To observe the therapeutic effect of icariin derivative YS-10 on testicular radiation injury，and to explore its potential mode of action.

Eighteen 10-week-old male SD rats were selected and randomly divided into three groups，six in each group，which were blank control group（Control group），radiation injury group（Model group）and YS-10 treatment group（YS-10 group）.The testicular index and serum testosterone content of each group were detected.HE staining was used to observe the pathological changes of testicular tissue.Histochemical kit method was used to detect the levels of superoxide dismutase（SOD），malondialdehyde（MDA）and reduced glutathione（GSH）in testicular tissue.GC-2 cells were selected and divided into Control group，Model group and YS-10 group.Mouse spermatocyte cell line GC-2 cells were induced by 8 Gy X-ray irradiation（2 Gy/min）for 24 h to construct a radiation injury model，and the treatment group was also intervened with YS-10.CCK-8 was used to detect cell viability in each group.Fluorescent probe was used to detect reactive oxygen species（ROS）and Western blot was used to determine the levels of Kelch-like ECH-associated protein 1（Keap1），GSH，nuclear factor erythroid-derived-2-like 2（Nrf2）and heme oxygenase-1（HO-1）in GC-2 cells were determined by Western blot.

Animal experiments confirmed that compared with those in the Control group，the testicular index and testosterone secretion level of rats in the Model group were significantly reduced（P<0.05），the MDA content in testicular tissues was elevated，and the levels of SOD and GSH were reduced（P<0.05）.Compared with that of the Model group，the testicular index of the YS-10 group increased from about 0.81% to 1.25%.The testosterone secretion level increased from about 4.203 U/mg to 5.042 U/mg（P<0.05）.The MDA content decreased from about 36.559 nmol/g to 26.882 nmol/g，and the SOD activity of the testicular tissue increased from about 14.727 U/mg increased to 18.417 U/mg，and GSH content approximately increased from 20.21μmol/L to 32.922μmol/L（P<0.05）.The cellular experiments confirmed that compared with that of the Control group，the viability of GC-2 cells in the Model group was significantly decreased（P<0.01）.The fluorescent probe showed that the average fluorescence intensity of ROSwas increased about 5-fold（P<0.01），the protein expression of Keap1 was elevated about 1.35-fold，and the protein expressions of Nrf2 and HO-1 were decreased about 1.46-fold each（P<0.05）.Compared with that in the Model group，the viability of GC-2 cells in the YS-10 group approximately increased from 73.564% to 86.427%（P<0.01），the average fluorescence intensity of ROS approximately decreased from 255 to 78.378（P<0.01），the level of Keap1 protein expression approximately decreased from 0.951 to 0.73，the level of Nrf2 protein expression approximately increased from 0.498 to 0.805，and HO-1 protein expression level approximately increased from 0.492 to 0.599（P<0.05）.

YS-10，a derivative of icariin，can effectively alleviate radiation-induced oxidative stress and protect testicular tissue to reduce the effects of radiation.The mechanism of action may be achieved through the Keap1/Nrf2/HO-1 signaling pathway.