Abstract: Abstract: Objective To observe the protective effect of anthocyanin on irradiation induced bone marrow c- kit positive cell injury, and further explore its possible mechanism. Methods Mouse bone marrow c-kit positive cells were collected by cell sorting method. There were 2 groups: control group and anthocyanin group, which were sub-divided into three groups and received 0 Gy, 1 Gy and 4 Gy irradiation respectively. The control group was added 700 μL cell suspension and an equal volume of serum-free hematopoietic stem/progenitor cell culture medium. The 2×10- 5 mol/L anthocyanin was co-cultured with mouse bone marrow c-kit positive cells of anthocyanin group half an hour before irradiation exposure, then cells were cultured for 18 hours under the conventional culture conditions (37 ℃， 5%CO2). Mouse c-kit positive cell viability was measured by bioluminescence, and which was reflected by relative light units (RLU). The ability of colony-forming units was reflected by CFU-GM. The reactive oxygen species (ROS) level and mean fluorescence intensity (MFI) of γ-H2AX were detected by flow cytometry. Results Compared to un-irradiated control group, the cell viability and the number of CFUGM were decreased significantly, while the ROS level and MFI of γ-H2AX were increased in c-kit positive cells irradiated with 1 Gy and 4 Gy (P < 0.05). Compared to 1 Gy and 4 Gy irradiation groups, c-kit positive cell viability and the number of

Key words: bone marrow, c-kit positive cell, anthocyanin, ros, DNA damage