Primary Study On The Radioprotection Effect And Its Mechanism Of Rosmarinic Acid Against Gamma Ray Induced DNA Damage

Recently,more and more research show that reactive oxygen species(ROS) play an important role in DNA damage induced by ionizing radiation(IR). What can get rid of free radical is named antioxidants. For several decades,the radioprotectants continually appear. Owing to their non- or lower-toxicity at pharmacological doses than synthetic radioprotectants,generous antioxidants source from natural products were more and more popular to be thought as a radioprotectant.Objective:To explore the effect of rosmarinic acid,a small-molecule natural product:rosmarinic acid,has been reported as an antioxidant on micronucleus formation rate of cells irradiated with cobalt-60γ-rays in vitro and in vivo,and to investigate the preliminary mechanism of action.Methods:V79 cells were treated with rosmarinic acid before irradiated 4.0Gy cobalt-60γ-rays,and the micronucleus rate in the cells was counted to explore rosmarinic acid as a radioprotectant;C57BL/6J mice were irradiated with 2Gy after with administration rosmarinic acid,and the micronucleus rate in polychromatic erythrocytes of bone marrow cells was counted to explore rosmarinic acid as a radioprotectant;The content of ROS in cells and the lever of glutathione (GSH) in bone marrow cells were messured by VICTORTMX5.Results:Firstly,the micronucleus rate of V79 cells was counted to prove rosmarinic acid against gamma ray induced micronucleus rate in vitro. We confirmed that the experiment used 4Gyγ-ray as the cell model of radiation injury in vitro. Radiation-induced micronucleus rate (23.65‰) of V79 cells could be reduced dependently by with administration rosmarinic acid. And the result of cellular toxicity test indicated that rosmarinic acid 200μM was nontoxic to the growth of cells. Secondly,The micronucleus rate in polychromatic erythrocytes of bone marrow cells was counted. We confirmed that the experiment used 2Gyγ-ray as the animal model of radiation injury in vivo. Radiation-induced micronucleus rate in polychromatic erythrocytes of bone marrow cells could be reduced dependently by with administration rosmarinic acid. It was more obvious before 2Gyγ-ray with administration rosmarinic acid than after 2Gyγ-ray with administration rosmarinic acid,and it could increase efficacy to appropriately prolong action time of rosmarinic acid. Mice received a daily oral of rosmarinic acid 100mg/kg for 7 consecutive days , and bone marrow micronucleus rate(6.50‰) could reduce to compare with radiation-induced (23.65‰),and it's lower than vitamin C(14.51‰).What′s more,primary study on the mechanism of rosmarinic acid against gamma ray induced DNA damage. Rosmarinic acid could reduce the content of ROS inV79 cells and increase the level of GSH in murine bone marrow cells. We infer that rosmarinic acid against gamma ray induced DNA damage may be connected with ROS and GSH.Conclusion:Radiation-induced micronucleus rate in cells could be reduced dependently by with rosmarinic acid. It was more obvious beforeγ-ray with administration rosmarinic acid than afterγ-ray with administration rosmarinic acid,and it could increase efficacy to appropriately prolong action time of rosmarinic acid. Primary study on the mechanism of rosmarinic acid against gamma ray induced DNA damage. Rosmarinic acid could reduce the content of ROS inV79 cells and increase the level of GSH in murine bone marrow cells. These results suggest that rosmarinic acid can be a high effective and low toxic radioprotectant.