Davis Thomas A, Clarke Tara K, Mog Steven R, Landauer Michael R
Naval Medical Research Center, Silver Spring, Maryland, USA.
Int J Radiat Biol. 2007 Mar;83(3):141-51. doi: 10.1080/09553000601132642.
Genistein, a non-toxic isoflavone from soybeans, has immunomodulating and radioprotective properties. In this study we investigated the mechanism for genistein-induced radioprotection by evaluating the recovery of bone marrow cells and peripheral blood hematology in lethally irradiated mice.
CD2F1 male mice received a single subcutaneous injection of genistein (200 mg/kg) 24 h prior to a lethal, total body irradiation dose (8.75 Gy) of cobalt-60 gamma radiation. Survival and hematopoietic reconstitution were evaluated over nine weeks post-irradiation. Hematopoietic progenitor colony-forming cell assays were used to assess the reconstitution of bone marrow after radiation-induced myelosuppression.
A total of 97% of genistein-treated mice survived after 30 days while 31% of vehicle-treated and 0% of untreated mice survived. The improvement in survival was related to accelerated neutrophil and platelet recovery, resulting from earlier and more pronounced multilineage, hematopoietic progenitor cell reconstitution in the femoral marrow compartment. Myeloid and erythroid progenitor cell numbers at day 15 post-irradiation were 6-fold to 20-fold higher in genistein-treated animals than in control animals.
These results demonstrate that a single subcutaneous administration of genistein 24 h before irradiation provides significant radioprotection to the hematopoietic progenitor cell compartment.
金雀异黄素是一种来自大豆的无毒异黄酮，具有免疫调节和辐射防护特性。在本研究中，我们通过评估致死性照射小鼠骨髓细胞的恢复情况和外周血血液学指标，来研究金雀异黄素诱导辐射防护的机制。
CD2F1雄性小鼠在接受60钴γ射线致死性全身照射剂量（8.75 Gy）前24小时，单次皮下注射金雀异黄素（200 mg/kg）。在照射后9周内评估小鼠的存活率和造血重建情况。采用造血祖细胞集落形成细胞测定法评估辐射诱导骨髓抑制后骨髓的重建情况。
30天后，接受金雀异黄素治疗的小鼠中有97%存活，而接受赋形剂治疗的小鼠存活率为31%，未治疗的小鼠存活率为0%。存活率的提高与中性粒细胞和血小板恢复加速有关，这是由于股骨骨髓区多谱系造血祖细胞重建更早且更明显。照射后第15天，接受金雀异黄素治疗的动物的髓系和红系祖细胞数量比对照动物高6至20倍。
这些结果表明，照射前24小时单次皮下注射金雀异黄素可为造血祖细胞区提供显著的辐射防护。
