茶多酚对铀矿尘致支气管上皮细胞损伤保护作用

Protective effects of tea polyphenols on oxidative damage induced by uranium-mineral dust in BEAS-2B cells

目的探讨铀矿尘诱发细胞氧化损伤及茶多酚(tea polyphenols,TPs)的保护作用。方法以人支气管上皮细胞(BEAS-2B)为靶细胞,分别用辣根过氧化物酶介导的酚红氧化法、细胞色素C还原法和番红花红褪色法测定细胞外液过氧化氢、超氧阴离子和羟自由基含量;细胞内H2O2和O2.-分别用2,7-二氯荧光黄双乙酸盐和氢化乙锭标记,荧光法测定荧光产物2,7’-二氯荧光黄和溴乙锭荧光强度,多核细胞法体外研究细胞次黄嘌呤磷核糖基转移酶基因(HPRT)突变,自动生化仪测量乳酸脱氢酶。结果 BEAS-2B细胞经铀矿尘染毒后,细胞内和细胞外ROS含量明显增高,高剂量组细胞上清中超氧阴离子为(10.48±0.75)μmol/L,茶多酚保护组为(9.31±0.71)μmol/L;细胞乳酸脱氢酶溢出,HPRT突变率升高,高剂量组细胞突变率为1.092‰,茶多酚保护组为0.925‰,TPS对铀矿尘诱发的损伤有明显的抑制作用。结论铀矿尘可造成细胞的氧化损伤,TPS通过清除活性氧而达到保护作用,可为铀矿尘损伤的防护提供有效措施。

Objective To observe oxidative damage of human bronchial epithelial cells（BEAS-2B） induced by uranium-mineral dust（UD） and protective effect of tea polyphenols（TPs）.Methods The measurement of extracellular superoxide anions（O2·-） was based on the reduction of ferricytochrome C.The quantitation of extracellular hydrogen peroxides（H2O2） was based on horseradish peroxidase-dependent oxidation of phenol red.The determination of extracellular hydroxyl radicals（·OH） was based on the decoloration of safranine T.Ethidium bromide,2,7＇-dichlorofluorescein,and fluorescent products of membrane-permeable dyes-hydroethine and 2,7＇-dichloroflurescein diacetate were used to monitor intracellular production of O2· and H2O2,respectively.The content of lactate dehydrogenase was measured by AUTOLAB.Cytokinesis-block（CB） assay was used to detect the mutation frequency of hyloxanthine-guanice phosphoribosyl tranferase（HPPT）.Results The reactive oxygen species（ROS） production including H2O2,O2·-,and ·OH induced by UD increased remarkably in BEAS-2B cells.Superoxide anion was 10.48±0.75 μmol/L in high dose group and 9.31±0.71 in TPs group.The mutation frequency（MF） of HPRT gene increased.MF of HPRT gene was 1.092‰ in high dose group and 0.925 ‰ in TPs group.The changes could be inhibited effectively by 250mg/L of TPs.Conclusion UD causes oxidative damage in BEAS-2B cells.Through removing active oxygen,TPs can inhibit oxidative damage of UD.It can provide an effective measure to the protection of UD