Sugiyama M, Tsuzuki K, Matsumoto K, Ogura R
Department of Medical Biochemistry, Kurume University School of Medicine, Japan.
Photochem Photobiol. 1992 Jul;56(1):31-4. doi: 10.1111/j.1751-1097.1992.tb09598.x.
The effect of pretreatment with vitamin E on cytotoxicity, DNA single strand breaks, and chromosomal aberrations as well as on mutation induced by ultraviolet-B light (UV-B) was investigated in Chinese hamster V-79 cells. Cellular pretreatment with non-toxic levels of 25 microM alpha-tocopherol succinate (vitamin E) for 24 h prior to exposure resulted in a 10-fold increase in cellular levels of alpha-tocopherol. Using a colony-forming assay, this pretreatment decreased the cytotoxicity of UV-B light. However, alkaline elution assays demonstrated that pretreatment with vitamin E did not affect the number of DNA single strand breaks caused by UV-B light. In addition, UV-B exposure produced a dose-dependent induction of chromosomal aberrations and mutations at the HGPRT locus, and neither of these actions of UV-B was influenced by pretreatment with the vitamin. These results suggest that vitamin E protects cells from UV-B-induced cytotoxicity, possibly through its ability to scavenge free radicals. The results also suggest that the extent of genotoxicity induced by UV-B light may not correlate directly with the cytotoxic action of this wavelength region in sunlight.
在中国仓鼠V - 79细胞中,研究了维生素E预处理对细胞毒性、DNA单链断裂、染色体畸变以及紫外线B(UV - B)诱导的突变的影响。在暴露前,用无毒水平的25微摩尔α - 生育酚琥珀酸酯(维生素E)对细胞进行24小时预处理,导致细胞内α - 生育酚水平增加了10倍。使用集落形成试验,这种预处理降低了UV - B光的细胞毒性。然而,碱性洗脱试验表明,维生素E预处理并不影响UV - B光引起的DNA单链断裂数量。此外,UV - B照射在次黄嘌呤 - 鸟嘌呤磷酸核糖转移酶(HGPRT)位点产生了剂量依赖性的染色体畸变和突变诱导,UV - B的这些作用均未受到维生素预处理的影响。这些结果表明,维生素E可能通过其清除自由基的能力保护细胞免受UV - B诱导的细胞毒性。结果还表明,UV - B光诱导的遗传毒性程度可能与该波长区域在阳光下的细胞毒性作用没有直接相关性。