Objective To observe the effect and the mechanisms of ferulic acid on radiationinduced damage of mice peripheral blood and bone marrow hematopoietic function.Methods Ninety-six mice were randomly divided into sham irradiation group,irradiation group,positive drug group and 10,30,90 mg·kg-1 ·d-1 ferulic acid group,16 mice per group.Mice were exposed to 3.5 Gy γ-rays 24 h after first drug taken.Then,mice were given drugs for 7 d after irradiation.White blood cells in peripheral blood of 10 mice per group were counted 2 d before irradiation and 3,7,10,15 and 22 days after irradiation.The bone narrow of the other six mice was taken to detect the micronuclei frequency of polychromatic erythrocyte,the hematopoietic progenitor cell colony formation capacity,Thbd and HMGB1 protein expressions in mice bone marrow on the seventh day after irradiation.Results Compared with the irradiation alone group,the treatment of mice with ferulic acid 90 mg· kg-1 · d-1 increased the number of white blood cells in peripheral blood at 3,10,15 and 22 d after irradiation (t =2.267,2.399,1.945,2.828,P ＜ 0.05).Treatment with mice with ferulic acid 90 mg· kg-1 · d 1 decreased the micronuclei rate of erythrocytes in irradiated bone marrow (t =4.013,P ＜ 0.05),increased the clone numbers of CFU-E,BFU-E and CFU-GM of hematopoietic progenitor cells (t =2.366,2.953,3.115,P ＜0.05),improved the relative expression of the Thbd protein in bone marrow and the HMGB1 protein in nuclear (t =17.75,23.39,P ＜ 0.01).Conclusions Ferulilc acid could protect the bone marrow hematopoietic of mice exposed to irradiation by regulating the expressions of Thbd and HMGB1 protein,and then accelerate the peripheral cells recovery.

OBJECTIVE: To observe the in vivo metabolism and distribution characteristics of nano-cerium oxide( nanoCeO_2) in rats,and to explore the radio-protective effect of nano-CeO_2. METHODS: i) A total of 18 specific pathogen free( SPF) SD rats were randomly divided into 3 groups. Rats of experiment group and CeO_2 blood group were gavaged with1. 0 g/kg body weight( bw) nano-CeO_2 suspension. Rats of control group were gavaged with double distilled water( DDW)in equal volume. At different time-points after treatment,venous blood was collected from the rats' eye socket in CeO_2 blood group,meanwhile urine and excrement of rats of experiment group were also collected. Organ and tissue samples of experiment group and control group were collected 24. 0 hours after treatment. The concentrations of cerium in biological samples were detected by inductively coupled plasma mass spectrometry. ii) A total of 72 SPF BALB/c mice were randomly divided into 6 groups. Mice of low-,medium-and high-dose groups were gavaged with 100,300 and 900 mg/kg bw nano-CeO_2 suspension respectively. Mice of negative control group,irradiation control group and drug positive control group were gavaged with DDW in equal volume once daily. After 14 days,mice of the other 5 groups were exposed by60Coγ-rays once with 3. 5 Gy( 1 Gy/min) except the negative control group. Mice of drug positive control group were given intraperitoneal injection with 200 mg/kg bw amifostine half an hour before irradiation. After exposure,mice were treated by the above gavages once daily. After 3 and 8 days,6 mice were randomly selected to collect the peripheral blood for the count of white blood cell( WBC) and lymph cell measuring. RESULTS: i) The cerium concentration in blood reached peak value in 4. 0 hours after exposure of nano-CeO_2,and the cerium concentration of urine and excrement reached maximum in8. 0 hours after exposure. After 24. 0 hours of exposure,the cerium concentration of brain in experiment group was higher than that of control group( P < 0. 05). Among the experiment group,the cerium concentrations of sternum,duodenum and brain were higher than that of kidney and heart( P < 0. 05),meanwhile the cerium concentrations of thymus and lung were higher than that of kidney( P < 0. 05). ii) There was no statistical difference in interactive effect of WBC count and lymph cell counts between nano-CeO_2 exposure ways and time( P > 0. 05). The WBC counts of the low-and medium-dose groups were lower than those of the negative control group and the drug positive control group( P < 0. 05). The WBC count of high-dose group was lower than those of irradiation control group,drug positive control group and medium-dose group( P <0. 05). The lymph cell counts of the 3 dose groups were lower than that of drug positive control group( P < 0. 05).CONCLUSION: The nano-CeO_2 is mainly cumulated in organs such as sternum,duodenum,brain,thymus and lung. After induced by radiation,nano-CeO_2 has a certain degree of promotion role in increasing the WBC counts.