S-异戊烯基-L-半胱氨酸对辐射诱导小鼠DNA损伤的保护作用

Protective Effect of S-isopentenyl-L-cysteine against DNA Damage in Irradiated Mice

目的采用动物急性辐射损伤模型评估S-异戊烯基-L-半胱氨酸对辐射诱导DNA损伤的保护作用。方法将40只ICR小鼠随机分为空白对照组、1.0Gy伽马射线照射组、1.0Gy伽马射线照射联合S-异戊烯基-L-半胱氨酸给药组、7.2Gy伽马射线照射组、7.2Gy伽马射线照射联合S-异戊烯基-L-半胱氨酸给药组5组,每组8只,采用外周血淋巴细胞彗星实验和骨髓嗜多染红细胞微核实验检测1.0Gy和7.2Gy伽马射线照射后不同处理组小鼠DNA双链断裂情况。结果7.2Gy伽马射线照射组小鼠外周血淋巴细胞的尾部DNA百分含量、尾长、尾矩和Olive尾矩明显高于空白对照组(P均<0.01)。7.2Gy伽马射线照射联合S-异戊烯基-L-半胱氨酸给药组的DNA百分含量、尾长、尾矩和Olive尾矩明显低于7.2Gy伽马射线照射组(P均<0.05)。1.0Gy伽马射线照射组和7.2Gy伽马射线照射组的微核率明显高于空白对照组(P均<0.01);照射前给予S-异戊烯基-L-半胱氨酸可明显降低1.0Gy与7.2Gy伽马射线所致的微核率,分别由(39.5000±3.3141)‰降至(28.1667±4.1345)‰(P=0.033)和(76.5000±4.6242)‰降至(22.8333±3.6553)‰(P=0.000)。1.0Gy伽马射线照射组和7.2Gy伽马射线照射组的骨髓嗜多染红细胞(PCE)与正染红细胞(NCE)的比值(PCE/NCE)明显低于空白对照组(P均<0.05);照前给予S-异戊烯基-L-半胱氨酸可明显升高相应剂量组的PCE/NCE值(P均<0.05)。结论 S-异戊烯基-L-半胱氨酸具有良好的DNA辐射损伤防护作用。

Objective To evaluate the protective effect of S-isopentenyl-L-cysteine,a new cysteine derivative,on DNA damage induced by radiation by using acute radiation injury animal models. Methods Forty ICR mice were randomly divided into five groups： the control group,1. 0Gy gamma irradiation group,1. 0Gy gamma irradiation combined with S-isopentenyl-L-cysteine group,7. 2Gy gamma irradiation group,and 7. 2Gy gamma irradiation combined with S-isopentenyl-L-cysteine group,with 8 mice in each group. The comet assayand bone marrow polychromatic micronucleus experiments were performed to evaluate the double-strand DNA breaks in ICR mice exposed to 1. 0 and 7. 2Gy gamma-ray,respectively. Results The tail DNA percentage,tail length,tail moment, and olive tail moment of peripheral blood lymphocytes in 7. 2Gy gamma irradiation group were significantly higher than that of the control group（ P〈0. 01）. And it was also observed that above experimental indexes of 7. 2Gy gamma irradiation combined with S-isopentenyl-L-cysteine group was significantly less than that of 7. 2Gy gamma irradiation group（ P〈0. 05）. In addition,the micronucleus rate of 1. 0Gy gamma irradiation group and 7. 2Gy gamma irradiation group were both significantly higher than in the control group（ P〈0. 01）. In addition,in mice given S-isopentenyl-L-cysteine before irradiation,the micronucleus rate of ICR mice exposed to 1. 0 and 7. 2Gy gamma-ray decreased from（ 39. 5000 ± 3. 3141） ‰ to（ 28. 1667 ±4. 1345） ‰（ P = 0. 033） and from（ 76. 5000 ± 4. 6242） ‰ to（ 22. 8333 ± 3. 6553） ‰（ P = 0. 000）,respectively. The bone marrow polychromatic micronucleus experiment indicated that the value of polychromatic erythrocyte（ PCE） / normochromatic erythrocyte（ NCE） of ICR mice exposed to 1. 0 and 7. 2Gy gamma-ray was less than the control group（ P〈0. 05）. Meanwhile,after irradiating by certain dose,the value of PCE / NCE in mice given S-isopentenyl-L-cysteine before irradiation was significantly higher than the corresponding groups（ P〈0. 05）. Conclusion S-isopentenyl-L-cysteine has a good protective effect against DNA damage induced by radiation.