银杏叶黄酮抗辐射效应研究

THE RADIOPROTECTIVE EFFECT OF FLAVONOIDS FROM GINKGO BILOBA LEAVES

目的:研究银杏叶中黄酮的抗辐射作用。方法:以碱性水提取法从银杏叶中分离出总黄酮(GBF),调配成低剂量(10 mg/100 ml)、中剂量(20 mg/100 ml)、高剂量(100 mg/100 ml)水溶液,分别给小鼠灌胃,10 d后,以总剂量8.5 Gy 60Co-γ射线整体辐射,再灌胃10 d,观察30 d存活率。另取小鼠,分六组(低、中、高GBF剂量组,辐射对照组,正常对照组,及环磷酰胺组),分别灌胃低、中、高剂量GBF水溶液,另三组灌胃蒸馏水,连续11 d后,低、中、高剂量GBF组及辐射对照组以总剂量1.0 Gy γ射线照射,再灌胃7 d,灌胃停止后D21 测小鼠骨髓微核率及精子畸变率及淋巴细胞测转化率。结果:低、中、高剂量GBF水溶液可分别提高辐射小鼠存活率31.7 %,25.3 %和26.5 %( P<0.05),低剂量GBF使淋巴细胞转化率显著提高(P<0.01),骨髓微核率及精子畸变率有一定程度降低。结论:低剂量银杏叶黄酮具有较强的抗辐射作用,其作用机制与提高小鼠免疫力有关。

Objective: To study the radioprotective effect of flavonoids from Ginkgo biloba leaves(GBF). Methods: Three water extracts of GBF were prepared (low dosage 10 mg/100 ml, medium dosage 20 mg/100 ml and high dosage 100 mg/100 ml) and orally administered to mice . After 10 d, the mice were exposed to 8.5Gy -rays. After another 10 d of oral administration, the survival rates were recorded in 30 d. In another experiment, six groups of mice (three GBF groups, radiation control, normal control and cyclophosphamide group) were arranged. The first three groups were orally administered with low, medium and high dosage of GBF respectively for 11d; the other three groups with distilled water. Then the three GBF groups and radiation group were exposed to 1.0Gy -rays. Then they were orally administered again in the following 7d . Micronucleated polychromatic erythrocytes in bone-marrow and sperms (AFS) in mice were observed on the 21st day after termination of oral administration. Proliferation rates of lymphocyte (PRL) were determined in the three GBF groups and normal control. Results: Low, medium and high dosage of GBF increased the survival rates by 31.7%, 25.3% and 26.5% respectively(P<0.05), Low dosage of GBF obviously improved PRL (P<0.01), and decreased MF and AFS to some extent, as compared with radiation control. Conclusion: GBF has remarkable radioprotective effect. Its mechanism is related to regulation of immune function.