Radiation protection effects of Vam3 on mouse thymocyte in vitro

The aim is to observe the protective effect of Vam3 on irradiation-induced injury of thymocytes isolated sterilely from mice. The thymocytes were divided into 6 groups: control group, resveratrol group, Vam3 group, irradiation group, irradiation with resveratrol group and irradiation with Vam3 group. Except the control group, resveratrol group and Vam3 group, the rest groups were exposed to radiation at a single dose of 4 Gy γ-rays from ¹³⁷Cs after 30 min treatment by vehicle and tested drug, respectively. The thymocytes' viability was measured by bioluminescence; the level of thymocytes' reactive oxygen species (ROS) was measured by DCFH-DA; the level of thymocytes' γ-H2AX was measured by fluorescent antibody labeling; the early apoptosis was detected by FITC-Annexin V and PI labelling using flow cytometry (FCM) after radiation. Compared with control group, the thymocytes' cell viability decreased obviously after irradiation, and the level of cell ROS, γ-H2AX and early apoptosis cell increased. By comparing the resveratrol group and Vam3 group with the irradiation group, we can find that Res and Vam3 could reduce the decrease of thymocytes' cell viability and inhibit the increase of ROS, γ-H2AX and early apoptosis cell induced by irradiation. The comparison between irradiation with resveratrol group and irradiation with Vam3 group showed that the effects of Vam3 in increasing cell viability, decreasing the level of ROS and γ-H2AX and lowering the early apoptosis rate were more obvious than resveratrol. It can be concluded that Vam3 performs better than resveratrol in the protection of mice thymocytes against the acute radiation injury. (authors)