in high-dose Yisui Shengxue granule group obviously decreased in G0/G1 phase (P<0.05)

its PI was obviously elevated (P<0.05)

and the BMC population in all the Yisui Shengxue granule groups obviously increased in S phase (all P<0.05). Conclusion: These results suggest that Yisui Shengxue granule can promote the proliferation of BMCs in mice irradiated by 60Co-γ rays by activating the entry of G0/G1 phase into S phase.