Abstract: Objective To establish the mice model of radiation-induced lung injury, and to study the curative effect of quercetin on it. Methods Eighty BALB/c mice were randomly assigned to 6 groups and treated as follows: mice in normal control group(n=8)were intravenously injected with 4 mg/mL saline; mice in quercetin group(n=8)were intravenously injected with 4 mg/mL quercetin; mice in simply irradiated group(n=16)received a single 10 Gy dose of radiation; mice in quercetin(4 mg/mL)intervention group received a single 10 Gy dose of radiation and were intravenously injected with 4 mg/mL quercetin; mice in quercetin(2 mg/mL)intervention group received a single 10 Gy dose of radiation and were intravenously injected with 2 mg/mL quercetin; mice in amifostine intervention group received a single 10 Gy dose of radiation and were intravenously injected with 4 mg/mL amifostine. From week 1 to week 8 after irradiation, lung tissues in both sides of mice were harvested for further experiments. The expressions of marker proteins of mitogen-activated protein kinase(MAPK), p38, SAPK/JNK and p44/p42, were assayed by immunohistochemistry and Western blotting. Results Compared with the simply irradiated group, the quercetin(4 mg/mL)intervention group and quercetin(2 mg/mL)intervention group showed the alleviative inflammation, the decreased positive gradings and expressions of p38, SAPK/JNK and p44/p42 proteins in lung tissues. Conclusion Quercetin signifi- 山 东 大 学 学 报 (医 学 版)57卷5期 -程健,等.槲皮素通过抑制丝裂原活化蛋白激酶信号通路表达减轻小鼠放射性肺炎 \=-cantly attenuates radiation-induced lungs injury in mice, which may be associated with the inhibition of MAPK signal pathway.

Key words: Quercetin, Radiation-induced lung injury, Mitogen-activated protein kinase