牛磺酸对苯并(a)芘致L-02细胞损伤保护作用

Effect of taurine on micronuclei formation of L-02 cells exposed to benzo(a) pyrene

目的研究牛磺酸对苯并(a)芘(B(a)P)致人胚肝细胞(L-02细胞)染色体损伤的保护作用。方法以L-02细胞为靶细胞,按完全随机设计分成5组:(1)空白对照组;(2)溶剂对照组;(3)B(a)P染毒组:设12.5,25,50μmol/L3个剂量染毒细胞;(4)牛磺酸组:设1.0,2.0,4.0mmol/L3个浓度,加入培养体系后继续培养24h;(5)牛磺酸预防组:L-02细胞先以3个不同浓度的牛磺酸预处理24h,再加入25μmol/L的B(a)P培养24h。各组均设3个平行样。收获细胞后用微核实验检测染色体损伤,计算微核率和核分裂指数。结果牛磺酸单独作用于L-02细胞时,与空白对照组比较,中、高浓度牛磺酸诱导的微核率降低,核分裂指数增高,差异有统计学意义。从低到高3个剂量B(a)P单独染毒L-02细胞诱导的微核率为(34.67±2.52),(45.33±4.16),(60.00±7.21)%。核分裂指数分别为1.326±0.034,1.228±0.006,1.148±0.012,与溶剂对照组比较微核率升高,核分裂指数降低,差异有统计学意义,且两者均呈明显的剂量-反应关系。低、中、高浓度牛磺酸预防组诱导的微核率对应为(30.33±3.51),(25.67±1.53)和(23.00±1.00)%。均比单纯25μmol/LB(a)P染毒组诱导的微核率降低,差异有统计学意义。低、中、高浓度牛磺酸预防组对应的核分裂指数为1.455±0.011,1.474±0.015和1.1492±0.013,比单纯25μmol/LB(a)P染毒诱导的核分裂指数高,差异有统计学意义,且两者均呈剂量-反应关系。结论B(a)P能诱导肝细胞染色体损伤,且存在明显的剂量-反应关系;牛磺酸预处理对B(a)P引起的肝细胞毒性具有明显保护作用。

Objective To investigate the protective effect of taurine on chromosome damage of human derived fetal hepatocytes（L-02 cells） induced by benzo（a）pyrene（B（a）P）.Methods L-02 cells were randomized divided into 5 groups：blank control group（Ⅰ）;solvent control group（Ⅱ）;B（a）P group（Ⅲ）：exposed to B（a）P at concentration of 12.5,25,50μmol/L,in culture medium for 24 hours;taurine group（IV）：exposed to taurine at the concentration of 1.0,2.0,4.0mmol/L in culture medium for 24 hours;taurine preventive group（V）：exposed to taurine at three different concentration in culture medium for 24 hours and treated further for 24 hours by adding 25μmol/L B（a）P into the culture media.Chromosome damage was detected by cytokinesis-block micronucleus assay（CBMNT）.The frequencies of MN（‰） and nuclei division index（NDI）were calculated.Results Compared with the blank control,taurine at concentrations of 2.0 and 4.0mmol/L induced a significant decrease in MN frequencies and an increase in NDI in L-02 cells.Compared with the solvent control,B（a）P at concentrations of 12.5,25 and 50μmol/L induced a significant enhancement of MN frequencies and a reduce in NDI.Compared with the 25μmol/L B（a）P group,pretreatment with taurine could induce a significant decrease in MN frequencies and an increase in NDI in L-02 cells.The reductions of MN frequency and NDI showed a dose-effect manner.Conclusion B（a）P could induced chromosome damage in dose-effect manner.Taurine could play a protective role in hepatic cytotoxicity induced by B（a）P.