The Radiation Protection And Mechanism Of Amentoflavone

Objective To study radiation protection mechanism of amentoflavone(AMF)Methods 1.C57BL/6 mice pretreated with AMF by peritoneal injection, then C57BL/6 mice were injured by 60 Co γ-rays for total body irradiation. The 30 days survival rate and the average survival days were observed after irradiated with 7.5 Gy lethally 60Coγ–rays. The apoptosis of bone marrow cells was evaluated by using Tunel and DAPI stain, cell cycle was determined by PI stain and flow cytometry, the expression of Tnfaip2 was determined by western blot. After 3 Gy irradiation, the proliferation ability of bone marrow cells was evaluated by using cell colony culture, the numbers of HSCs was tested by flow cytometry with CD34 and CD117 antibody marked. 2. CD117+ cells from C57BL/6 mice bone marrow separated and cultured by MACS. Primary bone marrow cells of C57BL/6 mice were cultured. Two kinds of cells pretreated with AMF for 12 hours before 12 Gy 60 Co γ-rays radiation were given. 6 h and 12 h after radiation, apoptosis of primary bone marrow cells was evaluated by using Hoechst 33258 stain, apoptosis of CD117+ cells was evaluated by Tunel and DAPI stain, cell cycle was determined by PI stainand and flow cytometry, the level of TNF-α was tested by ELISA, the expression of Tnfaip2 gene was detected by RT-PCR.Results The results showed that AMF could increase 30% survival rate of C57BL/6 mice after 7.5 Gy radiated and average survival days were increased. AMF decreased cell apoptosis of C57BL/6 mice bone marrow cells, primary bone marrow cells and CD117+ cells. AMF increased the proliferation ability of bone marrow cells after radiation, but the number of hematopoietic stem cells(HSCs) was not well protected. AMF showed an inhibition to TNF-α production after radiation.Conclusion The study suggests that AMF has a certain anti-radiation effect and may act as a radioprotector. It may play a role in the protection of apoptosis by inhibiting the expression of TNF-α and regulating the disorder of the cell cycle after radiation.