体外研究牛磺酸对氯化镉致DNA损伤的保护作用

Protective Effect of Taurine on DNA Damage Induced by Cadmium Chloride in vitro

[目的]通过体外实验初步探讨牛磺酸对氯化镉所诱导DNA损伤遗传毒性的保护作用机制。[方法](1)单细胞凝胶电泳技术检测DNA损伤;(2)体外清除自由基检测。实验分5组:①阴性对照组,②氯化镉组:分别加入终浓度为10、20、40μmol/L的氯化镉。③同时处理组:终浓度为100mmol/L的牛磺酸与氯化镉10、20、40μmol/L同时加入。④后处理组:先加入终浓度为10、20、40μmol/L的氯化镉,45min后加入100mmol/L的牛磺酸。⑤预处理组:先加入终浓度为100mmol/L的牛磺酸,45min后加入10、20、40μmol/L的氯化镉。所有的处理组均培养72h。[结果]10μmol/L氯化镉即可引起细胞DNA损伤,并随着氯化镉浓度的增加而加重,呈一定的剂量-反应关系。用100mmol/L牛磺酸预处理组和同时用牛磺酸和氯化镉处理组的DNA损伤率明显低于相应的单纯氯化镉组(P<0.05),而羟自由基清除率明显高于单纯氯化镉组(P<0.05);牛磺酸预处理组的DNA损伤率明显低于同时处理组(P<0.05),而羟自由基清除率也明显高于同时处理组(P<0.05)。后处理组DNA损伤率与单纯氯化镉组比较差异无显著性。[结论]牛磺酸在体外对氯化镉引起的DNA损伤有预防作用。

[ Objective ] To investigate protective mechanism of taurine（ Tau ） for DNA damage by cadmium chloride （ CdCl2 ） in vitro. [ Methods ] （ 1 ） DNA damage was assessed by single cell gel electrophoresis （ SCGE ）. （ 2 ） Effects of free radical cleaning were detected in vitro. The whole blood cells of rat were divided into five groups： ①Control group; ②Cd group： CdCl2（ 10, 20, 40 μmol/L ）; ③Co-treatment group： corresponding CdCl2 and Tau（ 100 mmol/L ）were given simultaneously; ④ Post-treatment group： the cells were treated with CdCl2 and incubated for 45 min, then treated with Tau（ 100 mmol/L ）. ⑤Pretreatment group： the cells were treated with Tau（ 100 mmol/L ） and incubated for 45 min, then treated with CdCl2. All treatments were incubated for 72 h. [ Results ] 10 μmol/L cadmium chloride was able to induce DNA damage in vitro in a dose-dependent manner. DNA damage rates in pretreatment and co-treatment groups with 100 mmol/L Tau were significantly lower than in group treated with CdCl2 alone （ P 〈 0.05 ）. Hydroxy radical scavenge rates in pretreatment and co-treatment group were significantly increased compared with group treated with CdCl2 alone （ P 〈 0.05 ）. DNA damage rates in pretreatment group were significantly lower than in co-treatment group（ P 〈 0.05 ）, and hydroxy radical scavenge rates in pretreatment group were significantly increased compared with co-treatment group（ P 〈 0.05 ）. DNA damage rates in post-treatment group had no significant difference compared with group treated with CdCl2 alone. [ Conclusion ] Taurine possesses protective activity against cadmium-induced DNA damage and hydroxy radical scavenging activity in vitro.